MIL-PRF-55110 Printed Wiring Board, Rigid, General Specification ForThis specification establishes the performance and qualification requirements for rigid single??sided, double??sided, and multilayered printed wiring boards with or without plated through holes \(see 6.1\). Verification is accomplished through the use of one of two methods of product assurance \(QPL or QPL/QML\). Detail requirements, specific characteristics, and other provisions which are sensitive to the particular intended use are specified in the applicable master drawing.

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MIL�PRF�55110G

APPENDIX C

Sample size series: The sample size series is defined as the following series of letters: A, D, F, H, J, L,

and N that are listed in table C�I (see C.4.5 for examples). NOTE: Sample size series "A" was identified

as "B" in previous revisions.

Tightened inspection: Tightened inspection is defined as sampling using an increased sample size (see

Acceptance number (C): The acceptance number is defined as an integral number associated with the

selected sample size which determines the maximum number of defectives permitted for that sample size.

f. Rejection number (R): Rejection number is defined as one plus the acceptance number.

C.3.2

C.3.2 Symbols. The following symbols shall apply for all statistical sampling procedures:

C: Acceptance number.

R: Rejection number.

C.4

C.4. STATISTICAL SAMPLING PROCEDURES AND SAMPLE PLAN TABLE

C.4.1

C.4.1 General. Statistical sampling shall be conducted using the C = 0 method. The C = 0 method as specified

herein is a sampling plan that provides a high degree of assurance that a lot having a proportion defective greater

than the specified acceptance number (C = 0) will not be accepted. For all situations, the acceptance number (C)

shall be equal to 0 (C = 0) and the rejection number (R) shall be 1 or greater (R ≥ 1).

C.4.2

C.4.2 Acceptance and procedure.

C.4.2.1

C.4.2.1 Acceptance number (C = 0). Acceptance of inspection lots shall be based on an acceptance number of

zero (C = 0).

C.4.2.2

C.4.2.2 Rejection number (R ≥ 1). Failure of a sample unit for one or more tests of a subgroup shall be charged as

a single failure. One or more sample rejects shall be cause for failure of the lot or sublot, as applicable. Any failure

on any of the sample units shall constitute a failure of the entire inspection lot or sublot.

C.4.3

C.4.3 Tightened inspection (for reevaluation purposes). Tightened inspection shall be performed by sampling

using double the sample size as specified in table C�I with zero failures allowed or 100 percent.

C.4.4

C.4.4 Sample size. The sample size for each subgroup shall be determined from table C�I. If lot size is smaller

than sample size, test all of the units. The manufacturer may, at their option, select a sample size greater than that

required; however, the number of failures permitted shall not exceed the acceptance number.

C.4.5

C.4.5 C = 0 sample plan construction (selection and usage of the sample size series). The sample size series of

table C�I to be used will be directed from the appropriate inspection table. The inspection table will specify the C = 0

sample plan (test specimen identifier and sample size series) or plans (test printed wiring board, panels, or either

one) to use.

EXAMPLES: If an inspection table specified that "Plan BF or TL" be used when verifying test specimens, it

is specifying that sample size series "F" of table C�I shall be used for selecting printed wiring boards and

sample size series "L" shall be used for selecting test coupons from panels. If the same inspection table

specified that "Plan *H" be used, then sample size series "H" of table C�I can be used for either printed

wiring boards or panels.