Desoldering an SMD chip

Repairing an optical scanner by Biometrics fingerprint scanner. Removing MAXIM Max238CWG chip.

Category:

Howto & Style

Tags:

• desoldering
• smd
• smt
• aoyue
• electronic
• pcb repair

[TookMe20min2findThis]

Well, you've got a lot of nice equipment for soldering/de-soldering. However for those not so well equipped, I strongly suggest removing any ICs (QFP, PLCC etc.. no BGA) using Chip Quick. I just tried this stuff and I am in shock!

This is so easy and cheap. I've removed hundreds of ICs in my life with all sorts of tools and sometimes I ripped the pads off or what have you.. and Chip Quick was just so unbelievably great.

And no.. I don't work for the company ;)

[rkruetzfeldt]

@TookMe20min2findThis

I've always maintained that you have to consider all methods when you do rework or any other task and you have to accept technical changes that work or at least acknowledge them. I have also used Chip Quick and it is now a primary consideration for device removal. As for equipment, I enjoy collecting them provided they are inexpensive and functional. Thanks for your comment. :-)

[bluebird1422]

how did you find out that this chip was casue of problems?

[rkruetzfeldt]

@bluebird1422 Its been awhile, but as I recall, the unit had comms problem with the CPU recalling system.

[fireicer]

What temperature generally do you preheat the pcb board to if you dont mind me asking. It looked like you were up in the 200c.

[rkruetzfeldt]

@fireicer I generally like to keep the temps for preheating at approximately 150-175 C as this actually allows me to keep the hot air wand temp much lower to reduce damages such as "popcorning". Keeping rework temps below 350 C is becoming more popular to reduce failures in PCB's even though they passed the initial repair confidence tests.

[rkruetzfeldt]

@pozzo1979 Absolutely...most techs use several different methods to desolder. It's a matter of application need and comfort. The thing to remember is that while the component is dead, your PCB is still vulnerable. So picking the right method is resultant of past experience. Like all other techs...just an opinion.

[pozzo1979]

Wow, that's a really nice setup!

Just a question: would something like ChipQuik paste allow you to desolder the chip without needing a hot air gun??

I need to desolder a PLCC32 chip from my laptop's mainboard because of a bad bios flash, but I don't have hot air guns :(

[bPaIsNtKaYrd]

@rkruetzfeldt yes its helpfull coz of today i have destroyed 2 ics one was useless for me (la71750) i thinking of it is vid and musq driver for whs player as i have said useless for me and PT6955 (7X4 segment display contr.) this ic miss me from cause of i need it for my project . the preheater is useful machine but i thinking of that today my 2ics destroyed a lot of heat (290° for 20sec(hot air gun) from cause of fucking heat resistible glue) . i have to buy desolderin´ unit or sth similar

[rkruetzfeldt]

@bPaIsNtKaYrd Thermal shock can destroy just about any component, including but not limited to traces/pads on the PCB. Semiconductors internally and/or externally can be ruined in mechanical terms. Too much heat will destroy the semiconductors in a different way, thermal decomposition of the P-N materials. Hope this helps.