Electronics Forum | Thu Jul 12 20:20:31 EDT 2007 | seankim10
I�m having problem with PCB with 16mil thickness due to warpage. the board convex up in the middle after 1st reflow. It seams the warpage is caused by CTE mismatch between PCB and multiple TSOP's, which are covering ~80% of the bottom side board area
Electronics Forum | Sat Apr 26 08:18:47 EDT 2008 | davef
Your warpage problem could be caused by change in: * Multilayer board construction (not homogeneous or unbalanced - too resin rich or poor) * Supplier process capabilities (lamination cycles) * Material selections (usually cheap and dirty), etc.
Electronics Forum | Fri Jan 29 04:39:31 EST 2016 | thaneshsivanadian
Due to the imbalance of copper distribution between top and bottom side of PCB, may cause war-page after reflow?
Electronics Forum | Fri Apr 08 17:23:34 EDT 2005 | KEN
Warpage factors can cause: 1. Boards can not transfer down conveyor belts or wedge at transitions. 2. May not enter into machinery due to interferences (like board clamps) 3. May fall off conveyor chain in furnace. Especially true of thin (PCMCI
Electronics Forum | Thu Jul 22 05:00:45 EDT 1999 | George Verboven
| I have pcb's in which i am experiencing warping. | the boards are 12.8125" on a diagonal measurement. | they are out approximatley .010". | the boards are combination thru-hole,smt, they also have 3ounce copper.what is acceptable,and what is the pr
Electronics Forum | Thu Apr 14 13:24:18 EDT 2016 | davef
I doubt that your problem is driven primarily by irregularities in your circuit board. My bet is that you’re seeing defects caused primarily by the warpage in your LGA. Consider using advice often given for minimizing warpage caused defects in BGA
Electronics Forum | Wed May 02 12:12:23 EDT 2007 | SWAG
Restrictive carriers or lack of carrier in reflow can cause board warpage = bad for BGA's. Might be something to look at.
Electronics Forum | Tue Aug 28 08:28:30 EDT 2012 | rgduval
We agree with all of the previous comments, and would add the following: Warpage is generally caused by excess moisture in the raw boards. Have you tried baking the boards prior to assembly? We had this issue on a simple 4-layer board, and found t
Electronics Forum | Wed Sep 08 13:36:27 EDT 1999 | Wolfgang Busko
| Hello: | We are using a Heller 1500S reflow oven to solder surface mount parts. Just within the last two weeks, the larger I.C.'s are moving while going through the oven. The parts are checked for placement before putting into the oven. When
Electronics Forum | Wed Sep 08 14:31:48 EDT 1999 | John Thorup
| | Hello: | | We are using a Heller 1500S reflow oven to solder surface mount parts. Just within the last two weeks, the larger I.C.'s are moving while going through the oven. The parts are checked for placement before putting into the oven.
