Single axis accelerometer and method therefore
First Claim
1. An accelerometer of an implantable medical device having a first terminal corresponding to a first plate of a first capacitor, a second terminal corresponding to a second plate of said first capacitor and a first plate of a second capacitor, and a third terminal corresponding to a second plate of said second capacitor, the accelerometer comprising:
- a first substrate coupled to the first terminal of the accelerometer, said first substrate being said first plate of the first capacitor;
a second substrate bonded to said first substrate, said second substrate comprising;
a moveable mass coupled to the second terminal of the accelerometer, said moveable mass being the second plate of the first capacitor and a first plate of the second capacitor;
at least one S-shaped spring coupled to said moveable mass and said second substrate; and
a third substrate bonded to said second substrate, said third substrate coupled to the third terminal of the accelerometer, said third substrate being the second plate of the second capacitor, wherein the moveable mass is prevented from moving in a direction that inelastically flexes the at least one S-shaped spring.
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Accused Products
Abstract
Methods and apparatus are provided for an accelerometer. The apparatus includes first, second, and third substrates. The first substrate includes the first plate of a first capacitor. The second substrate includes a moveable mass that is coupled to the second substrate by at least one spring. The moveable mass is the second plate of the first capacitor and the first plate of a second capacitor. The third substrate includes the second plate of the second capacitor. The moveable mass is prevented from moving in any direction where the at least one spring is inelastically flexed. The first substrate couples to the second substrate. The third substrate couples to the second substrate. The method includes forming a moveable mass in a substrate. The moveable mass is formed having a plurality of springs coupling the moveable mass to the substrate. The moveable mass is released using a dry etch.
65 Citations
29 Claims
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1. An accelerometer of an implantable medical device having a first terminal corresponding to a first plate of a first capacitor, a second terminal corresponding to a second plate of said first capacitor and a first plate of a second capacitor, and a third terminal corresponding to a second plate of said second capacitor, the accelerometer comprising:
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a first substrate coupled to the first terminal of the accelerometer, said first substrate being said first plate of the first capacitor; a second substrate bonded to said first substrate, said second substrate comprising; a moveable mass coupled to the second terminal of the accelerometer, said moveable mass being the second plate of the first capacitor and a first plate of the second capacitor; at least one S-shaped spring coupled to said moveable mass and said second substrate; and a third substrate bonded to said second substrate, said third substrate coupled to the third terminal of the accelerometer, said third substrate being the second plate of the second capacitor, wherein the moveable mass is prevented from moving in a direction that inelastically flexes the at least one S-shaped spring. - View Dependent Claims (2, 3, 4, 5, 7, 8, 9, 10, 11, 12, 13)
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6. The accelerometer as recited in 5 wherein said first substrate and said second substrate are fusion bonded together with an oxide layer and wherein said second substrate and said third substrate are fusion bonded together with an oxide layer.
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14. An implantable medical device comprising:
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a substrate having interconnect for coupling to circuitry of the implantable medical device; and at least one accelerometer flip chip mounted to the substrate wherein the at least one accelerometer includes a moveable mass coupled to the at least one accelerometer by at least one spring and wherein movement of the moveable mass is limited to prevent inelastic flexing of the spring. - View Dependent Claims (15, 16, 17, 18)
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19. A method of manufacturing a single axis accelerometer comprising the steps of:
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providing a first semiconductor substrate; forming a moveable mass in a second semiconductor substrate having a plurality of S-shaped springs coupled from the moveable mass to the second substrate; releasing the moveable mass using a dry etch such that the moveable mass is limited from moving in any direction that inelastically flexes the plurality of S-shaped springs; providing a third semiconductor substrate; coupling the first semiconductor substrate to the second semiconductor substrate; and coupling the third semiconductor substrate to the second semiconductor substrate. - View Dependent Claims (20, 21, 22, 23, 24, 25, 26, 27, 28, 29)
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Specification