Introduction of UHP gas pipeline materials ( semiconductor technology world)
The original text comes the material supplier
A ultra pure, clean piping system
More than 20 years ago, the pipeline used to transport pure medium (gas) in semiconductor, integrated circuit biopharmaceutical industry was ordinary stainless steel pipeline. Although the material installation cost of pipeline was low, the yield (qualified rate) was very low. The more serious problem is: with the improvement of chip integration, the line width is getting smaller smaller, which puts forward higher requirements for the pipeline of gas medium transmission, the quality of pipeline has become the bottleneck restricting the improvement of chip production integration. At that time, a professor Tohoku University of Japan went to a chip factory in the United States to investigate these problems. Aiming at these problems, he cooperated with Kobe special steel factory in Japan to develop stainless steel pipes suitable for transmitting high-purity gas. After several times of research development, he successfully developed Ba pipes (bright annealed stainless steel pipes) with refined base metal after cold rolling. On this basis, he invented EP pipes. Through the improvement of the pipeline system, the chip integration output have been greatly improved, the high-tech industry has developed rapidly in recent years.
B ultra pure, the true meaning of clean pipeline system
Semiconductor, integrated circuit, biological industry, transportation of pure medium (gas) of high purity pipeline is a comprehensive consideration of organizational stability, corrosion resistance, processability optimization of stainless steel pipe. To ensure the neutrality of the system, we should emphasize the surface roughness Ra value its own cleanliness, so that the occurrence accumulation of particles can be restrained. In order to ensure weldability welding quality, dimensional tolerance chemical composition of base metal are required. Only in this way can the occurrence of smoke particles be reduced the corrosion resistance smoothness of the welding parts be improved. In a word, high purity pipeline should have beautiful appearance (external purity) genuine material (internal purity).
1. The external purity is different the gray uneven feeling of the internal external surface of the traditional stainless steel pipeline. The present ultra pure, clean pipeline has a polished appearance, also has a better internal surface roughness, so as to ensure that the pipeline system remains neutral to the transmission medium ensure the purging cleaning performance, Now the surface roughness Ra value often mentioned by engineers technicians is the basic requirement for the inner surface roughness of pipeline system. In order to ensure the quality efficiency of automatic rail welding, dimensional tolerance is also a basic requirement.
2. Intrinsic purity refers to pure material: in the true sense, super purity is far enough to clean the beautiful inner outer surface of the pipeline. There are also very strict requirements for the material of the pipeline system, there are certain definitions for chemical composition mechanical properties. Therefore, the pure pipe we mentioned is made of pure 316L, which means that the impurities in stainless steel should be reduced to a certain range as far as possible, the non-metallic inclusions gas composition should be controlled.