Lead with insulating resin film

Abstract

A lead wire with an insulating resin film has a conductor and an insulating resin film, the conductor has conductor tapered portions at both end portions along an X-axis, where the X-axis is an axis along both sides of the conductor and the Y-axis is an axis orthogonal to the X-axis, and the insulating resin film is disposed so as to straddle the conductor along the X-axis. In a cross section along the X-axis, a laminated body in which the insulating resin film and the conductor are laminated has a resin tapered portion, an end portion of the conductor tapered portion close to the first center is set as a first conductor end portion, an end portion of the resin tapered portion close to the first center is set as a first resin end portion, and an end portion of the resin tapered portion close to the second center is set as a second resin end portion. When an end portion of the resin tapered portion farther from the first center is defined as a second resin end portion, the first resin end portion is positioned at the same position as the first conductor end portion or positioned closer to the first center than the first conductor end portion, and the second resin end portion is positioned farther from the first center than the conductor end portion.

Description

Technical Field

[0001] The present disclosure relates to a lead wire with an insulating resin film. Background Art

[0002] Patent Document 1 discloses a lead wire member formed by laminating a pair of insulating resin films on portions other than both end portions in the longitudinal direction of a conductor made of a metal foil.

[0003] Prior Art Documents

[0004] Patent Documents

[0005] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2017 - 117705

[0006] When a lead wire with an insulating resin film having insulating resin films disposed on the upper and lower surfaces of a conductor is thermally adhered to an exterior body, voids sometimes occur between the exterior body and the insulating resin film of the lead wire with the insulating resin film.

[0007] The voids are the main cause of the weak adhesion between the exterior body and the insulating resin film. Summary of the Invention

[0008] An object of the present disclosure is to provide a lead wire with an insulating resin film having excellent adhesion to an exterior body.

[0009] The lead with an insulating resin film according to the present disclosure has: a plate-shaped conductor having a rectangular shape on its upper and lower surfaces; and an insulating resin film including a first insulating resin film disposed on the upper surface of the conductor and a second insulating resin film disposed on the lower surface of the conductor. When observing the conductor from above in the vertical direction along the upper surface, with the axis along the selected opposite sides set as the X-axis and the axis orthogonal to the X-axis set as the Y-axis, the conductor has conductor tapered portions at both ends along the X-axis, and the thickness of the conductor tapered portions becomes thinner as it moves away from the first center which is the center of the conductor along the X-axis. The first insulating resin film and the second insulating resin film are configured to cover the conductor across the conductor along the X-axis, have edge portions that extend and overlap from both ends of the conductor, and do not cover both ends of the conductor along the Y-axis. In the cross-section along the X-axis of the laminate formed by laminating the insulating resin film and the conductor, the laminate has resin tapered portions, and the thickness of the resin tapered portions becomes thinner as it moves away from the first center. When the end portion of the conductor tapered portion close to the first center is set as the first conductor end portion, the end portion of the resin tapered portion close to the first center is set as the first resin end portion, and the end portion of the resin tapered portion far from the first center is set as the second resin end portion, the position of the first resin end portion along the X-axis is the same as the position of the first conductor end portion or is located at a position closer to the first center than the position of the first conductor end portion, and the position of the second resin end portion along the X-axis is located at a position farther from the first center than the end of the conductor along the X-axis.

[0010] Advantages of the Invention

[0011] According to the present disclosure, a lead with an insulating resin film having excellent adhesion to an exterior body can be provided. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is an explanatory diagram of a battery of a lead with an insulating resin film to which one aspect of the present disclosure is applied.

[0013] Figure 2 It is a top view of a lead with an insulating resin film according to one aspect of the present disclosure.

[0014] Figure 3A It is Figure 1 a cross-sectional view taken along line A - A' of

[0015] Figure 3B It is Figure 1 another configuration example of the cross-sectional view taken along line A - A' of

[0016] Figure 4 It isFigure 2 Cross-sectional view taken along line B - B'.

[0017] Figure 5 Cross-sectional view of the surface including the laminate in the case where the outer package is heat-bonded to the lead wire with an insulating resin film produced in Experimental Example 2.

