KR20210028743A - Electrical component lead wire and electrical component - Google Patents

Abstract

The lead wire for an electric component according to an embodiment of the present invention includes a strip-shaped conductor and a pair of insulating films covering both sides of the strip-shaped conductor, and the elastic modulus of the strip-shaped conductor is D _m [Pa] and a width of 1 The second cross-sectional moment _{per mm is I m} [m ⁴ /1 mm], the average elastic modulus of the pair of insulating films is D _i [Pa], and the second cross-sectional moment per 1 mm of width is I _i [m ^4]. /1mm], the width of the insulating film represented by the formula (2) is 1mm for the shape retention force H[N·m²/1mm] per 1mm of the width of the strip-shaped conductor represented by the formula (1). The ratio (R/H) of the elastic recovery force R [N·m 2/1 mm] of sugar is 0.15 or less.
H=D _m ×I _m ... (One)
R=D _i ×I _i … (2)

Description

Electrical parts lead wire and electrical parts {ELECTRICAL COMPONENT LEAD WIRE AND ELECTRICAL COMPONENT}

The present invention relates to an electrical component lead wire and an electrical component.

In accordance with the demand for miniaturization of electronic devices, there is a strong demand for miniaturization and weight reduction of batteries used as power sources thereof. On the other hand, high energy density and high energy efficiency are also required for batteries. In order to satisfy such a demand, expectations for a non-aqueous electrolyte battery (for example, a lithium ion battery) in which an electrode, an electrolyte, and the like are enclosed in an encapsulant are increasing.

In such a non-aqueous electrolyte battery, it is common for the lead wire to extend from the sealing member in order to take out current to the outside. As a lead wire, it is known that the lead conductor is formed of only a lead conductor made of a metal such as aluminum, and the lead conductor is covered with an insulating layer of a thermoplastic resin. Then, the lead wire is attached to the sealing member by heat sealing the open end of the lead wire, for example, with the lead wire interposed between the inner surface of the open end of the sealing member.

In the method of attaching the lead conductor to the sealing member by such heat sealing, there is a possibility that the insulating layer is melted by heat during heat sealing and the lead conductor is shorted with the metal layer of the sealing member. Therefore, it has been proposed to avoid melting of the insulating layer by making the insulating layer include a crosslinked layer made of crosslinked polyolefin (see, for example, Patent Documents 1 and 2).

Japanese Patent Application Publication No. 2001-102016 Japanese Patent Publication No. 2009-259739

A lead wire for an electric component according to an aspect of the present invention is a lead wire for an electric component comprising a strip-shaped conductor and a pair of insulating films covering both sides of the strip-shaped conductor, wherein the strip-shaped conductor The modulus of elasticity of the conductor is D _m [Pa], the second moment of inertia of area _{per 1 mm of width is I m} [m ⁴ /1 mm], and When the average modulus of elasticity is D _i [Pa] and the cross-sectional second moment per 1 mm of width is I _i [m ⁴ /1 mm], the shape retention force per 1 mm of width of the strip-shaped conductor represented by the following equation (1) The ratio (R/H) of the elastic recovery force R [N·m 2/1 mm] per width 1 mm of the insulating film represented by the following formula (2) to H [N·m 2/1 mm] is 0.15 or less.

H=D _m ×I _m ... (One)

R=D _i ×I _i … (2)

An electric component according to an aspect of the present invention includes the electric component lead wire.

Fig. 1 is a schematic perspective view showing a part of a lithium ion battery according to another embodiment of the present invention by breaking it.
2 is a schematic cross-sectional view taken along line AA of FIG. 1.
Fig. 3(a) is a schematic cross-sectional view viewed from a longitudinal direction for explaining a second moment in cross section of a strip-shaped conductor and an insulating film in the lead wire for an electric component according to an embodiment of the present invention.
Fig. 3(b) is a schematic cross-sectional view showing only a strip-shaped conductor of the lead wire for an electric component of Fig. 3(a).
Fig. 3(c) is a schematic cross-sectional view showing only the insulating film of the lead wire for electric parts of Fig. 3(a).
Fig. 4(a) is a schematic plan view for explaining a lead wire used for evaluation of a spring back angle.
Fig. 4(b) is a schematic cross-sectional view of the lead wire of Fig. 4(a).
Fig. 5(a) is a schematic cross-sectional view for explaining one step of a method for evaluating a spring back angle.
Fig. 5(b) is a schematic cross-sectional view for explaining a step following Fig. 5(a).
6 is a graph showing the relationship between the measurement result of the spring back angle and the ratio of the elastic recovery force R per 1 mm width of a pair of insulating films to the shape retention force H per 1 mm width of a strip-shaped conductor. .

[Problems to be solved by this disclosure]

The conventional nonaqueous electrolyte battery having a lead wire is often accommodated in an electronic device while the lead wire is bent. Therefore, at the time of manufacture of the electronic device, the lead wire provided in the nonaqueous electrolyte battery is bent at a location where the lead conductor is covered with an insulating layer, and is sometimes sent to a downstream process while maintaining this bent shape. Therefore, when it is assumed that the lead wire is bent and used, it is difficult to generate a spring back and a lead wire capable of appropriately maintaining the bent shape is required.

