A multilayer potting structure for a high voltage sensor

Abstract

This utility model discloses a multi-layer potting structure for a high-voltage sensor, relating to the technical field of voltage sensor potting structures. It aims to solve the problem of electro-corrosion of IC devices caused by the aging of internal filling materials in existing sensors, ultimately leading to severe and unstable zero-point drift in the voltage sensor. The key technical solution includes a circuit board with components fixedly connected to its upper end. The components are coated with a conformal coating, and a silicone protective layer is fixedly connected to the outside of the conformal coating. A polytetrachloroethylene (PTFE) shell for protection is fixedly connected to the outside of the silicone protective layer, and a high-pressure epoxy adhesive layer is fixedly connected to the outside of the PTFE shell, achieving sufficient and multi-level protection.

Description

Technical Field

[0001] This utility model relates to the technical field of voltage sensor potting structure, and in particular to a multilayer potting structure for a high voltage sensor. Background Technology

[0002] As a key component in the main converter and auxiliary converter of locomotives and EMUs, the voltage sensor is mainly used to detect the DC bus voltage, AC output voltage or ground voltage, and send the detected voltage information to control units such as DCU or TCU for the logic control and calculation of the frequency converter. Due to various factors such as design, insulation materials, manufacturing, and application environment, the voltage sensor still has a relatively high failure rate in practical applications.

[0003] Because voltage sensors require the introduction of high voltage for testing and processing into a standard signal that can be isolated and used, both high-voltage and low-voltage terminals exist within the housing. Within the limited housing space of the sensor, sufficient insulation resistance needs to be ensured between the high and low voltage terminals. Therefore, insulating material needs to be filled into the housing of the voltage sensor.

[0004] The existing technical solutions mentioned above have the following defects: Under the harsh conditions of high voltage, the materials of the voltage sensor are very prone to change, which leads to electro-corrosion of the circuit components in the sensor and thus damage. The internal condition of the disassembled faulty voltage sensor shows that the aging of the filling material inside the sensor leads to electro-corrosion of the IC device, which ultimately causes serious zero-point drift of the voltage sensor and this drift is unstable. Utility Model Content

[0005] The purpose of this invention is to provide a multi-layer potting structure for a high-voltage sensor.

[0006] To achieve the above objectives, the present invention provides the following technical solution:

[0007] A multilayer potting structure for a high-voltage sensor includes a circuit board, on the upper end of which components are fixedly connected. The outer side of the components is coated with a conformal coating. A silicone protective layer is fixedly connected to the outer side of the conformal coating. A polytetrachloroethylene (PTFE) shell for protection is fixedly connected to the outer side of the silicone protective layer. A high-pressure epoxy adhesive layer is fixedly connected to the outer side of the PTFE shell.

[0008] By adopting the above technical solution and using multi-layer potting, high-voltage isolation is enhanced, and devices and circuit board traces are protected. The isolation shell is made of polytetrafluoroethylene to enhance electrical isolation capability, and various types of potting materials are used to achieve protection of devices and circuit board traces under high voltage.

[0009] Furthermore, the circuit board is fixedly connected to terminals at both ends, which are external connection ports for input signals, output signals, and power supply.

[0010] The above technical solution is used to facilitate the connection of wires, and is an external wiring port for input signals, output signals and power supply.

[0011] Furthermore, a high-voltage isolation slot is provided in the middle of the circuit board. The high-voltage isolation slot is used for electrical isolation between high voltage and low voltage or for electrical isolation between high voltage traces on the circuit board.

[0012] By adopting the above technical solution, high-voltage isolation slots are generally used for electrical isolation between strong and weak voltages, or for electrical isolation between strong voltage traces on a circuit board.

[0013] Furthermore, the conformal coating is used to protect the circuit board and components from environmental corrosion.

[0014] By adopting the above technical solution, conformal coating is a specially formulated coating used to protect circuit boards and devices from environmental corrosion. Conformal coating has good resistance to high and low temperatures. After curing, it forms a transparent protective film with superior insulation, moisture-proof, leakage prevention, shockproof, dustproof, corrosion-proof, aging-proof, and corona-resistant properties.

[0015] Furthermore, the polytetrachloroethylene shell is used to maintain stable electrical performance under high voltage conditions, preventing breakdown and leakage.

[0016] By adopting the above technical solution, the polytetrafluoroethylene shell is a high molecular polymer obtained by polymerization of tetrafluoroethylene as a monomer. The polytetrafluoroethylene shell has the characteristics of high voltage resistance. High-quality PTFE material can maintain stable electrical performance under high voltage environment and prevent breakdown and leakage.

