JP2010118276A - Module, welding method of module, and electronic device equipped with this module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a module making a welding point stable with a simple structure, connection strength improved and restraining variations, and a welding method of the module as well as an electronic device equipped with the module. <P>SOLUTION: The module includes a wiring substrate, a metal pattern formed on the wiring substrate and a metal lead. The metal lead has a plurality of protrusion parts each of which is provided from a voltage impression point with voltage impressed in an equal interval with each other. The metal pattern is connected with the plurality of protrusion parts in spot welding by impressing voltage on the voltage impression point. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a module in which a substrate and a metal plate are welded, a method for welding the module, and an electronic apparatus including the module.

  In recent years, electronic devices have been remarkably reduced in size and weight. In particular, this tendency is remarkable in portable terminals such as mobile phones. For this reason, there is a demand for miniaturization of a printed circuit board on which a large number of electronic components such as semiconductor devices and passive components are mounted.

  Against such a background, for example, it is required to incorporate a charge control circuit for controlling the charging of a pack-type secondary battery used in a mobile terminal in a battery pack. Is strong.

  Here, the connection between the electrode of the secondary battery built in the battery pack and the charge control circuit board is generally made of a nickel plate. This is because a nickel plate is used as a wiring material for extracting power from the electrode of the secondary battery, and this nickel plate is attached to the electrode of the battery by spot welding. That is, by connecting the nickel plate to the charge control circuit board as it is, it is possible to save troubles such as providing new wiring and contribute to miniaturization. Therefore, it is required that the nickel plate can be connected to the external connection terminal of the charge control circuit board by spot welding. In order to realize this requirement, a technique for configuring an external connection terminal by soldering a nickel block to a land portion made of a metal foil formed on the surface of a printed circuit board has become widespread.

  However, the above-described technique requires the use of a nickel block and solder. On the other hand, in recent years, a technique has been disclosed in which a nickel plate is not soldered via a nickel block but is directly spot-welded to a substrate. However, the method of spot welding directly on the substrate has a problem that, for example, when applied to a portable terminal, there is a possibility that the welding may be easily broken due to vibration generated when the portable terminal is used for portable use. .

  The above problem will be described with reference to FIGS. Here, FIG. 7 shows a configuration of the module, and FIG. 8 shows a method of welding the module. As shown in FIG. 7, the welding points are only two points of voltage application points. If a voltage is applied to perform welding in this state, the contact position between the Ni lead and the copper pattern is likely to vary, so that the welding current path is not determined as shown in FIG. Will occur. As a result, the strength of the welding is not stable, and there is a problem that the welding is easily broken due to vibration generated during portable use.

In order to improve the welding strength in relation to the above-described problem, for example, as a technique for welding a negative electrode lead, which is a nickel plate, to the inner surface of the battery can, a negative V lead is provided with a V-shaped protrusion, and the protrusion is formed by a welding machine. Has been disclosed (for example, Patent Document 1). Specifically, in Patent Document 1, the protrusion provided on the negative electrode lead of the above technique is a protrusion having a V-shaped cross section provided on a straight line along the length at the center in the width direction of the nickel plate. This is a technique for performing welding by applying a voltage to the protruding portion.
JP 09-330697 A

  However, in the technique described in Patent Document 1, since there is only one protrusion and the current flowing through the protrusion when welding the protrusion varies depending on the position of the protrusion, the connection strength becomes uneven. Furthermore, there is a problem that the connection strength is lowered.

  The present invention has been made in view of such circumstances, and provides a module that stabilizes welding points, improves connection strength, and suppresses variation with a simple configuration, a module welding method, and an electronic device including the module. The purpose is to provide.

  The module of the present invention includes a wiring board, a metal pattern formed on the wiring board, and a metal lead, and the metal pattern and the metal lead are welded by applying a voltage, The metal lead is provided with a plurality of protrusions, the plurality of protrusions are provided at equal intervals from a voltage application point for applying a voltage, and the metal pattern is connected to the plurality of protrusions by spot welding. And

  The module welding method of the present invention is a module welding method comprising a wiring board, a metal pattern formed on the wiring board, and a metal lead, wherein the surface of the wiring board on which the metal pattern is formed and the metal lead A step of bringing the surface into contact with the surface, and a step of applying a voltage from the surface of the metal lead. The metal lead has a plurality of protrusions on a surface in contact with the metal pattern, and the plurality of protrusions apply a voltage. The voltage application point is an area different from the area where the plurality of protrusions of the metal lead are formed, and the metal pattern is connected to the plurality of protrusions by spot welding. It is characterized by that.

  An electronic apparatus according to the present invention includes the above module.

  According to the present invention, it is possible to improve connection strength and suppress variations in connection strength.

  Hereinafter, examples of embodiments of the present invention will be described in detail with reference to the drawings. In addition, the same code | symbol is attached | subjected to the same structure and description is abbreviate | omitted.

