JPH06342830A - Wire bonding method and its device - Google Patents

Abstract

PURPOSE:To provide a wire bonding device which can position its capillary with high accuracy without being affected by the heat from a heat block to heat the object of heating. CONSTITUTION:A wire bonder, which has an ultrasonic horn 10 and a position controller 19 for shifting a capillary 4 back and forth and right and left on the basis of the control data using the length of the ultrasonic horn 10 at reference temperature as a basis so as to position it in a bonding position, is equipped with a temperature detecting means 13 which measures the temperature of the constituent member positioned near the ultrasonic horn 10 and besides positioned above a heat block 6 similar to the ultrasonic horn 10. This further has a quantity-of-elongation setting means 20, which sets the quantity of elongation of the ultrasonic horn 10, based on the relation with the quantity of elongation of the ultrasonic horn 10 corresponding to this detected temperature, and a correction means 21, which corrects the control data, based on the set quantity of elongation of the ultrasonic horn 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a wire bonding method and apparatus for connecting electrodes and electrode portions provided in a semiconductor device with wires.

[0002]

2. Description of the Related Art A wire bonding apparatus using a conventional wire bonding method and its operation will be described with reference to FIGS.

In FIGS. 5 and 6, the substrate 2 is placed and fixed on a heat block 6 having a heater 5. The bonding head 1 and the heat block 6 relatively move in the front, rear, left and right directions. The horn holder 9 is an ultrasonic horn 10.
Is rotatably supported in the vertical direction, the linear motor 11 rotates the ultrasonic horn 10 in the vertical direction, and as a result, the capillary 4 moves in the vertical direction. The ultrasonic vibration oscillator 7 in which the high frequency from the high frequency oscillator 8 is composed of a piezo element or the like.
The ultrasonic vibration oscillated by the ultrasonic vibration oscillator 7 is transmitted to the ultrasonic vibration horn 10 and is amplified by the ultrasonic horn 10.
Be transmitted to. The capillary 4 holds the wire 3 and bonds its tip to an electrode at a predetermined position.

In the conventional wire bonding method, first, the bonding head 1 and the heat block 6 relatively move in the front-rear, left-right directions, and the capillaries 4 are placed on the substrate 2 based on the standard length of the ultrasonic horn 10. The mounted IC component 14 is positioned above the electrode 16 to be connected. By this time, the electrode 16 is the substrate 2 and the IC
It is heated by the heat block 6 via the component 14. Then, the capillary 4 descends, and the tip of the wire 3 is fast-bonded to the electrode 16 by the heating and ultrasonic vibration. When this first bonding is completed, the capillary 4 is temporarily raised, the bonding head 1 and the heat block 6 are relatively moved in the front-rear, left-right direction, and based on the standard length of the ultrasonic horn 10,
It is positioned above the electrode portion 16a to be connected on the substrate 2. Then, the capillary 4 descends and the wire 3
The tip of the electrode is second-bonded to the electrode portion 16a by the heating and ultrasonic vibration. The above operation is performed by the electrode 16
The bonding is completed by repeating the number of combinations of the electrode and the electrode portion 16a.

[0005]

However, in the configuration of the above-mentioned conventional example, the ultrasonic horn 10 itself is heated by the convection of air and heat radiation from the heat block 6, and the length thereof expands and contracts. As in the conventional example, the bonding head 1 and the heat block 6 relatively move in the front-rear, left-right directions based on the standard length of the ultrasonic horn 10, and the capillaries 4 are connected to the electrodes 16 and electrode portions to be connected. If the positioning is performed above 16a, there is a problem that the positioning accuracy of the bonding is reduced by the amount of expansion and contraction due to the temperature of the ultrasonic horn 10.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and provide a wire bonding method and an apparatus therefor capable of performing highly accurate positioning without being affected by heat from a heat block for heating an object to be bonded. And

[0007]

