FITs (failures/billion hours) for tantalum capacitors as documented in Bellcore TR-332, Reliability Prediction Procedure for Electronic Equipment (Issue 6, December 1997) are very low. For solid, hermetic tantalum capacitors the FIT is 1.0 failure/billion hours (MTBF of 100,000,000 hours). For Solid, Non-Hermetic tantalum capacitors the FIT is 5 failues/billion hours (MTBF of 200,000,000 hours). For nonsolid tantalum capacitors the FIT is 7 failures/billion hours (MTBF of 142,857,142.9 hours).
The MIL-HDBK-217F, Notice 1 failure rates for tantalum capacitors varies on the environment in which they are used and whether the parts are MIL-SPEC or commercial. If your company does not have a copy of MIL-HDBK-217F, Notice 1, you can contact the Reliability Analysis Center which is located at Rome, NY. P.S. If anyone knows of a company(ies) that are looking for Reliability Engineers, please contact me at the following e-mail address. I am on a 6-month contract here at Samsung and my contract expires August 2, 1998. Thanks. Jon K. Ilseng Senior Reliability Engineer Samsung Telecommunications America Richardson, Texas 972-761-7438 Work Phone [email protected] > -----Original Message----- > From: [email protected] [SMTP:[email protected]] > Sent: Tuesday, June 30, 1998 10:09 AM > To: [email protected]; [email protected] > Subject: RE: Tantalum Capacitors > > The biggest drawback with tantalums is that their normal failure mode > is > a short circuit. I once spent a lot of time over a period of several > months trying to get MTBF figures from manufacturers, but had no > success. > > I finally decided to use tantalums in the design anyway, primarily > because of the real-estate savings. With the new low-voltage power > technology, they are used widely through out the computer industry. > So, > I figured that I was at least in good company. > > In the last year or so, in prototype systems, I haven't had any > failures > yet. There was one case where a half-dozen of them were reversed, > resulting in the predictable explosion, but the board wasn't damaged. > I > have seen boards previously that were damaged by tantalums, however. > > If you have an option, though, I would recommend electrolytics. > They're > like old soldiers; they never die, they just fade away. Another > option > is to use the new organic type of capacitor. As I recall (not sure) > Sanyo is the major supplier for these. > > Max Kelson > Evans & Sutherland > > -----Original Message----- > From: Brumbaugh, David [SMTP:[email protected]] > Sent: Tuesday, June 30, 1998 9:46 AM > To: 'emc-pstc' > Subject: Tantalum Capacitors > > Can anyone tell me if there are any drawbacks in using > tantalum capacitors in dc power supply filters? My recollection > is that they can "pop" if the voltage polarity is reversed, or > if > there are large negative voltage swings during transients. > > TIA, > > > David Brumbaugh > The BOEING Company > Information, Space & Defense Systems > Electromagnetic Effects > M/C 8H-11 > POB 3999 Seattle, WA 98124-2499 > Phone: Kent Space Center (253) 773-3733
