TWI802991B - Ultrasonic vibration type defect detection device and wire defect detection system - Google Patents

Abstract

The invention provides an ultrasonic vibration type defect detection device and a wire defect detection system. The ultrasonic vibration type defect detection device (100) for detecting defects of a semiconductor device (10) includes: an ultrasonic vibrator (42); a high frequency power supply (40) ); camera (45); and control unit (50), adjust the frequency of the high-frequency power supplied to the ultrasonic vibrator (42) from the high-frequency power supply (40), and carry out defective detection and control of the semiconductor device (10) The part (50) changes the frequency of the high-frequency power supplied from the high-frequency power supply (40) to the ultrasonic vibrator (42), and takes an image of the semiconductor device (10) with the camera (45) on the one hand, and based on The captured image is used to detect the defect of the semiconductor device (10).

Description

Ultrasonic vibration type defect detection device and wire defect detection system system

The present invention relates to a structure of an ultrasonic vibration type defect detection device, which detects defects of the object to be inspected by ultrasonically vibrating the object to be inspected.

A wire bonding device that connects electrodes of a substrate and electrodes of a semiconductor wafer with wires is widely used. In the wire bonding apparatus, the following method can be used, that is, by electrical means such as flowing current between the wire rod and the semiconductor chip, the detection of poor connection between the electrode of the semiconductor chip and the wire rod is carried out (for example, refer to Patent Document 1 ).

In addition, in the wire bonding device, the following method can be used, that is, by detecting the displacement of the ceramic nozzle in the Z direction until the end of the bonding, the poor connection between the electrode of the semiconductor chip and the wire is detected. Detection (for example, refer to Patent Document 2).

[Prior Art Literature]

[Patent Document]

Patent Document 1: Japanese Patent Laid-Open No. 9-213752

Patent Document 2: Japanese Patent Laid-Open No. 2010-56106

In addition, in recent years, it is required to increase the accuracy of defect detection of inspection objects such as wire rods. However, in the failure detections described in Patent Document 1 and Patent Document 2 by electrical means or mechanical means, false detections may occur in some cases.

In addition, it is required to perform defect detection of all the wires connecting the electrodes of the semiconductor wafer and the electrodes of the substrate. However, the defect detection methods described in Patent Document 1 and Patent Document 2 perform defect detection for each wire, so for example, for a semiconductor chip with more than a hundred wires connecting a semiconductor chip to a substrate, inspection takes a long time. And other issues.

Therefore, an object of the present invention is to perform defect detection of an inspection object with high accuracy and in a short time.

The ultrasonic vibration type defect detection device of the present invention detects the defect of the object to be inspected, and is characterized in that it includes: an ultrasonic vibrator that causes the object to be inspected to vibrate ultrasonically; a power supply that supplies high-frequency power to the ultrasonic vibrator; an imaging device , taking pictures of the object to be inspected by ultrasonic vibration; The frequency of the high-frequency power supplied by the sonic vibrator changes, while an image of the object to be inspected is captured by an imaging device, and defect detection of the object to be inspected is performed based on the captured image.

In this way, the frequency of the high-frequency power supplied from the power supply to the ultrasonic vibrator is changed, so that the inspection object can be ultrasonically vibrated at various frequencies, and high-precision Highly detect defects in inspection objects.

In the ultrasonic vibration type defect detection device of the present invention, the object to be inspected may also include an object part that becomes the object of defect detection and a non-object part that does not become the object of defect detection. When the frequency of the high-frequency power supplied by the vibrator is changed, the ratio of the amplitude of the target part detected from the image captured by the imaging device to the amplitude of the non-target part detected from the image captured by the imaging device becomes more than a predetermined value In this way, the voltage of the high-frequency power supplied from the power supply to the ultrasonic vibrator is adjusted.

Thereby, when the object to be inspected is subjected to ultrasonic vibration, the amplitude of the object portion becomes larger than the amplitude of the non-object portion, and a defect in the object portion of the object to be inspected can be detected with high precision.

In the ultrasonic vibration type defect detection device of the present invention, it may also include: a current sensor for detecting the current of the high-frequency power supplied from the power supply to the ultrasonic vibrator, and the control unit controls the power supply to the ultrasonic vibrator from the power supply. When the frequency of the high-frequency power changes, the voltage of the high-frequency power supplied from the power supply to the ultrasonic vibrator is adjusted so that the current detected by the current sensor falls within a predetermined range.

An ultrasonic vibrator has its own frequency at which it resonates. Therefore, if the high-frequency power of the resonance frequency is input to the ultrasonic vibrator during ultrasonic vibration, the impedance (impedance) of the ultrasonic vibrator will be reduced by resonance, the amplitude of the ultrasonic vibrator will become larger, and the inspection object will be larger overall. vibrating in magnitude. As a result, the amplitude of the target portion may be masked by the amplitude of the non-target portion, making it impossible to detect. The amplitude of the ultrasonic vibrator is proportional to the current of the high-frequency power input to the ultrasonic vibrator, so by using the electric The flow sensor detects the current of the high-frequency power input to the ultrasonic vibrator, and adjusts the voltage of the high-frequency power so that the detected current falls within a predetermined range, so that the current of the high-frequency power can be set to a predetermined value. The amplitude of the ultrasonic vibrator is set within a predetermined range. This prevents the entire inspection object from vibrating greatly when the inspection object is vibrated with ultrasonic waves, and the amplitude of the object portion is masked by the amplitude of the non-object portion, making it impossible to detect, and the object of the inspection object can be detected with high accuracy. Department of bad.

