Thermal-type flow sensor with a thermally conductive frame element in the form of a printed circuit board (PCB)

A method of producing a thermally conductive frame element for use in a thermal-type flow sensor of a flow meter, the thermal-type flow sensor comprising:

• a main channel part comprising a main channel for a medium whose flow is to be determined,
• a sensor tube, having:
• a first tube portion with an inlet for being fluidly connected to the main channel,
• a second, opposite tube portion with an outlet for being fluidly connected to the main channel at another downstream position,
• a sensing portion connecting the first and second tube portions to allow a fluid flow though the sensor tube from the inlet to the outlet,
• at least two sensing or heating elements for measuring a temperature differential or a power differential in the sensor tube in order to determine the flow,
• a thermally conductive frame element in contact with at least the first tube portion, the second tube portion and the main channel part, configured to equalize temperature gradients across the thermal-type flow sensor, first tube portion, the second tube portion and main channel part, characterized in that the thermally conductive frame element is a printed circuit board (PCB), the method comprising:
• providing a sheet of metal comprising one or more folding lines and folding the sheet of metal along the one or more folding lines to produce a printed circuit board (PCB) and shaping the PCB to comprise at least one of an elastically deformable deformation portion or a plastically deformable deformation portion, wherein the deformation portion comprises a contact surface for contacting the main channel part, wherein the PCB functions as the thermally conductive frame element and is configured to be in contact with the first tube portion, the second tube portion and the main channel part of the thermal-type flow sensor, and wherein the PCB equalizes temperature gradients across the first tube portion, the second tube portion and the main channel part.