  FIG. 1 is a plan view showing, in partial cross section, an example of a battery pack on which a module according to this embodiment is mounted. In the present embodiment, a charge control circuit module is taken as an example of a module, and a battery pack including the charge control circuit module will be described, but it goes without saying that the present invention is not limited to this. Here, in the charge control circuit module according to the present embodiment, nickel wiring (wiring member) for electrically connecting the load-side external terminal and the secondary battery is connected by spot welding.

  As shown in FIG. 1, the charging control circuit module 1, the secondary battery 30, and the nickel wiring 26 are disposed inside a housing 28 made of an insulating member. The charging control circuit module 16 has the back surface, that is, the surface on which the gold plating layer formed on the surface of the load side external terminal and the test terminal is formed outside, and the surface on which the nickel plate 10 and the sealing resin 18 are formed. It is arranged with the inside. An opening 28a is formed in the housing 28 corresponding to the gold plating layer formed on the surface of the load side external terminal and the test terminal.

  The nickel wiring 26 welded to one nickel plate 10 of the charge control circuit module 16 is connected to the electrode 30 a of the secondary battery 30. The nickel plate 10 to which the nickel wiring 26 is not connected is connected to the electrode 30 b of the secondary battery 30. According to the charge control circuit module 16, since the charge control circuit module can be reduced in size and cost, the battery pack can be reduced in size and cost.

  In the present embodiment, one nickel plate 10 is directly connected to the electrode 30b of the secondary battery 30, but the present invention is not limited to this, and both nickel plates 10 are connected to the two electrodes of the secondary battery 30. You may make it connect to 30a, 30b via a nickel wiring.

  Next, a description will be given of a method of spot welding a metal pattern formed on the surface of a printed board having a nickel plate. Hereinafter, in the present embodiment, a module having a printed board, a metal pattern formed in a printed board shape, and a metal lead will be described as an example of the module, but the present invention is not limited to this.

(Embodiment 1)
FIG. 2 shows a schematic configuration example of a module according to the present embodiment. FIG. 3 is a view for explaining a module welding method according to the present embodiment. In the present embodiment, a module and a module welding method will be described with reference to FIGS. 2 and 3.

  As shown in FIGS. 2 and 3, the module according to this embodiment has a Ni (nickel) lead 1, a substrate 2, and a copper pattern 4. The Ni lead 1 is formed on the copper pattern 4 formed on the substrate 2. Direct spot welding.

  A plurality of protrusions 6 formed by press molding or the like are provided on the surface of the Ni lead 1 to be welded with the copper pattern 4. Moreover, in order to weld the Ni lead 1 and the copper pattern 4, the electrode of the spot welder 5 is made to contact and a voltage is applied. The voltage application point 3 where the electrode of the spot welder 5 is in contact is different from the position where the projection 6 is provided.

  Referring to FIG. 3, the current flow when welding the Ni lead 1 and the copper pattern 4 is shown. The current path at the time of module welding in FIG. 8 that does not have the protrusion 6 described above was not determined, whereas in the module welding according to the present embodiment, the contact between the Ni lead 1 and the copper pattern 4 through the protrusion 6. The position is stable and the current path is constant.

  In the present embodiment, the example in which the shape of the protrusion 6 is hemispherical has been described. However, the present invention is not limited to this, and the metal lead and the metal pattern can be sufficiently brought into contact with each other when a voltage is applied. Any shape can be applied as long as it has a shape. Further, the number of the protrusions 6 is not particularly limited, and can be appropriately determined depending on the size of the module to be applied.

  According to this embodiment, by providing a large number of protrusions on the surface of the Ni lead, it is possible to increase the number of contact points with the copper pattern and further stabilize the contact position. Thereby, the current path at the time of welding becomes constant, and it becomes possible to improve the stability and connection strength of the connection location. Furthermore, the heat dissipation of the substrate can be improved. Here, when the heat dissipation property of the substrate is low, there is a problem of causing the substrate to melt, but this problem can also be suppressed.

  Further, since the metal lead and the metal pattern can be directly welded, the module can be welded with a simpler structure, and the cost can be suppressed.

(Embodiment 2)
FIG. 4 is a diagram illustrating a schematic configuration example of a module according to the present embodiment. FIG. 5 is a view for explaining a module welding method according to the present embodiment. In the present embodiment, a module and a module welding method will be described with reference to FIGS. 4 and 5.

  As shown in FIGS. 4 and 5, the module according to this embodiment has a Ni lead 1, a substrate 2, and a copper pattern 4, and the Ni lead 1 is directly spot welded to the copper pattern 4 formed on the substrate 2. Has been.

  The Ni lead has a crease lined so that the surface welded to the copper pattern 4 of the Ni lead 1 is a mountain fold. Moreover, in order to weld the Ni lead 1 and the copper pattern 4, the electrode of the spot welder 5 is made to contact and a voltage is applied. The voltage application point 3 where the electrode of the spot welder 5 is in contact is a position different from the fold.

  According to the present embodiment, since the Ni lead is only processed to be creased, the Ni lead can be easily processed.

