Electronics Forum | Wed Dec 06 21:59:37 EST 2006 | SMTrework
Hello, we rework BGA packages that come back from the field. I've seen on occasion a black and or red "epoxy" substance from the manufacturer on the corner of some board's BGA chips that I imagine are applied to increase corner bond of the chip to th
Electronics Forum | Wed Dec 06 22:46:39 EST 2006 | SMTrework
Hi Dave, This is manufacturer applied epoxy / adhesive to minimize package "lifing" from chassis flexing and thius board flexing. I have seen the complete array area covered with this black or red epoxy in some cases (i.e. the underfill that I've
Electronics Forum | Fri Aug 07 01:02:51 EDT 1998 | zeek - just wanna to get a word in here
| | I am looking for advice or information from anyone about the possible reliability problems associated with epoxy on solder pads of discrete devices. Will the epoxy expand and lift over time, Will there be adverse reaction between the solder and t
Electronics Forum | Fri Aug 06 03:51:06 EDT 1999 | Thomas
Could someone give recommendation on the stencil opening for printing epoxy on HAL FR4 PCB for 0805 and 0603 size chips capacitors and resisitors. My regular stencil manufacturer recommend the following: Thickness: 8 mils 0805 opening: Oblong 0.35 X
Electronics Forum | Thu Dec 07 12:18:28 EST 2006 | realchunks
It may be for a double sided reflow process. Yes, some people do put the BGA on first. I know this first hand.
Electronics Forum | Thu Dec 07 14:17:03 EST 2006 | russ
I would bet that it is a SMT adhesive used to ensure that the BGA does not move during a secoindary reflow prcess. this glue is easily removed with a soldering iron. Russ
Electronics Forum | Wed Dec 06 22:35:05 EST 2006 | davef
Questions are: * When you say, "corner of some board's BGA chips", is it on the top of the package or between the board and the bottom of the package? * If between the board and the bottom of the package, does it span the distance between the board a
Electronics Forum | Thu Dec 07 03:21:54 EST 2006 | Guest
Materials you see are corner bond adhesive, main purpose of this is mechanical shock absorber , it promotes additional adhession to lessen stress to solder joints incase device subjected to mechanical stress like dropping.By function, corner bond
Electronics Forum | Thu Dec 07 19:54:55 EST 2006 | davef
We agree with "guest" above. This a "chip bonder" type material used to improve the reliability of array type devices. "A relative comparison of the N50 values is given below: No underfill = 1.0X (baseline) Corner bond = 1.3X Non reworkable underfi
Electronics Forum | Sat Aug 07 11:10:03 EDT 1999 | JohnW
| Could someone give recommendation on the stencil opening for printing epoxy on HAL FR4 PCB for 0805 and 0603 size chips capacitors and resisitors. | My regular stencil manufacturer recommend the following: | Thickness: 8 mils | 0805 opening: Oblong
Products, services, training & consulting for the assembly, rework & repair of electronic assemblies. BGA process experts. Manufacturers Rep, Distributor & Service Provider for Seamark/Zhuomao and Shuttle Star BGA Rework Stations.
Training Provider / Manufacturer's Representative / Equipment Dealer / Broker / Auctions / Consultant / Service Provider
1750 Mitchell Ave.
Oroville, CA USA
Phone: (888) 406-2830
winsouce.jpg)