MEMS (Micro Electro Mechanical System) reflection device capable of buffering and resisting vibration by utilizing liquid immersion and manufacturing method

Abstract

The invention provides an MEMS reflection device utilizing liquid immersion buffer vibration resistance and a manufacturing method, the MEMS reflection device comprises an MEMS micro galvanometer, a packaging pipe cap and light path matching liquid, the MEMS micro galvanometer comprises a substrate and an MEMS reflector, a buffer cavity is formed between the packaging pipe cap and the substrate, the light path matching liquid is filled in the buffer cavity, the MEMS reflector is immersed in the light path matching liquid, and the packaging pipe cap and the light path matching liquid are filled in the buffer cavity. The packaging pipe cap is provided with a light-transmitting part on one side opposite to the MEMS reflector, incident light passes through the light-transmitting part and the light path matching liquid and then enters the MEMS reflector, and emergent light reflected by the MEMS reflector passes through the light path matching liquid and then exits from the light-transmitting part. According to the scheme, the MEMS reflecting mirror is immersed in the light path matching liquid, normal transmission and switching of light signals are guaranteed through the light path matching liquid, meanwhile, external impact and vibration are effectively buffered, direct influences on the mirror surface structure are avoided, the impact resistance and vibration resistance of the reflecting device are remarkably improved, and the service life of the reflecting device is prolonged. And an effective solution is provided for application of the MEMS reflection device in an extreme environment. Particularly, the MEMS reflecting device is applied to optical devices such as an MEMS optical switch, an MEMS optical attenuator and the like.

Description

Technical Field

[0001] The present invention relates to the field of optical devices, and in particular to a MEMS reflection device utilizing liquid immersion for buffering and vibration resistance and a manufacturing method thereof. Background Art

[0002] In the rapidly developing field of aerospace technology, high reliability and stability are the cornerstones for ensuring the proper functioning of spacecraft and their critical components in extreme environments. However, traditional MEMS (micro-electromechanical systems) reflectors often face the risk of performance degradation or even failure when dealing with the intense vibrations of rocket launches and the extreme pressure fluctuations in the space environment. This significantly limits their widespread application in aerospace and harsh environments.

[0003] To this end, the present invention aims to significantly improve the stability and reliability of the MEMS reflective device through innovative design. Summary of the Invention

[0004] A first object of the present invention is to provide a MEMS reflective device that utilizes liquid immersion to buffer against vibration.

[0005] A second object of the present invention is to provide a method for manufacturing the above-mentioned MEMS reflective device.

[0006] In order to achieve the first purpose of the present invention, the present invention provides a MEMS reflection device that utilizes liquid immersion buffering for vibration resistance, including a MEMS micro-vibration mirror, a packaging tube cap and an optical path matching liquid; the MEMS micro-vibration mirror includes a substrate and a MEMS reflector, the MEMS reflector is arranged on the substrate, the packaging tube cap is sleeved on the outer periphery of the MEMS reflector, the edge of the packaging tube cap is tightly connected to the substrate, a buffer cavity is formed between the packaging tube cap and the substrate, the buffer cavity is tightly arranged, the optical path matching liquid is filled in the buffer cavity, and the MEMS reflector is immersed in the optical path matching liquid; the packaging tube cap has a window end face on the side opposite to the MEMS reflector, and a light-transmitting portion is provided on the window end face, the MEMS reflector is opposite to the light-transmitting portion, the incident light passes through the light-transmitting portion and the optical path matching liquid and is incident on the MEMS reflector, and the outgoing light reflected by the MEMS reflector passes through the optical path matching liquid and is emitted from the light-transmitting portion.

[0007] As can be seen from the above scheme, this case immerses the MEMS reflector in the optical path matching liquid. While ensuring the normal transmission and switching of the optical signal, the optical path matching liquid also effectively buffers external shocks and vibrations, avoiding direct impact on the mirror structure, and significantly improving the impact and vibration resistance of the reflective device.

[0008] A further solution is that the light-transmitting portion has an inner end surface facing the MEMS reflector, and the inner end surface is in direct contact with the optical path matching liquid.

