MICROMECHANICAL COMPONENT FOR A CAPACITIVE PRESSURE SENSOR DEVICE
20220003621 · 2022-01-06
Inventors
- Thomas Friedrich (Moessingen-Oeschingen, DE)
- Christoph Hermes (Kirchentellinsfurt, DE)
- Hans Artmann (Boeblingen-Dagersheim, DE)
- Heribert Weber (Nuertingen, DE)
- Peter Schmollngruber (Aidlingen, DE)
- Volkmar Senz (Metzingen, DE)
Cpc classification
G01L9/0048
PHYSICS
G01L9/0042
PHYSICS
G01L9/0047
PHYSICS
B81B7/02
PERFORMING OPERATIONS; TRANSPORTING
B81B2203/0127
PERFORMING OPERATIONS; TRANSPORTING
B81B3/007
PERFORMING OPERATIONS; TRANSPORTING
International classification
G01L9/00
PHYSICS
B81B7/02
PERFORMING OPERATIONS; TRANSPORTING
Abstract
A micromechanical component for a capacitive pressure sensor device, including a diaphragm that is stretched with the aid of a frame structure in such a way that a cantilevered area of the diaphragm spans a framed partial surface, and including a reinforcement structure that is formed at the cantilevered area. A first spatial direction oriented in parallel to the framed partial surface is definable in which the cantilevered area has a minimal extension, and a second spatial direction oriented in parallel to the framed partial surface and oriented perpendicularly with respect to the first spatial direction is definable in which the cantilevered area has a greater extension. The reinforcement structure is present at a first distance from the frame structure in the first spatial direction, and at a second distance in the second spatial direction, the second distance being greater than the first distance.
Claims
1-10. (canceled)
11. A micromechanical component for a capacitive pressure sensor device, comprising: a substrate; a frame structure that frames a partial surface of the substrate and/or at least one intermediate layer that is present on the substrate; a diaphragm that is stretched using the frame structure in such a way that a cantilevered area of the diaphragm, with an outer side that is directed away from the partial surface and an inner side that is oriented toward the framed partial surface, spans the framed partial surface; and a reinforcement structure which, at the outer side of the cantilevered area or at the inner side of the cantilevered area, is configured as a local thickening of the cantilevered area in a direction oriented perpendicularly with respect to the outer side and/or the inner side, compared to a minimal layer thickness of the cantilevered area perpendicular to the outer side and/or the inner side; wherein a first spatial direction is a direction oriented in parallel to the framed partial surface in which the cantilevered area has a minimal extension, and a second spatial direction is a direction oriented in parallel to the framed partial surface and oriented perpendicularly with respect to the first spatial direction in which the cantilevered area has a greater extension compared to the minimal extension, wherein the reinforcement structure is present at a first distance from the frame structure in the first spatial direction, and at a second distance from the frame structure in the second spatial direction, the second distance being greater than the first distance, and wherein the reinforcement structure is a multipart reinforcement structure made up of individual reinforcement pieces.
12. The micromechanical component as recited in claim 11, wherein an edge area of the cantilevered area extends within the first distance from the frame structure in the first spatial direction, and extends within the second distance from the frame structure in the second spatial direction, and the edge area of the cantilevered area being kept away from the reinforcement structure.
13. The micromechanical component as recited in claim 11, wherein the reinforcement structure includes strip-shaped, and/or cubically shaped, and/or circular sector-shaped reinforcement pieces.
14. The micromechanical component as recited in claim 11, wherein an inner volume that is enclosed by the frame structure and the diaphragm is sealed off air-tight with a reference pressure present therein, the cantilevered area of the diaphragm with the aid of a physical pressure, unequal to the reference pressure, on the outer side of the cantilevered area being deformable in such a way that a distance between a measuring electrode situated on the framed partial surface and the reinforcement structure formed at the inner side varies, and the measuring electrode and the reinforcement structure or a counter electrode that is fastened to the reinforcement structure being electrically contactable in such a way that a measuring voltage present between the measuring electrode and the reinforcement structure or the counter electrode is tappable.
