Method for calibrating an ultrasonic bonding machine

Patent metadata

Field	Value
Publication number	US-11646291-B2
Application number	US-201916527289-A
Country	US
Kind code	B2
Filing date	Jul 31, 2019
Priority date	Jul 31, 2018
Publication date	May 9, 2023
Grant date	May 9, 2023

Abstract

A method for calibrating a second bonding machine based on a calibrated first bonding machine is disclosed. The first bonding machine includes a first ultrasonic transducer. The second bonding machine includes a second ultrasonic transducer and a power supply. The method includes providing a first electrical calibration supply that causes the first ultrasonic transducer to oscillate at a first calibration amplitude when it is damped by a mechanical damping, providing a second electrical calibration supply that causes the second ultrasonic transducer to oscillate at the same calibration amplitude when it is damped by the same mechanical damping. The second bonding machine is adapted to modify a second control signal based on a first electrical parameter of the first electrical calibration supply and on a second electrical parameter of the second electrical calibration supply in order to generate a modified second control signal, provide the modified second control signal to the power supply in order to cause the second power supply to generate a second electrical supply, and provide the second electrical supply to the second ultrasonic transducer.

First claim

The invention claimed is:

1. A method for calibrating a second bonding machine based on a calibrated first bonding machine, the first bonding machine comprising a first ultrasonic transducer, the second bonding machine comprising a second ultrasonic transducer and a power supply, the method comprising:
damping the first ultrasonic transducer by a first mechanical damping;
providing a first electrical calibration supply to the first ultrasonic transducer, the first electrical calibration supply causing the first ultrasonic transducer, when it is damped by the first mechanical damping, to oscillate at a first calibration amplitude;
providing a second electrical calibration supply to the second ultrasonic transducer, wherein the second electrical calibration supply is configured to cause the second ultrasonic transducer, when it is damped by a second mechanical damping identical to the first mechanical damping, to oscillate at a second calibration amplitude identical to the first calibration amplitude; and
adapting the second bonding machine to:
modify a second control signal based on a first electrical parameter of the first electrical calibration supply and on a second electrical parameter of the second electrical calibration supply in order to generate a modified second control signal;
provide the modified second control signal to the power supply in order to cause the power supply to generate a second electrical supply; and
provide the second electrical supply to the second ultrasonic transducer.

2. The method of claim 1 , wherein:
the first electrical parameter is an average of an electrical power of the first electrical calibration supply and the second electrical parameter is an average of an electrical power of the second electrical calibration supply; or
the first electrical parameter is an average of a first voltage of the first electrical calibration supply and the second electrical parameter is an average of a second voltage of the second electrical calibration supply; or
the first electrical parameter is a first amplitude of a first voltage of the first electrical calibration supply and the second electrical parameter is a second amplitude of a second voltage of the second electrical calibration supply.

3. The method of claim 1 , wherein modifying the second control signal based on the first electrical parameter of the first electrical calibration supply and the second electrical parameter of the second electrical calibration supply in order to generate the modified second control signal comprises modifying the second control signal based on a difference between the first electrical parameter of the first electrical calibration supply and the second electrical parameter of the second electrical calibration supply.

4. The method of claim 3 , wherein the second bonding machine is adapted to generate the modified second control signal such that a difference between
an electrical parameter of an unmodified second electrical power that the power supply would output to the second ultrasonic transducer if the second control signal instead of the modified second control signal was provided to the power supply and
an electrical parameter of the second electrical supply is equal to the difference between
the first electrical parameter of the first electrical calibration supply and
the second electrical parameter of the second electrical calibration supply.

5. The method of claim 1 , wherein adapting the second bonding machine to provide the second electrical supply to the second ultrasonic transducer includes:
adapting the second bonding machine to provide a second alternating voltage and a second alternating current to the second ultrasonic transducer, the second alternating current being in phase with the second alternating voltage.

6. The method of claim 5 , wherein the second alternating voltage and the second alternating current comprise zero crossings at common instants of time.

7. The method of claim 1 , wherein:
the first bonding machine comprises a first tool tip distant from the first ultrasonic transducer;
the second bonding machine comprises a second tool tip distant from the second ultrasonic transducer;
damping the oscillating first ultrasonic transducer comprises mechanically damping the oscillating first ultrasonic transducer at the first tool tip; and
damping the oscillating second ultrasonic transducer comprises mechanically damping the oscillating second ultrasonic transducer at the second tool tip.

8. The method of claim 7 , wherein damping the oscillating first ultrasonic transducer at the first tool tip and damping the oscillating second ultrasonic transducer at the second tool tip comprises one of:
pressing the first tool tip with a first pressing force against a first elastic pad and pressing the second tool tip with a second pressing force identical to the first pressing force against the first elastic pad or against a second elastic pad identically constructed as the first elastic pad;
pressing the first tool tip with a first pressing force against a first semiconductor chip and pressing the second tool tip with a second pressing force identical to the first pressing force against the first semiconductor chip or against a second semiconductor chip identically constructed as the first semiconductor chip;
clamping the first tool tip using a first clamp and clamping the second tool tip using the first clamp or a second clamp identically constructed as the first clamp; and
immersing the first tool tip into a first fluid and immersing the second tool tip into the first fluid or into a second fluid identical to the first fluid.

9. The method of claim 8 , wherein the first elastic pad comprises, at a temperature of 23° C., a hardness of more than 60 shore-A or of more than 16 shore-D.

10. The method of claim 1 , wherein damping the oscillating first ultrasonic transducer comprises:
pressing a first damping element directly against the first ultrasonic transducer or, at a same first distance from a first tool tip of the first bonding machine as the first ultrasonic transducer, against the first bonding tool; and
pressing the first damping element or a second damping element identical to the first damping element directly against the second ultrasonic transducer or, at a same second distance from a second tool tip of the second bonding machine as the second ultrasonic transducer, against the second bonding tool.

11. The method of claim 1 , further comprising:
adapting the second bonding machine to store the first electrical parameter and the second electrical parameter or a parameter or a function depending on the first electrical parameter and the second electrical parameter in a memory of the second bonding machine; and
modifying the second control signal based on the stored first and second electrical parameters, based on the stored parameter or based on the stored function.

12. The method of claim 1 , wherein:
providing the first electrical calibration supply to the first ultrasonic transducer comprises applying a first calibration voltage to the first ultrasonic transducer, the first calibration voltage causing a first calibration current through the first ultrasonic transducer;
providing the second electrical calibration supply to the second ultrasonic transducer comprises applying a second calibration voltage to the second ultrasonic transducer, the second calibration voltage causing a second calibration current through the second ultrasonic transducer;
the first calibration voltage and the first calibration current are in phase and comprise common zero-crossings; and
the second calibration voltage and the second ca

Assignees

• Infineon Technologies Ag

Inventors

• Eacock Florian
• Chajneta Michal
• Tophinke Stefan

Classifications

• H10W72/5363

  the connected ends being wedge-shaped · CPC title

• H10W72/0711 Primary

  Apparatus therefor · CPC title

• H10W72/07141

  Means for applying energy, e.g. ovens or lasers · CPC title

• H10W72/07113

  Means for calibration · CPC title

• G05B19/182 Primary

  characterised by the machine tool function, e.g. thread cutting, cam making, tool direction control (G05B19/21 - G05B19/40 take precedence) · CPC title