JPS6231131A - Wire bonding method - Google Patents

Abstract

PURPOSE:To securely bond a wire by a method wherein the pressurized state of a wire is altered in response to the floating state of a lead frame so as to produce a stable pressurized state of the wire for an electrode section and a lead terminal. CONSTITUTION:A CPU 55 detects the floating state of a IC led frame 22 with respect to a heating table 22 on the basis of the state of the ampltude of the signal of current fed to a monitoring circuit 65. Basing upon the floating state detected by the CPU 55, a pressure adjustment means 73 is activated so that the pressurizing load for a wire 42 is increased with driving adjustment of a linear motor 34, thereby decreasing the floating state of the frame 22 and providing the stable pressurized state of the wire 42 for the electrode section 25 and lead terminal 26. Thus,the wire bonding is performed in secured and syable state.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a wire bonding method.

[Conventional technology 1] Conventionally, for example, in manufacturing ICs, LSIs, etc., semiconductor pellets are attached to island parts of lead frames, and then the electrode parts of the semiconductor pellets and the lead terminals of the lead frames are wire-bonded using wires such as Au wires. It is done by doing. The wire-bonded lead frame is resin-sealed at the bonding portion, and the resin-sealed lead frame is cut into individual chips. As a result, a chip-shaped IC or LSI having a plurality of connection terminals is manufactured.

For wire bonding between the electrode portion and the lead terminal, a wire bonding apparatus disclosed in, for example, Japanese Patent Publication No. 19483/1983 is used. That is, in wire bonding using a wire bonding device, a wire supported by a bonding tool is pressed and crimped against the electrode portion of a pellet and the lead terminal of a lead frame placed on a table and to which the pellet is attached. , by connecting the electrode portion and the lead terminal with a wire.

By the way, when bonding the end of the wire to the electrode part or lead terminal, it is necessary to reliably crimp the end of the wire to the electrode part or lead terminal. Figure 8 (
A) to (C:) are cross-sectional views each showing the state of the wire end portion being crimped to the electrode portion of the pellet. this house,
FIG. 8(A) shows that the end of the wire 10 is attached to the heating table 1 by applying appropriate pressure by the bonding tool.
This is a state in which the pellet 13 is securely crimped onto the electrode portion 14 of the pellet 13 placed on the upper lead frame. On the other hand, if excessive pressure is applied by the bonding tool, as shown in FIG. There is a risk that the liquid may leak onto other parts, such as wiring patterns. Furthermore, if the bonding tool does not apply enough pressure, there is a risk that the end of the wire 10 may be poorly bonded to the electrode section 14, as shown in FIG. 8(C).

An example of a case where a bonding failure as shown in FIG. 8(C) occurs is when the lead frame floats up relative to the heating table 11. Possible causes of the floating of the lead frame include bending that occurs when the lead frame is die-cut, bending that occurs during transportation, etc.;
The entire lead frame is now floating above the heating table.

In other words, if floating occurs in the lead frame, the crimp force applied by the bonding tool may not be reliably transmitted from the end of the wire to the electrode or lead terminal, or heat transfer from the heating table may become poor. This results in poor bonding of the wire ends. As a result, in severe cases, the wires may come off, leading to a decrease in product yield and reliability.

[Problems to be Solved by the Invention] In order to solve the above-mentioned problems, conventionally, as shown in Japanese Patent Application Laid-open No. 59-227134, a lead frame is held down on a table by a holding plate, and thereby,
There is something that prevents the lead frame from floating.

However, it is difficult to prevent the lead frame from floating only by pressing the holding plate.・Despite the floating of the lead frame, it is necessary to ensure a reliable and stable crimped state of the wire end. It is desired to develop a wire bonding method.

An object of the present invention is to perform wire bonding reliably and stably.

[Means for Solving the Problems] In order to achieve the above object, the present invention connects a wire supported by a bonding tool to an electrode part of a pellet and a lead frame placed on a table and to which the pellet is attached. In the wire bonding method, in which the lead frame is pressed and crimped onto each of the lead terminals and the electrode portion and the lead terminal are connected by a wire, a means for detecting floating of the lead frame with respect to the table, and a means for detecting the floating of the lead frame with respect to the table, A crimp adjustment means is provided for adjusting the state of application of crimp force to the wire and the lead terminal.

