Hi Joe, This was an automotive electronic control unit that is mounted in the engine compartment, so yes, it did indeed see lots of wide thermal excursions. We haven't tried adding that variable to our re-creations, but I'm pretty certain you're correct in your message below. The part must have been working properly when it left our facility. We have three different electrical testing operations that will fail a unit when a crystal doesn't oscillate. I suppose we did damage the component during our repair, and the damage continued to propagate as the unit saw use. Thanks for your note. I'm thinking failure analysis is at least your second area of expertise! Leland -----Original Message----- From: Joe Russeau [mailto:[log in to unmask]] Sent: Thursday, April 24, 2008 2:15 PM To: TechNet E-Mail Forum; Leland Woodall Subject: Re: [TN] Crystal Damage Question - Failure Mode Hi Leland, First off this is not my area of expertise. However, you mentioned in your original post that this was a field return. Now, that being said, I don't recall anything about the end use environmental conditions being mentioned. So we don't know if this product was in a controlled or uncontrolled environment. Therefore, is it possible that the combination of excessive heat by rework may have been the mechanism to initiate the failure and the environment exacerbated the problem? Or is this a product that gets powered on and off regularly, where heating up and cooling off stressed the part resulting in the problem? The only reason that I ask is that you mention trying to recreate the issue, but you only mention in your other posts recreating the thermal exposure of the part. Seems to me that if the product made it into the field that there could be other factors that contributed and if you are only recreating one factor you may never reproduce the problem. Like I said, I'm not an expert in this area and/or perhaps I've just missed something along the way. Just my 2 cents. Best Regards, Joe Russeau Precision Analytical Laboratory, Inc. ----- Original Message ----- From: "Leland Woodall" <[log in to unmask]> To: <[log in to unmask]> Sent: Thursday, April 24, 2008 1:31 PM Subject: Re: [TN] Crystal Damage Question - Failure Mode Joyce, Our standard repair process has been to utilize a soldering iron temp at 370 degrees C, with a maximum exposure time of 5 seconds. We've probably repaired thousands at these settings, and this particular case was the first time we've seen a resultant depolarization condition (one which, by the way, we just can't seem to re-create). It seems kinda funny that now, all of a sudden, we're having to change our process for one single component... I guess we'll also need to go back and research a lot of other components to make certain we're operating within their suggested parameters. I assumed (yeah, I know that's a bad thing) that our parent facility had already done this. Oh well, guess you learn something new every day! Thanks for your input, Leland -----Original Message----- From: Joyce Koo [mailto:[log in to unmask]] Sent: Thursday, April 24, 2008 12:00 PM To: TechNet E-Mail Forum; Leland Woodall Subject: RE: [TN] Crystal Damage Question - Failure Mode Any particular reason you have to beyond the recommended temp? Normally, you try to stay within, or if not below the max temp. to avoid any damage. Single crystal at thermal shock temperature may result excessive dislocation network that can impact quality and reliability of the device. In addition, the combination of stress and temp may cause damage. As for standard repair process: Is it the same process you have used for this particular vendor part? If it is not, the "standard" does not apply to this part. If it is just this particular batch got this problem, your vendor is the one to blame... (the quality of the part is not the same as per your early design qualification). My almost 2 cents..jk -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Leland Woodall Sent: Thursday, April 24, 2008 10:41 AM To: [log in to unmask] Subject: Re: [TN] Crystal Damage Question - Failure Mode 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 ----------------------------------------------------- --------------------------------------------------------------------- This transmission (including any attachments) may contain confidential information, privileged material (including material protected by the solicitor-client or other applicable privileges), or constitute non-public information. Any use of this information by anyone other than the intended recipient is prohibited. If you have received this transmission in error, please immediately reply to the sender and delete this information from your system. Use, dissemination, distribution, or reproduction of this transmission by unintended recipients is not authorized and may be unlawful. --------------------------------------------------- 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 -----------------------------------------------------