Perhaps the B version has a barrier layer to prevent excess leaching of the end metallization? You may be getting warm. Suspect solderability. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Becerra Alejandro Sent: Tuesday, December 03, 2002 9:10 AM To: [log in to unmask] Subject: Re: [TN] Tombstoning Film Chip Capacitor Russell, We're using the (B) version, reviewing this information in the web I found that the (X) version is recommended for reflow only and (B) for Wave and Reflow. Do you know what is the difference in construction between (B) and (X) versions? I would suggest change the version and footprint. Regards Alejandro Becerra -----Original Message----- From: Nowland, Russell Howard (Russell) [mailto:[log in to unmask]] Sent: Tuesday, December 03, 2002 7:04 AM To: 'TechNet E-Mail Forum.'; Becerra Alejandro Subject: RE: [TN] Tombstoning Film Chip Capacitor Alejando, I had the same problem with the Panasonic ECHU family of thin film capacitors. I had 142 on my board so you can imagine my frustration. The problem is the polymer doesn't conduct heat therefore the part doesn't heat evenly. The part body also does not stand up to heat very well. During hand soldering you cannot apply much heat to the endcap or the body will melt. Also, if you are repairing an adjacent component you must be very careful because the body will easily melt. I don't like the parts but the circuit designers praise their functionality. I worked with Panasonic and found that a standard discrete footprint did not work with the part. I even ran a test vehicle that Panasonic provided to prove that the footprint is the biggest contributor to the phenomena. They also came out with an improved endcap on the part but they gave it a new suffix. The original version was the (C) and the new version has a (X) i.e. ECHU1H152JX5. Using the (X) version improved the solderability marginally. We then changed to their recommended footprint, which is in there datasheet, and the problem went away. There footprint is not much bigger than the endcap on the part. It is not what I would design but it works. We did not play with the solderpaste composition by adding 2% silver so, I do not know how much that will help. Here is the link to the Panasonic (X) version part. http://www.panasonic.com/industrial/components/pdf/ef029_echu_x_dne.pdf Good luck, Russell Nowland Lucent Technologies Oklahoma City Works Phone: (405) 782-7765 Fax: (405) 782-7905 email: [log in to unmask] -----Original Message----- From: Becerra Alejandro [mailto:[log in to unmask]] Sent: Monday, December 02, 2002 7:24 PM To: [log in to unmask] Subject: [TN] Tombstoning Film Chip Capacitor Hello to All, We have had tombstoning in a Film Chip Capacitor (Size 1206). It is being soldered in a normal reflow process, and this is the only component that it is showing tombstoning. Reviewing the specs. of the component in the web I found that this capacitor is recommended for Wave Soldering. Does anyone know the difference in construction between the Capacitors for Reflow and Wave Soldering? Is it possible that this be cause for the tombstoning? I am also sending pictures for cross section for the capacitors that we are using (Recommended for Wave Soldering). They could be seen at Steve's site. Regards Alejandro Becerra --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------