Research Of Micro-Pattern Electroless Ni-P/Cu Plating Technology And Coating Structure

The electronics industry has progressed rapidly; and electroless plating is a key technology for the fabrication of Micro-Electro-Mechanical Systems (MEMS) and microelement because of its particular characteristics. Many governments and enterprise have paid attention to it.In order to resolve the problem of contact resistance of super-lattice micro-cooler and the manufacture technology of multilevel thermoelectricity cell, this thesis adopts the electroless plating to deposit contact film on the semi-conductor silicon surface, and obtains selective metal film by making use of electroless plating.Firstly, the surface of semi-conductor silicon pretreatment technology of electroless plating is studied in this paper. Secondly, through a variety of experiments, the optimal technology of electroless plating is gained. Finally, the micro-pattern on the surface of semi-conductor silicon is made and selective metal film is obtained by making use of the YAG pulse laser and electroless plating. The main content and experiment results include:(1) The pretreatment technology of electroless plating on semi-conductor silicon is studied.The technological flow of pretreatment and the technological parameters of each working procedure are established. This pretreatment consists of working preparation of electroless plating, degreasing, etching, sensitization and activation, etc.(2) In order to obtain reasonable technological parameters of electroless nickel plating, the influences of the main salt, reductant, pH value and temperature on the deposition rate are studied.The morphology and structure of the coating are analyzed by the method of XRD, SEM and metallographic microscope, etc.(3) Adopting acidic electroless nickel plating solution of sodium hypophosphite as reducing agent under low temperature, excellent and homogenous coating is gained. The coating is Ni-P alloy and it has amorphous structure by observation and analysis of the coating using SEM and XRD.(4) Using alkaline electroless copper plating solution of sodium hypophosphite instead of conventional formaldehyde (HCHO) as the reducing agent and nickel sulfate as re-activation agent, Cu-Ni alloy coating has been acquired.(5)The micro-pattern on the sensitized and activated semi-conductor silicon substrate and selective metal film are obtained by adopting the YAG pulse laser and electroless plating.