Electronics Forum | Thu Oct 26 13:56:08 EDT 2000 | ptvianc
Hello: Pre-baking laminates should only be performed:(1) to meet contractual agreements or (2) in response to an actual defect that can be traced to PWB water absortion. Besides the fact that a pre-bake is an enormous process "bottleneck," it also
Electronics Forum | Wed Oct 29 06:17:45 EDT 2014 | julianf
As stated in the title I would like to know the thermo-elastic material properties, most preferably the E-modulus and CTE in x- and y-direction, for Epoxy/E-glass laminates and/or prepregs for various fibreglass cloth styles. Datasheets only give ro
Electronics Forum | Thu Oct 26 09:10:30 EDT 2000 | ptvianc
I am not familiar with the "HALT" terminology. Do you mean HAST testing? As for thermal fatigue, the most severe conditions are typically those cited for military and/or satellite applications. There are several temperature ranges that are used to
Electronics Forum | Thu Apr 22 16:15:26 EDT 1999 | Steve Gregory
| Could anyone recommend a good depanization tool for a PCMCIA | panel which has breakaways. For several reasons, we decided to | go with this approach rather than scoring and I'm less than | pleased with the punch presses we currently use. Any h
Electronics Forum | Wed Oct 07 15:25:02 EDT 1998 | Joe P.
Hi Everybody | | Is anyone aware of the possible causes that may lead to voids in the solder bumps after assembly. We assembled some dice on thin substrates and after assembly, void formation in the solder bumps were observed. | We have alread
Electronics Forum | Wed Jul 09 04:57:11 EDT 2003 | Matt Kehoe
Our company applies solid solder to surface mount lands. While processing a micro BGA design we had some pads fall off, peel, whatever you might call it, from the surface of the board when touched "GENTLY" with the tip of a blade to remove a small s
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 | Thu May 06 18:31:29 EDT 2004 | Dreamsniper
"Polymide Films absorb a great deal of moisture. Polymide laminates must be baked at more than 1 hour at 100'C or better for a double sided PWB prior to exposing the laminate to elevated temperatures such as that required for soldering. Moisture abso
Electronics Forum | Tue Aug 25 17:49:15 EDT 1998 | Earl Moon
| Hello, | Our PWB supplier has requested that a change in the laminate material to reduce the incidence of pad lifting. The standard laminate materials (Polyclad PCL-FR-226 with a glass transition temperature of 135 C) have greater z-axis thermal e
Electronics Forum | Tue Aug 22 16:13:08 EDT 2000 | Dr. Ning-Cheng Lee
FR-4 will be OK for small products such as cellular phones. Here the temperature gradient across the board may be 3-4C only, and the board temperature can be well controlled. At temperature above around 245C, the discoloration and delamination may be