Method for adjusting the test apparatus, and the test apparatus

Abstract

To propose a new technique related to a four-point bending test and capable of realizing accurate position adjustment of an indenter to a support part of a test piece.SOLUTION: An adjustment method of a test device having a pair of support parts 8b which is arranged while having a prescribed interval and supports a lower surface of a test piece; an indenter 39 which has a pair of contact parts 39a which contacts the test piece supported by the support part 8b to press the test piece; an indenter moving unit which relatively moves the indenter 39 so as to approach the test piece; and a load measurement unit which measures a load of pressing the test piece by the indenter 39, comprises: a photographed image formation step of forming a photographed image by imaging the pair of contact parts 39a and the pair of support parts 8b and displaying the photographed image; a detection step of detecting each tip position of the pair of support parts 8b from the photographed image and each tip position of the contact parts 39a; and a step of performing angle adjustment of the indenter 39 such that the pair of contact parts 8b and the pair of support parts 39a become in parallel to each other in the horizontal direction on the basis of each detected tip position.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a test apparatus for measuring the strength of test specimens such as semiconductor chips.

Background Art

[0002] Conventionally, for example, as disclosed in Patent Document 1, a test apparatus for performing a destructive test on a semiconductor chip and measuring the strength of the semiconductor chip is known. In this type of test apparatus, generally, the three-point bending test or the four-point bending test defined by the SEMI standard G86-0303 is widely used.

[0003] In the process of forming a semiconductor chip, grinding distortion is generated on the back surface of the wafer along with the back grinding of the semiconductor wafer. Further, cutting distortion is generated on the side surface of the semiconductor chip along with dicing by a cutting blade after back grinding. These grinding distortions and cutting distortions affect the strength of the semiconductor chip, and since the measurement of the strength of the semiconductor chip is important for ensuring the quality of the product, it is required to be able to measure more accurately.

[0004] In the three-point bending test, a test specimen is supported by a pair of support portions arranged at a predetermined interval, and with a indenter positioned at the center between the pair of support portions, the test specimen is pressed by the indenter to break the test specimen. Then, the load of the indenter when the test specimen breaks is measured, and based on the load at the time of test specimen breakage, the distance between the fulcrums of the support portions, the thickness of the test specimen, and the width of the test specimen, the flexural strength is calculated by the following calculation formula. Flexural strength σ = 3LW / 2bh 2 (Equation 1) (L: Distance between fulcrums mm, W: Indenter load value N, b: Test specimen width mm, h: Test specimen thickness mm)

[0005] As described above, in contrast to the three-point bending in which a load is applied to the center of a test specimen supported by a pair of support portions, in the four-point bending test, the tips of a pair of indenters are positioned at equal distances from a pair of support portions, and the test specimen is pressed and broken by applying two loads of the same magnitude.

Prior Art Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2005-017054 [Overview of the project] [Problems that the invention aims to solve]

[0007] In a four-point bending test, if the tips of two of the indenters are not at the same height, and the timing of pressing the test specimen changes, accurate measurements cannot be obtained.

[0008] Therefore, when relocating the testing equipment or replacing the indenter, precise positioning of the indenter is required. Traditionally, this involved the worker placing a ruler or similar object on the support and bringing the indenter closer while visually checking the markings on the ruler to adjust its position.

[0009] This manual and visual adjustment of the indenter position by workers is prone to variations depending on the worker, and improvement was urgently needed to achieve accurate strength measurements.

[0010] In view of the above, the present invention proposes a novel technology that enables precise positional adjustment of the indenter relative to the support portion of the test piece in a four-point bending test. [Means for solving the problem]

[0011] The problems that this invention aims to solve are as described above, and the means for solving these problems will now be explained.

[0012] According to one aspect of the present invention, there is a method for adjusting a test apparatus comprising: a pair of support parts arranged at a predetermined interval to support the lower surface of a test piece; an indenter having a pair of contact parts positioned above the support parts and between the pair of support parts, which contact and press against the test piece supported by the support parts; an indenter moving unit for moving the indenter relatively closer to the test piece supported by the pair of support parts; and a load measuring unit for measuring the load applied by the indenter to the test piece supported by the pair of support parts. The method for adjusting a test apparatus comprises: an image capture step of capturing images of the pair of contact parts of the indenter and the pair of support parts to form an image; a detection step of detecting the respective tip positions of the pair of support parts and the respective tip positions of the pair of contact parts of the indenter from the image capture; and a first adjustment step of adjusting the angle of the indenter based on the detected tip positions so that the pair of contact parts and the pair of support parts are parallel in the horizontal direction.

