Doug,



I have not.  I'll have to research is a bit.



Thanks,



Phil Nutting | Senior Development Engineer | Lab: +1-978-224-4334 | Mobile: +1-978-828-8664

35 Congress Street | Salem, MA 01970 | U.S.A. | www.excelitas.com









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From: TechNet <[log in to unmask]> On Behalf Of Douglas Pauls

Sent: Thursday, February 11, 2021 7:33 AM

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Subject: Re: [TN] [External] [TN] RTV Encapsulation of circuit boards



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Phil, have you considered plasma etching as a precursor process to replace the media blasting and priming?

---

*Douglas Pauls *| Principal Materials and Process Engr | Advanced Operations Engineering



*COLLINS AEROSPACE*



400 Collins Road NE, MS 108-101, Cedar Rapids, IA  52498  USA



*Tel:* +1 319 295 2109 | *Mobile: *+1 319 431 3773



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On Wed, Feb 10, 2021 at 2:22 PM Nutting, Phil <[log in to unmask]>

wrote:



> Technetters,

>

> We build several power supplies that use RTV in place of dielectric 

> oil for our high voltage multipliers.  The RTV allows us to get the 

> same output level in a smaller package than a similar design using the 

> dielectric oil as the insulator.  The proper process is to medial 

> blast (lightly) the circuit boards, prime them and then encapsulate the boards in the RTV.

> Both the media blasting and priming can be very subjective processes.  

> And both have process issues in our manufacturing group. Simply 

> eliminating the media blasting and priming is not a solution as the 

> RTV will not bond to the boards and ultimately creating the potential for arcing to ground.

>

> Ideally potting a small box makes a disposable assembly, so the 

> bonding quality and thermal size change of the RTV is not an issue.  

> We use between

> 20 and 100 pounds of RTV per potted assembly.  Disposal or repair of 

> failed units is expensive.

>

> I am looking for folks that use RTV for encapsulation and what they 

> use for a process to ensure good bonding between the RTV and circuit boards.

>

> Phil Nutting | Senior Development Engineer | Lab: +1-978-224-4334 |

> Mobile: +1-978-828-8664

> 35 Congress Street | Salem, MA 01970 | U.S.A. | 

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