Research On High Frequency Packaging Technology Of 905nm Semiconductor Laser

When the working rate of the laser increases gradually,the parasitic parameters brought by the package can hardly be ignored.In this paper,905nm pulse semiconductor laser is taken as the research object.By establishing the equivalent circuit model of encapsulation network and intrinsic network,ADS software is used to simulate and analyze the influence of encapsulation parameters on the high frequency characteristics of laser.First of all,this paper summarizes the development process,characteristics and classification of semiconductor lasers,and then introduces the research process of the equivalent circuit model of semiconductor lasers.This paper uses the model building method for reference.This paper introduces the research status of 905nm pulse semiconductor laser at home and abroad,and summarizes some representative laser parameter performance.Secondly,the light-emitting principle of semiconductor laser is described from the energy level structure and energy level transition theory.Then,several common packaging methods and their respective structural characteristics of semiconductor laser are introduced.Taking to packaging method as an example,the important technological process is described in detail,including the selection of heat sink and solder,cleaning of packaging materials,sintering process and bonding process.From the single-mode rate equation,the steady-state analysis and AC signal analysis of the equation are carried out to derive the intrinsic equivalent circuit,and then the package parasitic circuit is analyzed according to the package structure.The equivalent circuit model of semiconductor laser is established by combining the intrinsic equivalent circuit with the package parasitic circuit.Taking this model as the equivalent circuit model of 905nm laser,the S-parameter fitting extraction method is used to extract the equivalent circuit parameters,and the appropriate coplanar waveguide is designed and manufactured,and the laser is welded to test the S-parameters.ADS software is used to build the S-parameter curve from the circuit diagram fitting test,and the equivalent circuit parameter value of the laser is extracted.After that,ADS software is used to simulate the S parameter and frequency response of the package parasitic circuit,and the simulation results are used to analyze the influence of the package parasitic parameters on the high frequency characteristics of the semiconductor laser.The final conclusion is that the parasitic resistance R_P introduced by the lead and the inductor L_P,the contact capacitance C_C produced by the contact between the chip electrode and the active region and the solder have a greater impact on the frequency response,while the parasitic capacitance CP produced by the contact between the solder and the heat sink has a smaller impact on the resistance RC of the solder itself.Finally,the high-frequency characteristics of gold tin solder,indium solder and conductive adhesive were compared.In this paper,indium solder and gold tin solder were prepared by vacuum evaporation and magnetron sputtering.The surface morphology and composition of the solder were characterized by SEM and XRD.Then,the S-parameter fitting extraction method is used to extract the package parasitic parameters,and ADS software is used to simulate the package parasitic parameters.The conclusion is that the high frequency characteristics of gold tin solder and indium solder are better than that of conductive adhesive,and the high frequency characteristics of gold tin solder are slightly better than that of indium solder.