Structure Design And Multi-field Effect Of Composite Films Based On High Dielectric Constant Substrate

Satellite-borne microwave products continue to develop in the direction of high density and high integration.High dielectric constant substrates with a dielectric constant above 20 can significantly reduce the circuit size and meet the purpose of arranging circuit lines with high density.In order to meet the purpose of high density and high integration of microwave fixed-release products,it is necessary to realize low-frequency and high-power product design requirements on high-dielectric-constant substrates.Compared with thin-film circuits based on the same substrate,thin-film thickened circuit products based on high-dielectric-constant substrates have significantly increased power tolerance and current passing capacity as the film thickness increases.High-power circuits usually have lower frequencies and higher power,and the skin effect of electrical signals is not obvious.Therefore,the film thickness almost determines the current passing ability of the circuit.Therefore,research on the reliability of composite film circuits based on high dielectric constant substrates is necessary for the protection of military satellite products.In this paper,two kinds of high-dielectric constant substrates TD-36 and SF210K are used to design a multilayer thin-film structure,and their multi-physics effects such as electro-thermal force are studied.1.Several characteristic parameters of high dielectric constant substrates are discussed.The substrate characteristics refer to the chemical and physical characteristics that affect the manufacture,use,and reliability of microwave circuits based on this type of substrate,including dielectric constant,thermal expansion coefficient,and thermal conductivity.Rate,bending strength.Based on these parameters,the shape and size requirements of the substrate are further determined.This article does not recommend the design of heterostructures for these two materials.Generally,rectangular structures are used,and substrates with a larger thickness are used as much as possible.In the design of microwave integrated circuits,Microwave integrated circuit products with dielectric constant substrates are designed and used in accordance with the aspect ratio of the aspect ratio≤6:1.2.Through research on metals such as gold,silver,copper,etc.,it is found that the use of any single metal as the top layer structure of the conduction band material cannot meet the diverse functional requirements.Therefore,this article turns to the design of composite membranes.Finally,the film structure of(resistive layer-)adhesion layer-Au-Cu-Ni-Au was determined.3.Using COMSOL simulation software,a composite conductive film circuit based on a high-dielectric substrate was established,and multiphysics analysis such as electro-thermal force was performed to determine the temperature distribution and force of the film.The effects of film parameters and substrate parameters on multiphysics effects are discussed next.The results show that under the condition that the total film thickness is maintained,the temperature and force of the substrate and the composite film layer decrease with the increase of the thickness of the copper layer,and increase with the increase of the thickness of the nickel layer.The interfacial stress between layers is increasing under both conditions,but it is still an order of magnitude less than the maximum stress that can be withstood.The over-current capability of the conductive film layer was tested under the best and worst case design of the film structure.In addition,the influence of heat sink is discussed.When the heat sink is not used,the substrate and the film will be seriously damaged.According to the comparison of the reliability of two kinds of high-dielectric constant substrates and ceramic substrates,it is found that high-dielectric constant substrates have low overcurrent energy capacity due to low thermal conductivity,and in terms of force,the ceramic substrate is more stable in force,and The force of high dielectric substrate changes significantly with current.Finally,this paper proposes an aluminum box as an assembly box and radiator for the substrate.The work of this paper has certain theoretical guiding significance for the reliability research of military satellite products.