Bending strength measuring device

Abstract

To accurately determine the appropriate replacement timing for a pressing unit.SOLUTION: A bending strength measurement device 1 stores a first distance Z1 detected by an encoder (distance detection unit) 16 when a measurement block B disposed at one longitudinal end of a support portion 21 is pressed by a pressing portion 4 with a predetermined load value P, a second distance Z2 detected by the encoder 16 when a measurement block B disposed at the other longitudinal end of the support portion 21 is pressed by the pressing portion 4 with the predetermined load value P, and a third distance Z3 detected by the encoder 16 when a measurement block B disposed at a designated position in a central longitudinal region of the support portion 21 is pressed by the pressing portion 4 with the predetermined load value P. When the difference between the average of the first distance Z1 and the second distance Z2 and the third distance Z3, or the difference between the first distance Z1 and the third distance Z3, or the difference between the second distance Z2 and the third distance Z3 exceeds a preset threshold, the device determines that the pressing portion 4 is worn.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a flexural strength measuring device for measuring the flexural strength of a semiconductor chip. [Background technology]

[0002] A wafer on which a large number of devices are formed and dividing lines are formed is divided along the dividing lines using a cutting blade, a laser beam, or the like to obtain a plurality of semiconductor chips (hereinafter simply referred to as "chips").

[0003] Incidentally, in sample inspections of each chip, the chip's flexural strength is measured using a flexural strength measuring device, and only chips that are confirmed to have a flexural strength above a predetermined value are used in electronic devices such as personal computers and mobile phones (smartphones).

[0004] In a flexural strength measuring device for measuring the flexural strength of a chip, a three-point bending test is performed in which the underside of the chip is supported by two support parts spaced a predetermined distance apart, a knife-edge-shaped pressing part is lowered from above the center of the chip to press the chip with the tip of the pressing part, and the pressing load at the time the chip breaks is detected by a load sensor to measure the flexural strength (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-196183 Summary of the Invention [Problem to be solved by the invention]

[0006] However, since the measurement of the tip flexural strength using a flexural strength measuring device is performed by aligning the center of the tip with the center of the pressing part, problems arise in that the tip may be damaged or worn out by friction with the tip during the long-term measurement of the flexural strength of the center of the tip of the pressing part, making it impossible to accurately measure the tip flexural strength. For this reason, the pressing part is replaced periodically.

[0007] However, in reality, the amount of wear on the pressing part cannot be accurately determined, so the appropriate time to replace the pressing part is unclear, and there are problems such as the pressing part being replaced more frequently than necessary, or the bending strength being measured on a worn pressing part, making it impossible to make an accurate measurement.

[0008] The present invention has been made in view of the above problems, and an object of the present invention is to provide a bending strength measuring device that can accurately determine the appropriate time to replace a pressing part. [Means for solving the problem]

[0009] In order to achieve the above object, the present invention provides a flexural strength measuring device comprising: two support parts spaced apart in the length direction of two sides of one of two sets of two opposing pairs of two sides of a rectangular chip, extending in the length direction of the two sides for at least the length of the other set of two sides to support the underside of the chip; a pressing part that presses the chip supported by the support parts at a lower end extending in the length direction of the other set of two sides; an elevation mechanism that relatively raises and lowers the pressing part and the support parts; a distance detection part that detects the distance between the pressing part and the support parts that are relatively raised and lowered by the elevation mechanism; and a load sensor that measures the load when the chip is being pressed by the pressing part, wherein the device applies a predetermined load value to a measurement block that is located at one longitudinal end of the two support parts and has a width less than one-third the length of the support parts. a first memory unit that stores a first distance detected by the distance detection unit when the measurement block arranged at the other longitudinal end of the two support units is pressed by the pressing unit with a predetermined load value; a second memory unit that stores a second distance detected by the distance detection unit when the measurement block arranged at a specified position in the longitudinal center region of the two support units is pressed by the pressing unit with a predetermined load value; and a wear determination unit that determines that the pressing unit is worn when the difference between the average value of the first distance and the second distance and the third distance, or the difference between the first distance and the third distance, or the difference between the second distance and the third distance, becomes equal to or greater than a preset threshold value. [Effects of the Invention]

