We design our pads (using nominal component dimensions) to be:

    1.) Pad extension beyond toe = .025"
    2.) Pad extension beyond heel = .025"
    3.) Pad width to allow .010" between pads with a .005" soldermask dam

Bob Trinnes
Rockwell Automation
_______________________________________________________________________________
Subject: Top of pad measurements
From:    [log in to unmask] at Internet
Date:    12/11/95  2:36 PM

     
     I am conducting a survey to determine what is the typical 
     configuration of 20 (19.7) mil pitch surface mount pads.
     
     The questions:
        1) What is the typical bottom of pad measurement & requirement?
        2) What is the associated top of pad measurement & requirement?
        3) What dimension is the artwork plotted for the pad?
        4) Do these pads have soldermask webs (dams) between them? What     
           size is web and what is the spacing (web to pad) on the artwork?
     
     Any additional help and information would be appreciated.


Received: by ccmail from miso.wwa.com
>From [log in to unmask]
X-Envelope-From: [log in to unmask]
Received: from ipc by miso.wwa.com with uucp
    (Smail3.1.29.1 #2) id m0tPbmb-000YYFC; Tue, 12 Dec 95 14:58 CST
Received: by ipc.org (Smail3.1.28.1 #2)
    id m0tPY7f-0000SIC; Tue, 12 Dec 95 11:04 CST
Old-Return-Path: <miso!zycon.com!sbryan>
Date: Mon, 11 Dec 95 14:36:13 PST
From: "sbryan" <[log in to unmask]>
Message-Id: <[log in to unmask]>
To: [log in to unmask]
Subject: Top of pad measurements
Resent-Message-ID: <"SkJua1.0.TYE.AORpm"@ipc>
Resent-From: [log in to unmask]
X-Mailing-List: <[log in to unmask]> archive/latest/2037
X-Loop: [log in to unmask]
Precedence: list
Resent-Sender: [log in to unmask]