KR20120084669A - Ultrasonic bonding apparatus - Google Patents

Abstract

Provided is an ultrasonic bonding device in which deformation due to plastic flow is suppressed even when applied to a work having low rigidity such as foil. And an anvil 10 for stacking the superimposed workpiece to be joined, and a groove 211 formed in a surface on which the workpiece to be bonded is pressed and into which a plastic fluid flows during ultrasonic bonding. It has a horn 20 which joins the workpiece | work to be joined by vibrating.

Description

Ultrasonic Bonding Device {ULTRASONIC BONDING APPARATUS}

The present invention relates to an ultrasonic bonding device.

In ultrasonic bonding, the overlapped workpiece is stacked on the anvil on the fixed side, pressed by the horn on the movable side, and the ultrasonic horn is vibrated, thereby peeling off the oxide films on the contact surfaces of the workpiece on the upper and lower sides, and joining the metal surfaces together. It is a technique.

The face of the horn and the anvil is machined to form an uneven pattern. The pattern of the irregularities of the horn and the pattern of the irregularities of the anvil are different, so it is not common to fit them. Therefore, the workpiece | work which is joined to the convex part of a horn and anvil, the area which is not pinched by any convex part, and the area | region which any convex part contacts exists in the workpiece | work to be joined, and the distribution of pressing force became nonuniform. For this reason, joining may not be performed stably and there exists a possibility that joining quality may not be stabilized.

Therefore, in patent document 1, joining quality is stabilized by not forming an uneven | corrugated pattern in the face of a horn.

Japanese Patent Application Laid-Open No. 2005-254323

However, in the method of patent document 1, it could not apply unless it was a workpiece with high rigidity like a thick plate. The inventors have found a problem that, when attempting to apply to a work having a low rigidity such as foil, the work may generate a significant deformation due to plastic flow.

This invention is made | formed in view of such a conventional problem, and an object of this invention is to provide the ultrasonic bonding apparatus by which the deformation | transformation by plastic flow is suppressed, even if it applies to the workpiece with low rigidity like foil.

This invention solves the said subject by the following solving means.

This invention has the anvil which loads the superimposed bonding object workpiece | work, and the horn which joins the bonding object workpiece | work by pressing and bonding ultrasonic workpiece | work by ultrasonic vibration. And the horn is characterized in that it comprises a groove which is formed on the surface for pressing the workpiece to be bonded, the workpiece flows plastically flow at the time of ultrasonic bonding.

According to this invention, the workpiece which plastically flowed into the groove | channel flows in. Therefore, it is suppressed that the workpiece | work which baked plastically flowed out to the junction part outer side. Therefore, even if the workpiece is a work with low rigidity such as foil, deformation due to plastic flow is suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS The figure which shows the vicinity of the face of a horn in 1st Embodiment of the ultrasonic bonding apparatus which concerns on this invention.
The figure which shows the ultrasonic bonding apparatus of 1st embodiment.
3 is a diagram showing a distribution of pressing force when a workpiece to be bonded mounted on an anvil is pressed by a horn;
It is a figure which shows the vicinity of the face of a horn in 2nd Embodiment of the ultrasonic bonding apparatus which concerns on this invention.
It is a figure which shows the vicinity of the face of a horn in 3rd embodiment of the ultrasonic bonding apparatus which concerns on this invention.
It is a figure which shows the vicinity of the face of a horn in 4th embodiment of the ultrasonic bonding apparatus which concerns on this invention.

EMBODIMENT OF THE INVENTION Hereinafter, the form for implementing this invention is demonstrated in detail with reference to drawings.

(1st embodiment)

As described above, in the ultrasonic bonding, the overlapped workpiece is stacked on the anvil on the fixed side, pressed by the horn on the movable side, and the horn is vibrated so as to peel off the oxide films on the contact surfaces of the workpieces on the upper and lower joints, and thus the metal surfaces. It is a method of joining.

The uneven pattern formed on the face of the horn and the anvil is generally inconsistent as shown in FIGS. 2 to 4 of JP-A-6-155051. If the workpiece to be joined with such a horn and anvil is sandwiched, there is a possibility that the pressing force becomes uneven and the joining may not be performed stably, and the joining quality may not be stabilized.

In addition, as in Patent Document 1, when the horn face is not formed at all in the uneven pattern and is applied to a work having low rigidity such as foil, the work may generate a significant deformation due to plastic flow.

Therefore, in this invention, the horn was performed as follows.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the vicinity of the face of a horn in 1st Embodiment of the ultrasonic bonding apparatus which concerns on this invention, FIG. 1 (A) is a figure which looked at the face, and FIG. It is a right side view of (A). In addition, in FIG. 1 (A), the left and right direction of the paper is the ultrasonic vibration direction, and the up and down direction of the paper is the direction orthogonal to the ultrasonic vibration.

