Test method and test equipment

Abstract

A testing method is provided that makes it easier to accurately grasp the state of the surface (for example, side surface) to be imaged of a test piece (for example, a chip). [Solution] A test method for a test piece includes an imaging step of imaging an imaged surface of the test piece using light passing through an optical system, and a load measurement step of measuring the load at break of the test piece by pressing the test piece with an indenter while increasing the load applied to the test piece after the imaging step. In the imaging step, a plurality of images are formed by imaging the imaged surface in each of a plurality of states in which a first distance between the focal point of the optical system and a specific point included in the imaged surface in a first direction parallel to the optical axis of the optical system is different from one another.

Description

[Technical Field]

[0001] The present invention relates to a test method and a test device for a test piece. [Background technology]

[0002] To accurately determine the bending strength of the chips obtained by dividing the wafer, it is necessary to actually measure the breaking load of the chip by pressing the chip with an indenter while increasing the load applied to the chip. However, if the chip is destroyed to measure the bending strength, it will naturally become impossible to use the chip.

[0003] It is known that the die strength is affected by the state of the side of the die, which changes depending on the processing conditions when dividing the wafer, etc. Therefore, information on the state of the side of the die (for example, an image showing the side of the die) is useful as information that can effectively estimate the die strength without destroying the die.

[0004] Information about the condition of the side surface of the chip is obtained, for example, in a testing device for measuring the flexural strength of the chip as a test piece (see, for example, Patent Document 1). This testing device is equipped with an indenter for pressing the test piece and a measuring instrument for measuring the load applied to the test piece when the indenter presses the test piece, as well as a camera for capturing an image of the side surface of the test piece.

[0005] In this testing device, a camera can be used to form an image showing the side of the test piece prior to actually measuring the chip's breaking load using an indenter and measuring device. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2020-94832 Summary of the Invention [Problem to be solved by the invention]

[0007] The side surfaces of the chips produced by dividing the wafer may be inclined or curved, and may have an uneven shape including minute irregularities, which may result in unclear areas in the image formed by the camera capturing the side surface of the test piece.

[0008] In view of this, an object of the present invention is to provide a testing method and testing device that makes it easier to accurately grasp the state of the imaged surface (for example, side surface) of a test piece (for example, a chip). [Means for solving the problem]

[0009] According to one aspect of the present invention, there is provided a test method for a test piece, comprising: an imaging step of imaging an imaged surface of the test piece using light passing through an optical system; and a load measurement step of measuring the load at break of the test piece after the imaging step by pressing the test piece with an indenter while increasing the load applied to the test piece, wherein in the imaging step, a plurality of images are formed by imaging the imaged surface in each of a plurality of states in which a first distance between the focus of the optical system and a specific point included in the imaged surface in a first direction parallel to the optical axis of the optical system is different from one another.

[0010] Preferably, the imaging step alternately repeats a partial imaging step of forming a plurality of partial images by partially imaging the imaged surface in each of a plurality of states in which the first distance is equal to one another and a second distance between the focal point of the optical system and the specific point included in the imaged surface in a second direction orthogonal to the first direction is different from one another, and a distance changing step of changing the first distance. Furthermore, it is preferable that the testing method of the present invention further includes an orientation adjusting step of adjusting the orientation of the test piece before the imaging step.

[0011] According to another aspect of the present invention, there is provided a test device for a test piece, comprising: a holding mechanism for holding the test piece; a camera for imaging the imaged surface of the test piece held by the holding mechanism using light passing through an optical system; a moving mechanism for relatively moving the focal point of the optical system and the holding mechanism along a first direction parallel to the optical axis of the optical system; a support member for supporting the test piece; an indenter for pressing the test piece supported by the support member; a measuring instrument for measuring the load applied to the test piece when the indenter presses the test piece; and a controller for controlling the camera and the moving mechanism to form a plurality of images by imaging the imaged surface in each of a plurality of states in which a first distance between the focal point of the optical system in the first direction and a specific point included in the imaged surface is different from one another. [Effects of the Invention]

