Piezoelectric sensor chip, piezoelectric sensor and preparation method thereof

Abstract

The present invention provides a piezoelectric sensor chip, a piezoelectric sensor and a preparation method thereof, wherein the piezoelectric sensor chip comprises a piezoelectric material layer and an electrode layer laminated and arranged on the surface of the piezoelectric material layer; wherein the piezoelectric material layer is divided into a measuring area and a non-measuring area, and the thickness of the measuring area is less than the thickness of the non-measuring area. By setting the thickness of the measuring area in the piezoelectric material layer to be less than the thickness of the non-measuring area, that is, thinning the area corresponding to the measurement in the piezoelectric material layer, when the measuring area is thinned, the resonant frequency of the measuring area in the piezoelectric material layer can be increased, thereby improving the measurement sensitivity of the piezoelectric sensor chip; in addition, since the thickness of the non-measuring area of ​​the piezoelectric material layer remains unchanged, the hardness of the piezoelectric sensor chip can be ensured, and the piezoelectric chip has high fundamental frequency resonance frequency characteristics, and can also ensure that the prepared piezoelectric chip is easy to clamp and easy to use.

Description

Technical Field

[0001] The present invention relates to the field of biosensor technology, and in particular to a piezoelectric sensor chip, a piezoelectric sensor and a manufacturing method thereof. Background Art

[0002] Biosensor technology is a high-tech technology that has grown from the mutual penetration of multiple disciplines such as biology, chemistry, physics, medicine, and electronic technology. It has important application value in the fields of biomedicine, environmental monitoring, food, medicine, and military medicine. Among them, piezoelectric sensor chips have a wide range of applications in the biological field due to their unique properties. They are mainly used in the field of biological life analysis to achieve high-sensitivity detection and analysis of molecular interactions, kinetic research, cell adsorption, migration changes, drug effects, and screening of biological molecules. They can also be used in the fields of petroleum, chemical industry, aerospace, etc.

[0003] Piezoelectric sensor chips in the biological field use piezoelectric film technology to analyze the interface of biological molecules. Specifically, when a substance undergoes adsorption and desorption reactions on the surface of a piezoelectric material or the properties of the liquid on the surface change, the frequency of the piezoelectric material will change. That is, by analyzing the frequency changes of the piezoelectric material, it is possible to obtain information related to the mass of the substance adsorbed on the surface of the piezoelectric sensor chip, thereby realizing the analysis of the interface of biological molecules.

[0004] The frequency of the piezoelectric material is related to the thickness of the piezoelectric material itself, that is, the thicker the thickness, the lower the frequency and the lower the measurement sensitivity; the thinner the thickness, the higher the frequency and the higher the measurement sensitivity. Therefore, in the above technical solution, in order to improve the measurement sensitivity of the piezoelectric sensor chip, it is necessary to reduce the thickness of the piezoelectric material. The thinner the thickness of the piezoelectric material, the more fragile the piezoelectric sensor chip will be, thereby reducing the service life of the piezoelectric sensor chip. Therefore, in the prior art, it is usually not considered to extend the service life of the piezoelectric sensor chip by adjusting the thickness of the piezoelectric material. Summary of the invention

[0005] The present invention aims to solve the defect of low measurement sensitivity of the piezoelectric sensor chip caused by the thickness of the piezoelectric material in the prior art.

[0006] In view of this, according to the first aspect, an embodiment of the present invention provides a piezoelectric sensor chip, comprising: a piezoelectric material layer, and an electrode layer laminated on the surface of the piezoelectric material layer; wherein the piezoelectric material layer is divided into a measuring area and a non-measuring area, and the thickness of the measuring area is equal to or less than the thickness of the non-measuring area.

[0007] Optionally, the electrode layer includes a first sub-electrode layer and a second sub-electrode layer respectively arranged on both sides of the piezoelectric material layer.

[0008] Optionally, the electrode lead-out terminal of the first sub-electrode layer and the electrode lead-out terminal of the second sub-electrode layer are respectively arranged at two sides of the piezoelectric material layer.

[0009] Optionally, the electrode lead-out end of the first sub-electrode layer and the electrode lead-out end of the second sub-electrode layer are arranged on the same side of the piezoelectric material layer.

[0010] Optionally, the piezoelectric sensor chip further includes a dielectric film layer having an opening, the dielectric film layer covers the piezoelectric material layer, and the electrode layer is exposed from the opening of the dielectric film layer.

[0011] Optionally, the thickness of the measurement area is 5 μm-350 μm.

