JP2013229112A - Double core parallel lead wire and thermistor with lead wire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a double core parallel lead wire; and a thermistor with a lead wire, each having a structural form that can maintain a position of a thermistor element and detect an accurate temperature, and can be manufactured inexpensively.SOLUTION: A double core parallel lead wire 1 is comprised of two insulated electrical conductors 2 each having a solderable conductor 3 and an insulated coating layer 4 that covers the conductor 3 so as to allow the conductor 3 to be solderable. The conductor 3 has tensile strength of 350 N/mmor more, an elongation percentage of 5% or more, and a thermal conductivity of 100 W/m k or less. The two insulated electrical conductors 2 are adhered in parallel by a fusion layer 5 to a longitudinal direction in which the insulated electrical conductors 2 extend. A thermistor with a lead wire 10 includes the double core parallel lead wire 1. Hereat, the conductor 3 is preferably a copper alloy wire containing copper, nickel and manganese.

Description

  The present invention relates to a two-core parallel lead wire and a thermistor with a lead wire, and more particularly to a two-core parallel lead wire for a thermistor that detects the temperature of a component housed inside a portable terminal or the like and a thermistor with a lead wire. .

  Mounting boards for electronic devices such as mobile terminals and mobile personal computers are lighter, thinner, shorter, more functional, and higher in output, and are mounted with higher density. In recent years, mounting boards for electronic devices such as mobile terminals and mobile personal computers are required not only to be mounted with high density but also to ensure the safety of the electronic devices. Among safety, there is an increasing need to provide a thermistor in electronic devices to protect mounting boards from heat generated by batteries, etc., and demand for high quality levels in applications such as temperature detection, overcurrent protection, or temperature compensation. Is growing. As such a thermistor, one having a thermistor element and a lead wire connected to the thermistor element is used.

  In Patent Document 1, the first and second lead wires are metal wires, a covering portion that covers the metal wires with an insulating member, and first and second metal wire exposed portions that are formed in a flat shape. The first lead wire and the second lead wire are parallel to each other, the second lead wire is formed shorter than the first lead wire, and the first metal wire exposed portion is formed of the terminal electrode. Soldered to the side folded part, the second metal line exposed part is also soldered to the side folded part of the other terminal electrode, the first and second metal line exposed parts are located on the same plane, and the side folded part In addition to the above, there has been proposed a technique related to an electronic component with a lead wire in which solder fillets are formed not only on the end face and the gap. With this technology, the bonding strength can be easily improved with a simple structure and at a low cost, and the electrical connection is good and the reliability is high.

  The present applicant has so far developed the technical development of lead wires for thermistors for measuring the temperature of electronic devices such as portable terminals and mobile personal computers, and the technical development of thermistors with lead wires. Similar to the technique proposed in Patent Document 1, such a thermistor does not fix the thermistor element to the object to be measured, but arranges the thermistor element in the vicinity of the object to be measured, and utilizes the strength and rigidity of the lead wire. The element was prevented from moving.

JP 2010-73731 A

  The applicant has been researching the thermistor, and has come to recognize that there is a problem that the accurate temperature cannot be detected over time. As a result of research, thermistors with lead wires that are generally used use copper wire as the conductor of the lead wire, and the strength of the copper wire is low, so if the electronic device vibrates, the thermistor element It has been found that the temperature of the object to be measured cannot be accurately measured due to the deviation from the initial position.

  Moreover, since the insulation coating layer provided on the outer periphery of the conductor is thick, it is difficult to arrange the lead wire in a narrow part in the electronic device, and the thermistor element is sufficiently attached to the measurement object. I could n’t get close. For this reason, it has also been found that the thermistor element is disposed at a position away from the object to be measured, temperature compensation is lacking, and reliability is low. Moreover, since the lead wire uses a copper wire as a conductor, the thermal conductivity is high, and heat is transmitted through the conductor. For this reason, there is a problem that the temperature detected by the thermistor element is easily detected lower than the actual temperature.

  On the other hand, the lead wire for the thermistor is required to have a thin wire diameter as electronic devices such as portable terminals and mobile personal computers are miniaturized and the mounting board is densely mounted.

  Thus, the lead wire for the thermistor is required to have a strength that does not cause a positional shift with the passage of time, and is required to have a thin wire diameter.

  However, in the lead wire for thermistor, since the insulating coating layer provided on the outer periphery of the conductor is formed with a thickness of 100 μm or more by melt extrusion, it is difficult to reduce the thickness of the insulating coating layer, and the lead wire is made thin. It was difficult. In addition, when the lead wires having the insulating layer provided on the outer periphery of the conductor are fixed in parallel to form a two-core parallel lead wire, the lead wires are fixed to each other by melt extrusion. A thick insulating coating layer is formed by extrusion.

