Differences in Parts Classes

Process Wafer Fabrication	Grade 1 Class S QML V	Grade 2, Jan Class B, QML Q	Grade 3 883B	Grade 4 Commercial	Comments
Agency Team Certification of Plant and Operators	Yes	Yes	No	No	Does Fab meet good engineering practices. Is same fab (or contract fab)?
Baselined Process Flow	Yes	Yes	No	No	Vendor’s 883B flow may change as frequently as they want/need. No JPL control.
Traceability of Baseline Changes	Yes	Yes	No	No	883B = As long as meets data sheet, no explanation required; and Data sheet can change at will.
Number of Wafer Runs in lot	1	No longer controlled (but only from certified fab)			883B may use as many as they want, from different fabrication facilities, domestic or foreign - and mix together, change at will. Major radiation and DPA concern!
Wafer Lot Acceptance	Yes	No	No	No	B product, wafer thickness, metal thickness, glass thickness, gold backing thickness, and thermal stability not monitored. These were "early" indicators of ionic contamination, latent failures, etc.
Wafer Rework Control	Yes	Yes	Not controlled	No	A concern for homogeneity and radiation hardness assurance
Wafer Bonusing Controlled	Yes	No	No	No	A concern for homogeneity and radiation hardness assurance

Assembly	Grade 1 Class S QML V	Grade 2, Jan Class B, QML Q	Grade 3 883B	Grade 4 Commercial	Comments
Agency Team Certification of Plant and Operators	Yes	Yes	No	No	883B Assembles to internal controls, changes when they desire, contracts assembly out to cost effective sources, worldwide and mixes lots
Internal Visual Inspection	Yes Cond. A	Yes Cond. B	No=Mil Spec Yes=Internal Vendor Spec	Not done	Rejects to Grade 2 (Cond B) Parts are acceptable to 883B flow.
Tightened Lot Control (MIL-STD-976)	1				883B allows for multiple operators/machines, contract to outside assembly houses [uncertified: foreign or domestic]
Destructive Die Shear Monitor	2 hours	4 hours	No	No	883B = Vendor spec
Destructive Bond Pull Monitor	2 hours	4 hours	No	No	883B = Vendor spec
Non Destructive Bond Pull	Yes	No	No	No	Early indicator of bonding problems prior to seal/burn-in temperatures. (Commercial product uses gold wire on aluminum metalization). New bonders have NDBP built in.

Screening	Grade 1 Class S QML V	Grade 2, Jan Class B, QML Q	Grade 3 883B	Grade 4 Commercial	Comments
Agency Team Certification of Plant and Operators	Yes	Yes	No	No	883B may change electricals, burn-in boards, testers, handlers, etc. at will. Screening can be contracted out to lower cost outside and foreign screening house and mixed.
Electrical Subgroup 1-12 Tested	Yes	No	No	No	S only includes read and record, Slash Sheet vs. advertised data sheet
Extended Burn-In (Dynamic, 240 hours)	Yes	No	No	None	883B = Control of BI Board configuration may be changed at will.
100% PIND Test	Yes	No	No	No	Particles are a concern in Space hardware.
PDA	5%	10%	Some	No	Reject lots from Class S are acceptable for B.
Attributes Data	Yes	Yes	Yes	No
Variable Data (Read/Record)	Yes	No	No	No	S only
Failure Analysis Requirements	Yes	No	No	No	S only

Qualification	Grade 1 Class S QML V	Grade 2, Jan Class B, QML Q	Grade 3 883B	Grade 4 Commercial	Comments
Agency Team Certification of Plant and Operators	Yes	Yes	No	No	883B Qualification can be conducted by foreign or domestic contract house, to published or changed electricals, vendor’s life test burn in boards.
Frequency of 1000 hour Life test	Yes (every lot)	12 months	12 months	None	S = on every lot, Class B & 883B = may be completed by outside contractor, and may be completed on a "similar device". May be several years between actual qualification. < /FONT > < /FONT > < /FONT >
Frequency of Package Qual	6 months	12 months	12 months	None	883B = May be completed by outside contractor.