[0012] According to the second aspect, an embodiment of the present invention further provides a piezoelectric sensor, comprising:

[0013] The piezoelectric sensor chip according to any one of the first aspects of the present invention;

[0014] The packaging layer has a through hole, and the piezoelectric sensor chip is fixedly arranged at the through hole.

[0015] Optionally, a positioning edge is provided at the edge of the through hole of the packaging layer.

[0016] Optionally, the edge of the packaging layer has at least one positioning hole and / or at least one positioning groove.

[0017] Optionally, the packaging layer is a printed circuit board, and the electrodes of the piezoelectric sensor chip are electrically connected to the leads of the printed circuit board.

[0018] Optionally, two connection holes are formed on the packaging layer, the connection holes are filled with conductive paste, and the electrodes of the piezoelectric sensor chip are electrically connected to the leads of the printed circuit board through the connection holes.

[0019] According to the third aspect, an embodiment of the present invention further provides a method for preparing a piezoelectric sensor chip, comprising the following steps:

[0020] Providing a piezoelectric material layer, wherein the piezoelectric material layer is divided into a measurement area and a non-measurement area;

[0021] thinning the measurement area;

[0022] Covering a metal layer on the surface of the piezoelectric material layer;

[0023] patterning the metal layer to form an electrode layer;

[0024] Or, before the step of covering the surface of the piezoelectric material layer with a metal layer, the method further includes: a step of thinning the measurement area.

[0025] The technical solution provided by the embodiment of the present invention has the following beneficial effects:

[0026] 1. The piezoelectric sensor chip provided in the embodiment of the present invention sets the thickness of the measuring area in the piezoelectric material layer to be smaller than the thickness of the non-measuring area, that is, the area corresponding to the measurement in the piezoelectric material layer is thinned. When the measuring area is thinned, the resonant frequency of the measuring area in the piezoelectric material layer can be increased, thereby improving the measurement sensitivity of the piezoelectric sensor chip. In addition, since the thickness of the non-measuring area of ​​the piezoelectric material layer remains unchanged, the hardness of the piezoelectric sensor chip can be ensured, and the piezoelectric chip has the characteristics of high fundamental frequency resonance frequency, and the prepared piezoelectric sensor chip can be easy to clamp and easy to use, thereby avoiding the phenomenon of fragility caused by direct clamping, so that the piezoelectric sensor chip has the characteristics of high sensitivity and strong practicality. In addition, by setting the thickness of the measuring area and the non-measuring area in the piezoelectric material layer to be equal, the process can be simplified and the cost can be saved.

[0027] 2. The piezoelectric sensor chip provided in an embodiment of the present invention arranges the lead-out ends of the electrode layer on the same side of the piezoelectric material layer, that is, the excitation and signal receiving electrodes are arranged on the same side of the piezoelectric material layer when the electrode is designed. When preparing the electrode, only one side of the piezoelectric material layer needs to be processed, which can simplify the preparation process.

[0028] 3. The piezoelectric sensor chip provided in the embodiment of the present invention is used for different application requirements and simulation-related experimental environments by covering the surface of the piezoelectric material layer with a dielectric film layer. In addition, the dielectric film layer can also realize application requirements such as electrode production, surface passivation, hydrophilic and hydrophobic modification, and biocompatibility.

[0029] 4. The piezoelectric sensor chip provided by the embodiment of the present invention has a piezoelectric material layer with a thickness corresponding to the measurement area of ​​5μm-350μm, and accordingly, the resonant frequency range of the area is 5-200MHz. Among them, a high resonant frequency can meet the requirements of high-sensitivity molecular sensing, and a low resonant frequency can meet the requirements of low-sensitivity molecular sensing. Therefore, the piezoelectric sensor chip can be applied to scenarios with different sensitivity measurement requirements.

[0030] 5. The piezoelectric sensor provided in the embodiment of the present invention fixes the piezoelectric sensor chip on the packaging layer, and uses the packaging layer to protect the piezoelectric sensor chip. On the one hand, it can prevent the piezoelectric sensor chip from being damaged, and on the other hand, it can fix the piezoelectric sensor chip so that it can be used in conjunction with other devices for measurement.

