Electronics Forum | Thu Oct 26 13:56:08 EDT 2000 | ptvianc
Hello: Pre-baking laminates should only be performed:(1) to meet contractual agreements or (2) in response to an actual defect that can be traced to PWB water absortion. Besides the fact that a pre-bake is an enormous process "bottleneck," it also
Electronics Forum | Thu Oct 26 13:26:53 EDT 2000 | ptvianc
Hello: 1. Yes, it is necessary to reball a PBGA after removal from the board. Once the part has been removed, the quantity of solder on the balls is out of control. This condition will not only result in an unacceptable variation in solder quantity
Electronics Forum | Thu Jul 20 13:28:13 EDT 2000 | Bob Willis
On all the trials I have done I have made no changes to the stencil thickness or apertures than the normal changes we make for our process. I have not changed any thing in terms on volume of solder for more reliable joints. I fact I have not read any
Electronics Forum | Thu Jul 20 12:49:05 EDT 2000 | Bob Willis
So far on all my trials on PIHR I have only used standard products as the paste is defined by the printing requirements for fine pitch etc. As most people will have seen you just get a heap more residues with this process and even more with lead free
Electronics Forum | Mon May 14 22:24:11 EDT 2001 | davef
The time over liquidous of the profile seems short. But then again, who knows? Based on what you told us, I'm guessing at a board fabrication problem, either measling or delamination. Probably the former, rather than the latter. [Now, we remember
Electronics Forum | Thu Jul 12 10:32:59 EDT 2001 | Hussman
Wow, what a string of answers and nobody brought up the easiest way to eliminate solder balls. Yes, the paste being squished under the part does reflow and work it's way out to the side during reflow. I did a 5 week study on this (when I was a bori
Electronics Forum | Thu Jul 12 17:43:50 EDT 2001 | Steve
In order to understand your printing process, you cannot rely soley on 2D inspection. By implementing 3D-true volumetric measurement, a more comprehensive approach to correcting the process variation can be established. True volumetric / 3D inspect
Electronics Forum | Mon Jul 23 20:18:18 EDT 2001 | davef
Prasad�s book, that an earlier poster mentioned, is good, but other books to consider are: * MacLeod Ross �Guide Design & Manufacturing V1 & V2� Electrochemical Publications * Wassink & Verguld �Manufacturing Techniques For Surface Mount Assembly� El
Electronics Forum | Wed Jul 25 23:35:18 EDT 2001 | mugen
my guys SOP : Round #1 1) take double-side tape, and peel it flat to the PCB. 2) process this PCB only through P&P SMT. 3) confirm the SMD placement Round #2 4) take thin plastic sheet and tape corners flat to the PCB. 5) solder paste print over t
Electronics Forum | Wed Jul 25 23:37:11 EDT 2001 | mugen
my guys SOP : Round #1 1) take double-side tape, and peel it flat to the PCB. 2) process this PCB only through P&P SMT. 3) confirm the SMD placement Round #2 4) take thin plastic sheet and tape corners flat to the PCB. 5) solder paste print over t
.gif)
