This is great stuff. What are the ratios/concentration of the B-I solution. Is the part saturate with B.I solution at ambient, vacuum and/or pressure to force the solution into the crack, cavity. Victor, -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Guenter Grossmann Sent: Tuesday, June 06, 2006 6:00 AM To: [log in to unmask] Subject: Re: [TN] Antw: [TN] Finding cracked capacitors Victor Sure. The solution absorbs X- ray and penetrates readily in small cracks. However, it also penetrates underneath the component. This means that after applying the solution the entire capacitor looks pretty dark. We use the effect that the liquid evaporates easier from underneath the component than in the crack (does not work with hand soldered devices since in this case everything is blocked with flux residues and no B-I solution can penetrate into the crack). With other words, we apply the solution, start looking at the specimen as fast as possible and watch how the picture is getting brighter. Usually the solution in the crack stains the x- ray picture some seconds longer than the one underneath the components. Quite tricky and often we have to repeat the procedure to become confident about the results. And as I said we are not always successful. Mostly the 3 methods are used one after the other to get the puzzle together. Best regards Guenter EMPA Swiss Federal Laboratories for Materials Testing and Research Centre for Reliability Guenter Grossmann, Senior Engineer 8600 Duebendorf Switzerland Phone: xx41 1 823 4279 Fax : xx41 1 823 4054 mail: [log in to unmask] >>> [log in to unmask] 06.06.2006 12:44:58 >>> Can you elaborate some more on item 3 with the Boron-Iodine solved in methylene..... Victor, -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Guenter Grossmann Sent: Tuesday, June 06, 2006 2:42 AM To: [log in to unmask] Subject: [TN] Antw: [TN] Finding cracked capacitors Ioan We use 3 technologies to search cracks in ceramic caps: 1. Ultrasonic microscopy. Works pretty well if the cracks are not too close to the termination and if the structure of the caps is not too inhomogeneous. Otherwise you don't have a flat surface to couple the US into the component or the signal noise ratio ist too bad. 2. Infrared microscopy. Only applicable if you have a connecting path in the crack where you can pump some power though. I already thought once that using a penetrating material with a certain conductivity could help in this measurement but I didn't have the time to look at that in depth. 3. X- Ray. Works with a penetrating liquid that absorbs X-Rays(Boron- Iodine solved in methylene). However, you need to work with 100kV and a detector with a good energy resolution and whenever possible 12bit graphics since the ceramic of the caps is already absorbing a lot of the X- rays. Plus some tricks in handling. And its still not sure that we find the bastards. Best regards Guenter EMPA Swiss Federal Laboratories for Materials Testing and Research Centre for Reliability Guenter Grossmann, Senior Engineer 8600 Duebendorf Switzerland Phone: xx41 1 823 4279 Fax : xx41 1 823 4054 mail: [log in to unmask] >>> [log in to unmask] 05.06.2006 16:11:04 >>> Hi Technos, a never ending story, ceramic caps that crack, possibly due to depanelizing. The damage is not visible, unless the cap is cross sectioned. Is there any testing, thermal cycling or something like that, that could show the damage real fast? Thanks, Ioan --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------