Ultrasonic transducer assembly

• US 20040245893A1
• Filed: 06/03/2003
• Published: 12/09/2004
• Est. Priority Date: 06/03/2003
• Status: Active Grant

• Current Assignee: ASM Assembly Automation Limited (ASMPT Ltd.)
• Original Assignee: ASM Assembly Automation Limited (ASMPT Ltd.)
• Inventors: Li, Hing Leung Marchy, Ng, Ming Wai Kelvin, Hung, Kin Yik
• Granted Patent: US 7,002,283 B2
• Time in Patent Office: Days
• US Class Current: 310/323.19
• CPC Class Codes: B06B 3/00 Methods or apparatus specially adapted for transmitting mechanical vibrations of infrasonic, sonic, or ultrasonic frequency
• CPC Class Codes: B23K 20/106 Features related to sonotrodes
• CPC Class Codes: B23K 2101/40 Semiconductor devices
• CPC Class Codes: H01L 2224/45124 Aluminium (Al) as principal constituent
• CPC Class Codes: H01L 2224/45144 Gold (Au) as principal constituent
• CPC Class Codes: H01L 2224/48 of an individual wire connector
• CPC Class Codes: H01L 2224/78313 Wedge
• CPC Class Codes: H01L 2224/85201 Compression bonding
• CPC Class Codes: H01L 2224/85205 Ultrasonic bonding
• CPC Class Codes: H01L 24/45 of an individual wire connector
• CPC Class Codes: H01L 24/78 Apparatus for connecting with wire connectors
• CPC Class Codes: H01L 24/85 using a wire connector wire bonding in general B23K20/004
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/00015 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed as prior art
• CPC Class Codes: H01L 2924/01005 Boron [B]
• CPC Class Codes: H01L 2924/01006 Carbon [C]
• CPC Class Codes: H01L 2924/01013 Aluminum [Al]
• CPC Class Codes: H01L 2924/01033 Arsenic [As]
• CPC Class Codes: H01L 2924/01079 Gold [Au]
• CPC Class Codes: H01L 2924/01082 : Lead [Pb]
• CPC Class Codes: H01L 2924/3011 : Impedance

Abstract

The invention provides an ultrasonic transducer assembly for a bonding apparatus, comprising a bonding tool mounted to an amplifying horn secured between first and second ultrasonic-generating means. A method of forming a transducer for a bonding apparatus is also provided, comprising the steps of providing an amplifying horn, securing first and second ultrasonic-generating means to the amplifying horn such that the amplifying horn is located between said first and second ultrasonic-generating means and mounting a bonding tool to the amplifying horn.

Claims

1. A transducer for a bonding apparatus, comprising a bonding tool mounted to an amplifying horn secured between first and second ultrasonic-generating means.

2. A transducer as claimed in claim 1, wherein each of the first and second ultrasonic-generating means comprises a stack of piezoelectric elements.

3. A transducer as claimed in claim 2, wherein each stack comprises an equal number of piezoelectric elements.

4. A transducer as claimed in claim 2, wherein the poling directions of said first and second stacks of piezoelectric elements are arranged whereby the first and second stacks of piezoelectric elements are excitable in opposite directions.

5. A transducer as claimed in claim 4, including a single electrical source for applying electric fields to the first and second stack of piezoelectric elements.

6. A transducer as claimed in claim 2, wherein each stack of piezoelectric elements together with a back mass is secured to the amplifying horn by a fastening device.

7. A transducer as claimed in claim 1, including a mounting device by which the transducer is mountable to a bonding apparatus.

8. A transducer as claimed in claim 7, including first and second mounting supports associated with the mounting device to which the first and second ultrasonic-generating means respectively are mountable with respect to.

9. A transducer as claimed in claim 8, wherein the transducer is mountable to said mounting supports at vibration nodal points of the transducer.

10. A transducer as claimed in claim 8, wherein the bonding tool is located substantially centrally between the first and second mounting supports.

11. A transducer as claimed in claim 7, wherein the mounting device is operable to rotate the transducer about a rotary axis.

12. A transducer as claimed in claim 11, wherein the rotary axis is substantially aligned with a longitudinal axis of the bonding tool.

13. A transducer as claimed in claim 1, wherein the amplifying horn is substantially bi-conical.

14. A transducer as claimed in claim 1, wherein the bonding tool is mounted substantially centrally between each end of the transducer.

15. A transducer as claimed in claim 14, wherein the distance between the bonding tool and each end of the transducer is equivalent to half of the vibrational wavelength of the transducer.

16. A transducer as claimed in claim 14, wherein a longitudinal axis of the bonding tool is substantially perpendicular to an axis of the transducer.

17. Method of forming a transducer for a bonding apparatus, comprising the steps of:

providing an amplifying horn;

securing first and second ultrasonic-generating means to the amplifying horn such that the amplifying horn is located between said first and second ultrasonic-generating means; and

mounting a bonding tool to the amplifying horn.

18. Method as claimed in claim 17, wherein each of the first and second ultrasonic-generating means comprises a stack of piezoelectric elements.

19. Method as claimed in claim 18, including arranging the poling directions of said first and second stacks of piezoelectric elements whereby the first and second stacks of piezoelectric elements are excitable in opposite directions.

20. Method as claimed in claim 19, including applying electric fields to the first and second stack of piezoelectric elements using a single electrical source.

21. Method as claimed in claim 17, including mounting the transducer to a bonding apparatus by way of a mounting device having first and second mounting supports.

22. Method as claimed in claim 21, including locating said mounting supports at vibration nodal points of the transducer when mounting the transducer.

23. Method as claimed in claim 21, including locating the bonding tool substantially centrally between the first and second mounting supports.

24. Method as claimed in claim 21, including mounting the bonding tool substantially centrally between each end of the transducer.

25. Method as claimed in claim 24, including aligning a longitudinal axis of the bonding tool substantially perpendicularly to an axis of the transducer.

26. Method as claimed in claim 25, wherein said alignment includes drilling a hole in the amplifying horn for mounting the bonding tool which is substantially perpendicular to the axis of the transducer after securing the ultrasonic-generating means and mounting supports.

27. Method as claimed in claim 17, wherein the amplifying horn is substantially bi-conical.