JP2004050236A - Heat-pressurizing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-pressurizing device by which the yield is improved while quality is secured in a weld zone between metallic workpieces and by which welding is efficiently performed. <P>SOLUTION: The heat-pressurizing device 10 is equipped with a first and second electrode exothermic bodies 12, 14 which are arranged in parallel and made of carbon material. An electrode reed section 5 in a lithium ion polymer secondary battery 4 laminated on the lead wire 3 in a protective circuit board 1, is pressurized by both electrode exothermic bodies 12, 14 and fused by their heat generation. With elements diffusing from this fused material to the lead wire 3, the electrode reed section 5 and the lead wire 3 are welded to each other. Incidentally, between the first and second electrode exothermic bodies 12, 14, an electric current is passed through the electrode reed section 5 or the lead wire 3. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to, for example, a heating and pressure welding method capable of joining a metal lead wire for supplying a current to a metal pattern on a printed circuit board without intervening solder or the like.
[0002]
[Prior art]
FIG. 6 shows an example of a battery pack protection circuit board mounted on various portable electronic devices such as a mobile phone, a video camera, and a notebook computer. The protection circuit board 1 has conductors 2 and 3 made of copper, respectively.
[0003]
The electrode lead 5 of the lithium ion polymer secondary battery 4 as a power source is joined to the conductor 3 as shown in FIG. 7, for example. In this case, the electrode lead portion 5 is made of aluminum.
[0004]
At present, ultrasonic welding is mainly employed as a method for joining the conductive wire 3 made of copper and the electrode lead portion 5 made of aluminum to each other. However, the ultrasonic welding has a disadvantage that the ultrasonic welding device itself is expensive and therefore expensive. In addition, if the reproducibility is poor and the work days are different, it is difficult to keep the quality constant because there are cases where joining can be easily performed and cases where it is extremely difficult even when welding is performed under the same conditions. There are drawbacks.
[0005]
Other attempts to join the conductor 3 and the electrode lead 5 to each other include resistance welding, laser welding, and the like. However, in the case of resistance welding, there is a problem that the copper pattern is lifted from the substrate with heating, that is, peeling occurs. In addition, since aluminum, which is a metal material of the electrode lead portion 5, is welded to the electrode heating element, maintenance must be frequently performed on the electrode heating element.
[0006]
On the other hand, in laser welding as well, the problem that peeling occurs similarly to resistance welding has become apparent. When the thickness of the electrode lead portion 5 is small, a through hole may be formed in the electrode lead portion 5, so that it is extremely difficult to join the electrode lead portion 5 and the conductive wire 3.
[0007]
[Problems to be solved by the invention]
The present invention has been made to solve the above-described problems, and it is possible to easily join different kinds of metal works to each other. For example, for example, copper or copper alloy formed on an electronic circuit board It is an object of the present invention to provide a heating and pressing method capable of securely joining a metal lead made of aluminum or an aluminum alloy to a metal pattern made of the same without peeling.
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a method according to the present invention, wherein a second metal work made of a metal material having a lower melting point than a constituent metal material of the first metal work is laminated on the first metal work, The first metal and the second metal are brought into pressure contact with the two-metal work, and a current is applied between the first electrode and the second electrode to join the first metal work and the second metal work. A heating pressure welding method,
Raising the temperature of the first electrode and the second electrode to melt the second metal work to form a melt, and diffusing an element into the first metal work using the melt as a source. Then, the first metal work and the second metal work are joined to each other.
[0009]
Also, the present invention provides a method in which a second metal work made of a metal material having a lower melting point than the constituent metal material of the first metal work is laminated on the first metal work, and the first metal work is provided with a first metal work. The first metal workpiece and the second metal workpiece are brought into contact with each other by pressing the electrode and the second metal against the second metal workpiece, and applying a current between the first electrode and the second electrode. Heating and pressure welding method for joining
By raising the temperature of at least the first electrode to melt the second metal work to form a melt, and diffusing an element into the first metal work by using the melt as a source, the second metal work is melted. The first metal work and the second metal work are joined to each other.
