JP2014164964A - Method of manufacturing terminal, terminal material for use in manufacturing method, terminal manufactured by manufacturing method, terminal connection structure of wire and manufacturing method therefor, and copper or copper alloy plate material for terminal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a terminal which allows for butt welding while enhancing laser welding efficiency, without reducing the strength significantly in a weld zone and the vicinity thereof.SOLUTION: A method of manufacturing a terminal 1 having a tube body caulking portion 30 being crimped to a wire includes a step for preparing a base material composed of copper or a copper alloy of a terminal material including a tube development part for forming the tube body caulking portion 30 by being bent, a step for forming a nickel layer containing 10-70% volume fraction of high melting point inorganic particles having a grain size of 10-300 nm on the tube development part, a step for forming a tin layer, as the uppermost layer, on the nickel layer, a step for shaping into a tube body by bending and butting the tube development part, and a step for forming the tube body caulking portion 30 by jointing the butting part by laser welding of near-infrared laser light irradiation, in this order.

Description

  The present invention provides a method for manufacturing a terminal excellent in laser welding efficiency without greatly reducing the strength, a terminal material used in the manufacturing method, a terminal manufactured by the manufacturing method, a terminal connection structure for an electric wire, and its manufacturing The present invention relates to a method and a copper or copper alloy sheet for a terminal.

  In recent years, there has been a demand for weight reduction of each component in order to improve the fuel efficiency of automobiles. Therefore, replacing the core wire of the electric wire used for the wire harness etc. in a motor vehicle with aluminum or aluminum alloy lighter than copper or copper alloy is advanced. Since a metal material is usually used for a terminal to be crimped and connected to the tip of this aluminum electric wire or aluminum alloy electric wire (hereinafter simply referred to as “aluminum electric wire”), these terminals are appropriately connected at the terminal connection portion of the electric wire. It will be necessary.

Generally, the terminal is made of copper or a copper alloy from the viewpoints of mechanical strength and springiness. Since the aluminum or aluminum alloy of the wire conductor is exposed at the crimping part of the terminal, if moisture adheres to the connection part of the aluminum wire and the terminal, the aluminum or aluminum alloy of the aluminum wire and the copper or copper alloy of the terminal Since the potential difference is different between different metals, corrosion (electrocorrosion) may occur, and defects may occur when corrosion progresses. Further, due to the progress of corrosion, the connection portion between the electric wire and the terminal is cracked or has poor contact, and the product life has been shortened.
In order to prevent these problems, it is desirable to block aluminum or an aluminum conductor (hereinafter simply referred to as “aluminum conductor”) from the outside. As an example, there is a method (for example, see Patent Document 1) in which the entire crimped portion of the terminal is molded with resin, and corrosion can be reliably prevented. Moreover, the technique (for example, refer patent document 2) which interrupts | blocks an aluminum conductor from the external world by the method of crimping | bonding after covering a metal cap on an electric wire conductor is disclosed.

  On the other hand, the present applicant forms the terminal caulking portion of the terminal material by butt welding the both ends of the terminal material cut out from the copper alloy plate material by laser welding, and the aluminum electric wire is formed in the caulking portion of the tubular body. A structure in which an aluminum conductor is inserted and caulked to house the conductor in a terminal for electrical continuity, and the connection between the dissimilar metal joint and the caulking portion of the tube does not come into contact with external moisture It is proposed that

  Copper or copper alloy has a high reflectivity of near infrared laser light, which is widely used as laser light for welding, as high as 90% or more (low absorption of laser light), so that the efficiency of laser welding is poor. Therefore, for example, Patent Document 3 describes a technique for improving laser weldability by forming a tin plating layer on the surface of copper or a copper alloy.

  By the way, since such a terminal is configured to be detachable from the connection port, the electrical conductivity, lubricity, wear resistance, etc. with the connection port etc. are improved, and the composite used as the terminal or the material of the terminal Plating materials are described in Patent Documents 4 to 8. Specifically, a metal-containing coating layer containing particles having wear resistance, carbon particles, dispersed particles for reducing frictional force, and the like is formed on the surface of these terminals or composite plating materials. However, Patent Documents 4 to 8 only have a metal-containing coating layer on the terminal or the plate material forming the terminal, and the method of connecting the aluminum electric wire and the terminal in a state of being cut off from the outside also includes the plate material. There is no description of a method for manufacturing a terminal by laser welding.

JP 2011-222243 A JP 2004-207172 A JP-A-8-218137 JP 2005-529242 Gazette JP 2007-9304 A JP 2007-92144 A JP 2009-218096 A JP 2006-97062 A

In the technique described in Patent Document 1 described above, since the mold portion is enlarged, it is necessary to increase the size of the connector housing, and as a result, the connector is enlarged. For this reason, the entire assembled electric wire (for example, a wire harness for automobiles) using this connector cannot be molded in a high density and small size. Moreover, it is necessary to process each crimping | compression-bonding part after a crimping | compression-bonding, the number of processes of manufacturing an assembled electric wire increases greatly, and each operation | work is complicated.
Moreover, in the technique described in Patent Document 2, the process of attaching a metal cap to each conductor before crimping is complicated, and the metal cap is broken by the wire barrel during crimping, and the water immersion path There was a risk that would occur.

  On the other hand, laser welding efficiency can be improved to some extent if a tin plating layer or the like is provided by applying the technique of Patent Document 3 when butt welding the tubular caulked portion of the terminal. However, even when tin plating is performed, since the plating form affects laser weldability, it is necessary to realize an efficient plating form in order to further improve the laser welding efficiency. Thus, from the viewpoint of laser welding efficiency, the technique of Patent Document 3 is not sufficient, and there is room for further improvement.

  In addition, when the tube caulking portion is formed by butt welding, the welded portion and the heat-affected zone by welding (sometimes referred to as “the welded portion and its vicinity”) exhibit a solidified structure, an annealed structure, and the like. The mechanical properties, particularly the strength, may be lower than other portions (see, for example, [0005] of Patent Document 3). If the mechanical properties of the welded part and its vicinity are greatly reduced, even if the aluminum wire can be connected to the terminal in a state of being cut off from the outside, the welded part and its vicinity have a significantly lower proof stress than the surroundings. The part and the vicinity thereof are destroyed when being processed, and are easily broken by receiving a load during use. Therefore, in laser welding, in addition to improving laser welding efficiency, it is also required to suppress deterioration of mechanical properties.

  The present invention relates to a method of manufacturing a terminal that can be butt-welded without greatly reducing the material strength, and with improved laser welding efficiency, a terminal material used in the manufacturing method, a terminal manufactured by the manufacturing method, and an end connection of an electric wire It is an object to provide a structure, a manufacturing method thereof, and a copper or copper alloy sheet for a terminal.

  As a result of intensive studies to solve the above-mentioned problems, the present inventor has adopted a structure in which an electric wire is inserted into a tubular terminal and is crimped. As a base barrier layer for preventing diffusion of copper and tin between the copper alloy base material and the tin layer, high-melting-point inorganic particles having a particle size of 0.3 μm or more and 10 μm or less are contained at a volume fraction of 10 to 70%. A welded portion obtained by disposing a nickel layer (hereinafter also referred to as a “specific nickel layer”) and a tin (Sn) layer thereon and irradiating the outermost Sn layer with a laser And a laser welding method capable of laser welding a copper alloy at high speed without significantly reducing the strength in the vicinity thereof. The present invention has been made based on this finding.

That is, the said subject is solved by the following means.
(1) A method of manufacturing a terminal having a tubular caulking portion that is crimp-bonded to an electric wire, wherein the base material is made of copper or a copper alloy of a terminal material that is bent to form the tubular caulking portion. A nickel layer containing high melting point inorganic particles having a particle size of 10 nm or more and less than 300 nm at a volume fraction of 10 to 70% is formed on the pipe development portion, and the tin layer is formed on the nickel layer. Forming as a surface layer, curving and butting the tube development portion to form a tube body, and joining the abutted portion by laser welding with near infrared laser light irradiation to form the tube caulking portion in this order The manufacturing method of the terminal which has.
(2) The method for manufacturing a terminal according to (1), wherein the tin layer is formed on the surface of the tube development portion on the laser welded side.
(3) The method for manufacturing a terminal according to (1) or (2), wherein the tin layer is formed in the region where the laser is welded in the pipe expanding portion.
(4) The method for manufacturing a terminal according to any one of (1) to (3), wherein the tin layer is formed on the laser welded end of the tube development portion.
(5) The method for manufacturing a terminal according to any one of (1) to (4), wherein the laser welding uses laser light having an oscillation wavelength in a near infrared region.