[0012] In the present invention, multiple images are formed by capturing images of the imaged surface of the test piece in multiple states in which a first distance between the focal point of the optical system of the camera and a specific point included in the imaged surface of the test piece is different from one another in a first direction parallel to the optical axis of the optical system of the camera. In this case, the state of the imaged surface of the test piece can be grasped by referring to the multiple images. Therefore, according to the present invention, it is easier to accurately grasp the state of the imaged surface of the test piece compared to referring to a single image. [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 is a perspective view schematically showing an example of a testing device. [Figure 2] FIG. 2 is a perspective view schematically showing the chip unit. [Figure 3] FIG. 3(A) is a perspective view that schematically shows the arm and the like, and FIG. 3(B) is a front view that schematically shows the arm and the like. [Figure 4] FIG. 4(A) is a perspective view that schematically shows the vibration isolation table and the like, and FIG. 4(B) is a front view that schematically shows the vibration isolation table and the like. [Figure 5]FIG. 5 is a flow chart that schematically illustrates an example of a test method. [Figure 6] FIG. 6 is a flowchart showing a schematic example of the imaging step. [Figure 7] 7(A), 7(B), and 7(C) are plan views each showing a schematic view of the partial imaging step. [Figure 8] FIG. 8 is a plan view schematically showing the interval changing step. [Figure 9] FIG. 9 is a flow chart schematically illustrating another example of a test method. DETAILED DESCRIPTION OF THE INVENTION

[0014] An embodiment of the present invention will be described with reference to the accompanying drawings. Fig. 1 is a perspective view showing a schematic example of a test apparatus. In Fig. 1, some components of the test apparatus are simply shown as blocks such as rectangular parallelepipeds or rectangles. Note that the direction indicated by the arrow +X (+X direction) and the direction indicated by the arrow +Y (+Y direction) are orthogonal to each other on a horizontal plane, and the direction indicated by the arrow +Z (+Z direction) is orthogonal to both the +X direction and the +Y direction.

[0015] Furthermore, the direction indicated by the arrow -X (-X direction) is the opposite direction to the +X direction, the direction indicated by the arrow -Y (-Y direction) is the opposite direction to the +Y direction, and the direction indicated by the arrow -Z (-Z direction) is the opposite direction to the +Z direction. Furthermore, for convenience, hereinafter, the +X direction and -X direction will be collectively referred to as the X-axis direction, the +Y direction and -Y direction will be collectively referred to as the Y-axis direction, and the +Z direction and -X direction will be collectively referred to as the Z-axis direction.

[0016] The test apparatus 2 shown in Fig. 1 has a base 4. A cassette elevator (not shown) for raising and lowering a cassette 6 is provided on the top surface 4a of the base 4 near a corner located in the -X direction and the +Y direction from the center of the base. The cassette 6 is placed on the cassette elevator. The cassette 6 contains chip units each including a plurality of chips that serve as test pieces.

[0017] FIG. 2 is a perspective view schematically illustrating this chip unit. The chip unit 11 shown in FIG. 2 includes a plurality of chips 13 arranged in a matrix. Each chip 13 is manufactured by processing a wafer having a plurality of devices formed in a matrix on its surface. For example, each chip 13 is manufactured by grinding the back side of the wafer using a grinding device, and then dividing the wafer along the boundaries of the plurality of devices using a cutting device or laser processing device.

[0018] The plurality of chips 13 are integrated with a metal ring frame 17 via a resin dicing tape 15. The chip unit 11 is housed in a cassette 6 with the plurality of chips 13 and the ring frame 17 positioned on the dicing tape 15.

[0019] A transport unit 8 is provided near the cassette elevator, and includes an arm that is substantially L-shaped in side view and a movement mechanism (not shown) connected to the arm. This movement mechanism includes, for example, a ball screw for moving the arm along the Y-axis direction and a ball screw for moving the arm along the Z-axis direction. When this movement mechanism is operated, the arm moves along the Y-axis and / or Z-axis direction.

[0020] Furthermore, clamp mechanisms 8a and 8b are provided on the front lower ends of a pair of side surfaces of the arm of the transport unit 8. Each of the clamp mechanisms 8a and 8b has a pair of thin plate portions configured to be able to move toward and away from each other along the Z-axis direction. Clamp mechanism 8a can clamp the ring frame 17 of a chip unit 11 located in the +Y direction as viewed from the arm between the pair of thin plate portions. Clamp mechanism 8b can clamp the ring frame 17 of a chip unit 11 located in the -Y direction as viewed from the arm between the pair of thin plate portions.

[0021] A pair of temporary placement rails 10, each extending along the Y-axis direction, is provided in the -Y direction as viewed from the cassette elevator. Chip units 11 drawn out from cassettes 6 are placed on the pair of temporary placement rails 10.

[0022] When the chip unit 11 is extracted from the cassette 6 and placed on the pair of temporary placement rails 10, first the cassette elevator is raised or lowered so that the chip unit 11 is positioned at a height corresponding to the pair of temporary placement rails 10. Next, the arm of the transport unit 8 is moved so that one end of the ring frame 17 is positioned between the pair of thin plate portions of the clamp mechanism 8a.