In order to solve the above-mentioned problems, a wire bonding method according to the first invention of the present application is based on control data in which a position control section uses the length of an ultrasonic horn at a reference temperature as a reference. The capillary at the tip of the ultrasonic horn is moved forward, backward, leftward and rightward to be positioned at the bonding position, and the ultrasonic horn amplifies the ultrasonic vibration from the ultrasonic vibration oscillator and transmits it to the capillary to bond the wire. In the wire bonding method, the temperature detecting means is attached to the constituent member of the wire bonding apparatus which is in the vicinity of the ultrasonic horn and above the heat block similarly to the ultrasonic horn, and the temperature is detected, and the temperature is detected. The control data is supplemented based on the amount of elongation of the ultrasonic horn or the calculation result of the amount of elongation calculation formula set correspondingly. Characterized in that it.

In order to solve the above problems, the wire bonding apparatus of the second invention of the present application is an ultrasonic horn that amplifies ultrasonic vibration from an ultrasonic vibration oscillator and transmits it to a capillary, and an ultrasonic horn at a reference temperature. A wire bonding apparatus having a position controller for moving a capillary at the tip of the ultrasonic horn in the front-rear and left-right directions to position the bonding position based on control data based on the length of the ultrasonic horn. And the temperature detecting means for measuring the temperature of the constituent member of the wire bonding apparatus, which is near the heat block and above the heat block, and the extension amount of the ultrasonic horn corresponding to the detected temperature of the constituent member. An extension amount setting means for setting an extension amount of the ultrasonic horn based on the above, and the set ultrasonic horn And having a correction means for correcting the control data based on the elongation amount.

In order to solve the above problems, the wire bonding apparatus of the third invention of the present application is an ultrasonic horn that amplifies ultrasonic vibration from an ultrasonic vibration oscillator and transmits it to a capillary, and an ultrasonic horn at a reference temperature. A wire bonding apparatus having a position controller for moving a capillary at the tip of the ultrasonic horn in the front-rear and left-right directions to position the bonding position based on control data based on the length of the ultrasonic horn. And a correction means for correcting the control data on the basis of the detected extension amount of the ultrasonic horn.

[0010]

In the wire bonding method of the first invention of the present application and the wire bonding apparatus of the second invention of the present application, the temperature of the ultrasonic horn whose temperature cannot be directly measured is in the vicinity of the ultrasonic horn and the ultrasonic horn is used. Similarly, the temperature detection means is attached to the component of the wire bonding device above the heat block to detect the temperature, and the detected temperature and the extension amount of the ultrasonic horn preset corresponding to this detected temperature. The expansion amount of the ultrasonic horn is calculated from this relationship, and the capillary of the ultrasonic horn is positioned based on this expansion amount, so it is possible to correct the positioning error due to the expansion of the ultrasonic horn due to the temperature rise accompanying bonding. The bonding can be performed with high precision positioning.

In the wire bonding apparatus of the third invention of the present application, the extension amount detecting means detects the extension amount of the ultrasonic horn, and the correcting means positions the capillary of the ultrasonic horn based on the detected extension amount of the ultrasonic horn. Since the reference control data is corrected, it is possible to correct the positioning error due to the ultrasonic horn extending due to the temperature rise accompanying the bonding, and it is possible to perform the bonding with high precision positioning.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the present invention will be described with reference to FIGS.

In FIG. 1, the substrate 2 is placed and fixed on a heat block 6 having a heater 5. The substrate 2 has an IC
The component 14 is mounted, and the wire 16 is used to bond between the electrode 16 of the IC component 14 and the electrode portion 16a of the substrate 2 by the wire bonding apparatus of this embodiment. The bonding head 1 is an XY table 1 which is movable in XY directions.
It is placed on top of 8. In the bonding head 1,
A holder 9 that is vertically swingable around a fulcrum 9a is provided, and an ultrasonic horn 10 is attached to the holder 9. The wire 3 is attached to the tip of the ultrasonic horn 10.
A capillary 4 for bonding is attached, and an ultrasonic vibration oscillator 7 composed of a piezo element or the like is attached to the base side of the ultrasonic horn 10. The holder 9 swings up and down around the fulcrum 9a by the linear motor 11. The ultrasonic vibration oscillator 7 oscillates ultrasonic vibration by the high frequency from the high frequency oscillator 8, and the ultrasonic horn 10 amplifies this ultrasonic vibration and transmits it to the capillary 4 to connect the wire 3 to the electrode 16 and the electrode 16. Bonding to the electrode portion 16a.

