Main uses of tungsten metals:
1, processing lathe knife head, lighting equipment with tungsten wire and a variety of thermal conductivity;
2, the manufacture of high-grade automobile crankshaft, Tungsten Metals cylinder of the ingredients, casting a variety of special steel ingredients;
3. Widely used in the manufacture of guns, artillery, rockets, satellites, airplanes and warships.
Tungsten metal is the highest melting point of nature metal (3410°c), Tungsten Metals at the same time has high strength, high hardness, low resistivity characteristics. Tungsten metal resistance to high temperature, impact resistance, wear resistance, thermal stability, to ensure that the device at high temperature stability of the work, is the MEMS device processing and manufacturing of structural materials good choice, Tungsten Metals especially for high-temperature and other harsh or extreme environment. Traditional tungsten materials use physical or chemical deposition methods to form thin films, but the thickness of thin films is generally no more than 2 microns due to the process limitation and stress, which affects the design and manufacture of the device. If the tungsten metal material is used as structural material instead of the traditional monocrystalline silicon material to make MEMS switches, MEMS resonators, MEMS probes, micro-EDM electrodes and other devices, Tungsten Metals these devices will have more excellent electrical, mechanical and high-temperature resistance characteristics because of the characteristics described above. Tungsten metal is the main material of microelectronic chip test probes, and with the reduction of chip pitch, Tungsten Metals probes and probe cards also need to be miniaturized with new micro-machining methods, compared with the current single crystal Silicon microprobe (card), tungsten metal material formed by micro-probe (card) with high hardness, low wear rate, low resistance, high reliability. Because of the high density and hardness of tungsten metal, the etching rate of the traditional reactive ion etching process is very low, and the transverse drilling is also larger, it is not possible to achieve large depth and high aspect ratio etching in relatively short time, which can not meet the manufacturing demand of MEMS devices. Therefore, the current application of tungsten metal is mostly in the integrated circuit technology, Tungsten Metals a thin film with a thickness of less than 2 microns is prepared by physical or chemical deposition, and then the traditional reactive ion etching process is used to prepare a part of the device, such as a metal grating, a metal interconnect, a metal diode, etc. The use of etched gas or gas combinations involves CF4, cf4+02, Cl2, cl2+02, SF6, sf6+02, NF3, ccl4+02, etc., using etching methods involving flat-panel plasma etching (PE), reactive plasma etching (RIE), and electron cyclotron resonance plasma etching ( ECR) and so on, because the plasma density is relatively low (less than IOICI-IO12CNT3), low energy, the resulting etching rate is generally much less than 1 microns per minute. At present, there is no report on the use of tungsten metal materials as the main structure of the MEMS devices, Tungsten Metals while the existing thin film tungsten material etching process is generally low, anisotropy difference, becoming the main bottleneck. For the processing of tungsten metal material, it is not reported that the process of etching with high rate and aspect ratio can be achieved.