[0010] When measuring the flexural strength of a chip using a flexural strength measuring device, both longitudinal ends of the pressing part are hardly worn because they do not press against the chip, but the longitudinal center part of the pressing part is worn because it presses against the chip. Therefore, as in the present invention, when a measuring block is placed at one longitudinal end of two support parts and the measuring block is pressed with a predetermined load value by the pressing part, the distance between the pressing part and the support part detected by the distance detection part is stored as a first distance in a first memory part, when a measuring block is placed at the other longitudinal end of the two support parts and the measuring block is pressed with a predetermined load value by the pressing part, the distance between the pressing part and the support part detected by the distance detection part is stored as a second distance in a second memory part, and when a measuring block is placed at a specified position in the longitudinal central region of the two support parts and the measuring block is pressed with a predetermined load value by the pressing part, the distance between the pressing part and the support part detected by the distance detection part is stored as a third distance in a third memory part, the difference between the average value of these first distances and second distances and the third distance, or the difference between the first distance and the third distance, or the difference between the second distance and the third distance, can be calculated as the amount of wear of the pressing part.

[0011] The wear determination unit determines whether the amount of wear on the pressing part is equal to or greater than a predetermined threshold value. If the amount of wear is equal to or greater than the threshold value, it is determined that the pressing part has worn out and replacement of the pressing part is recommended. If the amount of wear is less than the threshold value, there is no need to replace the pressing part and it can continue to be used.

[0012] Therefore, according to the present invention, the amount of wear of the pressing part can be quantitatively and accurately determined, and the appropriate time to replace the pressing part can be accurately determined, thereby solving the problems of replacing the pressing part more frequently than necessary and of not being able to measure the flexural strength accurately because it is measured on a worn pressing part. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 2 is a perspective view of the bending strength measuring device according to the present invention, other mechanisms, and a workpiece holding table. [Figure 2]1 is a perspective view of a bending strength measuring device according to the present invention. [Figure 3] FIG. 2 is a perspective view of a tip jig transport mechanism. [Figure 4] 1 is a perspective view of a main part of a bending strength measuring device according to the present invention. [Figure 5] 4. (a) is a view taken in the direction of an arrow A in FIG. 4, and (b) and (c) are views taken in the direction of an arrow B in FIG. [Figure 6] 4 is a flowchart showing a procedure for inspecting wear of a pressing portion of a flexural strength measuring device according to the present invention. [Figure 7] 5(a) to 5(c) are partial perspective views showing the procedure for inspecting the wear of the pressing portion of the bending strength measuring device according to the present invention. [Figure 8] 5(a) to 5(c) are partial side views showing the procedure for inspecting the wear of the pressing portion of the bending strength measuring device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the present invention will be described below with reference to the accompanying drawings. In the following description, the directions of the arrows shown in Figure 1 are the X-axis (left-right direction), the Y-axis (front-rear direction), and the Z-axis (up-down direction), respectively.

[0015] As shown in FIG. 1, around the flexural strength measuring device 1 according to the present invention, there are arranged a work holding table 80 that holds a work set WS including a wafer W, a chip transport mechanism 90 that picks up and transports chips C separated from the wafer W included in the work set WS set on the work holding table 80, a chip jig holding table 41 that holds a chip jig on which the chip C received from the chip transport mechanism is placed, and a chip jig transport mechanism 40 that suction-holds the chip C or measurement block B held on the chip jig holding table 41 and transports it to the flexural strength measuring device 1.

[0016] The workpiece holding table 80 is a horizontally supported rectangular plate-like member, and a workpiece set WS is placed on its upper surface. The workpiece set WS is configured by bonding the back surface (lower surface) of a disk-shaped wafer W to a sheet T that is attached to a metal (e.g., SUS) ring frame F, covering the circular opening of the ring frame F, thereby supporting the wafer W on the ring frame F via the sheet T, and integrating the wafer W, ring frame F, and sheet T.

[0017] The chip transport mechanism 90 functions to pick up chips C from wafers W included in a work set WS set on the work holding table 80 and transport them to the chip jig holding table 41, and its specific configuration will not be shown or described here. The configurations of the die strength measuring device 1 and the die jig transport mechanism 40 according to the present invention will be described below.

