Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


0402 Adhesive Screen Printing

#23988

0402 Adhesive Screen Printing | 1 April, 2003

Is anyone out there successfully screen-printing SMD adhesive on an 0402 layout? We have successfully done 0603 and larger, but the deposition consistency on the 0402's is just not there. We don't always get enough epoxy on the board. We have tried an array of different aperture sizes and shapes on a .006" thick stencil. Some designs we tried seem to work better than others do, but I am still not as confident as I would be printing 0603 adhesive dots. I am using Loctite 3616, printing on MPM/SPM, and AP25 printers.

What am I doing wrong.....?

Thanks in advance

reply »


CPI

#23990

0402 Adhesive Screen Printing | 1 April, 2003

I have NOT done 0402's yet but also have no trouble with 0603's. Did you try any thinner stencils? I don�t know this for a fact just speculating, I would think the 0402's have a smaller brd to chip gap and that you might be able to get away with a 4 or 5 mil stencil. Doing this you may get better release in the smaller apps? Just a thought!

reply »

#23991

0402 Adhesive Screen Printing | 1 April, 2003

The problem is that there are also SOT23's present. I would use a .004 or a .005 stencil, but I don't think that the dots are going to contact the bottom of the larger packages on a thinner stencil.

...Thanks for the input.

reply »

#23996

0402 Adhesive Screen Printing | 1 April, 2003

I've never printed adhesive but I assume that aspect ratio still plays a part with release. Maybe that .006" is just to thick to get good release.

Can you step your stencil down from .006" to .004" or .005" for the 0402's?

reply »

Print Master

#24019

0402 Adhesive Screen Printing | 3 April, 2003

0402 Adhesive printing is possible with thicker stencils in order to allow mixed component technology.

We have successfully printed 0402's with a 0.008" thick SS foil. Total material release is not achievable at this thickness, but not required using what is sometimes referred to as a "PumpPrint" process.

reply »

SMT in-printer dispensing

Heller Industries Mark 5获得了 2015年中国SMT远见奖 - 回焊炉领域