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CN-122007994-A - Processing method and processing system for hard and brittle material workpiece

CN122007994ACN 122007994 ACN122007994 ACN 122007994ACN-122007994-A

Abstract

The present disclosure relates to a processing method and processing system for a workpiece of brittle material. In one aspect, the method includes applying a viscous medium to a surface of a workpiece to be machined and contacting and producing relative motion of a fixed abrasive tool with the surface to be machined for grinding machining, wherein in grinding machining, the viscous medium captures and suspends abrasive particles of the fixed abrasive tool that fall off during grinding machining at a contact interface of the fixed abrasive tool with the workpiece to form a free abrasive layer such that the abrasive particles in the free abrasive layer abrade the surface to be machined in situ. Therefore, the tool grain is reduced or even eliminated, and the surface processing quality of the workpiece is improved.

Inventors

  • Shi Yuechuan
  • Request for anonymity

Assignees

  • 重庆欣晖材料技术有限公司

Dates

Publication Date
20260512
Application Date
20260408

Claims (12)

  1. 1. A method of processing a workpiece of a hard and brittle material, the method comprising: applying a viscous medium to a surface of the workpiece to be processed, and Contacting a fixed abrasive tool with the surface to be machined and producing relative motion to perform a grinding process, Wherein, in the grinding process, the viscous medium captures and suspends the abrasive particles falling off by the fixed abrasive tool in the grinding process at the contact interface of the fixed abrasive tool and the workpiece to form a free abrasive layer, so that the abrasive particles in the free abrasive layer grind the surface to be processed in situ.
  2. 2. A method of working on a workpiece of brittle material according to claim 1, characterized in that the viscous medium contains no abrasive particles prior to application to the surface to be worked, the abrasive particles in the free abrasive layer being abrasive particles that are detached from the fixed abrasive tool.
  3. 3. A process for the production of workpieces of brittle and hard material according to claim 1, the viscous medium is an emulsified paste, and the emulsified paste comprises: An oil phase component comprising at least one of hydrocarbons, vegetable oils and fatty alcohols for providing lubrication at the contact interface; An aqueous phase component comprising a humectant and a water soluble polymeric thickener for providing the viscous drag necessary to suspend the abrasive particles, and An emulsifier for mixing the aqueous phase component with the oil phase component to form a stable dispersion.
  4. 4. A method of processing a workpiece of brittle material according to claim 3, characterized in that the water-soluble polymer thickener comprises carbomer and the humectant comprises at least one of glycerol and propylene glycol.
  5. 5. A method of processing a workpiece of brittle material according to claim 3, characterized in that the emulsifier comprises at least one of glycerol stearate and triglycerol diisostearate.
  6. 6. The method of claim 1, wherein the fixed abrasive tool is a ceramic bond diamond tool, and wherein during the grinding process the bond on the surface of the ceramic bond diamond tool breaks to release diamond abrasive particles.
  7. 7. The method of claim 1, wherein the brittle material is silicon carbide, sapphire or gallium nitride.
  8. 8. A method of working a workpiece of brittle and hard material according to claim 1, characterized in that the surface to be worked is an annular groove in the workpiece, the grinding section of the fixed abrasive tool extends into the annular groove, and the viscous medium is filled between the grinding section and the annular groove.
  9. 9. A method of machining a workpiece of brittle and hard material according to claim 1, characterized in that it further comprises continuously or intermittently replenishing the contact interface with the viscous medium during the grinding process.
  10. 10. The method of claim 1, wherein the relative movement comprises rotation of the workpiece about a first axis and rotation of the fixed abrasive tool about a second axis.
  11. 11. The method of claim 1, wherein the workpiece is fixed to a tool carrier by wax adhesion, and the tool carrier is fixed to a turntable of a machine tool by vacuum suction.
  12. 12. A machining system, characterized in that it performs a machining method for a workpiece of brittle material according to any of claims 1 to 11, comprising: A numerically controlled machine tool comprising a first drive for driving the workpiece and a second drive for driving the fixed abrasive tool; The fixed abrasive tool is arranged on the second driving device and is used for grinding the surface to be processed of the workpiece arranged on the first driving device, and And a medium supply unit configured to supply the viscous medium to the surface to be processed.

