Understanding MIL-PRF-31032, Part 3

Estimated reading time: 3 minutes

Continuing with Part 3 of the discussion on understanding the military PCB performance standard MIL-PRF-31032, the next step in the process is to create a technical review board (TRB) to oversee the quality plan.

Establishing the TRB
As outlined in Part 2, the TRB is a small group of internal management staff that ensures the quality management plan (QMP) is in place and working properly. The function and responsibilities of the TRB must be documented in the TRB operating procedure. In most organizations, the TRB members are the same as the management review team and is usually a cross-functional group of leaders of the core business functions (manufacturing, quality, sales, engineering). There can also be ad-hoc members that can participate in meetings as specific subject-matter experts on a particular topic.

During meetings, the TRB members are typically responsible for bringing information and data, such as information and progress reports on action items assigned to them at previous meetings, information on planned changes that could affect the QMS, quality planning needs and activities, and recommendations for improvements to the QMS.

Organizational Structure
The TRB operational procedure must define the members of the TRB by name and title, and responsibilities need to be outlined in detail. The members of the TRB must have the responsibility and authority to make decisions and the resources to implement these decisions. Any changes made to the TRB membership shall be concurrently communicated to the qualifying activity, which means that any change in membership must be reported. Records of the TRB deliberations and decisions shall be maintained, and the records shall be made available to the qualifying activity.

Responsibilities
The overarching responsibility of the TRB is the implementation, maintenance, review, and verification of the QMP. The duties of the team include, but are not limited to, oversight of the following:

1. Technology: The process of research, development, approval, and maintenance of technology, including qualification testing, add-on qualification testing, and information systems and technology.
2. Manufacturing: The monitoring and approving of existing, temporary, and new manufacturing processes, procedures, and work instructions. This includes the process flow diagram, process flow documentation index, and process control.
3. Testing: The process of testing PCBs, including verification test and inspection methods, test optimization, documentation and data retention of results, and storage and disposition of specimens.
4. Quality Assurance: Ensuring that all PCBs meet specified performance, quality, and reliability requirements of MIL-PRF-31032. This includes failure analysis, corrective action, periodic conformance inspection, and capability verification inspection.
5. Contract Service Organizations: The control of any subcontracted manufacturing, processing, or testing.
6. Conversion of Customer Requirements: The processes that review customer requirements, verify manufacturability, and create the appropriate traveler or work order to manufacture the order.

Note: Change control is an integral responsibility of the TRB, including the previous six managing duties of the TRB.

Meetings
The purpose of TRB meetings is to review the various functions of the QMP and monitor the effectiveness of the plan. The TRB assesses PCB quality and reliability thorough review of the process controls, inspection and test results, board or lot failure rates, and failure analysis results of internal rejects and customer returns. Also reviewed during meetings are the specifics of all MIL-PRF-31032 orders that were manufactured during the last period (number of jobs, yield/rejection rates, delivery, etc.).

A typical TRB meeting agenda includes the following:

• Summary of TRB activity
• Self-assessment results
• Add-on qualifications
• Continuous improvement updates
• Process control
• Corrective actions
• Fabrication and test facility
• QML compliant printed boards shipped, including QPL compliant printed boards produced under the certified QM plan
• Customer returns
• Summary of inspection lot data, including part fallout and lot rejection
• Results of periodic conformance inspection and capability verification inspection assessment
• Summary and approval of major and minor changes

Conclusion
That wraps up the TRB. Part 4 will focus on the unique procedures and work instruction changes needed to produce MIL-PRF-31032 PCBs.

Editor’s note: Read Part 1 and Part 2.

Anaya Vardya is president and CEO of American Standard Circuits; co-author of The Printed Circuit Designer’s Guide to… Fundamentals of RF/Microwave PCBs and Flex and Rigid-Flex Fundamentals; and author of Thermal Management: A Fabricator's Perspective. Visit I-007eBooks.com to download these and other free, educational titles. He also co-authored “Fundamentals of PCB Technology.”