Construction method of SU-8 photoresist swelling stress and deformation constitutive model

The invention provides a method for constructing a swelling stress and deformation constitutive model of an SU-8 photoresist, which is characterized by comprising the following steps of: testing the SU-8 photoresist under different strain rates and temperature conditions, and recording stress-strain curve data; a generalized Maxwell model is adopted to describe the viscoelastic behavior of the SU-8 photoresist; a nonlinear least square method is adopted to fit generalized Maxwell model parameters; establishing a neural network framework, and determining a loss function and an optimization algorithm; and optimizing parameters of the generalized Maxwell model by adopting a genetic algorithm so as to obtain the SU-8 photoresist stress-strain constitutive model. The constitutive model obtained through the scheme can well represent the constitutive relation between the thermal swelling property of the SU-8 photoresist and the internal stress of the photoresist layer, meanwhile, the initial constitutive model param