15. A capacitive pressure sensor device, comprising: a micromechanical component, including: a substrate; a frame structure that frames a partial surface of the substrate and/or at least one intermediate layer that is present on the substrate; a diaphragm that is stretched using the frame structure in such a way that a cantilevered area of the diaphragm, with an outer side that is directed away from the partial surface and an inner side that is oriented toward the framed partial surface, spans the framed partial surface; and a reinforcement structure which, at the outer side of the cantilevered area or at the inner side of the cantilevered area, is configured as a local thickening of the cantilevered area in a direction oriented perpendicularly with respect to the outer side and/or the inner side, compared to a minimal layer thickness of the cantilevered area perpendicular to the outer side and/or the inner side; wherein a first spatial direction is a direction oriented in parallel to the framed partial surface in which the cantilevered area has a minimal extension, and a second spatial direction is a direction oriented in parallel to the framed partial surface and oriented perpendicularly with respect to the first spatial direction in which the cantilevered area has a greater extension compared to the minimal extension, wherein the reinforcement structure is present at a first distance from the frame structure in the first spatial direction, and at a second distance from the frame structure in the second spatial direction, the second distance being greater than the first distance, wherein the reinforcement structure is a multipart reinforcement structure made up of individual reinforcement pieces, and wherein an inner volume that is enclosed by the frame structure and the diaphragm is sealed off air-tight with a reference pressure present therein, the cantilevered area of the diaphragm with the aid of a physical pressure, unequal to the reference pressure, on the outer side of the cantilevered area being deformable in such a way that a distance between a measuring electrode situated on the framed partial surface and the reinforcement structure formed at the inner side varies, and the measuring electrode and the reinforcement structure or a counter electrode that is fastened to the reinforcement structure being electrically contactable in such a way that a measuring voltage present between the measuring electrode and the reinforcement structure or the counter electrode is tappable; and evaluation electronics that are configured to establish and output a measured value with regard to the physical pressure prevailing in each case on the outer side of the cantilevered area, at least taking the tapped measuring voltage into account.
16. A manufacturing method for a micromechanical component for a capacitive pressure sensor device, comprising the following steps: forming a frame structure on and/or at a substrate, the frame structure framing a partial surface of the substrate and/or at least one intermediate layer that is present on the substrate; stretching a diaphragm using the frame structure in such a way that a cantilevered area of the diaphragm, with an outer side directed away from the framed partial surface and an inner side oriented toward the framed partial surface, spans the framed partial surface, a first spatial direction being a direction oriented in parallel to the framed partial surface in which the cantilevered area has a minimal extension, and a second spatial direction being a direction oriented in parallel to the framed partial surface and perpendicularly with respect to the first spatial direction in which the cantilevered area has a greater extension compared to the minimal extension; and forming a reinforcement structure at the outer side of the cantilevered area or at the inner side of the cantilevered area as a local thickening of the cantilevered area in a direction oriented perpendicularly with respect to the outer side and/or the inner side, compared to a minimal layer thickness of the cantilevered area perpendicular to the outer side and/or the inner side, the reinforcement structure being formed at a first distance from the frame structure in the first spatial direction, and at a second distance from the frame structure in the second spatial direction, the second distance being greater than the first distance; wherein the reinforcement structure is a multipart reinforcement structure made up of individual reinforcement pieces.
17. The manufacturing method as recited in claim 16, wherein an edge area of the cantilevered area extends within the first distance from the frame structure in the first spatial direction, and extends within the second distance from the frame structure in the second spatial direction, and the edge area of the cantilevered area being kept away from the reinforcement structure.
18. The manufacturing method as recited in claim 16, wherein the reinforcement structure is formed from strip-shaped, and/or cubically shaped, and/or circular sector-shaped reinforcement pieces.
19. The manufacturing method as recited in claim 16, wherein an inner volume that is enclosed by the frame structure and the diaphragm is sealed off air-tight with a reference pressure present therein in such a way that the cantilevered area of the diaphragm with the aid of a physical pressure, unequal to the reference pressure, on the outer side of the cantilevered area is deformable in such a way that a distance between a measuring electrode situated on the framed partial surface and the reinforcement structure formed at the inner side varies, and the measuring electrode and the reinforcement structure or a counter electrode that is fastened to the reinforcement structure being electrically contactable in such a way that a measuring voltage present between the measuring electrode and the reinforcement structure or the counter electrode is tappable.