[Operation] According to the present invention, since the state of applying crimping force to the wire is changed depending on the floating state of the lead frame, a stable state of crimping the wire to the electrode portion and the lead terminal can be obtained. This allows wire bonding to be performed reliably and stably.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing a wire bonding apparatus according to a first embodiment of the present invention, FIG. 2 is a perspective view showing a state in which wire bonding is performed by the wire bonding apparatus, and FIG.
The figure is the same plan view, Figure 4 is the main circuit diagram of Figure 1, Figure 5 (
A) is a state diagram showing the drive displacement state of the capillary as a bonding tool, FIG. 5(B) is a state diagram when bonding is performed normally, and FIG. 5(C) is a state diagram when the capillary is in an unloaded state. Waveform diagram showing each current waveform,
FIGS. 6(A) to 6(C) are diagrams showing the relationship between current waveforms, wire pressing, and load.

The wire bonding apparatus 20 sequentially supplies the IC lead frames 22 shown in FIG. 2 onto the upper surface of the heating table 21 so that the IC lead frames 22 can be placed thereon. The IC lead frame 22 to be mounted has an island portion 23 in the center thereof, and a substantially square semiconductor pellet 2 is placed in the island portion 23.
4 is installed. At the periphery of the semiconductor pellet 24,
A plurality of electrode sections 25 are provided, and the IC lead frame 22 is provided with a plurality of lead terminals 26 connectable to the electrode sections 25.

A heater 27 is housed inside the heating table 21, and the heater 27 heats the upper surface of the table 21. As a result, the IC lead frame 22 on the heating table 21 is heated by the heater 27.
The plurality of electrode parts 25 and lead terminals 26 are also heated in the same way. IC placed on heating table 21
The lead frame 22 has a frame-shaped holding plate 28 shown in FIG.
This causes the table to be pressed against the top surface of the table 21.
The semiconductor pellet 24 and each lead terminal 26 are placed inside the frame-shaped holding plate 28.

Above the heating table 21, a pumping device main body 2 is provided.
9 is disposed, and the device main body 29 is movable in the XY directions by driving the xY table 30. Device body 2
9 includes a support stand 31, and a tool lifter arm 32 is disposed on the support stand 31. The tool lifter arm 32 is driven by a linear motor 34 and supported so as to be swingable in the vertical direction [direction A] around a shaft portion 33 . This linear motor 34 is composed of an electromagnet 35 disposed on the device main body 29 and a movable ring 37 that is attached downward to the lower surface of the tool lifter arm 32 and swings vertically between the gap 36 of the electromagnet 35. has been done.

The tool arm 3 is located below the tool lifter arm 32.
8 is disposed, and a capillary 40 as a bonding tool is disposed at the tip of the tool arm 38 (which serves as a horn in this embodiment). capillary 4
0 allows a wire 42 made of an Au wire or the like wound around a spool 41 to be inserted through the wire 42, and feeds the wire 42 toward the tip end side. The base end side of the tool arm 38 is held by an arm holder 43, and the arm holder 43 is attached to the lower part of the tool lifter arm 32 via a leaf spring 44. Thereby, the tool arm 38 is also allowed to swing in the direction of arrow A as the tool lifter arm 32 swings.

One end of the arm holder 43 extends upward, and an initial tension adjustment device 45 is provided at the upper part.

This initial tension adjustment device 45 includes a tension mechanism 46 and a WR knot mechanism 47. Of these, the tension mechanism 46 is composed of a spring 49 provided between the arm holder 43 and a spring support 48 provided thereon. On the other hand, the adjustment mechanism 47 is disposed between the arm holder 43 and the spring support 48. This adjustment mechanism 47 is made by using a spring (not shown) to constantly bring the spherical tip of a threaded rod 50 into contact with the inside of the arm holder 43 and moving the nut 51 in the front and back direction. Arm 3
The initial tension of 8 is 'tA! i.

At the tip of the tool lifter arm 32.

