JEDEC JESD22-B120

This test method provides a means for determining the strength and failure mode of a wire bonded to, and the corresponding interconnects on, a die or package bonding surface and may be performed on pre-encapsulation or post-encapsulation devices. This test method may be performed on gold alloy, copper alloy, and silver alloy thermosonic (ball and stitch) bonds made of wire ranging in diameter from 15 μm to 76 μm (0.6 mils to 3.0 mils); and on gold alloy, copper alloy, and aluminum alloy ultrasonic (wedge) bonds made of wire ranging in diameter from 18 μm to 600 μm (0.7 mils to 24.0 mils).

This wire bond pull test method is destructive. It is appropriate for use in process development, process control, and/or quality assurance.

This test method allows for two distinct methods of pulling wires:
1) One method incorporates the use of a hook that is placed under the wire and is then pulled.
2) One method requires that after the wire be cut, a clamp is placed on the wire connected to the bond to be tested, and this clamp is used to pull the wire.

This test method defines three pull tests. The Wire Pull Test (WPT) is appropriate for all bonded wires. The Bond Pull Test (BPT) and Stitch Pull Test (SPT) are appropriate for thermosonically bonded wires.

This test method can also be used on the following four applications of thermosonic and ultrasonic bonds, though each requires special considerations when performing the test method:
a) Pulling aluminum wires and aluminum ribbons (see 3.5.1) that are bonded with multiple ultrasonic bonds. See 5.3.1.1.1 for special considerations. Multiloop wires and ribbons are used in some highpower device packages.
b) Pulling wires of reverse bonds which are also known as “stitch on ball”. These types of bonds can include gold stitch on gold ball, copper stitch on copper ball, and copper stitch on gold ball. See Clause A.1 in Annex A for additional information.
c) Pulling a thermosonically bonded wire that has a security bond (see 3.9) or security loop (see 3.9.1) placed on top of the stitch bond (see 3.1.2) in order to provide additional strength. See Clause A.2 for additional information.
d) Pulling thermosonic wire bonds on stacked dice when wires and/or bonds are not accessible to allow for proper pull testing. See 5.3.1.1.3 for special considerations.