Electronics Forum | Wed Jul 21 20:52:52 EDT 1999 | Scott
| | 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 i
Electronics Forum | Thu Jul 22 06:54:45 EDT 1999 | Earl Moon
| | | 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,an
Electronics Forum | Thu Jun 10 12:05:22 EDT 1999 | Deon Nungaray
| | Hello all! | | Recently we got a problem about the Funtional test. Some boards passed tests by using the auto-fixture(vacuum), but failed by using manual test fixture(need to plug CPU, DIMM etc.). The error symptom is no picture. We doubt it's th
Electronics Forum | Wed Aug 19 12:20:24 EDT 1998 | MARK J.
| Hi there, | I'm actually facing a lot of trouble with PCB's presenting up to 3mm of bow /twist at reception i.e. before assembly. The PCB size is 220 by 230mm. The boards are to be assembeled SMD double sides with 05.mm pitch on both sides. In orde
Electronics Forum | Thu May 18 08:31:28 EDT 2006 | marc
Hi James Short answer... yes... long answer...impingement velocity is excellent for heat transfer but it also is a higher risk of moving components. Variable speed blowers allow you to reduce the speed / impingment and more than likly your compone
Electronics Forum | Wed Oct 04 09:55:51 EDT 2006 | borgie
Hi. I have product in lead containing process that consist lead free BGAs and also big ceramic BGAs with high temperature bumbs. Pcb tends to bow in a reflow profile, since I need long preheating times and relatively high peak temperature to melt BG
Electronics Forum | Wed Feb 10 08:37:31 EST 2016 | davef
bga hosed by physics ... to find some older threads on the topic BGA Bowing on the corners. - SMTnet [http://www.smtnet.com/Forums/index.cfm?fuseaction=view_thread&Thread_ID=6405 ] www.smtnet.com › Electronics Forum • Aug 22, 2003 - 5 posts - 1 au
Electronics Forum | Wed Aug 19 08:00:55 EDT 1998 | Earl Moon
| Hi there, | I'm actually facing a lot of trouble with PCB's presenting up to 3mm of bow /twist at reception i.e. before assembly. The PCB size is 220 by 230mm. The boards are to be assembeled SMD double sides with 05.mm pitch on both sides. In orde
Electronics Forum | Wed Jul 12 05:04:01 EDT 2000 | JohnW
Hi Guy's.... Was thinkng about i more this moning..in the shower actually...sometimes think I do my best work there!. So far I'm looking at stuff like integrating the DFM study to show thing's that are going to present production / process issues e
Electronics Forum | Wed Jul 12 21:32:59 EDT 2000 | Dave F
John: Several thoughts: 1 What on your wave machine are these bowed boards catching on? It has to be something on either wave. Are you getting hung-up on the chimney? That doesn't seem correct!!! 2 Why do you want to measure the defection of y
