Patent Number: 6,308,881

Title: Quality control method

Abstract: A quality control method for ultrasonic wire bonding is provided whereinthe deformation of the wire to be bonded to a contact surface issubstantially constantly monitored. The method includes generating anultrasonic output table. In the table, the current status of the bondingprocess is represented as a function of the gradient of deformation of thewire, the impedance of the transducer-bond wedge unit, as well as thecurrently reached deformation of the wire. The desired gradient ofdeformation of the wire, a function of the particular status of theprocess, is specified as the desired value. A correcting variable for theultrasonic generator is calculated by the addition of correction valuesformed in the controller to the respective current table values.

Inventors: Hesse; Hans Jurgen (Paderborn, DE), Holtgrewe; Dietmar (Paderborn, DE)


International Classification:

Expiration Date: 10/32013