Complex frequency sandwich structure ultrasonic transducer

Abstract

The invention discloses a complex frequency ultrasonic transducer for thermal ultrasonic lead bonding and thermal ultrasonic inversion seal equipment. An energy concentrator comprises a first-class energy concentrator tapered section, a column section and a second-class tapered energy concentrator, wherein the tail part of the first-class energy concentrator tapered section is provided with a front cover plate, and a plurality of copper sheet electrodes and a plurality of piezoelectric ceramic wafers are installed at intervals; and each copper sheet electrode and each piezoelectric ceramic wafer are clamped between the front cover plate and a rear cover plate and tightly pressed and fixed by pre-tightening screws. A third-class energy concentrator, a second-class energy concentrator, a clamping flange, the front cover plate and the rear cover plate are machined by using the same material as a whole. The transducer works near a frequency point of 60kHz and 100kHz and has no modal dense condition near a resonance point, and the seal at low temperature below 60 DEG C can be realized by adopting a high-frequency transducer of 100kHz. The invention adopts an integrated two-class energy concentrator structure, realizes high-power magnification, reduces the weight and inertia of a mechanism by adopting a titanium alloy material and improves the heat radiating performance and the service life of the transducer.

Description

technical field [0001] The invention belongs to the field of ultrasonic processing and manufacturing, and in particular relates to a multiple-frequency ultrasonic transducer device for thermosonic wire bonding and thermosonic flip-chip packaging equipment. Background technique [0002] "Thermosonic wire bonding" is an important technology of IC packaging, and its packaging forms account for more than 90% of IC packaging. "Thermal ultrasonic flip-chip packaging" is a new IC packaging method developed in recent years. These two packaging forms are the electrical interconnection methods that play a leading role in the IC manufacturing process. Both thermosonic wire bonding and thermosonic flip-chip packaging processes use ultrasonic energy. Piezoelectric ultrasonic transducers are an important component of the ultrasonic system of IC packaging equipment, which take on the important task of converting electrical energy into mechanical ultrasonic vibration energy. The piezoelec...

AI Technical Summary

Problems solved by technology

Traditional piezoelectric transducers used for ultrasonic machining (such as ultrasonic cutting, ultrasonic welding) mostly work in the base frequency band, that is, around the frequency point of 20kHz to 60kHz, and piezoelectric ultrasonic transducers used for IC packaging generally work at the frequency point of 60kHz Nearby, with the continuous development of chips, the packaging process requires piezoelectric transducers to have a higher operating frequency, mainly because IC packaging at high frequencies has the following advantages: the chip is gradually miniaturized, and its I / O density is greatly improved. As the lead spacing is getting smaller and smaller, the existing traditional frequency transducers cannot meet the requirements of chip packaging with ultra-fine pins. In the high-frequency modal vibration, the amplitude of the transducer just becomes smaller, which meets the requirements of chip development; A transducer with high-frequency vibration can increase the packaging speed, thereby improving the packaging efficiency; in thermosonic packaging, heat, pressure and ultrasonic energy need to be applied at the same time, and the use of high-frequency transducers is equivalent to increasing the ultrasonic energy and correspondingly reducing the application of heat , so that low-temperature packaging can be achieved, which is very important for some chips that cannot withstand high temperatures

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