Ultrasonic imaging apparatus

Abstract

[Project] To provide an ultrasonic imaging device capable of easily discharging fine bubbles attached around a wafer mounted on a sample stand. [Solution] An ultrasonic imaging device (1) that irradiates ultrasound onto a wafer (2) and acquires the transmitted waves to create an image, and is equipped with a sample stand (20) that fixes the wafer (2) in water (W), the sample stand (20) has an opening (21), and at the edge of the opening (21), a gripping member that grips the wafer (2) is provided, the opening (21) is configured to be larger than the wafer (2), and by gripping the wafer (2) by the gripping member, a gap (S) that is a bubble discharge part is formed between the outer periphery of the wafer (2) and the edge of the opening (21).

Description

Technology Field

[0001] The present invention relates to an ultrasonic imaging device. Background Technology

[0002] Since ultrasound has the property of being difficult to transmit through gases, ultrasonic imaging devices generally use water as a medium for transmitting ultrasound, and the examination is performed by immersing the specimen and the ultrasonic probe. At this time, if air bubbles adhere to the specimen, there is a problem in that it becomes difficult to inspect the interior of the specimen at the part where the bubbles are attached. In addition, if air bubbles are confirmed in the examination results after the ultrasonic examination, there is a problem in that it is necessary to perform a re-examination after removing the bubbles. To solve these problems, the following invention is proposed.

[0003] For example, the ultrasonic inspection device disclosed in Patent Document 1 comprises a water tank for holding water, a sample stand disposed within the water tank for placing a test subject, a first ultrasonic probe disposed facing in the vertical direction for irradiating ultrasound toward the test subject, and a second ultrasonic probe for receiving ultrasound transmitted through the test subject, wherein a hydrophilic film is formed on the lower side of the sample stand. Additionally, the lower side of the sample stand has an ejection part for ejecting water.

[0004] In addition, the ultrasonic inspection device disclosed in Patent Document 2 has an ultrasonic probe that performs ultrasonic irradiation and reception, a sample stand on which an object to be inspected by ultrasonics (test subject) is loaded, a water tank in which a liquid medium (water) into which the sample stand is immersed is stored, and a nozzle that discharges the liquid medium to the sample stand, wherein the ultrasonic probe moves within the inspection range and the nozzle moves in accordance with the movement of the ultrasonic probe. Prior art literature

[0005] Japanese Patent Publication No. 2014-215154 and Japanese Patent Publication No. 2019-219234 The problem to be solved

[0006] However, the ultrasonic inspection device described in Patent Documents 1 and 2 removes bubbles by spraying liquid onto bubbles remaining on the lower surface of the sample stand on which the test object is placed. In this method, it is difficult to discharge fine bubbles attached around the test object when the test object is placed on the sample stand.

[0007] The present invention aims to solve the aforementioned conventional problems by providing an ultrasonic imaging device capable of easily discharging fine bubbles attached around a subject mounted on a sample stand. means of solving the problem

[0008] The present invention is an ultrasonic imaging device that irradiates ultrasound onto a subject and acquires and visualizes the transmitted waves, and is characterized by having a sample stand that fixes the subject in water, wherein the sample stand has an opening, and a gripping member that grips the subject is provided at the edge of the opening, wherein the opening is configured to be larger than the subject, and a bubble discharge portion is formed between the outer periphery of the subject and the edge of the opening by gripping the subject with the gripping member. Effects of the invention

[0009] According to the present invention, an ultrasonic imaging device capable of easily discharging fine bubbles attached around a subject mounted on a sample stand can be provided. Brief explanation of the drawing

[0010] FIG. 1 is a configuration diagram showing an ultrasonic imaging device according to an embodiment of the present invention. FIG. 2 is a perspective view showing an ultrasonic imaging device according to an embodiment of the present invention. FIG. 3 is a perspective view showing the state in which a sample stand is installed on a sample stand holding support. FIG. 4 is a perspective view showing the state in which the pressing member is removed from the sample holder support of FIG. 3. Figure 5 is an enlarged view of the receiving member of Figure 4. FIG. 6 is a perspective view showing the state in which a sample holder is supported by a sample holder support. FIG. 7 is a top view showing a sample stand with a wafer installed installed in a sample stand holding support. FIG. 8 is a top view showing the state of a sample holder holding a wafer while being mounted to a sample holder support. Specific details for implementing the invention

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings; however, the present invention is not limited to the following embodiments, and various modifications and applications within the technical concept of the present invention are also included within its scope.

