TWI735862B - Ultrasonic inspection device and ultrasonic inspection method - Google Patents

Abstract

The present invention extracts the reflected wave obtained from each measurement point of the inspected body from the local peaks generated from the specific interface in the inspected body, compares the polarities of the extracted local peaks with the reference polarity, and compares the extracted local peaks The measurement point whose polarity is different from the reference polarity is detected as abnormal.

Description

Ultrasonic inspection device and ultrasonic inspection method

The invention relates to an ultrasonic inspection device and an ultrasonic inspection method.

As a non-destructive inspection method for inspecting defects in the image of the inspected body, there is a method of irradiating the inspected body with ultrasonic waves and detecting the reflected waves to produce the ultrasonic image.

Generally speaking, in order to detect defects existing in the inspected body with a multi-layer structure with ultrasonic waves, the reflection characteristics of different acoustic impedances are used. Ultrasonic waves propagate in liquid or solid materials, and produce reflected waves (echoes) at the boundary surfaces or gaps of materials with different acoustic impedances.

Here, the reflected wave from defects such as peeling has a higher intensity than the reflected wave from a place where there is no defect. Therefore, by imaging the reflection intensity in the boundary surface of each layer of the inspected body, an image can be obtained that makes the peeling defect existing in the inspected body more conspicuous.

However, in recent years, the wiring patterns of the inspected objects represented by electronic components have gradually become finer, and the peeling to be detected has also become minute, and it is difficult to specify the presence or absence of peeling only based on the reflection intensity.

When ultrasonic waves are incident from a substance with a smaller acoustic impedance to a larger substance, the reflected wave from the peeling defect has the property of reversing the phase of the reflected wave from the part without peeling. High-sensitivity detection of tiny peeling or voids can be achieved by capturing the peeling defect with low reflection intensity of the phase reversal detection.

As a method of detecting peeling etc., there is Patent Document 1, for example. In Patent Document 1, the polarity of the rising peak of the reflected wave and the polarity of the rising peak of the transmission wave are compared, and if the polarity is different, it is judged as peeling. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2012-154877

[The problem to be solved by the invention]

The method of Patent Document 1 compares the rising peak polarity of the reflected wave from the desired interface with the rising peak polarity of the transmitted wave for each reflected wave obtained from each measurement point, so there is no need to establish a correspondence between the peaks between the measurement points. .

However, if the occurrence time of the reflected wave (peak) from each interface is close due to the thinning of the structure in the subject, it is difficult to specify the reflected wave from the desired interface. As a result, it is difficult to detect minute peeling or the like with high sensitivity.

The purpose of the present invention is to detect minute peeling and the like with high sensitivity even when the structure in the body to be inspected is thinner. [Technical means to solve the problem]

An ultrasonic inspection apparatus of one aspect of the present invention is characterized by having a processing unit that scans the surface of the inspected body with an ultrasonic probe and emits ultrasonic waves from the ultrasonic probe to the inspected body, and receives the return from the inspected body Reflected waves and inspect the internal state of the inspected body based on the characteristics of the received reflected waves; The processing unit extracts the reflected waves obtained from each measurement point of the inspected body from the inspected body Compare the polarity of the extracted local peak with the reference polarity for the local peaks that occur at the specific interface, and detect the measurement points where the polarity of the extracted local peaks are different from the reference polarity as abnormal.

One aspect of the ultrasonic inspection device of the present invention is characterized in that it scans the surface of the inspected body with an ultrasonic probe, emits ultrasonic waves from the ultrasonic probe to the inspected body, and receives the reflected waves returned from the inspected body And check the internal state of the object under inspection based on the characteristics of the received reflected wave, and have the following mechanism: set a local peak generated from the desired interface of the object under inspection within the reflected wave at one measurement point; Set the gate for the length of time below one of the wavelengths of the ultrasonic wave emitted to the subject; set the polarity of the local peaks that occur from the desired heterogeneous interface of the subject; use the gate with the set length of the above time from other Each of the above-mentioned reflected waves sequentially explores and specifies the above-mentioned local peaks that are the same as the set above-mentioned local peaks, which are generated from the above-mentioned heterogeneous interface; based on the reflection intensity of the above-mentioned specified above-mentioned partial peaks, a cross-sectional image of the above-mentioned heterogeneous interface is generated and displayed ; And if the polarity of the local peak of the reflected wave obtained from each measurement point that is explored and identified is different from the polarity of the set local peak, it is judged to be abnormal, and the measurement site judged to be abnormal is displayed in the above generated The profile image is displayed and output.

