JP2002043377A - Tool for ultrasonic oscillation bonding - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tool for ultrasonic oscillation bonding which can be positioned accurately by remedying its defect that the tool is not positioned accurately in the lateral direction and, accordingly, the position of the tool is deviated from a pressurizing mechanism which raises and lowers a holder, and the tool becomes impossible of performing appropriate bonding. SOLUTION: Upper and lower clampers 21 and 22 hold the supporting section 4 of a resonator 1 between them from the upside and downside in a state where slopes 5 and 25 are brought into contact with each other, slopes 5 and 29 are also brought into contact with each other under the elastic action of an elastic body 33, and the lower clamper 22 positions the tool for ultrasonic oscillation boding by utilizing the wedging actions of the slopes 5, 25, and 29 which are in contact with each other even when the resonator 1 swells.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a tool for joining a plurality of members to be joined by ultrasonic vibration.

[0002]

2. Description of the Related Art FIG. 9 shows the appearance of a resonator supporting device disclosed in the bulletin of Japanese Patent Application Laid-Open No. Hei 11-307585. In FIG. 9, a support portion 102 protruding outward from the minimum vibration amplitude point of the tool 101 has a flat surface 104 parallel to the joining action surface 103 of the tool 101, and a holder 105 mounted on the movable end of the pressurizing mechanism. A flat surface 106 parallel to the flat surface 104 of the support portion 102 is provided, and the flat surface 104 of the support portion 102 and the flat surface 106 of the holder 105 are vertically contacted and fixed to each other.

[0003]

However, since the conventional example has a structure in which the flat surface 104 and the flat surface 106 are fixed to each other, when the tool 101 is mounted on the holder 105, the flat surface 104 and the flat surface 106 are fixed. The position of the tool 101 with respect to the pressing mechanism that drives the holder 105 up and down is displaced, and proper joining cannot be performed.

Accordingly, an object of the present invention is to provide an ultrasonic vibration bonding tool capable of accurately positioning.

[0005]

According to the present invention, a support portion protruding outside the minimum vibration amplitude point of the resonator and a slope formed as a mounting surface on the support portion are provided. And Therefore, according to the present invention, the attachment position of the tool to the holder becomes accurate, and the joining target members can be appropriately joined. Also, in the present invention, if the inclined surface is formed as a lower mounting surface of the support portion, and the upper mounting surface of the support portion is formed as a flat surface parallel to the bonding operation surface of the horn, the bonding at the time of bonding is performed. The load is applied to the support portion in the vertical direction without generating an oblique component force, and the support portion does not receive an external force that moves in the vibration direction.

[0006]

1 to 6 show a first embodiment of the present invention. FIG. 1 shows an exploded appearance of a tool 1 and a supporting device 20, and FIG. 3 shows a front view of the tool 1, FIG. 4 shows a front view of the tool 1 supported by the support device 20, and FIG.
FIG. 6 shows an ultrasonic bonding apparatus 41.
The front of is shown.

Referring to FIG. 1, the tool 1 and its supporting device will be described. In the first embodiment, the tool 1
Alloy or quenched alloy such as aluminum or titanium with horn body 2, joint working surface 3, support 4, slope 5, connection 6, root 7, tip 8, middle 9, joint 10 It is formed as a single body made of a material with good acoustic characteristics such as iron. The tool 1 has a rod shape having a length of one wavelength of the resonance frequency of the ultrasonic vibration transmitted from the vibrator 35 (the length from the maximum vibration amplitude point fl to the maximum vibration amplitude point f5). A vibrator 35 is attached to the tool 1 at the joint 10.
Alternatively, a screw hole for attaching a booster (not shown) coaxially with a headless screw 36 is formed at the center of the left and right end surfaces of the horn body 2. The vibrator 35 generates and outputs longitudinal ultrasonic vibration having a predetermined frequency by electric energy received from an ultrasonic oscillator (not shown). In order to amplify the vibration amplitude with the tool 1, the constriction 11 is formed in the middle of the horn body 2 located between the roots 7, but the constriction 11 may not be provided.

