Test device

Abstract

Test device (2) for measuring the strength of a sample (11), wherein the test device (2) comprises: a lower container (4) having an opening (4b) that opens upwards; an upper container (52) having an opening (52b) that opens downwards and is dimensioned to fit into the opening (4b) of the lower container (4); a support unit (6) which is provided in the opening (4b) of the lower container (4) and which carries the sample (11); a pressure unit (26), comprising a stamp (38) that presses the sample (11), and a load measuring unit (32) that measures a load applied to the punch (38); and a movement mechanism (40) that moves the piston (38) relative to the support unit (6) closer to and away from it, wherein when the sample (11) carried by the support unit (6) is pressed by the plunger (38) moved by the movement mechanism (40), the upper container (52) is positioned so that it covers the sample (11).

Description

TECHNICAL BACKGROUND Technical field

[0001] The present invention relates to a test device for measuring the strength of a sample. Description of the related technique

[0002] Several components, such as an integrated circuit (IC) or a large-scale integration (LSI), are formed on a semiconductor wafer. Cutting the semiconductor wafer produces multiple component chips, each containing one of these components. These component chips are used in various electronic devices, such as mobile phones and PCs.

[0003] A cutting device is used to divide a semiconductor wafer. The cutting device typically includes a clamping table and a cutting unit. The clamping table holds the semiconductor wafer. The cutting unit has an attached ring-shaped cutting blade. The cutting blade is used to cut the semiconductor wafer. By rotating the cutting blade and causing it to cut into the semiconductor wafer, the wafer is cut and divided into multiple component chips. In recent years, electronic devices have become smaller and thinner. This has created a demand for thinner component chips. To meet this demand, a process is available that grinds and thins the semiconductor wafer before dividing it. The semiconductor wafer is ground using a grinding device. The grinding device typically includes a clamping table and a grinding unit.The clamping table holds the semiconductor wafer. The grinding unit has a grinding wheel attached to it. The grinding wheel has a grinding stone for grinding the semiconductor wafer.

[0004] When the semiconductor wafer is processed using the cutting or grinding device described above, a processing stress (such as cutting or grinding stress) can develop within the wafer. If this processing stress remains in a component chip obtained by cutting the semiconductor wafer, the chip's strength is likely to decrease, potentially leading to damage. Therefore, the processing conditions of the semiconductor wafer are designed to maintain the component chip's strength above a certain level.

[0005] The strength of the component chip is measured, for example, by a three-point bending test using the component chip as a specimen. The three-point bending test measures the specimen's strength by pressing a punch against a central section of the specimen, supporting both ends, and monitoring the load applied to the punch pressing the specimen. For example, Japanese patent application JP H09-229838A discloses a test device (measuring device) for measuring the strength (flexural strength) of the specimen by performing the three-point bending test.

[0006] Further information helpful for understanding this application can be found in the following documents: CN 1 09 253 913 B relates to a device and a method for measuring the dynamic fracture strength of a material. US 2012 / 0289060A1 concerns a wafer processing method for processing the back side of a wafer. PRESENTATION OF THE INVENTION

[0007] When the test device measures the strength of a sample, it presses, for example, the punch against the sample until it breaks and detects the maximum value of the load applied to the punch. When the sample breaks, fragments are scattered. Therefore, the operator wearing protective equipment such as safety glasses during the test is responsible for this. However, wearing protective equipment restricts the operator's field of vision and reduces the visibility of the sample and the components (such as the punch) of the test device. This reduced visibility makes it more difficult to accurately test the sample's strength.

[0008] The present invention was developed in consideration of the problem described above. One objective of the present invention is to provide a test device capable of facilitating a strength test of a sample.

[0009] According to one aspect of the present invention, a test apparatus for measuring the strength of a specimen is provided. The test apparatus comprises: a lower container having an opening that opens upwards; an upper container having an opening that opens downwards and which is dimensioned to be inserted into the opening of the lower container; a support unit provided in the opening of the lower container and supporting the specimen; a pressing unit comprising a plunger that presses the specimen and a load-measuring unit that measures a load applied to the plunger; and a movement mechanism that moves the plunger relative to the support unit closer to and away from it, wherein, when the specimen supported by the support unit is pressed by the plunger moved by the movement mechanism, the upper container is positioned to cover the specimen.

