Thanks Steve,
I've seen it coming!
I have an interesting curing temperature constraint, need to stay below 80 C. Honestly, I haven't been able to find too many epoxies that would comply. If the Ablestik you mention is the one I know, it normally requires 2 hours@ 160 C to properly cure.
I guess it will cost a lot in terms of scrapped chemical, but the only way I see is to lay the epoxy on the stencil, quickly print a certain quantity of products and discard the epoxy on the stencil as soon as it loses its properties. Then clean the stencil and start over.
Process wise, how did you find epoxy printing compared with solder? Is it more consistent? The area ratio constraint for stencil apertures, is it more relaxed when dealing with epoxies?
Thanks,
Ioan
-----Message d'origine-----
De : Steven Creswick [mailto:[log in to unmask]]
Envoyé : Friday, April 29, 2016 12:22 PM
À : 'TechNet E-Mail Forum'; Ioan Tempea
Objet : RE: [TN] Stencil printing of conductive epoxy
Ioan,
With only a 4 hour pot life, you won't have much screen life at all.
As the adhesive gets wiped across the stencil, and large surfaces of the adhesive get exposed to the air, its properties will change quickly.
For example, I used to use a single part Ablestik material that had a 7 day pot life!! We only allowed its use on a stencil/screen printing application for 8 hrs before we discarded it. You could detect the rheological changes, even then.
If you need to attain and maintain that kind of print geometry, I recommend you search for another adhesive with a much longer pot life...
Alternatively, they do make some really small dispense needles, but with the short pot life I still think you have a challenge in front of you
Steve C
-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Ioan Tempea
Sent: Friday, April 29, 2016 9:29 AM
To: [log in to unmask]
Subject: [TN] Stencil printing of conductive epoxy
Dear Technos,
I need to stencil print 4 mil in diameter, as thick as possible, dots of the Epotek E4110-PFC, see http://www.epotek.com/site/administrator/components/com_products/assets/file
s/Style_Uploads/E4110.pdf
What is your experience with this material?
Any suggestions regarding stencil design/squeegee material/printing program parameters?
Thanks,
Ioan Tempea, P. Eng.
Manufacturing Engineer, Satellite Systems
[cid:[log in to unmask]]
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