[0023] Next, one end of the ring frame 17 is clamped by the pair of thin plate portions of the clamp mechanism 8a. Next, the arm is moved in the -Y direction until the chip unit 11 is placed on the temporary placement rails 10. Next, the pair of thin plate portions of the clamp mechanism 8a are moved away from the one end of the ring frame 17. This completes the transfer of the chip unit 11 from the cassette 6 to the pair of temporary placement rails 10.

[0024] A frame holding unit 12 is provided in the -Y direction as viewed from the pair of temporary placement rails 10. This frame holding unit 12 includes a frame support portion 12a and a frame pressing portion 12b that face each other in the Z-axis direction. In plan view, the frame support portion 12a and the frame pressing portion 12b each have a C-shape like a circular ring having an inner diameter roughly equal to the inner diameter of the ring frame 17, with a portion of the ring cut out in the +Y direction as viewed from the center.

[0025] Then, the chip unit 11 pushed out from the pair of temporary placement rails 10 is placed on the frame support part 12a. When the chip unit 11 is pulled out from the pair of temporary placement rails 10 and placed on the frame support part 12a, first, the arm of the transport unit 8 is moved so that the other end of the ring frame 17 is positioned between the pair of thin plate parts of the clamp mechanism 8b.

[0026] Next, the other end of the ring frame 17 is clamped by the pair of thin plate portions of the clamp mechanism 8b. Next, the arm is moved in the -Y direction until the chip unit 11 is placed on the frame support portion 12a. Next, the pair of thin plate portions of the clamp mechanism 8b are moved away from the other end of the ring frame 17. This completes the transfer of the chip unit 11 from the pair of temporary placement rails 10 to the frame support portion 12a.

[0027] Furthermore, the frame holding unit 12 includes a drive mechanism 12c such as an air actuator for moving the frame support part 12a and the frame presser part 12b closer to and farther apart in the Z-axis direction. When the drive mechanism 12c is operated to move them closer to each other, the ring frame 17 placed on the frame presser part 12b is clamped between the frame support part 12a and the frame presser part 12b.

[0028] The drive mechanism 12c is connected to a Y-axis direction moving mechanism 16 via a pair of moving blocks 14 that are spaced apart from each other in the X-axis direction. The Y-axis direction moving mechanism 16 has a pair of Y-axis direction guide rails 18 that each extend along the Y-axis direction and are spaced apart from each other in the X-axis direction.

[0029] The pair of Y-axis guide rails 18 is connected to the pair of moving blocks 14 located on the -X-axis side in a manner that allows them to slide along the Y-axis. A screw shaft 20 extending along the Y-axis direction is disposed between the pair of Y-axis guide rails 18.

[0030] This screw shaft 20 is disposed near the one of the pair of Y-axis direction guide rails 18 that is located on the +X direction side. Furthermore, the one of the pair of Y-axis direction guide rails 18 that is located on the +X direction side is connected to the one of the pair of moving blocks 14 that is located on the +X direction side in a manner that allows it to slide along the Y-axis direction.

[0031] A nut (not shown) that houses a plurality of balls and constitutes a ball screw together with the screw shaft 20 is provided on the underside of the moving block 14. Furthermore, a drive source 22 such as a stepping motor is provided on one end of the screw shaft 20. When the drive source 22 is operated, the frame holding unit 12 moves along the Y-axis direction together with the pair of moving blocks 14.

[0032] The Y-axis direction moving mechanism 16 is fixed on an X-axis direction moving frame 24. In plan view, this X-axis direction moving frame 24 has a ring shape with a rectangular through-hole 24a formed in its center. Specifically, the X-axis direction moving frame 24 has a pair of X-axis direction extending portions each extending along the X-axis direction and a pair of Y-axis direction extending portions each extending along the Y-axis direction. The pair of Y-axis direction guide rails 18 of the Y-axis direction moving mechanism 16 are each provided on the pair of Y-axis direction extending portions of the X-axis direction moving frame 24.

[0033] An X-axis direction moving mechanism 26 is connected to the lower side of the X-axis direction moving frame 24. This X-axis direction moving mechanism 26 has a pair of X-axis direction guide rails 28 that each extend along the X-axis direction and are spaced apart from each other in the Y-axis direction. A pair of X-axis direction extending portions of the X-axis direction moving frame 24 are connected to the upper sides of the pair of X-axis direction guide rails 28, respectively, in a manner that allows them to slide along the X-axis direction.