Here, the lead conductor is a metal such as aluminum, which is plastically deformed when bent, and generates a force that attempts to maintain the bent shape. On the other hand, since the insulating layer is made of resin or the like, it elastically deforms when it is bent, and a force to return to its original shape from the bent shape is generated. Among these two forces, when the force that tries to return to the original shape from the bending shape caused by the elastic deformation of the insulating layer acts strongly, the lead wire cannot maintain the bending shape and returns to the original shape slightly (spring Back) is formed. However, since springback is a complex phenomenon caused by the interaction of two members having different materials, such as a metal lead conductor and a resin insulation layer, springback can be sufficiently suppressed if any member is applied to the lead conductor and the insulation layer. It is difficult to accurately predict whether there will be.

It is an object of the present invention to provide a lead wire for electric parts and an electric part that is less likely to produce a spring back when bent and used, and which can adequately maintain a bent shape.

[Effects of the Invention]

Advantageous Effects of Invention According to the above invention, it is possible to provide an electric component lead wire capable of appropriately maintaining a bent shape, and an electric component excellent in work efficiency because it is difficult to generate a spring back when bent and used.

[Description of the embodiment of the present invention]

An electrical component lead wire according to an aspect of the present invention is a lead wire for electrical components comprising a strip-shaped conductor and a pair of insulating films covering both sides of the strip-shaped conductor, wherein the strip-shaped conductor has an elastic modulus of D _m [Pa], the cross-sectional secondary moment per 1 mm of width is I _m [m ⁴ /1 mm], and the average elastic modulus of the pair of insulating films is D _i [Pa], and the cross-sectional secondary moment per 1 mm of width is In the case of I _i [m ⁴ /1 mm], in the following equation (2) for the shape retention force H [N·m 2 /1 mm] per 1 mm width of the strip-shaped conductor represented by the following equation (1) The ratio (R/H) of the elastic recovery force R [N·m 2/1 mm] per 1 mm of the width of the insulating film shown is 0.15 or less.

H=D _m ×I _m ... (One)

R=D _i ×I _i … (2)

Here, the reason for the occurrence of the spring back on the lead wire is that it tries to return to its original shape from the bending shape caused by the elastic deformation of the insulating film, rather than the force trying to maintain the bending shape caused by the plastic deformation of the strip-shaped conductor as described above. I think it is because the force acts strongly. Therefore, when the force due to plastic deformation of the strip-shaped conductor is increased and the force due to elastic deformation of the insulating film is decreased, it is considered that springback is suppressed and the bending shape of the lead wire is easily maintained. Here, it is considered that whether or not the lead wire can maintain the bent shape, that is, the ease of occurrence of springback, depends not only on the material of the strip-shaped conductor or the insulating film, but also on their thickness and shape. Therefore, the present inventors have determined the effect of the strip-shaped conductor of the lead wire for the electrical component on the springback, and the shape per 1 mm of width represented by the above equation (1), which uses the modulus of elasticity and the second cross-sectional moment per 1 mm of width as parameters. I found that it can be judged by holding power. In addition, the present inventors, etc., the effect of the insulating film of the lead wire for the electrical component on the spring back, the elasticity modulus and the elastic recovery force per 1 mm of width represented by the above equation (2) as parameters of the cross-sectional secondary moment per 1 mm of width as parameters. I found that it can be judged by. In addition, the inventors of the present invention are concerned with the effect of the insulation film of the lead wire for electric parts and the springback of the strip-shaped conductor on the elastic recovery force per 1 mm of the width of a pair of insulating films relative to the shape-retaining force per 1 mm of the strip-shaped conductor. It was found that it is difficult to generate a spring back when bent and used, and that the bent shape can be appropriately maintained by relating the ratio to the ratio of the above upper limit or less.

As described above, when the ratio of the elastic recovery force per 1 mm width of the pair of insulating films to the shape retention force per 1 mm width of the strip-shaped conductor is less than or equal to the above upper limit, it is difficult to generate a spring back, and thus the bent shape is reduced. You can keep it appropriately. Therefore, when the lead wire is bent and used, it is not necessary to fix the bent lead wire to other elements using a fixing tape or the like after the lead wire is bent, since the bent shape is easily maintained. As a result, it is possible to simplify the manufacturing process when the lead wire for electric parts is bent and used, and can contribute to space saving by being bent and used.