[0018] [Configuration of flexural strength measuring device] 1, the flexural strength measuring device 1 includes a rectangular block-shaped base 3 attached to the front surface (the end surface in the -Y axis direction) of a vertically standing rectangular support plate 2, and a pressing unit 4 is supported on the base 3 via an elevating mechanism 10 so that it can be raised and lowered in the Z axis direction. The detailed configuration of the flexural strength measuring device 1 will be described below with reference to FIG. 2.

[0019] The lifting mechanism 10 provided in the flexural strength measuring device 1 lifts and lowers the pressing unit 4 in the vertical direction (Z-axis direction), and includes a pair of guide rails 11 attached parallel to and perpendicular to the front surface (negative Y-axis direction end surface) of the base 3, and a rectangular plate-like lifting plate 12 that can move in the vertical direction (Z-axis direction) along these guide rails 11. A rotatable ball screw 13 is vertically disposed between the pair of guide rails 11, and the lower end of the ball screw 13 is rotatably supported by the base 3 via a bearing 14.

[0020] Additionally, a servo motor 15, which is a rotary drive source, and an encoder 16, which detects the rotation direction and rotation speed of the servo motor 15, are connected to the upper end of the ball screw 13. Here, the encoder 16 constitutes a distance detection unit that detects the distance between the pressing unit 4 and a support unit 21, which will be described later. A nut member (not shown) is attached to the rear surface (end surface on the +Y-axis direction side) of the lifting plate 12, and the ball screw 13 is threadedly inserted into this nut member vertically.

[0021] A control unit 70 is electrically connected to the servo motor 15 and the encoder 16. When a detection signal detected by the encoder 16 is transmitted to the control unit 70, the control unit 70 controls the operation of the servo motor 15. The control unit 70 includes a CPU (Central Processing Unit) that performs calculations according to a control program, and storage units such as a ROM (Read Only Memory) and a RAM (Random Access Memory). In particular, in this embodiment, the control unit 70 calculates the amount of wear of the pressing unit 4 based on the distance between the pressing unit 4 and the support unit 21 detected by the encoder 16, and determines whether or not the pressing unit 4 needs to be replaced based on the calculated amount of wear; this will be described in detail later.

[0022] A rectangular movable block 5 is attached horizontally to the front surface (negative Y-axis direction end surface) of the lifting plate 12 of the lifting mechanism 10, and a clamping block 8 is attached to the lower end of a cylindrical support shaft 6 extending vertically downward from the movable block 5, via a load sensor 7 such as a load cell. A slit-like groove 8a is formed in the lower end of the clamping block 8 along the Y-axis direction, and on both sides of this groove 8a, block-shaped clamping portions 8A are formed along the Y-axis direction, respectively, to sandwich the upper portion of the pressing portion 4. The load sensor 7 is electrically connected to the control unit 70, and a detection signal from the load sensor 7 is sent to the control unit 70.

[0023] The pressing unit 4 is a rectangular plate-like member that is long in the Y-axis direction, and its lower end is shaped like an inverted triangular prism that narrows downward, with the lower edge forming a sharp knife edge. The lower edge of the pressing unit 4 along the Y-axis direction is rounded and chamfered to form an arc-shaped curved surface. The upper end of the pressing unit 4 is inserted and fitted from below into a groove 8a formed in the clamping block 8, and is clamped by the opposing clamping units 8A across the groove 8a of the clamping block 8. In this way, the pressing portion 4 inserted into the groove 8a of the clamping block 8 is supported at its longitudinal (Y-axis) middle portion so as to be rotatable up and down by an axis 9a inserted in the X-axis direction through each clamping portion 8A of the clamping block 8, and by tightening the set bolts 9b that are screwed into both ends of each clamping portion 8A of the clamping block 8 in the Y-axis direction, the pressing portion 4 is clamped at its upper end by the pair of clamping portions 8A of the clamping block 8 and is attached vertically to the clamping block 8.

[0024] Thus, the pressing unit 4 supported vertically by the clamping block 8 as described above can be raised and lowered along the Z-axis direction by the lifting mechanism 10. That is, by starting the servo motor 15 to rotate the ball screw 13 forward or backward, the lifting plate 12, to which a nut member (not shown) that screws onto the ball screw 13 is attached, rises and falls along the pair of guide rails 11 together with the movable block 5, so that the clamping block 8 attached to the movable block 5 via the support shaft 6 and the pressing unit 4 supported by the clamping block 8 can rise and fall along the Z-axis direction.