[0012] FIG. 1 is a configuration diagram showing an ultrasonic imaging device according to an embodiment of the present invention, and FIG. 2 is a perspective view showing an ultrasonic imaging device according to an embodiment of the present invention.

[0013] As illustrated in FIG. 1, the ultrasonic imaging device (1) measures the interior of a test subject non-destructively by ultrasound in water (W) as a medium for transmitting ultrasound, displays an image of the test subject, or determines whether internal defects are acceptable.

[0014] The ultrasonic imaging device (1) is configured to be placed in a water tank (10) and to have a sample stand (20) on which a wafer (2) (subject) is placed, a first ultrasonic probe (40) provided on the upper side of the wafer (2), and a second ultrasonic probe (50) provided on the lower side of the wafer (2). The first ultrasonic probe (40) and the second ultrasonic probe (50) are positioned opposite each other in the vertical direction (Z direction). In addition, the wafer (2) is in the shape of a circular thin plate, for example, which is used as a material for a semiconductor integrated circuit.

[0015] The first ultrasonic probe (40) is a probe that irradiates ultrasonic waves toward the wafer (2). The second ultrasonic probe (50) is a probe that receives ultrasonic waves that have passed through the wafer (2). In addition, contrary to the present embodiment, the second ultrasonic probe (50) may be a probe for irradiation and the first ultrasonic probe (40) may be a probe for reception.

[0016] The sample stand (20) is horizontally positioned within the water tank (10) and supported by the sample stand holding support member (30). Additionally, the water within the water tank (10) is not limited to pure water, but may be tap water, and is not specifically limited. Furthermore, the shape of the water tank (10) is not limited to a rectangular box shape as in the present embodiment, but may be, for example, a cylindrical shape with a bottom. Additionally, the configuration and function of the sample stand (20) will be explained in detail later.

[0017] The first ultrasonic probe (40) and the second ultrasonic probe (50) are configured to be movable by an X-axis scanning unit (61), a Y-axis scanning unit (62) (see FIG. 2) and a Z-axis scanning unit (63), which are positioned vertically with the wafer (2) being the subject of the test placed between them and connected to a driving device (not shown).

[0018] As shown in FIG. 2, the X-axis scanning unit (61) is provided above the water tank (10) and operates both the first ultrasonic probe (40) and the second ultrasonic probe (50) in the X-axis direction (left and right direction).

[0019] The Y-axis scanning unit (62) is provided as a pair on both sides of the outer X-axis direction of the tank (10), and operates both the first ultrasonic probe (40) and the second ultrasonic probe (50) in the Y-axis direction (forward and backward direction).

[0020] The Z-axis scanning unit (63) is installed on the X-axis scanning unit (61) via a slider (65) and operates the first ultrasonic probe (40) in the Z-axis direction (up and down direction). Additionally, the first ultrasonic probe (40) is installed on the Z-axis scanning unit (63) via a probe holder (64).

[0021] The slider (65) is provided with an arm (66) on which a second ultrasonic probe (50) is installed. The arm (66) extends downward in the Z-axis direction and extends in the Y-axis direction (horizontal direction). At the tip of the arm (66), the second ultrasonic probe (50) is positioned opposite the first ultrasonic probe (40). Additionally, the second ultrasonic probe (50) is configured not to operate in the Z-axis direction. Furthermore, in this embodiment, although the second ultrasonic probe (50) is configured to be fixed in the Z-axis direction, the second ultrasonic probe (50) may be configured to operate in the Z-axis direction (up and down direction) together with the first ultrasonic probe (40).

[0022] The wafer (2) is supported on a sample stand (20) and placed in water (W) stored in a water tank (10). Additionally, the first ultrasonic probe (40) is positioned on the upper side in the Z-axis direction of the wafer (2), and the second ultrasonic probe (50) is positioned on the lower side in the Z-axis direction of the wafer (2).