[0010] Preferably, the test device further comprises: a fragment discharge path having one end coupled to a fragment discharge path formed at the bottom of the lower container, and another end coupled to a suction source; and a fragment collector provided in the fragment discharge path that collects a fragment of the sample. Preferably, the test device further comprises a nozzle that blows air towards the plunger.Preferably, the support unit further comprises a pair of support sections spaced apart from each other and supporting a lower surface of the sample, and a pair of contact elements, each provided on respective sides of the pair of support sections and each having a contact surface that touches and supports the sample, wherein each of the contact elements is provided such that the contact surface is positioned higher than the upper ends of the pair of support sections, wherein the plunger is positioned above the pair of support sections such that it overlaps with an area between the pair of support sections, and wherein, when the sample is pressed by the plunger, the sample is supported by the pair of support sections.

[0011] In the test apparatus according to the described aspect of the present invention, the upper container is positioned so that it covers the sample when the sample, carried by the support unit, is pressed by the plunger. Therefore, the upper container, positioned in this way, prevents sample fragments from scattering outside the test apparatus when the sample is pressed and broken by the plunger. As described above, because the upper container prevents sample fragments from scattering outside the test apparatus, the operator of the test apparatus does not need to wear protective equipment such as safety glasses when testing the sample's strength. This, in turn, prevents a reduction in the visibility of the sample and the components (such as the plunger) of the test apparatus due to wearing protective equipment and facilitates the strength test of the sample.

[0012] The above and further aims, features and advantages of the present invention and the way in which they are realized will become more apparent, and the invention itself will best be understood by studying the following description and the attached claims with reference to the attached drawings, which show a preferred embodiment of the invention. SHORT FIGURE DESCRIPTION Fig. Figure 1 is a perspective view of a test device; Fig. 2 is a perspective view of a support unit; Fig. Figure 3 is a perspective view of a pressing unit; Fig. Figure 4 is a cross-sectional view of the test device with a sample carried by the support unit; Fig. Figure 5 is a cross-sectional view of the test apparatus with the specimen touching the bearing sections of a pair of bearing bases; and Fig. Figure 6 is a cross-sectional view of the test apparatus with the broken sample. DETAILED DESCRIPTION OF THE PREFERRED EXECUTION FORM

[0013] An embodiment according to one aspect of the present invention will be described below with reference to the accompanying drawings. First, an example of a test device configuration according to the present embodiment will be described. Fig. Figure 1 is a perspective view of a test device 2 for testing the strength of a sample (test piece).

[0014] Test device 2 measures the flexural strength (deflection strength) of the sample, such as a component chip. A silicon wafer has regions, each defined by several intersecting division lines (roads). Each region contains a component, such as an IC or an LSI. Dividing the silicon wafer along the multiple division lines produces, for example, component chips.

[0015] There are no restrictions regarding, for example, the type, material, shape, structure, and size of the sample whose strength is measured by the test device 2. For example, the sample can be a test chip obtained by splitting a wafer with a front face that has no component formed on it and a back face that has been ground or polished under a specified condition. The result of measuring the chip's strength using the test device 2 can be used, for example, to select the processing conditions of the semiconductor wafer. The sample can also be a chip or the like obtained by splitting a substrate made from a semiconductor other than silicon (SiC, GaAs, InP, GaN, or the like), or from another material such as sapphire, glass, ceramic, plastic, or metal.

[0016] The test apparatus 2 has a box-shaped lower container (receptacle) 4 with a rectangular parallelepiped shape. The lower container 4 has an opening 4b with a rectangular parallelepiped shape. The opening 4b is formed on one side of an upper surface 4a of the lower container 4 and opens upwards. A support unit (support means) 6 is provided within the opening 4b. The support unit 6 carries the specimen whose strength is measured by the test apparatus 2.

