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Microscreen stencils

Views: 1727

#37975

Microscreen stencils | 18 November, 2005

We seem to be having a problem with our stencils delaminating from the emulsion quite frequently.

Does anyone else out there that buys stencils from Microscreen have this problem ?

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#38088

Microscreen stencils | 26 November, 2005

Dude - one thing you may want to look at is the detergent your adding to your stencil wash. If it's geared for epoxy removal, it will also remove "that" epoxy as well. The rule of thumb is, under one year, the manufacturer fixes the stencil, over one year, you pay for it.

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#38108

Microscreen stencils | 28 November, 2005

Se�or Tech

We use stencils from other suppliers. So, we have no specific problems from Microscreen.

Generalizing, most stencil manufacturers recommend that their product not be exposed to temperatures in excess of 110*F (43*C). Our old buddy B Scheibner has posted several times on the topic.

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PWH

#38118

Microscreen stencils | 29 November, 2005

I've had stencils delaminate when accidentally left in the UT cleaner for excessive time.

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#38123

Microscreen stencils | 29 November, 2005

Hello Billy,

You are correct when you say that you may want to look at the detergent (chemistry) you're adding to the stencil wash. However, "geared for epoxy removal" depends on how the chemistry is designed to remove the epoxy. If it is a "water-based" solvent, it is likely to not only clean the wet adhesive, but also breakdown the stencil adhesive and cause delamination. If it is a detergent (surfactant) it will remove the wet epoxy as a wetting agent (form a film between the wet epoxy and the stencil) and likely not attack the cured stencil epoxy.

Another cause of delamination (other than heat) is long exposure to moisture. The stencil adhesive will absorb moisture and swell if allowed to "soak" in the washer. When the stencil dries, the adhesive is weakened and delaminates under slight pressure.

At Smart Sonic, we have tested hundreds of stencils and have found three major causes of delamination: 1) Harsh chemistries that will dissolve wet and cured adhesives. 2) Hot wash solutions and/or hot drying air because the stencil adhesives are heat-cured. 3) Moisture absorption due to long cleaning cycles or soak times.

There is a good article by Richard Clouthier on our web site regarding these issues: http://www.smartsonic.com/article1.html If would like to discuss your application, please call or e-mail me. Tel: 1(800) 806-440R E-mail: bill@smartsonic.com

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