Electronics Forum | Thu Apr 17 14:01:26 EDT 2014 | hegemon
And digging a bit further, are the opens at the device level (all the solder on PWB pad, none on device pad) or at the PWB (similar to pillow defect?) After answering that, I would start thinking about(in this order)paste print quality and consisten
Electronics Forum | Thu Oct 08 22:06:44 EDT 1998 | Eric R
| | | Does sombbody know what DPM rate a good and reliable SMT assembly line (incl. solder paste print, assembly and feflow soldering) has? | | | DPM is Defects per million, usually measured on components. We run a process consisting of small to medi
Electronics Forum | Tue Sep 14 10:54:37 EDT 1999 | Scott Davies
| Can anyone out there pls enlighten me on how to solve chip tombstone defects. | I am running a board with a lot of 0603 chip. i had fine the profile and the alignment, but it still happen randomly on the board itself. Is there any other way to sol
Electronics Forum | Thu Aug 27 13:14:49 EDT 2009 | ghepo
I have already told you that is not possible solve this problem by e-mail, without perform a detailed failure analysis. Also I have told you to procede by exclusion. Are you sure, by tests, regarding the PCB quality ? Are you sure regarding the solde
Electronics Forum | Wed Sep 22 21:23:03 EDT 1999 | se
| | I've had some trouble pasting a test board for a MicroBGA trial. Most of the paste remains in the stencil apertures. | | The stencil is 6 mil thick, laser cut and electo-polished. | | The apertures are 12 mil in diameter with 20 mil pitch. | | We
Electronics Forum | Thu Sep 23 12:47:48 EDT 1999 | Earl Moon
| | | I've had some trouble pasting a test board for a MicroBGA trial. Most of the paste remains in the stencil apertures. | | | The stencil is 6 mil thick, laser cut and electo-polished. | | | The apertures are 12 mil in diameter with 20 mil pitch.
Electronics Forum | Thu Jun 25 09:13:25 EDT 1998 | Brad Stapley
| Has anyone seen/used these yet? They seem to have lower coefficient of friction for release of paste and less wear and tear as well as conforming to the board better (plastic has better memory than stainless). Also there is no mesh so a larger ima
Electronics Forum | Tue Nov 05 16:41:53 EST 2002 | Ray M
This one's got me stumped, so I thought I'd throw it out for discussion: I have a 20 pin SMT ribbon connector by Molex that I've been using for about a year without problem, but recently things aren't looking so good. The solder is pulled up off of
Electronics Forum | Mon Sep 17 15:27:51 EDT 2001 | jschake
Challenges: The basic defects that impact assembly yield are bridging, satellite solder balls, and opens (i.e. tombstones / draw bridges). There are many variables with the stencil printing process that can impact these; several of them are listed
Electronics Forum | Wed Nov 18 11:03:45 EST 1998 | Scott Lolmaugh
| | | | Does sombbody know what DPM rate a good and reliable SMT assembly line (incl. solder paste print, assembly and feflow soldering) has? | | | | DPM is Defects per million, usually measured on components. We run a process consisting of small to
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