Preparation method of optical fiber fixing device and optical fiber fixing device
By first bonding two substrates and then forming optical fiber fixing holes with guide structures, the problems of high precision and poor stability of existing optical fiber fixing devices are solved, and higher yield and stable fixing effects are achieved .
Patent Information
- Application Number
- CN202411496878.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-10-25
- Publication Date
- 2025-02-11
AI Technical Summary
The preparation process of existing optical fiber fixing devices has high requirements for accuracy, which can easily lead to defective rates, and the preparation accuracy of optical fiber fixing holes is strict, which can easily lead to poor fiber stability and impedance of plugging.
The preparation method of bonding two substrates first and then forming optical fiber fixed holes is adopted. By forming a first micropore with a guide structure on the silicon oxide layer and forming a second micropore on the silicon wafer, the docking accuracy of the optical fiber fixed holes is ensured. and stability.
It reduces the difficulty of preparing fiber fixing devices, improves yield, ensures stable fixation of optical fibers, and avoids plug-in obstacles.
Smart Images
Figure CN119414539A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of micro-electromechanical system manufacturing, and in particular to a preparation method of an optical fiber fixing device and the optical fiber fixing device. Background Art
[0002] Fiber optic fixing devices are widely used in the fiber optic communication industry. A plurality of through holes are formed on the fiber optic mold, and a plurality of optical fibers pass through the through holes. During installation, the fiber optic fixing device is installed on one side of the fiber optic docking port, and a plurality of optical fibers are docked with the fiber optic docking port.
[0003] Existing optical fiber fixing devices are manufactured using the Micro Electro Mechanical Systems (MEMS) process, and the process is usually as follows: first, two silicon wafers are etched to form through holes, and then the two silicon wafers are bonded, wherein the through holes on the two silicon wafers need to be aligned. Existing optical fiber fixing devices are first etched to form through holes, and then bonded. During the bonding process, since the through holes need to be butt-jointed with each other, the overall process requires high precision and is prone to defective rates. Summary of the invention
[0004] The object of the present invention is to provide an optical fiber fixing device which can reduce the difficulty of preparation and improve the yield rate.
[0005] To achieve the above object, the present invention provides the following technical solution: a method for preparing an optical fiber fixing device, comprising:
[0006] S1, performing silicon-oxygen bonding on at least two substrates, each of the substrates comprising a silicon wafer and a silicon oxide layer formed on the front side of the silicon wafer;
[0007] S2. Etching each of the substrates from top to bottom in sequence to form a plurality of optical fiber fixing holes; wherein each of the optical fiber fixing holes comprises a first microhole and a second microhole formed on each of the substrates and correspondingly connected, the first microhole being formed on the silicon oxide layer, the second microhole being formed on the silicon wafer, the first microhole having a guide structure, the entrance of the guide structure being located on a side of the second microhole of the substrate away from the guide structure.
[0008] Furthermore, the guide structure is in the shape of a bell.
[0009] Furthermore, the first microhole is formed by the guide structure.
[0010] Furthermore, the first microhole also has a straight tube portion, and the guide structure is formed at the end of the straight tube portion.
[0011] Furthermore, the guide structure has a guide surface facing away from the silicon wafer thereunder, and an angle formed between the guide surface and the front surface of the silicon wafer thereunder is 20°-70°.
[0012] Furthermore, the pore size of the second micropore is 102-104 um.
[0013] Furthermore, the maximum opening in the guide structure is larger than the aperture of the second micropore, and the difference between the two is not less than 50 um.
[0014] Furthermore, the thickness of the silicon oxide layer is 2-5 um, and the thickness of the silicon wafer is 500-800 um.
[0015] Furthermore, the silicon oxide layer is etched by wet etching to form the first micropores; and the silicon wafer is etched by dry etching to form the second micropores.
[0016] The present invention also provides an optical fiber fixing device, which adopts the preparation method of the optical fiber fixing device mentioned above.
