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Paste Printing Problems - Toshiba SSM3K15CT(TPL3) FET CST3 package

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#67003

Paste Printing Problems - Toshiba SSM3K15CT(TPL3) FET CST3 package | 10 August, 2012

Anyone have experience printing solder paste for a Toshiba SSM3K15CT(TPL3) FET with CST3 package? Using 1 to 1 rectangular apertures with a 4 mil stencil and Alpha OM 338 #4 powder size lead free solder paste. Print head speed is 15 mm/sec and solvent wiping every 2 panels. Still having problems with the apertures clogging causing poor prints. Any comments or recommendations should be appreciated. Thanks.

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#67007

Paste Printing Problems - Toshiba SSM3K15CT(TPL3) FET CST3 package | 13 August, 2012

Maybe the area ratio between the sides of the stencil apertures and the aperture opening is too low for the spec of the paste ? So it will tend to stick in the apertures. ...only solution is thinner stencil or a paste that can release easily when area ratio is so small...maybe a size 5 paste will help...almit does a paste for release from small apertures.....other manufacturers may do too. One question...what size are the 2 smaller pcb pads for the device? If they are per Toshibas recommendation (0.22 x 0.35mm)then the area ratio is about 67%...most modern pastes will work with this ratio, but OM338 has been around a few years now.

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