[0025] In the flexural strength measuring device 1, two support parts 21 are arranged side by side along the X-axis direction below the pressing part 4 and are fixed on a rectangular support base 20 and are arranged parallel to each other along the Y-axis direction. Each support part 21 is a triangular prism-shaped member, and its upper edge along the Y-axis direction forms a sharp knife edge, but is rounded and chamfered to form an arc-shaped curved surface. The pressing part 4 and support parts 21 are made of metal such as highly hard alloy or stainless steel (SUS).

[0026] The two support units 21 can be moved along the Y-axis direction together with the support base 20 that supports them by a Y-axis movement mechanism 30. Here, the Y-axis movement mechanism 30 is configured to include a pair of guide rails 32 laid parallel to each other along the Y-axis direction on a rectangular base plate 31, a slider 33 that is movable in the Y-axis direction along these guide rails 32, a rotatable ball screw 34 arranged along the Y-axis direction between the pair of guide rails 32, and a servo motor 35 that rotates the ball screw 34 forward and backward. Here, one axial end of the ball screw 34 is rotatably supported by the base plate 31 by a bearing 36, and the other axial end of the ball screw 34 is connected to the servo motor 35.

[0027] A nut member (not shown) into which the ball screw 34 is threadedly inserted is attached to the lower surface of the slider 33, and two support parts 21 are attached to the upper surface of the slider 33 via support bases 20.

[0028] Therefore, in the Y-axis moving mechanism 30, when the servo motor 35 is started to rotate the ball screw 34 forward and backward, the slider 33, which is attached with a nut member (not shown) that screws onto the ball screw 34, moves in the Y-axis direction, and the two support parts 21 attached to the slider 33 via the support base 20 can also move along the Y-axis direction.

[0029] In the flexural strength measuring device 1 configured as described above, as shown in Figures 4 and 5, a square (rectangular) chip C is placed horizontally on two support parts 21, the pressing part 4 is lowered by the lifting mechanism 10, and the chip C is pressed by the pressing part 4 until it breaks, and the pressing load when the chip C breaks is detected by the load sensor 7, thereby measuring the flexural strength of the chip C.Here, we will explain the dimensions of the chip C and the positional relationship between the two support parts 21 and the pressing part 4.

[0030] 4 and 5, if the length of one of a pair of opposing sides of the chip C, i.e., the long side of the pair of sides, is a and the length of the other of the pair of sides is b, the two support parts 21 are spaced apart in the length direction of the long sides (X-axis direction) by a distance d (d≦a), which is less than or equal to the length a of the long sides of the chip C. Furthermore, the support parts 21 extend in the length direction of the short side (Y-axis direction) for a distance greater than or equal to the length b of the other of the pair of sides of the chip C. Here, in this embodiment, as shown in FIGS. 4 and 5(b), the length L of each support part 21 in the Y-axis direction is set to be greater than the length b of the short side of the chip (L>b).

[0031] Also, as shown in Figure 5(a), the pressing portion 4 is located in the center between the two support portions 21 in the X-axis direction, and its position is set so that its lower edge presses the center of the chip C in the long side direction (X-axis direction).

[0032] [Configuration of chip jig transport mechanism] Next, the configuration of the tip jig transport mechanism 40 will be described with reference to FIG.

[0033] The tip jig transport mechanism 40 holds the tip C or the square pillar-shaped measurement block B placed on the rectangular plate-shaped tip jig holding table 41, transports it to the flexural strength measuring device 1, and places it on the two support parts 21. When measuring the flexural strength of the tip C, the tip C on the tip jig holding table 41 is transported to the flexural strength measuring device 1, and when inspecting the wear of the pressing part 4, the measurement block B on the tip jig holding table 41 is transported to the flexural strength measuring device 1; the wear inspection of the pressing part 4 will be described later.

[0034] 3, the chip jig transport mechanism 40 is provided with an X-axis movement mechanism 50 installed on the front surface (negative Y-axis direction end surface) of the support plate 2. This X-axis movement mechanism 50 is provided with a pair of upper and lower guide rails 51 arranged parallel to each other along the X-axis direction on the front surface of the support plate 2, a slider 52 that is movable in the X-axis direction along these guide rails 51, and a ball screw 53 that is arranged between the pair of guide rails 51 along the X-axis direction and can rotate forward and backward.