A gap sensor 52 is disposed facing the tool arm 38. The gap sensor 52 is connected to the tool arm 3
8 can be detected at all times, and the gap detection circuit 53 can detect changes in the interval T1. That is, when the tool arm 38 is swung in the A direction and, for example, the tip of the capillary 40 comes into contact with the electrode section 25 or the lead terminal 26, the interval Tl is changed to a small value. Such a change in the interval T1 is caused by the gap detection circuit 5.
3 to the central processing unit 55 in the ponder control means 54 (
(hereinafter referred to as CPU 55).

On the other hand, the tool lifter arm 32 swings in the direction of arrow A around the shaft portion 33, so that its swing angle θ can be detected at all times by an encoder 56 disposed on the support base 31. The swing angle θ detected by the encoder 56 is output to a tool swing position detection circuit 57. The tool swing position detection circuit 57 is capable of constantly outputting the swing angle θ of the tool arm 38 to the CPU 55. The CPU 55 detects changes in the gap TI input from the gap detection circuit 53,
Based on the swing angle θ of the tool lifter arm 32 inputted from the tool swing position detection circuit 57, a drive control signal can be transmitted to the motor driver 58. That is,
The CPU 55 can control the amount of drive of the motor driver 58 by transmitting a drive control signal based on a predetermined amount of rocking. The linear motor 34 is a motor driver 58
As a result, the tool lifter arm 32 is swung to a predetermined position.

The tool lifter arm (horn) 38 having a capillary 40 attached to its tip is subjected to slight vibration in the direction of arrow Y by a transducer 60 as a vibrator, and the transducer 60 generates an output from an ultrasonic oscillator 61. The drive current P causes ultrasonic vibration in the direction of the arrow Y.

The ultrasonic oscillator 61 controls the CP in the ponder control means 54.
Its drive can be controlled by U55.

For example, based on the output command sent from the CPU 55, 8
Oscillation of 0KHz starts. The ultrasonic oscillator 61 amplifies the power of the 80KHz oscillation signal, and outputs the output transformer 62.
The transducer 60 is caused to vibrate slightly in the Y direction. A resistor 70 for detecting the flowing current is interposed on the secondary side of the output transformer 62, and the current is detected from the voltage drop across the resistor 70.

Note that the tool arm (horn) 38 and capillary 4
It has been found through experiments that the vibration amplitude at 0 is approximately proportional to the above-mentioned current.

The current flowing through the secondary circuit of the output transformer 62 is fed back to the CPU 55 via the monitoring circuit 65. That is, the current signal Q is first input to a monitoring circuit 65 shown in FIG. 4, and is rectified by a diode 66. The rectified current signal Q is output to an AD converter 69 via a resistor 67 and a capacitor 68. The current signal Q output to the AD converter 69 is in an integrated state. Further A
The current signal Q input to the D converter 69 is output to the CPU 55 in a digitized state. Note that 71 in the monitoring circuit 65 is grounded.

In the bonding operation by the wire bonding apparatus 20, first, the xY table drive control section 72 is operated based on a command from the CPU 55, and the XY table 30 is moved by a predetermined amount. This makes it possible to position the capillary 40 at the tip of the tool arm 38 above the corresponding electrode section 25. In this state, the CPU 55 then outputs a drive control signal to the motor driver 58. This results in
The linear motor 34 is driven, and the tool lifter arm 3
2 and the tool arm 38 will be swung downward. The swing state of the tool arm 38 is fed back from the tool swing position detection circuit 57 to the CPU 55. As the tool arm 38 swings downward, the tip of the capillary 4o comes into contact with the electrode section 25. This state is detected by the gap sensor 52. Then, the CPU 55 stops sending the drive signal to the motor driver 58, and the capillary 40 stops in a state where the tip end is in contact with the electrode section 25. At this time, the rocking stop position of the capillary 40 is set in advance by the crimp adjustment means 73. As a result, a prescribed pounding load is applied to the electrode section 25 by the tip of the capillary 40 whose swinging is stopped. That is, the prescribed pounding load is set by further swinging the tool lifter arm 32 after the capillary 40 contacts the electrode section 25 and controlling the amount of deformation of the spring 49.