[0013] Furthermore, according to one aspect of the present invention, a first auxiliary line display step is provided between the detection step and the first adjustment step, which displays an auxiliary line connecting the tip positions of the detected pair of support parts and an auxiliary line connecting the tip positions of the detected pair of corresponding contact parts.

[0014] Furthermore, according to one aspect of the present invention, after the first adjustment step, the invention includes a second auxiliary line display step in which a first center, which is the center between the respective tip positions of the pair of support parts, and a second center, which is the center between the respective tip positions of the contact part, are detected, and vertical auxiliary lines are displayed at the positions of the first center and the second center, respectively, and a second adjustment step in which the first center and the second center are aligned in the horizontal direction.

[0015] Furthermore, according to one aspect of the present invention, a test apparatus comprising: a pair of support parts arranged at a predetermined interval and supporting the lower surface of a test piece; an indenter having a pair of contact parts positioned above the support parts and between the pair of support parts and contacting and pressing against the test piece supported by the support parts; an indenter moving unit for moving the indenter relatively close to the test piece supported by the pair of support parts; a load measuring unit for measuring the load applied by the indenter to the test piece supported by the pair of support parts; an imaging unit for imaging the indenter and the support parts; a display monitor for displaying the images captured by the imaging unit; and a controller for controlling at least the indenter moving unit, wherein the controller detects the respective tip positions of the pair of support parts and the respective tip positions of the pair of contact parts of the indenter from the images formed by imaging the pair of contact parts of the indenter and the pair of support parts, and displays auxiliary lines connecting the tip positions of the pair of contact parts and the tip positions of the pair of support parts on the display monitor.

[0016] Furthermore, according to one aspect of the present invention, a first center, which is the center between the respective tip positions of a pair of support parts, and a second center, which is the center between the respective tip positions of a pair of contact parts, are detected, and vertical auxiliary lines are displayed on the display monitor at the positions of the first center and the second center, respectively.

[0017] Furthermore, according to one aspect of the present invention, the pair of contact portions are formed at the tip of a single indenter. [Effects of the Invention]

[0018] The present invention provides the following effects: In other words, according to one aspect of the present invention, in a four-point bending test, the position of the indenter tip and the position of the support part of the test piece can be detected based on the captured image, making it possible to adjust the position of the indenter with higher precision and ease.

[0019] Further, according to one aspect of the present invention, since the pair of contact portions are formed at the tip of one indenter, it is possible to adjust the tip positions of the pair of contact portions as a whole instead of individually, and it is possible to easily perform the adjustment of the entire indenter.

Brief Description of the Drawings

[0020] [Figure 1] It is a perspective view showing a test apparatus. [Figure 2] It is a perspective view showing a support unit. [Figure 3] It is a diagram for explaining the configuration of the support unit and the indenter. [Figure 4] It is a diagram showing a configuration example of a controller. [Figure 5] (A) is a diagram for explaining a state in which a test piece is set. (B) is a diagram showing a state in which the indenter contacts the test piece. (C) is a diagram showing a state in which the test piece is broken. [Figure 6] It is a flowchart for adjusting the position of the indenter. [Figure 7] It is a diagram showing an example of a captured image. [Figure 8] It is a diagram showing an example of a captured image after the first adjustment step. [Figure 9] It is a diagram for explaining the second adjustment step. [Figure 10] It is a diagram showing an example of a captured image after the second adjustment step.

Embodiments for Carrying Out the Invention

[0021] Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, a test apparatus 2 according to an embodiment of the present invention includes a box-shaped lower container 4 formed in a rectangular parallelepiped shape. In the lower container 4, a rectangular parallelepiped-shaped opening 4b that opens upward on the upper surface 4a side of the lower container 4 is formed. Inside this opening 4b, a support unit 6 that supports a test piece whose strength is measured by the test apparatus 2 is provided.

