Co-sintering of barium strontium titanate (BST) thick films inside a LTCC substrate with pressure-assisted sintering

Tunable Microwave Phase Shifters Using LTCC Technology with Integrated BST Thick Films

“…A method to lower the sintering temperature (900°C) of BST was reported by Timo et al ., This enables the use of silver electrodes in tunable microwave devices based on screen printed BST thick films. The utilization of BST paste inside LTCC module was demonstrated using pressure assisted sintering process (PAS) . A relatively large area of the screen printed BST thick film inside LTCC module results in bending of the module due to difference in rate of shrinkage of LTCC sheets and BST paste; hence a PAS system enables to restrict the shrinkage of LTCC and BST.…”

Effect of CuO and MnO2 doping on electrical properties of 0.92(K0.48Na0.54)NbO3–0.08LiNbO3 under low-temperature sintering

“…However, pure KNN ceramics are difficult to densify by normal sintering due to the high volatility of alkaline elements at high sintering temperatures. Therefore, in order to solve the above problems, various methods have been utilized, such as hot isostatic pressing (HIP), pressure assisted sintering (PAS) and spark plasma sintering (SPS) [11][12][13], although these methods can produce high densities and better properties compared to conventional sintering. However, they are more expensive and complicated routes compared to conventional sintering process [14].…”

Implementation of Ba0.6Sr0.4TiO3‐ZnO‐B2O3 based tunable microwave phase shifters in LTCC technology

“…Nevertheless, the cross‐sections of the buried phase shifters unit cells in Figure revealed an intact functional MIM structure for single as well as for double printing of the dielectric thick‐films. Although the thickness of the BST films is inhomogeneous and dependent on its position, in contrary to Tick et al., there is no collapse of the film, no critical infiltration of silver, and no direct contact between top and bottom electrode. The thickness of the silver electrodes is between 14 and 16 μm, while the BST films in between two LTCC layers show a thickness of 6‐7 μm for single printing and 14‐15 μm for double printing.…”

“…Additionally, low‐temperature sintered BST thick‐films enable the integration of tunable microwave components into the LTCC (low temperature co‐fired ceramics) technology, which is an established method for the fabrication of low‐cost, highly integrated multilayer modules for mobile communication and electronic applications. So far, only a few previous studies reported about the fabrication of LTCC integrated BST thick‐film components . However, the achieved microwave characteristics, such as a Figure of merit (FoM) of 6.5°/dB for an integrated phase shifter, are of limited suitability for the use in phased array applications.…”