Liquid sensing device and its preparation method

Abstract

This disclosure provides a liquid sensing device and a method for fabricating the same. The liquid sensing device includes: a substrate; a working electrode disposed on the substrate, wherein the working electrode includes a first metal portion and a first sensing portion, and the first sensing portion is disposed on the first metal portion; and a reference electrode disposed on the substrate.

Description

Technical Field

[0001] This disclosure relates to a liquid sensing device, and more particularly to a liquid sensing device including a pH value sensing group. Background Technology

[0002] In the past, industrial liquid sensing devices used separate components, such as the working electrode and the reference electrode, which were then assembled into a liquid sensing device. This process was relatively complex, and the accuracy of the liquid sensing device needed to be improved.

[0003] In view of this, there is an urgent need to develop a liquid sensing device. Summary of the Invention

[0004] To achieve the above objectives, this disclosure provides a liquid sensing device, comprising: a substrate; a working electrode disposed on the substrate, wherein the working electrode includes a first metal portion and a first sensing portion, and the first sensing portion is disposed on the first metal portion; and a reference electrode disposed on the substrate.

[0005] This disclosure also provides a method for manufacturing a liquid sensing device, comprising the following steps: providing a substrate; forming a metal layer on the substrate; patterning the metal layer to form a first metal portion and a second metal portion; and forming a working electrode and a reference electrode, the working electrode including the first metal portion and the reference electrode including the second metal portion. Attached Figure Description

[0006] Figures 1A-1D This is a schematic diagram of the process steps of a liquid sensing device according to an embodiment of the present disclosure.

[0007] Figure 2A For along Figure 1A A cross-sectional diagram of line segment A-A'.

[0008] Figure 2B For along Figure 1B A cross-sectional view of line segment B-B'.

[0009] Figure 2C For along Figure 1C A cross-sectional view of line segment CC′.

[0010] Figure 2D For along Figure 1D A cross-sectional diagram of line segment D-D'.

[0011] Figure 3A This is a cross-sectional schematic diagram of a liquid sensing device according to an embodiment of the present disclosure.

[0012] Figure 3B for Figure 3A Enlarged view of the working electrode W.

[0013] Figure 3C for Figure 3A A partially enlarged view of the reference electrode R.

[0014] Figure 4A This is a top view of a liquid sensing device according to an embodiment of the present disclosure.

[0015] Figure 4B For along Figure 4A A cross-sectional diagram of line segment E-E'.

[0016] Figure 4C For along Figure 4A Another cross-sectional view of line segment E-E'.

[0017] Figure 5 This is a top view of a liquid sensing device according to an embodiment of the present disclosure.

[0018] [Explanation of reference numerals in the attached figures]

[0019] 100: Liquid sensing device

[0020] 1: Substrate

[0021] 11: First sidewall

[0022] 12: Side

[0023] 2: Metal layer

[0024] 21: First Metal Section

[0025] 22: Second metal part

[0026] 221: Bottom surface

[0027] 3: Sensing layer

[0028] 31: First Sensor Unit

[0029] 311: Surface

[0030] 311a: Edge

[0031] 32: Second Sensor Unit

[0032] 4: First insulating layer

[0033] 41: Second sidewall

[0034] 5: Light Obscuration

[0035] 6: Metal Compounds Section

[0036] 61: Bottom surface

[0037] 7: Adhesion layer

[0038] 71: First attachment part

[0039] 72: Second attachment part

[0040] 8: Second insulation layer

[0041] 9: Third insulation layer

[0042] S1: Sensor Group

[0043] S2: Temperature sensing element

[0044] S3: Conductivity sensing electrode assembly

[0045] S31: Conductivity sensing electrode

[0046] W: Working electrode

[0047] R: Reference electrode

[0048] E1: Curved edge

[0049] L: Cutting line

[0050] CL: Wire

[0051] P: Contact pad

[0052] D1: Distance

[0053] D2: Pre-determined distance

[0054] T1: First thickness

[0055] T2: Second thickness

[0056] T3: Third Thickness

[0057] W1, W2, W3: Width

[0058] Wd: Width difference

[0059] X, Y: Direction

[0060] Z: Normal direction, top view direction Detailed Implementation

[0061] The following specific embodiments illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. This disclosure can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed for different viewpoints and applications without departing from the spirit of this disclosure.

