A quartz micro accelerometer

Abstract

The present application provides a quartz micro-accelerometer, comprising two edge plates and a middle plate, wherein the edge plates are provided with edge bonding areas, a capacitor area, an edge electrical isolation area, and a capacitor lead sealing area; the middle plate is disposed between the two edge plates; the middle plate is provided with an intermediate bonding area, a mass block, a flexible beam, an intermediate electrode lead area, and an edge electrode lead area; the edge bonding areas and the middle bonding areas are disposed correspondingly; the capacitor area and the mass block are disposed correspondingly; and the capacitor lead sealing area is disposed correspondingly to the position of the edge electrode lead area. The accelerometer according to the present application can be effectively airtightly packaged.

Description

Technical Field

[0001] The present application belongs to the technical field of accelerometers, and in particular relates to a quartz micro-accelerometer. Background Art

[0002] At present, capacitive accelerometers implemented using micro-electromechanical systems (MEMS) technology have the advantages of small size, light weight and low cost, and have broad application prospects in military, automotive technology, consumer electronics and other fields.

[0003] However, there are currently three main types of capacitive accelerometers: "sandwich," "comb," and quartz flexure pendulum. Sandwich and comb accelerometers are fabricated from silicon, making them easy to process. However, silicon is a semiconductor material and is easily affected by temperature and contamination, leading to further improvements in device stability. Quartz flexure pendulum accelerometers utilize the excellent mechanical elasticity, temperature characteristics, high quality factor, and chemical stability of quartz. While offering high measurement accuracy and stable performance, they are complex, involving multiple components and materials assembled through precision mechanical assembly. This results in poor reliability and manufacturability, and they face challenges with permanent magnet degradation, adhesive aging, and difficulty in further increasing the measurement range.

[0004] Therefore, how to provide a quartz micro accelerometer that can be effectively airtightly packaged and conveniently packaged with leads has become a problem that needs to be solved urgently by those skilled in the art. Summary of the Invention

[0005] Therefore, the technical problem to be solved by the present application is to provide a quartz micro-accelerometer that can be effectively airtightly packaged and conveniently packaged with leads.

[0006] In order to solve the above problems, the present application provides a quartz micro accelerometer, comprising:

[0007] Two side plates; the side plates are provided with a side bonding area, a capacitor area, a side electrical isolation area and a capacitor lead sealing area;

[0008] and an intermediate plate, the intermediate plate being arranged between the two side plates; the intermediate plate being provided with an intermediate bonding area, a mass block, a flexible beam, an intermediate electrode lead area, and a side electrode lead area; the side bonding area and the intermediate bonding area being arranged correspondingly; the capacitor area and the mass block being arranged correspondingly; the capacitor lead sealing area being arranged correspondingly to the position of the side electrode lead area.

[0009] Furthermore, the capacitor lead sealing area is connected to the edge electrode lead area.

[0010] Furthermore, the edge electrode lead region has a first surface and a second surface disposed opposite to each other; the edge electrode lead region has a side surface; a metal layer is disposed on the first surface, the second surface, and the side surface; the metal layer on the first surface is electrically connected to the metal layer on the second surface and the metal layer on the side surface;

[0011] And / or, the intermediate electrode lead area has a first surface and a second surface arranged opposite to each other, and a metal layer is provided on the side of the mass block; a metal layer is provided on both the first surface and the second surface; the metal layer on the side of the mass block is electrically connected to the metal layer on the first surface and the metal layer on the second surface.

[0012] Furthermore, a metal layer is provided on the surface of the capacitor lead sealing area; a metal layer is provided on the surface of the capacitor area, and the metal layer on the surface of the capacitor lead sealing area is connected to the metal layer on the surface of the capacitor area.

[0013] Furthermore, a metal layer is provided on the surface of the middle bonding area facing the edge plate;

[0014] And / or, a metal layer is provided on the surface of the edge electrode lead region facing the edge electrode plate.

