Electronics Forum | Mon Jul 09 10:00:29 EDT 2007 | davef
DB Comments on things that should be set and controlled and not adjusted are: * We agree that pot temperature should be excluded. * We'd like you to add parallelism to your list of items to exclude from CK's list. It's given that parallelism is impo
Electronics Forum | Thu Jul 05 08:11:45 EDT 2007 | naynayno
This is wave soldering process and design question since most folks associated with SMT are processing mixed assemblies. We have a 3-leaded sensor (radial) with such a tight pitch always bridges. Solutions unders disussion are pre-forming and addin
Electronics Forum | Thu Jul 05 10:41:37 EDT 2007 | realchunks
Hi BR, Are you screen printing adhesive to the bottom of the board? If so, have your stencil make put openings between the leads of the thru-hole part. SMT adhesive acts as a natural solder resist. So placing a small sliver between the pads works
Electronics Forum | Fri Jul 06 11:00:50 EDT 2007 | shrek
Krikies my friend. A good wave ogre will be able to look at a wave and tweak in a way to minimize contact length (by slowing the conveyor speed), thus improving peelback, and lower it to the bare minimum without disrupting it's backward and forward
Electronics Forum | Thu Jul 05 13:47:10 EDT 2007 | arun2382
QFN assembled on a PCB indicates paramteric fails when tested. When the QFN on PCB is reflowed a second time, it recovers and passes testing. Visual, X-ray inspection revealed no anomalies. Cross-section images of solder joint revealed no anomalies (
Electronics Forum | Thu Jul 05 15:13:46 EDT 2007 | joeherz
We've seen non-functional QFNs cured by touching up the toe fillets. Especially with parts that are not plated on the edge/face where you get minimal/no wetting due to oxidation of bare copper. I'm not suggesting that you touch everything up but th
Electronics Forum | Thu Jul 05 17:10:29 EDT 2007 | arun2382
Thanks all! I'm facing this issue with one specific batch of QFNs. It could be a plating issue. But, nothing was evident from visual inspection,No sign of voiding or non-wetting. Cross-section images of solder joints were clean as well. Could this s
Electronics Forum | Thu Jul 05 16:06:56 EDT 2007 | petep
What process / equipment have you found to best mark Revision levels / date codes and such onto small areas on PC Boards? I need a repeatable, economic solution that will endure processing temps and saponifier in the cleaners. Have used RoHS co
Electronics Forum | Thu Jul 19 14:30:46 EDT 2007 | barryg
Hi Pete, we use and have been using Brady Lasertab markers, they hold up through oven and wash, we use a standard laser printer (I believe we use a special toner though) and a software package called labels unlimited (can find on ebay or amazon) whic
Electronics Forum | Fri Jul 06 10:08:21 EDT 2007 | blnorman
The coating thickness is more a property of the individual coating itself. The 0.03 - 0.13 is based on average properties of acrylics in general. It's like trying to pour 3 mils of motor oil on a table. The material will find it's own thickness.
