Wafer level MEMS force dies
First Claim
1. A MEMS force die, comprising:
- a spacer for receiving an applied force; and
a sensor having a center and an outer edge, wherein the sensor is bonded to the spacer at a plurality of linking areas along at least a portion of the outer edge, the sensor comprising at least one flexible sensing element having one or more sensor elements formed on an upper surface of the at least one flexible sensing element, the at least one flexible sensing element having a thickness less than a thickness at the center of the sensor, the at least one flexible sensing element being configured to deflect in response to the applied force received by the spacer and transferred to the sensor, and the one or more sensor elements changing at least one electrical characteristic based on an amount of the applied force,wherein at least one of the spacer or the sensor defines a gap, the gap being arranged between the spacer and the sensor, the gap extending over the center of the sensor, the plurality of linking areas being arranged to at least partially surround the gap, and a depth of the gap being configured to limit an amount of deflection of the at least one flexible sensing element,wherein the spacer is above the at least one flexible sensing element in a thickness direction, andwherein the plurality of linking areas are arranged over the at least one flexible sensing element.
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Accused Products
Abstract
A composite wafer level MEMS force dies including a spacer coupled to a sensor is described herein. The sensor includes at least one flexible sensing element, such as a beam or diaphragm, which have one or more sensor elements formed thereon. Bonding pads connected to the sensor elements are placed on the outer periphery of the sensor. The spacer, which protects the flexible sensing element and the wire bonding pads, is bonded to the sensor. For the beam version, the bond is implemented at the outer edges of the die. For the diaphragm version, the bond is implemented in the center of the die. An interior gap between the spacer and the sensor allows the flexible sensing element to deflect. The gap can also be used to limit the amount of deflection of the flexible sensing element in order to provide overload protection.
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Citations
20 Claims
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1. A MEMS force die, comprising:
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a spacer for receiving an applied force; and a sensor having a center and an outer edge, wherein the sensor is bonded to the spacer at a plurality of linking areas along at least a portion of the outer edge, the sensor comprising at least one flexible sensing element having one or more sensor elements formed on an upper surface of the at least one flexible sensing element, the at least one flexible sensing element having a thickness less than a thickness at the center of the sensor, the at least one flexible sensing element being configured to deflect in response to the applied force received by the spacer and transferred to the sensor, and the one or more sensor elements changing at least one electrical characteristic based on an amount of the applied force, wherein at least one of the spacer or the sensor defines a gap, the gap being arranged between the spacer and the sensor, the gap extending over the center of the sensor, the plurality of linking areas being arranged to at least partially surround the gap, and a depth of the gap being configured to limit an amount of deflection of the at least one flexible sensing element, wherein the spacer is above the at least one flexible sensing element in a thickness direction, and wherein the plurality of linking areas are arranged over the at least one flexible sensing element. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A method for manufacturing a MEMS force die, comprising:
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etching a sensor wafer to form at least one flexible sensing element; etching at least one of the sensor wafer or a spacer wafer to form a gap; forming one or more sensor elements on the at least one flexible sensing element; bonding at least a portion of the sensor wafer and at least a portion of the spacer wafer to form a plurality of bonded areas, wherein the gap is arranged between the bonded sensor and spacer wafers; and dicing the bonded sensor and spacer wafers along one or more lines intersecting the bonded area, wherein the at least one flexible sensing element is configured to deflect in response to an applied force received by the diced spacer wafer and transferred to the diced sensor wafer, the diced sensor wafer having a center and an outer edge, the gap extending over the center of the diced sensor wafer, the plurality of bonded areas being arranged to at least partially surround the gap along at least a portion of the outer edge of the diced sensor wafer, the one or more sensor elements changing at least one electrical characteristic based on an amount of the applied force, a depth of the gap being configured to limit an amount of deflection of the at least one flexible sensing element, and the at least one flexible sensing element having a thickness less than a thickness at the center of the diced sensor wafer, wherein the diced spacer wafer is above the at least one flexible sensing element in a thickness direction, wherein the one or more sensor elements are arranged on an upper surface of the at least one flexible sensing element, and wherein the plurality of bonded areas are arranged over the at least one flexible sensing element. - View Dependent Claims (17, 18, 19, 20)
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Specification