[0010]
That is, in the present invention, the first electrode and the second electrode serve to press the first metal work and the second metal work, and one electrode is provided via the first metal work and the second metal work. From the first electrode to the other electrode, and a role to generate heat by itself to melt the second metal work.
[0011]
According to the present invention, a melt (liquid phase) is generated as the second metal work having a low melting point is first melted. The element diffuses into the first metal work using the melt as a source, and as a result, the first metal work and the second metal work are diffusion-bonded to each other. For this reason, it is possible to easily and easily join metal materials that have been difficult to join by welding resistance or laser welding.
[0012]
Further, the second metal work does not melt during the diffusion bonding. Therefore, for example, when the first metal work is a metal pattern formed on the electronic circuit board, the second metal work can be joined before the metal pattern peels off.
[0013]
Moreover, in the present invention, a current flows between the first electrode and the second electrode via the first metal work and the second metal work. For this reason, resistance welding is also performed at the layered portion immediately below both electrodes in conjunction with the above-described diffusion bonding, so that the first metal work and the second metal work can be more firmly bonded.
[0014]
Here, preferred examples of the constituent material of the first electrode or the second electrode include a carbon material or a carbon alloy. In this case, the temperature of the first electrode or the second electrode rises very quickly. Therefore, only the second metal work having a low melting point can be reliably and quickly melted.
[0015]
Preferably, both the first electrode and the second electrode are made of a carbon material or a carbon alloy. This is because these have high thermal conductivity and can be heated in a relatively short time.
[0016]
Preferred examples of the constituent metal material of the first metal work include copper or copper alloy, and preferred examples of the constituent metal material of the second metal work include aluminum or an aluminum alloy. be able to.
[0017]
Specific examples of the first metal work made of copper or copper alloy include a metal pattern formed on an electronic circuit board, and specific examples of the second metal work made of aluminum or an aluminum alloy For example, a metal lead wire for supplying electricity to a metal pattern can be given.
[0018]
When the electrode is made of a carbon material or a carbon alloy and the second metal work is made of aluminum or an aluminum alloy, the second metal work is not welded to the electrode. This is particularly preferable because it is not necessary to frequently perform electrode maintenance.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a preferred embodiment of a heating and pressing method according to the present invention will be described in detail with reference to the accompanying drawings.
[0020]
FIG. 1 shows a schematic overall configuration of a heating pressure welding apparatus for performing the heating pressure welding method according to the present embodiment. The heating and pressing apparatus 10 includes a first electrode heating element 12 and a second electrode heating element 14 arranged in parallel with each other, and a first pressing mechanism 16a having the first electrode heating element 12 and the second electrode heating element 14, respectively. A second pressing mechanism 16b, a displacement mechanism 18 for displacing the two pressure mechanisms 16a, 16b in a direction to approach or separate from the pedestal 17, a controller 20 for controlling the displacement operation of the displacement mechanism 18, And a power supply 22 for supplying a current directed from the first electrode heating element 12 to the second electrode heating element 14 under the control of the above. The power supply 22 and the first electrode heating element 12 and the second electrode heating element 14 are electrically connected to each other via lead wires 24 and 26, respectively.
[0021]
The heating and pressing apparatus 10 has a base 28, and the pedestal 17 is installed on the base 28.
[0022]
In addition, a support 32 is erected on the base 28. A motor 34 constituting the displacement mechanism 18 is installed above the support column 32. As shown in FIGS. 1 and 2, the motor 34 is connected to a clutch brake mechanism 36 disposed above the motor 34. ing. Further, the motor 34 is electrically connected to the controller 20 via a lead wire 37.
[0023]
An output shaft 38 constituting the clutch brake mechanism 36 is fitted in an insertion hole of a cylindrical member 42 constituting a cylindrical groove cam 40. A groove 44 is formed around the outer periphery of the columnar member 42, and a roller 48 constituting a follower 46 is rotatably inserted into the groove 44. The rollers 48 are rotatably provided on a displacement plate 52 via a support member 50.
