1
\$\begingroup\$

I need to solder a WLCSP chip (FAN3852) to a DIP breakout board.

Since the WLCSP chip already has tiny solder balls, would it be possible to hold the chip in place on the breakout board with tape and then heat it with a heat gun? I'd have to monitor the surface temperature to ensure it doesn't exceed the max reflow tolerance (~260C).

https://www.youtube.com/watch?v=T75VzHjnExc

\$\endgroup\$
3
  • \$\begingroup\$ That's quite unlikely to go well. Stranger things have happened, but you'd want a hot air rework tool not a "heat gun". If you had to improvise some sort of heat from below like a hot plate (before soldering the header pins) might work better. Also, there are services which will mount things on breakouts, they've been mentioned here in the past. \$\endgroup\$ – Chris Stratton Dec 6 '20 at 8:32
  • \$\begingroup\$ google sand soldering \$\endgroup\$ – jsotola Dec 6 '20 at 19:28
  • \$\begingroup\$ Thanks guys, I figured that using a heat gun was kind of a redneck approach... Sand Soldering looks super cool! As it turns out, I have a spare IH lying around that I can use. I've never used a PCB assembly service before - any recommended online retailers for manufacturing this simple standalone WLCSP-6 to DIP-6 breakout? \$\endgroup\$ – Joel Dec 6 '20 at 23:39
1
\$\begingroup\$

Is it possible? Yes. Keep in mind its harder if you have other parts already on the board (use foil as a heat blocker). And the small size vs the heat gun's diameter and air flow speed. I've done it on a similar wlp chip using a small butane soldering iron with the heat gun option. About the diameter of a AA battery.

But overall its not a good way to do it. And especially not an easy way to do multiple at a time or repeatedly. There are other solutions you could try like a toaster oven converted for soldering or a pan etc etc but if you need to do multiple a proper hot air soldering station is used.

Alternatively, you can solder to it dead bug style. A 6 pin WLP like that is easy (relatively) to solder to with some spare wire as there would be no overlapping. Still not a walk in the park though. http://dangerousprototypes.com/blog/2012/11/15/fine-pitch-bga-deadbug-soldering/

\$\endgroup\$
2
  • \$\begingroup\$ I contemplated doing "dead bug" soldering, but honestly I would be terrible at it (tried my hand at 28-TSSOP once, didn't go well...). Might be worthwhile to invest in the toaster oven or sand soldering method. \$\endgroup\$ – Joel Dec 6 '20 at 23:41
  • \$\begingroup\$ A recent one i saw used a clothes iron. Looked like they added some extra parts like temperature control but very cool. But considering how many you may need a cheap dollar store or thrift store pan and some sand is all you need for a quick board or two. \$\endgroup\$ – Passerby Dec 7 '20 at 10:25

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.