The ultrasonic inspection method of one aspect of the present invention is characterized in that it scans the surface of the inspected body with an ultrasonic probe, and emits ultrasonic waves from the ultrasonic probe to the inspected body, and receives the return from the inspected body The reflected wave is used to inspect the internal state of the inspected body based on the characteristics of the received reflected wave, and the reflected wave obtained from each measurement point of the inspected body is extracted from a specific interface in the inspected body For the local peak that occurs, compare the polarity of the extracted local peak with the reference polarity, and detect the measurement point where the polarity of the extracted local peak is different from the reference polarity as an abnormality. [Effects of Invention]

According to one aspect of the present invention, even when the structure in the subject is thinned, it is possible to detect minute peeling or the like with high sensitivity.

The embodiment relates to an ultrasonic inspection device and an ultrasonic inspection method that uses ultrasonic waves to determine the presence or absence of defects such as peeling, voids, etc., and visualize the internal state of an electronic component or other object to be inspected.

In the ultrasonic inspection for 2.5-dimensional and 3-dimensional mounting parts with complex and multi-layered structures, the unevenness of the surface (e.g., the uneven thickness of the mold resin) or the inclination and deformation of the internal structure (e.g., chip The warpage, etc.), or the height of the installed parts is different, etc., and the distance between the dissimilar interfaces may vary due to the measurement point.

In this case, in the implementation form, for example, for the reflected wave of each measurement point obtained from the inspected body with a complicated and multi-layer structure, the local peak is extracted and the characteristic quantity is calculated, and the total reflection wave is performed based on the characteristic quantity. Consider the establishment of correspondence between the local peaks of the polarity reversal. In addition, the phase inversion peak is detected by comparing the local peak of the specific boundary surface corresponding to the total reflection wave with the reference peak signal.

In the implementation form, in the ultrasonic non-destructive inspection, the simple condition setting is used to identify the reflected wave from the heterogeneous boundary surface of the inspected body with complex and multi-layer structure, and produce a clear cross-sectional image, which can be specified. The part where the polarity is reversed. For example, IC (Integrated Circuit) chips, etc., have a multilayer structure of silicon mold as the inspection object. Even if there is an uneven thickness of silicon or deformation of the structure, only simple condition settings are used to generate the different species desired by the user. The image of the joint interface of the structure.

In this way, in the embodiment, in the ultrasonic inspection for semiconductor electronic parts, the local peak signal reflected and received from the dissimilar joint surface is recognized, and the phase inversion with the reference signal is captured. With this, even when the structure in the body to be inspected is thinner, it is possible to detect minute peeling and the like with high sensitivity.

Hereinafter, the embodiment will be described using drawings. [Example]

As a characteristic of ultrasonic waves, it propagates inside the inspected body, and when there is a boundary where the material properties (acoustic impedance) change, part of it is reflected. In particular, if there are voids, most of them are reflected. Therefore, it is possible to detect defects such as voids or peeling in a heterogeneous boundary surface with high sensitivity based on the reflection intensity of ultrasonic waves. Hereinafter, the peeling in the dissimilar bonding interface of the multilayer structure product is used as the detection target for description.

2, the structure of the ultrasonic inspection device will be described. As shown in FIG. 2, the ultrasonic inspection apparatus has a detection unit 1, an A/D (Analog/Digital) converter 6, a signal processing unit 7, and an overall control unit 8. The detection unit 1 has an ultrasonic probe (ultrasonic probe) 2 and a flaw detector 3. The flaw detector 3 drives the ultrasonic probe 2 by applying a pulse signal to the ultrasonic probe 2. The ultrasonic probe 2 driven by the flaw detector 3 generates ultrasonic waves, and sends the ultrasonic waves to the test object, which is the sample 5, using water as a medium. When the transmitted ultrasonic wave is incident on the sample 5 with a multilayer structure, a reflected wave 4 is generated from the surface of the sample 5 or a heterogeneous boundary surface, and the reflected wave 4 is received by the ultrasonic probe 2 and processed by the flaw detector 3 as necessary. Converted into a reflected intensity signal.

Then, the reflection intensity signal is converted into digital waveform data by the A/D converter 6 and input to the signal processing unit 7. The ultrasonic wave is sent and received by scanning successively in the inspection area on the sample 5. In addition, for the convenience of description, the ultrasonic waves generated by the ultrasonic probe 2 are referred to as "transmitted waves", and the ultrasonic waves received by the ultrasonic probe 2 are referred to as "reflected waves."

The signal processing unit 7 suitably includes an image generation unit 7-1, a defect detection unit 7-2, and a document output unit 7-3. For the waveform data input from the A/D converter 6 to the signal processing section 7, the image generating section 7-1 performs signal conversion described later, and generates the cross-section of the specific joint surface of the sample 5 from the digital waveform data image. The defect detection unit 7-2 performs processing described later in the cross-sectional image of the joint surface generated by the image generation unit 7-1 to detect defects such as peeling. In the data output section 7-3, data output as inspection results such as information on each defect detected by the defect detection section 7-2 or cross-sectional observation images are generated and output to the overall control section 8.

