Microelectromechanical holding device, image sensor device and method for producing a microelectromechanical holding device

Abstract

A microelectromechanical holding device for an image sensor comprises a substrate and at least two deflection units arranged on the substrate. Each deflection unit has a frame for connection to the image sensor and at least one electrode arrangement. The electrode arrangement has at least one electrode pair. For each electrode pair, a first electrode is connected fixedly to the substrate. A second electrode is coupled to the frame. The electrode pair is able to be controlled such that the frame is deflected in a predefined first direction that depends on the electrode pair.

Description

[0001] Description

[0002] title

[0003] Microelectromechanical holding device, image sensor device, and method for producing a microelectromechanical holding device

[0004] The present invention relates to a microelectromechanical holding device, an image sensor device and a method for producing a microelectromechanical holding device.

[0005] State of the art

[0006] For optical image stabilization in portable devices, such as smartphones, the lenses can be moved. In another approach, the imager chip (contact image sensor, CIS) is moved. Such a displacement using a microelectromechanical system (MEMS) is known from US 11,274,033 B2. A MEMS actuator comprises a first set of actuator fingers, a second set of actuator fingers, and a first bridging structure that couples at least two fingers of the first set of actuator fingers while bridging at least one finger of the second set of actuator fingers. A capacitively driven frame is provided onto which a CIS can be mounted. Lateral displacement of the entire structure in the x / y plane as well as rotation in the plane is possible.

[0007] Disclosure of the invention

[0008] The invention provides a microelectromechanical holding device, an image sensor device and a method for producing a microelectromechanical holding device having the features of the independent patent claims.

[0009] Preferred embodiments are the subject of the respective subclaims. According to a first aspect, the invention accordingly relates to a microelectromechanical holding device for an image sensor, comprising a substrate and at least two deflection devices arranged on the substrate. Each deflection device has a frame for connection to the image sensor and at least one electrode device. The electrode arrangement has at least one electrode pair. For each electrode pair, a first electrode is fixedly connected to the substrate. A second electrode is coupled to the frame. The electrode pair can be controlled such that the frame is deflected in a predetermined first direction dependent on the electrode pair.

[0010] According to a second aspect, the invention accordingly relates to an image sensor device comprising an image sensor and a microelectromechanical holding device according to the second aspect, wherein the image sensor is arranged on the holding device.

[0011] According to a third aspect, the invention accordingly relates to a method for producing a microelectromechanical holding device for an image sensor. A substrate is provided. At least two deflection devices are arranged on the substrate. Each deflection device has a frame for connection to the image sensor and at least one electrode device. The electrode arrangement has at least one electrode pair. For each electrode pair, a first electrode is fixedly connected to the substrate, and a second electrode is coupled to the frame. The electrode pair can be controlled such that the frame is deflected in a predetermined first direction dependent on the electrode pair.

[0012] Advantages of the invention

[0013] The holding device comprises a plurality of segmented and independently controllable and movable deflection devices, which together support the image sensor and enable a deflection of the image sensor.

[0014] This segmentation allows the micromechanical holding device to be designed independently of the size of the image sensor and, conversely, to use a micromechanical holding device for image sensors of any size. The micromechanical holding device can be made small, so that the total area is significantly smaller than the area of ​​the image sensor, simplifying manufacturing.

[0015] According to a further development of the microelectromechanical holding device, the predetermined first direction of an electrode pair of the electrode device of a first deflection device is orthogonal to the predetermined first direction of an electrode pair of the electrode device of a second deflection device. The two electrode pairs thus enable deflections of the image sensor in orthogonal directions.

[0016] According to a further development of the microelectromechanical holding device, the second electrode of an electrode pair is arranged on a carrier which is coupled to the substrate in such a way that the carrier is deflectable in the predetermined first direction of the electrode pair and is substantially fixed in a second direction orthogonal to the predetermined first direction of the electrode pair.

[0017] According to a further development of the microelectromechanical holding device, the carrier is connected to the outer frame via a coupling device such that the outer frame can be deflected relative to the carrier along the second direction. This can prevent such deflections from being transmitted to the electrode device.

[0018] According to a further development of the microelectromechanical holding device, the coupling device is configured such that the outer frame is fixed relative to the carrier along the first direction. Such deflections are thereby transmitted.

[0019] According to a further development of the microelectromechanical holding device, the coupling device is a push rod or a spring element.

[0020] According to a further development of the microelectromechanical holding device, the coupling device has a first coupling element and a second coupling element, which are connected to the carrier on opposite sides of the electrode device.

