Packaging method of piezoelectric quartz sensor and piezoelectric quartz sensor

Abstract

The application relates to the technical field of sensors, in particular to a packaging method of a piezoelectric quartz sensor and the piezoelectric quartz sensor. The method comprises the following steps: forming a piezoelectric sensor wafer, the piezoelectric sensor wafer comprising a first pin area on a front surface and a second pin area on a back surface, the first pin area and the second pin area being arranged in a diagonal direction; providing a first quartz wafer, forming a first notch on the first quartz wafer at a position corresponding to the first pin area and forming a second notch at a position corresponding to the second pin area, thereby forming a first packaging side part; providing a second quartz wafer, forming a third notch on the second quartz wafer at a position corresponding to the second pin area and forming a fourth notch at a position corresponding to the first pin area, thereby forming a second packaging side part; and bonding the first packaging side part with the front surface of the piezoelectric sensor wafer and bonding the second packaging side part with the back surface of the piezoelectric sensor wafer respectively, so that the bonding mode is adopted to improve the performance of the device.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensors, in particular to a packaging method of a piezoelectric quartz sensor and the piezoelectric quartz sensor. BACKGROUND

[0002] Piezoelectric sensors have piezoresistive, piezoelectric and resonant types. The sensitive unit of the piezoresistive pressure sensor is a piezoresistor. When the piezoresistor is subjected to external pressure, the resistance value changes, and the external pressure can be converted by measuring the change of the output voltage value. The disadvantage of this type of sensor is that the temperature drift is serious, and the creep effect is easy to occur after long-term use, so it is not suitable for testing low static force with high precision requirements.

[0003] The piezoelectric sensor uses piezoelectric quartz or ceramic materials. The biggest feature of this type of sensor is high piezoelectric coefficient and high Q value, so the test precision is high. However, it can only test dynamic force. In recent years, resonant pressure sensors have attracted more and more attention. They are made of piezoelectric resonant components. The frequency change of the resonant component can sense the size of the external force. The direct digital frequency signal output is characterized by high precision compared with the above two types. In addition, this type of sensor can test both static and dynamic forces. It is highly concerned in high-precision force testing.

[0004] However, the biggest problem in manufacturing the above-mentioned sensors is the installation problem between the sensitive component and the structure. The existing method is to connect the two by pasting. However, there are the following problems:

[0005] The paste used in the pasting process will age with the influence of the external temperature, causing problems in the adhesion between the sensitive component and the structure.

[0006] The connection of the glue point cannot control the adhesion between the sensitive component and the structure, resulting in inconsistent pre-stress of the sensitive component in each device, which will inevitably lead to poor consistency of the final product and cannot be mass-produced.

[0007] It is difficult to ensure the positioning relationship between the sensitive component and the structure during the dispensing process.

[0008] Moreover, due to the use of dispensing, the materials between the sensitive component and the structure are different, and their thermal expansion coefficients are also different. When the external temperature changes, the temperature drift of the sensor cannot be controlled.

[0009] The use of metal welding and plastic packaging methods has inconsistent temperature expansion coefficients between the quartz sensor body and the sealing surface. Long-term operation in high and low temperature environments will produce packaging cracks. Water vapor enters the interior of the quartz sensor through the cracks, causing changes in the force frequency coefficient, resulting in large deviations in force measurement, and making the sensor measurement deviate or fail.

[0010] Therefore, how to improve the performance of the sensor is a technical problem to be solved at present. SUMMARY

[0011] In view of the above problems, the present application is proposed in order to provide a packaging method of piezoelectric quartz sensor and piezoelectric quartz sensor which overcomes the above problems or at least partially solves the above problems.

[0012] In a first aspect, the present application provides a packaging method of piezoelectric quartz sensor, comprising:

[0013] forming a piezoelectric sensor wafer, the piezoelectric sensor wafer being square-shaped, comprising a first pin area on the front face of the piezoelectric sensor wafer and a second pin area on the back face of the piezoelectric sensor wafer, the first pin area and the second pin area being arranged in a diagonal direction;

[0014] providing a first quartz wafer, forming a first notch on the first quartz wafer and corresponding to the position of the first pin area on the front face of the piezoelectric sensor wafer, forming a second notch on the first quartz wafer and corresponding to the position of the second pin area on the back face of the piezoelectric sensor wafer, forming a first packaging side part;

[0015] providing a second quartz wafer, forming a third notch on the second quartz wafer and corresponding to the position of the back face of the piezoelectric sensor wafer and the second pin area, forming a fourth notch on the second quartz wafer and corresponding to the position of the first pin area on the front face of the piezoelectric sensor wafer, forming a second packaging side part;

[0016] bonding the first packaging side part with the front face of the piezoelectric sensor wafer, and bonding the second packaging side part with the back face of the piezoelectric sensor wafer.

