Residual chlorine detection chip manufacturing method and residual chlorine detection module

Abstract

The invention discloses a manufacturing method of a residual chlorine detection chip and a residual chlorine detection module. The manufacturing method comprises the following steps: S1, coating photoresist on an insulating substrate 1; s2, performing exposure treatment on the insulating substrate 1 according to the shape of the electrode layer structure 2 to construct and form an electrode attachment area; s3, performing metal evaporation treatment on the insulating substrate 1 to form an electrode layer structure, wherein the electrode layer structure comprises a working electrode, a counter electrode, a first circuit L1, a second circuit L2, a first contact electrode and a second contact electrode; s4, removing the photoresist on the insulating substrate 1 by using a photoresist removing solution; s5, growing metal oxide on the working electrode, the counter electrode, the first contact electrode and the second contact electrode to form a passivation layer structure; s6, etching the passivation layer structure to obtain a first exposed structure, a second exposed structure and a third exposed structure; and S7, coating hydrogel to form a protective layer structure. In conclusion, the method has remarkable technical effects in the aspects of detection speed, precision, cost control and equipment service life.

Description

Technical Field

[0001] The present invention relates to the field of sensor technology, and in particular to a residual chlorine detection chip and a manufacturing method thereof. The present invention also relates to a residual chlorine detection module. Background Art

[0002] With the rapid development of my country's economy, environmental pollution is becoming increasingly serious, with water pollution being a particularly prominent issue. Chlorine disinfection, a widely used disinfection method in my country's waterworks, effectively kills harmful substances such as bacteria and viruses in the water, ensuring water quality safety. However, the chlorine disinfection process produces residual chlorine. Excessive residual chlorine levels can be harmful to the human body, while too low a level can be ineffective. Therefore, real-time monitoring of residual chlorine concentration is crucial for ensuring water quality safety.

[0003] There are currently two mainstream residual chlorine detection technologies. The first is the optical method: this method utilizes the fact that the hypochlorite generated by the reaction of residual chlorine with a chlorine-containing reagent absorbs light of a specific wavelength, thereby changing the color of the solution. By comparing the color difference between the standard solution and the sample to be tested, the residual chlorine content in the sample can be calculated; the second is the electrochemical method: this method determines the residual chlorine content in the sample by measuring the change in current between electrodes. Among them, the most commonly used is the current titration method, which applies a constant current between the electrodes. When the sample contains residual chlorine, a corresponding current change will occur. In the existing technology, the above-mentioned residual chlorine detection technology still has technical problems such as long response time and high detection cost.

[0004] Therefore, how to provide a method for manufacturing a residual chlorine detection chip that can overcome the above-mentioned technical problems, reduce detection costs, shorten response time, achieve rapid response, and improve service life and stability has become a technical problem that needs to be urgently solved by technical personnel in this field. Summary of the Invention

[0005] To solve the above technical problems, the present invention provides a method for manufacturing a residual chlorine detection chip and a residual chlorine detection module, which can use micro-nano technology to reduce the electrode size and improve the integration, thereby reducing the cost of a single sensor; shorten the response time, achieve rapid response, increase the test range, realize high-concentration residual chlorine detection, reduce electrode loss, and improve service life and stability.

[0006] The technical solutions provided by the present invention are as follows:

[0007] The present invention provides a method for manufacturing a residual chlorine detection chip, comprising:

[0008] S1: coating photoresist on an insulating substrate;

[0009] S2 performs exposure processing on the insulating substrate according to the shape of the electrode layer structure to form an electrode attachment area;

[0010] S3: performing metal evaporation processing on the insulating substrate to form an electrode layer structure, wherein the electrode layer structure includes: the working electrode, the counter electrode, the first circuit, the second circuit, the first contact electrode, and the second contact electrode;

[0011] S4 uses a degumming solution to remove the photoresist on the insulating substrate;

[0012] S5: growing a metal oxide on the working electrode, the counter electrode, the first contact electrode, and the second contact electrode to form a passivation layer structure;

[0013] S6: etching the passivation layer structure to obtain the first exposed structure, the second exposed structure, and the third exposed structure;

[0014] S7 is coated with hydrogel to form a protective layer structure.