Next, referring to FIG. 3, a configuration example of a specific ultrasonic inspection apparatus 100 that realizes the configuration shown in FIG. 2 will be described. In Figure 3, 10 represents the orthogonal three-axis coordinate system of X, Y, and Z. 1 in FIG. 3 is equivalent to the detection unit 1 described in FIG. 2.

The detection unit 1 contains a scanning table 11, 12 is a water tank installed on the scanning table 11, and 13 is a scanner that can be moved in the X, Y, and Z directions on the scanning table 11 so as to straddle the water tank 12 . The scanning table 11 is a base set substantially horizontally. In the water tank 12, pour water 14 to the height shown by the dotted line, and place the sample 5 on the bottom of the water tank 12 (in the water). The sample 5 is a packaged product including a multilayer structure and the like as described above. The water 14 is a medium required for the ultrasonic wave emitted from the ultrasonic probe 2 to effectively propagate inside the sample 5. The 16 series mechanical controller drives the scanner 13 along the X, Y, and Z directions.

For the sample 5, the ultrasonic probe 2 transmits the ultrasonic wave from the ultrasonic emission part at the lower end, and receives the reflected wave returned from the sample 5. The ultrasonic probe 2 is installed in the holder 15 and the scanner 13 driven by the mechanical controller 16 can move freely in the X, Y, and Z directions. As a result, the ultrasonic probe 2 can move in the X and Y directions while receiving reflected waves at a plurality of measurement points set in advance in the sample 5 to obtain a two-dimensional image of the joint surface in the measurement area (XY plane) for inspection defect. The ultrasonic probe 2 is connected via a cable 22 to a flaw detector 3 that converts the reflected wave into a reflected intensity signal.

As shown in FIG. 2, the ultrasonic inspection apparatus 100 further includes an A/D converter 6, a signal processing unit 7, an overall control unit 8, and a mechanical controller 16.

The signal processing unit 7 processes the reflection intensity signal after A/D conversion by the A/D converter 6 and detects the internal defects of the sample 5. The signal processing unit 7 includes an image generation unit 7-1, a defect detection unit 7-2, a data output unit 7-3, and a parameter setting unit 7-4.

The image generating section 7-1 generates an image based on digital data. The digital data returns the reflection from the surface and various boundary surfaces of the sample 5 preset on the XY plane and received by the ultrasonic probe 2 The wave is obtained by the A/D converter 6 for A/D conversion. The defect detection unit 7-2 processes the image generated by the image generation unit 7-1 to make the internal defect visible, or performs detection. The data output unit 7-3 outputs the inspection result that the defect detection unit 7-2 makes the internal defects visible or detected. The parameter setting unit 7-4 accepts parameters such as measurement conditions input from the outside, and sets the defect detection unit 7-2 and the data output unit 7-3. In addition, in the signal processing unit 7, for example, the parameter setting unit 7-4 is connected to the database 18.

The overall control unit 8 includes a CPU (Central Processing Unit) (built in the overall control unit 8) that performs various controls, and accepts parameters and the like from the user. Furthermore, the overall control unit 8 and a user interface (GUI (Graphical User Interface: Graphical user interface) 17 and a memory device 18 that stores the characteristic quantities or images of the defect detected by the signal processing unit 7 are properly connected. The mechanical controller 16 drives the scanner 13 based on a control command from the overall control unit 8. In addition, the signal processing unit 7, the flaw detector 3 and the like are also driven in accordance with instructions from the overall control unit 8.

Referring to Fig. 4, an example of sample 5 will be described. Here, the 400 series schematically shows an example of the vertical structure of an electronic component (subject to be inspected) having a multilayer structure that is the main inspection target. The inspected body 400 is one in which the semiconductor device 42 is joined to the printed wiring board 40 of the lowermost layer via the solder balls 41. The semiconductor device 42 is formed by laminating a plurality of wafers (here, 3 of 43, 44, and 45), and is formed by connecting with the interposer substrate 46 via bumps 47, and is protected from the outside with resin 48 (shaded part in the figure). When the ultrasonic wave 49 is incident from the surface side of the inspected body 400 (upper in the figure), the ultrasonic wave 49 is transmitted to the interior of the inspected body 400, and the acoustic impedance of the surface, the boundary surface between the wafers, the bump layer, etc. A different part is reflected, and these are received by the ultrasonic probe 2 as a reflected wave.

50 in FIG. 5 is an example of the partial reflection wave received by the ultrasonic probe 2, and the horizontal axis is the receiving time (distance), and the vertical axis is the waveform when the reflection intensity (peak value). The time indicates the depth of the inspected body 400, the peak of the vertical axis is set to 0 at the center, and the upward direction from this point indicates the positive polarity, and the downward direction indicates the negative polarity. The reflected waves alternately show peaks of different polarities. Hereinafter, each peak is described as a local peak.

