G O D D A R D S P A C E F L I G H T C E N T E R Workmanship Requirements Compliance Jeannette Plante...

G O D D A R D S P A C E F L I G H T C E N T E R

Workmanship Requirements Compliance

Jeannette PlanteProject LeadBldg 32, Rm [email protected]

G O D D A R D S P A C E F L I G H T C E N T E R 2

Generic View of Workmanship

Visually-verifiable, unintended features, may prevent performance or reliability

May be design or process driven or non-compliancy with requirements

Design error?

No pre-assembly inspection

requirements?Manufacturing process uncontrolled?

Loose tolerance on dimensional requirements?

No debris

requirements?


Workmanship in High Reliability Electronics

Thru-hole connector pins (cPCI)


NASA GSFC Workmanship Scope

Machine Soldering (SMT)

Polymeric Applications

Electrical Cable HarnessConformal Coating

Staking

Bonding

Encapsulation

Hand Soldering

Optical Cable Harness

ESD

PWA’s, Cable Harnesses, ESD

NASA-STD-8739.1A

NASA-STD-8739.2 w/ch1




NPR 8730.5 NASA Quality Assurance Program Policy, Eff. 10/27/05

PWB Design (Layout)

PWB Manufacturing (Quality)IPC-2221

IPC-2222IPC-2223IPC-2225

IPC A-600IPC-6011IPC-6012IPC-6013IPC-6015IPC-6018

ANSI/ESD S20.20

GSFC-WM-001B

GSFC MAR (draft) 11/26/07

J-STD-001xS IPC/WHMA-A-620AS


Compliance With 8739 Series Workmanship Standards

Design

Fabrication Process Control

Inspection Requirements (Observable Defects)

Electrical Engineers

Packaging Engineers

Mechanical Engineers

Packaging Engineers

Process Development Engineers

Materials Engineers

OperatorsProcess Development Engineers

Operators

Inspectors

When left ONLY to operators and inspectors, Workmanship Standards compliance is not likely (unless number of applicable processes are very, very low)

Non-compliances are in the “built-in” stages of Design which are difficult to change later and causes costly scrap.


Examples of Workmanship Design Requirements

50 included in NASA Workmanship Standard SeriesDesign Rule/Requirement Standard

The use of new interconnect materials and technologies must be validated through testing and accept/reject criteria must be established for quality inspection. Special handling or processing conditions associated with material selected must be documented in the assembly instructions.

Poly AppsCable Harness Fiber Optic

High strength copper alloy is required for wire gauges of 24 AWG and higher. Wires of size 24 AWG and larger are preferred. Cable Harness

Staking materials and locations must be defined on the engineering documentation Poly AppsFiber Optic

Conformal coating material must be defined. Conformal coating materials with a fluorescent indicator are preferred Poly Apps

Bonding material and bonding locations must be defined on the engineering drawings. Bond line requirements must be defined. For thermal joints, acceptable voiding criteria must be defined.

Poly Apps

Materials and processes must meet performance, compatibility, contamination, and reworkability requirements. Process controls must be put in place to ensure acceptable solder joints when design features drive partially or fully hidden solder joints. Material shall meet project outgassing requirements.

Poly Apps

Soldering

Cable Harness

Fiber Optics

Staking material selected must be electrically insulative, shall not negate stress relief features. Poly Apps

Conformal coating maskant material and areas to be masked on PCBs must be defined Poly Apps

Exceptions to the requirement to stake all fastener heads must be recorded on the engineering drawings. Poly Apps

Demoisturizing conditions for PWAs prior to polymeric applications (time, temperature, ramp rates) must be defined Poly Apps

Minimum spacing between non-common conductors must be defined [to support inspection requirements]. Soldering


Examples of Workmanship Fabrication Process Control

Requirements29 included in NASA Workmanship Standard SeriesManufacturing Rule/Requirement Standard

Work orders or Travelers must establish each inspection point and a method for data collection. Cable Harness

Manufacturing production area environmental conditions must be controlled (temperature, humidity, ventilation, lighting). For field operations considerations must also be given to controlling the work environment.

