MIL-PRF-38535K
APPENDIX A
A.3.4 Quality assurance requirements. The quality assurance provisions provided in this appendix are intended to
provide a compliant MIL-STD-883 class level B or level S device (see A.3.1.3.34 and A.3.1.3.35). Devices or lots
which have failed to pass any tests applied or acceptance criterion (PDA) shall not be downgraded to any lower
quality assurance level even though that test or criterion may not be a requirement of the lower level (a failed device
or lot shall not be accepted). Where shown, method references are in accordance with MIL-STD-883.
A.3.4.1 Qualification. The manufacturer supplying devices in compliance to this appendix shall perform sufficient
product qualification testing to assure the devices supplied meet the minimum class level B or S performance
requirements as described herein. The manufacturer shall maintain documentation of qualification testing for review
of the preparing or acquiring activity upon request.
A.3.4.1.1 Compliance validation. Although on-site audits are not a condition to begin supplying under the
requirements of this appendix, all manufacturers supplying in compliance to this appendix are subject to periodic
Government compliance validation audits on a drop-in basis with a minimum of notice.
A.3.4.1.2 Process monitor programs. Process monitor programs performed by the manufacturer shall be
established as a minimum for the following processes: Scanning Electron Microscope (SEM), wire bonding, die
attachment, lid seal, particle detection, lead trimming, and final lead finish thickness. The implementing procedures
shall provide for frequency, sample size, reject criteria, allowable rework, and disposition of failed product/lot(s). With
the exception of the particle detection monitor, a procedure is required for the traceability, recovery, and disposition of
all units monitored since the last successful test. As with all monitors, the particle detection procedure shall provide
for continual process improvement. Records of these monitors and procedures shall be maintained and available for
review.
A.3.4.1.2.1 Inspection by scanning electron microscope (SEM). A continuing SEM program shall be established to
ensure adequate process control and coverage of metallization at oxide steps, contact openings, and general
metallization. A monthly (minimum frequency) SEM evaluation shall be performed on product that is in the
manufacturing process. The SEM program shall establish routine control over metallization processes by process
families or inspection of products.
A.3.4.1.2.2 Wire bonding. The manufacturer shall monitor the wire bond strength in accordance with the
manufacturer's documented procedure. The frequency of this procedure shall be performed at machine setup and at
the end of the production run as a minimum. At the manufacturer's option, this procedure shall consider shift start
and stop, change of operators, spools, packages, wire size, lot size, and other related factors.
A.3.4.1.2.3 Die attachment. The manufacturer shall monitor the die attachment integrity in accordance with the
manufacturer's documented procedure. This procedure shall be performed at each equipment setup and at the end
of the production run as a minimum. At the manufacture's option, this procedure shall consider other related factors.
A.3.4.1.2.4 Lid seal. The manufacturer shall monitor, as a minimum, glass frit packages for seal integrity in
accordance with the manufacturer's documented procedure. A sample and test plan shall be available for review by
the qualifying or preparing activity.
A.3.4.1.2.5 Particle detection. The manufacturer shall establish a particle detection monitoring program which
assesses the particle contamination of sealed devices on an individual manufacturing line basis. The monitor shall
have provisions for testing in accordance with TM 2020, condition A of MIL-STD-883. JEP114, "Guidelines for
Particle Impact Noise Detection (PIND) Testing, Operator Training and Certification" may be used as a guideline.
Suitable data for each manufacturing line shall be used to establish an appropriate need, sample size, and sampling
frequency for each package family. Unless otherwise approved by the qualifying activity (QA), the minimum sampling
frequency of those devices in production shall be once each month per package family. Investigative and corrective
actions shall be established which address noted deficiencies. Records of this monitor shall be made available for
review and shall represent at least the six-month period preceding the audit.
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