[0017] The beneficial effects of the present invention are as follows: the optical fiber fixing device of the present application reduces the difficulty of preparing the optical fiber fixing device by first bonding two substrates and then forming an optical fiber fixing hole, which helps to improve the yield rate; and by forming a first microhole with a guiding structure, the optical fiber fixing device avoids plug-in obstacles while ensuring the stable fixation of the optical fiber by the optical fiber fixing hole.
[0018] The above description is only an overview of the technical solution of the present invention. In order to more clearly understand the technical means of the present invention and implement it according to the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 This is a schematic diagram of the structure of an optical fiber fixing device shown in an embodiment of the present application;
[0020] Figure 2 A flowchart of a method for preparing an optical fiber fixing device according to an embodiment of the present application;
[0021] Figures 3a to 3e It is a structural schematic diagram of the preparation process of the optical fiber fixing device shown in one embodiment of the present application. DETAILED DESCRIPTION
[0022] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0023] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.
[0024] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.
[0025] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0026] See also Figure 1 The optical fiber fixing device 10 shown in one embodiment of the present invention comprises two substrates 1, and the two substrates 1 are bonded by silicon-oxygen to form the optical fiber fixing device 10. Each substrate 1 comprises a silicon wafer 12 and a silicon oxide layer 11 formed on the front surface of the silicon wafer 12. A plurality of optical fiber fixing holes 2 are formed on the substrate 1, and the plurality of optical fiber fixing holes 2 pass through the two substrates 1. Each optical fiber fixing hole 2 is composed of four holes from top to bottom. Figure 3e In detail, each optical fiber fixing hole 2 includes two first microholes 21 and two second microholes 22, the two first microholes 21 and the two second microholes 22 are arranged in an upper and lower interval, the first microhole 21 is formed on the silicon oxide layer 11, and the second microhole 22 is formed on the silicon wafer 12. The first microhole 21 has a guide structure 23. In this embodiment, the guide structure 23 is a bell mouth, and the first microhole 21 is formed by the guide structure 23. The maximum opening of the guide structure 23 is larger than the aperture of the second microhole 22, and the minimum opening is usually equal to or approximately equal to the aperture of the second microhole 22. The axis of the first microhole 21 overlaps the axis of the second microhole 22. In other embodiments, the first microhole 21 can also be partially formed with the guide structure 23, and the guide structure 23 is located at the entrance of the first microhole 21. The rest of the first microhole 21 can be a straight tube part (not shown), and the aperture of the straight tube part can be equal to or approximately equal to the aperture of the second microhole 22.
[0027] The optical fiber fixing device 10 is prepared by the following preparation method, see Figure 2 , the preparation method comprises:
[0028] S1. Please combine Figure 3a , performing silicon-oxygen bonding on at least two substrates 1, each substrate 1 comprising a silicon wafer 12 and a silicon oxide layer 11 formed on the front side of the silicon wafer 12;
[0029] S2. Please combine Figure 3b to Figure 3e , each substrate 1 is etched from top to bottom in sequence to form a plurality of optical fiber fixing holes; wherein each optical fiber fixing hole includes a first microhole 21 and a second microhole 22 formed on each substrate 1 and correspondingly connected, the first microhole 21 is formed in the silicon oxide layer 11, the second microhole 22 is formed on the silicon wafer 12, the first microhole 21 has a guide structure 23, and the entrance of the guide structure 23 is located on a side of the second microhole 22 of the substrate 1 away from the guide structure 23.
[0030] The optical fiber fixing device in the present application is formed by first bonding two substrates 1 and then forming an optical fiber fixing hole 2, so as to reduce the difficulty of preparing the optical fiber fixing device and help improve the yield rate.
[0031] When the optical fiber holder is in use, the optical fiber is fixed through the optical fiber fixing hole 2. The diameter of the existing optical fiber is usually 100-150um. In order to ensure the stability of the optical fiber holder to fix the optical fiber, the optical fiber fixing hole 2 should not be set too large. In the art, the aperture of the optical fiber fixing hole 2 is set to be 2-4um larger than the diameter of the optical fiber. After experimental testing, the optimal tolerance of the optical fiber fixing hole 2 is ±2um. It can be seen that for the optical fiber holder, the accuracy required for the preparation of the optical fiber fixing hole 2 is very strict. However, in the prior art, since the hole is opened first and then bonded, in order to avoid errors during bonding, in actual operation, the tolerance of the optical fiber fixing hole 2 is +2um, or even greater than 2um, which leads to insufficient stability of the optical fiber holder in the prior art, and then causes the optical fiber to shake.