[0018] Explanation of reference numerals

[0019] 10: Battery

[0020] 11: Outer package

[0021] 110: Sealing part

[0022] 111: First resin layer

[0023] 112: Metal layer

[0024] 113: Second resin layer

[0025] 12: Electrode laminate

[0026] 13: Lead wire (lead wire with insulating resin film)

[0027] 14: Conductor

[0028] 141: Upper surface

[0029] 142: Lower surface

[0030] 14A: Flat part

[0031] 14B: Conductor tapered part

[0032] 14C: End part

[0033] 15: Insulating resin film

[0034] T15: Thickness

[0035] 151: First insulating resin film

[0036] 152: Second insulating resin film

[0037] 15A: First flat part

[0038] 15B: Resin tapered part

[0039] 15C: Second flat part

[0040] 15D: End part

[0041] 21: Side

[0042] 22: Side

[0043] 23: Side

[0044] 24: Edge

[0045] 25: First end region

[0046] 26: Second end region

[0047] L14: Length

[0048] W14: Length

[0049] L15: Length

[0050] W15: Length

[0051] 31: Base layer

[0052] 32: Surface layer

[0053] 33: Intermediate layer

[0054] 400: Laminate

[0055] 40: Edge portion

[0056] 41: First resin end

[0057] 42: Second resin end

[0058] 43: First conductor end

[0059] C1: First center

[0060] C2: Second center

[0061] L40: Length

[0062] L401: Length

[0063] L402: Length

[0064] 500: Laminate

[0065] 51: Void

[0066] 53: Lead (lead with insulating resin film)

[0067] X: X-axis

[0068] Y: Y-axis

[0069] Z: Z-axis. Detailed implementation manners

[0070] Hereinafter, the detailed implementation manners will be described.

[0071] [Description of the embodiments of the present disclosure]

[0072] First, embodiments of the present disclosure will be described. In the following description, the same reference numerals are assigned to the same or corresponding elements, and the same description thereof will not be repeated.

[0073] (1) The lead wire with an insulating resin film according to one aspect of the present disclosure includes: a plate-shaped conductor having a rectangular shape on its upper and lower surfaces; and an insulating resin film including a first insulating resin film disposed on the upper surface of the conductor and a second insulating resin film disposed on the lower surface of the conductor. When the conductor is viewed from above in the vertical direction along the upper surface, with the axes along the selected opposite sides being the X-axis and the axis orthogonal to the X-axis being the Y-axis, the conductor has conductor tapered portions at both ends along the X-axis, and the thickness of the conductor tapered portions becomes thinner as it moves away from the first center which is the center of the conductor along the X-axis. The first insulating resin film and the second insulating resin film are configured to cover the conductor across the conductor along the X-axis, have edge portions that extend from both ends of the conductor and overlap, and do not cover both ends of the conductor along the Y-axis. In the cross-section along the X-axis of the laminate formed by laminating the insulating resin film and the conductor, the laminate has a resin tapered portion, and the thickness of the resin tapered portion becomes thinner as it moves away from the first center. When the end portion of the conductor tapered portion closer to the first center is the first conductor end portion, the end portion of the resin tapered portion closer to the first center is the first resin end portion, and the end portion of the resin tapered portion farther from the first center is the second resin end portion, the position of the first resin end portion along the X-axis is the same as the position of the first conductor end portion or is located closer to the first center than the position of the first conductor end portion, and the position of the second resin end portion along the X-axis is located farther from the first center than the end portion of the conductor along the X-axis.

[0074] By providing conductor tapered portions at both ends of the conductor, it is possible to prevent a gap from being generated between the outer package of the battery and the insulating resin film near the edge portion. In particular, when the conductor is thickened, the effect of preventing the generation of a gap is significant.

[0075] By arranging the positions of the first resin end portion and the second resin end portion of the resin tapered portion as described above, the length of the resin tapered portion along the X-axis can be extended, and the inclination of the outer surface of the resin tapered portion can be made gentle. Therefore, when the lead wire with an insulating resin film according to one aspect of the present disclosure is thermally welded to the outer package, the resin of the outer package is also easily filled into the resin tapered portion, thereby improving the adhesion to the outer package and suppressing the generation of voids.