The support device 20 is formed by upper and lower clampers 21 and 22 and an elastic body 33. Upper and lower clampers 21; 2
Reference numeral 2 denotes a form in which the support portion 4 is divided so as to be supported in the vertical direction. The upper clamper 21 is formed as a single body made of an iron-based material and provided with a grip portion 24, a slope 25, and a coupling portion 26. The grip 24 protrudes below the four corners of the upper clamper 21 so that the position of the grip 24 corresponds to the position of the support 4. The lower surface of the grip portion 24 is formed as a flat slope 25 so as to contact the upper slope 5 of the support portion 4. The coupling portion 26 is a screw hole for attaching the upper clamper 21 to a piston rod 45 of an air cylinder 44 which is a pressing mechanism of the ultrasonic vibration bonding device 41 shown in FIG. You.

The lower clamper 22 is divided into front and rear,
Each of the lower clampers 22 is formed as a single body made of an iron-based material and provided with a grip portion 28 and a slope 29. The gripping portions 28 of the lower clampers 22 project upward from the left and right ends of the lower clampers 22 so that the positions correspond to the support portions 4. The upper surface of the grip portion 28 is the lower slope 5 of the support portion 4.
Is formed on a flat inclined surface 29 so as to contact with.

The upper and lower clampers 21 and 22 are provided with spring hooks 31 and 32 for anchoring the elastic body 33. Elastic body 33
Urges the upper and lower clampers 21 and 22 toward each other, and is formed by a coil spring. The upper end of the elastic body 33 is hooked on the spring hook 31 of the upper clamper 21, and the lower end of the elastic body 33 is held by the spring hook 3 of the lower clamper 22.
2, the elastic body 33 connects the upper clamper 21 and the lower clamper 22.

The details of the tool 1 will be described with reference to FIGS. The joining surface 3 is disposed on the outer surface of the horn body 2 at the position of the center maximum vibration amplitude point f3 in the horn main body 2, and the support portion 4 is located at the same vibration minimum point f2 on the left and right sides of the maximum vibration amplitude point f3. Placed on the outer side of the horn body 2 at the position f4. The bonding action surface 3 and the support portion 4 are orthogonal to each other, such that the bonding action surface 3 is provided on the upper and lower surfaces of the horn body 2 and the support portions 4 are provided on the front and rear surfaces of the horn body 2. Is provided. The joining action surface 3 may be the same as the upper and lower surfaces or may be recessed from the upper and lower surfaces. However, as shown in FIG. In the case of joining, the joining action surface 3 comes into contact with the article to be joined, and the surface around the joining action face 3 of the horn body 2 does not come into contact with the article to be joined. The imaginary line Ll is a waveform indicating the displacement of the vibration amplitude.

The support portion 4 is provided on the horn body 2 symmetrically about a line symmetry axis L parallel to the vibration direction X of the tool 1. That is, the support portion 4 is a symmetrical shape disposed on the front, rear, left and right sides of the horn main body 2, and the upper and lower surfaces of the support portion 4 are formed as flat attachment surfaces 3 with flat slopes 5 inclined with respect to the joint action surface 3. The connecting portion 6 connects the horn body 2 and the supporting portion 4 in a non-contact manner, and includes a root portion 7, a tip portion 8, and an intermediate portion 9.
And a crank shape consisting of The joining action surface 3 is a flat flat surface parallel to the vibration direction X. The left and right slopes 5 located on the upper side intersect at a certain point Pl on a perpendicular L3 passing through the minimum vibration amplitude point f3, and the angle θ1 formed with the perpendicular L3 of the upper and left slopes 5 is the same. The left and right slopes 5 located on the lower side intersect at another point P2 on the perpendicular L3, and the angle θ2 formed with the perpendicular L3 of these lower left and right slopes 5
Is the same. The perpendicular L3 is orthogonal to the axis of symmetry L2.

Although the crank shape of the connecting portion 6 is symmetrical in the front-rear and left-right directions, the right-left and right directions may be the same. The root portion 7 is at a minimum vibration amplitude point f2;
It is a thick plate that projects straight out of the horn body 2 at a position 4 so as to be orthogonal to the vibration direction X. Tip 8
Is a thick plate that protrudes straight from one end of the support 4 so as to be orthogonal to the vibration direction X. The intermediate portion 9 connects the root portion 7 and the distal end portion 8 and has a thin plate shape in a direction parallel to the vibration direction X.

