Micromechanical restoring element, component

Abstract

The invention relates to a micromechanical restoring element, comprising a first micromechanical element and a second micromechanical element. The first micromechanical element and the second micromechanical element can be moved relative to each other. The micromechanical restoring element has a first movement region and a second movement region. In the first movement region, a recess in the first micromechanical element is at least partially closed by the second micromechanical element. In the second movement region, the recess is open. In the first movement region, a restoring force acts on the second micromechanical element on account of the at least partially closed recess.

Description

[0001] Description

[0002] title

[0003] Micromechanical reset element, component

[0004] The invention relates to a micromechanical reset element and a micromechanical or microelectromechanical component.

[0005] Micromechanical and microelectromechanical components are known from the state of the art. These can, in particular, have structures that can move relative to each other. One challenge in the design of such components is to absorb shocks and vibrations to the component in such a way that the movable structures are not damaged.

[0006] Disclosure of the invention

[0007] One object of the invention is to provide a micromechanical reset element that can reduce damage to the movable structures. A further object of the invention is to provide a component. These objects are achieved by the subject matter of the independent patent claims. Advantageous developments are specified in the dependent patent claims.

[0008] According to a first aspect, the invention relates to a micromechanical reset element comprising a first micromechanical element and a second micromechanical element. The first micromechanical element and the second micromechanical element are movable relative to one another. In particular, the first micromechanical element can be directly or indirectly mechanically connected to a first movable functional element of a movable structure of a component. In particular, the second micromechanical element can be directly or indirectly mechanically connected to a second movable functional element of a movable structure of a component. The functional elements are in particular movable relative to one another; one of the functional elements can in principle also be immovable, as long as the other functional element is movable relative to this immovable functional element.The micromechanical reset element has a first movement range and a second movement range. In the first movement range, a recess in the first micromechanical element is at least partially closed by the second micromechanical element. In the second movement range, the recess is open. In the first movement range, a restoring force acts on the second micromechanical element due to the at least partially closed recess.

[0009] The first range of motion can represent an overload range in which, due to the restoring force, a movement of the movable structure can be decelerated and / or dampened. This can prevent the functional elements from colliding with each other or at least reduce the relative impact speed of the functional elements. This can lead to a reduction in damage. The second range of motion can, in particular, represent a normal operating range in which the movement of the functional elements should be as unaffected as possible.

[0010] In one embodiment of the micromechanical reset element, a restoring force acting on the second micromechanical element in the second movement range is significantly smaller than in the first movement range. In the second movement range, the restoring force can in particular be a maximum of 10%, preferably a maximum of 5%, more preferably a maximum of 1%, particularly preferably a maximum of 0.5%, and ideally a maximum of 0.1% of the restoring force. The forces occurring in the second movement range due to the relative movement of the functional elements to one another can in particular be greater than the restoring force in the second movement range, so that the micromechanical reset element has no or only a minor effect on the relative movement of the functional elements in the second movement range.

[0011] In one embodiment of the micromechanical return element, the restoring force has a component proportional to the relative position of the micromechanical elements. The micromechanical return element then acts similarly to a spring. In particular, sticking of the functional elements to one another can be prevented, since the restoring force separates the functional elements from one another again. In one embodiment of the micromechanical return element, the restoring force has a component proportional to the relative speed of the micromechanical elements. The micromechanical return element then acts like a damper. In particular, the relative speed of the functional elements relative to one another can be reduced before an impact, thereby reducing damage. It can also be provided that the restoring force has a component related to both the relative position and the relative speed of the micromechanical elements.This represents a combination of spring and damper, meaning the micromechanical return element acts as both a spring and a damper.

[0012] In one embodiment of the micromechanical return element, an opening in the recess in the first movement range is at least partially closed by the second micromechanical element. In the second movement range, the opening is open. Thus, a fluid, for example, ambient air, is compressed in the recess by the second micromechanical element and / or an outflow velocity of the fluid from the recess is adjusted by the second micromechanical element. This enables the micromechanical return element to act as a spring or damper.

[0013] In one embodiment of the micromechanical reset element, the first micromechanical element and the second micromechanical element form a closure element. The closure element has a closure pin that can be moved into a closure cavity. In particular, the closure pin can be moved into the closure cavity due to a relative movement of the micromechanical elements to one another. The closure pin can be assigned to the first micromechanical element, and the closure cavity can be assigned to the second micromechanical element. The closure pin can be assigned to the second micromechanical element, and the closure cavity can be assigned to the first micromechanical element. The closure element allows compression and / or outflow of the fluid from the recess to be more precisely adjusted and controlled, so that the micromechanical reset element is adaptable to different conditions.