Then, the position recognition camera 17 detects the positions of the electrode portion 16a of the substrate 2 and the electrode 16 of the IC component 14 to be bonded. To position the capillary 4 at the position of the electrode 16 or the electrode portion 16a, the position control unit 19
Moves the XY table 18 in the front-rear direction and in the left-right direction, and the capillary 4 is moved to the electrode
6 and the position of the electrode portion 16a.

A clamper 12, which is located immediately above the ultrasonic horn 10 and moves in synchronization with the ultrasonic horn 10, supplies the wire 3 to the capillary 4 and stops it. Since it is directly above the horn 10, like the ultrasonic horn 10, the temperature changes due to the influence of heat from the heat block 6. This temperature change is related to the temperature change of the ultrasonic horn 10, and Since the table or the calculation formula showing the relation between the temperature change of the clamper 12 and the temperature change of the ultrasonic horn 10 by the block 6 is created in advance and stored in the position control unit 19, the temperature change of the ultrasonic horn 10 is Although it cannot be directly measured due to the nature of the ultrasonic horn 10, the thermocouple 13 is used as a clamper 12.
The temperature of the clamper 12 is detected and the expansion amount setting means 20 of the position controller 19 estimates the temperature of the ultrasonic horn 10 from the detected temperature according to the above table or calculation formula.

Next, the operation of this embodiment will be described with reference to FIGS.

In order to perform the bonding with high accuracy of positioning according to this embodiment, the heat block 6 in FIG. 1 is used.
The substrate 2 is placed and fixed on the top. The positions of the electrode portion 16a of the substrate 2 and the electrode 16 of the IC component 14 to be bonded are positioned below the position recognition camera 17 by the XY table 18, and the positions X _C and Y of the electrode 16 and the electrode portion 16a are positioned.
Recognize _C. At this time, the IC component 14 is heated by the heat block 6, and when the wire 3 is a gold wire, it is heated to 350 ° C. which is higher than the recrystallization temperature of gold. 12 also rises in temperature. Therefore, the expansion due to the temperature rise of the ultrasonic horn 10 causes an error in the positioning of the capillary 4 with respect to the electrode 16 and the electrode portion 16a.

The operation of compensating for this positioning error is shown in FIG.
A description will be given based on the flowchart.

In the clamper temperature detecting step of step # 1 of FIG. 2, the temperature t of the clamper 12 is detected by the thermocouple 13, and the process proceeds to step # 2.

In the step of converting the horn temperature to step # 2, the expansion amount setting means 20 of the position control section 19 sets T =
The temperature t of the clamper 12 is calculated by the calculation formula of f (t).
Is converted to the temperature T of the ultrasonic horn 10, and step # 3
Proceed to.

In the horn elongation ΔL _H calculation step of step # 3, the expansion amount setting means 20 of the position controller 19 obtains the temperature change ΔT of the ultrasonic horn 10 from the temperature T, and the temperature change ΔT. use coefficient k _2, which is set in advance with respect to the horn elongation [Delta] L _H,
ΔL _H = k ₂ × ΔT is calculated, and the process proceeds to step # 4.

In the corrected camera offset ΔL _CH calculation step of step # 4, the expansion amount setting means 20 of the position control section 19 sets the horn expansion ΔL _H = k ₂ × ΔT
The corrected camera offset ΔL _CH is calculated by adding the offset amount ΔL _C between the center position of the position recognition camera 17 and the center position of the capillary 4, ΔL _CH = ΔL _C + Δ
The corrected camera offset Δ is calculated according to the calculation formula of L _H.
Obtain L _CH and proceed to step # 5.