In the ultrasonic vibration type defect detection device of the present invention, the control unit may also include a map (map), which is predetermined in such a manner that the current of the high-frequency power supplied from the power supply to the ultrasonic vibrator falls within a predetermined range. The change of the voltage of the high-frequency power supplied from the power supply to the ultrasonic vibrator relative to the frequency of the high-frequency power supplied from the power supply to the ultrasonic vibrator is to change the frequency of the high-frequency power supplied from the power supply to the ultrasonic vibrator , the voltage of the high-frequency power supplied from the power supply to the ultrasonic vibrator is adjusted based on the map.

Thereby, it is not necessary to adjust the voltage of the high-frequency power according to the feedback of the current detected by the current sensor, and it is possible to suppress the overall large vibration of the inspection object when the inspection object is subjected to ultrasonic vibration with a simple structure, and the object If the amplitude of the part is masked by the amplitude of the non-target part and cannot be detected, it is possible to detect a defect in the target part of the inspection object with high precision.

In the ultrasonic vibration type defect detection device of the present invention, the object to be inspected may also be a semiconductor device, and the semiconductor device includes: a substrate; a semiconductor element mounted on the substrate; and a wire connecting the electrodes of the semiconductor element to the electrodes of the substrate, Alternatively, one electrode of the semiconductor element is connected to the other electrode of the semiconductor element, and when the control unit changes the frequency of the high-frequency power supplied from the power supply to the ultrasonic vibrator, the frequency of the wire detected by the image captured by the imaging device is changed. The voltage of the high-frequency power supplied from the power source to the ultrasonic vibrator is adjusted so that the ratio of the amplitude to the amplitude of the substrate and the semiconductor element detected from the image captured by the imaging device becomes more than a predetermined value.

Thereby, when the substrate and the semiconductor element are ultrasonically vibrated, the amplitude of the wire becomes larger than that of the substrate or the semiconductor element, and it is possible to detect a defect in the target portion of the inspection target with high precision.

In the ultrasonic vibration type defect detection device of the present invention, the control unit may adjust the voltage of the high-frequency power supplied from the power source to the ultrasonic vibrator so that the amplitude of the detected wire rod exceeds a predetermined upper limit amplitude.

Thereby, excessive vibration of the wire rod when the semiconductor device is subjected to ultrasonic vibration can be suppressed.

In the ultrasonic vibration type defect detection device of the present invention, the control unit can also change the frequency of the high-frequency power supplied from the power supply to the ultrasonic vibrator, and use the imaging device to capture the video of the semiconductor device, and calculate the frequency of the semiconductor device. When the difference between one frame of the captured animation and the image of the wire in the previous previous frame exceeds a predetermined threshold value, a bad detection signal of the wire is output.

Thereby, the defect detection of a wire rod can be performed based on the amplitude of a wire rod.

In the ultrasonic vibration type defect detection device of the present invention, the control unit can also change the number of frames between one frame and the previous frame for calculating the difference, or the frame rate of the animation. Calculate the difference.

Thereby, even when the frequency of the wire rod changes, the difference in the image of the wire rod can be detected, and the detection accuracy of the defect can be improved.

In the ultrasonic vibration type defect detection device of the present invention, the ultrasonic vibrator may also be an ultrasonic vibrator connected to the object to be inspected to cause the object to be inspected to vibrate ultrasonically, or an ultrasonic vibrator arranged around the object to be inspected. trumpet.

Thereby, it is possible to detect a defect of the inspection object with a simple configuration.

The wire defect detection system of the present invention detects a defect of a wire of a semiconductor device comprising: a substrate; a semiconductor element mounted on the substrate; and a wire connecting an electrode of the semiconductor element to an electrode of the substrate, or connecting one of the semiconductor elements The electrode is connected to another electrode of the semiconductor element, and the wire defect detection system is characterized in that it includes: an ultrasonic vibrator, which makes the semiconductor device perform ultrasonic vibration; a power supply, which supplies high-frequency power to the ultrasonic vibrator; an imaging device, The semiconductor device vibrated by ultrasonic waves is photographed; the monitor displays the image captured by the imaging device; and the control unit adjusts the frequency of the high-frequency power supplied from the power supply to the ultrasonic vibrator and performs faulty inspection of the wire rod on the one hand. Detection, and the control part changes the frequency of the high-frequency power supplied from the power supply to the ultrasonic vibrator on the one hand, and uses the imaging device to shoot the animation of the semiconductor device on the one hand, and calculates a frame of the animation taken and the preceding information. When the difference of the image of the frame exceeds a predetermined threshold value, the displayed image of the wire is displayed on the display differently from the displayed images of other wires.

In this way, when the difference exceeds a predetermined threshold value, the displayed image of the wire is made different from the displayed images of other wires, so that the defect of the wire can be easily detected through the display on the display.

The present invention can perform defect detection of an inspection object with high precision and in a short time.

10: Semiconductor device

11: Substrate

12, 25~28: electrode

20: Semiconductor components

21~24: Semiconductor wafer

30, 30a, 31~34: wire rod

30b: bad wire

31a, 31b: first-order wire rod

32a, 32b: the second-order wire

33a, 33b: third-order wire

34a, 34b: fourth-order wire

35, 36: beyond the area

39a, 39b: center line

40: High frequency power supply

42:Ultrasonic vibrator

43: Ultrasonic horn

45: camera

48: display

50: Control Department

51: CPU (central processing unit)

52: Memory

53: Voltage sensor

54: Current sensor

55, 56: Mapping

100: Ultrasonic vibration type defect detection device

200: Wire defect detection system

a: dotted line

b0, d1, d2, d3: solid line

c0, c1, c2, c2: one point chain line

f1, f2: frequency

f3: maximum frequency

L: Interval

S101~S107, S201, S202: steps

△da, △db: difference

△S:Threshold value

FIG. 1 is a system diagram showing the configuration of an ultrasonic vibration type defect detection device according to an embodiment.

