Electronics Forum | Mon Mar 27 21:09:29 EST 2006 | ms
Thanks Dave I'm not convinced the air is necessarily in the paste from manufacture - suspicious that it may be folding in during the change in direction of the print cycle - or as the paste travels across apertures. It is not necessarily in the fir
Electronics Forum | Sun Mar 26 19:02:05 EST 2006 | ms
Hi We are running automatic stencil printers, open squeegees, stainless stencil, stainless blades, print speed 25-30mm/sec. We have a frustrating consistency issue printing .37x.3mm apertures on a 45pin LGA (11 pads each side, 1 large ground in mid
Electronics Forum | Mon Feb 07 12:47:18 EST 2005 | Indy
1. use 6-7mils stencil. 2. reduce aperture opening to 60-70% of pad size. 3. check viscosity of solder paste. According to that you might want to alter your print speed and pressure. Cheers Indy
Electronics Forum | Thu Dec 09 07:21:10 EST 2010 | scottp
You won't have 2 mil height because the solder doesn't remain brick shaped. It's a dome. In the past I tried doing some calculations using the formula for the volume of a spherical section and also tried using a simulation program that accounts for
Electronics Forum | Thu Mar 05 23:52:26 EST 1998 | Ron Costa
| Hi Ron, | Your question really opens up a "Pandora's box", but when you say you're not able to print perfectly, what is it exactly that you mean? Is the print lacking volume? Is it mis-registered? Are you bridging? Also, what printers have you used
Electronics Forum | Sat Aug 07 11:10:03 EDT 1999 | JohnW
| Could someone give recommendation on the stencil opening for printing epoxy on HAL FR4 PCB for 0805 and 0603 size chips capacitors and resisitors. | My regular stencil manufacturer recommend the following: | Thickness: 8 mils | 0805 opening: Oblong
Electronics Forum | Fri Apr 03 02:52:42 EST 1998 | Jacqueline Coia
At this moment in time we are using water soluble solder paste on our PCBs these are cleaned using water only, agitated with ultrasonics. After drying a white/grey residue is left around solder joints. Reflow profile is fine and a reliable wash proce
Electronics Forum | Wed Mar 04 10:36:10 EST 2009 | milroy
Hi If you mean your PCB stayed in the Reflow oven more than the reflow time required for the solder paste specs then I suggest to throw away the board because it would lead over heated solder joints all over the board. Think what could happen to an
Electronics Forum | Wed Oct 19 18:47:28 EDT 2022 | winston_one
I can understand the situation, when there is now possibilitie to change board design, or something like this at the moment, and now you have to work with what you have now... Customers and management can bring a stupid situations... But I'm agree w
Electronics Forum | Wed Oct 19 07:04:06 EDT 2022 | winston_one
If any changes in design is not possible and you have to solder it, it's a real headache, I know... I see only 3 options here that you can try consiquently: 1) Accurately profile the board and optimize a profile (go to lower limit of process windo