[0015] Furthermore, in a preferred embodiment of the present invention, the insulating substrate is made of silicon oxide;

[0016] The process of coating the photoresist is a LOR+S1813 double-layer photoresist combination process.

[0017] Furthermore, in a preferred embodiment of the present invention, the exposure process is performed using a photolithography machine;

[0018] The metal evaporation process is to use an electron beam evaporation coating device to perform evaporation of one or more electrode materials selected from Ti / Au, Ti / Pt, Pt, and Au.

[0019] Furthermore, in a preferred embodiment of the present invention, “forming a passivation layer structure” specifically includes: using CVD equipment to grow metal oxide, a combination of one or more metal oxides, or epoxy resin glue on the surface to form the passivation layer structure.

[0020] Furthermore, in a preferred embodiment of the present invention, the etching process is specifically:

[0021] An ICP dry etching device is used to perform etching on the electrode layer structure to obtain the first exposed structure, the second exposed structure, and the third exposed structure, thereby forming a reaction area.

[0022] Furthermore, in a preferred embodiment of the present invention, the residual chlorine detection chip manufactured by the residual chlorine detection chip manufacturing method comprises:

[0023] Insulating substrate, working electrode, counter electrode, passivation layer structure, first contact electrode, second contact electrode, protective layer structure;

[0024] The working electrode and the counter electrode are disposed on the insulating substrate, with a space between the working electrode and the counter electrode; the first contact electrode is electrically connected to the working electrode via a first circuit; and the second contact electrode is electrically connected to the counter electrode via a second circuit;

[0025] The passivation layer structure is provided on the insulating substrate, and the passivation layer structure covers the working electrode, the counter electrode, the first contact electrode, and the second contact electrode;

[0026] The passivation layer structure is provided with a first exposed structure, a second exposed structure, and a third exposed structure, wherein the first exposed structure is provided on the working electrode; the second exposed structure is provided on the counter electrode; and the third exposed structure is provided on the first contact electrode and the second contact electrode;

[0027] The protection layer structure is arranged on the insulating substrate, and the protection layer structure covers the passivation layer structure.

[0028] Furthermore, in a preferred embodiment of the present invention, the first contact electrode and the second contact electrode are arranged side by side on one side of the region where the working electrode and the counter electrode are located;

[0029] The counter electrode is arranged in a wrapped shape outside the working electrode; the spacing space is a uniform spacing space;

[0030] The working electrode is a circular sheet structure, the counter electrode is a circular sheet structure wrapped around the outside of the working electrode, and the circular sheet structure has a gap (202a) for the first circuit to pass through;

[0031] The working electrode and the counter electrode are Ti / Au electrode structures; the Ti / Au electrode structure consists of a titanium substrate and a gold plating layer.

[0032] Furthermore, in a preferred embodiment of the present invention, the thickness of the working electrode and the counter electrode are both 20-1000 nm;

[0033] The thickness of the passivation layer structure is 300-1000 nm;

[0034] A ratio of an area of the first exposed structure to an area of the second exposed structure is greater than 1:2.

[0035] In addition, the present invention also relates to a residual chlorine detection module, comprising:

[0036] A residual chlorine detection chip manufactured by the above-mentioned residual chlorine detection chip manufacturing method;

[0037] PCB substrate;

[0038] The residual chlorine detection chip is arranged on the PCB substrate;

[0039] A detection rod is provided on the PCB substrate, and one end of the detection rod is located above the area where the working electrode and the counter electrode are located;

[0040] The PCB substrate is provided with a first substrate electrode electrically connected to the first contact electrode;

[0041] The PCB substrate is provided with a second substrate electrode electrically connected to the second contact electrode.

