NTC (Negative Temperature Coefficient) temperature sensor and electric appliance with NTC temperature sensor

Abstract

The utility model relates to the technical field of NTC (Negative Temperature Coefficient) temperature sensors, in particular to an NTC temperature sensor and an electric appliance with the NTC temperature sensor. The NTC temperature sensor comprises a metal shell, an NTC thermosensitive chip, a first lead and a water absorption expansion material layer. One end of the first lead is electrically connected with the NTC thermosensitive chip; the NTC thermosensitive chip is packaged in one end of the metal shell through the first packaging layer; the water absorption expansion material layer is mounted in the metal shell and seals the first packaging layer; the other end of the first lead is led out from the first packaging layer and the water absorption expansion material layer. The water-absorbing expansion material layer is made of a material which can cause expansion after absorbing water, the water-absorbing expansion material layer seals the first packaging layer, so that the NTC thermosensitive chip can be further sealed, meanwhile, the water-absorbing expansion material layer expands after absorbing water, and when water vapor invades, the water-absorbing expansion material layer further expands, so that the NTC thermosensitive chip can be further sealed. Therefore, the sealing performance of the water-absorbing expansion material layer is improved, and the waterproof and moistureproof performance of the NTC temperature sensor is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of NTC temperature sensors, in particular to an NTC temperature sensor and an electrical appliance with the NTC temperature sensor. Background Art

[0002] An NTC (Negative Temperature Coefficient) temperature sensor, also known as a thermistor sensor, is a temperature-sensing element made of semiconductor ceramic materials. Its resistance decreases as temperature increases, making it widely used in temperature measurement and control.

[0003] NTC temperature sensors are used to measure temperature in a variety of environments, and their use is complex and varied. Whether used in appliances like smart toilets, smart bathtubs, and air conditioners, or in new energy charging stations and charging guns, waterproofing is a requirement.

[0004] Current waterproof NTC temperature sensors are being packaged with various sealing materials to prevent moisture intrusion. This design can block most moisture intrusion, but over long-term use, due to temperature fluctuations and differences in the expansion coefficients of various materials, there is a risk of gaps forming. While the probability of this occurring is extremely low, NTC temperature sensors can fail due to small amounts of moisture intrusion during mass production. Therefore, there is an urgent need to further improve the waterproof and moisture-proof performance of NTC temperature sensors. Utility Model Content

[0005] The embodiments of the present utility model provide an NTC temperature sensor and an electrical appliance having the NTC temperature sensor, thereby improving the waterproof and moisture-proof performance of the NTC temperature sensor.

[0006] The utility model discloses an NTC temperature sensor, comprising a metal shell, an NTC thermistor chip, a first lead and a water-swelling material layer; one end of the first lead is electrically connected to the NTC thermistor chip; the NTC thermistor chip is encapsulated in one end of the metal shell through a first encapsulation layer; the water-swelling material layer is installed in the metal shell and seals the first encapsulation layer; the other end of the first lead is led out from the first encapsulation layer and the water-swelling material layer.

[0007] Optionally, the water-swellable material layer includes a water-swellable rubber sheet and / or a water-swellable resin sheet.

[0008] Optionally, the water-swellable material layer includes a water-swellable rubber sheet and two water-swellable resin sheets stacked together; the water-swellable rubber sheet is disposed between the two water-swellable resin sheets.

[0009] Optionally, the water-swellable material layer further includes two resin gaskets, one of which is arranged on a side of the water-swellable resin sheet away from the water-swellable rubber sheet, and the other resin gasket is arranged on a side of the other water-swellable resin sheet away from the water-swellable rubber sheet.

[0010] Optionally, the inner wall of the metal shell is provided with latching protrusions corresponding to the two resin gaskets respectively, and the edge of the resin gasket is provided with a groove corresponding to the latching protrusions; the latching protrusions are latched on the resin gaskets.

[0011] Optionally, the first encapsulation layer includes a first epoxy resin encapsulation layer, a silicone resin encapsulation layer and a second epoxy resin encapsulation layer;

[0012] The first epoxy resin encapsulation layer encapsulates the NTC thermistor chip, the silicone resin encapsulation layer is wrapped around the surface of the first epoxy resin encapsulation layer, and the second epoxy resin encapsulation layer encapsulates the silicone resin encapsulation layer and the NTC thermistor chip and fills the internal space of the metal shell where the NTC thermistor chip is located.

