Sweeping- and multi-frequency systems do not eliminate the problem, although they reduce the time that the resonance occurs; consequently, the makers claim that the weakening of the bonds is lessened. This would seem logical. I have not studied the structural strength of the bonds, but I feel that even a short exposure to resonance could work-harden the ends of the wire causing embrittlement. Perhaps a metallurgist could advise? My feeling is that it would be safer to apply the precautionary principle until scientific studies prove the contrary. Brian Charles Caswell wrote: > There are manuf. Of ultrasonic cleaning equipment that use a sweeped freq. > which is supposed to eliminate the resonance problem. I would search the > archives. > > -----Original Message----- > From: Blair K. Hogg [mailto:[log in to unmask]] > Sent: Monday, 18 April 2005 9:39 AM > To: [log in to unmask] > Subject: Re: [TN] Ultrasonics > > At a former employer we used resistor divider networks which had stamped > leads soldered to the component. The component was made from resistive ink > which was sliced in a serpentine pattern to create a high resistance. The > legs of the device had three prongs that would straddle the device in an > offset pattern. The manufacturer ultrasonically cleaned the parts after > soldering, which caused the stress areas in the stamped legs to develop > cracks and fail at a later date. Once the U/S cleaning was eliminated, the > problem disappeared. > > Blair > > >>>>[log in to unmask] 04/18/05 09:15AM >>> > > Technetters > > I seem to remember somewhere that ultrasonics shouldn't be used to clean > populated PCB's. I have believed this to be due to damage inflicted to the > wire bonds within IC's and Xtals. > > Is this the case can someone clarify what components (if any) cannot be > cleaned using ultrasonics? > > Cheers > > Mark > > > ******************************************************************* > This email and any files transmitted with it are confidential and > intended solely for the use of the individual or entity to whom they > are addressed. If you have received this email in error please notify > the system manager. > > This footnote also confirms that this email message has been swept > for the presence of computer viruses. > > www.hubbell.com - Hubbell Incorporated > > --------------------------------------------------- > 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 > ----------------------------------------------------- > --------------------------------------------------- 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 -----------------------------------------------------