Temperature sensor

Abstract

Disclosed is a temperature sensor, comprising: an NTC thermistor, two parallel wires respectively bonded to both ends of the NTC thermistor, and the two parallel wires are isolated by a first insulating material; a second insulating material layer covering at least the NTC thermistor and the first insulating material.

Description

Technical Field

[0001] The present invention relates to a temperature sensor, in particular to a high-temperature or low-temperature deep-water temperature sensor. Background Art

[0002] The existing NTC (Negative Temperature Coefficient) temperature sensor is obtained through the following process: First, the wire is cut into the required length. After peeling, the NTC thermistor chip is welded, and then the head of the wire with the NTC thermistor chip welded is encapsulated with epoxy resin. Some are inserted into various housings and then encapsulated with epoxy resin again. This brings a problem. Since epoxy resin and the plastic of the wire are not the same substance, there are always problems with the compatibility of the two substances. Therefore, most NTC temperature sensors on the market will fail within a few months in a humid environment due to water intrusion into the NTC temperature sensor. Summary of the Invention

[0003] In view of one or more problems in the prior art, a temperature sensor is proposed.

[0004] In one aspect of the present invention, a temperature sensor is proposed, including: an NTC thermistor; two parallel wires respectively bonded to both ends of the NTC thermistor, and the two parallel wires are isolated by a first insulating material; a second insulating material layer covering at least the NTC thermistor and the first insulating material.

[0005] According to some embodiments of the present invention, the first insulating material includes at least one of glue, plastic, fiber, PCB board, rubber, bakelite, and film, and the second insulating material layer includes at least one of PVC (polyvinyl chloride), XLPVC (cross-linked PVC), XLPE (cross-linked PE), PE (polyethylene), polyether ester, polyurethane, TPE (thermoplastic elastomer), PP (polypropylene), PO (propylene oxide), silica gel, rubber, or polytetrafluoroethylene.

[0006] According to some embodiments of the present invention, the NTC thermistor includes a single-end glass-encapsulated thermistor, a diode-type thermistor, a chip-type thermistor, or a chip resistor.

[0007] According to some embodiments of the present invention, the thickness of the second insulating material layer is: 0.1 mm to 4 mm.

[0008] According to some embodiments of the present invention, there is a plated metal layer, or a metal tube is sleeved, or a metal sticker is adhered on the second insulating layer covering the NTC thermistor.

[0009] The above description is only an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features and advantages of the present invention more obvious and understandable, the following preferred embodiments are specifically given, and in conjunction with the accompanying drawings, the details are described as follows. Brief Description of the Drawings

[0010] In order to better understand the present invention, the present invention will be described in detail according to the following drawings:

[0011] Figure 1A and Figure 1B are schematic diagrams of an NTC diode glass-encapsulated thermistor and a single wire according to an embodiment of the present invention;

[0012] Figure 2A and Figure 2B are schematic diagrams of an NTC chip-type thermistor and parallel lines according to an embodiment of the present invention;

[0013] Figure 3A and Figure 3B are schematic diagrams of an NTC chip-type and wires printed and sprayed on a PCB board according to an embodiment of the present invention;

[0014] Figure 4A and Figure 4B are schematic diagrams of an NTC single-end glass-encapsulated thermistor and parallel wires isolated by insulating materials according to an embodiment of the present invention;

[0015] Figure 5A and Figure 5B are schematic diagrams of two groups of deep water temperature sensors formed by an NTC diode glass-encapsulated thermistor, an NTC chip-type thermistor, and two double-parallel wires according to an embodiment of the present invention;

[0016] Figure 6A and Figure 6B are schematic diagrams of two groups of deep water temperature sensors formed by an NTC single-end glass-encapsulated thermistor, an NTC diode glass-encapsulated thermistor, a double-parallel wire, and a single wire according to an embodiment of the present invention. Detailed Description of the Preferred Embodiments

[0017] The specific embodiments of the present invention will be described in detail below. It should be noted that the embodiments described here are only for illustrative purposes and are not used to limit the present invention. In the following description, in order to provide a thorough understanding of the present invention, a large number of specific details are set forth. However, it is obvious to those of ordinary skill in the art that the present invention does not have to employ these specific details. In other instances, well-known structures, materials, or methods have not been specifically described in order to avoid obscuring the present invention.