[0035] One axial end (left end in FIG. 3) of the ball screw 53 is rotatably supported by the support plate 2 via a bearing 54, and the other axial end (right end in FIG. 3) of the ball screw 53 is connected to a servo motor 55, which is a rotation drive source. The ball screw 53 is threadedly inserted into the slider 52.

[0036] An elevating mechanism 60 is attached to the slider 52. The elevating mechanism 60 includes a base plate 61 attached perpendicularly to the slider 52, a guide rail 62 attached perpendicularly to the base plate 61, an elevating block 63 that moves up and down in the Z-axis direction along the guide rail 62, and a reversible ball screw 64 that is vertically arranged next to the guide rail 62. The lower end of the ball screw 64 is rotatably supported by the base plate 61 via a bearing 65, and the upper end of the ball screw 64 is connected to a servo motor 66, which is a rotation drive source. The ball screw 64 is threadedly inserted into the elevating block 63 in the vertical direction.

[0037] An L-shaped bent arm 42 is attached to the lifting block 63, and two arms 43 and 44 extending horizontally along the -Y-axis direction are attached to the end of the horizontal part of arm 42, and a support bar 45 extends vertically downward from the tip of arm 44. A collet 46 that holds the chip C or measuring block B by suction is attached to the lower end of support bar 45. Here, collet 46 is connected to a suction source 48 via piping 47.

[0038] Therefore, collet 46, which holds chip C or measurement block B by suction, can be moved in the X-axis direction by X-axis movement mechanism 50, and can be raised and lowered in the Z-axis direction by lifting mechanism 60. That is, in X-axis movement mechanism 50, when servo motor 55 is started and ball screw 53 rotates forward and backward, slider 52, into which ball screw 53 is threadedly inserted, moves along the X-axis direction together with lifting mechanism 60, arms 42 to 44, support bar 45, etc., and therefore collet 46 attached to the lower end of support bar 45 also moves along the X-axis direction.

[0039] Furthermore, in the lifting mechanism 60, when the servo motor 66 is started and the ball screw 64 rotates forward and backward, the lifting block 63 into which the ball screw 64 is threadedly fitted moves up and down along the Z-axis together with the arms 42 to 44 and the support bar 45, and so the collet 46 attached to the lower end of the support bar 45 also moves up and down along the Z-axis. Therefore, as described above, the collet 46 holding the chip C or the measurement block B by suction can move in the X-axis direction and move up and down in the Z-axis direction.

[0040] In the flexural strength measuring device 1 according to the present invention, as shown in FIGS. 4 and 5 , a three-point bending test is performed in which a tip C is placed on two support members 21, a knife-edge-shaped pressing member 4 is lowered from above the center of the tip C to press the tip C with the tip of the pressing member 4, and the pressing load at which the tip C breaks is measured with a load sensor 7 to measure the flexural strength. Repeated three-point bending tests result in wear at the longitudinal (Y-axis) center of the pressing member 4 that presses the tip C, as shown in FIG. 5( c), forming a recess 4a with an arc-shaped curved surface in the center of the pressing member 4. Conventionally, there has been no method for quantitatively and accurately measuring the amount of wear of the pressing member 4. This has resulted in unclear timing for replacing the pressing member 4, leading to problems such as excessive frequency of replacement of the pressing member 4 and inaccurate measurement of the flexural strength due to the worn pressing member 4, as described above.

[0041] Therefore, a wear inspection as a method for quantitatively and accurately grasping the amount of wear of the pressing part 4 of the bending strength measuring device 1 will be described below with reference to FIGS.

[0042] 3, in this wear inspection, a square pillar-shaped measurement block B placed on a tip jig holding table 41 is suction-held by a collet 46 provided on a tip jig transport mechanism 40. That is, the holding surface (lower surface) of the collet 46 is sucked by a suction source 48, thereby suction-holding the measurement block B by the collet 46.

