Electronics Forum | Wed May 07 21:20:53 EDT 2008 | davef
Causes of Delamination ["Quality Assessment of Printed Circuit Boards" Lund, Preben; Bishop Graphics 1985 0137450354] The reason for delamination is epoxy starvation in the glass cloth layers or an incomplete curing of the base material. It has been
Electronics Forum | Sun Jun 07 09:01:47 EDT 2009 | davef
IPC T-50, Revision H, Terms and Definitions for Interconnecting and Packaging Electronic Circuits, 96.2176 Pad Cratering. A separation of the pad from the printed board resin/weave composite or within the composite immediately adjacent to the pad as
Electronics Forum | Thu Nov 20 13:00:36 EST 2008 | jameskelch
Calling out materials by name locks you into laminates by brand. If these are typically phenolic materials it can lead to moisture absorption, less mechanical strength and more prone to delamination during assembly. It is more effective to refer
Electronics Forum | Wed Jul 19 20:30:38 EDT 2000 | Dave F
Lennart: I think most laminators offer a halide free laminate. Two are Isola and Mica-Micanite. Contact the IPC Halogen-Free Materials Task Group
Electronics Forum | Wed Jul 18 11:19:58 EDT 2001 | genny
I didn't wade thru all of the info you presented above, but your comment about ampacity of printed circuit boards brought to mind a copy of an article I keep in my files. Luckily I photocopied the whole page from the magazine and can actually tell y
Electronics Forum | Wed May 28 08:25:08 EDT 2003 | davef
That's what we do [no more than three reworks or mods]. Your "four reworks permissable" was probably based on the 55110 five thermal cycles, counting wave soldering as the first cycle. How do you plan to keep track of each of those rework actions?
Electronics Forum | Wed Jun 26 08:53:32 EDT 2002 | davef
We have not done a DOE on board warping. Consider: * How close the board gets to its Tg during the reflow cycle * Amount of copper on each side and the balance between the two * Thickness of the board * Overall length x width * Time at temperature
Electronics Forum | Mon Oct 03 22:12:53 EDT 2005 | davef
When we see warp and twist, we usually jump the fabricator for: * MLB construction (not homogeneous or unbalanced - too resin rich or poor) * Supplier process capabilities (lamination cycles) * Material selection (usually cheap and dirty), etc. War
Electronics Forum | Mon Oct 16 11:12:42 EDT 2000 | NLykus
CEM 1 is a laminate base board material. The other boards in the experiment were manufactured using FR4 as the base board material. What I'm leaning towards is that the glass transition temperature "Tg". What do you think? Topside temperatures in
Electronics Forum | Wed Jul 03 10:32:05 EDT 2002 | davef
First, we have talked about drying / baking / demoisturizing / whatevering bare board previously. Search the fine SMTnet Archives to get started on recipes. Second and more importantly, you gotta fix this delamination problem. If it is delaminatio