(6) The tube development portion of the terminal material provided with the tube expansion portion that becomes the tube caulking portion for crimping and joining the electric wire is bent and butted to form a tube body, and the butted portion is joined and caulked to the tube body 10 to 70% of high-melting-point inorganic particles having a particle size of 10 nm or more and less than 300 nm on the tube development portion. A terminal material comprising a nickel layer contained at a volume fraction of 5 and a tin layer as an outermost layer on the nickel layer.
(7) The terminal material used for manufacturing a terminal according to (6), wherein the tin layer is formed on a surface of the tube development portion on the laser beam irradiation side of laser welding.
(8) The terminal material used for manufacturing the terminal according to (6) or (7), wherein the tin layer is formed in the laser welded region of the pipe expanding portion.

(9) A terminal having a tubular caulking portion that is crimp-bonded to an electric wire, wherein the terminal material forming the terminal is made of copper or a copper alloy, and the tubular caulking portion curves the tube expanding portion of the terminal material. High-melting-point inorganic particles having a particle diameter of 10 nm or more and less than 300 nm contained in the nickel layer disposed in the pipe expanding portion, the butted portions being joined together by laser welding. Are contained or dispersed in the welded portion of the tubular caulked portion by laser welding.
(10) An electric wire for crimping and connecting a terminal produced by the method for producing a terminal according to any one of (1) to (5) and an aluminum or aluminum alloy electric wire at a tubular caulking portion of the terminal A method for manufacturing a terminal connection structure, wherein the aluminum or aluminum alloy electric wire is inserted into the caulking portion of the tube, the caulking portion is caulked, and the aluminum or aluminum alloy electric wire is crimped and connected to the caulking portion of the tubular body. The manufacturing method of the termination | terminus connection structure of an electric wire.

(11) A terminal connection structure of an electric wire in which the terminal according to (9) and an aluminum or aluminum alloy electric wire are crimped and connected at a tube caulking portion of the terminal.
(12) A nickel layer containing a high melting point inorganic particle having a particle size of 10 nm or more and less than 300 nm on a copper or copper alloy base material at a volume fraction of 10 to 70%, and a tin layer on the nickel layer A copper or copper alloy sheet for a terminal.

According to the method for manufacturing a terminal of the present invention, it is possible to increase the laser welding efficiency and form the caulking portion in the tube without significantly reducing the material strength of the joining by butt welding of copper or copper alloys. it can. Thereby, in crimping connection of an aluminum electric wire or the like, it is possible to provide a terminal that contributes to prevention of corrosion between different metals between the terminal base material and the metal material of the electric wire.
Specifically, by forming the above-described nickel layer and tin layer on the surface of copper or copper alloy, it is possible to increase the absorption of near-infrared laser light and to improve the mechanical properties of the welded part and the heat-affected part by welding. Reduction can be effectively suppressed.
Moreover, the terminal material of this invention is used suitably for manufacturing a terminal with the said manufacturing method. Furthermore, the copper or copper alloy plate material for a terminal of the present invention is a material suitably used for the manufacturing method and the terminal manufacturing.

It is the perspective view which showed one preferable embodiment of the terminal of this invention. It is sectional drawing which showed the longitudinal direction cross section of the tubular caulking part of the terminal which concerns on this invention. It is the perspective view which showed the termination | terminus connection structure of the electric wire of this invention. It is the perspective view which showed typically one state during manufacture of the terminal of this invention. It is the top view which showed the terminal material (expanded state before shaping | molding) of the female terminal produced by punching and pressing a base material. It is the perspective view which showed the state which processed the terminal material and shape | molded in the tubular body crimp part.

  A preferred embodiment of the present invention will be described with reference to the drawings. The embodiment shown below is an example, and various embodiments can be taken within the scope of the present invention.

  FIG. 1 shows a terminal 1 which is a preferred embodiment of a terminal manufactured by the manufacturing method of the present invention. This terminal 1 has a box portion 20 of a female terminal, and a tubular caulking portion 30 that connects the electric wire and the base material of the terminal 1 by crimping after an aluminum electric wire is inserted. A transition portion 40 that communicates with the tubular caulking portion 30 is provided. Further, the terminal 1 has a laser welding portion 50 (portion indicated by hatching in the drawing) in the tube caulking portion 30. The terminal 1 is basically made of a metal material, for example, a base material such as copper or a copper alloy, in order to ensure conductivity and strength. The shape of the laser weld 50 is not particularly limited. It is preferable to form in a band shape in the longitudinal direction of the tubular caulking portion 30 like the laser welding portion 50.

  The terminal material 32 (base material) constituting the terminal 1 is preferably formed of a copper alloy. Although the thickness of the terminal material 32 is not specifically limited, For example, 0.08-0.64 mm is preferable.

  As the material of the terminal material 32, copper (tough pitch copper, oxygen-free copper, etc.) can be used instead of the copper alloy.

  Examples of the copper alloy used for the terminal material 32 include, for example, brass (for example, C2600, C2680 of CDA (Copper Development Association)), phosphor bronze (for example, C5210 of CDA), corson-based copper alloy (Cu—Ni—). Si- (Sn, Zn, Mg, Cr) -based copper alloy) and the like. Among these, a Corson-based copper alloy is preferable.

Examples of the Corson copper alloy are not limited to these, but include, for example, Furukawa Electric Co., Ltd. copper alloys FAS-680 and FAS-820 (both trade names), Mitsubishi Shindoh copper alloys MAX-375, MAX251 (both are trade names) and the like can be used. Also, CDA C7025 or the like can be used.
An example of the alloy composition of the FAS-680 is 0.15% by mass of tin (Sn), 0.5% by mass of zinc (Zn), 2.3% by mass of nickel (Ni), and 0 of silicon (Si). .55% by mass and 0.1% by mass of magnesium (Mg), with the balance being copper (Cu) and inevitable impurities.
An example of the alloy composition of FAS-820 is as follows: tin (Sn) 0.15 mass%, zinc (Zn) 0.5 mass%, nickel (Ni) 2.3 mass%, silicon (Si) 0.65 mass%, magnesium (Mg) 0.1 mass%, and chromium (Cr) 0.15 mass%, with the balance being copper (Cu) and inevitable impurities.

Examples of other copper alloy compositions include, for example, Cu—Sn—Cr based copper alloys, Cu—Sn—Zn—Cr based copper alloys, Cu—Sn—P based copper alloys, Cu—Sn—P—Ni. Examples thereof include a copper alloy, a Cu—Fe—Sn—P copper alloy, a Cu—Mg—P copper alloy, and a Cu—Fe—Zn—P copper alloy.
Here, it is natural that inevitable impurities may be included in addition to the essential elements described above.

A specific nickel layer (also referred to as Ni layer) and a tin layer (also referred to as Sn layer) are formed in this order in advance on the surface of the terminal 1 and at least the tube caulking portion 30 before laser welding. Of the Ni layer and the tin layer, the Ni layer and the Sn layer that existed in the region irradiated with the laser, that is, the Ni layer and the Sn layer formed at the end portion (butting portion 37) of the tube expanding portion 30a are laser-welded. Later, the Ni layer and the Sn layer that apparently disappeared from the surface and existed in the region not irradiated with the laser remain. The nickel metal and the tin metal constituting the disappeared Ni layer and Sn layer are melted and taken into the laser weld 50. Further, metal tin may be taken in or dispersed in the heat affected zone near the laser weld 50. The dispersion state of metallic nickel and metallic tin cannot be generally stated depending on the laser welding conditions, but is considered as follows. The laser weld has a structure in which the copper alloy and the plated metal species are melted and solidified. Metal nickel and metal tin may be, for example, columnar crystals in a solidified structure containing Cu as a main component, a form dispersed in equiaxed crystal grain boundaries, or a form present at the crystal interface.
On the other hand, the high melting point inorganic particles are dispersed inside the laser weld 50. The dispersion state of the high-melting-point inorganic particles cannot be generally stated depending on the laser welding conditions, but for example, columnar crystals and equiaxed crystals in a solidified structure mainly composed of Cu formed by melting and solidifying by laser welding. The form dispersed in the crystal grain boundary is considered, and the form taken into the crystal grain may coexist.