[0043] As described above, when the measurement block B is sucked and held by the collet 46, the measurement block B sucked and held by the collet 46 is transported to the flexural strength measuring device 1 shown in Figures 1 and 2 by the X-axis moving mechanism 50 and the lifting mechanism 60 of the chip jig transport mechanism 40 shown in Figures 1 and 3, and as shown in Figures 7(a) and 8(a), the measurement block B is placed at one end of the longitudinal direction (Y-axis direction) of the two support parts 21 of the flexural strength measuring device 1 (step S1 in Figure 6). When the measurement block B is placed at one end of the longitudinal direction (Y-axis direction) of the two support parts 21, the two support parts 21 are moved in the Y-axis direction by the Y-axis moving mechanism 30 (see Figure 2) provided in the flexural strength measuring device 1.

[0044] The width (distance in the X-axis direction) of the measurement block B placed on the support portion 21 is less than one-third the length of the support portion 21, and in this embodiment, it is one-tenth the length of the support portion 21. In other words, the length L of the support portion 21 is 20 mm, and the width b of the measurement block B is 2 mm. Furthermore, the distance d between the two support portions 21 is 5 mm, the length a of the measurement block B is 10 mm, and the height (thickness) is 1 mm.

[0045] Next, the pressing portion 4 is lowered by the lifting mechanism 10 (see FIG. 2) of the flexural strength measuring device 1, and the pressing portion 4 presses the measurement block B with a predetermined load value P (step S2 in FIG. 6). The distance Z1 between the pressing portion 4 and the support portion 21 at that time (hereinafter referred to as the "first distance") is detected by the encoder 16 (see FIG. 2) of the lifting mechanism 10 (step S3 in FIG. 6), and this first distance Z1 is stored in the first memory portion 71 (see FIG. 2) of the control portion 70 (step S4 in FIG. 6).

[0046] Then, the pressing portion 4 is moved upward by the lifting mechanism 10 (see Figure 2) of the flexural strength measuring device 1, and then the collet 46 and the measurement block B held therein are lifted above the two support portions 21 by the lifting mechanism 60 (see Figure 3) of the chip jig conveying mechanism 40, the two support portions 21 are moved a predetermined distance in the -Y-axis direction by the Y-axis moving mechanism 30 (see Figure 2) of the flexural strength measuring device 1, and the collet 46 and the measurement block B held therein are lowered by the lifting mechanism 60 of the chip jig conveying mechanism 40, and the measurement block B is positioned on the other end of the two support portions 21 in the longitudinal direction (Y-axis direction) as shown in Figures 7(b) and 8(b) (step S5 of Figure 6).

[0047] Then, from the above state, the pressing portion 4 is lowered by the lifting mechanism 10 of the flexural strength measuring device 1, and the pressing portion 4 presses the measurement block B with a predetermined load value P (step S6 in Figure 6), and the distance Z2 between the pressing portion 4 and the support portion 21 at that time (hereinafter referred to as the "second distance") is detected by the encoder 16 (see Figure 2) (step S7 in Figure 6), and this second distance Z2 is stored in the second memory portion 72 (see Figure 2) of the control portion 70 (step S8 in Figure 6).

[0048] Then, the pressing portion 4 is moved upward by the lifting mechanism 10 of the flexural strength measuring device 1, and then the collet 46 and the measurement block B held therein are lifted above the two support portions 21 by the lifting mechanism 60 of the chip jig conveying mechanism 40, the two support portions 21 are moved a predetermined distance in the +Y-axis direction by the Y-axis moving mechanism 30 of the flexural strength measuring device 1, and the collet 46 and the measurement block B held therein are lowered by the lifting mechanism 60 of the chip jig conveying mechanism 40, and the measurement block B is positioned at the center of the longitudinal direction (Y-axis direction) of the two support portions 21, as shown in Figures 7(c) and 8(c) (step S9 of Figure 6).

[0049] Then, from the above state, the pressing portion 4 is lowered by the lifting mechanism 10 of the flexural strength measuring device 1, and the pressing portion 4 presses the measurement block B with a predetermined load value P (step S10 in Figure 6), and the distance Z3 between the pressing portion 4 and the support portion 21 at that time (hereinafter referred to as the "third distance") is detected by the encoder 16 (step S11 in Figure 6), and this third distance Z3 is stored in the third memory portion 73 (see Figure 2) of the control portion 70 (step S12 in Figure 6).

