An electrochemical deposition plating tank based on MEMS micro-device manufacturing
By designing an electrochemical deposition plating tank with arc-shaped inner plating tank body, agitator and oscillator in the manufacturing of MEMS micro devices, the problem of uneven coating is solved, and more efficient electrodeposition effect and higher accuracy are achieved. The manufacturing requirements for micron-scale devices.
Patent Information
- Application Number
- CN202011076105.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2020-10-10
- Publication Date
- 2024-12-31
- Estimated Expiration
- 2040-10-10
AI Technical Summary
During the manufacturing process of MEMS micro-device, the limitation of electrodeposition equipment leads to the 'sharp angle effect' and 'edge effect' in the suspended structure in large areas and large thickness, resulting in uneven thickness of the suspended structure and affecting the measurement accuracy.
An electrochemical deposition plating tank including an outer plating tank body and an inner plating tank body was designed, using an arc-shaped inner plating tank body, agitator, shielding plate and oscillator to recycle the plating solution, uniformly distribute ions and remove bubbles. , ensure the flatness of the coating.
The surface coating of MEMS microdevice is achieved to be smoother and smoother, improve device performance, and reduce manufacturing costs through automated processes to meet manufacturing needs in micron and even submicron sizes.
Smart Images
Figure CN112195495B_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of electrochemical deposition, and in particular relates to an electrochemical deposition plating tank manufactured based on MEMS micro-devices. Background Art
[0002] MEMS is the abbreviation of Micro-Electro-Mechanical System. Common MEMS sensors have the following characteristics: first, the device size is in the micrometer or nanometer level; second, the structure has a high aspect ratio and large local line width difference; third, there is a suspended moving part to realize the sensing or transmission function. The size grade and the manufacturing accuracy of the suspended structure determine the accuracy of the MEMS sensor. The manufacturing process of MEMS is complex. Among them, electrodeposition is an important link in the manufacturing process of MEMS micro-device structure. Its device performance depends entirely on the effect of electroplating. Due to the limitations of electrodeposition equipment, in the process of making large-area and thick suspended structures, the coating often has "sharp corner effect" and "edge effect", resulting in uneven thickness of the suspended structure, which reduces the measurement accuracy of MEMS. The reason for the above two effects is the different regional electrodeposition rates. Summary of the invention
[0003] The purpose of the present invention is to solve the technical problems existing in the manufacturing process of the above-mentioned MEMS micro-devices and to design an electrochemical deposition plating tank that can make the structure of the MEMS micro-device smooth and flat.
[0004] In order to achieve the above-mentioned purpose, the present invention provides the following technical solution: an electrochemical deposition plating tank manufactured based on MEMS micro-devices, comprising an outer plating tank body and an inner plating tank body.
[0005] The outer plating tank body is a cylindrical cavity with an opening at the top. A reflux pipe is connected to the bottom of the outer plating tank body, a pump is connected to the reflux pipe, and an inlet / outlet liquid pipe is connected to the pump.
[0006] The inner plating tank body is a cylindrical cavity with an open top and an arc-shaped bottom. The diameter of the inner plating tank body is smaller than that of the outer plating tank body. The inner plating tank body is placed in the outer plating tank body. The top of the inner plating tank body is sealed and fixed to the top of the outer plating tank body. The inner wall of the outer plating tank body and the outer wall of the inner plating tank body form a sealed cavity. The outer plating tank body and the top of the inner plating tank body are provided with sealing covers that can be opened / closed, and the sealing covers are provided with a vacuum gauge and a vacuum hole.
[0007] The bottom of the inner plating tank is connected to the pump through a pipeline. The inner plating tank is provided with a stirrer blade, a shielding plate, an oscillator, a cathode plate and an anode plate. The stirrer is a magnetic stirrer. The inner plating tank is provided with a cathode drain port and an anode drain port.
[0008] Beneficial effects: The present invention recycles the plating solution and saves resources; an arc-shaped inner plating tank body is adopted to reduce the excessive ion concentration caused by the accumulation of plating solution at the lower end of the plating tank, thereby accelerating the deposition rate, causing the surface of the plated device to be uneven, thereby affecting the performance of the device; a shielding plate is used to adjust the distribution of electric lines on the cathode, and a stirring device is used to evenly distribute the ions in the plating solution, so that the ions are deposited at the same speed in various places, thereby increasing the flatness of the coating; the use of an oscillator during the electro-deposition process can effectively remove bubbles in the plating solution and prevent the formation of pinholes.