[0017] Preferably, the forming of the piezoelectric sensor wafer comprises:

[0018] providing a third quartz wafer;

[0019] forming a first recess and a second recess on the front face and the back face of the third quartz wafer opposite to each other, the first recess and the second recess are both circular recesses;

[0020] forming a first through hole and a second through hole from the first recess to the second recess, the first through hole is a first half-arc columnar hole along one side edge of the bottom end of the first recess, and the second through hole is a second half-arc columnar hole along the other side edge of the bottom end of the first recess, so that an oscillation area is formed between the first through hole and the second through hole;

[0021] A first electrode is formed on the front surface of the oscillation region and extends along the side wall of the first groove to the outside of the first groove, and the end of the first electrode is located in the first pin region; a second electrode is formed on the back surface of the oscillation region and extends along the side wall of the second groove to the outside of the second groove, and the end of the second electrode is located in the second pin region, so as to form a piezoelectric sensor wafer.

[0022] Preferably, the first via and the second via are formed from the first groove to the second groove, comprising:

[0023] The first via and the second via are formed from the first groove to the second groove by using a photolithography process; or

[0024] The first via and the second via are formed from the first groove to the second groove by using a laser cutting process.

[0025] Preferably, before the first notch is formed on the first quartz wafer corresponding to the position of the front surface of the piezoelectric sensor wafer and facing the first pin region, further comprising:

[0026] The first quartz wafer is ground and polished so that the surface roughness of the first quartz wafer is less than 10 nm;

[0027] Preferably, before the second notch is formed on the second quartz wafer corresponding to the position of the back surface of the piezoelectric sensor wafer and facing the second pin region, further comprising:

[0028] The second quartz wafer is ground and polished so that the surface roughness of the second quartz wafer is less than 10 nm.

[0029] Preferably, before the first quartz wafer is bonded to the front surface of the piezoelectric sensor wafer and the second quartz wafer is bonded to the back surface of the piezoelectric sensor wafer, further comprising:

[0030] A bonding layer is formed on the surface of the first quartz wafer and the surface of the second quartz wafer.

[0031] Preferably, the bonding layer is formed on the surface of the first quartz wafer and the surface of the second quartz wafer by using any of the following methods:

[0032] Coating, PVD, CVD, PECVD and sintering.

[0033] Preferably, the first quartz wafer is bonded to the front surface of the piezoelectric sensor wafer and the second quartz wafer is bonded to the back surface of the piezoelectric sensor wafer, comprising:

[0034] bonding the first quartz wafer and the piezoelectric sensor wafer on the front side, and bonding the second quartz wafer and the piezoelectric sensor wafer on the back side.

[0035] Preferably, after bonding the first quartz wafer and the piezoelectric sensor wafer on the front side, and bonding the second quartz wafer and the piezoelectric sensor wafer on the back side, the method further comprises:

[0036] forming a first plating layer on the first electrode of the first pin area;

[0037] forming a second plating layer on the second electrode of the second pin area.

[0038] In a second aspect, the present application provides a piezoelectric quartz sensor, comprising:

[0039] a piezoelectric sensor wafer, a first packaging side part and a second packaging side part;

[0040] the piezoelectric sensor wafer comprises a first pin area on the front side edge and a second pin area on the back side edge, and the first pin area and the second pin area are arranged in a diagonal direction;

[0041] the first quartz wafer comprises a first notch and a second notch;

[0042] the second quartz wafer comprises a third notch and a fourth notch;

[0043] the first packaging side part and the second packaging side part are bonded to the front side and the back side of the piezoelectric sensor wafer respectively, so that the first notch and the fourth notch are opposite to the first pin area, and the second notch and the third notch are opposite to the second pin area.

[0044] Preferably, the cross section of the first notch, the cross section of the second notch, the cross section of the third notch and the cross section of the fourth notch are all semicircular or rectangular.

