JP3367652B2 - Spark torch body for wire bonding apparatus and wire bonding apparatus - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spark torch body for a wire bonding device and a wire bonding device.

[0002]

2. Description of the Related Art Wire bonding is an integrated circuit device,
It has been widely used as a means for connecting electrodes of a semiconductor element or various electronic component elements to a lead frame or the like. Wire bonding is used for thin-film magnetic heads, etc., for taking out electrodes (bumps) of the thin-film magnetic head.
Is also used when connecting to a lead conductor provided on the gimbal. For wire bonding, for example, Japanese Patent Application No. 62-136833 and Japanese Patent Application Laid-Open No. 6-45390.
As disclosed in Japanese Patent Publication No. 2798515 and Japanese Patent Publication No. 2798515, it includes a spark torch body and a capillary tool. The tip of the metal wire of the Au wire or the Al wire guided through the capillary tool is opposed to the spark electrode portion of the spark torch body with a minute gap. In this state, a high voltage (DC voltage) is applied between the tip of the metal wire and the spark electrode portion of the spark torch body to generate a spark. The heat of this spark melts the tip of the metal wire to form a metal ball.

Next, the spark torch body is retracted from the position facing the capillary tool. Below the spark torch body, at the position facing the capillary tool,
A support (work) on which the wire bonding component is mounted is arranged in advance, and the retracting operation of the spark torch body causes the wire bonding component mounted on the work to face the capillary tool.

Then, the capillary tool is lowered and the metal ball formed at the tip of the metal wire is pressure-bonded to the position of the wire bonding component mounted on the work for wire bonding. In crimping, usually, the capillary tool is excited by ultrasonic excitation means, and this ultrasonic excitation energy is used.

[0005]

However, in wire bonding, a high voltage (DC voltage) is applied between the tip of the metal wire and the spark electrode portion of the spark torch body to generate a spark. The electromagnetic waves caused by are induced. Electromagnetic waves are most often induced in a spark torch body made of metal. The spark torch body is covered with an insulating film except for the spark electrode portion, but this insulating film only contributes to electrical insulation and is ineffective in suppressing electromagnetic waves.

Therefore, electromagnetic interference occurs in the surroundings. In particular, an integrated circuit element, a semiconductor element, various electronic component elements, a thin film magnetic head or the like to which wire bonding is applied are arranged near the spark torch body through which the spark current flows. Moreover, these elements are inherently vulnerable to external noise. For this reason, various elements used for the wire bonding are affected by electromagnetic waves caused by the spark current, so that the functions are deteriorated and electrical breakdown is caused.

In the above-mentioned publicly known documents, there is no mention of generation and suppression means of such electromagnetic waves.

An object of the present invention is to provide a spark torch body and a wire bonding apparatus which are effective in suppressing electromagnetic interference caused by a spark current.

[0009]

In order to solve the above problems, a spark torch body according to the present invention includes a base body and an insulating coating. The base body is made of a metal body and partially has a spark electrode portion. The insulating coating is an electromagnetic wave absorbing insulating coating and covers the surface of the base body excluding the spark electrode portion.

The spark torch body according to the present invention is used in a wire bonding device. The wire bonding apparatus includes a capillary tool as well as a spark torch body. The capillary tool holds a metal wire,
The tip of the held metal wire is arranged at a position facing the spark electrode portion of the spark torch body.

Specifically, the tip of the metal wire of Au wire or Al wire guided through the inside of the capillary tool is opposed to the spark electrode portion of the spark torch body with a minute gap.

Then, a high voltage (DC voltage) is applied between the tip of the metal wire and the spark electrode portion of the spark torch body to generate a spark, and the heat of the spark causes
The tip of the metal wire is melted to form a metal ball.

Here, the spark torch body according to the present invention includes an insulating coating, and since this insulating coating is an electromagnetic wave absorbing insulating coating and covers the surface of the substrate, the spark current is caused by the spark current. The electromagnetic wave induced in the torch body is absorbed by the electromagnetic wave absorbing insulating coating, and electromagnetic wave interference to various elements provided for wire bonding is suppressed.

Since the electromagnetic wave absorbing insulating coating is formed on the surface of the base body excluding the spark electrode portion, spark is generated between the spark electrode portion and the tip of the metal wire to form a metal ball, and wire bonding is performed. Can be used for

After forming the metal balls by the spark discharge, the spark torch body is retracted from the position facing the capillary tool. Next, the capillary tool is lowered, and the metal ball formed at the tip of the metal wire is pressure-bonded to the position for wire bonding of the wire bonding component mounted on the work.

