Electronics Forum | Wed Apr 22 15:50:24 EDT 2009 | emilioescatel
Hi: I would like to know their opinion about the critical variables that I need to control in a screenprinter(solder paste aplication on PCBs) process and how I can control them. Thanks.
Electronics Forum | Thu Apr 30 13:09:53 EDT 2009 | scottp
One factor I see missing is separation speed (or snap off speed). I've run experiments with different pastes where it was the biggest factor in standard deviation of print volume for small apertures.
Electronics Forum | Thu Apr 23 21:07:09 EDT 2009 | luismolinero
Emilio: Several factors you need to take into account and your process parameters will depend on: Solder Alloy, Is there any Fine Pitch?; BGA?; Smaller chip size?. Tipically you should go for controls in: Solder Temperature and viscosity; blade and s
Electronics Forum | Sat Apr 25 19:17:36 EDT 2009 | newtfly
Emilio, I have a fishbone diagram that I can e-mail to you that shows the MANY variables in the paste print process. There is only one way to determine for certain that the printer is doing it's job, and that is with a true 3D paste inspection proc
Electronics Forum | Thu Apr 30 12:59:16 EDT 2009 | realchunks
I have run design of experiments on screen printers and most times people forget about the type of board you are running; the condition of the board; manufacturer of the paste as I have seen Type 4 no-clean no-lead pastes react very differently using
Electronics Forum | Sun Apr 26 08:36:55 EDT 2009 | davef
First, in direct answer to your question, DOE printer setup variables (MPM): * Squeegee speed: 0.5 to 1.0 in/sec * Pressure (metal): 1lb/in of blade * Pressure (plastic): 1.6-3 lb/in Second, supprting earlier responses, most people monitor paste hei
Electronics Forum | Tue Apr 12 08:25:43 EDT 2005 | davef
Q1 Can anyone explain to me what is the clean and non clean solder? A1 The trend away from CFCs has lead many users to evaluate switching to no-clean soldering processes. The term "no-clean" is actually a common misnomer when used to describe a flux
Electronics Forum | Wed Dec 09 09:47:32 EST 2009 | dyoungquist
I am curious as to why you need to mix.... We use a 500g cartridge with air gun. Our process is remove the cartridge from the fridge, allow it to warm up to room temperature before inserting into air gun, then apply bead of paste to the stencil. N
Electronics Forum | Wed Jul 27 09:58:05 EDT 2011 | davef
Pressure printing systems Conventional stencil printing techniques have fundamental limitations as regards paste handling: The volume of paste available for printing is limited, so frequent replenishment is necessary Paste is difficult to c
Electronics Forum | Fri Apr 27 10:33:58 EDT 2007 | ck_the_flip
Jeremy, well said! Thanks for "validating" my theory... LOL I agree that the sampling frequency, AND methodology are key things with 3D inspection. 3D will give you some insight onto how your paste (rheology, viscosity, thixotropy)AND process are
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