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| Date: | Thu, 30 Jan 2020 22:35:09 +0000 |
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Tin plating is a use full etch resist when accuracy has margin - for fine feature a photo resist will provide a more robust image and resulting feature geometry. Combinations of both have benefits in formation of structures and line features.
Jeffrey Bush
Program Quality Engineering Manager
BAE SYSTEMS
Electronic Systems Division
C4ISR Solutions – Space Systems Group
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Nashua, NH 03061-0868
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-----Original Message-----
From: TechNet <[log in to unmask]> On Behalf Of Dennis Fritz
Sent: Tuesday, January 28, 2020 1:35 PM
To: [log in to unmask]
Subject: Re: [TN] PWB core, Develop Etch Strip, DES
*** WARNING ***
EXTERNAL EMAIL -- This message originates from outside our organization.
Victor,
If you need to use alkaline etchant for making inner layers, tin plating is
useful. Modern photoresists are sensitive to alkaline solutions. If you
have buried vias in the cores that require copper pattern electroplated via holes, then alkaline etching and hence tin plating is useful.
You can use photoresist only for cupric chloride etching of double sided copper cores without holes, or if you panel plate the two entire copper surfaces including any buried via holes, then you can "tent and etch" the pattern you want, and etch with cupric or other acid etchants.
Hope this helps.
Denny Fritz
On Tue, Jan 28, 2020 at 1:09 PM <[log in to unmask]> wrote:
> Fellow TechNetters:
>
> Can tin plating of some sort be used on copper core for a DES
> processing?
> All I can remember was photo resist in the OLD days........
>
> Victor,
>
--
Denny Fritz
Consultant
812 584 2687
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