TECHNET Archives

June 1997

TechNet@IPC.ORG

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

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

Print Reply
>From bergdi Tue Jun 3 22:
40:37 1997
Old-Return-Path:
Date:
Tue, 03 Jun 1997 20:07:00 -0700
Precedence:
list
Resent-From:
From [log in to unmask] Wed Jun 4 08:
46:29 1997
Cc:
"Gary_Willard-G10982" <[log in to unmask]>
X-Status:
Status:
O
X-Mailing-List:
<[log in to unmask]> archive/latest/13133
TO:
"TechNet" <[log in to unmask]>, "Dennis Ostendorf" <[log in to unmask]>
Return-Path:
<TechNet-request>
Resent-Message-ID:
<"pH1rG1.0.W98.ZEEbp"@ipc>
Subject:
From:
"Duane B. Mahnke" <[log in to unmask]>
Received:
by ipc.org (Smail3.1.28.1 #2) id m0wZ6vs-000BjGC; Tue, 3 Jun 97 22:40 CDT
X-Loop:
Message-ID:
Resent-Sender:
TechNet-request [log in to unmask]
Parts/Attachments:
text/plain (140 lines)
     The term "dentritic growth" is becoming more synonymous with 85 C /85 
     RH electrical testing. Some refer to it as "hydrolytic stability" as 
     well. This results in basically "shorts" in systems with tight 
     spacings and high voltages. The limiting factors really become the 
     substrate and covercoat types, as the minimum spacing at 100 volts to 
     be acceptable will depend on which combinations of materials are used. 
     Not all materials are equivalent!!!  See recent proceedings from May 
     '96 IPC meeting in Phoenix.


______________________________ Reply Separator
_________________________________
Subject: DES: Track spacing for 100V on internal layers -Reply
Author:  "Dennis Ostendorf" <[log in to unmask]> at -FABRIK/Internet
Date:    6/2/97 8:50 AM


From: Dennis Ostendorf
Date: Mon, Jun 2, 1997 8:50 AM
Subject: DES: Track spacing for 100V on internal layers -Reply 
To: Duane B. Mahnke; TechNet
Cc: Gary_Willard-G10982
Gary,
     
You should not have a problem with .015 inch spacing for 100V (unless 
you have contaminant(s) between the traces).  In fact, I believe the 
spacing is conservative & could be reduced.
     
     
Dennis Ostendorf
aaeee2o @snds.com
     
     
>>> Gary Willard-G10982
<[log in to unmask]> 06/02/97 
06:15am >>>
     
     
        Hello All
     
        I am in need of some input on a design issue relating to track 
        spacing for 100V operation for the internal layers of a 4-layer 
        PCB.
     
        This PCB is 2.0mm thick with a 1mm core and 35um copper. This
     
        design has to withstand 85% humidity / 85deg temperature testing
     
        for 500 Hours some of which is under 'power-up' conditions.
     
        The current design has an epoxy based solder mask and conformal
     
        coating and has an internal spacing of .015", which I believe 
        should be adequate as IPC-D-275 suggests a spacing of only 
        .004-.008" for class 3 assemblies, this figure of .015" has been 
        put to question so I am seeking further input.
     
        my questions are:-
     
1)      What does class 3 mean in terms of general environmental testing
     
        and in particular 85/85 testing.
     
2)      Does any body have practical knowledge of what a 'better 
spacing'
        may be.
     
        Any input would be most appreciated.
     
        Regards  Gary Willard  -  Substrate Design Engineer
                                  Motorola (UK)
     
*************************************************************************** 
* TechNet mail list is provided as a service by IPC using SmartList v3.05 * 
*************************************************************************** 
* To subscribe/unsubscribe send a message <to:
[log in to unmask]>   *
* with <subject: subscribe/unsubscribe> and no text in the body.          * 
*************************************************************************** 
* If you are having a problem with the IPC TechNet forum please contact
*
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]      * 
***************************************************************************
     
     
*************************************************************************** 
* TechNet mail list is provided as a service by IPC using SmartList v3.05 * 
*************************************************************************** 
* To subscribe/unsubscribe send a message <to: [log in to unmask]>   * 
* with <subject: subscribe/unsubscribe> and no text in the body.          * 
*************************************************************************** 
* If you are having a problem with the IPC TechNet forum please contact   * 
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]      * 
***************************************************************************
     
     
----------
Received: from vanness6.fabrik.com by post.fabrik.com
        with SMTP (Fabrik F07.0-000)
        id [log in to unmask] ; Mon, 2 Jun 1997 08:54:48 -0700
Received: from kani.wwa.com ([198.49.174.58]) by vanness6.fabrik.com
          (post.office MTA v2.0 0813 ID# 0-0U10) with SMTP id AAA84 
          for <[log in to unmask]>;
          Mon, 2 Jun 1997 08:54:14 -0700
Received: from ipc.org/ipc.ipc.org [209.42.29.23] by kani.wwa.com with smtp
        (Smail3.2.WWA) id m0wYZPb-003rjdC; Mon, 2 Jun 1997 10:53:54 -0500 (CDT)
Received: by ipc.org (Smail3.1.28.1 #2)
        id m0wYZG4-000BjbC; Mon, 2 Jun 97 10:42 CDT
Resent-Sender: TechNet-request
Old-Return-Path: <[log in to unmask]> 
Message-Id: <[log in to unmask]> 
X-Mailer: Novell GroupWise 4.1
Date: Mon, 02 Jun 1997 10:50:55 -0500
From: Dennis Ostendorf <[log in to unmask]> 
To: [log in to unmask]
Cc: [log in to unmask]
Subject: DES: Track spacing for 100V on internal layers -Reply 
Mime-Version: 1.0
Content-Type: text/plain
Content-Disposition: inline
Resent-Message-ID: <"XNnt-.0.XQI.pdkap"@ipc> 
Resent-From: [log in to unmask]
X-Mailing-List: <[log in to unmask]> archive/latest/13095 
X-Loop: [log in to unmask]
Precedence: list
Resent-Sender: [log in to unmask]
     
----------

***************************************************************************
* TechNet mail list is provided as a service by IPC using SmartList v3.05 *
***************************************************************************
* To subscribe/unsubscribe send a message <to: [log in to unmask]>   *
* with <subject: subscribe/unsubscribe> and no text in the body.          *
***************************************************************************
* If you are having a problem with the IPC TechNet forum please contact   *
* Dmitriy Sklyar at 847-509-9700 ext. 311 or email at [log in to unmask]      *
***************************************************************************


ATOM RSS1 RSS2