Water meter waterproof method

Abstract

The invention discloses a waterproof method for a water meter. The waterproof method comprises the following steps: optimizing a structural layout; according to the water meter installation environment, all key components are arranged on one face of a PCB in a centralized mode, the face is defined as a face A, and the other face of the PCB is defined as a face B; performing thick potting protection on the A surface; constructing a metal foil layer on the surface B; and carrying out thin potting sealing on the surface B. The metal foil is additionally arranged, an ideal water vapor barrier can be provided, the problem of water vapor permeation of the water meter in a long-term soaking environment is solved, the potting layer and the metal foil layer are compounded to form a gas-proof and water-proof barrier difficult to permeate, and the protection efficiency of the gas-proof and water-proof barrier is far better than that of a technical scheme purely depending on the potting layer. The scheme of large-area metal foil covering and a small amount of potting materials has the optimal comprehensive performance in the water meter application environment, and the protection effect, cost control and process maturity are optimally balanced.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of instrument waterproof process, more specifically, it relates to a kind of water meter waterproof method. BACKGROUND

[0002] Intelligent water meter has water flow channel inside, and the main control board of PCB and the electronic control components mounted on PCB is worked in the small environment of greater humidity for a long time, and the reliable sealing of main control board is directly related to the service life and measurement accuracy of water meter, so waterproof is a basic requirement for intelligent water meter.Potting process is a kind of waterproof means commonly used in existing intelligent water meter product, but traditional potting process faces severe challenges in water meter application: although silicone potting has certain waterproof property, but silicone itself has high air permeability, which cannot effectively block water vapor penetration, and is easy to cause component corrosion failure in long-term immersion environment; epoxy resin potting needs to reach a large thickness to ensure sealing reliability, but this is directly contradictory to the limited internal cavity space and lightweight design requirements of water meter. SUMMARY

[0003] The existing intelligent water meter waterproof process still has various defects, or the waterproof effect is poor due to the congenital deficiency of waterproof material, or the amount of waterproof material and waterproof capacity are difficult to achieve ideal balance, in order to overcome these defects, the present application provides a kind of water meter waterproof method, which improves the comprehensive performance of waterproof material without significantly increasing the amount of waterproof material, and greatly enhances the waterproof capacity.

[0004] The technical scheme of the present application is: a kind of water meter waterproof method, comprising the following steps: Step one. Optimize structure layout; all key components are concentrated and arranged on one side of PCB according to water meter installation environment, and the side is defined as A side, and the other side of PCB is defined as B side; Step two. Thick potting protection is carried out on A side; Step three. Metal foil layer is constructed on B side; Step four. Thin potting sealing is carried out on B side.

[0005] Metal foil layer itself is absolutely dense, completely impermeable to water vapor, and water molecules cannot penetrate, which can completely block water molecule penetration in long-term immersion environment.The present application uses large-area metal foil layer combined with thin-layer epoxy resin to significantly improve the protection performance while reducing the total thickness.A side thick potting is relative to B side, since the composite structure of B side greatly improves the performance, the actual thickness of A side also does not need to maintain the thickness of prior art, and can be thinned on the basis of conventional thickness.

[0006] Preferably, the thickness of the potting layer in step two is controlled to be 2.5-3.0 mm.

[0007] Preferably, the thickness of the potting layer in step four is controlled to be 1.3-1.5 mm.

[0008] Preferably, the material used for potting in step two and step four is epoxy resin. Epoxy resin is resistant to hydrolysis and has excellent adhesion to metal, and is a material suitable for water meter working conditions.

[0009] Alternatively, the material used for potting in step four is a combination of polyimide and polyurethane. Polyimide is also a flexible material with extremely low permeability, and can form an effective bond with polyurethane sealant. Without considering factors such as overall mechanical strength and process maturity, it can also be used as an alternative to the epoxy resin-copper foil combination.

[0010] Preferably, the metal foil layer in step three is pre-treated by a gold plating process. The use of a gold plating process for surface treatment of the metal foil layer ensures that the surface of the metal foil layer is clean and free of oxidation.

