Research On The Properties Of Laser Sintering High Viscosity Silver Paste To Form Conductive Circuits

Conductive silver paste has become an ideal material for forming conductive circuits of electronic products due to its excellent conductive properties and low sintering temperature.It has made preliminary attempts in the fields of three-dimensional structure electronics,flexible electronics and printed electronics,showing great potential and broad commercial application prospects.However,the current hot sintering process of conductive silver paste has problems such as sintering temperature limited by matrix and low sintering efficiency.Therefore,this article used laser beam to rapidly sinter the conductive circuit,and conducted in-depth research on the performance of the conductive circuit,mainly including the following points:(1)The performance of conductive circuit formed by laser sintering conductive silver paste were systematically studied through full factor experiments.The influence of laser process parameters on the surface morphology of the conductive circuit was illustrated,and the influence of the surface morphology on the performance was preliminarily analyzed,and the causes of the morphologic changes of the conductive circuit were deeply revealed.The influence law of laser process parameters on the resistivity of forming conductive circuit was studied,and the cause of its formation was deeply revealed.Finally,the optimal parameters of single sintering were obtained by optimizing the target parameters.The influence law and cause of laser process parameters on the interface bonding performance of the formed conductive circuit were studied,and the interface bonding quality between the conductive circuit and the matrix was determined.(2)In order to solve the problem of stoma defects in laser sintering conductive circuits,the research on porosity suppression was carried out.A variable parameter sintering method was proposed based on the sintering characteristics of conductive silver paste.The method first selected appropriate sintering parameters according to the changes in the morphology of the conductive circuit,and then determined the optimal sintering method through a single factor test,and finally verified the effectiveness of the optimal sintering method to suppress pore formation,and analyzed the reason why the optimal sintering method improves the conductivity from the perspective of sintering mechanism.(3)In order to balance the sintering quality and efficiency,a temperature-controlled sintering method was proposed based on the thermal characteristics of conductive silver paste.Firstly,the composition of conductive silver paste was analyzed to determine its main components,and the thermal analysis and test of conductive silver paste and its organic matter were carried out respectively,and the thermal reaction process of the conductive silver paste was clarified.Then,thermocouple was used to measure the temperature of laser sintering conductive silver paste,and the relationship between laser sintering parameters and sintering temperature was established,and appropriate laser temperature was used for active temperature control sintering according to the thermal characteristics of conductive silver paste.Finally,the effectiveness of active temperature control sintering in forming high quality conductive circuits with high efficiency was analyzed and verified.