Electronics Forum | Fri Dec 17 01:21:54 EST 1999 | Victor Salazar
Weare using a Home plate design on 1210 or larger, 20% reduction on pkgs from 1206 to 1210, 10% reduction on 1206 or smaller, 0 reduction on all leaded components(sot-23, IC's) with a 6 mil stencil. For fine pitch we are using 4mil stencils. We h
Electronics Forum | Fri Dec 24 04:22:11 EST 1999 | Keith Stone
When you get to fine pitch you might want to try reducing the aperture on the long dimension of the pad only. If you reduce the width of the pad you can get solder paste left in the stencil giving insufficient or unsoldered joints. Reducing the lengt
Electronics Forum | Fri Dec 17 15:11:34 EST 1999 | Alvin Kevichusa
Let's look at it this way... Imagine a multileaded component sitting on a flat surface. If all the leads touch the flat surface, they are all in the same plane (that of the flat surface) and are coplanar. Coplanarity is desirable because if a lead is
Electronics Forum | Tue Dec 14 14:49:57 EST 1999 | Larry Johnson
Okay, I have recently found tiny little ball bearings in side our CP4-2. Some have even been reported by operators to be found on top of the PCB while it is running. We have found about ten total so far, any ideas of where these would be comming fr
Electronics Forum | Tue Dec 14 13:39:16 EST 1999 | KA
Hello Everyone! I have encountered a situation where I have surface mount components on the backside of the board and I need to wave all the through hole leads on the backside as well. Can this be done? I thought of the possibility of adhering the
Electronics Forum | Tue Dec 14 14:26:20 EST 1999 | John Thorup
Sure KA, it's done every day. Be sure that the components to be used on the bottom can take the maximum heat of the wave and the delta T of entering the wave. Depending how complex the bottom side is you will get better results with attention paid
Electronics Forum | Mon Dec 13 15:56:16 EST 1999 | David Spilker
In our DFM guidelines for PWB layout we have discouraged placing BGAs in the longitudinal center of a PWB. We believed the increase stress through reflow and wave was not good for BGAs - probably read it or reasoned it. Now, this position is being
Electronics Forum | Wed Dec 15 15:51:42 EST 1999 | cb
Tracy, Gary made some good points, you could also to check to see if you have the printer taking a long enough stroke over the board. I have seen some people not have the squeege come across the board enough and the paste roll is still setting over
Electronics Forum | Thu Dec 09 15:14:41 EST 1999 | Ron Costa
I have been seeing wetting problems with Texas Instruments componets. I am using Kester 596L OA water soluble solder paste. My reflow profile is in spec. for this formula. Has anybody else seen this problem and if so how did you resolve it? Any feed
Electronics Forum | Tue Dec 14 15:21:41 EST 1999 | BJL
This may be the nickle paladium lead material or an 87/13 tin lead plating on the leads. Paladium and 87/13 has a slower disolution rate and takes longer for solid joint to be created between two metal surfaces. Reflow temp must allow the joint to be
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