- PWB Related Activities -

Quality Leadership ForumGoddard Space Flight Center

July 17-19, 2001Garry McGuire

http://workmanship.nasa.gov

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Background:• There have been several high visibility mission

failures due to PWB’s that were improperly spec’d, manufactured, or validated.

• Cancellation of NHB 5300.4(3I) & (3K), along with the dilution of important requirements in the current version of MIL-P-55110 created a void for low volume, high reliability PWB’s.

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• So, what IS out there? The NWTC works with the IPC for PWB and other standards. The IPC started in the late 1950’s as an organization to promote many aspects of the printed wiring board industry. Among the services they provide:– World-wide market research and trending reports.

– Governmental lobbying for the PWB industry (lead-free solder alloys are particularly high profile at the moment).

– Annual symposia for information exchange and technology updates. Design, manufacturing, and acceptance standards created and

maintained by committees comprised of users and manufacturers of electronic products. This includes NASA and many of NASA’s prime suppliers such as Boeing, Lockheed/Martin, TRW, Hughes, Northrup Grumman, others.

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• NASA is represented at several IPC meetings a year. The goal of this representation is to work NASA’s unique PWB issues into voluntary consensus standards (VCS). This is not always possible because:– Being such a [small] niche market, many issues important to

NASA get outvoted during committee discussions.– NASA’s unusually low volume (per assembly) makes it

difficult to generate support for important issues.– Data is not always available to support historical issues, nor

are the resources to generate data consistently available.

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• What Then? The NWTC identifies areas where the VCS committee(s) will not incorporate issues that are important to the reliability of NASA’s flight hardware. These issues are discussed during NWTC meetings to determine whether or not a particular issue is worth fighting for. If so:– Generate data to support for the need for the requirement and

resubmit to the appropriate committee for consideration.– If still not accepted by the committee, the NWTC will generate

a supplement to the VCS and recommend it be used as a mandatory part of the standard it supplements.

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• What else needs to be done?– Awareness. The NWTC website is a “living document” and

will be updated when new standards, technologies, processes, or techniques are recognized, including lessons learned from other organizations’ experiences.

– Training. Improve access to (and requirements for) training, particularly in the areas of product acceptance and coupon cross-section analysis.

– Teaming with industry. Take the next step past standards participation and work with PWB manufacturers, users, and test facilities to establish uniform acceptance of NASA’s requirements.

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– Currently recommended for use are:• Design

– IPC-2221, Generic Standard on Printed Wiring Board Design

– IPC-2222, Sectional Standard on Rigid Printed Wiring Board Design

• Fabrication– IPC-6011, Generic Performance Specifications for

Printed Boards– IPC-6012, Qualification and Performance

Specification for Rigid Printed Boards

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– Currently recommended (continued):• Fabrication (continued)

– GSFC S312-P003B, procurement specification for rigid PWB’s. This document is a supplement to the IPC-6011 and IPC-6012 documents for rigid PWB’s. Note: This document is currently being reworked for re-release as an Agency document)

• Acceptance– IPC A-600, Guidelines for Acceptability of Printed

Boards (this standard contains visual depictions of the requirements found in IPC-6011 and IPC-6012 and should not be used by itself as a procurement specification).