[0045] The one or more technical solutions in the embodiments of the present application have at least the following technical effects or advantages:

[0046] The application provides a packaging method of a piezoelectric quartz sensor, which comprises the following steps: forming a piezoelectric sensor wafer, the piezoelectric sensor wafer is square-shaped, comprising a first pin area on the front surface of the piezoelectric sensor wafer and a second pin area on the back surface of the piezoelectric sensor wafer, the first pin area and the second pin area are arranged in a diagonal direction; providing a first quartz wafer, forming a first notch on the first quartz wafer corresponding to the position of the first pin area on the front surface of the piezoelectric sensor wafer, and forming a second notch on the first quartz wafer corresponding to the position of the second pin area on the back surface of the piezoelectric sensor wafer, thereby forming a first packaging side part; providing a second quartz wafer, forming a third notch on the second quartz wafer corresponding to the position of the second pin area on the back surface of the piezoelectric sensor wafer, and forming a fourth notch on the second quartz wafer corresponding to the position of the first pin area on the front surface of the piezoelectric sensor wafer, thereby forming a second packaging side part; and bonding the first packaging side part with the front surface of the piezoelectric sensor wafer and bonding the second packaging side part with the back surface of the piezoelectric sensor wafer, so that the bonding method can avoid the poor performance of the device caused by the pasting method, and the performance of the device is improved. BRIEF DESCRIPTION OF DRAWINGS

[0047] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The detailed description is made with reference to the accompanying drawings.

[0048] Figure 1 A step flow diagram of the packaging method of the piezoelectric quartz sensor in the embodiment of the application is shown;

[0049] Figures 2 to 5 A schematic diagram of forming the piezoelectric sensor wafer in the embodiment of the application is shown;

[0050] Figures 6 to 8 A schematic diagram of forming the first packaging side part and the second packaging side part in the embodiment of the application is shown;

[0051] Figure 9 A schematic diagram of bonding the first packaging side part, the second packaging side part and the piezoelectric sensor wafer in the embodiment of the application is shown. DETAILED DESCRIPTION

[0052] Exemplary embodiments of the present disclosure will be described herein below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that the present disclosure can be more thoroughly understood, and the scope of the present disclosure can be accurately conveyed to those skilled in the art.

[0053] Embodiment one

[0054] Embodiments of the present invention provide a packaging method for a piezoelectric quartz sensor, such as... Figure 1 As shown, it includes:

[0055] S101, forming a piezoelectric sensor wafer, the piezoelectric sensor wafer is square, including a first pin area on the front side of the piezoelectric sensor wafer and a second pin area on the back side, the first pin area and the second pin area are arranged diagonally;

[0056] S102, a first quartz wafer is provided, a first notch is formed on the first quartz wafer at the position corresponding to the first pin area on the front side of the piezoelectric sensor wafer, and a second notch is formed on the first quartz wafer at the position corresponding to the second pin area on the back side of the piezoelectric sensor wafer, forming a first package side component;

[0057] S103, a second quartz wafer is provided, a third notch is formed on the second quartz wafer at the position corresponding to the second pin area on the back side of the piezoelectric sensor wafer, and a fourth notch is formed on the second quartz wafer at the position corresponding to the first pin area on the front side of the piezoelectric sensor.

[0058] S104, the first package side component is bonded to the front side of the piezoelectric sensor chip, and the second package side component is bonded to the back side of the piezoelectric sensor chip.

[0059] The steps for forming the piezoelectric sensor chip in S101 are described in detail below:

[0060] like Figures 2 to 5 As shown, a third quartz wafer 201 is provided; a first groove 202 and a second groove 203 are formed at opposite positions on the front and back sides of the third quartz wafer 201, and both the first groove 202 and the second groove 203 are circular grooves.

[0061] A first through hole 204 and a second through hole 205 are formed from the first groove 202 to the second groove 203. The first through hole 204 is a first semi-circular columnar hole along one side edge of the bottom end of the first groove 202, and the second through hole 205 is a second semi-circular columnar hole along the other side edge of the bottom end of the first groove 202, so that an oscillation region is formed between the first through hole 204 and the second through hole 205.

[0062] A first electrode 208 is formed on the front side of the oscillation region and extends along the sidewall of the first groove 202 to the outside of the first 202. The end of the first electrode 208 is located in the first pin region 211. A second electrode 209 is formed on the back side of the oscillation region and extends along the sidewall of the second groove 203 to the outside of the second groove 203. The end of the second electrode 209 is located in the second pin region 212.

[0063] The first pin area 211 is located on the front surface of the third quartz wafer 201, the second pin area 212 is located on the back surface of the third quartz wafer 201, and the first pin area 211 and the second pin area 212 are arranged in a diagonal direction.