[0042] Furthermore, in a preferred embodiment of the present invention, the probe rod is an Ag-Agcl wire;

[0043] Silver dowsing rod;

[0044] The first substrate electrode is electrically connected to the first contact electrode via a conductive gold wire;

[0045] The second substrate electrode is electrically connected to the second contact electrode through a conductive gold wire.

[0046] The present invention provides a method for manufacturing a residual chlorine detection chip, comprising: S1 coating a photoresist on an insulating substrate; S2 exposing the insulating substrate according to the shape of an electrode layer structure to construct an electrode attachment area; S3 performing metal evaporation on the insulating substrate to form an electrode layer structure, wherein the electrode layer structure comprises: the working electrode, the counter electrode, the first circuit, the second circuit, the first contact electrode, and the second contact electrode; S4 using a degumming solution to remove the photoresist on the insulating substrate; S5 growing metal oxide on the working electrode, the counter electrode, the first contact electrode, and the second contact electrode to form a passivation layer structure; S6 etching the passivation layer structure to obtain the first exposed structure, the second exposed structure, and the third exposed structure; and S7 coating a hydrogel to form a protective layer structure. As described above, the present invention optimizes the design of the micropore array, reduces the electrode size and improves the mass transfer efficiency of the hydrogel layer through the above-mentioned technical means, thereby realizing real-time monitoring, covering the water quality detection needs in a higher concentration range, extending the service life of the electrode, effectively resisting sulfide corrosion and pollutant adhesion, reducing equipment maintenance costs, and improving detection accuracy and anti-interference capabilities. Through material innovation, structural optimization and process upgrades, significant technical effects are achieved in detection speed, accuracy, cost control and equipment life. In addition, the present invention also provides a residual chlorine detection module, which also has the above-mentioned technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0048] Figure 1 A process flow chart of a method for manufacturing a residual chlorine detection chip provided in an embodiment of the present invention;

[0049] Figure 2 A schematic diagram of the electrode layer structure provided by an embodiment of the present invention;

[0050] Figure 3 A schematic diagram of the exposed structure of the passivation layer structure provided in an embodiment of the present invention;

[0051] Figure 4 A schematic diagram of the coating area of the protective layer structure provided by an embodiment of the present invention;

[0052] Figure 5 A schematic diagram of a cross-sectional layer of a residual chlorine detection chip provided in an embodiment of the present invention;

[0053] Figure 6 A schematic diagram of the position of the notch of the counter electrode provided in an embodiment of the present invention;

[0054] Figure 7 This is a schematic structural diagram of the residual chlorine detection module provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0055] In order to enable those skilled in the art to better understand the technical solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. 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 those skilled in the art without making any creative efforts shall fall within the scope of protection of the present invention.

[0056] It should be noted that when an element is referred to as being “fixed on” or “set on” another element, it can be directly on the other element or indirectly set on the other element; when an element is referred to as being “connected to” another element, it can be directly connected to the other element or indirectly connected to the other element.

[0057] It should be understood that the terms "length", "width", "up", "down", "front", "back", "first", "second", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore cannot be understood as limiting the present invention.

[0058] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Thus, features defined as "first" or "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, "two or more" or "several" means two or more, unless otherwise specifically defined.

[0059] It should be noted that the structures, proportions, sizes, etc. depicted in the drawings of this specification are only used to match the contents disclosed in the specification so that people familiar with this technology can understand and read them. They are not used to limit the conditions under which the present invention can be implemented. Therefore, they have no substantive technical significance. Any structural modification, change in proportional relationship or adjustment of size should still fall within the scope of the technical content disclosed in the present invention without affecting the efficacy and purpose that can be achieved by the present invention.

