Conformal Coat Thermal Conductivity

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We currently have an assembly that we have to mask the surfa... - Apr 18, 2007 by

SMTA

We use 1B73 Acrylic and coat right over an IBM processor whi... - Apr 18, 2007 by jdumont

Thermal conductivity [W/m-*C] * Conformal coating [AR, ER, ... - Apr 18, 2007 by davef

Dave, Where did you find that info? having a hard time g... - Apr 19, 2007 by

SMTA

Look here: Apr 19, 2007 by davef

Thanks for the link!!! Don't know why I couldn't find it. ... - Apr 19, 2007 by

SMTA

Dave, When we converted the Humiseal thermal conductivity i... - Apr 19, 2007 by

SMTA

Try this: Apr 19, 2007 by davef

Cecil

#49108

Conformal Coat Thermal Conductivity | 18 April, 2007

We currently have an assembly that we have to mask the surface of several (24)SMT components where thermal compound is applied at a latter operation. These component packages vary from BGA's to QFP's. After the thermal compound is applied the PWA is then attached to a heat sink plate. Conformal coating used is Humiseal 1B31. I am trying to get thermal conductivity info from Humiseal but in the mean time thought I would see is any of the experts here have dealt with this in the past.

I am just wondering if it is really necessary to mask off the components. Is pretty labor intensive and would like to eliminate this step if possible. Does anyone apply thermal compound over CC then mount your heat sinks? Has anyone performed any experiments in the past to determine if conformal coating reduces thermal transfer efficiency?

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jdumont

#49111

Conformal Coat Thermal Conductivity | 18 April, 2007

We use 1B73 Acrylic and coat right over an IBM processor which gets a heat sink mounted on top. Never had an issue after 5 years of production. Dont forget to post if you find anything out though.... JD

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davef

#49122

Conformal Coat Thermal Conductivity | 18 April, 2007

Thermal conductivity [W/m-*C] * Conformal coating [AR, ER, UR]: 17-21 * Epoxy molding compound: 0.6

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cecil

#49130

Conformal Coat Thermal Conductivity | 19 April, 2007

Dave, Where did you find that info?

having a hard time getting info from Humiseal.

Thanks