FIG. 2 is a view showing an image of a semiconductor device captured by a camera of the ultrasonic vibration type defect detection device shown in FIG. 1 from above.

3 shows changes in the impedance of the ultrasonic vibrator and changes in the current of the high-frequency power with respect to the frequency of the high-frequency power when the voltage of the high-frequency power supplied to the ultrasonic vibrator in the prior art is constant. diagram.

Fig. 4 is a diagram showing a state where the voltage of the high-frequency power supplied to the ultrasonic vibrator is changed so that the current detected by the current sensor becomes constant in the ultrasonic vibration-type defect detection device according to the embodiment. A diagram of changes in voltage and changes in current of electric power.

Fig. 5 is a flowchart showing the operation of the ultrasonic vibration type defect detection device shown in Fig. 1 .

Fig. 6 is an enlarged plan view of part A of Fig. 2 when the substrate is subjected to ultrasonic vibration and the enlarged plan view of part B shown in FIG. 6 .

Fig. 7 is a diagram showing a change in the voltage of the high-frequency power with respect to the frequency of the high-frequency power predetermined in such a way that the current of the high-frequency power supplied to the ultrasonic vibrator is constant in the ultrasonic vibration type defect detection device according to the embodiment. map of the map.

FIG. 8 is a graph showing the voltage of the high-frequency power relative to the high-frequency power of the predetermined range so that the current of the high-frequency power supplied to the ultrasonic vibrator is within a predetermined range in the ultrasonic vibration type defect detection device according to the embodiment. A graph of another map of the change in frequency.

Fig. 9 is a system diagram showing the configuration of a wire rod defect detection system according to the embodiment.

Fig. 10 is a flowchart showing the operation of the wire rod defect detection system shown in Fig. 9 .

Fig. 11 is a plan view showing an excess region when the substrate is subjected to ultrasonic vibration.

Hereinafter, the ultrasonic vibration type defect detection device 100 according to the embodiment will be described with reference to the drawings. In the following description, it is assumed that the ultrasonic vibration type defect detection device 100 performs defect detection of the wire rod 30 of the semiconductor device 10 as an inspection object, but it can also be used for defect detection of other inspection objects.

As shown in FIG. 1 , an ultrasonic vibration-type defect detection device 100 includes an ultrasonic vibrator 42 as an ultrasonic vibrator, a high-frequency power supply 40 , a camera 45 as an imaging device, and a control unit 50 .

As shown in Figure 1, the semiconductor device 10 that becomes the inspection object of the ultrasonic vibration type defect detection device 100 has semiconductor chips 21 to 24 stacked in four steps on a substrate 11, and each semiconductor chip 21 is connected with a wire 30. ~24 The electrodes 25 to 28 are continuously connected to the electrode 12 of the substrate 11 . Here, the semiconductor wafer 21 to the semiconductor wafer 24 constitute the semiconductor element 20 . A wire 30 includes: a first-level wire 31 connecting the electrode 25 of the first-level semiconductor chip 21 to the electrode 12 of the substrate 11; and a second-level wire 32 to a fourth-level wire 34 connecting the second-level to the The electrodes 26 to 28 of the semiconductor chips 22 to 24 of the fourth stage are connected to the electrodes 25 to 27 of the semiconductor chips 21 to 23 of the first to third stages, respectively. The substrate 11 and the semiconductor wafers 21 to 24 of the semiconductor device 10 constitute non-target parts that are not subject to defect detection, and the wire rod 30 constitutes a target part for defect detection.

The high-frequency power supply 40 outputs AC power at a frequency in the ultrasonic region, and causes the ultrasonic vibrator 42 to vibrate ultrasonically. The ultrasonic vibrator 42 is a member that is driven by high-frequency power in the ultrasonic frequency range input from the high-frequency power source 40 to vibrate ultrasonically. For example, piezoelectric elements and the like may be included. The ultrasonic vibrator 42 is connected to the substrate 11 of the semiconductor device 10 and causes the substrate 11 to vibrate ultrasonically.

Between the high-frequency power source 40 and the ultrasonic vibrator 42, a voltage sensor 53 for detecting the voltage of the high-frequency power supplied from the high-frequency power source 40 to the ultrasonic vibrator 42 and a current sensor for detecting the current of the high-frequency power are installed. Detector 54.

The camera 45 is disposed on the upper side of the semiconductor device 10, and as shown in FIG. 28. The electrodes 12 of the substrate 11 disposed around the semiconductor wafer 21 of the first stage, and the wires 30 continuously connecting the electrodes 12, 25 to 28.

The control unit 50 includes a central processing unit (Central Processing Unit, CPU) 51 and memory 52 components (component). The high-frequency power supply 40 is connected to the control unit 50 , and operates according to an instruction from the control unit 50 . The camera 45 is connected to the control unit 50 and operates in accordance with an instruction from the control unit 50 . The video imaged by the camera 45 is input to the control unit 50 . The voltage sensor 53 and the current sensor 54 are connected to the control unit 50 , and the voltage and current data of the high-frequency power detected by the voltage sensor 53 and the current sensor 54 are input to the control unit 50 . The control unit 50 changes the frequency of the high-frequency power supplied from the high-frequency power supply 40 to the ultrasonic vibrator 42, and captures an image of the semiconductor device 10 captured by the camera 45, and based on the captured image, Defect inspection of the semiconductor device 10 is performed.

