Electronics Forum | Wed Jul 21 13:12:11 EDT 1999 | John Thorup
| 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 | Tue Feb 25 10:32:09 EST 2003 | davef
I don't know the precise scheme, but it goes something like this ... WHAT TO DO * Use the general work instruction that applies to all boards. It goes into dimension and hole checking processes. It talks to visual instection of solder mask, solder
Electronics Forum | Wed Jan 29 14:22:56 EST 2003 | russ
Most bowing I see is caused by an asymetrical layer stackup of the PCB. (different copper thicknesses throughout the stackup) e.g. for a 4 layer board - 2 oz. copper on layer 1, 1 oz. copper on layer 4, etc... I would doubt that is the V-score since
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 Oct 11 16:05:16 EDT 2000 | NLykus
Does anyone have any experience with running a double sided/surface mount(bottom)board manufactured with CHEM 1 material? We are currently looking at cost cuts. My personal experience recently in running a D.O.E. against other materials and solder
Electronics Forum | Fri Apr 16 13:15:17 EDT 1999 | Justin Medernach
| Hi, | I just cheesed my previous attempt at this. I looked through IPC 600 and couldn't find anything relating to dimensional stability of a board with regard to stretch. I found bow and twist but nothing on size. I have a PCB that is .030" over
Electronics Forum | Thu Aug 12 11:00:42 EDT 2010 | hegemon
Without seeing a picture, my first instinct would be first and foremost some fixturing that provides full support for your print process. After that, since you are citing bow and twist, consider that the fixturing might as well travel through the ov
Electronics Forum | Mon Oct 29 18:21:43 EST 2001 | slthomas
We recently have received a lot of warped (bowed and/or twisted behond IPC 600 specs.) bare boards (some our fabricator's fault, some ours by design) and I can't help but figure that long term reliability will suffer when building product with them.
Electronics Forum | Mon Oct 28 18:59:25 EST 2002 | tkenny007
Specs for Bow and Twist for PCBs (IPC-A-610C, 10.6. There may be an update by now). I also have a note in our quality guide referencing (IPC-TM-650, 2.4.22) and (MIL-STD-105D). In summary, a PCB should not bow more than 0.040" with all four corner
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