[0018] Throughout the specification, references to "one embodiment", "an embodiment", "an example" or "an example" mean that a particular feature, structure, or characteristic described in connection with the embodiment or example is included in at least one embodiment of the present invention. Thus, the phrases "in one embodiment", "in an embodiment", "an example" or "an example" that appear throughout the specification do not necessarily all refer to the same embodiment or example. Additionally, the particular features, structures, or characteristics may be combined in any suitable combination and / or sub-combination in one or more embodiments or examples. Further, those of ordinary skill in the art will understand that the term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0019] The NTC temperature sensor can be obtained through the following process: First, cut the wire into the required length. After stripping the wire, solder the NTC thermistor chip, and then epoxy encapsulate the head of the wire with the NTC thermistor chip soldered on it. Some are inserted into various housings and then epoxy encapsulated again. However, the above process brings a problem. Since epoxy resin and the plastic of the wire are not the same substance, there are always problems with the compatibility of the two substances. Therefore, most NTC temperature sensors on the market will fail within a few months in a humid environment due to water intrusion into the NTC temperature sensor. The common solutions on the market are to increase the length of the housing, or add a heat-shrinkable sleeve with glue between the housing and the wire for heat shrinkage, or select an epoxy resin glue with better compatibility with PVC material, in order to extend the time of water intrusion and thus extend the life of the NTC temperature sensor (an NTC temperature sensor is obtained by connecting an NTC thermistor to a wire and passing a voltage-withstanding test and a performance test).

[0020] The inventors of the present invention have once conducted an experiment. They soldered NTC thermistors to two parallel wires, cut them off, and then separately fed them into an injection molding machine for injection molding. The result found that: due to the strong pressure in the injection molding machine, the two parallel wires could not remain parallel after injection molding in the injection molding machine. Therefore, to solve the above problems, the object of the present invention is to overcome the deficiencies of the prior art and provide a brand-new method.

[0021] According to an embodiment of the present invention, a high-temperature deep-water type NTC temperature sensor includes several parallel lines with a certain length, each of which is at least welded with a single NTC thermistor. The parallel lines successively enter an injection molding machine through a guiding structure for re-injection molding. Any one of the melted PVC (Poly Vinyl Chioride), XLPVC (cross-linked PVC), XLPE (cross-linked PE), PE (polyethylene), PU (polyether ester, polyurethane), TPE (thermoplastic elastomer), PP (polypropylene), PO (propylene oxide), silica gel, rubber, and / or polytetrafluoroethylene is used to completely wrap the NTC thermistor and a certain length of the parallel lines connected thereto. After water cooling, it is connected to an external circuit through subsequent processes such as traction, peeling, terminal punching, and socket insertion.

[0022] In other embodiments, a low-temperature deep-water type NTC temperature sensor is provided, which includes several parallel lines with a certain length, each of which is at least welded (bonded) with a single NTC thermistor. The parallel lines successively enter an injection molding machine through a guiding structure for re-injection molding. Any one of the melted PVC (Poly Vinyl Chioride), XLPVC (cross-linked PVC), PVC (Poly VinylChioride), and XLPVC (cross-linked PVC) is used to completely wrap the NTC thermistor and a certain length of the parallel lines connected thereto. After water cooling, it is connected to an external circuit through subsequent processes such as traction, peeling, terminal punching, and socket insertion.

[0023] In other embodiments, a preferred solution is that the thickness of the plastic is determined according to the required waterproof level and the plastic material characteristics to determine the thinnest thickness of the plastic on the re-injected deep-water type NTC temperature sensor; generally speaking, the higher the waterproof level, the thicker the plastic thickness. The deep-water type NTC temperature sensor refers to an NTC temperature sensor that is completely water-proof.

[0024] In other embodiments, a preferred solution is that the wire of the parallel line is a conductive metal solid or a metal connecting wire after chemical corrosion, and a metal connecting wire after printing or spraying.

[0025] In other embodiments, a preferred solution is that the parallel lines are separated by an insulating material between two parallel wires, or two single wires are kept parallel after being isolated by an insulating material. The insulating material includes materials such as glue, plastic, fiber, PCB board, rubber, bakelite, and film.