The wire bonding device further includes a high voltage power supply device, a metal wire fixing means, a cable wire and the like as general constituent parts. The high-voltage power supply device generates a high voltage sufficient to generate a spark between the tip of the metal wire and the spark electrode portion of the spark torch body.

The metal wire fixing means fixes or releases the middle portion of the metal wire, and when the metal wire is fixed, the metal wire is electrically connected to the metal wire, Is supplied to the capillary tool.

The cable wire constitutes an electric circuit for electrically connecting the metal wire fixing means, the metal wire and the spark torch body in series and is led to the high voltage power supply device.

The metal wire fixing means is usually connected to the high-potential side of the high-voltage power supply device via the cable wire, and is further grounded via another cable wire.
The spark torch body is connected to the low potential side of the high voltage power supply device via the cable wire.

In such an overall structure, the portion through which the spark current flows can be covered with an insulating film having electromagnetic wave absorption characteristics. For example, at least a part of the cable wire, an inner surface or an outer surface of a housing that houses the metal wire fixing means, or the like.

The wire bonding apparatus may further include ultrasonic exciting means, and the ultrasonic exciting means may have a structure for exciting the capillary tool.

Other objects, configurations and advantages of the present invention will be described more specifically with reference to the accompanying drawings. The figures are merely exemplary.

[0023]

1 is a diagram showing the configuration of a wire bonding apparatus according to the present invention. The wire bonding apparatus according to the present invention includes a spark torch body 1 and a capillary tool 3.

FIG. 2 is an enlarged view showing a part of the spark torch body 1 and the capillary tool 3, and FIG. 3 is a perspective view showing a part of the spark torch body 1. As shown, the spark torch body 1 includes a base 101 and an insulating coating 103. The base body 101 is made of a metal body having a low electric resistance, such as copper, and has a spark electrode portion 105 in a part thereof. The insulating coating 103 is an electromagnetic wave absorbing insulating coating,
It covers the surface of the base body 101 excluding the spark electrode portion 105. In the figure, in the spark electrode portion 105, the electromagnetic wave absorbing insulating coating 103 is provided only on the side surface thereof, but the electromagnetic wave absorbing insulating coating 103 is provided only in the spark electrode portion 1.
It may be configured to extend to the surface of 05 to secure an area required for planar spark discharge and expose the spark electrode portion 105 in, for example, a circular shape or a rectangular shape.

A specific example of the electromagnetic wave absorbing insulating coating 103 is a mixture of magnetic powder and synthetic resin. Examples of the magnetic powder include ferrite powder, metal powder, and combinations thereof. As the synthetic resin, various insulating resins such as epoxy resin, acrylic resin or phenol resin can be used. Also,
The electromagnetic wave absorbing insulating coating 103 may be a coating film or a sheet member. In the case of a coating film, a magnetic paste containing magnetic powder, synthetic resin, solvent, etc. is formed on the surface of the base 101 of the spark torch body 1 by coating. In the case of a sheet member, a tape-shaped or sheet-shaped electromagnetic wave absorbing insulating member is bonded to the surface of the base 101 using an adhesive or the like. Electromagnetic wave absorbing insulation coating 10
The shape of 3 may be a shape having unevenness on the surface.
In this case, heat dissipation characteristics and electromagnetic wave absorption characteristics can be improved.

The capillary tool 3 holds the metal wire 2, and the tip of the held metal wire 2 is arranged at a position facing the spark electrode portion 105 of the spark torch body 1. The metal wire 2 is supplied from the wire supply unit 11. As the metal wire 2, a conventionally known wire such as an Au wire or an Al wire can be used.

Further, the wire bonding device includes a high voltage power supply device 5, metal wire fixing means 71 and 72, and cable wires 91, 92 and 93. The high voltage power supply device 5 generates a DC high voltage sufficient to generate a spark between the tip of the metal wire 2 and the spark electrode portion 105 of the spark torch body 1. The power-on switch 4 is inserted on the high potential side (+) of the high-voltage power supply device 5.

The metal wire fixing means 71, 72 fixes or releases the intermediate portion of the metal wire 2, and is electrically connected to the metal wire 2 when the metal wire 2 is fixed. The metal wire fixing means 71, 72
Supplies the metal wire 2 to the capillary tool 3 before the capillary tool 3.

The cable wires 91, 92, 93 constitute an electric circuit for electrically connecting the metal wire fixing means 71, 72, the metal wire 2 and the spark torch body 1 in series. The metal wire fixing means 71, 72 is a cable wire 92.
Is connected to the high-potential side (+) of the high-voltage power supply device 5 via, and is further grounded via a cable wire 93. The spark torch body 1 is connected to the low potential side (−) of the high voltage power supply device 5 via a cable wire 91.

