Electronics Forum | Fri Aug 22 09:50:20 EDT 2003 | Mike Snider
I am placing a plastic Cypress, 256 pin BGA on a small assembly, and I cannot stop the corners from bowing. I've moved my profile up and down with no results. Any suggestions?
Electronics Forum | Fri Jun 25 22:30:47 EDT 2010 | smthexi
i think you need to use a PCB central support. do you know that part ? it specializes in preventing PCB board from bowing during wave soldering.
Electronics Forum | Tue Jul 20 16:02:12 EDT 2010 | mikesewell
You may want to look at IPC 7721 Method 3.2 Bow and Twist Repair. In extreme cases you may need clamp or weight the pcb with bow in the other direction to yield a "flat" pcb in the unrestrained state. You will have to take the PCB up to or slightly
Electronics Forum | Thu Aug 09 07:53:16 EDT 2012 | davef
Allowable bow & twist: Together, both IPC-A-600G and IPC-6012B represent the core IPC documents for describing the acceptable and nonconforming conditions that are either externally or internally visible on finished printed boards. IPC-A-600G relies
Electronics Forum | Tue Feb 23 09:26:34 EST 2016 | tombstonesmt
Good to hear! Never dealt with an assembly that large. 24" is the longest we've built. One issue we encountered was bowing due to the vacuum seal being too tight. Bowing caused transfer issues between conveyors and equipment. -TSS
Electronics Forum | Wed Oct 17 10:37:13 EDT 2001 | davef
Help us understand your situation better: ARE THE QFP BOWED? If so, * Where are the QFP bowed? * Is the QFP body bowed or is it just the leads? * How much are the QFP bowed? * Are all QFP the same part number, from the same supplier, date code
Electronics Forum | Thu Dec 26 12:12:55 EST 2013 | igorfo
Dear Friends, I need your help to understand requirements and measurement methods for bow and twist of assembled PCB (PCBA have and SMT and TH components). I already check all posts on the site but didn't found any related to my question answers.
Electronics Forum | Mon Apr 23 07:56:20 EDT 2001 | dougie
Hi Kris, DISCO!!!! Cheers, Dougie.
Electronics Forum | Mon Apr 23 14:36:16 EDT 2001 | CAL
Ah Yes.............My 600 A version has it in the back as well Cal
Electronics Forum | Thu Sep 26 11:06:45 EDT 2002 | slthomas
Maybe you're well ahead of me, but make sure you search the archives for "bow" and "twist" as well as warp.....
