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

Vendorís 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, vendorís 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.