[0050] As described above, when the first distance Z1 detected by the encoder 16 when the measuring block B is placed at one longitudinal end of the two support parts 21 and pressed by the pressing part 4 with a predetermined load value P, the second distance Z2 detected by the encoder 16 when the measuring block B is placed at the other longitudinal end of the two support parts 21 and pressed by the pressing part 4 with a predetermined load value P, and the third distance Z3 detected by the encoder 16 when the measuring block B is placed at a specified position in the longitudinal central region of the two support parts 21 and pressed by the pressing part 4 with a predetermined load value P are stored in the first memory part 71, the second memory part 72, and the third memory part 73 of the control part 70, respectively, the control part 70 calculates the wear amount δ of the pressing part 4 by one of the following first to third methods.

[0051] The third distance Z3 may be measured by placing the measurement block B at the center (middle) of the support part 21, or by placing the measurement block B at a position slightly moved from one end or the other end of the support part 21 to the center. That is, the movement of the measurement block B in the longitudinal direction of the support part 21 and the pressing of the measurement block B are repeated to perform height measurements multiple times, and the value with the largest difference from the first distance Z1 and the second distance Z2 may be selected and used as the third distance Z3 (step S13 in FIG. 6).

[0052] 1) First method: The first method is to calculate the difference between the average value (Z1+Z2) / 2 of the first distance Z1 and the second distance Z2 and the third distance Z3 as the wear amount δ of the pressing portion 4. That is, the wear amount δ of the pressing portion 4 is calculated by the following formula. δ=(Z1+Z2) / 2-Z3 …(1)

[0053] 2) Second method: The second method is a method of calculating the difference between the first distance Z1 and the third distance Z3 as the amount of wear δ of the pressing portion 4. That is, the amount of wear δ of the pressing portion 4 is calculated by the following formula. δ = Z1 - Z3 … (2)

[0054] 3) The third method: The third method is a method of calculating the difference between the second distance Z2 and the third distance Z3 as the amount of wear δ of the pressing portion 4. That is, the amount of wear δ of the pressing portion 4 is calculated by the following formula. δ = Z2 - Z3 … (3)

[0055] Once the wear amount δ of the pressing portion 4 is calculated by any of the above methods (step S13), it is determined whether or not this wear amount δ is equal to or greater than a predetermined threshold (step S14 in FIG. 6). If the result of this determination is that the wear amount δ of the pressing portion 4 is equal to or greater than the predetermined threshold (step S14: Yes), it is determined that the wear amount δ of the pressing portion 4 is large and therefore replacement of the pressing portion 4 is necessary (step S15 in FIG. 6), and the series of wear inspections is completed (step S17).

[0056] On the other hand, if the wear amount δ is less than the predetermined threshold (step S14: No), it is determined that the wear amount δ of the pressing portion 4 is small and therefore replacement of the pressing portion 4 is unnecessary (step S16 in FIG. 6), and the series of wear inspections is terminated (step S17).

[0057] Incidentally, when measuring the flexural strength of chip C using a three-point bending test with the flexural strength measuring device 1, both longitudinal ends of the pressing portion 4 are hardly worn because they do not press against the chip C, but the longitudinal center portion of the pressing portion 4 is worn because it presses against the chip C.

[0058] Therefore, as in this embodiment, when the measurement block B is placed at one end of the two support parts 21 in the longitudinal direction and the measurement block B is pressed by the pressing part 4 with a predetermined load value P, the distance between the pressing part 4 and the support parts 21 detected by the encoder 16 is stored as a first distance Z1 in the first storage part 71, and when the measurement block B is placed at the other end of the two support parts 21 in the longitudinal direction and the measurement block B is pressed by the pressing part 4 with a predetermined load value P, the distance between the pressing part 4 and the support parts 21 detected by the encoder 16 is stored as a second distance Z2 in the second storage part 71. 2, and when a measurement block B is placed at a specified position in the longitudinal central region of the two support parts 21 and the measurement block B is pressed by the pressing part 4 with a predetermined load value P, the distance between the pressing part 4 and the support parts 21 detected by the encoder 16 is stored as a third distance Z3 in a third memory part 73, and the difference between the average value of the first distance Z1 and the second distance Z2 and the third distance Z3, or the difference between the first distance Z1 and the third distance Z3, or the difference between the second distance Z2 and the third distance Z3, can be calculated as the wear amount δ of the pressing part 4.