In the general door control method, first, the S door 51 for detecting the reflected wave from the surface is set. Next, set the timing of the occurrence of the first peak exceeding the critical value in the time range set by the S gate as the reflection signal from the surface, which is the trigger point. In the figure, 53 is the trigger point.

Next, apply a visualized gate (F gate) (52 in the figure) to the time region delayed from the trigger point 53 by the preset time, and detect the peak with the preset polarity in the F gate 52, which has the largest peak value (in the polarity When it is negative, it is the local peak with the smallest peak value. When the positive polarity is set, a local peak 54 is detected. In order to perform this processing, the F gate needs to be set to include at least one of the positive partial peaks and the negative partial peaks for a long period of time.

The image generation section 7-1 of the signal processing section 7 calculates the trigger point based on the reflection waves obtained by scanning in the measurement area (XY plane), and sets the F gate to a time area delayed by a fixed time, and repeats the set polarity. The detection of the local peak with the largest peak value and the conversion of the peak value into a shading value (for example, 0-255 in the case of generating an image with 256 gray scales), thereby generating an image of a profile with a fixed depth from the surface.

In this way, the previous door control method 400 in Figure 4 is effective when the distance from the surface to the boundary surface of each chip is fixed. However, when the distance between the surface (trigger point) and the boundary surface of each chip is not uniform due to the uneven thickness of the mold resin or the warpage of the internal wafer, the desired boundary surface map cannot be generated across the entire measurement area. picture. In addition, in recent years, due to the development of miniaturization and thinning of electronic components, internal structures have gradually become thinner. If the F gate is set to a long time as shown in Figure 5, the reflected signals from multiple boundary surfaces will coexist. In the F gate, the signal of the boundary surface that caused the detection error.

Here, the reflection intensity of the ultrasonic wave in the boundary surface, that is, the peak value increases as the difference between the acoustic impedance of the material before and after the reflection increases. However, if there is peeling (void) on the boundary surface, the acoustic impedance is approximately zero, so the ultrasonic wave is completely reflected and becomes larger than the portion without peeling. In addition, when ultrasonic waves are incident from a substance with a small acoustic impedance to a substance with a larger acoustic impedance, if there is separation (a void) here, the reflected wave at the boundary usually reverses the phase with respect to the portion where there is no separation. However, in the previous door control method, the polarity reversal cannot be detected.

In contrast, the ultrasonic inspection device of the embodiment is also obtained from the entire measurement area when the distance between the surface and each boundary surface is not uniform due to the uneven thickness of the mold resin (surface unevenness) or deformation of the internal structure The reflected wave specifies the local peak corresponding to the reflected signal from the desired boundary surface. Moreover, peeling is detected by detecting the reversal of its polarity, regardless of the magnitude of the peak.

1, the processing method of the ultrasonic inspection device of the embodiment will be described. This processing is performed by the image generating unit 7-1 shown in FIG. 2. Here, the image generation unit 7-1 is composed of, for example, the following mechanism: set the local peaks generated from the desired interface of the test object (sample 5) within the reflected wave of one measurement point; ) The gate for the length of time under one wavelength of the emitted ultrasonic wave; set the polarity of the local peak that occurs from the expected heterogeneous interface of the object to be inspected (sample 5); use the gate for the set time for the long time to be based on each of the other reflected waves The sequence explores and specifies the local peaks that are the same as the set local peaks that occur from the heterogeneous interface; and based on the reflection intensity of the specified local peaks, the desired cross-sectional image of the heterogeneous interface is generated and displayed.

If the polarities of the local peaks of the reflected waves obtained from the searched and identified measurement points are different from the polarities of the set local peaks, the defect detection unit 7-2 determines that it is abnormal. The data output unit 7-3 constitutes a mechanism for displaying and outputting the measurement location determined to be abnormal on the generated cross-sectional image.

Here, the mechanism setting for setting the gate includes, for example, the time length of each of the above-mentioned local peaks each including one positive and negative polarity as the time length of one wavelength or less of the ultrasonic wave.

First, as the conditions for detecting peeling from the desired boundary surface, input the conditions of the gate position (the depth of the boundary surface), the gate width (local peak search range), and the reference polarity (S101). The conditions are basically set by the user. Figure 6 shows a conceptual diagram of an example. 60 is the object to be inspected, and it shows that the surface is uneven due to the uneven thickness of the mold resin.

First, set the measurement range on the object 60 in the XY plane of the coordinate system shown in 62, and designate any measurement point within the measurement range for setting the door (M601 in the figure). 601 is the reflected wave obtained from the designated measuring point M601, and G601 is an example of the gate set. The gate width is set to include a stenosis time ΔT around a local peak with positive and negative polarities each. Here, when setting "positive" as the reference polarity, select P601 as the local peak to be the reference. 602 denotes the reflected wave obtained from the measurement point M602 which is separated from the measurement point M601 in the XY space. It can be seen that due to the uneven thickness of the mold resin, the reflected wave 602 is delayed in time to receive the reflected signal from the surface and the interface compared to 601.