[0031] 6. In the piezoelectric sensor provided by an embodiment of the present invention, the packaging layer is configured as a printed circuit board, and the electrodes of the piezoelectric sensor chip can be led out to the end of the printed circuit board through the printed circuit board, that is, the piezoelectric sensor chip can be fixed through the printed circuit board on the one hand, and the piezoelectric sensor can be easy to carry on the other hand. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0033] Figure 1a A schematic diagram of the structure of a piezoelectric material layer in an embodiment of the present invention;

[0034] Figure 1b Another structural schematic diagram of the piezoelectric material layer in an embodiment of the present invention;

[0035] Figure 2a to Figure 2b A schematic diagram of the structure of the front and back sides of a piezoelectric sensor chip in an embodiment of the present invention;

[0036] Figure 3a to Figure 3b Another structural schematic diagram of the front and back sides of the piezoelectric sensor chip in an embodiment of the present invention;

[0037] Figure 4a to Figure 4b Another structural schematic diagram of the front and back sides of the piezoelectric sensor chip in an embodiment of the present invention;

[0038] Figure 5 A schematic diagram of a structure of an encapsulation layer in an embodiment of the present invention;

[0039] Figure 6 Another schematic diagram of the structure of the encapsulation layer in an embodiment of the present invention;

[0040] Figure 7 A schematic diagram of the structure of a piezoelectric sensor in an embodiment of the present invention;

[0041] Figure 8 Another structural schematic diagram of a piezoelectric sensor in an embodiment of the present invention;

[0042] Fig. 9 In the embodiment of the present invention Figure 7 A schematic structural diagram of another side of the piezoelectric sensor shown;

[0043] Fig.10a A process flow chart of a preparation process of a piezoelectric sensor chip in an embodiment of the present invention;

[0044] Fig.10b Another process flow chart of preparing a piezoelectric sensor chip according to an embodiment of the present invention;

[0045] Figures 11a to 11e A preparation structure diagram of a piezoelectric sensor chip in an embodiment of the present invention;

[0046] Figures 12a to 12d Another preparation structure diagram of a piezoelectric sensor chip in an embodiment of the present invention;

[0047] Reference numerals:

[0048] 1-piezoelectric material layer; 11-non-measurement area; 12-measurement area; 21-first sub-electrode layer; 22-second sub-electrode layer; 4-packaging layer; 41-positioning hole; 42-positioning groove; 43-first positioning edge; 44-lead; 45-connection hole; 46-bracket; 5-adhesive layer; 6-dielectric film layer. DETAILED DESCRIPTION

[0049] 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.

[0050] In the description of the present invention, it should be noted that the terms “first”, “second” and “third” are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0051] 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.

[0052] Example

[0053] The embodiment of the present invention provides a piezoelectric sensor chip, comprising a piezoelectric material layer 1 and an electrode layer laminated on the surface of the piezoelectric material layer, wherein the piezoelectric material layer 1 is divided into a measuring area 12 and a non-measuring area 11. Figure 1a As shown, the thickness of the measuring area 12 and the non-measuring area 11 in the piezoelectric material layer 1 are equal. Figure 1b As shown, the thickness of the measuring area 12 is less than the thickness of the non-measuring area 11. After the measuring area 12 in the piezoelectric material layer is thinned, the piezoelectric sensor chip is processed peripherally, so that the piezoelectric sensor chip can have a high measurement sensitivity and ensure that the chip is not fragile, easy to use, and has practical application value. It should be noted that the measuring area 12 in the piezoelectric material layer 1 is the area directly facing the subsequent first sub-electrode layer 21 and the second sub-electrode layer 22.

[0054] Specifically, the measurement principle of the piezoelectric sensor chip is to use the fact that the piezoelectric material layer (usually quartz crystal) is a material with piezoelectric effect, and its oscillation frequency is related to its cut and thickness. When a rotating adsorption film is attached to the electrode surface attached to the piezoelectric material layer 1, the oscillation frequency changes due to the adsorption of specific substances, and the frequency change is related to the mass of the adsorbed substance. Therefore, when a material with adsorption is deposited on the electrode layer of the piezoelectric material layer 1 to form a film, it has an inherent frequency. When the film molecules accommodate a certain mass of gas molecules through polar adsorption and diffusion, their frequency will change. The frequency shift of the mass can be obtained by the Saubery equation. .

[0055] Among them, the resonant frequency of the piezoelectric material layer 1 is related to the thickness. Therefore, by setting the thickness of the measuring area 12 in the piezoelectric material layer 1 to be smaller than the thickness of the non-measuring area 11, that is, thinning the area corresponding to the measurement in the piezoelectric material layer 1, when the measuring area 12 is thinned, the resonant frequency of the measuring area in the piezoelectric material layer 1 can be increased, thereby improving the measurement sensitivity of the piezoelectric sensor chip; in addition, since the thickness of the non-measuring area 11 of the piezoelectric material layer 1 remains unchanged, the hardness of the piezoelectric sensor chip can be guaranteed, and the fragility caused by bumps can be avoided. While ensuring that the piezoelectric chip has a high fundamental frequency resonant frequency characteristic, it can also ensure that the prepared piezoelectric sensor chip is easy to clamp and easy to use, and avoids the phenomenon of fragility caused by direct clamping, so that the piezoelectric sensor chip has the characteristics of high sensitivity and strong practicality; in addition, by setting the thickness of the measuring area 12 and the non-measuring area 11 in the piezoelectric material layer to be equal, the process can be simplified and the cost can be saved.