[0013] Optionally, in the metal housing, a side of the two resin gaskets away from the NTC thermistor chip is filled with a third epoxy resin packaging layer.

[0014] Optionally, the NTC temperature sensor further includes a second lead, one end of the second lead is electrically connected to the first lead, and the other end of the second lead is led out from the third epoxy resin packaging layer.

[0015] Optionally, there are two first leads, the resin gasket is provided with two oppositely arranged arc holes, and the water-swellable rubber sheet and the water-swellable resin sheet are both provided with two oppositely arranged openings; the two first leads are respectively led out from the two arc holes and the two openings.

[0016] The utility model also discloses an electrical appliance with an NTC temperature sensor. The electrical appliance includes the NTC temperature sensor as described above.

[0017] Compared with the prior art, the beneficial effect of the NTC temperature sensor provided by the embodiment of the present invention is that: the NTC temperature sensor of the present invention is provided with a water-absorbing and expanding material layer on one side of the first packaging layer inside the metal shell. The water-absorbing and expanding material layer is made of a material that will expand after absorbing water. The water-absorbing and expanding material layer seals the first packaging layer, thereby further sealing the NTC thermistor chip. At the same time, since the water-absorbing and expanding material layer expands after absorbing water, the water-absorbing and expanding material layer will further expand when water vapor invades, thereby further improving the sealing performance of the water-absorbing and expanding material layer and improving the waterproof and moisture-proof performance of the NTC temperature sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments, in which:

[0019] Figure 1 This is a schematic diagram of the path of water vapor intrusion into the NTC temperature sensor;

[0020] Figure 2 Schematic diagram of an NTC temperature sensor according to an embodiment of the present invention;

[0021] Figure 3 This is a schematic diagram of a water-swelling rubber sheet according to an embodiment of the present invention;

[0022] Figure 4 This is a side view of a water-swelling rubber sheet according to an embodiment of the present utility model;

[0023] Figure 5 Schematic diagram of a resin gasket according to an embodiment of the present invention;

[0024] Figure 6 It is a side view of the resin gasket of the embodiment of the utility model;

[0025] Figure 7 This is a schematic diagram of the preparation of an NTC temperature sensor according to an embodiment of the present utility model;

[0026] Figure 8 This is a second schematic diagram of the preparation of the NTC temperature sensor according to the embodiment of the present utility model;

[0027] Figure 9 This is a third preparation diagram of the NTC temperature sensor according to an embodiment of the present invention.

[0028] The reference numerals in the figures are:

[0029] 1. Metal shell; 11. Positioning protrusion; 2. NTC thermistor chip; 3. First lead; 4. Water-swellable material layer; 41. Water-swellable rubber sheet; 42. Water-swellable resin sheet; 43. Resin gasket; 431. Slot; 432. Arc-shaped hole; 44. Opening; 5. First packaging layer; 51. First epoxy resin packaging layer; 52. Silicone resin packaging layer; 53. Second epoxy resin packaging layer; 6. Second lead; 7. Solder; 8. Third epoxy resin packaging layer; 9. Packaging material; 10. Metal shell; 20. Lead; 30. Gap. DETAILED DESCRIPTION

[0030] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. Now, in conjunction with the accompanying drawings, a detailed description of the preferred embodiments of the present utility model will be given.

[0031] like Figure 1 As shown, the applicant's research found that in the package of the NTC temperature sensor, due to the inconsistent thermal expansion coefficients of the packaging material 9 (such as resin) and the metal shell 10 and the lead 20, during the temperature alternation process, small gaps 30 appear between the inner wall surface of the metal shell 10 and the surface of the lead 20. These gaps 30 will become paths for water vapor to invade. Water vapor invades the NTC thermistor chip 2 through these gaps 30, causing the NTC thermistor chip 2 to fail.

[0032] The present invention provides an NTC temperature sensor. Figure 2 As shown, the NTC temperature sensor includes a metal housing 1, an NTC thermistor chip 2, a first lead 3 and a water-swellable material layer 4; one end of the first lead 3 is electrically connected to the NTC thermistor chip 2; the NTC thermistor chip 2 is encapsulated in one end of the metal housing 1 through a first encapsulation layer 5; the water-swellable material layer 4 is installed in the metal housing 1 and seals the first encapsulation layer 5; the other end of the first lead 3 is led out from the first encapsulation layer 5 and the water-swellable material layer 4.