[0017] Fig. Figure 2 is a perspective view of a support unit 6. The support unit 6 has a pair of support bases 8 which support the specimen. The pair of support bases 8 have a rectangular parallelepiped shape and are spaced apart to provide a gap 10 between them. Each of the support bases 8 has a top surface 8a, and one longitudinal direction of the top surface 8a is parallel to a first horizontal direction (X-axis direction, front-back direction). The specimen, whose strength is to be measured, is placed on the pair of support bases 8.

[0018] A column-like (rod-shaped) support section 8b is formed on each of the upper surfaces 8a of the pair of support bases 8. In particular, each support section 8b projects upwards from one of the respective upper surfaces 8a. Each support section 8b is, for example, made of a metal such as stainless steel. Each support section 8b is positioned next to the gap 10 such that a longitudinal direction of each support section 8b is parallel to the X-axis direction. The pair of support sections 8b are spaced apart from each other, with the gap 10 between them, and support a lower surface of the specimen. With reference to Fig. 2 Each load-bearing section 8b has a curved upper surface.

[0019] A plate-like contact element 12 is formed on each of the upper surfaces 8a of the pair of support bases 8 and is made of a material (such as a rubber sponge) that is more flexible than the support section 8b. The pair of contact elements 12 has a rectangular shape in a top view and is provided on each side of the pair of support sections 8b. In particular, each contact element 12 is provided on the side of each of the pair of support sections 8b that faces the gap 10, and the pair of support sections 8b is positioned between the pair of contact elements 12. The upper surfaces of the pair of contact elements 12 form respective contact surfaces 12a. The contact surfaces 12a touch and support the specimen.Each contact element 12 is positioned such that its corresponding contact surface 12a is raised above the upper ends of the pair of support sections 8b (for example, approximately 1 mm higher than the upper ends of the pair of support sections 8b). Therefore, when the sample is placed on the pair of support bases 8, the lower surface of the sample does not touch the pair of support sections 8b, but rather the contact surfaces 12a of the pair of contact elements 12. Details of the contact between the pair of support sections 8b and the pair of contact elements 12 with the sample are described later (see ). Fig. 4, Fig. 5 to Fig. 6).

[0020] A support base movement mechanism (support base motion device) 14 is provided on a rear side of the pair of support bases 8. The support base movement mechanism 14 moves each of the pair of support bases 8 in a second horizontal direction (X-axis direction, left-right direction) perpendicular to the first horizontal direction. The support base movement mechanism 14 has a support structure 16 with a rectangular parallelepiped shape. A pair of guide rails 18 is attached to a front surface (front side) of the support structure 16 in the Y-axis direction with a predetermined gap arranged between the pair of guide rails 18. A pair of ball screws 20 are provided between the pair of guide rails 18 and are substantially parallel to the pair of guide rails 18. A pulse motor 22 is coupled to one end of each of the pair of ball screws 20 and rotates the respective ball screw 20 of the pair.

[0021] The support base movement mechanism 14 comprises a pair of movement plates 24. Each movement plate 24 is attached to a rear surface side of each of the pair of support bases 8. Each movement plate 24 is slidably mounted on the pair of guide rails 18 provided on the front surface side of the support structure 16. A nut section (not shown) is provided on a rear surface side (rear side) of each of the pair of movement plates 24. The nut section provided in one of the pair of movement plates 24 is screwed into one of the pair of ball screws 20, and the nut section provided in the other of the pair of movement plates 24 is screwed into the other of the pair of ball screws 20.When the pair of ball screws 20 is rotated by the respective pulse motors 22, the pair moves along the pair of guide rails 18 in the Y-axis direction, along the motion plates 24 screwed into the respective ball screws 20. In this way, the position of each of the pair of support bases 8 in the Y-axis direction and the width of the gap 10 are controlled.

[0022] There is no restriction on, for example, the shapes and sizes of the lower container 4 and the opening 4b, which are in Fig. 1 are shown. The shapes and sizes of the lower container 4 and the opening 4b are modified appropriately according to the shapes and sizes of the support unit and the support base movement mechanism 14.