  When manufacturing a thermistor with a two-core parallel lead wire using such a two-core parallel lead wire, the lead wire is first processed, and then the lead wire is soldered to the thermistor element. In the end processing of lead wires, the lead wires are split into parallel wires that are fixed in parallel to tear them into single wires, and then the melt-extruded insulation coating layer is peeled off with a dedicated wire stripper to expose the conductors. ing. Thereafter, the exposed conductor is soldered to the thermistor element, and the thermistor element portion is hermetically sealed to manufacture the thermistor. Therefore, the machining process is complicated and the manufacturing cost is increased.

  The present invention has been made in order to solve the above-described problems, and an object of the present invention is to provide a structure that can maintain the position of the thermistor element, can detect an accurate temperature, and can be manufactured at a low cost. The object is to provide a two-core parallel lead wire and a thermistor with lead wires.

A two-core parallel lead wire according to the present invention for solving the above-described problems is provided with two insulated conductors having a solderable conductor and an insulating coating layer that covers the conductor and enables the conductor to be soldered. The conductor has a tensile strength of 350 N / mm ² or more, an elongation of 5% or more, and a thermal conductivity of 100 W / m · k or less, and the two insulated conductors are the insulated conductors. It is characterized by being fixed in parallel with the fusion layer in the longitudinal direction in which is extended.

According to the present invention, since the tensile strength of the conductor is 350 N / mm ² or more, even when an external force such as vibration is applied, the distance between the measurement object in the electronic device and the thermistor element can be maintained without misalignment. Further, since the elongation percentage of the conductor is 5% or more, the lead wire becomes flexible and is easy to route. As a result, the lead wire can be easily arranged in a narrow portion in the electronic device. Moreover, since the elongation percentage of the conductor is 5% or more, the spring back phenomenon of the conductor can be prevented. Therefore, even if the thermistor element supported only by the lead wire is arranged in the vicinity of the measurement object, the thermistor element can be prevented from being displaced due to the springback phenomenon of the conductor. A thermistor in which a conductor has the above-mentioned tensile strength and elongation rate and a two-core parallel lead wire having the conductor is connected to the thermistor element is capable of highly reliable temperature detection, overcurrent protection, temperature compensation, etc. It can be carried out. Moreover, since the heat conductivity of a conductor is 100 W / m * k or less, the heat transfer of a conductor can be suppressed. If such a two-core parallel lead wire is connected to the thermistor element, the temperature of the measurement object can be accurately detected. Furthermore, according to the two-core parallel lead wire according to the present invention, since both the conductor and the insulating coating layer can be soldered, the insulated conductor can be directly soldered to the thermistor element, and the terminal peeling with a wire stripper or the like can be performed. There is no need to do it. As a result, the structure form of the two-core parallel lead wire can be said to be a structure form in which complicated processing steps can be omitted and the manufacturing cost can be reduced.

  In the two-core parallel lead wire according to the present invention, the conductor is a copper alloy wire containing copper, nickel and manganese, preferably, the copper content is 50 mass% or more and 96 mass% or less, nickel and manganese, Is 4 mass% or more and 50 mass% or less.

  According to this invention, since the copper alloy wire described above is used as the conductor, the thermal conductivity of the conductor can be set in the range of 20 W / m · k to 100 W / m · k. As a result, compared to the thermal conductivity of copper wire, 390 W / m · k, the thermal conductivity can be reduced by 1 / 3.9 to 1 / 19.5 times, improving the temperature measurement performance of the thermistor element. Can be made.

  In the two-core parallel lead wire according to the present invention, the insulating coating layer has a heat resistance index of at least 150 ° C. and a thickness of 30 μm or less.

  According to this invention, since the insulating coating layer has a heat resistance index of at least 150 ° C., it is possible to suppress the thermal deterioration of the insulating layer, and to prevent the conductor from being exposed or the conductor from being short-circuited by contacting the substrate, for example. The electronic device can be prevented from malfunctioning. Further, the diameter can be reduced by setting the thickness of the insulating coating layer to 30 μm or less.