[0009] As can be seen from the above, the inner end face is in direct contact with the optical path matching liquid, thereby preventing the optical signal from passing through the air, reducing refraction and reflection at the air end face, and thus effectively improving the light transmission efficiency.

[0010] A further solution is that the packaging tube cap is provided with a liquid injection hole, the liquid injection hole is communicated with the buffer cavity, and the liquid injection hole is provided with a sealing plug.

[0011] As can be seen from the above, after the optical path matching liquid is injected through the injection hole, a sealing plug or a sealing plug formed by welding can be used to achieve seamless sealing, which not only ensures the compactness of the packaging structure, but also greatly enhances its impact and vibration resistance, and at the same time achieves long-term sealing reliability.

[0012] A further solution is that the liquid injection hole is provided through the end surface of the window, and the liquid injection hole is located outside the light-transmitting portion.

[0013] As can be seen from the above, the liquid injection hole is located on the end face of the window, so that air can be discharged at the same time as filling, thereby preventing bubbles from affecting the normal propagation of the optical signal.

[0014] A further solution is that a light-transmitting hole is provided through the end face of the window, the light-transmitting portion adopts a plane light-transmitting plate, and the plane light-transmitting plate is sealed in the light-transmitting hole or inside the light-transmitting hole.

[0015] As can be seen from the above, the flat window packaging structure of the flat light-transmitting plate makes the packaging and sealing easier and effectively improves the sealing stability.

[0016] A further solution is that the light-transmitting hole is provided with a sealing section and an injection section along the depth direction, the sealing section and the injection section are connected, the aperture of the sealing section is larger than the aperture of the injection section, the sealing section is located outside the injection section, and the sealing plug is arranged inside the sealing section; the plane light-transmitting plate has an inner end face facing the MEMS reflector, the lowest position of the injection section in the depth direction is higher than or equal to the position of the inner end face, and the filling height of the optical path matching liquid is higher than or equal to the lowest position.

[0017] As can be seen from the above, by filling to the position of the injection hole section, the air can be discharged and the inner end surface can be directly in contact with the optical path matching liquid, which can improve the convenience of assembly.

[0018] A further solution is that the substrate is provided with an annular pad on the periphery of the MEMS reflector, and the edge of the packaging cap is welded to the annular pad.

[0019] A further solution is that the packaging tube cap is connected to the outer periphery of the window end surface with an annular peripheral wall, and the end edge of the annular peripheral wall is welded to the annular welding pad.

[0020] A further solution is that a positioning step is provided on the inner periphery of the annular pad, and the annular peripheral wall is located on the outer periphery of the positioning step and is in clearance with the positioning step.

[0021] As can be seen from the above, the assembly sealing and stability of the packaging tube cap can be improved by assembling the annular pad, the annular peripheral wall and the positioning step.

[0022] In order to achieve the second object of the present invention, the present invention provides a method for manufacturing a MEMS reflective device applied to the above-mentioned scheme, the manufacturing method comprising: adding optical path matching liquid through an injection hole so that the MEMS reflective mirror is immersed in the optical path matching liquid and the inner end surface is in direct contact with the optical path matching liquid; and sealing the injection hole with a sealing plug. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 Schematic diagram of the structure of the MEMS reflection device embodiment of the present invention.

[0024] Figure 2 1 is a schematic diagram of the optical path of an embodiment of the MEMS reflection device of the present invention.

[0025] The present invention will be further described below with reference to the accompanying drawings and embodiments. DETAILED DESCRIPTION

[0026] Reference Figures 1 to 2 The MEMS reflective device includes a MEMS micro-vibration mirror 11, a packaging tube cap 12 and an optical path matching liquid 13. The MEMS micro-vibration mirror 11 includes a substrate 111 and a MEMS reflector 114. The MEMS reflector 114 is arranged on the substrate 111. The substrate 111 is provided with an annular pad 115 on the periphery of the MEMS reflector 114. The annular pad 115 can be a square or circular pad. The inner periphery of the annular pad 115 is provided with a positioning step 112. The positioning step 112 is located on the periphery of the MEMS reflector 114. The substrate 111 is provided with a solder foot 113 on the back side of the MEMS reflector 114. In addition to the plug-in soldering arrangement, the solder foot 113 can also be located on the side and arranged using surface mounting soldering.