  The box part 20 of the female terminal 1 is a box part that allows insertion of an insertion tab such as a male terminal. In the present invention, the detailed shape of the box portion is not particularly limited. That is, in another embodiment of the terminal of the present invention, the box portion may not be provided. For example, an insertion tab of a male terminal may be used instead of the box portion. Moreover, the edge part of the terminal which concerns on another form may be sufficient. In this specification, in order to explain the terminal of the present invention, an example of a female terminal is shown for convenience. Whatever the terminal having any connecting end, it is sufficient that the tube caulking portion 30 is provided via the transition portion 40. Moreover, it is preferable that the laser welding part 50 formed in the tubular caulking part 30 is softer than the base material constituting the tubular caulking part.

The tubular caulking part 30 is a part for crimping and joining the terminal 1 and an electric wire (not shown). One end has an electric wire insertion port (conductor insertion port) 31 into which an electric wire such as an aluminum electric wire or its conductor can be inserted, and the other end is connected to the transition portion 40. The tube caulking portion 30 is formed on the transition portion 40 side by crushing two opposing tube walls (usually upper and lower tube walls) of the tube caulking portion 30 by, for example, crushing processing such as press processing. It is closed by a welding process such as welding, and has a “can-like” structure having the closed portion as the bottom and opening at the wire or conductor insertion port 31. If moisture adheres to the contact between the terminal 1 base material (copper or copper alloy, etc.) and the aluminum wire, either metal (alloy) will corrode due to the difference in electromotive force between the two metals. 30 has a tubular structure that prevents moisture and the like from entering from the outside. If the crimped portion of the terminal of the present invention is a tubular body, a certain effect against corrosion can be obtained, so the cross section does not necessarily have to be a cylinder in the longitudinal direction. It may be a tubular tube. Further, the cross-sectional diameter does not need to be constant, and the cross-sectional diameter may change in the longitudinal direction.
If the terminal 1 is used, the tube caulking portion 30 is a tube, so that it is difficult for moisture from the outside to adhere to the contact between the aluminum electric wire and the base material of the terminal 1.

  In the tubular caulking part 30, the terminal material 32 and the aluminum (aluminum alloy) electric wire constituting the tubular caulking part 30 are mechanically pressure-bonded to ensure electrical joining at the same time. The caulking is performed by plastic deformation of the terminal material 32 and the electric wire (core wire). Therefore, the tubular caulking portion 30 needs to be designed to be thick enough to be caulked and joined, but can be freely joined by human processing, machining, or the like, and thus is particularly limited. It is not a thing.

The tubular caulking portion 30 of the present invention is configured by abutting plate-like tube development portions 30a of the terminal material 32, and a laser formed by joining the abutted portions (also referred to as “butting portions”) 37. A weld 50 is provided. That is, the laser welded portion 50 is continuously provided in the longitudinal direction along the abutted portion of the tubular caulking portion 30. And it is provided as a linear area | region from the transition part 40 to the electric wire insertion port 31. FIG.
Further, as described above, the laser welded portion 50 is a welded portion formed by laser welding the tube development portion 30a in which the Sn layer and the specific Ni layer are formed below the Sn layer before the laser welding. In addition, the Sn layer and the specific Ni layer formed before laser welding enhance the absorption of the laser light at the time of laser welding of the tube expanding portion 30a.

  A part of a longitudinal sectional view of the tubular caulking portion 30 is shown in FIG. In FIG. 2, the description of the laser weld 50 is omitted. As described above, the tubular caulking portion 30 is configured by the tube expanding portion 30a made of copper or a copper alloy. Further, the inner wall surface 33 of the tubular caulking portion 30 may have an electric wire locking groove 34a or 34b for maintaining the contact pressure with the electric wire. Aluminum and aluminum alloy, which are the core wires of electric wires, have an oxide film on the surface that is higher in insulation than copper oxide film compared to copper alloy, so there is anxiety in connection. Therefore, by providing such a groove, the contact pressure is increased by the crest of the groove. In FIG. 2, the wire locking groove 34a is a groove having a rectangular cross section, and the wire locking groove 34b is a groove having a semicircular cross section. Such a wire locking groove is easy to be provided if the tube expanding portion 30a itself is processed before the tube caulking portion 30 is formed, and the terminal 1 can be produced efficiently. It can be provided by cutting with a fiber laser or a machine, which will be described later. In addition, if such an electric wire latching groove is provided in advance before the tube caulking portion 30 is formed, efficient production can be achieved.

In addition, since an aluminum electric wire or its conductor is inserted into the tubular caulking portion 30 from the electric wire insertion port 31, it is preferable that the electric wire locking grooves 34a and 34b are provided at positions in contact with the aluminum core wire. An aluminum electric wire is usually composed of an aluminum core wire (conductor) and an insulating coating covering the same. Then, the electrical connection between the electric wire and the terminal is performed by crimping and joining the aluminum core wire from which the insulating covering portion at the tip is removed (peeled) to the tube caulking portion 30 of the terminal. Therefore, ensuring sufficient contact pressure leads to maintenance of electrical performance, so that a groove such as a wire locking groove is required. Such grooves are also called serrations.
And since a terminal and an electric wire are reliably crimped | bonded by providing at least 1 or more wire locking groove in the inner surface of the tubular caulking part 30, it can be made more excellent in long-term reliability.

  FIG. 3 shows an end connection structure 10 for an electric wire according to the present invention. The terminal connection structure 10 has a structure in which the terminal 1 of the present invention and an aluminum electric wire or an aluminum alloy electric wire (electric wire 60) are crimped and connected. The terminal connection structure 10 of the electric wire inserts the aluminum alloy electric wire 60 or its conductor into the tube caulking portion 30 and caulks the tube caulking portion 30, so that the aluminum alloy electric wire 60 enters the tube caulking portion 30. Crimp connected. In the terminal connection structure 10, the terminal 1 and the electric wire 60 are crimped and connected by the tube caulking portion 30. The manner of pressure bonding is not particularly limited, but in FIG. 3, it is composed of a first pressure-reduced diameter portion 35 and a second pressure-reduced diameter portion 36. Normally, when crimped and connected, the tubular caulking portion 30 undergoes plastic deformation and is crimped to the electric wire 60 by being reduced in diameter from the original diameter. In the example shown in FIG. 3, the first pressure-reducing diameter portion 35 is a portion having the highest diameter reduction ratio. In this way, the pressure bonding may be performed with two stages of diameter reduction, or may be performed with three or more stages of diameter reduction.

  The electric wire 60 includes an insulating coating 61 and a core wire of an aluminum or aluminum alloy electric wire (not shown). Although the electric wire 60 may be a bare wire, from the viewpoint of corrosion prevention, an electric wire with an insulation coating is usually used.

The terminal end connection structure of the electric wire according to the present invention contributes to prevention of corrosion between different metals between the electric wire made of an aluminum-based material and the base material of the terminal 1 made of a copper-based material. In addition, since the laser welded portion 50 and the heat affected zone in the vicinity thereof do not greatly impair the mechanical properties of the base material before laser welding, the laser welded portion 50 is not easily damaged during manufacturing and use, and the yield and long-term reliability are improved. Contribute to. On the other hand, the laser welded portion 50 and the heat affected zone have mechanical properties that are not as high as those before laser welding and can be an annealed portion that is softer than the terminal material 32 that is a base material. Springback can be prevented, and long-term reliability is also excellent in this respect.
The spring back is a phenomenon in which the processed part attempts to return to its original shape. That is, the deformed portion of the tube caulking portion 30 that has been crimped and joined to an electric wire (not shown) tries to return to its original shape with an elastic force or the like, so that there is a gap between the inner surface of the tube caulking portion 30 and the electric wire. I can do it. If such a springback occurs in the crimping portion of the terminal, not only will the contact between the electric wire 60 and the terminal 1 be inferior, but also water may easily enter the gap and cause corrosion.

