JP2002334908A - Ultrasonic bonding device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure stable vibration characteristic, regardless of the fitting conditions or the attaching/detaching of a transducer to a holding member. SOLUTION: A transducer 13, having an ultrasonic vibrator 11 and a horn 12 for transmitting vibration are connected to each other, is connected with a holding member 14 connected with a head body 20, and a bonding tool 15 is held on the tip end side of the horn 12. In such an ultrasonic bonding device, a flange 13a for connection facing the side surface of the holding member 14 is provided in a part equivalent to a mode of vibration in the transducer 13, and the transducer fitting part of the holding member 14 is formed in an elastically deformable manner, in the direction of fitting surface of the flange 13a.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ultrasonic bonding apparatus for applying an ultrasonic vibration to an electronic component such as a chip component to a mounting object such as a substrate or a package and pressing the same.

[0002]

2. Description of the Related Art FIGS. 8 and 9 show an ultrasonic bonding head used in a conventional ultrasonic bonding apparatus.

[0003] Ultrasonic vibrator 11 and horn 1 for transmitting vibration
2 are connected to form a transducer 13.

The transducer 13 is connected to a holding member 14 connected to a head body 20 in a horizontal posture.

[0005] The bonding tool 15 is vertically supported on the tip side of the horn 12, and the upper end thereof is connected to a vacuum device 18 via a flexible tube 17.

An electronic component is suction-held on a component suction surface at the lower end of the bonding tool 15.

In the above case, the transducer 1
Reference numeral 3 is inserted into a slot 14b provided in the split-type holding member 14, and is fixed by being tightened with a bolt 22.

[0008]

In the case of the above conventional structure,
The transducer 13 is provided with the slit 1 of the holding member 14.
4B, the vibration characteristics change depending on the degree of the tightening of the split tightening. Therefore, in order to obtain excellent bonding quality with constant and stable vibration characteristics for the transducer 13, it is necessary to strictly control the tightening force.

In order to meet this demand, for example, in the case of a form in which the tightening is performed at a constant torque using a torque wrench or the like, since the tightening force is affected by the friction coefficient of the bolt, it is difficult to control the tightening force strictly. In particular, each time the transducer 13 is detached or attached for maintenance or the like, the tightening state changes, and the vibration characteristics of the transducer 13 tend to change.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to achieve a stable vibration characteristic irrespective of how the transducer is attached to the holding member and to improve the bonding quality.

[0011]

According to the present invention, a transducer having an ultrasonic vibrator and a horn for transmitting vibration is connected to a holding member connected to a head main body, and a bonding tool is provided on a tip side of the horn. Is supported, and a flange for connection to the holding member is provided at a portion corresponding to a node of vibration of the transducer, while the holding member is connected to the ultrasonic vibration at the flange. Is characterized by being elastically deformable in the vibration direction.

According to the present invention, the flange of the transducer is in a spread vibration mode in a plane along the flange surface. On the other hand, since the transducer mounting portion of the holding member to which the flange is connected is elastically deformable in the vibration direction, the transducer mounting portion of the holding member is integrated with the flange portion by the spread vibration in the surface direction of the flange. Vibrating, and the state of connection of the transducer to the holding member is less likely to affect the vibration characteristics of the transducer.

As a result, according to the present invention, it is possible to provide an ultrasonic bonding apparatus capable of performing a constant and stable bonding operation in quality.

As a preferred embodiment of the present invention,
A spacer having a different specific acoustic impedance may be interposed between the head body and the holding member, or the spacer may be formed of a resin material.

In this embodiment, the vibration of the transducer is reflected by the spacer provided between the head body and the holding member and having a material having a different specific acoustic impedance, and the minute vibration generated at the mounting portion of the holding member to the head body. Ultrasonic bonding apparatus capable of reducing the influence on the vibration characteristics of the transducer due to the vibration, reducing the influence of the connection state of the transducer to the holding member on the vibration characteristics of the transducer, and performing a constant and stable bonding operation in quality. Can be provided.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below based on embodiments shown in the drawings.

FIG. 1 shows a schematic configuration of an ultrasonic bonding apparatus according to an embodiment of the present invention.

