Electronics Forum | Tue Jul 19 11:21:50 EDT 2005 | russ
You may want to try reducing the large center aperture on your stencil to 50-70% of the area of the pad. This is what we do with QFNs and it may be applicable in this case also.
Electronics Forum | Wed Oct 11 05:58:13 EDT 2023 | kojotssss
Hello all, I know there are very skilled guys. Can anyone suggest a stencil design to avoid component displacement during reflow to improve tension of surface forces and selfalignment? There are cases where the inductors are shifted. All parameters
Electronics Forum | Wed Oct 11 13:26:59 EDT 2023 | cyber_wolf
Its highly doubtful that stencil design will fix this. The Inductor floats during reflow and ends up going where it wants to go. The only way you are going to keep it in place is to put a dot of chipbonder beneath it or change the size of the lands
Electronics Forum | Wed Oct 11 18:30:21 EDT 2023 | kojotssss
Thanks for the opinions! You're right, it can't be solved with a stencil. I have made investigation, the problems are related to the quality of the component land surface, one of the terminal is oxidized.
Electronics Forum | Wed Oct 11 18:12:55 EDT 2023 | alexv
I don't think it's a stencil issue. You have an identical inductor next to t=it, that's perfectly straight. You have a problem in that location. I've seen some inductors be affected by slight magnetic forces in the reflow oven. Try to rotate the boar
Electronics Forum | Wed Oct 11 13:40:20 EDT 2023 | proceng1
Agreed. Your "leads" are fairly small compared to the PAD area, so you leave your part lots of room to "stretch it's legs". One thing that I have trouble communicating to my operators is that placement does not have to be perfect, and neither does t
Electronics Forum | Fri Jan 19 06:52:36 EST 2001 | pteerink
We have had the same problem with several boards, and the problem was with the land pattern design on the PCB, not the stencil. We found that the part tends to center itself on the one large pad, and if the two smaller pads are not the right distance
Electronics Forum | Thu Jan 18 19:16:42 EST 2001 | slowe
I am having problems with D-Packs shifting during reflow. Does anyone know of a good aperture design to solve this problem ? Possibly bow tie.
Electronics Forum | Fri Apr 11 06:22:04 EDT 2008 | andrzej
Hi Andrzej, > > We are using for BGA (0.8 pitch) > square apertures size 0.4 mm (rounded corners r = > t) and stencil thickness t=5 mils. So area > ration-_ w/4t=0.8 > > Regards Jan Hello Jan, I understand that you have the same pad dimensio
Electronics Forum | Sun Sep 19 10:54:24 EDT 2004 | rohman23
This (along w/ everything else we do) is not high volume. Actually, we're dropping a batch of 7 the first of the week, and that's fairly sizeable for us. I talked with my stencil design folks and sent them a scrap board and all my gerber info. I t
