Received: |
by ipc.org (Smail3.1.28.1 #2)
id m0uGnKD-0000CqC; Tue, 7 May 96 09:01 CDT |
Old-Return-Path: |
|
Date: |
Tue, 7 May 1996 07:07:15 -0700 |
Precedence: |
list |
Resent-From: |
|
Resent-Sender: |
|
X-Status: |
|
Status: |
O |
X-Mailing-List: |
|
From [log in to unmask] Wed May 15 16: |
38:17 1996 |
TO: |
|
Return-Path: |
<DesignerCouncil-request> |
Resent-Message-ID: |
<"_TnT-.0.Z5F.eUrZn"@ipc> |
Subject: |
|
From: |
|
X-Loop: |
|
Cc: |
|
Message-Id: |
|
Parts/Attachments: |
|
|
Tom Kavendek writes:
>
> On Board Fiducials:
>
> Quick guidelines we use -
> 1. Place them in all four corners of board. At least 2 diagonally.
> 2. There are light fiducials or dark fiducials -
> Light fiducial is 50 mil pad (typically used) with a 20 mil min.
> non-interference area (via and etch keepout)
> Dark fiducial is a "donut shape" where the "hole" of the donut
> is 50 mils and the "donut" is 20 mils.
> 3. Brd Fiducials should be placed on both top and bottom of the board.
> 4. Fiducials should not be covered with soldermask. ( 100 mil opening min.)
Tom,
My feeling is whatever works for you is right, but there is a "Fiducial Mark
Standard" available from SMEMA (Surface Mount Equip Manufacturers Assn.)
Their address is:
SMEMA
4113 Barberry Drive
Lafayette Hill, PA 19444
Ph.(215)825-1008 Fax: (215)941-6773
I've got the standard from 1991. I'd be happy to fax a copy to anyone (up to
a reasonable amount) who needs one and can't wait for SMEMA to send one. It's
always worked for me and I have, on occassion, talked the board house into using
this as the fiducial requirement.
Good Luck,
Mitch Morey
Sr. PCB Designer
TRW, Inc.
Redondo Beach, CA 90278
Phone: (310)814-5765
Fax: (310)812-4949
EMAIL: [log in to unmask]
|||||
((o o))
____________________________oOO_(_)_OOo_____________________________
PCB layout is like fine art. You have to DIE to be famous!
____________________________________________________________________
(_) (_)
|
|
|