| 摘要 |
PURPOSE:To realize a ceramic multilayer circuit board having an excellent heat sinking quality and a small quantity of transmission loss, by creating a composite dielectric made of air and AlN while creating a porous substance, and by decreasing the effective dielectric constant of the circuit board. CONSTITUTION:As the fundamental composition of a slurry, the materials, which are AlN powder of 100 pts.wt., calcium carbonate of 5 pts.wt., polyvinyl butyral of 6 pts.wt. and di-n-butyl phthalate of 6 pts.wt., are used. To the materials, terephthalic acid corresponding to 10-30 pts.wt. of the AlN powder is added, and by kneading the material while adding further a solvent a them, the slurry is created. By the doctor blade method, a green sheet is formed out of the slurry, and therein, holes are formed. Thereafter, using a tungsten conductor paste, screen printings are performed on the sheet, and by fillings of the holes, viae are formed in the sheet, and further, wiring patterns are printed on the sheet. Then, after the four layers of the green sheets are laminated while aligning them with each other, to the top and bottom surfaces of the laminated sheets, the green sheets whereto no terephthalic acid is added are respectively thermocompression-bonded in a body while aligning them with each other. Therafter, the degreasing and burning of the laminated sheets are performed, and a porous AlN board is formed. Thereby, a circuit board for processing high-speed signals can be realized. |