The case where the tool 1 is assembled to the upper and lower clampers 21 and 22 will be described. First, the upper clamper 21 is turned over from the state shown in FIG. 1 and placed on a work table (not shown).
That is, the upper clamper 21 placed on the workbench has a shape in which four grip portions 24 are directed upward. In this state, the tool 1 is turned over from the state shown in FIG. 1, and the slopes 5 of the four support portions 4 are placed on the slopes 25 of the four grip portions 24 of the upper clamper 21. Thus 4
When the four supporting portions 4 are placed on the four grips 24, the joining surface 3 and the connecting portion 6 of the tool 1 are not in contact with the upper clamper 21.

Next, the two lower clampers 22 are turned over from the state shown in FIG.
It is placed on the slope 5 of the support part 4 at the location. In the state where the four grip portions 28 are placed on the four support portions 4 as described above, the joining action surface 3 and the connecting portion 6 of the tool 1 are not in contact with the lower clamper 22.

Further, the support portion 4 of the tool 1 is mounted on the holding portion 24 of the upper clamper 21, and the holding portion 28 of the lower clamper 22 is mounted on the support portion 4 of the tool 1. 1 comes into contact with the slope 5 and the lower clamper 2
In a state where the second inclined surface 29 and the inclined surface 5 of the tool 1 are in contact with each other, the four elastic bodies 33 are hooked on the spring engaging portions 31; 32 of the upper and lower clampers 21; 22.

In a state where the four elastic members 33 are moored by the four spring hooks 31 and 32, the elastic members 33 are separated from the tool 1 and the upper and lower clampers 21 and 22. 33 generates a spring force in the contracting direction, and the spring force urges the upper and lower clampers 21 and 22 in directions approaching each other. Thereby, as shown in FIGS. 4 and 5, the upper and lower clampers 21 and 22 support the tool 1 so as to sandwich it under elastic action. In FIG. 4, the lower joining operation surface 3 of the tool 1 projects below the lower surface of the lower clamper 22.

Referring to FIG. 6, an ultrasonic vibration bonding apparatus 41 using the upper and lower clampers 21 and 22 supporting the tool 1 shown in FIGS. 4 and 5 under the elastic action of the elastic body 33 will be described. Apparatus main body 42 of ultrasonic vibration bonding apparatus 41
Is a work space 4 open to the front and lower left and right
Apparatus main body 42 having an upper part of a work space 43
Air cylinder 44 as a pressurizing mechanism
Having. The lower end of the piston rod 45 projecting below the air cylinder 44 is disposed in the working space 43.

At the lower end of the piston rod 45 disposed in the work space 43, upper and lower clampers 21 and 22 which support the tool 1 shown in FIG. The lower part of the apparatus main body 42 that divides the back of the work space 43 is installed on a surface plate 46 that constitutes a base for mounting the ultrasonic vibration bonding apparatus 41 on a production line or the like. A receiving table 47 is installed on the upper surface of the surface plate 46 that defines the lower part of the work space 43.

The manner of ultrasonic vibration bonding using the ultrasonic vibration bonding apparatus 41 will be described. The support device 20 to which the tool 1 is attached is attached to the lower end of the piston rod 45, and the tool 1 and the vibrator 35 are connected by the headless screw 36. This connection is a form in which one end of the tool 1 and the output end of the vibrator 35 are in contact. A plurality of members to be joined 51 and 52 made of metal are mounted on the cradle 47 so as to overlap each other.

In this state, the support device 20 is lowered in the direction of arrow Y in FIG.
The joining action surface 3 and the receiving table 47 press and hold the joining target members 51 and 52, and the ultrasonic vibration output from the vibrator 35 is transmitted to the tool 1, so that the joining action surface 3 vibrates in the arrow X direction. Then, this vibration is generated from the joining action surface 3 by the joining target member 5.
1; 52, the joining surfaces of the joining target members 51; 52 are alternately vibrated in the lateral direction while being pressed by the joining action surface 3 and the receiving table 47, and are joined while being activated.