Therefore, shift the gate to an appropriate time range (move to G602), and select the local peak of the two local peaks in gate G602 that is most similar to the reference peak in characteristics. By performing this processing on each of the reflected waves obtained from all the measurement points, the local peaks corresponding to the set peak P601 are sequentially determined regardless of the polarity of the local peaks.

Therefore, first, a reflected wave is acquired at each measurement point within the measurement range (S102). Then, for all the measurement points in the input measurement range, after the reflected wave is obtained (S103®Yes), the local peaks are established corresponding to the total reflected wave.

For each reflected wave, first, a local peak is detected (S104). As an example of the local peak detection method, there is a smoothed differential of two-dimensional polynomial fitting. It deconvolves each reflected wave with a linear weighting coefficient to obtain a differential waveform (Equation 1), and the local peak is located where the sign of the differential waveform changes from positive to negative, or from negative to positive. This is an example of local peak detection method, but it can also be other methods.

S(z)= -(a*f(z-2)+b*f(z-1))+c*f(z)+(b*f(z+1)+c*f(z+2 )) (Formula 1) S(z): Differential waveform f(z): reflected echo a=2, b=1, c=0

Next, a feature amount is calculated for each of the detected local peaks (S105). As an example, the occurrence time (z) and the peak value (f(z)) at this time are the characteristic quantities. However, the characteristic quantities can be plural kinds of 1 or more, such as the number of local peaks (peak density) near the occurrence time, and The cross-correlation function of the reference waveform, etc., can be other characteristics as long as it is a characteristic of a local peak. In addition, the reference waveform when the cross-correlation function is used as the characteristic quantity can be a transmission wave, a reflection wave obtained from a good product, a reflection wave from a surface, etc. as an example.

And, according to whether it is located in the gate G601 of the initial setting, each partial peak is grouped into two levels, and any one of the two labels is assigned (S106). Perform the above S105 and S106 on all the detected local peaks.

The 70 in FIG. 7 is the reflected wave, and P1 to P8 are part of the local peaks detected from the reflected wave 70. For each of P1 to P8, whether it is located inside or outside the setting gate G701 is the feature quantity of the local peak, and a label is attached. 71 of FIG. 7 shows an example of assigning any one of labels L0 and L1 to the local peaks P1 to P8. In this example, labels L0 are assigned to P1 and P2 located in the setting gate G701, and labels L1 are assigned to P3 to P8.

After S104 to S106 are performed on the acquired total reflection waves, local peaks are established and corresponded between the reflection waves (S107). This refers to the local peaks that occur from the same boundary surface of the total reflection wave.

Fig. 8 shows an example of the local peak corresponding establishment processing S107. In the reflected wave 81 obtained from the measurement point U of the eye, the local peak relative to the reference peak has been specified as P801.

In the embodiment, the reflected waves obtained from the measurement points M and D near the measurement point U of the corresponding local peak are specified to correspond to the local peak of the peak P801.

First, the local peaks of the reflected wave 82 obtained from the measurement point M are the peaks with the most similar characteristics to the peak P801. In this case, it is P802. And, the door position is updated to include P802 (S108). G802 stands for the door of renewal. At the same time, the label of the local peak of the reflected wave 82 is also updated.

Next, each of the local peaks of the reflected wave 83 obtained from the measurement point D specifies the peak with the most similar characteristic to the peak P802. In this case, it is P803. The same processing is carried out on the measurement points separated by the distance in the XY space in order to establish the correspondence between the peaks of the total reflection wave.

As described above, a specific local peak is shifted in the time direction while the gate is shifted. In this way, it is possible to detect if the time difference from the trigger point is not fixed, or the reflection signal from a specific interface where the time is not fixed can be detected. In addition, by using a plurality of feature quantities to evaluate the similarity, it is possible to establish a correspondence regardless of the difference in polarity.

The above description shows an example of establishing correspondence between the local peaks and the local peaks between the reflected waves by using a plurality of features and updating the narrow gate. However, it is also possible to perform the reflected wave and the reflected wave based on the elastic matching of the dynamic programming method. Establish correspondence of the unity. There are multiple ways to establish correspondences in this way, but by establishing correspondences between local peaks due to the total reflection waves, when the reflected signal from the surface cannot be obtained, that is, the reflected wave from the trigger point cannot be obtained, but the reflected wave from the edge can also be obtained. The reflected signal of the interface.

Figure 9 is the result of extracting partial peaks corresponding to the desired interface from the total reflection wave (P21, P22, P23, P24 in Figure 9) (S108) according to the processing flow of Figure 1 relative to the set reference peak P20的例。 Examples. In the image generating section 7-1, the peak values of the local peaks corresponding to these are converted into shade values and set as the pixel values of each measurement point, thereby generating the bonding interface image 1-1.