Cable Harness

Vinyl dust caps shall not be used for flight applications. Fiber Optic Cable

Requirements apply for calibration of tools and equipment and proper selection and control of tools to protect the hardware. Cable Harness

Repairs require prior project quality authorization. [Applies to in-house production and contracted suppliers.] Polymeric Apps

Materials and material lots must be validated and approved Polymeric Apps

Fixturing used for controlling device placement during bonding processes must be defined on assembly drawings Polymeric Apps

PWA demoisturizing conditions must be defined on the assembly drawings including temperature ramp rates. Polymeric Apps

For thermal joints, the bond line must be inspected by engineering. Polymeric Apps

Engineering drawings must specify when vacuum-degassing is also required after application of the encapsulation Polymeric Apps

Engineering drawings must specify when components must be underfilled prior to encapsulation. Polymeric Apps

Major changes to materials used for reproducing a pre-existing design must be validated prior to use. Soldering

A controlled cooling process, if used in the soldering process, must be documented. Soldering

Stress relief shall be built into wires soldered to terminals. Service loop requirements may also apply. Soldering


Design-related Workmanship Issues

Operators must be provided drawings and documented procedures, with complete information about materials, how to prepare assembly prior to applying, how to apply, where to apply and safety.

Special processes (not defined in 8739 series) must be tested and nailed down (CM) in advance. Test vehicles should be used to validate special processes, not qualification units. Qual units contain high dollar value EEE parts and should be demonstrating performance margin, not proving out R&D concepts. Accept/reject inspection criteria must be defined for inspection of Qual units.

Inspection criteria must be defined and documented for inspectors for special processes. If 8739 criteria will be “borrowed” for this purpose, that must be stated explicitly. Referencing “NASA-STD-8739.x Inspection Criteria” is not enough.


Examples of Special ProcessesColumn Grid Array/Ball Grid Array Attach

Chip on Board

Special Solders: In, Pd, Pt, Au, Ag

Stacked Substrates

Examples of Special Processes Outside of Workmanship PurviewQualification of EEE Parts e.g. connectors, magnetics

Multi-chip Modules: EEE Part, See Hybrid Microcircuits

Optical assemblies

Microwave Assemblies

Approval is at the Project Level ONLY. Cross-GSFC approval process being explored. Also may be useful to NCAS process.


Log#: COCORP01 Date: 9/12/08 Type: Alternate Process

Applicable NASA Workmanship Standard: NASA-STD-8739.4 w/ch 4

Title/Description: Crimping of Contacts and Splices, Non-standard

Proposal References: COCORP Procedure E.6.21.9, para. 3.3.6.3, 6.2.1.1, 3.3.6.2

NASA Requirement Reference: 8739.4, 12.3.3, 13.8.2.a,

Attachments: COCORP Qualification Data Report

Proposal:1. use these words or value instead of the standard words or values.2. use these process steps3. use these inspection criteria

Assessments:1. Accept. The use of the additional strain relief mitigates risk from not having the one described in the NASA standard.

Approval: Accept Reject Requires Project MRB Approval Inconclusive Recalled

Approval Caveats and/or LimitationsNotice: Regardless of the method used, standard, non-standard, or pre-approved via this process, all repairs require review and approval via an MRB, prior to implementation. Extreme application conditions may invalidate the suitability of this process or the standard processes described in the Workmanship Standards.1. This process only applies to XYZ-plated wire conductors.

Preparer: 300 Date

Reviewer/Approver: 541 Date

Reviewer/Approver: 300 Date


Suppliers Who “Work to the NASA Workmanship Standards”

• Must have translated the REQUIREMENTS in the standards into their shop floor procedures.

• Must certify their in-house trainers (Level B Trainers), operators and inspectors.

• Certification has four elements:

1. Training every two years (traceable to Level A at JPL or GSFC)

2. Vision Acuity including color differentiation tested every two years

3. Competency

4. Actively performing work with less than 6 months break (1 yr for Trainers).


Suppliers Who “Work to the NASA Workmanship Standards”

• NASA Standards must be flowed to sub-tiers

• Some small sub-tiers may not be compliant. Prime can modify training to only cover the processes used.

• Verifying shop floor procedures contain all NASA Workmanship requirements:- Design and Process Control requirements may not be captured in shop floor documents.

- Requirements from five 8739 documents may fan out into many, many shop floor procedures. (current effort looking at 80+ documents)

- Project may not have the fortitude to carry out the gap analysis and risk management.


Electrostatic Discharge

ANSI/ESD S20.20 Requires local implementation plan. NASA does not dictate add-on requirements to ANSI/ESD S20.20.

NASA Workmanship Project available for guidance to Projects and Suppliers.

NASA GSFC local implementation plan is GSFC-WM-001B. B revision leverages off of all existing NASA Center implementation plans. Plans to publish as a NASA Handbook. ONLY GSFC civil servants and on-site contractors must comply with GSFC-WM-001.

