TECHNET Archives

September 2010

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:
Phil Bavaro <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, [log in to unmask]
Date:
Wed, 22 Sep 2010 08:13:11 -0700
Content-Type:
text/plain
Parts/Attachments:
text/plain (57 lines)
I have a process where a metal backed PWA is being put on a hot plate in
order to preheat the assembly high enough (140 C) so that a soldering
iron can be used to solder (2-5 seconds) hand installed parts as well as
to touch up any reflow defects.

One customer has raised questions relative to the hot plate temperature
overstressing the devices due to the extended time necessary to solder
all the devices.   Subsequently all the Storage and Operating
temperatures for the components needed to be presented.

Across all of the devices, Storage Temperature maximum is either 150 C
or 200 C.

The Operating temperature rating for most of the devices is below 140 C
(70, 125, 150).

One can see how there might be some concern incorrectly focused on the
assembly soldering temperatures violating this parameter.

I know that soldering requires temperatures which exceed the operating
and storage temperature rating ranges for our components, but how do I
explain this to a customer who is asking such questions about the
assembly soldering process.

Certainly I can show the typical reflow curves listed by the SMT device
manufacturer's, but since this application is post reflow hand solder,
the manufacturer's don't have recommended hand soldering profiles to
show the customer.  And certainly the preheated cycles are not reflected
in a device curves.

Any comments are welcome.


Phil


------------------------------------------------------------------------------
This message and any attachments are solely for the use of the addressee and may contain L-3 proprietary information that may also be defined as USG export controlled technical data. If you are not the intended recipient, any disclosure, use or distribution of its content is prohibited. Please notify the sender by reply e-mail and immediately delete this message and any attachments.




______________________________________________________________________
This email has been scanned by the MessageLabs Email Security System.
For more information please contact helpdesk at x2960 or [log in to unmask] 
______________________________________________________________________

---------------------------------------------------
Technet Mail List provided as a service by IPC using LISTSERV 15.0
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