An on-line analyzer for sulfite in electroplating gold bath solution

Abstract

An embodiment of the present application provides an on-line analyzer for sulfite in electroplating gold bath solution, which relates to the field of chemical detection equipment. An on-line analyzer for sulfite in electroplating gold bath solution includes a chassis, and a multi-channel valve group, a reaction cup, an injection pump, a dual-wavelength colorimetric sensor, a peristaltic pump and a two-way three-way solenoid valve are installed inside the chassis. A stirring mechanism is built in the reaction cup and is connected to the multi-channel valve group through a pipeline. The injection pump is connected to the reaction cup via an independent pipeline and is used to control and add iodine titrant to the reaction cup. Through the integrated application of the multi-channel valve group, the reaction cup, the injection pump, the dual-wavelength colorimetric sensor, the peristaltic pump and the two-way three-way solenoid valve, the present invention realizes the full-process automated operation from automatic sampling to analysis, not only greatly saving labor costs and reducing human errors, but also ensuring the consistency and reliability of the analysis results, and can monitor and adjust the sulfite concentration in real time, thereby optimizing the process stability and resource utilization efficiency.

Description

Technical Field

[0001] This application relates to the technical field of chemical detection equipment, and more particularly, to an on-line analyzer for sulfite in electroplating gold bath solution. Background Art

[0002] The cyanide-free gold plating process is widely used in fields such as aerospace, PCB, electronic products, industrial equipment, communication equipment, semiconductor laser devices, and wafer packaging. Gold plating modification of the surfaces of metals, non-metals, and composite materials can improve the corrosion resistance, wear resistance, conductivity, solderability, heat resistance, etc. of products. The sulfite system for gold plating has excellent performance, high efficiency, environmental protection, and significant economic benefits. As an important component in the electroplating gold solution, sulfite has a significant impact on the properties such as the uniformity, glossiness, and adhesion of the electroplated layer. However, during the electroplating process, sulfite will be continuously consumed due to oxidation or the use of the electroplating solution, resulting in an imbalance in the composition of the electroplating solution. If it cannot be added and maintained in a timely manner, the quality of the plating layer will decline, affecting the qualification rate of products.

[0003] Relying on manual periodic analysis of the sulfite content using chemical titration method, directly adding the consumption amount according to the analysis result, and controlling it within the process range, which depends on the experience of the operator and manual operation, will cause large fluctuations in the sulfite concentration in the electroplating gold solution, affecting the electroplating quality and increasing the operation difficulty and labor cost. Summary of the Invention

[0004] This application aims to at least solve the technical problem in the prior art that relies on manual periodic analysis of the sulfite content using chemical titration method, directly adding the consumption amount according to the analysis result, and controlling it within the process range, which depends on the experience of the operator and manual operation, will cause large fluctuations in the sulfite concentration in the electroplating gold solution, affecting the electroplating quality and increasing the operation difficulty and labor cost. For this reason, this application proposes an on-line analyzer for sulfite in electroplating gold bath solution.

[0005] An on-line analyzer for sulfite in electroplating gold bath solution according to an embodiment of this application includes a chassis. Inside the chassis, a multi-channel valve group, a reaction cup, an injection pump, a dual-wavelength colorimetric sensor, a peristaltic pump, and a two-way three-way solenoid valve are installed. A magnetic stirrer is installed inside the reaction cup and is connected to the multi-channel valve group through a pipeline. The injection pump is connected to the reaction cup via an independent pipeline and is used to control and add iodine titrant to the reaction cup. The dual-wavelength colorimetric sensor forms a closed loop with the reaction cup through a circulation pipeline. The peristaltic pump is installed on the circulation pipeline between the reaction cup and the dual-wavelength colorimetric sensor. The two-way three-way solenoid valve is arranged on the pipeline between the reaction cup and the peristaltic pump.

[0006] Further, a touch screen interface is installed on one side of the chassis.

[0007] Further, the multi-channel valve group sequentially introduces accurately metered samples, starch indicator, and pure water into the reaction cup in a predetermined order, and evenly mixes all components through a stirring mechanism.

[0008] Further, the height of the chassis is 600 mm, the width is 450 mm, and the depth is 1750 mm.

[0009] Further, the chassis supports Ethernet TCP / IP network communication and uploads analysis data, chemical addition records, and alarm information according to the Modbus protocol.