In the step of recognizing the corrected bonding position (X, Y) in step # 5, the correction means 21 of the position control section 19 detects the positions X _C and Y of the electrode 16 and the electrode section 16a recognized by the position recognition camera 17. and _C, a camera offset [Delta] L _CHX corrected, in addition to [Delta] L _CHY, bonding position after correction for the electrode 16 and the electrode portion 16a (X, Y) formula to calculate the _{X = X C + ΔL CHX Y} = Y C The corrected bonding position (X, Y) is _obtained by + ΔL _CHY . As a result, the offset amounts X _C and Y _C based on the standard length of the ultrasonic horn 10 can be corrected to the offset amounts based on the actual length of the ultrasonic horn 10 after the temperature change. Ends. Then, the position control unit 19 moves the capillary 4 to the electrode 16 or the electrode unit 16 based on the position recognition of the position recognition camera 17.
Bonding position (X, Y) after the correction with respect to a
, And the process proceeds to step # 6.

In the bonding process of step # 6, bonding is performed and the process ends.

The operation of each part after step # 5 will be described with reference to FIG.

When the post-correction positioning of each electrode 16 and electrode portion 16a is completed, the linear motor 11
The holder 9 swings and the capillary 4 descends. One end of the wire 3 held by the capillary 4 is connected to the electrode 16
And simultaneously, the capillary 4 is ultrasonically vibrated by the ultrasonic horn 10 for bonding. After bonding, the capillary 4 is raised by a predetermined distance, and the position control unit 19 causes the electrode connected to the bonded electrode 16 based on the corrected bonding position (X, Y) with respect to the electrode 16 or the electrode unit 16a. The portion 16a is positioned below the capillary 4. The holder 9 is swung by the linear motor 11, the capillary 4 is lowered, and the wire 3 is bonded to the electrode portion 16a. After this bonding, the clamper 12 fixes the wire 3 while the capillary 4 is rising at a position where it is lifted by a certain distance,
Simultaneously with fixing, the wire 3 is cut. Then, a gold ball is formed at the tip of the wire 3 by a torch portion (not shown).

Thereafter, similarly, the electrode 16 and the electrode portion 16a to be connected are bonded by the wire 3.

Although the thermocouple 13 is attached to the clamper 12 in this embodiment, any component such as a torch may be used as long as it is a component near the ultrasonic horn 10 and above the heat block 6. .

A second embodiment of the present invention will be described with reference to FIGS. 3 and 4.

The second embodiment differs from the first embodiment in that
In the first embodiment, the temperature of the ultrasonic horn 10 is estimated from the temperatures of the parts in the vicinity of the ultrasonic horn 10, the temperature change amount of the length of the ultrasonic horn 10 is calculated, and the temperature of the ultrasonic horn 10 is calculated. Although the temperature of the length is corrected, in the second embodiment, the temperature change of the length of the ultrasonic horn 10 is directly measured.

In the second embodiment, a temperature change correction portion for positioning different from that of the first embodiment will be described with reference to FIGS. 3 and 4.

In the second embodiment, as shown in FIGS. 3 and 4, in addition to the position recognition camera 17 in the first embodiment, the center position of the capillary 4 is measured and measured by the elongation measuring camera 17a. From the center position and the reference position of the capillary 4, the capillary 4 is set to the electrode 16 and the electrode portion 16a.
Offset amount for temperature change when positioning to
L _CHX and ΔL _CHY are directly _calculated .

Except for the above differences, the second embodiment is the same as the first embodiment, and the description thereof will be omitted.

In the second embodiment, the position recognition camera 17
Separately, the elongation measuring camera 17a is used, but the position recognition camera 17 may also be used as the elongation measuring camera. Further, position measuring means such as laser displacement measuring means may be used instead of the camera.