[0062] It should be noted that, unless otherwise specified, the term "one" in this document is not limited to having a single element, but may include one or more of the elements.

[0063] Furthermore, the ordinal numbers used in the specification and claims, such as "first," "second," and "third," are used only to modify the claimed element and do not themselves contain or represent any prior ordinal number of the claimed element, nor do they represent the order of one claimed element with another, or the order of manufacturing methods. The use of these ordinal numbers is only to enable a claimed element with a certain name to be clearly distinguished from another claimed element with the same name.

[0064] In this disclosure, the term "about" generally means within 20%, or 10%, or 5%, or 3%, or 2%, or 1%, or 0.5% of a given value or range. The quantities given here are approximate quantities, meaning that the meaning of "about" may be implied even without a specific description of "about".

[0065] Furthermore, the terms "above," "upper," or "above" used in this specification and claims can refer to the two elements being in direct contact or not. Similarly, the terms "below," "under," or "below" used in this specification and claims can refer to the two elements being in direct contact or not. It is also understood that if the apparatus in the drawings is flipped upside down, the element described as being on the "below" side will become the element on the "above" side.

[0066] The following are exemplary embodiments of this disclosure, but this disclosure is not limited thereto. A feature of one embodiment can be applied to other embodiments through suitable modifications, substitutions, combinations, or separations. Furthermore, this disclosure can be combined with other known structures to form another embodiment.

[0067] Figure 1 shows directions X, Y, and Z. Direction Z can be the normal direction of the upper surface of substrate 1 or the top view direction of the liquid sensing device. Direction Z can be perpendicular to directions X and Y, and direction X can be perpendicular to direction Y.

[0068] Figures 1A-1D This is a schematic diagram of the process steps of a liquid sensing device according to an embodiment of the present disclosure. Figures 2A-2D for Figures 1A-1D A cross-sectional schematic diagram. More specifically, Figure 2A For along Figure 1A A cross-sectional diagram of line segment A-A'. Figure 2B For along Figure 1B A cross-sectional diagram of line segment B-B'. Figure 2C For along Figure 1C A cross-sectional view of line segment CC′. Figure 2D For along Figure 1D A cross-sectional diagram of line segment D-D'.

[0069] Figure 1D This is a top view of a liquid sensing device according to an embodiment of the present disclosure. Figure 2D For along Figure 1D A cross-sectional diagram of line segment D-D'. Please refer to... Figure 1D and Figure 2D The liquid sensing device 100 includes a substrate 1; a working electrode W disposed on the substrate 1; and a reference electrode R disposed on the substrate 1. The working electrode W includes a first metal portion 21 and a first sensing portion 31, and the first sensing portion 31 is disposed on the first metal portion 21.

[0070] The following describes the manufacturing process of the liquid sensing device 100. For example... Figures 1A to 2D As shown, firstly, a substrate 1 is provided. Substrate 1 can be a non-flexible substrate, a flexible substrate, a thin film, or a combination thereof. The material of substrate 1 may include, for example, quartz, glass, silicon wafer, sapphire, polycarbonate (PC), polyimide (PI), polypropylene (PP), polyethylene terephthalate (PET), or other plastic or polymeric materials, other inorganic or organic materials, or combinations thereof, but this disclosure is not limited thereto. In one embodiment of this disclosure, the material of substrate 1 includes glass, thereby improving the acid and alkali resistance of the liquid sensing device.

[0071] Then, a metal layer 2 is formed on the substrate 1. The metal layer 2 is patterned to form a first metal portion 21 and a second metal portion 22. The first metal portion 21 and the second metal portion 22 may be the same layer. Here, the material of the metal layer 2 may include, for example, gold, silver, copper, aluminum, titanium, chromium, nickel, molybdenum, combinations thereof, or other conductive materials with good conductivity or low resistance, but this disclosure is not limited thereto. In addition, the metal layer 2 may have a single-layer or multi-layer structure. The thickness of the metal layer 2 may be [missing information]. to However, this disclosure is not limited thereto. In one embodiment of this disclosure, the material of the metal layer 2 includes silver, which simplifies the process.