[0014] In one embodiment of the micromechanical return element, the closure element is formed from multiple closure cavities and multiple closure pins. This allows for a greater return force and thus a greater spring effect and / or a greater damping effect.

[0015] In one embodiment of the micromechanical return element, the opening defines an outflow direction. The outflow direction is angled to a relative movement direction of the micromechanical elements, in particular perpendicular to the relative movement direction of the micromechanical elements.

[0016] In one embodiment of the micromechanical reset element, the recess has a further opening. The further opening is arranged opposite the opening with respect to the second micromechanical element.

[0017] In one embodiment of the micromechanical reset element, the second micromechanical element has a slide with a through-opening. In the second movement range, the opening and the through-opening are at least partially aligned. In the first movement range, the opening is at least partially closed by the slide.

[0018] According to a second aspect, the invention relates to a micromechanical or microelectromechanical component. This can be, for example, a microphone, a loudspeaker, or a micropump, but other components are also conceivable. The micromechanical or microelectromechanical component has a first movable functional element and a second functional element, as well as a micromechanical reset element. The micromechanical reset element can correspond to the embodiments already described. The first movable functional element is directly or indirectly mechanically connected to the first micromechanical element of the micromechanical reset element, and the second movable functional element is mechanically connected to the second micromechanical element of the micromechanical reset element. The functional elements can form a movable structure of the component. In particular, the functional elements can be movable relative to one another.The first movable functional element can be configured as a single piece with the first micromechanical element. The second movable functional element can be configured as a single piece with the second micromechanical element.

[0019] Embodiments of the invention are explained with reference to the following drawings. The schematic drawing shows:

[0020] Fig. 1 shows a microelectromechanical component;

[0021] Fig. 2 shows a first micromechanical return element in a first position;

[0022] Fig. 3 the first micromechanical return element in a second position;

[0023] Fig. 4 shows a second micromechanical return element in a first position;

[0024] Fig. 5 the second micromechanical return element in a second position;

[0025] Fig. 6 shows a third micromechanical return element in a first position;

[0026] Fig. 7 the third micromechanical return element in a second position;

[0027] Fig. 8 shows a fourth micromechanical return element in a first position;

[0028] Fig. 9 the fourth micromechanical reset element in a second position;

[0029] Fig. 10 shows a fifth micromechanical reset element in a first position; Fig. 11 shows the fifth micromechanical reset element in a second position;

[0030] Fig. 12 shows a sixth micromechanical return element in a first position;

[0031] Fig. 13 the sixth micromechanical reset element in a second position;

[0032] Fig. 14 a seventh micromechanical return element in a first position;

[0033] Fig. 15 the seventh micromechanical return element in a second position;

[0034] Fig. 16 the seventh micromechanical return element in a third position;

[0035] Fig. 17 an eighth micromechanical return element in a first position;

[0036] Fig. 18 the eighth micromechanical reset element in a second position; and

[0037] Fig. 19 the eighth micromechanical reset element in a third position.

[0038] In the following description of the figures, the same reference numerals may be used for elements and features with the same effect. In particular, the features disclosed in connection with the figures may also be provided individually in specific embodiments, if necessary.

[0039] Fig. 1 shows a microelectromechanical component 10 having a chip frame 11 as the first functional element 12 and a membrane 13 as the second functional element 14. The membrane 13 can be set into vibration by means of optional drive elements 15 and / or a movement of the membrane 13 can be read out by means of optional readout elements 16. For this purpose, the component 10 can have an interior space 17 and acoustic openings 18, wherein sound generated by the membrane 13 with the aid of the drive elements 15 can leave the component 10 through the acoustic openings 18 (loudspeaker) or sound impinging through the acoustic openings 18 can be transmitted to the readout elements 16 by means of the membrane 13 (microphone). However, other micromechanical or microelectromechanical components 10 can also be provided using the principle shown in Fig. 1.

[0040] The component 10 further comprises a plurality of micromechanical reset elements 100. The micromechanical reset elements 100 can be used to absorb shocks and vibrations of the component 10 in such a way that the movable structures, for example, the membrane 13 and / or the drive elements 15 and / or the readout elements 16, are not damaged. The micromechanical reset elements 100 can be arranged between the chip frame 12 and the membrane 13.

