TECHNET Archives

September 2006

TechNet@IPC.ORG

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

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

Print Reply
Subject:
From:
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, [log in to unmask]
Date:
Wed, 13 Sep 2006 15:21:16 -0400
Content-Type:
text/plain
Parts/Attachments:
text/plain (105 lines)
Tom,

     You picked up on an obvious issue....the lithium battery temp
limits.  You'll need to check temp specifications for all the components
on the board to find out what the design temp limits for the board will
be.  A common temperature range for board Environmental Stress
Screen(ESS) would be -10C to +70C, special case component population
withstanding(lithium battery).

     In order to determine your board temp stress limits you'll need to
know what the objective of testing will be....infant mortality issues,
board process validation, board design/functionality verification,
Highly Accelerated Life Test(HALT)?  

     Since the customer is asking for a specific temperature range and
electrical test to be completed after stress, you should be sure none of
the product components storage temp specs are beyond the temp the
customer wants.  Hopefully they did that homework but anyone who has
seen a lithium battery go up in flames would understand your concerns to
double check the specs.

     Time of temp stress should be at least long enough to get the board
to the stress temp or into a valid soak and based on board process
specs.  Some board processes can take cold with no issues while other
board processes will develop cracked vias at cold.  Too much time at
heat can cause board delamination.  Ideally you should perform a
destructive level test on a small board sample to determine limit
baseline after you think you have the right temp limits/time picked.

     The customer is not asking for electrical test during temp stress,
so it seems as though they are looking more for process related issues
than design related issues.  

     The product stress field is kinda like black magic and you almost
have to develop a feel based on stress test experience.  Just thought
I'd trow in my two cents.  Hope all goes well for you.

Barrie Fraley
EMC Corporation
Engineering HWQA
Electrical DVT/HALT
1-508-249-4472

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Tom Parkinson
Sent: Wednesday, September 13, 2006 2:38 PM
To: [log in to unmask]
Subject: [TN] Temp Testing

Hello DN & TN people

We have a customer that wants us to thermally stress a completed PC
assembly
(all the SMT & THT parts are soldered in).

The question comes up as to the temp range and time.

They are suggesting:  
Room temp to +150F to -40F to room temp.
I'm concerned because of the populated parts (one is a lithium battery).
Not
to mention I have no idea on the time periods from extreme to room temp.

Following this test, an electrical test would be performed.

Any suggestions / Comments??

Thanks

Tom



Tom Parkinson 
Quality System Manager - CIT
WinTronics, Inc.
Phone: 724-981-5770 - extension 235

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text
in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to
[log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to
[log in to unmask]: SET Technet Digest
Search the archives of previous posts at:
http://listserv.ipc.org/archives
Please visit IPC web site
http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional
information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100
ext.2815
-----------------------------------------------------

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 1.8e
To unsubscribe, send a message to [log in to unmask] with following text in
the BODY (NOT the subject field): SIGNOFF Technet
To temporarily halt or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL)
To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest
Search the archives of previous posts at: http://listserv.ipc.org/archives
Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815
-----------------------------------------------------

ATOM RSS1 RSS2