MIL-PRF-28776F
4.7.2.2.1.2 Rejected lots. Relays that do not meet the requirements of the tests in A1 and A4 shall be rejected and
shall be removed from the lot. If more than 5 percent of the relays are discarded during A2 testing, the production lot
shall be rejected and not offered for reinspection.
4.7.2.2.2 A3 tests.
4.7.2.2.2.1 Sampling plan. Two samples shall be selected randomly from each inspection lot and subjected to the
A3 solderability test. If there are one or more defects, the lot shall be considered to have failed. Relays failing the A2
electrical tests, or rejected for other criteria which will not influence solderability, may be used for solderability testing.
All rejected relays used as samples must accompany the acceptable relays through all processing environments.
The rejected relays shall be marked in a definite manner in order to preclude mixing with acceptable parts.
4.7.2.2.2.2 Rejected lots. In the event of one or more defects, the inspection lot is rejected. The manufacturer
may use one of the following options to rework the lot:
a.
Each production lot that was used to form the failed inspection lot shall be individually submitted to the
solderability test as required in 4.8.3. Production lots that pass the solderability test are acceptable for
shipment. Production lots failing the solderability test can be reworked as described in 4.7.2.2.2.2b and
b.
The manufacturer submits the failed lot to a 100 percent solder dip using an approved solder dip process in
accordance with 3.5.7.4. Two additional samples shall be selected and subjected to the solderability test
with zero defects allowed. If the lot fails this solderability test, the lot shall be rejected and shall not be
furnished against the requirements of this specification.
c.
The manufacturer may submit the failed lot to a strip and replate process followed by a complete group A
inspection. The reworked lot shall be considered a new lot for the purpose of the 5 percent requirement of
A2. If the lot fails this solderability test, the lot shall be rejected and shall not be furnished against the
requirements of this specification.
4.7.3 Periodic inspections. Periodic inspections shall consist of groups B and C. Except where the results of
these inspections show noncompliance with the applicable requirements (see 4.7.3.3), delivery of products which
have passed group A shall not be delayed pending the results of these periodic inspections.
4.7.3.1 Group B inspection. Group B inspection shall consist of the tests in the order specified in table VI and shall
be made on sample units which have been subjected to and have passed the group A inspection.
4.7.3.1.1 Sampling plan. The test sample size shall be determined by the manufacturer so that the relay cycles
generated meet the maintenance of qualification requirements specified for the qualified failure rate level (see 4.4.4).
A minimum quantity of samples shall be selected from each inspection lot as determined by the quantity needed to
maintain the FR level divided by the number of inspection lots in the reporting period. In all cases, the sampling plan
shall be approved by the qualifying activity. As far as is practicable, the relays tested during a maintenance period
shall be representative of all relays produced during this period. The accumulated information shall be used for
maintenance and extension of failure rate qualification.
4.7.3.1.2 Disposition of sample units. Sample units which have been subjected to group B inspection shall not be
delivered on the contract or purchase order.
19
For Parts Inquires call Parts Hangar, Inc (727) 493-0744
© Copyright 2015 Integrated Publishing, Inc.
A Service Disabled Veteran Owned Small Business