[0023] A pressure unit 26 is provided above the lower container 4. The pressure unit 26 presses the sample carried by the support unit 6 and measures the load applied to the pressure unit 26 at the moment the sample is pressed.

[0024] Fig. Figure 3 is a perspective view of the push unit 26. The push unit 26 has a motion base 28 coupled to a motion mechanism (movement means) 40. A cylindrical first support element 30 is coupled to a lower surface of the motion base 28 and extends downwards from the lower surface of the motion base 28. A load measuring unit (load measuring means) 32 is attached to a lower end face of the first support element 30. The load measuring unit 32 has a load cell and the like. A retaining element 36 is coupled to a lower face of the load measuring unit 32, with a cylindrical second support element 34 arranged between the retaining element 36 and the load measuring unit 32. The retaining element 36 is substantially gate-shaped in a front view and has a pair of retaining surfaces 36a facing each other.A punch 38 is attached between the pair of holding surfaces 36a and presses the sample carried by the support unit 6.

[0025] A tip section (lower end section) of the punch 38 has a tapered shape, with its width decreasing towards the bottom. In particular, both side surfaces of the tip section of the punch 38 are inclined relative to a vertical direction (Z-axis direction, top-bottom direction). Even though the tip (lower end) of the punch 38 has a rounded shape (R-shape) (see Fig. 4), the shape of the punch 38 is not limited to a rounded shape. The punch 38 is supported by the retaining element 36 such that the lower end of the punch 38 is parallel to the X-axis direction. In other words, the lower end of the punch 38 and the pair of support sections 8b (see Fig. 2), which are present in the support unit 6, are essentially parallel to each other.

[0026] The motion mechanism 40 is located on a rear side (back) of the pressing unit 26. The motion mechanism 40 moves the pressing unit 26 in the vertical direction. The motion mechanism 40 has a support structure 42 with a rectangular parallelepiped shape. A pair of guide rails 44 is attached to a front surface (front) of the support structure 42 in the Z-axis direction, with a predetermined gap between the pair of guide rails 44. A ball screw 46 is located between the pair of guide rails 44 and is substantially parallel to the pair of guide rails 44. A pulse motor 48 is coupled to one end of the ball screw 46 and rotates the ball screw 46.

[0027] A rear surface (back) of the motion base 28 of the push unit 26 is slidably mounted on the pair of guide rails 44. A nut section (not shown) is provided on the rear surface of the motion base 28 and is screwed into the ball screw 46. When the ball screw 46 is rotated by the pulse motor 48, the motion base 28 moves in the Z-axis direction along the pair of guide rails 44. In this way, the position of the push unit 26 in the Z-axis direction is controlled. When the motion mechanism 40 moves the push unit 26 in the Z-axis direction, the punch 38 moves relative to the support unit 6, either closer to or away from it.

[0028] As in Fig. As shown in Figure 1, a pair of coupling elements 50, each having a plate shape, is attached to each side surface of the motion base 28. Specifically, each coupling element 50 extends downwards from one of the side surfaces of the motion base 28. A lower end of each coupling element 50 is positioned lower than a lower end of the retaining element 36. A pair of support sections 50a of the upper container is formed on each of the lower end sections of the pair of coupling elements 50 and projects towards the punch 38. An upper container (cover) 52 with a rectangular parallelepiped shape is attached between the pair of support sections 50a of the upper container and covers the tip section of the punch 38. The upper container 52 is positioned above the lower container 4. Both side surfaces of the upper container 52 are supported by the pair of support sections 50a of the upper container.