[0056] Optionally, the thickness of the piezoelectric material layer 1 corresponding to the measurement area is 5μm-350μm, and accordingly, the resonant frequency range of the area is 5-200MHz. Among them, a high resonant frequency can meet the needs of high-sensitivity molecular sensing, and a low resonant frequency can meet the needs of low-sensitivity molecular sensing. Therefore, the piezoelectric sensor chip can be applied to scenarios with different sensitivity measurement requirements.

[0057] In addition, the electrode layer in the piezoelectric sensor chip includes a first sub-electrode layer 21 and a second sub-electrode layer 22 respectively arranged on both sides of the piezoelectric material layer 1. The electrode lead-out end 21a of the first sub-electrode layer 21 and the electrode lead-out end 22a of the second sub-electrode layer 22 can be arranged on the same surface of the piezoelectric material layer 1, or respectively arranged on both sides of the piezoelectric material layer 1, or arranged on both sides of the piezoelectric material layer 1.

[0058] Specifically, Figure 2a as well as Figure 2b As shown. Figure 2a In FIG. 1 , it is shown that the first sub-electrode layer 21 is arranged on the first surface of the piezoelectric material layer 1; Figure 2b In the embodiment, the first sub-electrode layer 21 is bent along the edge of the piezoelectric material layer 1 to the second surface of the piezoelectric material layer 1 to form an electrode lead-out end 21a of the first sub-electrode layer 21; Figure 2b In the figure, the second sub-electrode layer 22 and its electrode lead end 22a are located on the second surface of the piezoelectric material layer 1, that is, the electrode lead end 21a of the first sub-electrode layer 21 and the electrode lead end 22a of the second sub-electrode layer 22 are located on the same surface of the piezoelectric material layer 1.

[0059] By setting the lead ends of the electrode layer on the same side of the piezoelectric material layer 1, that is, setting the excitation and signal receiving electrodes on the same side of the piezoelectric material layer 1 when designing the electrode, only one side of the piezoelectric material layer 1 needs to be processed when preparing the electrode, which can simplify the preparation process.

[0060] like Figure 3a as well as Figure 3b As shown, the electrode lead-out terminal 21a of the first sub-electrode layer 21 and the electrode lead-out terminal 22a of the second sub-electrode layer 22 are respectively arranged on two surfaces of the piezoelectric material layer 1. Figure 3a As shown, on the first surface of the piezoelectric material layer 1, the electrode lead-out ends 22a of the first sub-electrode layer 21 and the second sub-electrode layer 22 are provided; Figure 3b As shown, on the second surface of the piezoelectric material layer 1, a second sub-electrode layer 22 and an electrode lead-out end 21a of the first sub-electrode layer 21 are provided; that is, the first sub-electrode layer 21 and the second sub-electrode layer 22 are respectively provided on both sides of the piezoelectric material layer 1, and the two sub-electrode layers are bent in opposite directions so that the electrode lead-out ends corresponding to the two sub-electrode layers are respectively located on both sides of the piezoelectric material layer 1.

[0061] like Figure 4a as well as Figure 4b As shown, the electrode lead-out end 21a of the first sub-electrode layer 21 and the electrode lead-out end 22a of the second sub-electrode layer 22 extend to the edges of both sides of the piezoelectric material layer 1 respectively. Figure 4a As shown, the electrode lead-out terminal 21a of the first sub-electrode layer 21 is connected to the first spring ring 23a arranged on the side of the piezoelectric material layer; Figure 4b As shown, the electrode lead-out end 22a of the second sub-electrode layer 22 is connected to the second spring coil 23b arranged on the other side of the piezoelectric material layer; that is, the electrode lead-out ends corresponding to the two sub-electrode layers lead out the electrodes through their corresponding spring coils respectively.

[0062] like Fig.12d or Fig.11dAs shown, the piezoelectric sensor chip also includes a dielectric film layer 6 covering the piezoelectric material layer 1, which is used for different application requirements and simulation-related experimental environments. In addition, the dielectric film layer 6 has an opening, and the electrode layer is exposed from the opening to avoid electrode insulation caused by the setting of the dielectric film layer 6.

