TECHNET Archives

August 2014

TechNet@IPC.ORG

Options: Use Monospaced Font
Show Text Part by Default
Show All Mail Headers

Message: [<< First] [< Prev] [Next >] [Last >>]
Topic: [<< First] [< Prev] [Next >] [Last >>]
Author: [<< First] [< Prev] [Next >] [Last >>]

Print Reply
Subject:
From:
Ron Feyereisen <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Ron Feyereisen <[log in to unmask]>
Date:
Fri, 15 Aug 2014 19:33:10 +0000
Content-Type:
text/plain
Parts/Attachments:
text/plain (132 lines)
According to the reported testing in the white paper, there was little insertion loss (db/in) with coating when compared to bare copper up to the test sample limit of around 11GHz.

Ron


-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Wayne Thayer
Sent: Friday, August 15, 2014 2:03 PM
To: [log in to unmask]
Subject: Re: [TN] surface finish for "bare" copper

Most RF antenna guys get a little too crazy about this. Up to about 10GHz I see a lot of ENIG used without complaint. If you want to see someone freak out, go ahead and put a conformal coat on the traces!

The original fabricator talking about bare copper may have been referring to a chromate anti-tarnish, which is often on the FR4 panels as delivered to the fab. That will hold up for quite a while also, but I don't know if it can be applied post-fabrication.

Nickel has poor RF performance. Ag oxidizes and will eventually look ugly, but the performance will probably be good for a long time, particularly with some anti-tarnish applied. Direct Au over copper might be something to consider.

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Yuan-chia Joyce Koo
Sent: Friday, August 15, 2014 2:43 PM
To: [log in to unmask]
Subject: Re: [TN] surface finish for "bare" copper

(1) you need radar guy (2) my guess would be Ag.
just a guess.
   jk
On Aug 15, 2014, at 2:37 PM, Larson, Mark wrote:

> Thank you but I guess I should have been more clear, there are no 
> components and no holes on this board, it is an antenna board, I'm 
> pretty sure, a couple decades ago perhaps, I had a similar situation 
> and I ordered bare copper because that's what the engineer said, I got 
> a call from the fabricator asking, no, make that telling me, we really 
> didn't want that. Maybe finish isn't the right word, treatment 
> perhaps, he said the copper could be treated with something that would 
> prevent oxidizing. I think it was part of their normal process before 
> applying HASL, but maybe with lead free it is no longer used.
>
> Maybe I could ask the question, what would you apply to prevent 
> oxidation yet not affect the performance of the antenna in the several 
> GigaHertz range.?
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Yuan-chia Joyce 
> Koo
> Sent: Friday, August 15, 2014 1:04 PM
> To: [log in to unmask]
> Subject: Re: [TN] surface finish for "bare" copper
>
> agree with steve 100%.  It also depend upon your assembly condition:
> flux activity, number of reflow, reflow profile, subsequent exposure 
> to environment.... your design group should pick and choose the right 
> finishing... not on the MFG floor... my 2 cents.
>                  jk
> On Aug 15, 2014, at 1:55 PM, Stephen Gregory wrote:
>
>> To add to Wayne's input, make sure you call out the right OSP 
>> depending on the board technology...not all OSP's are the same.
>>
>> Steve
>>
>> Sent from my BlackBerry 10 smartphone.
>>   Original Message
>> From: Wayne Thayer
>> Sent: Friday, August 15, 2014 11:28 AM
>> To: [log in to unmask]
>> Reply To: TechNet E-Mail Forum
>> Subject: Re: [TN] surface finish for "bare" copper
>>
>> OSP
>>
>> -----Original Message-----
>> From: TechNet [mailto:[log in to unmask]] On Behalf Of Mark Larson
>> Sent: Friday, August 15, 2014 1:12 PM
>> To: [log in to unmask]
>> Subject: [TN] surface finish for "bare" copper
>>
>> Hi,
>>
>> I've got a board that needs bare copper, many years ago I had this as 
>> well and seem to recall that they can put on some kind of finish in 
>> the process that does not leave it bare, but does protect it in the 
>> processing of the board, and consequently does offer some protection 
>> to the end user.
>> Anybody know what
>> that is or how I call it out?
>>
>> --
>>
>>
>> This email and any attachments are only for use by the intended
>> recipient(s) and may contain legally privileged, confidential, 
>> proprietary or otherwise private information. Any unauthorized use, 
>> reproduction, dissemination, distribution or other disclosure of the 
>> contents of this e-mail or its attachments is strictly prohibited. If 
>> you have received this email in error, please notify the sender 
>> immediately and delete the original.
>>
>> _____________________________________________________________________
>> _
>> This email has been scanned by the Symantec Email Security.cloud 
>> service.
>> For more information please contact helpdesk at x2960 or 
>> [log in to unmask] 
>> _____________________________________________________________________
>> _
>
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud 
> service.
> For more information please contact helpdesk at x2960 or 
> [log in to unmask] 
> ______________________________________________________________________
>
> ______________________________________________________________________
> This email has been scanned by the Symantec Email Security.cloud 
> service.
> For more information please contact helpdesk at x2960 or 
> [log in to unmask] 
> ______________________________________________________________________


______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] ______________________________________________________________________

______________________________________________________________________
This email has been scanned by the Symantec Email Security.cloud service.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________

ATOM RSS1 RSS2