[0021] According to a further development of the microelectromechanical holding device, the first electrode and the second electrode are interdigital electrodes.

[0022] Further advantages, features and details of the invention will become apparent from the following description, in which various embodiments are described in detail with reference to the drawings.

[0023] Short description of the drawings

[0024] They show:

[0025] Figure 1 is a schematic plan view of an image sensor device according to an embodiment of the invention;

[0026] Figure 2 is a schematic plan view of a deflection device of a micromechanical holding device according to an embodiment of the invention;

[0027] Figures 3a-c are schematic plan views of the image sensor device according to Figure 1 to explain the deflection of the image sensor;

[0028] Figure 4 is a schematic plan view of a deflection device of a micromechanical holding device according to an embodiment of the invention;

[0029] Figures 5a-d show schematic plan views of deflection devices of micromechanical holding devices according to embodiments of the invention;

[0030] Figure 6 shows a schematic plan view of an image sensor device according to an embodiment of the invention; and Figure 7 shows a flowchart of a method for producing a micromechanical holding device according to an embodiment of the invention.

[0031] In all figures, identical or functionally equivalent elements and devices are provided with the same reference numerals. The numbering of process steps serves the purpose of clarity and is generally not intended to imply a specific chronological order. In particular, several process steps can be performed simultaneously.

[0032] Description of the implementation examples

[0033] Figure 1 shows a schematic top view of an image sensor device 100. The image sensor device 100 comprises an image sensor 400 (e.g., imager chip) and a microelectromechanical holding device 200. The image sensor 400 is arranged or fixed on the holding device 200. The micromechanical holding device 200 comprises four deflection devices 10a to 10d, which are firmly attached to a substrate.

[0034] The four deflection devices 10a to 10d are arranged in a matrix, ie in a 2x2 grid.

[0035] By controlling the deflection devices 10a to 10d, the image sensor 2 can be displaced along a first direction y or a second direction x or can also be rotated in the xy plane, as will be described in more detail below.

[0036] Figure 2 shows a schematic plan view of a deflection device 10 of the microelectromechanical holding device 200 shown in Figure 1.

[0037] The deflection device 10 has a frame 1. To attach the image sensor 400 to the holding device 200, the image sensor 400 can be attached to the frame 1 in connection areas 300, which are illustrated in Figure 1.

[0038] The deflection device 10 has an electrode device. For this purpose, several

[0039] Electrode pairs are provided. A plurality of first electrodes 7a, 7b and second electrodes 6 are provided, each having a comb structure, with the fingers of the combs extending parallel to one another along the first direction y. The electrodes 6, 7a, 7b are thus designed as interdigital electrodes.

[0040] The second electrodes 6 are fixedly connected to a carrier 2, which extends along the second direction y. The second electrodes 6 each have fingers that are interlocked with fingers of one of the first electrodes 7a, as well as fingers that are interlocked with fingers of another of the first electrodes 7b, thus forming two electrode pairs. In the embodiment shown in Figure 2, a total of six electrode pairs are formed, although the invention is not limited to a specific number of electrode pairs.

[0041] The carrier 2 is connected to armatures 5a, 5b via two rocker springs 3a, 3b located on opposite sides of the electrode device, wherein the armatures 5a, 5b are fixedly arranged on the substrate. Via the rocker springs 3a, 3b, the carrier 2 can be deflected in the predetermined first direction y of the electrode pairs 6, 7a, 7b and is essentially fixed in a second direction x orthogonal to the predetermined first direction y of the electrode pair 6, 7a, 7b. Thus, only deflections in the form of a parallelogram are possible, wherein essentially only the coordinate along the predetermined first direction y changes, while the coordinate along the orthogonal second direction x remains essentially the same.

[0042] The support 2 is further connected to the outer frame 1 via a coupling device 4. The coupling device 4 can be a push rod, which essentially prevents movements of the frame 1 relative to the support 2 along the predetermined first direction y, while allowing movements of the frame 1 relative to the support 2 along the predetermined second direction x. The outer frame 1 is thus deflectable relative to the support 2 along the second direction x.

[0043] The flexible push rod 4 thus allows for a movement of the outer frame 1 in the second direction x to be cushioned by the flexible push rod 4 and not transmitted to the electrode device. The first electrodes 7a, 7b are fixedly connected to the substrate. The second electrodes 6 are coupled to the frame 1 and can move relative to the substrate.

