Open Source Design Centre
.
开源设计中心
Bitcoin Mining with a Raspberry Pi and DE0-Nano
Using a Raspberry Pi with an FPGA development board for a first foray into Bitcoin mining.
With a performance of only 0.2 million hashes per second (MH/s) a Raspberry Pi alone is a non-starter for Bitcoin mining. However, the low cost and low energy consumption computer makes the perfect platform for coordinating mining across more capable hardware.
In the mining rig described here an FPGA does all the hard work (SHA-256 hashing) and communicates over a serial link with a Raspberry Pi. The latter requesting new work from, and submitting proof of work done to, a Bitcoin mining pool.
DE0-Nano Bitcoin Miner
The Open Source FPGA Bitcoin Miner port for DE0-Nano was created by GitHub user kramble, who has published a repository containing the HDL along with software for use with Raspberry Pi.
In order to compile the Verilog design it's necessary to install the Altera Quartus II software (the free-of-charge Web Edition version will suffice).
Building the miner design
The GitHub repo contains various different Bitcoin miner HDL designs and the one that was used here is located in the Hashers22_serial folder.
In order to compile this we start Quartus II, browse to the Hashers22_serial directory and open fpgaminer.qpf. Upon selecting compile you may want to go and make a cup of tea, as on my laptop this took around 20 minutes!
At this stage it would be possible to download the compiled design to the FPGA, but it would be lost as soon as power to the board is removed. To make it permanent we must convert the SOF file to a JIC file which can be used to program the configuration device, an EPCS16 flash memory IC.
From the File menu select Convert Programming Files and set the following parameters:
Programming file type: JTAG Indirect Configuration File
Configuration device: EPCS16
File name: fpgaminer.jic
Then highlight Flash Loader and select Add Device→ Cyclone IV E→ EP4CE22. Next highlight SOF Data and select Add File and browse to fpgaminer.sof.
Finally, select Generate to create the JIC file.
Next open up the programmer by selecting Tools→ Programmer. If there is an entry for the .SOF file delete this, then add the JIC file, ensure Program/Configure is ticked, and then select Start.
Setting up the Raspberry Pi
By default the Raspberry Pi UART is set up as a hardware console and since here it will be used for communicating with the DE0-Nano, some configuration is required. This is straightforward enough and covered in the provided instructions.
The Raspberry Pi software lives in the serial_solo directory. Running make builds the mine application, but for some reason not the send_json binary which is also required. This can be compiled with:
$gcc -g -c -o send_json send_json.c
$gcc -o send_json send_json.o
Mining pool account details are then set in config-live2.tcl.
Connecting the two together
The DE0-Nano and Raspberry Pi both use 3v3 logic levels, however, the instructions still recommend using optoisolators between the two.
I went for a much more direct connection between the boards, placing 1K resistors in series with TX and RX just to give some measure of protection. Since this was my first attempt at Bitcoin mining I also added LEDs so that I could at least confirm when data was being exchanged.
Starting mining
The DE0-Nano miner powers up in a halted state and is started by pressing KEY0. Following which the minelive2.sh script is executed on the Raspberry Pi.
With any luck after a little while it should then be reported that a sha256 match was found and the “GOLD number” will be incremented by 1.
After a few successful matches we can then check the mining pool dashboard to see that these have been registered.
The estimated speed shown in the dashboard screenshot above should be disregarded as the miner hadn't been running for very long and this is based on insufficient data.
Final thoughts
I left the DE0-Nano clock speed set at the fpgaminer default of 40MHz, which supposedly gives a performance of 6.67 MH/s. The BTC Guild performance charts showed that in practice the miner varied between around 5 and 10 MH/s on average.
I find Bitcoin fascinating and although I have no intention of trying to make a fortune with the cryptocurrency, there is something strangely compelling about Bitcoin mining. When starting out I didn't give a second thought to increasing the FPGA clock speed, but now I find I'm tempted to put a heatsink on the FPGA, double the clock speed or more and try out higher performing designs.
If money is not the motivation, then what is? Well, simple geeky fun, the pursuit of amassing a volatile stash of what may amount to absolutely nothing, and playing a very small part in what is very likely to be a fun ride however it turns out.
code::XtremeApps:: 2013
code::XtremeApps:: is a 24-hour programming competition taking place in Singapore on 2 and 3 August.
Organised by the Information Technology Standards Committee (ITSC) of Singapore, this year's competition challenges participants to develop innovative and creative solutions based on the theme "Smart Living - Build. Code. Play." by using either Arduino Uno or Raspberry Pi.
Participants will be challenged to develop innovative, new applications by creatively integrating software and hardware in their solutions. Through this stimulating, hands-on experience of creating applications, participants will also get to discover the interesting standards behind the various IT technology platforms.
The code::XtremeApps:: 2013 Competition comprises two categories:
Junior Category
- Kids 12 years and below - here is YOUR chance to program and build wacky stories or applications using the Scratch programming language, MaKey MaKey invention kits, and household objects such as food or plants. The Junior Category competition will be held on 3 August 2013 at the Singapore Management University. On top of an exciting experience, participants stand to win cool gadgets!
Open Category
- The Open Category competition is open to programming-enthusiasts of all ages. You will be required to develop your own innovative applications using Raspberry Pi and Arduino Uno. One can take part on an individual basis or in teams comprising 2 - 3 members. This 24-hour competition will be held from 2 - 3 August 2013 at the Singapore Management University. Participants stand to win prizes of up to S$9,000 per team.
For more information, visit www.codextremeapps.org
Forum: http://www.designspark.com/discuss/viewforum.php?f=66
2013
DesignShare分享專案比賽
DESIGN SPARK 3周年おめでとう!
今週、DESIGN SPARKは生誕3周年を迎えました。いつもDESIGN SPARKをご覧いただきありがとうございます。
DESIGN SPARKは現在世界で14万人以上のメンバーを有し、PCBツールは5回の受賞歴を記録しています。また、RSコンポーネンツも昨年9月に75周年を迎えました。
(続きはこちらをご覧ください!)
EarthRover - Ra the Sun God - Part1
Would you plan a trip without checking out where your going first? Well the same applies if you're going to Mars or going to the beach. So in this blog I’m going to look at the weather on Earth, more importantly the sun and the power we can get from it!
NASA have sent quite a lot of hardware into space and all for a good reason. Its very important to carry out experiments and to find out where you're going and what to expect. When traveling to a far planet mankind has sent satellites and probes to test the environment first. Only once they know what they are letting themselves in for, do we start sending larger robots like the Mars rover, and then one day people too.
These experiments don't only make repeat trips more reliable but give vital data that can be built upon. For example knowing how much solar power you actually get can allow you to calculate the size of your solar panels, the angle to fit them at and even know what size battery you will need. So before sending EarthRover off on its mission, we also need to find out the same.
It took me less than 5 seconds to find hundreds of websites telling me how to fit a solar panel and how much money I could make. For the UK I read that a roof between 30’ and 50’ facing south is great. But that can't be the opium results can it? We know the sun is high in the summer and much lower in the winter. We also know just from stepping outside that the sun generates more power the higher in the sky it is. So my quest was to find the best results.
To do this I’m building a probe that I’ll be talking about over the coming months. Named ‘Ra’ from the egyptian Sun God, Ra will use solar experiments to measure the amount of solar energy that can be generated. However the probe can’t move so will need a first best guess when collecting data - no point facing north after all!
So it all comes down to calculation at first, to find the first best guess for Ra. Searching the internet did not take long till I found a really nice little Excel sheet that calculates the solar power for you. This generates a table of results for any time period for any number of days.
The tool first needs some data about where you are. I found my Latitude and Longitude from a website called EarthTools which also helped me find my height above the sea too. This data I entered into the tool and hit go. To get an idea of what we are dealing with I asked for the midday results for each day of the year. Assuming this would give me the highest power reading for each day.
The tool gave me three very important data values; the Azimuth or the angle of the sun from north, the elevation in degrees from the horizon and lastly the estimated power output per square meter. The power output however assumes that the panel is facing directly at the sun, the opium power output. So I then plotted these to see what the results looked like. No surprise to find the power output was highest during the summer! However I was surprised to find that the sun, due to the earth rotation and orbit, is not exactly in the same place at noon every day. In fact it seems to swing back and forward around south. We already know that the height changes so I wondered what this movement looks like. What I found was at noon the sun over a year forms a figure eight shape in the sky. Most movement was during the winter and less during the summer. This was going to make working out which way to point the panel harder-!? For example you need to work out where on the figure eight you get the best power from the sun.