  When manufacturing the terminal connection structure 10 of the electric wire according to the present invention, it is preferable to perform crimp bonding that positively plastically deforms the laser welding portion 50 of the tube caulking portion 30. When crimping the tube caulking portion 30 of the terminal 1 and the electric wire 60, it is performed with a dedicated jig or a press machine. At this time, the entire diameter of the tubular caulking portion 30 may be reduced. However, the tubular caulking portion 30 may be partly strongly processed and crimped in a concave shape. At this time, the position may be adjusted so that the amount of plastic deformation of the laser weld 50 is increased. That is, when the adjustment is performed so that the tip of the convex portion at the time of press working is directly above (outside) of the laser weld 50, the amount of deformation of the laser weld 50 increases. If it does in this way, since the comparatively soft laser welding part 50 can bear much plastic deformation, it can contribute to reduction of a springback.

  Next, the manufacturing method of the terminal 1, the terminal material 32 of the terminal 1, etc. are demonstrated. Since the terminal 1 of the present invention has a tubular caulking portion 30 and the tubular caulking portion 30 has a laser welded portion (see FIG. 1), the manufacturing method is limited if this configuration can be achieved. It is not something.

The terminal 1 and the terminal material 32 are preferably manufactured as follows.
A specific Ni layer is formed on at least a portion (pipe expanding portion 30a) of the base material that is made of copper or copper alloy and punches the terminal material 32, and a Sn layer is further provided thereon. Next, as shown in FIG. 5, a plurality of terminal members 32 are obtained by punching out the base material and processing the terminal 1 into a terminal shape in which the terminal 1 is planarly extended so as to be continuous in the longitudinal direction (chain type). Thereafter, the box part 20 and the transition part 40 are formed by bending. This is preferable in terms of production efficiency. On the other hand, after a plurality of chain-type terminal members 32 are obtained by punching the base material, a specific Ni layer is provided on the tube development portion 30a, and an Sn layer is further provided thereon. Thereafter, the box part 20 and the transition part 40 are formed by bending. This is preferable in that the formation area of the specific Ni layer and the Sn layer thereon can be reduced in addition to the production efficiency. As described above, the order of the plating process and the punching process is appropriately selected. In addition, after providing a specific Ni layer and a Sn layer on the specific Ni layer in a specific region of a plate or strip as a base material, each terminal material 32 may be punched out.

Next, the tubular caulking portion 30 is formed by laser welding the butted portion 37 that is curved and butted both ends 30S of the tubular body expanding portion 30 by bending or the like. Therefore, the terminal material 32 punched into the terminal shape only needs to have a shape that can form the box portion 20, the transition portion 40, and the tubular caulking portion 30 by bending or the like. The shape of the tube deployment portion 30a that can form the tubular caulking portion 30 by bending or the like is typically rectangular, but is not particularly limited as long as the shape can form a tubular body with one end closed. You may have a substantially fan shape, or the shape which combined the rectangle and the substantially fan shape. The shapes that can form the box portion 20 and the transition portion 40 are appropriately selected according to the shapes of the box portion 20 and the transition portion 40. In addition, the terminal material 32 has a specific Ni layer and an Sn layer, which will be described later, formed on the surface of the tube development portion 30a. The terminal material 32 of the present invention having such a shape and a specific Ni layer and Sn layer is formed into a tubular body by curving and butting a portion of the tube expanding portion 30a which becomes the tubular caulking portion 30 to be crimped and joined to the electric wire. And it is suitably used for the manufacturing method of the terminal 1 which joins the faced part and forms the tubular caulking part 30.
When the tubular caulking portion 30 is formed, since the flat tube expanding portion 30a has a C-shaped cross section by bending or the like, the end surface of this open part is abutted and joined by laser welding, and the tubular body The caulking part 30 is used. As a preferable manufacturing method of the tubular caulking portion 30, laser welding is performed using a fiber laser processing machine that oscillates near infrared laser light.

  Usually, copper alloys have a low absorption efficiency of laser light having an oscillation wavelength in the near-infrared region, so that there are cases where the weld width cannot be reduced or the heat affected zone (HAZ) cannot be reduced. In addition, the mechanical properties of the welded part and the vicinity thereof may be significantly reduced by laser welding of the copper alloy. Therefore, a specific Ni layer is formed on the surface of the tube expanding portion 30a that becomes the laser welded portion 50, and in addition, an Sn layer that absorbs near infrared laser light better than a copper alloy is formed on the Ni layer. In addition, the above problem can be overcome by using laser light having a high energy density such as fiber laser light. Moreover, the laser welding part 50 can also be made into an annealing part, welding the butt | matching part 37 of the pipe | tube crimping part 30 by welding with a fiber laser beam. Thus, since the welding process and the annealing process of the tubular caulking part 30 can be performed in one process, the terminal 1 can be manufactured efficiently.

The Sn layer surface (the surface of the Sn or Sn alloy constituting the Sn layer, excluding the high melting point inorganic particles described later) has less near-infrared laser light reflection than the copper alloy surface, and therefore has a near-infrared laser light absorbability. good. In the reflectance measurement of near infrared light by the spectrophotometric method, the Sn layer surface has a reflectance of about 60 to 80%, which is lower than the copper alloy surface having a reflectance of 90% or more. When the near-infrared laser light is irradiated to the region where the Sn layer having high absorption of the near-infrared laser light is thus irradiated, the Sn layer having a low melting point is rapidly melted to form a molten pool. The absorption of the laser beam is further increased, and the specific Ni layer on the base is melted. Here, Sn melts by absorbing thermal energy by irradiation with near-infrared laser light, and Ni combines with the action of high-melting-point inorganic particles to be described later, thermal energy by irradiation with near-infrared laser light. And melts by absorbing the heat energy transferred from Sn. In this way, when the Ni layer is also melted, the absorption of the laser beam is remarkably increased and the surface of the expanded tube portion is also melted, and the melted region absorbs the laser beam and melts the butted portion of the expanded tube portion. As a result, welding proceeds. Thus, by forming the Sn layer having a high reflectance and the Ni layer containing the high melting point inorganic particles as the underlayer, the laser light is absorbed by the Sn layer and converted into heat, and the heat causes the Sn layer and the Ni layer to be converted into heat. Since the layer is melted and the melted Sn and Ni contribute to welding, the weldability is further improved. At this time, the Ni layer and the Sn layer are melted and nickel and tin are mixed with the base copper to form, for example, a copper nickel tin alloy, a copper tin compound, a copper nickel tin compound, and the like.
Moreover, it is considered that the high melting point inorganic particles contained in the Ni layer are mixed with molten copper and taken into the molten part and dispersed. Thus, it is speculated that laser welding can compensate for the deterioration of mechanical properties by alloying and dispersion of intermetallic compounds and high melting point inorganic particles in the base copper component.

On the surface of the tube development portion 30a, a nickel layer and a tin layer (sometimes referred to as Sn layers in the present invention) containing high melting point inorganic particles having a particle size of 10 nm or more and less than 300 nm at a volume fraction of 10 to 70%. ) Is provided. As long as this laminated metal layer has a tin layer as an outermost layer and a specific Ni layer as an underlayer, other layer configurations are not particularly limited. For example, the laminated metal layer may be a laminated structure of three or more layers having at least one of a lowermost layer between the tubular caulking portion 30 and the nickel layer and an intermediate layer between the nickel layer and the tin layer. Good. Examples of such an intermediate layer include a Sn layer containing high melting point inorganic particles described later and a Ni layer not containing high melting point inorganic particles.
This laminated metal layer preferably has a two-layer structure consisting of a specific nickel layer as the lowermost layer and a tin layer as the outermost layer in terms of laser weldability and strength.

