TECHNET Archives

April 2008

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:
Leland Woodall <[log in to unmask]>
Reply To:
TechNet E-Mail Forum <[log in to unmask]>, Leland Woodall <[log in to unmask]>
Date:
Thu, 24 Apr 2008 10:40:58 -0400
Content-Type:
text/plain
Parts/Attachments:
text/plain (187 lines)
Murata has not provided us with that bit of information.  They will only
tell us that we're not to exceed 275 degrees C for a maximum of 4
seconds.

We've ran experiments at much higher temps and exposure times and have
yet to destroy a component.  That's why it's so hard for me to believe
that our standard repair process is responsible for the failure...

Leland

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Honsowetz, Eric
Sent: Thursday, April 24, 2008 10:13 AM
To: [log in to unmask]
Subject: Re: [TN] Crystal Damage Question - Failure Mode

Just wondering what temperature would the crystal withstand before it
depolarized...?  Perhaps Murata could provide this information.

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Stadem, Richard D.
Sent: Tuesday, April 22, 2008 1:50 PM
To: [log in to unmask]
Subject: Re: [TN] Crystal Damage Question - Failure Mode

If the original rework was due to an electrical test failure such as
would be seen if some other component failed, the crystal may have been
electrically overstressed. In that case, the assembly may still contain
the issue that caused this to happen. The rework may have been
incidental, but possibly the voltage or current overstress is what
caused the original component to fail, not necessarily the heat from the
rework. You may wish to check the assembly to see if a wrong value cap
or resistor was installed in the same (driver) circuit as the crystal
location that was replaced and failed again.

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Leland Woodall
Sent: Tuesday, April 22, 2008 12:26 PM
To: [log in to unmask]
Subject: Re: [TN] Crystal Damage Question - Failure Mode

Folks,

I just went over the vendor's analysis report.  In it, we were told
that:

"The crystal failed to oscillate in the initial check.  The
impedance-phase characteristics were checked, and we confirmed the
impedance response was small due to the anti-resonant point being close
to the resonant point.  We confirmed that the piezoelectric
characteristics became bad, and such were caused by depolarization.
This can be caused by the application of excessive heat.  Had this
condition been present before shipment, our electrical characteristics
sorting process would have been rejected this component, so we think the
failure was caused after shipping from Murata."

That's all the info I have.

Thanks again for your help.

Leland 


-----Original Message-----
From: Stadem, Richard D. [mailto:[log in to unmask]]
Sent: Tuesday, April 22, 2008 12:26 PM
To: TechNet E-Mail Forum; Leland Woodall
Subject: RE: [TN] Crystal Damage Question

Was the crystal open, exhibiting wrong frequency, shorted, or what? Was
there any test analysis/troubleshooting data?
We need that in order to hazard a guess as to how the rework may have
affected the part or suggest a failure analysis strategy. 

-----Original Message-----
From: TechNet [mailto:[log in to unmask]] On Behalf Of Leland Woodall
Sent: Tuesday, April 22, 2008 10:16 AM
To: [log in to unmask]
Subject: [TN] Crystal Damage Question

Technetters,

We recently had a Murata SMD crystal to cause a failure in the field.
This particular unit had been to Repair and the component was manually
replaced during the manufacturing process.

The vendor analysis reported the component saw excessive heat during the
rework and caused internal depolarization which led to failure.

We made 10 attempts to re-create this condition and were unsuccessful in
doing so.  We used dual soldering irons, had the temps cranked as far as
they would go, and gave them excessive exposure times.

Could the vendor analysis have been incorrect, or was their explanation
a real possibility?

Why were we not able to replicate this?

Thanks in advance,

Leland

---------------------------------------------------
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
-----------------------------------------------------

---------------------------------------------------
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
-----------------------------------------------------

---------------------------------------------------
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
-----------------------------------------------------

**********************
** LEGAL DISCLAIMER **
**********************

This E-mail message and any attachments may contain 
legally privileged, confidential or proprietary 
information. If you are not the intended recipient(s),
or the employee or agent responsible for delivery of 
this message to the intended recipient(s), you are 
hereby notified that any dissemination, distribution 
or copying of this E-mail message is strictly 
prohibited. If you have received this message in 
error, please immediately notify the sender and 
delete this E-mail message from your computer.

---------------------------------------------------
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
-----------------------------------------------------

---------------------------------------------------
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