Tin Whisker Investigation
NASA Goddard has a presentation on Tin Whisker on Toyota accelerator pedal position sensor failure. It shows ribbon connector leads (copper alloy with 2um pure tin) shorted by tin whisker ~2mm long,1um diameter, 240 Ohms. Standard Ohm-meters may not be able to detect the whiskers because the voltage is too low to break down insulating films.
Analog Devices iCoupler
The analog devices iCoupler technology is described in this article. The transform is built with CMOS metal layer, a high breakdown polyimide layer and a gold layer. High speed CMOS circuits with 1ns edges are connected to the transformer with wafer scale packaging.
Free PCB Layout Software
Some free PCB layout software worth noting are the open-source KiCAD and gEDA, Sunstone PCB123, DesignSpark PCB. These tools seem to be able to handle moderately complex designs.
Make You Own PCB
A relatively simple and low-cost procedure of making your own PCB is shown here. It starts with pre-sensitized circuit board, then developer and etching solution. A board can be made for less than $50.
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