With the introduction of surface mount components comes the decline of electronic component recovery and reuse. But as a hobbyist I am still strongly inclined towards reuse of scavenged ICs. Why you may ask, when it cost little over $5 for the IC and breakout board. Well, every dollar count and the waiting time for shipping. More importantly I just see it as a challenge against the "throw-away" society.
Before undertaking this project I must forewarn you that it is VERY VERY VERY tedious work, with a lot of "one step forwards, two steps back".
Step 1: IC Removal
So here is the IC ready for scavenging. I will not go into great details about the process but be sure to check of other ibles covering this topic such as:
Step 2: IC Holder
To ensure that the legs of the IC don't bend too much and break, we are going to solder it onto a small piece of PCB with only the pads. To get this I took a Dremel to the PCB that housed the IC before and cut out the pads. Then I made a shallower cut around the pad to ensure that all the connection to the pads are cut. There are also extensive Instructables on how to solder surface mounts.
You can hit two birds with one stone if you choose to just cut the IC from the old PCB. That will save you de-soldering and soldering the IC. Just make sure to cut through PCB on the underside of the IC to break all existing connections because it is hard to know if the connection are what you need. If it is then life just got easier.
Step 3: Baseplate
So before any soldering happens we must first have a sturdy base to mount everything. For this I used a piece of scrap plastic I cut from an old printer. So this is to hold everything in place while we do the soldering. It is possible without it but it would be extremely difficult unless a temporary holder is used.
Step 4: Pinouts
So this is the output of the breakout board. For this I used some standard stripped proto-board cut into two thin strips. The end facing the IC have been tinned and a bit of extra solder left on. This makes the process later much easier.
Step 5: Preparing for Soldering
Before soldering all the points that are to be soldered on should be fixed. The photo shows the general layout of all the components.
Step 6: Soldering!
So this is the most tedious and time consuming task. I had a really thick tip on my soldering iron which made the whole process much much more challenging.
Use the thinnest enamel wire you have available on a spool.
1) The first step of soldering is to tin the wire.
2) Then place the wire on the pin and apply heat. There should be enough solder to hold. DO NOT APPLY SOLDER AT THIS POINT.
3) Tension the wire to the pinout board. Apply solder and heat to the pinout till the enamel melts away.
The final result should be a lightly tensioned wire from the IC to the pinout board.
NOTE: if a wire comes undone, do not try to resolder. Simple remove the wire and start again. It will save so much time.
Rest and repeat for all the pins.