[0026] In other embodiments, a preferred solution is that the NTC thermistor is a single-end glass-sealed thermistor, a diode-type thermistor, a chip-type thermistor, or a chip-type thermistor.

[0027] In other embodiments, a preferred solution is that the deep - water type NTC temperature sensor has a plated metal layer, or is sleeved with a metal tube, or has a metal sticker adhered to the injection - molded surface position of the NTC thermistor.

[0028] Since in the present invention, the NTC thermistor and the parallel lines are covered with the same kind of plastic formed by hot - melt injection molding and cooling, there are no two substances. And the waterproof performance of the plastics on the current market is very excellent. Therefore, as long as the thickness of the plastic for re - injection molding is well controlled, the waterproof grade of the NTC temperature sensor can be directly controlled. For temperature sensors with very strict waterproof grade requirements, the present invention is called a deep - water type temperature sensor.

[0029] The high - temperature deep - water type temperature sensor and the low - temperature deep - water type temperature sensor are new products of the NTC temperature sensor, and there will be many new uses for it. That is to say, not only does it cover the basic uses of ordinary NTC temperature sensors on the current market, but also it will bring many unexpected breakthroughs.

[0030] Currently, the waterproof grade of the plastic used to manufacture ordinary wires is already very good. The inventor of the present invention has done the following experiment: for an NTC temperature sensor encapsulated with epoxy resin in a boiling water experiment, the boiling time generally does not exceed 300 hours, and its insulation resistance is already less than 1 megohm; while for a 26# PVC wire in a boiling water experiment, the boiling time exceeds 1000 hours, and its insulation resistance is still greater than 100 megohms. Therefore, if we still need a temperature sensor with a higher waterproof grade, we only need to guide the single NTC thermistor and a certain length of parallel lines welded to enter the injection - molding machine for re - injection molding, and thicken the thinnest thickness of the plastic covering the deep - water temperature sensor, then we can easily meet the requirements.

[0031] In the present invention, high - temperature electric welding and laser welding can be used. At the same time, the glass - encapsulated NTC thermistor chip can withstand a high temperature of 300 °C, and the wires include normal - temperature and low - temperature PVC wires, high - temperature resistant Teflon wires, and silicone wires. Therefore, not only can we obtain a normal - temperature and low - temperature deep - water temperature sensor with an extremely high waterproof grade, but also a high - temperature deep - water temperature sensor with an extremely high waterproof grade. And these two types of NTC temperature sensors are blank in the whole industry.

[0032] For example, as is well known, since high - temperature Teflon wires are insoluble with other materials, neither epoxy resin nor glue can stick to high - temperature wires. However, according to the solution of this patent, we can easily obtain a high - temperature deep - water temperature sensor with a truly extremely high waterproof grade. Its temperature resistance can reach above 200 °C.

[0033] Since there is insulating material between the parallel lines to support the wires to remain parallel all the time, when several parallel lines with NTC thermistors welded on them enter the injection molding machine through the guiding structure for re-injection molding, although the strong pressure in the injection mold still keeps the wires in the parallel lines parallel, at the same time, the new and molten plastic material re-covers the NTC thermistors and the parallel lines connected thereto. After water cooling, it is connected to the external circuit through subsequent processes such as traction, peeling, terminal punching, and jack socket operations. The key point here is that the parallel lines entering the injection molding machine through the guiding structure for re-injection molding are many parallel lines with only one NTC thermistor welded on each, and there is insulating material between the parallel lines to support the wires to remain parallel all the time. In this way, what comes out after re-injection molding through the guiding structure and entering the injection molding machine is a continuous and whole piece. However, after water cooling and subsequent processes such as traction, peeling, terminal punching, and jack socket operations, multiple deep water temperature sensors are born.

