Electronics Forum | Wed Dec 22 19:09:17 EST 2004 | rohman23
Very strange...I just logged into the internet to come post this very question for all the lurking experts. We have a 16 layer rigid-flex that we have never baked. Our board vendor is expressing concern that we do not perform a pre-bake before assy
Electronics Forum | Wed Dec 22 23:29:57 EST 2004 | KEN
Check with Dupont's web site. They have a wealth of information on the various polyimide products they manufacture. I was quite surrised at the differences in materials and in particular the dimensional stability and hydroscopy. Good stuff mayna
Electronics Forum | Thu Feb 27 15:14:53 EST 2020 | SMTA-Alex
This happens with either old tape, the cover tape doesn't stay sealed on the left side, or is the seal is too far to the right, the knife lifts the cover tape. There isn't much you can do in this case. Your choices are: switch the component into an A
Electronics Forum | Thu Aug 10 03:30:42 EDT 2000 | JohnW
Ramon, Solder ball' are a bitch aint they?, identifying the right location to fix em is a bigger one. As you and the rest of teh guy's have said yes you'll need to look at your stenil..but maybe your stencil is good so you'll need to look else where
Electronics Forum | Wed Feb 02 20:53:34 EST 2000 | Dave F
Dennis: Several points: 1 If you're talking AlphaLevel process (?): � Good solderability, as HASL, even no-cleans bite well. � Planarity, uniform deposit, no bridgin� of FP. � Doesn't store as well as NiAu ... LT 6 months sealed � Very sensitive t
Electronics Forum | Wed Nov 19 18:43:04 EST 2014 | gregcr
Hi All, I've been in the CM world for a long time and it seems like there has been little change in the packaging techniques used at the end of the day. Assembled circuit boards in small/flex volume are bagged or bubble wrapped and boxed up to ship
Electronics Forum | Wed Sep 21 12:30:03 EDT 2005 | Rob
Hi Greg, We've used lots of machines over the years & seen lots of different tape related issues - the main one being snap off of the cover tape, usually due to too much glue, over entusiastic heat seal, or a feeder requiring maintainance. Also the
Electronics Forum | Fri Jul 09 18:36:48 EDT 2010 | rway
We don't use flex pcbs but have the same issue here. Most of our pcbs are HASL finish. I have looked at silver and gold immersion and both look really good under my color camera on my AOI. However, gold is more pricey. There is no additional cost
Electronics Forum | Tue May 26 20:18:09 EDT 1998 | Justin Medernach
| | | | I'm reviewing my board fab spec. It calls for a minimum SnPb thickness of 50 microinches on HASL PWB's. I've looked at other specs that call out anything from 30 to 80 microinches, and others that just say the copper pad must be covered and
Electronics Forum | Tue May 26 21:27:33 EDT 1998 | Earl Moon
| | | | | I'm reviewing my board fab spec. It calls for a minimum SnPb thickness of 50 microinches on HASL PWB's. I've looked at other specs that call out anything from 30 to 80 microinches, and others that just say the copper pad must be covered a
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