[0017] Furthermore, the high-pressure epoxy adhesive layer is used to isolate higher voltages after curing.

[0018] By adopting the above technical solution, epoxy resin is a high molecular polymer, which refers to a class of polymers containing two or more epoxy groups in the molecule. Due to the chemical activity of epoxy groups, many compounds containing active hydrogen can react with it to open the ring, thereby curing and cross-linking to form a network structure. Therefore, it is a thermosetting polymer synthetic material. The cured epoxy resin colloid has high insulation strength and can isolate high voltage.

[0019] In summary, the beneficial technical effects of this utility model are as follows:

[0020] 1. Multi-layer potting with different protective materials is adopted to protect components from electrolytic corrosion under high voltage conditions and when the high-voltage potting compound ages, thus providing sufficient protection.

[0021] 2. One or more layers of polytetrafluoroethylene (PTFE) shell are used for electrical isolation protection, which enhances the electrical isolation capability, protects the performance and safety of the sensor, and produces an enhanced electrical isolation effect;

[0022] 3. Multi-layer potting is adopted, which enhances high-voltage isolation and protects devices and circuit board traces. The isolation shell is made of polytetrafluoroethylene to enhance electrical isolation capability, and various types of potting materials are used to achieve protection of devices and circuit board traces under high voltage, resulting in multiple protection effects. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the injection structure of this utility model;

[0024] Figure 2 This is a schematic diagram of the overall structure of this utility model.

[0025] In the diagram, 1 is the circuit board; 2 is the component; 3 is the conformal coating; 4 is the silicone protective layer; 5 is the polytetrachloroethylene shell; 6 is the high-voltage epoxy adhesive layer; 11 is the terminal block; and 12 is the high-voltage isolation groove. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to the accompanying drawings.

[0027] Reference Figure 1A multi-layer potting structure for a high-voltage sensor includes a circuit board 1, a component 2 fixedly connected to the upper end of the circuit board 1, a conformal coating 3 coated on the outside of the component 2, a silicone protective layer 4 fixedly connected to the outside of the conformal coating 3, a polytetrachloroethylene shell 5 fixedly connected to the outside of the silicone protective layer 4 for protection, and a high-pressure epoxy adhesive layer 6 fixedly connected to the outside of the polytetrachloroethylene shell 5. The conformal coating is a specially formulated coating used to protect the circuit board and components from environmental corrosion. The conformal coating has good high and low temperature resistance. After curing, it forms a transparent protective film with superior insulation, moisture resistance, leakage prevention, shock resistance, dust resistance, corrosion resistance, aging resistance, and corona resistance. Silica gel is a highly active adsorbent material, usually made by reacting sodium silicate with sulfuric acid and then undergoing a series of post-treatment processes such as aging and acid soaking. Silica gel is an amorphous substance, insoluble in water and any solvent, non-toxic and odorless, and chemically stable. Different types of silica gel form different microporous structures due to different manufacturing methods. Through the flexible treatment of silicone, the stress changes of epoxy resin can be absorbed by the flexibility of silicone when subjected to changes in the external environment. Terminals 11 are fixedly connected to both ends of the circuit board 1. Terminals 11 are external connection ports for input signals, output signals, and power supply. A high-voltage isolation groove 12 is opened in the middle of the circuit board 1. The high-voltage isolation groove 12 is used for electrical isolation between strong and weak voltages or between strong voltage traces on the circuit board. The conformal coating 3 is used to protect the circuit board and components from environmental corrosion. After curing, it forms a transparent protective film with excellent insulation, moisture resistance, leakage prevention, shock resistance, dust resistance, corrosion resistance, aging resistance, and corona resistance. It is used to protect the circuit board and related equipment from environmental corrosion. The polytetrachloroethylene shell 5 is used for... To maintain stable electrical performance under high voltage conditions and prevent breakdown and leakage, the polytetrafluoroethylene (PTFE) shell 5 is a high molecular polymer polymerized with tetrafluoroethylene as the monomer. The PTFE shell has properties such as high voltage resistance. High-quality PTFE material can maintain stable electrical performance under high voltage conditions and prevent breakdown and leakage. The high-voltage epoxy adhesive layer 6 is used to isolate higher voltages after curing. Epoxy resin is a high molecular polymer, which refers to a class of polymers containing two or more epoxy groups in the molecule. Due to the chemical activity of epoxy groups, many compounds containing active hydrogen can react with it to open the ring, thereby curing and cross-linking to form a network structure. Therefore, it is a thermosetting polymer synthetic material. The cured epoxy resin colloid has high insulation strength and can isolate higher voltages.