According to the structure of the first embodiment, the elastic body 33
The upper and lower clampers 21 and 22 grip the support portion 4 of the tool 1 from above and below while the slope 5 and the slope 25 are in contact with each other and the slope 5 and the slope 29 are in contact with each other under the elastic action of It is a form. Therefore, the tool 101 can be accurately positioned with respect to the upper and lower clampers 21 and 22 by the wedge action of the inclined surfaces 5; 25 and 29 which are in contact with each other, and the members 51 and 52 can be appropriately bonded.

At the time of joining, the weight is applied to the tool 1 from the upper clamper 21, so that the position of the minimum vibration amplitude point f2; f4 of the tool 1 with respect to the root 7 is shifted from the theoretical position, and the root 7 is vibrated. Even in this case, the intermediate portion 9 absorbs the vibration from the root 7 to the tip 8.
Therefore, the ultrasonic vibration generated by the vibrator 35 can be efficiently and appropriately transmitted from the tool 1 to the joining operation surface 3, and the upper and lower clampers 21 and 22, the elastic body 33, and the piston rod 45 do not rattle.

When the tool 1 is mounted on the support device 20 in the form of both supports, the distance between the supports from one root 7 to the other root 7 can be set within one wavelength of the resonance frequency. Is small and lightweight. For example, when the bonding target members 51 and 52 are a semiconductor chip and a circuit board, and the semiconductor chip is surface-mounted on the circuit board by ultrasonic vibration bonding, the number of bumps on the semiconductor chip is small, so that the bonding weight is low. Even in this case, it was easy to control the joining weight at the time of joining. Even when the number of bumps on the semiconductor chip is large and the bonding weight is high, the distance between supports is set within one wavelength of the resonance frequency, so that the bending that adversely affects the surface mounting of the semiconductor chip on the circuit board is performed. Did not occur in the tool 1, and all the bumps of the semiconductor chip and all the pads of the circuit board were properly bonded.

FIG. 7 shows a second embodiment of the present invention. FIG.
As shown in FIG. 2, in the second embodiment, the upper clamper 21 has an arm portion 55 extending downward, and the arm portion 55 has the lower clamper 22 movable vertically through a guide (not shown). The elastic body 57 is arranged in a contracted state in a gap between the lower clamper 22 and the spring receiving part 56 mounted and protruding inward from the arm part 55, and the lower end of the elastic body 57 contacts the receiving part 56. The upper end of the elastic body 57 contacts the lower clamper 22.

In this state, the elastic body 57 generates a spring force in the extending direction, and the spring force is applied to the upper and lower clampers 2.
1:22 are urged toward each other. Thereby, the slope 5 and the slope 25 come into contact, the slope 5 and the slope 5 and the slope 29 come into contact, and the upper and lower clampers 21;
Are supported so as to be clamped under elastic action, and the lower joining action surface 3 of the tool 1 projects below the lower surface of the receiving portion 56, and the slopes 5 which are in contact with each other as in the first embodiment. 25; 29, the upper and lower clampers 21; 2
Positioning of the tool 1 with respect to 2 can be accurately performed, and the joining target members 51 and 52 can be appropriately joined.

In each embodiment, the tool 1 is set at the resonance frequency of 1
Although the length is set to the wavelength, it may be an integral multiple thereof.

In each embodiment, the vibrator 3 is attached to one end of the tool 1.
5 were directly coupled, but the tool 1
The vibrator 35 may be mounted with a booster (not shown) having a length equal to an integral multiple of two wavelengths or 波長 wavelength. In this case, the tool 1 and the booster are coaxially connected by a headless screw corresponding to the headless screw 36 in FIG. Further, the present invention can be similarly applied to a structure in which the tool 1 has the bonding action surface 3 formed by an ultrasonic horn and a booster having the support portion 4. In this case, the ultrasonic horn and the booster are coaxially coupled by a headless screw corresponding to the headless screw 36.

It is also possible to form a slot, a hole or a slit in the intermediate portion 9 to adjust the balance of vibration.

Although the horn body 2, the joining action surface 3, the support portion 4, the connecting portion 6, and the like are formed as a single body, the horn body 2, the joining action surface 3, the supporting portion 4, the connecting portion 6, and the like are formed separately. And
The bonding surface 3, the support portion 4, and the connecting portion 6 may be fixed to the horn body 2 by screws.

