Mmi Semiconductor Co., Ltd.

Koji Momotani

Takashi Kasai

A flow sensor chip includes a substrate in which a cavity having an opening is formed; a membrane provided on a surface of the substrate so as to cover the opening; a heater provided inside the membrane; a first thermopile and a second thermopile provided in the membrane, the heater being interposed between the first thermopile and the second thermopile; and a heat conduction member serving as a heat conduction path between the substrate and the membrane. A first hot junction and a first cold junction of a thermocouple provided in the first thermopile and a second hot junction and a second cold junction of a thermocouple provided in the second thermopile are arranged at positions overlapping with the opening as viewed from a direction normal to the surface of the substrate.

Flow sensor chip

A thermal flow sensor chip has a heater part, and a pair of thermopiles provided so as to be opposite each other across the heater part. The heater part is famed by doping silicon with an impurity that reduces the electrical resistance. In each of the thermopiles: a silicon region is formed by doping silicon with an impurity that reduces the electrical resistance; the concentration of the impurity in a heater main part, including the lengthwise center of the heater part extending in the first direction, is lower than the concentration of the impurity in a heater outer peripheral part, the heater outer peripheral part being different from the heater main part and including a lengthwise end part of the heater part; and the concentration of the impurity in the heater main part is the same as the concentration of the impurity in at least part of the silicon region of the thermopile.

Thermal flow sensor chip

A thermopile sensor includes a thermopile. The thermopile is formed by connecting thermocouples, in series on an insulating film, in which a first PolySi interconnect and a metal interconnect including a metal portion in at least a part thereof are connected, each of the thermocouples connected in series is arranged side by side with a predetermined gap, the metal interconnect is arranged to overlap the first PolySi interconnect in each of the thermocouples, at a connection portion between a thermocouple and an adjacent thermocouple, the metal interconnect crosses the gap between the first PolySi interconnects, and a first width of a portion of the gap where the metal interconnect crosses the gap between the first PolySi interconnects is greater than a second width of a remaining portion of the gap between the first PolySi interconnects.

Thermopile sensor

The thermal sensor chip includes a substrate in which a cavity having an opening is formed, a membrane provided on a surface of the substrate so as to cover the opening, and a heater provided on or inside the membrane, wherein the heater includes wires in a mesh form constituted by a conductive member.

Thermal sensor chip

A flow sensor chip includes a substrate in which a cavity having an opening is formed, a membrane provided on a surface of the substrate so as to cover the opening, a heater provided inside the membrane, a first thermopile and a second thermopile provided in the membrane, and a heat conduction member for heat conduction between the substrate and the membrane. A first hot junction and a first cold junction of a thermocouple provided in the first thermopile and a second hot junction and a second cold junction of a thermocouple provided in the second thermopile are arranged at positions overlapping with the opening in a plan view. The heat conduction member includes a first heat conduction member for heat conduction between the first cold junction and the substrate and a second heat conduction member for heat conduction between the second cold junction and the substrate.

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Kyoto, Japan

Koji Momotani