  The Ni layer as the underlayer is a layer made of nickel containing or dispersing high melting point inorganic particles. As long as the Ni layer contains or disperses high melting point inorganic particles, the Ni layer may be an Ni alloy layer containing an alloy component other than Ni as desired and the balance being Ni and inevitable impurities. The high melting point inorganic particles may be inorganic particles having a melting point higher than that of nickel (melting point: about 1455 ° C.) or a nickel alloy so that the form thereof is not impaired by laser welding. For example, the high melting point inorganic particles have a melting point of 1500 ° C. or more. Inorganic particles are preferable, and inorganic particles having a melting point of 2000 ° C. or higher are more preferable. When high-melting inorganic particles are irradiated with a laser, the thermal energy of the Sn layer melted by the laser and the optical energy of the laser are absorbed to promote the melting of nickel and copper alloy, and after the laser irradiation. Does not melt, decompose and volatilize, but disperses within the weld and exhibits the function of maintaining its strength.

  Examples of such inorganic particles include particles made of ceramics or carbon materials, and may or may not have conductivity. The particles made of ceramics are not particularly limited as long as they have the melting point described above. For example, oxide ceramics, nitride ceramics, carbide ceramics, oxynitride ceramics, boride ceramics, halogens Examples thereof include chemical ceramics. Examples of the oxide-based ceramics include silica, alumina, titanium dioxide, and the like. Examples of the nitride-based ceramics include silicon nitride, aluminum nitride, titanium nitride, and boron nitride. Examples of the carbide-based ceramics include silicon carbide, Examples thereof include aluminum carbide, titanium carbide, boron carbide and the like. Examples of boride-based ceramics include zirconium boride. Examples of the halide ceramic include SiFnXm (X represents a chlorine atom or a bromine atom, n represents an integer of 1 to 4, and m represents an integer of 0 to 3).

  The particles made of the carbon material are not particularly limited as long as they have the melting point described above, and include carbon allotropes. For example, diamond (including conductive diamond), carbon black (including Ketjen black, etc.), carbon nanotube (CNT), carbon fiber, graphite, graphene, and these carbon nanoparticles (CNP) can be used.

  The high melting point inorganic particles are preferably particles made of ceramics in terms of laser welding efficiency and strength, and more preferably oxide-based ceramics. On the other hand, it is preferable to have conductivity in terms of electric resistance of the welded portion, Particles made of a carbon material (excluding insulating diamond) are more preferable.

The high melting point inorganic particles have a particle size of 10 nm or more and less than 300 nm. When the particle size of the high-melting-point inorganic particles is in the range of 10 nm or more and less than 300 nm, laser welding can be performed with high laser welding efficiency without greatly reducing the material strength, that is, the strength of the welded portion and its vicinity. Moreover, when the particle diameter of the high-melting-point inorganic particles is in the range of 10 nm or more and less than 300 nm, conductivity as a terminal can be secured without impairing the electrical resistance of the tubular body including the welded portion. The particle diameter of the high-melting-point inorganic particles is preferably 10 to 100 nm, more preferably 20 to 50 nm, from the viewpoint of laser welding efficiency and strength, and conductivity.
Here, the particle size of the high-melting-point inorganic particles is measured using, for example, a laser light scattering particle size distribution measuring device (manufactured by Horiba, Ltd., laser diffraction / scattering particle size distribution measuring device “LA-950” (trade name)). The particle size is 50% in cumulative distribution. When the particles are not in a spherical shape such as a fiber like CNT, the dynamic image analysis method particle size distribution / particle shape evaluation device “QICPIC” ((trade name), manufactured by Sympatec) is used as the image analysis device. Measure the maximum length of 10,000 pieces (major axis length) and take the average value.

  The high melting point inorganic particles are contained in the Ni layer at a volume fraction of 10 to 70%. When the volume fraction of the high melting point inorganic particles is less than 10%, the laser welding efficiency is not sufficiently improved, and the strength of the laser welded portion 50 or the heat affected zone may be lowered. On the other hand, when the volume fraction exceeds 70%, the effect of improving the laser welding efficiency is high, but the strength of the laser welded portion 50 or the heat affected zone is greatly reduced. Further, when the volume fraction is in the range of 10 to 70%, the conductivity as the terminal 1 can be ensured without impairing the electrical resistance of the tubular caulking portion 30 including the laser welding portion 50. From the viewpoint of improving laser welding efficiency, maintaining strength, and ensuring conductivity, the volume fraction of the high melting point inorganic particles of the Ni layer is preferably 10 to 50%, more preferably 20 to 30%. . The volume fraction of the high melting point inorganic particles is the ratio of the total volume of the high melting point inorganic particles to the volume of the entire Ni layer containing the high melting point inorganic particles. The volume of the Ni layer containing the high melting point inorganic particles can be obtained from the dimensions of the Ni layer, and the total volume of the high melting point inorganic particles can be obtained from observation of the Ni layer cross section. The cross section is preferably mechanical polishing or electrolytic polishing, and observation is possible with an optical microscope, a scanning electron microscope (SEM), or a transmission electron microscope (TEM). In the micrograph, the high melting point inorganic particles and Ni can be distinguished by the difference in contrast. The volume fraction of the high melting point inorganic particles can be calculated on the assumption that the ratio of the area of the high melting point inorganic particles appearing in the observed cross section is equal to the ratio of the entire volume. In addition, a more accurate volume ratio can be calculated by observing and averaging about 10 cross-sections.

  As described above, this Ni layer improves laser weldability together with the Sn layer during laser welding, and suppresses diffusion of the copper or copper alloy of the base material into the Sn layer except during laser welding. It suppresses that Sn in the Sn layer diffuses into the base material. Therefore, even when a metal such as iron, cobalt, or chromium that can form an alloy with copper as a base material at the time of melting and does not easily diffuse with copper or Sn below the melting point, such as iron, cobalt, or chromium, is an object of the present invention. Is achieved. Therefore, in the present invention, the base layer of the laminated metal layer is not limited to the Ni layer, and an Fe layer, a Co layer, a Cr layer, or an alloy layer thereof can be used.

  The thickness of the Ni layer is 0.3 to 1.5 μm, preferably 0.4 to 0.8 μm, more preferably 0.4 to 0.5 μm. If the Ni layer is too thick, the amount of high-melting-point inorganic particles taken into the laser welded portion 50 may increase so that the strength of the laser welded portion 50 may decrease. On the other hand, if the Ni layer is too thin, the total amount of the high-melting-point inorganic particles decreases, so that the effect of improving the welding efficiency may be reduced.

Such a Ni layer containing high melting point inorganic particles is not particularly limited as long as it can contain high melting point inorganic particles, for example, a plating method using a plating bath containing high melting point inorganic particles. As a plating method that is preferable in terms of cost to be formed on the surface of the tube development portion 30a, electroplating, electroless plating, or the like is possible. In addition to the plating method, various film forming techniques such as vapor deposition, ion plating, sputtering, and chemical vapor deposition can be employed.

For the plating method, any nickel plating solution can be used without particular limitation. For example, using a nickel sulfamate bath containing high melting point inorganic particles, a plating temperature of 70 ° C. or less, a current density of 1 to 30 A / at dm ² . The content of the high melting point inorganic particles in the nickel sulfamate bath is preferably, for example, 30 to 100 g / L. However, the plating conditions are not limited to this and can be set as appropriate.

  There is no restriction | limiting in particular about the component composition and kind of Ni layer formed in this invention. The Ni layer that can be used in the present invention is not limited to a pure nickel layer, but may be a nickel alloy layer. Examples of the nickel alloy layer include a nickel-silver alloy layer, a nickel-tin alloy layer, a nickel-copper alloy layer, a nickel-lead alloy layer, a nickel-antimony alloy layer, and a nickel-phosphorus alloy.

The Sn layer as the outermost layer is a tin layer made of tin and unavoidable impurities, and may be a tin alloy layer containing alloy components other than Sn and the balance being made of Sn and unavoidable impurities as desired. The Sn layer as the outermost layer preferably does not substantially contain the above-described high melting point inorganic particles. Here, “substantially does not contain” includes not only the case where the high melting point inorganic particles are not contained in the Sn layer but also the case where it is unavoidably contained.
Sn layer containing Sn with low melting point and good absorption of near-infrared laser light, when irradiated with laser, absorbs and melts the light energy of laser and transfers thermal energy to Ni layer to make copper alloy Promote melting of Therefore, the object of the present invention can be achieved even when a metal that has good absorption of near-infrared laser light and has a melting point lower than that of copper, for example, silver or gold, is used instead of Sn. Therefore, in the present invention, the outermost layer of the laminated metal layer is not limited to the Sn layer, and an Ag layer, an Au layer, or an alloy layer thereof can be used.