A thermistor with a lead wire according to the present invention for solving the above problems is a thermistor with a lead wire composed of a thermistor element and a two-core parallel lead wire soldered to the thermistor element,
The two-core parallel lead wire is composed of two insulated conductors each having a solderable conductor and an insulating coating layer that covers the conductor and enables the conductor to be soldered. 350 N / mm ² or more, the elongation is 5% or more, and the thermal conductivity is 100 W / m · k or less, and the two insulated conductors are parallel to the longitudinal direction in which the insulated conductors extend with the fusion layer. The insulated conductors are separated from each other by a desired length from the longitudinal end portion where the insulated conductor extends, and the conductor is soldered to the thermistor element at the end portion. It is characterized by.

  According to the present invention, it is possible to provide a two-core parallel lead wire and a thermistor with a lead wire, which can maintain the position of the thermistor element, can detect an accurate temperature, and can be manufactured at a low cost. Can do.

It is a cross-sectional view of a two-core parallel lead wire according to an embodiment of the present invention. It is a top view of the thermistor with a lead wire concerning one embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. The technical scope of the present invention is not limited only to the following description and drawings.

[2-core parallel lead wire]
As shown in FIGS. 1 and 2, the two-core parallel lead wire 1 according to the present invention includes a solderable conductor 3, and an insulating coating layer 4 that covers the conductor 3 and enables the conductor 3 to be soldered. It is comprised by the two insulated conducting wires 2 which have. The conductor 3 has a tensile strength of 350 N / mm ² or more, an elongation of 5% or more, and a thermal conductivity of 100 W / m · k or less. The two insulated conductors 2 are fixed in parallel with the fusion layer 5 in the longitudinal direction in which the insulated conductors 2 extend. The two-core parallel lead wire 1 is a lead wire in which the insulated conductor wires 2 are parallel to each other in all the regions in the longitudinal direction, and the insulated conductor wires 2 are not twisted together.

  The thermistor 10 with a lead wire in which the two-core parallel lead wire 1 is soldered to the thermistor element 11 can keep the distance between the measurement object and the thermistor element 11 without misalignment. Moreover, the heat transfer of the conductor 3 can be suppressed and the temperature of the measurement object can be accurately detected. Further, the insulated conductor 2 can be directly soldered to the thermistor element 11, and the manufacturing cost can be reduced by omitting complicated processing steps.

  Hereinafter, each configuration of the two-core parallel lead wire 1 will be described in detail.

<Conductor>
The conductor 3 is a solderable conductor and constitutes a core material of the insulated conductor 2. The conductor 3 has the characteristics that the tensile strength is 350 N / mm ² or more, the elongation is 5% or more, and the thermal conductivity is 100 W / m · k or less.

  The constituent material of the conductor 3 is not particularly limited, but the conductor 3 is plastically processed and work hardened, or heat treated and softened to adjust to the above-described characteristic range. The type of the metal conductor is not particularly limited as long as it can be adjusted as such. As a preferable conductor, a copper alloy wire can be exemplified, and more preferably, a copper alloy wire containing copper, nickel and manganese can be exemplified. Such a copper alloy wire will be described in detail later.

(Tensile strength and elongation)
The tensile strength of the conductor 3 is 350 N / mm ² or more, and the elongation percentage of the conductor 3 is 5% or more. The two-core parallel lead wire 1 manufactured using the conductor 3 having the tensile strength and elongation rate in this range can be easily routed in the electronic apparatus. Further, since the two-core parallel lead wire 1 has a tensile strength and an elongation rate in the above range, it has a strength that does not cause deformation due to an external force such as vibration, and an elongation rate that does not cause a springback phenomenon. Yes. When such a thermistor 10 with a two-core parallel lead wire (see FIG. 2) is disposed in an electronic device, the thermistor element 11 can be easily disposed at a position slightly away from the temperature measurement target. In addition, the thermistor element 11 disposed further can be held for a long time without misalignment. The preferred tensile strength of the conductor 3 is 450 N / mm ² or more, and the preferred elongation is 20% or more and 40% or less.

When the tensile strength of the conductor 3 is less than 350 N / mm ² , when an external force such as vibration is applied to the thermistor 10 with the two-core parallel lead wire, the position of the thermistor element 11 may deviate from the initial position. is there. Although the upper limit of the tensile strength of the conductor 3 is not specifically limited, Since the preferable conductor 3 is a copper alloy wire, it will be about 600 N / mm < ² >.

Incidentally, conductors used for general leads are copper wire is small tensile strength, tensile strength of such a copper wire is usually, 240 N / mm ² or more 340 N / mm ² or less. Therefore, the lead wire using a copper wire has a low strength, and there is a problem that the position of the thermistor element is easily displaced when an external force such as vibration is applied to the thermistor.