[0076] (2) In the above (1), it is also possible that the position of the second resin end along the X-axis is located at a position farther from the first center than the second center along the X-axis which is the center of the edge portion.

[0077] By setting the position of the second resin end along the X-axis to a position farther from the first center of the conductor than the second center of the edge portion, the length of the resin tapered portion along the X-axis can be particularly extended, and the inclination of the resin tapered portion can be made particularly gentle. Therefore, when the lead with an insulating resin film of one aspect of the present disclosure is heat-bonded to the exterior body, the resin of the exterior body is also easily filled into the resin tapered portion, so that the adhesion to the exterior body can be particularly improved, and the generation of voids can be suppressed.

[0078] (3) In the above (1) or (2), it is also possible that the insulating resin film has two or more layers.

[0079] By the insulating resin film having two or more layers, the strength of the insulating resin film after heat-bonding the exterior body to the insulating resin film, the adhesion between the insulating resin film and the exterior body, and the adhesion between the insulating resin film and the conductor can be easily adjusted.

[0080] (4) In any one of the above (1) to (3), it is also possible that the thickness of the insulating resin film is 100 μm or more.

[0081] By setting the thickness of the insulating resin film to 100 μm or more, the generation of a gap between the insulating resin film and the conductor can be prevented.

[0082] (5) In any one of the above (1) to (4), it is also possible that the length of the edge portion along the X-axis is 5 mm or less.

[0083] By setting the length of the edge portion to 5 mm or less, the width of the sealing portion for clamping the lead with an insulating resin film of one aspect of the present disclosure as an inclusion can be shortened, so that the sealing performance can be improved.

[0084] [Details of the Embodiment of the Present Disclosure]

[0085] Hereinafter, a specific example of a lead with an insulating resin film of one embodiment of the present disclosure (hereinafter, referred to as "this embodiment") will be described with reference to the drawings. It should be noted that the present invention is not limited to these examples, but is shown by the claims, and is intended to include all modifications within the meaning and scope equivalent to the claims.

[0086] In this specification, for components such as the first insulating resin film and the second insulating resin film, the names of the components may sometimes be appended with first, second, etc. for description. The first, second, etc. are merely for distinguishing each component and preventing confusion during description, and do not indicate configuration, priority order, etc. Therefore, when there is no particular concern about confusion and when presenting in a summary, it may be simply noted as an insulating resin film.

[0087] [Lead with insulating resin film]

[0088] Figure 1 The explanatory drawing showing a configuration example in the case where the lead with an insulating resin film of the present embodiment (hereinafter, also referred to as "lead") is applied to a battery is shown. Figure 2 It is an explanatory drawing when observing the lead with an insulating resin film of the present embodiment vertically above the upper surface of the conductor. Figure 3A Shows Figure 1 A cross-sectional view taken along line A - A' of Figure 3B Shows the equivalent of Figure 1 Another configuration example of the cross-sectional view taken along line A - A' of Figure 4 Shows Figure 2 A cross-sectional view taken along line B - B' of Figure 3B Becomes a modified example of the lead with an insulating resin film of the present embodiment, and thus mainly uses Figure 1 , Figure 2 , Figure 3A , Figure 4 for description, and uses Figure 3B as needed.

[0089] Figure 1 , Figure 2 , Figure 3A , Figure 3B , Figure 4 , Figure 5 The Z-axis in

[0090] The lead 13 of the present embodiment can be applied to a battery. Therefore, after describing the battery to which the lead 13 of the present embodiment can be applied, the details of the lead 13 of the present embodiment will be described.

[0091] (1) Regarding the battery

[0092] Regarding the configuration example of the battery to which the lead 13 of the present embodiment is applied, it is shown in Figure 1 . As Figure 1 shown, the battery 10 may have: an outer package 11; an electrode laminate 12 formed by laminating a positive electrode, a separator, and a negative electrode and impregnated with an electrolytic solution; and a lead 13 of one aspect of the present disclosure, which is connected to the electrode laminate 12.

[0093] (Outer package)

[0094] The outer package 11 is a container for housing and sealing the electrode laminate 12 and the electrolytic solution. The outer package 11 may have at least one resin layer on the surface facing the electrode laminate 12 in a manner capable of heat fusion bonding.