[0022] Figure 2 is a perspective view showing the support unit 6. The support unit 6 comprises a pair of support bases 8 for supporting the test specimen. Each of the support bases 8 is formed in the shape of a rectangular parallelepiped and is spaced apart from each other so that a gap 10 is provided between them. The pair of support bases 8 are also positioned so that the longitudinal direction of their upper surfaces 8a aligns with the first horizontal direction (Y-axis direction, front-back direction). The test specimen (tip) whose strength is to be measured is placed on this pair of support bases 8.

[0023] Each of the pair of support bases 8 has a support portion 8b formed on its upper surface 8a, which is a convex ridge projecting upward from the upper surface 8a. The support portion 8b is made of a metal such as stainless steel and is positioned adjacent to the gap 10 with its length aligned with the Y-axis direction. The pair of support portions 8b are positioned spaced apart from each other across the gap 10 and support the lower surface of the test piece. In Figure 2, the support portion 8b has a curved upper surface.

[0024] Furthermore, the upper surfaces 8a of the pair of support bases 8 are each provided with plate-shaped contact members 12 made of a material more flexible than the support portion 8b (such as rubber sponge). The pair of contact members 12 are formed in a rectangular shape in plan view and are provided on both sides of the pair of support portions 8b. That is, the contact members 12 are each positioned on the opposite side of the gap 10 of the support portion 8b, and the pair of support portions 8b are positioned between the pair of contact members 12.

[0025] The upper surface of the contact member 12 constitutes a contact surface 12a that contacts the test specimen and supports it. The contact member 12 is positioned such that its contact surface 12a is located above the upper end of the support portion 8b (for example, about 1 mm above the upper end of the support portion 8b). Therefore, when the test specimen is placed on the pair of support bases 8, the lower surface of the test specimen does not come into contact with the support portion 8b, but comes into contact with the contact surface 12a of the contact member 12.

[0026] A support movement mechanism 14 is provided on the rear side of the pair of support bases 8, which moves each of the pair of support bases 8 along a first horizontal direction and a second horizontal direction perpendicular to it (X-axis direction, left-right direction). The support movement mechanism 14 comprises a rectangular parallelepiped support structure 16, and a pair of guide rails 18 are fixed to the front side (surface side) of the support structure 16 at predetermined intervals along the X-axis direction.

[0027] Between the pair of guide rails 18, there is a pair of ball screws 20 arranged approximately parallel to the pair of guide rails 18. A pulse motor 22 for rotating the ball screws 20 is connected to one end of each of the ball screws 20.

[0028] Furthermore, the support section movement mechanism 14 includes a pair of movable plates 24, each fixed to the rear side of a pair of support bases 8. Each movable plate 24 is slidably mounted on a pair of guide rails 18 provided on the front side of the support structure 16.

[0029] Furthermore, a nut portion (not shown) is provided on the rear side (back side) of each of the pair of movable plates 24. The nut portion on one of the pair of movable plates 24 is screwed onto one of the pair of ball screws 20, and the nut portion on the other of the pair of movable plates 24 is screwed onto the other of the pair of ball screws 20.

[0030] When the pulse motor 22 rotates the ball screw 20, the movable plate 24, which is screwed onto the ball screw 20, moves along the guide rail 18 in the X-axis direction. This controls the position of each of the pair of support bases 8 in the X-axis direction and the width of the gap 10.

[0031] As shown in Figure 1, a pressing unit 26 is provided above the lower container 4. The pressing unit 26 presses the test piece supported by the support unit 6 and measures the load applied to the pressing unit 26 when the test piece is pressed.

[0032] The pressing unit 26 includes a vertical movement unit 28 connected to the indenter movement unit 40. A cylindrical first support member 30 is connected to the lower surface of the vertical movement unit 28, and a load measuring unit 32, such as a load cell, is fixed to the lower end of the first support member 30.

[0033] A third support member 36 is connected to the lower side of the load measurement unit 32 via a second support member 34. An indenter fixing member 37 is fixed to the lower part of the third support member 36, and an indenter 39 is fixed to the indenter fixing member 37.