The wire bonding apparatus shown in the figure further includes an ultrasonic wave excitation means 6. The ultrasonic wave excitation means 6 excites the capillary tool 3.

Below the spark torch body 1 and at a position facing the capillary tool 3, a support (work) 8 on which a wire bonding component 12 is mounted is arranged in advance. The wire bonding component 12 is a thin film magnetic head using a GMR (giant magnetoresistive) element in the figure, and is mounted on a gimbal 13 made of an insulating substrate. The GMR element includes a spin valve film structure or a ferromagnetic tunnel junction. On the surface of the gimbal 13, the extraction electrodes (bumps) 12 of the thin film magnetic head 12 are formed.
1 and a conductor 131 to be connected by wire bonding. When the spark torch body 1 retracts, the wire bonding component 12 mounted on the work 8 faces the capillary tool 3. The component 12 to be mounted on the work 8 may be one that is used for wire bonding. For example,
It may be for connecting electrodes of an integrated circuit element, a semiconductor element, or various electronic component elements to a lead frame or the like.

Next, the operation of the wire bonding apparatus according to the present invention will be described with reference to FIGS.

As shown in FIG. 4, the tip of the metal wire 2 of Au wire or Al wire guided through the capillary tool 3 is opposed to the spark electrode portion 105 of the spark torch body 1 with a minute gap. Let

Then, as shown in FIG. 5, the intermediate portion of the metal wire 2 is clamped by the metal wire fixing means 71 and 72, and the metal wire 2 is fixed and electrically connected. In this state, as shown in FIG. 5, the power-on switch 4 is turned on, and a high voltage (DC voltage) is applied between the tip of the metal wire 2 and the spark electrode portion 105 of the spark torch body 1. As a result, a spark is generated between the tip of the metal wire 2 and the spark electrode portion 105 of the spark torch body 1, and the heat of the spark causes the metal wire 2
The tip portion of is melted, and the metal ball 21 is formed.

Here, the spark torch body 1 according to the present invention
Includes an insulating coating 103, which is an electromagnetic wave absorbing insulating coating 103 and covers the surface of the base body 101. Therefore, electromagnetic waves induced in the spark torch body 1 due to the spark current are generated. Electromagnetic wave absorbing insulation coating 1
Absorbed by 03. Therefore, the electromagnetic interference to the component 12 such as the thin-film magnetic head on the work 8 arranged at the lower position of the spark torch body 1 and close thereto is suppressed.

The insulating coating 103 is a spark electrode portion 105.
Since it is formed on the surface of the base body 101 except for, the spark can be generated between the spark electrode portion 105 and the tip of the metal wire 2, and the metal ball 21 can be formed for wire bonding.

Next, as shown in FIG. 6, the power-on switch 4 is turned off, and the spark torch body 1 is retracted from the position facing the capillary tool 3 in the direction indicated by the arrow a1.

Next, as shown in FIG. 7, the capillary tool 3 is lowered in the direction shown by the arrow b1, and the metal wire 2 is attached to the position for wire bonding of the wire bonding component 12 mounted on the work 8. The metal ball 21 formed at the tip is pressed.

Then, the capillary tool 3 is excited by ultrasonic waves by the ultrasonic wave excitation means 6, and as shown in FIG. 8, the capillary tool 3 is formed at the tip of the metal wire 2 at the position for wire bonding of the wire bonding component 12. The metal ball 21 thus formed is pressure-bonded. In the illustrated embodiment, the take-out electrode (bump) 121 of the thin film magnetic head 12 and the gimbal 1
The wire bonding 22 is performed between the conductor 131 and the conductor 131 on the upper part 3.

Thereafter, as shown in FIG. 9, the capillary tool 3 is moved in the direction of arrow b2, and the spark torch body 1 is moved in the direction of arrow a2 to return to the position shown in FIG.

At least a part of the cable wires 91, 92, 93 may have an electromagnetic wave absorbing insulating coating having the same composition as that used in the spark torch body 1.
Further, when the metal wire fixing means 71, 72 are surrounded by the housing 73, at least one of the inner surface and the outer surface of the housing 73 may have an electromagnetic wave absorbing insulating coating.

The electromagnetic wave absorbing insulation coating of the cable lines 91, 92, 93 and the electromagnetic wave absorbing insulation coating of the housing 73 are made of a mixture of magnetic powder and synthetic resin, and a coating film or a sheet member is used. The fact that the surface may have irregularities is the same as in the case of the electromagnetic wave absorbing insulating coating provided on the spark torch body 1.