[0072] Next, a sensing layer 3 is formed on the metal layer 2. The sensing layer 3 is patterned to form a first sensing portion 31 and a second sensing portion 32. The first sensing portion 31 is disposed on the first metal portion 21, and the second sensing portion 32 is disposed on the second metal portion 22. The first sensing portion 31 and the second sensing portion 32 can be on the same layer. Thus, as... Figure 1A and Figure 2AAs shown, a working electrode W is formed, which may include a first metal portion 21 and a first sensing portion 31. In subsequent processes, the sensing layer 3 can be used to provide protection to prevent the metal layer 2 from being scratched, reacting with air or chemicals, or other forms of degradation. This improves the accuracy of the liquid sensing device. Here, the material of the sensing layer 3 may be a metal oxide, such as indium tin oxide (ITO), zinc dioxide, tin dioxide, indium zinc oxide (IZO), indium tin zinc oxide (ITZO), indium gallium zinc oxide (IGZO), aluminum zinc oxide (AZO), or ruthenium oxide (RuO2; RuO4), but this disclosure is not limited to these. The thickness of the sensing layer 3 may be [missing information]. to However, this disclosure is not limited thereto. Furthermore, the thickness of the metal layer 2 may be 5 to 40 mm greater than the thickness of the sensing layer 3. In one embodiment of this disclosure, the material of the sensing layer 3 includes indium tin oxide.

[0073] In some embodiments, the metal layer 2 and the sensing layer 3 can be formed using deposition methods, such as vapor deposition, sputtering, ion beam deposition, etc. The patterning of the metal layer 2 and the sensing layer 3 can be achieved using photolithography and etching methods. Etching methods include, for example, dry etching or wet etching. According to some embodiments, the patterning of the metal layer 2 and the patterned sensing layer 3 can be performed in the same step. According to some embodiments, the patterning of the metal layer 2 and the patterned sensing layer 3 can be performed in different steps, and this disclosure is not limited thereto. The patterning methods in this disclosure can utilize photolithography and etching methods; for simplicity, these will not be described in detail in the following embodiments.

[0074] Then, as Figure 2B As shown, an insulating layer is formed on the sensing layer 3 at a temperature below 180°C, and the insulating layer is patterned to form a first insulating layer 4 on the sensing layer 3. The first insulating layer 4 partially covers the first sensing portion 31 and the second sensing portion 32. In other words, the first insulating layer 4 partially covers the sensing layer 3, exposing a portion 31P of the first sensing portion 31 and a portion 32P of the second sensing portion 32. When the temperature is below 180°C, for example, it can be 120°C to 150°C or 70°C to 150°C, but this disclosure is not limited to this. This avoids the sensing layer 3 from crystallizing due to excessively high process temperatures, which would affect subsequent processing. Here, the first insulating layer 4 may include inorganic materials, organic materials, or combinations thereof. Organic materials may include, for example, acrylic-based, silicon oxide (SiO2)-based, or mixed-based organic protective layer materials, but this disclosure is not limited to this. Inorganic materials may include, for example, silicon nitride (SiN).x ), SiN x H, silicon oxynitride (SiO) x N y ), SiO x N y The inorganic material may be H, aluminum nitride, aluminum oxynitride, or other suitable nitriding materials, but this disclosure is not limited thereto. The thickness of the first insulating layer 4 may be from 0.1 μm to 20 μm, for example, less than 1 μm, 2 μm to 15 μm, but this disclosure is not limited thereto. In one embodiment of this disclosure, the inorganic material is silicon nitride to avoid the presence of oxygen in the material, which can improve the accuracy of acid and alkalinity detection.