[0059] The wear determination unit 74 of the control unit 70 determines whether the amount of wear δ of the pressing unit 4 is equal to or greater than a predetermined threshold value. If the amount of wear δ is equal to or greater than the threshold value, it is determined that the pressing unit 4 is worn and replacement of the pressing unit 4 is recommended. If the amount of wear δ is less than the threshold value, there is no need to replace the pressing unit 4 and it can continue to be used.

[0060] Therefore, according to the bending strength measuring device 1 of this embodiment, the wear amount δ of the pressing part 4 can be quantitatively and accurately determined, and the appropriate time to replace the pressing part 4 can be accurately determined, thereby solving the problem of replacing the pressing part 4 more frequently than necessary or of not being able to measure the bending strength accurately because a worn pressing part 4 is used.

[0061] In the above embodiment, a configuration is adopted in which the pressing portion 4 is raised and lowered relative to the support portion 21, but a configuration may be adopted in which the support portion 21 is raised and lowered relative to the pressing portion 4, on the contrary.

[0062] Furthermore, the present invention is not limited to the application of the above-described embodiments, and it goes without saying that various modifications are possible within the scope of the claims and the technical ideas described in the specification and drawings. [Explanation of symbols]

[0063] 1: bending strength measuring device, 2: support plate, 3: base, 4: pressing portion, 4a: recessed portion, 5: Movable block, 6: Support shaft, 7: Load sensor, 8: Clamping block, 8A: Clamping part, 8a: groove, 9a: shaft, 9b: set bolt, 10: lifting mechanism, 11: guide rail, 12: lifting plate, 13: ball screw, 14: bearing, 15: servo motor, 16: Encoder (distance detection unit), 20: Support base, 21: Support unit, 30: Y-axis movement mechanism, 31: base plate, 32: guide rail, 33: slider, 34: ball screw, 35: Servo motor, 36: Bearing, 40: Chip jig transport mechanism, 41: tip jig holding table, 42 to 44: arm, 45: support bar, 46: collet, 47: Piping, 48: Suction source, 50: X-axis movement mechanism, 51: Guide rail, 52: slider, 53: ball screw, 54: bearing, 55: servo motor, 60: lifting mechanism, 61: base plate, 62: guide rail, 63: lifting block, 64: ball screw, 65: bearing, 66: servo motor, 70: control unit, 71: first storage unit, 72: second storage unit, 73: third memory unit, 74: wear determination unit, 80: workpiece holding table, 90: Chip transport mechanism, B: Measuring block, C: Chip, F: Ring frame, P: Predetermined load value, T: Sheet, W: Wafer, WS: Work set, Z1: First distance, Z2: second distance, Z3: third distance, δ: wear amount

Claims

[Claim 1] two support portions that are spaced apart in the length direction of two sides of one of two sets of two opposing pairs of sides of the rectangular chip and extend in the length direction of the two sides for a length equal to or greater than the length of the other set of two sides, supporting the underside of the chip; a pressing portion that presses the chip supported by the support portion at a lower end extending in the length direction of the other pair of two sides; a lifting mechanism that lifts and lowers the pressing portion and the support portion relative to each other; a distance detection unit that detects the distance between the pressing unit and the support unit that are relatively raised and lowered by the lifting mechanism; a load sensor for measuring a load when the tip is pressed by the pressing portion; A flexural strength measuring device comprising: a first storage unit configured to store a first distance detected by the distance detection unit when a measurement block having a width less than one-third the length of the support unit and disposed at one end of the two support units in the longitudinal direction is pressed by the pressing unit with a predetermined load value; a second storage unit configured to store a second distance detected by the distance detection unit when the measuring block disposed at the other longitudinal end of the two support units is pressed by the pressing unit with a predetermined load value; a third storage unit configured to store a third distance detected by the distance detection unit when the measuring block, which is disposed at a specified position in the longitudinal center region of the two support units, is pressed by the pressing unit with a predetermined load value; and a wear determination unit that determines that the pressing unit is worn when a difference between the average value of the first distance and the second distance and the third distance, or a difference between the first distance and the third distance, or a difference between the second distance and the third distance, is equal to or greater than a preset threshold value; A bending strength measuring device comprising:

Images