08 August 2007

SOIC to DIP homemade adapter

Got the ICS512 chips for the 4m TX and I suddenly have to deal with a SOIC-8 package. I remember seeing some solutions around the web for adapting SOIC to DIP, to which I'll add my own:
  1. Sijosae's DIY Gallery, scroll down to "Tip"
  2. commercial adapters (search for "Browndog", or check what Futurlec or eBay offer)
  3. The saltwater etch process
  4. my own cutter etch process
I cannot quickly buy the commercial adapter. I also seem unable to use Sijosae's method(s), and I don't want to abuse the chip since I've gotten very few of them. So I'll go for the 4th method.
  • Take a piece of unetched PCB.
  • Sit the IC (or an identical one) on the board and hold it in place with a crococlip, near a corner of the board.
  • Mark on the PCB empty areas between pins using a permanent marker with 1mm tip. With a SOIC-8 you'll get 3 marks per side. The result:
__ __
__ __
__ __

  • Remove the chip
  • Very carefully with a cutter and a ruler draw connections between twin marks on each side of the IC, and extend them beyond your marks:
_____________________
_____________________
_____________________

  • With the cutter also etch a line across in the middle, so that you'll have 8 pads once...
  • ...you cut the copper clad board with your favorite method so that the PCB is composed of 8 pads
  • Check insulation between adjacent pads with an ohm-meter, "dig" more with the cutter if you measure zero ohms
  • Pre-solder pads
With a little patience and firm hand you can produce several adapters in a row.

That's it. Hopefully I'll add some pictures of the process.