NASA adopted ANSI/ESD S20.20 for NASA ESD Safety Standard in 1999. NASA-STD-8739.7 Retired. NASA confirms adoption following 2007 revision of S20.20

Conformance must be to ANSI/ESD S20.20


ESD Technical Issues

NASA & Industry standards were written on the assumption of that the operator would manually handle the parts (HBM)

The HBM Class O sensitivity rating (≤250V) not uncommon for new devices. New sensitivity levels such as C1, C2 being considered for low sensitivities.

Currently HBM does not simulate the actual processes in laboratory/assembly areas. There is a lack of understanding of CDM (triboelectric & inductive). HMM (HBM+MM) is not properly covered by current standards (manual operations) and believed to be cause of some Class 0 devices failures.

Standard test equipment needs to reach into the GHz range to validate that the theoretical pulse for new models is occurring during the test. Device can have a worst-case operational mode for ESD robustness.

CDM-based Cable Charging model in development and critical for understanding NASA I&T environment threats


GSFC ESD Bench Certification Process

Code 300 team supports CSO’s and Lab Monitors who request bench certifications.

Certification team provides Lab Monitor with preparation package. Intent is also to reinforce concepts from Training.

Follow-ups done without prior request.

Requirements for temporary and permanent benches defined in GSFC-WM-001

Lab Monitors ultimately responsible for maintaining certification status. Code 300 certifies and revokes certification.


Printed Wiring Board Design and Manufacturing

IPC-2221, GenericIPC-2222, Rigid Board DesignIPC-2223, Flex Board DesignIPC-2225, MCM-L (COB)IPC-6011, GenericIPC-6012, Rigid Board QualityIPC-6013, Flex Board QualityIPC-6015, MCM-L (COB) QualityIPC-6018, Microwave

Contains Aerospace Appendix defining coupon analysis requirements and criteria. Includes requirements formerly found in GSFC S-312-P-003. Must specify “Class 3/A”.

Others, use Class 3

IPC-7095, BGA Major contributions by JPL and MSFC


Ground Support EquipmentInterfacing parts will not create or be susceptible to

early-life failure or failure in environmental testing environment.

J-STD-001 and IPC-A-610 allowed for GSE. These are “either/or” specifications. J-STD-001 preferred due to inclusion of process control requirements. IPC-A-610 caters to inspections-only users.

G O D D A R D S P A C E F L I G H T C E N T E R

React to Cross-Industry Change Proposals

Coordinate NASA-driven Changes

Document Adoption

Facilitate Use of New Document System

Process for Adopting and Maintaining Industry Standards for Workmanship

Standards Lifecycle

Achieve Meets-or-Exceeds Revision

Training Programs, Supporting Standards, and Supporting Requirements

Impact to Contracts and Quality Processes


Document Stewardship

Widespread & Consistent Usage

Status of Industry Standards for Workmanship

Ensure Cohesive Implement-able Requirements Set

Standards Lifecycle

ANSI/ESD S20.20: Implementation Plan for Cross-Agency Use (content complete)

J-STD-001 Space Addendum (Soldering): NASA Proposal included in Final Draft.

Ballot expected in last quarter of 2008.

CxP Workmanship Requirements adapted to carry requirements in parallel (doc in coordination).

IPC will allow Space-only Training program and adapted training programs for companies performing limited processes. Training slides in production.

IPC-A-620 Space Addendum (Harness Mfrg): Initial draft near ballot. Formal NASA gap analysis in process.

Qtrly IPC coordination meetings

ANSI/ESD S20.20: Examining requirements for tools, gloves, cables, new discharge models.


Highlights ReviewWorkmanship requirements flow from NASA HQ to Programs, Projects,

Suppliers and Sub-Tier Suppliers

Workmanship includes: polymeric applications, soldering, cable harnessing, fiber optic cables, ESD, printed wiring board design and quality.

Workmanship requirements include design, process controls, inspection requirements, personnel certification.

Special processes must be approved. Applicable inspection criteria must be identified.

Compliance to NASA Workmanship standards is very difficult to assess when company offers existing shop floor documents as “equivalent”

Each company must prepare and train to their own ESD implementation plan. They are free to “copy” GSFC-WM-001.

J-STD-001DS nearing adoption for soldering. IPC/WHMA-A-620AS starting path to adoption for cable harnesses.

G O D D A R D S P A C E F L I G H T C E N T E R Workmanship Requirements Compliance Jeannette Plante...

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