JP2676438B2 - Wire bonding apparatus and method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a process for assembling a semiconductor device by using a wire at a first bonding point, for example, an electrode on a semiconductor chip, and a second bonding point, for example, an external lead provided on a lead frame. And a wire bonding apparatus for performing connection.

[0002]

2. Description of the Related Art FIG. 2 shows a conventional apparatus for connecting an electrode on a semiconductor chip serving as a first bonding point and a lead serving as a second bonding point using a gold wire or a wire such as copper or aluminum. A wire bonding apparatus having a simple circuit is known.

The device shown in FIG. 2 includes a DC power supply circuit 11 for generating a high voltage, a constant current circuit 12 connected to the DC power supply circuit 11 for generating a constant current, and a switching circuit 13.
A timer 14 for turning on / off the switching circuit 13 for a certain time, a ballast 15 connected to the switching circuit 13, a discharge electrode 19, a clamper 16, a capillary 18, and a capillary 18 inserted through the capillary 18. It is composed of a wire 17. A resistor R for stabilizing the spark discharge is used for the ballast 14.

In order to form a ball using the apparatus having the above-described configuration, a timer 14 is triggered by an external trigger signal Tr to drive a switching circuit 13 to turn on a switch. When this switch is turned on, a constant current is supplied from the constant current circuit 12, and a high voltage is applied to the discharge electrode 19 via the ballast 15, for example, the constant current circuit 12
About 1200V from the high voltage circuit of another system and about 300
A voltage of about 0 V is applied simultaneously to cause discharge between the discharge electrode 19 and the tip of the wire 17, and the discharge energy melts the tip of the wire to form a ball.

[0005]

However, in the conventional device, the inter-electrode voltage V required to start the discharge is almost equal to the inter-electrode distance S, that is, the distance between the discharge electrode 19 and the tip of the wire 17. Since it changes in direct proportion, there is a drawback that when the inter-electrode distance S becomes slightly larger than a predetermined value, the discharge is not performed or the discharge is interrupted. Moreover, in the conventional device, the voltage applied to the discharge electrode 19 needs to be about 1200 V and about 3000 V,
There is a drawback that a high voltage is required for spark discharge.

Therefore, the present invention has been made in view of the above-mentioned drawbacks of the prior art, and it is a case where the inter-electrode distance fluctuates due to the initiation of spark discharge by a discharge voltage lower than that of the conventional device. Another object of the present invention is to provide a wire bonding apparatus and method capable of stably performing and maintaining spark discharge.

[0007]

SUMMARY OF THE INVENTION The present invention is a capillary tip.
High between the tip of the wire sent from the end and the discharge electrode.
A voltage is applied to cause a discharge, and the discharge
Forming balls by melting the tip of the wire by energy
Wire bonding apparatus for direct current power supply circuit
A constant current circuit connected to the DC power supply circuit,
Switching circuit connected to constant current circuit, and control means
The switch is driven by the trigger signal output from
A time controller for driving and controlling the switching circuit;
And a coil disposed between the discharge circuit and the discharge electrode.
Ballast, one connected to the time controller and the other
High voltage high frequency connected between the ballast and the discharge electrode
A generator circuit, and the time controller includes a switch circuit.
Drive the high-voltage high-frequency generator circuit at the same time for a specified time.
The high-voltage high-frequency generator circuit,
And a high-frequency high-voltage amplifier circuit,
It is configured to apply a high frequency high voltage. Ma
Also, the present invention relates to a wire delivered from the tip of a capillary.
By applying a high voltage between the tip of the
A discharge is generated, and the discharge energy causes the tip of the wire to
Wire bonding method that melts the ends to form balls
The method of controlling the switching circuit and high
Simultaneously drive and control the high-frequency pressure generation circuit for a predetermined time, and
The high-voltage high-frequency generator circuit is composed of the discharge electrode and coil.
The high frequency high voltage applied between the ballast
Prevents the reverse flow of high frequency and high voltage by
Induce a voltage corresponding to the decrease to stabilize the discharge
It was made.

[0008]

Next, a wire bonding apparatus according to the present invention will be described. Parts that are the same as or correspond to those of the conventional apparatus shown in FIG. 2 will be described using the same reference numerals.

