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Electronics => Projects, Designs, and Technical Stuff => Topic started by: ginbot86 on July 12, 2013, 09:50:02 am

Title: Dead-bug soldering a 9-ball BGA chip - Featured on Hack A Day too!
Post by: ginbot86 on July 12, 2013, 09:50:02 am
(obligatory "First Post!" statement here)

Hey everyone. I decided to put up a post on here about my adventures with hand-soldering the dreaded BGA chip.

My article: http://ripitapart.wordpress.com/2013/06/15/convenient-chips-inconvenient-packages-making-use-of-the-texas-instruments-bq27421-g1-lithium-ion-battery-fuel-gauge-chip/ (http://ripitapart.wordpress.com/2013/06/15/convenient-chips-inconvenient-packages-making-use-of-the-texas-instruments-bq27421-g1-lithium-ion-battery-fuel-gauge-chip/)
Hack A Day post: http://hackaday.com/2013/07/03/hand-soldering-bga-wafer-chips/ (http://hackaday.com/2013/07/03/hand-soldering-bga-wafer-chips/)

I used a small SOIC-to-DIP board to mount the chip, and used 40-gauge magnet wire and some 30-gauge wire-wrap wire for the higher-current pins.
Title: Re: Dead-bug soldering a 9-ball BGA chip - Featured on Hack A Day too!
Post by: amyk on July 12, 2013, 10:01:35 am
Want to try a bare die next? :D
Title: Re: Dead-bug soldering a 9-ball BGA chip - Featured on Hack A Day too!
Post by: millerb on July 12, 2013, 01:16:26 pm
The epoxy used is definitely important as noted in the article. For this kind of work I drill a hole in the board and embed chips in dental resin cured with a blue light. The material used in composite fillings withstands extreme temperatures, so much so that forensics people can find them intact in the charred remains of airplane crashes. It certainly holds up to the heat of a soldering iron. Good stuff to work with, you have all the time in the world to set your piece and takes only seconds to cure.

Title: Re: Dead-bug soldering a 9-ball BGA chip - Featured on Hack A Day too!
Post by: amiq on July 18, 2013, 02:24:38 pm
The epoxy used is definitely important as noted in the article. For this kind of work I drill a hole in the board and embed chips in dental resin cured with a blue light. The material used in composite fillings withstands extreme temperatures, so much so that forensics people can find them intact in the charred remains of airplane crashes. It certainly holds up to the heat of a soldering iron. Good stuff to work with, you have all the time in the world to set your piece and takes only seconds to cure.

That looks like interesting stuff - is it possible to cure this resin if it's in a "blob" of say 3-4 mm deep?  I've looked on ebay andthere seems to be lots of different types - can you recommend a brand suitable for this type of electronic work?