Next, referring to FIG. 3 on the one hand, the impedance and current with respect to the frequency f when the voltage V0 of the high-frequency power supplied from the high-frequency power supply 40 to the ultrasonic vibrator 42 is set constant as in the prior art on the one hand. The change of A0 will be explained.

Like the one-dot chain line c0 shown in Figure 3, if the voltage V0 of the high-frequency power supplied from the high-frequency power supply 40 to the ultrasonic vibrator 42 is set constant, and the frequency f of the high-frequency power is changed, the ultrasonic vibrator 42 itself resonates at frequency f1. As a result, the impedance of the ultrasonic vibrator 42 is greatly reduced at the frequency f1 as shown by the dotted line a in FIG. 3 . On the other hand, at the frequency f2 between the frequency f1 and the maximum frequency f3, the impedance of the ultrasonic vibrator 42 increases significantly.

If the impedance of the ultrasonic vibrator 42 is greatly reduced near the frequency f1 as shown by the dotted line a in FIG. 3 , as shown by the solid line b0 in FIG. The current A0 rises substantially. Conversely, if the impedance of the ultrasonic vibrator 42 rises substantially in the vicinity of the frequency f2, the ultrasonic The current A0 of the high-frequency power supplied by the vibrator 42 is greatly reduced. The magnitude of the current A0 supplied to the ultrasonic vibrator 42 is proportional to the amplitude of the ultrasonic vibrator 42 . Therefore, in the vicinity of the frequency f1 of the resonance of the ultrasonic vibrator 42, the amplitude of the ultrasonic vibrator 42 is greatly increased and the amplitude of the substrate 11 is greatly increased, and in the vicinity of the frequency f2, the amplitude of the ultrasonic vibrator 42 is greatly reduced and the substrate 11 The amplitude of 11 is greatly reduced.

Therefore, when the frequency f1 of the ultrasonic vibrator 42 resonates, the substrate 11, the semiconductor chip 21~semiconductor chip 24, and the wire rod 30 all vibrate greatly, so sometimes the amplitude of the wire rod 30 is controlled by the substrate 11 and the semiconductor chip 21~semiconductor chip 24. Amplitudes are obscured and difficult to detect.

On the contrary, at the frequency f2, the amplitude of the substrate 11, the semiconductor chips 21-24, and the wire 30 becomes very small, and sometimes the amplitude of the wire 30 cannot be detected.

As described above, when the voltage V0 supplied from the high-frequency power supply 40 to the ultrasonic vibrator 42 is set constant and the frequency is changed as in the prior art, it may be difficult to obtain a frequency near the frequency f1 at which the ultrasonic vibrator 42 resonates. The amplitude of the wire 30 is detected.

Therefore, in the ultrasonic vibration type defect detection device 100 of the embodiment, focusing on the fact that the amplitude of the ultrasonic vibrator 42 is proportional to the current of the high-frequency power input to the ultrasonic vibrator, the current sensor 54 detects the current input to the ultrasonic vibrator. The current A1 of the high-frequency power of the sonic vibrator 42 is adjusted so that the detected current A1 falls within a predetermined range and the voltage V1 of the high-frequency power is adjusted. Thereby, the current A1 of the high-frequency power can be set within a predetermined range, and the amplitude of the ultrasonic vibrator 42 can be set within a predetermined range. Furthermore, the semiconductor device 10 is ultrasonically vibrated by changing the frequency of the high-frequency power. , it is possible to suppress the situation that the amplitude of the substrate 11 or the semiconductor element 20, which is the non-target portion of detection, vibrates greatly at a specific frequency, and the amplitude of the wire rod 30, which is the detection target portion, is suppressed by the substrate 11 or the semiconductor element 20. An amplitude of 20 is masked and cannot be detected.

Hereinafter, referring to FIG. 4 on the one hand, in the ultrasonic vibration type defect detection device 100 of the embodiment, the high-frequency power supplied to the ultrasonic vibrator 42 is adjusted so that the current A1 detected by the current sensor 54 becomes constant. The operation of changing the voltage V1 of the high-frequency power and changing the current A1 in the case where the voltage V1 is changed will be described.

In the ultrasonic vibration type defect detection device 100 of the embodiment, the current A1 detected by the current sensor 54 is fed back to the control unit 50, and the current A1 of the high-frequency power increases in the vicinity of the frequency f1, as shown in the chain line of FIG. 4 The voltage V1 of the high-frequency power supplied to the ultrasonic vibrator 42 is lowered as shown in c1. On the other hand, around the frequency f2 at which the current A1 detected by the current sensor 54 decreases, the voltage V1 of the high-frequency power supplied to the ultrasonic vibrator 42 rises as shown by the chain line c1 in FIG. 4 . Thereby, as shown by the solid line d1 in FIG. 4 , the magnitude of the current A1 detected by the current sensor 54 can be substantially constant regardless of the frequency f.

In this way, by performing feedback control such that the current A1 of the high-frequency power supplied from the high-frequency power supply 40 to the ultrasonic vibrator 42 becomes substantially constant, even when the frequency f of the high-frequency power is changed, the The amplitude of the ultrasonic vibrator 42 is substantially constant, and the amplitudes of the substrate 11 and the semiconductor element 20 are substantially constant.

