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 | Thu Apr 07 20:16:23 EDT 2005 | davef
Q1) Simple way to measure the PCB warpage A1) IPC-TM-650; Method 2.4.22 Bow & Twist Q2) What is the maximum warpage can the SMT machine allow the to accept and place the component without problem. A2) That depends. IPC-A-610 Acceptability of Elect
Electronics Forum | Sun Apr 10 06:27:50 EDT 2005 | WarpSpeed
1.) First of all: What is Your customers requirements??? 2.) If the customer or You don't have a specification; I will strongly recommend that you follow the "IPC-IPC-TM-650 Method 2.4.22 Bow & Twist" that [DaveF] suggested. 3.) If You have "critic
Electronics Forum | Fri Jul 16 11:27:57 EDT 2010 | davef
Consider: * Bow & Twist IPC-TM-650; Method 2.4.22 * Previous threads on SMTnet, like: http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=54498
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 | Mon Apr 23 14:03:18 EDT 2001 | Ryan Jennens
Dougie- We,too, have the IPC-A-600F, and the spec. refers to IPC-TM-650 test method in the back of the book. Look on page Number 2.4.22 of the test methods appendix. This outlines the procedure for determining the percentage of bow and twist,
Electronics Forum | Mon Nov 20 19:49:03 EST 2006 | davef
Sorry for stating this incorrectly. It should been: Bow & twist for bare boards and panels: IPC-A-610 Acceptability of Electronic Assemblies, 10.6: 1.5% for PTH only and 0.75% for SMT, acording to test method TM-650, method 2.4.22 IPC-6012, par. 3.
Electronics Forum | Thu Feb 27 12:27:10 EST 2003 | stevel
Hi all, We got some bare pwb in our incoming inspecion looked really wrapped. The maximum twist of the pwb we messured is 0.056inch by following the method in IPC-TM-650 2.4.22 C. (The diagonal size of our pwb is 7.5inch) According to the IPC standa
Electronics Forum | Sat Nov 18 21:20:58 EST 2006 | Fer
Dave, May I ask where did you find the 1.5%, or the goal of .005" (or .007") per inch? The IPC-A-600 bow and twist standard calls for a .75% based on the calculation of the test method TM-650, method 2.4.22, which calculates the percentage based on
Electronics Forum | Sat Feb 01 09:01:14 EST 2003 | davef
It sounds like your board is "dome shaped", some call it "cupped". If so, this is more of a twist than a bow. Before moving on, if we receive a board that is so torqued that we can't figure-out how to measure it, we reject it. Go back to your TM-
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