[0060] like Figures 1 to 7As shown, the manufacturing method of the residual chlorine detection chip provided by the embodiment of the present invention includes: S1 coating photoresist on the insulating substrate 1; S2 exposing the insulating substrate 1 according to the shape of the electrode layer structure 2 to form an electrode attachment area; S3 performing metal evaporation treatment on the insulating substrate 1 to form an electrode layer structure 2, and the electrode layer structure 2 includes: the working electrode 201, the counter electrode 202, the first circuit L1, the second circuit L2, the first contact electrode 501, and the second contact electrode 502; S4 using a degumming solution to remove the photoresist on the insulating substrate 1; S5 growing metal oxide on the working electrode 201, the counter electrode 202, the first contact electrode 501, and the second contact electrode 502 to form a passivation layer structure 3; S6 etching the passivation layer structure 3 to obtain the first exposed structure 301, the second exposed structure 302, and the third exposed structure 303; S7 coating hydrogel to form a protective layer structure 4. As described above, the present invention optimizes the design of the micropore array, reduces the electrode size and improves the mass transfer efficiency of the hydrogel layer through the above-mentioned technical means, thereby realizing real-time monitoring, covering the water quality detection needs in a higher concentration range, extending the service life of the electrode, effectively resisting sulfide corrosion and pollutant adhesion, reducing equipment maintenance costs, and improving detection accuracy and anti-interference capabilities. Through material innovation, structural optimization and process upgrades, significant technical effects are achieved in detection speed, accuracy, cost control and equipment life. In addition, the present invention also provides a residual chlorine detection module, which also has the above-mentioned technical effects.

[0061] The technical solution of the present invention is described in detail below with reference to the embodiments:

[0062] Specifically, in the embodiment of the present invention, the material of the insulating substrate 1 is silicon oxide; the process of coating the photoresist is a LOR+S1813 double-layer photoresist combination process.

[0063] Specifically, in an embodiment of the present invention, the exposure process is performed using a photolithography machine;

[0064] The metal evaporation process is to use an electron beam evaporation coating device to perform evaporation of one or more electrode materials selected from Ti / Au, Ti / Pt, Pt, and Au.

[0065] Specifically, in the embodiment of the present invention, “forming the passivation layer structure 3 ” specifically includes: using CVD equipment to grow metal oxide, a combination of one or more metal oxides, or epoxy resin glue on the surface to form the passivation layer structure.

[0066] Specifically, in the embodiment of the present invention, the etching process is specifically:

[0067] An ICP dry etching device is used to perform etching on the electrode layer structure 2 to obtain the first exposed structure 301 , the second exposed structure 302 , and the third exposed structure 303 , thereby forming a reaction area.

[0068] Specifically, in an embodiment of the present invention, a residual chlorine detection chip A1 manufactured by the residual chlorine detection chip manufacturing method includes: an insulating substrate 1, a working electrode 201, a counter electrode 202, a passivation layer structure 3, a first contact electrode 501, a second contact electrode 502, and a protective layer structure 4; the working electrode 201 and the counter electrode 202 are arranged on the insulating substrate 1, and a separation space 6 is provided between the working electrode 201 and the counter electrode 202; the first contact electrode 501 is electrically connected to the working electrode 201 through a first circuit L1; the second contact electrode 502 is electrically connected to the counter electrode 202 through a second circuit L2;

[0069] The passivation layer structure 3 is provided on the insulating substrate 1 , and the passivation layer structure 3 covers the working electrode 201 , the counter electrode 202 , the first contact electrode 501 , and the second contact electrode 502 ;

[0070] A first exposed structure 301, a second exposed structure 302, and a third exposed structure 303 are arranged on the passivation layer structure 3, wherein the first exposed structure 301 is arranged on the working electrode 201; the second exposed structure 302 is arranged on the counter electrode 202; the third exposed structure 303 is arranged on the first contact electrode 501 and the second contact electrode 502; the protective layer structure 4 is arranged on the insulating substrate 1, and the protective layer structure 4 covers the passivation layer structure 3.