Moreover, at this time, the wire rod that can be detected based on the image captured by the camera 45 The voltage is adjusted so that the ratio of the amplitude of 30 to the amplitude of the substrate 11 and the semiconductor element 20 detected from the image captured by the camera 45 becomes more than a predetermined value. Thereby, at each frequency f, the amplitude of the wire 30 is suppressed from being disturbed by the amplitude of the substrate 11 or the semiconductor element 20 and the detection accuracy is lowered, the amplitude of the wire 30 is reliably detected, and a defect of the wire 30 can be detected with high precision. In addition, at this time, by checking the image of the wire 30 captured by the camera 45 and adjusting the voltage of the high-frequency power so that the amplitude of the wire 30 does not exceed the upper limit amplitude, it is possible to suppress the failure of the wire 30 during defect detection. Damaged by excessive vibration.

Next, the defect detection operation of the wire rod 30 by the ultrasonic vibration type defect detection device 100 according to the embodiment will be described with reference to FIGS. 5 and 6 .

As shown in step S101 of FIG. 5 , the CPU 51 of the control unit 50 adjusts the voltage V1 of the high-frequency power so that the current A1 detected by the current sensor 54 becomes substantially constant, and changes the frequency f of the high-frequency power. In addition, the semiconductor device 10 is subjected to ultrasonic vibration.

As shown in step S102 of FIG. 5 , the control unit 50 captures an animation of the vibrating semiconductor device 10 , and stores the captured image data in the memory 52 as shown in step S103 of FIG. 5 .

The CPU 51 of the control section 50 changes the frequency of the high-frequency power in the range of the predetermined ultrasonic frequency, takes a video of the semiconductor device 10 and saves it in the memory 52, then enters step S104 in FIG. The image of the wire 30 is compared, and the position difference Δd is calculated.

The wire 30 a shown in detail in Part A of FIG. 6 is normally connected to the electrodes 12 , 25 to 28 . If the wire rod 30a is subjected to ultrasonic vibration, the electrodes 12, 25-27 connected to the lower ends of the first-order wire rod 31a to the fourth-order wire rod 34a and the electrodes connected to the upper ends of the first-order wire rod 31a to the fourth-order wire rod 34a are respectively connected to each other. The natural frequency g0 among the electrodes 25-28 vibrates in the transverse direction. The natural frequency 90 differs depending on the diameter of the sight line 30 and the distance L between the electrodes 25 and 26 and the electrodes 26 and 27 , but it is often on the order of several tens of Hertz (Hz) in a typical semiconductor device 10 .

On the other hand, the defective wire 30 b is not connected to the electrode 26 of the second-stage semiconductor wafer 22 . Therefore, if the defective wires 30b are ultrasonically vibrated, the second-order wires 32b and the third-order wires 33b are naturally connected between the electrodes 25 of the first-stage semiconductor chip 21 and the electrodes 27 of the third-stage semiconductor chip 23. The frequency g1 vibrates in the transverse direction. In this example, as shown in detail in Part B of FIG. 6 , the distance L between the electrodes 25 and 27 becomes twice the distance L between the electrodes 25, 26 and the electrodes 26, 27, that is, 2L, so the second-order wire of the defective wire 30b The natural frequency g1 of 32b and the third-order wire 33b is about 1/2 of g0, and in a typical semiconductor device 10, it is often on the order of 20 Hz to 30 Hz.

The first-order wires 31 a to the fourth-order wires 34 a of the normally connected wires 30 a vibrate laterally at a natural frequency g0 of tens of Hz. The frame rate of the animation is 24 frames to 60 frames per second. Therefore, for example, the images of the first-order wires 31a to the fourth-order wires 34a of one frame become a dot chain line on the left side of the centerline 39a of the wire 30a in detail in Part A of FIG. The image of is like a dot chain line on the right side of the center line 39a of the wire 30a in detail in the part A of FIG. 6 .

In step S104 of FIG. 5, the CPU 51 of the control unit 50 combines the images of the first-order wires 31a to the fourth-order wires 34a of one frame shown in detail in Part A of FIG. 6 with the images of the previous previous frame. The images of the first-order wire 31a to the fourth-order wire 34a are compared to calculate the difference Δda therebetween. As shown in detail in Part A of FIG. 6 , the difference Δda is small in the case of a normal wire 30 a. In addition, this difference Δda is an amount proportional to the amplitudes of the first-order wires 31 a to the fourth-order wires 34 a.

On the other hand, the second-order wires 32 b and third-order wires 33 b of the defective wires 30 b not connected to the electrodes 26 of the second-stage semiconductor wafer 22 vibrate largely in the lateral direction at 20 Hz to 30 Hz. As mentioned above, the frame rate of the animation is 24 frames to 60 frames per second. For example, the images of the second-order wire 32b and the third-order wire 33b of one frame are detailed in Part A and Part B of FIG. 6 In detail, it becomes like a chain line of dots on the left side of the center line 39b of the defective wire 30b, and the image of the previous front frame becomes the center line 39b of the defective wire 30b in the details of part A and part B of FIG. 6 . A little chain line on the right.

The CPU 51 of the control unit 50 calculates the image of the second-order wire 32b and the third-order wire 33b of one frame, and the image of the previous frame of the previous frame, as shown in detail in Part B of FIG. 6 . The difference Δdb between the images of the second-order wire 32b and the third-order wire 33b. As shown in detail in Part B of FIG. 6 , for the second-order wire 32b and the third-order wire 33b of the defective wire 30b, the difference Δdb is very large, exceeding the predetermined threshold value ΔS. In addition, this difference Δdb is an amount proportional to the amplitude of the second-order wire 32b and the third-order wire 33b.