[0034] Furthermore, a screw shaft 30 extending along the X-axis direction is disposed between the pair of X-axis guide rails 28. This screw shaft 30 is disposed near the one of the pair of X-axis guide rails 28 that is located on the -Y direction side. Furthermore, a nut (not shown) that accommodates multiple balls and forms a ball screw together with the screw shaft 30 is provided on the underside of the one of the pair of X-axis extending portions of the X-axis direction moving frame 24 that is located on the -Y direction side.

[0035] Furthermore, a drive source 32 such as a stepping motor is provided at one end of the screw shaft 30. When the drive source 32 is operated, the X-axis direction moving frame 24 moves along the X-axis direction. Therefore, by operating the drive source 22 of the Y-axis direction moving mechanism 16 and / or the drive source 32 of the X-axis direction moving mechanism 26, the frame holding unit 12 can be moved along the X-axis direction and / or the Y-axis direction.

[0036] For example, by operating the drive source 22 of the Y-axis direction moving mechanism 16 and / or the drive source 32 of the X-axis direction moving mechanism 26, the frame holding unit 12 can be moved between a receiving position A1 where the chip unit 11 can be received and a pick-up position A2 where the chip 13 can be picked up from the chip unit 11.

[0037] A rectangular opening 4b is formed on the top surface 4a of the base 4 near a corner located in the +X direction and the -Y direction when viewed from the center of the base. This opening 4b is located at a position overlapping with the pickup position A2 in the Z-axis direction. A push-up mechanism 34 is provided in the opening 4b to push up any one of the multiple chips 13 included in the chip unit 11. The push-up mechanism 34 has a cylindrical suction tube 34a.

[0038] The suction tube 34a can be selectively connected to a vacuum pump (not shown) or an air supply source (not shown). When the vacuum pump is connected to the suction tube 34a and the vacuum pump is operated, a negative pressure is created inside the suction tube 34a and a suction force acts on the space above the suction tube 34a. When the air supply source is connected to the suction tube 34a and the air supply source is operated, the pressure inside the suction tube 34a returns to normal and the suction force acting on the space above the suction tube 34a disappears.

[0039] A drive unit (not shown), such as a stepping motor or an air cylinder, is connected to the lower end of the suction tube 34a. When this drive unit is operated, the suction tube 34a moves along the Z-axis direction. Furthermore, a needle-shaped or pin-shaped push-up member (not shown) that is movable along the Z-axis direction is provided at the center of the suction tube 34a in the radial direction.

[0040] When one of the multiple chips 13 included in the chip unit 11 is pushed up by the push-up mechanism 34, the frame holding unit 12 is first moved so that one of the multiple chips 13 included in the chip unit 11, whose ring frame 17 is clamped by the frame support portion 12a and the frame pressing portion 12b, is positioned directly above the push-up member of the push-up mechanism 34.

[0041] Next, the suction tube 34a is raised so that it contacts the dicing tape 15. Next, a vacuum pump communicating with the suction tube 34a is operated so that the suction tube 34a applies a suction force to the dicing tape 15. Next, the push-up member of the push-up mechanism 34 is raised so as to push up the chip 13 located directly above the push-up member. This makes it easier to separate the chip 13 from the dicing tape 15.

[0042] A Z-axis direction movement mechanism 36 is provided in the +X direction as seen from the cassette elevator. This Z-axis direction movement mechanism 36 has a pair of Z-axis direction guide rails 38 that each extend along the Z-axis direction and are spaced apart from each other in the Y-axis direction.

[0043] A screw shaft 40 extending along the Z-axis direction is disposed between the pair of Z-axis guide rails 38. Furthermore, a Z-axis moving base 42 is connected to the +X direction side of each of the pair of Z-axis guide rails 38 in a manner that allows it to slide along the Z-axis direction.

[0044] A nut (not shown) that houses a plurality of balls and forms a ball screw together with the screw shaft 40 is provided on the back surface of the Z-axis direction moving base 42. Furthermore, a drive source 44 such as a stepping motor is provided on the lower end of the screw shaft 40. When the drive source 44 is operated, the Z-axis direction moving base 42 moves along the Z-axis direction together with the nut.

[0045] A Y-axis direction movement mechanism 46 is provided on the surface of the Z-axis direction movement base 42, with one end located in the +X direction as viewed from the Z-axis direction movement base 42 and the other end located in the -X direction as viewed from the pickup position A2. This Y-axis direction movement mechanism 46 has a pair of Y-axis direction guide rails 48 that each extend along the Y-axis direction and are spaced apart from each other in the Z-axis direction.