[0034] As shown in Figure 3, the tip (lower end) of the indenter 39 is provided with a pair of contact portions 39a, 39a, and is configured to be approximately V-shaped. The upper end of the indenter 39 is fixed to the indenter fixing member 37. The indenter 39 is a member that extends in the direction perpendicular to the plane of the paper, and, similar to the support base 8 shown in Figure 2, is composed of a member that has a width in the Y-axis direction of Figure 2. Note that the indenter 39 may be composed of a single member having a pair of contact portions 39a, 39a, or it may be composed of two members having contact portions fixed to the indenter fixing member 37 to form a single indenter.

[0035] As shown in Figure 1, an indenter movement unit 40 is provided on the rear side (back side) of the pressing unit 26 to move the pressing unit 26 along the vertical direction (Z-axis direction, up and down direction). The indenter movement unit 40 has a rectangular parallelepiped support structure 42, and a pair of guide rails 44 are fixed at predetermined intervals along the Z-axis direction on the front side (surface side) of the support structure 42.

[0036] Between the pair of guide rails 44, a ball screw 46 is provided, which is positioned approximately parallel to the pair of guide rails 44. A pulse motor 48 that rotates the ball screw 46 is connected to one end of the ball screw 46.

[0037] The rear side (back side) of the vertical movement unit 28 of the pressing unit 26 is slidably mounted on a pair of guide rails 44. A nut portion (not shown) is also provided on the rear side of the vertical movement unit 28, and this nut portion is screwed onto a ball screw 46.

[0038] When the pulse motor 48 rotates the ball screw 46, the vertical movement unit 28 moves along the guide rail 44 in the Z-axis direction. This controls the position of the pressing unit 26 in the Z-axis direction. Then, by moving the pressing unit 26 along the Z-axis direction using the indenter movement unit 40, the indenter 39 moves relatively closer to and further away from the support unit 6.

[0039] Furthermore, a pair of plate-shaped connecting members 50 are fixed to both sides of the vertical movement unit 28. The connecting members 50 are provided extending downward from the sides of the vertical movement unit 28, and the lower ends of the connecting members 50 are positioned below the lower ends of the third support member 36.

[0040] A pair of upper container support portions 50a are formed at the lower ends of the pair of connecting members 50, projecting toward the indenter 39. A rectangular parallelepiped upper container 52 (cover) that covers the tip of the indenter 39 is fixed between this pair of upper container support portions 50a. The upper container 52 is positioned above the lower container 4, and both sides are supported by the pair of upper container support portions 50a.

[0041] As shown in Figure 3, the upper container 52 is made of a transparent material (glass, plastic, etc.) and is formed in a box shape. The upper container 52 has a rectangular parallelepiped opening 52b that opens downwards on the lower surface 52a (Figure 1) side of the upper container 52. In addition, an indenter insertion hole 52d is formed on the upper surface 52c side of the upper container 52, into which the tip of the indenter 39 is inserted, and the tip of the indenter 39 is positioned inside the upper container 52. In Figure 1, a portion of the indenter 39 inserted inside the upper container 52 is shown with a dashed line.

[0042] As shown in Figure 1, the upper container 52 is sized to be insertable into the opening 4b (Figure 1) of the lower container 4, and is positioned inside the opening 4b (Figure 1) of the lower container 4 in a plan view. The opening 52b (Figure 3) of the upper container 52 is also sized to accommodate the support unit 6. Therefore, when the indenter moving unit 40 moves the pressing unit 26 downward, the upper container 52 is inserted into the opening 4b (Figure 1) of the lower container 4, and the upper side of the support unit 6 is covered by the upper container 52.

[0043] As shown in Figure 1, a gas supply pipe insertion hole 52f is provided in the side wall 52e of the upper container 52. As shown in Figure 3, a gas supply pipe 56 is inserted through this gas supply pipe insertion hole 52f to supply gas for air blowing by injecting gas onto the side and surrounding area of ​​the indenter 39. The gas supply pipe 56 can be made of a flexible resin tube and is connected to a gas supply source 60 via a valve 58 of the gas supply unit 54.

[0044] As shown in Figure 1, a fragment discharge port 4d is formed at the bottom of the lower container 4, penetrating from the bottom of the opening 4b of the lower container 4 to the lower surface (bottom surface) 4c of the lower container 4. A fragment discharge unit 62 is connected to this fragment discharge port 4d to discharge fragments of the test specimen present inside the lower container 4.