As described above, the tip of the capillary 40 is connected to the electrode part 2.
5, the CPU 55 issues an output command to the ultrasonic oscillator 61.

Based on the output command, the ultrasonic oscillator 61 is capable of outputting a drive current P having a predetermined amplitude value set in advance by the ultrasonic output adjusting means 74. As a result, the tool arm 38 is slightly vibrated in the direction of arrow Y through the ultrasonic vibration of the transducer 60, and therefore the wire 42 held at the tip of the capillary 40 is also slightly vibrated in the direction of arrow Y. . When the wire 42 is slightly vibrated, the end of the wire 42 that is pressed against the electrode part 25 is rubbed and heated by the tension of the spring 49. Combined with the heating power of the heater 27, the end of the wire 42 melts. As a result, the tip of the wire 42 is crimped onto the predetermined electrode section 25.

When one end of the wire 42 is crimped to the electrode part 25, CP
In response to the command from U55, the drive current P output from the ultrasonic oscillator 61 is stopped. At the same time, the linear motor 34 is driven to swing the tool lifter arm 32 and the tool arm 38 upward. When the tool arm 38 is swung to a predetermined upper position, the CPU 5
5 operates the XY table drive control section 72, and the XY table 30 is moved by a predetermined amount in the XY directions. Thereby, the capillary 40 at the tip of the tool arm 38 is positioned above the corresponding lead terminal 26. In this state, the linear motor 34 is operated again based on a command from the CPU 55, and the tool lifter arm 32 and the tool arm 38 are swung downward. When the tip of the capillary 40 comes into contact with the lead terminal 26 due to the swinging of the tool arm 38, this state is transmitted from the gap detection circuit 53 to the CPU 55, and the CPU 55 stops the linear motor 34. In addition, capillary 40
The rocking stop position is set in advance by the crimping adjustment means 73 so that a prescribed pounding load can be applied in the same way as explained in connection with the pounding on the electrode section 25. For this purpose, an output command will be issued. The ultrasonic oscillator 61 is capable of outputting a drive current P having a predetermined amplitude value based on the output command. As a result, the tool arm 38 is slightly vibrated in the Y direction through the ultrasonic vibration of the transducer 60. Therefore, the wire 42 held by the capillary 40 is also slightly vibrated in the Y direction. When the wire 42 held by the capillary 40 is slightly vibrated, the tension of the spring 49 causes the wire 42 crimped to the lead terminal 26 to be rubbed against the lead terminal 26 . The wire 42 being rubbed is melted in combination with the heating power of the heater 27, thereby crimping the wire 42 to the lead terminal 26. In this state, the wire 42 held by the capillary 40 is cut at the crimped portion, and the wire 42
One end is crimped to the electrode portion 25 and the other end is crimped to the lead terminal 26.

In this way, when one electrode section 25 and the corresponding lead terminal 26 are wire-bonded, the output of the drive current P that was being output from the ultrasonic oscillator 61 is stopped according to a command from the CPU 55, and at the same time, the output of the drive current P that has been output from the ultrasonic oscillator 61 is stopped. By driving 34, the tool lifter arm 32 and tool arm 38 are swung to a predetermined upper position.

The process of wire bonding in one cycle is shown in FIG.
This is represented by the diagram shown in . In this figure, the tip of the capillary 40 is moved to the electrode portion 25 by the downward drive of the tool arm 38.
The time range in which the lead terminal 26 is contacted is represented by Bl, and the time range in which the lead terminal 26 is contacted is represented by B2. Further, the ultrasonic oscillation time regions corresponding to each time region B1 and B2 are represented by CI and C2 in FIG. 5(B), and the current signal when pounding is normally performed in the region The waveform of Q is shown in Figure 5 (B). On the other hand, when the cavity 40 is not in contact with the pellet 24, that is, under no load, the waveform shown in Figure 5 (C) is obtained. The comparison reveals that the waveform shown in FIG. 5(B) is attenuated in each of the time domains B1 and B2 compared to the waveform shown in FIG. 5(C), and that the waveform shown in FIG. In addition to B2, the amplitudes R1 and R2 of both waveforms and the corresponding amplitude S1
．． B2 and 1C may show the same value. This is because when the capillary 40 rubs the wire 42 against the electrode section 25 or the lead terminal 26 and crimps it, a load (mechanical restraining force) is applied to the tip of the capillary 40, and the tool arm (
This is because the resonance state of the horn 38 changes, and therefore both current and displacement become smaller.

