Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


ULISES PENAHERRERA

#13733

SOLVENT/PROCEDURE TO REMOVE CURED EPOXY ON SMT COMPONENTS | 21 October, 1998

I'M LOOKING FOR A SOLVENT TO MAKE REMOVING EPOXY FROM THE BOTTOMSIDE OF BOARD ON SMT COMPONENTS. THIS IS MOST IMPORTANT AFTER THE EPOXY HAS CURED AND EVEN RAN THROUGH THE WAVE. I'M LOOKING FOR A WAY OF MAKING THE REWORK PROCESS ON THE CURED EPOXY MORE EFFECIENT AND LESS ARCHAIC(USING HOT IRON AND PICK). IF THERE IS ANOTHER WAY OTHER THAN THE SOLVENT PLEASE LET ME KNOW. THANKS, ULISES

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Stefan Witte

#13734

Re: SOLVENT/PROCEDURE TO REMOVE CURED EPOXY ON SMT COMPONENTS | 21 October, 1998

You'll not find any solvent, which removes cured epoxy and not attack the board material as well. If there are traces underneath the surface mount components even mechanical removal of the epoxy may mess up your boards. As a mechanical tool I recommend the Dremel tool ( which should be available in any hardware store ). In order to remove more than one component you may want to run the boards through a reflow oven. By shutting off the cooling fans or zones, the boards come out with the solder molten and will give you a few seconds to twist off some components. I honestly feel sorry for you and I know how this feels.

| I'M LOOKING FOR A SOLVENT TO MAKE REMOVING EPOXY FROM THE BOTTOMSIDE OF BOARD ON SMT COMPONENTS. THIS IS MOST IMPORTANT AFTER THE EPOXY HAS CURED AND EVEN RAN THROUGH THE WAVE. I'M LOOKING FOR A WAY OF | MAKING THE REWORK PROCESS ON THE CURED EPOXY MORE EFFECIENT AND LESS ARCHAIC(USING HOT IRON AND PICK). IF THERE IS ANOTHER WAY OTHER THAN THE SOLVENT PLEASE LET ME KNOW. THANKS, ULISES |

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Earl Moon

#13735

Re: SOLVENT/PROCEDURE TO REMOVE CURED EPOXY ON SMT COMPONENTS | 21 October, 1998

| I'M LOOKING FOR A SOLVENT TO MAKE REMOVING EPOXY FROM THE BOTTOMSIDE OF BOARD ON SMT COMPONENTS. THIS IS MOST IMPORTANT AFTER THE EPOXY HAS CURED AND EVEN RAN THROUGH THE WAVE. I'M LOOKING FOR A WAY OF | MAKING THE REWORK PROCESS ON THE CURED EPOXY MORE EFFECIENT AND LESS ARCHAIC(USING HOT IRON AND PICK). IF THERE IS ANOTHER WAY OTHER THAN THE SOLVENT PLEASE LET ME KNOW. THANKS, ULISES | Stefan is absolutely right. I mean, most boards are epoxy/glass composites. So are most solder masks. What works to remove epoxy from components, surely works to remove the epoxy from the substrate supporting them. Also, never use "super glue" on epoxy boards unless you want glass fabric showing everywhere.

Earl Moon

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Chris Fontaine

#13736

Re: SOLVENT/PROCEDURE TO REMOVE CURED EPOXY ON SMT COMPONENTS | 22 October, 1998

| I'M LOOKING FOR A SOLVENT TO MAKE REMOVING EPOXY FROM THE BOTTOMSIDE OF BOARD ON SMT COMPONENTS. THIS IS MOST IMPORTANT AFTER THE EPOXY HAS CURED AND EVEN RAN THROUGH THE WAVE. I'M LOOKING FOR A WAY OF | MAKING THE REWORK PROCESS ON THE CURED EPOXY MORE EFFECIENT AND LESS ARCHAIC(USING HOT IRON AND PICK). IF THERE IS ANOTHER WAY OTHER THAN THE SOLVENT PLEASE LET ME KNOW. THANKS, ULISES | We use a micro-abrasion process to remove some conformal coatings and adhesives which can not be removed with a solvent. Micro-abrasion is essentially a miniturized sand blasting process, and variety of different types of abrasion media can be used to remove some cured adhesives. We use a plastic media because of ESD concerns, but others are available. This process is more effective at removing hard, brittle adhesives than it is at removing softer, more rubbery adhesives, though not sure how well it will do with a particularly tough epoxy.

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SMT Equipment

HeatShield Gel- thermal PCB shield during reflow