Electronics Forum | Wed Apr 14 14:51:10 EDT 2010 | jgalarza
After checking some of our stencil data for the correct aspect ratio I found that a few are wrong. I would like to change them from 5mil thk to 4mil thk but do not know how much paste volume I need to keep. We are using 0201,0402, and BGA with 0.80 p
Electronics Forum | Mon Apr 12 15:52:12 EDT 2004 | wgaffubar
I am using Indium 92J type 4 solder paste due to a BGA site with .008" pads and stencil opening of .009" square and .005" stencil thickness. When I try the type 3 we get insuffecient print. The aspect ratio tells me that I should be using a type 4. T
Electronics Forum | Mon Mar 27 20:53:12 EST 2006 | davef
If you believe: * There is air in your paste AND * You are not whipping the air into the paste ... You should: * Return the paste to your supplier * Get it replaced * Begin qualifying a replacement supplier. One thing before you go racing off to ly
Electronics Forum | Tue May 22 20:27:34 EDT 2007 | davef
What are the area and aspect ratio of the apertures that clog? When you print, you should be able to fit at least 4 of the mean sized solder sphere across the width or diameter of your smallest apertures.
Electronics Forum | Thu Oct 02 17:00:44 EDT 2008 | davef
Is that accurate? If so, what are your aspect & area ratios? [Similar to the JerryS comment above.] * You say, � � and the average height is very high: nearly 200 pct.� => Our troop can make paste that height too. They snap the stencil-off a fast as
Electronics Forum | Tue Jan 16 09:23:26 EST 2001 | P.Gerits
Hello, Standard way to calculate stencil design can be done as follows: A normal ratio of aperture width/stencil thickness = 1.5 for pitches below 650u A normal ratio of stencil aperture width against pad width = 0.8-0.9 (or stencil aperture 10%-20
Electronics Forum | Thu May 24 08:55:25 EDT 2007 | ck_the_flip
Here's some quick things to look for: 1. Does your solder paste feel like concrete, does it roll-up into your squeegee blades, and stick to your stencil? If so, your problem is the solder paste. The mixture of powder and flux, or metal load is ou
Electronics Forum | Fri Jun 25 16:32:45 EDT 1999 | MMurphy
| | | 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 | Tue Dec 17 20:25:13 EST 2002 | iman
Check : 1) design aspect ratio / are ratio required to fabricate the stencil you r using. 2) check if the stencil maker is using your checked aspect ratio / area ratio? if not the same, what are they using? any QA report confirming actual dimension
Electronics Forum | Mon Jul 16 21:25:26 EDT 2001 | davef
Sure, use of U-shape apertures is another way to reduce the amount of paste that you apply. That and similar schemes mentioned in the article are not a function of the flux used. We have used U-shaped apertures for MELF and mini-MELF. They are sug