[0064] In the forming of the first groove 202 and the second groove 203, specifically, two film layers are formed on the front surface and the back surface of the third quartz wafer 201 by magnetron sputtering, the bottom layer is a chromium film, and the top layer is a gold film, wherein the thickness of the chromium film is 5-50 nm, and the thickness of the gold film is greater than 100 nm.

[0065] A photoresist layer is formed on the two film layers, and after exposure and development, the preset area is etched to form the first groove 202 and the second groove 203.

[0066] The etching process specifically uses etching liquid, which includes gold etching liquid, chromium etching liquid, and BOE etching liquid. The gold etching liquid is used to etch the gold film in the preset area, the chromium etching liquid is used to etch the chromium film in the preset area, and then the BOE etching liquid etches the quartz wafer in the preset area. The photoresist layer is removed by plasma degreasing and chemical degreasing.

[0067] The gold etching liquid includes an aqueous solution of iodine and potassium iodide in a certain proportion, the chromium etching liquid includes an aqueous solution of nitric acid and ammonium nitrate in a certain proportion, and the BOE etching liquid includes an aqueous solution of hydrofluoric acid, hydrogen fluoride, and corrosion inhibitor, thereby realizing corrosion without affecting roughness.

[0068] The remaining two film layers are removed by using the gold etching liquid and the chromium etching liquid in the etching liquid.

[0069] In the forming of the first through hole 204 and the second through hole 205, the etching method described above is also used, thereby forming an oscillation area between the first through hole 204 and the second through hole 205, which will not be described in detail here.

[0070] In the forming of the first through hole 204 and the second through hole 205 from the first groove 202 to the second groove 203, etching process or laser cutting process can be used, which is not limited here.

[0071] The laser of the laser cutting process uses short pulse laser to reduce thermal effect and avoid the occurrence of double crystal in piezoelectric quartz material.

[0072] Next, the steps of forming the first electrode 208 and the second electrode 209 are described. Specifically, a metal layer is first formed on the front surface and the back surface of the third quartz wafer 201 after the forming of the first through hole 204 and the second through hole 205, and then the metal layer in the excess area is removed by etching to obtain the first electrode 208 and the second electrode 209.

[0073] The first electrode 208 is formed on the front surface of the oscillation region and extends along the sidewall of the first groove 202 to the outside of the first groove 202, and the end of the first electrode 208 is located in the first lead region 211; the second electrode 209 is formed on the back surface of the oscillation region and extends along the sidewall of the second groove 203 to the outside of the second groove 203, and the end of the second electrode 209 is located in the second lead region 212, to form a piezoelectric sensor wafer 210, as shown in Figure 5 .

[0074] Next, the process of forming the package side surface is described.

[0075] S202 and S203 are performed, a first quartz wafer is provided, a first notch is formed on the first quartz wafer and corresponds to the position of the first lead region on the front surface of the piezoelectric sensor wafer, a second notch is formed on the first quartz wafer and corresponds to the position of the second lead region on the back surface of the piezoelectric sensor wafer, to form a first package side surface component; a second quartz wafer is provided, a third notch is formed on the second quartz wafer and corresponds to the position of the second lead region on the back surface of the piezoelectric sensor wafer, a fourth notch is formed on the second quartz wafer and corresponds to the position of the second lead region on the front surface of the piezoelectric sensor wafer, to form a second package side surface component.

[0076] As shown in Figure 6 , Figure 7 , Figure 8 , taking the first quartz wafer as an example, a first quartz wafer 601 is provided, then the first quartz wafer 601 is ground and polished so that the surface roughness of the first quartz wafer 601 is less than 10 nm, then a first notch 602 is formed on the first quartz wafer 601 and corresponds to the position of the first lead region 211 on the front surface of the piezoelectric sensor wafer, and a second notch 603 is formed on the first quartz wafer 601 and corresponds to the position of the second lead region 212 on the back surface of the piezoelectric sensor wafer, to form a first package side surface component 604.

[0077] The cross section of the first notch 602 and the second notch 603 is semicircular or rectangular.

[0078] As shown in Figure 8 , a first bonding layer 605 is formed on the surface of the first quartz wafer 601.

[0079] Similarly, after the second quartz wafer 607 is provided, the second quartz wafer 607 is ground and polished so that the surface roughness of the second quartz wafer 607 is less than 10 nm, then a third notch 608 is formed on the second quartz wafer 607 at a position corresponding to the second lead region 212 on the back surface of the piezoelectric sensor wafer, and a fourth notch 609 is formed on the second quartz wafer at a position corresponding to the first lead region 211 on the front surface of the piezoelectric sensor wafer, so as to form a second packaging side surface component 606.

