Electronics Forum | Tue Sep 25 13:01:48 EDT 2001 | Hussman
If the flux you are applying by brush is alcohol based, use some alcohol on a few failed PCBs and retest. It souldn't take a lot of flux to reflow the balls to a pad that's already covered with solder and flux from the first BGA - unless you are cle
Electronics Forum | Tue Sep 25 14:25:30 EDT 2001 | davef
Points in response are: * Microstencils work fine with paste, although they are a little fussy to use. * Never have used microstencils for flux. * Like Hussman, we dab the uBGA into a puddle of tacky flux and then place it on the board. * On contro
Electronics Forum | Tue Sep 25 14:38:05 EDT 2001 | nwyatt
1. SRT has been recently calibrated - problem is too many hands in the machine and careless mistakes. The profile is good and has been recently checked by a fellow from Genrad. 2. We are relying on the left over solder from the previous joint and
Electronics Forum | Thu Sep 27 16:11:38 EDT 2001 | flipchip
Monkey, I have read all the replies you received. I have extensive experience in reworking these parts. There are several ways to approach your problem. If the chips are bumped you will need to have a stencil to apply the flux. If the chips are u
Electronics Forum | Wed Sep 26 09:56:50 EDT 2001 | John S
This will probably sound like a dumb question, but... I have a specific 1206 chip resistor that routinely ends up placed upside down on the pcb. We use Juki 750 placement machines. I normally run the machine with the auto-correct for the pick posi
Electronics Forum | Wed Sep 26 16:32:40 EDT 2001 | davef
Placing a component the correct side up: * May affect heat dissipation. [Umm, that sounds like stretch, but who knows what designers think about?] * Allows reading the markings on those components that have markings, however cryptic the notation of
Electronics Forum | Wed Sep 26 11:15:59 EDT 2001 | Hussman
What do you folks use for control on your wave solder process? Primarily after wave. I know there are a variety of "wave riders" that will assure proper wave solder parameters, but would like to know what down stream controls some are using. We ar
Electronics Forum | Thu Sep 27 10:28:29 EDT 2001 | John S
It seems to depend on your situation. We're an OEM manufacturer and run the same products for extended periods of time. We monitor process indicators such as Dave listed, but we also monitor process defect trends. This is product specific of cours
Electronics Forum | Wed Sep 26 16:33:45 EDT 2001 | davef
Your first inclination is correct. You should start by asking your friends and colleagues on SMTnet: * What is that SMT or MEMS or COB etc.? * What are the considerations when processing a SMT or MEMS or COB etc.? We�re one smart crew that won�t st
Electronics Forum | Tue Oct 02 22:13:56 EDT 2001 | davef
IPC-D-356 is a data transfer language developed by the IPC to replace Gerber. It is a far more intelligent form of physical definition for PCB/PWB. The only segment of the language that seems to have developed any market support is the physical netl
