Electronics Forum | Tue Oct 24 09:35:56 EDT 2000 | Wister
Our important customer demanded us to use 12mil thick stencil,it is too difficult to release solder paste from stencil.it is not helpful even I ask stencil supplier polished the openings.The flux content is 10%. I want to ask if the polyurethane sque
Electronics Forum | Tue Jul 11 12:59:26 EDT 2006 | mattkehoe@sipad.com
We are trying to apply solder to boards with 80 microinches of electro plated hard gold. No components involved, just print 63/37 paste and reflow. The results are very poor on some boards, not so bad on others? Pictures at http://www.sipad.net/thick
Electronics Forum | Wed Jul 12 11:26:12 EDT 2006 | flipit
Hi, I believe you have classic gold imbrittlement here. With 80 microinches of gold you are way over the limit. You can try to reflow longer time and at a higher temperature. The gold does not melt into the solder joint. The gold dissolves into
Electronics Forum | Wed Nov 01 12:19:42 EST 2000 | Fraser
Steve, someone somewhere is feeding you a line!! if you increase the draft angle from || to / \ on your laser cut stencil you increase the surface area of the side wall and hence increase the likelyhood of the paste sticking in the aperture. Whats m
Electronics Forum | Tue Oct 24 19:50:34 EDT 2000 | Dave F
In response to your questions: * Will a polyurethane squeegee blade help? NO * Will a Pro-Flow head help? NO, but it might be a cool excuse to buy one. Unfortunately, you will look like a jerk, if you talk your boss into buying one and then he /
Electronics Forum | Thu Oct 11 22:25:50 EDT 2001 | davef
Bruce I�m with yall. Designers and fabricators say �pins�. You say: * BGA pins are 1mm [0.039�] pitch. * BGA pads are 0.4mm [0.0157�] diameter. * BGA pins are 0.6 mm [0.024�] side-to-side. * Board thickness is ~0.4 mm [0.015�] First, as you can
Electronics Forum | Tue Jan 07 23:38:08 EST 2014 | m_imtiaz
want to know the tolerance the paste height in the solder paste printing. for example if stencil thickness is 7 mil, what will the acceptance level of paste height ( upper and lower) kindly share if any guidelines or formula for the same
Electronics Forum | Tue Jul 11 20:13:05 EDT 2006 | davef
We agree with Chunks. You need to turn-up the heat [slow the conveyor] because you have significantly changed the melting point of the solder alloy by adding so much gold. Relative to ENIG you should expect: * Similarly smooth surface, possibly a l
Electronics Forum | Wed Jul 12 11:46:00 EDT 2006 | flipit
Hi, One other note. You don't want gold to be more than 1% to 2% of the the solder joint. Above this percentage you will have embrittlemant issues. Lots of information on gold embrittlement on this site and on the Internet. I estimate your produ
Electronics Forum | Tue Jul 11 14:09:54 EDT 2006 | Chunks
Not reflowing completely. Slower = hotter. Try a slower conveyor speed.
