Study On Electrical And Mechanical Properties Of Circuit Board Based On Shape Memory Epoxy Resin

As one of the key technologies of flexible electronic packaging technology,flexible substrate technology has broad prospects because of its advantages of durability,flexibility and light weight.With the development of integrated circuit technology,the requirements for flexible substrate technology are becoming higher and higher.The existing flexible substrate material lacks the ability to intelligently adjust its flexibility and maintain a certain mechanical strength according to the changes of the external environment.Shape memory polymer,especially thermosetting shape memory epoxy resin,as a new intelligent material,can make up for the shortcomings of the existing materials,and also has the advantages of stable size,high mechanical properties and stable chemical properties.In this paper,a novel thermosetting shape memory hydro-epoxy resin was developed which can be used as an intelligent flexible substrate.Meanwhile,the performance of the novel thermosetting shape memory hydro-epoxy resin was investigated.The content of this paper is mainly summarized as follows:First,a novel thermosetting shape memory hydro-epoxy resin was developed in which methyl tetrahydrophthalic anhydride(MeTHPA)was used as hardener and Tris(dimethylaminomethyl)phenol(DMP-30)was used as accelerator to cure hydro-epoxy resin.The bending properties and shape memory properties were investigated.The following conclusions can be obtained:(1)With the increase of hardener,the flexural strength of the resin system showed an upward trend.(2)The flexural modulus of the system increases first and then decreases,and the flexural modulus reaches the highest when the degree of cure is 90%.(3)At the time of glass transition,the modulus of elasticity can be reduced by 2 orders of magnitude and has good shape memory properties.Secondly,based on the thin plate deflection theory,the differential equation of the thin plate of shape memory polymer is derived.Then the clamp of the thin plate is designed and the actual force of the plate is analyzed.The stress,strain and deformation of thin plates were analyzed by ANSYS Workbench finite element simulation software,and the steady-state and transient thermodynamic simulation results of thin plates were obtained.The simulation results show that:(1)when the external force is constant,the deformation of thin plates increases and the deformation increases from 0.57613mm to 10.802mm with the decrease of elastic modulus.The temperature will make the deformation of the thin plate larger and cause the measurement error to increase.Thirdly,the results of the change of the elastic modulus of the shape memory epoxy resin thin plate under different temperatures and the same loads were tested and verified.The results show that given the heating rate of 1?/min,in 0 to 30 minutes,the change rate of elastic modulus of the thin plate increased slowly.After 30 minutes,the rate of change increased sharply,and reached the maximum in 42 minutes,up to 1 80Mpa/min.In 44 to 52 minutes,the change rate of elastic modulus decreased significantly until finally remained unchanged.Finally,based on the theory of circuit analysis,a circuit is designed to test the electrical properties of the shape memory epoxy resin thin plate.Meanwhile,the.simulation of DC signal and AC signal is carried out.The circuit diagram was converted into a circuit board layout by Altium Designer software.FR-4 circuit boards and shape memory epoxy resin printed circuit boards were manufactured as well.The electrical properties of two kinds of printed circuit boards were tested,which verified the feasibility of the prepared shape memory epoxy resin material as the substrate material of flexible circuit board.