On the other hand, D20, D21, D22, D23, and D24 in Fig. 10 represent the distances of establishing corresponding local peaks (P21, P22, P23, P24) in Fig. 9. In the image generating part 7-1, the distance distribution of the same in the measurement area is generated, and this is converted into a distance to generate an internal deformed shape 1-3. With this, automatic measurement and visualization of the inclination or peeling angle of the structure in the specified interface can be performed.

Finally, in the defect detection section 7-2 of Fig. 2, compare the reference polarity set in S101 of Fig. 1 with the polarity of the local peak from the desired boundary surface specified by each reflected wave (S109), if the polarity is consistent with the reference polarity It is normal, if not, it is captured as peeling (1-2).

Change the color, etc. to overlay the captured result on the interface image 1-1. P110, P111, and P112 in FIG. 11 represent examples of self-reflected waves 1100, 1101, and 1102 to establish corresponding reflected signals from the same interface. When the reference polarity is set to negative, the reflected signal P110 with a positive polarity is detected as a peeling defect. In addition, the signal itself can also be set to the reference value instead of the polarity.

One example is the transmission signal, and the reflected signal whose phase is reversed from the transmission signal is detected as a peeling defect. In addition, it is also possible to set the reflected signal from the surface as the reference signal, and set the phase-inverted reflected signal as the peeling defect.

S110, S111, and S112 in Fig. 11 represent reflected signals from the surface. In this case, the reflected signals P111 and P112 are detected as peeling defects.

Furthermore, when the reference polarity or reference signal is not set, the peeling can also be detected by establishing the characteristic distribution of the corresponding local peak. 1200 and 1201 in Fig. 12 are examples of the characteristic distribution of the reflected signal from the same interface detected from each measurement point. The distribution 1200 is the polarity distribution of the detected local peaks, and the part shown in white represents the positive polarity, and the part shown in black represents the negative polarity. According to the area ratio of the black and white regions or the shape of the distribution, it can be judged which of the positive and negative is equivalent to the peeling part. Here, a region of positive polarity with a small area and a circular shape is captured as peeling.

1201 is the distribution of the comparison value (intensity difference) between the peak value of the detected local peak and the peak value of the reference signal. Here, the area where the comparison value is greater than the fixed critical value is referred to as peeling. In addition, a combination of 1200 and 1201 can also be used to determine defects. The characteristic distribution is not limited to the polarity, the intensity difference with the reference signal, and can be any of the correlation function with the reference signal, the polarity of the rising peak, the peak ratio between the positive peak and the negative peak, and so on.

As explained above, according to the embodiment, for the total reflection wave obtained from the measurement area of the subject, the local peaks obtained from the same interface and the reflected waves are matched irrespective of the difference in polarity, so that the phase can be captured with high precision. Reversal position. In this way, it is possible to detect defects such as tiny peeling or voids.

1‧‧‧Testing Department 1-1‧‧‧Interface image 1-2‧‧‧Capture and peel 1-3‧‧‧Internal deformed shape 2‧‧‧Ultrasonic Probe 3‧‧‧Flaw detector 4‧‧‧Reflected wave 5‧‧‧Sample 6‧‧‧A/D converter 7‧‧‧Signal Processing Department 7-1‧‧‧Image Generation Department 7-2‧‧‧Defect Inspection Department 7-3‧‧‧Data output department 7-4‧‧‧Parameter setting section 8‧‧‧All control department 10‧‧‧Coordinate System 11‧‧‧Scanning table 12‧‧‧Sink 13‧‧‧Scanner 14‧‧‧Water 15‧‧‧Holder 16‧‧‧Mechanical Controller 17‧‧‧User Interface 18‧‧‧Database 18‧‧‧Memory device 22‧‧‧Cable 40‧‧‧Printed Wiring Board 41‧‧‧Solder Ball 42‧‧‧Semiconductor device 43‧‧‧Chip 44‧‧‧Chip 45‧‧‧chip 46‧‧‧Plug-in base plate 47‧‧‧ bump 48‧‧‧Resin 49‧‧‧Ultrasonic 50‧‧‧Partially reflected wave 51‧‧‧S door 52‧‧‧F door 53‧‧‧Trigger point 54‧‧‧Local Peak 60‧‧‧Subject 62‧‧‧Coordinate System 70‧‧‧reflected wave 71‧‧‧Label local peaks 81‧‧‧reflected wave 82‧‧‧reflected wave 83‧‧‧reflected wave 100‧‧‧Ultrasonic inspection device 400‧‧‧Examined body 601‧‧‧reflected wave 602‧‧‧reflected wave 1100‧‧‧reflected wave 1101‧‧‧reflected wave 1102‧‧‧reflected wave 1200‧‧‧distribution 1201‧‧‧distribution D‧‧‧Measurement point D20～D24‧‧‧Route G601‧‧‧Set door G602‧‧‧Set door G701‧‧‧Set door G802‧‧‧Gate of Renewal L0‧‧‧label L1‧‧‧label M‧‧‧Measurement point M601‧‧‧Measurement point M602‧‧‧Measurement point P1～P8‧‧‧Part of the local peak P20‧‧‧reference peak P21～P24‧‧‧Local peak P110～P112‧‧‧Reflected signal P601‧‧‧Set Peak P602‧‧‧Set Peak P801‧‧‧peak P802‧‧‧peak P803‧‧‧peak S101～S109‧‧‧Step S110～S112‧‧‧Reflected signal U‧‧‧Measurement point X‧‧‧direction Y‧‧‧ direction Z‧‧‧ direction

