Electronics Forum | Tue Feb 22 07:59:54 EST 2000 | Hany A. Salam
Hello friends: In a few weeks we will have to assemble PC motherboards. We decided to use to purchase an ICT for testing the semi assembled boards (I mean with only SMD components on). Would anyone kindly like to recommend a SPECIFIC brand or model
Electronics Forum | Wed Feb 07 09:46:20 EST 2001 | pjc
I need some guidance here. I've got a new board w/ a FBGA-48 package, Samsung CMOS SRAM. It's a full matrix BGA w/ 0.30mm-0.40mm ball diameter @ 0.75mm pitch. Balls are eutectic. PCB land diameter is 0.4mm. There are TSOP I 0.5mm lead pitch component
Electronics Forum | Mon Feb 19 18:57:49 EST 2001 | davef
Expanding on the limit of the portion of gold acceptable in a solder connection [mentioned in an earlier post]: The embrittlement culprit, AuSn4, is 29 weight percent gold. So even if one had 100% tin as the solder alloy and 10% gold were dissolved
Electronics Forum | Thu Feb 22 20:53:44 EST 2001 | davef
You're not sposed to pull the mask from the BGA when reworking it!!!! ;-) Well, if you insist. You can be as fancy as you want. Basically, all you need to do form a dam to prevent the solder from flowing from the pad to the via and starving the
Electronics Forum | Fri Mar 23 11:58:01 EST 2001 | mparker
You are mixing long exposed paste back into fresh? How long has your fresh jar been open to the air? You are probably doing yourself a disservice by scavenging the paste (it could have moisture entrapped). Your visocity has definitely changed. You a
Electronics Forum | Thu Mar 22 16:52:10 EST 2001 | kaopsahl
Yes, there are adhesives designed just for stencil application. Usually plastic squeegee blades are recommended for best printing results. Plastic stencils are also available for this application. Both Alpha Metals and Loctite have articles on this s
Electronics Forum | Tue Mar 27 18:00:35 EST 2001 | Mike Konrad
I would recommend pH neutral chemistries, particularly if a semi-automatic machine is to be used. There are many chemistries available. A partial list of chemistries that I have tested, and that are compatible with a variety of cleaning equipment i
Electronics Forum | Thu Mar 29 18:14:19 EST 2001 | kerryn
Hi Dave, I looked into the South Coast Air Quality Management District Clean Air Solvent Certification when I was having my problems with VOCs. The problem with the SCAQMD CAS Certification is that it only certifies chemicals as they are found in t
Electronics Forum | Fri Oct 19 00:37:43 EDT 2001 | ianchan
Hi, my guys did such solder paste deposits on PCB bareboards before, (before my physical join with my current company), approximately 2-3 years ago, for a small Lot run. What the PCB supplier did was to apply "block" shaped Sn/Pb paste alloy onto t
Electronics Forum | Thu Aug 24 09:41:46 EDT 2000 | Dr. Ning-Cheng Lee
The optimal profile to choose is determined by the following factors, (1) thermal mass and distribution across the board, (2) reflow temperature range needed for a particular alloy, (3) the nature of flux. When the thermal mass is small, such as cell
