JP4314564B2 - How to connect electronic components and lead wires - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a connection method for suitably connecting a lead wire to an electrode in an electronic component such as a gas discharge tube.
[0002]
[Prior art]
Conventionally, as shown in FIG. 7, a gas discharge tube 50 for absorbing a surge current called a gas arrester or a lightning arrester sandwiches an envelope 51 made of an insulating material made of cylindrical ceramics or the like. The copper electrodes 52 are arranged opposite to each other, and an end portion of a copper lead wire is welded to the outer central portion of the copper electrode 52. In the conventional gas-filled discharge tube 50, a lead wire 53 having a copper wire diameter of approximately 1.0 mm is usually resistance-welded to a copper electrode 52 having a diameter of approximately 8 mm using a silver solder. Since copper has a high thermal conductivity, heating to the tip of the lead wire 53 is compared with the copper electrode 52 even if the lead wire 53 is heated through a current with the end face of the lead wire 53 in contact with the center of the copper electrode 52. However, while the wire diameter (cross-sectional area) is small and the heat capacity is small, the temperature immediately rises. On the other hand, the heating through the current to the center of the copper electrode 52 immediately brings the heat to the surroundings and the temperature of the center is reduced. Therefore, it is difficult to perform welding in a state where both portions in contact with each other are raised to a suitable temperature, and it is difficult to obtain a desired welding strength. In contrast, spot welding can be performed in a short time with an instantaneous current, but the welding strength is not so strong as compared to the long-time welding by resistance welding described above. When a large surge current exceeding 10 kA that is used as a lightning arrester passes, there is a possibility that the welded portion may be damaged. (For example, refer to Patent Document 1). Reference numeral 54 denotes an intermediate electrode in the two-section gas-filled discharge tube 50.
[0003]
[Patent Document 1]
JP 55-9399 A [Problems to be Solved by the Invention]
[0004]
The problem to be solved is that when copper having a high thermal conductivity is used, a strong bonding state cannot be obtained even if resistance welding is performed on an electrode having a large heat capacity and a lead wire having a small heat capacity.
[0005]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, in the method for connecting an electronic component and a lead wire according to the present invention, in the connection method for resistance welding the end surface of the lead wire to the electrode, the tip of the electrode portion to which the end surface of the lead wire is connected A connecting portion having an outer diameter smaller than the lead wire diameter protrudes, and the connecting portion has a distal end diameter of 70% to 90% of the lead wire diameter and a proximal end portion diameter substantially equal to the lead wire diameter. In the welding apparatus in which the same height is formed in a truncated cone shape of 70% to 90% of the lead wire diameter, and the electrode and the lead wire are welded, the welding electrode on the electrode side holds the electrode, and the lead wire side The welding electrode is configured to hold the amount of protrusion of the lead wire substantially the same as the capacity of the connection portion, and to feed and weld the welding electrode with the connection portion and the lead wire tip in contact with each other. It is a feature.
[0006]
The welding electrode on the electrode side holds the outer periphery of the electrode, and the welding electrode on the lead wire side is formed by projecting and holding a lead wire having a capacity substantially the same as the capacity of the connecting portion. .
[0007]
The connecting portion is formed in a truncated cone shape in which the tip end diameter of the lead wire is 80% of the lead wire diameter, the base end portion diameter is the same as the lead wire diameter, and the height is 80% of the lead wire diameter. It is a feature.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows an electronic component 1 connected by the connection method of the present invention, and will be described below by taking a two-section gas-filled discharge tube as an example. Reference numeral 2 denotes two cylindrical envelopes made of an insulating material such as ceramics, 3 denotes a substantially frustoconical oxygen-free copper side electrode disposed at both ends of the envelope 2, and 4 denotes two envelopes 2 Similarly, intermediate copper electrodes 5 and 5 are lead wires made of annealed copper wires connected to the outer central portion of the side electrode 3 and the intermediate electrode 4. Inside the envelope 2, the side electrode 3 and the intermediate electrode 4 face each other with a discharge gap, and a discharge gas is sealed in the discharge space.