As judged from FIG. 1B, when viewed from the vibration direction or in a cross section orthogonal to the vibration direction, the base shape of the face 21 of the horn 20 is an arc shape. And as judged from FIG.1 (A), the concave pattern (groove) 211 is formed in the face 21 of the horn 20. As shown in FIG. The concave pattern (groove) 211 is formed over the stool 23 extending in the direction orthogonal to the ultrasonic vibration direction.

The concave pattern (groove) 211 is formed in the vicinity of the periphery 22 of the horn 20 and extends in the ultrasonic vibration direction. Such concave pattern 211 can be easily formed by grinding or discharging, for example. And an area inside the concave pattern (groove) 211 (near the centerline CL of the horn 20; Near the apex of an arc shape, unevenness | corrugation is not formed.

It is a figure which shows the ultrasonic bonding apparatus of 1st Embodiment. It is a figure which shows the distribution of the pressing force at the time of pressing the workpiece | work to be joined mounted on the anvil with a horn.

The ultrasonic bonding device 1 includes an anvil 10 and a horn 20.

The anvil 10 is a fixed member. The anvil 10 loads the superposed workpiece to be stacked. In FIG. 2, the electrode tab 51 and the current collector foils 521 to 524 are the workpieces to be bonded.

The horn 20 is a member that vibrates ultrasonically. The horn 20 bonds the workpiece to be joined by pressing the workpiece to be mounted on the anvil 10 with a face and ultrasonically vibrating. That is, when the horn 20 vibrates ultrasonically, the oxide film of the contact surface of the upper and lower joining workpiece | work is peeled off, and metal surfaces are joined. In FIG. 2, the horn 20 vibrates ultrasonically from side to side of the ground. In addition, the horn 20 is chamfered at the front end side and the rear end side of the vibration direction.

At this time, since the pressing force in the vicinity of the center line CL (near the apex of an arc shape) is the highest, it joins from that part.

And in this embodiment, the area | region inside the recessed pattern (groove) 211 (near the centerline CL of the horn 20; Since an unevenness | corrugation is not formed in circular arc shape vertex], the pressing force is leveled as shown in FIG. Therefore, joining is started stably at the beginning of joining start. Since the site | part joined at the beginning of joining expansion expands with progress of a joining process, when the stable joining is performed at the beginning of joining, joining of the whole joining part will be performed stably. Therefore, the quality of the joint is stabilized.

In addition, when a workpiece with low rigidity such as foil is placed in an anvil and pressed by an horn and ultrasonically bonded, the workpiece on the horn side and the workpiece on the anvil side move relative to each other by ultrasonic vibration of the horn. When relative motion occurs between the workpieces, plastic flow occurs in the workpieces and the horns settle. As time passes (increases the energy applied to the joint), the horn settles on the workpiece. And the volume of the workpiece | work corresponded to the sedimentation amount of a horn plastically flows. The horn-side workpiece plastically flowed moves from the vicinity of the centerline CL having a high pressing force (near the apex of the arc shape) to the peripheral side having a low pressing force, and tries to flow out to the outside.

However, since the outer part on the peripheral side (that is, the part outside the joining part) is not in the plastic flow state, it cannot spread out on the same plane as the workpiece surface. Therefore, a deformation | transformation arises at the boundary of a junction part and an outer part. When the deformation is excessive with respect to the rigidity of the workpiece, the entire workpiece is deformed.

On the other hand, in this embodiment, since the concave pattern (groove) 211 extended in the ultrasonic vibration direction is formed in the vicinity of the peripheral edge, the workpiece which plastically flows into this concave pattern (groove) 211 flows in. Therefore, it is suppressed that outflow of the horn-side workpiece which flowed by plastic flows outward of the junction part. Therefore, even if the horn-side work is a work with low rigidity such as foil, deformation due to plastic flow is suppressed.

(Second Embodiment)

It is a figure which shows the vicinity of the face of a horn in 2nd Embodiment of the ultrasonic bonding apparatus which concerns on this invention, FIG. 4 (A) is a figure which looked at the face, and FIG. 4 (B) is FIG. It is a right side view of (A).

In addition, below, the same code | symbol is attached | subjected to the part which functions similar to the above, and the overlapping description is abbreviate | omitted suitably.

In this embodiment, as determined from FIG. 4A, a concave pattern (groove) 212 is formed in the face 21 of the horn 20. The concave pattern (groove) 212 is formed over the stool 22 parallel to the ultrasonic vibration direction. The concave pattern (groove) 212 is formed near the stool 23 in the vicinity of the stool 23 extending in the direction orthogonal to the ultrasonic vibration direction. Such concave pattern 212 can be easily formed by grinding or discharging, for example.