Here, "average thickness" means the average value of the thickness measured at arbitrary five points. ``Elastic modulus'' is the rising slope of the SS curve (stress-strain curve) when tensile strain is applied to strip-shaped conductors and insulating films using a precision universal testing instrument. Represents. In the measurement of this modulus of elasticity, the sample gripping (chuck) interval of the tensile testing machine is set to 50 mm, and tensile is performed at 50 mm/min. However, when measuring the elastic modulus of the strip-shaped conductor, in order to take into account the influence of slipping between the specimen and the gripper of the testing machine, a strain gauge capable of measuring a small displacement is provided on the specimen and measured. In addition, it is the test force [N]-moving distance [mm] curve that is obtained directly from the measurement of this modulus of elasticity, but as shown in the following equations (3) and (4), the stress [Pa Convert it to a ]-deformation [%] curve and calculate the modulus of elasticity. Further, even when the strip-shaped conductor and the insulating film are a multilayer structure, the modulus of elasticity can be obtained by the above-described method. In addition, the "average elastic modulus of a pair of insulating films" means the average of the measured values of the elastic modulus of each of the two insulating films. Hereinafter, in the case of "average thickness" or "elastic modulus", it is defined in the same manner.

Stress [Pa] = test force [N] ÷ width [㎜] ÷ thickness [㎜]… (3)

Deformation [%] = moving distance [㎜] ÷ chuck spacing [㎜] × 100… (4)

It is preferable that the lead wire for electric parts has a bending recovery angle of 20° or less after being bent by 180°. According to such a lead wire, the bending recovery angle after being bent by 180°, that is, a spring back angle of 20° or less, makes it possible to more appropriately maintain the bent shape, so that the work of bending the lead wire and maintaining its shape becomes easier. Workability is further improved.

The elastic recovery force R ^{is preferably 3.0×10 -5} N·m 2 /1 mm or more and 6.0×10 ^-3 N·m 2 /1 mm or less. According to such a lead wire, when the elastic recovery force R is within the above range, the spring back after the lead wire for electric component is bent can be appropriately reduced. As a result, the bending operation of the lead wire for electric parts becomes easier, and workability is further improved.

The shape retention force H ^{is preferably 3.0×10 -4} N·m 2 /1 mm or more and 6.0×10 ^-2 N·m 2 /1 mm or less. According to such a lead wire, when the shape-retaining force H is within the above range, the bent shape can be more appropriately maintained. Therefore, the shape-retaining property capable of appropriately maintaining the bent shape can be imparted to the lead wire for electric parts. As a result, the bending operation of the lead wire for electric parts becomes easier, and workability is further improved.

The average thickness of the strip-shaped conductor is preferably 30 µm or more and 200 µm or less, and the elastic modulus of the strip-shaped conductor is preferably 50 GPa or more and 300 GPa or less. According to such a lead wire, the shape-retaining force of a strip-shaped conductor is made into an appropriate range, and the shape-retaining property which can appropriately maintain a bent shape can be provided to the said lead wire for electric parts. As a result, the bending operation of the lead wire for electric parts becomes easier, and workability is further improved.

The average thickness of each of the insulating films is preferably 25 µm or more and 200 µm or less, and the elastic modulus of each of the insulating films is preferably 100 MPa or more and 1,400 MPa or less. According to such a lead wire, the elastic recovery force of an insulating film is made into an appropriate range, and the spring back after bending of the said lead wire for electric components can be suitably reduced. As a result, the bending operation of the lead wire for electric parts becomes easier, and workability is further improved.

An electrical component according to one embodiment of the present invention includes the electrical component lead wire. Since the said electric part is provided with the said electric part lead wire, it can bend the said electric part lead wire, and work efficiency can be improved by being able to simplify the operation of maintaining the shape.

The electric component may be a non-aqueous electrolyte battery. As described above, since the electric component is excellent in work efficiency, it can be suitably used as a non-aqueous electrolyte battery.

[Details of the embodiment of the present invention]

A specific example of an electric component lead wire and an electric component according to an embodiment of the present invention will be described with reference to the drawings. In addition, the present invention is not limited to these examples, but is represented by the claims, and it is intended that the meanings equivalent to the claims and all changes within the scope are included.

<Lead wire for electrical components>

1 and 2, the lead wire 1 for an electric component according to an embodiment of the present invention includes a strip-shaped conductor 2, and a pair of insulating films covering both sides of the strip-shaped conductor 2 (3) is provided.

(Strip shape conductor)

The strip-shaped conductor 2 is connected to an electrode (positive electrode 5A and negative electrode 5B) of an electric component such as a lithium ion battery 4 or the like. This strip-shaped conductor 2 is made of a material having high conductivity. Examples of such highly conductive materials include metal materials such as aluminum, titanium, nickel, copper, aluminum alloy, titanium alloy, nickel alloy, and copper alloy, and materials in which these metal materials are plated with nickel, gold, or the like. I can. As a material for forming the strip-shaped conductor 2 connected to the positive electrode 5A of an electric component such as a lithium ion battery 4, those that do not dissolve during discharge, specifically aluminum, titanium, aluminum alloy, and titanium alloy are used. desirable. On the other hand, as a material for forming the strip-shaped conductor 2 connected to the cathode 5B, nickel, copper, nickel alloy, copper alloy, nickel plated copper, and gold plated copper are preferable. Further, the strip-shaped conductor 2 may be subjected to surface treatment such as chromate treatment, trivalent chromium treatment, non-chromate treatment, and roughening treatment in order to improve electrolyte resistance and the like. By such a surface treatment, the electrolytic solution resistance of the strip-shaped conductor 2 can be improved.

