JPL’s Commercial Off-The-Shelf (COTS) Program A Step Towards Infusion of Reliable COTS Plastic Parts in NASA Flight Hardware Mike Sandor & Shri Agarwal

JPL’s Commercial Off-The-Shelf (COTS) Program

A Step Towards Infusion of Reliable COTS Plastic Parts in NASA Flight Hardware

Mike Sandor & Shri Agarwal 4800 Oak Grove Drive

Pasadena, CA 91109 Phone: (818) 354-0681 FAX: (818) 393-4559

Military & Aerospace Applications of Programmable Devices and

Technologies ConferenceGoddard Space Flight Center

1998

JET PROPULSION LABORATORYElectronic Parts Engineering Office

The Meaning of COTS• “Buy and Fly”

• “Procuring via catalog part number to QML-V standards”

• “Procurement is performed without formal specification”

• “The usage of any COTS equipment does not constitute any waiver to fundamental applicable requirements”

COTS are parts whose specification is manufacturer-controlled as opposed to traditional “Hi-Rel”parts whose specification was Government or customer-controlled

JPL Interpretation:

Why Put COTS Plastic Parts in Space ?

1. The availability of COTS plastic parts is proliferating.

2. COTS plastic parts performance capabilities continue to increase (e.g. processing power & high density memories)

3. COTS plastic parts enable reduction of hardware weight and volume

4. COTS plastic parts typically cost much less than ceramic

5.COTS plastic parts have been reported to demonstrate good to excellent reliability in commercial and aerospace applications

6. Often they are the only option available to using state-of-the-art technologies



JPL’s Concerns About Using COTS Plastic Parts

• Reliability/RH of Plastic in Space Applications

• Process/Designs Change Frequently

• Lack of Lot Traceability & Uniformity

• Narrow Temperature Range for Commercial Grade

• Non Rad Hard Designed (maybe Rad Tolerant)


Assessment Options for COTS Plastic Parts & Their Relative Test Costs

• Temperature/ Humidity Corrosion ($)

• Temperature Cycling Assembly Defects ($$)

• Moisture Absorption Popcorning ($$)

• Radiation TID Degradation ($$$$)

• Outgassing Condensables ($)

• Glass Transition Epoxy Stability ($$)

• Delamination Voids/Stresses ($)

• Upscreening/Burn-in Performance/Reliability ($$$$)

• DPA Manufacturing Quality ($$)


Conclusion: Most if not all plastic parts will absorb moisture >> 0.1% weight gain.

Moisture Absorption at 85C/85% R.H. for 3 Different Plastic Packages

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 50 100 150 200 250 300 350 400

Time (hours)

We

igh

t G

ain

(%

)

AM28F020

CAT28F020P

DA28F016SV

Average

S.D.=1 with 5% Error

Reported to be a safe limit for reliability.

32 Ld

56 Ld SSOP


Note: Weight Gain (%) = (Wt-Wi)/Wi*100 Weight Loss (%) = (Wtd-Wi)/(Wf-Wi)*100

Moisture Absorption/Desorption for Intel 56 Ld SSOP Package

0.00000.05000.10000.15000.20000.25000.30000.35000.4000

0 55 116

261

521

531

555

624

857

1309

Time (hours)

Wei

gh

t G

ain

(%

)

Unit#1Unit#2Unit#3

85°C/85%RH

70°C Bake

100°C Bake

125°C Bake

Preconditioned @ 105°C for 10 days

Irreversible weight gain


Moisture Multiple Absorption Model for SCR265 (Plastic)

0.0000

0.5000

1.0000

1.5000

2.0000

2.5000

3.0000

3.5000

4.0000

0

48 96

144

194

242

290

338

386

434

482

530

578

626

674

722

770

818

866

914

962

1010

Time (hours)

Wei

gh

t G

ain

@ 8

5RH

/85C

(m

gs)

W1+W2+W3

W3(t)

W2(t)

W1(fast)

We @ Infinity

Empircal Data

W(t)=We(1-e-kt)

W1

W3W2


85%RH/85ºC Moisture Absorption Mechanisms for SCR265

W1(t): Fast Irreversible Weight Gain 24 hours (1mg)

W2(t): Intermediate Reversible Weight Gain, 80 to 140 hours

W3(t): Slowest Reversible Weight Gain, Reaches We @ t=SCR265 Package

Plastic Body Heat Sink

Leads (Pb/Sn) Plastic Flash

W1path

W3 path W2 path


Nickel Plated Heatsink Shows No Oxidation

Leads Show Extreme Oxidation W1(t)

Post 85%RH/85ºC for SCR265

Conclusion: Weight gain is solely attributed to oxidation of leads. The internal chip has miniscule Al area available for oxidation because of Cu intermetallic bonding to the Al.