  The thickness of the Sn layer is 0.2-2 μm, preferably 0.3-1 μm, more preferably 0.3-0.5 μm. If the Sn layer is too thick, the effect of improving the welding efficiency may be reduced, and if it is too thin, the effect of reducing the contact resistance between the terminals and the crimped portion resistance may be reduced. The thickness of the Sn layer or the like is measured by a fluorescent X-ray film thickness meter.

  The manufacturing method is not particularly limited as long as the Sn layer can be formed on the Ni layer. For example, it is preferable that the Sn layer is formed by a plating method using a plating bath in terms of cost. As a plating method, electroplating, electroless plating, hot dipping, and the like are possible. In addition to the plating method, various film forming techniques such as an evaporation method, an ion plating method, a sputtering method, and a chemical vapor deposition method can be employed. In addition, since the specific Ni layer is formed as a base layer, the reflow process which heats the Sn layer formed by the plating method can also be performed.

For the plating method, any tin plating solution can be used without particular limitation. For example, a tin sulfate bath can be used at a plating temperature of 70 ° C. or less and a current density of 1 to 10 A / dm ² . However, the plating conditions are not limited to this and can be set as appropriate.

  There is no restriction | limiting in particular about the component composition and kind of Sn layer formed in this invention. The Sn layer that can be used in the present invention is not limited to a pure tin layer, and may be a tin alloy layer. Examples of the tin alloy layer include a tin-silver alloy layer, a tin-nickel alloy layer, a tin-copper alloy layer, a tin-lead alloy layer, and a tin-antimony alloy layer.

  In addition, when forming a specific Ni layer and Sn layer by a plating method, a conventional pretreatment means, for example, cathode electrolytic degreasing in an aqueous solution of sodium hydroxide, pickling treatment by dilute sulfuric acid immersion, activation treatment, etc. is performed. Thereby, the plating film excellent in adhesiveness can be formed.

The laminated metal layer, that is, the specific Ni layer and the Sn layer, is in a region where the laser beam irradiation of the tube expanding portion 30a in the terminal material 32 or the base material is performed, that is, the tube expanding portion 30a corresponding to the butting portion 37 in FIG. Alternatively, it may be formed at least at one end portion or both end portions (also referred to as “laser-welded end portions”) in the longitudinal direction of the portion that becomes the tube expanding portion 30a. For example, the laminated metal layer may be formed on the surface (including the end face 30S) of the end portion to be laser welded with a width equal to or greater than the spot diameter of the laser beam.
Moreover, it is preferable that the laminated metal layer is formed on the surface of the portion that becomes the tube expanding portion 30a or the tube expanding portion 30a that is irradiated with the laser beam. Specifically, it is preferably formed on the entire surface on the side where laser light irradiation is performed or on the surface in the vicinity of the butt portion 37. When forming a laminated metal layer, when forming a base material made of copper or a copper alloy, for example, a terminal material 32 having a shape in which a strip 1 is punched and the terminal 1 is developed, laser light irradiation is performed before punching. The laminated metal layer is formed in a stripe shape so as to include a portion, that is, to include a tube development portion 30 a that becomes the tube caulking portion 30. Usually, it is preferable to produce a plurality of terminal materials 32 by punching one base material by punching, rather than forming a laminated metal layer for each terminal material 32. When the laminated metal layer is formed on 32, the number of steps is reduced. The punching of the terminal material 32 from the base material is performed so that the portion where the laminated metal layer is formed becomes the tube expanding portion 30a of the terminal material 32.
Further, in the case where the laminated metal layer is formed on the end or end surface 30S of the tube expanding portion 30a to be the butt portion 37, the end or end surface 30S is immersed in a plating bath after the terminal material 32 is stamped. Alternatively, a plating process is performed by masking a portion where the plating layer is unnecessary. Furthermore, when the pipe development part 30a is intermediately formed into one U-shape and the leg part is immersed in the plating solution, a laminated metal layer can be formed on the end face 30S and its periphery (end part).

  Thus, in the present invention, in order to solve the above-described problems of the present invention, the specific Ni layer and the Sn layer may be formed at least on the above-described laser welded end portion, and the box portion 20 and the transition portion. Although it is preferable not to form in 40, it can also form.

  In the present invention, as described above, by starting the melting of the tube expanding portion 30a at the time of laser light irradiation by the outermost Sn layer and the specific Ni layer, the effect of improving the laser welding efficiency and the strength of the welded portion and the vicinity thereof are obtained. A holding effect is obtained. Therefore, it is preferable to form a laminated metal layer on the surface of the pipe development part 30a without interposing another layer, in order to sufficiently exhibit these expected effects.

  In this way, the terminal material 32 of the present invention is produced. The terminal material 32 may be a chain type as described above, or may be a separate body.

  Since it changes depending on the material of the terminal material 32 constituting the terminal 1, it cannot be generally stated, but if the copper alloy terminal material 32 has a laminated metal layer formed on its surface, the laminated metal layer is irradiated by near infrared laser light irradiation. The Sn layer and the Ni layer absorb the laser beam and melt to form a molten pool. Further, the heat and thermal energy converted into light energy by the irradiation of the laser beam are propagated, and the copper alloy of the terminal material 32 is melted. The molten metal nickel, metal tin, and metal copper are solidified after the laser irradiation, and the butted portions are joined to form the laser weld 50. Therefore, the laser welding part 50 is provided when the temperature of the terminal material 32 is raised above the melting point of the copper or copper alloy that is the material. Specifically, the butted portion 37 of the tube caulking portion 30 is raised to a temperature not lower than the melting point of copper or a copper alloy and not higher than the boiling point of the terminal material 32 including the laminated metal layer, and held for a predetermined time if necessary for laser welding. By applying, the laser welding part 50 is formed. Usually, since the laser light is swept, the temperature of the laser light irradiation region may be set to be equal to or higher than the melting point of the terminal material by appropriately determining the sweep speed. Preferably, the laser beam irradiation conditions are adjusted so that the terminal material 32 is melted through by laser irradiation.

  The laser welding uses near infrared laser light. The near-infrared laser beam has an oscillation wavelength of 700 nm to 2.5 μm, and preferably a laser beam having an oscillation wavelength of 1000 nm to 2000 nm. Examples of such laser light include yttrium (Yt) doped glass fiber laser light (oscillation wavelength 1084 nm), erbium (Er) doped glass fiber laser light (oscillation wavelength 1550 nm), and the like. A yttrium-doped glass fiber laser beam is more preferable because the reflectance is lower in the region where the wavelength is about 1000 nm.

  For the welding, a fiber laser device that continuously oscillates near-infrared laser light is used, but the tube caulking portion 30 may be formed by welding using a laser device different from this. For example, a continuous wave YAG laser light oscillation device, a glass laser light oscillation device, etc., a pulsed laser light oscillation device, etc. can be mentioned. It is preferable to use a fiber laser oscillator from the viewpoint of performance.

FIG. 4 is a diagram schematically showing one state during manufacture of the terminal 1 of the present invention.
As shown in FIG. 4, the butted portions 37 of both end faces 30S of the tube expanding portion 30a formed into a tubular body by bending the tube expanding portion 30a into a C-shape are irradiated with laser light having a near infrared wavelength of 1084 nm ± 5 nm. The laser beam L emitted from the oscillating fiber laser welding apparatus FL is irradiated so as to be welded, and the energy of the laser beam is converted into heat, so that the Sn layer on the butt portion 37 is first changed to the specific Ni layer. However, the melting heat energy is also propagated, the base material (Cu) itself of the butt portion 37 is melted, and then cooled to provide the laser weld 50. The laser welding part 50 can be provided by a heat treatment at or above the melting point of the material to be welded. However, if the energy of the fiber laser beam L is too high or the energy density is low, the heat-affected zone is formed in a wider range than necessary, and in the extreme case, the entire caulking portion 30 is softened. . Therefore, the fiber laser light L is preferably welded at an output of 100 to 400W. Moreover, the laser welding part 50 is provided in a suitable range by adjusting sweep speed.