[0046] A screw shaft 50 extending along the Y-axis direction is disposed between the pair of Y-axis guide rails 48. Furthermore, a Y-axis movement base 52 is connected to the +X direction side of each of the pair of Y-axis guide rails 48 in a manner that allows it to slide along the Y-axis direction.

[0047] A nut (not shown) that houses a plurality of balls and constitutes a ball screw together with the screw shaft 50 is provided on the back surface of the Y-axis direction moving base 52. Furthermore, a drive source 54 such as a stepping motor is provided on one end of the screw shaft 50. When the drive source 54 is operated, the Y-axis direction moving base 52 moves along the Y-axis direction together with the nut.

[0048] An elevator mechanism 56 is provided on the surface of the Y-axis direction moving base 52. Although the elevator mechanism 56 is shown as a rectangular parallelepiped in Fig. 1 for convenience, the elevator mechanism 56 has, for example, the same structure as the Z-axis direction moving mechanism 36, that is, a ball screw or the like. When the elevator mechanism 56 is operated, the arm 58 moves up and down.

[0049] Fig. 3(A) is a perspective view that schematically shows the arm 58 and the like, and Fig. 3(B) is a front view that schematically shows the arm 58 and the like. The arm 58 extends in the +X direction from the lifting mechanism 56, and has a mounting part 58a provided below the tip of the arm 58. A holding mechanism 60 is detachably mounted to this mounting part 58a.

[0050] The holding mechanism 60 includes a mounting portion 60a that can be mounted on the mounting portion 58a, a plate-shaped support portion 60b that extends in the +Y direction from the mounting portion 60a, and a cylindrical suction tube 60c that is provided below the tip of the support portion 60b. The inner diameter of the lower surface of the suction tube 60c is smaller than the width of the tip 13.

[0051] Furthermore, the suction cylinder 60c is connected to a drive source (not shown), such as a stepping motor, provided inside the support part 60b. When this drive source is operated, the suction cylinder 60c rotates around a rotation axis that is a straight line passing through the center of the suction cylinder 60c along the Z-axis direction.

[0052] In addition, the suction tube 60c can be selectively connected to a vacuum pump (not shown) and an air supply source (not shown) via a flow path, piping, etc. formed in the support portion 60b. When the vacuum pump is operated while connected to the suction tube 60c, a negative pressure is created inside the suction tube 60c and a suction force acts on the space below the suction tube 60c. When the air supply source is operated while connected to the suction tube 60c, the pressure inside the suction tube 60c returns to normal and the suction force acting on the space below the suction tube 60c disappears.

[0053] Then, the chip 13 pushed up by the push-up mechanism 34 is separated from the chip unit 11 and held by the holding mechanism 60. When the holding mechanism 60 holds this chip 13, first, the holding mechanism 60 is moved so that the suction tube 60c of the holding mechanism 60 comes into contact with the chip 13 pushed up by the push-up member of the push-up mechanism 34.

[0054] Next, the vacuum pump communicating with the suction cylinder 60c is operated so that suction force is applied from the suction cylinder 60c to the chip 13. Next, the holding mechanism 60 is raised and the push-up member of the push-up mechanism 34 is lowered. As a result, the chip 13 is separated from the dicing tape 15 and held below the suction cylinder 60c.

[0055] A vibration isolation table 62 is provided in the +Y direction as viewed from the opening 4b formed in the base 4. FIG. 4(A) is a perspective view schematically showing the vibration isolation table 62 and other components, and FIG. 4(B) is a front view schematically showing the vibration isolation table 62 and other components. A movement mechanism 64 is provided on the vibration isolation table 62. This movement mechanism 64 includes, for example, an XYZ stage 64a whose position on its upper surface can be adjusted in each of the X-axis direction, Y-axis direction, and Z-axis direction. Furthermore, a mounting part 64b is provided on the upper surface of the XYZ stage 64a.

[0056] Then, the mounting portion 64b of the moving mechanism 64 is mounted with the mounting portion 64a of the holding mechanism 60, which holds the tip 13 below the suction tube 60c. When mounting the mounting portion 60a of the holding mechanism 60 to the mounting portion 64b of the moving mechanism 64, first, the arm 58 and the holding mechanism 60 are moved so that the mounting portion 60a of the holding mechanism 60 comes into contact with the mounting portion 64b of the moving mechanism 64. Next, the mounting portion 60a of the holding mechanism 60 is removed from the mounting portion 58a of the arm 58 and mounted to the mounting portion 64b of the moving mechanism 64.

