Electronics Forum | Fri Apr 20 07:30:14 EDT 2001 | wbu
In short: the measured deviation / the length this deviation occurs * 100% = % of deviation Actually we encounter mostly "twist" so we put the board on a flat surface, hold it down at the corners to see if any of the corners lifts, measure the heig
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 | 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 | Thu Apr 07 10:58:01 EDT 2005 | Dhanish
Need help from the experts on 1)simple way to measure the PCB warpage 2)what is the maximum warpage can the SMT machine allow the to accept and place the component without problem. 3)I have seen some people are using 7mils/inch as a Warpage spec. a
Electronics Forum | Mon Jun 14 14:30:42 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 d
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 Jul 20 14:07:23 EDT 2000 | JohnW
Mike, we use carrier's as a matter of course on all wave products, it let's us keep the conveyor width the same all the time so speed's up change overs and eleimiates one more thing that can be set wrong. The main aim of the exercise is to be able
Electronics Forum | Mon Jun 14 09:16:58 EDT 1999 | Adam Pratt
| | | | | 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 d
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 | 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
Products, services, training & consulting for the assembly, rework & repair of electronic assemblies. BGA process experts. Manufacturers Rep, Distributor & Service Provider for Seamark/Zhuomao and Shuttle Star BGA Rework Stations.
Training Provider / Manufacturer's Representative / Equipment Dealer / Broker / Auctions / Consultant / Service Provider
1750 Mitchell Ave.
Oroville, CA USA
Phone: (888) 406-2830
