BACKGROUND

Field of the Invention

The present invention relates to an electric wire arranging jig for arranging a plurality of electric wires when conductors of the electric wires are ultrasonically bonded to one another, and an ultrasonic bonding apparatus provided with the electric wire arranging jig.

Description of Related Art

In the background art, for example, a technique disclosed in Patent Literature 1 is known as a technique of ultrasonic bonding (also called ultrasonic welding) in which ultrasonic vibration is applied to respective conductors belonging to a plurality of electric wires so as to bond the conductors to one another.

As shown in FIG. 7 of Patent Literature 1, respective conductors110belonging to a plurality of electric wires are disposed to be gathered between a chip132(also called a horn) and an anvil134by a pair of guide jigs120. After that, the conductors110are retained by respective opposed faces of the chip132and the anvil134, and ultrasonic vibration is applied to the conductors110while applying pressure thereto between the chip132and the anvil134. Thus, the conductors110are bonded to one another.

As for details of the above protector, refer to JP JP-A-2006-15354.

SUMMARY

However, in the background art, there is no restriction on how to arrange a plurality of conductors between a horn and an anvil. Therefore, in ultrasonic bonding of respective conductors306belonging to a plurality of electric wires205, it is likely that the conductors306may be arranged in parallel when the conductors306are arranged in two or more rows (four rows inFIG. 8) along the depth direction between a pair of guide jigs203and204, as shown inFIG. 8of the present application.

As shown inFIG. 8of the present application, when ultrasonic vibration is applied to the conductors306while applying pressure thereto between a horn201and an anvil202in the state where the conductors306are arranged in parallel, the ultrasonic vibration travels in the depth direction (directions indicated by a plurality of arrows illustrated inFIG. 8) between the guide jigs203and204. As a result, the ultrasonic vibration hardly travels in the width direction between the guide jigs203and204. There is a fear that energy derived from the ultrasonic vibration in the width direction cannot be sufficiently applied to the conductors306.

When the energy derived from the ultrasonic vibration in the width direction between the guide jigs203and204is not sufficiently applied to the conductors306as described above, oxide films in the surfaces to be bonded in adjacent ones of the conductors306in the width direction cannot be broken easily. Thus, there is a fear that the metal surfaces cannot be cleaned sufficiently. As a result, in the surfaces to be bonded in the conductors306adjacent to each other in the width direction, activated metal atoms exposed by the removal of the oxide films hardly come in contact with one another. Thus, there is a fear that excellent bonding strength cannot be obtained.

An object of the present invention is to provide an electric wire arranging jig capable of obtaining excellent bonding strength in ultrasonic bonding of conductors to one another, and an ultrasonic bonding apparatus provided with the electric wire arranging jig.

Embodiments of an “electric wire arranging jig” according to the present invention provide the following item (1) and (2).

(1) An electric wire arranging jig arranging a plurality of electric wires upon conductors of the electric wires being ultrasonically bonded to one another,

the electric wire arranging jig comprising an electric wire arranging groove configured to be inserted the electric wires, the electric wire arranging groove having a pair of arranging surfaces facing each other,

the electric wire arranging groove being configured to have a cross-sectional shape, in a section perpendicular to a direction of the electric wires extending within the electric wire arranging groove, having a distance in a width direction of the electric wire arranging groove continuously narrowed from an insertion start portion for the electric wires toward a bottom portion of the electric wire arranging groove and the arranging surfaces each inclining from a vertical direction, at least in a part of a segment between the insertion start portion and the bottom portion.

According to the electric wire arranging jig of the aforementioned item (1), when the electric wires are inserted into the electric wire arranging groove, the electric wires are disposed so that any pair of the electric wires adjacent to each other in a depth direction of the electric wire arranging groove are displaced from each other in the width direction of the electric wire arranging groove due to the sectional shape of the electric wire arranging groove. Accordingly, differently from those in the aforementioned background art, the electric wires are arranged inside the electric wire arranging groove so as to be piled up in the depth direction of the electric wire arranging groove while central axes of the electric wires are offset in the width direction of the electric wire arranging groove, for example, as shown inFIG. 4.

(2) The electric wire arranging jig according to the item (1), wherein

the electric wire arranging groove is a V-shaped groove having a V-shape in the section, or a composite groove having a V-shaped groove having a V-shape in the section and a concave groove communicating with a bottom portion of the V-shaped groove, the concave groove has a concave shape in which a distance in the width direction in the section is fixed.