[0032] In addition, since the optical fiber holder is formed by bonding multiple substrates 1, and correspondingly, the optical fiber fixing hole 2 is formed by docking multiple microholes, in addition to the deviation caused by the error in bonding in the prior art, the microholes may also cause a step surface facing upwards between the two microholes due to the manufacturing error. In this way, when the optical fiber enters the microhole below the upper microhole, the plugging is not smooth due to the existence of the step surface. In order to solve this problem, the conventional method of the prior art is to set the aperture of the lower microhole to be larger than the aperture of the upper microhole. However, this method will cause problems with the stability of the optical fiber. In order to ensure stability, the method further adopted in the prior art is: strictly control the aperture of the upper microhole to ensure that it is only 2-4um larger than the diameter of the optical fiber, and set the diameter of the lower microhole to be 2um larger than the aperture of the upper microhole. In this way, although the stability of the optical fiber can be ensured, since the aperture of the upper microhole is only 2-4um larger than the diameter of the optical fiber, it will bring inconvenience to the plugging of the optical fiber.
[0033] For the above technical problems, the present application forms a first microhole 21 with a guide structure 23, so that the optical fiber fixing device can avoid plugging obstacles while ensuring the effective fixation of the optical fiber by the optical fiber fixing hole 2. It should be noted that in the application, since each substrate 1 includes a silicon chip 12 and a silicon oxide layer 11, and the thickness of the silicon chip 12 is much greater than the silicon oxide layer 11, the second microhole 22 in the optical fiber fixing device is used to fix the optical fiber, so in the present application, it is sufficient to limit the aperture of the second microhole 22. In this embodiment, the thickness of the silicon oxide layer 11 is 2-5um, and the thickness of the silicon chip 12 is 500-800um. The aperture of the second microhole 22 in the present application is 102-104um, and the maximum opening in the guide structure 23 is larger than the aperture of the second microhole 22, and the difference between the two is not less than 50um. The tolerance of the first microhole 21 and the second microhole 22 is ±2um. In order to avoid an upward step surface between the first microhole 21 and the second microhole 22, in the present application, the minimum opening of the first microhole 21 is not larger than the diameter of the second microhole 22, thereby improving the smoothness of movement of the optical fiber in the optical fiber fixing device.
[0034] The guide structure 23 is in the shape of a bell mouth. In this embodiment, the first microhole 21 is formed by the guide structure 23. The guide structure 23 has a guide surface 23 facing away from the silicon wafer 12 below it, and the angle formed between the guide surface 23 and the front surface of the silicon wafer 12 below it is 20°-70°. In other embodiments, the first microhole 21 also has a straight barrel portion, and the guide structure 23 is formed at the end of the straight barrel portion.
[0035] In the above step S2 , the silicon oxide layer 11 is etched by wet method to form the first micropores 21 ; and the silicon wafer 12 is etched by dry method to form the second micropores 22 .
[0036] For details, please combine Figure 3b , a first micropore 21 is formed on the silicon oxide layer 11 of the upper substrate 1 by wet etching, and the etching angle of the silicon oxide layer 11 is 20°-70°, wherein the etching angle is preferably controlled between 35°-55°. The etching angle is related to factors such as the adhesion between the photoresist and the silicon oxide layer 11, the etching pre-treatment and the ratio of the etching solution. The etching conditions used in this embodiment are: first apply a layer of HMDS, then spin-coat 2.2um AR87 photoresist, and then expose and develop. Before etching, plasma pre-treatment is used, and the gas used is oxygen, the flow rate is 1000-3000sccm, the power is 500-1000W, the pressure is 0.8-1.5Torr, and the time is 1-2min. Then, BOE etching solution is used for etching for 20-50min, wherein the BOE solution uses NH4F:HF=6:1 ratio.