[0015] Furthermore, a metal layer is provided on the surface of the intermediate electrode lead area facing the edge electrode plate; a metal layer is provided on the surface of the mass block facing the edge electrode plate; an electrode connecting line is provided on the surface of the flexible beam facing the edge electrode plate; the metal layer on the mass block and the metal layer on the surface of the intermediate electrode lead area are connected through the electrode connecting line.

[0016] And / or, the metal layer is made of Ti / Pt / Au or Cr / Au.

[0017] Furthermore, a capacitance gap is provided between the capacitance region and the mass block.

[0018] Furthermore, the side plates are also provided with lead holes, side lead sealing areas and middle lead sealing areas.

[0019] Furthermore, the two side plates include a first side plate and a second side plate, and the first side plate and the second side plate are respectively arranged on both sides of the middle plate;

[0020] And / or, the flexible beam is a straight beam.

[0021] Furthermore, the edge plate is made of quartz; further, the edge plate is made of quartz single crystal or quartz glass;

[0022] And / or, the intermediate plate is made of quartz; further, the intermediate plate is made of quartz single crystal or quartz glass.

[0023] The accelerometer provided in this application can be effectively airtightly packaged. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic structural diagram of an accelerometer according to an embodiment of the present application;

[0025] Figure 2 This is a schematic structural diagram of the first edge plate of an embodiment of the present application;

[0026] Figure 3 This is a schematic structural diagram of the intermediate plate of an embodiment of the present application;

[0027] Figure 4 This is a schematic structural diagram of an accelerometer according to an embodiment of the present application;

[0028] Figure 5 This is a schematic structural diagram of the second edge plate of the first embodiment of the present application;

[0029] Figure 6 This is a structural diagram of the second edge plate of the second embodiment of the present application.

[0030] The reference numerals indicate:

[0031] 1. First side plate; 11. First side bonding area; 12. First capacitor area; 13. First lead hole; 14. First lead sealing area; 15. First intermediate lead sealing area; 16. First capacitor lead sealing area; 17. First side electrical isolation area; 18. First metal layer; 2. Intermediate plate; 21. Intermediate bonding area; 22. Mass block; 23. Flexible beam; 24. First side electrode lead area; 25. Intermediate electrode lead area; 26. Second side electrode lead area; 27. Intermediate electrical isolation area; 28. Electrode connecting line; 29. ​​Intermediate metal layer; 3. Second side plate; 31. Second side bonding area; 32. Second capacitor area; 33. Second lead hole; 34. Second lead sealing area; 35. Second intermediate lead sealing area; 36. Second capacitor lead sealing area; 37. Second side electrical isolation area; 38. Second metal layer. DETAILED DESCRIPTION

[0032] See also Figure 1-6As shown, a quartz micro-accelerometer includes two side plates and an intermediate plate 2, and the side plates are provided with a side bonding area, a capacitor area, a side electrical isolation area, and a capacitor lead sealing area; the intermediate plate 2 is arranged between the two side plates; the intermediate plate 2 is provided with an intermediate bonding area 21, a mass block 22, a flexible beam 23, an intermediate electrode lead area 25, and a side electrode lead area; the side bonding area and the intermediate bonding area 21 are arranged correspondingly; the capacitor area and the mass block 22 are arranged correspondingly; the capacitor lead sealing area is arranged correspondingly to the position of the side electrode lead area. The present application can effectively perform airtight packaging through the capacitor lead sealing area, and solves the difficulty of airtight packaging of quartz micro-accelerometers in the prior art. The accelerometer of the present application is a micro-accelerometer, and further, the micro-accelerometer of the present application is a quartz micro-accelerometer. The side plates of the present application include a first side plate and a second side plate, and the first side plate and the second side plate are respectively arranged on both sides of the intermediate plate 2. Furthermore, the first side plate is an upper plate; the second side plate is a lower plate.

[0033] This application also discloses some embodiments in which the capacitor lead seal area is connected to the edge electrode lead area. A first lead seal area 14 is provided on the first edge plate; a second lead seal area 34 is provided on the second edge plate. A first edge electrode lead area 24, a second edge electrode lead area 26, and an intermediate electrical isolation area 27 are provided on the middle plate 2.