[0027] The packaging cap 12 is arranged in a bottomed cylindrical shape. It has a window end face 121 on the side opposite the MEMS mirror 114. An annular circumferential wall 122 is provided around the periphery of the window end face 121. A light-transmitting hole 124 is provided through the window end face 121. A light-transmitting portion 128 is provided on the window end face 121. The MEMS mirror 114 faces the light-transmitting portion 128. The light-transmitting portion 128 is a flat light-transmitting plate, which can be made of fused quartz. The flat light-transmitting plate is sealed inside the light-transmitting hole 124 and has a larger area than the light-transmitting hole 124. The flat light-transmitting plate can be sealed using common low-temperature glass sealing or metal fiber welding techniques to achieve a long-term, reliable seal.

[0028] The packaging tube cap 12 is provided with an injection hole 125, which is connected to the buffer cavity 120. The injection hole 125 is provided on the window end surface 121, and the injection hole 125 is located on the outside of the light-transmitting portion 128. The light-transmitting hole 124 is provided with a sealing section 126 and an injection section 127 along the depth direction. The sealing section 126 and the injection section 127 are connected. The aperture of the sealing section 126 is larger than the aperture of the injection section 127. The sealing section 126 is located on the outside of the injection section 127. The sealing plug 14 is provided in the sealing section 126. The plane light-transmitting plate has an inner end surface 129 facing the MEMS reflector 114. The lowest position of the injection section 127 in the depth direction is higher than or equal to the position of the inner end surface 129.

[0029] The packaging tube cap 12 is sleeved on the outer periphery of the MEMS reflector 114, and the edge of the packaging tube cap 12 is tightly connected to the substrate 111. Specifically, the end edge of the annular circumferential wall 122 is welded to the annular pad 115, and the annular circumferential wall 122 is located on the outer periphery of the positioning step 112 and is gap-fitted with the positioning step 112.

[0030] A buffer cavity 120 is formed between the packaging tube cap 12 and the substrate 111. The buffer cavity 120 is sealed and filled with the optical path matching liquid 13. The filling height of the optical path matching liquid 13 is higher than or equal to the lowest position of the injection hole section 127. The MEMS reflector 114 is immersed in the optical path matching liquid 13, and the inner end surface 129 is in direct contact with the optical path matching liquid 13.

[0031] When manufacturing a MEMS reflective device, its manufacturing method includes first injecting an optical path matching liquid through a needle. Since the filling needle is smaller than the diameter of the injection hole section 127, the exhaust problem can be solved while filling the optical path matching liquid. The optical path matching liquid can preferably be mineral oil, and the flat light-transmitting plate can preferably be fused quartz. The refractive indices of the two are relatively close, which can reduce the optical path return loss. At the same time, the filling height of the optical path matching liquid 13 is higher than or equal to the lowest position of the injection hole section 127.

[0032] Finally, the sealing plug 14 formed by sealing with glass solder can be used to seal the sealing section 126 of the injection hole 125.

[0033] Reference Figure 2 The laser source outputs incident light, which passes through the light-transmitting portion 128 and the optical path matching liquid 13 and is incident on the MEMS reflector 114. By adjusting the rotation angle of the MEMS reflector 114, the deflection adjustment of the outgoing light can be achieved. The MEMS reflector 114 reflects the output outgoing light, which then passes through the optical path matching liquid 13 and is emitted from the light-transmitting portion 128.

[0034] Of course, the above embodiments are only preferred embodiments of the present case, and may have more variations in actual applications. For example, a flat light-transmitting plate may be sealed in the light-transmitting hole, or the entire packaging tube cap may be made of light-transmitting material, which can also achieve the functions of sealing and light transmission. In addition to a columnar or cylindrical arrangement, the packaging tube cap may also be arranged in a hemispherical or partially spherical shape, which can also achieve the formation and sealing of the buffer cavity, and the injection hole may also be set at other positions of the packaging tube cap. The above changes all fall within the scope of protection of the present invention.

