Thick film accelerometer

Claim 2

A thick film accelerometer on an alumina substrate having opposed planar major surfaces, said accelerometer comprising: an alumina substrate base portion; a support member integrally formed with said alumina substrate base portion; a U-shaped flexure member integrally formed with said alumina base portion essentially surrounding said support member so that a gap is provided substantially everywhere therebetween said U-shaped flexure member and said support member except at said alumina substrate base portion, whereby said U-shaped flexure member has an unsupported end capable of flexing under acceleration; a mass provided on the unsupported end of said U-shaped flexure member so as to be oppositely disposed to said alumina base portion; and means for detecting acceleration of said mass in a direction perpendicular to the major surfaces of said alumina substrate base portion and support member, wherein said means for detecting acceleration is provided on said U-shaped flexure member adjacent said alumina substrate base portion.

Claim 3

A thick film accelerometer as recited in claim 1 wherein said alumina substrate provides opposed planar major surfaces on said unsupported end of said U-shaped flexure member, and said mass is provided on both of said surfaces of said unsupported end of said U-shaped flexure member.

Claim 4

A thick film accelerometer as recited in claim 1 wherein said means for detecting acceleration comprises four piezoresistors electrically connected to form a Wheatstone bridge circuit.

Claim 5

A thick film accelerometer as recited in claim 1 further comprising a means for preventing excessive deflection of said mass past a predetermined distance in a direction perpendicular to opposed major surfaces of said base portion and said support member.

Claim 6

A thick film accelerometer as recited in claim 4 wherein said means for preventing excessive deflection of said mass is provided by configuration and disposition of said mass, wherein said mass is prevented from excessive deflection by contacting said support member.

Claim 7

A thick film accelerometer as recited in claim 1further comprising signal conditioning and amplifying circuitry to produce an analog output voltage from an output voltage of said means for detecting acceleration, wherein said signal conditioning and amplifying circuitry is provided on said support member.

Claim 8

A thick film accelerometer as recited in claim 1 further comprising a backplate to which said base portion and said support member are rigidly secured.

Claim 9

A thick film accelerometer comprising a substantially flat alumina substrate having opposed planar major surfaces and said alumina substrate including: an alumina base portion; a support member integrally formed with said alumina base portion; a U-shaped flexure member integrally formed with said alumina base portion essentially surrounding said support member so that a gap is provided substantially everywhere therebetween said U-shaped flexure member and said support member except at said base portion, said U-shaped flexure member having opposed major surfaces and an unsupported end; a mass provided on both of said opposed major surfaces of the unsupported end of said U-shaped flexure member so as to be oppositely disposed on said surfaces from said alumina base portion, such that said support member is disposed substantially intermediate between said alumina base portion and said mass on said unsupported end surfaces; means for preventing excessive deflection of said mass past a predetermined distance in a direction perpendicular to opposed major surfaces of said base portion and said support member; means for damping vibration of said mass so as to achieve a frequency bandwidth greater than about 500 Hertz; means for detecting acceleration of said mass in a direction perpendicular to the plane of said base portion and said support member, wherein said means for detecting acceleration is provided on said U-shaped flexure member adjacent said base portion and said means for detecting acceleration comprising four piezoresistors electrically connected to form a Wheatstone bridge circuit; and signal conditioning and amplifying circuitry to produce an analog output voltage from said means for detecting acceleration, wherein said signal conditioning and amplifying circuitry is provided on said support member.

Claim 10

A thick film accelerometer comprising a substantially flat alumina substrate having opposed planar major surfaces and said alumina substrate including: an alumina base portion; a support member integrally formed with said alumina base portion; a U-shaped flexure member integrally formed with said alumina base portion essentially surrounding said support member so that a gap is provided substantially everywhere therebetween said U-shaped flexure member and said support member except at said base portion, said U-shaped flexure member having opposed major surfaces and an unsupported end; a mass provided on both of said opposed major surfaces of the unsupported end of said U-shaped flexure member so as to be oppositely disposed on said surfaces from said alumina base portion, such that said support member is disposed substantially intermediate between said alumina base portion and said mass on said unsupported end surfaces; means for preventing excessive deflection of said mass past a predetermined distance in a direction perpendicular to opposed major surfaces of said base portion and said support member; means for damping vibration of said mass so as to achieve a frequency bandwidth greater than about 500 Hertz; means for detecting acceleration of said mass in a direction perpendicular to the plane of said base portion and said support member, wherein said means for detecting acceleration is provided on said U-shaped flexure member adjacent said base portion and said means for detecting acceleration comprising four piezoresistors electrically connected to form a Wheatstone bridge circuit; and signal conditioning and amplifying circuitry to produce an analog output voltage from said means for detecting acceleration, wherein said signal conditioning and amplifying circuitry is provided on said support member.

