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1B73LOC Conformal Coating

Views: 1529

#50828

1B73LOC Conformal Coating | 25 June, 2007

We're using the 1B73LOC conformal coating from Humiseal. We've seen some bubbling of the coating. Their tech handbook suggested reducing our oven ramp speed. Does anyone have a good profile for this? They've always pointed me to Nordson, and Nordson points me to them....

Thanks John S.

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#50829

1B73LOC Conformal Coating | 25 June, 2007

i difagee

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#50831

1B73LOC Conformal Coating | 25 June, 2007

I don't think THEY (Humiseal) know how their material cures.

I have a data sheet from them for 1B73, and it says 24 hours at room temperature or 30 min. @ 170�F.

We use our in-line oven mainly to dry the material and make it tack-free.

You would think that the entire 1B familiy of acrylics all have similar curing characteristics. My guess for your bubbles/fish eyes would be on your application (spray or dip?), and not the curing.

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#50832

1B73LOC Conformal Coating | 25 June, 2007

Once the HumiSeal conformal coating has been applied to the printed circuit board it is usually best to allow the material to reach a touch-dry stage, before heating the board to accelerate the cure schedule. This avoids potential problems such as bubbles and other defects being introduced by the cure profile. [Humiseal]

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#50833

1B73LOC Conformal Coating | 25 June, 2007

As for the bubbles/fisheyes, try increasing your thinner ratio. This sounds like your coating is thickening up before you are able to apply it to your application.

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