[0071] Specifically, in an embodiment of the present invention, the first contact electrode 501 and the second contact electrode 502 are arranged side by side on one side of the area where the working electrode 201 and the counter electrode 202 are located; the counter electrode 202 is arranged in a wrapped shape on the outside of the working electrode 201; the spacing space 6 is a uniform spacing space; the working electrode 201 is a circular sheet structure, and the counter electrode 202 is a circular sheet structure wrapped around the outside of the working electrode 201, and the circular sheet structure has a gap 202a for the first circuit L1 to pass through; the working electrode 201 and the counter electrode 202 are Ti / Au electrode structures; the Ti / Au electrode structure is composed of a titanium substrate and a gold plating layer.

[0072] Specifically, in the embodiment of the present invention, the thickness of the working electrode 201 and the counter electrode 202 are both 20-1000 nm;

[0073] The thickness of the passivation layer structure 3 is 300-1000 nm;

[0074] The ratio of the area of the first exposed structure 301 to the area of the second exposed structure 302 is greater than 1:2.

[0075] In addition, the present invention also relates to a residual chlorine detection module, comprising:

[0076] A residual chlorine detection chip A1 manufactured by the residual chlorine detection chip manufacturing method described above;

[0077] PCB substrate A2;

[0078] The residual chlorine detection chip A1 is arranged on the PCB substrate A2;

[0079] A probe rod 701 is provided on the PCB substrate A2, and one end of the probe rod 701 is located above the area where the working electrode 201 and the counter electrode 202 are located;

[0080] The PCB substrate A2 is provided with a first substrate electrode 702 electrically connected to the first contact electrode 501;

[0081] The PCB substrate A2 is provided with a second substrate electrode 703 electrically connected to the second contact electrode 502 .

[0082] Specifically, in the embodiment of the present invention, the detection rod 701 is a silver detection rod;

[0083] The first substrate electrode 702 is electrically connected to the first contact electrode 501 via a conductive gold wire;

[0084] The second substrate electrode 703 is electrically connected to the second contact electrode 502 via a conductive gold wire.

[0085] To be more specific, with the rapid development of my country's economy, environmental pollution problems are becoming increasingly serious, among which water pollution is particularly prominent. Chlorine disinfection, as a disinfection method commonly used by my country's tap water plants, can effectively kill bacteria, viruses and other harmful substances in the water to ensure water quality safety. However, residual chlorine will be produced during the chlorine disinfection process. Excessive residual chlorine will cause harm to the human body, and too low residual chlorine will not achieve the disinfection effect. Therefore, real-time monitoring of residual chlorine concentration is of great significance to ensure water quality safety.

[0086] Currently, there are two mainstream residual chlorine detection technologies. The first is the optical method: this method uses the fact that hypochlorite generated by the reaction of residual chlorine with chlorine-containing reagents absorbs light of a specific wavelength, thereby changing the color of the solution. By comparing the color difference between the standard solution and the sample to be tested, the residual chlorine content in the sample can be calculated. The second is the electrochemical method: this method determines the residual chlorine content in the sample by measuring the change in current between electrodes. Among them, the most commonly used method is the current titration method, that is, applying a constant current between the electrodes. When the sample contains residual chlorine, a corresponding current change will occur.

[0087] At present, the existing technology has the following technical problems, such as long response time: a single measurement takes 2 to 10 minutes, which cannot meet the needs of real-time monitoring; high cost of use: reagents need to be replaced regularly, about once a month, and the stability of the reagents is affected by temperature, such as high temperature accelerates decomposition; susceptibility to interference: high turbidity water samples need to rely on blank absorbance compensation, and complex water quality may affect accuracy.