Claim 11

A thick film accelerometer as recited in claim 8 wherein said means for preventing excessive deflection of said mass is provided by disposition of said mass so as to overhang an inner edge of said unsupported end, wherein said U-shaped flexure member is prevented from excessive deflection by said mass contacting said support member.

Claim 12

A thick film accelerometer as recited in claim 8 wherein said means for damping vibration is provided by a viscous silicone oil.

Claim 13

A thick film accelerometer as recited in claim 8 further comprising a backplate to which said base portion and said support member are rigidly secured.

Claim 14

A thick film accelerometer comprising a substantially flat alumina substrate having opposed planar major surfaces and said alumina substrate including: an alumina base portion; a support member integrally formed with said alumina base portion; a backplate to which said base portion and said support means are rigidly secured; a U-shaped flexure member integrally formed with said alumina base portion essentially surrounding said support member so that a gap is provided substantially everywhere therebetween said U-shaped flexure member and said support member except at said base portion, said U-shaped flexure member having opposed major surfaces and an unsupported end; a mass provided on both of said opposed major surfaces of the unsupported end of said U-shaped flexure member so as to be oppositely disposed on said surfaces from said alumina base portion, such that said support member is disposed substantially intermediate between said alumina base portion and said mass, said mass also having a configuration and having a disposition on said unsupported end for preventing excessive deflection of said U-shaped member past a predetermined distance in any direction perpendicular to opposed major surfaces of said base portion and said support member by contacting said support member; means for damping vibration of said mass so as to achieve a frequency bandwidth greater than about 500 Hertz wherein said damping means is provided by a viscous silicone oil; means for detecting acceleration of said mass in a direction perpendicular to the plane of said base portion and said support member, wherein said means for detecting acceleration is provided on said U-shaped flexure member adjacent said base portion and said means for detecting acceleration comprising four piezoresistors electrically connected to form a Wheatstone bridge circuit; and signal conditioning and amplifying circuitry to produce an analog output voltage from said means for detecting acceleration, wherein said signal conditioning and amplifying circuitry is provided on said support member.

Claim 15

A thick film accelerometer comprising a substantially flat alumina substrate having opposed planar major surfaces and said alumina substrate including: an alumina base portion; a support member integrally formed with said alumina base portion; a backplate to which said base portion and said support means are rigidly secured; a U-shaped flexure member integrally formed with said alumina base portion essentially surrounding said support member so that a gap is provided substantially everywhere therebetween said U-shaped flexure member and said support member except at said base portion, said U-shaped flexure member having opposed major surfaces and an unsupported end; a mass provided on both of said opposed major surfaces of the unsupported end of said U-shaped flexure member so as to be oppositely disposed on said surfaces from said alumina base portion, such that said support member is disposed substantially intermediate between said alumina base portion and said mass, said mass also having a configuration and having a disposition on said unsupported end for preventing excessive deflection of said U-shaped member past a predetermined distance in any direction perpendicular to opposed major surfaces of said base portion and said support member by contacting said support member; means for damping vibration of said mass so as to achieve a frequency bandwidth greater than about 500 Hertz wherein said damping means is provided by a viscous silicone oil; means for detecting acceleration of said mass in a direction perpendicular to the plane of said base portion and said support member, wherein said means for detecting acceleration is provided on said U-shaped flexure member adjacent said base portion and said means for detecting acceleration comprising four piezoresistors electrically connected to form a Wheatstone bridge circuit; and signal conditioning and amplifying circuitry to produce an analog output voltage from said means for detecting acceleration, wherein said signal conditioning and amplifying circuitry is provided on said support member.