[0010] The beneficial effects of this application are as follows: By using a multi-channel valve group, reaction cup, injection pump, dual-wavelength colorimetric sensor, peristaltic pump, and two-way three-way solenoid valve, the entire process of automatic sampling to automatic analysis is realized, and the whole analysis process can be completed without manual intervention. This not only greatly saves labor costs but also reduces the influence of human factors on the analysis results, improves work efficiency and stability. The sample analysis is carried out according to a preset program, and the concentration analysis result is automatically judged by a high-precision colorimetric sensor. Compared with traditional manual analysis methods, this method reduces operation errors, ensures the consistency and reliability of analysis results, and helps to maintain the stability of production process parameters. Since it can achieve high-frequency automatic analysis, this device can monitor the concentration change of sulfite in the production process in real time and quickly adjust the chemical addition amount accordingly, avoiding waste caused by excessive addition and preventing process instability caused by insufficient addition.

[0011] Additional aspects and advantages of this application will be given in part in the following description, become apparent in part from the following description, or be understood through the practice of this application. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings required for use in the embodiments of this application will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as limiting the scope. For those of ordinary skill in the art, other related drawings can also be obtained based on these drawings without creative efforts.

[0013] Figure 1 is the front view of the overall electroplating gold bath sulfite on-line analyzer according to the embodiment of this application;

[0014] Figure 2 is the side view schematic diagram of the overall structure according to the embodiment of this application;

[0015] Figure 3 is the schematic diagram of the detection process according to the embodiment of this application;

[0016] Figure 4 Schematic diagram of a colorimetric probe adopting post - spectroscopic technology according to an embodiment of the present application Figure 1 ;

[0017] Figure 5 Schematic diagram of a colorimetric probe adopting post - spectroscopic technology according to an embodiment of the present application Figure 2 。

[0018] Icons: 1. Chassis; 2. Touch screen interface; 3. Multi - channel valve group; 4. Reaction cup; 5. Syringe pump; 6. Dual - wavelength colorimetric sensor; 7. Peristaltic pump; 8. Two - way three - way solenoid valve. Detailed implementation manners

[0019] Next, the technical solutions in the embodiments of the present application will be described with reference to the accompanying drawings in the embodiments of the present application.

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0021] Therefore, the detailed description of the embodiments of the present application provided in the accompanying drawings is not intended to limit the scope of the present application claimed, but merely represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present application without creative efforts shall fall within the protection scope of the present application.

[0022] It should be noted that: like reference numerals and letters denote similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0023] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present application.

[0024] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of this application, "a plurality of" means two or more unless otherwise specifically defined.

[0025] In this application, unless otherwise clearly specified and defined, terms such as "installed", "connected", "linked", "fixed", etc. shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal connection of two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0026] In this application, unless otherwise clearly specified and defined, the first feature being "on" or "under" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over" and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "under", "beneath" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0027] The following describes an on-line analyzer for sulfite in a gold electroplating bath according to an embodiment of the present application with reference to the accompanying drawings.

[0028] As Figures 1 - 3 shown, an on-line analyzer for sulfite in a gold electroplating bath according to an embodiment of the present application includes a chassis 1. The chassis 1 is a sheet metal painted chassis, with a height of 600 mm, a width of 450 mm, and a depth of 1750 mm.

[0029] A touch screen interface 2 is installed on the front of the chassis 1. The touch screen interface 2 provides an intuitive platform for users to interact with the on-line sulfite analysis device. Through the touch screen interface 2, users can conveniently set analysis parameters, start or stop the analysis process, adjust system settings, etc., and view the status and results of the analysis process in real time, including information such as the currently ongoing analysis steps, the change trend of solution concentration, and the system operation status. This helps to timely understand the working conditions of the device and make a quick response when necessary.

[0030] As Figure 3As shown in the figure, a multi-channel valve group 3, reaction cups 4, an injection pump 5, a dual-wavelength colorimetric sensor 6, a peristaltic pump 7, and a two-way three-way solenoid valve 8 are installed inside the chassis 1. The multi-channel valve group 3 has a seven-in-one-out structure for the groove solution, reagents, pure water, and standard sample injection for switching sampling. The reaction cups 4 are internally equipped with magnetic stirrers and are connected to the multi-channel valve group 3 through pipelines. The reaction cups 4 are containers for the titration reaction of the groove solution and reagents. The injection pump 5 is connected to the reaction cups 4 via an independent pipeline and is used to control and add iodine titrant to the reaction cups 4 to accurately add the titrant.