[0080] Similarly, a second bonding layer 610 is formed on the surface of the second packaging side surface component 606.

[0081] In specific embodiments, the first bonding layer 605 and the second bonding layer 610 are formed in any of the following manners:

[0082] coating, physical vapor deposition (PVC), chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), and sintering.

[0083] Finally, S104 is performed to bond the first packaging side surface component 604 to the front surface of the piezoelectric sensor wafer 210 and bond the second packaging side surface component 606 to the back surface of the piezoelectric sensor wafer 210, as shown in FIG. 6C. Figure 9 By using the bonding method, the performance of the device can be improved.

[0084] The bonding operation described above is specifically performed in a vacuum environment to achieve hermetic packaging.

[0085] After S104, a first plating layer can be formed on the first electrode 208 of the first lead region 211, and a second plating layer can be formed on the second electrode 209 of the second lead region 212, so as to facilitate wire bonding. By increasing the thickness of the first plating layer and the second plating layer, the bonding strength can be increased.

[0086] The one or more technical solutions in the embodiments of the present application have at least the following technical effects or advantages:

[0087] The application provides a packaging method of a piezoelectric quartz sensor, comprising the following steps: forming a piezoelectric sensor wafer, the piezoelectric sensor wafer is square-shaped, comprising a first pin area on the front surface of the piezoelectric sensor wafer and a second pin area on the back surface of the piezoelectric sensor wafer, the first pin area and the second pin area are arranged in a diagonal direction; providing a first quartz wafer, forming a first notch on the first quartz wafer corresponding to the position of the first pin area on the front surface of the piezoelectric sensor wafer, and forming a second notch on the first quartz wafer corresponding to the position of the second pin area on the back surface of the piezoelectric sensor wafer, thereby forming a first packaging side part; providing a second quartz wafer, forming a third notch on the second quartz wafer corresponding to the position of the second pin area on the back surface of the piezoelectric sensor wafer, and forming a fourth notch on the second quartz wafer corresponding to the position of the first pin area on the front surface of the piezoelectric sensor wafer, thereby forming a second packaging side part; bonding the first packaging side part to the front surface of the piezoelectric sensor wafer, and bonding the second packaging side part to the back surface of the piezoelectric sensor wafer, so that the bonding method can avoid the problem of poor device performance caused by the pasting method, thereby improving the performance of the device.

[0088] Embodiment two

[0089] Based on the same invention, the application further provides a piezoelectric quartz sensor, as shown in the drawings, comprising: Figure 9

[0090] a piezoelectric sensor wafer 210, a first packaging side part 604 and a second packaging side part 606;

[0091] The piezoelectric sensor wafer 201 comprises a first pin area on the front surface edge and a second pin area on the back surface edge, and the first pin area and the second pin area are arranged in a diagonal direction;

[0092] The first packaging side part 604 comprises a first notch 602 and a second notch 603;

[0093] The second packaging side part 606 comprises a third notch 608 and a fourth notch 609;

[0094] The first packaging side part 604 and the second packaging side part 606 are bonded to the front surface and the back surface of the piezoelectric sensor wafer 210 respectively, so that the first notch 602 and the fourth notch 609 are opposite to the first pin area, and the second notch 603 and the third notch 608 are opposite to the second pin area.

[0095] In an optional embodiment, the cross sections of the first notch 602, the second notch 603, the third notch 608 and the fourth notch 609 are all semicircular or rectangular.

[0096] ​In an alternative real-time manner, a first plating layer and a second plating layer are further included, the first plating layer is located on the first electrode 208 of the first pin area, and the second plating layer is located on the second electrode 209 of the second pin area.

[0097] While the preferred embodiments of the application have been described, additional variations and modifications can be made to the preferred embodiments by those skilled in the art once they learn of the basic inventive concepts. Therefore, the appended claims are intended to encompass within their scope all such variations and modifications as are included within the spirit and scope of the application.

[0098] It is apparent that those skilled in the art can make various changes and modifications to the application without departing from the spirit and scope thereof. It is therefore intended to include within the ambit of the application all such changes and modifications as fall within the scope of the claims and their equivalents.

