Electronics Forum | Thu Oct 28 16:11:43 EDT 2010 | dwonch
Dealing with these intermittent issues can be frustrating! Can you narrow down if the defects occur during a specific time in the run? i.e. beginning or end? Or, maybe after a pause in printing such as stopping the line for lunch? Are there a lot of
Electronics Forum | Thu Jul 20 14:05:59 EDT 2000 | Mike McMonagle
With 0402 components becoming more common today outside of the telecommunications industry, our company is qualifying equipment and processes for an upcoming product incorporating 0402s. Having used 0402s in a previous position, I am planning a DOE o
Electronics Forum | Fri Mar 06 16:17:38 EST 2009 | aj
whats your board finish?
Electronics Forum | Fri May 06 08:39:59 EDT 2016 | kahrpr
The first issue I see is that you have a high potential of the 402 tombstoning.
Electronics Forum | Thu Mar 05 11:53:09 EST 2009 | dcell_1t
Hello to all. for certain time, we have been struggling with some issues on a PCB where have tombstoning on 0402 components (due to pad design) and dewetting in qfp256 0.5 mil pitch (discussed on another threads on this forum) component, we have pro
Electronics Forum | Thu Mar 12 06:37:48 EDT 2009 | gregoryyork
I agree you are too cold for the profile get it up to 230C and possibly allow it to dwell a little longer in preheat as opposed to pushing up the reflow zone only. Sn90/Pb10 melts at 220C so 2C hotter than your profile so you are reliant on it alloyi
Electronics Forum | Mon Jun 11 21:27:43 EDT 2001 | procon
Way to go CPI! This is a classic example of design. Many people experience this when the have an 0402 close to a QFP or other large components. The pad closest to the larger component will become liquidous later than the pad farthest. Hence, a new t
Electronics Forum | Fri May 06 08:47:05 EDT 2016 | davef
You're correct. This design will have a record amount of 0402 rework for tombstoning and misalignments. Suggest that the pads on each end of all components be the same size in order to balance wetting forces during reflow.
Electronics Forum | Mon May 09 09:23:45 EDT 2016 | markhoch
I agree with the previous two replies. This is a perfect design....if you're trying to create a graveyard full of tombstones.
Electronics Forum | Mon Jun 11 14:25:36 EDT 2001 | CPI
I had the very same problem but, did not question my oven as I knew the profile was good and I should have had even heating. So I then looked at pad size and layout. When Layout and size were found to be ok. I attached a prob to each pad and ran a pr
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