[0009] The present invention can meet the manufacturing and processing of MEMS devices with micron or even submicron size. The electroplating effect is better than that of existing equipment. The surface coating of the plated part is flatter and smoother, which meets the requirements of electroplating processing of MEMS micro-devices and effectively improves the performance of MEMS devices. The present invention has a simple overall structure, low manufacturing cost, good electroplating effect, and can realize full automation by setting parameters before electroplating, without manual participation, saving manpower. BRIEF DESCRIPTION OF THE DRAWINGS
[0010] Figure 1 It is a structural schematic diagram of the present invention.
[0011] Figure 2 Schematic diagram of agitator blades.
[0012] Figure 3 Schematic diagram of the shielding plate.
[0013] In the figure: 1. outer plating tank body; 2. inner plating tank body; 3. pump; 4. liquid inlet / outlet pipe; 5. reflux pipe; 6. agitator blade; 7. shielding plate; 8. cathode plate; 9. cathode drain port; 10. vacuum gauge; 11. vacuum hole; 12. sealing cover; 13. anode drain port; 14. anode plate; 15. oscillator; 16. cross bracket; 17. straight bracket. DETAILED DESCRIPTION
[0014] The following is a further description of the technical solution as an embodiment in conjunction with the accompanying drawings. An electrochemical deposition plating tank manufactured based on MEMS micro-devices comprises an outer plating tank body 1 and an inner plating tank body 2.
[0015] The outer plating tank body 1 is a cylindrical cavity with an opening at the top. A reflux pipe 5 is connected to the bottom of the outer plating tank body 1. A pump 3 is connected to the reflux pipe 5. The pump 3 is connected to an inlet / outlet pipe 4. A valve is provided on the inlet / outlet pipe 4.
[0016] The inner plating tank body 2 is a cylindrical cavity with an open top and an arc-shaped bottom. The diameter of the inner plating tank body 2 is smaller than that of the outer plating tank body 1. The inner plating tank body 2 is placed in the center of the outer plating tank body 1. The top of the inner plating tank body 2 is sealed and fixed to the top of the outer plating tank body 1. The inner wall of the outer plating tank body 1 and the outer wall of the inner plating tank body 2 form a sealed cavity. The tops of the outer plating tank body 1 and the inner plating tank body 2 are provided with openable / closable sealing covers 12. The sealing cover 12 is located at the top of the opening of the inner plating tank body 2 and is provided with a vacuum gauge 10 and a vacuum hole 11.
[0017] The center of the bottom of the inner plating tank body 2 is connected to the pump 3 through a pipeline. The inner plating tank body 2 is provided with a stirrer blade 6, a shielding plate 7, a cathode plate 8, an anode plate 14 and an oscillator 15. The inner plating tank body 2 is provided with a cathode drain port 9 and an anode drain port 13. In this embodiment, the inner plating tank body 2 is 30 cm high and 18 cm in diameter.
[0018] The stirrer is a magnetic stirrer, and the stirrer blade 6 can be horizontally rotated and fixed in the inner plating tank body 2 through a cross-shaped bracket 16. The shielding plate 7 is vertically fixed in the center of the inner plating tank body 2 through a straight bracket 17. The shielding plate 7 is located above the stirrer blade 6, and circular holes are evenly distributed on the shielding plate 7. By adjusting the aperture of the shielding plate 7, the path of the electric line from the anode to the cathode in the plating solution is changed, thereby controlling the distribution of the electric line on the surface of the coating. The cross-shaped bracket 16 and the straight bracket 17 are made of Teflon material.
[0019] The oscillator 15 is symmetrically arranged on the inner wall of the inner plating tank body 2 on both sides of the agitator blade 6; the cathode plate 8 and the anode plate 14 are symmetrically arranged on the inner wall of the inner plating tank body 2, and the cathode plate 8 and the anode plate 14 are perpendicular to the center of the shielding plate 7; the cathode drain port 9 and the anode drain port 13 are respectively located above the cathode plate 8 and the anode plate 14.
[0020] The pump 3, the reflux pipe 5, the cathode drain port 9 and the anode drain port 13 together form a plating solution reflux route to improve the flow field, thereby ensuring the ion concentration on the surface of the cathode deposition layer during the electroplating process.
[0021] The oscillator 15 cooperates with the vacuum pumping device to achieve pre-wetting, remove bubbles on the surface of the coating during the electrodeposition process, and prevent the formation of pinholes that cause coating defects.
