Research On The Preparation Of Three-dimensional Ceramic Substrate By Electroplating Bonding

Miniaturized,integrated and high-power electronic devices are increasingly welcomed by the times,so electronic packaging technology puts forward higher requirements for the substrate: high thermal conductivity,high heat resistance,low coefficient of thermal expansion,high graphic accuracy,low cost and so on.Planar electroplated ceramic substrate basically meets the above requirements,and has been widely used in power device packaging.Because some optoelectronic devices are greatly affected by environmental factors,it is necessary to use three-dimensional ceramic substrate with cavity structure to realize hermetic packaging and improve the reliability of devices.In this paper,based on the existing planar ceramic substrate preparation technology,electroplating bonding technology is proposed to prepare three-dimensional ceramic substrate.The main research contents are as follows:1)Structure design of 3D ceramic substrate.According to the characteristics of electroplating bonding process,the processing materials and three-dimensional ceramic substrate structure were selected,including electroplating ceramic substrate(DPC)for substrate and copper porous substrate for dam.After the graphic accuracy and roughness detection,The DPC ceramic substrate and dam enclosure substrate meet the design requirements.The simulation results of COMSOL show that the coating quality can be improved by optimizing the additive components.2)The effect of additives on the bonding process of electroplating.The electrochemical behavior of accelerator SH110 and SPS in different convective intensity was tested and analyzed by electrochemical method.The results of plating showed that SH110 was suitable for bonding process.Secondly,the inhibition effect of PEG and EPE was tested and analyzed by cyclic voltammetry.The different convective intensity of the levelling agents NTBC and JGB were analyzed by constant current polarization test.The electrochemical behavior of the additives was compared with the experiments of the basic plating solution and the additive plating solution.The mechanism of the additives in the bonding process was analyzed.By the XRD and EDS analysis,SH110-EPE6400-JGB was used as the additive of electroplating bonding.3)Process optimization of electroplating bonding.Taking the plating deposition rate and shear strength of the coating as the evaluation indexes,the best additive concentration combinations with better comprehensive performance were 7mg/L SH110,260mg/L EPE6400 and 3mg/L JGB.Then the process parameters such as current density,temperature,plating time and stirring rate were optimized.Finally,the reliability of the three-dimensional ceramic substrate prepared by electroplating bonding is tested and analyzed.The results show that the substrate has good air tightness,and even after 30 thermal cycles,it still has high reliability.