[0033] The NTC temperature sensor of the present invention is provided with a water-absorbing and expanding material layer 4 on one side of the first packaging layer 5 inside the metal shell 1. The water-absorbing and expanding material layer 4 is made of a material that will expand after absorbing water. The water-absorbing and expanding material layer 4 seals the first packaging layer 5, thereby further sealing the NTC thermistor chip 2. At the same time, since the water-absorbing and expanding material layer 4 expands after absorbing water, the water-absorbing and expanding material layer 4 will further expand when water vapor invades, thereby further improving the sealing performance of the water-absorbing and expanding material layer 4 and improving the waterproof and moisture-proof performance of the NTC temperature sensor.

[0034] Specifically, one end of the first lead 3 is soldered to the NTC thermistor chip 2 via solder 7. The first lead 3 is a CP (Control Pilot) line. The NTC temperature sensor of the present invention can be applied to electrical appliances such as smart toilets, smart bathtubs, air conditioners, new energy charging piles, and charging guns.

[0035] Specifically, the water-swellable material layer 4 includes a water-swellable rubber sheet 41 and / or a water-swellable resin sheet 42. Water-swellable rubber (WSR) and water-swellable resin have excellent water absorption and expansion properties. Upon contact with water, they can rapidly absorb water and expand to form a gel-like substance, effectively blocking any possible tiny gaps 30, thereby improving the waterproof performance of the NTC temperature sensor.

[0036] More specifically, the water-swellable material layer 4 comprises a stacked water-swellable rubber sheet 41 and two water-swellable resin sheets 42; the water-swellable rubber sheet 41 is disposed between the two water-swellable resin sheets 42. In this embodiment, the water-swellable material layer 4 comprises a water-swellable rubber sheet 41 and two water-swellable resin sheets 42; the water-swellable rubber sheet 41 is disposed between the two water-swellable resin sheets 42. The water-swellable rubber sheet 41 acts like a sealing ring and can fill most of the gap 30 by absorbing water and expanding. The two water-swellable resin sheets 42 are used to fill the small gaps 30 that the water-swellable rubber sheet 41 cannot fill.

[0037] Furthermore, the combination of the water-swellable rubber sheet 41 and the water-swellable resin sheet 42 provides an even better seal. The water-swellable rubber sheet 41, due to its flexibility, provides a good seal initially. The water-swellable resin sheet 42 expands after absorbing water, further enhancing the seal and preventing moisture from entering the sensor. The water-swellable resin sheet 42 provides additional support after absorbing water, which, combined with the elasticity of the water-swellable rubber sheet 41, improves the overall compressive strength of the structure. Furthermore, the layered structure of the water-swellable rubber sheet 41 and the water-swellable resin sheet 42 allows the materials to expand evenly after absorbing water, avoiding the uneven expansion that can occur with a single material, thereby reducing internal stress and potential damage caused by water absorption.

[0038] The water-swellable material layer 4 also includes two resin gaskets 43. One of the resin gaskets 43 is positioned on the side of the water-swellable resin sheet 42 facing away from the water-swellable rubber sheet 41, and the other resin gasket 43 is positioned on the side of the other water-swellable resin sheet 42 facing away from the water-swellable rubber sheet 41. The combination of the water-swellable rubber sheet 41 and the water-swellable resin sheet 42, along with the resin gaskets 43, provides a more comprehensive sealing effect. The water-swellable rubber sheet 41 and the water-swellable resin sheet 42 form a tight fit when they absorb water, while the resin gaskets 43 further ensure the integrity of the water-swellable material layer 4, preventing moisture from entering the sensor through potential gaps 30 or holes. The resin gaskets 43 provide additional support for the water-swellable material layer 4, reducing stress concentration that may occur during water absorption and expansion, thereby reducing the risk of damage to the water-swellable material layer 4 and helping to maintain the stability of the sensor in various temperature and humidity environments.