So to calculate the angle our panel needs to be at we now need to consider two factors; direction from north and elevation. Both can be worked out using a little trigonometry. Using the COS rule you can subtract the angle of the panel (lets assume 180’ or due south) from the suns location (say 179’). This then gives you a value that you can use as a scale factor - The closer to 1 the value is the more aligned the panel and the sun is. If you then repeat this for each day of the year you will get a range of values. What we want however is the best direction for the panel that gives us the highest average over the year. You can do this in Excel using the ‘solver’ which searches a range of values to give you the best results. From this I found for my location that a direction of 180.59’ was the best - well as close to due south as you can get. Was a lot of work but atleast we confirmed our results!
This was then repeated for the angle of the panel to the sun with respect to the elevation. This time using the SIN rule we could work out what angle gives the highest average output for the year. Again for my location I got a angle of 51.3’. This fits with the information I read online about being between 30-50’ (at one end of the scale anyway) and with another article that suggested you fit the panel at the same angle as your latitude.
As you can see from the plots I generated the power dips a little mid summer but give the all round best results for the year. If you’re fitting solar panels on your house you could also do this same calculation to get the best results.
However.... And here is the interesting bit. Will our solar panels really work best this way? Will the high temperatures in the sun lower its efficiency? Will the panel just peek out at a set light level meaning we could lower the angle? These can only be answered with real results and thats why building and get test results from Ra is so important.
Another key issue is the winter results. We can see that we will get lower than optimal results at this time. We need to be careful that we don't sacrifice power in the winter to keep the EarthRover running for more than enough power in the summer. This is what I will look at in part 2 and try and look at the effects of tuning the angle for the best power usage when we need it most - winter.
To see more about the Earth Rover project check out the first blog here - paul-clarke-needs-you-help-me-with-my-massive-earth-rover-project, or you can follow the project on facebook and twitter.
Many Thanks
Paul
(aka @monpjc)
DesignSpark PCB bug resolution centre
This page lists fixes to software bugs. This page is about the known issues with installation or functionality of the software and NOT about design techniques or guidance. For advice on designing with DSPCB, click here.
The bug fixes below were discovered as a result of users reporting them and actively participating in investigations. Only with your involvement our developers can track down some issues so we would like to thank you for your continued support, helping us to make DesignSpark PCB even better. As DesignSpark PCB is a very stable software, most of the issues you report are not easy to reproduce and only affect a very small proportion of the overall user base. Neverheless every improvement is important to us and every fix matters.
The fixes are incorporated in subsequent DSPCB revisions (to view 'change log' click here) so the ones listed below would only apply to the latest available software version.
1. Online DRC not appearing in tools menu |
2. Invisible / nonstarting DesignSpark PCB |
より進化したマイコンボード「BeagleBone Black」
・BeagleBone Blackとは
BeagleBoneとはTexas Instruments(TI)の開発・販売している小型マイコンボードのシリーズです。初期BeagleBoneが発売された当時、パワフルなARMコアのSoC・ハッカー特性・低価格で大きな話題となりましたが、さらに安価な同種のRaspberry Pi の登場によってBeagleBoneの存在は薄れていきました。
しかし、BeagleBoneの最新作である「BeagleBone Black(以下BBB)」は価格を可能な限りRaspberry Pi(以下RPI)に近づけ、なおかつ性能もRaspberry Piよりも優れたものとなっています。
初期のものと比べると、値段が$45と約半額までコストダウン、CPUが500Hz-750Hz駆動だったものが1GHz駆動に、メモリが256MBから512MB、2GBのeMMC FLASHのSDカードがなくてもLinuxが動作するようになり、MicroHDMIポートが搭載され、単体でGUI環境が利用できるようになった点など、大幅にグレードアップしています。
以下仕様書
CPU | Sitara AM3359AZCZ100, 1GHz, 2000 MIPS(?Cortex-A8) |
GPU | SGX530 3d, 20M Polygons/S |
メモリ | 512MB DDR3L 400MHz |
オンボードフラッシュメモリ | 2GB, 8-bit 埋め込み型MMC ※ボード上についている交換不可能なUSBメモリ(2GB)という感じ |
PMIC | TPS65217C PMIC regulator and one additional LDO |
デバッグサポート | Optional onboard 20-pin CTI JTAG, Serial Header |
電源 | ミニUSBまたはDCジャック; 5VDC External via Expansion Header |
PCB | 3.4” x 2.1”; 6 Layers |
インジケータ | 1-Power, 2-Ethernet, 4-User Controlled LEDs |
HS USB 2.0 クライアントポート | 1,USB0としてアクセス, Client mode via miniUSB |
HS USB 2.0 ホストポート | 1,USB1としてアクセス, タイプA, 500mA LS/FS/HS |
シリアルポート | UART0 access via 6 pin 3.3V TTL Header (header is populated) |
LAN端子 | 10/100メガ, RJ45 |
SDカード | microSD, 3.3V |
ユーザー入力 | リセットボタン,起動ボタン,電源ボタン |
映像出力 | 16b HDMI, 1280×1024 (max), 1024×768, 1280×720, 1440×900 w/EDID Support ※ビーグルボーンブラック本体側はmicroHDMI端子 ※最高解像度が1280×1024 |
音声出力 | HDMI上、ステレオ音声 |
拡張コネクタ | Power 5V, 3.3V, VDD_ADC (1.8V); 3.3V I/O on all signals; McASP0, SPI1, I2C, GPIO(65), LCD, GPMC, MMC1, MMC2, 7 AIN (1.8V max), 4 Timers, 3 Serial Ports, CAN0, EHRPWM (0,2), XDMA Interrupt, Power Button, Expansion Board ID (up to 4 can be stacked) |
重さ | 39.68グラム |
消費電力 | 210-460mA@5V(CPU速度に応じて変化します) |
・Raspberry Piとの比較
プロセッサ速度・I/Oの数・内蔵フラッシュ・Ubuntuを含めた多くのLINUXとAndroidの両方をサポートしていることなど、BBBにはRPIより優れている点が多々あります。しかしBBBは残念なことにビデオのエンコード・デコード機能がありません。HDMI解像度は1280×1024に制限されており、コンポジット出力も使用できません。もしも想定しているプロジェクトで高解像度のビデオ出力が必要となる場合はRPIが優れていると言えるでしょう。しかし、ビデオ出力を必要としないのであればBBBに軍配があがります。
元々BBBはハードウェアハッキングを目的としたハードユーザをターゲットにしているので、その点は大きな問題ではないと考えられたのだと思います。BBBでは65ピンのGPIOに加え、Arduinoでいうシールドと同様のケープと呼ばれる拡張ボードがサポートされています。
また、BBBでは解像度12ビットの7つのアナログ入力に対応していますが、RPIにはオンボードADCがありません。
コストに関してはボード自体の値段はBBB$45、RPI$35とRPIの方が安くなりますが、電源やブートストレージなどの周辺機器の値段を加味すると大きな差はでません。
いろいろと比較点をあげていきましたが、結局のところはプロジェクトに合わせて使用するボードを変えるのがベストだと思います。個人用メディアプレー・生徒用の教育教材・メディアアートなど、それほど高度なパフォーマンスを必要としないプロジェクトなどの場合はRaspberry Piを、またセンサや制御モーターを多く使用したいという場合にはBeagle Bone Blackを、それぞれ選択することになると思います。
どんなプロジェクトでもベストな選択となるようなボードは存在しません。それを踏まえた上であなたのニーズに合致するボードを選びましょう。
ARMのCortexコアについて
かつて、電子工作におけるプロセッサ選びはさほど難しいことではありませんでした。当時は選択肢もあまりなく、Intel8080、Motorola6800、CBM6502、H8 といった主要なものを使用していればよかったのです。これらのチップは、現代のものとは異なり、メモリ未搭載のシンプルな8bitプロセッサーでした。
それが現在では非常に複雑な構成をもつようになってきました。特にNXP製マイクロコントローラを搭載したmbedモジュールは
クラウドによる開発環境を提供するにまでに至りました。今回の記事では、プロセッサの選び方を考えるとともに、このmbedモジュールの優位性をお話します。
近年、独自の命令セットとアーキテクチャを持った、8・16・32、さらには64bitのプロセッサが、多くのチップメーカーからリリースされています。さらに、ほとんどのマイクロコントローラーファミリーは、クロック速度、メモリサイズ、周辺制御などの部分で幅広い商品ラインナップを持っています。ここに、近年普及が著しいARM社製コアを搭載したモデルを考えると、状況はさらに複雑になっています。実質的にメインチップメーカーの主要製品にはARMのコアを使用している状況です。
一見選択が容易になるように思われますが、ARMコアには非常に多くのバリエーションがあり、フラストレーションが溜まり、頭をかきむしりたくなります。ARM7,ARM9,ARM11、そして新しいCortexシリーズとそれらすべてに亜種が存在しています。
これら全てを見ていくことは難しいので、今回はARM製品の中のCortexシリーズだけを見ていきましょう。CortexにはCortex-M、Cortex-A、Cortex-Rの3つの主要なグループがあります。他のARMコアからCortexデバイスに分ける主な共通の特徴は、組み込み制御システムにより適した内蔵の割り込みコントローラーです。
Cortex-A
Cortex-Aベースのデバイスは、プログラム用の外部動的RAMを使用しているため、非常に速いマイクロプロセッサです。RAMが使用されているのは、フラッシュメモリ技術では、ハイエンドのマルチディアや通信システムに必要な500MHzを超過するプロセッサのクロック速度には十分な速度が出せないからです。
Cortex-R
Cortex-Rベースもまたプログラム用に外部メモリを使用した高速なプロセッサです。さらにリアルタイム制御だけではなく、信頼性を確保するためエラー訂正などの機能を持っています。これにより自動車などの高信頼性を求められるアプリケーションに用いられます。Texas InstrumentsのHerculesのfault-tolerantマイコンはCortex-R4Fに基づいています。このテーマに関しては、こちらの記事を参照してください。
Cortex-M
Cortex-Mベースのデバイスはその応用範囲の広さが武器です。最も汎用の組込みアプリケーションに適したオンチップ・フラッシュ・プログラム・メモリ・を搭載したマイコンです。ほとんどのメーカーはそのラインナップにCortex-Mデバイスを採用しています。Mシリーズ内のそれぞれの違いを詳しく見ていきましょう。
