TECHNET Archives

May 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
Received:
by ipc.org (Smail3.1.28.1 #2) id m0wPSlx-000BisC; Thu, 8 May 97 07:58 CDT
Content-Type:
text/plain; charset=iso-8859-1
Old-Return-Path:
Date:
Thu, 08 May 1997 09:02:56 -0400
Precedence:
list
Reply-To:
From [log in to unmask] Thu May 8 08:
54:40 1997
Message-ID:
MIME-Version:
1.0
Status:
O
X-Mailing-List:
<[log in to unmask]> archive/latest/12523
TO:
X-Status:
Return-Path:
<TechNet-request>
X-Loop:
Resent-From:
References:
Content-Transfer-Encoding:
8bit
Resent-Message-ID:
<"L_82j1.0.pPA.atSSp"@ipc>
Subject:
From:
[log in to unmask] (Doug McKean)
X-Mailer:
Mozilla 3.01 (Win95; I)
Resent-Sender:
TechNet-request [log in to unmask]
Organization:
Paragon Networks Int'l
>From bergdi Thu May 8 07:
58:30 1997
Parts/Attachments:
text/plain (58 lines)
Vitor José Parreira Chatinho wrote:
> 
> Could someone help me finding suitable reliability test methods or standards for reliability characterization of electronic/system assemblies ?
> 
> I've heard of Mil-hdbk-217, but this is used for reliability prediction (from design) and not for reliability evaluation of the assembly.
> 
> Thank you in advance for anyone willing to answer.

Hello Vitor, 

Yes, you might want to try 

     Bellcore TR-332, Issue 5, December 1995. 

It is used to determine the overall FITs/MTBF 
rating of an assembly. 

Try - 

     Bellcore
     Customer Service
     60 New England Avenue
     DSC 1B-252
     Piscataway, NJ 08854-4196
     Tel: 1-800-521-2673

Or their website  

     http://www.bellcore.com/ 

As to FITs. 
A FIT = 1 is 1 failure in 1 billion hours. 
Obviously a higher FIT number means a less reliable part. 

MTBF and FITs are related by  MTBF = [1/FIT]*10^9 

Bellcore 322 gives a standard set of FITs for all sorts of 
components. The semiconductor stuff you'll have to try to 
dig out of the mfrs by way of gate count or the FIT itself. 

If you're using accelerated temp testing to confirm this, 
don't pick a particular activation energy for a semiconductor 
to use in the Arrenhius relation. You'll have to come up with 
that emprically. 

Regards, Doug

***************************************************************************
* 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