SMD: Surface Mount Device Adapter PCBs

You can make your own PCB adapters (for breadboarding or whatever) by designing and producing a PCB. The pads and traces must be small, so the PCB's are difficult to produce. Using a Socket may be easier, or a commercial pre-made adapter may be available. (see links below)

As an example: If you want to use 100 pin IC with 0.5 mm pitch, you will need SMD pads 0.3 mm wide and an isolation gap of 0.2 mm or 8 mil = 0.008 inch. One dot of a 300 dpi printer is 3.333 mil ; 0.00333 inch or 0.08467 mm. The 0.2 mm isolation gap or track width are only 2.36 dots of a 300 dpi printer and only 4.72 dots of a 600 dpi printer.

Laser printers may not have sufficient resolution. Try to print a line of 100 mm length in both directions and measure it with a high precision ruler. You will see errors of up to 0.5 mm and these errors are different for both directions. Using InkJet's for photo-resist is generally a better idea than laser printers - the ink on a transparency is a little more opaque than toner on a transparency generally. Some of the newer Epson Stylus inkjets are at 1440dpi, which results in higher accuracy tracks at smaller pitch

See Also:

• http://www.futurlec.com/SMD_Adapters.shtml
• http://www.beldynsys.com/
• http://landpatterns.ipc.org/default.asp IPC land pattern spec and calculator

An SMT layout for prototyping analog circuits with transistors and resistors in a premade layout. Useful for adding front end / back end signal conditioning to proto boards so I could "figure that bit out later" and just get the main part of the PCB off to production sooner. Add a terminal block for power with a couple through hole pads to route power around with jumper wires. Often, just half the circle works +

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