最も人気のシリーズは、効率的で包括的な32bit命令セットを持つM3でしょう。Cortex-mデバイスは、32bitの力を使わずに効率を向上させる、"Thumb"と呼ばれる16bit命令セットを備えています。mbed 「NXP LPC 1768デバイス」などに採用されており、性能的にはマイクロチップ社のPIC32とほぼ同等であると考えられます。
つぎに、M3の命令セットにDSP用のセットを追加したM4。リアルタイム・デジタルFIRフィルタを実装したり、高速フーリエ変換(FFT)を用いて周波数分析を行うとき、遙かに効率的なコードをつくることができます。M4コアを持つ製品には、フリースケールのKinetis K40があります。
続いてM4セットに浮動小数点数学の命令が追加されたM4Fを見てきましょう。これらの命令を使用するコードは、ソフトウェア・ルーチンを使用した時、他のものよりも5~6回分高速に実行できます。STマイクロエレクトロニクス社がSTM32F4デバイスでこのコアを使用しています。
次にmbedモジュールの話に戻りましょう。mbed NXP LPC11U24は、Cortex-M0を採用したNXPのLPC11U24プロセッサを搭載しています。16bitのThumb命令セットを搭載したRISCマシンで、非常にシンプルで、安く、省電力で動作します。したがって、携帯機器・バッテリ駆動システムといったアプリケーションに用いられます。複数のスリープモードがあり、割り込みと次の割り込みの間をスリープ状態に戻ることで、消費電力を抑えています。詳しくはこちらの記事をご覧下さい。
DesignSpark PCB - Setting Component Height for IDF export
Setting Component Height for IDF export
Components in DSPCB contain precise dimensions in 2D domain and the third dimension is not present. All components will be assumed to be of zero height during the export. It is therefore up to an engineer to identify the components that require precise height set. A good example is a relay as it is likely to be taller than the rest of component that could go on that board and could collide with enclosure.This is when the component datasheet comes handy. If you don't have it opened, the easiest way to get to it is to right click the component, select 'values', and copy the RS Part Number. This can be then searched on RS-online to guarantee a correct datasheet for the part. Once datasheet open, find the dimensions. For our relay is is 8.4mm. Endure your PCB design units are set to mm if you choose to use this unit type for 3D export.
To set the height for a component edit values in library by right-clicking on the component:
Note: When assigning Component Values to define the height of components, it is advised they are defined in the Component Library and not local Value attributes on component instances. Each device would then have a height assigned to it. This avoids having different values on different instances of a component, which the export cannot handle. This tutorial shows the correct way that will save you from making mistakes.
A component edit view will show, fro mthe menu select Edit>Values>Add:
Make sure to save changes to the component in the library. The last step is to update the component. Right click > Update Component. The velues can be checked at any time by right click>Values:
Note: this only need to be done for a handful of distinctive component on a board like connectors, etc - vast majority of components are low profile and do not need any manual intervention.
Raspberry Pi Pip-boy, Personal arm Computer
I would like to present my first raspberry-pi project.
A Pip-boy ! :
It is a Raspberry-pi model B froom RS with Raspbian OS + a 2.8" LCD 8bits parallel TouchScreen connected on GPIOS.
It is powered with a 5/1A 2200mAh battery which gave approx 3h of autonomy (about 2h if wifi dongle is used) :
XWindow Desktop session can be controlled with Touchscreen or Keyboard :
Everything is mounted on a self-made case, so the Raspi Pip-oy can be attached to arm.
- It supports USB wifi dongle and Bluetooth mini-keyboard and many other USB devices
- It can connect to video stream (like IP network cameras) and run AdvanceMame Arcade Game Emulator.
- 2 switches are connected to GPIOS : the first to switch between displays (console/Dektop) and to command and the second to perform a safe shutdown.
For more details - photos - videos about this project,
El_Panda -
DesignSpark PCB Glossary of Terms
This tutorial lists the terminology that is used in the wider Electronics Industry and therefore used in the DesignSpark PCB software
The glossary is arranged in an alphabetical order. Please click on a letter below or scroll down the page.
A¦ B¦ C¦ D¦ E¦ F¦ G¦ H¦ I¦ J¦ K¦ L¦ M¦ N¦ O¦ P¦ Q¦ R¦ S¦ T¦ U¦ V¦ W¦ Z
A
Acid Trap - Describes an area in a PCB where the acid used in the manufacturing process cannot escape. This can cause problems of under-etching or over-etching.
Active Components - Semiconductor devices, such as transistors and diodes, that can change its basic characteristics in an powered electrical circuit, such as amplifiers and rectifiers. See also Passive Components.
Analogue Circuit - An electrical circuit that provides a continuous quantitative output as a response from its input. See also Digital Circuit.
Annotation - The adding of notes to a schematic.
Annular Ring - The width of the conductor pad surrounding a drilled hole.
Aperture - A description of the shape and size of the tool used to create a pad or track.
Aperture List - A list of the shapes and sizes for describing the pads and tracks used to create a layer of a circuit board.
Array - A group of elements that are arranged in rows and columns.
Artwork - Artwork for printed circuit design is photoplotted film (or merely the Gerber files used to drive the photoplotter), NC Drill file and documentation which are all used by a board house to manufacture a bare printed circuit board.
ASIC - Application Specific Integrated Circuit. Semiconductor circuits specifically designed to suit a customer's particular requirement, as opposed, for example, to a DRAM or micro-controller, which are general purpose parts.
ASCII - A basis of character sets used in almost all present day computers. US-ASCII uses only the lower seven bits (character points 0 to 127) to convey some control codes, space, numbers, most basic punctuation, and unaccented letters a-z and A-Z.
ATE - See Automatic Test Equipment.
Automated Test Equipment (ATE) - Equipment that automatically tests and analyses functional parameters to evaluate performance of the tested electronic devices.
Automatic Placement - A program that places components on the board depending on various factors such as length of connections and size of components.
Automatic Routing or Autorouter - A program that takes the connections paths between component pins and automatically places tracks in an orderly pattern. This automates what can be a time-consuming stage in the design of the PCB.
Axial leaded component - Axial leaded components are flat down type discrete components (i.e. resistors).
Back Annotation - The carrying back into the schematic from PCB of name changes that occur after the components are renumbered in the PCB, usually following placement.
B
BGA - see Ball Grid Array.
Ball Grid Array (BGA) - A flip-chip type of package in which the internal die terminals form a grid style array, and are in contact with solder balls ( solder bumps ), which carry the electrical connection to the outside of the package. The PCB footprint will have round landing pads to which the solder balls will be soldered when the package and PCB are heated in a reflow oven.
BBT - Bare Board Test. The testing of an unpopulated PCB.
Bandolier - Components mounted in a double sided strip used for feeding Pick and Place machines.
Bare Board - An unpopulated PCB.
Bed of Nails - A test that contacts many points on a PCB to provide Automatic Test Equipment machines access to internal nodes of a PCB.
Bill of materials (BOM) - A comprehensive listing of all sub-assemblies, components, and raw materials that go into a parent assembly, showing the quantity of each required to make the assembly.
Bitmap - A rectangular set of pixels.
Blind via - A via extending from an interior layer to only one surface of a printed board.
Board - A printed circuit board.
