ASTM F 458 : 2013

1.1This practice covers nondestructive testing of individual wire bonds made by either ultrasonic, thermal compression or thermosonic techniques. The test is intended to reveal (by breaking) nonacceptable wire bonds but is designed to avoid damage to acceptable wire bonds.

1.2The practice covers wire bonds made with small-diameter (from 0.0007 to 0.003-in. (18 to 76-μm)) wire such as the type used in integrated circuits and hybrid microcircuits, system in package, and so forth.

1.3This practice can be used only when the loop height of the wire bond is large enough to allow a suitable hook for pulling to be placed under the wire.

1.4While the procedure is applicable to wire of any composition and metallurgical state, criteria are given only for gold and aluminum wire.

1.5A destructive pull test is used on wire bonds of the same type and geometry to provide the basis for the determination of the nondestructive pulling force to be used in this practice. This may only be used if the sample standard deviation, s, of the pulling forces required to destroy at least 25 of the same wire bonds tested by the destructive pull-test method is less than or equal to 0.25 of the sample average, x. If s > 0.25 x, this practice may not be used.

1.6The nondestructive wire-bond pull test is to be performed before any other treatment or screening following bonding and at the same point in processing as the accompanying destructive test. Preferably, this is done immediately after bonding.

1.7The procedure does not ensure against wire-bond failure modes induced after the test has been performed.

1.8The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.

1.9This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.