Patent ID: 6886401
Filing Date: 2005-05-03
Classification: G01F

Abstract:
1. A thermal flow sensor including a sensor passage, a bypass passage with respect to the sensor passage, and a hot wire for measuring a flow rate being bridged across the sensor passage, wherein the thermal flow sensor further includes a filter placed between the bypass passage and the sensor passage, and wherein the bypass passage is made of a board having a front side on which an electrode connected to an electric circuit for performing a measurement principle using the hot wire is provided and a body formed with a fluid passage having a side opening, the board being attached to the body in close contact relation to close the side opening, and the sensor passage is made of a groove formed in at least one of a measuring chip and the board when the measuring chip provided thereon with the hot wire and an electrode connected to the hot wire is mounted on the board so that the electrode for the hot wire is joined to the electrode for the electric circuit.