Study On Preparation And Properties Of Nitride Ceramic Copper Cald Plate

With the rapid development of high-power electronic devices,the heat generated by circuits has also increasing rapidly.If scientific packaging is not carried out,high temperatures can cause thermal stress and thermal fatigue between the chip and the substrate,and even directly burn the device.Packaging mainly includes two parts:the selection of substrate materials and the connection between the conductive layer and the substrate.AlN and Si3N4 ceramics are considered ideal packaging substrate materials due to their comprehensive advantages such as matching thermal expansion coefficients with chip materials,high thermal conductivity,and good insulation performance.However,as ceramic materials are strong covalent compounds,their electronic coordination stability makes it difficult for metal conductive layers to wet them.Therefore,a transition layer is needed to connect the ceramic substrate and the metal conductive layer to achieve good bonding ability and thermal conductivity between the substrate and the conductive layer.Based on it,this paper uses the method of thin-film metallization to deposit CuO film as a transition layer to connect ceramic substrate and conductive Cu layer,to obtain well-adhered AIN and Si3N4 ceramic copper clad plate.The specific research content is as follows:(1)CuO transition layer was prepared by reactive sputtering,and Cu conductive layer was prepared by DC sputtering.In the preparation of CuO film,it was found that the crystalline quality of the film increased with the increase of sputtering power,while the conductivity decreased with the increase of oxygen flow rate.Therefore,the optimal preparation parameters for CuO film were determined to be a sputtering power of 90 W and an oxygen flow rate of 14 sccm.In the preparation of Cu film,it was found that the conductivity decreased with the increase of sputtering power and pressure.The optimal preparation parameters for Cu film were determined to be a sputtering power of 30 W and a sputtering pressure of 3.0 Pa,with a resistivity of 25.9 μΩ·cm.(2)AlN/CuO/Cu ceramic copper clad plate was successfully prepared by thin-film metallization.When the thickness of CuO transition layer was 200 nm,the sheet resistance and resistivity of Cu conductive layer were 333.0 mΩ and 33.4 μΩ·cm,and the thermal conductivity at 25℃ was 240.7 W/m K.The adhesion strength of the film layer could reach 11.4 MPa.After annealing,the electrical conductivity of the AlN/CuO/Cu ceramic coated copper plate was significantly improved.When the annealing temperature was 250℃,the sheet resistance and resistivity of Cu conductive layer were 82.4 mΩ and 8.3 μΩ·cm,and the thermal conductivity at 25℃ was 129.8 W/m K.The adhesion strength of the film layer could reach 13.1 MPa.(3)Si3N4/CuO/Cu ceramic copper clad plate was successfully prepared by thin-film metallization.When the thickness of CuO transition layer was 400 nm,the sheet resistance and resistivity of Cu conductive layer were 335.3 mΩ and 35.6 μΩ·cm,and the thermal conductivity at 25℃ was 21.0 W/m·K.The adhesion strength of the film layer could reach 6.5 MPa.After annealing,the electrical conductivity of the Si3N4/CuO/Cu ceramic coated copper plate was significantly improved.When the annealing temperature was 300℃,the sheet resistance and resistivity of Cu conductive layer were 27.1 mΩ and 2.7 μΩ·cm,and the thermal conductivity at 25℃ was 17.1 W/m K.The adhesion strength of the film layer was 5.3 MPa.