JPH0652146U - Ultrasonic horn and bonding device equipped with the same - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide an ultrasonic horn capable of quickly and easily performing position adjustment for ensuring bonding accuracy, and a bonding apparatus equipped with the ultrasonic horn. [Structure] The ultrasonic horn 1 is provided with a fitting portion 1e that slidably fits into an insertion hole 2a formed in a support member 2 that supports the ultrasonic horn 1 to obtain the above effect.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bonding apparatus that performs bonding using ultrasonic waves when assembling semiconductor components such as semiconductor integrated circuits (ICs) and large-scale integrated circuits (LSIs), and ultrasonic waves installed in the bonding apparatus. And an ultrasonic horn that makes the transmission of.

[0002]

[Prior art]

 In a conventional bonding apparatus, a lead frame for wire bonding, in which a plurality of IC chips (semiconductors) are arranged side by side in the longitudinal direction, is intermittently fed by one pitch in the longitudinal direction by a transfer means, and this lead frame is sent. After being transferred to the bonding stage that is overheated by the heater block, the electrodes (pads) of each IC chip and the leads around them are bonded and connected by a wire made of an aluminum wire or a gold wire. FIG. 6 shows the main part of the bonding means provided in this bonding apparatus.

As shown in FIG. 6, the bonding means includes an ultrasonic horn 1, a support member 2 for supporting the ultrasonic horn 1, an ultrasonic transducer for exciting the ultrasonic horn 1 (electrical -Acoustic conversion element) 3 and a capillary 4 as a bonding tool. The ultrasonic oscillator 3 is excited by applying a frequency output from a frequency generator (not shown). The ultrasonic oscillator 3 and the frequency generator are collectively referred to as ultrasonic vibrating means.

The ultrasonic horn 1 has a straight horn portion 1a to which an ultrasonic transducer 3 is attached at a rear end portion thereof, and a capillary 4 attached to a front end portion thereof, and an ultrasonic wave transmitted by the straight horn portion 1a. It has a conical portion 1b for enlarging the amplitude of vibration. The rear portion of the straight horn portion 1a is inserted into the insertion hole 2a formed in the support member 2 together with the ultrasonic transducer 3.

The straight horn portion 1a is formed in a columnar shape, and a flange portion 1c having a diameter larger than that of the straight horn portion 1a is formed at a nodal point (node position of vibration of ultrasonic vibration) of the straight horn portion 1a. The flange portion 1c is fastened to the support member 2 with bolts 5. A male screw portion 1d is formed at the rear end of the straight horn portion 1a, and the ultrasonic transducer 3 is screwed into the male screw portion 1d.

By the way, the ultrasonic horn 1 is mainly made of stainless steel or titanium alloy, and although not shown, pads and leads on an IC chip having a large area such as a hybrid IC and a thermal head substrate are formed. In order to connect the leads of the frame to the leads by wires, the degree of freedom in moving an XY table (not shown) disposed below the straight horn portion 1a and the recognition of a camera or the like disposed above. In consideration of the relationship with the device, the length of the resonance mode is about 3/2 wavelength (λ), for example. Here, the 3/2 wavelength (λ) resonance mode length means that the frequency of the ultrasonic wave that is normally used is about 50 kHz to 100 kHz. For example, the frequency is 60 kHz, and the ultrasonic horn material is stainless steel. In this case, the length of the 3/2 wavelength (λ) in the axial direction is appropriately set to about 125 mm. The lengths of the straight horn portion 1a and the conical portion 1b are appropriately set.

In the case of performing bonding in the above configuration, the ultrasonic horn 1 together with the supporting member 2 is vertically moved by a drive mechanism (not shown) on a bonding stage (not shown) in a vertical direction (direction perpendicular to the plane of the drawing). The ball formed at the tip of the wire that has been moved to and inserted into the capillary 4 is pressed against the electrode (pad) of the IC chip and is thermocompression bonded. At the same time as this pressure bonding, ultrasonic vibration is applied from the ultrasonic horn 1. All of the above steps are performed for each chip and lead, and a series of bonding steps are completed.