[0029] The upper container 52 has a box shape and is made, for example, of a transparent material (glass, plastic, or the like). The upper container 52 has an opening 52b which has a rectangular parallelepiped shape (see Fig. 4) The opening 52b is formed on one side of a lower surface 52a of the upper container 52 and opens downwards. A punch insertion hole 52d is formed on one side of an upper surface 52c of the upper container 52, and the tip section of the punch 38 is inserted into the punch insertion hole 52d. Therefore, the tip section of the punch 38 is covered by the upper container 52. With reference to Fig. Figure 1 shows a dashed line representing part of the punch 38 that is covered by the upper container 52. The upper container 52 is dimensioned to fit into the opening 4b of the lower container 4 and is positioned within the opening 4b of the lower container 4 in a top view. The opening 52b (see Figure 1) Fig. 4) The upper container 52 is dimensioned to accommodate the support unit 6. Therefore, when the pressure unit 26 is moved downwards by the movement mechanism 40, the upper container 52 is inserted into the opening 4b of the lower container 4 and covers one upper side of the support unit 6.

[0030] A nozzle insertion hole 52f is provided in a side wall 52e of the upper container 52. An air supply unit 54 is coupled to the nozzle insertion hole 52f and blows air towards the tip section of the piston 38. The air supply unit 54 has a nozzle 56. The nozzle 56 blows air towards the piston 38. One end of the nozzle 56 is inserted into the upper container 52 through the nozzle insertion hole 52f, with the other end of the nozzle 56 being coupled to an air supply source 60 via a valve 58. A tip 56a of one end of the nozzle 56 opens towards a side surface of the tip section of the piston 38 (see Fig. 4) Blowing air from the air supply source 60 to the side surface of the tip section of the piston 38 through the valve 58 and the nozzle 56 removes foreign substances that adhere, for example, to the tip section of the piston 38, the pair of support sections 8b and the contact surfaces 12a (see Fig. 2) Details of the operation of the air supply unit 54 will be described later.

[0031] A fragment discharge opening 4d is formed at the bottom of the lower container 4. Specifically, the fragment discharge opening 4d extends from the bottom of the opening 4b of the lower container 4 through a lower surface (bottom surface) 4c of the lower container 4. A fragment discharge unit 62 is coupled to the fragment discharge opening 4d and discharges fragments of the sample located within the lower container 4. The fragment discharge unit 62 has a fragment discharge path 64. The fragment discharge path 64 forms a path for discharging the sample fragments. One end of the fragment discharge path 64 is coupled to the fragment discharge opening 4d, while the other end of the fragment discharge path 64 is coupled to a suction source 68 via a valve 66. A fragment collector 70 is provided in the fragment discharge path 64 and collects the sample fragments.The fragment collector 70, for example, has a filter and captures the sample fragments that pass through the fragment discharge path 64. When the valve 66 is open, the sample fragments distributed within the openings 4b of the lower container 4 are drawn in through the fragment discharge opening 4d and collected by the fragment collector 70. Details of the operation of the fragment discharge unit 62 will be described later.

[0032] An imaging unit (camera) 72 is provided on a rear side of the lower container 4. A light source 74 is provided on a front side of the lower container 4 and emits light in the direction of the imaging unit 72. The positions of the imaging unit 72 and the light source 74 are adjusted so that the imaging unit 72 can image, for example, the sample carried by the support unit 6 and the tip position of the punch 38. While the light source 74 emits light, the imaging unit 72 images the tip section of the punch 38. Accordingly, the operator can observe the sample as it is pressed by the punch 38 and the condition of the tip section of the punch 38 (the presence / absence of adhering foreign matter, flaking, or the like). If the imaging unit 72 performs the imaging in a sufficiently bright environment, the light source 74 can be omitted.

[0033] Each component in the test device 2 is coupled to a control unit (not shown) that controls the operation of the test device 2. For example, the actuations of the support base movement mechanism 14, the load measuring unit 32, the movement mechanism 40, the air supply unit 54, the fragment dispensing unit 62, the imaging unit 72, the light source 74, and the like are controlled by the control unit.

[0034] A three-point bending test can be performed on the specimen using the test apparatus 2 described above. The three-point bending test is performed to measure the flexural strength (deflection strength) of the specimen. The following section describes an example of the operation of test apparatus 2 during a measurement of the specimen's strength. Fig. Figure 4 is a cross-sectional view of the test device 2 with a sample (test piece) 11 carried by the support unit 6. As in Fig. As shown in Figure 4, the punch 38 is positioned above the pair of support sections 8b such that it overlaps the area (gap 10) between the pair of support sections 8b. The punch 38 is designed such that its tip (lower end) is parallel to the longitudinal direction (X-axis direction) of the support section 8b.