  When the elongation percentage of the conductor 3 is less than 5%, a springback phenomenon is likely to occur in the conductor 3 due to the elastic deformation of the conductor 3 when the two-core parallel lead wire 1 is routed in the electronic device. When the conductor 3 causes a springback phenomenon, the position of the thermistor element 11 may be displaced from the position where it is initially disposed. If the elongation percentage of the conductor 3 is less than 5%, it is difficult to work around the two-core parallel lead wire 1 in the electronic device.

  Incidentally, the elongation rate of the copper wire used for a general lead wire is about 3%, and since there is not enough elongation, a springback phenomenon is likely to occur, and it is difficult to route in an electronic device.

(Thermal conductivity)
The thermal conductivity of the conductor 3 is 100 W / m · k or less. Since the conductor 3 having the thermal conductivity in this range can effectively prevent heat transfer, the two-core parallel lead wire 1 manufactured using the conductor 3 is a typical measurement in an electronic device. The thermistor 10 with a lead wire that can accurately measure the temperature of a battery (battery) that is an object can be configured. In addition, the preferable heat conductivity of the conductor 3 is 20 W / m * k or more and 80 W / m * k or less.

  When the thermal conductivity of the conductor 3 exceeds 100 W / m · k, the conductor 3 easily transfers heat, and the temperature detected by the thermistor element 11 is lower than the actual temperature. The copper wire used for the conductor of the general lead wire has a thermal conductivity of about 390 W / m · k, and the conductor 3 constituting the present invention has a heat conduction of 1/3 compared to the copper wire. .9 times to 1 / 19.5 times can be reduced, and the temperature measurement performance of the thermistor element can be improved.

  Since the conductor 3 having a thermal conductivity of 100 W / m · k or less has a small resistance temperature coefficient, the thermistor 10 with the two-core parallel lead wire 1 using the conductor 3 is a temperature of a battery pack or the like used in an electronic device. It is preferably used to detect Since the temperature of the battery pack changes in the range from room temperature to about 200 ° C., the temperature measurement is performed by transmitting the electromotive force generated in the thermistor element 11 to the arithmetic unit (not shown). At this time, if the resistance of the conductor 3 changes according to the temperature change, the electromotive force generated in the thermistor element 11 cannot be accurately transmitted to the arithmetic unit, and accurate temperature measurement cannot be performed. Occurs. In order to prevent such a problem, it is preferable to employ a conductor 3 having a small resistance temperature coefficient that does not easily change resistance even when the temperature of an object to be measured such as a battery pack changes. The resistance temperature coefficient is a coefficient representing how much the resistance changes according to a change in temperature, and the conductor 3 used in the two-core parallel lead wire 1 according to the present invention has a thermal conductivity of 100 W / m. -It is preferable to use a copper alloy wire having a small resistance temperature coefficient of k or less.

(Specific examples of conductors)
The conductor 3 is preferably a copper alloy wire that satisfies the above-described ranges of tensile strength, elongation, and thermal conductivity. Specifically, a copper alloy wire containing copper, nickel and manganese is preferably used. In addition, the diameter of such a copper alloy wire is not particularly limited, but can be about 0.2 mm or more and 0.4 mm or less.

  The copper alloy wire containing copper, nickel and manganese preferably has a copper content of 50% by mass to 96% by mass and a total content of nickel and manganese of 4% by mass to 50% by mass.

  Specifically, for example, it is preferable to use a copper nickel resistance wire represented by CN10, CN15, CN30 and CN49 of JIS standards. Table 1 shows the composition of such a copper-nickel resistance wire.

  As shown in Table 1, CN10 has a nickel content of 4.0% by mass or more and 7.0% by mass or less, a manganese content of 1.0% by mass or less, and copper, nickel, and manganese. The total content is 99% by mass or more. Therefore, the copper content of CN10 is 93% by mass or more and 96% by mass or less. CN15 has a nickel content of 8.0% by mass or more and 12.0% by mass or less, a manganese content of 1.0% by mass or less, and a total content of copper, nickel and manganese of 99%. It is at least mass%. Therefore, the copper content of CN15 is 88% by mass or more and 92% by mass or less. CN30 has a nickel content of 20.0 mass% or more and 25.0 mass% or less, a manganese content of 1.5 mass% or less, and a total content of copper, nickel and manganese of 99. It is at least mass%. Therefore, the copper content of CN30 is not less than 75% by mass and not more than 80% by mass. In addition, CN49 has a nickel content of 42.0% by mass or more and 48.0% by mass, a manganese content of 0.5% by mass or more and 2.5% by mass or less, and includes copper, nickel, and manganese. The total content is 99% by mass or more. Therefore, the copper content of CN49 is 49.5 mass% or more and 57.5 mass% or less.