[0045] As shown in Figure 1, the fragment discharge unit 62 includes a fragment discharge passage 64 that constitutes a path for discharging fragments of the test specimen. One end of the fragment discharge passage 64 is connected to the fragment discharge port 4d, and the other end of the fragment discharge passage 64 is connected to the suction source 68 via a valve 66.

[0046] As shown in Figure 1, a fragment collection unit 70 for collecting fragments of the test specimen is provided in the fragment discharge passage 64. The fragment collection unit 70 is composed of a filter or the like and captures fragments of the test specimen passing through the fragment discharge passage 64. When the valve 66 is opened, the fragments of the test specimen scattered inside the opening 4b of the lower container 4 are sucked in from the fragment discharge port 4d and collected in the fragment collection unit 70.

[0047] As shown in Figure 1, an imaging unit (camera) 72 is provided on the rear side of the lower container 4, and a light source 74 that irradiates light toward the imaging unit 72 is provided on the front side of the lower container 4. The positions of the imaging unit 72 and the light source 74 are adjusted so that the imaging unit 72 can image the test piece and the tip of the indenter 39, which are supported by the support unit 6.

[0048] By irradiating the test specimen with light from the light source 74 and photographing the tip of the indenter 39 with the imaging unit 72, it is possible to observe how the test specimen is being pressed by the indenter 39 and the condition of the tip of the indenter 39 (presence or absence of foreign matter, presence or absence of chipping, etc.). However, if imaging by the imaging unit 72 is performed in a sufficiently bright environment, the light source 74 may be omitted.

[0049] As shown in Figure 1, each component of the test apparatus 2 is connected to a controller 200 that controls the operation of the test apparatus 2. This controller 200 controls the operation of the support mechanism 14, load measurement unit 32, indenter movement unit 40, gas supply unit 54, fragment discharge unit 62, imaging unit 72, light source 74, etc.

[0050] Figure 4 shows an example of the configuration of the controller 200, which includes a position detection unit 201 for detecting the two tip positions of the indenter 39 and the tip positions of the pair of support parts 8b shown in Figure 1, an auxiliary line creation unit 202 for displaying auxiliary lines based on the two tip positions of the indenter 39 and the tip positions of each support part 8b, a parallelism determination unit 203 for determining whether the auxiliary lines are parallel to each other, a center position calculation unit 204 for calculating the horizontal centers of the two tip positions of the indenter 39 and the tip positions of the pair of support parts 8b, a horizontal position determination unit 205 for determining whether the horizontal positions of each center coincide, a tone setting unit 206 for setting the tone of the sound generated from the speaker 301, and a speaker control unit 207 for controlling the volume of the speaker 301, etc.

[0051] As shown in Figure 4, the controller 200 includes an indenter movement control unit 208 that controls the operation of an indenter movement unit 40 (Figure 1) that moves the indenter 39 (Figure 1) up and down, a support part movement control unit 209 that controls the movement of a support part movement mechanism 14 (Figure 2) that moves a pair of support parts 8b (Figure 2) left and right, and an imaging control unit 210 that controls imaging of the indenter and support parts by the imaging unit 72.

[0052] As shown in Figure 4, the controller 200 is connected to a speaker 301 for providing audio to the operator, a display monitor 302 that displays various information and allows the operator to perform input operations, and an imaging unit 72. The display monitor 302 can be configured as a touch panel, for example, as shown in Figure 1. Alternatively, an operation unit for input operations may be provided independently of the display monitor, and the display monitor may only display information.

[0053] Next, we will explain how to measure the strength using the above configuration. As shown in Figure 5(A), the test specimen 11 is set on the upper surface of the contact member 12 so as to straddle the pair of support bases 8. The test specimen 11 is, for example, a rectangular semiconductor chip, but is not particularly limited.

[0054] As shown in Figures 5(A) and 5(B), the indenter 39 is lowered so that the pair of contact portions 39a come into contact with the upper surface of the test piece 11. At this time, the load (force in the Z-axis direction) applied to the indenter 39 is measured by the load measurement unit 32 (Figure 1).

