Editing Techniques

== Printed circuit board fabrication ==
=== Homebrew ===
* [[Toner Transfer]] -- This method involves laser printing your PCB design onto paper, then transferring toner onto copper-clad board.
* [[Photoetching]] -- Exposure of PCB designs onto photosensitized copper-clad board.
* [[Chemical Etchants]]

=== Commercial PCB fabrication ===
* [[Submitting PCB's for fabrication]] -- Common processes for submitting PCB's for fabrication.
* [[PCB Manufacturers]]

== Circuit construction (non PCB) ==

* [[Solderless protoboard]] ([http://en.wikipedia.org/wiki/Breadboard Wikipedia:Breadboard])
* [[Point-to-point]] ([http://en.wikipedia.org/wiki/Point-to-point_construction Wikipedia:Point-to-point construction])
* [[Wirewrap]] ([http://en.wikipedia.org/wiki/Wire_wrap Wikipedia:Wire Wrap])
* [[Dead bug style]] -- and a similar method, [http://ciphersbyritter.com/RADELECT/BREADBD/BREADBD.HTM "A Modern Breadboarding Technology: Insulating Pads Soldered to a Ground Plane"]
* [[Manhattan style]]

[[http://www.techlib.com/electronics/construction.html "Construction Ideas"]] has nice photographs of the above circuit construction techniques.

== Soldering techniques ==

* [[Basic soldering]] -- How to use a soldering iron.
* Surface Mount
** [[Skillet reflow]]
** [[Toaster oven reflow]]
** [[Hot air soldering]]
* [[Rework]] -- Techniques for fixing mistakes, or for adding new features to a board that ''almost'' does what you want.
** [http://workmanship.nasa.gov/lib/insp/2%20books/links/sections/302_jumper%20wires.html official NASA recommendations for adding discrete wiring ("jumper wires") to PCBs]

(Have you seen this [http://www.hackaday.com/2007/06/04/cnc-solder-paste-pick-n-place/ CNC solder paste/pick n place] ?)

== Software design tools ==

Some people still build circuits without ever using any software tools.
For complicated circuits, software design tools can save a lot of time.

Here we list "suites" that combine schematic capture, component editor for the components used in schematic capture, circuit simulation, PCB layout, autorouter, and footprint editor for the footprints used in PCB layout.
(Is there another place for listing stand-alone tools such as a switching power supply "wizard" and a RF analysis tool?)

Quite often people mix-and-match tools -- using a schematic capture from one suite to generate pretty schematics and a netlist, then importing the netlist a third party Specctra autorouter, then importing the result into a PCB layout program from another suite for the final manual clean-up and design rule checking.

In no particular order:

* [[gEDA]] http://geda.seul.org/ ; [http://geda.seul.org/wiki/ gEDA wiki] -- free version; open source. Includes schematic and [http://sourceforge.net/projects/pcb/ PCB].
* McCAD EDS Lite http://mccad.com/ -- free demo version available for download, 200 pin limit
* McCAD EDS SE is free with the book [http://applefritter.com/replica "Apple I Replica Creation" ]  -- supports 750 pins, 11"x17" sheet size, 6-8 data layers. <tangent>(any useful tips in this book for those who want to build a CPU from scratch?)   <reply>No, there are not.  The book is more entry-level. - Tom Owad</reply></tangent>
* FreePCB http://www.freepcb.com/ -- free version; open source, Win32 PCB Design Software
* TinyCAD http://tinycad.sourceforge.net/ -- free version; open source, Win32 Schematic Drawing Software
* KiCad http://kicad.sourceforge.net/ and http://www.lis.inpg.fr/realise_au_lis/kicad/ -- free version; open source, eda suite, Both Win32 and Linux Version
* Express PCB http://expresspcb.com/ -- "free" software

* Protel DXP http://altium.com/ ; [http://techref.massmind.org/techref/app/protel.htm independent Protel users FAQ]
* Eagle  http://cadsoftusa.com/ ; http://cadsoft.de/ ; [http://www.sparkfun.com/tutorial/PCB/eagle-output-tutorial.htm Eagle tutorial from Sparkfun] ; [http://www.makezine.com/blog/archive/2006/03/how_to_make_a_custom_library_p.html another Eagle tutorial] -- free demo version available
* DipTrace http://diptrace.com/ -- free 30 day demo version available for download.
* WinQcad http://winqcad.com/ -- free demo version (up to 499 pins) available for download
* Rimu Schematic and Rimu PCB http://www.hutson.co.nz/ -- ???
* SuperCAD and SuperPCB http://mentala.com/

''(Should I make a huge grid here, with checkmarks for "runs on Mac", "runs under Linux", "open source", "includes autorouter", etc. ?)''
(yes!! yes you should!! now get back to work slave!!)

