Electronics Forum | Thu Jul 31 10:37:25 EDT 2008 | 18424
I agree with RLM. What i have seen is that quad had a problem with the gounding system of the quad align unit. An additional ground wire was added at the quad align cage,and to the PCB located inside the front right access panel. I don't have a machi
Electronics Forum | Thu Jul 31 10:45:13 EDT 2008 | miroyu
thank you very much. In my case quadalign board is at rear right corner but it does not have cage just is fitted on vertical aluminum metal sheet plate.I will add ground wire to the board and aluminum plate from machine ground. I will post what is o
Electronics Forum | Thu Aug 07 10:02:39 EDT 2008 | rgduval
Is this part placed on first-side processing? Is this defect being detected after second-side processing? We've had this happen before when running the second side of the board, parts being pulled, apparently, by the belt in the oven while being re
Electronics Forum | Wed Aug 20 08:05:06 EDT 2008 | pjc
They are faster today, but still not up to fixed-pin machine speeds. They tend to be 7x to 10x slower. Any of the machine suppliers can run a test evaluation and give you a report on test coverage and test times. There are techniques to make them fas
Electronics Forum | Mon Aug 11 10:45:04 EDT 2008 | eyalg
I assume you mean the balls of the BGA, not pads > (laugh it up guys - I said balls). If so, you > may have a no-lead BGA or a high temp BGA. hi I mean that the the balls were left on the board and the BGA pads were found clean. What do you
Electronics Forum | Mon Aug 11 10:47:40 EDT 2008 | dphilbrick
Sounds like bad BGA's to me. I suspect this is rare but you can get black pad on the BGA attach pads just like you get them on a PCB. Do you have un-processed BGA's?(still in package) I would have one tested (not by the manufacturer)!
Electronics Forum | Mon Aug 11 10:35:32 EDT 2008 | realchunks
What does your top side wetting look like? This is a perfect case where top side wetting will tell you when you have a good joint. Without seeingor knowing your process, I would suggest either more pre-heat or longer dwell in the solder. Either on
Electronics Forum | Fri Aug 15 10:23:56 EDT 2008 | ck_the_flip
Ovens, and any other process for that matter, will ALWAYS vary. It's called process variation. I do Cpk (process capability) on my ovens. I track time-above-liquidus and peak temperatures. Statistics will validate how repeatable your oven is.
Electronics Forum | Wed Aug 20 08:16:10 EDT 2008 | grics
Chunks... You are pretty damn awesome! Anyways, in regards to the original thread, we do get good boards from china as well, but we have had issues with stack-up tolerances and even mouse bite (drilled break away) tabs. Not to long ago, we left t
Electronics Forum | Fri Aug 22 10:01:52 EDT 2008 | robinj
I have seen this problem before. If the color is yellow usually it is caused by moisture left on the boards from poor drying after immersion silver. One of the ways to get rid of this is by dipping in acid cleaner solution. If the board supplier uses