Claims

1. A method of packaging a piezoelectric quartz sensor, characterized by, The method comprises the following steps: forming a piezoelectric sensor wafer, the piezoelectric sensor wafer is square-shaped, comprising a first pin area on the front surface of the piezoelectric sensor wafer and a second pin area on the back surface of the piezoelectric sensor wafer, the first pin area and the second pin area are arranged in a diagonal direction; providing a first quartz wafer, forming a first notch on the first quartz wafer and corresponding to the position of the first pin area on the front surface of the piezoelectric sensor wafer, forming a second notch on the first quartz wafer and corresponding to the position of the second pin area on the back surface of the piezoelectric sensor wafer, and forming a first packaging side part; providing a second quartz wafer, forming a third notch on the second quartz wafer and corresponding to the position of the back surface of the piezoelectric sensor wafer and the second pin area, forming a fourth notch on the second quartz wafer and corresponding to the position of the first pin area on the front surface of the piezoelectric sensor wafer, and forming a second packaging side part; forming a bonding layer on the surface of the first quartz wafer and the surface of the second quartz wafer; bonding the first packaging side part with the front surface of the piezoelectric sensor wafer, and bonding the second packaging side part with the back surface of the piezoelectric sensor wafer.

2. The method of claim 1, wherein, The method for forming a piezoelectric sensor wafer comprises the following steps: providing a third quartz wafer; forming a first groove and a second groove on the front surface and the back surface of the third quartz wafer, the first groove and the second groove are both circular grooves; forming a first through hole and a second through hole from the first groove to the second groove, the first through hole is a first half-arc columnar hole along one side edge of the bottom end of the first groove, the second through hole is a second half-arc columnar hole along the other side edge of the bottom end of the first groove, so that an oscillation area is formed between the first through hole and the second through hole; forming a first electrode on the front surface of the oscillation area and extending to the outside of the first groove along the side wall of the first groove, the end of the first electrode is located in the first pin area, forming a second electrode on the back surface of the oscillation area and extending to the outside of the second groove along the side wall of the second groove, the end of the second electrode is located in the second pin area, so as to form a piezoelectric sensor wafer.

3. The method of claim 2, wherein, The method for forming a first through hole and a second through hole from the first groove to the second groove comprises the following steps: using a photoetching process to form a first through hole and a second through hole from the first groove to the second groove; or using a laser cutting process to form a first through hole and a second through hole from the first groove to the second groove.

4. The method of claim 1, wherein, Before the step of forming a first notch on the first quartz wafer and corresponding to the position of the first pin area on the front surface of the piezoelectric sensor wafer, the method further comprises the following steps: grinding and polishing the first quartz wafer so that the surface roughness of the first quartz wafer is less than 10 nm; Before the step of forming a second notch on the second quartz wafer and corresponding to the position of the second pin area on the back surface of the piezoelectric sensor wafer, the method further comprises the following steps: grinding and polishing the second quartz wafer so that the surface roughness of the second quartz wafer is less than 10 nm.

5. The method of claim 1, wherein, The bonding layer is formed on the surface of the first quartz wafer and the surface of the second quartz wafer, and the following any one of the following methods is adopted: coating, PVD, CVD, PECVD and sintering.

6. The method of claim 1, wherein, The first quartz wafer is front bonded to the piezoelectric sensor wafer, and the second quartz wafer is back bonded to the piezoelectric sensor wafer, including: The first quartz wafer is front bonded to the piezoelectric sensor wafer, and the second quartz wafer is back bonded to the piezoelectric sensor wafer in a vacuum environment.

7. The method of claim 2, wherein, After the first quartz wafer is front bonded to the piezoelectric sensor wafer, and the second quartz wafer is back bonded to the piezoelectric sensor wafer, it further includes: A first plating film layer is formed on the first electrode of the first pin area; A second plating film layer is formed on the second electrode of the second pin area.

8. A piezoelectric quartz sensor, characterized by It includes: a piezoelectric sensor wafer, a first packaging side part and a second packaging side part; The piezoelectric sensor wafer includes a first pin area at the front edge and a second pin area at the back edge, and the first pin area and the second pin area are arranged in a diagonal direction; The first packaging side part includes a first notch, a second notch; The second packaging side part includes a third notch, a fourth notch; Therefore, the first packaging side part and the second packaging side part are both provided with a bonding layer The first packaging side part and the second packaging side part are respectively bonded to the front and back of the piezoelectric sensor wafer through the bonding layer, so that the first notch and the fourth notch are opposite to the first pin area, and the second notch and the third notch are opposite to the second pin area.

9. The piezoelectric quartz sensor of claim 8, wherein, The cross section of the first notch, the cross section of the second notch, the cross section of the third notch and the cross section of the fourth notch are all semicircular or rectangular.

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