Electronics Forum | Wed Feb 20 16:03:19 EST 2013 | bocci572
I am wondering if anyone has had issues with their Heller oven rails warping. It appears that our 1800EXL and 1900W oven rails sag after time. They eventually contact the safety mesh and then create hestitation of the chain, thus creating defects.
Electronics Forum | Fri Nov 08 05:08:28 EST 2002 | zolasteven
Can anyone advise on the following : 1. Insufficient pcboard support during printing We are printing on double sided pc boards (approx. 8 ins by 6 ins). There is a problem of high paste when we are printing the second side. The reason bsing the boa
Electronics Forum | Thu Jul 26 23:43:49 EDT 2007 | gioblast
check your stencil design on the ground pad. You might have a big aperture opening that pushing the component away from the paste. Look alos the way your pcb warp. Prioritize side that has component that need flat pcb as much as possible. hope this h
Electronics Forum | Tue Jul 20 15:02:49 EDT 2010 | vetteboy86
I've seen this warp issue across several different PCB's we assemble. One of the biggest head ache's is getting the boards to transfer between machines, converyors, and inside our pick and place. Due to the warpage, transport between conveyors is dif
Electronics Forum | Fri Jul 16 08:14:15 EDT 2010 | vetteboy86
We're expereincing issues in our pick and place machine due to what I consider a server warping of the PCB. The PCB is received this way from our PCB manufacturer. Before I push to much, I would like to know options for a cause. The warp is so bad,
Electronics Forum | Wed Jul 21 11:12:05 EDT 2010 | remullis
I have some 13" long boards that warp considerably during first pass through reflow (no center support), what I've done to improve this type of warpage is stiffeners along the front and back edge. This may help with twisted boards as well.
Electronics Forum | Mon Oct 03 19:15:32 EDT 2005 | cn
is this a single brd or multi up array? What is the thickness? where were the brds made, state/country? I had an issues with a brd which was fabed in mexico during the humid months there was mosture trapped in the brds which caused many strang things
Electronics Forum | Wed Jul 28 08:41:47 EDT 2010 | vetteboy86
I believe we are seeing some wetting issues as we have tried to bake these assemblies ourselves. Our PCB supplier is coming in next week to address the issue. Is there a rule of thumb or formula for determining correct parameters. Thanks
Electronics Forum | Wed Jul 21 12:19:01 EDT 2010 | mb_mfg
To eliminate warping during processing, we have provided customers with composite fixtures to support the board on all 4 edges, with retractable pull down claps that can be added to the top of the PCB after the screen printing. Simply by pushing the
Electronics Forum | Mon Oct 02 20:17:38 EDT 2006 | davef
The different coefficient of expansion of materials used in some BGA can cause warping issues. We've talked about this previously on SMTnet. Search the fine SMTnet Archives. For instance: http://www.smtnet.com/forums/Index.cfm?CFApp=1&Message_ID=2
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