[0075] According to some embodiments, the first insulating layer 4 may include organic materials, inorganic materials, or combinations thereof. The insulating layer may be formed by dip coating, spin coating, roller coating, blade coating, spraying, or deposition. The insulating layer may be patterned by etching, such as dry etching or wet etching. According to some embodiments, the first insulating layer 4 may include organic and inorganic materials. In this case, an inorganic insulating layer may be formed first on the sensing layer 3, and then an organic insulating layer may be formed on the inorganic insulating layer, but this disclosure is not limited to this.

[0076] Next, please refer to Figure 2B and Figure 2C A photoresist 5 is formed on the first insulating layer 4, wherein the photoresist 5 covers the first insulating layer 4 and the working electrode W. Specifically, the photoresist 5 covers a portion 31P of the first sensing part 31 in the working electrode W and exposes a portion 32P of the second sensing part 32. Here, the photoresist 5 is not particularly limited, for example, it can be a positive photoresist or a negative photoresist.

[0077] Then, at least part of the exposed second sensing portion 32P is removed to expose at least part of the second metal portion 22. There are no particular limitations on the method of removing the second sensing portion 32; for example, dry etching or wet etching can be used, but this disclosure is not limited thereto.

[0078] Next, at least a portion of the exposed second metal portion 22 is reacted to form a metal compound portion 6. For example... Figure 1C and 2CAs shown, a metal compound portion 6 is disposed on the second metal portion 22. The material of the metal compound portion 6 may include silver chloride, silver oxide, or a combination thereof, but this disclosure is not limited thereto. When the material of the metal layer 2 includes silver, for example, a portion of the metal layer 2 may undergo a redox reaction by electrolysis or solution method to form the metal compound portion 6, but this disclosure is not limited thereto. The portion of the metal layer 2 undergoing the redox reaction refers to the portion of the second metal portion 22 not covered by the photoresist 5 or the first insulating layer 4. More specifically, a redox reaction may be performed on the portion of the second metal portion 22 not covered by the photoresist 5 or the first insulating layer 4, thus consuming a portion of the second metal portion 22 and converting it into the metal compound portion 6. Furthermore, when the material of the metal layer 2 does not include silver, a silver layer may be formed on the metal layer 2 first, and then the silver layer may undergo a redox reaction by electrolysis or solution method to form the metal compound portion 6. In one embodiment of this disclosure, the metal compound portion 6 includes silver chloride.

[0079] After removing the photoresist 5, the liquid sensing device 100 of this disclosure can be obtained. For example... Figure 1D and 2D As shown, the liquid sensing device 100 of this disclosure includes: a substrate 1; a working electrode W disposed on the substrate 1, wherein the working electrode W includes a first metal portion 21 and a first sensing portion 31, and the first sensing portion 31 is disposed on the first metal portion 21; and a reference electrode R disposed on the substrate 1. The reference electrode R may include a second metal portion 22 and a metal compound portion 6, the metal compound portion 6 being disposed on the second metal portion 22. According to some embodiments, the first metal portion 21 and the second metal portion 22 may be the same layer. Furthermore, as Figure 1D As shown, the working electrode W and the reference electrode R are electrically isolated. The working electrode W and the reference electrode R can constitute a sensing group S1. A liquid sensing device may include the sensing group S1.

[0080] According to some embodiments, the sensing group S1 can be an acid-base value sensing group. The acid-base value sensing group can be used to detect the acid-base value (pH value) of the solution to be tested. When the working electrode W is affected by different pH values ​​in the solution to be tested, that is, when the solution has different hydrogen ion concentrations, the working electrode W can have different sensing voltage changes to detect the pH value of different solutions to be tested. More specifically, pH sensing can utilize the fact that when the sensing layer 3 comes into contact with the solution to be tested, hydrogen ions or hydroxide ions in the solution to be tested are adsorbed onto the surface of the sensing layer 3 (first sensing part 31). The first sensing part 31 in the sensing layer 3 can generate a surface potential change with the amount of hydrogen ions or hydroxide ions adsorbed, and by pre-calibrating with a solution of known acid-base value, the pH value of the solution to be tested can be detected. According to some embodiments, the first sensing part 31 can be a metal oxide, and when detected, hydrogen ions or hydroxide ions in the solution to be tested can be adsorbed onto the surface of the metal oxide. Furthermore, according to some embodiments, the surface of the first sensing part 31 can be modified with gold nanoparticles. In this case, the working electrode W can be used as a glucose sensing electrode and can be applied to glucose sensing.

