| 摘要 |
<p>PURPOSE:To obtain a multilayer circuit substrate having high reliability and fast signal processing speed by employing a material to which one or more oxides of group IIIa elements are added in specific amount for the substrate material. CONSTITUTION:A front surface layer 1 and a rear surface layer 3 employs a sintered material to which 0.1-10 pts. wt. of oxide of a group IIIa element as a sintering assistant for a mullite material is added. Silica material is used for an insulating layer 2 disposed near line wirings. After conductors are wired, a laminated substrate is manufactured by a laminating press, the profile of the substrate is cut, and set in a furnace. It is heated at 50 deg.C/hr of temperature rising speed up to 1200 deg.C in an (N2 gas + H2 gas) atmosphere containing steam for extracting resin. Then, it is heated at 100 deg.C/hr of temperature rising speed in the N2 gas + H2 gas atmosphere, temporarily held at 1600 deg.C of the highest temperature for 1 hour to form a ceramic multilayer circuit substrate. The substrate thus formed is electroless nickel-plated and gold-plated, a kovar pin 4 is connected by a normal method using a carbon jig in a gold-germanium furnace 8, and an Si chip 6 is directly placed by a solder 5.</p> |
