APPLICATION NOTES FOR DSCC-DWG-87106

DSCC-DWG-87106 was officially CANCELED on January 5, 2005.  More robust, direct replacements are available from MIL-PRF-49470.  Quoting from DSCC Cancellation notice...

"MIL-PRF-49470 capacitors are preferred over DSCC 87106 capacitors. The MIL-PRF-49470 specification was developed as part of a cooperative effort between the US Military, NASA and the switch mode power supply capacitor manufacturers to produce a robust direct replacement for the DSCC drawing. The military specification product provides additional quality assurance provisions that are NOT required by the DSCC drawing. Two product levels are offered in MIL-PRF-49470: the standard "B" level and the high reliability "T" level. Some of the benefits of the MIL-PRF-49470 product over the 87106 product include: Formal qualification process (QPL established); MIL-STD-790 compliance; DSCC audits; routine qualification maintenance testing (ie. life testing); group A percent defective allowed (PDA) specified; prohibits mixing of chips from different production lots within a single SMPS capacitor stack lot. MIL-PRF-49470 "T" Level product is recommended for all high reliability applications. MIL-PRF-49470 "T" level product requires in-process inspections and additional group A and B screening inspections that are not part of the normal "B" level flow: In-process screening that includes non-destructive internal examination (chip level) and destructive physical analysis (chip level); group A destructive physical analysis (finished stack level); group B lot specific humidity, steady-state, low voltage (lot sample test); and group B lot specific thermal shock & life test (lot sample test)."

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1) When available MIL-PRF-49470 SMPS capacitors are preferred over DSCC-DWG-87106 capacitors. The MIL-PRF-49470 specification was developed as part of a cooperative effort amongst the US Military, NASA and the SMPS suppliers to produce a robust replacement for the DSCC drawing. The MIL spec product provides additional quality assurance provisions which are NOT required by the DSCC drawing. Some of the benefits of the MIL-PRF-49470 product over the DSCC-DWG-87106 product include:

Requirement	MIL-PRF-49470	DSCC-DWG-87106
Formal Qualification Process (QPL Established)	Yes	No
MIL-STD-790 Compliance	Yes	No
DSCC Audits	Yes	No
Routine Qualification Maintenance Testing (ie., Life Testing)	Yes	No
Group A Percent Defective Allowed (PDA) Specified	Yes	No
Prohibits Mixing of Chips from Different Production Lots within a Single SMPS Stack Lot	Yes	No

2) WARNING! All capacitance values offered by this DSCC drawing may not be available from all (or any) of the sources listed in the manufacturer column of the parts list tables. This drawing is not an Established Reliability specification and does not contain a Qualified Products List (QPL). Hence, some values (especially the higher cap values in a given voltage and case size) may not be available or may have very long lead times due to manufacturing complexity.

3) CAUTION! Designers must consider the geometry and relatively high mass of capacitors described by this drawing. Devices which are not mounted properly may be susceptible to damage, including lead shearing, in high vibration and shock environments. The taller stacks where the stack height exceeds the minimum base dimension are particularly at risk. Special mounting techniques may be necessary to ensure safe application in these environments. Consult the manufacturer or parts engineering for recommendations to avoid potential damage from misuse of straps, coefficient of thermal expansion mismatches, etc.

4) The maximum capacitance values in each case size in each voltage rating should be considered reliability suspect. Use of parts in this classification should be discouraged.

5) Capacitors described by this drawing are very susceptible to thermal shock damage due to their large mass of ceramic. Installation temperature profiles should provide adequate temperature rise and cool-down time to prevent damage from thermal shock.

6) Capacitors described by this drawing are fragile and should be handled with extreme care. Parts which have been dropped or mishandled should be considered suspect due to the risk of microcracking which may result in latent failures.