Directional accelerometer and its microlithographic fabrication process
First Claim
1. A monodirectional accelerometer for measuring one component of an acceleration of a moving body, comprising:
- a substrate formed of a material and having at least one recess;
at least one parallelepipedic beam placed in the recess and having a first end which is integral with said substrate, said beam being formed of said material, being oriented in a first direction, having a width in a second direction and being able to deform in the second direction in said recess and having a thickness higher than its width, said thickness being oriented in a third direction perpendicular to said first and second directions so that said beam is only deformable in said second direction, said second direction being parallel to the surface of said substrate and perpendicular to said first direction, said deformation in said second direction corresponding to said component of said acceleration to be measured;
means for measuring deformations of said beam in said second direction to determine the value of said component of said acceleration; and
electrical contacts formed on said substrate for connecting said means for measuring with said beam.
1 Assignment
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Accused Products
Abstract
A directional accelerometer and a process for the microlithographic fabrication of such an accelerometer. The accelerometer includes a substrate having at least one recess to define at least one beam in the substrate. One of the ends of the beam is integrally formed with the remainder of the substrate. The beam, which is oriented in the first direction, is deformable into the recess in a second direction only, parallel to the substrate surface and perpendicular to the first direction. The second direction corresponds to the acceleration component to be measured. Electrical connections and contacts are formed in the substrate for the device measuring the deformations of the beam. These measurements make it possible to determine the acceleration components.
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Citations
25 Claims
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1. A monodirectional accelerometer for measuring one component of an acceleration of a moving body, comprising:
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a substrate formed of a material and having at least one recess; at least one parallelepipedic beam placed in the recess and having a first end which is integral with said substrate, said beam being formed of said material, being oriented in a first direction, having a width in a second direction and being able to deform in the second direction in said recess and having a thickness higher than its width, said thickness being oriented in a third direction perpendicular to said first and second directions so that said beam is only deformable in said second direction, said second direction being parallel to the surface of said substrate and perpendicular to said first direction, said deformation in said second direction corresponding to said component of said acceleration to be measured; means for measuring deformations of said beam in said second direction to determine the value of said component of said acceleration; and electrical contacts formed on said substrate for connecting said means for measuring with said beam. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A process for the fabrication of a monodirectional accelerometer used for measuring one component of an acceleration of a moving body, said component being parallel to a first direction, said accelerometer comprising a substrate having at least one recess, at least one parallelepipedic beam placed in the recess and having a first end which is integral with said substrate, said beam oriented to a second direction parallel to a surface of said substrate and perpendicular to said first direction being able to deform only in said first direction and having a thickness higher than its width, said thickness being oriented to a third direction perpendicular to said first and second directions and said width being oriented to said first direction, measuring means for measuring deformations of said beam in said first direction and electrical contacts formed on said substrate for connecting said measuring means with said beam, said process comprising the following stages:
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forming on said substrate a mask which defines the shape of said recess, said beam and in particular the width of said beam, etching mask-free substrate regions in said third direction in order to form said recess and beam, the thickness of said beam being defined by said etching, forming said measuring means, eliminating said mask and metallizing the etched substrate in order to produce said electrical connections and contacts. - View Dependent Claims (11, 12, 13, 14, 15)
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16. A process for the fabrication of a monodirectional accelerometer used for measuring one component of an acceleration of a moving body, said component being parallel to a first direction, said accelerometer comprising a substrate having at least one recess, at least one parallelepipedic beam placed in the recess and having a first end which is integral with said substrate, said beam oriented to a second direction parallel to a surface of said substrate and perpendicular to said first direction being able to deform only in said first direction and having a thickness higher than its width, said thickness being oriented to a third direction perpendicular to said first and second directions and said width being oriented to said first direction, measuring means for measuring deformations of said beam in said first direction and electrical contacts formed on said substrate for connecting said measuring means with said beam, said process comprising the following stages:
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metallizing the substrate surface in order to produce said electrical connections and contacts, forming on said metallized substrate a mask which defines the shape of said recess, said beam and in particular the width of said beam, etching mask-free substrate regions in said third direction in order to form said recess and beam, the thickness of said beam being defined by said etching, forming said measuring means and eliminating said mask. - View Dependent Claims (17, 18)
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19. A process for the fabrication of a monodirectional accelerometer used for measuring one component of an acceleration of a moving body, said component being parallel to a first direction, said accelerometer comprising a substrate having at least one recess, at least one parallelepipedic beam placed in the recess and having a first end which is integral with said substrate, said beam oriented to a second direction parallel to a surface of said substrate and perpendicular to said first direction being able to deform only in said first direction and having a thickness higher than its width, said thickness being oriented to a third direction perpendicular to said first and second directions and said width being oriented to said first direction, measuring means for measuring deformations of said beam in said first direction and electrical contacts formed on said substrate for connecting said measuring means with said beam, said process comprising the following stages:
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forming on said substrate a conductive mask which defines the shape of said recess, said beam and in particular the width of said beam and which produces said electrical connections and contacts, said mask being shaped like a grid, of which bars have a limited spacing in the substrate regions which are to be free from said electrical connections, etching mask-free substrate regions in said third direction in order to form said recess and beam, the thickness of said beam being defined by said etching, and forming said measuring means. - View Dependent Claims (20, 21, 22, 23, 24)
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25. A monodirectional accelerometer for measuring component of an acceleration of a moving body, comprising:
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a substrate formed of a material and having at least one recess; at least one parallelepipedic beam placed in the recess and having a first end which is integral with said substrate, said beam being formed of said material, being oriented in a first direction and being able to deform in a second direction in said recess and having a thickness higher than its width so that said beam is only deformable in said second direction, said second direction being parallel to the surface of said substrate and perpendicular to said first direction, said deformation in said second direction corresponding to said component of said acceleration to be measured; said beam having a second end which supports a block, said block being formed in said substrate and being able to move in said recess in the second direction, said block being connected to the substrate in the first direction with a spring which is formed in the substrate; means for measuring deformations of said beam in said second direction to determine the value of said component of said acceleration; and electrical contacts formed on said substrate for connecting said means for measuring with said beam.
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Specification