[0011] Alternatively, the metal foil layer in step three is pre-treated by a tin plating process. The use of a tin plating process for surface treatment also ensures that the surface of the metal foil layer is clean and free of oxidation.

[0012] Preferably, in step four, the potting material not only covers the B face of the PCB, but also forms a climbing and wrapping on the side of the PCB. If the side of the PCB is not protected, water vapor may still penetrate from the edge of the side of the PCB, so when potting, it is ensured that the potting material not only covers the B face, but also covers the side of the PCB, effectively protecting the edge of the PCB.

[0013] Preferably, the metal foil layer in step three is a copper foil layer. Copper foil can provide a smooth and uniform plane, allowing the shrinkage stress of the potting material covering it to be evenly distributed, greatly reducing the probability of internal micro-cracks, and producing excellent adhesion between the epoxy resin and the copper foil, thereby forming a strong composite structure. Copper foil also provides excellent tensile strength and modulus, improving the tensile, bending and impact resistance of the composite structure.

[0014] Alternatively, the metal foil layer in step three is an aluminum foil layer. Aluminum foil has properties similar to copper foil, but at a lower cost.

[0015] The beneficial effects of the present application are: Overall protection performance is improved. The present application adds a metal foil layer, which provides an ideal water vapor barrier and solves the problem of water vapor penetration in a long-term immersion environment for water meters. The combination of the potting layer and the metal foil layer forms a difficult-to-penetrate air and water barrier, and its protection performance is much better than that of a technical solution that relies solely on a potting layer.

[0016] The thickness and weight of waterproof materials are significantly reduced. By using a composite method of potting layer and metal foil layer, the waterproof requirements can be achieved without an excessively thick potting layer. The amount of potting material used is greatly reduced, and the overall weight is also reduced accordingly. This greatly meets the design requirements of lightweight and thin equipment, while also improving cost-effectiveness.

[0017] The waterproof structure enhances mechanical reliability. The composite structure of the potting layer and metal foil layer in this invention can effectively resist stress changes caused by water pressure fluctuations, and its impact resistance can meet the mechanical requirements during water meter installation and use, ensuring reliability under varying water pressure environments.

[0018] Excellent overall performance. The solution proposed in this invention, which combines large-area metal foil coverage with a small amount of potting material, exhibits optimal overall performance in water meter applications, achieving the best balance in terms of protection effect, cost control, and process maturity. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of a general integrated control module for water meters in this invention.

[0020] In the diagram, 1-main control board, 2-general integrated control module, 3-side A. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0022] Example 1: A water meter waterproofing method is disclosed for use in ordinary residential buildings. The water meter is a smart water meter, requiring power supply and control by a main control board 1. The main control board 1 includes a PCB and key components such as a flow sensor, microprocessor, and communication module mounted on and electrically connected to the PCB. These key components play a crucial role in the normal operation of the smart water meter. The power supply and main control board 1 are centrally installed within a general-purpose integrated control module 2. Figure 1 As shown. The installation environment of water meters in ordinary residential buildings is relatively stable, but daily water use can lead to high humidity inside the water meter, and occasional water immersion may occur. For this application scenario, the waterproof performance of the water meter is crucial. It must ensure that the components are not damaged by water vapor penetration during long-term use, while also meeting the requirements of being lightweight and thin for easy installation and maintenance.

[0023] The waterproofing method for this water meter includes the following steps: Step 1: Optimize the structural layout. Optimize the structure of the PCB inside the water meter, concentrating all key components on one side of the PCB, which is defined as side A3; the other side of the PCB has few or no components, which is defined as side B. This layout facilitates subsequent waterproofing.

[0024] Step Two: Apply a thick potting compound to surface A. Epoxy resin is selected as the potting compound, and the potting layer thickness is controlled at 2.5mm. During the potting process, ensure that the epoxy resin evenly covers all critical components on surface A, forming a robust protective layer. The potting process is carried out in a professional cleanroom using vacuum potting equipment to prevent impurities from contaminating the potting material and affecting the waterproof effect, and to ensure that no air bubbles form between the epoxy resin and surface A. After the potting compound has cured, the critical components on surface A are effectively protected and can resist a certain degree of moisture erosion.