The CPU 51 of the control unit 50 is shown in detail in Part B of FIG. 6 . The difference Δdb between the image of the second-order wire 32b and the third-order wire 33b of the frame and the image of the second-order wire 32b and the third-order wire 33b of the previous frame exceeds the predetermined threshold In the case of ΔS, it is determined as YES in step S105 of FIG. 5, and the process proceeds to step S106 of FIG.

On the other hand, when the CPU 51 of the control part 50 does not exceed the predetermined threshold value ΔS in the situation where the difference Δd of any one of the wire rods 30 does not exceed the predetermined threshold value ΔS, it is judged as NO (NO) in step S105 of FIG. 5 , and enters FIG. 5 In step S107, a wire good signal indicating that the wire 30 of the semiconductor device 10 is good is output to the outside.

As described above, the ultrasonic vibration-type defect detection device 100 of the embodiment performs feedback control so that the current A1 of the high-frequency power supplied from the high-frequency power source 40 to the ultrasonic vibrator 42 is substantially constant, thereby making high When the frequency f of the high-frequency power changes, the amplitude of the ultrasonic vibrator 42 can be made substantially constant, and the amplitude of the substrate 11 and the semiconductor element 20 can be made substantially constant. In addition, by adjusting the voltage so that the ratio of the amplitude of the wire 30 detected from the image captured by the camera 45 to the amplitude of the substrate 11 and the semiconductor element 20 detected from the image captured by the camera 45 becomes more than a predetermined value, Accordingly, it is possible to suppress the amplitude of the wire 30 from being buried in the amplitude of the substrate 11 and the semiconductor element 20 . Thereby, the amplitude of the wire 30 buried in the substrate 11 and the semiconductor element 20 can be suppressed at various frequencies, and the amplitude of the wire 30 can be reliably detected at various frequencies.

In addition, the frequency at which the wire 30 vibrates greatly due to the disconnection of the wire 30 depends on the unconnected position, the distance L between the electrode 12 and the electrodes 25 to 28, and the wire rod 30. 30 diameter and so on and there are various changes. The ultrasonic vibration type defect detection device 100 of the embodiment can reliably detect the amplitude of the wire 30 at various frequencies, so it can detect the amplitude of the wire 30 at each frequency at which the amplitude of the wire 30 is large due to disconnection, and can achieve high precision and short time. The defect detection of the wire rod 30 is performed accurately.

In the above description, it was assumed that the feedback control was performed so that the current A1 of the high-frequency power supplied from the high-frequency power supply 40 to the ultrasonic vibrator 42 was substantially constant, thereby making it easier to control the high-frequency power. Even when the frequency f of the frequency power changes, the amplitude of the ultrasonic vibrator 42 is substantially constant, but the present invention is not limited thereto.

For example, as described with reference to FIG. 3 , the change in the current A0 of the high-frequency power when the voltage V0 of the high-frequency power is kept constant and the frequency is changed is obtained in advance through experiments, etc., and the change shown by the dotted line c2 in FIG. 7 is generated. A voltage waveform in which the increase and decrease of the current A0 are reversed is shown, and this voltage waveform is stored in the memory 52 in advance as a map 55 showing changes in the voltage V2 with respect to the frequency f. As shown by the chain line c2 in FIG. 7 , the map 55 becomes a waveform in which the voltage decreases around the frequency f1 and the voltage becomes high at the frequency f2. Furthermore, when ultrasonic vibration is performed, the voltage with respect to the frequency f may be adjusted with reference to the map 55 held in the memory 52 . At this time, as shown by the solid line d2 in FIG. 7 , even if the frequency changes, the current A2 supplied to the ultrasonic transducer 42 becomes substantially constant.

Thereby, it is possible to use a simple configuration to suppress the situation that when the semiconductor device 10 is subjected to ultrasonic vibration in various frequency bands, the semiconductor device 10 as a whole vibrates greatly, and the amplitude of the wire 30 as the target part is controlled by the substrate 11. Or the amplitude of the semiconductor element 20 is masked and cannot be detected, and the object to be inspected can be detected with high precision. Defects in the elephant department.

In addition, to simplify the test, for example, as shown by dot chain line c3 in FIG. In this case, as shown by the solid line d3 in FIG. 8 , although the current A3 supplied to the ultrasonic vibrator 42 is not substantially constant, it is within a predetermined range ΔA. Thereby, defect detection of the wire rod 30 can be performed with high accuracy and in a short time using a simpler method.

In addition, when the CPU 51 of the control unit 50 performs ultrasonic vibration on the semiconductor device 10, the number of frames between one frame and the previous frame for calculating the difference Δd of the image of the wire 30, or the number of frames of the animation The frame rate is changed, and the difference Δd of the image of the wire 30 is calculated. Thereby, even when the frequency of the wire 30 changes, the difference Δd of the image of the wire 30 can be detected, and the accuracy of defect detection can be improved.