  Table 2 shows the tensile strength, elongation, and thermal conductivity of CN10, CN15, CN30, and CN49.

Tensile strength, as shown in Table 2, CN10 is 430N ^/ mm 2, CN15 is 430N ^/ mm 2, CN30 there is 450N ^/ mm 2, CN49 was 500 N / mm ^2, none of the copper-nickel resistance wire, The tensile strength required by the two-core parallel lead wire 1 of the present invention is 350 N / mm ² or more. In particular, CN30 and CN49 are 450 N / mm ² or more, which is a preferable tensile strength of the conductor 3.

  As shown in Table 2, the elongation rate is 5% for CN10, 25% for CN15, CN30 and CN49, and the elongation rate required for the two-core parallel lead wire 1 of the present invention is 5% or more. CN30 and CN49 are 20% or more and 40% or less which is a preferable elongation.

  As shown in Table 2, the thermal conductivity is 96 W / m · k for CN10, 61 W / m · k for CN15, 35 W / m · k for CN30, and 20 W / m · k for CN49. The resistance wire also has a thermal conductivity of 100 W / m · k or less, which is required for the two-core parallel lead wire 1 of the present invention, and a preferable thermal conductivity of 20 W / m · k or more and 80 W / m · k or less.

  Thus, since each copper nickel resistance wire of CN10, CN15, CN30, and CN49 has the above-described tensile strength, elongation rate, and thermal conductivity, it is suitable as the conductor 3 of the two-core parallel lead wire 1 of the present invention. Can be used. In particular, CN30 and CN49 can be used more preferably because they are within the preferred ranges of tensile strength, elongation, and thermal conductivity.

<Insulation coating layer>
The insulating coating layer 4 is an insulating layer that covers the conductor 3 and enables the conductor 3 to be soldered, and acts to prevent contact between the conductors 3 and prevent a short circuit. The insulating coating layer 4 preferably has a heat resistance of at least 150 ° C. or higher. By applying the insulating coating layer 4 having a heat resistance index in this range, it can be preferably used for temperature measurement of a battery pack whose temperature rises from 100 ° C. to 200 ° C., for example. When the heat resistance index of the insulating coating layer 4 is less than 150 ° C. and the heat resistance is not sufficient, the insulating coating layer 4 is deteriorated when the two-core parallel lead wire 1 is used for a long period of time. The “heat resistance index” is an index representing heat resistance over a long period of time, and means a temperature at which a sample exposed to a predetermined temperature can withstand 100,000 hours.

  When the two-core parallel lead wire 1 is connected to the thermistor element 11, not only the conductor 3 but also the insulating coating layer 4 is soldered. For this reason, the insulating coating layer 4 itself needs to be made of a solderable material. The constituent resin of the insulating coating layer 4 having such characteristics (heat resistance and solderability) can be selected from a heat resistant polyurethane resin, a solderable polyester resin, and a solderable polyesterimide resin, and more preferably heat resistant. Examples thereof include polyurethane resins and solderable polyesterimide resins. The heat resistance can be adjusted by adding an epoxy resin or the like to the heat resistant polyurethane resin at a predetermined blending ratio.

  The thickness of the insulating coating layer 4 is arbitrarily designed according to the type of electronic device in which the thermistor with lead wire 10 is used, but is preferably 1 μm or more and 30 μm or less, more preferably 3 μm or more and 15 μm or less. is there. By forming with such a thickness, the diameter of the two-core parallel lead wire 1 can be reduced, and lead wiring can be performed in a narrow portion in the electronic device. On the other hand, if the thickness of the insulating coating layer 4 exceeds 30 μm, it may be difficult to perform lead wiring in a narrow portion of the electronic device. The insulating coating layer 4 may have a single layer structure or a multilayer structure. When the insulating coating layer 4 is formed in a multilayer structure, it may be formed of layers having different insulating properties, a layer imparting slipperiness may be formed on the outer layer, or heat fusion or solvent fusion. A layer having properties may be formed on the outer layer.

<Fusion layer>
The fusion bonding layer 5 is provided around the two insulated conductors 2 and fixes the insulated conductors 2 in a state of being arranged in parallel. Although the constituent material of the fusion | melting layer 5 is not specifically limited, Nylon etc. are used preferably. Such a fusion layer 5 is formed by applying a fusion layer forming resin around the insulating coating layer 4 of the two insulated conductors 2 arranged in parallel, and baking the applied fusion layer forming resin. Is done.