  Thus, in the terminal manufacturing method of the present invention, a specific Ni layer and Sn layer containing high-melting-point inorganic particles are formed in advance on the tube development portion 30a to be laser-welded, and this Sn layer is irradiated with laser. Then, as described above, the Sn layer melts, and then the high melting point inorganic particles absorb the light energy of the laser, the thermal energy from the Sn layer, etc., and promote the melting of the Ni layer and the copper alloy. At this time, the high melting point inorganic particles exist in the state of particles without being melted or decomposed. After the laser irradiation, it is considered that the molten copper alloy remains in the laser welded portion 50 after being cooled and remains dispersed while being dispersed. On the other hand, it is considered that the Sn and Ni layers melted by the laser irradiation are dissolved in the surfaces of the laser weld 50 and the heat affected zone.

  In this way, the tubular caulking portion is formed, and the terminal of the present invention is manufactured.

  In the method for manufacturing a terminal according to the present invention, specific Ni layers and Sn layers are formed on the surface of the terminal material 32, particularly the tube development portion 30a before laser welding, and the terminal material 32 after laser welding, particularly the tube development portion 30a. Although a slight trace is observed on the surface of Ni, the Ni layer and the Sn layer apparently disappear. As described above, when the terminal material 32 of the present invention is used for laser welding in a state where the specific Ni layer and Sn layer are formed and is used as a terminal after being laser-welded, at least the surface of the laser welded portion 50 is used. Is different from the above-described terminals or composite plating materials of Patent Documents 4 to 8 in that the specific Ni layer and Sn layer do not appear.

The copper or copper alloy plate material (sometimes simply referred to as plate material) for the terminal of the present invention is specified on the base made of the copper or copper alloy, preferably in the predetermined portion of the pipe expanding portion 30a. A Ni layer and a Sn layer thereon. The kind of the base material, the kind of the high melting point inorganic particles, the Ni layer, the Sn layer, and the details and preferred ranges thereof are as described above.
The width of the plate material is not particularly limited as long as the terminal material 32 can be punched by, for example, press working. For example, the width of the plate material can be 10 to 60 mm, preferably 15 to 40 mm.
Here, the board | plate material of this invention is the meaning also including what is called a narrower strip | belt material.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.

(Example 1 and Comparative Example 1)
A copper alloy FAS-680 (trade name, thickness 0.25 mm, H material) manufactured by Furukawa Electric Co., Ltd. was used as a base material for punching the terminal material 32.
The alloy composition of FAS-680 is as follows: tin (Sn) 0.15 mass%, zinc (Zn) 0.5 mass%, nickel (Ni) 2.3 mass%, and silicon (Si) 0.55 mass%. It contains 0.1% by mass of magnesium (Mg), and the balance is copper (Cu) and inevitable impurities. FAS-680 has a melting point of 1078 ° C. (liquid phase), a specific heat of 377 J / (kg · K), a thermal conductivity of 170 W / (m · K), and a linear expansion coefficient of 17.7 × 10 ⁻⁶ / K (20 ˜300 ° C.), and conductivity 40% IACS. Further, the tensile strength is 600 to 700 N / mm ² , the elongation (tensile elongation at break, the same applies hereinafter) is 15% or more, the 0.2% proof stress is 500 to 600 N / mm ² , and the Vickers hardness is 160 to 220 Hv. is there.

  This plate material was subjected to electrolytic degreasing and acid dipping treatment, and then the “plating thickness” and “silica volume fraction (%) shown in Tables 1 and 2 were applied to the surface of the substrate in a Ni plating bath having the following composition. Then, an Ni layer containing high melting point inorganic particles (silica particles) was formed, and an Sn layer was further formed on the Ni layer in an Sn plating bath having the following composition. Next, the substrate was heated for 10 seconds in a heating furnace at 350 ° C. and reflow-treated. In this way, a copper alloy sheet 5 having specific Ni and Sn layers was produced.

(Electrolytic degreasing)
Treatment liquid: 10% sodium hydroxide aqueous solution Treatment temperature: 60 ° C
Cathode current density: 3.5 A / dm ²
Treatment time: 30 seconds (acid dipping treatment)
Treatment liquid: 10% sulfuric acid aqueous solution Treatment temperature: 25 ° C
Immersion treatment time: 30 seconds

(Ni plating treatment)
Treatment liquid: nickel sulfamate 300 to 450 g / L, silica having “silica particle size” shown in Tables 1 and 2 in the range of 20 to 120 g / L Treatment temperature: 60 ° C.
Current density: 20 A / dm ²
Treatment time: Adjust the time for each plating thickness in 10 to 10 minutes. The concentration of silica was set as follows within the above range according to the volume fraction of silica (see Table 1 and Table 2). . That is, 20 g / L when the volume fraction is 5%, 35 g / L when the volume fraction is 10%, 70 g / L when the volume fraction is 50%, and 70% when the volume fraction is 70%. 100 g / L and 120 g / L when the volume fraction is 80%

(Sn plating treatment)
Treatment liquid: tin sulfate (SnSO ₄ ) 20-100 g / L, sulfuric acid 50-200 g / L
Processing temperature: 60 ° C
Current density: 2 A / dm ²
Processing time: Adjust the time for each plating thickness in 2 to 15 minutes

As shown in FIG. 5, the copper alloy sheet material 5 in which the Ni layer and the Sn layer are formed in this way is punched out and processed into a shape in which the terminals are expanded so as to be continuous in the longitudinal direction (chain type). A terminal material 32 was produced. Furthermore, as shown in FIG. 6, the tube expanding portions 30 a of the terminal members 32 are each curved in a C-shaped cross section, and the end surfaces 30 </ b> S are butted together to form a butting portion 37. In the terminal material 32, the specific Ni layer and Sn layer were formed on the entire surface of the tube development portion 30a. Further, each of the terminal materials 32 was bent to form the box portion 20 and the transition portion 40. Then, as described with reference to FIG. 4, through welding of a length of 10 mm along the butted portion 37 by laser welding in which both sides (both end faces 30S) are irradiated with near-infrared laser light under the following conditions. As a result, the butted portion 37 was joined to produce the tubular caulking portion 30. Moreover, the annealed part was also obtained in the tubular caulking part 30 by this laser welding.
In this way, terminals 1 to 48 and c1 to c32 were manufactured.

The laser welding conditions are as follows.
(1) Laser welding apparatus: Furukawa Electric Co., Ltd. single mode fiber laser ASF1J221 (trade name)
Laser light source: Yb-doped glass fiber laser oscillator Laser light oscillation wavelength: 1084 ± 5 nm
Maximum laser beam output: 500W (continuous oscillation)

(2) Laser light irradiation conditions Laser light output: 400 W (used for continuous oscillation)
Laser light sweep speed: 90 to 450 mm / sec. Adjust with laser sweep distance: 10mm
All conditions Just focus laser irradiation (spot diameter size: 20μm)
Output density: 380 MW / cm ²

(Welding efficiency)
The laser beam sweep speed is 90 to 450 mm / sec. In the terminals 1 to 48 and c1 to c32 that were laser-welded while being changed in the above range, the welding efficiency was evaluated based on the speed at which the penetration welding by laser light was possible. From the relationship between the laser beam sweep speed and the laser beam sweep time, it can be judged that the laser beam sweep rate is high, that is, that the laser beam sweep time is short, that is, it is desirable from the industrial viewpoint because it requires less energy for laser welding.
Evaluation was made at a laser light sweep speed of 450 mm / sec. However, the case where the butt portion 37 could be welded through was “AAA (extremely excellent)”, 400 mm / sec. 450 mm / sec. If the butt portion 37 could be welded through at less than “AA (excellent)”, 300 mm / sec. 400 mm / sec. If the butt portion 37 could be through-welded at less than “A (good)”, 100 mm / sec. 300 mm / sec. The case where the butt portion 37 was able to be through welded at less than “B (possible)”, 100 mm / sec. The case where the butt portion 37 could not be welded through was determined as “C (poor)”.

