For what it's worth clean both parts tin both parts and use silver solder. it melts with less heat and sticks a lot better. and also use an alligator clip to keep the heat from getting into the semiconductor.

 

Thanks a lot for all the great ides. To get a better heat sink, should I put the actual chip in the alligator clips (so it's squeezing down on the chip), or put the alligator clips on the leads before the chip?

Is 700F too hot for this job?

Does anyone have any thoughts on that example I posted?

 

Thanks a lot for all the great ides. To get a better heat sink, should I put the actual chip in the alligator clips (so it's squeezing down on the chip), or put the alligator clips on the leads before the chip?

Is 700F too hot for this job?

Does anyone have any thoughts on that example I posted?

700 is quite high. You could probably get away with 500 or 600, perhaps less.

And I agree with the heatsink idea. Some companies even make aluminum heat sinks designed to clamp onto chips while soldering. It may be worth investing in a couple of these.

 

Use good leaded rosin core solder, such as Multicore, Kester, or Chip-Quik, in a small diameter. The flux is important, good solder will provide enough and have a low melting point, more questionable solder use a paste flux applied with toothpick or liquid flux brushed on.

I stick with 0.035" or smaller diameter solder for most work (0.015" for SMD), it is far harder to get too much solder onto a joint that way. The 1mm/0.04"+ is useful when soldering large parts or two 16 gauge wires together, but that's about it.