  The fusion layer 5 formed by coating and baking is formed to a thickness of 5 μm or less, more preferably 1 μm to 3 μm. Since the fused layer 5 has a thickness of 5 μm or less, the fused insulated conductors 2 can be easily torn apart and, as a result, the end of the two-core parallel lead wire 1 is connected to the thermistor element 11. When soldering, the insulated conductors 2 can be separated efficiently.

  The two-core parallel lead wire 1 to which the two insulated conducting wires 2 are fixed as described above is formed with a minor axis of 0.204 μm or more and 0.47 mm or less, and a major axis of 0.407 mm or more and 0.935 mm or less. Is done. Further, the two-core parallel lead wire 1 is used by being cut to a total length of 3 mm to 50 mm according to the type of electronic equipment used.

[Thermistor with lead wire]
As shown in FIG. 2, the thermistor 10 with a lead wire according to the present invention includes a thermistor element 11 and the two-core parallel lead wire 1 according to the present invention soldered to the thermistor element 11.

Specifically, as described above, the two-core parallel lead wire 1 includes two conductors having a solderable conductor 3 and an insulating coating layer 4 that covers the conductor 3 and enables the conductor 3 to be soldered. The conductor 3 is composed of a conductor 2, the tensile strength is 350 N / mm ² or more, the elongation is 5% or more, and the thermal conductivity is 100 W / m · k or less, and the two insulated conductors 2 are insulated. The conductive wire 2 is fixed in parallel with the fusion layer 5 in the longitudinal direction in which the conductor 2 extends. Then, the insulated conductors 2 and 2 are separated from each other by a desired length from the end in the longitudinal direction in which the insulated conductor 2 extends, and the conductor 3 is soldered to the thermistor element 11 at the end described above. ing.

  The thermistor element 11 is an NTC thermistor element. This thermistor element 11 is obtained by mixing and sintering oxides such as nickel, manganese, cobalt and iron. The thermistor element 11 has a negative temperature coefficient, and its resistance decreases with increasing temperature. The surfaces of both end portions of the thermistor element 11 are covered with solder 12.

[Production method]
A method for manufacturing the two-core parallel lead wire 1 and the thermistor 10 with lead wires will be described. First, a conductor 3 that has been previously annealed and adjusted to a predetermined tensile strength and elongation is prepared (preparation step). The annealing conditions at this time are set according to the type of conductor used. The predetermined tensile strength and elongation rate are set so that the tensile strength and elongation rate of the two-core parallel lead wire 1 obtained after all manufacturing steps are within the above-described range.

  Next, the insulating coating layer 4 is formed around the conductor 3 (insulating coating layer forming step). This process includes an application process for applying a resin paint around the conductor 3 and a baking process for baking the applied resin paint. By repeating the application process and the baking process once or a plurality of times, insulation is performed. The covering layer 4 is formed.

  Next, the fused layer 5 is formed around the insulating coating layer 4 (fused layer forming step). The formation of the fusion layer 5 is the same as the method for forming the insulating coating layer 4 described above, and includes an application step of applying a resin coating around the insulating coating layer 4 and a baking step of baking the applied resin coating. In addition, the fusion bonding layer 5 is formed by repeating the coating process and the baking process once or a plurality of times.

  Next, two insulated conductors 2 and 2 provided with a fusion layer 5 are prepared, guided so as to be in parallel contact, and in that state, hot air is blown or contacted with a solvent (alcohol or the like). Then, the insulated insulated wires 2 and 2 are fused via the fusion layer 5. In this way, the two-core parallel lead wire 1 can be manufactured.

  The thermistor 10 with a lead wire is manufactured by soldering the manufactured two-core parallel lead wire 1 to the thermistor element 11. First, the insulated conductors 2 are torn apart from each other by a desired length from the end 6 in the longitudinal direction of the two-core parallel lead wire 1 and separated. The separation is performed by tearing at the position of the fusion layer 5. Next, the end portion 6 of the two-core parallel lead wire 1 is soldered to the thermistor element 11. By the soldering, the insulating coating layer 4 is thermally decomposed, and the conductor 3 which is a core wire is soldered to the thermistor element 11. When the end 6 of the insulated conductor 2 is soldered, the conductor 3 is covered with solder 8 as shown in FIG. In such a soldering process, the end 6 of each insulated conductor 2 is soldered to the thermistor element 11 together with the insulation coating layer 4, so that it is not necessary to expose the conductor 3 from the insulated conductor 2 using a wire stripper, and the manufacturing process. Can be reduced. Therefore, the manufacturing cost can be reduced.

  Hereinafter, the present invention will be described in more detail with reference to examples.