(Embodiment 3)
FIG. 6 is a diagram illustrating a schematic configuration example of a module according to the present embodiment. In the present embodiment, a module and a module welding method will be described with reference to FIGS. 6 and 3.

  As shown in FIGS. 6 and 3, the module according to this embodiment has a Ni lead 1, a substrate 2, and a copper pattern 4, and the Ni lead 1 is directly spot welded to the copper pattern 4 formed on the substrate 2. Has been.

  Moreover, in order to weld the Ni lead 1 and the copper pattern 4, the electrode of the spot welder 5 is made to contact the Ni lead 1 side, and a voltage is applied. On the surface to be welded to the copper pattern 4 of the Ni lead 1, a plurality of protrusions 6 formed by press molding or the like are provided around the voltage application point 3 so as to be equidistant from the voltage application point 3. ing.

  Referring to FIG. 3, the current flow when welding the Ni lead 1 and the copper pattern 4 is shown. The current path at the time of module welding in FIG. 8 that does not have the protrusion 6 described above was not determined, whereas in the module welding according to the present embodiment, the contact between the Ni lead 1 and the copper pattern 4 through the protrusion 6. The position is stable and the current path is constant.

  In the present embodiment, the example in which the shape of the protrusion 6 is hemispherical has been described. However, the present invention is not limited to this, and the metal lead and the metal pattern can be sufficiently brought into contact with each other when a voltage is applied. Any shape can be applied as long as it has a shape. Further, the number of the protrusions 6 is not particularly limited, and can be appropriately determined depending on the size of the module to be applied.

  The positions where the plurality of protrusions 6 are provided are not particularly limited as long as they are equidistant from the voltage application point 3.

  According to this embodiment, by providing a large number of protrusions on the surface of the Ni lead, it is possible to increase the number of contact points with the copper pattern and further stabilize the contact position. Thereby, the current path at the time of welding becomes constant, and it becomes possible to improve the stability and connection strength of the connection location. Furthermore, the heat dissipation of the substrate can be improved. Here, when the heat dissipation property of the substrate is low, there is a problem of causing the substrate to melt, but this problem can also be suppressed.

  Further, since the metal lead and the metal pattern can be directly welded, the module can be welded with a simpler structure, and the cost can be suppressed.

  Furthermore, by providing a plurality of protrusions at equal intervals from the voltage application point, the current flowing through each protrusion can be made uniform, and the connection strength can be made uniform.

  In the above-described embodiment, the Ni lead is taken as an example of the metal lead and the copper pattern is taken as an example of the metal pattern. However, the present invention is not limited to this.

  Although specifically described based on the preferred embodiments, the present invention is not limited to the above-described module, module welding method, and electronic device including the module, and various modifications can be made without departing from the scope of the invention. It goes without saying that it is possible.

It is a top view which shows the example of the battery pack which mounts the module which concerns on this embodiment in a partial cross section. It is a figure which shows the schematic structural example of the module which concerns on this embodiment. It is a figure for demonstrating the welding method of the module which concerns on this embodiment. It is a figure which shows the schematic structural example of the module which concerns on this embodiment. It is a figure for demonstrating the welding method of the module which concerns on this embodiment. It is a figure which shows the schematic structural example of the module which concerns on this embodiment. It is a figure which shows the schematic structural example of the conventional module. It is a figure for demonstrating the welding method of the conventional module.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Metal plate 2 Board | substrate 3 Voltage application point 4 Pattern 5 Spot welder 6 Protrusion part 10 Metal plate 16 Protection circuit module 18 Sealing resin 26 Copper wiring 28 Case 30 Secondary battery 30a, 30b Electrode

Claims (7)

A module having a wiring board, a metal pattern formed on the wiring board, and a metal lead, wherein the metal pattern and the metal lead are welded by applying a voltage;
The metal lead is provided with a plurality of protrusions,
The plurality of protrusions are provided at equal intervals from a voltage application point for applying a voltage,
The module, wherein the metal pattern is connected to the plurality of protrusions by spot welding.   The module according to claim 1, wherein the protrusion is hemispherical.   The module according to claim 1, wherein the metal lead contains nickel.   4. The module according to claim 1, wherein the voltage application point is a region different from a region where the plurality of protrusions are provided on the metal lead. 5. A method of welding a module having a wiring board, a metal pattern formed on the wiring board, and a metal lead,
Contacting the surface of the wiring board on which the metal pattern is formed and the metal lead surface;
Applying a voltage from the surface of the metal lead, and
The metal lead is provided with a plurality of protrusions on a surface in contact with the metal pattern,
The plurality of protrusions are provided at equal intervals from a voltage application point for applying a voltage,
The voltage application point is a region different from a region where the plurality of protrusions of the metal lead are formed,
The method for welding modules, wherein the metal pattern is connected to the plurality of protrusions by spot welding. The step of applying the voltage is performed only once,
The joule welding method according to claim 5, wherein the metal pattern is connected to the plurality of protrusions by one spot welding.   An electronic device comprising the module according to claim 1.

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