ACTIVE VIBRATION ABSORBER

• US 20150219176A1
• Filed: 02/06/2014
• Published: 08/06/2015
• Est. Priority Date: 02/06/2014
• Status: Active Grant

• Current Assignee: Asmpt Singapore Pte Limited
• Original Assignee: Ping Kong Choy
• Inventors: CHOY, Ping Kong, HUANG, Jinchun, XING, Xianghua, YUNG, Hoi Yue
• Granted Patent: US 9,689,453 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: F16F 15/03 using magnetic or electromagnetic means F16F9/53, F16F15/005 take precedence
• CPC Class Codes: F16F 15/035 by use of eddy or induced-current damping dynamo-electric brakes of the eddy-current type H02K49/04
• CPC Class Codes: F16F 7/1011 by electromagnetic means
• CPC Class Codes: F16F 7/104 the inertia member being resiliently mounted F16F7/1022 takes precedence
• CPC Class Codes: F16F 7/108 on plastics springs

Abstract

An active vibration absorber is attachable to a structure incorporating a positioning system which serves to vibrate the structure during its operation. The active vibration absorber comprises a mounting portion for attachment to the structure, an inertial mass that is resiliently coupled to the mounting portion and a force actuator which is operative to controllably move the inertial mass relative to the mounting portion. The force actuator is configured to move the inertial mass relative to the mounting body according to a motion profile during a motion cycle of the positioning system in order to attenuate vibrations in the structure. The motion profile is determined from a motion command which is operative to drive the positioning system during the motion cycle.

Claims

1. An active vibration absorber comprising:

a mounting portion that is attachable to a structure, the structure incorporating a positioning system which serves to vibrate the structure during its operation;

an inertial mass that is resiliently coupled to the mounting portion; and

a force actuator which is operative to controllably move the inertial mass relative to the mounting portion;

wherein the force actuator is configured to move the inertial mass relative to the mounting body according to a motion profile during a motion cycle of the positioning system in order to attenuate vibrations in the structure, the motion profile being determined from a motion command which is operative to drive the positioning system during the motion cycle.

2. The active vibration absorber as claimed in claim 1, wherein the force actuator is configured to move the inertial mass relative to the mounting body only along a single axis.

3. The active vibration absorber as claimed in claim 2, further comprising leaf springs for resiliently coupling the inertial mass to the mounting portion.

4. The active vibration absorber as claimed in claim 3, wherein one end portion of each leaf spring is affixed to the inertial mass and an opposite end portion of each leaf spring is affixed to the mounting portion to elastically support the inertial mass relative to the mounting portion.

5. The active vibration absorber as claimed in claim 1, wherein the force actuator is configured to move the inertial mass relative to the mounting body along dual axes that are orthogonal to each other.

6. The active vibration absorber as claimed in claim 5, further comprising flexible columnar supports with substantially square cross-sections for resiliently coupling the inertial mass to the mounting portion.

7. The active vibration absorber as claimed in claim 6, wherein one end portion of each flexible columnar support is affixed to the inertial mass and an opposite end portion of each flexible columnar support is affixed to the mounting portion to elastically support the inertial mass relative to the mounting portion.

8. The active vibration absorber as claimed in claim 1, wherein the force actuator comprises a linear motor having a magnet and a coil that are movable relative to each other, one of the magnet and coil being attached to the inertial mass and the other being attached to the mounting portion.

9. The active vibration absorber as claimed in claim 8, wherein the linear motor is configured to drive the coil to move relative to the magnet in two axes along a plane.

10. The active vibration absorber as claimed in claim 1, wherein the force actuator is configured to drive the inertial mass to vibrate and oscillate at a desired frequency relative to the mounting portion.

11. The active vibration absorber as claimed in claim 10, wherein the inertial mass is driven to vibrate and oscillate according to a sinusoidal signal.

12. The active vibration absorber as claimed in claim 1, further comprising a processor which determines the required motion profile for moving the inertial mass relative to the mounting portion based upon an expected force that would be experienced by the structure caused by the motion command during the motion cycle.

13. The active vibration absorber as claimed in claim 12, wherein the motion profile includes a time delay between a start of a motion associated with the structure and movement of the inertial mass.

14. The active vibration absorber as claimed in claim 12, wherein the processor is operative to determine and adjust a force amplitude of the motion profile for actuation of the force actuator.

15. The active vibration absorber as claimed in claim 1, further comprising a reference table created during calibration of the active vibration absorber which is used for determination of a suitable motion profile of the active vibration absorber based upon various motion commands.

16. The active vibration absorber as claimed in claim 1, wherein the structure comprises a semiconductor wire bonder or a die bonder.

17. The active vibration absorber as claimed in claim 1, wherein the structure comprises a casting base on which the active vibration absorber is attached, and the casting base further rests on a resilient isolator which separates the casting base from a support platform for isolating the casting base from external vibrations.

18. The active vibration absorber as claimed in claim 1, wherein a period of motion of the force actuator is approximately equal to an operation cycle time of the positioning system.

19. A method for attenuating vibrations in a structure, comprising the steps of:

attaching an active vibration absorber as claimed in claim 1 to the structure;

receiving with a processor the motion command sent to the positioning system for driving the positioning system during the motion cycle;

determining a motion profile of the inertial mass relative to the mounting portion; and

thereafter

controlling the inertial mass to move relative to the mounting portion according to the motion profile that has been determined.

20. A semiconductor processing apparatus, comprising:

a processing station incorporating a positioning system which serves to vibrate the processing station during its operation;

an active vibration absorber having a mounting portion that is attachable to the processing station and an inertial mass that is resiliently coupled to the mounting portion; and

a force actuator which is operative to controllably move the inertial mass relative to the mounting portion;

wherein the force actuator is configured to move the inertial mass relative to the mounting body according to a motion profile during a motion cycle of the positioning system in order to attenuate vibrations in the processing station, the motion profile being determined from a motion command which is operative to drive the positioning system during the motion cycle.