To enhance the value of Taiwan's machine tool industry and to assist the Taiwanese manufacturing industry in responding to future technological challenges, the National Science and Technology Council (NSTC) actively promotes the research projects regarding of smart manufacturing key technology in the Taiwan’s universities. Professor Chen Jenq-Shyong from the Department of Mechanical Engineering at National Chung Hsing University, with long-term support from the NSTC, has developed ultrasonic-vibration assisted machining technology for computer numerical control (CNC) precision machining of advanced materials that are hard and brittle or difficult to cut. This technology can improve machining efficiency, tool life, and machining quality. In addition, the integrated solution of online monitoring, on-machine optical measurement, and digital technology for intelligent ultrasonic machining technology has been developed and demonstrated.
Linking Domestic Industries and Developing Ultrasonic Machining Technology with Deep Technical Integration
In industries, such as semiconductors, electronics, optoelectronics, aerospace, energy, medical equipment, and precision mechanical components, there has an increased demand of using the advanced lightweight, high-hardness, and high-temperature-resistant materials such as silicon carbide (SiC), sapphire, quartz, ceramics, glass, and composite materials. The NSTC granted project "Intelligent real-time monitoring and remote service technology for ultrasonic vibration assisted machining of semiconductor materials." has successfully developed an integration solution to enhance the machining efficiency and quality of these advanced materials. The team, led by Prof. Chen, is an across discipline team with professors from National Chung Hsing University, Ching Yun University of Science and Technology. This project integrates ultrasonic machining technology, on-machine automated optical tool measurement technology, intelligent ultrasonic drivers, wireless power transmission technology, and IoT smart tool holder technology.
The technical highlights and application benefits are as follows:
1.The development of the world's smallest non-contact electrical energy transmission high-speed ultrasonic tool holder has been developed for ultrasonic micro-drilling of brittle materials. With wireless electricity transmission technology and patented carbon fiber restraint design , the maximum spindle speed can reach over 40,000 rpm.
2.An on-machine vision-based measurement technology was developed to measure the ultrasonic tool vibration amplitude. It can measure the two-dimensional (2D) vibration of the tool tip of ultrasonic tools with frequencies up to 50kHz. It can also be used to measure the 2D dynamic run-out error of small tools at high rotating speeds. The minimum tool diameter that can be measured is 0.01mm. This vision-based measurement technique has obtained a patent in Taiwan  and has been licensed to partner companies for commercialization. It also won an award in the "Research and Development of Machine Tool Innovation Product" competition at the 16th Machine Tool Show in 2023.
3.The research team has developed a 1kW high-power broadband ultrasonic driver and obtained the Taiwan patent [4, 5]. It can control the ultrasonic frequency range from 20kHz to 42kHz. In addition, this patented ultrasonic driver also has a high energy conversion efficiency of over 95%, which is superior to the general energy conversion efficiency of 90% or less commonly seen on the market .
4.Developed a smart tool holder which integrates the non-contact electric power transmission, IoT sensors, microcontrollers, power control modules, Wi-Fi modules, and antennas into the interior of the tool holder. The tool holder is powered and charged continuously during operation using wireless electric power transmission technology. The smart cutting tool holder is designed with a Lego-like concept and can be easily customized according to different application scenarios such as semiconductors, electronics, aerospace, automotive, medical, and precision mechanical components.
The Development of Key Technologies has Made Taiwan a Creative Research and Development Base for New Materials Processing.
It has been proved that the developed ultrasonic machining technology can increase processing speed by more than 2 times and tool life by more than 2 times according to actual testing results from end customers of the semiconductor industry. This technology had been used in the mass production lines of Taiwan’s domestic semiconductor supply chain companies. It is also being tested by semiconductor supply chain companies in Korea and Japan. The application of ultrasonic machining technology can be extended to various industries such as electronics, optoelectronics, displays, electric vehicles, aerospace, energy, medical equipment, and precision mechanical components with new materials such as glass, sapphire, ceramics, quartz, composite materials, and superalloys. Professor Chen's team hopes this new technology can become a common usage in the CNC machining of advanced materials in the near future.
.Taiwan Patent I669185, 2020, 「Non-contact high-frequency vibration spindle system for electric energy transmission and production method of re-straint part」
.Tainwan Patent I780777, 2022
.T. Mishima and Ching-Ming Lai, “Load-Adaptive Resonant Frequency-Tuned Δ-Σ Pulse Density Modulation Class-D ZVS High-Frequency Invert-er-Based Inductive Wireless Power Transfer,” IEEE Journal of Emerging and Selected Topics in Industrial Electronics, vol. 3, no. 3, pp. 411-420, Jul. 2022
.Taiwan Patent I754946, 2021, 「Capacitance value adjusting apparatus and wireless power supply apparatus」
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Department of Engineering and Technologies National Science and Technology Council