[0063] The material of the dielectric film layer 6 may be Si, ZnO, ZnS, SiO2, AlN, Parylene (C / N / TH), PS, PE, CNT, ABS, etc., including but not limited to the above materials and their corresponding composite materials. The above materials can be deposited on the surface of the piezoelectric sensor chip by thermal evaporation, electron beam evaporation, magnetron sputtering, chemical vapor deposition, spin coating (including but not limited to) to achieve specific thickness of metal, semiconductor, dielectric, polymer film to achieve electrode production, surface passivation, hydrophilic and hydrophobic modification, and biocompatibility application requirements.

[0064] Optionally, the proportion of the measurement area 12 to the piezoelectric material layer 1 can be specifically set according to actual conditions, and it is only necessary to ensure that the thinning process is only for a part of the piezoelectric material layer 1 rather than the whole area.

[0065] Alternatively, part of the measurement region 12 may be thinned instead of the entire region.

[0066] Optionally, the piezoelectric sensor chip may be circular, or may be configured to other shapes as required.

[0067] As an optional implementation of this embodiment, the dielectric film layer 6 is only arranged on one side of the piezoelectric material layer 1 having the electrode body, or it can be arranged on both sides of the piezoelectric material layer 1 respectively. It is only necessary to ensure that the dielectric film layer 6 is arranged on one side of the electrode body of the piezoelectric material layer 1.

[0068] The embodiment of the present invention further provides a piezoelectric sensor, including a piezoelectric sensor chip and a packaging layer 4. The structure of the piezoelectric sensor chip is shown in FIG. Figures 1a to 4b The relevant description of the illustrated embodiment will not be repeated here.

[0069] The structure of the encapsulation layer 4 is as follows Figure 5 As shown, a through hole is provided on the packaging layer 4 for fixing the piezoelectric sensor chip; that is, the piezoelectric sensor chip is fixed in the through hole of the packaging layer 4. Figure 5 As shown, the encapsulation layer 4 has two positioning holes 41 and two positioning grooves 42. The positioning holes 41 and the positioning grooves 42 are respectively arranged at the ends of each edge of the encapsulation layer 4, and the positioning holes 41 and the positioning grooves 42 are arranged at intervals.

[0070] By providing the positioning hole 41 and the positioning groove 42 , it is convenient to set the piezoelectric sensor within a preset range of the detection device when the piezoelectric sensor is fixed on the detection device, so as to improve the detection accuracy of the piezoelectric sensor and the detection device.

[0071] Furthermore, the two positioning holes 41 have different sizes, and / or the two positioning grooves 42 have different sizes, so as to distinguish the installation direction of the piezoelectric sensor.

[0072] Optionally, the positioning mark on the encapsulation layer 4 is not limited to the positioning hole or the positioning groove, and other types of positioning marks may also be used. It is only necessary to ensure that the positioning mark is provided on the encapsulation layer 4.

[0073] In addition, if Figure 6 As shown, a first positioning edge 43 is provided on the through hole of the packaging layer 4. When the piezoelectric sensor chip is mounted on the packaging layer 4, the piezoelectric sensor chip is clamped by a fixture, and a second positioning edge is provided on the fixture, and the second positioning edge matches the first positioning edge 43. The piezoelectric sensor chip is positioned on the packaging layer 4 by the cooperation of the first positioning edge 43 and the second positioning edge. It should be noted that positioning on the packaging layer 4 can also be achieved by other means, not limited to the first positioning edge 43.

[0074] As an optional implementation of the present embodiment, a support surface may also be installed on the other side of the through hole in the packaging layer 4 away from the piezoelectric sensor chip, for setting the through hole as a blind hole to support the piezoelectric sensor chip; or, a blind hole may be directly opened on the packaging layer 4, and the piezoelectric sensor chip may be installed in the blind hole, and the connecting wires of the piezoelectric sensor chip may be led out by opening a hole at the bottom of the blind hole.

[0075] Among them, when using Figure 5 or Figure 6 When the packaging layer 4 in the piezoelectric sensor chip is packaged, the structure of the corresponding piezoelectric sensor is as follows Figure 7 Specifically, the piezoelectric sensor chip is fixed in the through hole of the packaging layer 4, and a bracket is provided on one side of the packaging layer 4 for fixing and installing the piezoelectric sensor chip.

