Study on Tungsten Conductor Pastes for High Temperature Co-fired Process

Techniques to manufacture tungsten conductor pastes for high temperature co-fired process were researched in this paper,and the effects of Microstructure and distribution of tungsten powders,the content of nonmetallic on printing,metallization combination strength and sheet resistance of the paste were analyzed as well.In order to meet the needs of microelectronic packaging,two kinds of tungsten powder with globularity and the diameter under 5μm were mixed up.A certain quantum of nonmetallic powder and organic carrier were added.Tungsten powder,nonmetallic powder and organic carrier were separated with muller.As a result,tungsten paste with sheet resistance of 6mΩ/□and combination strength of up to 54 MPa of the metallization and alumina co-fired ceramic substrate were realized,which could be used in fine line printing of 100μm on thick film integrated circuits process.Tungsten paste was applied on insulator of microwave package as conductor material connecting the devices in the shell and the assembly.Tested in 29 GHz to 31 GHz Ka band,VSWR was less than 1.15 and insertion loss was 0.4dB.