Patent · US Expired

Ultrasonic transducer

US6286747A · kind A · utility

12Cited by

23References

5Claims

0Family size

Assignee

The Hong Kong Polytechnic University · CN

Inventors

Helen Lai Wa Chan · Forbes, AU
Siu Wing Or · Sha Tin, CN
Chung Loong Choy · Kowloon, CN

Key dates

Filing date	Mar 24, 2000
Grant date	Sep 11, 2001
Priority date	—
Expiry date	Mar 24, 2020

Classification

Technology area (CPC H)Electricity
CPC primaryH01L2924/00014
WIPO fieldChemical engineering
WIPO sectorChemistry

Abstract

A bonding tool has a driver of piezoelectric elements in a stack. A sensor is positioned and held in the stack and includes a piezoelectric element sandwiched between electrodes and insulating wafers. Voltage developed between the electrodes is monitored and used to determine a bonding parameter, including the amplitude and duration of each ultrasonic burst.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.