When the elastic modulus of the strip-shaped conductor 2 is D _m [Pa] and the cross-sectional second moment per 1 mm of width is I _m [m ⁴ /1 mm], the strip-shaped conductor 2 represented by the following equation (1) ) As the lower limit of the shape retention force H [N·m 2/1 mm] per 1 mm of width, 3.0×10 ^-4 N·m 2/1 mm is preferable, and 2.0×10 ^-3 N·m 2/1 mm is more preferable. Do. As the upper limit of this shape retention force H, 6.0×10 ^-2 N·m 2 /1 mm is preferable, and 1.0×10 ^-2 N·m 2 /1 mm is more preferable.

H=D _m ×I _m ... (One)

Since the strip-shaped conductor 2 can maintain the bent shape more appropriately when the shape-retaining force H is in the above range, it is possible to impart shape-retaining property to the lead wire 1 for electric parts to properly maintain the bent shape. I can. As a result, it becomes easier to bend the lead wire 1 for electric parts and maintain its shape, and the workability is further improved.

Here, the cross-sectional second moment per 1 mm of the width of the strip-shaped conductor 2 in the above equation (1) and the cross-sectional moment per 1 mm of the width of the pair of insulating films 3 in the later-described equation (2) The calculation method will be described using the lead wire 11 for electric components in Fig. 3A as an example. The lead wire 11 for electric components shown in FIG. 3(a) has the same average thickness of the pair of insulating films 13 and the same average width. The average thickness of the lead wire 11 for electrical components is T, the average thickness of the strip-shaped conductor 12 is T _m [m], and the average thickness of each pair of insulating films 13 is T _i [m]. . In addition, the average width of the strip-shaped conductor 12 is W _m [m], and the average width of a pair of insulating films 13 is W _i [m]. In addition, the surface where the lead wire 11 for electric parts is divided into two in the thickness direction (the surface where the strip-shaped conductor 12 is divided in two in the thickness direction) is regarded as the center plane M of the bending deformation of the lead wire for electric parts 11 can do.

Next, the cross-sectional moment of the strip-shaped conductor 12 can be calculated by the following equation (5) based on the cross-sectional shape shown in Fig. 3(b). Similarly, the cross-sectional moment of the pair of insulating films 13 can be calculated by the following equation (6) based on the cross-sectional shape shown in Fig. 3(c).

Secondary moment of cross-section per 1 mm width of strip-shaped conductor [m ⁴ /1 mm] = 1/12 × average width of strip-shaped conductor W _m [m] × (average thickness of strip-shaped conductor T _m [m]) ³ /Average width of strip-shaped conductor W _m [mm]… (5)

Secondary moment of cross-section per 1 mm width of a pair of insulating films [m ⁴ /1 mm] = 1/12 × Average width of a pair of insulating films W _i [m]×{ (average thickness T of lead wires for electrical components [m]) ³ -(average thickness of strip-shaped conductor T _m [m]) ³ }/1 average width of insulating film W _i [mm]… (6)

In addition, when the average thickness or average width of the pair of insulating films 3 of the lead wire 1 for electrical components is not the same, the average value of each average thickness or the average width of the pair of insulating films 3 is calculated. , Assuming that the average thickness or the average width of the pair of insulating films 3 are all the average values, the above-described calculation is performed. Then, the shape holding force H and the elastic recovery force R are determined using the cross-sectional secondary moment per 1 mm of width of the strip-shaped conductor 2 and the pair of insulating films 3 obtained by this calculation.

As the lower limit of the cross-sectional moment per 1 mm of width of the strip-shaped conductor 2, 5.0 × 10 ^-15 m ⁴ /1 mm is preferable, and 2.0 × 10 ^-14 m ⁴ /1 mm is more preferable. On the other hand, as the upper limit of the cross-sectional moment, 8.0×10 ^-13 m ⁴ /1 mm is preferable, and 1.0×10 ^-13 m ⁴ /1 mm is more preferable. By setting the cross-sectional moment to be within the above range, the shape holding force H per 1 mm of the width of the strip-shaped conductor 2 can be easily and reliably adjusted within the above range.

The average thickness of the strip-shaped conductor 2 is preferably 30 µm or more and 200 µm or less. The lower limit of the average thickness of the strip-shaped conductor 2 is more preferably 40 µm, and still more preferably 47 µm. On the other hand, as the upper limit of the average thickness of the strip-shaped conductor 2, 150 µm is more preferable, and 120 µm is more preferable. When the average thickness of the strip-shaped conductor 2 is less than the above lower limit, the electrical resistance value of the lead wire 1 for electric components may increase. Conversely, when the average thickness exceeds the above upper limit, the lead wire 1 for electric components becomes unnecessarily thick, and there is a fear that it may not be able to sufficiently respond to the demand for thickness reduction.