[Example 1]
Copper alloy wire (copper nickel resistance wire: CN10 equivalent) consisting of 93% by mass of copper, 5.0% by mass of nickel, 1.0% by mass of manganese, and the balance of inevitable impurities of less than 1% by mass ) Was used as a conductor 3 to produce a two-core parallel lead wire 1.

  First, the conductor 3 was annealed in an inert gas atmosphere at 680 ° C. Next, an insulating coating layer 4 of a solderable polyesterimide (manufactured by Tohoku Paint Co., Ltd., trade name: TS-521) was formed around the conductor 3. The insulating coating layer 4 was formed by repeating the solderable polyesterimide coating process and baking process until the thickness reached 10 μm. Next, a nylon coating process and a baking process were performed on the surface of the insulating coating layer 4 so as to have a thickness of 3 μm. Next, the obtained two insulated conductors 2 with the fusion layer 5 were guided so as to contact in parallel and fused with alcohol. In this way, the two-core parallel lead wire 1 was manufactured. The obtained two-core parallel lead wire 1 had a major axis of about 0.650 mm and a minor axis of 0.328 mm.

[Example 2]
In Example 1, a copper alloy wire (copper nickel) having a wire diameter of 0.3 mm, consisting of 88% by mass of copper, 10% by mass of nickel, 1.0% by mass of manganese and less than 1% by mass of the remaining inevitable impurities as the conductor 3 A two-core parallel lead wire 1 was manufactured in the same manner as in Example 1 except that the annealing temperature was slightly changed to 750 ° C. using a resistance wire: CN15 equivalent).

[Example 3]
In Example 1, a copper alloy wire having a wire diameter of 0.3 mm (copper nickel) comprising 75% by mass of copper, 23% by mass of nickel, 1.0% by mass of manganese, and less than 1% by mass of inevitable impurities as the conductor 3 A two-core parallel lead wire 1 was manufactured in the same manner as in Example 1 except that the annealing temperature was slightly changed to 800 ° C. using a resistance wire: CN30 equivalent).

[Example 4]
In Example 1, a copper alloy wire (copper nickel) having a wire diameter of 0.3 mm comprising 50 mass% of copper, 47 mass% of nickel, 2.0 mass% of manganese, and less than 1 mass% of inevitable impurities as the conductor 3 as the conductor 3 A two-core parallel lead wire 1 was manufactured in the same manner as in Example 1 except that the annealing temperature was slightly changed to 820 ° C. using a resistance wire: CN49 equivalent).

[Example 5]
In Example 4, a two-core parallel lead wire 1 was manufactured in the same manner as in Example 1 except that the insulating coating layer 4 was changed to modified polyureta (trade name: TSF400, manufactured by Tohoku Paint Co., Ltd.).

[Example 6]
In Example 4, the two-core parallel lead wire 1 was manufactured in the same manner as in Example 1 except that the insulating coating layer 4 was changed to modified polyurethane (trade name: TSF100, manufactured by Tohoku Paint Co., Ltd.).

[Comparative Example 1]
In Example 1, a two-core parallel lead wire was manufactured in the same manner as in Example 1 except that a copper wire having a wire diameter of 0.3 mm was used as the conductor 3 and the annealing temperature was changed to 450 ° C.

[Comparative Example 2]
In Example 1, a copper wire containing silver having a wire diameter of 0.3 mm (silver content: 3 mass%) was used as the conductor 3, and the annealing temperature was changed to 700 ° C., in the same manner as in Example 1, A two-core parallel lead wire was manufactured.

[Comparative Example 3]
A two-core parallel lead wire was manufactured in the same manner as in Example 4 except that the annealing temperature was changed to 600 ° C. in Example 4.

[Comparative Example 4]
In Example 4, a two-core parallel lead wire was produced in the same manner as in Example 4 except that the annealing temperature was changed to 950 ° C.

[Comparative Example 5]
A two-core parallel lead wire 1 was manufactured in the same manner as in Example 4 except that the insulating coating layer 4 in Example 4 was changed to urethane (trade name: LS23, manufactured by Tohoku Paint Co., Ltd.).

[Measurement]
The tensile strength and elongation rate of the conductor 3 were measured using a tensile tester (manufactured by Shimadzu Corporation, model number: EZ-TEST) under conditions of a pulling speed of 100 mm / min.

  The thermal conductivity of the conductor 3 is measured by a thermal conductivity measuring device (manufactured by ULVAC-ES Co., Ltd., model number: GH-1).

  The composition of the conductor 3 is measured with an ICP emission spectroscopic analyzer (manufactured by Perkin Elmer, model number: Optima 8000).