[0057] A camera 66 is provided in the +Y direction as viewed from the moving mechanism 64 for capturing an image of the underside of the tip 13 held on the underside of the suction tube 60c of the holding mechanism 60, whose mounting portion 60a is mounted on the mounting portion 64b of the moving mechanism 64. This camera 66 includes, for example, an optical system whose optical axis is parallel to the Z-axis direction, and an imaging element that converts light passing through this optical system into an electrical signal.

[0058] A camera 68 for capturing an image of the side surface of the chip 13 is provided in the +X and +Z directions as viewed from the camera 66. The camera 68 includes, for example, an optical system whose optical axis is parallel to the X-axis direction, and an imaging element that converts light passing through the optical system into an electrical signal.

[0059] A test unit 70 for performing a three-point bending test using the chip 13 as a test specimen is provided in the +Y direction as viewed from the vibration isolation table 62. This test unit 70 has a support member 72 for supporting the chip 13 at two points. This support member 72 has a generally concave shape in side view.

[0060] An indenter 74 is provided above the support member 72 to press the chip 13 supported by the support member 72. The indenter 74 has a rod or plate shape with its lower surface extending along the Y-axis direction. The indenter 74 has a shape such that its width, i.e., its length in the X-axis direction, decreases as it approaches its lower surface, for example, having a substantially triangular shape in side view.

[0061] A measuring device 76 is provided above the indenter 74 to measure the load applied to the tip 13 when the indenter 74 presses against the tip 13. The measuring device 76 is connected to the indenter 74 via a connecting member, and includes, for example, a strain gauge load cell that converts the load into an electrical signal. The measuring device 76 measures the load that occurs as a reaction from the tip 13 to the indenter 74 when the indenter 74 presses against the tip 13.

[0062] Furthermore, the measuring device 76 is connected to a Z-axis direction movement mechanism 78. This Z-axis direction movement mechanism 78 has a pair of Z-axis direction guide rails 80 that each extend along the Z-axis direction and are spaced apart from each other in the X-axis direction. Furthermore, a screw shaft 82 that extends along the Z-axis direction is disposed between the pair of Z-axis direction guide rails 80.

[0063] Furthermore, a Z-axis direction moving base 84 is connected to the −Y direction side of each of the pair of Z-axis direction guide rails 80 in a manner that allows it to slide along the Z-axis. Note that the measuring device 76 is connected to the underside of this Z-axis direction moving base 84 via a connecting member.

[0064] A nut (not shown) that houses a plurality of balls and forms a ball screw together with the screw shaft 82 is provided on the +Y direction side of the Z-axis direction moving base 84. Furthermore, a drive source 86 such as a stepping motor is provided on the lower end of the screw shaft 82. When the drive source 86 is operated, the Z-axis direction moving base 84 moves along the Z-axis direction together with the nut.

[0065] In the test unit 70, the breaking load of the chip 13 is measured after the bottom and / or side surfaces have been imaged by the cameras 66, 68 while the chip 13 is held, for example, below the suction tube 60c of the holding mechanism 60, whose mounting portion 60a is attached to the mounting portion 64b of the moving mechanism 64.

[0066] When measuring the breaking load of this chip 13, first, the arm 58 is moved so that the mounting portion 58a of the arm 58 contacts the mounting portion 60a of the holding mechanism 60. Next, the mounting portion 60a of the holding mechanism 60 is removed from the mounting portion 64b of the moving mechanism 64 and attached to the mounting portion 58a of the arm 58.

[0067] Next, the arm 58 and the holding mechanism 60 are moved so that the tip 13 contacts the upper surface of the support member 72. Next, instead of the vacuum pump, an air supply source is operated while being connected to the suction tube 60c of the holding mechanism 60. As a result, the tip 13 is separated from the suction tube 60c and supported by the support member 72.

[0068] Next, the arm 58 and the holding mechanism 60 are moved away from the test unit 70. Next, the indenter 74 is lowered until the chip 13 is broken by being pressed by the indenter 74. This allows the load at break of the chip 13 (specifically, the peak load observed in the load that changes over time measured by the measuring device 76) to be measured.

[0069] The test device 2 is provided with a controller 88 for controlling the above-mentioned components. The controller 88 includes a memory 88a and a processor 88b. The memory 88a is configured, for example, by a volatile memory such as a DRAM (Dynamic Random Access Memory) or an SRAM (Static Random Access Memory), and a non-volatile memory such as an SSD (Solid State Drive) (NAND flash memory) or an HDD (Hard Disk Drive) (magnetic storage device). The processor 88b is configured, for example, by a CPU (Central Processing Unit) or the like.