[0076] In some optional embodiments of the present invention, Figure 8 As shown, the packaging layer 4 is a printed circuit board, the piezoelectric sensor chip is fixed on the printed circuit board, and the electrode lead-out ends of the two sub-electrode layers in the piezoelectric sensor chip are located on the same surface of the piezoelectric material layer 1. The electrodes of the piezoelectric sensor chip are electrically connected to the leads 44 of the printed circuit board for leading out the electrodes of the piezoelectric sensor chip. Specifically, Fig. 9As shown, a connection hole 45 is provided on the printed circuit board, and a conductive paste is filled in the connection hole 45. The connection holes 45 on the printed circuit board are located at the same position as the piezoelectric sensor chip is fixed on the printed circuit, and the two electrode lead ends are respectively connected to the two connection holes 45. That is, the electrode lead ends are connected to the leads 44 of the printed circuit board through the conductive paste in the connection holes 45.

[0077] The printed circuit board can be used to lead the electrodes of the piezoelectric sensor chip to the end of the printed circuit board. That is, the printed circuit board can fix the piezoelectric sensor chip on the one hand, and on the other hand, the piezoelectric sensor can be prepared into the form of a U disk through secondary packaging of the piezoelectric sensor. Since the electrodes of the piezoelectric sensor are led out to the side through the leads 44 of the printed circuit board, the piezoelectric sensor after secondary packaging can be directly plugged into the detection device. The packaging method of the printed circuit board can make the piezoelectric sensor easy to carry and convenient to use.

[0078] The present invention also provides a method for preparing a piezoelectric sensor chip. Fig.10a As shown, the method includes:

[0079] S11, providing a piezoelectric material layer.

[0080] like Fig.11a As shown, the piezoelectric material layer is divided into a measurement area and a non-measurement area. The piezoelectric material layer can be prepared by quartz wafers or aluminum nitride (AlN). When using quartz wafers, the quartz crystal is cut along a specific tangent (for example, AT35°18'), and the thickness of the quartz crystal can be achieved by dry and wet etching, grinding and polishing, etc. to achieve a thickness of several to hundreds of microns; when using AlN, it is cut along a certain orientation, and its deposition thickness can be controlled by its deposition rate and time.

[0081] S12, thinning measurement area.

[0082] Since the thickness of the piezoelectric material layer 1 is between 10-400 microns (the resonance frequency of the corresponding measurement area after thinning is 5-200MHz), and the quartz crystal with extremely thin thickness is extremely easy to be damaged, when processing the piezoelectric material, only the small central area (also called the measurement area) is thinned, while the minimum thickness of the edge (also called the non-measurement area) is still relatively thick to facilitate the subsequent polymer packaging. Fig.11b As shown, the measuring area 12 of the piezoelectric material layer is thinned so that the thickness of the measuring area 12 is smaller than the thickness of the non-measuring area 11 .

[0083] S13, covering the surface of the piezoelectric material layer with a metal layer.

[0084] The metal layer can be directly covered on the surface of the piezoelectric material layer, or Fig.11c As shown, a layer of adhesive layer 5 is first coated on the piezoelectric material layer 1 at the position corresponding to the electrode layer to be prepared, so as to fix the metal layer and the piezoelectric material layer 1. Fig.11d As shown, the metal layer is covered on the adhesive layer 5 .

[0085] S14, patterning the metal layer to form an electrode layer.

[0086] The MEMS process (including coating, photolithography, development, metal film deposition, stripping, dry and wet etching, and degumming) or metal mask is used to produce a microarray of excitation and signal receiving metal electrodes (processing accuracy 0.5 microns) (refer to the actual electrode design size for specific reference). The selection of electrode material needs to be combined with factors such as the stability, oxidation resistance, corrosion resistance, and biocompatibility of the material itself. Generally, Au, Ag, Al, Ti, Mo, Cr, Cu, Sn, Mn, Ni, W, V, Nb, B, Fe, etc. are selected but not limited to. Among them, the metal layer is patterned to form a Fig.11d The first sub-electrode layer 21 and the second sub-electrode layer 22 are shown.

[0087] In some optional implementations of this embodiment, such as Fig.11e As shown, one of Si, ZnO, ZnS, SiO2, AlN, Parylene (C / N / TH), PS, PE, CNT, ABS or their corresponding composite materials can be deposited on the surface of the electrode layer at the same time to form a dielectric film layer 6 for different application requirements and simulation-related experimental environments. The above materials can be deposited on the surface of the piezoelectric sensor chip by thermal evaporation, electron beam evaporation, magnetron sputtering, chemical vapor deposition, and spin coating to achieve electrode production, surface passivation, hydrophilic and hydrophobic modification, and biocompatibility application requirements. Among them, the dielectric film layer 6 can be set according to the specific use environment, and it is only necessary to ensure that the dielectric film layer 6 is set on the measuring surface of the piezoelectric sensor chip, and the electrode layer is exposed from the opening of the dielectric film layer 6.