[0008]

[Problems to be solved by the device]

 In the above-mentioned configuration, the length and the like of the ultrasonic horn 1 need to be accurately set in order to make the ultrasonic horn 1 ideally resonate, while also mounting the ultrasonic horn to the support member 2. It needs to be done with high precision. Specifically, the axial center of the ultrasonic horn 1 is made to coincide with the center of the insertion hole 2a of the support member 2, and the capillary 4 does not incline with respect to a bonding target surface such as a pad. You must adjust the angular position of axis 1 around the axis.

This is because the vibrating direction of the tip of the capillary 4 is not parallel to the ultrasonic horn 1 that generates longitudinal vibration, and thus the vibration amplitude of the ultrasonic wave becomes unstable if the angular position deviates from the normal position. This is because. In other words, the ultrasonic horn 1 generates vertical vibration and the capillary 4 generates horizontal vibration, but if the ultrasonic horn 1 is not adjusted in angular position, the capillary 4 will generate linear vibration or elliptical vibration with an inclination. As a result, the bonding accuracy is lowered.

However, in the above configuration, the axial center of the ultrasonic horn 1 is made to coincide with the center of the insertion hole 2a of the support member 2, and the angular position around the axial center of the ultrasonic horn 1 is adjusted. Both are difficult, and they have the drawback of spending a great deal of time and requiring skill.

Therefore, the present invention has been made in view of the above-mentioned drawbacks of the prior art, and an object thereof is to provide an ultrasonic horn capable of performing position adjustment quickly and easily, and a bonding apparatus including the ultrasonic horn. I am trying.

[0012]

[Means for Solving the Problems]

 The present invention provides an ultrasonic horn which is inserted into an insertion hole formed in a predetermined support member and is used by being attached to the support member. The ultrasonic horn is provided with a fitting portion slidably fitted in the insertion hole. It is configured in. Further, the present invention provides an ultrasonic horn that holds a bonding tool and is excited by ultrasonic vibrating means, and a support member that has an insertion hole through which the ultrasonic horn is inserted to support the ultrasonic horn. In the bonding apparatus having the above, the ultrasonic horn is formed with a fitting portion slidably fitted in the insertion hole.

[0013]

【Example】

 Next, a wire bonding apparatus according to the present invention will be described with reference to the accompanying drawings. The wire bonding apparatus is configured in the same manner as the bonding apparatus shown in FIG. 6 except the part described below. Moreover, in the following description, the same reference numerals are used for the same or corresponding components as those of the conventional bonding apparatus.

In FIG. 1, a supporting member 2 supporting the ultrasonic horn 1 is fitted to a rotatable supporting shaft 11. A swing arm 12 is swingably fitted to the support shaft 11. A solenoid 14a and an electromagnetic attraction piece 14b are fixed to the swing arm 12 and the support member 2 in correspondence with each other. When swinging the support member 2, the solenoid 14a is not shown in the drawing. The support member 2 and the swing arm 12 are fixed to each other by supplying an electric power from the power source to generate an attractive force between the support member 2 and the swinging arm 12. A magnet 15a and a coil 15b are attached to the swing arm 12 and the support member 2 in front of the electromagnetic adsorption means. The magnet 15a and the coil 15b constitute means for generating an attraction force for urging the tip of the ultrasonic horn 1, that is, the portion holding the capillary 4 downward in FIG.

As shown in FIG. 2, a support shaft 16a is provided at the rear end of the swing arm 12, and the arm side cam follower 16 and the swing base 19a rotate around the support shaft 16a. It is free. A bearing guide 19b is fixed to the swing base 19a at one end thereof, and a preload arm 19d is rotatably attached to the other end of the bearing guide 19b via a support pin 19e. A support shaft 17a is provided at the free end of the preload arm 19d, and a cam follower 17 is rotatably attached to the support shaft 17a. A preload spring 19f, which is a tension spring, is laid between the tip of the preload arm 19d and the tip of the swing base 19a, and the arm side cam followers 16 and the cam followers 17 are formed in a substantially heart shape. It is pressed against the cam surface, which is the outer peripheral surface of the cam 18. The two contact points of the arm side cam follower 16 and the cam follower 17 with respect to the cam 18 are located with the rotation center of the cam 18 interposed therebetween.

