Electronics Forum | Thu Dec 07 19:20:28 EST 2006 | ganoi
Most likely there is movement during reflow. How about conduction oven over convection oven for reflow? This is a small PCB with the LED sitting on a Flex-Rigid extension from the PCB. I was thinking if the stencil aperature for the LED was to be cu
Electronics Forum | Fri Feb 16 06:47:38 EST 2007 | CL
vshan, We were using pallets (delmat with cavities for the flex) We put stips of double sided Kapton tape in the critical areas. The tape held up to the heat and kept the circuit flat for the QFP's and BGA's. We based our assembly process for this c
Electronics Forum | Thu Aug 20 08:23:23 EDT 2009 | ratsalad
One diagnostic tool that I have found useful in the past is the "hot plate test". Place suspect components and/or PCB's on a hot plate and turn it on High. Then observe. Granted the conditions on the hot plate are not the same as in a reflow oven,
Electronics Forum | Thu Aug 10 03:30:42 EDT 2000 | JohnW
Ramon, Solder ball' are a bitch aint they?, identifying the right location to fix em is a bigger one. As you and the rest of teh guy's have said yes you'll need to look at your stenil..but maybe your stencil is good so you'll need to look else where
Electronics Forum | Tue Sep 14 09:13:34 EDT 1999 | Chris McDonald
| | | Has anybody have any experience with Top placement of BGA's. GLue descretes on bottom and then wavesolder.? | | | | | | | | | | | Hi Chris, | | Why don't you process a double side reflow and use selective wave fixture for wave process. T
Electronics Forum | Thu Jul 03 12:03:00 EDT 2003 | slthomas
So, there is a crack or gap between: * Solder and component termination. Bingo Correct? Describe: * Coarseness / smoothness of the metal on the termination underneither the crack. * Solder left on the termination. Unfortunately at 45X I can't rea
Electronics Forum | Tue Aug 29 10:36:09 EDT 2006 | Chunks
With the UP2000 that has vacuum board hold down, the Grid Loc hoses defeat the vacuum in order for them to exit the work table. Big boards require more girds, thus more hoses. Set-up between large and small boards takes time to remove or add the gr
Electronics Forum | Fri Jun 08 15:37:41 EDT 2007 | ck_the_flip
Jim: I have limited knowledge, but here's what I know: 1. Yes, it's a standard process. In today's SMTNet, it's rarely mentioned, and few people reply to postings. 2. Nope. It's a "specialty" piece of equipment for most CEM's. Depending on you
Electronics Forum | Sat Nov 22 09:58:29 EST 2008 | realchunks
The only easy solution is not to handle the boards. Purchase true double sided reflow lines. Buy automated magazine loading conveyors. Check machine board supposrts. Are you sure it's from handling? We found it was 50/50 between board handling
Electronics Forum | Wed Aug 12 14:39:09 EDT 1998 | Mike C
| Have an SRT w/preheat, 18 layer board all copper, 456 BGA needs to be removed and replaced. The manufacturer is Chip Express and during reflow it warps up or down. Causing either opens or shorts on the corners. I was using gel flux with multiple
