Electronics Forum | Sat May 06 08:46:46 EDT 2000 | Dave F
Sal: Now you�re talkin�, buddy!!! Darrell is correct. All things being equal, thermal relieved vias (and through holes) should be the hottest spot on the board at reflow temperatures. Vias are gonna take on solder like drippin�s take to biscuits.
Electronics Forum | Mon Feb 26 20:02:42 EST 2001 | davef
First, I don�t understand why your board fabricator can�t do a good job plugging your vias. Additionally, when you consider that they forgot to plug the first batch of boards, it makes me wonder if they are desirable as a supplier. Generally, we us
Electronics Forum | Wed May 09 10:40:10 EDT 2001 | davef
First, your primary side component pads should be designed according to SM-782A, "Surface Mount design & Land Pattern Standard". Next if you did that and your secondary side component pads are the same size as your primary side components, your diff
Electronics Forum | Mon Dec 13 00:48:33 EST 1999 | armin
Hi All I have a 0.7 mm diameter hole for vias, what�s the minimum annular ring for this hole diameter? What�s the term unsupported and supported holes refer to in IPC-2221 9.1.2 Annular Ring Requirements? I have a proto-type PCB (designed by our R&
Electronics Forum | Tue Dec 07 14:21:41 EST 1999 | Brian W.
In my experience, the most commonly accepted theory is that 100% inspection is only 80% effective AT BEST. That means that if your inspoectors are happy, noy outside concerns, well-rested, etc, they will catch 80% of the defects. This number goes d
Electronics Forum | Wed Oct 06 08:49:36 EDT 1999 | Dave F
| | | | Can someone suggest what material I have to use to protect components by electrical discharge on ptfe based boards? | | | | It should have high resistivity, thermal stability (-40 +70 'C),perfect adherence on ptfe... | | | | Many tahnks | |
Electronics Forum | Sun Sep 12 08:20:04 EDT 1999 | se
| | | | hi, i m college student. i m currently doing my Final year project in PCB drilling. the main task is to design auto feeder which allign the PCB properly in position before drilling take place. the close tolerance becomes a big problem to the
Electronics Forum | Fri Aug 20 13:00:16 EDT 1999 | ScottM
| I'm trying a second time to post this very important message, to me, concerning Air-Vac's following creation. Does any own and use this stuff successfully to remove solder from 20 layer and up MLB's with .020" diameter holes? Also, is any of the ad
Electronics Forum | Thu Jul 15 14:55:24 EDT 1999 | JohnW
| I'm designing a board where the parts will only fit if I do one of the following: | | 1. Put BGAs on both sides | | 2. Put BGAs on top, smt TSOPs directly underneath and using blind vias to keep the real estate on the bottom side below the BGA pa
Electronics Forum | Wed Jul 14 11:36:56 EDT 1999 | Jimmy Strain
| | | Hi All, | | | Does any one experienced the solder on gold finger after | | | reflow. Its about 5 to 8 mils diameter . | | | We'd clean the entire screen printer, mounter & reflow as well, | | | but doesn't help much. | | | | | | | | Mr Kong..