On the upper surface of the apparatus frame 1, a mounting stage 3 for mounting and supporting a substrate 2, which is an example of a mounting object, and a component supply unit 5 in which electronic components 4, such as chip components with bumps, are aligned and accommodated. And is equipped with.

Above the apparatus frame 1, a component transport stage 6, a component supply unit 7 for supplying the electronic component 4 taken out from the component supply unit 5 to the component transport stage 6, and an electronic component supplied to the component transport stage 6. A bonding head 8 that receives the component 4 and presses it against the substrate 2 on the mounting stage 3
And an elevating block 9 that supports and lowers the bonding head 8.

The mounting stage 3 includes a bonding head 8
For alignment with the electronic component 4 held in
It is configured to be able to move horizontally back and forth and left and right.

The component transfer stage 6 is configured to be able to move vertically and horizontally so as to carry the electronic component 4 supplied by the component supply unit 7 into the vertical movement path of the bonding head 8 and transfer it to the bonding head 8. ing.

FIGS. 2 and 3 show the bonding head 8.
Is shown in detail.

In the bonding head 8, a transducer 13 is formed by connecting an ultrasonic transducer 11 and a horn 12 for transmitting vibration.

The transducer 13 is horizontally connected and supported below a holding member 14 made of a metal material such as stainless steel or aluminum.

A round pipe-shaped bonding tool 15 is vertically attached to the tip of the transducer 12.

The bonding tool 15 is inserted into a slot 12a at the tip of the horn 12, fastened and fixed with a bolt 16, and connected to a vacuum device 18 via a flexible tube 17, for example.

A plate-like flange 13a is provided at a portion of the transducer 13 corresponding to a node of vibration (a point of no vibration).

As shown in FIG. 4 and FIG.
An inverted U-shaped concave portion 14a which is opened downward is formed in a lower portion of the lower portion 4. The transducer 1 is inserted into the recess 14a.
3 is engaged from below, a pair of left and right bolts 19 is attached to the side surface of the lower end of the holding member 14 by the flange 13a.
And fixed. Thereby, the transducer 13 is fixed horizontally to the holding member 14.

The holding member 14 itself is connected to the head body 21 via a spacer 20 made of a material having a different intrinsic acoustic impedance, for example, a resin material such as an acrylic plate.

The component mounting process in the ultrasonic bonding apparatus having the above configuration will be described in detail.

When it is confirmed that the mounting of the electronic component 4 on one substrate 2 is completed, the bonding head 8 starts to rise. At the same time, the component transfer stage 6 advances toward the vertical movement path of the bonding head 8.

When the bonding head 8 rises, the mounting stage 3 moves in the horizontal direction at a pitch, and the substrate 2 to be mounted next is set at a position immediately below the bonding head 8.

When the bonding head 8 rises, the component transfer stage 6 that holds the electronic component 4 and moves horizontally while moving into the vertical movement path of the bonding head 8 operates to move upward, and the electronic component 4 is moved by the bonding head 8. It is applied to the lower end of the bonding tool 15 and is held by suction.

When the delivery of the electronic component 4 to the bonding tool 15 is completed, the component transport stage 6 is retracted from the vertical movement path of the bonding head 8 and returns to the standby position for receiving the next component supply.

At the same time, the bonding head 8 holding the electronic component 4 is moved down to press the electronic component 4 held at the lower end of the bonding tool 15 against the substrate 2 with an appropriate load, and the transducer 13 is driven to drive the bonding. Ultrasonic vibration is applied (vibrated) to the tool 15, and the bumps 4 a on the lower surface of the component are securely bonded (compressed) on the circuit pattern of the substrate 2.

In the vibration compression bonding process, the flange 13a of the transducer 13 is in a vibration mode in which the plane extends along the flange surface, and the transducer mounting portion of the holding member 11 to which the flange 13a is connected is also provided. Since the flange 13a can be elastically deformed in the mounting surface direction, the transducer mounting portion of the holding member 14 also vibrates integrally with the flange 13a by the spread vibration of the flange 13a in the surface direction.

As a result, the state in which the transducer 13 is held by the holding member 14 has less influence on the vibration characteristics of the transducer 13.

FIGS. 6A and 6B show the results of measuring the effect of the structure for holding the transducer on the holding member 14 on the vibration characteristics. This result is a measurement result in a state where the holding member is not attached to the head main body.