Board Outline - The physical outline of the PCB. Is is formed from an unfilled closed space on a dedicated layer.
Board Profiling - Cutting a PCB board to the required shape.
BOM - see Bill of Materials.
Boundary Scan - An approach to the testing of printed circuit board assemblies that can be used to diagnose individual circuit failures by embedding the test circuits into the board and in the most failure prone integrated circuits.
Breakout - Describes poor registration between the hole and the pad on a printed circuit board such that the hole is not within the area of the pad.
Bridging - Where build-up of solder between tracks or pads causes a short circuit.
Buried via - A via that connects two or more interior layers of a printed circuit board and does not extend to either surface of the printed circuit board.
C
CAD - Computer-Aided Design. The use of computer aids (hardware and software) in the electrical and physical design and verification of new things.
CAE - Computer-Aided Engineering. The use of computer aids (hardware and software) in electrical design.
CAM - Computer-Aided Manufacturing. The use of computer aids (hardware and software) in planning, tracking, analysing, and implementing the construction of manufactured items.
Capacitor - A two pin device providing electrical capacitance.
Capture - To draw (schematics) in such a way that data, especially connectivity, can be extracted electronically. Also see Schematic Capture.
Card - A printed circuit board of smaller dimensions is commonly referred to as a card. A card is generally one level lower than the printed circuit board in the hierarchy of packaging. A card is also referred to as a daughter board.
Card edge connector - A connector which is fabricated as an integral portion of a printed circuit board along part of its edge.
Ceramic Ball Grid Array (CBGA) - A ball grid array package with a ceramic substrate.
CERDIP - Ceramic Dual In-line Package. A package assembled with the leadframe sandwiched between two ceramic layers and sealed with a glass.
CERPACK - Ceramic Package. A CERDIP like package with the leadframe extended out on two or four sides, typically in surface-mounting format. Characteristics similar to CERDIP.
Chamfer - A corner that is shaped to remove an otherwise sharp edge.
Chip - The uncased and normally leadless form of an electronic component part, either passive or active, discrete or integrated.
Chip and wire - Assembly technique which uses discrete wires to interconnect backbonding die to lands, lead frames, etc.
Chip carrier - A low profile, usually square, surface mount component semiconductor package whose die cavity or die mounting area is a large fraction of the package size and whose external connections are usually on all four sides of the package.
Chip-on-Board (COB) - One of the many configurations in which a chip is directly bonded to a circuit board or substrate. These approaches include wirebonding, TAB, or solder interconnections, similar to the C4 structure. In low end consumer systems, Chip-on-Board generally refers to wirebonding of chips directly to board bonded and subsequently protected with a bit of resin material.
Chip Scale Package (CSP) - Chip scale package not much greater than the chip itself (typically not greater than 20% larger).
Circuit - The interconnections of electrical elements and devices that perform a desired electrical function.
Circuit Layer - A layer, on or within, a printed board containing conductors, including ground and voltage planes.
Clearance Rules - The required clearances between unconnected conducting structures on the PCB (for example track to pad).
CMOS - Complementary Metal Oxide Semiconductor. The primary technology in the design of Integrated circuits for digital circuitry.
Component - An element of equipment which unto itself does not form a complete system. Components can be integrated circuits, semiconductors, resistors, etc.
Component density - Quantity of components per unit area of printed circuit board.
Component lead - A wire or formed conductor that extends from a component and serves as a mechanical and/or electrical connection.
Component Side - The side of a PCB on which most of components are mounted.
Conductor, electrical - A class of materials -- usually metals -- that easily conducts electricity. Examples include silver, copper, gold, and super conducting ceramics.
Conductor, thermal - A class of materials, usually metals, that easily conduct heat. Examples include copper, aluminium, and beryllium.
Connectivity - The intelligence inherent in PCB CAD software which maintains the correct connections between pins of components as defined by the schematic.
Connector - A plug or receptacle which can be easily joined to or separated from its mate. Multiple contact connectors join two or more conductors with others in one mechanical assembly.
Coordinate - A position relative to an origin.
Conductor - Something that carries electricity with very little resistance. e.g. A Copper track on a PCB.
Connectors - A component mounted on a PCB that is used to provide electrical connection with external equipment.
Copper (Cu) - A metal used in semiconductor technology to form the interconnects between devices on a chip.
Copper Fill - Filling an area of a PCB with copper not directly needed for carrying a signal. This can provide for control of electrical noise (Susceptibility and emission), to provide a Heat Sink, and/or to prevent warping of the board.
Copper Pour - An enclosed area, usually defined by a polygon, flooded with copper, with solid/hatch pattern to create copper plane or section of copper plane. This is then connected to all instances of a given signal, usually O volts or 5 volts, by thermal relief pads. See also Thermal Relief.
Copper Sharing - Using a single section of track to carry a signal to more than one pin.
Crosshatch - Filling an area with two sets of parallel lines at an angle to one another.
Circuit - The interconnections of electrical elements and devices that perform a desired electrical function.
Cursor - The indicator on the screen.
D
Daughter board - A PCB mounted, (piggy backed), onto another circuit board
Design entry - The process of creating a new design of any type chip, board, module, or system using schematic capture. Also referred to as design capture.
Design Rules Check - A program used to check the manufacturability of the circuit board. The checks include track to track gaps, track to pad gaps, track to board edge gaps, etc
Device - Any type of electrical component on a PC board. It will have functions and properties unique to its type
Digital Circuit - A circuit comprised of mostly integrated circuits which operates like a switch (i.e., it is either on or off).
Dielectric - Material that does not conduct electricity. Generally used for making capacitors, insulating conductors (as in crossover and multi-layered circuits) and for encapsulating circuits
DIL or DIP - Abbreviation for Dual In-line Package. A type of housing for integrated circuits. The standard form is a molded plastic container of varying lengths and 0.3 inch wide (although there are other standard widths), with two rows of through-hole pins spaced 0.1 inch between centres of adjacent pins
Diode - A two pin component conducting current in one direction only.
Dimension - To annotate a drawing or PCB with sizes, distances between critical positions.
Discrete Component - A component which has been fabricated prior to its installation (i.e., resistors, capacitors, diodes and transistors)
Double Sided - PCB assembly with components on both sides of the substrate but no inner layers. See also Single Sided and Multi-layer.
DRAM - Dynamic Random Access Memory
DRC - See Design Rules Check
Drill Table - A description of the drill sizes used to create the circuit board. The drill equivalent of an aperture list
Drilled Size - The size of the drill used to make a hole in a PCB
Dual-in-Line Package (DIP) - A package having two rows of leads extending at right angles from the base and having standard spacing between leads and between rows of leads. DIPs are made of ceramic (CERDIP) and plastic (PDIP)
DXF - Data Exchange Format originated for import/export of mechanical designs
E
Earth - Another name for Ground
ECL - Emitter Coupled Logic - A type of unsaturated logic performed by emitter coupled transistors. Higher speeds may be achieved with ECL than are obtainable with standard logic circuits. ECL is costly, power hungry, and difficult to use, but it is four times faster than TTL
EDA - Electronic Design Automation: has largely taken the place of the term CAD in electronics, to cover all areas of electrical / electronic design and simulation using computer aids
Edge Connector - A connector on the circuit board edge in the form of gold plated pads or lines of coated holes used to connect other circuit board or electronic device
Edge Clearance - The smallest distance from any conductors or components to the edge of the PCB
EEPLD - Electrically Erasable Programmable Logic Device. A CMOS PLD made by using EEPROM technology. It can be erased and re-programmed
Effort - The resources applied to produce a suitable route. The higher the effort, the more resources router applies to routing the track. The lower the resources required, the shorter will be the time taken, and the neater the result.
