MPP & KnS How to Measure Static Bond Force

The static bond force is the force that is applied to the bonding wedge or capillary when the force dial is set to zero and no external force is provided from the force coil during bonding. Typically when bonding 25 micron wire the static force should equate to:

• 15 – 18 grams for Wedge bonding.
• 23 – 25 grams for Ball bonding.

Larger or smaller wire diameters will require additional or lower static force respectively. The static force is adjusted with two counter balance weights on the rear of the bond arm. One is located near the dashpot assembly (left) and the other is located near the bond head pivot (right). If higher bonding force is required, one or both of these counter balance weights can be removed.

Adjust Static Bond Force:

• Isolate bonder.

• Open right hand side cover and remove the return spring from one end; this will allow the bond head and transducer assembly to naturally fall to the end of its travel.

• Place a suitably scaled Gram Gauge under the wedge / capillary.

• Adjust the counter balance weights until you have a suitable static bond force.

• Reconnect return spring and close covers.