[0044] The electrode pairs 6, 7a, 7b can be controlled such that the frame 1 is deflected in the predetermined first direction x, which depends on the electrode pair 6, 7a, 7b. By applying a voltage to one of the first electrodes 7a, the carrier 2 and thus the frame 1 can be deflected in a positive direction along the first direction y. By applying a voltage to a first electrode 7b opposite the second electrode 2, the carrier 2 and thus the frame 1 can be deflected in a negative direction along the first direction y. By appropriately selecting the voltages, the precise position of the frame 1 and thus of the image sensor 400 can be adjusted.

[0045] In the image sensor device 100 shown in Figure 1, the deflection devices 10 shown in Figure 2 are oriented differently. Thus, the carrier 2 is located at the upper edge when the deflection device 10a is arranged at the top left, at the right edge when the deflection device 10b is arranged at the top right, at the left edge when the deflection device 10c is arranged at the bottom left, and at the bottom edge when the deflection device 10d is arranged at the bottom left.

[0046] Figures 3a-c show schematic top views of the image sensor device 100 according to Figure 1 to explain the deflection of the image sensor 400.

[0047] As shown in Figure 3a, the deflection devices 10a, 10d located at the top left and bottom right of the 2x2 grid can be controlled to deflect the frame 1 and thus the image sensor 400 to the right (or left). Due to the connection via the image sensor 400, the frames 1 of the two differently oriented deflection devices 10b, 10c are also deflected in the second direction x. However, this movement is cushioned by the push rods 4 and is not transmitted to the electrode device.

[0048] As shown in Figure 3b, the deflection devices 10b, 10c located at the top right and bottom left of the 2x2 grid can be controlled to deflect the frame 1 and thus the image sensor 400 upwards (or downwards). The image sensor 400 can thus be deflected in all directions via an electrostatic comb drive with fixed comb electrodes.

[0049] As shown in Figure 3c, by jointly controlling all deflection devices 10a to 10d, a deflection in the counterclockwise (or clockwise) direction can be generated, resulting in a rotation of the image sensor 400.

[0050] Overall, by using several deflection devices 10a to 10d, any desired displacement or rotation of the image sensor 400 is possible within predetermined limits.

[0051] Figure 4 shows a schematic plan view of a deflection device of a micromechanical holding device 20 for use in an image sensor device or in a micromechanical holding device. Compared to the micromechanical holding device 10 shown in Figure 2, the arrangement is symmetrical, i.e., first and second supports 2a, 2b are located on both sides of the electrode device, which are coupled to the frame 1 by respective push rods 4a, 4b and connected to the armatures 5a, 5b by respective rocker springs 3c to 3f.

[0052] Figures 5a-d show schematic top views of deflection devices 30 to 60 of micromechanical holding devices.

[0053] In Figure 5a, a spring 4c is provided as a coupling device between the support 2 and the outer frame 1. The spring is connected to the support 2 in an outer region of the support 2 and extends to the opposite outer region of the support 2.

[0054] In Figure 5b, two springs 4d are provided as a coupling device between the carrier 2 and the outer frame 1, resulting in a symmetrical structure.

[0055] In Figure 5c, a single spring 4e is provided as a coupling device between the support 2 and the outer frame 1, which, however, is connected to the support 2 in a central region of the support 2. This also allows for a symmetrical structure.

[0056] In Figure 5d, a spring 4f is provided as a coupling device between the carrier 2 and the outer frame 1, which has a more pointed profile compared to the coupling device 4c shown in Figure 5a.

[0057] Figure 6 shows a schematic top view of another image sensor device 101. In contrast to the image sensor device 100 shown in Figure 1, the micromechanical holding device 201 comprises only two holding devices 80a, 80b. These holding devices 80a, 80b each consist of two interconnected components, each of which corresponds to one of the holding devices 10a of the image sensor device 100 shown in Figure 1 and is rotated by 90 degrees relative to each other. According to further embodiments, the two holding devices 80a, 80b can also each comprise a one-piece frame.

[0058] A single holding device 80a, 80b can cause a movement of the carrier 2 both along the first direction y and along the second direction x.

[0059] Figure 7 shows a flowchart of a method for producing a micromechanical holding device for an image sensor 400, in particular one of the microelectromechanical holding devices 200, 201 described above.

[0060] A substrate is provided in a first step S1.

