JP2020079808A5

JP2020079808A5 -

Info

Publication number: JP2020079808A5
Application number: JP2020034597A
Authority: JP
Filing date: 2020-03-02
Publication date: 2020-07-30

Description

上記目的を達成するために、本発明の熱式空気流量計は、例えば、被計測流体の一部を取り込む副通路と、前記副通路に配置され前記被計測流体の流量を計測するセンサチップと、前記センサチップにより検出した流体流量を電気信号に変換し内部に抵抗体を有する電子部品と、前記センサチップ及び前記電子部品を搭載する基板と、を有し、前記基板は、固定領域にて筐体に固定され、前記筐体に囲まれた前記電子部品が搭載された側の面が充填材により覆われ、前記基板と前記充填材のヤング率及び線膨張係数が、前記基板と前記充填材のヤング率の比と線膨張係数の比とで決まり、前記基板と前記充填材のヤング率の比をＹ、前記基板と前記充填材の線膨張係数の比をＸとすると、Ｙ＜０．４Ｘ ^−０．９なる関係がある。また、例えば、被計測流体の一部を取り込む副通路と、前記副通路に配置され前記被計測流体の流量を計測するセンサチップと、前記センサチップにより検出した流体流量を電気信号に変換し内部に抵抗体を有する電子部品と、前記センサチップ及び前記電子部品を搭載する基板と、を有し、前記基板は、固定領域にて筐体との一体成型により固定され、前記筐体に囲まれた前記電子部品が搭載された側の面が充填材により覆われ、前記基板と前記充填材のヤング率及び線膨張係数が、前記基板と前記充填材のヤング率の比と線膨張係数の比とで決まり、前記基板と前記充填材のヤング率の比をＹ、前記基板と前記充填材の線膨張係数の比をＸとすると、Ｙ＜０．４Ｘ ^−０．９なる関係がある。 In order to achieve the above object, the thermal air flow meter of the present invention includes, for example, a sub-passage for taking in a part of the fluid to be measured, and a sensor chip arranged in the sub-passage for measuring the flow rate of the fluid to be measured. A flow rate of the fluid detected by the sensor chip is converted into an electric signal, and an electronic component having a resistor inside, and a substrate on which the sensor chip and the electronic component are mounted, the substrate in a fixed region. The surface fixed to the housing and surrounded by the housing on the side where the electronic component is mounted is covered with a filler, and the Young's modulus and the linear expansion coefficient of the substrate and the filler are the same as those of the substrate and the filler. It is determined by the ratio of the Young's modulus of the material and the ratio of the linear expansion coefficients, where Y is the ratio of the Young's modulus of the substrate and the filler, and X is the ratio of the linear expansion coefficient of the substrate and the filler. There is a relationship of 4 × ^−0.9 . In addition, for example, a sub-passage for taking in a part of the fluid to be measured, a sensor chip arranged in the sub-passage for measuring the flow rate of the fluid to be measured, and a fluid flow rate detected by the sensor chip is converted into an electric signal for internal measurement. An electronic component having a resistor and a substrate on which the sensor chip and the electronic component are mounted, the substrate being fixed by integral molding with a casing in a fixing region and surrounded by the casing. The surface on the side on which the electronic component is mounted is covered with a filler, and the Young's modulus and the linear expansion coefficient of the substrate and the filler are the ratio of the Young's modulus and the linear expansion coefficient of the substrate and the filler. Where Y is the Young's modulus ratio of the substrate and the filler and X is the linear expansion coefficient ratio of the substrate and the filler, there is a relationship of Y<0.4X ^−0.9 .