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TSQFP->DIL (kinda)

(*steve*)

¡sǝpodᴉʇuɐ ǝɥʇ ɹɐǝɥd
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Jan 21, 2010
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In a rather more extreme version of the SOIC>DIP thread, tonight I soldered a 64 pin quad flat pack device with 0.5mm spacing onto a breakout board.

I have confirmed I have no pins shorted together. It's not the first 0.5mm pitch device I've and soldered, and it's not the first quad flat pack, but it is the first quad flat pack with so many pins at such a fine pitch.

I will post some pictures tomorrow.

The worst moment was after I knocked the chip hard enough to rip a pad off the board (the one I'd tacked the first pin to :() Fortunately the track was still attached and I was able to solder it to the pin.

The other less than amusing aspect was the fact that it has Vss and Vdd pins in pairs on all 4 sides of the board. When I shorted one of them, they all registered as shorted. Fortunately the difference in resistance pointed out which one was really shorted.

I do have a tool which is designed to hold a chip in position while it is hand-soldered. I will definitely be using this next time... 0.2mm of error in positioning is enough to ruin your day...

In the meantime, here's someone who did a better job than me. (although that doesn't look like 0.5 pitch either)
 

BobK

Jan 5, 2010
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Hey Steve,

Did you do it a pin at a time, like the video you linked, or drag solder?

Bob
 

Harald Kapp

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Another method I've seen is to use reflow solder paste (!toxic!). The paste is applied in small doses (e.g. using a syringe) to the empty pads. The chip is set atop the paste and soldered pin by pin without additional solder. The solder paste flows by cohesive force to the pins when heated by the tip of the solder iron. Not using additional solder makes for a rather uniform distribution of solder and a low risk of shorts.

Then again I have to admit I haven't done it myself, just watched people do it,
 
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