[0037] Please combine Figure 3c , and then the silicon wafer 12 of the upper substrate 1 is dry-etched to form a second micropore 22, and the second micropore 22 stops above the silicon oxide layer 11 of the lower substrate 1. The dry etching adopts the Bosch process, and the etching gases used are SF6 and C4F8, with flow rates of 500-1000sccm and 100-300sccm respectively, etching power of 1000-3000W, and pressure of 40-80mTorr. Etching requirements: The side wall angle of the second micropore 22 is as vertical as possible, and the silicon wafer 12 is etched and stopped at the silicon oxide layer 11 of the lower substrate 1.
[0038] Please combine Figure 3d , a first micropore 21 is formed on the silicon oxide layer of the lower substrate 1 by wet etching. The etching conditions and steps of the first micropore 21 are the same as those described above. Figure 3e Then, the second micropore 22 is formed on the silicon wafer 12 of the lower substrate 1 by dry etching. The dry etching adopts Bosch process, and the etching gas used is SF6 and C4F8, with flow rates of 500-1000sccm and 100-300sccm respectively, etching power of 1500-4000W, and pressure of 40-80mTorr. Etching requirements: the side wall angle of the second micropore 22 of the silicon wafer 12 of the lower substrate 1 is as vertical as possible, and the silicon wafer 12 of the lower substrate 1 is etched through, and the line width needs to be basically consistent with the aperture of the second micropore 22 on the upper substrate 1.
[0039] In the above steps, wet etching can also be replaced by HF vapor etching, which will not be described in detail here. In the above embodiment, two substrates are given. In other embodiments, more than two substrates can be set according to actual needs. When a pair of substrates is used, compared with the prior art, the low preparation difficulty of the present application can be better reflected, and the yield rate is higher.
[0040] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0041] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.
Claims
1. A method for preparing an optical fiber fixing device, characterized in that: The preparation method comprises: S1, performing silicon-oxygen bonding on at least two substrates, each of the substrates comprising a silicon wafer and a silicon oxide layer formed on the front side of the silicon wafer; S2. Etching each of the substrates from top to bottom in sequence to form a plurality of optical fiber fixing holes; wherein each of the optical fiber fixing holes comprises a first microhole and a second microhole formed on each of the substrates and correspondingly connected, the first microhole being formed on the silicon oxide layer, the second microhole being formed on the silicon wafer, the first microhole having a guide structure, the entrance of the guide structure being located on a side of the second microhole of the substrate away from the guide structure.
2. The method for preparing the optical fiber fixing device according to claim 1, characterized in that: The guide structure is in the shape of a bell mouth.
3. The method for preparing the optical fiber fixing device according to claim 1 or 2, characterized in that: The first microhole is formed by the guide structure.
4. The method for preparing the optical fiber fixing device according to claim 1 or 2, characterized in that: The first micro hole also has a straight tube portion, and the guide structure is formed at an end of the straight tube portion.
5. The method for preparing the optical fiber fixing device according to claim 1, characterized in that: The guide structure has a guide surface facing away from the silicon wafer below it, and the angle formed between the guide surface and the front surface of the silicon wafer below it is 20°-70°.
6. The method for preparing the optical fiber fixing device according to claim 1, characterized in that: The pore size of the second micropore is 102-104 um.
7. The method for preparing the optical fiber fixing device according to claim 1, characterized in that: The maximum opening in the guide structure is larger than the aperture of the second micropore, and the difference between the two is not less than 50 um.
8. The method for preparing the optical fiber fixing device according to claim 1, characterized in that: The thickness of the silicon oxide layer is 2-5 um, and the thickness of the silicon wafer is 500-800 um.
9. The method for preparing the optical fiber fixing device according to claim 1, characterized in that: The silicon oxide layer is wet-etched to form the first micropores; and the silicon wafer is dry-etched to form the second micropores.
10. An optical fiber fixing device, characterized in that: A method for preparing an optical fiber fixing device according to any one of claims 1 to 9.