[0095] As Figure 1 shown by the single-dot chain line in the figure, a sealing portion 110 is formed on the periphery of the outer package 11, and the electrode laminate 12 and the electrolytic solution are sealed by the sealing portion 110.

[0096] (2) Regarding the lead

[0097] Each component of the lead 13 of the present embodiment will be described.

[0098] (2-1) Conductor

[0099] The conductor 14 is a component for connecting the electrode laminate 12 disposed inside the outer package 11 to devices disposed outside the outer package 11. The conductor 14 may be formed in a plate shape, and the upper surface 141 and the lower surface 142 of the conductor 14 (refer to Figure 3A ) have a rectangular shape. As Figure 2 shown, the upper surface 141 of the conductor 14 has sides 21 and 22 as opposite sides and sides 23 and 24 intersecting the sides 21 and 22. However, the rectangular shape does not refer to a strictly geometric shape, and the conductor 14 may also be a shape with rounded corners.

[0100] In the following description, when observing the conductor 14 from above in the vertical direction along the upper surface 141, the axis along the sides 21 and 22 as the selected opposite sides is set as the X axis. In addition, the axis orthogonal to the X axis is set as the Y axis.

[0101] Figure 4 shows a cross-sectional view along the X axis, which is a cross-sectional view of the laminate 400 formed by laminating the insulating resin film 15 and the conductor 14 at the Figure 2 B-B' line. As Figure 4 shown, the conductor 14 may have conductor tapered portions 14B at both ends 14C along the X axis, and the thickness of the conductor tapered portions 14B becomes thinner as it moves away from the first center C1 which is the center of the conductor 14 along the X axis. The first center C1 refers to the center between the two ends 14C of the conductor 14 along the X axis.

[0102] By having the conductor tapered portions 14B at both ends 14C of the conductor 14, it is possible to prevent a gap from being generated between the outer package 11 of the battery and the insulating resin film 15 near the edge portion 40. Especially when the conductor 14 is thickened, the effect of preventing the generation of a gap is significant.

[0103] In Figure 4 , the conductor tapered portion 14B of the conductor 14 has a bilaterally symmetric shape at both end portions 14C of the conductor 14, but is not limited to this form. The gradient of the conductor tapered portion 14B, the shape of the taper, and the length along the X-axis may also be different on the left and right. In addition, the gradient of the conductor tapered portion 14B, the shape of the taper, the length along the X-axis, etc. may also be different between the upper surface 141 and the lower surface 142 of the conductor 14, and either the upper surface 141 or the lower surface 142 may be a flat surface. Moreover, in Figure 4 , the shapes of both end portions 14C of the conductor 14 are straight lines (planes), but may also be curves such as arc shapes, etc.

[0104] The conductor 14 may have a flat portion 14A with a fixed thickness in the region including the first center C1 disposed between the conductor tapered portions 14B. The outer surface of the flat portion 14A does not need to be flat in a strict sense, and the flat portion 14A may also include portions that are not flat with the thickness varying within the manufacturing tolerance range.

[0105] In the following description, the end portion of the conductor tapered portion 14B close to the first center C1 is defined as the first conductor end portion 43. The first conductor end portion 43 is the connecting portion between the flat portion 14A and the conductor tapered portion 14B. Focusing on the change in the thickness of the conductor 14, the first conductor end portion 43 may be set as the point where the thickness starts to become thinner than the thickness of the flat portion 14A.

[0106] The material of the conductor 14 is not particularly limited. For example, various materials used in the conductors of leads can be used. Examples of the material of the conductor 14 include metal materials such as aluminum, titanium, nickel, copper, aluminum alloy, titanium alloy, nickel alloy, copper alloy, etc., or materials obtained by plating these metal materials with nickel, gold, etc.