[0039] Further, combined with Figure 8As shown in (b), the inner wall of the metal shell 1 is provided with a locking protrusion 11 corresponding to the two resin gaskets 43, and the edge of the resin gasket 43 is provided with a slot 431 corresponding to the locking protrusion 11; the locking protrusion 11 is locked on the resin gasket 43. During assembly, the slot 431 can avoid the locking protrusion 11, allowing the resin gasket 43 to pass through the locking protrusion 11. After passing through the locking protrusion 11, the resin gasket 43 is rotated, and the slot 431 is staggered with the locking protrusion 11. As a result, the locking protrusion 11 will be locked on the edge of the resin gasket 43, thereby limiting the resin gasket 43. Specifically, there are two corresponding locking protrusions 11 for each resin gasket 43, and two slots 431 are also provided on the resin gasket 43.

[0040] Specifically, combined Figures 3 to 6 As shown, there are two first leads 3, two arc-shaped holes 432 are provided on the resin gasket 43, and two openings 44 are provided on the water-swelling rubber sheet 41 and the water-swelling resin sheet 42; the two first leads 3 are respectively led out from the two arc-shaped holes 432 and the two openings 44, which facilitates the lead-out of the first leads 3.

[0041] The first encapsulation layer 5 includes a first epoxy resin encapsulation layer 51, a silicone resin encapsulation layer 52, and a second epoxy resin encapsulation layer 53. The first epoxy resin encapsulation layer 51 encapsulates the NTC thermistor chip 2, the silicone resin encapsulation layer 52 wraps around the surface of the first epoxy resin encapsulation layer 51, and the second epoxy resin encapsulation layer 53 encapsulates the silicone resin encapsulation layer 52 and the NTC thermistor chip 2, and fills the internal space of the metal housing 1 where the NTC thermistor chip 2 is located. Epoxy resin has excellent mechanical strength and hardness. The first epoxy resin encapsulation layer 51 directly encapsulates the NTC thermistor chip 2, providing it with preliminary mechanical protection and encapsulation. The second epoxy resin encapsulation layer 53 further encapsulates the silicone resin encapsulation layer 52 and the NTC thermistor chip 2, increasing the mechanical stability and sealing of the overall structure. Both epoxy resin and silicone resin have good thermal stability. The multi-layered packaging structure of first epoxy resin encapsulation layer 51, silicone resin encapsulation layer 52, and second epoxy resin encapsulation layer 53 helps maintain the sealing of the NTC thermistor chip 2 at different temperatures, improving stability, reducing the impact of temperature changes on sensor performance and reducing the intrusion of moisture. Silicone resin, a thermally conductive material, improves heat conduction between the NTC thermistor chip 2 and the metal housing 1, ensuring that temperature changes on the chip are quickly transmitted to the housing, thereby improving the sensor's response speed.

[0042] Furthermore, within the metal housing 1, one side of the two resin gaskets 43 away from the NTC thermistor chip 2 is filled with a third epoxy resin encapsulation layer 8. The third epoxy resin encapsulation layer 8 is filled on the side of the resin gasket 43 away from the NTC thermistor chip 2, which helps to enhance the structural integrity of the entire sensor, provide additional mechanical support for the resin gasket 43, reduce displacement or damage caused by vibration or impact, and thus protect the reliability of the sensor. Epoxy resin generally has good thermal stability and insulation properties. The third epoxy resin encapsulation layer 8 can serve as a thermal barrier to help maintain the working environment of the NTC thermistor chip 2 and reduce the impact of external temperature fluctuations on its performance. The third epoxy resin encapsulation layer 8 can further improve the waterproof and moisture-proof performance of the sensor and prevent water vapor intrusion, especially in humid environments, which is crucial to improving the durability and reliability of the sensor.

[0043] The NTC temperature sensor also includes a second lead 6, one end of which is electrically connected to the first lead 3 and the other end of which is led out of the third epoxy resin encapsulation layer 8. The second lead 6 facilitates the lead-out of the first lead 3 and can be soldered to the first lead 3 via solder 7. Specifically, the second lead 6 is an electronic wire.