[0041] Fig. 2 shows a first micromechanical reset element 100 in a first position. Fig. 3 shows the first micromechanical reset element 100 in a second position. The micromechanical reset element 100 has a first micromechanical element 110 and a second micromechanical element 120. The first micromechanical element 110 and the second micromechanical element 120 are movable relative to one another, as shown by the different positions in Figs. 2 and 3. In particular, the first micromechanical element 110 can be directly or indirectly mechanically connected to a first movable functional element of a movable structure of a component 10. In particular, the second micromechanical element 120 can be directly or indirectly mechanically connected to a second movable functional element of a movable structure of a component 10. The functional elements can be, for example, the membrane 13 shown in Fig. 1 and the membrane 13 shown in Fig.1. The functional elements are in particular movable relative to one another; one of the functional elements (for example, the chip frame 11) can in principle also be immobile, as long as the other functional element (the membrane 13) is movable relative to this immobile functional element. The micromechanical restoring element 100 has a first range of motion and a second range of motion. In the first range of motion, a recess 111 of the first micromechanical element 100 is at least partially closed by the second micromechanical element 120 (as shown in Fig. 1). In the second range of motion, the recess 111 is open, here by an optional opening 112 (as shown in Fig. 2). In the first range of motion, a restoring force acts on the second micromechanical element 120 due to the at least partially closed recess 111.

[0042] The first movement range can represent an overload range in which a movement of the movable structure can be decelerated and / or dampened due to the restoring force. This can prevent the functional elements from colliding with one another or at least reduce the relative impact speed of the functional elements. This can lead to a reduction in damage. The second movement range can, in particular, represent a normal operating range in which the movement of the functional elements should not be influenced as much as possible. This can mean that during normal operation of the component 10 of Fig. 1, the micromechanical restoring elements 100 are continuously arranged in the second position shown in Fig. 3, and the arrangement shown in Fig. 2 is only achieved in the event of an overload.The fluid present in the recess 111 can then flow through a fluid channel 113 and through the opening 112, so that a movement of the second micromechanical element 120 is dampened.

[0043] A cross-section of the opening 112 can be, in particular, two and a half times to one hundred times the cross-section of the fluid channel 113, in particular two and a half times to fifty times. For example, a dimension 114 of the opening 112 can be between one and five hundred micrometers, in particular between five and fifty micrometers. A distance 115 of the second micromechanical element 120 in the region of the fluid channel 113 can be between ten nanometers and one hundred micrometers, in particular between 100 nanometers and twenty micrometers.

[0044] The restoring force here has a component proportional to the relative speed of the micromechanical elements 110, 120. The micromechanical restoring element 100 then acts like a damper. In particular, this can reduce the relative speed of the functional elements 110, 120 relative to each other before an impact, thereby reducing damage.

[0045] By appropriately selecting the distance 115, an alternative embodiment can ensure that only very little or no fluid can escape from the recess 111 through the fluid channel 113 and the opening. In the first position of Fig. 2, the second micromechanical element thus closes the recess 111. The restoring force then has a component proportional to the relative position of the micromechanical elements 110, 120. The micromechanical restoring element 100 then acts similarly to a spring. In particular, this prevents the functional elements 110, 120 from sticking together, since the restoring force separates the functional elements 110, 120 from one another.

[0046] It can also be provided that the restoring force has a relationship to both the relative position and the relative speed of the micromechanical elements 110, 120. This represents a combination of spring and damper, meaning that the micromechanical restoring element 100 acts as both a spring and a damper. This can also be achieved by a suitable choice of the distance 115.

[0047] It can be provided that in the second movement range, a restoring force acting on the second micromechanical element 120 is significantly smaller than in the first movement range. In the second movement range, the restoring force can in particular be a maximum of 10%, preferably a maximum of 5%, more preferably a maximum of 1%, particularly preferably a maximum of 0.5% and ideally a maximum of 0.1% of the restoring force. The forces occurring in the second movement range due to the relative movement of the functional elements to one another can in particular be greater than the restoring force in the second movement range, so that the micromechanical restoring element 100 has no or only a slight effect on the relative movement of the functional elements in the second movement range. In the exemplary embodiment of Figs. 2 and 3, the opening 112 of the recess

[0048] 111 is at least partially closed by the second micromechanical element 120 in the first movement range. In the second movement range, the opening

[0049] 112 is opened. Thus, a fluid, for example, ambient air, is compressed in the recess 111 by the second micromechanical element 120 and / or an outflow velocity of the fluid from the recess 111 is adjusted by the second micromechanical element 120. This enables the micromechanical return element 100 to act as a spring or damper.