[0088] It should be noted that a too thick dielectric film layer 6 will cause the piezoelectric sensor chip as a mass sensor to effectively detect the attenuation of the signal, and a too thin dielectric film layer 6 will form a discontinuous structure resulting in incomplete coating. Therefore, in this embodiment, the piezoelectric sensor electrode and the selective coating of the dielectric film are prepared in batches through the MEMS process.

[0089] The present invention also provides a method for preparing a piezoelectric sensor chip. Fig.10b As shown, Fig.10aThe difference of the embodiment shown is that the piezoelectric material layer 1 does not need to be thinned, that is, the thickness of the measuring area 12 and the non-measuring area 11 in the piezoelectric material layer 1 are equal. Specifically, the following steps are included:

[0090] S21, providing a piezoelectric material layer. Fig.10a The S11 of the embodiment shown is the same and will not be described in detail here. Fig.12a shown.

[0091] S22, covering the surface of the piezoelectric material layer with a metal layer. Fig.10a The S13 of the embodiment shown is the same and will not be described in detail here. Figure 12b shown.

[0092] S23, patterning the metal layer to form an electrode layer. Fig.10a The S14 of the embodiment shown is the same and will not be described in detail here. Fig.12c shown.

[0093] Optionally, with Fig.11e The same as the embodiments shown is that a dielectric film layer 6 is formed on the surface of the piezoelectric material layer 1. Fig.11e The relevant description of the illustrated embodiment will not be repeated here.

[0094] The embodiment of the present invention further provides a method for preparing a piezoelectric sensor, wherein the piezoelectric sensor comprises a piezoelectric sensor chip and a packaging layer. For the method for preparing the piezoelectric sensor chip, please refer to Fig.10a S11 to S14 of the illustrated embodiment, or, Fig.10b S21 to S23 of the illustrated embodiment will not be described in detail here.

[0095] By packaging the piezoelectric sensor chip, it is used to prevent the piezoelectric sensor chip from being easily broken due to clamping during actual use, or the problem of poor stability when directly connected to the biomolecular interface analyzer. Specifically, it can be achieved in the following ways:

[0096] The usual selection of packaging materials will be combined with factors such as the stability, oxidation resistance, corrosion resistance and biocompatibility of the material itself. In specific applications, PMMA, PET, PEEK, PTFE, PVC, PP polymers, etc., including but not limited to the above materials, are generally selected. At the same time, Au, Al, Sn metal leads and PC sheets, etc., including but not limited to the above materials and their corresponding composite materials, are also considered for different application requirements and simulation of related experimental environments. The above materials can be selected by but not limited to epoxy AB glue, single-sided and double-sided adhesive tape, plasma, ultraviolet light and hot pressing bonding to achieve effective packaging of piezoelectric sensor chips and easy-to-clamp polymers (used to form packaging layers); at the same time, metal wires, silver paste, gold paste, carbon paste and other materials will be selected but not limited to realize the electrical signal connection between piezoelectric sensor chips and biomolecular interface analyzers.

[0097] The specific process is as follows:

[0098] First, the easy-to-clamp polymer sheet (i.e., the encapsulation layer) is produced by mechanical stamping, injection molding, laser processing, etc., wherein a through hole is opened in the polymer sheet for fixing the piezoelectric sensor chip. Since the piezoelectric sensor chip is a high-sensitivity mass weighing sensor, the effective combination of the piezoelectric sensor chip and the polymer sheet needs to consider the best matching method, which can be achieved by hot pressing bonding, plasma bonding, ultraviolet light irradiation bonding, and adhesive bonding. In this embodiment, high-precision processing is used for the polymer sheet, and optionally, the module processing accuracy is: <0.05 mm.

[0099] Secondly, the installation requires that positioning marks be set on the packaging layer to achieve effective connection between the piezoelectric sensor and the biomolecular interface analyzer. The positioning marks can be positioning grooves, positioning holes, or a combination of the two. Figures 5 to 9 The relevant description of the illustrated embodiment will not be repeated here.

