Electronics Forum | Mon May 07 16:07:05 EDT 2012 | davef
Start with targets based on the stencil thickness (for height) and stencil thickness times the aperture size (for volume). * Set reasonable upper and lower control limits (+ 25% and –25 % of the targets, for example). * Next, check the printer set-u
Electronics Forum | Wed Jan 16 15:22:29 EST 2002 | Terry Burnette
In his book titled "Manufacturing Techniques for Surface Mount Assemblies" author R.J. Klein Wassink describes the relationship between solder land dimensions, component lead coplanarity, board warpage, solder volumes, and solder paste flux wetting b
Electronics Forum | Mon May 07 10:42:09 EDT 2012 | saju86ece
Hi, I need one clarification about solder paste printing height tolerance. How to define and fix the solder paste height tolerance after screen printing for inspection purpose. Currently we are using 5mils thickness of stencil, in that we are gave
Electronics Forum | Thu Sep 08 03:40:59 EDT 2005 | GS
do not forget also wich Type of paste used( granulometry) if Type-3 ? Type 4? etc, it could change in final metal on your pads/joints. Regards GS
Electronics Forum | Thu Oct 24 03:03:13 EDT 2002 | harriss
Hi: The component height will increase on the PCB after reflow soldering. But i don't know the accurate data of the increased height. Who can help me to get it? The stencil thickness is 5 mil we used. Thanks Harriss
Electronics Forum | Wed Jan 30 02:50:33 EST 2019 | electronics101
Hi Steve Thanks for coming back to me, you are correct IPC class 3 is required. We are getting great wetting onto the device but not as per IPC 3 with the wetting rising about 0.25mm. I am questioning whether it is actually possible with such a (re
Electronics Forum | Tue Nov 28 15:10:50 EST 2006 | M. Sanders
Unfortunately, I don't have a copy of IPC-A-610 D on hand, however, I believe in IPC-610, this �floating height� between lead and pad has no maximum specification restriction. As long as there is no voiding, it is still acceptable for all 3 classes.
Electronics Forum | Sat Jun 01 04:27:37 EDT 2019 | gregoryyork
Increase paste volume and use ramp soak spike profiling. Reducing volume of paste often leads to entrapment. Good idea to know difference between voiding and dewetting due to contamination
Electronics Forum | Mon May 27 04:46:11 EDT 2019 | SMTA-Rogers
Dear CW, Yes, we also tested many different brands and models of solder paste, under the same stencil design and reflow profile the condition of the voids will have great difference.
Electronics Forum | Mon May 06 06:22:39 EDT 2019 | SMTA-Rogers
Hello! Do you have a better stencil design to reduce the large area of solder joint voids? Or is there a suggested way to set the reflow profile? Or are there other process improvements to make the solder joint at the LED pad less than 10% per void?