[0050] It can be provided that the opening 112 defines an outflow direction 116. The outflow direction 116 is angled to a relative movement direction of the micromechanical elements 110, 120, in particular perpendicular to the relative movement direction of the micromechanical elements 110, 120.

[0051] Fig. 4 shows a second micromechanical reset element 100 in a first position. Fig. 5 shows the second micromechanical reset element 100 in a second position. The second micromechanical reset element 100 corresponds to the first micromechanical reset element 100 of Figs. 2 and 3, unless differences are described below. The first micromechanical element 110 and the second micromechanical element 120 form a closure element 130. The closure element 130 has a closure mandrel 132 that can be moved into a closure cavity 131. In particular, the closure mandrel 132 can be moved into the closure cavity 131 due to a relative movement of the micromechanical elements 110, 120 to one another. The closure mandrel 132 can be assigned to the second micromechanical element 120 and the closure cavity 131 to the first micromechanical element 110, as shown in Figs. 4 and 5.However, the closure mandrel 132 can also be assigned to the first micromechanical element 110, and the closure cavity 131 to the second micromechanical element 120. The closure element 130 allows compression and / or outflow of the fluid from the recess 111 to be more precisely adjusted and controlled, so that the micromechanical return element 100 can be adapted to various conditions. In particular, the fluid can flow out of the recess 111 via a fluid channel 113 into the closure cavity 131 and from the closure cavity 131 via a fluid channel 113 through the opening 112. This again leads to damping. Analogous to the description of Figs. 2 and 3, the recess 111 can also be completely or almost completely closed by means of the closure element 130, thus allowing the micromechanical return element 100 to act as a spring.

[0052] Fig. 6 shows a third micromechanical reset element 100 in a first position. Fig. 7 shows the third micromechanical reset element 100 in a second position. The third micromechanical reset element 100 corresponds to the second micromechanical reset element 100 of Figs. 4 and 5, unless differences are described below. The closure element 130 is formed from a plurality of closure cavities 131 and a plurality of closure pins 132. This makes it possible to achieve a greater restoring force and thus a greater spring action and / or a greater damping effect. In the illustrations in Figs. 6 and 7, the closure element 130 is formed from three closure cavities 131 and three closure pins 132, but a different number of closure cavities 131 and closure pins 132 can also be provided.

[0053] Fig. 8 shows a fourth micromechanical reset element 100 in a first position. Fig. 9 shows the fourth micromechanical reset element 100 in a second position. The fourth micromechanical reset element 100 corresponds to the first micromechanical reset element 100 of Figs. 2 and 3, unless differences are described below. The recess 111 has a further opening 117. The further opening 117 is arranged opposite the opening 112 with respect to the second micromechanical element 120. The recess forms two fluid channels 113, which lead to the openings 112, 117.

[0054] Fig. 10 shows a fifth micromechanical reset element 100 in a first position. Fig. 11 shows the fifth micromechanical reset element 100 in a second position. The fifth micromechanical reset element corresponds to the second micromechanical reset element 100 of Figs. 4 and 5, unless differences are described below. Analogous to the fourth micromechanical reset element 100 of Figs. 8 and 9, the recess 111 has a further opening 117. The further opening 117 is arranged opposite the opening 112 with respect to the second micromechanical element 120. The recess forms two fluid channels 113, which lead to the openings 112, 117. Both openings 112, 117 are closed or closable with the closure element 130 already explained in connection with Figs. 4 and 5.

[0055] Fig. 12 shows a sixth micromechanical reset element 100 in a first position. Fig. 13 shows the sixth micromechanical reset element 100 in a second position. The sixth micromechanical reset element corresponds to the second micromechanical reset element 100 of Figs. 4 and 5, unless differences are described below. The second micromechanical element 120 has a slide 121 with a through-opening 122. In the second movement range (Fig. 13), the opening 112 and the through-opening 122 are at least partially aligned. In the first movement range (Fig. 12), the opening 112 is at least partially closed by the slide 121. In this way, the fluid channels 113 present in the first position (Fig. 12) can also be used for damping.

[0056] In Figures 6 to 13, the recesses 111 are each connected to the respective openings 112, 117 via one or more fluid channels 113. The micromechanical return element then acts as a spring. In the embodiments of Figures 6 to 13, the recess 111 can also be completely or almost completely closed by means of the closure element 130, thus allowing the micromechanical return element 100 to act as a spring.

