Electronics Forum | Mon Feb 06 21:24:21 EST 2012 | gaz
By changing paste and making a better profile, it seems like we have enough paste. The process was just not working very well with SN100. So far the 5mil looks good, so thanks for the input!
Electronics Forum | Mon Jan 23 22:53:31 EST 2012 | davef
= 0.66 aperture opening to the stencil wall has been shown to provide the best transfer efficiency and repeatability of the deposited paste. Values from 0.66 to 0.8 insure a good paste release from the stencil. The biggest impact on area ratio is the
Electronics Forum | Thu Mar 02 13:04:22 EST 2006 | Chunks
0603 parts at .2mm spacing is pretty easy. But are there any other parts, like fine pitch QFPs? Is your board HASL or something else? Is there resist/mask between all pads? If it's just 0603's at .2mm, then you can probably go 7 mils and get good
Electronics Forum | Sun Sep 27 22:39:55 EDT 2009 | rajeshwara
The same issue i faced 2 yrs before , i sugest 1. Use stencil of 4 mils ( Take care of Aspect Ratio and Area Ratio ). 2. Use Solder Paste of Type 4.5 and Viscosity in between 1100 to 1300. ( Try Solder Paste of Cookson or Alpha metals : OM338 T45-L
Electronics Forum | Tue Jan 24 20:00:39 EST 2012 | kahrpr
If you failed math like I did. A 0.005 inch stencil would work fine for those parts. Most stencils are 0.004in for fine pitch 1005s 201s. 0.005in is probably the most common generic stencil. 0.006in generally is if you need extra solder for big parts
Electronics Forum | Fri Sep 25 16:47:57 EDT 2009 | esoderberg
0.5mm pitch QFP's are typically mixed with large components on all of my boards. I usually use a 6 mil stencil with a minimum aperture width of 10 mils. Normal aperture size is 10 x 50 which causes shorts about 20% of the time. A recent purchase of
Electronics Forum | Fri Feb 03 09:50:37 EST 2012 | mosborne1
Thanks very much everyone. > > I'll try out a > 5mil and see how that goes. If you are using 6mil stencil and you are saying that you need more on the 0603 parts then you might want to look at your squeege pressure. What kind of squeege blades ar
Electronics Forum | Sat Dec 10 07:03:59 EST 2005 | mdemos1
Hi. I am trying to find out the minimum copper thickness I should see on a through hole barrel. The board has 1 ounce copper and the board thickness is 0.062". I am finding thicknesses of 0.6 to 1.2 mils. Thanks, Mike.
Electronics Forum | Sun Sep 08 22:38:23 EDT 2019 | sssamw
what's your final verified ok stencil thickness for the QFN and BGA?
Electronics Forum | Wed Dec 11 13:00:07 EST 2019 | slthomas
Excessive mask thickness also can wreak havoc on stencil printing.