[0028] Reference Figure 2The upper part of circuit board 1 is equipped with a high-voltage divider module, a primary signal processing circuit, a secondary signal processing circuit, a signal transmission circuit, an isolation power supply module, and power and output ports. The high-voltage divider module divides the high-voltage signal into a smaller voltage signal, which is in principle less than 2V, through multiple resistors connected in series. This voltage signal is then sent to the operational amplifier for electrical signal processing. The primary signal processing circuit amplifies the low-voltage signal from the high-voltage divider module. Simultaneously, the secondary signal processing circuit standardizes the signal transmitted from the primary signal through the signal transmission circuit and transmits it to the customer through the port. At the terminal, the primary signal is transmitted to the secondary signal processing circuit through electrical isolation, such as optocoupler isolation, coil isolation, or amplifier isolation circuit. The isolation power supply module isolates and converts the input power signal into the required power signal. The isolation voltage is generally not less than 2000V and can be adjusted as needed. The power input signal of the power supply and output ports can be selected as needed, such as single power supply, dual power supply, 5V, 12V, 24V, ±15V, etc. The output port signal can be selected according to customer needs, with the value determined by the customer or by both parties.

[0029] The implementation principle of this embodiment is as follows: First, a conformal coating layer 3 is used to protect the component 2. The conformal coating layer 3 is a specially formulated coating used to protect the circuit board and components from environmental corrosion. The conformal coating has good high and low temperature resistance. After curing, it forms a transparent protective film with superior insulation, moisture resistance, leakage prevention, shock resistance, dust resistance, corrosion resistance, aging resistance, and corona resistance. Then, a silicone protective layer 4 is set on the outside of the conformal coating layer 3 for double protection. Silica gel is a highly active adsorbent material, usually made by reacting sodium silicate with sulfuric acid and then undergoing a series of post-treatment processes such as aging and acid soaking. Silica gel is an amorphous substance and is insoluble in water and any The solvent is non-toxic and odorless, with stable chemical properties. Different types of silicone have different microporous structures due to their different manufacturing methods. Through the flexible treatment of silicone, the stress changes of epoxy resin can be absorbed by the flexibility of silicone when subjected to changes in the external environment. A tetrachloroethylene shell 5 is set on the outside of the silicone protective layer 4 for high voltage protection. The tetrachloroethylene shell 5 is a high molecular polymer made by polymerization of tetrafluoroethylene as a monomer. The polytetrafluoroethylene shell has the characteristics of high voltage resistance. High-quality PTFE material can maintain stable electrical performance under high voltage environment, prevent breakdown and leakage, and ensure a good overall multi-layer protection effect.

[0030] The embodiments described herein are preferred embodiments of this utility model and are not intended to limit the scope of protection of this utility model. Therefore, all equivalent changes made to the structure, shape, and principle of this utility model should be included within the scope of protection of this utility model.

Claims

1. A multi-layer potting structure of a high voltage sensor comprising a wiring board (1), characterized by: The circuit board (1) is fixedly connected to the upper end of the component (2), the component (2) is coated with a three-proof paint layer (3), the three-proof paint layer (3) is fixedly connected to the outside of the silicone protective layer (4), the silicone protective layer (4) is fixedly connected to the outside of the polytetrachloroethylene shell (5) for protection, and the polytetrachloroethylene shell (5) is fixedly connected to the outside of the high-pressure epoxy adhesive layer (6).

2. The multi-layer potting structure of a high voltage sensor according to claim 1, characterized by: The circuit board (1) has terminals (11) fixedly connected to both ends. The terminals (11) are external connection ports for input signals, output signals and power supply.

3. The multi-layer potting structure of a high voltage sensor according to claim 1, characterized by: The circuit board (1) has a high-voltage isolation groove (12) in the middle. The high-voltage isolation groove (12) is used for electrical isolation between high voltage and low voltage or electrical isolation between high voltage traces on the circuit board.

4. The multi-layer potting structure of a high voltage sensor according to claim 1, characterized by: The conformal coating (3) is used to protect the circuit board and devices from environmental corrosion.

5. The multilayer potting structure of the high-voltage sensor according to claim 1, characterized in that: The polytetrachloroethylene shell (5) is used to maintain stable electrical performance under high voltage conditions and to prevent breakdown and leakage.

6. The multi-layer potting structure of a high voltage sensor according to claim 1, characterized by: The high-pressure epoxy adhesive layer (6) is used to isolate higher voltages after curing.

Images