Electronics Forum | Thu Sep 05 03:23:14 EDT 2002 | manic
Hi, I encountered a problem with pbga. One edge either warp downwards or upwards creating bridging or open. This pbga have fr4 at the bottom (compound molding at the top). The fr4 is bigger than the top compound by 3mm at each edge. Pls help. Than
Electronics Forum | Tue Sep 10 08:22:36 EDT 2002 | davef
I doubt that the interposer is FR4, it's more likely to be BT. Warp during reflow is a function of material a reflow recipe. Your ramp is too fast and is causing the interposer to bend like a potato chip.
Electronics Forum | Thu Oct 26 14:41:33 EDT 2000 | Derek Vanditmars
We are planning on replacing a SMT 100Pin QFP with a COB module that will have two dies that are functionaly equivalent to the old part that will not be available. Questions: 1)Suggestions on substrate material FR-4 or something better? 2)Are there d
Electronics Forum | Thu Oct 26 17:48:47 EDT 2000 | Dave F
In response to your questions: 1) Suggestions on substrate material FR-4 or something better? Most PBGA are on BT. That might good for you, also. 2) Are there design guidelines for wire bonding pattern on the substrate? Several things: 1 Doesn�t
Electronics Forum | Tue Apr 18 10:08:51 EDT 2006 | russ
We use materials such as G10, durapol, or FR4. We put a lot of holes in the fixtures so that only enough material is left to support the board during reflow to prevent sag/ warp or whatever. We also try and keep all bot side material in unpopulated
Electronics Forum | Fri Jan 19 14:32:35 EST 2007 | Mike Hunt
What pitch IC? Perhaps a nickel stencil will work. Are your board FR4? Warping the board could play a major factor in solder shorting.
Electronics Forum | Mon Mar 08 19:52:54 EST 2004 | Ken
I have processed the following materials in lead free processes: CEM FR1 FR4-120 FR4-140 FR4-170 Each material has different responses to thermal stresses. Issues to consider are: Panel size, smt only, wave only, double sided smt...and smt / wave
Electronics Forum | Thu Aug 03 10:12:31 EDT 2017 | bspoon
DCS testing has detected exotherming in samples of stock FR4 laminate material. The exotherming subsequently disappears from the heat flow plots when DSC testing is repeated a second time on the same samples. Can this non/ under-cured material cause
Electronics Forum | Thu Jan 21 09:55:14 EST 2016 | Sam
We are running a project that is 5 years old. We have yet to resolve all of the issues. Out biggest is warping due to the board being .012" thick. We have created a custom pallet (ricocel) and pallet cover (FR4) to sandwich the board but I am afraid
Electronics Forum | Wed Jun 03 09:04:19 EDT 1998 | Steve Gregory
Hi Anthony! Earl's right, things can get rather involved when you start discussing ALL the things that affect whether or not a board is going to warp. The way I look at the issue is try to separate the warp issue into two catagories; 1. The board bei
