Electronics Forum | Thu May 29 14:35:37 EDT 2008 | rdmundo
Gents, We've been using a round 1:1 aperture for a 5 mils thickness on our stencil design on 0402 and recently, IPC guidelines recommend oblong, homeplate or reverse homeplate. I believed the PCB pad for 0402's area within the recommended size/dimen
Electronics Forum | Thu May 29 17:19:51 EDT 2008 | dyoungquist
On 0402s we use 20x25 mil pads with a 15 mil gap between the pads on the pcb with ENIG finish, 5 mil stencil with a 1:1 aperture (20x25 mil) and SAC305 lead free solder paste. We very rarely see any tombstoning on 0402s using this setup.
Electronics Forum | Wed Dec 11 13:00:07 EST 2019 | slthomas
Excessive mask thickness also can wreak havoc on stencil printing.
Electronics Forum | Tue Dec 10 13:35:34 EST 2019 | scotceltic
I am looking to see what people are using for a min-max range to supply your PCB fabricators regarding solder mask thickness. I saw some points in the archives but not too much regarding what people are providing as their spec ? Any help would be a
Electronics Forum | Tue Jun 07 10:38:34 EDT 2011 | davef
Boots: Here's several methods for guessing at the amount of solder on your connection: * First, 'Down & Dirty' ** Assume that the solder is flat, which is reasonable since it's 'flattened' by the component package ** Assume 100% paste transfer from t
Electronics Forum | Wed Dec 11 11:35:15 EST 2019 | dilogic
Just out of curiosity - what is the rationale behind specifying mask thicknes?
Electronics Forum | Wed Dec 11 12:07:33 EST 2019 | scotceltic
Our company has a spec on their current PCB dwg to make sure the fab house meets a specific thickness (min-max). The current spec reads: 13.5um min - 38.5um max. I assume it is to keep the board house honest and to make sure there is no exposed co
Electronics Forum | Tue Jun 07 08:31:57 EDT 2011 | bootstrap
I am building a rugged digital video camera product that essentially is just a sandwitch of 3 parts: #1: front piece is machined aluminum with C-mount thread #2: middle piece is 1/16" printed circuit board #3: back piece is machined aluminum The
Electronics Forum | Thu Apr 12 09:50:51 EDT 2007 | pjc
There have been many designs of apertures for 0402, round, home plate, inverted home plate and various reduction amounts for square or rectangular apertures. What works best for a given application depends on PCB design, solder land finish, stencil t
Electronics Forum | Tue Feb 04 22:28:16 EST 2003 | davef
You could reduce the paste by about 70%. Solder balling and tombstoning will be the issues to fight. The drivers to these don't change with the component size. Use the fine SMTnet Archives for background. Aperture Size and Thickness of Solder Pas