Engineering Change Order (ECO) - A change in design
Embedded - Of a micro-processor(s), or system controlled by such) Dedicated to doing one job or supporting one device and built into the product
EMC - electro-magnetic compatibility - (1) The ability of electronic equipment to operate without degradation in an intended electro-magnetic environment (2) The ability of equipment to operate in its electro-magnetic environment without creating interference with other devices
EPROM - Erasable Programmable Read Only Memory. Can be erased and re-programmed
Etch - A process using a chemical bath (wet etch) or a plasma (dry etch) that removes unwanted substances from the wafer surface
Excellon - The de-facto standard for Computer Numerical Control CNC data for PCB drilling data originated for use with Excellon drilling equipment
F
Fab - Short for fabrication
Failure - The temporary or permanent functional impairment of a component or device caused by physical, mechanical, chemical, or electrical damage
FC - Flexible Circuit, flexible circuitry
FET - Field Effect Transistor
Fibreglass - A common material for the Substrate of a PCB
Fiducial mark - Faducial marks are dots etched on board panel for which SMD assembly is required (provide viewing targets for camera to locate correct position)
Fillet - Applying a radius to an otherwise sharply angled edge
Fine Pitch - Fine pitch is more commonly referred to surface-mount components with a lead pitch of 25 mils or less Also, a general term for a PCB design where spacings of pads, tracks etc. is close to manufacturing limits
Fixed - Routes or tracks which may not be changed by the Router
Flash memory - Flash memory is a non-volatile memory device that retains its data when the power is removed. The device is similar to EPROM with the exception that it can be electrically erased, whereas an EPROM must be exposed to ultra-violet light to erase
Flat pack - An integrated circuit package with leads on two or four sides. The leads on these packages are either gull wing or flat, and have standard spacing. Packages with a lead pitch below 50 mils are referred to as fine pitch packages
Flex circuits - Flexible printed circuit boards made using thin polyimide or polyester film with copper circuitry on one or both sides of the flex. Flex circuits can be single or multi-layer
Flip - In PCB CAD context:- moving a component onto the opposite side of the PCB
Flip Chip - Unpackaged silicon dies that have been supplied with solder balls directly on the active side of the die. They are called flip chips because they are flipped upside down, compared to a conventional wirebonded chip
Flux - A chemically or physically active formulation capable of cleaning oxides and enabling wetting of metals with solder
Folder - A disk file, or the bottom level of a disk drive, that contains the names, dates, sizes, and filing system references to files and/or further folders. Also called a Directory
Footprint - The physical layout required for a PCB mounted component, including its pads and outline
Footprint Library - A ready built, or user built, selection of Component Footprints
Font, True Type - A Character or symbol Typeface designed to be easily scaled to different sizes
Forward Annotation - The process of applying the changes made to a schematic 'forward' to the PCB design. See also Backward Annotation
FPC - Flexible Printed Circuit, or flex circuit
FPGA, Field Programmable Gate Array - A type of logic device that allows its operation to be modified by means of on board programming
FR-4 - A NEMA grade of Flame-Retardent industrial laminate having a substrate of woven glass fabric and resin binder of epoxy. FR-4 is the most common dielectric material used in the construction of PCBs in the USA. Its dielectric constant is from 4.4 to 5.2 at below microwave frequencies. As frequency climbs over 1 GHz, the dielectric constant of FR-4 gradually drops
Free Pad - A pad not associated with a component. For example, a mounting hole.
Functional test - A test to verify product's behaviour after the components are mounted on board. Generally, functional test are performed as an alternative to in-circuit test in most application
G
Gate - An part of the component representation. A component can be single-gate (one schematic symbol) or multi-gate (for example an Operational Amplifier IC in which each circuit is represented as a separate gate. Power supply can become yet another gate).
Gate Swapping - Exchanging pins in multi-gate packages, or between similar packages, to make routing easier
Gerber Data - A type of data that consists of graphics commands, usually describing how to draw a picture of a circuit. Intended for directing a photoplotter, it is the most common format for data transfer from PCB CAD systems to the manufacturing process
Glue Spot - What is used to hold Surface mount devices in placed on a bare PCB until soldering takes place
GND - See Ground
Grid - A two-dimensional network consisting of a set of equally spaced parallel lines superimposed upon another set of equally spaced parallel lines so that the lines of one set are perpendicular to the lines of the other
Ground - The nominal voltage reference, often called GND or 0V
Ground Plane - A conductive plane as a common ground reference in a multi-layer PCB for current returns of the circuit elements and shielding
Gull wing lead - A lead configuration, usually found on small outline packages, where the leads are bent. The end view of these packages resembles a gull in flight
H
Hatch - The filling of an area with a set of parallel lines, Normal chosen to be horizontal, vertical or at 45 degrees
Heat sink - A structure, attached to or part of a semiconductor device that serves the purpose of dissipating heat to the surrounding environment; usually metallic. Some packages serve as heat sinks
Hertz or Hz - The unit for frequency of oscillation
I
In-circuit test (ICT) - Combination of hardware and software that identifies manufacturing induced faults of printed circuit board assemblies (PCBAs) by isolating and individually testing devices using a bed-of-nails fixture. Potential faults include shorts, opens, wrong components, missing components, etc
Inner Layer - The layers of a circuit board that are sandwiched in between the outer layers. These may be tracking layers or plane layers
Insulators - A class of materials that do not conduct electricity and are characterised by high resistivity
Integrated Circuit (IC) - A miniature or micro-electronic device that integrates such elements as transistors, resistors, dielectrics and capacitors into an electrical circuit possessing a specific function. Form the basis of all modern electronic products
Interconnect - The conductive path required to achieve connection from one circuit element to another
I/O - Input/Output. Generally refers to the external connections of an IC that tie it to the outside world. Supply pins and control pins are usually not considered I/O
J
J-lead - A lead configuration usually used on plastic chip carrier packages. J-leads are bent underneath the body of the package, with a side view resembling the shape of the letter "J"
K
Kitting List - The list of parts needed to populate a bare PCB with components
L
Laminate - A composite material made by bonding together several layers of same or different materials
Land - A portion of a conductive pattern that is usually used for making electrical connections or for component attachment, or both. See also Pad
Laser Photoplotter (also laser plotter) - A photoplotter which simulates a vector photoplotter by using software to create a raster image of the individual objects in a CAD database, then plotting the image as a series of lines of dots at very fine resolution. A laser photoplotter is capable of more accurate and consistent plots than a vector photoplotter
Laser soldering - A method of soldering in which the heat required to reflow a solder interconnection is provided by a laser
Layer - Is a side of copper foil. In a standard 2 layer board there are copper tracks and copper areas only on both sides of the laminate; 4 layer would mean there are 2 additional sides of copper track and copper areas "sandwiched" on internal layers between the exterior sides of the board. On more complex boards more layers may be sandwiched to improve the routability: 6 layer, 8 layer, and so on. Also see Multi-layer
Layer direction - Routers works most effectively when routes on a specific layer are biased to one axis. Routes requiring tracks in the different axis would be routed on another routing layer
LCC - Leadless Chip Carrier. A surface-mounted package having metallised contacts (terminals) at its periphery. Usually made of ceramic material
Lead - A wire that connects two points in a circuit; it is usually self-supporting
Leadless device - Electronic devices which do not have electrical leads extending from the body of the package. These packages could have solder bumps or lands located on the package
Lead pitch - The sum of the lead width and lead spacing. Typically stated as the distance between the centre of one lead to the centre of an adjacent lead
LED - Light Emitting Diode
Legend - Silk screened component identification marks or component outlines
M
Manufacturability - A term defines the ability of meeting manufacturing requirements
MHz or Megahertz - a measurement of clock cycles in millions of cycles per second
Micro-controllers - Similar to micro-processor, but dealing with a simpler information set
Micro-processor - A standard circuit design that provides functions similar to central processing units by interpreting and executing instructions, usually incorporating arithmetic capabilities
Micron - A unit of measure equivalent to one millionth of a meter
Microvia - Small holes (0.002 - 0.004) that connect an outer layer of PCB to the nearest inner layers
Micro ball grid array - A fine pitch ball grid array. Fine pitch for BGAs is anything less than 1.27 mm
Mil - One thousands of an inch.
Mitre - Applying a straight edge at 45 degrees cut across an otherwise sharply angled 90 degree corner or edge. Quite common on PCB at right angled track junctions to improve manufacturability, reduce electrical reflections, and sometimes for purely cosmetic purpose
Misregistration - The lack of conformity between two or more patterns or features
Mixed Signal Products - Products that can process both digital and analog data
Mixed Technology - When pin through hole, surface mount, and other mounting technologies are processed on the same printed circuit board
MOS - Metal-Oxide-Semiconductor. Layers used to create a semiconductor circuit. A thin insulating layer of oxide is deposited on the surface of the wafer. Then a highly conductive layer of tungsten silicide is placed over the top of the oxide dielectric
Mother Board - Also called the Back Plane, or Matrix Board. A relatively large Printed Circuit Board on which modules, connectors, sub-assemblies or other Printed Circuit Boards are mounted and interconnections made by means of traces on the board
Multi Chip Module (MCM) - A module or package capable of supporting several chips in a single package
Multi-layered PCB - PCB layers are referred to as number of sides of copper foil used. PCBs with more than 2 sides of copper are defined as multi-layered, generally 4 layers, 6 layers and sometimes up to 16 layers
N
NC drill or Numeric Control drill machine - A machine used to drill the holes in a printed board at exact locations, which are specified in a data file
Net - A line linking equipotential points in a design. It may branch, and form loops. Each net has a unique designation, and is linked to a net class which defines the style.