Next, the lead terminal 26 of the IC lead frame 22
or the bottom of the lead frame 22 below the electrode section 25 is connected to the heating table 2 as shown in the 11th ifflZ section.
The case where it is floating relative to 1 will be explained. If the IC lead frame 22 is lifted up as described above, a current signal close to the no-load waveform shown in FIG. 5(C) is input to the monitoring circuit 65 when bonding is performed. That will happen. This is because when crimping the wire 42 to the electrode section 25 and lead terminal 26,
This is due to the above-mentioned lifting occurring in the C lead frame 22, and is due to the low load resistance during crimping.

That is, during crimping, the ultrasonic vibration energy output based on the drive current P is not attenuated because the load resistance of the electrode portion 25 or the lead terminal 26 is small. Therefore, if wire bonding is performed in this state, the wire 42 will be crimped incorrectly.

For this reason, when the amplitude of the current signal Q input to the monitoring circuit 65 is equal to or above a certain value close to the amplitude S1.32 when the capillary 40 is in an unloaded state, the CPU 55 It is determined that the lead frame 22 is floating, and the ponder control means 54
A control signal U is transmitted to the crimp adjustment means 73 of. The crimp adjustment means 73 adjusts the state of the crimp force applied by the tip of the capillary 40 based on the input control signal U.

At this time, the floating state of the IC lead frame 22 relative to the heating table 21 is determined by detecting the amplitude value of the current signal Q input to the monitoring circuit 65, and this detection is performed in the time domain B1 and B2. my first 5
It is detected at the time of ms. That is, the input waveform of the current signal Q shown in FIG. 6(A) is rectified by the diode 66 of the monitoring circuit 65, and further passes through the resistor 67 and capacitor 68, so that it is represented by the integral value shown in FIG. 6(CB). That will happen. When this integral value exceeds a certain slice level D, these states are outputted to the CPU 55 of the ponder control means 54 via the AD converter 69, and the CPU 5
5 detects the floating state of the IC lead frame 22. In this way, the detected floating condition is
It is output from the CPU 55 to the crimp adjustment means 73. The crimp adjustment means 73 is capable of transmitting a predetermined drive signal to the motor driver 58 depending on the detected floating state. As a result, the motor driver 58 adjusts the drive amount of the near motor 34 based on the drive signal, and the tool arm 38 is swung further downward to the swing stop position. Therefore, when the wire 42 is pressed against the electrode portion 25 or the lead terminal 26, the load is increased as shown in FIG. 6(C). When the load increases, the pressing of the wire 42 by the capillary 40 causes an increase in I on the heating table 21.
The floating state of the C lead frame 22 is eliminated. As a result, the integral value corresponding to the area to which the load G shown in FIG. 6(C) is applied becomes the slice level D as shown in FIG. 6(B).
The following conditions will occur. Also, Figure 5 CD) and 6
The current signal Q shown in Figure (A) also exhibits the same amplitude state as the normal current signal shown in Figure 5 (CB). Therefore, an appropriate frictional state is obtained between the wire 42 and the electrode portion 25 or the lead terminal 26, and the wire 42
2 will be securely crimped to each part.

Next, the operation of the above embodiment will be explained.

According to the wire bonding apparatus 20 according to the above embodiment, the floating state of the IC lead frame 22 with respect to the heating table 21 is detected by the CPU 55 based on the amplitude state of the current signal Q input to the monitoring circuit 65. becomes. As a result, based on the detection of the floating state by the CPU 55, the crimp adjustment means 73 is operated, and the drive adjustment of the linear motor 34 increases the pressing load of the wire 42. Therefore, the floating state of the IC lead frame 22 is reduced, and a stable state of crimping of the wire 42 to the electrode portion 25 and the lead terminal 26 can be obtained. This allows wire bonding to be performed reliably and stably.