Outgassing Test Flow for Plastic Packages

50% RH @ 25Cfor 24 hrs + Weighed

5x10-5 torr @ 125C for 24 hrs

Collect Condensables on CP (25C) CVCM

Cool & Dry Test Chamber

Weigh Specimen & CP for TML

50% RH @ 25C for 24 hrs + Weighed for

WVR

Ref: ASTM E595-93


Outgassing Results of Plastic Packages

MaterialMCR 7612382FBA, E24,

DA28F016SV, K8055, U6240332AM28F020-150PC, 9618FBB CSI, CAT28F020F, 1-15 09550B

Part Motorola SCR Intel 16 M Flash Memory AMD 2M Flash Memory Catalyst 2M Flash Memory

Sample No. 5 6 7 8 a 9 10 11 24

WT. Loss % 0.45 0.46 0.45 0.23 0.22 0.22 0.41 0.45 0.43 0.40 0.41 0.40

Water Vapor Recovered, WVR,

%

0.28 0.25 0.26 0.14 0.11 0.12 0.19 0.17 0.18 0.21 0.18 0.19

TML (WT, LOSS-WVR) %

0.17 0.21 0.19 0.09 0.11 0.10 0.22 0.28 0.25 0.19 0.23 0.21

CVCM % 0.04 0.08 0.06 0.02 0.01 0.01 0.03 0.05 0.04 0.04 0.04 0.04

DEPOSIT on CP Opaque Negligible Opaque Opaque

FTIR Results Amine cured epoxy Anhydride cured epoxy Amine cured epoxy Amine cured epoxy

Conclusion: All materials passed. These tests are suited for lot-to-lot comparisons, tracking manufacturing continuity/changes, and measuring absorbed moisture at a known environment.


M o is tu re A b s o rp tio n / B a k e fo rIn te l D A 2 8 F 0 1 6 S V in P la s tic P a c k a g e

(0 .6 m E T O X IV P r o cess T ech n o lo g y)C o n d it io n s : T e s t T e m p e ra tu re = 2 5 C , V d d = 5 .0 V , V p p = 5 .0 V

T ID R e s p o n s e o f In te l 1 6 M F la s h M e m o r y

0

1 0 0

2 0 0

3 0 0

4 0 0

5 0 0

6 0 0

7 0 0

0 4 8 1 0 1 2 1 6 1 8 2 0 2 2 2 4 2 6 2 8 3 0 3 2

T o ta l D o se (K ra d s)

Eras

e Ti

me

of 3

2 Bl

ocks

(sec

s)

s n 2

s n 8 0 7 1

s n 8 0 6 9

s n 8 0 7 2

s n 8 0 7 3

F ig u re 1 J e t P ro p u ls io n L a b o ra to ry E le c tro n ic P a r ts E n g in e e r in g O f f ic e 5 0 7

N o p re c o n d it io n in g , w o rs t c a se o b se rv e d . F a ile d to e ra se @ 2 4 K ra d s

8 5 C /8 5 % R H fo r 4 4h o u rs ( > 9 0 % sa tu ra t io n )

N o p re c o n d it io n in g ty p ic a l c a se .

1 0 0 C B a k e fo r 4 4 h o u rs . IC C D fa i le d @ 1 8 K ra d s . F u n c t io n a l @ 3 2 K ra d s .

S p e c = 6 0 se c s

In tr in s ic p a r t h a r d n ess

Dose rate = 25r/s

Radiation Results on Plastic Parts

COTS Plastic Infusion Baseline Flow


DPA C-SAM TEMP CYCLE

ELECTRICAL

ELECTRICAL

Burn-in ELECTRICAL

ASSEMBLE HARDWARE

IDENTIFY & REVIEW REQUIREMENTS

ASSEMBLY TEST

ASSEMBLY QUALIFICATION

FLIGHT READY

Part Level Screening

COST & TAILOR OBJECTIVES

In Summary


• Using COTS plastic parts without understanding their pedigree can lead to mission delay or worst Mission Failure

• A methodology is in place in Office 507 to help JPL users of plastic parts ascertain their risk and acceptance for Space Application

• Work is underway in Office 507 to evaluate all risk factors when using COTS plastic parts (quality, reliability, radiation,package). • JPL is currently infusing plastic parts into flight hardware utilizing

a Better-Faster-Cheaper Program tailored individually for each Project

Documents

JPL’s Commercial Off-The-Shelf (COTS) Program A Step Towards Infusion of Reliable COTS Plastic Parts in NASA Flight Hardware Mike Sandor & Shri Agarwal