The elastic modulus of the strip-shaped conductor 2 is preferably 50 GPa or more and 300 GPa or less. As the lower limit of the elastic modulus of the strip-shaped conductor 2, 60 GPa is more preferable, and 67 GPa is more preferable. On the other hand, as the upper limit of the elastic modulus of the strip-shaped conductor 2, 250 GPa is more preferable, and 210 GPa is more preferable. When the elastic modulus of the strip-shaped conductor 2 is less than the above lower limit, there is a fear that it becomes difficult to suppress the springback of the lead wire 1 for electric components. Conversely, when the elastic modulus exceeds the above upper limit, there is a concern that workability may be deteriorated by requiring force to bend the lead wire 1 for electric components. Further, the modulus of elasticity of the strip-shaped conductor 2 can be adjusted by changing the material, and in particular, by using the strip-shaped conductor 2 as an alloy, fine adjustment of the modulus of elasticity is possible by changing the alloy component.

In addition, since the strip-shaped conductor 2 has an average thickness of 30 µm or more and 200 µm or less, and an elastic modulus of 50 GPa or more and 300 GPa or less, the shape holding force H is in a very suitable range, and the lead wire for electric parts (1) It is possible to impart a shape-retaining property capable of appropriately maintaining a bent shape. As a result, the shape fixing operation at the time of bending the lead wire 1 for electric components becomes easier, and workability is further improved.

(1 pair of insulating film)

A pair of insulating films 3 covers both sides of the center portion of the strip-shaped conductor 2 in a state where both ends of the strip-shaped conductor 2 are exposed. It is a part which is fixed to the sealing body 6 of an electric component.

Each insulating film 3 is formed of a resin material having high insulating properties. This resin material is preferably a resin material having high adhesion to the strip-shaped conductor 2 or a resin material that is difficult to melt by heating when heat sealing the sealing member 6.

Examples of the resin material having high adhesion to the strip-shaped conductor 2 include thermoplastic polyolefins. Examples of this thermoplastic polyolefin include reactive resins such as polyethylene, acid-modified polyethylene, polypropylene, acid-modified polypropylene (for example, maleic anhydride-modified polypropylene), and ionomers. Mixtures, etc. are mentioned.

On the other hand, as a resin material that is difficult to melt by heating when sealing the sealing body 6 by heat, for example, a crosslinked polyolefin or the like can be mentioned. As this crosslinked polyolefin, what crosslinked the polyolefin mentioned above can be used. As a method of crosslinking the polyolefin, crosslinking by irradiation of ionizing radiation such as electron beams or gamma rays, chemical crosslinking by peroxide or the like, silane crosslinking, and the like are used. In the case of crosslinking the polyolefin by ionizing radiation, a cross-linking assistant is added to the polyolefin if necessary. As this crosslinking aid, for example, trimethylol propane methacrylate, pentaerythritol triacrylate, ethylene glycol dimethacrylate, triallyl cyanurate ( triallyl cyanurate), triallyl isocyanurate, and the like are used.

The gel fraction in the crosslinked polyolefin is preferably 20% or more and 90% or less. In addition, the gel fraction is an index indicating the degree of crosslinking, and refers to the ratio of the gel (insoluble polymer chain) in the crosslinked polyolefin that is not dissolved in a solvent such as xylene. If the gel fraction is less than 20%, the degree of crosslinking is insufficient, and the insulating film 3 may be melted during heat sealing. Conversely, when the gel fraction exceeds 90%, the degree of crosslinking is too large, and there is a fear that the adhesion between the crosslinked polyolefin and the sealing member 6 may deteriorate.

In addition, each insulating film 3 may be a single layer or may be laminated in a plurality of layers. In the case of configuring the insulating film 3 as a plurality of layers, the insulating film 3 is heat-sealed with the insulating layer formed of a resin material having high adhesion to the strip-shaped conductor 2 and the sealing member 6. It is preferable to include an insulating layer formed of a resin material that is difficult to melt by heating. When the insulating film 3 having such a laminated structure is employed, adhesion to the strip-shaped conductor 2 can be ensured, and melting during heat sealing can be prevented.

When the average modulus of elasticity of a pair of insulating films 3 is D _i [Pa] and the cross-sectional second moment per 1 mm of width is I _i [m ⁴ /1 mm], one pair represented by the following equation (2) The lower limit of the elastic recovery force R [N·m 2/1 mm] per 1 mm of the width of the insulating film 3 ^{is preferably 3.0×10 -5} N·m 2/1 mm, and 1.0×10 ^-4 N·m 2 / 1 mm is more preferable. On the other hand, as the upper limit of the elastic recovery force R, 6.0×10 ^-3 N·m 2 /1 mm is preferable, and 1.0×10 ^-3 N·m 2 /1 mm is more preferable.

R=D _i ×I _i … (2)

When the elastic recovery force per 1 mm of width of the pair of insulating films 3 is in the above range, it is possible to appropriately suppress the springback of the lead wire 1 for electric parts after bending. As a result, the work of bending the lead wire 1 for electric components and maintaining the shape becomes easier, and workability is further improved. In addition, the elastic modulus of the insulating film 3 can be adjusted by changing the material, and when each insulating film 3 is formed of a crosslinked resin, the elastic modulus can be adjusted by changing the degree of crosslinking.