[0035] When the strength of specimen 11 is measured, the support base movement mechanism 14 (see Fig. 2) Set the positions of the pair of support bases 8 in the Y-axis direction. The positions of the pair of support bases 8 are adjusted so that the gap 10 has a suitable width, for example, according to the dimensions of the specimen 11. The specimen 11 is then placed on the pair of support bases 8. In particular, the specimen 11 is positioned so that both end sections of the specimen 11 are supported by the pair of support bases 8 and a central section of it overlaps with the gap 10.

[0036] If the lower surface of sample 11 touches the pair of support sections 8b when sample 11 is placed on the pair of support bases 8, the lower surface of sample 11 may be damaged by impact during placement. This damage can alter the strength of sample 11 and make it difficult to measure the strength of multiple samples 11 under the same conditions. Therefore, in the present embodiment, contact elements 12, made of a flexible material, are provided on the respective upper surfaces 8a of the pair of support bases 8, and the contact surfaces 12a of the contact elements 12 are positioned higher than the upper ends of the pair of support sections 8b. Accordingly, when sample 11 is placed on the pair of support bases 8, it does not touch the support sections 8 but rather contacts the contact surfaces 12a of the contact elements 12 and is supported by them.This design prevents the lower surface of specimen 11 from touching and being damaged by the pair of support sections 8b when specimen 11 is placed. This, in turn, minimizes any change in the strength of specimen 11.

[0037] Next, the pressure unit 26 is lowered by the movement mechanism 40 (see Fig. 3) When the pressing unit 26 is lowered, the tip of the punch 38 touches an upper surface of the specimen 11 and the specimen 11 is pressed by the punch 38. The load measuring unit 32 (see Fig. 3) The load (force in the Z-axis direction) applied to the punch 38 pressing on the specimen 11 is measured. As the pressing unit 26 is lowered further, the specimen 11 is pressed further by the punch 38. Consequently, the pair of contact elements 12 supporting the specimen 11 is deformed, and the specimen 11 is bent. As a result, the lower surface of the specimen 11 contacts the bearing sections 8b of the pair of bearing bases 8. At this point, the pair of contact elements 12 may be deformed, but depending on the flexibility of the pair of contact elements 12, the specimen 11 may not be bent. Fig. Figure 5 is a cross-sectional view of the test device 2, where the specimen 11 is in contact with the support sections 8b of the pair of support bases 8. In particular, when the specimen 11 is in contact with the pair of support sections 8b, the specimen 11 is supported by the pair of support sections 8b and the load applied to the punch 38 pressing on the specimen 11 increases.

[0038] As the pressing unit 26 is lowered further, the specimen 11, supported by the pair of bearing sections 8b, is pressed further by the punch 38. Consequently, the specimen 11 is bent. If the pressing force applied to the specimen 11 by the punch 38 exceeds a certain value, the specimen 11 breaks. Fig. Figure 6 is a cross-sectional view of the test device 2 with the broken specimen 11. When the specimen 11 is broken, the load measured by the load measuring unit 32 decreases from the maximum value to 0.

[0039] Accordingly, the time at which specimen 11 breaks can be detected based on the change in the value of the load measured by the load measuring unit 32. The maximum value of the load measured by the load measuring unit 32 corresponds to the strength of specimen 11. In particular, the bending stress of specimen 11 is calculated based on the maximum value of the load applied to the punch 38, the distance between the upper ends of the pair of support sections 8b, and the dimensions of specimen 11. The bending stress σ of specimen 11 is given by σ = 3 WL / 2bh 2represented where W [N] represents the maximum value of the load applied to the punch 38 pressing the specimen 11, L [mm] represents the distance between the upper ends of the pair of support sections 8b, b [mm] represents the width of the specimen 11 (the length of the specimen 11 in the direction (X-axis direction) perpendicular to a straight line connecting the pair of support sections 8b), and h [mm] represents the thickness of the specimen 11.