[0061] In a second step S2, at least two deflection devices 10 to 80 are arranged on the substrate. Each deflection device 10 to 80 has a frame 1 for connection to the image sensor 400 and at least one electrode device. The electrode arrangement has at least one electrode pair 6, 7a, 7b. For each electrode pair 6, 7a, 7b, a first electrode 7a, 7b is fixedly connected to the substrate and a second electrode 6 is coupled to the frame 1. The electrode pair 6, 7a, 7b is designed to be controllable such that the frame 1 can be deflected in a predetermined first direction y dependent on the electrode pair 6, 7a, 7b. The second electrode 6 of an electrode pair 6.7a, 7b can be arranged on a carrier 2 which is coupled to the substrate in such a way that the carrier 2 is deflectable in the predetermined first direction y of the electrode pair 6, 7a, 7b and is substantially fixed in a second direction x orthogonal to the predetermined first direction y of the electrode pair 6, 7a, 7b.

[0062] The carrier 2 can be connected to the outer frame 1 via a coupling device 4, 4a-4f such that the outer frame 1 can be deflected relative to the carrier 2 along the second direction x.

[0063] The coupling device 4, 4a-4f can be designed such that the outer frame 1 is fixed relative to the carrier 2 along the first direction y. The coupling device 4, 4a-4f can be a push rod or a spring element. The coupling device 4a, 4b can comprise a first coupling element 4a and a second

[0064] coupling element 4b, which are connected to the carrier 2 on opposite sides.

[0065] The first electrode 7a, 7b and the second electrode 6 may be interdigital electrodes.

Claims

Claims 1. A microelectromechanical holding device (200; 201) for an image sensor (400) comprising: a substrate; and at least two deflection devices (10-80) arranged on the substrate, wherein each deflection device (10-80) has a frame (1) for connection to the image sensor (400) and at least one electrode device, wherein the electrode arrangement has at least one electrode pair (7a, 7b), wherein for each electrode pair (6, 7a, 7b) a first electrode (7a, 7b) is fixedly connected to the substrate and a second electrode (6) is coupled to the frame (1), and wherein the electrode pair (6, 7a, 7b) is controllable such that the frame (1) is deflected in a predetermined first direction (y) dependent on the electrode pair (6, 7a, 7b).

2. Microelectromechanical holding device (200; 201) according to claim 1, wherein the predetermined first direction (y) of an electrode pair (6, 7a, 7b) of the electrode device of a first deflection device (10-80) is orthogonal to the predetermined first direction (y) of an electrode pair (6, 7a, 7b) of the electrode device of a second deflection device (10-80).

3. Microelectromechanical holding device (200; 201) according to claim 1 or 2, wherein the second electrode (6) of an electrode pair (6, 7a, 7b) is arranged on a carrier (2) which is coupled to the substrate in such a way that the carrier (2) is deflectable in the predetermined first direction (y) of the electrode pair (6, 7a, 7b) and is substantially fixed in a second direction (x) orthogonal to the predetermined first direction (y) of the electrode pair (6, 7a, 7b).

4. Microelectromechanical holding device (200; 201) according to claim 3, wherein the carrier (2) is connected to the outer frame (1) via a coupling device (4, 4a-4f) such that the outer frame (1) relative to the carrier (2) is deflectable along the second direction (x).

5. Microelectromechanical holding device (200; 201) according to claim 4, wherein the coupling device (4, 4a-4f) is arranged such that the outer frame (1) is fixed relative to the carrier (2) along the first direction (y).

6. Microelectromechanical holding device (200; 201) according to one of the preceding claims, wherein the coupling device (4, 4a-4f) is a push rod or a spring element.

7. Microelectromechanical holding device (200; 201) according to one of the preceding claims, wherein the coupling device (4a, 4b) has a first coupling element (4a) and a second coupling element (4b) which are connected to the carrier (2) on opposite sides of the electrode device.

8. Microelectromechanical holding device (200; 201) according to one of the preceding claims, wherein the first electrode (7a, 7b) and the second electrode (6) are interdigital electrodes.

9. An image sensor device (100; 101), comprising: an image sensor (400); and a microelectromechanical holding device (200; 201) according to one of the preceding claims, wherein the image sensor (400) is arranged on the holding device (200; 201).

10. A method for producing a microelectromechanical holding device (200; 201) for an image sensor (400) comprising the steps: Providing (S1) a substrate; and Arranging (S2) at least two deflection devices (10-80) on the substrate, each deflection device (10-80) having a frame (1) for Connection to the image sensor (400) and at least one electrode device, wherein the electrode arrangement has at least one electrode pair (6, 7a, 7b), wherein for each electrode pair (6, 7a, 7b) a first electrode (7a, 7b) is fixedly connected to the substrate and a second electrode (6) is coupled to the frame (1), and wherein the electrode pair (6, 7a, 7b) can be controlled in such a way that the frame (1) is deflected in a predetermined first direction (y) dependent on the pair of electrodes (6, 7a, 7b).

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