As shown in FIG. 1, a DC power supply circuit 11
A high voltage of about 1200 V is generated. The constant current circuit 12, which is connected to the DC power supply circuit 11 and generates a constant current,
It is connected to the switching circuit 13 in the subsequent stage. The switching circuit 13 is turned on / off for a certain period of time by the time controller 2. The time controller 2 is driven by a trigger signal Tr output from an external control means (not shown). The time controller 2 is also connected to the high voltage high frequency generation circuit 1. The time controller 2 continuously outputs drive signals L ₁ and L ₂ for simultaneously driving the switching circuit 13 and the high voltage high frequency generation circuit 1 for a predetermined time. Further, the drive signals L ₁ and L ₂ are supplied to the time controller 2
However, only L ₂ may be stopped after a predetermined time has passed from the beginning so that the high frequency high voltage from the high voltage high frequency generation circuit 1 is generated only for the first predetermined time. The high voltage high frequency generation circuit 1 is composed of a high frequency oscillation circuit 1a and a high frequency high voltage amplification circuit 1b. The high-frequency oscillator circuit 1a is composed of a known Hartley oscillator circuit or the like, and is about 100 KHz to about 1 KHz.
It oscillates high frequencies in the range of 0 MHz. The value of the high frequency can be appropriately set within the above range. The high frequency high voltage amplifier circuit 1b amplifies and boosts the high frequency oscillated by the high frequency oscillator circuit 1a.
The voltage at which this high frequency is boosted has an effective value of 100 V to 10 V.
The voltage is boosted within the range of 00V. The value of this high voltage can be set to an optimum value within the above range. The boosted high frequency high voltage is applied to the discharge electrode 19. In addition, the switching circuit 13 includes a discharge electrode 19 via the ballast 3.
Is connected to The ballast 3 is composed of a coil L. The coil L, high frequency high electrostatic applied to the discharge electrode 19 by the high voltage high frequency generator 1 the discharge by inducing a voltage corresponding to the decrease of the discharge current with stabilizing
It also works as a high-frequency blocker that blocks backflow of pressure .

On the other hand, the other end of the DC power supply 11 is connected to a clamper 16, and the clamper 16 has a capillary 18
It is configured to clamp the wire 17 inserted in the.

In order to form a ball for wire bonding using the apparatus having the above-mentioned structure, the time controller 2 is triggered by an external trigger signal Tr to drive the switching circuit 13 to turn on the switch and to increase the height. The voltage high frequency generation circuit 1 is operated. As a result, a constant current high voltage is applied to the discharge electrode 19 from the switching circuit 13 via the ballast 3, and a high frequency high voltage from the high voltage high frequency generation circuit 1 is applied to the discharge electrode 19 to Electric discharge is started between 19 and the tip of the wire 17, and the tip of the wire is melted by the discharge energy to form a ball.

Therefore, even if the inter-electrode voltage V fluctuates due to the fluctuation of the inter-electrode distance S, the spark discharge is started at a voltage lower than that of the conventional device, and even if the inter-electrode voltage V changes, the fluctuation is dealt with. Since they can follow each other, there is no discharge or no interruption even if a discharge occurs.

[0013]

As described above, according to the present invention, the inter-electrode voltage for initiating the discharge can be reduced, so that the discharge can be performed even if the inter-electrode voltage V changes due to the variation of the inter-electrode distance S. There is an effect that it is not performed, or there is no interruption even if it is discharged.

[Brief description of the drawings]

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

FIG. 2 is a diagram showing a circuit configuration of a conventional wire bonding apparatus.

[Explanation of symbols]

 1 High-voltage high-frequency generation circuit 2 Time controller 3 Ballast (high-frequency blocker) 18 Capillary 19 Discharge electrode

Claims (4)

(57) [Claims] 1. A wire delivered from the tip of a capillary.
By applying a high voltage between the tip of the
A discharge is generated, and the discharge energy causes the tip of the wire to
Wire bonding equipment that melts the ends to form balls
A DC power supply circuit, a constant current circuit connected to the DC power supply circuit, a switching circuit connected to the constant current circuit, and a drive signal driven by a trigger signal output from the control means.
A time controller for driving and controlling the switching circuit, and a time controller disposed between the switching circuit and the discharge electrode.
And a ballast composed of a ball, one of which is connected to the time controller and the other of which is the ballast.
A high-voltage high-frequency generation circuit connected between the discharge electrodes,
The time controller includes the switching circuit and the high voltage.
The high-frequency generation circuit is driven and controlled at the same time for a predetermined time, and the high-voltage high-frequency generation circuit includes a high-frequency oscillation circuit and a high-frequency
It consists of a high voltage amplifier circuit, and high frequency high voltage
Wire wire characterized by being configured to apply pressure
Binding device. 2. The high voltage high frequency generating circuit
High frequency is within the range of 100 KHz to 10 MHz.
The wire bonding apparatus according to claim 1, wherein
Place. 3. The high voltage high frequency generating circuit
The effective voltage should be in the range of 100V to 1000V rms value.
The wire button according to claim 1 or 2, characterized in that
Binding device. 4. A wire delivered from the tip of a capillary.
By applying a high voltage between the tip of the
A discharge is generated, and the discharge energy causes the tip of the wire to
Wire bonding method that melts the ends to form balls
Method, high-frequency high-frequency generation with switching circuit by time controller
The high-voltage high-frequency generation circuit is configured by the discharge electrode and the coil by controlling the driving of the circuit and the circuit at the same time for a predetermined time.
The high frequency high voltage applied between the
The high voltage and high voltage reverse flow are blocked by
Stabilize the discharge by inducing a voltage corresponding to the decrease in the flow
A wire bonding method characterized by the above.