FIG. 7 shows a wire bonding apparatus according to another embodiment of the present invention. The wire bonding apparatus 20 according to the embodiment is a thermo-ultrasonic vibration combination method that thermocompresses the wire 42 through the ultrasonic vibration outputted by the ultrasonic oscillator 61 and heating by the heater 27. In contrast, the wire bonding apparatus 80 according to the present embodiment has a heater 2
This relates to the thermocompression bonding method according to No. 7. That is, this wire bonding apparatus 80 heats the upper surface of the heating table 21 with the heater 27, and heats the IC lead frame 22 supplied to the upper surface of the heating table 21.

The pumping device main body 29 above the heating table 21 is
Based on commands from the XY table drive control unit 72, the XY table 30 can be vibrated slightly in the Y direction by approximately ±10 g. As a result, the capillary 40 attached to the tip of the tool arm 38 is also slightly vibrated in the Y direction.

Bonding by the wire bonding device 80 is first performed by the XY table drive control section 72 according to a command from the CPU 55.
Activate. The XY table 30 is moved in the XY directions according to a command from the control section 72, and first the capillary 40 is positioned above the corresponding electrode section 25. In this state, a drive signal is output to the motor driver 58 based on a command from the CPU 55. As a result, the linear motor 34 is activated, and the tool arm 38 is swung downward.

When the tool arm 38 is swung downward and the tip of the capillary 40 comes into contact with the electrode section 25, a prescribed pounding load is applied to the electrode section 25 from the tip of the wire 42 held by the capillary 40. It will be. Thereby, the tip of the wire 42 held by the capillary 40 is brought into pressure contact with the electrode section 25 heated by the heater 27. The tip of the wire 42 that is pressed is melted by coming into contact with the heated electrode section 25. In this state, the XY table drive control section 72 is activated by a command from the CPU 55, and the XY table drive control section 72 slightly vibrates the XY table 30 in the Y direction (so-called scrubbing).

As a result, the tip of the wire 42 to be melted is transferred to the electrode portion 25.
The tip of the wire 42 is scrubbed between the electrode part 2 and
5 will be crimped.

When one end of the wire 42 is crimped to the electrode part 25, CP
The tool arm 38 is raised by the command from U55, and the XY table 30 is then moved in the XY directions. The XY table 30 is moved while the capillary 40 is positioned above the corresponding lead terminal 26. When the capillary 40 is positioned above the corresponding lead terminal 26, the tool arm 38 is again swung downward by a command from the CPU 55. As a result, the tip of the capillary 40 comes into contact with the lead terminal 26. When the tip of the capillary 40 comes into contact with the corresponding lead terminal 26, the wire 42 held by the capillary 40
is pressed against the lead terminal 26 with a specified pounding load. The wire 42 to be pressure-welded is melted by contacting the heated lead terminal 26, and in this state C
The PU 55 will issue a command to the XY table drive control section 72. The XY table drive control section 72 is activated by the command, and causes the XY table 30 to vibrate slightly in the Y direction. As a result, the wire 42 to be melted is scrubbed with the lead terminal 26, and the wire 42 is crimped to the lead terminal 26. In this state, the wire 42 held by the capillary 40 is cut at the crimped portion, and one end of the wire 42 is crimped to the electrode portion 25 and the other end to the lead terminal 26.

The wire bonding device 80 as described in 1.
Perform cycle wire bonding.

Corresponding electrode portions 25 and lead terminals 26 are crimped in sequence. In this way, when wire bonding is performed using the thermocompression bonding method, the IC lead frame 22
If the IC lead frame 22 floats above the heating table 21 as shown in section W in FIG. 9, the IC lead frame 22 will not be heated sufficiently. In addition, the lead frame 22
If floating occurs in the wire 4, the pounding load or scrubbing force by the spring 49 will not be transmitted sufficiently.
2 and the corresponding electrode portion 25 or lead terminal 26 will result in poor crimping.