As the lower limit of the cross-sectional moment per 1 mm of width of the pair of insulating films 3, 1.0 × 10 ^-13 m ⁴ /1 mm is preferable, and 5.0 × 10 ^-13 m ⁴ /1 mm is more preferable. On the other hand, as the upper limit of the cross-sectional moment, 8.0×10 ^-12 m ⁴ /1 mm is preferable, and 1.0×10 ^-12 m ⁴ /1 mm is more preferable. By setting the cross-sectional moment to be within the above range, the elastic recovery force per 1 mm in width of the pair of insulating films 3 can be easily and reliably adjusted within the above range.

The average thickness of each insulating film 3 is preferably 25 µm or more and 200 µm or less. As the lower limit of the average thickness, 40 µm is more preferable, and 60 µm is still more preferable. On the other hand, as the upper limit of the average thickness, 120 µm is more preferable, and 80 µm is still more preferable. When the average thickness of each insulating film 3 is less than the above lower limit, the thickness of the insulating film 3 becomes too thin with respect to the thickness of the strip-shaped conductor 2, and as a result, the lead wire 1 for electric parts is encapsulated. In order to adhere to (6), when heat-sealing, there is a possibility of a short circuit between the strip-shaped conductor 2 and the sealing member 6. The fear of this short circuit is particularly remarkable at the edge portions (both ends in the width direction) of the strip-shaped conductor 2. Conversely, when the average thickness exceeds the above upper limit, there is a fear that the spring back of the lead wire 1 for electric components cannot be sufficiently suppressed.

It is preferable that the average thickness and the elastic modulus of each of the insulating films 3 are approximately the same. Specifically, the ratio of the average thickness of the insulating film 3 on the other side to the average thickness of the insulating film 3 on one side (average thickness of the insulating film 3 on one side / the insulating film 3 on the other side) ) Is preferably 0.95 or more and 1.05 or less. In addition, the ratio of the elastic modulus of the insulating film 3 on the other side to the elastic modulus of the insulating film 3 on one side (the elastic modulus of the insulating film 3 on one side / the elastic modulus of the insulating film 3 on the other side) is It is preferably 0.7 or more and 1.5 or less.

In addition, as the lower limit of the ratio of the average thickness of each insulating film 3 to the average thickness of the strip-shaped conductor 2 (average thickness of the insulating film/average thickness of the strip-shaped conductor), all are preferably 0.2, and 0.3 is It is more preferable and 0.35 is still more preferable. On the other hand, as the upper limit of the ratio, 1.5 is preferable, 1.2 is more preferable, and 1.0 is still more preferable. By setting the ratio of the average thickness of each insulating film 3 to the average thickness of the strip-shaped conductor 2 in the above range, the elasticity of the pair of insulating films 3 with respect to the shape-holding force of the strip-shaped conductor 2 The ratio of the recovery force can be adjusted in an appropriate range, and as a result, it becomes possible to reduce the spring back angle and maintain a desired bent shape.

The ratio of the second cross-sectional moment per 1 mm of the width of the strip-shaped conductor 2 to the second moment of cross-section per 1 mm of the width of the pair of insulating films 3 (second cross-section per 1 mm of the width of the pair of insulating films) As the lower limit of the moment/secondary moment in cross section per 1 mm of the width of the strip-shaped conductor), 1.0 is preferable and 3.0 is more preferable. On the other hand, as the upper limit of the ratio, 4.0×10 is preferable, and 2.5×10 is more preferable. By setting the ratio within the above range, the ratio of the elastic recovery force of the pair of insulating films 3 to the shape holding force of the strip-shaped conductor 2 can be adjusted to an appropriate range, and as a result, the spring back angle is reduced, It becomes possible to maintain a desired bending shape.

As the elastic modulus of each insulating film 3, 100 MPa or more and 1,400 MPa or less are preferable. As the lower limit of the elastic modulus, 150 MPa is more preferable, and 200 MPa is still more preferable. On the other hand, as the upper limit of the elastic modulus, 720 MPa is more preferable, and 350 MPa is more preferable. When the elastic modulus of the insulating film 3 is in the above range, the elastic recovery force of the insulating film 3 can be made appropriate.

In addition, each insulating film 3 has an average thickness of 25 µm or more and 200 µm or less, and both have an elastic modulus of 100 MPa or more and 1,400 MPa or less, thereby appropriately reducing the spring-back angle after bending of the lead wire 1 for electrical components. can do. As a result, the work of bending the lead wire 1 for electric components and maintaining the shape becomes easier, and workability is further improved.

As the lower limit of the ratio of the average elastic modulus of the pair of insulating films 3 to the elastic modulus of the strip-shaped conductor 2 (the average elastic modulus of the pair of insulating films 3 / the elastic modulus of the strip-shaped conductor 2), 1.0 ×10 ^-3 is preferable, and 2.0×10 ^-3 is more preferable. On the other hand, as the upper limit of the ratio, 4.0 × 10 ^-2 it is preferably, 1.5 × 10 ^- more preferably ^2. By setting the ratio within the above range, the ratio of the elastic recovery force of the pair of insulating films 3 to the shape holding force of the strip-shaped conductor 2 can be adjusted to an appropriate range, and as a result, the spring back angle is reduced, It becomes possible to maintain a desired bending shape.

