To obtain an air flow sensor having a high strength to a thermal stress, small characteristic change even in a severe environment and high reliability by disposing a semiconductor sensor element having a measuring site including a temperature measuring resistor formed on a semiconductor substrate and a heating resistor formed on a thin portion of the substrate on a recess of a ceramic laminate board having the recess.
A recess of the degree that a semiconductor element 2 is contained in laminate boards 8a, 8b and 8c made of several layer ceramics for constituting the air flow sensor 1 is provided, and the element 2 is adhered to the board 8c with a sensor adhesive. A wiring pattern for mounting electrodes for connecting the element 2 and a control circuit 16 for controlling the element 2 by connecting wirings 27a, 27b and electric components is mounted on a surface of the boards 8a of the upper layer of the boards 8a, 8b and 8c laminated in three layers. Thus, the circuit 16 and the element 2 are integrally constituted to be reduced in size. Thus, the element 2 and the circuit can be connected to a housing 15 in one time step.
YAMADA MASAMICHI
NAKADA KEIICHI
HITACHI CAR ENG CO LTD