[0025] Step 3: Construct a metal foil layer on side B. Select copper foil as the metal foil layer material and pre-treat it with an immersion gold process. Immersion gold processing can improve the copper foil's oxidation resistance and electrical properties, and enhance its effect as a moisture barrier. Precisely attach the treated copper foil to side B of the PCB, ensuring a tight bond between the copper foil and the PCB without gaps.

[0026] Step 4: Apply a thin potting sealant to side B. Epoxy resin is again used as the potting compound, with the potting layer thickness controlled at 1.3mm. During the potting process, the potting material not only covers side B of the PCB but also forms a coating and wrap around the sides of the PCB, further enhancing the waterproof effect. The complete copper foil provides an extremely smooth and uniform plane, allowing the shrinkage stress of the epoxy resin to be evenly distributed, greatly reducing the probability of internal micro-cracks. Excellent adhesion is generated between the epoxy resin and the copper foil, forming a robust composite structure. The copper foil provides excellent tensile strength and modulus, while the epoxy resin provides support and chemical protection. The tensile, bending, and impact resistance of this epoxy resin-copper foil composite structure far exceeds that of a simple epoxy resin layer, making it less prone to cracking due to external impact or internal stress. Therefore, the thin potting layer and the metal foil layer work together to form a complete waterproof structure, greatly enhancing the mechanical reliability of this waterproof structure.

[0027] The stability and reliability of the bonding interface between the metal foil layer and the thin potting compound layer on surface B is the core issue for the implementation of this invention: the reliability of the entire protection system ultimately depends on the strength of the bonding interface between the epoxy resin and the copper foil. Therefore, before formally implementing this water meter waterproofing method, it is necessary to select an epoxy potting compound with excellent adhesion to metal and conduct bonding strength tests and thermal cycling tests to ensure that the bonding interface will not peel off under harsh environments.

[0028] Water meters treated with the above waterproofing method were observed to have excellent waterproofing performance after one year of use in ordinary residential buildings. No component corrosion or failure due to moisture penetration was observed, and all functions of the water meters operated normally. Compared to traditional single-layer potting processes, this method, while meeting waterproofing requirements, reduces the overall weight of the water meter by approximately 20% and its thickness by less potting material, better meeting the installation needs of thinner and lighter water meters in residential buildings. Furthermore, the composite structure of the potting layer and the metal foil layer enhances the water meter's impact resistance, ensuring the integrity of the waterproof structure even under certain external impacts during daily use.

[0029] Example 2: A water meter waterproofing method is disclosed for use in high-rise commercial buildings. The water meter is a smart water meter, requiring power supply and control operation by a main control board 1. The main control board 1 includes a PCB and key components such as a flow sensor, microprocessor, and communication module mounted on the PCB and electrically connected to it. These key components play a crucial role in the normal operation of the smart water meter. The power supply and main control board 1 are centrally installed within a general-purpose integrated control module 2. Water usage in high-rise commercial buildings is complex, and the water meter may face significant water pressure fluctuations. Furthermore, due to the needs of commercial activities, there are stricter restrictions on the size and weight of the water meter, requiring it to be both lightweight and possess highly reliable waterproof performance.

[0030] The waterproofing method for this water meter includes the following steps: Step 1: Optimize the structural layout. Optimize the structure of the PCB inside the water meter, concentrating all key components on one side of the PCB, which is defined as side A3; the other side of the PCB has few or no components, which is defined as side B. This layout maximizes space utilization and creates favorable conditions for subsequent waterproofing.

[0031] Step Two: Apply a thick potting seal to surface A. Epoxy resin is used for potting. Unlike Example 1, the potting layer thickness is set to 2.8mm in this example to enhance the protection of critical components under fluctuating water pressure. During the potting process, temperature and curing time are strictly controlled to ensure the quality and uniformity of the potting layer, enabling it to effectively resist stress caused by water pressure changes. The potting process is carried out in a professional cleanroom using vacuum potting equipment to prevent impurities from contaminating the potting material and affecting the waterproof effect, and to ensure that no air bubbles are generated between the epoxy resin and surface A. After the potting compound has cured, the critical components on surface A are effectively protected and can resist a certain degree of moisture erosion.

