Method for the calibration of a wire bonder

A method for the calibration of one or several Wire Bonders by means of a sensor integrated into a semiconductor chip, whereby each Wire Bonder has a capillary clamped onto a horn, whereby ultrasonics are applied to the horn by an ultrasonic transducer, whereby the ultrasonic transducer is controlled by means of a parameter P and whereby a reference value URef is determined by means of a first Wire Bonder in accordance with the following steps:

• a1) Placing the capillary without wire or wire ball onto a contact area of the sensor,
• b1) Applying a bond force to the capillary which is great enough so that, in the next step, the capillary does not slide back and forth on the contact area of the sensor,
• c1) Applying a predetermined value P1 of the parameter to the ultrasonic transducer and obtaining the value U1 of the amplitude of the sensor signal once a stationary condition has set in, and
• d1) Storing the value U1 of the sensor signal as reference value URef,
• and whereby the parameter P of the first Wire Bonder is recalibrated or the parameter P of another Wire Bonder is calibrated in order to operate its ultrasonic transducer in production with a value P2=γ*P1 of the parameter P, whereby γ is a correction factor which is determined in accordance with the following steps:
• a2) Placing the capillary without wire or wire ball onto the contact area of the same sensor or a different sensor of the same type,
• b2) Applying the same bond force to the capillary, and
• c2) Operating the ultrasonic transducer under the control of the parameter P, and
• d2) Determining the correction factor γ so that the amplitude of the sensor signal assumes the value URef when the value P2=γ*P1 is applied to the ultrasonic transducer.