Electronics Forum | Sat Aug 05 12:12:05 EDT 2000 | Ramon I Garcia C
Hello Friends: I'm new in SMT process, I have a problem with little balls of solder beside of the component, I'm tried reducing the apertures in the stencil and making home base, some times the balls desappear, but some time not, and some times
Electronics Forum | Fri Oct 27 08:59:17 EDT 2000 | Wolfgang Busko
Antonio: A lot has been said on this topic before. You might try the archives with "solder balling" and than check your process step by step ( you will find enough ) to find the cause of your problem. Any other advice would be repeating and repeating
Electronics Forum | Thu Oct 26 08:59:56 EDT 2000 | Antonio A. Medina
Ok guys, I need help. Here's the deal. We're getting micro solder balls under discreets on the bottomside of the board. Here's my set up... MPM screener w/vacuum plate 6 mil metal screen with 90% circular (rounded) apertures 7 mil (measured) past
Electronics Forum | Wed Aug 09 04:09:04 EDT 2000 | Jarno Py�ri�
Hello. I think, good stencil apertures is 80% from pad. And stencil thickness is 0.15mm - 0.20mm. I use 0.15mm thick stencil almost every pcb. Sorry my very bad english but i too learning. :)
Electronics Forum | Wed Aug 09 04:16:25 EDT 2000 | Jarno Py�ri�
And little more... If you use chip components, then that 80% from pads is good stencils apertures size. But if you use fine pitch components, example QFP, then you can use apertures, 90% from pads. I hoping that you understand something abou
Electronics Forum | Mon Aug 07 10:22:13 EDT 2000 | genglish
Ramon, I have had experience in the problems you are witnessing. The problem can relate to a number of factors. Obviously the printing process is the first place to start your investigations, try looking at the stencil apertures for bleed under the
Electronics Forum | Mon Aug 07 14:02:54 EDT 2000 | Brian W.
If you are satisfied with the apertures, then you need to check placement pressure, plant humidity, and the reflow profile. If the placement pressure is too great, it will separate minute portions of the solder from the pad. When the solder reflo
Electronics Forum | Thu Aug 10 13:16:17 EDT 2000 | Bob Willis
Here is some thing that I wrote a while back on solder beading. First what is a Solder Bead? The term solder bead is used to differentiate it from solder balls. A solder bead is a solder ball but its location is normally constant unlike solder bal
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 | Mon Aug 07 16:23:34 EDT 2000 | Ramon I Garcia C
Hi!!! Thanks frieds for your advising, I have a MPM UP2000, I'm going to chek the humidity control, too I'll chek the profiles again, this plant it's located close to the beach about 1/2 mile from. However if you know some table to calculate t
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