Thousand-story "skyscraper" in millimeter-level parts Ultra-compact electronic components packed with Chinese wisdom

February 09, 2022 Ye Qing (Science and Technology Daily Reporter)

Image courtesy of Visual China

210%These new products are being applied in fields such as mobile communications, car electronics, industrial automation control, and smart home appliances, and sales have increased by 150-210% year-on-year. Among them, more than 30% of the total is resistor-related parts necessary for smartphones and base stations of ZTE and Huawei, which are exported to Europe, the United States and Southeast Asian countries.

Fu Zhenxiao, chief engineer of Guangdong Fenghua Hi-Tech Co., Ltd. (hereafter referred to as Fenghua Hi-Tech) and director of the research institute, said, "One small smartphone can contain 1,100 chip capacitors and resistors. 300 to 400 are used, but not many people know how small the size of chip capacitors is, and among not just small, but very small electronic components, there are hundreds, even is a complex structure with more than 1,000 layers."

However, even with this small precision electronic component, the so-called technical hurdles made domestic production of chip resistors a thorny road.

10 years ago, a team led by Mr. Fu researched and developed the technology, and started the project "Precision Manufacturing Technology and Application of Ultra-Small Chip Resistors". Established the key technology of ultra-small chip resistors, realized the industrialization and independent supply of microchip resistors and key materials, and the independent supply of resistors for 5G base stations. The project recently won the first prize of the 2020 Guangdong Technology Progress Award.

The steep road to domestic production

What is a chip resistor?

Mr. Fu said, "This is actually a basic part in the electronic information field, and this part is used in all places where electricity passes through in an electric circuit. It is mainly used in filter circuits and electric It plays a role of controlling the output of radio waves in the circuit.”

With the advent of the smart age, the demand for space for chip resistors in smartphones and wearable devices is getting higher and higher. Mr. Fu said, "The smallest high-capacity chip multilayer ceramic capacitor (MLCC) developed by our team is only 0.4mm x 0.2mm. It has a complex structure consisting of 100 to 1,000 layers, and the thickness of each layer is on the order of micrometers.” Even the slightest mistake is unacceptable.The requirements for the precision of the manufacturing method and the strength of the materials are extremely high."

It looks like a very small electronic component, but its domestic production was a thorny road. Although China's consumption of chip resistors accounts for about 70% of the world's total, its own production rate has not reached 8%. It is more than 30 billion yuan (1 yuan is about 17.9 yen).

What are the difficulties in research and development of chip resistors?

According to Mr. Fu, there are three main points. The first is that due to its extremely small size, even the slightest error in the positioning of the high-precision electrodes will reduce the accuracy and reliability of the product. In particular, large-scale production is difficult because high precision is required for the positioning of several hundred layers of electrodes. The second point is that the nanocrystalline medium material of the ultra-thin medium layer suffers from insulation failure and dielectric breakdown under the electric field action of the product with structural defects and difficulty in dispersion. The third is that the mismatch between the ceramic material and the metal electrode material co-firing will cause the electrode to be intermittent, resulting in poor electrical performance and reliability of the product.

“Without the ability to develop independently, it will be difficult for a company to survive in the highly competitive technology and market,” said Fu, who immediately became a postdoctoral researcher at Fenghua High School's scientific research activity base. Over the nearly 20 years since I started working, I have faced many times the severe challenges brought about by technological breakthroughs brought about by my peers around the world, and I have come to realize the importance of independent research and development.

Ten years ago, the team led by Mr. Fu, which focused on the technical needs of "ultra-compact, ultra-thin, high-precision, and high-reliability," has established Tsinghua University, Shenzhen Advanced Technology Research Institute of the Chinese Academy of Sciences, (hereinafter referred to as “Zhongxing”) and Tsinghua University Shenzhen International Graduate School, jointly set up a project team to develop a high-capacity chip multilayer ceramic capacitor with a thin medium.

Breaking through overseas blockades and establishing key manufacturing methods and technologies

Targeting various technical challenges that may arise, the R&D team formulated a detailed development plan, divided the big problem into several smaller problems, and shared the tasks to tackle the challenges one by one. .

During the most difficult time, in order to solve one technical problem, the research and development team was divided into three groups, approached from different perspectives, and searched for the best technical solution.

Taking the rapid co-firing technology innovation of ultra-small chip resistors as an example, the research and development team, based on the temperature of various materials, reaction By shortening this time, it is possible to effectively reduce the structural dynamics and interfacial reactions of low-temperature firing.” Based on this, we invented MLCC rapid co-firing technology, and eventually found that the mismatch between ultra-small MLCC ultra-thin media and nickel internal electrode sintering, and the interfacial diffusion between the micro-chip resistor resistor and electrode are serious. By solving the problem, the suppression accuracy of the reaction layer at the interface was further improved. As a result of this achievement, we have established key manufacturing methods and technologies that have been blocked by foreign countries, and in addition to improving the product capacity by more than 30%, the pass rate has also increased to more than 94%.

In addition, using China's first base metal terminal electrode new low-temperature sintering technology, the surface porosity of the terminal electrode is reduced to 0.2%, and the product failure rate is less than 1/1,000,000, making it one of the world's leading companies. has reached the level of

After unremitting efforts, the research team has developed a high-capacity chip multilayer ceramic capacitor, a high-precision 01005 chip resistor, and a high-performance nanocrystalline medium material in a thin medium with its own intellectual property rights. These new products are being applied in fields such as mobile communications, car electronics, industrial automation control, and smart home appliances, with sales increasing by 150-210% year-on-year. Of these, over 30% of the total is resistor-related parts necessary for smartphones and base stations of Zhongxing and Huawei, and they are exported to Europe, the United States and Southeast Asian countries.

Fu said, "In this project, we succeeded in researching and developing the key technology of ultra-small chip resistors, filling the gap in China, and realizing the industrialization and independent supply of small chip resistors and key materials. As a result, it has effectively alleviated the problem that China's high-end resistors are subject to foreign restrictions, and realized the independent supply of resistors for 5G base stations."

Based on that, the research and development team further develops new products. By adding flexible terminals on top of hard ceramics, it greatly improves product reliability, supports the domestic production of China's key basic components, and strengthens the safety and development of China's electronic information industry and the security of its national strategy. provides great support.

*This article is based on Science and Technology Daily, "Thousand-storied 'Tall Tower' Ultra Miniature Electronic Element Exhibition 'Chinese Kung Fu'" (November 10, 2021, page 5) with permission from Science and Technology Daily. This is a Japanese translation/reprint.