Another [http://techref.massmind.org/techref/pcbcads.htm list of software design tools at the Massmind].

Is there any way to objectively compare these tools?
How well did they do at the
[http://www.pcbwest.com/topgun/ PCB Top Gun contest] ?

=== Checklist for "The flow of PCB fabrication/PCB 製作流程" using Software Design Tool===
*Format and shape of PCB are conformed./底板的幾何圖形和尺寸確認
*Via size and location are conformed./定位和開孔尺寸確認
*Fixed location item are placed on suitable place./對有所要求之硬件放置的明白確認
*A one-first PCB silk layout is made./做一張1:1的PCB白油圖
*All item get enough clearance between them./所有硬件排放後檢查相鄰是否過於緊貼
*All vias get enough size to install them components./所有孔徑是否符合要求
*Make sure no worng footprint is created./肯定了腳銲盤無錯誤
*PCB is drew./完成了PCB
*Netlist is ran and got a no error result./執行netlist指令直無錯誤
*DRC is ran and got a no error result./執行DRC直至無錯誤
*Location of item is reasonable./模擬實物放置是否合理
*All items are put on to a hard copy of PCB./放置所有零件在影印本的PCB上	
*Overall is checked./全面檢查確認無誤

And then the Gerbers are sent to a [[PCB Manufacturers]].

== embedded system programming and testing ==

* Many systems use [[JTAG]] for programming and testing. (Such as [http://en.wikibooks.org/wiki/Atmel_AVR Atmel AVR embedded systems]]).
* Other systems use some other kind of in-circuit programming.
* Some people use [http://en.wikibooks.org/wiki/Embedded_Systems/Bootloaders_and_Bootsectors bootloaders] to make re-programming a little quicker.

== Enclosure ==

* The Earth Signal should short to whole metal Case
* Digital/Analog GND should separate to this Earth Signal, and should connect a Y-cap. to filter the noise between them.
* Attention: do not place near between Earth Signal and Digital/Analog GND, otherwise some spark come out, and affect your whole system.

== further reading ==

* [http://airborn.com.au/method/ "Electronics Design" from Airborn] gives an overview of the complete process: specification, (schematic) circuit design, layout, prototypes, firmware, pilot run, production.
* EDA electronic design automation software is a subset of CAD in general. Is there a wiki that discusses CAD in general? Until I find it, I'm going to post these tools here: "Google SketchUp is a powerful yet easy-to-learn 3D software tool" http://sketchup.google.com/ ; "Inkscape is the best tool for SVG standard vector graphics" http://wiki.inkscape.org/ ; Visual Wiki http://visualwiki.org/
* [http://www.national.com/rap/Story/0,1562,18,00.html "What's All This Ground Noise Stuff, Anyhow?"] by Robert A. Pease
* [http://www.elecdesign.com/Articles/ArticleID/6150/6150.html "What's All This Teflon Stuff, Anyhow?"] by Robert A. Pease -- explains a situation using lots of metal (instead of carefully insulating everything with lots of Teflon) causes less noise. Also mentions "why am I telling you all of these details? If I design a tester with greatly improved performance to help me test a really high-performance product, why should I tell all our competitors so that anybody in the world can test their products using the improved tester? Why should I give away all of these hard-earned secrets?" and gives some very good reasons.
* [http://groups.google.to/group/sci.electronics.design/browse_thread/thread/889153f0e77b1718/fcaac532bb6d4b12?fwc=1 sci.electronics.design: EDN: Measuring Nanoamperes] discusses some ways to measure extremely small currents.



[[Category:Techniques]]