Net Class - Defines the minimum and nominal (desired) widths for a net when converted to a track by the Router
Netlist - A list of all the nets on a circuit board generated from a PCB's design data. This is known as a physical netlist in that it provides information on electrical connectivity between points on a board. This facilitates the testing of the PCB. This is distinguishable from the more general CAD sense of a netlist, which specifies component connectivity with no regard to actual physical locations of the points
Node - A pin or lead which will have at least one track connected to it
Non-plated-through - A type of holes on circuit board generally used as mounting holes
O
ODB++ - A format for PCB manufacturing data developed by the Valor Corporation
Open - A circuit interruption that results in an incomplete path for the current flow. (e.g. an open wire which opens the path of the current)
Optimise - The re-organising of the connections too find the shortest length
Orthogonal Routing - A style of routing with horizontal and Vertical tracks
Origin - Some nominal starting point for a coordinate system
Output - A pin on a component that consistently drives the signal to a level determined by the component
P
Package - 1) a printed circuit board component. 2) A type of PCB component which contains a chip and acts to make a convenient mechanism for protecting the chip while on the shelf and after attachment to a PCB
Packaging density - The quantity of components, interconnections, and mechanical devices per unit volume
Pad - A shape of copper used for mounting components
Padstack - A collection of the shape and size information of the subject pad
PAL - Programmable Array Logic. A device that can be programmed to do certain logic functions. Then a fuse inside of the device can be blown so the programmed information can never be changed. Sometimes called a PLD (Programmable Logic Device) Language
Panel - Material (most commonly an glass/epoxy-copper laminate known as core) sized for fabrication of printed circuit boards. Panels come in many, many sizes, the most common being 12 by 18 and 18 by 24. Subtract 1/2 to 1 margins (check with your board house) from the panel size to arrive at the space available for printed circuitry
Panelisation - A general term in CAM editing refers to step/repeat and other CAM editing to prepare data in panel format
Part - Component located by a manufacturers name or other unique identifier rather than the the logical or electrical function or package type identifier. A part may be a combined Schematic symbol and relevant footprints or, it can be just a schematic only part, or pcb footprint only part.
PBGA (Plastic ball grid array) - generic name for a BGA component constructed on organic substrate material, such as FR-4, overmolded with plastic
Parts List - A list of the parts required to build specific quantities of one or more PCB
Passive component - A device which does not add energy to the signal it passes. Examples: resistor, capacitor, inductor
PCB - see Printed Circuit Board
PCB design - 1) The creation of artwork for the manufacture of bare PCBs. 2) The artwork so created. 3. A computer database used to generate such artwork as data files ( CAM files ). Also called PCB layout
PCB designer - One who creates the artwork for printed circuit boards
PCB design bureau - A business engaged in PCB design as a service for others
PGA - See Pin Grid Array
Photoplotting or photoplot - Photoplotting is an electronic optical process to scan rasterised image data on films. Some times refer to as laser plotting
Photoplotter - A device for generating photographic images by directing a controlled light beam that directly exposes a light-sensitive material
Photoresist - A light sensitive liquid or a film, which when selectively exposed to light, masks off areas of the design that can then be etched away
Pick and Place - A manufacturing operation of assembly process in which components are selected and placed onto specific locations according to the assembly file of the circuit
Pin - a terminal on a through-hole component
Pin count - Number of pins any component, whether through-hole or SMT
Pin-Grid Array - A packaging technology for high pin count packages. Name derived from the array of pins at the bottom of the package. The pins go through holes in a printed circuit board. I/O lead counts as high as 600 can be achieved with PGA designs
Pin-out - Pin number assignment, the relation between the logical inputs and outputs of an electronic device and their physical counterparts in the PCB package
Pin Swapping - Exchanging signal connections to a device (with equivalent functions) so that routing is easier
Pitch - The centre to centre spacing between conductors, such as pads and pins. Pads for example of a 100 mils pitch will be spaced 100 mils between the pad centres. This can also be related to the pitch of screen grid dots
Pixel - Short for Picture Element, each 'dot' element of an image is a pixel
PLA - Programmable Logic Array. An array of logic elements that can be programmed to perform a specific logic function. It can be as simple as a gate or as complex as a ROM and can be programmed (often by mask programming) so that a given input combination produces a known output function
PLCC - Plastic Leaded Chip Carrier - An SMT chip package that is rectangular or square- shaped with leads on all four sides. The leads are spaced at 0.050 inches, so this package is not considered fine pitch
Placement - The arranging the components on a PCB to fit the required board outline
Placement, Automatic - See Automatic Placement
Plated-through hole - A hole in a PCB with metal plating added after it is drilled. Its purpose it to serve either as a contact point for a through-hole component or as a via
Polygon - An open or closed, non-intersecting figure formed from a continuous line on a single layer. One form of a 'Shape'. Closed polygons may be filled
Polyimide - A material used as a Substrate for a PCB
Populated board - A PCB with components
Powerplane - A layer of a multi-layer PCB that is used to provide an earth reference or Power feed. Connections to the plane may need to provide a Thermal Break
Powerplane, Split - A Powerplane that carries more than one power supply or ground on a single layer. As the name denotes this is split on the same layer
PQFP - Plastic Quad Flat Pack. A square, flat package with gullwing leads located around all four sides of the package
Programmable Logic Devices - Devices with 10-100 times higher level of integration than a TTL; called programmable because they can be customised in software rather than in hardware.
Printed circuit board (PCB) - A printed circuit board is a component carrier that contains etched copper patterns that connect the leads of one component to the leads of other components. PCBs are often composed of a glass fabric impregnated with a resin (usually epoxy), cured, and clad with metal (almost always copper) upon which a pattern of conductive traces is formed to interconnect components. PCBs can be rigid or flexible and composed of single, double, or multi layers
Printed circuit board assembly (PCBA) - Second level integration of active and passive devices (electrical, electronic, optical and/or mechanical) on a rigid substrate
Q
QFP - Quad Flat Pack, a fine pitch surface mount package that is rectangular or square with gull wing shaped leads on all four sides
QSOP - Quarter Size Small Outline Package. An SO style IC package that has leads on a 25 mil pitch. The name derives from the fact that the package is approximately half the length and half the width of a standard SOIC
R
Radial Lead - A lead extending out the side of a component, rather than from the end. Radial leaded components are standing type discrete components; examples are disc capacitors and TO-92 type transistors
Rats-nest - A bunch of straight lines (unrouted connections) between pins which represents graphically the connectivity of a PCB CAD database. [Derived from the pattern of the lines: as they crisscross the board, the lines form a seemingly haphazard and confusing mess similar to a rat 's nest.
Reference designator - Component ID use in schematic and PCB, such as C1, C2, R1, R2, etc.
Reflow - The application of heat to a surface containing a thin deposit of a low melting point metal or alloy (e.g., solder paste tin lead alloy), resulting in the melting of the deposit, followed by its solidification
Reflow soldering - The process of joining metallic surfaces through the mass heating of solder/solder paste to form solder fillets at the metallised areas. Reflow soldering creates a mechanical and electrical connection between the components and the PCB
Registration - A term frequently used in the PCB industry. It refers to layer alignment of data, artwork, films, imaging process, screening, lamination, drilling, routing, etc
Resist - A coating material that is used to mask or protect selected areas of a circuit board from etching or plating processes
Resistor - A two pin component that nominally 'resists' electrical current flow in a linear manner
Route (or Track) - A layout or wiring of an electrical connection
Routing - The process of converting connections into tracks without crossing tracks, going outside the board area, entering disallowed areas, etc. This can be accomplished manually - i.e. by explicitly arranging signals interactively, or by using Automatic Routing
RS-274D - The basic specification of data for Gerber Photoplot output. See Gerber Data.
RS-274-X - A variant of Gerber data which contains aperture shape information in addition to the usual tool selection and movement commands. See Gerber Data.
S
Schematic - A diagram which shows, by means of graphic symbols, the electrical connections, components and functions of an electrical system. The components are represented by agreed-upon symbols, and the conductors connecting them by lines
Schematic Capture - The capture of circuit design by graphical means. The symbols representing functional blocks or individual circuit elements and interconnected by graphical representations of wires, pins, etc
Screening - Providing an earthed, conducting box, outer sheath, or area of copper on a PCB to protect from external electrical interference, or from generating such interference
SDRAM - Synchronous Dynamic Random Access Memory
Semiconductor - Components that amplify, switch, or rectify electronic signals. These devices, also known as active components, include transistors, diodes, and integrated circuits
Short or Short circuit - An abnormal connection of relatively low resistance between two points of a circuit. The result is excess (often damaging) current between these points. Such a connection is considered to have occurred in a printed wiring CAD database or artwork anytime conductors from different nets either touch or come closer than the minimum spacing allowed for the design rules being use
Silkscreen - The decals and reference designators in epoxy ink on a printed wiring board, so called because of the method of application, the ink is squeezed through a silk screen, the same technique used in the printing of T-shirts
Signal - A Digital or Analogue voltage or current that passes between components. More casually, the pieces of track that join together 2 or more pins.
