Electronics Forum | Tue Mar 21 02:15:26 EST 2006 | pavel_murtishev
Good morning Dave, Here are some of my assumptions. Please correct me if I am wrong. 1. Mask opening. Due to mask to PCB misregistration mask is not always centered relative to pad center how is should be. Sometimes edge of the mask matches with ed
Electronics Forum | Thu Oct 15 11:04:28 EDT 2009 | spitkis2
Thanks Jim. Pressing the QFN into paste was what I thought of, just wasn't sure if it would cause solder paste to be pressed outside the pad area and possibly bridge with an adjacent pad. Do you recall the ratio of paste coverage to the pad area?
Electronics Forum | Wed Oct 21 08:06:06 EDT 2009 | scottp
I agree with Dave. If the device has a lot of power we'll put thermal vias between the solder deposits with annular rings of soldermask to keep solder out of the holes. We've never had to mess with placement pressure. We've been using QFNs for yea
Electronics Forum | Wed Sep 30 13:10:49 EDT 2009 | spitkis2
Hi guys, Can someone please clarify whether adjustment of Z axis travel is a critical parameter during placement of QFN devices. If so, to within what tolerance? In other words, should a pick and place machine position a QFN down on the board so t
Electronics Forum | Mon Jun 28 11:47:54 EDT 1999 | Christopher Cross
| | | hello, | | | | | | has anyone tried dispensing solder paste in thru holes instead of waving or hand soldering. if so how did it work out for you. | | | thanks for the input | | | | | | wayne | | | | | | | | | | | We have tried this mainly
Electronics Forum | Wed Dec 05 03:33:22 EST 2007 | longlee
We have done Paste-In-Hole process for 4 years.I think this prcess is suitable for 28-pins connector. Of course, you must assure the connecotr can endure high temperature firstly.Secondly, you need calculate the volume of solder paste, you can refere
Electronics Forum | Tue Sep 21 13:12:56 EDT 1999 | Dave F
| My stencil thickness is 6 mil and we got qfp's with fine pitch. | how many percent should i reduce my stencil aperture using a 6 mil stencil for 0.5 mm pitch and 0.4 mm pitch ? | | thanks | Greg: I was going to link you to the IPC land pattern c
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