Electronics Forum | Thu Feb 24 14:58:11 EST 2000 | Greg denham
Does anyone have any information on baking boards to remove moisture before reflowing and waving assemblies? I've been told that we should do this to stop such problems as delamination of boards, blow holes, solder balls, etc. I don't know have any e
Electronics Forum | Thu Feb 24 18:08:42 EST 2000 | Travis Slaughter
Baking boards, especially multi layer, will help with blowholes and delimitation, but not with solder balls. Normally about 120c for 1 hour or so is sufficient. I usually will not go to this trouble unless a board has proven to be a problem or if th
Electronics Forum | Thu Feb 15 07:25:05 EST 2001 | Nick
0.5um(Ni~6.5um) after reflow(data taken in 48hrs).But after performing temperature cycle test ,the former aging rate(from the shear strength ) seems faster than the latter.Why!?Someone call this the 'precipitation hardness',but what actually is it! A
Electronics Forum | Sun Jan 23 08:18:14 EST 2000 | Dave F
Jeff: I feel your pain. Your points about pin-in-paste stuff are well taken. Consider increasing the size of the pad containing the via. * Calculate volume of the finished via. * Multiply this volume by 2 to determine the volume of paste that mus
Electronics Forum | Wed Dec 15 10:47:57 EST 1999 | Christopher Lampron
I agree with Wolfgang. We are currently reducing appertures by approx. 10% even on the chip components. This still gives us an adequate fillet volume and very greatly reduces the probability of solder balling/beading. We generally refer to the manufa
Electronics Forum | Thu Nov 11 05:30:09 EST 1999 | Wolfgang Busko
For me it sounds like to much paste. If it worked in former runs with the same design and stencil look for changes in your printing process, check the volume and shape of your deposit. Redesigning pads and playing with aperture size allowing for mor
Electronics Forum | Wed Dec 09 07:48:23 EST 1998 | EFData
Does anybody out there have any special insights into utilizing no clean paste in high frequency RF applications? I would imagine there may be some issues with solder balls that would affect functional test (Earl, do you have something for me here?)
Electronics Forum | Thu Jun 18 09:26:38 EDT 1998 | Maurice McClain
WHAT SHOULD THE RATIO BE OF STENCIL APERATURE TO PAD TO GET GOOD QUALITY RESULTS. BY THAT I MEAN, A MINIMM OF SOLDER BALLS, AND LITTLE TO NO BRIDGING, SHORTS, ETC.. RIGHT NOW WE ARE USING A 1:1 RATIO, BUT ARE INVESTIGATING REDUCING THE APERATURE S
Electronics Forum | Wed Nov 21 21:50:50 EST 2001 | Glenn Robertson
Tony, What you are seeing can occasionally be caused by gaps in the plating of the blind vias. If they are not "airtight" you can get moisture coming from the laminate that shows up as voids in the solder balls. You might check on the board sup
Electronics Forum | Tue Mar 05 22:34:27 EST 2002 | YoYo
You better be careful how you plug vias at screenprint - we currently have a customer that wants vias plugged, so we had a 2% aperature reduction so we would not have to much paste, I believe it should have been reduced more because some of the solde
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