SIMM - Single In-line Memory Module: a high-density DRAM package alternative consisting of several components connected to a single printed circuit board
Simulation - The process of using software to model an electronic system
Single in Line - A component with all its pins in a single row
Single Sided Board - A printed circuit board that contains tracks and pads on one side of the board and no plating in the through holes
SMD - Surface Mount Device
SMT - Surface Mount Technology
SMSO or Surface Mount Small Outline - a standardised footprint
Small outline J-leaded (SOJ) - An integrated circuit surface mount package with two parallel rows of J-leads
Small outline transistor (SOT) - Discrete surface mount transistors with a molded plastic outline that serve small and medium power applications
SO or Small Outline - A package resembling a flat pack with leads on only two sides
SoC (System on Chip) - A single chip on which multiple specialised blocks of logic have been combined
SOIC - Small Outline Integrated Circuit. A plastic IC package for surface mounting applications that has leads on two opposite sides
SOP - Small Outline Package. Similar to SOIC
Solder - A low melting point alloy used in numerous joining applications in micro-electronics. The most common solders are lead-tin alloys. Typical solder contains 60% tin and 40% lead - increasing the proportion of lead results in a softer solder with a lower melting point, while decreasing the proportion of lead results in a harder solder with a higher melting point
Solder Mask - A coating applied over selected areas of a circuit board thereby permitting soldering only of the exposed (uncoated) areas, usually only the pads
Solder paste - Form of solder to be printed on SMD pads by using a stencil in assembly
Solder Resist also known as Solder Mask - A coating that during manufacturing prevents solder wetting undesirable areas
Solder Side - On printed circuit boards with components on only one side, solder side describes the side of the PCB that is opposite to the component side
Solder Wave - One technique for soldering Surface Mount and the primary technique for conventional components, is to arrange that a 'wave' of molten solder ripples along back side of the board. See also Solder Paste
SOIC or Small-Outline Integrated Circuit - A miniature plastic flat pack designed for surface mount with gullwing leads
SOP or Small Outline Package - Similar to a miniature plastic flat pack, but with gullwing leadforms primarily or wholly constructed for surface mounting
SPICE or Simulation Program with Integrated Circuit Emphasis - Simulator used to model electrical circuits at the transistor level
SSI (Small Scale Integration) - An integrated circuit (IC) having fewer than 100 elements
SSOIC - Shrink Small Outline IC. An SO style IC package that has leads on a 25 mil pitch
Step & Repeat - A process where the printed circuit board layout or component placement is repeated many times in evenly spaced rows
Stroke Font - A stroke font is made up of small 'drawn' line segments of a given width
Stripline - A technique to tightly control the Transmission Line characteristics of a PCB trace by running parallel tracks for signal and return path, or differential pair
Substrate - The base material of a PCB onto which the Copper tracks and subsequent coating (e.g. Solder Resist) are applied. Examples of these materials are Fibreglass, SRBP, FR4, CEM1, Polyimide, Duroid and Teflon. Specialist ceramic materials are often used for Hybrids
Surface Mount - See surface mount technology
Surface Mount Technology (SMT) - A method of assembling hybrid circuits and printed wiring boards where component parts are mounted onto, rather than into, the printed wiring boards, as in the mounting components on substrates in hybrid technology
Symbol - A graphical representation of a component that contains information about the ports of the component
T
T-Junction - The point (in Schematic or a PCB Layout) where a connection is made to another by contacting it at some position along a line (as in the upright of a letter T contacting the top bar)
Teardrop Pad Shape - A basically circular Pad with one side stretched out to provide a connection point
Terminal - A point of connection for two or more conductors in an electrical circuit; one of the conductors is usually an electrical contact, lead or electrode of a component
Testing - A method for determining whether sub-assemblies, assemblies and/or a finished product conform to a set of parameter and functional specifications. Test types include: in-circuit, functional, system level, reliability, environmental
Test board - A printed circuit board deemed to be suitable for determining the acceptability of a group of boards produced with the same fabrication process
Test Point - A specific point in a circuit board used for specific testing for functional adjustment or quality test in the circuit based device
Test Strategy - Defining a test methodology for a given product that translates into test requirements and test development
Thermal Analysis - Estimating the thermal (temperature) performance of a design to determine whether changing layout would reduce 'hot spots'
Thermal Break - Used for improving soldering of holes connected to a powerplane
Thermal Relief - A wagon wheel shaped relief pad etched in the copper of a ground plain around a through hole. It connects to the plane through one or more narrow track across an opening in the plane, rather than connecting directly to the plane, so that heat transfer to the plane is minimised during soldering
Thermal Cutout - See Thermal Break
Through-hole - Refers to a component having pins designed to be inserted into holes and soldered to pads on a printed board. Contrasts with surface mount
Tooling hole - Manufacturing tooling holes are used for PCB fabrication, assembly and other test purposes. These holes serve the purpose of holding PCB panel to fixture during manufacturing
TQFP - Thin Quad Flat Pack. Essentially the same as a QFP except low profile, that is, thinner
Track - A copper 'line' on a PCB to conduct signal current
Track Clearance - The minimum permitted close approach to another signal
Transistor - A three terminal active semiconductor device that serves as a switch or provides current amplification. Comprised of a base, emitter, and collector (bipolar transistor) or gare, source, and drain electrodes (field effect transistor). Invented by Shockley (Bell Labs) in 1947
TrueType Font - These are fonts that may be scaled on the system jointly developed by Apple and Microsoft
TSOP - Thin Small Outline Package. It is thinner and slightly smaller than an SOJ and with gullwing shaped leads. A thin, rectangular package with leads sticking out the sides of the package
TTL - Transistor - Transistor Logic. Also called multiple emitter transistor logic. A widely used form of semiconductor logic
U
Unfixed - Tracks and routes which the autorouter may edit when routing nets to improve the finished design
V
Vapour phase reflow - A solder reflow technique in which the solder joints are heated by the condensation of an inert vapour
Vector Image - An image stored as a series of lines. The benefit being they can be scaled up and down without distortion.
Vector Photoplotter (also vector plotter, or Gerber photoplotter) - named after Gerber Scientific Co., which built the first vector photoplotters for commercial use)
Vcc - A name for a power net meaning voltage collector, usually +5V for TTL circuits
Via - A plated through hole used as a through hole connection between the layers on a circuit board. These holes are generally the smallest as no components are inserted in them
VSP or Vapour Phase Soldering - Soldering accomplished by using heat generated by the condensing of a vapour ion a cooler assembly.
VSOIC - Very Small Outline IC. An SO style IC package that has leads with a pitch of 30mils or less
W
Warping - Warping generally refer to finished board warp and twist. All boards may have certain degree of warp as result of manufacturing
Wave Soldering - A manufacturing operation in which solder joints are soldered simultaneously using a wave of molten solder
Wire bonding - The method used to attach very fine wire to semiconductor components (dice) to interconnect these components with each other or with package leads
WYSIWYG - What You See Is What You Get
Z
Zero width - Zero width represents a outline shape drawn by thickness line width
If you have any suggestions on how to improve this tutorial please drop us a comment below
DesignSpark Team (RS Components/Allied Electronics)
ISO-TECH Oscilloscopes, How to capture a signal event / glitch / transient
Tutorial: How to use an Oscilloscope #3 - How to capture a signal event / glitch / transient .
In this tutorial Martin Lorton uses our ISO-TECH IDS 6072A-U oscilloscope and a bench power supply to demonstrate how you can use the single shot feature with triggering to capture a signal event / glitch / transient. He also demonstrates the use of the cursor feature to measure a signal.
More about Iso-Tech Oscilloscopes
RS Components has expanded its test and measurement portfolio with the introduction of the ISO-TECH IDS-6000A-U Series of general-purpose 2-channel digital storage oscilloscopes.
With bandwidths ranging from 70MHz to 150MHz, the IDS6000A-U Series offers a 5.7-inch colour TFT LCD display to enhance the measurement experience of the user. Compact and ergonomic in design, and weighing just 2.5kg, the IDS6000A-U Series features sampling modes, 4000-point record length, a real-time sampling rate of 250MSa/s, and an equivalent-time sampling rate of 25GSa/s to enable user flexibility when processing incoming signals. Several acquisition modes and up to 27 auto measurement functions allow the user to quickly measure the accurate property of the waveforms.
The IDS-6000A-U Series provides complete remote control or data capture over USB host and device interfaces. It supports PictBridge which, when connected to a compatible printer with a USB cable, facilitates push-button printing. It is designed to optimise balance of performance between memory length and sampling speed. Its MemoryPrime technology allows 2Mega points of waveform data. Full advantage of this capability can be taken using Horizontal Page Skip and Set Time functionalities.