[0044] refer to Figure 7 The manufacturing process of one of the NTC temperature sensors shown is briefly shown. After the first lead 3 is welded to the NTC thermistor chip 2, it is immersed in epoxy resin liquid to form a first epoxy resin encapsulation layer 51 after curing, and then immersed in silicone resin liquid to form a silicone resin encapsulation layer 52. Figure 8 The preparation process of the second NTC temperature sensor is briefly shown. Figure 7 After the NTC temperature sensor semi-finished product is obtained by the preparation process shown in the figure, the first lead 3 and the second lead 6 are welded and then installed in the metal housing 1. Figure 8 As shown in (a), epoxy resin liquid is injected to obtain Figure 8 The second epoxy resin encapsulation layer 53 shown in (b) is shown in FIG. Figure 9 The preparation process of the second NTC temperature sensor is briefly shown. Figure 8 After the preparation process shown, a resin gasket 43, a water-swelling rubber sheet 41, a water-swelling resin sheet 42, another water-swelling rubber sheet 41, another resin gasket 43 are sequentially loaded into the metal shell 10, and finally epoxy resin liquid is injected to obtain a third epoxy resin encapsulation layer 8.

[0045] The present invention also discloses an appliance with an NTC temperature sensor, wherein the appliance includes the NTC temperature sensor as described above. The appliance with the NTC temperature sensor may be a smart toilet, a smart bathtub, an air conditioner, a new energy charging station, a charging gun, etc.

[0046] It should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Those skilled in the art may modify the technical solutions described in the above embodiments, or make equivalent replacements for some of the technical features therein; and all these modifications and replacements should fall within the scope of protection of the claims attached to the present invention.

Claims

1. An NTC temperature sensor, characterized in that: The device comprises a metal shell, an NTC thermistor chip, a first lead and a water-swelling material layer; one end of the first lead is electrically connected to the NTC thermistor chip; the NTC thermistor chip is encapsulated in one end of the metal shell through a first encapsulation layer; the water-swelling material layer is installed in the metal shell and seals the first encapsulation layer; the other end of the first lead is led out from the first encapsulation layer and the water-swelling material layer.

2. The NTC temperature sensor according to claim 1, characterized in that The water-swelling material layer includes a water-swelling rubber sheet and / or a water-swelling resin sheet.

3. The NTC temperature sensor according to claim 2, characterized in that: The water-swelling material layer includes a water-swelling rubber sheet and two water-swelling resin sheets stacked together; the water-swelling rubber sheet is disposed between the two water-swelling resin sheets.

4. The NTC temperature sensor according to claim 3, characterized in that The water-swellable material layer further includes two resin gaskets, one of which is arranged on the side of the water-swellable resin sheet away from the water-swellable rubber sheet, and the other resin gasket is arranged on the side of the other water-swellable resin sheet away from the water-swellable rubber sheet.

5. The NTC temperature sensor according to claim 4, characterized in that: The inner wall of the metal shell is respectively provided with latching protrusions corresponding to the two resin gaskets, and the edge of the resin gasket is provided with slots corresponding to the latching protrusions; the latching protrusions are latched on the resin gaskets.

6. The NTC temperature sensor according to any one of claims 1 to 5, characterized in that: The first encapsulation layer includes a first epoxy resin encapsulation layer, a silicone resin encapsulation layer and a second epoxy resin encapsulation layer; The first epoxy resin encapsulation layer encapsulates the NTC thermistor chip, the silicone resin encapsulation layer is wrapped around the surface of the first epoxy resin encapsulation layer, and the second epoxy resin encapsulation layer encapsulates the silicone resin encapsulation layer and the NTC thermistor chip and fills the internal space of the metal shell where the NTC thermistor chip is located.

7. The NTC temperature sensor according to claim 4 or 5, characterized in that: In the metal shell, a side of the two resin gaskets away from the NTC thermistor chip is filled with a third epoxy resin packaging layer.

8. The NTC temperature sensor according to claim 7, characterized in that: The NTC temperature sensor further includes a second lead, one end of which is electrically connected to the first lead, and the other end of which is led out from the third epoxy resin packaging layer.

9. The NTC temperature sensor according to claim 4 or 5, characterized in that: There are two first leads, the resin gasket is provided with two oppositely arranged arc holes, and the water-swellable rubber sheet and the water-swellable resin sheet are both provided with two oppositely arranged openings; the two first leads are respectively led out from the two arc holes and the two openings.

10. An electrical appliance having an NTC temperature sensor, characterized in that: The electrical appliance comprises the NTC temperature sensor according to any one of claims 1 to 9.

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