[0055] As shown in Figure 5(B), as the indenter 39 descends further, the test piece 11 is pressed more firmly by the indenter 39, compressing the contact member 12 that supports the test piece 11 and causing the test piece 11 to flex. As a result, the lower surface of the test piece 11 comes into contact with the support portion 8b of the support base 8. When the test piece 11 comes into contact with the support portion 8b, the test piece 11 is supported by the pair of support portions 8b, and the load on the indenter 39 that presses the test piece 11 increases.

[0056] As shown in Figure 5(C), as the indenter 39 descends further, the test specimen 11 bends further and breaks. When the test specimen 11 breaks, the load measured by the load measurement unit 32 (Figure 3) decreases from its maximum value to zero. Therefore, the timing of the test specimen 11's breakage can be detected from the change in the load value measured by the load measurement unit 32. In addition, the maximum value of the load measured by the load measurement unit 32 is measured as the strength of the test specimen 11.

[0057] Next, we will explain how to adjust the position of the indenter, following the flowchart shown in Figure 6. <Image acquisition and formation step S1> As shown in Figure 7, the step involves capturing images of the pair of contact portions 39a and the pair of support portions 8b of the indenter 39, forming an captured image 80, and displaying it.

[0058] Specifically, the indenter 39 is lowered to position the contact portion 39a near the support base 8, and the imaging control unit 210 (Figure 4) activates the imaging unit 72 (Figure 1) to image the area including the pair of contact portions 39a at the tip of the indenter 39 and the pair of support portions 8b, thereby acquiring an image 80. This image 80 is displayed on the display monitor 302 and may be a still image or a video that updates in real time showing the state of the imaging area.

[0059] <Detection step S2> As shown in Figure 7, the step involves detecting the tip positions 8c of each of the pair of support parts 8b and the tip positions 39c of each of the pair of contact parts 39a of the indenter 39 from the captured image 80.

[0060] Specifically, the position detection unit 201 (Figure 4) analyzes the captured image 80 to detect the tip positions 8c of each support part 8b and the tip positions 39c of each contact part 39a. The tip positions 8c of each support part 8b can be detected, for example, by identifying the highest point of each support part 8b. The tip positions 39c of each contact part 39a can be detected, for example, by identifying the lowest point of each contact part 39a.

[0061] <Step S3: Displaying the first auxiliary line> As shown in Figure 7, the auxiliary line creation unit 202 (Figure 4) displays an auxiliary line 8h connecting the tip positions 8c of the detected pair of support parts 8b, and an auxiliary line 39h connecting the tip positions 39c of the detected pair of contact parts 39a.

[0062] In addition to the auxiliary lines 8h and 39h, the angles of both auxiliary lines 8h and 39h, as well as the numerical values ​​of the angle deviation, may also be displayed. This would allow the operator to recognize the deviation in the inclination of the auxiliary lines 8h and 39h.

[0063] <First adjustment step S4> As shown in Figure 7, the step involves adjusting the angle of the indenter 39 so that the pair of contact portions 39a and the pair of support portions 8b are parallel in the horizontal direction, based on the detected tip positions 8c and 39c.

[0064] Specifically, as shown in Figure 7, the angle of the indenter 39 is adjusted so that the auxiliary line 39h for the pair of contact parts 39a is parallel in the horizontal direction to the auxiliary line 8h for the pair of support parts 8b. Figure 7 shows that the auxiliary line 39h for the contact part 39a is not parallel to the auxiliary line 8h for the support part 8b, but is inclined.

[0065] The angle of the indenter 39 can be adjusted by the operator adjusting the fixed angle of the indenter 39 (Figure 3) while viewing the display monitor 302. The fixed angle can be adjusted, for example, by adjusting the angle of the indenter fixing member 37 relative to the third support member 36 (Figure 3). Alternatively, for example, an electrically operated automatic adjustment mechanism for adjusting the angle of the third support member 36 may be provided, allowing the operator to automatically complete the angle adjustment of the indenter 39 by operating the display monitor 302.

