si4735: AM/FM LW/SW radio on a chip, DIY circuit etching

I noticed this chip on sparkfun the other day, and immediately knew I had to have it in the project.   Since this mixer is meant to sit next to the media PC and handle all audio, it's just too cool to have a radio in the box as well.

The chip looks awesome, but there's a small problem - the largest package available is SSOP in a narrower-than-normal size.  This means that any commonly available SSOP-24 breakout board is worthless.   However, I've gotta break it out to bread-boardable pins because I have no hope of getting it set up correctly without testing first.

That left me with only one real option - I've gotta make the breakout myself.   Instead of using one of the many PCB fab companies, I thought I'd try my hand at etching a circuit myself.

First, a design.  Seems simple enough for a first attempt:

Narrow SSOP-24 breakout.  Click for full size

So there are several methods for DIY etching.   After some research, I decided to try the toner transfer technique, where you print your design on glossy paper and then iron the plastic toner right onto the copper.   The toner resists the etchant, and boom hot dog.

My first attempts were failures of course - it took me a while to find the right combination of paper and heat and time, but in the end I got a good transfer. Etched it, and all traces were good!

Soldering to a board without plated pin holes is trickier than I'm used to.   Also, I drilled the holes a little big, so I had to bridge the gap between the pad and the pin.   It took some re-working and the result is ugly as hell, but all pins are clean and working.

SSOP breakout board.  This is an earlier design than the one above, and the solders are /ugly/

I'm extremely encouraged to know I can cheaply and quickly make PCBs with tiny SMDs.