A frame structure is formed by the swing base 19a, the bearing guide 19b, and the preload arm 19d, and is collectively referred to as a swing frame 19. A bearing guide 19b as a constituent member of the swing frame 19 is in contact with an outer ring of a radial bearing 21 attached to a cam shaft 22 in which the cam 18 is fitted. The cam 18 is rotated by the torque applied to the cam shaft 22 by the motor 23.

Here, the configuration of the ultrasonic horn 1 will be described in detail.

As shown in FIGS. 3 to 5, the ultrasonic horn 1 is provided with a fitting portion 1e slidably fitted in an insertion hole 2a formed in a supporting member 2 for supporting the ultrasonic horn 1. There is. As is clear from FIGS. 4 and 5, the fitting portion 1e has a cylindrical shape and is integrally formed on the flange portion 1c provided at the nodal point (node position of ultrasonic vibration) of the ultrasonic horn 1. Has been formed.

As described above, the fitting portion 1e has a circular cross-sectional shape perpendicular to the axial center thereof, and is fitted closely in the axial direction into the insertion hole 2a having a circular cross section. It is rotatable in this fitted state. By providing the fitting portion 1e, both the axial center of the ultrasonic horn 1 and the axial center of the ultrasonic horn 1 can be adjusted quickly and easily with respect to the center of the insertion hole 2a. You can

As described above, since the fitting portion 1e is formed on the flange portion 1c provided at the nodal point portion, the resonance characteristic of the ultrasonic horn 1 is provided by providing the fitting portion 1e. Little impact.

In addition, in the present embodiment, the cross-sectional shape of the fitting portion 1e is circular, but in addition, for example, the cross-sectional shape is substantially square, and the four corners thereof have a curvature approximately equal to the radius of the insertion hole 2a. It may be configured to have a curved surface having a radius so that these curved surface portions are brought into sliding contact with the inner wall surface of the insertion hole 2a.

[0022]

[Effect of device]

 As described above, according to the present invention, since the ultrasonic horn is provided with the fitting portion that slidably fits into the insertion hole formed in the supporting member that supports the ultrasonic horn, the bonding accuracy is improved. There is an effect that the position of the ultrasonic horn for securing the position can be adjusted quickly and easily.

[Brief description of drawings]

FIG. 1 is a side view of a main part of a bonding apparatus according to the present invention including a partial cross section.

2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view taken along line BB in FIG.

FIG. 4 is a view taken along the line CC of FIG.

FIG. 5 is a DD arrow view including a partial cross-section with respect to FIG. 3;

FIG. 6 is a bottom view including a partial cross section of a main part of a conventional bonding apparatus.

[Explanation of sign]

 1 Ultrasonic Horn 1c Flange 1e Fitting 2 Supporting Member 2a Insertion Hole 3 Ultrasonic Transducer 4 Capillary (bonding tool)

Claims (4)

[Scope of utility model registration request] 1. An ultrasonic horn which is used by being inserted into an insertion hole formed in a predetermined support member and attached to the support member, wherein a fitting portion slidably fitted in the insertion hole is provided. An ultrasonic horn that is equipped with. 2. The ultrasonic wave according to claim 1, wherein the nodal point portion has a flange portion for attaching to the support member, and the fitting portion is provided on the flange portion. Horn. 3. The ultrasonic horn according to claim 1, wherein the fitting portion has a circular cross-sectional shape perpendicular to the axis center thereof. 4. An ultrasonic horn that holds a bonding tool and is excited by ultrasonic vibrating means, and a support member that has an insertion hole through which the ultrasonic horn is inserted and that supports the ultrasonic horn. A bonding apparatus, wherein the ultrasonic horn is provided with a fitting portion slidably fitted in the insertion hole.