[0034] The present application also discloses some embodiments, wherein the edge electrode lead region has a first surface and a second surface disposed opposite to each other; the edge electrode lead region has a side surface; a metal layer is disposed on the first surface, the second surface, and the side surface; the metal layer on the first surface and the metal layer on the second surface and the metal layer on the side surface are electrically connected;

[0035] And / or, the intermediate electrode lead area 25 has a first surface and a second surface arranged opposite to each other, and a metal layer is provided on the side of the mass block 22; a metal layer is provided on both the first surface and the second surface; the metal layer on the side of the mass block 22 is electrically connected to the metal layer on the first surface and the metal layer on the second surface.

[0036] The edge electrode lead area includes a first electrode lead area and a second electrode lead area. The front and back metal layers of the upper and lower electrode lead areas of the intermediate plate 2 are electrically connected through the metal layers of the sidewalls, respectively. The front and back metal layers of the intermediate electrode lead area 25 are electrically connected through the metal layers on the side of the mass 22. The capacitor lead sealing area of ​​the first plate 1 is connected to the front surface of the upper electrode lead area of ​​the intermediate plate 2, while the capacitor lead sealing area of ​​the second plate 3 is connected to the back surface of the second electrode lead area of ​​the intermediate plate 2.

[0037] The present application also discloses some embodiments, in which a metal layer is provided on the surface of the capacitor lead sealing area; a metal layer is provided on the surface of the capacitor area, and the metal layer on the surface of the capacitor lead sealing area is connected to the metal layer on the surface of the capacitor area.

[0038] The present application also discloses some embodiments in which a metal layer is provided on the surface of the middle bonding region 21 facing the edge plate;

[0039] The bonding area on one side of the metal layer of the first side plate 1 and the bonding area on one side of the metal layer of the second side plate 3 are respectively connected to the bonding areas on the front and back surfaces of the intermediate electrode to form a whole device.

[0040] The present application also discloses some embodiments, in which a metal layer is provided on the surface of the edge electrode lead region facing the edge electrode plate.

[0041] The present application also discloses some embodiments, in which a metal layer is provided on the surface of the intermediate electrode lead region 25 facing the edge plate; a metal layer is provided on the surface of the mass block 22 facing the edge plate; an electrode connection line 28 is provided on the surface of the flexible beam 23 facing the edge plate; and the metal layer on the mass block 22 is connected to the metal layer on the surface of the intermediate electrode lead region 25 via the electrode connection line 28. The electrode connection line 28 is formed by a metal layer; that is, the front and back surfaces of the flexible beam 23 have electrode connection lines 28 composed of a metal layer, and the front and back surfaces of the mass block 22 are covered with a metal layer. Whether the side surfaces of the mass block 22 are covered with a metal layer is optional, and at least one side surface needs to be covered with a metal layer so that the metal layers on the front and back surfaces of the mass block 22 are connected and electrically conductive. The metal layers on the surfaces of the mass block 22 and the intermediate electrode lead region 25 are connected and electrically conductive via the electrode connection lines 28 on the surface of the flexible beam 23.

[0042] And / or, the metal layer is made of Ti / Pt / Au or Cr / Au. The metal layers on the same surface, i.e., the first metal layer 18, the intermediate metal layer 29, and the second metal layer 38, have the same thickness, and the metal layers are made of Ti / Pt / Au, Cr / Au or other metal materials.

[0043] The capacitor lead sealing area of ​​the first side plate 1 and the first electrode lead area of ​​the middle plate 2 are connected together on the front side, and the capacitor lead sealing area of ​​the second side plate 3 and the second electrode lead area of ​​the middle plate 2 are connected together on the back side.

[0044] This application also discloses some embodiments in which a capacitive gap is provided between the capacitor region and the mass 22. The capacitor region of the first side plate and the capacitor region of the second side plate 3 each have a capacitive gap with the front and back surfaces of the mass 22 of the middle electrode, and the size of the gap is determined by design parameters.

[0045] The present application also discloses some embodiments, in which the edge plates are further provided with lead holes, edge lead sealing areas and middle lead sealing areas; the lead holes are through holes.

