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From [log in to unmask] Wed Oct 2 16: |
29:50 1996 |
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Vigourous stirring of paste will cause its viscosity to fall. (Sheer thinning)
If your paste works after treatment like this, but not before, it suggests that
the start/supplied viscosity is too high.
I assume you are not trying to use paste taken straight from the refrigerator
(cold paste is thicker than warm paste) so
Maybe you are using a formulation which was correct when frst determined a while
ago but has not followed changes in your work .
Alternatively some paste suppliers do supply pastes with high initial
viscosities which are intended to be sheer thinned on/by the printer into a
usable viscosity range in continuing production. If this is so try using a more
appropriate product.
As a start suggest you check your supplier data sheet recomendations and compare
to what you are actually doing and using, then speak to your supplier .
Caution: This would be a break from standard industry practise: most people
don't read anything before beating up on their supplier.
Mike Fenner
BSP
-----------------------------------------------------------
Paul Stolar wrote
Does anyone else have the problem with their no-clean solder paste
needing about 20 kneeds to get the proper volume? If so, are there
other ways to get there quicker?
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