[0034] Figure 1A and Figure 1B are schematic diagrams of using NTC diode glass-encapsulated thermistors and single branch lines according to an embodiment of the present invention. As Figure 1A and Figure 1B shown, the NTC diode glass-encapsulated thermistor 11 is laser welded on two single branch lines 12 (parallel first wire and second wire and isolated by insulating material plastic or rubber), forming solder joints 13. The two single branch lines 12 are in a parallel state and are introduced into the injection mold of the injection molding machine through a manipulator or a guide rail for re-injection molding to form a deep water temperature sensor. After the tails of the single branch lines in the parallel lines 12 are re-injection molded, they are connected to the external circuit through peeling or terminal punching holes. Figure 1B The plastic for re-injection molding in

[0035] Figure 2A and Figure 2B is represented as 14, which can be high-temperature resistant plastic. In this way, a high-temperature deep water temperature sensor is formed, and the level of the waterproof grade is determined according to the thinnest thickness of the plastic completely covering the deep water temperature sensor. The higher the waterproof grade, the thicker the plastic thickness. Figure 2A and Figure 2B shown, the NTC chip-type thermistor 21 is soldered with tin on the double parallel lines 22 (parallel first wire and second wire and isolated by insulating material plastic or rubber), and is introduced into the injection mold of the injection molding machine through a manipulator or a guide rail for re-injection molding to form a deep water temperature sensor. Figure 2B In

[0036] Figure 3A andFigure 3B is a schematic diagram of using an NTC chip type, with wires printed and sprayed on a PCB board according to an embodiment of the present invention. As Figure 3A and Figure 3B shown, the copper wires 35 (parallel first and second wires and isolated by the insulating material PCB board) on the PCB board 36 are presented on the PCB board 36 by printing. The NTC chip type thermistor 31 is ultrasonically welded to the wire 35 to form a solder joint 33, and then introduced into the injection mold of an injection molding machine by a manipulator or a guide rail for re-injection molding to form a deep water temperature sensor. Figure 3B shows the re-injected plastic 34.

[0037] Figure 4A and Figure 4B is a schematic diagram of using an NTC single-ended glass-encapsulated thermistor and parallel wires isolated by an insulating material according to an embodiment of the present invention. As Figure 4A and Figure 4B shown, two parallel wires 45 are separated by an insulating material glue 47. The NTC single-ended glass-encapsulated thermistor 41 is ultrasonically welded to the wire 45 to form a solder joint 43, and then introduced into the injection mold of an injection molding machine by a manipulator or a guide rail for re-injection molding to form a deep water temperature sensor. Figure 4B shows the re-injected plastic 44.

[0038] Figure 5A and Figure 5B is a schematic diagram of two sets of deep water temperature sensors using an NTC diode glass-encapsulated thermistor, an NTC chip type thermistor, and two double-parallel wires according to an embodiment of the present invention. As Figure 5A and 5B shown, the NTC diode glass-encapsulated thermistor 51 is laser welded to two single-branch wires 52 to form a solder joint 53. The wires in the two single-branch wires 52 are in a parallel state (parallel first and second wires and isolated by an insulating material plastic or rubber). The NTC chip type thermistor 56 is soldered to the parallel wires 55. These two sets of semi-finished products are introduced into the injection mold of an injection molding machine by a manipulator or a guide rail for re-injection molding to form two sets of deep water temperature sensors. The single-branch wires 52 and the parallel wires 55 at the tails are re-injected, and then connected to external wires by peeling or punching terminal holes.

[0039] Figure 5B shows the re-injected plastic 54. Since this example uses the NTC chip type thermistor 56 and welding technology, the re-injected plastic 54 cannot be a high-temperature resistant plastic, but can only be a normal-temperature plastic or a low-temperature plastic.

[0040] Figure 6A and Figure 6BIt is a schematic diagram of two sets of deep - water temperature sensors formed by an NTC single - end glass - encapsulated thermistor, an NTC diode glass - encapsulated thermistor, a double - parallel wire (a parallel first wire and second wire and isolated by an insulating material such as plastic or rubber), and a single - branch wire (a third wire) according to an embodiment of the present invention. As Figure 6A and 6B shown, one lead of the NTC diode glass - encapsulated thermistor 61 is welded to a single - branch wire 62 by electric welding, and the other lead is welded to a parallel wire 65 by electric welding. The NTC single - end glass - encapsulated thermistor 66 is welded to the parallel wire 65 by electric welding. One of the wires in the parallel wire 65 becomes a common solder joint 63. This set of semi - finished products is introduced into the injection mold of an injection molding machine through a manipulator or a guide rail for re - injection molding, thus forming two sets of deep - water temperature sensors sharing one wire.

