JP2005199301A - Joining assist mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the quality of joining by ultrasonic combined joining in a joining device for joining metals by assembling electric parts without increasing the size of the device.
SOLUTION: A joining auxiliary mechanism comprising an ultrasonic oscillator, an ultrasonic horn, an ultrasonic vibrator, and a vibration tool fixed to or formed on the ultrasonic horn, the ultrasonic horn, An assembly assisting mechanism is provided in which an assembly including the ultrasonic transducer and the vibration tool is provided independently of a joining tool provided in a joining apparatus.

[Selection] Figure 1

Description

The present invention relates to an apparatus used for bonding between metals, particularly for a relatively small-scale bonding used for assembling electric components, and to a bonding auxiliary mechanism for a bonding apparatus used for resistance welding or brazing. is there.

Conventionally, resistance welding and brazing have been widely used for joining metals to each other, particularly for relatively small joints used for assembling electrical components. As resistance welding, a stacked object to be joined is sandwiched between electrodes, and a potential difference is applied to the electrode together with pressing, and spot welding using the current heating action of the object to be joined, or a pair from one side of the superimposed object to be joined. Parallel gap welding is known in which a potential difference is applied between the electrodes while pressing the electrodes, and a current is passed through the work piece.

On the other hand, brazing is performed by interposing a member (a brazing material) having a melting point lower than that of the base material of the object to be joined and heating and melting the brazing material at a temperature that does not lead to the melting of the base material. Is what
Solder that is soft solder is most widely used as a brazing material for assembling electrical components, but other metals are also used, and the plating layer applied to the base metal functions as a brazing material. Sometimes it does.

In addition, various heating methods are used. In addition to those using a thermal atmosphere, those using radiant heat, or those using laser irradiation, a heater chip heated by energization is brought into contact with the object to be joined and brazed. The method of doing is known.

A conventional bonding method and apparatus will be described with reference to FIGS. FIG. 3 is a side view showing joining by resistance welding, and FIG. 4 is a side view showing soldering joining by pulse heat. In this document,
Bonding shall include resistance welding and brazing, and brazing shall include soldering using a low melting soft solder.

FIG. 3 is a side view of a resistance welding apparatus disclosed in Patent Document 1 and used for assembling electric components. In FIG. 3, 51 is a capacitor | condenser, The apparatus for welding the anode wire 51A and anode lead 52 of this capacitor | condenser is shown.

In this resistance welding, an object to be welded is sandwiched between the welding electrode 56A supported by the electrode support part 59A and the welding electrode 56B supported by the electrode support part 59B, and the pressurizing part 55 driven by the vertical drive part 54 is provided. While the welding electrode 56A is pushed down, the welding power source 58 applies a voltage to the welding electrodes 56A and 56B.

At the same time, the ultrasonic vibrator 53 vibrates by the output of the ultrasonic generator 57, and ultrasonic vibration is applied to the joint surface via the welding electrode 56A. By removing the oxide layer and impurities on the joint surface of the work piece by the action of this vibration, stable resistance welding is obtained.

FIG. 4 is a side view of a soldering apparatus disclosed in Patent Document 2 and used for assembling electrical components. In FIG. 4, 61 is an electronic component, and the lead 61A of this electronic component.
And an apparatus for soldering the electrode 62A of the printed wiring board 62 are shown.

Here, the printed wiring board 62 is placed on the stage 63, and the electronic component 61 is placed on the printed wiring board 62. At this time, a solder layer 64 is formed in advance between the electrode 62A and the lead 61A.

Next, the heater chip 65 is lowered and brought into contact with the joint, and the pulse current generator 66
Heats the heater chip 65. At the same time, the first ultrasonic oscillator 67 outputs and vibrates the ultrasonic vibrator 68, and the second ultrasonic oscillator 69 outputs and vibrates the ultrasonic vibrator 70. Thereby, the stage 63 and the heater chip 65 vibrate, and the wettability of the solder is improved by the action of the vibration, and the reliability of soldering is improved.

JP 2002-64033 A (first page, FIG. 4) JP-A-6-350241 (first page, FIG. 1)

However, in the method of Patent Document 1 shown in FIG. 3, the ultrasonic transducer 53 must electrically insulate and support the welding electrode 56A, and needs to support it through the electrode support portion 59A. Thereby, not only the material selection of the member for transmitting the ultrasonic vibration from the ultrasonic vibrator 53 to the welding electrode 56A is limited, but also electrically insulating and connecting different materials,
A large loss occurs in the transmission of ultrasonic vibration.

Furthermore, in order to support the welding electrode 56A with the ultrasonic vibrator 53 and apply a load to the workpiece,
Not only is it difficult to make a large load, but the load directly acts on the vibration transmission system including the ultrasonic vibrator 53, and the amplitude of vibration is greatly changed. In other words, in the actual joining scene, there is a high possibility that the action of the ultrasonic vibration on the joining surface deviates greatly from the expected design value.