[0107] (2-2) Insulating resin film

[0108] As Figure 3A , Figure 4 shown, the insulating resin film 15 includes a first insulating resin film 151 disposed on the upper surface 141 of the conductor 14 and a second insulating resin film 152 disposed on the lower surface 142 of the conductor 14. As Figure 2 , Figure 3AAs shown, in the upper surface 141 and the lower surface 142, the first insulating resin film 151 and the second insulating resin film 152 are arranged not to cover both end portions of the conductor 14 along the Y-axis, that is, both end portions including the side 21 and the side 22, but to expose these end portions. Therefore, in the upper surface 141 and the lower surface 142 of the conductor 14, the first insulating resin film 151 and the second insulating resin film 152 are arranged to cover the conductor 14 across the conductor 14 along the X-axis at an intermediate portion that is a portion other than both end portions of the conductor 14 along the Y-axis.

[0109] The upper surface 141 and the lower surface 142 of the conductor 14 refer to the surfaces that face the exterior body 11 of the battery 10 when manufacturing the battery 10.

[0110] As Figure 2 shown, both end portions of the conductor 14 along the Y-axis refer to the first end region 25 including the side 21 and the second end region 26 including the side 22. The intermediate portion becomes the portion located between the first end region 25 and the second end region 26.

[0111] When applying the lead wire 13 to the battery, for example, the first end region 25 is a portion exposed to the outside of the exterior body 11, and its size can be selected in a manner that enables connection to external devices. In addition, when applying the lead wire 13 to the battery, for example, the second end region 26 is a portion located inside the exterior body 11 and connected to the electrode laminate 12, and its size can be selected in a manner that enables connection to the electrode laminate 12. The sizes such as the area of the first end region 25 and the sizes such as the area of the second end region 26 can be the same or different.

[0112] Therefore, the length L14 of the conductor 14 along the Y-axis is longer than the length L15 of the insulating resin film 15 along the Y-axis. In addition, the length W15 of the insulating resin film 15 along the X-axis is longer than the length W14 of the conductor 14 along the X-axis.

[0113] As Figure 4 shown, the first insulating resin film 151 and the second insulating resin film 152 are arranged to have edge portions 40 that extend from both end portions 14C of the conductor 14 along the X-axis and overlap. The edge portions 40 are portions located outside the conductor 14 relative to both end portions 14C of the conductor 14, and the first insulating resin film 151 is in direct contact with and bonded to the second insulating resin film 152.

[0114] As Figure 4 shown, in the cross-section along the X-axis of the laminate 400 formed by laminating the insulating resin film 15 and the conductor 14, the laminate 400 has a resin tapered portion 15B, and the thickness of the resin tapered portion 15B becomes thinner as it moves away from the first center C1.

[0115] AsFigure 4 As shown, in a cross-section along the X-axis, the laminate 400 has a first flat portion 15A including the conductor 14 with a first center C1 and a second flat portion 15C at both end portions 15D along the X-axis. Further, a resin tapered portion 15B is disposed between the first flat portion 15A and the second flat portion 15C so as to connect the first flat portion 15A and the second flat portion 15C. The outer surfaces of the first flat portion 15A and the second flat portion 15C do not need to be flat in a strict sense, and the first flat portion 15A and the second flat portion 15C may also include portions that are not flat with the thickness varying within the manufacturing tolerance.

[0116] In the following description, the end portion of the resin tapered portion 15B closer to the first center C1 is defined as a first resin end portion 41. Further, the end portion of the resin tapered portion 15B farther from the first center C1 than the first resin end portion 41 is defined as a second resin end portion 42.

[0117] The lead 13 of the present embodiment is bonded to the sealing portion 110 (refer to Figure 1 ) at the insulating resin film 15 portion.

[0118] The inventor of the present invention has studied the reason why voids sometimes occur between the outer package and the lead with an insulating resin film during fusing.

[0119] As a result, as shown in the cross-section along the X-axis when the conventional lead 53 is hot-fused to the outer package 11, that is, Figure 5 it is confirmed that the voids 51 mainly occur in the resin tapered portion 15B of the insulating resin film 15. In the conventional lead 53, the position of the first resin end portion 41 along the X-axis is located farther from the first center C1 than the position of the first conductor end portion 43, and the length of the resin tapered portion 15B along the X-axis becomes shorter and the inclination becomes steeper. Therefore, it is considered that the resin of the outer package 11 cannot fill in the vicinity of the resin tapered portion 15B, resulting in the generation of the voids 51.

