Electronics Forum | Tue Feb 14 09:10:43 EST 2017 | davef
Assuming the traces run parallel and perpendicular to each other, I'd choose one direction the traces run as "x" and the other direction for "y." Then I'd pick a unique identifier on the board to insure proper orientation. Next, I'd measure warp and
Electronics Forum | Thu Jun 27 17:24:17 EDT 2002 | Daan Terstegge
Never did a DOE on that, but I think it would be quite difficult to warp a board inside the oven if it was flat when it entered the machine. If there's no center-board support then it's another story, then the board will bend due to it's own weight.
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 | Wed Jun 26 21:05:15 EDT 2002 | ianchan
Hi Dave F, customer calls it "warp", we can call it "twist/bow"..etc. the "warp" occurs on individual PCB cells of 28per each panel. the overall dimension of the panel is 139mm x 168mm, and each individual PCB cell is 2.4mm x 1.2mm. Thickness is 0.
Electronics Forum | Sun Dec 19 10:02:55 EST 1999 | ron chua
Hi, how to ensure flexible boards do not warp after reflow and still remain flat for subsequent operations. What is the best way to hold and transport these strips from one process to another. Thanks!
Electronics Forum | Mon Jan 09 19:09:45 EST 2006 | Mike
Basically the same exact way as a much smaller board. The only difference is the profile. Most of our boards are 0.063" thick. Looks like you found your problem. If the edges of the board are cold relative to the rework site (high difference in t
Electronics Forum | Mon Jan 09 17:35:32 EST 2006 | russ
How are people getting BGAs reworked on boards that are 15"x15" at .06" thick? The BGAs are pretty much in the center of these assemblies. We have just received these and I cannot keep from warping/bowing as much as 1/2" at the heated area. Our bot
Electronics Forum | Fri Jun 18 10:46:10 EDT 1999 | Scott Cook
| | | first of all what is the technical term for the small amount of solder on a plated pad. we are getting poor screen printing gasketing on a 20 mil qfp due to this solder not being even or too high in spots and not covering the length of the pads
Electronics Forum | Fri Jun 18 11:37:10 EDT 1999 | Earl Moon
| | | | first of all what is the technical term for the small amount of solder on a plated pad. we are getting poor screen printing gasketing on a 20 mil qfp due to this solder not being even or too high in spots and not covering the length of the pa
Electronics Forum | Wed Oct 30 01:23:19 EST 2002 | jasper
Normally warp max 1% of diagonal board measurement is acceptable. What's your p&p like? Some will not experience problems at all! reg Jasper
