Preparation of BaO-MgO-Al2O3-SiO2/Al2O3 glass-ceramic/ceramic LTCC substrate material for microwave application

Through the avenue of adjusting the thermal properties of BaO-MgO-Al2O3-SiO2 (BMAS) glass-ceramic by changing the MgO/BaO ratio, a BMAS glass-ceramic with the MgO/BaO ratio of 1:2 has been obtained, which shows satisfactory softening and crystalline behavior. Then, this BMAS glass-ceramic is used to lower the sintering temperature of Al2O3 ceramic. After systematic research on the sintering and physical properties of BMAS /Al2O3 composite with different glass-ceramic content, we find that when the content of BMAS glass-ceramic is 50%, the composite presents adorable comprehensive properties: dielectric constant of 5.40 @ similar to 10 GHz, dielectric loss of 1.91 x 10(- 3) @ similar to 10 GHz and bending strength of 143 MPa, meeting the requirement of LTCC substrate material for microwave application.