Homebrew PCBs

Thanks Peter for a very fast reply.

Actually I have an equivalent USA made unit that I paid about three times
more for.  

This is a very good price and I will buy an extra one for adhesive
dispensing.

Unfortunately it will not help since when I put a small enough tip on the
syringe, the paste is too sticky to come out.

Bertho

+++++++++++++++++++++++++++++++++++++++++++++++

From Peter Loron   Sent: Saturday, May 07, 2011 16:18
Something like this may be what you need:

http://cgi.ebay.com/SMT-SMD-Solder-Paste-Adhesive-Glue-Liquid-Dispenser-EFD-
/220767109957?pt=LH_DefaultDomain_0
<http://cgi.ebay.com/SMT-SMD-Solder-Paste-Adhesive-Glue-Liquid-Dispenser-EFD
-/220767109957?pt=LH_DefaultDomain_0&hash=item3366bec345#ht_1230wt_907>
&hash=item3366bec345#ht_1230wt_907

I have no experience with that specific product or seller...

-Pete

On May 7, 2011, at 1:05 PM, Boman33 wrote:

> For regular SMT assembly I use commercial stencils to screen print the
> solder paste but I am having problems dispensing solder paste by hand in
> small amounts for rework or prototypes. 
> 
> I have seen somewhere that individual stencils are sold but that adds the
> requirement to accurately align the stencil which will be very difficult
on
> a rework board.
> 
> Using a syringe and placing a single long bead across all the IC pin pads
> work fine on wider pitch ICs but as the pitch is getting smaller I am
having
> trouble getting the line thin enough. In other words, there is too much
> solder so when I reflow there are solder bridging.

> If I use a finer tip on the syringe I cannot squeeze it hard enough for
the
> paste to come out. If I add some flux it gets thinner but too runny. I
> like the normal consistency since it helps to keep the ICs in place with
its
> stickiness. My current smallest bead diameter is 0.5mm (20mils). I like to
> be able to get about half of that size.
> 
> I am basically looking for a solder paste with less solder and more thick
> flux material so I can squeeze out a reasonably sized bead but after
reflow
> there is less solder than a normal paste.
> 
> Any suggestions on a paste like that?

> Any other suggestions on how to place a very small amount of solder on the
> IC pads?
> 
> Thanks in advance for suggestions. 
> Bertho

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