[0022] This embodiment is to produce a MEMS device by electroplating copper on a 4-inch substrate with a line width of 1-2μm and a depth-to-width ratio of 3:1. When in use, first fix the MEMS device substrate to be plated on the cathode plate 8, and then fix the copper sheet on the anode plate 14. The distance between the two plates is 10-15cm. Then, the air in the outer plating tank body 1 and the inner plating tank body 2 is evacuated by a vacuum device through the vacuum hole 11, and the vacuum degree in the outer plating tank body 1 and the inner plating tank body 2 is measured by a vacuum gauge 10. When the vacuum degree reaches 1×10-3Pa, the plating solution is slowly supplied from the inlet / outlet pipe 4, and the plating solution is pressurized and sprayed into the inner plating tank body 2 by the pump 3. At the same time, the oscillator 15 is turned on to remove bubbles on the substrate to achieve substrate pre-wetting. The spray force of the pump 3 and the agitator blade 6 are combined to allow the plating solution to fill the inner plating tank body 2 and flow at a uniform speed, and then a current is applied to the cathode plate 8 and the anode plate 14 for electrodeposition. The shielding plate 7 is used to adjust the distribution of the electric lines and control the deposition speed. The required electroplating time (20 min) is calculated by the target deposition thickness of 20 μm, and then the power supply time of the plating tank is set. After the electroplating is completed, the electro-deposited MEMS device substrate is taken out through the sealing cover 12, and 5 test points are taken at every 90 degrees on the edge of the substrate and the center of the substrate. The flatness of the coating on the surface of the MEMS device is measured by a surface profiler, the detection distance is 80 μm, the surface roughness of the coating Ra=0.05-0.1, and the surface is very smooth. Through the electroplating of this embodiment, it is tested that its performance fully meets the electroplating processing of micron-level and submicron-level MEMS devices.
Claims
1. An electrochemical deposition plating tank manufactured based on MEMS micro-devices, comprising an outer plating tank body (1) and an inner plating tank body (2), characterized in that: The outer plating tank body (1) is a cylindrical cavity with an opening at the top, the bottom of the outer plating tank body (1) is connected to a reflux pipe (5), the reflux pipe (5) is connected to a pump (3), the pump (3) is connected to an inlet / outlet pipe (4), and the inlet / outlet pipe (4) is provided with a valve; the inner plating tank body (2) is a cylindrical cavity with an opening at the top and an arc-shaped bottom, the diameter of the inner plating tank body (2) is smaller than the diameter of the outer plating tank body (1), the inner plating tank body (2) is placed at the center of the outer plating tank body (1), the top of the inner plating tank body (2) is sealed and fixed to the top of the outer plating tank body (1), and the inner wall of the outer plating tank body (1) forms a sealing with the outer wall of the inner plating tank body (2). The outer plating tank body (1) and the inner plating tank body (2) are provided with an openable / closable sealing cover (12) at the top, and the sealing cover (12) is located at the top of the opening of the inner plating tank body (2) and is provided with a vacuum gauge (10) and a vacuum hole (11); the center of the bottom of the inner plating tank body (2) is connected to the pump (3) through a pipeline, and the inner plating tank body (2) is provided with a stirrer blade (6), a shielding plate (7), a cathode plate (8), an anode plate (14) and an oscillator (15), and the shielding plate (7) is evenly distributed with circular holes; the inner plating tank body (2) is provided with a cathode liquid discharge port (9) and an anode liquid discharge port (13); The shielding plate (7) is vertically fixed at the center of the inner plating tank body (2) through a straight-line bracket (17), the shielding plate (7) is located above the agitator blade (6), and the agitator blade (6) is horizontally rotatably fixed in the inner plating tank body (2) through a cross-shaped bracket (16), and the agitator is a magnetic agitator; The cathode plate (8) and the anode plate (14) are symmetrically arranged on the inner wall of the inner plating tank body (2), and the cathode plate (8) and the anode plate (14) are perpendicular to the center of the shielding plate (7); the cathode liquid discharge port (9) and the anode liquid discharge port (13) are respectively located above the cathode plate (8) and the anode plate (14).
2. The electrochemical deposition plating tank based on MEMS micro-device manufacturing according to claim 1, characterized in that: The oscillators (15) are symmetrically arranged on the inner wall of the inner plating tank body (2) on both sides of the agitator blades (6).