[0120] Therefore, in the lead 13 of the present embodiment, the position of the first resin end portion 41 along the X-axis is the same as the position of the first conductor end portion 43, or is disposed at a position closer to the first center C1 than the position of the first conductor end portion 43. Further, the position of the second resin end portion 42 along the X-axis is disposed at a position farther from the first center C1 than the end portion 14C of the conductor 14 along the X-axis.

[0121] As from Figure 4As is obvious, in any cross-section of the laminate 400, the first resin end 41 and the second resin end 42 can each exist at most at two locations on the upper surface 141 of the conductor 14 and at two locations on the lower surface 142 of the conductor 14, for a total of four locations. In any cross-section of the laminate 400, regarding the first resin end 41 and the second resin end 42, at least one of the total of four locations may be the above configuration, or all four locations may be the above configuration.

[0122] By setting the positions of the first resin end 41 and the second resin end 42 of the resin tapered portion 15B to the above configuration, the length of the resin tapered portion 15B along the X-axis can be extended, and the inclination of the outer surface of the resin tapered portion 15B can be made gentle. Therefore, when the lead 13 of the present embodiment is heat-bonded to the outer package 11, the resin of the outer package 11 is also easily filled into the resin tapered portion 15B, thereby improving the adhesion to the outer package 11 and suppressing the generation of voids.

[0123] It should be noted that in this specification, the lead 13 having excellent adhesion to the outer package 11 refers to the lead 13 that can suppress the generation of voids between the outer package 11 and the insulating resin film 15 when the lead 13 is heat-bonded to the outer package 11.

[0124] The position of the second resin end 42 along the X-axis can also be arranged at a position farther from the first center C1 of the conductor 14 than the second center C2 along the X-axis of the edge portion 40.

[0125] By setting the position of the second resin end 42 along the X-axis at a position farther from the first center C1 of the conductor 14 than the second center C2 of the edge portion 40, the length of the resin tapered portion 15B along the X-axis can be particularly extended, and the inclination of the resin tapered portion 15B can be made particularly gentle. Therefore, when the lead 13 of the present embodiment is heat-bonded to the outer package 11, the resin of the outer package 11 is also easily filled into the resin tapered portion 15B, thereby particularly improving the adhesion to the outer package 11 and suppressing the generation of voids.

[0126] The edge portion 40 is the region between the end portion 14C of the conductor 14 and the end portion 15D of the insulating resin film 15. When the distance from the end portion 15D of the insulating resin film 15 to the second center C2 along the X-axis is set to L401 and the distance from the end portion 14C of the conductor 14 to the second center C2 is set to L402, the second center C2 of the edge portion 40 is the position where L401 = L402. When the length of the edge portion 40 along the X-axis is set to L40, L40 = L401 + L402.

[0127] The shape of the resin tapered portion 15B of the insulating resin film 15, for example, the positions of the first resin end portion 41 and the second resin end portion 42 can be easily adjusted by, for example, selecting the shape of the mold used when fusing the insulating resin film 15 to the conductor 14, the fusing conditions, and the like.

[0128] The length L40 of the edge portion 40 along the X-axis is not particularly limited, but can be set to, for example, 5 mm or less. By setting the length L40 of the edge portion 40 to 5 mm or less, the width of the sealing portion 110 for clamping the lead 13 as an inclusion can be shortened, thereby improving the sealing performance.

[0129] The lower limit value of the length L40 of the edge portion 40 along the X-axis is also not particularly limited, but can be set to, for example, 1 mm or more. By setting the length L40 of the edge portion 40 along the X-axis to 1 mm or more, the adhesion between the first insulating resin film 151 and the second insulating resin film 152 can be improved, and the generation of a gap between the insulating resin film 15 and the conductor 14 can be particularly suppressed.

[0130] As described above, the length of the edge portion 40 along the X-axis can be set to, for example, 1 mm or more and 5 mm or less.

