Method for acquiring residual stress distribution in thickness direction of thin substrate

Abstract

The invention relates to a method for acquiring residual stress distribution in the thickness direction of a thin substrate. The method comprises the steps: building an abrasive particle grinding molecular dynamics initial configuration, and obtaining a three-dimensional size molecular dynamics simulation model; determining simulation parameters, and completing system environment setting; performing heat dissipation processing on the molecular dynamics model, and outputting position and stress information of particles at each heat dissipation moment; selecting regional particles avoiding the boundary, calculating the equivalent stress of each particle in the region, and representing the residual stress of the particles; and analyzing the residual stress of the selected area in the thickness direction, dividing the selected area into a plurality of layer sections in the thickness direction, solving the residual stress of each layer section, obtaining the distribution of the residual stress in the thickness direction, and obtaining the position of the maximum value of the residual stress. According to the method, heat dissipation treatment is carried out after molecular dynamics simulation abrasive particle grinding is finished, the influence of thermal stress on residual stress in the simulation grinding process is eliminated, and related information of particle residual stress calculation can be directly and accurately obtained.

Description

technical field [0001] The invention relates to the technical field of residual stress testing, in particular to a method for obtaining residual stress distribution in the thickness direction of a thin substrate. Background technique [0002] Residual stress refers to the stress system that exists inside the object to maintain self-equilibrium when it is not subjected to external force or after it is unloaded by external force. A thin substrate is a thin plate in mechanics, and its thickness is much smaller than the plane size, such as a large-diameter ultra-thin silicon wafer in integrated circuit manufacturing, that is, the diameter is greater than 200 mm and the thickness is less than 2 microns. In the ultra-precision grinding process of thin substrates, residual stress is inevitably generated, and residual stress is the direct cause of deformation of thin substrates. The existence of residual stress seriously affects the performance and service life of thin substrates. T...

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Problems solved by technology

Sun Jinglong of Beijing University of Technology used the method of combining step-by-step corrosion and micro-Raman spectrometer measurement to measure the residual stress at different positions in the thickness direction of the thin substrate, but the results reflect the microstructural changes of processing damage, and the measured values ​​​​at different positions Relatively large fluctuations

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