Incorporating user-friendly menu tree operations, the IDS-6000A-U Series has been designed for ease-of-use in applications spanning laboratories and educational facilities, product testing and quality assurance, service operation and post-sales support, and product development and debugging.
The IDS-6000A-U Series is part of the ISO-TECH range of test and measurement products, an RS private label brand offering exceptional value for money with the same specifications and performance as many higher priced brands, says the company.
ISO-TECH + Arduino bundle offer
I want one of those... August 2013
As a self confessed Geek and Gadgeteer i'm always being sent links by my friends and colleques, with the "have you seen this!" tagline.
So, knowing that many of you are probably as tech hungry as I am, I'd thought I'd start to share some of this stuff with you on a regular basis. If you have something you'd like to share, please feel free to click on my avatar and send me a message, post it in the comments below, tweet us @designsparkrs or Facebook at www.facebook.com/DesignSparkRS
Devkits/Add-on Boards
There are so many add-on boards now available for Raspberry Pi's and Arduino's, however, this one really caught my attention. It's by a company called SparqEE and is tiny Cellular development board that gives you Wireless Worldwide. That means internet to anything anywhere! Great for remote applications. This is their kickstarter video below. You can also find out more about this great product on their KickStarter page.
New Technologies
No batteries?... no problem! Ambient Backscatter is Wireless Communication out of thin air. Like a sponge, it basically collects surrounding wireless signals and uses them as a source of power and communications medium, allowing two battery free devices to communicate with each other.
Gadgets
PeterJFrances posted this one recently in his DesignSpark blog. It's a great new inexpensive little gadget from Leapmotion that allows you to interact with a PC/Mac and regular screen, using your hands and nothing else.
Tools
I bumped into Saar Drimer at a recent Open Source meetup (OSHUG) in London. Saar is a developing a new kind of a PCB layout tool called Boldport. It's probably really a tool you would use for your day to day circuit design, but what's different about Saar's PCB Tool is that your not restricted to straight tracks...it's kind of art on a PCB. Here's an example of the kind of things Saar has created.
Websites/Podcasts
Having fallen out with radio lately, I've started listening to more podcasts. I bumped into these guys at a recent event for the 100th Birthday of the Radio Society of Great Britain. Frequency Cast UK is a monthly podcast about all things tech and is a quite entertaining in the morning rush hour.
Gaming
This is one of my favourite KickStarter projects to date!. Having grown up on a gaming diet of Doom, Duke Nukem and Quake, I'm a big fan of First Person Shooter games. Finally an affordable set of Immersive virtual reality technology that's wearable and affordable. It's designed by a company called Oculus VR, and will certainly appear on my Christmas list this year. Check these out!
Toys not for the kids
I'm a major Back to the Future fan, and I recently learnt that Lego has released a Lego DeLorean. I couldn't wait until Christmas for this one, so I've aready made a purchase.
Image from lego website
So thats it for this time, and don't forget to tell me about things that you've found and want to share.
COSCUP注冊有禮活動
活動日期: 即日至9月30日
不要再想,立即填寫活動登記表就有機會贏到Raspberry Pi 鏡頭和BeagleBone Black!
讚好DesignSpark (Chinese) 粉絲專頁就可以知這活動最新消息和更多比賽活動!
機械設計ツール(3)
こちらの英語記事の翻訳です。
前回の二つの記事では、機械設計ツールの概要と使い方について解説しました。今回の最後の記事では、技術者によく使われている機械設計ツールをご紹介します。
数多くの機械設計ツールが市場に存在していますが、最近よく使われているのは、Solidworks、AutoCAD、Pro/ENGINEERそしてSpaceClaimの4種類です。
これらのソフトは、機械設計やその他の設計において、技術者たちに幅広く使用されています。そして、今回する4種類のソフトのうち以下の3種類は、国際的な認定資格も発行しています。
- SolidWorks:CSWP (Certified SolidWorks Professional)
- AutoCAD:Autodesk Certification
- PTC:Pro/ENGINEER Official professional certification program
それでは、4つのソフトを簡単にご紹介いたします。
Solidworks
SolidWorksは、世界最初のWindows用3DCADシステムとして開発され、近年のソリッドモデリングおよびサーフェスモデリングの礎を築いてきました。便利で使いやすく革新的な技術によって、技術者たちに根強く支持されています。また、SolidWorksを用いて作られたデザインは、自由自在に修正することができ、部分設計・組み立て設計および作図機能は非常に使いやすいものとなっています。
SolidWorksのデモ動画はこちらです。
AutoCAD
AutoCADはもともと2Dでの作図に使われており、精密な作図機能・設計書を作る機能しか持っていませんでした。後に、3Dでの設計機能も加えられました。最も初期に開発された2D設計ツールの一つであるため、AutoCADの.dwgというファイル形式は、2Dでの作図において標準規格の一つとなっています。AutoCADは、完璧といっても差支えないほどのレンダリング機能や画像編集機能を持っており、幅広いハードウェアデバイスや開発環境に対応しています。処理速度が比較的遅いため、実際の精細度で描画を行うためには、AutoCAD内で様々なテーブルを開く必要があります。
AutoCADのデモ動画はこちらです。
Pro/Engineer
Pro/Engineerは、パラメトリックモデリングを導入した世界初のソフトであり、3Dモデリングソフトウェアの中で重要な位置を担っています。パラメトリックモデリングとは、CADで設計している製品が、各部位の長さなどの空間的な情報だけではなく、全体的な寸法などについての拘束条件を持っており、一部の寸法を変更するだけで、全体の形状を上手くCADが調整してくれるような機能を指しています。
Pro/ ENGINEERは、上記の機能を実現するために、単一のデータベースを用いています。PRO / Eはフィーチャ選択メソッドに基づいており、コンカレントエンジニアリングを実現するために、全体の生産・設計プロセスを統合することができます。
Cf. コンカレントエンジニアリング
CAD・CAE・PDMなどのシステムを通じてデータの共有・共用を行い、例えば意匠デザインと構造解析、強度計算などを同時並行して作業することで、製品品質の向上と同時に開発期間の劇的な短縮を目指すこと。
Pro/Engineerのデモ動画はこちらです。
SpaceClaim
SpaceClaimは、世界初の3D設計システムです。パラメトリックなCADシステムとは異なり、作図の専門知識が無くても、直感的な方法でモデルの編集を行うことができます。次に挙げるような数種類のモデリング機能しか搭載していないものの、設計および編集を行うには十分です。ダイレクトモデリング機能では簡単に設計・編集を行うことができます。マージ機能では簡単に様々なモデルやセグメンテーションを結合することができます。フィル機能では様々な特徴を簡単に付加・除去することができます。
SpaceClaimのデモ動画はこちらです。
以下は、これまで紹介した4種類のソフトに対して感じた印象です。
AutoCADは未だに2D機能に力を入れており、3D設計業界で必要とされているいくつかの機能も欠けていることから、他の3種類のソフトウェアと比較すると、3D設計機能は不十分と言えます。
SolidWorksのユーザーインタフェースは、より人間の感覚に近く、使いやすいものであり、膨大な部品の集合を扱うには最も効果的と言えるでしょう。また、AutoCADのシミュレータも提供しています。欠点としては、ユーザーに優れた空間認識能力が求められること、2D図がしばしば間違った形で出力されること、そしてハイスペックなコンピュータが必要である点が挙げられます。
Pro / Engineerは、完全かつ多くのモジュールを搭載しており、強力な作業環境を持っています。欠点としては、ファイルの構造を明らかにするために、ユーザーにきちんとしたファイルの管理能力が求められる点です。
SpaceClaimは、シンプルかつ便利で使いやすく、CADソフトを使用した経験が無くても、簡単に使い始めることができます。また、3DCADツールの中で、マウスジェスチャー機能に対応する唯一のソフトでもあります。開発されてまだ日が浅いため、他の3種類のソフトと比較すると、機能がまだ不十分である印象を受けます。
本記事で紹介した4つのソフトの中で、個人的にはSolidworksかSpaceClaimを使うことをお勧めします。使いやすさに加えて、モノづくりの世界で幅広く使われていることが挙げられます。とりわけ、CADの世界観を大きく変えたSpaceClaimのダイレクトモデリング技術は、多くのCAD開発企業が重要なものとして認識しています。
Solidworks 公式サイト: http://www.solidworks.com/
AutoCAD公式サイト: http://www.autodesk.com/products/all-autocad
Pro/Engineer公式サイト: http://zh-cn.ptc.com/
SpaceClaim公式サイト: http://www.spaceclaim.com/