[0031] The dual-wavelength colorimetric sensor 6 forms a closed loop with the reaction cups 4 through a circulation pipeline, continuously measures the solution undergoing titration reaction in the reaction cups 4, and outputs the actual result as an electrical signal. The peristaltic pump 7 is installed on the circulation pipeline between the reaction cups 4 and the dual-wavelength colorimetric sensor 6, continuously operates during the titration reaction to provide real-time solution for the dual-wavelength colorimetric sensor 6, and can discharge waste at the end of the titration. The two-way three-way solenoid valve 8 is set on the pipeline between the reaction cups 4 and the peristaltic pump 7. When titrating, the normally open end is enabled to circulate the dual-wavelength colorimetric sensor 6, and when the titration ends, the normally closed end is switched to drain the waste liquid in the reaction cups 4.

[0032] Specifically, the accurately volumetric sample enters the reaction cups 4 from the multi-channel valve group 3, the starch indicator enters the reaction cups 4 from the multi-channel valve group 3, and pure water enters the reaction cups 4 from the multi-channel valve group 3, taking into account adding the remaining sample or indicator in the entire multi-channel valve group 3 into the reaction cups 4. The stirring mechanism works to volumetrically fix the groove solution and stir it evenly. The peristaltic pump 7 is turned on to keep the solution color in the reaction cups 4 and the solution color in the dual-wavelength colorimetric sensor 6 changing synchronously. The injection pump 5 starts to work and slowly adds iodine titrant until the signal of the dual-wavelength colorimetric sensor 6 shows that the color change stops. The sulfite concentration is calculated based on the volume recorded by the injection pump 5. The normally closed end of the two-way three-way solenoid valve 8 is opened, the peristaltic pump 7 is turned on to drain the waste liquid in the reaction cups 4, the multi-channel valve group 3 is washed with water, the two-way three-way solenoid valve 8 is switched to the normally open state, the peristaltic pump 7 is turned on to clean the inside of the reaction cups 4 and the dual-wavelength colorimetric sensor 6, the normally closed end of the two-way three-way solenoid valve 8 is opened, the peristaltic pump 7 is turned on to drain the waste liquid in the reaction cups 4, and the number of cleaning times can be set.

[0033] Among them, the device uses the titration method, determines whether the titration end point is reached according to the developed colorimetric probe, and then accurately calculates the concentration of sulfite ions. The automatic sampling, automatic analysis, and automatic dosing control of the entire system are realized through the PLC program.

[0034] Specifically, the main principle of the titration method is as follows:

[0035] The principle of iodine titrating sulfite is based on an oxidation-reduction reaction, in which iodine ( ) acts as an oxidizing agent to oxidize sulfite ions ( ) is oxidized to sulfate ions ( ), while iodine itself is reduced to iodide ions ( ). At the end point of the reaction, the excess iodine combines with the starch indicator to form a dark blue complex, indicating the completion of the titration. The specific analysis is as follows:

[0036] Reaction mechanism and equation

[0037] Main reaction: In acidic or neutral solution, sulfite ions ( ) react with iodine ( ) in an oxidation-reduction reaction.

[0038] Oxidation process: Loses 2 electrons and is oxidized to .

[0039] Reduction process: Gains 2 electrons and is reduced to .

[0040] Balanced ionic equation:

[0041]

[0042] The corresponding molecular equation is:

[0043]

[0044] The core of this reaction is the interaction between the reducibility of sulfite and the oxidizing property of iodine.

[0045] Endpoint indication principle:

[0046] The starch indicator is added near the end point. When the sulfite in the solution is completely oxidized, a slight excess of iodine will combine with the starch to form a dark blue starch-iodine complex, with a sensitivity of up to .

[0047] This instrument uses a visible light wavelength (400 - 700 nm) sensor. After passing through the titration solution, it can convert the concentration signal of the starch-iodine complex into an electrical signal to judge the end point of the reaction.

[0048] Endpoint judgment principle of the dual-wavelength colorimetric sensor 6:

[0049] Dual-wavelength spectrophotometry

[0050] Its main principle is: The same incident light (composite light source) passes through a sample to be measured with a concentration of C and a cell width of B. After the light beam passes through two different filters, two receivers receive two different wavelengths of monochromatic light (PrimaryWavelength, main wavelength, also called measurement wavelength) and (second Wavelength, reference wavelength), if and are properly selected, light scattering and background absorption can be ignored, measurement accuracy can be improved, and interference can be eliminated by selecting a filter, thereby improving selectivity. From Lambert-Beer's law, it can be derived that:

[0051] (1)

[0052] (2)

[0053] (3)

[0054] , are the incident light intensity and the transmitted light intensity of the sample to be measured, , are the incident light intensity and the transmitted light intensity of the reference sample. From equation (3), it can be obtained that: the ion concentration in the sample to be measured has a linear relationship with the or lg( ) of the two wavelengths.

