US 5,861,811 AGranted

Fluid sensor

OwnerBenjamin N. Lease, Lee Paul Dollisoninventors

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Abstract

A fluid sensor (100) senses a level of fluid (20) in a receptacle (10). The fluid sensor comprises a detector assembly (200) for detecting fluid and comprises sensor circuitry. The detector assembly comprises a detector body (201) comprising an electrically insulative material and defining first and second surfaces (210, 220) in a predetermined spaced relation. The detector body defines a space (250) between the first and second surfaces and defines a port (255, 257) for allowing fluid to pass in the space between the first and second surfaces. The detector assembly also comprises first and second conductive layers (212, 222) deposited over at least a portion of the first and second surfaces of the detector body, respectively. The sensor circuitry is conductively coupled to at least one of the first and second conductive layers for generating an electrical signal based on whether fluid is present in the space between the first and second surfaces.

Claims26

Dependent claims

A fluid sensor comprising:

a) a detector assembly for detecting fluid, said detector assembly comprising:
i) a detector body comprising an electrically insulative material and defining a first surface and a second surface in a predetermined spaced relation with said first surface, said detector body defining a space between said first surface and said second surface and defining a port for allowing fluid to pass into said space between said first and second surfaces,
ii) a first conductive layer deposited over at least a portion of said first surface of said detector body, and
iii) a second conductive layer deposited over at least a portion of said second surface of said detector body;
wherein said detector body comprises a first molded portion and a second molded portion around said first molded portion to define patterns for said first and second conductive layers, said first and second molded portions comprising different materials;
and
b) a printed circuit board for supporting sensor circuitry conductively coupled to at least one of said first and second conductive layers for generating an electrical signal based on whether fluid is present in said space between said first and second surfaces;
wherein said detector body further defines a mounting surface for supporting for electrical contact to said sensor circuitry and defines a via extending between said mounting surface and one of said first and second conductive layers, said contact conductively coupled to said one of said first and second conductive layers through said via.

5 more elements

A method for manufacturing a fluid sensor comprising the steps of:

a) forming a detector body comprising an electrically insulative material and defining a first surface and a second surface in a predetermined spaced relation with said first surface, said detector body defining a space between said first surface and said second surface and defining a port for allowing fluid to pass into said space between said first and second surfaces;
b) depositing a first conductive layer over at least a portion of said first surface of said detector body;
c) depositing a second conductive layer over at least a portion of said second surface of said detector body;
and
d) conductively coupling sensor circuitry supported by a printed circuit board to at least one of said first and second conductive layers, said sensor circuitry for generating an electrical signal based on whether fluid is present in said space between said first and second surfaces;
wherein said forming step (a) comprises the steps of molding a first portion of said detector body and molding a second portion of said detector body around said first molded portion to define patterns for said first and second conductive layers, said first and second molded portions comprising different materials;
and
wherein the method further comprises the step of forming a contact on a mounting surface of said detector body for electrical contact to said sensor circuitry, said contact conductively coupled to one of said first and second conductive layers through a via extending between said mounting surface and said one of said first and second conductive layers.

5 more elements

Dependencies are inferred from the claim text.