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
Electronics Forum | Thu Jul 12 20:55:37 EDT 2001 | davef
First, we don�t like pallets, but ya gotta do wat ya gotta do!!! Second, we used to pallet after print and before place, but we lost so many prints messing with palleting boards that we now pallet, print, place. Third, most of our pallets are �home
Electronics Forum | Fri Jul 16 13:33:31 EDT 1999 | Dale
We are converting from COB to SMT on a product line and want to optomize the PCB as far as Laminate, plating, passivation etc. This is a high temp application 150C. We are presently using BT Laminate but would like to get away from this. We are lo
Electronics Forum | Wed Sep 30 11:57:19 EDT 1998 | Manish Ranjan
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 already trie
Electronics Forum | Mon Jun 17 13:45:29 EDT 2002 | genny
When the pad comes off, is it leaving behind a "black" area? Your board may be suffering from black pad - a condition that occasionally affects ENIG finish boards. It is a process control issue with your board fabricator. The nickel is oxidising b
Electronics Forum | Mon Apr 25 22:56:44 EDT 2005 | davef
rush316 First, no one stated that PBB and/or PCBE are in FR4. FR4 contain tetra-bromo-bisphenol A [TBBA]. Second, there are classes [and grades] of dielectric materials used in fabricating printed circuit boards. Grades, NEMA LI-1. From these gr
Electronics Forum | Thu Jun 12 03:37:05 EDT 2008 | benefon
It is also possible to etch the barcodes directly on the PCB by using a laser. The solder resist mask is easily burned by laser and if there is copper underneath the contrast is quite good. The contrast is satisfactory even if there is no metal under
Electronics Forum | Mon Feb 23 05:37:23 EST 2009 | emmanueldavid
Necoleta, PWB Blistering/De-lamination may not be due for Titanium finished threads / holders which is typically being used to draw high Shelf Life of Pallets and even flow across Auto Wave Soldering rails. There is also nothing to suspect on Liquid