[0088] It should be noted that the traditional electrochemical method is subject to electrode contamination and loss. During the use of the electrochemical sensor, the electrode may be contaminated by other chemicals in the sample, resulting in a decrease in electrode performance. Long-term use may also cause electrode loss, requiring regular replacement. The sensitivity of the traditional PT / IR alloy working electrode in sulfide-containing water decreases by 42% after 6 months. In the embodiment of the present invention, a micro-nano process is used to reduce the electrode size and improve the integration, thereby reducing the cost of a single sensor, significantly shortening the response time, achieving a fast response of <30S, increasing the test range, and realizing high-concentration residual chlorine detection; reducing electrode loss, and improving service life and stability.

[0089] In addition, considering that traditional sensors require frequent reagent replacement and are complex to maintain, the embodiment of the present invention has all-solid-state packaging and a zero-reagent consumption design, that is, a hydrogel layer replaces liquid reagents, a calibration curve adaptive algorithm, and a constant potentiostat that automatically compensates for electrode aging. The maintenance cycle is extended to 12 months, the on-site installation qualification rate is increased to 98%, and the long-term stability error is less than 3% / year. The solid-state packaging prevents environmental erosion, the reagent-free design eliminates dependence on consumables, and the algorithm compensation delays performance degradation, thereby realizing an "install and use" maintenance-free system.

[0090] This solution uses a three-electrode system, namely a working electrode, a counter electrode, and a reference electrode to detect residual chlorine. The functions of the three electrodes are as follows:

[0091] Working electrode: This is the electrode where the main electrochemical reaction occurs. When detecting residual chlorine, an oxidation-reduction reaction occurs on the working electrode. The residual chlorine CL2 is reduced to chloride ions CL- on the electrode, while releasing electrons.

[0092] Counter electrode: The counter electrode is also called auxiliary electrode. Its function is to provide a path for electrons to flow to complete the circuit.

[0093] Reference electrode: The reference electrode provides a stable potential reference point to ensure accurate potential measurement on the working electrode;

[0094] A constant voltage is applied to the working electrode through an external power supply. This voltage is sufficient to drive the reduction reaction of residual chlorine. Due to the redox reaction on the working electrode, electrons flow through the external circuit, generating current. There is a direct relationship between the current passing through the working electrode and the concentration of residual chlorine in the water. The measured current can be converted into the concentration of residual chlorine through the calibration curve.

[0095] It should be noted that traditional PT / IR alloy electrodes are susceptible to sulfide contamination, with a sensitivity drop of 42% in 6 months, and the cost of precious metals is high. The embodiment of the present invention uses a TI / AU composite electrode with a TI layer to enhance adhesion, a chemically inert AU layer, a silicon nitride passivation layer grown on the surface to physically isolate pollutants, and a hydrogel porous protective layer with a pore size of 10-500NM, which selectively filters large molecular impurities, thereby improving the electrode's resistance to sulfide corrosion and achieving a sensitivity attenuation of <10% in 6 months. In addition, the embodiment of the present invention reduces the amount of precious metals used and the micro-nano process reduces the thickness of the single electrode AU layer to 100-500NM, extending the electrode life to more than three times that of the traditional process. The AU substrate provides a stable conductive interface, the passivation layer blocks chemical corrosion, and the hydrogel layer physically intercepts pollutants. The three form a multi-protection system. In the embodiment of the present invention, a working electrode and a counter electrode are respectively made on a metal oxide or other insulating substrate by a micro-nano processing method. The electrode material is TI / AU, wherein TI is mainly used to increase adhesion. AU, as a metal with good stability and conductivity, hardly reacts with other materials and can maintain good reliability during use. At the same time, after the electrode processing is completed, a passivation layer is made on the electrode surface. The material is usually a resin such as a photoresist or other metal oxide. The passivation layer is formed on the working electrode and the counter electrode. The exposed area is formed on the surface of the electrode. 1. It is to control the area ratio of the working electrode and the counter electrode, usually above 1:2, to avoid electrode polarization; 2. It is to form dense and evenly distributed small holes on the surface of the working electrode to improve the reaction speed and reaction area of the chip, thereby improving the detection range of the chip for residual chlorine and shortening the response time; after completing the processing of the working electrode and the counter electrode, a protective layer is spin-coated on the surface of the chip, usually a hydrogel or other porous material. By controlling the pore size and thickness of the hydrogel, the selectivity and stability are improved; after the hydrogel coating is completed, the core is first coated with photoresist on an insulating substrate such as silicon oxide, usually with LOR+S 1813, then use a photolithography machine to expose to form an electrode pattern; then use an electron beam evaporation coating instrument to evaporate metal TI / AU, usually with a thickness of 20-1000nm, and use a debonding solution to remove the photoresist after coating, thereby forming a metal electrode of a specific shape on the silicon oxide wafer, a working electrode and a counter electrode, and use a CVD device to grow a metal oxide on the surface, usually silicon nitride, or directly use photoresist, as a passivation layer, usually with a thickness of 300-1000nm, and use an ICP dry etching device to etch specific areas of the electrode to remove the passivation layer grown in the previous step and open windows to form reaction areas; the prepared hydrogel is spin-coated onto the wafer surface;The wafer is then diced using a dicing machine to obtain individual residual chlorine chips. The chips are then attached to a designed PCB for gold wire bonding. AG / AGCL wire is then soldered to the PCB as a reference electrode. The chip is then encapsulated using epoxy resin or other encapsulation glue to create a dam, exposing the working electrode, counter electrode, and reference electrode. The bonding area is then protected and the chip is bonded to the PCB. Gold wire bonding is performed for encapsulation, and AG / AGCL wire is soldered to the PCB as a reference electrode.

