Electronics Forum | Tue Mar 09 20:08:08 EST 2004 | davef
Warping BGA are the usual cause of shorts in the corners and are usually caused by the reflow profile. BGA have a natural tendency to warp due to CTE and package thermal mismatch, as you have seen at rework. The PBGA will go from a bowl shape to an
Electronics Forum | Wed Mar 24 20:19:09 EST 2004 | Ken
I recently did a no clean flux eval and by far the leader in the category for remainder (residue) was Interflux 2005MZ 1. You first mission is to provide acceptable solder joints. 2. Only apply what you need to achieve acceptable results. Spray f
Electronics Forum | Mon Apr 12 09:39:38 EDT 2004 | cedams
Ken, Thanks for the feedback. Unfortunately (or fortunately) I am in Mexico and we make our own PCBs. That is another conversation entirely and another of my fix-it projects but currently we drill the PCBs and align the artwork to the holes visually
Electronics Forum | Tue Apr 13 13:18:50 EDT 2004 | arcandspark
David F. thanks for information about the copper plating issues, I will check out the Indium site as you suggest. You are right about Thermount being Unreworkable, but T.I. makes us do it due to the cost of these RF proto types, $250 each bard board.
Electronics Forum | Wed Apr 14 08:15:18 EDT 2004 | arcandspark
We have tried other stencils with different size openings but this company will not allow us time or money to run any experiments to define stencil criteria and printer settings, its just run, run, run. They really dont care about post reflow yields.
Electronics Forum | Fri Apr 16 10:34:29 EDT 2004 | kauer
A couple of questions for You. How old is this oven? Does it have a history of problems? When I have seen speed variations with our Omniflow 7s it is usualy the encoder but it usually spikes rather hard in one spot. You can see this physically and by
Electronics Forum | Thu Apr 22 00:14:08 EDT 2004 | snehal acharya
we are in Process controls field we have set up our own SMT line , we have MYDATA TP9-2U Pick & Place M/C & reflow oven & manual printer. since now our product demand is increasing so for enhancement of the quality & for speedy production i wanted to
Electronics Forum | Fri Apr 23 16:36:27 EDT 2004 | davef
Comments. Comments. Hell yeh, we got comments!!! You are correct to question the appearance of this solder connection. Based on your description, it's defective. Well at best, it's VERY suspect. That's the rule. If it's suspect, question it.
Electronics Forum | Tue May 04 10:59:23 EDT 2004 | Evtimov
Hi, It depends of your boards(are they for SMD or not) and how many boards you assemble. The process at all is like that: 1.Stencil printer - to adjust the paste 2. Pick and place machine(for your quantity) 3.Reflow oven Theese are the machines you
Electronics Forum | Fri Apr 30 10:56:27 EDT 2004 | Bryan She
We tested J6 open on .5mm pitch CSP(In fact,only resistance much lower than normal).J6 is one of the corner ball of the CSP.Defect rate is about 3%. Stencil:4 mil thickness,10 mil square aperture, solder mask openning:10 mil diameter circle. Board fi