[0023] A sample stand (20) on which a wafer (2) is installed is supported by a sample stand holding support member (30) that holds and supports the sample stand (20). This sample stand holding support member (30) is located in water (W) and is fixed to the bottom of a water tank (10) via a leg member (22). Additionally, a space is formed between the sample stand holding support member (30) and the bottom of the water tank (10) for the second ultrasonic probe (50) to move in the X-axis and Y-axis directions. Furthermore, although the case where the leg member (22) is provided at the four corners of the sample stand holding support member (30) has been described as an example, the present embodiment is not limited to any configuration that allows the sample stand holding support member (30) to be fixed to the water tank (10).

[0024] FIG. 3 is a perspective view showing a sample stand installed in a sample stand holding support, FIG. 4 is a perspective view showing a state in which a pressing member is removed from the sample stand holding support of FIG. 3, and FIG. 5 is an enlarged view of the receiving member of FIG. 4. In addition, FIG. 3 to FIG. 5 all show a state in which a wafer (2) is not installed on the sample stand (20).

[0025] As illustrated in FIGS. 3 and 4, the sample stage (20) is formed in a thin plate with a circular opening (21). In addition, the thickness of the sample stage (20) is such that it can secure rigidity to stably support the wafer (2) when placed on it, and is set to, for example, a thickness of about 2 to 10 mm. Furthermore, as the material for the sample stage (20), a strong material such as aluminum or stainless steel is preferred. By using such a material, it is difficult to be affected by vibration when the first ultrasonic probe (40) and the second ultrasonic probe (50) (probe) move in water (W). In addition, the shape of the sample stage (20) is not limited to a rectangular shape, but may be, for example, an elliptical shape.

[0026] The sample stand (20) is provided with a receiving member (71) for holding and supporting a wafer (2) in the opening (21). Additionally, the sample stand (20) is provided with a pressing member (72) for holding the wafer (2) at the edge portion on the upper side of the opening (21). By fitting the edge of the wafer (2) into the receiving member (71) and the pressing member (72), the wafer (2) is held and supported within the opening (21). At the edge portion of the opening (21), three pairs of receiving members (71) and pressing members (72) (hereinafter collectively referred to as holding members) are arranged to stably hold the wafer (2). Additionally, the wafer (2) can be stably held and supported if at least three holding members are provided, but depending on the size of the wafer (2), two or fewer, or four or more, may be provided.

[0027] Additionally, the pressing member (72) is formed to be long and slender along the edge of the opening (21) and is positioned opposite the receiving member (71) in the vertical direction. Additionally, the pressing member (72) is screw-fixed to the edge of the opening (21) of the sample stand (20). In this embodiment, it is fixed at both ends of the long side of the pressing member (72).

[0028] The sample holder support member (30) holds and supports the sample holder (20) and is configured to include a sample holder lower pressing member (31) that presses the lower side of the sample holder (20) and a sample holder upper pressing member (32) that presses the upper side of the sample holder (20). In this way, the sample holder support member (30) is formed in an inverted U-shape, and holds and supports both sides of the sample holder (20) in the X-axis direction. That is, the sample holder lower pressing member (31) has a lower pressing member (31a) arranged along both edges in the X-axis direction of the sample holder (20) and a connecting member (31b) connecting the lower pressing member (31a) in the Y-axis direction (inner end). The sample holder upper pressing member (32) is installed along both edges in the X-axis direction of the sample holder (20) and is provided overlapping the lower pressing member (31a). Additionally, the upper pressing portion (32) of the sample stand is screw-fixed over the lower pressing portion (31a). Furthermore, on the upper surface of the joint portion (31b) of the sample stand holding support portion (30), a position determining member (33) is provided to contact the rear end of the sample stand (20) and to determine the insertion position of the sample stand (20).

[0029] As illustrated in FIG. 5, the receiving member (71) is formed to protrude inward in the radial direction from the surrounding wall surface (21a) of the opening (21). Additionally, the receiving member (71) is formed in a trapezoidal shape, and a contact portion (71a) is formed at the tip of the inner diameter side to contact the outer circumference of the wafer (2). Furthermore, a support portion (71b) is formed on the receiving member (71) to support the wafer (2) by protruding inward in the radial direction at the bottom of the contact portion (71a). The support portion (71b) is shaped like a sunshade and is configured to contact and support the lower surface of the edge portion of the wafer (2). By providing three receiving members (71) in this manner, the position of the wafer (2) relative to the opening (21) is determined, and a gap (S) (see FIG. 1) is formed between the outer circumference of the wafer (2) and the surrounding wall surface (21a) of the opening (21).