After a plurality of members to be joined are mounted on the pedestal 47, pressure is applied between the joining surface 3 and the pedestal 47. However, a suction hole is formed in the joining surface 3 and the suction operation by the suction means is performed. 6, one of the members 5 to be joined in FIG.
6 and the other joining target member 52 of FIG.
A structure in which the tool 1 is lowered by the lowering operation of the air cylinder 44 and the member to be welded 51 is pressed while being overlapped with the member to be welded 52 is also applicable.

In this case, a hose connecting portion to which a hose of a suction means is connected is provided on an outer surface other than the joining operation surface 3 of the tool 1, and a suction hole connected to the suction hole and the hose connecting portion is provided inside the tool 1. A passage is formed. When the joining target member 51 to be attracted to the joining action surface 3 is small like a semiconductor chip, a joining tip having a small-diameter suction hole on the joining action surface 3 may be joined by brazing or the like. Also, FIG.
At the position of the minimum vibration amplitude point f2; f4 (see FIG. 1) from the upper surface of the tool 1 to the inside of the tool 1, and heating the tool 1 with an electric heater inserted and mounted in the heater hole. Also, it is possible to join a plurality of members to be joined with both the joining energy by the ultrasonic vibration and the joining energy by the electric heater.

The same applies to the case where the slope 5 is provided on either the upper surface or the lower surface of the support portion 4 and the slope corresponding to the slope 5 of the support portion 4 is provided on one of the upper and lower clampers 21 and 22.
For example, when the upper surface of the support portion 4 is formed on the slope 5 and the lower surface of the support portion 4 is formed as a flat flat surface parallel to the bonding surface 3, the slope 25 is formed on the upper clamper 21 and the lower clamper 22 is formed. Is formed on a flat surface corresponding to the flat surface of the support 4.

As shown in FIG. 8, when the upper surface of the support portion 4 is formed on a flat flat surface 61 parallel to the bonding action surface 3 and the lower surface of the support portion 4 is formed on the inclined surface 5, 2
The lower surface of one grip portion 24 is formed on a flat surface 62 corresponding to the flat surface 61 of the support portion 4, and the inclined surface 29 is formed on the lower clamper 22. In the case of FIG. 8, the load from the upper clamper 21 is applied to the support portion 4 of the tool 1 in the vertical direction without generating an oblique component force, and the oblique external force such that the support portion 4 moves in the vibration direction X. It was easy to control the joining weight at the time of joining without receiving any.

The inclination of the slope 5 may be opposite to the inclination of FIG. 1 so that the vertical width of the support portion 4 gradually increases from the center side to both end sides of the tool 1. In this case, the inclinations of the slopes 25 and 29 in contact with the slope 5 in the opposite direction are also opposite to those in FIG.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of the present invention.

FIG. 2 is a top view showing the resonator of the first embodiment.

FIG. 3 is a front view showing the resonator of the first embodiment.

FIG. 4 is an assembled front view of the first embodiment.

FIG. 5 is an assembled right side view of the first embodiment.

FIG. 6 is a front view showing the ultrasonic bonding apparatus according to the first embodiment.

FIG. 7 is an assembled right side view of the second embodiment of the present invention.

FIG. 8 is an assembled front view of a third embodiment of the present invention.

FIG. 9 is a perspective view showing a conventional resonator supporting device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Tool 2 Horn main body 4 Support part 5 Slope 61; 62 Flat surface

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) B23K 20/10 B23K 20/10 F term (Reference) 4E067 BF00 CA01 5D107 AA14 AA16 AA20 BB01 CC04 CC10 FF01 FF03 FF06 FF09 5F044 PP16

Claims (2)

[Claims] An ultrasonic vibration bonding tool comprising: a support portion protruding outside a minimum vibration amplitude point of a horn main body; and a slope formed as a mounting surface on the support portion. 2. The device according to claim 1, wherein the inclined surface is formed as a lower mounting surface of the support portion, and the upper mounting surface of the support portion is formed as a flat surface parallel to the joining action surface of the horn body. The ultrasonic vibration bonding tool according to the above.