Also, in the method of Patent Document 2 shown in FIG. 4, the heater chip 65 also needs to be electrically insulated and supported, and is shown as an electrical insulating plate 71. In addition, heater chip 65
Is heated to a high temperature, it is necessary to be insulated from the ultrasonic transducer 70 as much as possible.

Furthermore, since the heater chip 65 has poor solder wettability and needs to select an ideal material having electrical resistance and strength, it is extremely difficult to select an ideal material as an ultrasonic vibration transmission member. . Therefore, there is a problem similar to the case of Patent Document 1 described above.

Furthermore, since the ultrasonic vibrator 68 that vibrates at the output of the first ultrasonic oscillator needs to vibrate the stage 63 that tends to have a large mass and area, in addition to being inevitably large, Those equipped with vacuum suction holes for sucking and fixing printed wiring boards placed on the upper surface and vacuum flow paths connecting them to vacuum pumps, and those equipped with positioning drive mechanisms for horizontal two-dimensional directions and horizontal rotation angles In general, it is structurally difficult to provide these mechanisms and an ultrasonic transducer at the same time.

The present invention has been created to solve the above-described problems, and does not require a large-scale mechanism, and is stable by using a joining auxiliary mechanism that is not easily affected by the load and temperature that are joining conditions. It obtains the bonding quality.

The present invention provides, as a first aspect, a joining auxiliary mechanism that is provided and used in a joining apparatus for joining metals when assembling electrical components, and includes at least an ultrasonic oscillator, an ultrasonic horn, An assembly comprising an ultrasonic transducer and an excitation tool fixed to or formed on the ultrasonic horn, and an assembly including the ultrasonic horn, the ultrasonic transducer, and the excitation tool includes the joining device. A joining auxiliary mechanism is provided that is provided independently of the joining tool provided on the joint.

Moreover, this invention provides the joining auxiliary | assistant mechanism as a 1st aspect characterized by the said vibration tool contacting a to-be-joined object from the same side as the said joining tool as a 2nd aspect.

According to the present invention, a joining auxiliary mechanism that imparts ultrasonic vibrations to an object to be joined is provided independently of the joining tool, and the influence of potential difference and heat generated in the joining tool is greatly reduced. An optimal material for transmission of ultrasonic vibration can be selected as the vibration tool, and the coupling between the ultrasonic vibrator and the ultrasonic horn or the ultrasonic horn and the vibration tool can also be made an optimal structure for vibration transmission.

Further, according to the present invention, the setting is usually changed depending on the type of the object to be joined, and the vibration tool is brought into contact with the object to be joined with a load setting different from the joining load which is an important joining condition. Therefore, the optimum ultrasonic vibration can be applied to the workpiece.

Further, according to the present invention, the contact surface shape of the vibration tool can be formed separately from the tip shape of the welding tool (contact area or surface shape of the contact surface), so that the vibration transmission efficiency from the vibration tool to the workpiece Can be increased freely.

In addition, according to the present invention, it is possible to separately maintain a joining tool for resistance welding and brazing and a joining auxiliary mechanism for applying ultrasonic vibration, thereby reducing the labor of repair and parts replacement. Can be made.

Therefore, according to the present invention, it is possible to obtain an ultrasonic combined bonding apparatus having stable bonding quality and good maintainability without making the apparatus large. In the case of resistance welding, this stable joint quality is achieved by destroying the oxide film on the joint surface and the adhered foreign material layer to stabilize the contact resistance. This is achieved by improving the wettability of the material to the base material.

First, a description will be given of a case of a resistance welding apparatus among the joining apparatuses according to the present invention using a parallel gap welding apparatus. FIG. 1 is a perspective view of a joining apparatus according to the present invention, FIG. 1 (a) is a perspective view of a principal part of the apparatus, and FIG. 1 (b) is a diagram in which only a joining auxiliary mechanism is extracted from this principal part.
Here, 1A is one article to be joined, and 1B is the other article to be joined, and both are positioned and placed on the stage 2.

Reference numeral 3 denotes a joining tool, which includes a pair of welding electrodes 5, a pair of power supply blocks 6 to which these are fixed, an insulating block 7 to which the pair of power supply blocks 6 are fixed, and a pair of power supply blocks 6.
And a pair of power supply cables 8 connected to each other.

This joining tool is held by a guide 9 so as to be movable up and down, and a predetermined vertical movement is possible by a drive mechanism (not shown). The pair of power supply cables 8 are connected to a welding power source 10, and a predetermined potential difference can be applied between the pair of welding electrodes 5 by the output of the welding power source 10.