[0032] Step 3: Construct a metal foil layer on side B. Select copper foil as the metal foil layer material and pre-treat it with an immersion gold process. Immersion gold processing can improve the copper foil's oxidation resistance and electrical properties, and enhance its effect as a moisture barrier. Precisely attach the treated copper foil to side B of the PCB, ensuring a tight bond between the copper foil and the PCB without gaps.

[0033] Step 4: Apply a thin potting seal to side B. Epoxy resin is again used as the potting compound, but unlike Example 1, the potting layer thickness is 1.4 mm. During the potting process, the potting layer not only covers side B of the PCB but also forms a coating and wrap around the sides of the PCB, further enhancing the waterproof effect. The complete copper foil provides an extremely smooth and uniform plane, allowing the shrinkage stress of the epoxy resin to be evenly distributed, greatly reducing the probability of internal microcracks. Excellent adhesion is generated between the epoxy resin and the copper foil, forming a robust composite structure. The copper foil provides excellent tensile strength and modulus, while the epoxy resin provides support and chemical protection. The tensile, bending, and impact resistance of this epoxy resin-copper foil composite structure far exceeds that of a simple epoxy resin layer, and it is less prone to cracking due to external impact or internal stress. Therefore, the thin potting layer and the metal foil layer work together to form a complete waterproof structure, which also greatly enhances the mechanical reliability of the waterproof structure, enabling it to meet waterproof requirements while adapting to water pressure fluctuations.

[0034] The stability and reliability of the bonding interface between the metal foil layer and the thin potting compound layer on surface B is the core issue for the implementation of this invention: the reliability of the entire protection system ultimately depends on the strength of the bonding interface between the epoxy resin and the copper foil. Therefore, before formally implementing this water meter waterproofing method, it is necessary to select an epoxy potting compound with excellent adhesion to metal and conduct bonding strength tests and thermal cycling tests to ensure that the bonding interface will not peel off under harsh environments.

[0035] The water meters installed in high-rise commercial buildings have demonstrated excellent waterproof performance after six months of use. Even with frequent water pressure fluctuations, the internal components of the water meters remained unaffected by moisture and maintained normal operation. Thanks to the waterproofing method of this invention, the overall weight and thickness of the water meters have been effectively controlled, meeting the requirements of commercial buildings for lightweight and thin water meters. Simultaneously, the composite structure of the potting layer and the metal foil layer greatly enhances the mechanical reliability of the water meters, enabling them to withstand a certain degree of impact and vibration, and adapting to the complex installation and usage environment of commercial buildings.

[0036] Example 3: A waterproofing method for water meters is disclosed, applied to rural centralized water supply systems. The water meter is a smart water meter, requiring power supply and control by a main control board 1. The main control board 1 includes a PCB and key components such as a flow sensor, microprocessor, and communication module mounted on and electrically connected to the PCB. These key components play a crucial role in the normal operation of the smart water meter. The power supply and main control board 1 are centrally installed within a general-purpose integrated control module 2. The installation environment of water meters in rural centralized water supply systems can be harsh, with the meters potentially exposed to humid outdoor environments for extended periods and even susceptible to natural disasters such as floods. Furthermore, rural areas are cost-sensitive regarding water meters, necessitating cost reduction while ensuring waterproofing performance.

[0037] The waterproofing method for this water meter includes the following steps: Step 1: Optimize the structural layout. Optimize the structure of the PCB inside the water meter, concentrating all key components on one side of the PCB, which is defined as side A3; the other side of the PCB has few or no components, which is defined as side B. This layout facilitates subsequent waterproofing.

[0038] Step Two: Apply a thick potting seal to surface A. Epoxy resin is selected as the potting material. Unlike Example 1, the potting layer thickness is controlled at 3.0 mm in this example to enhance the waterproof protection of key components in harsh environments. During the potting process, automated potting equipment is used to ensure the accuracy and quality of the potting, so that the potting layer evenly covers the components on surface A.