[0009]
As shown in FIG. 2, a concave portion 6 is provided in the outer central portion of the side electrode 3 having a diameter of about 8 mm, and a truncated cone-shaped connecting portion 7 for connecting the lead wire 5 is provided in the central portion of the concave portion 6. It is protruding. The shape of the connecting portion 7 is such that when the diameter of the lead wire 5 is about 1.0 mm, the tip diameter is 0.7 to 0.9 mm which is 70 to 90% of the lead wire diameter, and the base end portion diameter is The lead wire diameter is about 1.0 mm, and the height is 0.7 to 0.9 mm which is 70 to 90% of the lead wire diameter, and the tip diameter is particularly preferably 0 to 80% of the lead wire diameter. .8 mm, its base end diameter is about 1.0 mm, which is the same as the lead wire diameter, and its height is 0.8 mm which is 80% of the lead wire diameter. Thus, by making the connection part 7 of the side electrode 3 into the truncated cone shape having the above-mentioned dimensions, the current density at the joint portion with the lead wire 5 is increased and the heat capacity is reduced, thereby making it easy to increase the temperature during welding. As a result, weldability is improved and welding strength is ensured.
[0010]
FIG. 3 shows how to use the welding electrode when the lead wire 5 is welded to the connecting portion 7 of the side electrode 3 by a resistance welding apparatus. The welding electrode 8 on the lead wire side holds the lead wire 5, the welding electrode 9 on the side electrode 3 side holds the outer periphery of the side electrode 3, and the tip of the lead wire 5 is brought into contact with the connection portion 7 of the side electrode 3. In the pressed state, power is supplied between the welding electrode 8 and the welding electrode 9 to heat and weld the joint portion. The protruding amount of the lead wire 5 held by the welding electrode 8 is determined by the amount of the side electrode 3 described above. It is set to 0.8 to 0.85 mm so as to be almost the same as the capacity (volume) of the connecting portion 7. In this way, the balance (heat balance) of the temperature rise between the connecting portion 7 that is a joint portion and the lead wire 5 protruding from the welding electrode 8 is balanced, so that the connecting portion 7 and the lead wire 5 are the same during resistance welding. As a result of melting, a strong and suitable welded state can be obtained.
[0011]
Further, as shown in FIG. 4, the lead wire 5 to be welded to the intermediate electrode 4 is cut from the top and bottom with a cutting blade 10 having a sharp tip (one side of the blade is formed as a single blade, and the other than the cutting edge is aligned substantially straight). The ridge portion 11 is formed to protrude from the cut surface by being nipped and pressed. As shown in FIG. 5, the ridge 11 has a vertical width of about 30% of the wire diameter, a height of about 10% of the wire diameter, and the displacement of the ridge 11 from the center of the lead wire 5. The wire diameter is about 10%.
[0012]
When the lead wire 5 is resistance-welded to the intermediate electrode 4 using a welding device, as shown in FIG. 6, the lead wire-side welding electrode 12 has a lead wire 5 protruding dimension of about 0.9 mm smaller than the lead wire diameter. The welding electrode 13 on the side of the intermediate electrode 4 holds the outer periphery of the intermediate electrode 4 and makes the ridge 11 face sideways so as to be in line contact with the outer peripheral surface of the intermediate electrode 4. A resistance welding current is passed between the welding electrode 12 and the welding electrode 13 with the ridge 11 of the lead wire 5 pressed against the outer periphery of the electrode 4. As described above, the contact area of the ridge 11 with respect to the intermediate electrode 4 is small because it is a line contact, and the heat capacity is reduced by increasing the current density of the joint portion, and the lead wire 5 protruding from the welding electrode 12 and the middle By balancing the temperature rise balance (heat balance) with the joint portion of the electrode 4, the lead wire 5 and the intermediate electrode 4 become high in temperature and have a similar melting condition, thereby obtaining a strong and suitable welded state. It is done.
[0013]
When the intermediate electrode 4 and the lead wire 5 are welded, when the lead wire 5 is plated with tin or the like, copper and plated tin or the like are eutectic with the intermediate electrode 4. Since it becomes easier to join, it is preferable that the intermediate electrode 4 is further plated with tin or the like, thereby further facilitating the joining. The plating thickness is preferably about 10 to 14 μm so that the plating extends to a flat surface other than the ridge 11 when cut by the cutting blade 10.