Next, a wire rod defect detection system 200 according to the embodiment will be described with reference to FIG. 9 . The wire defect detection system 200 shown in FIG. 9 detects defects of the wire 30 of the semiconductor device 10. The semiconductor device 10 includes: a substrate 11; a semiconductor chip 21 to a semiconductor chip 24 mounted on the substrate 11; and a wire 31 to a wire 34, The electrodes 25 to 28 of the semiconductor wafer 21 to the semiconductor wafer 24 are connected to the electrode 12 of the substrate 11, or one electrode 25 to 28 of the semiconductor wafer 21 to the semiconductor wafer 24 is connected to another electrode 25 of the semiconductor wafer 21 to the semiconductor wafer 24. ~28 connections. The wire defect detection system 200 may also use the ultrasonic vibrator 42 as the ultrasonic vibrator 100 of the ultrasonic vibration type defect detection device 100 described above as the ultrasonic horn 43, and additionally display the images captured by the camera 45 to the control unit 50. display of the image 48. In addition, the wire defect detection system 200 does not include the voltage sensor 53 and the current sensor 54 installed in the ultrasonic vibration type defect detection device 100, and the memory 52 of the control unit 50 saves the information shown in FIGS. 7 and 8 . Mapping 55 or Mapping 56 illustrated. Furthermore, when the CPU 51 of the control unit 50 changes the frequency f of the high-frequency power supplied from the high-frequency power supply 40 to the ultrasonic horn 43, it adjusts the frequency f of the high-frequency power supplied from the high-frequency power supply 40 to the ultrasonic horn 43 based on the map 55 or the map 56. The voltage of high-frequency electricity. The configuration other than the above is the same as that of the ultrasonic vibration type defect detection device 100 described above.

The ultrasonic horn 43 is disposed around the semiconductor device 10 and causes the semiconductor device 10 to vibrate ultrasonically.

The operation of the wire defect detection system 200 will be described with reference to FIGS. 10 and 11 . For the same operations as those of the ultrasonic vibration type defect detection device 100 described above with reference to FIG. 5 and FIG. 6 , the same step numbers are assigned and descriptions are omitted.

As shown in Step S201, Step S102 to Step S104 in FIG. 10, the CPU 51 of the control unit 50 adjusts the voltage V1 of the high-frequency power so that the current A1 detected by the current sensor 54 becomes substantially constant, and on the other hand makes the high The frequency f of the frequency power is changed and the semiconductor device 10 is ultrasonically vibrated. Next, the CPU 51 of the control unit 50 captures a moving image of the wire 30 of the semiconductor device 10 vibrating, and stores the captured image data in the memory 52 . Then, the control unit 50 changes the frequency of the high-frequency power within the range of the predetermined ultrasonic frequency, takes a video of the semiconductor device 10 and saves it in the memory 52, and, in the same way as described above, compares one frame with the previous one. The images of the frames are compared, and the difference Δd between the images of the wire rod 30 is calculated.

The CPU 51 of the control unit 50, as shown in detail in Part B of FIG. When the difference Δdb of the image of the third-order wire 33b exceeds the predetermined threshold value ΔS, it is judged as YES in step S105 of FIG. 10 , and the step S202 of FIG. The images displayed on the display 48 of the images of the third-order wires 32b and 33b are different from those of the first-order wires 31a to the fourth-order wires 34a of the normally connected wires 30a.

There are various displays about the different display, and for example, the images of the second-order wire 32b and the third-order wire 33b of the defective wire 30b may be displayed in red. In addition, it can also be displayed in white with high brightness, and can be distinguished from the images of the substrate 11 and the semiconductor chips 21 to 24, or the images of the first-order wires 31a to the fourth-order wires 34a of the normally connected wires 30a. show.

When the inspector looks at the image on the display 48, for example, the defective wire 30b is displayed in red, so that the presence or absence of the defective wire 30b and its position can be detected at a glance.

When the CPU 51 of the control unit 50 judges as negative (NO) in step S105 of FIG. 10 , the processing is terminated without changing the image.

In addition, the CPU 51 of the control unit 50 can also, as shown in FIG. When the difference Δdb of the image of the third-order wire 33b exceeds the predetermined threshold value ΔS, the difference in the vibration region of the second-order wire 32b and the third-order wire 33b shown by hatching in FIG. The image display of the excess area 35 and the excess area 36 where Δdb exceeds the predetermined threshold value ΔS, and the image display of other areas Differently displayed on the display 48 . For example, when the excess area 35 and the excess area 36 are displayed in red, the wider area of the image of the second-order wire rod 32b and the third-order wire rod 33b than the defective wire rod 30b is displayed in red, so the inspector can be more accurate. Defective wires 30b are easily detected.

As described above, in addition to the same effect as the ultrasonic vibration type defect detection device 100 described above, the wire rod defect detection system 200 according to the embodiment can distinguish the displayed image of the defective wire rod 30b from other displayed images. displayed on the display 48. In this way, the inspector can detect the defective wire 30 b through the image on the display 48 . Since the difference between the amplitude of the defective wire 30b and the amplitude of the normally connected wire 30a is significant, the defective wire 30b can be detected with high precision. In addition, the images of all the wires 30 included in the semiconductor device 10 can be captured by the camera 45, analyzed at the same time, and displayed on the display 48. Therefore, even if the number of the wires 30 increases, all the wires 30 can be scanned in a short time. bad check.