[0039] Step 3: Construct a metal foil layer on side B. Unlike Example 1, this example uses relatively cheaper aluminum foil as the metal foil layer material and performs a tin-plating surface treatment. Tin-plated aluminum foil has good oxidation resistance and conductivity, and can better block moisture. The aluminum foil is precisely adhered to side B of the PCB, ensuring a tight bond between the aluminum foil and the PCB.

[0040] Step 4: Apply a thin potting seal to side B. Epoxy resin is still used as the potting material, but unlike Example 1, the potting layer thickness is 1.5 mm in this example. The intact copper foil provides an extremely smooth and uniform plane, allowing the shrinkage stress of the epoxy resin to be evenly distributed, greatly reducing the probability of internal microcracks. Excellent adhesion is generated between the epoxy resin and the copper foil, thus forming a robust composite structure. Therefore, the thin potting layer and the metal foil layer work together to form a complete waterproof structure, meeting waterproof requirements while minimizing the amount of potting material used and reducing costs.

[0041] The stability and reliability of the bonding interface between the metal foil layer and the thin potting compound layer on surface B is the core issue for the implementation of this invention: the reliability of the entire protection system ultimately depends on the strength of the bonding interface between the epoxy resin and the copper foil. Therefore, before formally implementing this water meter waterproofing method, it is necessary to select an epoxy potting compound with excellent adhesion to metal and conduct bonding strength tests and thermal cycling tests to ensure that the bonding interface will not peel off under harsh environments.

[0042] Water meters treated with this waterproofing method in rural centralized water supply systems have successfully withstood the tests of humid environments and floods after more than a year of practical use. No corrosion or damage was observed in the internal components, ensuring the normal operation of the water meters. Compared with traditional potting processes, this method significantly improves waterproofing performance without significantly increasing costs by optimizing the potting layer thickness and adding a metal foil layer. Due to the reduction in the amount of potting material used, costs are reduced by approximately 15%, simultaneously meeting the dual requirements of waterproofing and cost-effectiveness in rural water meters.

[0043] Example 4: A water meter waterproofing method is disclosed for use in industrial plants. The water meter is a smart water meter, requiring power supply and control by a main control board 1. The main control board 1 includes a PCB and key components such as a flow sensor, microprocessor, and communication module mounted on and electrically connected to the PCB. These key components play a crucial role in the normal operation of the smart water meter. The power supply and main control board 1 are centrally installed within a general-purpose integrated control module 2. Figure 1 As shown. The water environment in industrial plants is complex; water meters may come into contact with various chemicals. Furthermore, industrial production places extremely high demands on the accuracy and reliability of water meters, and their waterproof performance must be reliable to ensure long-term stable operation. In addition, industrial plants typically have specific space requirements for water meter installation, necessitating a slim and lightweight design.

[0044] The waterproofing method for this water meter includes the following steps: Step 1: Optimize the structural layout. Optimize the structure of the PCB inside the water meter, concentrating all key components on one side of the PCB, which is defined as side A3; the other side of the PCB has few or no components, which is defined as side B. This layout facilitates subsequent waterproofing.

[0045] Step Two: Apply a thick potting seal to surface A. Epoxy resin is used as the potting material, with a potting layer thickness of 2.6mm. During the potting process, ensure that the epoxy resin evenly covers all critical components on surface A, forming a robust protective layer. The potting process is carried out in a professional cleanroom using vacuum potting equipment to prevent impurities from contaminating the potting material and affecting the waterproof effect, and to ensure that no air bubbles are formed between the epoxy resin and surface A. After the potting compound has cured, the critical components on surface A are effectively protected and can resist a certain degree of moisture erosion. In addition, during the potting process, a special formula for the epoxy resin is adjusted to increase its chemical corrosion resistance, addressing potential chemical corrosion issues in industrial environments.