20. A method for manufacturing a capacitive pressure sensor device, including the steps: manufacturing a micromechanical component by: forming a frame structure on and/or at a substrate, the frame structure framing a partial surface of the substrate and/or at least one intermediate layer that is present on the substrate, stretching a diaphragm using the frame structure in such a way that a cantilevered area of the diaphragm, with an outer side directed away from the framed partial surface and an inner side oriented toward the framed partial surface, spans the framed partial surface, a first spatial direction being a direction oriented in parallel to the framed partial surface in which the cantilevered area has a minimal extension, and a second spatial direction being a direction oriented in parallel to the framed partial surface and perpendicularly with respect to the first spatial direction in which the cantilevered area has a greater extension compared to the minimal extension, and forming a reinforcement structure at the outer side of the cantilevered area or at the inner side of the cantilevered area as a local thickening of the cantilevered area in a direction oriented perpendicularly with respect to the outer side and/or the inner side, compared to a minimal layer thickness of the cantilevered area perpendicular to the outer side and/or the inner side, the reinforcement structure being formed at a first distance from the frame structure in the first spatial direction, and at a second distance from the frame structure in the second spatial direction, the second distance being greater than the first distance, wherein the reinforcement structure is a multipart reinforcement structure made up of individual reinforcement pieces, wherein an inner volume that is enclosed by the frame structure and the diaphragm is sealed off air-tight with a reference pressure present therein in such a way that the cantilevered area of the diaphragm with the aid of a physical pressure, unequal to the reference pressure, on the outer side of the cantilevered area is deformable in such a way that a distance between a measuring electrode situated on the framed partial surface and the reinforcement structure formed at the inner side varies, and the measuring electrode and the reinforcement structure or a counter electrode that is fastened to the reinforcement structure being electrically contactable in such a way that a measuring voltage present between the measuring electrode and the reinforcement structure or the counter electrode is tappable; and forming evaluation electronics in such a way that the evaluation electronics establish and output a measured value with regard to the physical pressure that prevails in each case on the outer side of the cantilevered area, at least taking the tapped measuring voltage into account.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] Further features, advantages, and example embodiments of the present invention are explained below with reference to the figures.
[0012]
[0013]
[0014]
[0015]
[0016]
DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
[0017]
[0018] The micromechanical component illustrated in cross section in
[0019] The micromechanical component also includes a frame structure 12, which on a substrate side 10a of substrate 10 or at least one intermediate layer 14 present on substrate 10 is designed in such a way that frame structure 12 frames a partial surface 16 of substrate 10 and/or of the at least one intermediate layer 14. For example, frame structure 12 may be formed as an intermediate layer 14, on an insulating layer 14 that covers substrate side 10a. Intermediate layer 14 may also include multiple sublayers, for example a silicon oxide layer and a (silicon-rich) silicon nitride layer.
[0020] With the aid of frame structure 12, a diaphragm/diaphragm layer 18 is stretched in such a way that a cantilevered area 20 of diaphragm 18 spans framed partial surface 16. Diaphragm 18 may include at least one semiconductor material, for example silicon. However, it is pointed out that diaphragm 18 may include at least one further material instead of or in addition to silicon.
[0021] Cantilevered area 20 includes a one-part or multipart reinforcement structure 22 that is formed at an outer side 20a of cantilevered area 20 directed away from framed partial surface 16 or at an inner side 20b of cantilevered area 20 oriented toward framed partial surface 16. Reinforcement structure 22 may be understood in particular to mean a “local thickening” of cantilevered area 20 in a direction oriented perpendicularly with respect to outer side 20a and/or inner side 20b, compared to a minimal layer thickness d of cantilevered area 20 perpendicular to outer side 20a and/or inner side 20b. In the example in
[0022]
[0023] It is also apparent in
[0024] Different distances a1 and a2 of reinforcement structure 22 from frame structure 12 in the various spatial directions x and y allow good deformability of cantilevered area 20. In particular, reinforcement structure 22 is thus adapted to different extensions I1 and I2 of cantilevered area 20 in the various spatial directions x and y. Despite the deviation of the shape of cantilevered area 20 from a circular shape, maintaining different distances a1 and a2 of reinforcement structure 22 from frame structure 12 allows a deformability of cantilevered area 20 that is (almost) like that for a circular cantilevered area. As explained in greater detail below, cantilevered area 20 of diaphragm 18 may thus be advantageously used for carrying out measurements, such as pressure measurements in particular.
[0025] For cantilevered area 20, an edge area 20-1 of cantilevered area 20 is definable which extends within first distance a1 from frame structure 12 in first spatial direction x, and within second distance a2 from frame structure 12 in second spatial direction y. As is apparent in
[0026] The formation of reinforcement structure 22 solely at middle area 20-2 of cantilevered area 20 effectuates the desired reinforcement of middle area 20-2, while at the same time a good deformability/bendability of edge area 20-1 is maintained. This is advantageous, since when cantilevered area 20 is used to carry out a measurement, in particular a pressure measurement, a good deformability of edge area 20-1 of cantilevered area 20 as a response to a change in at least one variable to be measured is often desired, while at the same time, the reinforcement of middle area 20-2 of cantilevered area 20 facilitates carrying out the particular measurement. This advantage is reliably ensured by maintaining different distances a1 and a2 of reinforcement structure 22 from frame structure 12 in the various spatial directions x and y.