[0035]

According to the wire bonding method and apparatus of the present invention, the temperature change amount of the length of the ultrasonic horn generated by the heat from the heat block can be corrected, so that the positioning accuracy of the bonding is improved. .

Further, the wire bonding method and the apparatus thereof according to the present invention have an effect that it is possible to perform narrow pitch bonding by improving the positioning accuracy of the bonding, and it is possible to downsize the electronic component.

[Brief description of drawings]

FIG. 1 is a side view showing a configuration of a wire bonding apparatus of a second invention of the present application using the wire bonding method of the first invention of the present application.

FIG. 2 is a flowchart showing the operation of the wire bonding method of the first invention of the present application.

FIG. 3 is a front view showing a main part of the wire bonding apparatus of the third invention of the present application.

FIG. 4 is a side view showing a main part of the wire bonding apparatus of the third invention of the present application.

FIG. 5 is a side view showing the configuration of a conventional wire bonding apparatus.

FIG. 6 is a perspective view showing an operation of wire bonding.

[Explanation of symbols]

 1 Bonding Head 2 Substrate 3 Wire 4 Capillary 5 Heater 6 Heat Block 7 Ultrasonic Vibration Oscillator 8 High Frequency Oscillator 9 Holder 9a Support Point 10 Ultrasonic Horn 11 Linear Motor 12 Clamper (Component) 13 Thermocouple (Temperature Detecting Device) 14 IC parts 16 Electrode 16a Electrode part 17 Position recognition camera 17a Expansion measurement camera (expansion detection means) 18 XY table 19 Position control part 20 Expansion amount setting means 21 Correction means

Claims (3)

[Claims] 1. A position controller moves a capillary at the tip of the ultrasonic horn in the front-rear and left-right directions to position it at a bonding position based on control data based on the length of the ultrasonic horn at a reference temperature. In a wire bonding method in which an ultrasonic horn amplifies ultrasonic vibration from an ultrasonic vibration oscillator and transmits the amplified ultrasonic vibration to a capillary to bond a wire, in the vicinity of the ultrasonic horn and in the same manner as the ultrasonic horn, a heat block Based on the calculation result of the extension amount or the extension amount calculation formula of the ultrasonic horn, which is set in advance in correspondence with the detected temperature, by attaching the temperature detecting means to the constituent member of the wire bonding device above A wire bonding method comprising: correcting the control data. 2. An ultrasonic horn that amplifies ultrasonic vibrations from an ultrasonic vibration oscillator and transmits the ultrasonic vibrations to a capillary, and the ultrasonic horn of the ultrasonic horn based on control data based on the length of the ultrasonic horn at a reference temperature. In a wire bonding apparatus having a position control unit for moving a capillary at the tip end in the front-rear and left-right directions to position it at a bonding position, it is in the vicinity of the ultrasonic horn and above the heat block like the ultrasonic horn. A temperature detecting means for measuring the temperature of a constituent member of the wire bonding device, and an extension amount setting means for setting the extension amount of the ultrasonic horn based on the relationship between the extension amount of the ultrasonic horn corresponding to the detected temperature of the constituent member. And a correction means for correcting the control data based on the set extension amount of the ultrasonic horn. Wire bonding equipment to collect. 3. An ultrasonic horn that amplifies ultrasonic vibrations from an ultrasonic vibration oscillator and transmits the ultrasonic vibrations to a capillary, and the ultrasonic horn of the ultrasonic horn based on control data based on the length of the ultrasonic horn at a reference temperature. In a wire bonding apparatus having a position control unit that moves a capillary at the tip end part in the front-rear and left-right directions to position it at a bonding position, an extension amount detecting means for measuring an extension amount of the ultrasonic horn, and the detected ultrasonic wave. A wire bonding apparatus comprising: a correction unit that corrects the control data based on the extension amount of the sound wave horn.