Processing method for flattening large dimension diamond diaphragm

Abstract

A method for smoothing and polishing a large-area diamond membrane includes such steps as fixing a CVD diamond membrane (2-5 inches in diameter) onto a bench by vacuum suction cup, installing a cup-shaped abrasive disc to the mainshaft of high-speed super-precision machine-tool, and making the mainshaft and bench to rotate in different directions at 1000-10000 rpm and 0-500 rpm respectively for grinding while controlling the surface temp of diamond membrane to 650-950 deg.C for preventing thermochemical reaction.

Description

technical field [0001] The invention belongs to the technical field of ultra-precision machining. It relates to a planarization processing method for large-size diamond films, in particular to a method for high-efficiency and low-cost grinding of large-size (φ≥1 inch) chemical vapor deposition diamond (CVD) films by using a titanium-aluminum alloy-based grinding wheel to obtain high-quality diamond A flattening processing method for the surface quality of the film. Background technique [0002] Since the 1990s, many breakthroughs have been made in the preparation technology and performance characterization of CVD diamond films. Diamond film has begun to move from the experimental research stage to the industrial application stage. However, the relatively lagging post-polishing technology of diamond films limits the wide application of diamond films, especially the polishing and smoothing technology of large-area diamond films has become a key problem in the application of ...

AI Technical Summary

Problems solved by technology

However, the relatively lagging post-polishing technology of diamond films limits the wide application of diamond films, especially the polishing and smoothing technology of large-area diamond films has become a key problem in the application of diamond films in high-tech fields

[0003] Since diamond is the material with the highest hardness and high chemical inertness known at present, and the thickness of the diamond film is small, the overall strength is low, and it is easy to break or produce microcracks, which makes the planarization technology widely used in the field of ultra-precision machining. Such as traditional chemical mechanical polishing, electrolytic polishing, etc. are difficult to apply to the processing of diamond film

Although laser beam polishing, ion beam polishing and other CVD diamond film planarization technologies have been developed, they are mainly aimed at small-sized (φ≤1 inch) diamond films; although mechanical grinding and polishing, hot iron plate polishing, chemical mechanical polishing and other technologies Both can realize the polishing of large-size diamond films. For example, the first domestic large-area CVD diamond film hot iron plate polishing machine successfully developed by Beijing University of Science and Technology can complete the polishing of 3 pieces of φ110mm diamond films at a time, but these methods usually require expensive heating. equipment and vacuuming equipment, the equipment is complicated, the cost is high, and at the same time, the deformation of the polishing disc is serious under high temperature, which affects the surface shape accuracy of the diamond film; The method of combining frictional heat and low-temperature heating on the bottom surface of the polishing disc makes the surface temperature of the diamond film polishing rapidly reach the diffusion temperature, thereby achieving the purpose of thermochemical polishing. However, this invention does not optimize the mechanical properties of the polishing disc material, but by heating The bottom of the equipment is heated to reduce the temperature gradient of the polishing disc to ensure the surface shape accuracy of the polishing disc, so heating equipment is required, and energy consumption is large. At the same time, the invention requires vacuum equipment, which increases the complexity and cost of the equipment, and when using this method to polish , the polishing disc is severely worn and oxidized, and the surface accuracy is difficult to control, which cannot meet the high-efficiency and low-cost planarization processing requirements of large-size CVD diamond films

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