[0014]
【The invention's effect】
As described above in detail, according to the method for connecting an electronic component and a lead wire of the present invention, in the connection method of resistance welding the end surface of the lead wire to the electrode, the outer diameter of the tip is provided on the electrode portion to which the end surface of the lead wire is connected. A connecting portion having a diameter smaller than the lead wire diameter, the outer diameter of the proximal end portion being substantially the same as the lead wire diameter and having a height smaller than the lead wire diameter, and welding the electrode and the lead wire. Temperature rise between the connecting portion and the lead wire protruding from the welding electrode by welding the lead wire protruding from the welding electrode that holds and supplies the lead wire in the welding apparatus with substantially the same capacity as the connection portion. Thus, the balance (heat balance) is balanced, whereby the connection portion and the lead wire have the same melting condition during resistance welding, and a strong and preferable welding state is obtained.
[0015]
In addition, the connection portion is formed into a truncated cone shape having a distal end outer diameter smaller than the lead wire diameter and a proximal end outer diameter substantially the same as the lead wire diameter and having a height smaller than the lead wire diameter. When the end of the lead wire is brought into contact with the end of the lead wire and resistance welding is performed, the tip of the connecting portion is smaller in diameter and smaller in cross-sectional area than the lead wire, and the volume of the connecting portion is small (the heat capacity is small). Heat generated by the current passing can be obtained immediately and the heating generated at the tip of the connecting part is difficult to lead to the electrode body, which makes it easier to raise the temperature at the connecting part of the electrode and the lead wire. Improves.
[Brief description of the drawings]
[0016]
FIG. 1 is a cross-sectional view showing electronic components connected by a connection method of the present invention.
FIG. 2 shows a side electrode of an electronic component according to the present invention, where (a) is a front view and (b) is a side sectional view.
FIG. 3 is an explanatory view showing a state in which a lead wire is welded to a connection portion of a side electrode in the electronic component of the present invention.
FIG. 4 is an explanatory view showing a state in which a lead wire welded to the intermediate electrode in the electronic component of the present invention is cut.
FIG. 5 is an explanatory view showing an end face of a lead wire welded to an intermediate electrode in the electronic component of the present invention.
6A and 6B show a state in which a lead wire is welded to a joint portion of an intermediate electrode in the electronic component of the present invention, where FIG. 6A is a front view, and FIG.
FIG. 7 is a cross-sectional view showing a conventional electronic component.
[Explanation of symbols]
[0017]
1: Electronic component 2: Envelope 3: Side electrode 4: Intermediate electrode 5: Lead wire 6: Recessed portion 7: Connection portion 8: Welding electrode 9: Welding electrode 10: Cutting blade 11: Ridge portion 12: Welding electrode 13: Welding electrode

Claims (3)

In the connection method in which the end surface of the lead wire is resistance-welded to the electrode, the electrode portion to which the end surface of the lead wire is connected is provided with a connecting portion having a tip outer diameter smaller than the lead wire diameter, and the connecting portion The tip diameter is 70% to 90% of the lead wire diameter, the base end diameter is substantially the same as the lead wire diameter, and the height is 70% to 90% of the lead wire diameter. In the welding apparatus for welding the electrode and the lead wire, the electrode-side welding electrode holds the electrode, and the lead wire-side welding electrode holds the protruding amount of the lead wire substantially the same as the capacity of the connecting portion, A method of connecting an electronic component and a lead wire, wherein the welding portion is fed with power and welded in a state where the connection portion and the lead wire tip are in contact with each other.   2. The welding electrode on the electrode side holds the outer periphery of the electrode, and the welding electrode on the lead wire side is formed by projecting and holding a lead wire having a capacity substantially the same as the capacity of the connecting portion. The connection method of the electronic component and lead wire as described in 1.   The connecting portion is formed in a truncated cone shape in which the tip end diameter of the lead wire is 80% of the lead wire diameter, the base end portion diameter is the same as the lead wire diameter, and the height is 80% of the lead wire diameter. 3. A method for connecting an electronic component and a lead wire according to claim 1 or 2.

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