Electronics Forum | Mon Jan 11 14:48:44 EST 2010 | davef
SR1000 is commonly used for tenting. Search the fine SMTnet Archives on : tenting Someone gave us this note. We have lost their name. It seems to be good advice. If Liquid Photo Image (LPI) solder mask is required, do not tent via holes. Tenting
Electronics Forum | Fri Mar 16 17:15:51 EDT 2007 | davef
Ask the board fabricator to: * Fill the vias with resin. * Then metalize and copper plate the filled via along with the pad. * Then plate with solderability protection. This results in what appears to be a solid pad. For more, look here: http://www
Electronics Forum | Mon Nov 11 11:28:32 EST 2002 | davef
Sand is not a great conductor, compared to copper. Never heard of using the stuff on RF boards. Our board fabricator uses Dupont CP100, now CP101, [or something like that cuse who's going to check?] when plugging via on cheap boards. Your board fa
Electronics Forum | Thu May 02 20:56:25 EDT 2002 | clunier
I remember reading a magazine article a few years ago that discused using the copper area of a pcb to transfer heat away from large SMT devices. Does anyone know of this article or something similar that I can obtain. The article covered copper area,
Electronics Forum | Wed Oct 06 04:23:09 EDT 1999 | Brian
| | I am a new employee at a company that has had a large turnover of employees over the past year. I am working on a board (components on one side only), the engineer (he is also new ) wants to use an .035 pad with a .021 dia. hole, there are no via
Electronics Forum | Thu Jan 06 08:03:47 EST 2005 | davef
On solder in vias: It looks like the via are not solder masked well and pick-up solder either: * Solder coating ... OR * During leveling It's possible that the design specifies openings in the solder mask for these via. On solder in the unsupporte
Electronics Forum | Thu Jan 06 06:15:49 EST 2005 | mattkehoe
We need some opinions about a situation that is causing problems in our process. The pcb's in question are .125 thick with a HASL finish. The boards are coming in with a large amount of solder trapped inside the via holes. Sometimes this solder is ac
Electronics Forum | Mon Apr 12 22:22:01 EDT 2004 | davef
Large voids are common in via in pad [seach the fine SMTnet Archives for earlier laments], especially in blind via. Observations on your via out gassing theory: * If the copper plating on your via is GT 1 thou, there will be no outgassing from the
Electronics Forum | Wed Apr 23 08:35:54 EDT 2003 | davef
Over time, copper in the via will form an oxide with oxygen in the air.
Electronics Forum | Wed Mar 05 09:34:32 EST 2003 | HAROLD LICHT
WE HAVE A NEED TO BOND SOME LOW TEMPERATURE LED'S TO A THIN CIRCUIT BOARD LAMINATED TO A HEAT SINK. HAS ANYONE USED AN ULTRASONIC WELDER TO WELD COPPER GUL WING LEADS TO A COPPER PAD USING ULTRASONICS? IF NOT HAS ANYONE USED RESISTANCE SPOT WELDING
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