In the 茫茫 universe, a metal-like alloy cosmic probe passes at superluminal speed. It consists of protons and neutrons that are locked by strong interactions. Because the surface is absolutely smooth, it can reflect all electromagnetic waves, and it is invincible... This is Liu Cixin mentioned in the science fiction "Three-body" a kind of spacecraft called "water droplets".
In fact, human pursuit of "absolutely smooth" has also changed from scientific fantasy to practice, such as the ultra-precision polishing technology that promotes "integrated circuit transformation revolution." As described in the Tris, the most advanced chemical mechanical polishing (CMP) technology has also entered the atomic size class. And when the electronics industry powers are rushing to climb or reach the peak of this process, we can only look up.
Modern electronics industry, ultra-precision polishing is the soul
Physical polishing is the most commonly used polishing technique before the 1980s, but the rapid development of the electronics industry places increasingly stringent requirements on the size and flatness of material devices. When a substrate having a thickness of one millimeter needs to be fabricated into an integrated circuit of several hundred thousand layers, the conventional old polishing process is far from satisfactory.
“In the case of wafer fabrication, polishing is the last step in the entire process. The goal is to improve the micro-defects left in the process before wafer processing to achieve the best parallelism.†Dr. Wang Qi, Research Fellow, National Nanoscience Center, Chinese Academy of Sciences The daily reporter introduced.
Today's level of optoelectronic information industry, the parallelism of sapphire, monocrystalline silicon and other materials as optoelectronic substrate materials is becoming more and more precise, and has reached the nanometer level. This means that the polishing process has also entered the nano-scale ultra-precision.
How important is the ultra-precision polishing process in modern manufacturing, and its field of application can directly explain the problem: integrated circuit manufacturing, medical equipment, auto parts, digital parts, precision molds, aerospace.
Wang Qi said: "The mission of ultra-precision polishing technology in the modern electronics industry is not only to flatten different materials, but also to flatten the multilayer material, so that a few millimeters of silicon wafers pass this 'global flattening'. 'Forming a very large-scale integrated circuit composed of tens of thousands to a million transistors. For example, the computer invented by humans has changed from a few tens of tons to a few hundred grams now. Without super-precision polishing, it is the technical soul."
Core technology is hidden in the snow, domestic demand is subject to people
Zhejiang Jingsheng Electromechanical Co., Ltd. is one of the pioneers in the pursuit of “global flattening†in China's electronics manufacturing industry. Sun Ming, the company's technical director who has been engaged in polishing process research for many years, told reporters: “If we compare the polishing process to making pancakes, we will The neck is the pot, the other people's pot does not stick to the bottom of the pot, and we can't do it."
Sun Ming’s “pot†is the core component of the polishing machine – “grinding discâ€. Ultra-precision polishing is almost demanding on the material composition and technical requirements of the grinding disc in the polishing machine. This steel disc synthesized by special materials not only needs to meet the nano-scale precision of automatic operation, but also has a precise coefficient of thermal expansion.
When the polishing machine is in a high-speed operation state, if the thermal expansion causes thermal deformation of the grinding disc, the flatness and parallelism of the substrate cannot be guaranteed. The thermal deformation error that cannot be allowed to occur is not a few millimeters or a few micrometers, but a few nanometers.
At present, the world's top polishing technology, such as the United States and Japan, can meet the precision polishing requirements of 60-inch substrate materials (which are oversized). They control the core technology of ultra-precision polishing process and firmly grasp the initiative of the global market. . In fact, grasping this technology has largely controlled the development of the electronics manufacturing industry.
Sun Ming introduced that the grinding discs of Japanese-made polishing machines are all customized, and they are not mass-produced, which directly limits the imitation of other countries. Wang Qi also told reporters that the polishing equipment of the United States is sold to China, and the price is generally more than 10 million yuan. Sales orders have been placed until the end of 2019 and no orders have been accepted before.
"In the face of such a strict technical blockade, we are very anxious. During the Spring and Autumn Period, Luban helped the human civilization to invent the civilization of agriculture. Now our progress in the electronics industry has once again been stuck in the neck by a kind of grinding disc. But now, we are urgent, now we Have to wait, either waiting for imports, or independent research and development." Wang Qi said.
Going to the top of the technology, asking for help
In fact, in the field of ultra-precision polishing, China is not without achievements. As a set of highly technically advanced synthesis processes, ultra-precision chemical mechanical polishing processes must consist of equipment and materials (polishing fluid), both of which are indispensable.
In 2011, Dr. Wang Qi's team researched and developed the "cerium dioxide microsphere size standard material and its preparation technology" won the first prize of the technical invention of the China Petroleum and Chemical Industry Federation, and the relevant nanoscale particle size standard materials obtained the national measurement instrument license and the state. Level 1 standard substance certificate. The ultra-precision polishing production test results of new cerium oxide materials have surpassed the traditional materials in foreign countries and filled the gap in this field.
But Wang Qi said: "This does not mean that we have climbed to the top of this field. For the whole process, there is only polishing liquid and no ultra-precision polishing machine. We only sell materials at most."
Sun Ming believes that to clarify the specific requirements of modern electronics industry manufacturing, we can accurately determine the direction of ultra-precision polishing process: "The polishing process needs to meet the requirements of current electronics manufacturing, and can be summarized as ultra-precision, large size. With top-level Polishing materials are only the basis, based on which we need to go in two steps, first to solve the problem of grinding discs, and secondly to solve the problem of enlarged polishing area."
Sun Ming introduced that the material composition and manufacturing process of polishing discs in the United States and Japan has always been a mystery. In other words, buying and using their products does not mean that they can copy or even copy their products. This is two different things.
“What kind of materials and processes can be used to synthesize such a grinding disc with low thermal expansion rate, high wear resistance and ultra-precision grinding surface? This is the technical problem that we need to concentrate on the first. Once this problem is solved, the 60-inch polished working surface will not be Then dreams. And such core technology can never be expected to be obtained from others. In addition to relying on ourselves, we have no choice." Sun Ming said.
Stone Plastic Composite Floor,Stone Plastic Composite Flooring,Stone Plastic Composite Vinyl Tile Spc Flooring,Stone Plastic Composite Rigid Core Spc Flooring
Linyi Hmbyan International Trading Co.,Ltd , https://www.lhialuminumcomposite.com