[0096] In summary, the solution involved in the embodiment of the present invention is processed using micro-nano technology, the size of a single electrode is about 4*6MM, and about 400 chips can be manufactured on a 4-inch wafer. The processing process is simple, and only two photolithography operations are required. The traditional process usually requires 4-5 photolithography operations and one coating operation, which greatly reduces the cost of micro-nano processing. Small and dispersed windows are made on the working electrode to avoid polarization while controlling the area ratio of the working electrode and the counter electrode, and to increase the test range, facilitate the rapid diffusion of residual chlorine to the surface of the working electrode, and accelerate the response. At the same time, precious metals are used as electrode materials, and a porous protective film is coated to extend the service life of the electrode, which has significant technical effects.

[0097] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for manufacturing a residual chlorine detection chip, characterized in that: The method includes: S1 coating a photoresist on an insulating substrate (1); S2 performs exposure processing on the insulating substrate (1) according to the shape of the electrode layer structure (2) to form an electrode attachment area; S3: performing metal evaporation processing on the insulating substrate (1) to form an electrode layer structure (2), the electrode layer structure 2 comprising: the working electrode (201), the counter electrode (202), the first circuit (L1), the second circuit (L2), the first contact electrode (501), and the second contact electrode (502); S4: using a degumming solution to remove the photoresist on the insulating substrate (1); S5: growing a metal oxide on the working electrode (201), the counter electrode (202), the first contact electrode (501), and the second contact electrode (502) to form a passivation layer structure (3); S6: etching the passivation layer structure (3) to obtain the first exposed structure (301), the second exposed structure (302), and the third exposed structure (303); S7 coats the hydrogel to form a protective layer structure (4).

2. The method for preparing a residual chlorine detection chip according to claim 1, wherein The insulating substrate (1) is made of silicon oxide; The process of coating the photoresist is a LOR+S1813 double-layer photoresist combination process.

3. The method for preparing a residual chlorine detection chip according to claim 1, wherein The exposure process is performed using a photolithography machine; The metal evaporation process is to use an electron beam evaporation coating device to perform evaporation of one or more electrode materials selected from Ti / Au, Ti / Pt, Pt, and Au.