Description

Processing method and processing system for hard and brittle material workpiece Technical Field The present disclosure relates to the field of semiconductor manufacturing technology, and in particular, to a processing method and a processing system for a workpiece of a brittle material. Background With the rapid development of semiconductor photoelectric industry, hard and brittle materials such as silicon carbide (SiC) are widely used in, for example, chip substrates, precision optical windows and electronic devices due to their excellent physicochemical properties. However, the high hardness and brittleness makes machining of such materials difficult. In the related art machining process, the flattening treatment of the surface of a workpiece made of a hard and brittle material, or the shaping machining of a specific geometry (such as an annular groove, a step surface, etc.), is mainly dependent on grinding by a numerical control machine tool in combination with a fixed abrasive tool (commonly referred to as a cutter). A bonded abrasive tool refers to an abrasive tool in which abrasive particles (abrasive grains for short) are held by a bond (e.g., ceramic, resin, etc.) on a tool substrate. However, in the actual manufacturing process, particularly when processing a workpiece of a hard and brittle material having a structure such as an annular groove, the related processing technique faces a serious challenge. Specifically, after the annular groove is machined, obvious periodic textures (commonly called knife lines) are often remained on the groove bottom or the groove wall surface. The presence of these striae not only affects the quality of the product, but also introduces deep subsurface damage, affecting the yield of subsequent processes such as polishing, epitaxial growth, etc., as the striae themselves are actually microcracks and stress concentration areas on the material surface. In this regard, related art attempts have often focused on changing grinding wheels with finer grit, adjusting the hardness of the bond, or changing grinding parameters, etc., to improve the surface quality of the workpiece. However, these improvements have had little effect and it has been difficult to effectively reduce or eliminate the moire. Disclosure of Invention This section is based on a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features. According to one aspect of the present disclosure, a method for machining a workpiece of brittle material is provided. The method of machining includes applying a viscous medium to a surface of a workpiece to be machined and contacting and producing relative motion of a fixed abrasive tool with the surface to be machined for grinding. In the grinding process, abrasive particles falling off by the fixed abrasive tool in the grinding process are captured and suspended at the contact interface of the fixed abrasive tool and a workpiece by the viscous medium to form a free abrasive layer, so that the abrasive particles in the free abrasive layer grind the surface to be processed in situ. According to another aspect of the present disclosure, a processing system is also provided. The processing system implements the processing method for the hard and brittle material workpiece. The machining system comprises a numerical control machine tool, a fixed abrasive tool and a medium supply unit. The numerical control machine tool comprises a first driving device for driving a workpiece and a second driving device for driving a fixed abrasive tool. The fixed abrasive tool is mounted on the second driving device and is used for grinding the surface to be machined of the workpiece mounted on the first driving device. The medium supply unit is configured to supply viscous medium to a surface to be processed. According to the technical scheme, by introducing the viscous medium, the characteristics that the fixed abrasive tool is worn in grinding are utilized, and the detached abrasive particles are captured and suspended at the contact interface of the fixed abrasive tool and the workpiece so as to convert the abrasive particles into the grinding medium. Thereby, the machining process is changed from a single mode of grinding by the fixed abrasive tool to a composite mode of grinding by the fixed abrasive tool and grinding media, thereby reducing or even eliminating moire and improving the surface machining quality of the workpiece. Drawings Features and advantages of embodiments of the present disclosure will become more readily appreciated from the following description with reference to the accompanying drawings. The figures are not drawn to scale and some features may be exaggerated or minimized to show details of particular components. In the drawings: Fig. 1 is a schematic diagram of a related art machining process for a workpiece of a brittle and hard material. Fig. 2 is a flow chart of a method of processing a workpiece of brit