[0070] The memory 88a stores, for example, data used by the processor 88b, data acquired by the test device 2, and programs for controlling the components of the test device 2. The memory 88a also stores data obtained by testing a test piece (e.g., a chip 13) in the test device 2.

[0071] The processor 88b uses the data stored in the memory 88a, reads out the program stored in the memory 88a, and controls the components of the test apparatus 2. For example, the processor 88b controls the components of the test apparatus 2 so that the program for carrying out a test method for imaging an imaged surface (e.g., a side surface) of a test piece (e.g., a chip 13) and then measuring the load at fracture is read out from the memory 88a and executed.

[0072] 5 is a flow chart showing a typical example of this test method. In this test method, first, the mounting portion 60a of the holding mechanism 60, which holds the tip 13 below the suction tube 60c, is mounted on the mounting portion 64b of the moving mechanism 64 (mounting step S1). Note that this mounting step S1 is performed as described above using the arm 58, etc. Therefore, a detailed description of the mounting step S1 will be omitted.

[0073] After the mounting step S1, the side surface of the chip 13 is imaged (imaging step S2) in a plurality of states where the distance (first distance) between the focal point of the optical system in the X-axis direction and a specific point included in the side surface of the chip 13 is different from one another. Fig. 6 is a flowchart schematically showing a specific example of the imaging step S2.

[0074] In this imaging step S2, first, the side surface of chip 13 is partially imaged in each of a plurality of states where the distance (second distance) between the focal point of the optical system in the Y-axis direction and a specific point included in the side surface of chip 13 is different from one another (partial imaging step S21). Figures 7(A), 7(B), and 7(C) are each a plan view schematically showing the state of partial imaging step S21.

[0075] 7(A), 7(B), and 7(C) show, as an example, chip 13 that is held in an orientation such that the side surface facing camera 68 is slightly tilted from the Y-axis direction. Specifically, chip 13 is held in an orientation such that the end (one end) of this side surface on the -Y direction side is located closer to the +X direction side than the end (other end) on the +Y direction side.

[0076] In this partial imaging step S21, first, the camera 68 partially images the side surface of the chip 13 (see FIG. 7(A)) with the focal point F of the optical system of the camera 68 aligned with point P located at one end of the side surface of the chip 13. That is, the camera 68 images an area in the vicinity of one end of the side surface of the chip 13, with the distance (first distance) between the focal point F and point P in the X-axis direction and the distance (second distance) in the Y-axis direction both set to 0.

[0077] Next, the holding mechanism 60 is moved a predetermined distance in the -Y direction, and then the camera 68 again partially images the side surface of the chip 13 (see FIG. 7(B)). That is, with the first distance set to 0 and the second distance set to the predetermined distance, the camera 68 images an area in the vicinity of a point inside one end of the side surface of the chip 13 as the center. Note that if the shape of the chip 13 in plan view is a substantial square with each side about 10 mm long, the predetermined distance is set to, for example, 100 μm.

[0078] Furthermore, the holding mechanism 60 is alternately moved a predetermined distance in the -Y direction and the camera 68 captures an image of a portion of the side surface of the chip 13 (see FIG. 7(C)) until an image of the area in the vicinity of the other end of the side surface of the chip 13 in the Y-axis direction is captured as the center (see FIG. 7(C)). This results in the formation of multiple partial images, each of which displays a portion of the side surface of the chip 13 and has a different center.

[0079] Then, the processor 88b stores the image signals for forming each partial image in the memory 88a. Alternatively, instead of or in addition to this image signal, the processor 88b may form an image showing the entire side surface of the chip 13 by combining multiple partial images, and then store the image signals for forming this image in the memory 88a. This completes the partial imaging step S21.

[0080] If the partial imaging step S21 has not been performed the predetermined number of times (step S22: NO), the first interval is changed (interval changing step S23). FIG. 8 is a plan view schematically showing the interval changing step S23. In this interval changing step S23, the holding mechanism 60 is moved a predetermined distance (for example, 2 μm) in the +X direction. As a result, the first interval becomes the predetermined distance. This completes the interval changing step S23.

[0081] After the interval change step S23, the partial imaging step S21 is performed again. The second partial imaging step S21 is performed in the same manner as the first partial imaging step S21, except that the movement of the holding mechanism 60, which is repeated alternately with the imaging of a portion of the side surface of the chip 13 by the camera 68, is in the +Y direction instead of the -Y direction. Therefore, a detailed description of the second partial imaging step S21 will be omitted.

[0082] Furthermore, the interval changing step S23 and the partial imaging step S21 are performed alternately. Then, when the partial imaging step S21 is performed a predetermined number of times (step S22: YES), the imaging step S2 is completed.