10: Semiconductor device

11: Substrate

12, 25~28: electrode

20: Semiconductor components

21~24: Semiconductor wafer

30, 31~34: wire

40: High frequency power supply

42:Ultrasonic vibrator

45: camera

50: Control Department

51: CPU (central processing unit)

52: memory

53: Voltage sensor

54: Current sensor

100: Ultrasonic vibration type defect detection device

Claims (9)

An ultrasonic vibration type defect detection device, which detects defects of an inspection object, is characterized in that it includes: an ultrasonic vibrator, which makes the inspection object undergo ultrasonic vibration; a power supply, which supplies high-frequency power to the ultrasonic vibrator an imaging device that photographs the object to be inspected that is vibrated by ultrasonic waves; and a control unit that adjusts the frequency of the high-frequency power supplied from the power source to the ultrasonic vibrator, and performs vibration of the object to be inspected. For defect detection, the control unit changes the frequency of the high-frequency power supplied from the power supply to the ultrasonic vibrator, and captures an image of the inspection object by the imaging device. , and perform defect detection of the inspection target object based on the captured image, the inspection target object includes a target part that becomes a defect detection target and a non-target part that does not become a defect detection target, and the control When changing the frequency of the high-frequency power supplied from the power supply to the ultrasonic vibrator, the amplitude of the target part detected from the image captured by the imaging device is compared to the The voltage of the high-frequency power supplied from the power supply to the ultrasonic vibrator is adjusted so that the ratio of the amplitude of the non-target portion detected by the image captured by the imaging device becomes more than a predetermined value. The ultrasonic vibration type defect detection device according to claim 1, comprising: a current sensor for detecting the current supplied from the power supply to the ultrasonic vibrator When the control unit changes the frequency of the high-frequency power supplied from the power supply to the ultrasonic vibrator, the current detected by the current sensor becomes constant. In a manner within the range, the voltage of the high-frequency power supplied from the power supply to the ultrasonic vibrator is adjusted. The ultrasonic vibration-type defect detection device according to claim 1, wherein the control unit includes a map in which the current of the high-frequency power supplied from the power supply to the ultrasonic vibrator is predetermined. In the method within the range, the voltage of the high-frequency power supplied from the power supply to the ultrasonic vibrator relative to the frequency of the high-frequency power supplied from the power supply to the ultrasonic vibrator is predetermined. changing the frequency of the high-frequency power supplied to the ultrasonic vibrator from the power supply, and adjusting the high-frequency power supplied to the ultrasonic vibrator from the power supply based on the map The voltage of electricity. The ultrasonic vibration type defect detection device according to claim 1 or claim 3, wherein the inspection object is a semiconductor device, including: a substrate; a semiconductor element mounted on the substrate; and a wire rod, the semiconductor element An electrode of the semiconductor element is connected to an electrode of the substrate, or one electrode of the semiconductor element is connected to the other electrode of the semiconductor element, and the control unit is configured to make the ultrasonic vibrator supplied from the power supply described When the frequency of high-frequency power changes, the amplitude of the wire rod detected from the image captured by the imaging device is compared to the amplitude of the substrate and the semiconductor element detected from the image captured by the imaging device The voltage of the high-frequency power supplied from the power supply to the ultrasonic vibrator is adjusted so that the ratio thereof becomes equal to or greater than a predetermined value. The ultrasonic vibration-type defect detection device according to claim 4, wherein the control unit adjusts the vibration of the ultrasonic vibrator from the power supply so that the detected amplitude of the wire rod does not exceed a predetermined upper limit amplitude. The voltage of the high-frequency power supplied. The ultrasonic vibration-type defect detection device according to claim 5, wherein the control unit changes the frequency of the high-frequency power supplied from the power supply to the ultrasonic vibrator, and utilizes the The camera device is used to shoot the animation of the semiconductor device, and the difference between one frame of the captured animation and the image of the wire rod in the previous frame is calculated. When the difference exceeds a predetermined threshold value, outputting a bad detection signal of the wire. The ultrasonic vibration type defect detection device as described in claim 6, wherein the control unit uses a frame between a frame in which the difference is calculated and the previous frame number, or the frame rate change of the animation, and calculate the difference. The ultrasonic vibration type defect detection device according to claim 1 or claim 3, wherein the ultrasonic vibrator is an ultrasonic vibrator connected to the inspection object and causing the inspection object to perform ultrasonic vibration, Or an ultrasonic horn disposed around the object to be inspected. A wire defect detection system for detecting defects of the wire of a semiconductor device, the semiconductor device including: a substrate; a semiconductor element mounted on the substrate; and a wire connecting an electrode of the semiconductor element to an electrode of the substrate , or connect one electrode of the semiconductor element to the other electrode of the semiconductor element, and the wire defect detection system is characterized in that it includes: an ultrasonic vibrator, which makes the semiconductor device perform ultrasonic vibration; a power supply, supplying high-frequency power to the ultrasonic vibrator; an imaging device that photographs the semiconductor device vibrated by ultrasonic waves; a display that displays an image captured by the imaging device; The frequency of the high-frequency power supplied by the ultrasonic vibrator is determined to detect the defect of the wire rod. On the one hand, the control unit makes the high-frequency power supplied from the power supply to the ultrasonic vibrator frequency change, on the one hand, use the camera device to shoot the animation of the semiconductor device, and calculate the difference between one frame of the captured animation and the image of the previous frame, When the difference exceeds a predetermined threshold value, the displayed image of the wire rod is displayed on the display differently from the displayed images of the other wire rods, and the inspection target includes a defective detection object. When the control unit changes the frequency of the high-frequency power supplied from the power supply to the ultrasonic vibrator for the target part of the target and the non-target part that is not a defective detection target, according to the The ratio of the amplitude of the target portion detected from the image captured by the imaging device to the amplitude of the non-target portion detected from the image captured by the imaging device is greater than a predetermined value, adjusted from the The voltage of the high-frequency power supplied by the power supply to the ultrasonic vibrator.

Images