[0046] Step 3: Construct a metal foil layer on side B. Select copper foil as the metal foil layer material and pre-treat it with an immersion gold process. Immersion gold on the copper foil not only provides excellent moisture barrier properties but also enhances its resistance to chemical corrosion. Tightly adhere the copper foil to side B of the PCB, using a special process to ensure a good electrical connection between the copper foil and the PCB, while preventing moisture penetration through the joint.

[0047] Step 4: Apply a thin potting seal to side B. Unlike Example 1, this example uses a combination of polyimide and polyurethane as the potting material, with a potting layer thickness of 1.3 mm. This potting material has a double-layer composite structure, with a polyurethane layer as the bottom layer bonded to a metal foil layer, and then covered with an impermeable polyimide layer. While ensuring waterproof performance, it also possesses good flexibility and chemical resistance, adapting to the special requirements of industrial environments. During the potting process, ensure the potting material fully covers and encapsulates the sides of the PCB, forming a comprehensive waterproof barrier. The intact copper foil provides an extremely smooth and uniform plane, allowing the shrinkage stress of the polyurethane layer to be evenly distributed, greatly reducing the probability of internal micro-cracks, thus forming a robust composite structure with good adhesion between the polyurethane layer and the copper foil. The copper foil provides excellent tensile strength and modulus, while the potting layer provides support and chemical protection. The tensile, bending, and impact resistance of this potting layer-copper foil composite structure far exceeds that of a simple potting layer, and it is less prone to cracking due to external impact or internal stress.

[0048] The stability and reliability of the bonding interface between the metal foil layer and the thin potting compound layer on surface B is the core issue for the implementation of this invention: the reliability of the entire protection system ultimately depends on the strength of the bonding interface between the epoxy resin and the copper foil. Therefore, before formally implementing this water meter waterproofing method, it is necessary to select an epoxy potting compound with excellent adhesion to metal and conduct bonding strength tests and thermal cycling tests to ensure that the bonding interface will not peel off under harsh environments.

[0049] Water meters installed and used in industrial plants, after a year of operation, were re-evaluated and found to exhibit excellent waterproof performance. Even after contact with some corrosive chemicals, the internal components of the water meters continued to function normally without any damage. Thanks to the waterproofing method of this invention, the water meters achieve a slim and lightweight design while meeting waterproofing requirements, facilitating installation and maintenance in the limited space of industrial plants. Maintenance personnel also reported that the reliability of the water meters has been greatly improved, reducing the number of production interruptions caused by water meter failures and increasing production efficiency.

Claims

1. A method for waterproofing water meters, characterized in that, Includes the following steps: Step 1. Optimize the structural layout; for the water meter installation environment, concentrate all key components on one side of the PCB and define this side as side A, and define the other side of the PCB as side B; Step 2. Apply a thick potting seal to surface A for protection; Step 3. Construct a metal foil layer on side B; Step 4. Apply a thin potting seal to side B.

2. The water meter waterproofing method according to claim 1, characterized in that, In step two, the thickness of the potting layer is controlled between 2.5 and 3.0 mm.

3. The water meter waterproofing method according to claim 1, characterized in that, In step four, the thickness of the potting layer is controlled between 1.3 and 1.5 mm.

4. The water meter waterproofing method according to claim 1, characterized in that, The potting material used in steps two and four is epoxy resin.

5. The water meter waterproofing method according to claim 1, characterized in that, The potting material used in step four is a combination of polyimide and polyurethane.

6. The water meter waterproofing method according to claim 1, characterized in that, In step three, the metal foil layer undergoes a surface treatment process involving immersion gold.

7. The water meter waterproofing method according to claim 1, characterized in that, In step three, the metal foil layer undergoes a surface treatment process involving tin plating.

8. The water meter waterproofing method according to claim 1, characterized in that, In step four, the potting material not only covers the B side of the PCB, but also forms a coating and wrapping on the side of the PCB.

9. The water meter waterproofing method according to any one of claims 1 to 8, characterized in that, The metal foil layer in step three is a copper foil layer.

10. The water meter waterproofing method according to any one of claims 1 to 8, characterized in that, The metal foil layer in step three is an aluminum foil layer.

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