4. The method for producing a residual chlorine detection chip according to claim 1, wherein “Forming a passivation layer structure (3)” specifically includes: A CVD device is used to grow metal oxide, a combination of one or more metal oxides, or epoxy resin glue on the surface to form a passivation layer structure (3).

5. The method for producing a residual chlorine detection chip according to claim 4, wherein: The etching process is specifically as follows: Using ICP dry etching equipment, etching is performed on the electrode layer structure (2) to obtain the first exposed structure (301), the second exposed structure (302), and the third exposed structure (303), thereby forming a reaction area.

6. The method for manufacturing a residual chlorine detection chip according to any one of claims 1 to 5, wherein: The residual chlorine detection chip (A1) manufactured by the residual chlorine detection chip manufacturing method comprises: Insulating substrate (1), working electrode (201), counter electrode (202), passivation layer structure (3), first contact electrode (501), second contact electrode (502), and protective layer structure (4); The working electrode (201) and the counter electrode (202) are arranged on the insulating substrate (1), and a space (6) is provided between the working electrode (201) and the counter electrode (202); the first contact electrode (501) is electrically connected to the working electrode (201) via a first circuit (L1); and the second contact electrode (502) is electrically connected to the counter electrode (202) via a second circuit (L2); The passivation layer structure (3) is arranged on the insulating substrate (1), and the passivation layer structure (3) covers the working electrode (201), the counter electrode (202), the first contact electrode (501), and the second contact electrode (502); The passivation layer structure (3) is provided with a first exposed structure (301), a second exposed structure (302), and a third exposed structure (303); the first exposed structure (301) is provided on the working electrode (201); the second exposed structure (302) is provided on the counter electrode (202); and the third exposed structure (303) is provided on the first contact electrode (501) and the second contact electrode (502); The protective layer structure (4) is arranged on the insulating substrate (1), and the protective layer structure (4) covers the passivation layer structure (3).

7. The method for manufacturing a residual chlorine detection chip according to claim 6, wherein: The first contact electrode (501) and the second contact electrode (502) are arranged in parallel on one side of the area where the working electrode (201) and the counter electrode (202) are located; The counter electrode (202) is arranged in a wrapped shape outside the working electrode (201); the spacing space (6) is a uniform spacing space; The working electrode (201) is a circular sheet structure, and the counter electrode (202) is a circular sheet structure wrapped around the outside of the working electrode (201), and the circular sheet structure has a notch (202a) for the first circuit (L1) to pass through; The working electrode (201) and the counter electrode (202) are Ti / Au electrode structures; the Ti / Au electrode structure consists of a titanium substrate and a gold plating layer.

8. The method for producing a residual chlorine detection chip according to claim 6, wherein: The thickness of the working electrode (201) and the counter electrode (202) are both 20-1000 nm; The thickness of the passivation layer structure (3) is 300-1000 nm; The ratio of the area of the first exposed structure (301) to the area of the second exposed structure (302) is greater than 1:

2.

9. A residual chlorine detection module, characterized in that: include: A residual chlorine detection chip (A1) manufactured by the residual chlorine detection chip manufacturing method according to any one of claims 1 to 8; PCB substrate (A2); The residual chlorine detection chip (A1) is arranged on the PCB substrate (A2); A probe rod (701) is provided on the PCB substrate (A2), and one end of the probe rod (701) is located above the area where the working electrode (201) and the counter electrode (202) are located; The PCB substrate (A2) is provided with a first substrate electrode (702) electrically connected to the first contact electrode (501); A second substrate electrode (703) electrically connected to the second contact electrode (502) is provided on the PCB substrate (A2).

10. The residual chlorine detection module according to claim 9, characterized in that: The probe rod (701) is an Ag-Agcl wire; The first substrate electrode (702) is electrically connected to the first contact electrode (501) via a conductive gold wire; The second substrate electrode (703) is electrically connected to the second contact electrode (502) via a conductive gold wire.

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