[0024]
The displacement plate 52 constituting the displacement mechanism 18 is displaced in the direction of the arrow (up and down) in FIG. A guide block 54 is fixed to the displacement plate 52, and a guide rod 58 is inserted into a hole 56 provided in the guide block 54 so as to extend in the vertical direction. Therefore, the displacement plate 52 is displaced by being guided by the guide rod 58.
[0025]
The guide rod 58 is positioned and fixed to the column 32 via support members 60a and 60b. Bushings 62a and 62b are interposed between the inner peripheral wall of the hole 56 and the guide rod 58.
[0026]
The first pressing mechanism 16a and the second pressing mechanism 16b are connected to the displacement plate 52. The first pressurizing mechanism 16a has a body 64, a pressing force transmission shaft 66, and a pressing force adjusting knob 70. The first electrode heating element 12 is mounted on a lower end portion of the pressing force transmission shaft 66. It is attached to the electrode holder 68. The second pressurizing mechanism 16b has the same configuration as the first pressurizing mechanism 16b. Therefore, the same components are denoted by the same reference symbols, and detailed description will be omitted.
[0027]
The first electrode heating element 12 and the second electrode heating element 14 attached to the electrode holders 68 of the first pressure mechanism 16a and the second pressure mechanism 16b are both made of a carbon material. The first electrode heating element 12 and the second electrode heating element 14 are substantially columnar bodies having a substantially constant diameter from the front end to the upper end.
[0028]
The controller 20 is provided with an LCD display 122 that indicates the operation status and the like of the heating and pressing device 10, and a plurality of setting switches 124 for setting and operating the heating and pressing device 10. Among them, the setting switch 124 is for executing each operation. The LCD display 122 is for monitoring what kind of work is currently being performed.
[0029]
The heating pressure welding method according to the present embodiment is performed as follows using the heating pressure welding apparatus 10 configured as described above.
[0030]
First, the electrode lead portion 5 of the lithium ion polymer secondary battery 4 made of an aluminum work is laminated on the conductive wire 3 (see FIG. 6) of the protection circuit board 1 made of a copper work. In this state, as shown in FIG. Then, it is placed on a pedestal 17 to face the first electrode heating element 12 and the second electrode heating element 14.
[0031]
Then, the setting switch 124 is turned ON, and the motor 34 is energized through the lead wire 37 under the control of the controller 20. When the rotational driving force of the energized motor 34 is transmitted to the cylindrical groove cam 40 via the clutch brake mechanism 36, the rotational motion is converted into linear motion by the rollers 48 engaging with the groove 44 of the cylindrical groove cam 40. As a result, the first pressing mechanism 16a and the second pressing mechanism 16b move downward following the downward movement of the displacement plate 52 while being guided by the guide rod 58. Finally, as shown in FIG. 3, the first electrode heating element 12 and the second electrode heating element 14 are both in contact with the upper surface of the electrode lead portion 5. This situation is displayed on the LCD display 122 as a graphic.
[0032]
When the two electrode heating elements 12 and 14 press the electrode leads 5 as the first pressure mechanism 16a and the second pressure mechanism 16b further descend, the controller 20 releases the operation of the clutch brake mechanism 36. A control signal is issued to stop the rotation of the cylindrical groove cam 40. Accordingly, the lowering of the first pressing mechanism 16a and the second pressing mechanism 16b is stopped, and the protection circuit board 1 and the electrode lead portion 5 are connected to the pedestal 17, the first electrode heating element 12, and the second electrode heating element 14, respectively. It is pinched by.
[0033]
Next, the controller 20 issues a control signal for applying a current for causing the first electrode heating element 12 and the second electrode heating element 14 to generate heat. Upon receiving the control signal, the power supply 22 supplies a current flowing from the first electrode heating element 12 to the second electrode heating element 14. Thereby, both the first electrode heating element 12 and the second electrode heating element 14 generate heat.
