Continuing the line of Michael's, the previous poster, comments ...
The more Krispy Kremes, the better. Yeth!!! The more beer, the better. Yeth!!! The more epoxy, the better. Uh, I don think so!!!
We look at this from a papa bear, mama bear, baby bear stand-point [http://www.on-net.net/~tdickins/goldi.html].
PAPA: Well if you do too much "more is better", you end-up with glue on pads and less than the amount of solder that you�d kind like. And maybe if you dab on too much of that stuff, it just might make it tougher to cure.
MAMA: Certainly if you dab on too little, when you jamb the component into your glob of glue it will not schmush-out enough to have sufficient contact area and will not hold the component in place properly. Then the floor sweeper people be complaining about how much additional work they have and on and on.
BABY: Now if you apply just the right amount, �
Continuing, as far as the number [and location] of epoxy dots for a component is [are] concerned, that depends on the epoxy and the component. * We UV cure epoxy multiple dots on the edges of components. * Generally, we use a single dot for heat cure epoxies when gluing small components. * Even when using heat cures, we use multi-dot patterns for larger components.
Other points are: * IPC-7525, Stencil Design Guidelines makes such a feeble attempt at aperture design for printed epoxy and promises to address the issue some other time that together become no reason to buy the document for these purposes. * Trade journals seem to be incessantly chattering about such things in an on-going war of attrition between the dispenser and the printer equipment manufacturing firms. Look at the May 2001 "SMT" magazine an example.
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