Provided is a thermal flow meter to improve the measurement accuracy of a temperature detector provided in a thermal flow meter. The thermal flow meter includes a bypass passage through which a measurement target gas 30 flowing through a main passage flows, and a circuit package 400 which includes a measurement circuit for measuring a flow rate of the measurement target gas 30 flowing through the bypass passage and a temperature detecting portion 452 for detecting a temperature of the measurement target gas. The circuit package 400 includes a circuit package body which is molded by a resin to internally envelope the measurement circuit and a protrusion 424 molded by the resin. The temperature detecting portion 452 is provided in the leading end portion of the protrusion 424, and at least the leading end portion of the protrusion protrudes to the outside from a housing 302.

Traditional flow sensors include an upstream resistive sensor element, a downstream resistive sensor element and an intervening heater resistive element. To help reduce the size and/or cost of such flow sensor, it is contemplated that the heater resistor may be eliminated. When so provided, the space required for the heater resistive element, as well as the corresponding heater control circuit, may be eliminated. This can reduce the cost, size and complexity of the flow sensor.

A multi-purpose Micro-Electro-Mechanical Systems (MEMS) thermopile sensor able to use as a thermal conductivity sensor, a Pirani vacuum sensor, a thermal flow sensor and a non-contact infrared temperature sensor, respectively. The sensor comprises a rectangular membrane created in a silicon substrate which has a thin polysilicon layer and a thin residual thermal reorganized porous silicon layer both attached on its back side, and configured to have its three sides clamped to the frame formed in the silicon substrate which surrounds and supports the membrane and the other side free to the frame, a cavity created in the silicon substrate, positioned under the membrane and having its flat bottom opposite to the membrane, its three side walls shaped as curved planes and the other side wall shaped as a vertical plane, a heater or an infrared absorber positioned on the membrane, close to and parallel with the free side of the membrane and a thermopile positioned on the membrane and consists of several thermocouples connected in series and having its hot junctions close to the heater and its cold junctions extended to the frame.

Provided is a thermal flow meter that can be prevented from being eroded due to adhesion of water or like to a cut end portion of the lead exposed from the mold resin of the circuit package. A thermal flow meter 300 of the present invention is a thermal flow meter having a circuit package 400 formed by mounting a detection element 518 on leads 544 and 545 supported by a support frame 512, sealing with a mold resin, and cutting off the support frame 512, wherein cut end portions 544a and 545a of the leads 544 and 545 exposed from the mold resin of the circuit package 400 by cutting off the support frame 512 is covered by a covering portion 371.

A thermal air flow sensor that offers high flow rate measurement accuracy is provided. The thermal air flow sensor includes a measuring element. The measuring element includes: a semiconductor substrate; a heating resistor and a temperature measuring resistor both formed as a result of thin films being stacked over the semiconductor substrate; an electronic insulator including a silicon oxide film; and a diaphragm portion formed after part of the semiconductor substrate is removed. The heating resistor and the temperature measuring resistor are formed over the diaphragm portion. In the thermal air flow sensor, a ratio of an area occupied by the thin films to an area of the measuring element ranges between 40% and 60%.

In order to provide a thermal flow meter for improving workability of a flow rate measurement device having a temperature measurement function for the measurement target gas and measurement accuracy for measuring a temperature, the thermal flow meter is structured such that a flow rate measurement circuit package having a protrusion for measuring a gas temperature is formed through resin molding. An inlet port opened to the upstream side of the measurement target gas is formed, a protrusion is arranged inside the inlet port, an inlet port and an outlet port are formed in the front and rear covers along the protrusion, and the measurement target gas received from the inlet port flows along the protrusion. Since the measurement target gas subjected to the measurement flows along the protrusion, it is possible to reduce influence of the heat from other heat resources and improve measurement accuracy.

The flow rate measuring apparatus according to one aspect of the present invention is a flow rate measuring apparatus that intermittently measures the flow rate of a fluid, comprising a heating unit for heating the fluid; a control unit that controls a drive voltage for driving the heating unit, or the interval at which the drive voltage is applied, to the desired value; a temperature sensing unit that senses information about the temperature of the heated fluid; and a flow rate measurement unit that measures the flow rate of the fluid on the basis of the sensing signal outputted from the temperature sensing unit, wherein, in intermittently measuring the flow rate, the control unit varies the heating amount of the heating unit in each measurement by varying the interval at which the drive voltage is applied.

Provided is a microfluidic device including a lower panel including flow velocity measuring structures for measuring a flow velocity of a fluid; an upper panel separated from the lower panel and including a microfluidic channel through which a sample passes; a thin film provided at a portion where the lower panel and the upper panel adjoin each other in order to prevent the sample passing through the microfluidic channel from coming into direct contact with the flow velocity measuring structures, the thin film being configured to separate the lower panel and the upper panel to enable the lower panel to be repeatedly used multiple times; a specific functional unit configured to perform a specific operation on the sample passing through the microfluidic channel; and a negative pressure forming means configured to suck the lower panel and the upper panel with a negative pressure.

To obtain a chip package positioning structure capable of adjusting a tilt and a position of a chip package with respect to the circuit board and reducing mounting variations. The chip package positioning and fixing structure that positions and fixes, to a circuit board 4, a chip package 5 in which a flow rate detection element 53 is sealed with a resin so that a detection portion is at least exposed, in which the chip package includes a solder fixation portion 52 that fixes the chip package to the circuit board by soldering, and a positioning portion 514 that performs positioning to the circuit board, and the positioning portion is provided closer to the flow rate detection element from the solder fixation portion.

Methods and apparatuses associated with an example flow sensing device are provided. In some examples, the flow sensing device may include a flow cap component and a sensor component. In some examples, the flow cap component may include a heating element disposed in a first layer of the flow cap component. In some examples, the sensor component may include at least one thermal sensing element disposed in a second layer of the sensor component. In some examples, the first layer and the second layer are noncoplanar. In some examples, the flow cap component may be bonded to a first surface of the sensor component to form a flow channel. In some examples, the first layer and the second layer may be noncoplanar and separated by the flow channel.