  The heat resistance index constituting the insulating coating layer 4 is measured by the measurement procedure described in JIS-C-3216-6, and the obtained results are plotted on a regression line.

  The wire diameter of the conductor 3, the thickness of the insulating coating layer 4, the thickness of the fusion layer 5, and the short diameter and long diameter of the two-core parallel lead wire 1 are represented by the results of measurement with a micro gauge.

  Comprehensive evaluation was conducted by holding a thermistor 10 with a lead wire obtained by soldering the two-core parallel lead wire 1 to the thermistor element 11 and holding the thermistor element 11 in the space within the case of a smartphone of 60 mm × 120 mm. (A) ease of routing, (b) shape retention after wiring, and (c) shape retention after applying vibration when wiring was performed so as to hold the circuit. The thermistor element 11 used is an NTC thermistor (manufactured by Murata Manufacturing Co., Ltd., model number: NCP03WF104E05RL, dimensions: width 0.3 × length 0.6 × height 0.3 mm, mass: 0.2 g).

  The ease of routing in (a) was evaluated on three levels of rank 1 (easy to route), rank 2 (intermediate), and rank 3 (not easy to route) in the case of the smartphone. The shape retention after wiring in (b) is the same as the shape retention after wiring in the case of the smartphone. Rank 1 (thermistor element's own weight does not change, and springback's position fluctuation occurs. No), rank 2 (intermediate), and rank 3 (positional change due to thermistor element's own weight or position fluctuation due to springback). (C) The shape retention after applying vibration is the shape after applying vibration (sine wave vibration for 30 minutes) to the good shape retention after wiring in (b). Retention was evaluated in three stages: rank 1 (position fluctuation did not occur), rank 2 (intermediate), rank 3 (position fluctuation occurred). In addition, the comprehensive column in Table 3 is a comprehensive evaluation obtained from the results of (a) to (c), and when the sum of (a) to (c) is 3, rank A (good), 4 to The evaluation was made in three stages, with Rank 5 (intermediate) when 5 and Rank C (defect) when 6 or more.

[result]
Table 3 shows the results obtained. As shown in Table 3, the two-core parallel lead wires 1 of Examples 1 to 6 showed good results in all of ease of routing, shape retention after wiring, and shape retention after applying vibration. It was. In particular, Examples 3, 4, 5, and 6 were good. On the other hand, the two-core parallel lead wires of Comparative Examples 1, 3, and 4 were insufficient in ease of routing, shape retention after wiring, and shape retention after applying vibration. Further, Comparative Example 2 was evaluated as NG because the thermal conductivity was too high, and Comparative Example 5 was too low in heat resistance index.

DESCRIPTION OF SYMBOLS 1 2 core parallel lead wire 2 Insulated conducting wire 3 Conductor 4 Insulation coating layer 5 Fusion layer 6 End part 8 Solder 10 Thermistor with lead wire 11 Thermistor element 12 Solder

Claims (5)

Comprising two insulated conductors having a solderable conductor and an insulating coating layer covering the conductor and allowing the conductor to be soldered;
The conductor has a tensile strength of 350 N / mm ² or more, an elongation of 5% or more, and a thermal conductivity of 100 W / m · k or less, and the two insulated conductors extend in the longitudinal direction in which the insulated conductors extend. A two-core parallel lead wire fixed in parallel with a fusion layer.   The two-core parallel lead wire according to claim 1, wherein the conductor is a copper alloy wire containing copper, nickel, and manganese.   The two-core parallel lead according to claim 2, wherein the copper alloy wire has a copper content of 50 mass% or more and 96 mass% or less, and a total content of nickel and manganese of 4 mass% or more and 50 mass% or less. line.   The two-core parallel lead wire according to any one of claims 1 to 3, wherein the insulating coating layer has a heat resistance index of at least 150 ° C and a thickness of 30 µm or less. A thermistor with a lead wire composed of a thermistor element and a two-core parallel lead wire soldered to the thermistor element,
The two-core parallel lead wire is composed of two insulated conductors each having a solderable conductor and an insulating coating layer that covers the conductor and enables the conductor to be soldered. 350 N / mm ² or more, the elongation is 5% or more, the thermal conductivity is 100 W / m · k or less, and the two insulated conductors are parallel to the longitudinal direction in which the insulated conductors extend in the fusion layer. The insulated conductors are separated from each other by a desired length from the longitudinal end portion where the insulated conductor extends, and the conductor is soldered to the thermistor element at the end portion. A thermistor with a lead wire.

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