[0131] The insulating resin film 15 is a layer that can be hot-fused between the outer package 11 when applied to a battery. Therefore, the insulating resin film 15 can contain, for example, a thermoplastic resin as the resin. As the thermoplastic resin, for example, one or more selected from polyolefin resins, polyester resins, polystyrene resins, polyvinyl chloride resins, etc. can be used. As the polyolefin resin, acid-modified polyolefin resins such as polyethylene, polypropylene, acid-modified polyethylene, and acid-modified polypropylene are cited. As the polyester resin, for example, polyethylene terephthalate resin is cited. As the acid-modified polyolefin, maleic anhydride-modified polyolefin is cited.

[0132] The insulating resin film 15 can also be as Figure 3A , Figure 3B shown and have two or more layers. The insulating resin film 15 can also be as Figure 3A shown and have a base layer 31 and a surface layer 32. The insulating resin film 15 can also be as Figure 3B shown and have a base layer 31, an intermediate layer 33, and a surface layer 32. In the case where the insulating resin film 15 has three layers, for example, the functions can be separated in each layer, such as a layer adhered to the conductor 14, a layer adhered to the outer package 11, and a layer that is not easily crushed and maintains strength when the lead 13 is fused to the outer package 11.

[0133] Therefore, for each layer, materials can be selected according to the intended function, etc. In terms of adhesive force, the layer adhered to the conductor 14 is preferably acid-modified polypropylene. The layer adhered to the exterior body 11 is preferably made of a material having good adhesiveness to the material of the exterior body 11.

[0134] By having two or more layers in the insulating resin film, it is possible to easily adjust the strength of the insulating resin film after heat-fusing the exterior body to the insulating resin film, the adhesion between the insulating resin film and the exterior body, and the adhesion between the insulating resin film and the conductor.

[0135] Regarding the thickness T15 of the insulating resin film 15, it is not particularly limited, but for example, the thickness T15 of the insulating resin film 15 can be set to 100 μm or more.

[0136] By setting the thickness T15 of the insulating resin film 15 to 100 μm or more, it is possible to prevent a gap from being generated between the insulating resin film 15 and the conductor 14.

[0137] The thickness T15 of the insulating resin film 15 can be set, for example, to 100 μm or more and 300 μm or less. It should be noted that in the first insulating resin film 151 and the second insulating resin film 152, the thickness T15 can be different or the same. In addition, in the case where the insulating resin film 15 has multiple layers, the total thickness of the multiple layers becomes the above-mentioned thickness T15.

[0138] By setting the thickness T15 of the insulating resin film 15 to 300 μm or less, it is possible to particularly prevent a gap from being generated between the insulating resin film 15 and the exterior body 11 after heat-fusing the exterior body 11.

[0139] [Examples]

[0140] Hereinafter, specific examples will be given for illustration, but the present invention is not limited to these examples.

[0141] Hereinafter, the leads and batteries in each experimental example will be described.

[0142] Experimental example 1 is an example, and experimental example 2 becomes a comparative example. In experimental example 1 and experimental example 2, the same configuration of the first insulating resin film 151 and the second insulating resin film 152 was adopted.

[0143] [Experimental example 1]

[0144] Fabricate Figure 2 , Figure 3A , Figure 4 shown lead 13, and heat-fuse the exterior body 11 to the lead 13. The insulating resin film 15 has two layers, a base layer 31 containing maleic anhydride-modified polypropylene and a surface layer 32 containing polypropylene, starting from a position close to the conductor 14.

[0145] When forming the insulating resin film 15 on the upper surface 141 and the lower surface 142 of the conductor 14, the shape of the mold and the heating conditions are selected so as to obtain the Figure 4 cross-sectional shape shown.

[0146] Therefore, in the cross-section along the X-axis, for the laminate 400 of the lead 13 in this experimental example, the position of the first resin end 41 along the X-axis is the same as the position of the first conductor end 43, or becomes a position closer to the first center C1 than the position of the first conductor end 43. In addition, the position of the second resin end 42 along the X-axis becomes a position farther from the first center C1 than the second center C2.

[0147] As Figure 4 shown, the first resin end 41 and the second resin end 42 each exist in two places on the upper surface 141 of the conductor 14 and in two places on the lower surface 142 of the conductor 14, for a total of four places. In this experimental example, all four places are set to the above configuration.