Also in this embodiment, the workpiece which plastically flowed at the time of ultrasonic bonding flows into the concave pattern (groove) 212. Therefore, even if the horn-side workpiece plastically flows in the ultrasonic vibration direction, it is suppressed that it flows out of the joint portion. Therefore, even if the horn-side work is a work with low rigidity such as foil, deformation due to plastic flow is suppressed.

(Third embodiment)

It is a figure which shows the vicinity of the face of a horn in 3rd Embodiment of the ultrasonic bonding apparatus which concerns on this invention, FIG. 5 (A) is a figure which looked at the face, and FIG. 5 (B) is FIG. It is a right side view of (A).

In this embodiment, as determined from FIG. 5A, a concave pattern (groove) 211 and a concave pattern (groove) 212 are formed in the face 21 of the horn 20. The concave pattern (groove) 211 is formed over the stool 23 extending in the direction orthogonal to the ultrasonic vibration direction. In addition, the concave pattern (groove) 211 is formed in the vicinity of the stool 22 of the horn 20 and extends along the stool 22. The concave pattern (groove) 212 is formed over the stool 22 parallel to the ultrasonic vibration direction. The concave pattern (groove) 212 is formed near the stool 23 extending in the direction orthogonal to the ultrasonic vibration direction, and extends along the stool 23.

According to this embodiment, the workpiece which plastically flowed at the time of ultrasonic bonding flows into the recessed pattern (groove) 211 and the recessed pattern (groove) 212. Therefore, even if the horn-side workpiece plastically flows in the ultrasonic vibration direction, it does not flow out of the joint portion. Therefore, even if the horn-side work is a work with low rigidity such as foil, deformation due to plastic flow is suppressed.

(Fourth Embodiment)

It is a figure which shows the vicinity of the face of a horn in 4th Embodiment of the ultrasonic bonding apparatus which concerns on this invention, FIG. 6 (A) is a figure which looked at the face, and FIG. 6 (B) is FIG. It is a right side view of (A).

In this embodiment, as judged from FIG. 6 (A), the concave pattern (groove) is applied to the face 21 of the horn 20 over the stool 23 extending in the direction orthogonal to the ultrasonic vibration direction. 214 is formed. The concave pattern (groove) 214 extends in the inclined direction with respect to the ultrasonic vibration direction without exceeding the center line CL extending in the ultrasonic vibration direction of the horn 20.

Depending on the shape of the workpiece and the restraint state of the workpiece during ultrasonic bonding, the workpiece rotates under the influence of ultrasonic vibration and plastic flow during bonding.

In the present embodiment, on the other hand, the amount of plastic-flowing horn-side work flowing out around the junction is adjusted by giving the horn face a nonuniformity at a constant angle and distribution with respect to the vibration direction. Thereby, the bias of the deformation which arises around a junction part can be adjusted. By adjusting the bias of deformation in the direction which suppresses rotation of the workpiece | work at the time of joining, rotation of a workpiece | work can be suppressed.

It is apparent that various modifications and changes are possible within the scope of the technical idea without departing from the embodiments described above, and they are also included in the technical scope of the present invention.

For example, the size of the concave pattern described above is merely an example and may be appropriately changed.

1: ultrasonic bonding device
10: Anvil
20: Horn
21: Face
211 to 214: concave pattern (groove)
22: feces parallel to the ultrasonic vibration direction
23: feces extending in a direction perpendicular to the ultrasonic vibration direction
51 electrode tab (work to be joined)
521 to 524: current collector foil (work to be joined)

Claims (6)

Anvil to load the superimposed workpiece to overlap,
An ultrasonic bonding including a groove formed on a surface pressing the workpiece to be joined, into which a plastic flow flows during ultrasonic bonding; Device. The ultrasonic bonding apparatus according to claim 1, wherein the groove is formed near the periphery of the horn and extends in the ultrasonic vibration direction. The ultrasonic bonding apparatus according to claim 1 or 2, wherein the groove is formed near the periphery of the horn and extends in a direction orthogonal to the ultrasonic vibration direction. The method of claim 1, wherein the groove is formed over a stool extending in a direction orthogonal to the ultrasonic vibration direction, and extends in an inclined direction with respect to the ultrasonic vibration direction without crossing a centerline extending in the ultrasonic vibration direction. Ultrasonic bonding device. The ultrasonic bonding apparatus according to claim 1 or 2, wherein unevenness is not formed in a region inside the groove. The ultrasonic joining apparatus according to claim 1 or 2, wherein the base shape of the surface pressing the workpiece to be joined to the horn is an arc when viewed from a cross section perpendicular to the vibration direction.

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