[0034]
Here, as described above, both electrode heating elements 12 and 14 are made of a carbon material. For this reason, the temperature of both electrode heating elements 12 and 14 rapidly rises to the melting point of aluminum or more and less than 1000 ° C. Along with this, the electrode lead portions 5 (aluminum) located immediately below the two electrode heating elements 12 and 14 are melted, and a liquid phase L is formed as shown in FIG.
[0035]
At this time, since both electrode heating elements 12 and 14 are substantially cylindrical bodies, the tips of both electrode heating elements 12 and 14 are pressed against electrode lead portion 5 in a wide range. Therefore, the electrode lead portion 5 can be melted over a wide range.
[0036]
Thereafter, the aluminum element in the liquid phase L diffuses into the conductive wire 3 (copper) in contact with the liquid phase L. Thereby, the electrode lead portion 5 and the conductive wire 3 are joined to each other by diffusion bonding. As described above, since the electrode lead portions 5 are melted over a wide range, diffusion bonding also extends over a wide range. Therefore, the electrode lead portion 5 and the conducting wire 3 are firmly joined.
[0037]
The above melting and diffusion are completed before reaching the melting point of the conductive wire 3 (copper) of 1083 ° C. That is, the conductive wire 3 does not melt during the diffusion bonding.
[0038]
As described above, according to the present embodiment, only the work having a low melting point is melted among the stacked works, so that the first electrode heating element 12 and the second electrode heating element 14 reach the predetermined temperature. Thereafter, there is no need to continue the heating. For this reason, the time required from the start of energization to the state where welding is possible for both electrode heating elements 12 and 14 becomes relatively short. In addition, since both electrode heating elements 12 and 14 are made of a carbon material having good thermal conductivity, it does not take a long time to heat both electrode heating elements 12 and 14.
[0039]
In other words, in the present embodiment, since the heating and pressing operation can be performed in a relatively short time, the operation efficiency can be improved.
[0040]
At this time, the current flowing from the first electrode heating element 12 to the second electrode heating element 14 is branched into currents i1 and i2 as shown by broken lines in FIG. Via Due to the current i2, a part of the electrode lead portion 5 is melted to form a nugget (not shown). On the other hand, the conductor 3 is not melted.
[0041]
That is, in the present embodiment, resistance welding is performed together with diffusion bonding. Therefore, the conductive wire 3 and the electrode lead portion 5 can be more firmly joined.
[0042]
Thereafter, the controller 20 rotates the motor 34 in the reverse direction and controls the clutch brake mechanism 36 to rotate the cylindrical groove cam 40 again. As a result, both the first pressurizing mechanism 16a and the second pressurizing mechanism 16b rise, and the first electrode heating element 12 and the second electrode heating element 14 are separated from the electrode lead portion 5.
[0043]
Since the wettability of aluminum to carbon is not so good, when the first electrode heating element 12 and the second electrode heating element 14 are separated from the electrode lead portion 5, aluminum moves along with the two electrode heating elements 12 and 14. There is very little to do. That is, occurrence of so-called pickup can be avoided. For this reason, a joint having good appearance and excellent welding strength can be obtained, so that the yield is improved. Moreover, since aluminum is suppressed from adhering to both electrode heating elements 12 and 14, the frequency of maintenance of both electrode heating elements 12 and 14 is significantly reduced. Therefore, work efficiency can be further improved.
[0044]
Furthermore, since aluminum is not easily eroded, the appearance of the joint can be further improved.
[0045]
In the present embodiment, both the first electrode heating element 12 and the second electrode heating element 14 are pressed against the electrode lead portion 5 laminated on the conductive wire 3, but FIG. As shown, the electrode lead portion 5 may be pressed against the first electrode heating element 12 and the conductive wire 3 may be pressed against the second electrode heating element 14. In this case, the second electrode heating element 14 may be made of tungsten.
[0046]
Further, in this embodiment, the conductor 3 made of a copper work and the electrode lead portion 5 made of an aluminum work have been described as examples of the work that comes into contact with the electrode heating element, but the work is not particularly limited to this. Absent. In addition, an aluminum alloy work may be used instead of the aluminum work, or a copper alloy work may be used instead of the copper work.