In the lead wire 1 for electric components, the ratio of the elastic recovery force R per 1 mm of the width of the pair of insulating films 3 to the shape retention force H per 1 mm of the width of the strip-shaped conductor 2 is 0.15 or less. As the upper limit of the ratio, 0.10 is preferable and 0.05 is more preferable. Moreover, although there is no restriction|limiting in particular about the lower limit of the said ratio, 0.001 is preferable and 0.002 is more preferable.

It is preferable that the lead wire 1 for electric parts has a bending recovery angle (spring back angle) of 20° or less after 180° bending. According to such a lead wire 1 for electric parts, the bending recovery angle (spring back angle) after 180° bending is 20° or less, so that the bending shape can be more appropriately maintained, so that the shape fixing operation at the time of bending is easier. So that the workability is further improved. Further, the smaller the bending recovery angle is, the better, 12° or less is more preferable, 5° or less is more preferable, and 0° is most preferable.

<Electrical parts>

An electric component according to an embodiment of the present invention includes a lead wire 1 for electric components. Examples of the electrical components in which the lead wire 1 for electrical components is used include non-aqueous electrolyte batteries such as lithium ion batteries, and capacitors such as lithium ion capacitors and electric double-layer capacitors (EDLC). have. Of course, the lead wire 1 for electric components can be applied to all electric components that require a lead wire, and the same effect can be obtained even when applied to a battery other than a nonaqueous electrolyte battery.

Hereinafter, a non-aqueous electrolyte battery including the lead wire 1 for electric components will be described with reference to the drawings, taking a lithium ion battery as an example.

(Lithium ion battery)

The lithium ion battery 4 shown in FIGS. 1 and 2 is a battery element containing a non-aqueous electrolyte solution enclosed in the encapsulant 6. The battery element holds a non-aqueous electrolyte solution with a separator (not shown) interposed between the positive electrode 5A and the negative electrode 5B. As the non-aqueous electrolyte, a lithium compound (LiClO ₄ , LiBF _4, etc.) dissolved in an organic solvent such as propylene carbonate and γ-butyrolactone is used.

The lead wire 1 for electric parts is fixed to the sealing body 6 with the insulating film 3. In the lead wire 1 for electric parts, one end 2A and the other end 2B of the strip-shaped conductor 2 are exposed from the insulating film 3, and the strip-shaped conductor 2 is exposed. One end 2A is electrically connected to the positive electrode 5A or the negative electrode 5B of the battery element, and the other exposed end 2B of the strip-shaped conductor 2 is removed from the encapsulant 6 It protrudes.

Since such a lithium ion battery 4 is provided with the lead wire 1 for electric parts, it is possible to bend the lead wire 1 for electric parts and simplify the operation for maintaining the shape, thereby improving work efficiency. I can.

Further, even in the case where the lead wire 1 for electric parts is applied to electric parts other than the lithium ion battery 4, the work efficiency can be improved by simplifying the operation for maintaining the bent shape.

(Example)

Next, the present invention is specifically described by experimental examples, but the present invention is not limited by the following experimental examples, and it is also possible to carry out appropriate modifications within a range suitable for the purpose of the present invention, all of which are the present invention. It is included in the technical scope of.

In this experimental example, the spring back angle of the lead wire was evaluated.

<Lead wire>

The lead wire was formed by covering the central portion of the strip-shaped conductor with a pair of insulating films so that both ends of the strip-shaped conductor were exposed. 4(a) and 4(b), as the strip-shaped conductor 7, the length L _m is 80 mm, the width W _m is 5 mm, and the elastic modulus and average thickness T _m are shown in Table 1 below. What is the indicated value was used. As the insulating film 8, the length L _i was 6 mm, the width W _i was 7 mm, and the elastic modulus and the average thickness T _i were used as values shown in Table 1 below. Moreover, the two insulating films 8 used the same thing. In addition, the total average thickness of the strip-shaped conductor 7 and the pair of insulating films 8 was taken as the average thickness T of the lead wire.

<Secondary Moment of Section>

The cross-sectional second moment [m ⁴ /1㎜] per 1㎜ width of the strip-shaped conductor 7 is 1/12×W _m [m]×(T _m [m]) ³ /W _m [㎜]. Was obtained by substituting. The second cross-sectional moment [m ⁴ /1㎜] of a pair of insulating films 8 is 1/12×W _i [m]×{(T[m]) ³ -(T _m [m]) ³ }/ Each numerical value was substituted for W _i [mm] and calculated|required.