[0043]

As described above, according to the present invention, it is possible to provide a spark torch body and a wire bonding apparatus which are effective in suppressing electromagnetic interference caused by a spark current.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration of a wire bonding apparatus according to the present invention.

FIG. 2 is an enlarged view showing a portion of a spark torch body and a capillary tool.

FIG. 3 is a perspective view showing a part of a spark torch body.

FIG. 4 is a diagram illustrating an operation of the wire bonding apparatus shown in FIG.

FIG. 5 is a diagram illustrating a next operation of the operation shown in FIG.

FIG. 6 is a diagram illustrating the next operation after the operation shown in FIG.

FIG. 7 is a diagram illustrating an operation subsequent to the operation shown in FIG.

FIG. 8 is a diagram illustrating the next operation of the operation shown in FIG.

FIG. 9 is a diagram illustrating an operation subsequent to the operation shown in FIG.

[Explanation of symbols]

1 spark torch body 101 base 103 Electromagnetic wave absorbing insulation coating 105 Spark electrode part 2 metal wire 3 Capillary tools 5 High voltage power supply 6 Ultrasonic excitation means 71, 72 Metal wire fixing means 8 work

Claims (16)

(57) [Claims] 1. A spark torch body for a wire bonding apparatus including a base and an insulating coating, wherein the base is a metal body and has a spark electrode portion in part, and the insulating coating is A spark torch body for a wire bonding apparatus, which is made of an electromagnetic wave absorbing insulating coating and covers the surface of the base body excluding the spark electrode portion. 2. The spark torch body for a wire bonding device according to claim 1, wherein the electromagnetic wave absorbing insulating coating is a mixture of magnetic powder and synthetic resin. 3. The spark torch body for a wire bonding device according to claim 1, wherein the electromagnetic wave absorbing insulating coating is a coating film. 4. The spark torch body for a wire bonding device according to claim 1, wherein the electromagnetic wave absorbing insulating coating is a sheet member. 5. The spark torch body for a wire bonding device according to claim 1, wherein the electromagnetic wave absorbing insulating coating has irregularities on a surface thereof. 6. A wire bonding apparatus including a spark torch body and a capillary tool, wherein the spark torch body is the one described in any one of claims 1 to 5, wherein the capillary tool is made of metal. For a wire bonding apparatus that holds a wire, and the tip of the held metal wire is arranged at a position facing the spark electrode portion of the spark torch body. 7. The wire bonding apparatus according to claim 6, further comprising a high voltage power supply device, a metal wire fixing means, and a cable wire, wherein the high voltage power supply device is the metal A high voltage sufficient to generate a spark is generated between the tip of the wire and the spark electrode portion of the spark torch body, and the metal wire fixing means fixes or fixes the middle portion of the metal wire. Which is electrically connected to the metal wire when the metal wire is fixed, supplies the metal wire to the capillary tool, and the cable wire includes the metal wire fixing means and the metal wire. A wire bonding device that constitutes an electric circuit that electrically connects a wire and the spark torch body in series and is guided to the high-voltage power supply device. 8. The wire bonding apparatus according to claim 6, wherein the metal wire fixing means is connected to the high potential side of the high voltage power supply device via the cable wire, and further, another cable. A wire bonding device that is grounded via a wire. 9. The wire bonding apparatus according to claim 8, wherein the spark torch body is connected to the low potential side of the high voltage power supply device via the cable wire. 10. The wire bonding apparatus according to claim 7, wherein at least a part of the cable wire has an electromagnetic wave absorbing insulating coating. 11. The wire bonding apparatus according to claim 7, wherein the metal wire fixing means is surrounded by a housing, and the housing is provided on at least one of an inner surface and an outer surface. A wire bonding device having an electromagnetic wave absorbing insulating coating. 12. The wire bonding apparatus according to claim 7, wherein the electromagnetic wave absorbing insulating coating of the cable wire and the electromagnetic wave absorbing insulating coating of the housing are magnetic. A wire bonding device made of a mixture of powder and synthetic resin. 13. The wire bonding apparatus according to claim 12, wherein the electromagnetic wave absorbing insulating coating is a coating film. 14. The wire bonding apparatus according to claim 12, wherein the electromagnetic wave absorbing insulating coating is a sheet member. 15. The wire bonding apparatus according to claim 12, wherein the electromagnetic wave absorbing insulating coating has unevenness on a surface thereof. 16. The wire bonding apparatus according to claim 7, further comprising an ultrasonic wave exciting means, wherein the ultrasonic wave exciting means excites the capillary tool.