[0035] As can be seen from the above, in this case, the MEMS reflector is immersed in an optical path matching liquid. While ensuring the normal transmission and switching of optical signals, the optical path matching liquid also effectively buffers external shocks and vibrations, avoiding direct impact on the mirror structure, significantly improving the impact and vibration resistance of the reflector, and providing an effective solution for the application of MEMS reflector devices in extreme environments. In particular, the MEMS reflector device is used in optical devices such as MEMS optical switches and MEMS optical attenuators.

Claims

1. A MEMS reflective device utilizing liquid immersion buffering for vibration resistance, characterized in that: Including MEMS micro-vibration mirror, packaging tube cap and optical path matching liquid; The MEMS micro-vibration mirror comprises a substrate and a MEMS reflector, wherein the MEMS reflector is arranged on the substrate, the packaging cap is sleeved on the outer periphery of the MEMS reflector, the edge of the packaging cap is tightly connected to the substrate, a buffer cavity is formed between the packaging cap and the substrate, the buffer cavity is tightly arranged, the optical path matching liquid is filled in the buffer cavity, and the MEMS reflector is immersed in the optical path matching liquid; The packaging tube cap has a window end face on the side opposite to the MEMS reflector, and a light-transmitting portion is arranged on the window end face. The MEMS reflector is opposite to the light-transmitting portion, and the incident light passes through the light-transmitting portion and the optical path matching liquid before entering the MEMS reflector, and the outgoing light reflected by the MEMS reflector passes through the optical path matching liquid before exiting from the light-transmitting portion.

2. The MEMS reflective device according to claim 1, characterized in that: The light-transmitting portion has an inner end surface facing the MEMS reflector, and the inner end surface is in direct contact with the optical path matching liquid.

3. The MEMS reflective device according to claim 2, characterized in that: The packaging tube cap is provided with a liquid injection hole through it, the liquid injection hole is communicated with the buffer cavity, and the liquid injection hole is provided with a sealing plug.

4. The MEMS reflection device according to claim 3, characterized in that: The liquid injection hole is arranged through the window end surface, and the liquid injection hole is located outside the light-transmitting portion.

5. The MEMS reflection device according to claim 4, characterized in that: The window end surface is penetrated with a light-transmitting hole, the light-transmitting portion adopts a plane light-transmitting plate, and the plane light-transmitting plate is sealed in the light-transmitting hole or on the inner side of the light-transmitting hole.

6. The MEMS reflection device according to claim 5, characterized in that: The light-transmitting hole is provided with a sealing section and an injection section along the depth direction, the sealing section is connected with the injection section, the aperture of the sealing section is larger than the aperture of the injection section, the sealing section is located outside the injection section, and the sealing plug is arranged inside the sealing section; The plane light-transmitting plate has an inner end surface facing the MEMS reflector, the lowest position of the injection hole section in the depth direction is higher than or equal to the position of the inner end surface, and the filling height of the optical path matching liquid is higher than or equal to the lowest position.

7. The MEMS reflection device according to any one of claims 1 to 6, characterized in that: The substrate is provided with an annular pad on the periphery of the MEMS reflector, and the edge of the packaging tube cap is welded to the annular pad.

8. The MEMS reflective device according to claim 7, characterized in that: The packaging tube cap is connected to an annular peripheral wall at the outer periphery of the window end surface, and the end edge of the annular peripheral wall is welded to the annular welding pad.

9. The MEMS reflective device according to claim 8, characterized in that: The inner periphery of the annular pad is provided with a positioning step, and the annular peripheral wall is located at the outer periphery of the positioning step and is in clearance fit with the positioning step.

10. A method for manufacturing a MEMS reflective device as claimed in any one of claims 3 to 6, characterized in that: The production method comprises: Filling the optical path matching liquid through the liquid filling hole, so that the MEMS reflector is immersed in the optical path matching liquid, and the inner end surface is in direct contact with the optical path matching liquid; The liquid injection hole is sealed by the sealing plug.

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