[0066] As shown in Figure 8, the auxiliary line creation unit 202 (Figure 4) updates the auxiliary line 39h in accordance with the angle adjustment of the indenter 39, and the parallelism determination unit 203 (Figure 4) determines whether the auxiliary line 39h is parallel to the auxiliary line 8h. If it is determined that they are parallel, for example, a display monitor 302 displays 304 indicating that they are parallel, and sound is output from the speaker 301 (Figure 1). This allows the operator to recognize that both auxiliary lines 39h and 8h are parallel.

[0067] Furthermore, the parallelism determination unit 203 (Figure 4) determines whether the auxiliary line 39h is parallel to the auxiliary line 8h when the first auxiliary line display step S3 is completed. If they are parallel, it displays 304 (Figure 8) or outputs sound in the same way as above, allowing the operator to recognize that both auxiliary lines 39h and 8h are parallel.

[0068] Furthermore, in the first adjustment step S4, it is necessary to adjust the angle of the indenter 39. As shown in Figure 3, in this embodiment, the pair of contact portions 39a, 39a are formed at the tip of one indenter 39 and fixed to the indenter fixing member 37. Therefore, it is possible to adjust the tip positions 39c, 39c of the pair of contact portions 39a, 39a as a whole rather than individually, making it easy to adjust the indenter 39 as a whole.

[0069] <Second auxiliary line display step S5> As shown in Figure 8, after the first adjustment step, the center position calculation unit 204 (Figure 4) detects the first center 8M, which is the center between the tip positions 8c of the pair of support parts 8b, and the second center 39M, which is the center between the tip positions 39c of the contact part 39a. The auxiliary line creation unit 202 (Figure 4) then displays vertical auxiliary lines 8k and 39k at the coordinate positions of the first center 8M and the second center 39M, respectively.

[0070] In addition to the auxiliary lines 8k and 39k, the numerical value of the horizontal displacement D between the auxiliary lines 8k and 39k may also be displayed. This allows the operator to recognize the horizontal displacement between the first center 8M and the second center 39M.

[0071] <Second adjustment step S6> This step involves aligning the first center 8M and the second center 39M in the horizontal direction. Specifically, as shown in Figures 8 and 9, the first center 8M and the second center 39M are aligned in the horizontal direction. In this embodiment, the support unit movement control unit 209 (Figure 5), as shown in Figure 9, drives the support unit movement mechanism 14 (pulse motor 22) to move the support base 8 horizontally while maintaining the distance L between the pivot points of the support units 8b, 8b, and performs position adjustment so that the first center 8M, which is the center of the tip positions 8c of both support units 8b, aligns with the second center 39M, which is the center of the two contact points 39a.

[0072] In the examples shown in Figures 8 and 9, a displacement D exists between the first center 8M and the second center 39M, and the support base 8 is moved to the left in the figure so that this displacement D becomes zero.

[0073] As shown in Figure 9, the distance L between each support 8b is predetermined according to the type of test specimen, and both support bases 8 are moved in the X-axis direction while maintaining this distance L.

[0074] In this second adjustment step S6, the support unit movement control unit 209 automatically drives and stops the support unit movement mechanism 14 based on the operator's operation of the display monitor 302, thereby automatically completing the position adjustment. Alternatively, the operator may manually operate the display monitor 302 while viewing the captured image 80 on the display monitor 302 to drive and stop the support unit movement mechanism 14 to perform the position adjustment. Furthermore, the support unit movement mechanism 14 (pulse motor 22) may be omitted, and the position of the support base 8 may be adjusted manually by the operator.

[0075] As shown in Figure 10, the horizontal position determination unit 205 (Figure 4) determines whether the horizontal coordinates of the first center 8M and the second center 39M coincide. If it is determined that they coincide, for example, the display monitor 302 displays a message 305 indicating that the centers coincide, and sound is output from the speaker 301 (Figure 1). This allows the operator to recognize that the first center 8M and the second center 39M coincide.

[0076] Furthermore, the horizontal position determination unit 205 (Figure 4) determines whether the first center 8M and the second center 39M coincide when the first adjustment step S4 and the second auxiliary line display step S5 are completed. If they coincide, it displays 305 (Figure 10) or outputs sound in the same way as above, allowing the operator to recognize that the first center 8M and the second center 39M coincide.

