Techniques

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Revision as of 23:09, 6 August 2007 by 85.25.140.211 (Talk)

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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

Circuit construction (non PCB)

["Construction Ideas"] has nice photographs of the above circuit construction techniques.

Soldering techniques

(Have you seen this 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:

Name Platform License AutoRouter Comments
gEDA Linux, *BSD Free,OSS Ar gEDA wiki includes schematic and PCB for makeing gerbers etc...
McCAD EDS Lite Pl Free demo max 200pin Ar Free demo version available for download, 200 pin limit
McCAD EDS SE "free" Free book, "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 Win32 Free, OSS Ar PCB Design Software
TinyCAD Win32 Free,OSS Ar Schematic Drawing Software
KiCad Win32,Linux,*BSD Free,OSS Ar http://www.lis.inpg.fr/realise_au_lis/kicad/ EDA suite
Express PCB Pl Free Ar
Protel DXP Pl Li Ar independent Protel users FAQ
Eagle Win32,Linux Limited demo Ar http://cadsoft.de/ Eagle tutorial from Sparkfun Eagle tutorial (makezine)
DipTrace Pl Free 30day demo Ar
WinQcad Pl Free demo Ar Demo with max 499 pins available for download
Rimu Schematic and Rimu PCB Pl Li Ar  ???
SuperCAD and SuperPCB Pl Li Ar
www.autotraxeda.com Pl Li Ar AUTOTraxEDA. Holy poop! It does EVERYTHING for NOTHING (ed: not anymore). It won't run on *nix or anything less than NT (nope, it don't work on '98) but other than that, it appears to be a complete violation of the TANSTAAFL rules. {ed: yep... now it costs.} And the user forums have shown a certain lack of satisfaction with the program.
www.expresspcb.com Pl Li Ar The ExpressPCB Windows layout software makes designing PC boards simple for the beginner and efficient for the professional. Its standard Windows user interface uses all the familiar commands such as copy, cut, paste & dragging. PC board manufacturing service delivers boards in 3 business days or less. Often orders for two boards cost under $100. They keep changeing the program and old files may not work (due to increased limitations on the placement of objects) in the new versions without some rework. See TCI which is just about the same and prints or outputs to Gerber / Excellon files.
www.holophase.com/dleval.htm Pl Li Ar Circad's DOS layout Demo is free for non-commercial use.
www.geda.seul.org/ Pl Li Ar xNIX Electronic Design Automation project has Schematic capture with PCB CAD.
www.vutrax.co.uk/pricing.htm Pl Li Ar Vutrax for Windows - free for under 256 component pins
www.interactiv.com Pl Li Ar Electronic Workbench * ( Interactive Image Technologies Ltd.) $ 400 for 500 pins. Includes schematic capture and simulation, virtual instruments , and PCB layout. Said to be stable.
bach.ece.jhu.edu/~haceaton/pcb/ Pl Li Ar Absolutely free (GPL'ed) PCB program which can work under any POSIX compliant operating system (eg. Linux) and can produce Gerber or PostScript files.
www.labcenter.co.uk/ Pl Li Ar They have a lite version "pic bundle" aprx. $149.00 includes schematic/simulation/pcb layout. You can write pic code for your pic schematic design and simulate. Even multi-pic,keypad,lcd display (really cool). Right now it can only simulate PIC1683/1684 (lite version limited to 1k program code), but it really works. They are working on more pic modules now. Will not produce Gerber/Excellion drill files only dxf, bmp, hpgl, tiff.
www.ivex.com/ Pl Li Ar Winboard PCB Layout
www.illuminated.com.au/ Pl Li Ar Draftcad
www.winqcad.com/ Pl Li Ar MicroCad

(Some of this information in this table came from the list of software design tools at the Massmind).

Is there any way to objectively compare these tools? How well did they do at the 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 Atmel AVR embedded systems]).
  • Other systems use some other kind of in-circuit programming.
  • Some people use 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.

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