[0055] By selecting appropriate reference wavelength and measurement wavelength, the drop at the end point of the titrant can be accurately judged, thereby obtaining the titration volume and calculating the concentration of the analyte.

[0056] Figure 4 and Figure 5 In, the composite light source: can be any light source that can provide white light, such as an LED or a tungsten lamp.

[0057] Sample cell: The container for placing the sample, with a width of 2 - 10 mm, and quartz is preferably used as the material, and glass can also be used.

[0058] Monochromatic filter 1: Obtain monochromatic light of the reference wavelength .

[0059] Monochromatic filter 2: Obtain monochromatic light of the reference wavelength .

[0060] Photoelectric signal converter 1: Receive the signal and convert it into an electrical signal for output.

[0061] Photoelectric signal converter 2: Receive the signal and convert it into an electrical signal for output.

[0062] Sample flow inlet: The sample enters the sample cell through this.

[0063] Sample flow outlet: Samples are discharged from the sample cell through this opening.

[0064] Signal output interface: The measured signal.

[0065] The chassis 1 supports Ethernet TCP / IP network communication and uploads analysis data, chemical dosing records, and alarm information according to the Modbus protocol. Through the built-in Ethernet interface, the chassis 1 can be connected to the existing local area network or wide area network to achieve connection with the enterprise internal network or other external systems. This networking function allows remote access and control of the device, enabling operators to monitor and manage the device from a location far away from the device. The TCP / IP protocol is a family of Internet protocols used for data exchange in a network. Using the TCP / IP protocol can ensure that data packets are accurately transmitted in a complex network environment, providing stable and reliable network communication. Modbus is a serial communication protocol widely used in the field of industrial automation. It is simple and open, and easy to implement. By adopting the Modbus protocol, the online sulfite analyzer can be seamlessly docked with other devices or systems that support this protocol (such as PLC, SCADA systems, etc.), facilitating integration into a larger industrial control system.

[0066] The above are only the embodiments of the present application and are not used to limit the protection scope of the present application. For those skilled in the art, various changes and modifications can be made to the present application. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application. It should be noted that similar reference numerals and letters represent similar items in the following drawings. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0067] The above is only the specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed by the present application, and all of them should be covered by the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An on-line analyzer for sulfite in an electroplating gold bath solution, characterized in that: It includes a chassis (1), inside which a multi-channel valve group (3), reaction cups (4), an injection pump (5), a dual-wavelength colorimetric sensor (6), a peristaltic pump (7) and a two-way three-way solenoid valve (8) are installed. A magnetic stirrer is built into the reaction cup (4) and is connected to the multi-channel valve group (3) through pipelines. The injection pump (5) is connected to the reaction cup (4) via an independent pipeline and is used to control and add iodine titrant into the reaction cup (4). The dual-wavelength colorimetric sensor (6) forms a closed loop with the reaction cup (4) through a circulation pipeline. The peristaltic pump (7) is installed on the circulation pipeline between the reaction cup (4) and the dual-wavelength colorimetric sensor (6). The two-way three-way solenoid valve (8) is arranged on the pipeline between the reaction cup (4) and the peristaltic pump (7).

2. The on-line analyzer for sulfite in the gold electroplating bath solution according to claim 1, wherein: A touch screen interface (2) is installed on one side of the chassis (1).

3. The online sulfite analyzer for electroplating gold bath solution according to claim 2, characterized in that: The multi-channel valve group (3) sequentially introduces accurately volumetric samples, starch indicator and pure water into the reaction cup (4) in a predetermined order and evenly mixes all components through a stirring mechanism.

4. The on-line sulfite analyzer for gold electroplating bath solution according to claim 3, characterized in that: The height of the chassis (1) is 600 mm, the width is 450 mm, and the depth is 1750 mm.

5. The on-line sulfite analyzer for electroplating gold bath solution according to claim 4, characterized in that: The chassis (1) supports Ethernet TCP / IP network communication and uploads analysis data, drug addition records and alarm information according to the Modbus protocol.

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