[0100] In addition, since the thickness of the piezoelectric material layer is between 10-400 microns (the resonant frequency of the corresponding measuring area after thinning is 5-200MHz), and the extremely thin quartz crystal is extremely easy to be damaged, the piezoelectric material is prepared only for a small central area, while the minimum thickness of the edge is still relatively thick for easy packaging; finally, physical pin contact, metal (Au, Al) leads and other methods can be used to achieve the connection between the piezoelectric sensor and the biomolecular interface analyzer.

[0101] The piezoelectric sensor chip provided in the implementation of the present invention can be used in a biomolecular interface analyzer to achieve high-sensitivity detection and analysis of molecular interactions, kinetic studies, cell adsorption, migration changes, drug effects and drug screening, biocompatibility, and assembly of polyelectrolyte membrane layers of biomolecules.

[0102] In summary, the embodiments of the present invention provide four packaging methods for piezoelectric sensor chips, which are as follows:

[0103] (1) If Figures 2a to 3b The bare die shown uses the piezoelectric sensor chip alone without other packaging;

[0104] (2) If Figure 4a As shown in Figure b, a spring ring is used for packaging;

[0105] (3) If Figure 7 As shown, polymer is used for encapsulation;

[0106] (4) If Figure 8 as well as Fig. 9 As shown, a PCB board is used for packaging.

[0107] For the above four packaging methods, please refer to the corresponding descriptions in the attached drawings and will not be repeated here.

[0108] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A piezoelectric sensor chip, characterized in that: include: A piezoelectric material layer, and an electrode layer laminated on the surface of the piezoelectric material layer; wherein the piezoelectric material layer is divided into a measuring area and a non-measuring area, the thickness of the measuring area is less than the thickness of the non-measuring area, and the thickness of the measuring area is 5 μm; an adsorbent material is deposited on the electrode layer to form a thin film; The thickness of the measurement area is smaller than the thickness of the non-measurement area, which comprises: thinning the area corresponding to the measurement in the piezoelectric material layer, while the thickness of the non-measurement area of ​​the piezoelectric material layer remains unchanged.

2. The piezoelectric sensor chip according to claim 1, characterized in that: The electrode layer includes a first sub-electrode layer and a second sub-electrode layer respectively arranged on both sides of the piezoelectric material layer.

3. The piezoelectric sensor chip according to claim 2, characterized in that: The electrode lead-out end of the first sub-electrode layer and the electrode lead-out end of the second sub-electrode layer are respectively arranged at two sides of the piezoelectric material layer.

4. The piezoelectric sensor chip according to claim 2, characterized in that: The electrode lead-out end of the first sub-electrode layer and the electrode lead-out end of the second sub-electrode layer are arranged on the same side of the piezoelectric material layer.

5. The piezoelectric sensor chip according to claim 2, characterized in that: The piezoelectric sensor chip further comprises a dielectric film layer having an opening, wherein the dielectric film layer covers the piezoelectric material layer, and the electrode layer is exposed from the opening of the dielectric film layer.

6. A piezoelectric sensor, characterized in that: include: The piezoelectric sensor chip according to any one of claims 1 to 5; The packaging layer has a through hole, and the piezoelectric sensor chip is fixedly arranged at the through hole.

7. The piezoelectric sensor according to claim 6, characterized in that: A positioning edge is arranged at the edge of the through hole of the packaging layer.

8. The piezoelectric sensor according to claim 7, characterized in that: The edge of the packaging layer has at least one positioning hole and / or at least one positioning groove.

9. The piezoelectric sensor according to claim 6, characterized in that: The packaging layer is a printed circuit board, and the electrodes of the piezoelectric sensor chip are electrically connected to the leads of the printed circuit board.

10. The piezoelectric sensor according to claim 9, characterized in that: The packaging layer is provided with two connection holes, the connection holes are filled with conductive paste, and the electrodes of the piezoelectric sensor chip are electrically connected to the leads of the printed circuit board through the connection holes.

11. A method for preparing a piezoelectric sensor chip, characterized in that: The following steps are involved: Providing a piezoelectric material layer, wherein the piezoelectric material layer is divided into a measuring area and a non-measuring area, the thickness of the measuring area is less than the thickness of the non-measuring area, and the thickness of the measuring area is 5 μm; Covering a metal layer on the surface of the piezoelectric material layer; Patterning the metal layer to form an electrode layer, and depositing an adsorptive material on the electrode layer to form a thin film; Before the step of covering the surface of the piezoelectric material layer with a metal layer, the step also includes: a step of thinning the measurement area, including thinning the area corresponding to the measurement in the piezoelectric material layer, and the thickness of the non-measurement area of ​​the piezoelectric material layer remains unchanged.

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