Electronics Forum | Thu May 09 17:19:28 EDT 2002 | davef
Can�t help you with the article that you read. Other places to start are: * 2221, 7.2 Heat Dissipation Considerations, 7.3 Heat Transfer Techniques, and 8.1.10 Heat Dissipation * 2222, 9.1.2 Thermal Relief In Conductor Planes
Electronics Forum | Fri Jun 06 18:44:26 EDT 2003 | davef
No, no. It's koscher to have thermal planes. You just need to: * Work with your fabricator to keep the layup balanced. * Relieve the plane so that it doesn't cause assembly problems. While probably not directly for your part, it gives a starting p
Electronics Forum | Mon Oct 21 11:49:20 EDT 2002 | sueph
Mike, We are currently wave soldering several assemblies with with a lot of ground plane. The soldering handbook we have in house suggests a preheat temp for metal core multilayer boards of 230 to 270 degrees F' (110 to 130 C'). It was scary at fir
Electronics Forum | Fri Nov 17 07:58:06 EST 2006 | markb
SWAG - I also forgot to mention a few things. Our delmaination was always between the large copper plane and the laminate. It is a multi-layered board, so even when the delamination appeared around components (through visual inspection), cross-sect
Electronics Forum | Thu Jan 14 04:43:15 EST 2016 | pcbgogo_downey
Do you have pictures? it may caused by the unproper temperature or pads or the adjacent copper plane or other reasons.
Electronics Forum | Wed Nov 10 02:20:07 EST 1999 | Marc
The padsfor large heat sinks are being designed on our boards with large copper ground planes surrounding them by our engineers. I am having great difficulty keeping the reflow temperature below 230 degrees in order for the temperature of the copper
Electronics Forum | Mon Sep 21 08:14:14 EDT 1998 | Steve Gregory
| Hello: | I would like to know what causes tombstombing and how can it be prevented? | Thx. | Nichol Hi Nichol! A tombstone happens when solder doesn't wet equally on both terminations during reflow...now why that happens can be found by looking at
Electronics Forum | Thu Oct 13 21:43:47 EDT 2022 | sarason
If you are running resonable volumes of the board, redesign it with equal copper on both sides. One way of achieving this is to just run copper flood planes on both sides of the board, this is a fairly common technique in RF and noise sensitive analo
Electronics Forum | Mon Jul 23 17:49:04 EDT 2007 | davef
We know nothing of DeFelsko, but do understand how they distinguish between the solder mask and the conformal coat. DeFelsko manufactures hand-held, non-destructive coating thickness gages that are ideal for measuring the dry film thickness of confo
Electronics Forum | Thu Nov 16 11:45:15 EST 2006 | markb
I still think the best bet is probably an SMT pre-bake operation to ensure that there is no moisture in the board. Vapor pressure is usually the leading cause for delamination, so removing the source should significantly help out. Unfortuantely, pr
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