[0081] like Figure 2D As shown in the cross-sectional view, the first insulating layer 4 is disposed on the working electrode W and the reference electrode R, and the first insulating layer 4 can partially cover the sensing layer 3 and the metal layer 2. More specifically, the first insulating layer 4 can partially cover the first sensing portion 31 and the second sensing portion 32 of the sensing layer 3, and partially cover the first metal portion 21 and the second metal portion 22 of the metal layer 2. In this way, the risk of electrode degradation caused by subsequent etching processes can be reduced. This can improve the accuracy of the liquid sensing device. According to some embodiments, the width W1 of the metal compound portion 6 can be smaller than the width W2 of the second metal portion 22. The term "partially cover" means that, in the normal direction Z of the substrate 1, the projection of the first insulating layer 4 on the substrate 1 can overlap with the projection portions of the sensing layer 3 and the metal layer 2 on the substrate 1. More specifically, the projection of the first insulating layer 4 on the substrate 1 can overlap with the projection portions of the first sensing portion 31 and the second sensing portion 32 of the sensing layer 3 on the substrate 1, and also overlap with the projection portions of the first metal portion 21 and the second metal portion 22 of the metal layer 2 on the substrate 1.

[0082] In addition, such as Figure 2C As shown, in the normal direction Z of the substrate 1, the first metal portion 21 has a first thickness T1, and a second thickness T2 is present between the bottom surface 61 of the metal compound portion 6 and the bottom surface 221 of the second metal portion 22. The second thickness T2 is 0.3 to 0.8 times thicker than the first thickness T1. When the second thickness T2 is greater than 0.8 times thicker than the first thickness T1, it indicates that the thickness of the metal compound portion 6 is small, resulting in a shorter lifespan for the liquid sensing device 100. When the second thickness T2 is less than 0.3 times thicker than the first thickness T1, it may affect the accuracy of pH value detection.

[0083] Furthermore, in the normal direction Z of the substrate 1, the metal compound portion 6 has a third thickness T3, wherein the third thickness T3 is 0.8 to 2.0 times thicker than the second thickness T2. When the third thickness T3 is greater than 2.0 times thicker than the second thickness T2, it indicates that the thickness of the metal compound portion 6 is relatively large. Since the metal compound portion 6 has a porous structure, it may lead to poor reliability. When the third thickness T3 is less than 0.8 times thicker than the second thickness T2, it may affect the reference accuracy of the reference electrode R.

[0084] In addition, such as Figures 1A-2D As shown, in one embodiment of this disclosure, before the step of forming the metal layer 2 on the substrate 1, a step of forming an adhesion layer 7 on the substrate 1 may be included. Therefore, the adhesion layer 7 can be formed between the substrate 1 and the metal layer 2. Next, the adhesion layer 7 is patterned to form a first adhesion portion 71 and a second adhesion portion 72. A first metal portion 21 is disposed on the first adhesion portion 71, and a second metal portion 22 is disposed on the second adhesion portion 72. Therefore, the first adhesion portion 71 is disposed between the substrate 1 and the first metal portion 21, and the second adhesion portion 72 is disposed between the substrate 1 and the second metal portion 22. According to some embodiments, the first adhesion portion 71 and the second adhesion portion 72 may be the same layer.

[0085] Furthermore, the materials of the adhesion layer 7 and the sensing layer 3 may be the same or different. When the adhesion layer 7 and the sensing layer 3 use the same material, the material and method can refer to the aforementioned section on sensing layer 3, and will not be repeated here. In one embodiment of this disclosure, the material of the adhesion layer 7 may be a metal oxide, such as indium tin oxide. When the material of the substrate 1 includes glass, there is a problem of poor adhesion between the metal layer 2 and the substrate 1, which may lead to deterioration such as peeling. The adhesion layer 7 can improve the adhesion between the substrate 1 and the metal layer 2 and reduce the deterioration.

