Author Topic: Need Advice Replacing QFP with E-Pad  (Read 237 times)

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Offline irobotTopic starter

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Need Advice Replacing QFP with E-Pad
« on: October 24, 2024, 04:17:39 am »
Need to replace a 176-pin thin QFP with an e-pad (ground pad) and looking for suggestions, or any tips on best way to do this.

I always use the "drag" method with QFP's, using conventional leaded solder and controlled temp iron.

I rarely come across having to deal with e-pads in my 40+ years of doing rework which includes fine-pitch SMD.
Obviously need to use hot air for the e-pad.

Do I use paste on pins and e-pad and "float" it into place with hot air, or what?

I've already scoured YT looking for help.
 

Online ataradov

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Re: Need Advice Replacing QFP with E-Pad
« Reply #1 on: October 24, 2024, 05:53:03 am »
I did not need to do that a lot, so I have  no idea how consistent the method is, but when I did it, I just used hot air to solder the pad and then drag soldered the rest of the pins. This let  me check that  the pas is actually soldered. The rest of the method is just just QFN - heat up the device, poke it a bit to make sure it settled, make sure pin alignment is still ok.

It was a bit annoying to manipulate the large package, since it did not fit entirely into the field of view of my microscope, but I managed to make it work in the end.
Alex
 


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