Electronics Forum | Mon Jun 03 22:16:49 EDT 2002 | alex_kirichenko
Hi Jim! Just an idea.... There are some reflow ovens which use cooling on the bottom side of pcb during reflow for doublesided boards. It prevents solder on the bottom side to melt. You might try cooling your BGA while reflowing parts on opposit s
Electronics Forum | Wed Jul 03 14:34:45 EDT 2002 | razorsek
Jeff, what I generally use as a rule of thumb on multi-row connectors was a strip on the trailing side of the connector as it flows through the wave. The strip was always the same width as the diameter of your through-hole. The distance of the stri
Electronics Forum | Thu Aug 01 08:31:51 EDT 2002 | patrickbruneel
Christopher, It looks like you might be close to the solution for your problem because you mentioned that you can make the solderballing worse with lowering the preheat temp. This means that the preheating has a significant impact. I would suggest t
Electronics Forum | Fri Sep 13 14:21:49 EDT 2002 | blnorman
Run a test, but in our experience, yes you can reuse the paste. We ran tests on paste that was left on the stencil at the end of second shift, we put the paste back on the stencil the next day on first shift with no problems. You definitely want to
Electronics Forum | Tue Oct 01 10:47:45 EDT 2002 | davef
Board fabricators purchase laminate in preferred panel sizes, such as: 16 x 18 inches, 18 x 24 inches, and 21 x 24 inches. A larger panel size provides more effective cost per unit area processed. In producing a board, the fabricator requires maybe 3
Electronics Forum | Thu Oct 17 23:25:53 EDT 2002 | redmary
We generally etch the copper back slightly using a 50/50 mix of 3% Hydrogen Peroxide and laboratory grade Ammonium Hydroxide. Swab for about 5 seconds, then rinse. and etch the tin in the solder to further delineate the intermetallic layer that shou
Electronics Forum | Wed Oct 30 23:14:41 EST 2002 | caldon
Doug is right contaminates can be transfered from hands to boards easily. I also know gloves are a good practice as some times people wear moisturizers and hand creams that can also cause issues. Another thought is that you do not want people handl
Electronics Forum | Thu Nov 21 14:17:27 EST 2002 | MA/NY DDave
Hi I can't give you the answer for your question because I have too many questions and would have to know a lot more before I was comfortable giving any advice. I have done mass Baking of piles of PCB's as a needed evil when piles of boards were ex
Electronics Forum | Sat Dec 14 10:10:04 EST 2002 | davef
This is a good idea. Heck, you could fill the bags with sand, if you wanted. Like anything else in the shop, bean bags require attention and maintenance. If you don't, eventually the seams on the bags loosen / break and you have to do a "clean-u
Electronics Forum | Mon Dec 16 08:19:20 EST 2002 | Randy Villeneuve
We trasfered a product in some time ago and they were using erasers to hold down parts. Some parts will move around during wave and some parts just need to be positioned correctly after wave so hold downs are required. I personaly have never used a b