(Weld strength)
The abutting portions 37 of the terminals 1 to 48 and c1 to c32 are arranged in the center, and the welded tube crimping portion 30 (laser welding portion 50. However, the crimping with the wire conductor is not performed) is mutually reversed. Pulling in the direction, the strength when the butt portion 37 was broken was measured.
The evaluation is “AA (excellent)” when the tensile strength when fractured is 90% or more of the tensile strength of the base material of the copper alloy FAS-680, and when it is 80% or more and less than 90% Is “A (good)”, 60% or more and less than 80% is “B (good)”, and less than 60% is “C (poor)”.

(Box part light load contact characteristics)
One simulated dimple obtained by molding a reflow Sn-plated copper alloy strip produced separately into a hemispherical shape having a diameter of 0.5 mm was used for forming the terminals 1 to 48 and c1 to c32. Surface after the Sn layer is disposed and before the forming process and on the non-laser welded copper alloy plate 5 (pipe unfolded portion 30a of the terminal member 32) with a load of 500 gf, and the contact resistance is based on the principle of the four-terminal method. Measured with a resistance meter.
The evaluation is “AA (excellent)” when the measured contact resistance value is less than 0.1 mΩ, “A (good)” when the measured contact resistance value is 0.1 mΩ or more and less than 0.5 mΩ, 0.5 mΩ. The case where it was less than 3 mΩ was “B (possible)” and the case where it was 3 mΩ or more was “C (poor)”.

(Crimping part conduction characteristics)
In the same manner as the terminals 1 to 48 and c1 to c32, the copper alloy sheet 5 (before forming and non-laser welding) provided with the high melting point inorganic particle-containing Ni layer and Sn layer is formed into a cylindrical shape, and the butt portion is formed. A cylindrical body was obtained by laser welding. Thereafter, one end of the cylindrical body was flattened by press molding, and sealed by laser welding. An aluminum electric wire conductor having a conductor cross-sectional area of 2.5 mm ² was inserted into this cylindrical body, and crimped and crimped to produce a terminal connection structure for electric wires. A temperature cycle test was performed for 500 cycles in which the manufactured terminal connection structure was held at a temperature of −40 ° C. and 120 ° C. for 30 minutes as a durable load. The initial resistance value in the termination connection structure and the post-endurance resistance value after the temperature cycle test were each measured by a four-terminal method using a voltage drop measuring device (AC milliohm meter, manufactured by Hioki).
The evaluation is “AA (excellent)” when the initial resistance is less than 0.5 mΩ and the resistance after durability is less than 1 mΩ, and is 0.5 mΩ or more and less than 1 mΩ, and the resistance after durability is 1 mΩ or more and less than 3 mΩ. “A (good)” when the initial resistance is 1 to 3 mΩ and the post-endurance resistance is 3 to 10 mΩ, “B (possible)”, the initial resistance is 3 mΩ or more, or the post-endurance resistance Was 10 CΩ or more, it was designated as “C (poor)”.

  The various test results and evaluation results are shown in Tables 1 and 2.

As is apparent from Tables 1 and 2, all of the terminals 1 to 48 of the present invention are excellent in welding efficiency and weld strength, and are also lightly contacted and crimped with a box portion light load contact characteristics assuming contact characteristics of the box portion. Excellent part conduction characteristics. In particular, according to the present invention using the Ni layer and the Sn layer containing the high melting point inorganic particles, the weld strength can be sufficiently maintained in addition to the improvement of the laser welding efficiency and the securing of the terminal conductivity.
On the other hand, regardless of the particle size of silica, the terminals c1 to c32 of the comparative example in which the volume fraction departs from the range of 10 to 70% were inferior in welding efficiency and weld strength or both. Moreover, when the volume fraction was too high, the light load contact characteristic of the box part and the conduction characteristic of the crimping part also deteriorated.

  Further, instead of copper alloy (FAS-680), Furukawa Electric Co., Ltd. copper alloy FAS-820 (trade name), Mitsubishi Shindoh copper alloy MAX251 (trade name) and Mitsubishi Shindoh copper alloy MAX-375 Even when (trade name) was used, the same tendency as the terminal of Example 1 was confirmed with respect to welding efficiency, welded portion strength, box portion light load contact point characteristics, and crimped portion conduction characteristics.

DESCRIPTION OF SYMBOLS 1 Terminal 5 Board | plate material 10 Termination connection structure 20 Box part 30 Tube caulking part 30a Pipe expansion | deployment part 30S End surface 31 Electric wire insertion port 32 Terminal base material 33 Inner wall surface 34a, 34b Electric wire latching groove 35 1st Crimp diameter-reduced part 36 2nd crimp diameter-reduced part 37 Butt part 40 Transition part 50 Laser welding part 60 Electric wire 61 Insulation coating FL Fiber laser welding apparatus L Fiber laser beam

Claims (12)

A method of manufacturing a terminal having a tubular caulking portion to be crimp-bonded to an electric wire,
Prepare a base material made of copper or a copper alloy of a terminal material provided with a tube development portion that is curved to form the tubular caulking portion,
A nickel layer containing high melting point inorganic particles having a particle size of 10 nm or more and less than 300 nm at a volume fraction of 10 to 70% is formed on the tube development part,
Forming a tin layer as an outermost layer on the nickel layer;
Curving and butting the tube deployment part to form a tube,
A method for manufacturing a terminal, comprising the steps of joining the butted portions by laser welding using near-infrared laser light irradiation to form the tubular caulking portion in this order.   The method for manufacturing a terminal according to claim 1, wherein the tin layer is formed on a surface of the pipe deployment portion on the laser welded side.   The method for manufacturing a terminal according to claim 1, wherein the tin layer is formed in the region where the laser beam is welded in the pipe expanding portion.   The manufacturing method of the terminal of any one of Claim 1 to 3 which forms the said tin layer in the said edge part by which the said laser expansion | deployment part is laser-welded.   5. The method of manufacturing a terminal according to claim 1, wherein the laser welding uses laser light having an oscillation wavelength in a near infrared region. The tube expansion portion of the terminal material provided with the tube expansion portion that becomes the tube caulking portion that crimps and joins the electric wire is bent and butted to form a tube body, and the butted portion is joined to form the tube caulking portion A terminal material used for manufacturing the terminal,
The terminal material is made of copper or a copper alloy, and has a nickel layer containing high-melting-point inorganic particles having a particle size of 10 nm or more and less than 300 nm at a volume fraction of 10 to 70% on the tube development part,
A terminal material having a tin layer as an outermost layer on the nickel layer.   The terminal material used for terminal manufacture according to claim 6, wherein the tin layer is formed on a surface of the tube development portion on the laser beam irradiation side of laser welding.   The terminal material used for terminal manufacture according to claim 6 or 7, wherein the tin layer is formed in the laser-welded region of the pipe expanding portion. A terminal having a crimped portion of a tubular body to be crimp-bonded to an electric wire,
The terminal material forming the terminal is made of copper or a copper alloy,
The tubular caulking portion is formed into a tubular body that is curved and abutted against the tube expansion portion of the terminal material, and the abutted portion is joined by laser welding, and the nickel layer disposed in the tube expansion portion A terminal in which high melting point inorganic particles having a particle size of 10 nm or more and less than 300 nm are contained or dispersed in a welded portion of the tubular caulking portion by laser welding. A terminal end connection structure for crimping and connecting a terminal produced by the terminal manufacturing method according to any one of claims 1 to 5 and an aluminum or aluminum alloy electric wire at a crimping portion of a tubular body of the terminal. A manufacturing method comprising:
Inserting the aluminum or aluminum alloy electric wire into the tube caulking part,
A method for manufacturing an end connection structure for electric wires, wherein the tubular caulking portion is caulked and the aluminum or aluminum alloy electric wire is crimped and connected into the tubular caulking portion.   An electric wire terminal connection structure in which the terminal according to claim 9 and an aluminum or aluminum alloy electric wire are crimped and connected at a tube caulking portion of the terminal. A terminal having a nickel layer containing high melting point inorganic particles having a particle diameter of 10 nm or more and less than 300 nm on a copper or copper alloy base material in a volume fraction of 10 to 70%, and having a tin layer on the nickel layer Copper or copper alloy sheet for use.

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