Tungsten has many excellent properties such as high melting point, high electrical conductivity, high electromigration resistance, high electron emission coefficient, high thermal stability and so on. Because of these excellent properties, high purity tungsten targets have wide applications and development prospects in the integrated circuit (IC) industry. In this paper, some manufacturing methods of tungsten targets was summarized and analyzed. The high melting point of tungsten makes powder metallurgy (PM) be the manufacturing methods of tungsten targets. After preforming of the tungsten powders, some sintering and densification processes like atmosphere pressure sintering, Hot Pressing (HP), Hot Isostatic Pressing(HIP) have been carried out. The grain size and the density of the tungsten targets is different by different manufacturing methods.

The FEM (finite element method) simulation was used to study the diffusion bonding deformation of high purity tungsten target. The influence of different welding structure, bonding temperature on the deformation of the final high-purity tungsten target was systematically studied. Meanwhile, some microscopic properties of tungsten target were developed, such as internal stress size and distributions, strain size and distributions. Finally, physical experiments are used to verify numerical simulation results. The results show that the method of adding an intermediate layer can release the residual stress between the high-purity target and back plate. The bonding stress of high-purity tungsten target is mainly concentrated with the tungsten target and the intermediate layer in between, which is easy to fail during the later leveling process. Small deformation of bonding tungsten target can be obtained by low diffusion bonding temperature.

MgO ceramics with the purity higher than 99.99% have been fabricated by a hot-isostatic press (HIP) technique of hot-pressed MgO compacts using nanometer MgO powder with an average particle size of 300 nm. The densification and grain growth behavior of MgO compacts during HIP process were investigated. The results indicate that the high-purity MgO ceramic with an average grain size of 9.76 μm and a density approximately to the theoretical density can be obtained by HIP method at 1350°C and 150 MPa for 60 min. HIP can significantly enhance the densification process of MgO compacts and cause a slightly change of grain size distribution.

Pass through flux (PTF) is an essential parameter for the magnetron sputtering process of ferromagnetic materials. In the present investigation the influence of deformation, recrystallized microstructure and thickness on PTF of Ni was examined by the analysis of microstructure and hardness of high purity Ni. The experimental results showed that PTF of rolled Ni increased significantly comparing to the annealing microstructure that is related to the dislocation and stress of microstructure. With the recrystallization and grain growth of deformed samples, PTF decreased to be about 30%. PTF was also associated with the thickness of material. It increased by 6% when the thickness of 0.5mm decreased. This research is useful to guide and improve the design, development and preparation of magnetic sputtering materials.

Abstract.A microwave miniaturized bandpass filter using (Mg 0.95 Ca 0.05 )TiO 3 (abbreviated as 95MCT hereafter) ceramic substrate is investigated in the present paper. The paper studies the sintering and microwave dielectric properties of Al 2 O 3 , La 2 O 3 and SiO 2 co-doped 95MCT. The XRD pattern shows that a secondary phase MgTi 2 O 5 is easily segregated in 95MCT ceramic, however, through co-doping it can be effectively suppressed, and the microwave dielectric properties, especially, the Qf value can be significantly improved. Through optimizing the co-doping ratio of Al 2 O 3 , La 2 O 3 and SiO 2 , the sintering temperature of 95MCT ceramic can be lowered by 80 o C, and the microwave dielectric properties can reach Qf=61856GHz and İ r =19.84, which indicates the modified 95MCT ceramic have a great potential application in microwave communication devices. Based on this, we also designed a miniaturized microwave bandpass filter (BPF) on modified 95MCT substrate. Through a full wave electromagnetic structure simulation, the results show that the center frequency of the BPF is 2.45GHz and the relative bandwidth is 4.09% with the insertion loss of less than 0.2dB in the whole bandpass.