Subject: | |
From: | |
Reply To: | TechNet E-Mail Forum. |
Date: | Tue, 14 Sep 1999 13:26:35 -0700 |
Content-Type: | text/plain |
Parts/Attachments: |
|
|
Lee is the man, living now in retirement (my ass) and it works.
Earl Moon
----- Original Message -----
From: Mcmaster, Michael <[log in to unmask]>
To: <[log in to unmask]>
Sent: Tuesday, September 14, 1999 10:19 AM
Subject: Re: [TN] Measuring copper thickness @ incoming inspection
> For OL, you can use an eddy current tester or something similar. We use
> a couple of different tools from CMI. You can reach them at
> http://www.cmiinternational.com/
>
> For IL, you could put a resistance coupon on the board.
>
> Lee Ritchey includes a nifty little trick in his High-Speed PCB and
> System Design Course. He calls it a stacking stripe. I'll assume he
> won't mind my posting it here in exchange for a plug to take his course
> (last I looked it was offered through the Continuing Education in
> Engineering, University Extension at University of California, Berkeley
> - Go Bears!) He places a strip of copper 50 mils wide by 200 mils long
> on layer 1. On each successive layer, the strip is 25 mils longer. The
> strip is placed so that the centerline of the 50 mil width will be on
> the finished card edge. When the board is routed, the strips are
> exposed and can be inspected without microsection. It looks something
> like this for a 4-layer board.
>
> Layer 1 _______
> Layer 2 __________
> Layer 3 _____________
> Layer 4 ________________
>
>
> The correct order of layers and copper weights can be verified this way.
> He even includes a trace of a specific width so that proper etching can
> be verified. Please note that this is contrary to the typical
> requirement to avoid exposing copper on the card edge. If you use this,
> you'll probably need to specify that exposed copper is acceptable in the
> stacking stripe area of the card. Obviously the stacking stripe needs
> to be isolated from functional circuits and planes inside the card.
>
> ----------
> From: Brian Gaynor [SMTP:[log in to unmask]]
> Sent: Tuesday, September 14, 1999 12:53 AM
> To: [log in to unmask]
> Subject: [TN] Measuring copper thickness @ incoming inspection
>
> Hi,
> What devices or techniques do you know of that can measure the
> thickness
> of external & internal copper on a PWB from a PWB Manufacturer
> that does not
> involve micro-section?
>
> Best regards,
> Brian Gaynor
> Artesyn Technologies Europe.
> [log in to unmask]
>
> ##############################################################
> TechNet Mail List provided as a free service by IPC using
> LISTSERV 1.8c
> ##############################################################
> To subscribe/unsubscribe, send a message to [log in to unmask]
> with following text in
> the body:
> To subscribe: SUBSCRIBE TECHNET <your full name>
> To unsubscribe: SIGNOFF TECHNET
> ##############################################################
> Please visit IPC web site (http://www.ipc.org/html/forum.htm)
> for additional
> information.
> If you need assistance - contact Gayatri Sardeshpande at
> [log in to unmask] or
> 847-509-9700 ext.5365
> ##############################################################
>
> ##############################################################
> TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
> ##############################################################
> To subscribe/unsubscribe, send a message to [log in to unmask] with
following text in
> the body:
> To subscribe: SUBSCRIBE TECHNET <your full name>
> To unsubscribe: SIGNOFF TECHNET
> ##############################################################
> Please visit IPC web site (http://www.ipc.org/html/forum.htm) for
additional
> information.
> If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
> 847-509-9700 ext.5365
> ##############################################################
##############################################################
TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c
##############################################################
To subscribe/unsubscribe, send a message to [log in to unmask] with following text in
the body:
To subscribe: SUBSCRIBE TECHNET <your full name>
To unsubscribe: SIGNOFF TECHNET
##############################################################
Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional
information.
If you need assistance - contact Gayatri Sardeshpande at [log in to unmask] or
847-509-9700 ext.5365
##############################################################
|
|
|