[0086] like Figure 1A As shown, in addition to the sensing group S1, the liquid sensing device of this disclosure may also include a temperature sensing element S2 and / or a conductivity sensing electrode group S3 to detect the temperature and / or conductivity of the solution to be tested. Furthermore, the liquid sensing device 100 of this disclosure may also include multiple contact pads P, which are electrically connected to the sensing group S1, the temperature sensing element S2, and / or the conductivity sensing electrode group S3 via wires CL, respectively, so that external electronic components can be electrically connected to the liquid sensing device 100 through the contact pads P. The signal measured by the liquid sensing device can also be transmitted to external electronic components. In addition, although not shown in the figure, the liquid sensing device 100 of this disclosure may also include other components such as an antenna to provide various functions. In this disclosure, the wires CL and contact pads P may each include a metal layer 2 and a sensing layer 3, but this disclosure is not limited thereto. When the adhesion layer 7 includes a conductive metal oxide, the wires CL and contact pads P may also each include an adhesion layer 7.

[0087] Figures 3A to 3C This is a partial cross-sectional schematic diagram of a liquid sensing device according to an embodiment of the present disclosure. More specifically, Figure 3B for Figure 3A An enlarged view of the working electrode W. Figure 3C for Figure 3A A partially enlarged view of the reference electrode R. Among them, Figure 3A Liquid sensing devices and Figure 2D Similar, except for the following differences.

[0088] When the first insulating layer 4 is an organic material, its thickness can be from 2 μm to 15 μm. This relatively large thickness allows for a leveling effect. Figure 2D As shown. When the first insulating layer 4 is an inorganic material, the thickness of the first insulating layer 4 can be less than 1 μm, such as... Figure 3A As shown.

[0089] Furthermore, the same process can be used to pattern the sensing layer 3, the attachment layer 7, and the metal layer 2 to simplify the process steps. Therefore, the width of the first sensing portion 31, the width of the first attachment portion 71, and the width of the first metal portion 21 can be approximately equal. According to some embodiments, the width of the first attachment portion 71 can be 0.98 to 1.02 times the width of the first sensing portion 31, and the width of the first sensing portion 31 can be 0.98 to 1.02 times the width of the first metal portion 21. In one embodiment of this disclosure, as... Figure 3B As shown in the cross-sectional view, the first sensing part 31, the first metal part 21, and the first attachment part 71 may have a trapezoidal structure. For example, the width of the first attachment part 71 may be greater than the width of the first sensing part 31, and the width difference Wd between the first sensing part 31 and the first attachment part 71 may be less than or equal to 5 μm; however, this disclosure is not limited to this.

[0090] In addition, to reduce the risk of electrode degradation, in the cross-sectional view, such as Figure 3B and 3C As shown, the first insulating layer 4 can partially cover the sensing layer 3 and the metal layer 2. More specifically, the first insulating layer 4 can partially cover the first sensing portion 31 and the second sensing portion 32 of the sensing layer 3, and partially cover the first metal portion 21 and the second metal portion 22 of the metal layer 2. In other words, in the normal direction Z of the substrate 1, the projection of the first insulating layer 4 on the substrate 1 can partially overlap with the projections of the first metal portion 21 and the second metal portion 22 of the metal layer 2 on the substrate 1, and the width W3 of this partial overlap can be from 0.4 μm to 500 μm. In one embodiment of this disclosure, the working electrode W includes a surface 311. In the top view direction Z, the surface 311 has an edge 311a that extends along the direction Y, wherein the first insulating layer 4 can cover the edge 311a of the surface 311 of the working electrode W.

[0091] Figures 4A-4C This is a schematic diagram of a liquid sensing device according to an embodiment of the present disclosure. More specifically, Figure 4A This is a top view of a liquid sensing device according to an embodiment of the present disclosure. Figure 4B For along Figure 4A A cross-sectional diagram of line segment E-E'. Figure 4C For along Figure 4A Another cross-sectional view of line segment E-E'. Wherein, Figures 4A to 4C Liquid sensing devices and Figure 2D Similar to liquid sensing devices, and their detailed structure can be referenced. Figure 2D As shown, except for the following differences.