FIG. 1 is a diagram showing an example of a processing procedure of an ultrasonic inspection method of a semiconductor package with a multilayer structure according to the embodiment. Fig. 2 is a block diagram showing the concept of the ultrasonic inspection device of the embodiment. Fig. 3 is a block diagram showing the schematic structure of the ultrasonic device of the embodiment. 4 is a schematic diagram of the vertical structure of a semiconductor package having a multilayer structure as an inspection target in the embodiment. FIG. 5 is a diagram showing an example of the reflected echo obtained from a semiconductor package having a multilayer structure as an inspection target and the gate setting of the previous gate control method. Figure 6 is a diagram showing an example of door setting. Figure 7 is a diagram showing an example of labeling of local peaks. Fig. 8 is a diagram showing an example of the corresponding processing of establishing a local peak. Fig. 9 is a diagram showing an example of the result of establishing the correspondence between the local peaks between the reflected echoes. Fig. 10 is a diagram showing an example of internal deformation shape measurement based on the establishment of corresponding local peaks. FIG. 11 is a diagram showing a comparative example of establishing the corresponding partial peak and the reference signal. FIG. 12 is a diagram showing an example of the feature distribution of corresponding local peaks in the embodiment of the present invention.

1‧‧‧Testing Department

2‧‧‧Ultrasonic Probe

3‧‧‧Flaw detector

4‧‧‧Reflected wave

5‧‧‧Sample

6‧‧‧A/D converter

7‧‧‧Signal Processing Department

7-1‧‧‧Image Generation Department

7-2‧‧‧Defect Inspection Department

7-3‧‧‧Data output department

8‧‧‧All control department

Claims (8)

