Abstract: A circuit device includes a ceramic substrate, an Al wiring layer provided on the ceramic substrate, and a semiconductor device and a bus bar which are electrically connected to the wiring layer. On part of the wiring layer, a Ni layer is plated. Thus a coated region in which the wiring layer is coated with nickel having solder wetability superior to aluminum and an exposing region in which the wiring layer is exposed as viewed from above the ceramic substrate are provided. The semiconductor device is connected onto the Ni layer within the coated region through solder. The bus bar is ultrasonically bonded to the wiring layer within the exposing region as viewed from above the ceramic substrate. Thus, the circuit device including the semiconductor device and the bus bar that are bonded to the ceramic substrate by sufficient bonding strength and its manufacturing method are provided.

Abstract: A circuit device includes a ceramic substrate, an Al wiring layer provided on the ceramic substrate, and a semiconductor device and a bus bar which are electrically connected to the wiring layer. On part of the wiring layer, a Ni layer is plated. Thus a coated region in which the wiring layer is coated with nickel having solder wetability superior to aluminum and an exposing region in which the wiring layer is exposed as viewed from above the ceramic substrate are provided. The semiconductor device is connected onto the Ni layer within the coated region through solder. The bus bar is ultrasonically bonded to the wiring layer within the exposing region as viewed from above the ceramic substrate. Thus, the circuit device including the semiconductor device and the bus bar that are bonded to the ceramic substrate by sufficient bonding strength and its manufacturing method are provided.

Abstract: A method for producing a molten iron in a blast furnace comprises the steps of: preparing an optical fiber covered with a metallic tube; measuring a temperature of the molten iron flow discharged from a tap hole of the blast furnace by means of making use of a metallic tube covered by the optical fiber to obtain an information of the temperature of the molten iron; and controlling a heat conditions of the blast furnace, based on the obtained information of the temperature of the molten iron. Controlling a heat conditions is achieved by using a heat conditions estimation model, and by inferring a level and a transition of the heat conditions in the furnace.