[0030] FIG. 6 is a perspective view showing a state in which a sample holder is supported by a sample holder support member. In FIG. 6, one side of the sample holder support member (30) in the X-axis direction is shown as if viewed from the front in the Y-axis direction.

[0031] As shown in FIG. 6, the sample stand (20) has a concave cutout in the portion excluding both ends in the Y-axis direction, and at both ends in the Y-axis direction, a retained portion (20a, 20a) is formed that is retained and supported by a sample stand retaining support portion (30).

[0032] The upper pressing portion (32) of the sample stand is cut in a concave shape at the portion excluding both ends in the Y-axis direction, and a pressing portion (32a) is formed at both ends in the Y-axis direction so as to overlap with the holding portion (20a). On the inner side of this pressing portion (32a), a cut portion (32b) is formed to guide the holding portion (20a) of the sample stand (20) so as to slide. That is, the holding portion (20a) is inserted from the front in the Y-axis direction and is inserted to a predetermined position of the sample stand holding support portion (30) while sliding. In addition, in this embodiment, only one side in the X-axis direction has been illustrated and described, but the other side is configured in the same way.

[0033] FIG. 7 is a top view showing a sample stand with a wafer installed installed in a sample stand holding support.

[0034] As shown in FIG. 7, the diameter R1 of the opening (21) is formed to be larger than the diameter R2 of the wafer (2). By doing so, a gap (S) (bubble discharge section) is formed between the outer periphery of the opening (21) and the outer periphery of the wafer (2) to exclude bubbles, which is formed in the sample stage (20). This gap (S) is an arc-shaped hole formed by penetrating the opening (21) in the axial direction (direction perpendicular to the ground). Additionally, the holes penetrating in the vertical direction (Z-axis direction) are blocked at the location where the receiving member (71) is provided and the location where the pressing member (72) is provided. That is, the opening (21) has a gap (S) on the outer periphery of the wafer (2), excluding the location where the holding member is placed, by gripping the wafer (2). As the gap (S) becomes larger, it becomes easier to exclude bubbles, while the gripping member needs to be configured to be large in order to hold and support the wafer (2).

[0035] Additionally, the wafer (2) is positioned within the opening (21) by contacting the contact portion (71a) (see FIG. 5) of the receiving member (71), thereby ensuring a gap (S) between the opening (21) and the wafer (2). Furthermore, the dimensions of the gap (S) (radial distance between the edge portion of the opening (21) and the outer periphery portion of the wafer (2)) are appropriately set according to the purpose, etc., within a range that does not impair the effect.

[0036] Additionally, the wafer (2) is pressed by the pressing member (72) so that the wafer (2) does not fall out of the opening (21). The pressing member (72) is in the shape of a long, slender plate extending in the circumferential direction, and a curved portion (72a) is formed on the inner side in the diameter direction, following the outer curvature of the wafer (2). By doing so, the overlapping area between the wafer (2) and the pressing member (72) in the Z-axis direction (a direction perpendicular to the ground) can be reduced, thereby expanding the inspection range of the wafer (2).

[0037] In addition, the materials of the receiving member (71) and the pressing member (72) are not particularly limited as long as they do not damage the wafer (2), and, for example, resin materials such as polyethylene and acrylic can be used. Also, although not shown, when screwing the pressing member (72) to the screw, the screw hole is made into an elongated hole in the direction of the wafer (2) (test subject), so that the pressing member (72) can move within the range of the elongated hole, making it easier to install the wafer (2).

[0038] Additionally, a plate spring (80) for holding and supporting the sample stand (20) is provided in the pressing part (32a) of the upper pressing part (32) of the sample stand. When the part to be held (20a) of the sample stand (20) (see FIG. 6) is inserted into the position of the pressing part (32a), the part to be held (20a) is held and supported by the plate spring (80). As a result, the sample stand (20) is stably held and supported by the sample stand holding support part (30). Furthermore, in this embodiment, the case where the plate spring (80) is provided at the four corners of the sample stand (20) has been described as an example, but as long as the configuration can hold and support the sample stand (20), it may be two locations at the front or two locations at the inside, and the number or location of the plate spring (80) is not limited.

