Electronics Forum | Sat Mar 05 22:44:44 EST 2005 | gpaelmo
You can also try the Florida Circtech website or call them direct. There is a min. thickness requirement and if the board house does not follow it you will end up with scrap boards after the second pass (from experience). I even sent blank boards to
Electronics Forum | Fri Feb 24 08:29:25 EST 2006 | davef
Step stencils are not widely used, due to: * Higher cost as compared to uniform thickness stencils * Danger of solder paste smearing at least close to the steps * Difficulty of cleaning the stepped stencil underside (the steps cannot be on the upper
Electronics Forum | Thu Jul 05 22:56:53 EDT 2007 | gyverlo
Hello Sirs: Recently we are having an issue with environmental stress (high humidity or moisture), so we decide to apply conformal coating on our motherboard to protect via holes. According to IPC-A-610D, spec of thickness for type AR is 0.03~0.13 m
Electronics Forum | Sat Mar 29 15:29:06 EDT 2008 | aw
I am printing a ceramic paste through a 160 mesh screen that should have a theoretical wet print thickness of 53um but the only way I can get the print that thin is to increase down stop and slow the stroke. This is causing problems with the mesh, s
Electronics Forum | Wed Aug 27 08:06:43 EDT 2008 | davef
Thick, hard conformal coatings of acrylic, urethane and epoxy have a well documented history of causing solder joint cracks and breaking glass/ceramic and other brittle components. Dissimilar expansion and fairly high surface bond strengths of the ma
Electronics Forum | Mon Jun 01 18:44:54 EDT 2009 | scunneen
Hello there, I have a new board, fairly heavily populated with a number of FPBGA on it. The smallest has a pitch of .4mm.I have 3 questions, 1st what is the best appeture for this small pitch. 2 Will type 3 paste work or will I need type 4, and fina
Electronics Forum | Tue Jun 02 20:47:12 EDT 2009 | isd_jwendell
I was hoping some-one would help you with this because I too would like more information about selecting stencil thickness. I have read some about apperature ratios, but this alone doesn't appear to be the only factor when chosing stencil thickness,
Electronics Forum | Thu Oct 25 13:33:18 EDT 2012 | cyber_wolf
Ken, The photo looks like results I have seen because the gold flash was too thick on the board. This causes a condition known as gold imbrittlement. You may want to get an analysis of the plating thickness. I'm not real experienced with immersion si
Electronics Forum | Fri Jan 24 08:14:24 EST 2014 | davem
m_imtiaz, Over the last 15 years or so I've found that using the stencil foil thickness +2mils/-0mils has worked very well. For example, if you have a 5mil stencil thickness your upper control limit would be 7mils and your lower control limit would
Electronics Forum | Mon Jun 09 10:03:40 EDT 2014 | clydestrum
Well, typically we put rails on a lot of the boards due to the absence of fids and/or tooling holes. We do have a fixture that is somewhat universal that I could try to introduce into the next run. Unfortunately, the next run does not help my proble