[0047]
【The invention's effect】
As described above, according to the heating and pressing method according to the present invention, when two electrodes are pressed into contact with each other to join two types of metal works, the work having a low melting point is dissolved to form a liquid phase. Diffusion bonding is performed by diffusing a phase source element into another work. For this reason, it is possible to easily and easily join metal materials that have been difficult to join by welding resistance or laser welding.
[0048]
In addition, in this case, since the temperature of the electrode can be raised in a relatively short time, the effect that the working efficiency at the time of welding can be improved can be achieved.
[0049]
Further, in the heating and pressure welding method according to the present invention, the current passing through both the first metal work and the second metal work is caused to flow from the first electrode to the second electrode in a directed manner. In addition to diffusion bonding, resistance welding is also performed. For this reason, works can be more firmly joined together.
[Brief description of the drawings]
FIG. 1 is a schematic overall configuration diagram of a heating pressure welding apparatus that performs a heating pressure welding method according to the present embodiment.
FIG. 2 is a partial longitudinal sectional view of the heating and pressing apparatus shown in FIG.
FIG. 3 is an enlarged longitudinal sectional view of a main part showing a state where a first electrode heating element and a second electrode heating element are brought into contact with an electrode lead portion (aluminum) laminated on a conductive wire (copper).
FIG. 4 is an enlarged vertical sectional view of a main part showing a state in which a current is flowing through a metal work.
FIG. 5 shows a state in which a first electrode heating element is brought into contact with an electrode lead portion (aluminum) laminated on a part of a conductor (copper), and a second electrode heating element is brought into contact with the conductor. It is a principal part enlarged longitudinal sectional view.
FIG. 6 is a schematic overall perspective view of a protection circuit board mounted on a portable electronic device.
7 is a schematic overall perspective view showing a state where an electrode lead portion of a lithium ion polymer secondary battery is joined to a conductive wire of the protection circuit board shown in FIG. 6;
[Explanation of symbols]
1: Protection circuit board 3: Conductor wire (copper work)
5 ... Electrode lead part (aluminum work) 10 ... Heating and pressing device 12, 14 ... Electrode heating element 16a, 16b ... Pressure mechanism 18 ... Displacement mechanism 20 ... Controller 22 ... Power supply 34 ... Motor 36 ... Clutch brake mechanism 52 ... Displacement Plate 54 Guide block 56 Hole 58 Guide rod 66 Pressure transmission shaft 122 LCD display 124 Setting switch L Liquid phase

Claims (5)

A second metal work made of a metal material having a lower melting point than the constituent metal material of the first metal work is laminated on the first metal work, and a first electrode and a second electrode are formed on the second metal work. A heating and pressure bonding method of bonding the first metal work and the second metal work by applying pressure between the first electrode and the second electrode,
Raising the temperature of the first electrode and the second electrode to melt the second metal work to form a melt, and diffusing an element into the first metal work using the melt as a source. Wherein the first metal work and the second metal work are joined to each other. A second metal work made of a metal material having a lower melting point than the constituent metal material of the first metal work is laminated on the first metal work, a first electrode is pressed against the first metal work, and the second metal work is pressed. A heating and pressure welding method in which a second electrode is pressed against a second metal work, and a current is applied between the first electrode and the second electrode to join the first metal work and the second metal work. And
By raising the temperature of at least the first electrode to melt the second metal work to form a melt, and diffusing an element into the first metal work by using the melt as a source, the second metal work is melted. (1) A method of heating and pressing, wherein the first metal work and the second metal work are joined to each other. 3. The method according to claim 1, wherein at least one of the first electrode and the second electrode is made of a carbon material or a carbon alloy. The method according to any one of claims 1 to 3, wherein a constituent metal material of the first metal work is copper or a copper alloy, and a constituent metal material of the second metal work is aluminum or copper. A heat welding method characterized by being an aluminum alloy. 5. The method according to claim 4, wherein the first metal work is a metal pattern formed on an electronic circuit board, and the second metal work is a metal lead wire. Method.

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