[0041] Figure 6B The re - injection - molded plastic 64 is shown, which can be a high - temperature - resistant plastic. Since high - temperature - resistant glass - encapsulated thermistors 61 and 66 are used, and at the same time a high - temperature - resistant electric - welding method is adopted, the sixth embodiment forms a high - temperature deep - water temperature sensor. The single - branch wire 62 and the double - parallel wire 65 at the tail are connected to an external circuit through peeling or punching terminal holes after re - injection molding. The temperature resistance of the high - temperature deep - water temperature sensor depends on the temperature resistance of the high - temperature - resistant plastic. Because this example uses high - temperature - resistant NTC glass - encapsulated thermistors and a high - temperature - resistant electric - welding method, the sixth embodiment is greater than 200 °C. Its waterproof level is determined according to the thinnest thickness of the plastic covering and encapsulating the deep - water temperature sensor and the characteristics of the plastic material. Generally speaking, the higher the waterproof level, the thicker the plastic thickness.

[0042] In the above first to sixth embodiments, the thickness of the outer plastic (the second insulating layer) is 0.1 mm to 4 mm, preferably 0.5 - 2 mm. Specifically, the thickness of the outer plastic is 0.1 mm, 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, 4.0 mm. Those skilled in the art can select the corresponding plastic thickness according to different waterproof levels.

[0043] In addition, in the above embodiments of the present invention, "low temperature" or "normal temperature" refers to - 30 degrees Celsius to 50 degrees Celsius, and "high temperature" refers to 100 degrees Celsius to 250 degrees Celsius.

[0044] In addition, although the above embodiments describe using plastic or PCB material as the first insulating material, those skilled in the art can think of using other insulating materials. For example, the insulating materials include insulating fibers, rubber, bakelite, thin films and other materials. Similarly, although the above embodiments use plastic as the material of the second insulating layer, those skilled in the art can think of using other materials, such as any one of PVC (Poly Vinyl Chioride), XLPVC (cross-linked PVC), XLPE (cross-linked PE), PE (polyethylene), PU (polyether ester, polyurethane), TPE (thermoplastic elastomer), PP (polypropylene), PO (propylene oxide), silica gel, rubber and / or polytetrafluoroethylene.

[0045] Although the present invention has been described with reference to several exemplary embodiments, it should be understood that the terms used are descriptive and exemplary rather than restrictive. Since the present invention can be embodied in many forms without departing from the spirit or essence of the invention, it should be understood that the above embodiments are not limited to any of the foregoing details, but should be broadly construed within the spirit and scope defined by the appended claims. Therefore, all changes and modifications falling within the scope of the claims or their equivalents should be covered by the appended claims.

Claims

1. A temperature sensor, comprising: NTC thermistor; Two parallel wires respectively welded to both ends of the NTC thermistor, and the two parallel wires are isolated and supported by a first insulating material; A second insulating material layer that covers at least the NTC thermistor and the first insulating material; The parallel wires isolated and supported by the first insulating material, and at least one NTC thermistor welded within the parallel wires of a certain length enter a wire injection molding machine, and the second insulating material layer is covered on the NTC thermistor and the first insulating material within the parallel wires through the wire injection molding machine.

2. The temperature sensor according to claim 1, wherein the first insulating material comprises at least one of glue, plastic, fiber, PCB board, rubber, bakelite, and film, and the second insulating material layer comprises at least one of PVC (polyvinyl chloride), XLPVC (cross-linked PVC), XLPE (cross-linked PE), PE (polyethylene), polyether ester, polyurethane, TPE (thermoplastic elastomer), PP (polypropylene), PO (propylene oxide), silica gel, rubber, or polytetrafluoroethylene.

3. The temperature sensor according to claim 1, wherein the NTC thermistor comprises a single-ended glass-encapsulated thermistor, a diode-type thermistor, a chip-type thermistor, or a surface-mount thermistor.

4. The temperature sensor according to claim 1, wherein the thickness of the second insulating material layer is: 0.1 mm to 4 mm.

5. The temperature sensor according to claim 1, wherein there is an electroplated metal layer, or a metal tube is sleeved, or a metal sticker is adhered on the second insulating layer covered by the NTC thermistor.

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