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Subject:
From:
Robert Kondner <[log in to unmask]>
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Date:
Tue, 21 Mar 2017 09:21:00 -0600
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I looked that up, better than most solder masks but still a little low at
733V / mil. 

Good insulating materials seem to be in the 3KV per mil region. 

Some time I wonder if different materials use different  test methods or is
some material must consider entrapped air or pin holes. That Red GLPT and
the Parylene materials see pretty good.

Bob K.

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Joyce Koo
Sent: Tuesday, March 21, 2017 6:54 AM
To: [log in to unmask]
Subject: Re: [TN] AW: [TN] WG: [TN] Screen On Insulation

not sure if it will work or not..
https://www.cslsilicones.com/en/explore-by-sector/manufacturing-industrial/i
tem/high-voltage-insulator-coating.html

there are alumina filled UV cure epoxy (thermal/UV dual cure), but not ad as
high voltage insulator.  it should be better than silicone, IMHO... but you
better get approved material as listed above.

> Hi Bob,
>
> parylene is closed at about 0,6µm, so at 1 mil you have a safety 
> margin of about 4200 %.
>
> We have payed about 1500€ for a batch of 32pcs bio sensor PCBs with 
> 40mm diameter...
>
> Take care,
> Torsten
>
>
> Best Regards
>
> KRISTRONICS GmbH
>
> Dipl.Ing. (FH) Torsten Hagge
> team leader HW development
> Gewerbegrund 5-9
> 24955 Harrislee
> Telefon +49 (0) 461 7741-624
> Telefax +49 (0) 461 7741-642
> [log in to unmask]
> www.kristronics.de
> Place of jurisdiction: Flensburg, commercial register: HRB 1433 FL CEO 
> Dipl.-Ing. oec. Thormod Ohm VAD-Id DE 811182059 Bank account: Deutsche 
> Bank AG Flensburg, account 4216610, bank number
> 21570011
> IBAN: DE32 2157 0011 0421 6610 00, BIC: DEUT DE HH 215  Please 
> consider the environment before printing this e-mail
>
>
>
>
> -----Ursprüngliche Nachricht-----
> Von: Robert Kondner [mailto:[log in to unmask]]
> Gesendet: Montag, 20. März 2017 17:06
> An: 'TechNet E-Mail Forum'; Torsten Hagge
> Betreff: RE: [TN] WG: [TN] Screen On Insulation
>
> Torsten,
>
>  Do you know how thick a parylene coating is? My recollection is 
> pretty thin.
>
>  So I checked, very high dielectric strength, thickness typically 
> under 1 mil but it can be built up further with longer processing time.
>
> Any idea wat coating with parylene cost for a small batch of boards?
>
> Thanks,
> Bob Kondner
>
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Torsten Hagge
> Sent: Monday, March 20, 2017 9:17 AM
> To: [log in to unmask]
> Subject: [TN] WG: [TN] Screen On Insulation
>
> Hi,
>
> cheap solution could be a 1mil kapton tape with the mention risk of 
> air gaps, fine and cost expensive solution parylene HT  coating before 
> placing the ferrite cores...
>
> Take care
> Torsten
>
>
>
> Best Regards
>
> KRISTRONICS GmbH
>
> Dipl.Ing. (FH) Torsten Hagge
> team leader HW development
> Gewerbegrund 5-9
> 24955 Harrislee
> Telefon +49 (0) 461 7741-624
> Telefax +49 (0) 461 7741-642
> [log in to unmask]
> www.kristronics.de
> Place of jurisdiction: Flensburg, commercial register: HRB 1433 FL CEO 
> Dipl.-Ing. oec. Thormod Ohm VAD-Id DE 811182059 Bank account: Deutsche 
> Bank AG Flensburg, account 4216610, bank number
> 21570011
> IBAN: DE32 2157 0011 0421 6610 00, BIC: DEUT DE HH 215  Please 
> consider the environment before printing this e-mail
>
>
>
> -----Ursprüngliche Nachricht-----
> Von: TechNet [mailto:[log in to unmask]] Im Auftrag von Robert Kondner
> Gesendet: Freitag, 17. März 2017 21:11
> An: [log in to unmask]
> Betreff: [TN] Screen On Insulation
>
> Hi,
>
>
>
> We have a PCB that turns out to require 2500VAC test for 60 seconds 
> and we had some flash over on pads to vias. We also have a planar 
> ferrite transformer with primary windings on one side.
>
>
>
> Does anyone know of a screen on insulation material that can be used 
> to increase flash over voltages? I would like to get a 2 or 3 mils of 
> material.
> My other option is to have a laser cut layer of isolation but that 
> could leave air paths under the material.
>
>
>
> Any other ideas welcome.
>
>
>
> Thanks,
>
> Bob K.
>
>

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