<Evaluation of spring back angle>

The spring back angle was evaluated as follows. First, as shown in Fig. 5(a), a cross section of a plate material X having a thickness of 0.5 mm is brought into contact near the center of the longitudinal direction of the insulating film 8 on one side of the lead wire, and the lead wire is slowly 180° so as to sandwich the plate material X. After bending, the load F was made to act by attaching a weight of 200 g on the other insulating film 8, and this state was maintained for 10 seconds. Next, as shown in Fig. 5(b), evaluation was made by measuring the springback angle θ[deg] (angle formed by the lead wire) when the load was removed and allowed to stand for 5 seconds or more. The measurement results of the spring back angle are shown in Table 1 below. In addition, the relationship between the springback angle θ and the ratio (R/H) of the elastic recovery force R per 1 mm width of the pair of insulating films to the shape retention force H per 1 mm width of the strip-shaped conductor is shown in FIG. 6. In addition, the elastic recovery force R and shape retention force H of the lead wire were calculated based on the above equations (1) and (2), respectively.

As shown in Table 1 and Fig. 6, group A (Production Examples 1 to 4), Group B (Production Examples 5 to 8), and Group C in which the average thickness T1 of the strip-shaped conductor was changed and other conditions were the same. In (Production Examples 9 to 12), the springback angle θ was also reduced in accordance with the increase in the average thickness T1 of the strip-shaped conductor, that is, the ratio (R/H) of the elastic recovery force R to the shape retention force H in any group. . In addition, although the thickness T2 of the insulating film is different between the groups A to C, when comparing these groups A to C, the thickness T2 of the insulating film is increased, that is, the ratio of the elastic recovery force R to the shape retention force H (R/H ), the springback angle θ also increased. From these results, by adjusting the average thickness of the strip-shaped conductor of the lead wire and the average thickness of the insulating film, the ratio (R/H) of the elastic recovery force R to the shape retention force H is 0.15 or less, so that a springback angle of 20° or less is good. It is judged that the bending restoration shape can be maintained.

In the group D (Production Examples 13-14) and Group E (Production Examples 15-16) in which the elastic modulus of the insulating film was changed and other conditions were the same, both of the groups D and E increased the elastic modulus of the insulating film, that is, The springback angle θ also increased as the ratio of the elastic recovery force R to the shape retention force H (R/H) increased. From this result, by adjusting the elastic modulus of the insulating film of the lead wire and making the ratio (R/H) of the elastic recovery force R to the shape retention force H to be 0.15 or less, it is possible to maintain a good bending recovery shape with a springback angle of 20° or less. Is judged.

In the group F (Production Examples 17 to 20) in which the thickness of the strip-shaped conductor and the insulating film was constant and the elastic modulus was changed, the elastic recovery force R by increasing the elastic modulus of the strip-shaped conductor, reducing the elastic modulus of the insulating film, or a combination thereof When the ratio (R/H) to the shape retention force H of was reduced, the springback angle θ was decreased accordingly. From this result, by adjusting the elastic modulus of the insulating film of the lead wire and making the ratio (R/H) of the elastic recovery force R to the shape retention force H to be 0.15 or less, it is possible to maintain a good bending recovery shape with a springback angle of 20° or less. Is judged.

In addition, as shown in Fig. 6, the ratio (R/H) of the elastic recovery force R to the shape retention force H and the spring back angle show a high correlation, and in particular, the ratio (R/H) is small (for example, 0.2 or less. ) In the preparation example, a higher correlation was shown. Therefore, in reducing the spring back angle, it can be confirmed that it is very effective to adjust the ratio (R/H).

1, 11: Lead wire for electrical components
2, 7, 12: strip-shaped conductor
2A: one end
2B: the other end
3, 8, 13: insulation film
4: Li-ion battery
5A: anode
5B: cathode
6: Encapsulant
M: Center plane of bending deformation

Claims (9)

A lead wire for electric components comprising a strip-shaped conductor and a pair of insulating films covering both sides of the strip-shaped conductor,
The elastic modulus of the strip-shaped conductor is 50 GPa or more and 300 GPa or less, and
Each insulating film has an elastic modulus of 100 MPa or more and 1,400 MPa or less.
Lead wire for electrical components. The method of claim 1,
The electric component lead wire has a bending recovery angle of 20° or less after 180° bending.
Lead wire for electrical components. The method according to claim 1 or 2,
The elastic modulus of the strip-shaped conductor is 60 ㎬ or more and 250 ㎬ or less
Lead wire for electrical components. The method according to claim 1 or 2,
The elastic modulus of each of the insulating films are all 200 MPa or more and 720 MPa or less
Lead wire for electrical components. The method according to claim 1 or 2,
The average thickness of the strip-shaped conductor is 30㎛ or more and 200㎛ or less
Lead wire for electrical components. The method according to claim 1 or 2,
The average thickness of each of the insulating films is 25㎛ or more and 200㎛ or less
Lead wire for electrical components. The method according to claim 1 or 2,
Each of the insulating films is laminated in a plurality of layers.
Lead wire for electrical components. Equipped with the lead wire for electric parts according to claim 1 or 2
Electrical parts. The method of claim 8,
Non-aqueous electrolyte battery
Electrical parts.

Images