[0046] The present application also discloses some embodiments, in which the two edge plates include a first edge plate and a second edge plate, and the first edge plate and the second edge plate are respectively arranged on both sides of the middle plate 2; one surface of the second edge bonding area 31, the second capacitor area 32, the second edge lead sealing area, the second middle lead sealing area 35, and the second capacitor lead sealing area 36 of the second edge plate is covered with a metal layer, and the metal layers on the surfaces of the second capacitor area 32 and the second capacitor lead sealing area 36 are connected together.

[0047] One surface of the first edge bonding area 11, the first capacitor area 12, the first lead sealing area 14, the first middle lead sealing area 15, and the first capacitor lead sealing area 16 of the first edge electrode plate 1 is covered with a metal layer, and the surfaces of the front and back surfaces of the middle bonding area 21, the mass block 22, the flexible beam 23, the first edge electrode lead area 24, the middle electrode lead area 25, and the second edge electrode lead area 26 of the middle electrode plate 2 are all covered with a metal layer.

[0048] The first edge plate 1 is composed of seven parts: a first edge bonding area 11, a first capacitor area 12, a first lead hole 13, a first lead sealing area 14, a first middle lead sealing area 15, a first capacitor lead sealing area 16 and a first edge electrical isolation area 17;

[0049] The intermediate plate 2 consists of seven parts: an intermediate bonding area 21, a proof mass 22, a flexible beam 23, a first edge electrode lead area 24, an intermediate electrode lead area 25, a second edge electrode lead area 26, and an intermediate electrical isolation area 27. One end of the proof mass 22 is suspended in the air, and the other end is connected to the intermediate electrode lead area 25 via the flexible beam 23.

[0050] The second electrode 3 consists of seven parts: a second edge bonding area 31, a second capacitor area 32, a second lead hole 33, a second edge lead sealing area, a second middle lead sealing area 35, a second capacitor lead sealing area 36 and a second edge electrical isolation area 37, among which the second lead hole 33, the second edge lead sealing area and the second middle lead sealing area 35 are optional.

[0051] The present application also discloses some embodiments in which the flexible beam 23 is a straight beam. The flexible beam 23 adopts a straight beam structure, which enables the mass 22 to move along the Z-axis direction of the quartz substrate.

[0052] The present application also discloses some embodiments in which the edge plates are made of quartz; The present application also discloses some embodiments in which the edge plates are made of quartz single crystal or quartz glass;

[0053] This application also discloses some embodiments in which the intermediate plate 2 is made of quartz; this application also discloses some embodiments in which the intermediate plate 2 is made of quartz single crystal or quartz glass. The first side plate, the intermediate plate 2, and the second side plate are made of quartz, including quartz single crystal and quartz glass (also called fused quartz).

[0054] As attached Figure 4 It can be seen that the capacitance area of ​​the upper plate of the present application forms a capacitor C1 with the upper surface of the mass block 22 of the intermediate plate 2, and the capacitance area of ​​the lower plate forms a capacitor C2 with the lower surface of the mass block 22 of the intermediate plate 2. In the non-measurement state, the mass block 22 is in the middle position, the upper and lower capacitances are equal, and the output signal is 0. When there is an upward acceleration, the mass block 22 moves upward under the action of the acceleration, the gap between the upper surface of the mass block 22 and the capacitance area of ​​the upper plate decreases, the capacitance increases, the gap between the lower surface of the mass block 22 and the capacitance area of ​​the lower plate increases, and the capacitance decreases. Similarly, when there is a downward acceleration, the gap between the upper surface of the mass block 22 and the capacitance area of ​​the upper plate increases, the capacitance decreases, the gap between the lower surface of the mass block 22 and the capacitance area of ​​the lower plate decreases, and the capacitance increases. The difference in the upper and lower capacitances and the positive and negative directions are measured using differential measurement technology to determine the magnitude and direction of the acceleration.

[0055] Compared with the existing technology, the present application has the following advantages and beneficial effects: the present invention adopts a "sandwich" structure, which is simpler than the existing quartz flexible accelerometer, uses the same material, does not require precision mechanical assembly, and can improve reliability and manufacturability; compared with the existing silicon "sandwich" structure accelerometer, the present invention can utilize the excellent mechanical elasticity, temperature characteristics, high quality factor, and chemical stability of the quartz material to improve the stability of the device; and solves the problems of difficult airtight packaging and inconvenient packaging leads of quartz micro accelerometers.