[0040] When sample 11 has been broken, fragments 11a of sample 11 are distributed. When sample 11 is pushed by the punch 38, the upper container 52 is positioned so that it holds sample 11 and the upper side of the support unit 6 as shown. Fig. Figure 6 covers the upper container 52. Therefore, the upper container 52, positioned in this way, prevents the fragments 11a of sample 11 from spreading outside the test device 2. As described above, because the upper container 52 prevents the fragments 11a from spreading outside the test device 2, the operator of the test device 2 does not need to wear a protective element such as safety goggles when testing the strength of sample 11. This, in turn, prevents a reduction in the visibility of sample 11 and the components (such as the punch 38) of the test device 2 due to wearing a protective element.

[0041] When sample 11 is pressed by the plunger 38, foreign matter (such as fragments 11a of sample 11) may adhere to the plunger 38. Since this foreign matter can affect the accuracy of the test, it is preferred to remove it. Therefore, after sample 11 has been tested, the air supply unit 54 preferably blows air towards the plunger 38 to remove the foreign matter adhering to it. In particular, after the valve 58 of the air supply unit 54 has been opened, the air supplied by the air supply source 60 is blown from the tip 56a of the nozzle 56 towards the side surface of the tip section of the plunger 38. Consequently, the foreign matter adhering to the tip section of the plunger 38 is blown away and removed. There is no restriction regarding the timing of the removal of the foreign matter using the air supply unit 54.For example, foreign materials can be removed as needed during the period after one sample 11 has been tested and before the next sample 11 is tested. The air blown towards the tip section of the plunger 38 flows within the upper container 52 and is also blown towards the pair of support bases 8. Consequently, foreign materials adhering to the pair of support sections 8b and the contact surfaces 12a of the pair of contact elements 12 (such as fragments 11a of sample 11) are blown away and removed by the air. This design can therefore prevent the foreign materials from touching the lower surface of sample 11 and damaging it in the next test.

[0042] When the tip 56a of the nozzle 56 is directed towards the upper surfaces 8a of the pair of support bases 8, the air blown by the nozzle 56 is forcefully blown towards the sides of the upper surfaces 8a of the pair of support bases 8. In this case, foreign substances adhering to the pair of support sections 8b or the pair of contact elements 12 may be blown away by the air and become suspended within the upper container 52. The foreign substances may then re-adhere to the pair of support sections 8b or the pair of contact elements 12. With this configuration, it is less likely that the foreign substances will be adequately removed from the sides of the upper surfaces 8a of the pair of support bases 8. In contrast, in the test device 2 according to the present embodiment, the tip 56a of the nozzle 56 opens towards the side surface of the tip section of the plunger 38.Consequently, the momentum is slightly attenuated by the air blown towards the sides of the upper surface 8a of the pair of support bases 8. This design effectively removes foreign substances from the sides of the upper surface 8a of the pair of support bases 8.

[0043] Repeated testing of sample 11 and removal of foreign substances using the air supply unit 54 collects the fragments 11a of sample 11 in the lower container 4. In the present embodiment, the fragment discharge unit 62 therefore collects (see Fig. 1) The fragments 11a accumulated in the lower container 4. In particular, after the valve 66 of the fragment discharge unit 62 is opened, the fragments 11a accumulated in the opening 4b are drawn out of the fragment discharge opening 4d provided at the bottom of the opening 4b of the lower container 4. The drawn-in fragments 11a pass through the fragment discharge path 64 and are collected by the fragment collector 70. In this way, the fragment discharge unit 62 can quickly remove the fragments 11a and eliminate the need for manual cleaning of the interior of the opening 4b of the lower container 4. In the test apparatus 2, the upper container 52 is smaller than the opening 4b of the lower container 4 and has the punch insertion hole 52d into which the punch 38 is inserted. Therefore, even when the upper container 52 is lowered towards the lower container 4, the opening 4b of the lower container 4 does not close.With this design, outside air can be easily drawn into the opening 4b when the fragments 11a of sample 11 are drawn in from the fragment discharge opening 4d, and the fragments 11a of sample 11 can be drawn in evenly.

