Thedevelopment of the power semiconductor industry has grown with the expansion ofdownstream applications. Power semiconductors are the core components thatconstitute power electronic conversion devices, and have entered variousindustrial sectors of the national economy and all aspects of social life. Withthe emergence and development of new application scenarios, the applicationscope of power semiconductors has expanded from traditional consumerelectronics, industrial control, power transmission, computers, rail transit,new energy and other fields to emerging applications such as the Internet ofThings, electric vehicles, cloud computing and big data. These new applicationareas bring new development opportunities and challenges to powersemiconductors.

From theperspective of industrial competition, global manufacturers of high-end powersemiconductor products are mainly concentrated in the United States, Europe,Japan and South Korea. Compared with international counterparts, China's powersemiconductor industry started late, mainly through foreign introduction andindependent innovation of domestic enterprises, gradually improve the degree oflocalization of the industry, to meet the growing downstream demand. Atpresent, in the low-end field, products with relatively simple productionprocesses such as diodes and thyristors have basically been localized. In thefield of high voltage and high reliability, such as transistor devicesrepresented by IGBT, due to the high threshold of the production process andrelatively complex structure, the high technical gold content and product addedvalue, most of the current market share is occupied by foreign manufacturers.

                Schematic diagram of the power semiconductor product range

There are two main types of packaging for power semiconductor devices:discrete and integrated.

Discrete packaging is the packaging of individual power semiconductordevices, such as diodes, MOSFETs, etc., into independent devices. The advantageof this package is that the structure is simple, maintenance and repair arerelatively easy, and it is widely used in applications such as frequencyconverters, UPS, AC dimmers, LED lighting, etc. However, it also has certaindisadvantages, such as large size, heavy weight, limited layout of the circuit,and relatively high manufacturing cost. The process of discrete packagingincludes a series of steps such as semiconductor packaging, substratemanufacturing, heat sink manufacturing, terminal manufacturing, and assembly.

Integrated packaging is a package that integrates multiple powersemiconductor devices on a chip, makes conductive circuits on the surface ofthe chip to connect these devices, and then encapsulates them through packagingmaterials such as metal cover sheets, metal plates, and plastic shells. Theadvantages of this package are small size, light weight, high integration,miniaturized design, and low manufacturing cost. The process of integratedpackaging includes a series of steps such as chip selection, chip mounting, pinconnection, encapsulation, and testing.

Both discrete andintegrated packaging involve the chip placement process stage, and thesolidcrystal machine is an indispensable equipment in the chip placemenprocess. A solid crystal machine is an automated device that mounts chips to apackage substrate

to improve production efficiency and placement quality. Themain function of the solid-crystal machine is to mount the chip to thesubstrate according to the preset position and angle, and at the same timeensure the electrical connection and mechanical fixation between the chip and thesubstrate. The operating accuracy and stability of the solidcrystal machineare essential to ensure a reliable connection between the chip and the package.

                Power device IGBT module structure andprocessing flow diagram

Before chipplacement on a solid-crystal machine, some preparatory work is required. First,the chip and substrate or package to be mounted need to be placed on theworkbench of the machine, and align and adjust; Solid-crystal machines areusually equipped with a nozzle that can be used to suck up chips. Beforesucking up the chip, you need to determine the position and angle of the chip,then move the nozzle to the appropriate position and press the suction buttonto make the chip suck up. When the chip is sucked, the solid-crystal machine needsto align the position of the chip. This process is usually done by themachine's vision system, which takes images of the chip and substrate orpackage, and uses software to align and position it. When the position of thechip is aligned, the solidifier places the chip on the substrate or package.This process is also controlled by the machine's vision system to ensure thatthe chip is placed at the correct position and angle. When the chip is placed,the solidifier cures it, for example by heating or UV irradiation, to make theconnection between the chip and the substrate or package stronger. After thesolid-crystal machine finishes mounting, the quality of the placement ischecked. By means of vision systems or automatic inspection devices, poorly placedor incorrectly positioned chips can be detected and processed accordingly.

There are many types of solidification machines, including automaticsolidification machines, semi-automatic solidification machines, etc. Theautomatic solidification machine can automatically complete all the placementsteps, including absorbing the chip, aligning the position, placing the chip,etc., with the characteristics of high precision, high speed and highefficiency. Semi-automatic solidification machines require manual completion ofsome placement steps, such as chip suction and alignment position.

The use of solid-crystal machine can greatly improve the packagingefficiency and quality, but also reduce the package volume and weight, andimprove the reliability and stability of the package. In addition,solid-crystal machines can also achieve high-precision alignment and bonding,enabling packaged semiconductor devices to have better electrical performanceand reliability.

               Takethe IGBT module processing process as an example

Suzhou Bozhon SemiconductorCompany focuses on AI computing power center, optical communication, lidar,high-power laser, power semiconductor and other market segments, and activelycarries out the research and development and cooperation of new semiconductorproducts. In terms of high-precision eutectic machine, since the launch of thefirst product last year, the company continues to strengthen the iterativedevelopment of technology and cost reduction, new customer orders continue toincrease, this year's launch of new product Xingwei EH9721, has obtained theindustry global leader 400G/800G batch orders, mainly for the computing powerimprovement requirements of 800G optical module product research anddevelopment, its core technology, such as high-precision pick-and-fit system,high-efficiency eutectic heating system, wafer feeding system, etc. havereached the international advanced level. The competitive advantage is clear.

The performance indicators ofBozhon semiconductor solid crystal machine equipment have reached the level ofsimilar international products, and will soon gain certain recognition in themarket, giving full play to its positive role in actual production. This isundoubtedly an important driving force for the domestic substitution of China'ssemiconductor equipment market.

Bozhon Semiconductorhigh-speed and high-precision die attach machine