[0039] FIG. 8 is a top view showing the state of a sample holder holding a wafer while being mounted to a sample holder support.

[0040] As illustrated in FIG. 8, after the wafer (2) is supported on the sample holder (20), the sample holder (20) is horizontally positioned in front of the sample holder support member (30) in the Y-axis direction, and the inner part to be supported (20a) is inserted from the front of the sample holder support member (30) and slid inward in the Y-axis direction. By doing so, the part to be supported (20a) is inserted while being guided inward in the Y-axis direction between the lower pressing member (31a) and the front pressing member (32a). Then, after the part to be supported (20a) passes through the pressing member (32a), the inner part to be supported (20a) reaches the space between the inner lower pressing member (31a) and the pressing member (32a) in the Y-axis direction, and the front part to be supported (20a) in the Y-axis direction reaches the front pressing member (32a). By sliding the sample stand (20) further inward from this state, all four corner holding parts (20a) are inserted between the lower pressing part (31a) and the pressing part (32a), and each holding part (20a) is held and supported by a plate spring (80).

[0041] Next, the steps from installing the wafer (2) on the sample stand (20) to installing the sample stand (20) on the sample stand holding support (30) are shown.

[0042] First, a wafer (2) is loaded into the opening (21) of the sample stand (20). By doing so, the edge portion of the wafer (2) is supported by the receiving member (71), and the outer surface of the wafer (2) comes into contact with the contact portion (71a), thereby forming a gap (S) between the outer surface of the wafer (2) and the opening (21), and the wafer (2) is positioned in the opening (21) (see FIG. 5 and FIG. 7). Then, a pressing member (72) is placed at the edge portion of the opening (21) so as to overlap with the edge of the wafer (2), and the pressing member (72) is fixed to the sample stand (20) using a screw. In this way, the wafer (2) is fixed to the sample stand (20) by the gripping member (receiving member (71) and the pressing member (72)).

[0043] Then, the sample stand (20) with the wafer (2) fixed thereon is immersed in the water (W) of the water tank (10), and the sample stand (20) is tilted to remove air bubbles that have accumulated on the lower surface of the wafer (2). In addition, if any remaining air bubbles that could not be removed in the above steps are identified, the air bubbles are removed by blowing a water stream at the location where the air bubbles were identified. In particular, fine air bubbles accumulated between the wafer (2) and the opening (21) are removed through the gap (S) (air bubble discharge part) by the water stream. Furthermore, the water stream becomes faster when blowing on the side where the gap (S) is narrow, and the water stream becomes slower when blowing on the side where the gap (S) is wide.

[0044] Then, the sample holder (20) holding the wafer (2) is positioned horizontally in front of the sample holder support (30), and the sample holder (20) is fixed to the sample holder support (30) by sliding it in from the front of the sample holder support (30). Additionally, the sample holder support (30) is fixed inside the water tank (10) (see FIG. 2).

[0045] In this way, after fixing the wafer (2) to the sample stand (20) outside the water tank (10), the sample stand (20) can be placed in water (W) and then slid and inserted into the sample stand holding support (30) to fix it, thereby improving workability when fixing the wafer (2).

[0046] Next, the operation and function of the ultrasonic imaging device (1) will be explained.

[0047] When a wafer (2) (subject) to be inspected is introduced into water (W), the first ultrasonic probe (40) and the second ultrasonic probe (50) move horizontally relative to the sample stand (20) to scan the wafer (2) for internal inspection of the wafer (2). Additionally, prior to inspection, the first ultrasonic probe (40) is retracted upwardly relative to the second ultrasonic probe (50), and when the wafer (2) is placed at a predetermined position, the first ultrasonic probe (40) is lowered from the origin position to the focal position.

[0048] The ultrasonic imaging device (1) utilizes the property that the intensity of the ultrasonic waves after passing through the wafer (2) differs due to the acoustic impedance of each part of the wafer (2) (test subject) to image the intensity of the received ultrasonic waves. By doing so, the internal condition of the wafer (2) can be inspected non-destructively.

[0049] Next, the method of operating the ultrasonic imaging device (1) is explained.

[0050] In order to obtain the desired effect in the ultrasonic imaging device (1) having a bubble discharge mechanism of the present embodiment, a test operation is performed in the preceding stage of operating the ultrasonic imaging device (1).