FIG. 6A shows that the transducer 13 is
FIG. 6B shows a measurement result of the structure of the present embodiment attached to the side surface of the holding member 14 via the flange 13a.
Shows the measurement result in the conventional structure.

Here, the vibration characteristics of the transducer 13 are evaluated based on the impedance at the time of vibration driving.
After the measurement is performed by attaching the transducer 13 to the holding member 14, the measurement is performed once by removing the transducer 13 and then reattaching the measurement. This measurement is repeated 10 times. The transducer 13
Is 7.6Ω when driven alone.

As can be seen from the measurement results, in the structure of the present embodiment, the average value of the vibration characteristics is closer to the vibration characteristics of the transducer alone, the deviation R between the maximum value and the minimum value is small, and the variation is small. It has become something.

Further, the vibration of the transducer 13 is reflected by the spacer 20 having a different intrinsic acoustic impedance from that of the transducer 13, and the influence of the minute vibration between the holding member 14 and the head body 21 on the vibration characteristics of the transducer 13 is reduced. Less.

FIGS. 7A and 7B show the results of measuring the effect of the interposition of the spacer 20 on the vibration characteristics of the transducer 13. FIG. FIG. 7A shows a measurement result when the holding member 14 of the present embodiment is attached to the head main body 21 with the spacer 20 interposed therebetween, and FIG. 7B shows the present invention without the spacer 20 interposed therebetween. The measurement result when the holding member 14 having the structure is attached to the head main body 21 is shown.

The measuring method is the same as that described above, and an acrylic plate having a thickness of 5 mm is used as the spacer 20.

As can be seen from the measurement results, the spacer 2
When 0 is interposed, the average value of the vibration characteristics is closer to the vibration characteristics of the transducer alone, the deviation R between the maximum value and the minimum value is smaller, and the variation is smaller.

The material of the spacer 20 is not limited to an acrylic plate, but a resin plate other than acrylic, a rubber material, a cloth material, or the like may be appropriately selected and used according to the output capacity of the transducer 12 or the like. I just need.

[0047]

As described above, according to the present invention, stable vibration characteristics can be ensured regardless of how the transducer is attached to or detached from the holding member. As a result, the vibration from the ultrasonic vibrator can be efficiently transmitted. The information is transmitted to the bonding tool, and a reliable and high-quality bonding operation can be performed.

[Brief description of the drawings]

FIG. 1 is a perspective view of an ultrasonic bonding apparatus according to an embodiment of the present invention.

FIG. 2 is a front view of the ultrasonic bonding head of FIG. 1;

FIG. 3 is a perspective view of a main part of the ultrasonic bonding head of FIG. 1;

FIG. 4 is a front view of a main part of the ultrasonic bonding head of FIG. 1;

FIG. 5 is an exploded perspective view of a main part of the ultrasonic bonding head of FIG. 1;

FIG. 6 is a view showing the result of measuring the effect of a transducer holding structure on vibration characteristics.

FIG. 7 is a view showing a result of measuring an influence of a mounting structure of a holding member to a head main body on a vibration characteristic.

FIG. 8 is a front view of a conventional ultrasonic bonding head.

FIG. 9 is a perspective view of a conventional ultrasonic bonding head.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 11 Ultrasonic vibrator 12 Horn 13 Transducer 13a Flange 14 Holding member 15 Bonding tool 20 Spacer 21 Head main body

Claims (3)

[Claims] 1. An ultrasonic bonding apparatus comprising: a transducer having an ultrasonic vibrator and a horn for transmitting vibration; a transducer connected to a holding member connected to a head body, and a bonding tool supported on a tip side of the horn. The device, wherein a portion corresponding to a node of vibration of the transducer is provided with a flange for connection to the holding member, while the holding member is elastically deformable in a vibration direction of ultrasonic vibration in the flange. An ultrasonic bonding apparatus characterized by being performed. 2. The ultrasonic bonding apparatus according to claim 1, wherein a spacer having a different intrinsic acoustic impedance is interposed between the head body and the holding member. 3. The ultrasonic bonding apparatus according to claim 2, wherein the spacer is made of a resin material.