[0092] like Figure 4A and 4B As shown, during the fabrication process, multiple liquid sensing devices 100 can be simultaneously formed on a substrate. They are then separated by cutting along the cutting line L in a cutting step to obtain the liquid sensing device 100 described in this disclosure. Therefore, in this disclosure, as... Figure 4B As shown, the cut substrate 1 has a first sidewall 11, and the first insulating layer 4 has a second sidewall 41. The minimum distance D1 between the first sidewall 11 and the second sidewall 41 can be from 25 μm to 1000 μm. This reduces defects such as cracking caused by cutting. Figure 4A and Figure 4B This example only illustrates the formation of two liquid sensing devices 100 on a substrate, but in other embodiments of this disclosure, multiple liquid sensing devices 100 may be formed simultaneously on a substrate.

[0093] Furthermore, in another embodiment of this disclosure, such as Figure 4C As shown, before the step of forming the metal layer 2 on the substrate 1, a step of forming a second insulating layer 8 on the substrate 1 is included. Therefore, the liquid sensing device 100 of this disclosure further includes a second insulating layer 8 disposed between the substrate 1 and the working electrode W and the reference electrode R. More specifically, the second insulating layer 8 is disposed between the metal layer 2 or the adhesion layer 7 and the substrate 1. In this way, the adhesion between the substrate 1 and the metal layer 2 or the adhesion layer 7 can be increased, and the occurrence of peeling degradation can be reduced.

[0094] Furthermore, such as Figure 4CAs shown, in another embodiment of this disclosure, the step of forming a third insulating layer 9 under the substrate 1 may be further included. Therefore, the liquid sensing device 100 of this disclosure further includes a third insulating layer 9 disposed under the substrate 1, and the substrate 1 is disposed between the third insulating layer 9 and the working electrode W and the reference electrode R. More specifically, the third insulating layer 9 is disposed on the side 12 of the substrate 1 away from the working electrode W and the reference electrode R, and the substrate 1 is disposed between the metal layer 2 or the adhesion layer 7 and the third insulating layer 9. In this way, the third insulating layer 9 can serve as a protective layer under the substrate 1, reducing the ability of the substrate 1 to adsorb hydrogen ions or hydroxide ions, and improving the accuracy of pH value detection.

[0095] like Figure 4C As shown, in one embodiment of this disclosure, the liquid sensing device 100 may include both the second insulating layer 8 and the third insulating layer 9. However, this disclosure is not limited to this. In other embodiments of this disclosure, the liquid sensing device 100 may include only the second insulating layer 8 or the third insulating layer 9. Here, the materials of the second insulating layer 8 and the third insulating layer 9 may be as described in the first insulating layer 4, and will not be repeated here.

[0096] Figure 5 This is a top view of a liquid sensing device according to an embodiment of the present disclosure. Figure 5 Liquid sensing devices and Figure 1D Similar, except for the following differences.

[0097] like Figure 5 As shown, the liquid sensing device 100 of this disclosure may include a sensing group S1, a temperature sensing element (not shown), and a conductivity sensing electrode group S3. In a top-view direction Z, the working electrode W of the sensing group S1 may have an arc-shaped edge E1. According to some embodiments, the radius of curvature of the arc-shaped edge E1 may be from 25 μm to 250 μm, thus improving the accuracy of pH detection. When the radius of curvature of the arc-shaped edge E1 is greater than 250 μm, the area of ​​the working electrode W is small, which may reduce the accuracy of pH detection. When the radius of curvature of the arc-shaped edge E1 is less than 25 μm, the tip is more prone to accumulating charge and adsorbing impurities, which may affect the accuracy of pH detection. Similarly, in the top-view direction Z, the reference electrode R of the sensing group S1 may also have an arc-shaped edge to improve the accuracy of pH detection.

