With the large size and high precision of planar display, the specific impedance of materials is more and more high. More and more display manufacturers choose targets of molybdenum-tantalum alloy with better resistance than * as gate electrode materials, and the demand for targets of molybdenum-tantalum alloy is on the rise sharply. However, with the improvement of production efficiency, display panel production equipment has been advanced to the mainstream of G4, G5 and G6, and G8- generation will be installed in large Numbers in the near future. Thus molybdenum and molybdenum tantalum alloy target material and molybdenum niobium alloy target material sheet size became the bottleneck of production.
1. The big size, fine grain molybdenum tantalum alloy sputtering target material preparation method, its characteristic is that includes the following steps: step one, the molybdenum powder and tantalum powder sieving after preprocessing, respectively, after the screening of tantalum powder and molybdenum powder particle size of Karl fischer ratio is 1.6:1, after the screening of molybdenum powder and tantalum powder according to 90 ~ 94:6 ~ 10 quality than ball mill mixing more than 16 h, molybdenum was tantalum powder mixture, spare; Step 2, according to the goal of the compact size, weigh and molybdenum required to form a compact tantalum powder mixed mass or volume, and manufacturing forming mixed with molybdenum tantalum powder of inner chamber volume of cold isostatic pressing mould, the hybrid send molybdenum powder making tantalum powder free fall into the cold isostatic pressing mould forming in the inner chamber, cold isostatic pressing process conditions as follows: under 150 ~ 200 mpa pressure maintaining 5 ~ 10 min; After processing to get a sequence of blank, spare; Step 3: demoulding, take out the first sequence blank, put the first sequence blank into the furnace body, raise the temperature to 2150~2200℃ at a heating rate of 30~40℃/min, and keep the temperature at this temperature for 8~9h, then take out the blank body and reserve it. Step 4. After leveling the blank body in the leveling mold, place the blank body in the shaping mold for shaping and spare; Step 5. After surface treatment, the blank body is subjected to thermal isostatic pressure treatment to obtain the second order blank body for standby; Among them, the thermal isostatic pressing process is: pre-firing for 30min at 800~1000℃, then heating and boosting to 1450~1500℃, 180~200MPa, heat preservation and pressure protection for 1~3h; Step 6: rolling along the longitudinal direction of the billet body at 1400℃. When the primary deformation of the billet body is 20~60%, rolling along the transverse direction of the billet body at 1200℃. When the secondary deformation of the billet body is 70%, keep the billet body at 1250℃ for 2h for backup. Step 7. Machining the second order blank body to make its shape reach the target size, and connecting it with the back plate to make the target material of molybdenum and tantalum alloy.