[0077] Furthermore, in the above embodiment, the second adjustment step S6 is performed by moving the pair of support bases 8 (support parts 8b) in the X-axis direction (horizontal direction) to adjust the relative position of the indenter 39 and the support bases 8 (support parts 8b) in the X-axis direction (horizontal direction). However, the relative position of the indenter 39 with respect to the pair of support bases 8 (support parts 8b) may also be adjusted by moving the indenter 39 in the X-axis direction (horizontal direction).

[0078] As described above, according to the present invention, in a four-point bending test, the position of the indenter tip and the position of the support part of the test piece can be detected based on the captured image, making it possible to adjust the position of the indenter with higher precision and ease. [Explanation of symbols]

[0079] 2. Test equipment 6 Support Units 8 Support stand 8M 1st center 8b Support part 8c Tip position 8h auxiliary lines 8k auxiliary lines 11 Test specimens 37 Indenter fixing member 39 Indenter 39M 2nd center 39a Contact part 39c Tip position 39h Auxiliary line 39k auxiliary line 72 Imaging Unit 74 Light source 80 captured images 200 controllers 201 Position detection unit 202 Auxiliary Line Creation Section 203 Parallelism determination unit 204 Center position calculation section 205 Horizontal position determination section 206 Tone setting section 207 Speaker Control Unit 208 Indenter movement control unit 209 Support Unit Movement Control Unit 210 Imaging control unit 301 Speaker 302 Display Monitor

Claims

1. A pair of support parts arranged horizontally at a predetermined interval and supporting the lower surface of the test piece, An indenter having a pair of contact parts positioned above the support part and between the pair of support parts, which contact and press against the test piece supported by the support part, An indenter moving unit that moves the indenter relatively close to a test piece supported by a pair of support parts, A load measuring unit that measures the load applied by the indenter to a test piece supported by a pair of support parts, A method for adjusting a test apparatus equipped with, Image acquisition image forming step, which involves imaging a pair of corresponding contact portions and a pair of corresponding support portions of the indenter to form an image, A detection step for detecting the tip positions of each of the pair of support parts and the tip positions of each of the pair of contact parts of the indenter from the captured image, A first adjustment step involves adjusting the angle of the indenter so that a pair of corresponding contacts and a pair of support parts are parallel in the horizontal direction, based on the detected tip positions. A method for adjusting a test apparatus equipped with the following features.

2. Between the detection step and the first adjustment step, An auxiliary line connecting the tip positions of each of the detected pair of support parts, The method for adjusting a test apparatus according to claim 1, further comprising a first auxiliary line display step of displaying an auxiliary line connecting the respective tip positions of a pair of detected contact portions.

3. After the first adjustment step, The first center, which is the center between the tip positions of the pair of support parts, and the second center, which is the center between the tip positions of the corresponding contact part, are detected. A second auxiliary line display step in which vertical auxiliary lines are displayed at the positions of the first center and the second center, A second adjustment step to align the first center and the second center in the horizontal direction, A method for adjusting a test apparatus according to claim 1 or 2, characterized by comprising the following:

4. A test apparatus, A pair of support parts arranged at a predetermined interval to support the lower surface of the test piece, An indenter having a pair of contact parts positioned above the support part and between the pair of support parts, which contact and press against the test piece supported by the support part, An indenter moving unit that moves the indenter relatively close to a test piece supported by a pair of support parts, A load measuring unit that measures the load applied by the indenter to a test piece supported by a pair of support parts, An imaging unit for imaging the indenter and the support portion, A display monitor that displays the captured image from the imaging unit, It comprises at least a controller for controlling the indenter movement unit, The controller is, A test apparatus that detects the tip positions of the pair of support parts and the tip positions of the pair of contact parts of the indenter from an image formed by imaging the pair of contact parts and the pair of support parts of the indenter, and displays auxiliary lines connecting the tip positions of the pair of contact parts and the tip positions of the pair of support parts on the display monitor.

5. The system detects a first center, which is the center between the tip positions of a pair of support parts, and a second center, which is the center between the tip positions of a pair of corresponding contact parts, and displays vertical auxiliary lines on the display monitor at the positions of the first center and the second center, respectively. The test apparatus according to feature 4.

6. The pair of contact portions are formed at the tip of one indenter. The test apparatus according to claim 4 or 5, characterized by the features described herein.

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