[0148] The length L40 of the edge portion 40 is set to 5 mm, and the thickness T15 of the insulating resin film 15, that is, the first insulating resin film 151 and the second insulating resin film 152, is set to 100 μm.

[0149] A laminated film is used as the exterior body 11. In this laminated film, the first resin layer 111 and the second resin layer 113 are polypropylene films, and the metal layer 112 is aluminum foil.

[0150] The positions of the lead 13 and the exterior body 11 are adjusted so that a part of the insulating resin film 15 along the Y-axis is covered by the exterior body 11, and heat fusion bonding is performed to form the sealing portion 110. There are two cases: one is when the heat fusion bonding time is set to 1.5 seconds and the other is when the heat fusion bonding time is set to 3.0 seconds. In each case, heat fusion bonding is performed ten times, and ten specimens are produced respectively. The heat fusion bonding conditions other than the time are set to be the same.

[0151] The cross-section of the insulating resin film 15 at the plane passing through the X-axis was observed. The evaluation results are shown in Table 1. In Experimental Example 1, even when the heat fusion bonding time was shortened, no gap was observed between the exterior body 11 and the insulating resin film 15, and close adhesion of the two members was observed.

[0152] [Experimental Example 2]

[0153] Except that the lead 13 has the Figure 5 morphology shown, the lead 53 was produced under the same conditions as in Experimental Example 1, the exterior body 11 was heat fusion bonded to the lead 53, and the cross-sectional shape was evaluated.

[0154] Therefore, in the cross-section along the X-axis, for the laminate 500 of the lead 53 in this experimental example, the position of the first resin end portion 41 along the X-axis is located farther from the first center C1 than the position of the first conductor end portion 43. In addition, although the position of the second resin end portion 42 along the X-axis is farther from the first center C1 than the end portion 14C of the conductor 14, it becomes a position closer to the first center C1 than the second center C2. The evaluation results are shown in Table 1.

[0155] When the cross-section at the plane passing through the X-axis of the insulating resin film 15 was confirmed at multiple locations, as Figure 5 shown, there were cases where voids 51 were observed in the resin tapered portion 15B and the second flat portion 15C.

[0156] [Table 1]

[0157]

Claims

1. A lead wire with an insulating resin film, comprising: a plate-like conductor having upper and lower surfaces with rectangular shapes; and an insulating resin film including a first insulating resin film disposed on the upper surface of the conductor and a second insulating resin film disposed on the lower surface of the conductor, When the conductor is viewed from above in a direction perpendicular to the upper surface, an axis along two selected opposite sides is defined as an X-axis, and an axis orthogonal to the X-axis is defined as a Y-axis. The conductor has conductor tapered portions at both ends along the X-axis, and the thickness of the conductor tapered portions becomes thinner as the conductor moves away from a first center which is the center of the conductor along the X-axis. The first insulating resin film and the second insulating resin film are configured to cover the conductor across the conductor along the X-axis, have edge portions extending from both ends of the conductor and overlapping, and do not cover both ends of the conductor along the Y-axis. In a cross section along the X-axis of a laminated body formed by laminating the insulating resin film and the conductor, the laminated body has a resin tapered portion, the thickness of the resin tapered portion becoming thinner as it moves away from the first center, When the end of the conductor tapered portion close to the first center is set as the first conductor end, the end of the resin tapered portion close to the first center is set as the first resin end, and the end of the resin tapered portion far from the first center is set as the second resin end, The position of the first resin end along the X-axis is the same as the position of the first conductor end, or is located closer to the first center than the position of the first conductor end. The position of the second resin end along the X-axis is located farther from the first center than the end of the conductor along the X-axis.

2. The lead wire with an insulating resin film according to claim 1, wherein The position of the second resin end portion along the X-axis is located farther from the first center than a second center which is a center of the edge portion along the X-axis.

3. The lead wire with an insulating resin film according to claim 1 or 2, wherein: The insulating resin film has two or more layers.

4. The lead wire with an insulating resin film according to claim 1 or 2, wherein: The insulating resin film has a thickness of 100 μm or more.

5. The lead wire with an insulating resin film according to claim 1 or 2, wherein: The length of the edge portion along the X-axis is 5 mm or less.

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