Multiple membrane structure and method of manufacture
First Claim
1. A structure carried on a substrate, comprising:
- a first membrane formed of a micro-machined mesh supported by the substrate; and
a second membrane supported by the substrate and positioned above said first membrane to form a chamber therebetween
1 Assignment
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Accused Products
Abstract
A direct digital microphone is constructed of a plurality of first membranes each formed by a micro-machined mesh supported by a substrate. Each of the membranes has a first and a second position. A second membrane is supported by the substrate and positioned above the plurality of first membranes to form a chamber between the plurality of first membranes and the second membrane. A pressure sensor is responsive to pressure in the chamber. Drive electronics are responsive to the pressure sensor for controlling the positions of each of the plurality of first membranes. Output electronics are responsive to the positions of the plurality of first membranes to produce a digital output signal. A stacked membrane structure and methods of fabrication and operation are also disclosed.
52 Citations
50 Claims
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1. A structure carried on a substrate, comprising:
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a first membrane formed of a micro-machined mesh supported by the substrate; and
a second membrane supported by the substrate and positioned above said first membrane to form a chamber therebetween - View Dependent Claims (2, 3, 4, 5, 6)
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7. A structure carried on a substrate, comprising:
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a first micro-machined mesh supported by the substrate;
a second micro-machined mesh supported by the substrate and positioned above said first mesh; and
a material for sealing said first and second meshes to form first and second membranes, respectively. - View Dependent Claims (8, 9, 10)
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- 11. A stacked structure comprising at least two membranes, and wherein at least one of said membranes is formed of a micro-machined mesh.
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17. A microphone constructed on a substrate, comprising:
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a plurality of first membranes each formed by a micro-machined mesh supported by the substrate, each of said membranes having a first and a second position;
a second membrane supported by the substrate and positioned above said first membrane to form a chamber between said plurality of first membranes and said second membrane;
a pressure sensor responsive to a pressure in said chamber;
drive electronics responsive to said pressure sensor for controlling the positions of each of said plurality of first membranes; and
output electronics responsive to the positions of said plurality of first membranes. - View Dependent Claims (18, 19, 20, 21, 22, 23, 24, 25, 26)
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27. A microphone, comprising:
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a substrate;
a plurality of first micro-machined meshes supported by said substrate;
a second micro-machined mesh supported by the substrate and positioned above said plurality of first meshes to form a chamber therebetween;
a material for sealing said plurality of first meshes to form a plurality of first membranes and for sealing said second mesh to form a second membrane, each of said plurality of first membranes having first and second positions;
a sensor responsive to said chamber;
drive electronics responsive to said sensor for controlling the positions of each of said plurality of first membranes; and
output electronics responsive to the positions of said plurality of first membranes for producing an output signal. - View Dependent Claims (28, 29, 30, 31, 32, 33, 34)
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35. A method, comprising:
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fabricating a first micro-machined mesh on a substrate;
sealing said mesh to form a membrane; and
positioning a second membrane above said first membrane. - View Dependent Claims (36)
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37. A method of fabricating stacked membranes, comprising:
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stacking alternating layers of at least two different materials on a substrate, certain of said layers being patterned;
using a top layer as an etch mask to form an upper mesh;
removing said top layer to expose a new top layer;
using said new top layer to protect said upper mesh while said upper mesh is released from said substrate;
removing said new top layer;
using said upper mesh as an etch mask to form and release a lower mesh from said substrate; and
depositing a sealant for sealing said upper and lower meshes. - View Dependent Claims (38, 39, 40)
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41. A method of fabricating stacked layers, comprising:
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forming a first layer of a first material;
forming a first layer of a second material;
patterning said first layer of said second material to form a lower mesh;
forming a second layer of said first material;
forming a second layer of said second material;
patterning said second layer of said second material to define a chamber above said lower mesh;
forming a third layer of said first material;
forming a third layer of said second material;
patterning said third layer of said second material to form an upper mesh above said chamber;
forming a fourth layer of said first material;
forming a fourth layer of said second material; and
patterning said fourth layer of said second material to act as an etch mask for forming said upper mesh. - View Dependent Claims (42)
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43. A method, comprising:
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forming an upper micro-machined mesh on a substrate;
releasing said upper mesh;
forming and releasing a lower mesh under said upper mesh; and
sealing said lower and upper meshes to form first and second membranes, respectively. - View Dependent Claims (44)
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45. A method, comprising:
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sensing a pressure between an upper membrane and a plurality of lower membranes, each of said plurality of lower membranes having a micro-machined mesh;
controlling the position of each of said plurality of lower membranes in response to said sensing; and
monitoring the positions of said plurality of membranes to provide an output signal. - View Dependent Claims (46, 47)
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48. A method of converting sound waves to a digital signal, comprising:
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sensing a pressure in a chamber formed of an upper membrane and a plurality of lower membranes, each of said lower membranes having first and second positions, each of said lower membranes having a micro-machined mesh;
controlling, in response to said sensing, whether each of said plurality of lower membranes is in its first or second position; and
outputting a digital signal responsive to the positions of each of said plurality of lower membranes. - View Dependent Claims (49, 50)
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Specification