An ultrasonic inspection device, characterized by having a processing unit that scans the surface of an inspected body with an ultrasonic probe, emits ultrasonic waves from the ultrasonic probe to the inspected body, and receives the reflected waves returned from the inspected body. The internal state of the inspected body is inspected based on the characteristics of the received reflected wave; and the processing unit: extracts the reflected wave obtained from each measurement point of the inspected body from a specific in the inspected body Compare the polarity of the extracted local peak with the reference polarity for the local peak generated on the interface, and detect the measurement point where the polarity of the extracted local peak is different from the reference polarity as abnormal; wherein the processing unit is: Extraction of the above-mentioned local peaks occurring from the above-mentioned specific interface: detecting a plurality of the above-mentioned local peaks from each of the above-mentioned reflected waves, and establishing a correspondence between the plurality of above-mentioned local peaks detected from each of the above-mentioned reflected waves and the total reflection wave, and The above-mentioned partial peak generated from the above-mentioned specific interface is extracted from the above-mentioned total reflection wave; and the above-mentioned processing unit: performs the establishment of correspondence between the above-mentioned partial peak and the above-mentioned total reflection wave as follows: calculates the above-mentioned partial peak for each of the above-mentioned reflected waves, A plurality of feature quantities including the occurrence time are calculated for each of the above-mentioned local peaks, and the similarity is calculated by considering the polarity inversion from the calculated plurality of the above-mentioned feature quantities, and the above-mentioned establishment of correspondence is performed based on the calculated similarity. An ultrasonic inspection device, characterized by having a processing unit that scans the surface of an inspected body with an ultrasonic probe, emits ultrasonic waves from the ultrasonic probe to the inspected body, and receives the reflected waves returned from the inspected body. The internal state of the inspected body is inspected based on the characteristics of the received reflected wave; and the processing unit: extracts the reflected wave obtained from each measurement point of the inspected body from a specific in the inspected body Compare the polarity of the extracted local peak with the reference polarity for the local peak that occurs on the interface, and detect the measurement point where the polarity of the extracted local peak is different from the reference polarity as abnormal; wherein the processing unit is to set the reference beforehand Polarity, and compare the polarity of the above-mentioned partial peak with the above-mentioned reference polarity set beforehand. An ultrasonic inspection device, characterized by having a processing unit that scans the surface of an inspected body with an ultrasonic probe, emits ultrasonic waves from the ultrasonic probe to the inspected body, and receives the reflected waves returned from the inspected body. The internal state of the inspected body is inspected based on the characteristics of the received reflected wave; and the processing unit: extracts the reflected wave obtained from each measurement point of the inspected body from a specific in the inspected body Compare the polarity of the extracted local peak with the reference polarity for the local peak that occurs at the interface, and detect the measurement point where the polarity of the extracted local peak is different from the reference polarity as Abnormal; wherein the processing unit: calculates the reference polarity based on the reflected signal received from the surface of the object to be inspected. An ultrasonic inspection device, characterized by having a processing unit that scans the surface of an inspected body with an ultrasonic probe, emits ultrasonic waves from the ultrasonic probe to the inspected body, and receives the reflected waves returned from the inspected body. The internal state of the inspected body is inspected based on the characteristics of the received reflected wave; and the processing unit: extracts the reflected wave obtained from each measurement point of the inspected body from a specific in the inspected body Compare the polarity of the extracted local peak with the reference polarity for the local peak generated on the interface, and detect the measurement point where the polarity of the extracted local peak is different from the reference polarity as abnormal; wherein the processing unit is: Extraction of the above-mentioned local peaks occurring from the above-mentioned specific interface: detecting a plurality of the above-mentioned local peaks from each of the above-mentioned reflected waves, and establishing a correspondence between the plurality of above-mentioned local peaks detected from each of the above-mentioned reflected waves and the total reflection wave, and The partial peak generated from the specific interface is extracted from the total reflection wave; and the processing unit: specifies the reference polarity according to the polarity distribution of the partial peak of the corresponding total reflection wave. An ultrasonic inspection device, characterized in that it scans the surface of the inspected body with an ultrasonic probe and emits ultrasonic waves from the ultrasonic probe to the inspected body, and receives the reflected waves returned from the inspected body based on the receiving The characteristics of the reflected wave that come to inspect the internal state of the inspected body, and have the following mechanism: set the local peaks generated from the desired interface of the inspected body within the reflected wave at one measurement point; set to the inspected body The gate for the length of time below one wavelength of the above-mentioned ultrasonic wave emitted by the inspection body; set the polarity of the above-mentioned local peak generated from the expected dissimilar interface of the above-mentioned inspected body; use the above-mentioned gate for the set time for the above-mentioned reflection wave from other Each of them sequentially explores and specifies the above-mentioned local peaks that are the same as the set above-mentioned local peaks from the above-mentioned heterogeneous interface; based on the reflection intensity of the specific above-mentioned partial peaks, generates and displays the cross-sectional image of the above-mentioned heterogeneous interface; and if self-exploring If the polarity of the local peak of the reflected wave obtained at each measurement point is different from the polarity of the set local peak, it is judged to be abnormal, and the measured part judged to be abnormal is displayed on the cross-sectional image generated above. Output. The ultrasonic inspection device of claim 5, wherein the mechanism setting the gate sets the time length each including one of the local peaks of the positive polarity and the negative polarity as the time length below the one wavelength of the ultrasonic wave. An ultrasonic inspection method, characterized in that it scans the surface of the inspected body with an ultrasonic probe, emits ultrasonic waves from the ultrasonic probe to the inspected body, and receives the reflected waves from the inspected body based on the received The characteristics of the above-mentioned reflected wave inspect the internal state of the above-mentioned object, and the above-mentioned reflected wave obtained from each measurement point of the above-mentioned object is extracted from the local peaks that occur at the specific interface in the above-mentioned object, and the The polarity of the extracted local peak is compared with the reference polarity, and the measurement point where the polarity of the extracted local peak is different from the reference polarity is detected as abnormal; wherein the extraction of the local peak from the specific interface is performed as follows: A plurality of the above-mentioned local peaks are detected from each of the above-mentioned reflected waves, and the plurality of above-mentioned local peaks detected from each of the above-mentioned reflected waves are corresponded to the total reflection waves, and the above-mentioned total reflection waves are extracted from the above-mentioned specific interface. The above-mentioned local peak; and the establishment of correspondence between the above-mentioned local peak and the above-mentioned total reflection wave is performed as follows: the above-mentioned local peak is calculated for each of the above-mentioned reflected waves, and the plural kinds of characteristic quantities including the occurrence time are calculated for each of the above-mentioned local peaks, and The similarity is calculated by considering the polarity reversal from the calculated plural kinds of the above-mentioned feature quantities, and the above-mentioned establishment of correspondence is performed based on the calculated similarity. The ultrasonic inspection method of claim 7, wherein the system to be inspected has a multi-layer structure with a dissimilar bonding interface, and the abnormality of the measurement point is detected as a peeling in the dissimilar bonding interface of the multi-layer structure.

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