In that case it's not for Thieving, but for copper balance to keep the layers
flat. Since we require ground stitch vias on our test boards and backplanes,
we have them perform a dual-purpose and place oversized square pads on them.
Scott McMorrow, CTO Signal Integrity Group
Samtec
Office 401-284-1827 | +1-800-726-8329
www.samtec.com
-----Original Message-----
From: Havermann, Gert [mailto:Gert.Havermann@xxxxxxxxxxx] ;
Sent: Friday, November 17, 2017 2:52 AM
To: leeritchey@xxxxxxxxxxxxx; CurtM@xxxxxxxxxxx; Scott McMorrow
<Scott@xxxxxxxxxxxxx>; w.maichen@xxxxxxx; riaziabe@xxxxxxxxx;
alexander.ippich@xxxxxxxxxxxxxxx
Cc: 'si-list' <si-list@xxxxxxxxxxxxx>; si-list-bounce@xxxxxxxxxxxxx
Subject: RE: [SI-LIST] Re: Thieving Article
Lee,
we do it on every second Backplane Design because we have to (production
yield). And the Backplane PCB supplier really always asks for thieving on inner
and outer layers. And as I said, it's mainly a backplane issue where you have
Layers with less than 2% copper fill.
BR
Gert
----------------------------------------
HARTING AG & Co. KG, Postfach 11 33, 32325 Espelkamp; Marienwerderstraße 3,
32339 Espelkamp Generalbevollmächtigte Gesellschafterin: Dipl.-Hdl. Margrit
Harting Persönlich haftende Gesellschafterin: HARTING WiMa AG (Luxemburg) & Co.
KG; Amtsgericht Bad Oeynhausen; HRA 8259; persönlich haftende Gesellschafterin:
HARTING Führungs AG (Registre de Commerce et des Sociétés Luxembourg), B
170749, Luxemburg
Vorstand: Dipl.-Kfm. Philip F. W. Harting (Vorsitzender), Dipl.-Kffr. Maresa W.
M. Harting-Hertz, Dipl.-Kfm. Dr.-Ing. E. h. Dietmar Harting, Dr. rer. nat.
Frank Brode, Dipl.-Ing. (FH), Dipl.-Wirtsch.-Ing. (FH) Andreas Conrad, Dr. iur.
Michael Pütz; Sitz der Gesellschaft: Espelkamp; Amtsgericht Bad Oeynhausen; HRA
9021; UST-ld Nr. DE812136745
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Lee Ritchey
Sent: Thursday, November 16, 2017 6:58 PM
To: CurtM@xxxxxxxxxxx; Scott@xxxxxxxxxxxxx; w.maichen@xxxxxxx;
riaziabe@xxxxxxxxx; alexander.ippich@xxxxxxxxxxxxxxx
Cc: 'si-list' <si-list@xxxxxxxxxxxxx>; si-list-bounce@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: Thieving Article
I have not seen thieving added to inner layers.
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Curt McNamara
Sent: Thursday, November 16, 2017 8:36 AM
To: Scott@xxxxxxxxxxxxx; w.maichen@xxxxxxx; riaziabe@xxxxxxxxx;
alexander.ippich@xxxxxxxxxxxxxxx
Cc: leeritchey@xxxxxxxxxxxxx; si-list <si-list@xxxxxxxxxxxxx>;
si-list-bounce@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: Thieving Article
Great points. Thieving is commonly added (to both external and internal
layers) to increase yield.
Here is an IPC article that mentions this along with other best practice
recommendations.
Curt
http://ipc-rtp.org/past_files/A-Z__2013_IPC_RTP.pdf
________________________________
From: si-list-bounce@xxxxxxxxxxxxx <si-list-bounce@xxxxxxxxxxxxx> on behalf of
Alexander Ippich <alexander.ippich@xxxxxxxxxxxxxxx>
Sent: Thursday, November 16, 2017 10:27:19 AM
To: Scott@xxxxxxxxxxxxx; w.maichen@xxxxxxx; riaziabe@xxxxxxxxx
Cc: leeritchey@xxxxxxxxxxxxx; si-list; si-list-bounce@xxxxxxxxxxxxx; Alexander
Ippich
Subject: [SI-LIST] Re: Thieving Article
If I would have to get down to these fractions of cents, I would side with
Scott. However, the big influence is regarding manufacturability / yield.
That's why thieving is added.
Don't put it on, and you may find that the outerlayer design is to irregular to
get the plating right (overplating isolated features), causing scrap.
Similar with thieving on innerlayers, this time protecting isolated features
from too aggressive etching.
So my point of view would be, that allowing your PCB supplier to add thieving
(don't forget to give them rules, as Lee has mentioned) is going to reduce
overall PCB cost. Probably not in the short run (cost models are most likely
not that detailed), but it can have an impact on yield and then on your ability
to negotiate cost reductions.
Best regards,
alex
----------------------------------------------------------------------------
------------------------------------------------------------
Alexander Ippich
Technical Director, Signal Integrity & Advanced Technology OEM Marketing Europe
e-mail: alexander.ippich@xxxxxxxxxxxxxxx
web: www.isola-group.com<http://www.isola-group.com>
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Scott McMorrow
Sent: Thursday, November 16, 2017 4:43 PM
To: w.maichen@xxxxxxx; riaziabe@xxxxxxxxx
Cc: leeritchey@xxxxxxxxxxxxx; si-list; si-list-bounce@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: Thieving Article
On the other side, there is less copper available for recycling. I'd guess it
is a push in terms of cost.
Scott McMorrow, CTO Signal Integrity Group Samtec Office 401-284-1827 |
+1-800-726-8329 www.samtec.com<http://www.samtec.com>
-----Original Message-----
From: si-list-bounce@xxxxxxxxxxxxx [mailto:si-list-bounce@xxxxxxxxxxxxx] On ;
Behalf Of Wolfgang Maichen
Sent: Thursday, November 16, 2017 10:38 AM
To: riaziabe@xxxxxxxxx
Cc: leeritchey@xxxxxxxxxxxxx; si-list <si-list@xxxxxxxxxxxxx>;
si-list-bounce@xxxxxxxxxxxxx
Subject: [SI-LIST] Re: Thieving Article
My guess would be that if anything it will result in slightly LOWER
manufacturing cost because you etch away less copper, thus consume less etchant.
From:Abe Riazi <riaziabe@xxxxxxxxx>
To:leeritchey@xxxxxxxxxxxxx
Cc:si-list <si-list@xxxxxxxxxxxxx>
Date:16.11.2017 16:35
Subject:[SI-LIST] Re: Thieving Article
Sent by:si-list-bounce@xxxxxxxxxxxxx
Hi Lee,
I reviewed your interesting article entitled "Thieving in Printed Circuit
Boards", and have two question:
1. Does thieving has any effect on "thermal" performance of the board ?
2. Does it increase the PCB manufacturing cost?
Thank you in advance for your response.
Abe
On Wed, Nov 15, 2017 at 3:13 PM, Lee Ritchey <leeritchey@xxxxxxxxxxxxx>
wrote:
I am often asked what the extra small dots are on the outer layers ofmany
dense PCBs. It is called thieving and I wrote an article explainingwhat
it is and why it is used. You can download a copy from our web site<http://www.speedingedge.com> .
www.speedingedge.com<http://www.speedingedge.com>
Lee Ritchey
Speeding Edge
P.O. Box 817
Bodega Bay, CA
94923
408-781-0253
I just used the energy it takes
To get mad and wrote some blues.
Count Basie
Or:
Worry is like a rocking chair,
It keeps you busy but.
It doesn't get you anywhere.
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