[0044] In the test device 2 according to the present embodiment, when the sample 11, supported by the carrying unit 6, is pressed by the punch 38, the upper container 52 is positioned such that it covers the sample 11. Therefore, the upper container 52, positioned in this way, prevents the fragments 11a of the sample 11 from distributing outside the test device 2 when the sample is pressed and broken by the punch 38. As described above, because the upper container 52 prevents the fragments 11a from distributing outside the test device 2, the operator of the test device 2 does not need to wear protective equipment such as safety glasses when testing the strength of the sample 11. This, in turn, prevents a reduction in visibility of the sample 11 and the components (such as the punch 38) of the test device 2 due to wearing protective equipment and facilitates the strength test of the sample 11.

[0045] In the example described above, test device 2 performs the three-point bending test to measure the strength of specimen 11. However, the contents of the test to be performed by test device 2 can be suitably modified. For example, test device 2 can perform a ball bending strength test or a four-point bending test to test the strength of specimen 11. When test device 2 performs the ball bending strength test, it has a spherical punch that compresses specimen 11. Contacting the punch with a predetermined point on specimen 11 compresses the specimen 11. When test device 2 performs the four-point bending test, it has a pair of punches arranged parallel to the pair of support sections 8b (see Figure 2). Fig.2) Contacting the pair of plungers with a predetermined area of ​​the specimen 11 compresses the specimen 11. In both the ball strength test and the four-point bending test, the upper container 52 of the test apparatus 2 is positioned so that it covers the specimen 11 when the plunger(s) compress or compress it. This prevents the fragments 11a from spreading outside the test apparatus 2 when the specimen 11 is broken.

[0046] The structure, methods and the like according to the embodiment described above can be suitably modified and set up without deviating from the scope and purpose of the present invention.

[0047] The present invention is not limited to the details of the preferred embodiment described above. The scope of the invention is defined by the attached claims, and all changes and modifications that fall within the equivalent scope of protection of the claims are therefore included in the invention.

Claims

[1] Test apparatus (2) for measuring the strength of a sample (11), wherein the test apparatus (2) comprises: a lower container (4) having an opening (4b) that opens upwards; an upper container (52) having an opening (52b) that opens downwards and is dimensioned to fit into the opening (4b) of the lower container (4); a support unit (6) which is provided in the opening (4b) of the lower container (4) and which carries the sample (11); a pressure unit (26), comprising a stamp (38) that presses the sample (11), and a load measuring unit (32) that measures a load applied to the punch (38); and a movement mechanism (40) that moves the piston (38) relative to the support unit (6) closer to and away from it, wherein when the sample (11) carried by the support unit (6) is pressed by the plunger (38) moved by the movement mechanism (40), the upper container (52) is positioned so that it covers the sample (11). [2] Test apparatus (2) according to claim 1, further comprising: a fragment discharge path (64) having one end coupled to a fragment discharge opening (4d) formed on the bottom of the lower container (4), and another end coupled to a suction source (68); and a fragment collector (70) which is provided in the fragment delivery path (64) and collects a fragment of the sample (11). [3] Test apparatus (2) according to claim 1 or 2, further comprising: a nozzle (56) that blows air towards the piston (38). [4] Test apparatus (2) according to one of the preceding claims, wherein the carrying unit (6) has: a pair of support sections (8b) spaced apart from each other and supporting a lower surface side of the sample (11), and a pair of contact elements (12) each provided on respective sides of the pair of support sections (8b) and each having a contact surface (12a) which touches and supports the sample (11), wherein each of the pair of contact elements (12) is provided such that the contact surface (12a) is positioned higher than the upper ends of the pair of support sections (8b), wherein the stamp (38) is positioned above the pair of support sections (8b) such that it overlaps with an area between the pair of support sections (8b), and wherein, when the sample (11) is pressed by the punch (38), the sample (11) is supported by the pair of support sections (8b).

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