[0056] It is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0057] The above are merely preferred embodiments of the present application and are not intended to limit the present application. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application. The above are merely preferred embodiments of the present application. It should be noted that those skilled in the art may make various improvements and variations without departing from the technical principles of the present application, and such improvements and variations shall also be considered within the scope of protection of the present application.

Claims

1. A quartz micro accelerometer, characterized in that: include: Two edge plates; the edge plates are provided with edge bonding areas, capacitor areas, edge electrical isolation areas and capacitor lead sealing areas; and an intermediate plate (2), the intermediate plate (2) being arranged between the two edge plates; the intermediate plate (2) being provided with an intermediate bonding area (21), a mass block (22), a flexible beam (23), an intermediate electrode lead area (25), and an edge electrode lead area; the edge bonding area and the intermediate bonding area (21) being provided correspondingly; the capacitor area and the mass block (22) being provided correspondingly; and the capacitor lead sealing area being provided correspondingly to the position of the edge electrode lead area; The edge electrode lead region has a first surface and a second surface disposed opposite to each other; the edge electrode lead region has a side surface; a metal layer is disposed on the first surface, the second surface, and the side surface; the metal layer on the first surface is electrically connected to the metal layer on the second surface and the metal layer on the side surface; And / or, the intermediate electrode lead region (25) has a first surface and a second surface disposed opposite to each other, a metal layer is disposed on the side surface of the mass block (22); a metal layer is disposed on both the first surface and the second surface; and the metal layer on the side surface of the mass block (22) is electrically connected to the metal layer on the first surface and the metal layer on the second surface; A metal layer is provided on the surface of the capacitor lead sealing area; a metal layer is provided on the surface of the capacitor area, and the metal layer on the surface of the capacitor lead sealing area is connected to the metal layer on the surface of the capacitor area.

2. The quartz micro-accelerometer according to claim 1, characterized in that: The capacitor lead sealing area is connected to the edge electrode lead area.

3. The quartz micro-accelerometer according to claim 1, characterized in that: A metal layer is provided on the surface of the middle bonding area (21) facing the edge plate; And / or, a metal layer is provided on the surface of the edge electrode lead area facing the edge electrode plate.

4. The quartz micro-accelerometer according to claim 1, characterized in that: A metal layer is provided on the surface of the intermediate electrode lead region (25) facing the edge electrode plate; a metal layer is provided on the surface of the mass block (22) facing the edge electrode plate; an electrode connection line (28) is provided on the surface of the flexible beam (23) facing the edge electrode plate; the metal layer on the mass block (22) and the metal layer on the surface of the intermediate electrode lead region (25) are connected via the electrode connection line (28); And / or, the metal layer is made of Ti / Pt / Au or Cr / Au; wherein Ti / Pt / Au includes Ti, Pt and Au; and Cr / Au includes Cr and Au.

5. The quartz micro-accelerometer according to claim 1, characterized in that: A capacitance gap is provided between the capacitance region and the mass block (22).

6. The quartz micro-accelerometer according to claim 1, characterized in that: The edge plate is also provided with a lead hole, an edge lead sealing area and a middle lead sealing area; the lead hole is a through hole.

7. The quartz micro-accelerometer according to claim 1, characterized in that: The two edge plates include a first edge plate and a second edge plate, wherein the first edge plate and the second edge plate are respectively arranged on both sides of the middle plate (2); And / or, the flexible beam (23) is a straight beam.

8. The quartz micro-accelerometer according to claim 3, characterized in that: The edge plate is made of quartz; And / or, the intermediate plate (2) is made of quartz.

9. The quartz micro-accelerometer according to claim 8, characterized in that: The edge plate is made of quartz single crystal or quartz glass.

10. The quartz micro-accelerometer according to claim 8, characterized in that: The intermediate plate (2) is made of quartz single crystal or quartz glass.

Images