[0051] In this test operation, the area and shape of the opening (21) provided in the sample stand (20) are set according to the area and shape of the subject (wafer (2)) to be inspected. That is, when the subject (wafer (2)) is held by the gripping member (receiving member (71) and pressing member (72)), the area and shape of the opening (21) are set so that a gap (S) (bubble discharge section) of sufficient size to discharge bubbles is formed between the subject (wafer (2)) and the opening (21). By undergoing this test operation, it becomes possible to prevent bubbles from remaining around the subject (wafer (2)) during the main operation, thereby enabling an improvement in operational efficiency.

[0052] As described above, the ultrasonic imaging device (1) of the present embodiment is an ultrasonic imaging device (1) that irradiates ultrasound onto a wafer (2) and acquires the transmitted waves to create an image, and is equipped with a sample stand (20) that fixes the wafer (2) in water (W). The sample stand (20) has an opening (21), and at the edge of the opening (21), a gripping member (receiving member (71) and pressing member (72)) that grips the wafer (2) is provided. The opening (21) is configured to be larger than the wafer (2), and by gripping the wafer (2) by the gripping member, a gap (S) (bubble discharge part) is formed between the outer periphery of the wafer (2) and the edge of the opening (21). According to this, fine bubbles attached around the wafer (2) mounted on the sample stand (20) can be easily discharged from the gap (S).

[0053] In addition, in this embodiment, a gap (S) (bubble discharge portion) is formed at a location excluding the placement position of the gripping member. According to this, the gripping member can be configured to stably grip the wafer (2).

[0054] In addition, the present embodiment is provided with three or more gripping members (receiving member (71) and pressing member (72)), and said gripping members are arranged at equal intervals at the edges of the opening (21). According to this, the wafer (2) can be stably held and supported on the sample stand (20).

[0055] In addition, in this embodiment, the gripping member is composed of a receiving member (71) positioned on the lower side of the wafer (2) to load the wafer (2), and a pressing member (72) positioned on the upper side of the wafer (2) to press the wafer (2). According to this, the wafer (2) can be stably held and supported on the sample stand (20) by pressing up and down from the edge of the wafer (2).

[0056] In addition, in this embodiment, the sample stand (20) is supported by a sample stand holding support member (30), and the sample stand holding support member (30) is fixed to a water tank (10) in which the sample stand (20) is submerged. According to this, since the wafer (2) is fixed to the sample stand (20) outside the water tank (10), workability is improved compared to the case where the wafer (2) is fixed inside the water tank (10).

[0057] The present invention is not limited to the above-described embodiments. For example, although the present embodiment was described using the case of a circular opening (21) as an example, it is not limited to a circular shape. The shape may be such that the part excluding the gripping member of the opening bulges outward, and the gap between the opening and the outer circumference of the wafer (2) becomes larger than that of the present embodiment. Explanation of the symbols

[0058] 1: Ultrasound imaging device 2: Wafer (subject) 10: Aquarium 20: Sample stand 21: Opening 30: Sample holder support 40: First ultrasonic probe 50: Second ultrasonic probe 71: Lack of reception 72: Pressing element S: Gap (bubble discharge section) W: Water

Claims

Claim 1 An ultrasonic imaging device that irradiates ultrasound onto a subject and acquires the transmitted waves to create an image, wherein the device is provided with a sample stand that fixes the subject in water, the sample stand has an opening, and a gripping member that grips the subject is provided at the edge of the opening, the opening is configured to be larger than the subject, and by gripping the subject with the gripping member, a bubble discharge section is formed between the outer periphery of the subject and the edge of the opening. Claim 2 An ultrasonic imaging device according to claim 1, wherein the bubble discharge portion is formed at a location excluding the placement position of the gripping member. Claim 3 An ultrasonic imaging device according to claim 1, characterized in that the gripping member is provided with three or more members, and the gripping members are arranged at equal intervals at the edges of the opening. Claim 4 An ultrasound imaging device according to claim 1, wherein the gripping member is composed of a receiving member positioned below the subject to load the subject and a pressing member positioned above the subject to press the subject. Claim 5 An ultrasonic imaging device according to claim 1, wherein the sample stand is supported by a sample stand holding support member, and the sample stand holding support member is fixed to a water tank in which the sample stand is submerged.

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