[0098] In this disclosure, the shapes of the working electrode W and the reference electrode R are not particularly limited and can be designed as needed. Furthermore, the conductivity sensing electrode assembly S3 includes at least two conductivity sensing electrodes S31, wherein the shape of the conductivity sensing electrodes S31 is not particularly limited; for example, it can be circular, rectangular, irregular, or a rectangle with curved edges. The areas of the two conductivity sensing electrodes S31 are approximately equal, and there is a predetermined distance D2 between the two conductivity sensing electrodes S31. The predetermined distance D2 divided by the area of ​​the conductivity sensing electrode S31 can be from 0.05 to 20.0 (cm²). -1 ).

[0099] In addition, the liquid sensing device disclosed herein can detect the basic properties of liquids such as acidity, alkaliness, temperature and / or conductivity, and can be applied to the detection of human body fluids (such as urine, sweat, tears, blood, bile, gastric juice, etc.), water quality sensing systems, such as water quality monitoring in aquaculture, wastewater monitoring in industrial effluent, quality monitoring of food or medicine, and concentration monitoring of chemicals used in factory manufacturing, etc.

[0100] In summary, this disclosure provides a liquid sensing device in which the working electrode and the reference electrode can be disposed on the same substrate. According to some embodiments, at least one layer (e.g., a metal layer) of the working electrode and the reference electrode can be the same layer, which can simplify the manufacturing process and improve the accuracy of the liquid sensing device.

[0101] The specific embodiments described above should be interpreted as merely illustrative and not as limiting the remainder of this disclosure in any way. Features of different embodiments may be combined and used in combination as long as they do not conflict with each other.

Claims

1. A liquid sensing device, comprising: a substrate; a working electrode disposed on the substrate, wherein the working electrode comprises a first metal portion and a first sensing portion, and the first sensing portion is disposed on the first metal portion; a reference electrode disposed on the substrate, wherein the reference electrode comprises a second metal portion and a metal compound portion, the metal compound portion is disposed on at least part of the second metal portion, and the first metal portion and the second metal portion are the same layer; a second sensing portion disposed on the second metal portion, wherein the first sensing portion and the second sensing portion are the same layer; a first adhesion portion disposed between the substrate and the first metal portion; and a second adhesion portion disposed between the substrate and the second metal portion; wherein the first adhesion portion and the second adhesion portion are the same layer, and the first adhesion portion and the second adhesion portion are metal oxide.

2. The liquid sensing apparatus of claim 1, wherein, The metal compound portion has a width smaller than a width of the second metal portion, and the metal compound portion comprises silver chloride, silver oxide, or a combination thereof.

3. The liquid sensing apparatus of claim 1, wherein, The first adhesion portion and the second adhesion portion comprise indium tin oxide.

4. The liquid sensing apparatus of claim 1, further comprising: a first insulating layer disposed on the working electrode, the working electrode comprises a surface having an edge, and the first insulating layer covers the edge of the surface of the working electrode. 5.The liquid sensing device of claim 1, further comprising a first insulating layer disposed on the working electrode, the substrate has a first sidewall, the first insulating layer has a second sidewall, and a minimum distance between the first sidewall and the second sidewall is 25 μm to 1000 μm.

6. The liquid sensing apparatus of claim 1, wherein, In a top view, the working electrode has an arc-shaped edge. 7.A method for manufacturing a liquid sensing device, comprising the following steps: providing a substrate; forming a metal layer on the substrate; patterning the metal layer to form a first metal portion and a second metal portion; forming a sensing layer on the substrate; patterning the sensing layer to form a first sensing portion and a second sensing portion, wherein the first sensing portion is disposed on the first metal portion, and the second sensing portion is disposed on the second metal portion; removing at least part of the second sensing portion to expose at least part of the second metal portion; reacting the at least part of the second metal portion to form a metal compound portion; and forming a working electrode comprising the first metal portion and a reference electrode comprising the second metal portion. 8.The method for manufacturing a liquid sensing device of claim 7, further comprising: before forming the metal layer, forming an adhesion layer on the substrate; patterning the adhesion layer to form a first adhesion portion and a second adhesion portion, wherein the first metal portion is disposed on the first adhesion portion, and the second metal portion is disposed on the second adhesion portion.

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