[0057] Fig. 14 shows a seventh micromechanical reset element 100 in a first position. Fig. 15 shows the seventh micromechanical reset element 100 in a second position. Fig. 16 shows the seventh micromechanical reset element 100 in a third position. In the first position (Fig. 14), the first micromechanical element 110 and the second micromechanical element 120 are so far apart that no or only a small reset force is generated between the micromechanical elements 110, 120, since, in particular, the openings 112, 117 between the first micromechanical element and the second micromechanical element 120 are large. If the second micromechanical element 120 is moved towards the first micromechanical element 110 (Fig. 15), the openings 112, 117 are formed, through which the fluid can flow out of the recess 111, thereby creating a damping effect.If the second micromechanical element 120 moves further toward the first micromechanical element 110 (Fig. 16), the openings 112, 117 are closed, and the remaining fluid within the recess 111 is compressed. The resulting overpressure allows a restoring force to separate the micromechanical elements 110, 120 from each other again. In this embodiment, the micromechanical restoring element initially acts as a damper, while the fluid flows out of the recess 111 through the openings 112, 117. If contact subsequently occurs between the micromechanical elements 110, 120, the micromechanical restoring element acts as a spring.

[0058] Fig. 17 shows an eighth micromechanical reset element 100 in a first position. Fig. 18 shows the eighth micromechanical reset element 100 in a second position. Fig. 19 shows the eighth micromechanical reset element 100 in a third position. The eighth micromechanical reset element 100 corresponds to the seventh micromechanical reset element of Figs. 13 to 15, unless differences are described below. Here, only the opening 112 is formed between the first micromechanical element 110 and the second micromechanical element, but not the further opening 117.

[0059] The dimensions 114 and distances 115 explained in connection with Figs. 2 and 3 can also be provided in the embodiments described in connection with Figs. 4 to 19.

[0060] Although the invention has been described in detail by way of preferred embodiments, the invention is not limited to the disclosed examples and other variations may be derived therefrom by those skilled in the art without departing from the scope of the invention.

Claims

Claims 1. A micromechanical reset element (100), comprising a first micromechanical element (110) and a second micromechanical element (120), wherein the first micromechanical element (110) and the second micromechanical element (120) are movable relative to one another, wherein the micromechanical reset element (100) has a first movement range and a second movement range, wherein in the first movement range a recess (111) of the first micromechanical element (110) is at least partially closed by the second micromechanical element (120) and wherein in the second movement range the recess (111) is open, wherein in the first movement range a restoring force acts on the second micromechanical element (120) due to the at least partially closed recess (111).

2. Micromechanical restoring element (100) according to claim 1, wherein in the second movement range a restoring force acting on the second micromechanical element (120) is significantly smaller than in the first movement range.

3. Micromechanical restoring element (100) according to one of claims 1 or 2, wherein the restoring force has a component proportional to the relative position of the micromechanical elements (110, 120) and / or a component proportional to the relative speed of the micromechanical elements (110, 120).

4. Micromechanical return element (100) according to one of the preceding claims, wherein an opening (112) of the recess (111) in the first movement range is at least partially closed by the second micromechanical element (120) and the opening (112) is open in the second movement range.

5. Micromechanical reset element (100) according to claim 4, wherein the first micromechanical element (110) and the second micromechanical element (120) form a closure element (130), wherein the closure element (130) has a closure mandrel (132) movable into a closure cavity (131).

6. Micromechanical return element (100) according to claim 5, wherein the closure element (130) is formed from a plurality of closure cavities (131) and a plurality of closure mandrels (132).

7. Micromechanical return element (100) according to one of claims 4 to 6, wherein the opening (112) defines an outflow direction (116), wherein the outflow direction (116) is at an angle to a relative movement direction of the micromechanical elements (110, 120), in particular at a right angle to the relative movement direction of the micromechanical elements (110, 120).

8. Micromechanical reset element (100) according to claim 7, wherein the recess (111) has a further opening (117), wherein the further opening (117) is arranged opposite the opening (112) with respect to the second micromechanical element (120).

9. Micromechanical reset element (100) according to claim 7 or 8, wherein the second micromechanical element (120) has a slider (121) with a through-opening (122), wherein in the second movement range the opening (112) and the through-opening (122) are at least partially aligned, wherein in the first movement range the slider (121) at least partially closes the opening (112).

10. Micromechanical or microelectromechanical component (10) with a first movable functional element (12) and a second functional element (14), further comprising a micromechanical reset element (100) according to one of the preceding claims, wherein the first movable functional element (12) is connected to the first micromechanical element (110) and the second movable functional element (14) is connected to the second micromechanical element (120) is directly or indirectly mechanically connected.

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