According to the electric wire arranging jig of the aforementioned item (2), a V-shaped groove or a composite groove having a V-shaped groove partially is used as the electric wire arranging groove. When the electric wires are inserted into the electric wire arranging groove shaped thus, the electric wires are guided by edge faces of the V-shaped groove, and arranged inside the electric wire arranging groove so as to be displaced from one another in the width direction of the electric wire arranging groove as described above.

Embodiments of an “ultrasonic bonding apparatus” according to the present invention provide the following item (3) and (4).

(3) An ultrasonic bonding apparatus comprising:

an ultrasonic bonding apparatus body applying ultrasonic vibration to conductors of a plurality of electric wires to bond the conductors with one another; and

the electric wire arranging jig according to the item (1) or (2).

According to the ultrasonic bonding apparatus of the aforementioned item (3), the ultrasonic bonding apparatus can be configured to have the electric wire arranging jig according to the aforementioned item (1) or (2).

(4) An ultrasonic bonding apparatus comprising:

an ultrasonic bonding apparatus body applying ultrasonic vibration to conductors of a plurality of electric wires to bond the conductors with one another; and

An electric wire arranging jig arranging a plurality of electric wires upon conductors of the electric wires being ultrasonically bonded to one another,

the electric wire arranging jig comprising an electric wire arranging groove configured to be inserted the electric wires,

the electric wire arranging groove being configured to have a cross-sectional shape, in a section perpendicular to a direction of the electric wires extending within the electric wire arranging groove, having a distance in a width direction of the electric wire arranging groove continuously narrowed from an insertion start portion for the electric wires toward a bottom portion of the electric wire arranging groove, at least in a part of a segment between the insertion start portion and the bottom portion,

the electric wire holding structure including: an electric wire holding portion having an electric wire insertion groove configured to be inserted the electric wires; and an electric wire pressing portion pressing the electric wires inserted into the electric wire insertion groove toward a bottom portion of the electric wire insertion groove.

According to the ultrasonic bonding apparatus of the item (4), the electric wires inserted into the electric wire insertion groove are pressed by the electric wire pressing portion so as to be held inside the electric wire insertion groove. In addition, each of the electric wires can be prevented from being easily displaced in a longitudinal direction thereof.

Advantageous Effects of Invention

According to the aforementioned item (1), the conductors of the electric wires can be prevented from being arranged in parallel inside the electric wire arranging groove as in the aforementioned background art. Description will be made below along an example in which the electric wires are arranged to be staggered as shown inFIG. 4. When ultrasonic vibration is applied to the conductors of the electric wires arranged thus, the ultrasonic vibration can be transmitted efficiently not only in the depth direction of the electric wire arranging groove but also in the width direction of the electric wire arranging groove, as compared with that in the aforementioned background art. As a result, ultrasonic energy can be applied to the conductors of the electric wires uniformly. Thus, oxide films in the surfaces to be bonded to each other in the conductors of the electric wires can be broken more easily than in the aforementioned background art. According to the present invention, therefore, the bonding strength is more excellent than in the aforementioned background art. Thus, excellent bonding strength can be obtained when the conductors are ultrasonically bonded to one another.

According to the aforementioned item (2), the following effect can be obtained in addition to the effect of the item (1). That is, since the electric wires inserted into the electric wire arranging groove are guided by the edge faces inside the groove having a V-shape, the electric wires can be easily arranged to be displaced and staggered from one another in the width direction of the electric wire arranging groove. As a result, the conductors of the electric wires can be more surely prevented from being arranged in parallel as in the aforementioned background art. Thus, excellent bonding strength can be obtained when the conductors are ultrasonically bonded to one another.

According to the aforementioned item (3), a similar effect to that of the item (1) or that of the item (2) can be obtained.

According to the aforementioned item (4), the following effect can be obtained in addition to the effect of the item (3). That is, since the electric wires held by the electric wire holding unit is prevented from being easily displaced in the direction (longitudinal direction) in which the electric wires extend inside the electric wire insertion groove, the conductors of the electric wires can be disposed in predetermined positions. Accordingly, ultrasonic vibration can be surely applied to the conductors when the conductors are ultrasonically bonded to one another. Thus, the conductors can be more surely ultrasonically bonded to one another.