Reference numeral 4 denotes a joining auxiliary mechanism. As shown in FIG. 1B, an ultrasonic transducer 13 is fixed to one end of the ultrasonic horn 12, and a vibration tool 14 is fixed to the other end. . In this embodiment, the vibration tool 14 is fixed to the ultrasonic horn 12 as a separate member.
The tip of 2 may be processed to form a vibration tool. This selection may be made by comprehensively considering the maintainability of the tool, the processing cost of the horn, and the like.

The ultrasonic horn 12 of the joining auxiliary mechanism 4 is formed to resonate at a predetermined frequency,
At the nodal point (vibration node) when vibrating at this frequency, it is fixed to the welding apparatus main body so as to be movable up and down. Further, the output of the ultrasonic oscillator 11 is connected to the ultrasonic vibrator 13 of the joining auxiliary mechanism 4, and the vibration generated by the vibrator 13 by this output is amplified by the ultrasonic horn 12 and applied to the vibration tool 14. The transmitted object 1B is vibrated.

Here, the vertical movement of the assembly of the joining auxiliary mechanism 4 including the ultrasonic horn 12, the ultrasonic vibrator 13, and the vibration tool 14 is performed separately from the method of operating integrally with the vertical movement of the welding tool 3. Although the method of operating can be considered, the pressing force can be set individually, and the pressing force for resistance welding and the pressing force for applying ultrasonic vibration are individually set to desired values.

Next, a description will be given of a case of a soldering device among the joining devices according to the present invention using a pulse heat soldering device. FIG. 2 is a perspective view of a pulse heat soldering apparatus according to the present invention. Here, 21A is one object to be joined, and 21B is the other object to be joined, and both are positioned and placed on the stage 22. Reference numeral 21C denotes an electrode formed on the upper surface of one of the objects to be bonded 21A, and a solder layer 31 is formed on the electrode 21C.

23 is a joining tool, a substantially V-shaped heater chip 25, a pair of power supply blocks 26 to which both ends of the heater chip 5 are fixed, an insulating block 27 to which the pair of power supply blocks 26 are fixed, A pair of power supply cables 28 respectively connected to the pair of power supply blocks 26 are configured.

The welding tool 23 is held by a guide 29 so as to be movable up and down, and can be moved in a predetermined vertical direction by a driving mechanism (not shown). The pair of power supply cables 28 are connected to a pulse heat power supply 30, and a predetermined pulse current can be supplied to the heater chip 25 by the output of the pulse heat power supply 30 to heat the heater chip 25.

Reference numeral 4 denotes a joining assistance mechanism, and the construction of the joining assistance mechanism 4 is the same as that described with reference to FIG. The output of the ultrasonic oscillator 11 as shown in FIG. 2 is connected to the ultrasonic vibrator 13 of the joining auxiliary mechanism 4, and the vibration generated in the vibrator 13 by this output is amplified by the ultrasonic horn 12. The vibration is transmitted to the vibration tool 14 and vibrates the workpiece 21B.

Here, the vertical movement of the assembly of the joining auxiliary mechanism 4 can be considered as a method of operating integrally with the vertical movement of the welding tool 23 and a method of operating individually, but the pressing force can be set individually, The pressing force for soldering and the pressing force for applying ultrasonic vibration are individually set to desired values.

In the present embodiment, the tip of the vibration tool 14 has a bifurcated shape, and is in contact with both sides in the vicinity of the joining portion. However, the contact is not limited to this form, and depends on the characteristics of the object to be joined. You may make it contact in one place or three or more places.

The perspective view which shows the joining apparatus of one Embodiment of this invention. The perspective view which shows the joining apparatus of other embodiment of this invention. Schematic diagram showing conventional technology Schematic diagram showing other conventional techniques

Explanation of symbols

1A, 1B, 21A, 21B Joined member 2, 22 Stage 3, 23 Joining tool 4 Joining auxiliary mechanism 5 A pair of welding electrodes 6, 26 A pair of power supply block 7, 27 Insulation block 8, 28 A pair of power supply cables 9, 29 Guide 10 Welding power supply 11 Ultrasonic oscillator 12 Ultrasonic horn 13 Ultrasonic vibrator 14 Excitation tool 25 Heater chip 30 Pulse heat power supply 31 Solder layer

Claims (2)

When assembling electrical parts, a joining auxiliary mechanism used in a joining device for joining metals,
At least an ultrasonic oscillator, an ultrasonic horn, an ultrasonic transducer, and an excitation tool fixed to or formed on the ultrasonic horn,
An assembly assisting mechanism, wherein an assembly including the ultrasonic horn, the ultrasonic transducer, and the vibration tool is provided independently of a bonding tool provided in the bonding apparatus. The joining support mechanism according to claim 1, wherein the vibration tool is in contact with an object to be joined from the same side as the joining tool.

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