[0027] As is apparent in
[0028] Reinforcement structure 22 may be understood to mean a one-part reinforcement structure 22. Likewise, the reinforcement structure may also have a multipart design, i.e., formed from individual reinforcement pieces 22a through 22c. Reinforcement structure 22 may include, for example, strip-shaped, cubically shaped, and/or circular sector-shaped reinforcement pieces 22a through 22c. However, reinforcement pieces 22a through 22c of reinforcement structure 22 may also have other shapes.
[0029] In the example in
[0030] The specific embodiment in
[0031] The micromechanical component illustrated with the aid of
[0032]
[0033]
[0034] Reinforcement structure 22 in
[0035] In reinforcement structure 22 shown in
[0036] Also for reinforcement structure 22 in
[0037] In reinforcement structure 22 shown in
[0038] In contrast, for the reinforcement structure in
[0039] Reinforcement structure 22 shown in
[0040] With regard to further features of the micromechanical components schematically illustrated in
[0041]
[0042] The specific embodiment described here is shown in cross section in
[0043] With regard to further features of the micromechanical component schematically illustrated in
[0044]
[0045]
[0046] In the specific embodiment in
[0047] In contrast, all strip-shaped partial electrodes 24a of counter electrode 24 in
[0048] In the specific embodiment in
[0049] With regard to further features of the micromechanical components schematically illustrated in
[0050] All micromechanical components described above may in each case be advantageously used in a capacitive sensor device, for example a capacitive pressure sensor device. Such a capacitive pressure sensor device preferably includes, in addition to the particular micromechanical component, evaluation electronics that are designed to establish and output a measured value with regard to physical pressure p prevailing in each case on outer side 20a of cantilevered area 20, at least taking the tapped measuring voltage into account.
[0051]
[0052] The manufacturing method described below may be designed, for example, for manufacturing one of the micromechanical components described above.
[0053] However, practicability of the manufacturing method is not limited to the manufacture of these micromechanical components.
[0054] A frame structure is formed on and/or at a substrate in a method step S1 in such a way that the frame structure frames a partial surface of the substrate and/or at least one intermediate layer that is present on the substrate. As method step S2, a diaphragm is stretched with the aid of the frame structure in such a way that a cantilevered area of the diaphragm spans the framed partial surface, a first spatial direction oriented in parallel to the framed partial surface being definable in which the cantilevered area has a minimal extension, and a second spatial direction oriented in parallel to the framed partial surface and perpendicularly with respect to the first spatial direction being definable in which the cantilevered area has a greater extension compared to the minimal extension.
[0055] As method step S3, a one-part or multipart reinforcement structure is also formed at an outer side of the cantilevered area directed away from the framed partial surface, or at an inner side of the cantilevered area oriented toward the framed partial surface. The reinforcement structure is formed at a first distance from the frame structure in the first spatial direction, and at a second distance from the frame structure in the second spatial direction, the second distance being greater than the first distance. Carrying out the manufacturing method described here thus also yields the advantages already explained above.
[0056] In particular, an edge area of the cantilevered area may be definable which extends within the first distance from the frame structure in the first spatial direction, and within the second distance from the frame structure in the second spatial direction, the edge area of the cantilevered area being kept away from the reinforcement structure. The reinforcement structure may likewise be formed from strip-shaped, cubically shaped, and/or circular sector-shaped reinforcement pieces.
[0057] As optional method step S4, an inner volume that is enclosed by the frame structure and the diaphragm may additionally be sealed off air-tight with a reference pressure present therein in such a way that the cantilevered area of the diaphragm with the aid of a physical pressure, unequal to the reference pressure, on the outer side of the cantilevered area is deformable in such a way that a distance between a measuring electrode situated on the framed partial surface and the reinforcement structure formed at the inner side varies. In addition, the measuring electrode and the reinforcement structure or a counter electrode that is fastened to the reinforcement structure may be designed to be electrically contactable in such a way that a measuring voltage present between the measuring electrode and the reinforcement structure or the counter electrode is tappable.
[0058] The manufacturing method described here may also be part of a method for manufacturing a capacitive pressure sensor device. In this case, an optional method step S5 is also carried out, in which evaluation electronics are designed in such a way that the evaluation electronics establish and output a measured value with regard to the physical pressure that prevails in each case on the outer side of the cantilevered area, at least taking the tapped measuring voltage into account.
[0059] Method steps S1 through S5 explained above may be carried out in (virtually) any order and/or at the same time, at least in part.