For this reason, the wire bonding apparatus 80 is equipped with a detection camera 81 as means for detecting floating of the IC lead frame 22. This detection camera 81 is supported by the holding plate 28 and is configured to irradiate an infrared signal between the upper surface of the heating table 21 and the IC lead frame 22. As a result, the fifth detection camera 81 detects the heating table 2.
The floating state of the IC lead frame 22 relative to 1 can be detected. The floating state detected by the detection camera 81 is input to the CPU 55, and the CPU 55 is capable of outputting an operation signal to the XY table drive control section 72 as scrub amount adjustment means based on the floating state. That is, the XY table drive control unit 72 controls the number of scrubs according to each floating state based on the input operation signal.
The scrubbing time can be adjusted, and the scrubbing frequency and scrubbing time can be adjusted to increase as the floating becomes larger. As a result, even if the IC lead frame 22 floats relative to the heating table 21, the amount of scrubbing can be adjusted as described above to properly maintain the distance between the wire 42 and the electrode section 25 or lead terminal 26. This results in a frictional state that allows wire bonding to be performed in a stable state. Furthermore, the wire bonding apparatus 80 transmits a control signal U to the crimp adjustment means 73 based on the detected floating state, and
3, it is also possible to increase the load by pressing the capillary. The other configurations and operations are the same as those of the previous embodiment.

In each of the above embodiments, the bonding load is applied by the spring 49, but the wire bonding load may be applied directly to the tool arm 38 using a 7-cut unit or the like. Furthermore, the floating state of the lead frame 22 can also be determined by measuring the temperature difference of the lead frame 22 and detecting a point of low temperature.

[Effects of the Invention] As described above, the present invention presses and crimps a wire supported by a bonding tool against each of the electrode portion of a pellet and the lead terminal of a lead frame placed on a table and to which the pellet is attached. In the wire bonding method in which the electrode part, the lead terminal, and the bonding part are connected by a wire, means for detecting floating of the lead frame with respect to the table, and means for detecting floating of the lead frame with respect to the table, and a means for detecting floating of the lead frame with respect to the table, and Since a crimping adjustment means is provided for adjusting the state of application of crimping force to the wire, there is an effect that wire bonding can be performed reliably and stably.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing a wire bonding apparatus according to a first embodiment of the present invention, FIG. 2 is a perspective view showing a state in which wire bonding is performed by the wire bonding apparatus, and FIG.
The figure is the same plan view, Figure 4 is the main circuit diagram of Figure 1, Figure 5 (
A) is a state diagram showing the drive displacement state of the capillary as a bonding tool, FIG. 5(B) is a state diagram when bonding is performed normally, and FIG. 5(C) is a state diagram when the capillary is in an unloaded state. Waveform diagram showing each current waveform,
6(A) to 6(C) are diagrams showing the relationship between current waveforms and wire pressing and load; FIG. 7 is a sectional view showing a wire bonding apparatus according to another embodiment of the present invention; FIG. 8 (A),
CB) and (C) are cross-sectional views showing the state in which the wire end portion is crimped to the pellet electrode portion. 20.80...Wire bonding device, 21...
Heating table, 22... IC lead frame, 24... Semiconductor pellet, 25... Electrode part, 26... Lead terminal, 38... Tool arm, 40... Capillary [bonding tool], 42・
... Wire, 54 ... Ponder control means, 55 ... CPU, 61 ... Ultrasonic oscillator, 65 ... Monitoring circuit, 72 ... XY table drive control section, 73 ... Crimping adjustment means , 74... Ultrasonic output adjustment means, 81... Detection camera. Agent Patent Attorney Osamu Shiokawa Figure 2 Figure 3 Figure 4 Figure 6'1ffi Time (TrLS)

Claims (3)

[Claims] (1) The wire supported by the bonding tool is pressed and crimped against the electrode part of the pellet and the lead terminal of the lead frame placed on the table and to which the pellet is attached, and the wire is crimped between the electrode part and the lead terminal. In a wire bonding method in which a lead frame is connected with a wire, a means for detecting floating of a lead frame with respect to a table, and a crimp adjustment means for adjusting a state of application of crimp force of the wire to an electrode part and a lead terminal according to the floating state. Equipped with wire bonding method. (2) The wire bonding method according to claim 1, wherein the crimp adjustment means is a wire end pressing load adjustment means. (3) The wire bonding method according to claim 1, wherein the crimp adjustment means is a scrub amount adjustment means for the end portion of the wire.