Bending a SIP package

On occasion I create pseudo-SMD parts from through-hole parts. For example, I'll take a 14pin dips and turn it into a SMD.

I've noticed that typically the metal used with IC's cannot handle repeated bending before snapping.

After a single 90 bend, I wouldn't be surprised if under a microscope metal tearing can be seen at the bend..

I'll guess you have 1 shot at getting the bend right... Once bent, do not correct or adjust or these's increased risky of rips.

I prebend my parts before soldering to get the bend in the preferred location and to get a 90 bend on a forming jig...

Just pushing over the part after soldering can have too much bend radius.. D from BC

Bending pins, yes. But I would bend the pins first, and then solder. This will trap a lot less push and pull between individual pins.

D from BC wrote: (snip)

The risk is having too little bend radius. Bending the pins over a curved surface really helps distribute the stretching forces along more of the pin,, rather than having all the bend take place at the weakest point.

Use the old sip as a model and bend it in a hobby vice in between a couple pieces of wood. You really have basically one shot so make it count.

And yes I've done this several times with 100% success.

There's a "just right" bend radius :)

I've pushed over some soldered parts with so much bend radius, I can't get 90 deg..the part makes contact with the PCB and then springs up. D from BC

As I said, the bend should be formed in unsoldered leads (using as much of the part that will not be soldered as possible), so the part drops into the holes and lies flat before it is soldered. The bend should not take place at the point where the leads neck down to fit the holes, but only at the wider part. Just as DIP lead frames are pre-bent between the case and the necked down spot.

Bend and form the legs *before* you solder it. And once bent, don't move them again. Keep the pins in the staggered arrangement. Make sure the device is physically attached to the PCB (or heatsink) before soldering.

Dave.