[0083] After the imaging step S2, the load at break of the chip 13 is measured (load measuring step S3). Note that this load measuring step S3 is performed as described above using the test unit 70. Therefore, a detailed description of the load measuring step S3 will be omitted.

[0084] Then, the processor 88b may, for example, associate the measured breaking load with the image signal and store them in the memory 88a. Alternatively, the processor 88b may assign an identification number to the chip 13 in advance, and associate this identification number with the image signal and breaking load and store them in the memory 88a.

[0085] 3, multiple images are formed by capturing images of the side surface of the chip 13 in multiple states where the first distance between the focal point F of the optical system of the camera 68 and point P included in the side surface of the chip 13 in the X-axis direction parallel to the optical axis of the optical system is different from each other. In this case, it is possible to understand the state of the side surface of the chip 13 by referring to the multiple images. Therefore, this method makes it easier to accurately understand the state of the side surface of the chip 13 compared to referring to a single image.

[0086] It should be noted that the above is one aspect of the present invention, and the present invention is not limited to the above. For example, in the test device 2, a moving mechanism for moving the camera 68 may be provided instead of or in addition to the moving mechanism 64 for moving the holding mechanism 60 that holds the chip 13 below the suction tube 60c. In this case, in the imaging step S2 (specifically, the partial imaging step S21 and / or the interval changing step S23), the camera 68 may be moved instead of or in addition to the holding mechanism 60.

[0087] Furthermore, in the test device 2, the camera 68 may be provided with an optical system capable of adjusting the position of the focal point F using an expander or the like. In this case, in the imaging step S2, the position of the focal point F of the optical system of the camera 68 may be adjusted instead of or in addition to moving the holding mechanism 60 and / or the camera 68. That is, in the test device 2 and the imaging step S2, it is only necessary to be able to relatively move the holding mechanism 60 that holds the chip 13 below the suction tube 60c and the focal point F of the optical system of the camera 68, and there are no limitations on the configuration for this.

[0088] Furthermore, in the imaging step S2, instead of the partial imaging step S21, a partial imaging step of partially imaging the side surface of the chip 13 in each of a plurality of states in which the first interval is different from one another may be performed, and instead of the interval changing step S23, a distance changing step of changing the second interval may be performed. That is, in the imaging step S2, it is sufficient that a portion of the side surface of the chip 13 is imaged under each of a plurality of conditions in which both the first interval and the second interval are parameters, and there is no restriction on the order in which these images are performed.

[0089] Furthermore, the test method of the present invention is not limited to the test method shown in Fig. 3. For example, the test method of the present invention may accurately grasp the state of the underside of chip 13, which serves as a test piece, rather than the side surface. Specifically, in the test method of the present invention, instead of or in addition to the imaging step S2, an imaging step may be performed in which the underside of chip 13 is imaged in each of a plurality of states in which the distance between the focal point of the optical system of camera 66 in the Z-axis direction and a specific point included in the underside of chip 13 is different from one another.

[0090] This imaging step is performed in the same manner as the imaging step S2 described above, although camera 66 is used instead of camera 68 and the direction of relative movement between the focal point of the optical system and holding mechanism 60 is different. Therefore, a detailed description of this imaging step will be omitted.

[0091] 9 is a flow chart showing another example of the test method of the present invention. In this test method, the orientation of the chip 13 is adjusted (orientation adjustment step S4) after the mounting step S1 and before the imaging step S2. This orientation adjustment step S4 is performed, for example, in the following order:

[0092] First, the holding mechanism 60 that holds the chip 13 below the suction tube 60c and the camera 66 are moved relatively to each other so that the focal point of the optical system of the camera 66 coincides with a point included in one end in the Y-axis direction of the side of the chip 13. Next, the holding mechanism 60 and the camera 66 are moved relatively to each other so that the focal point of the optical system of the camera 66 coincides with a point included in the other end in the Y-axis direction of the side of the chip 13.

[0093] At this time, the misalignment in the X-axis direction between one end of the side surface of the chip 13 in the Y-axis direction and the other end can also be determined. Next, the drive source provided inside the support portion 60b of the arm 58 is operated to rotate the suction tube 60c so as to eliminate this misalignment. This completes the orientation adjustment step S4. When the orientation adjustment step S4 is performed in this manner, it is preferable because, for example, the number of times the partial imaging step S21 is performed can be reduced.

[0094] It may be difficult to completely eliminate this misalignment in the orientation adjustment step S4. Also, the side surface of the chip 13 may be inclined or curved, and may have a non-flat shape including minute irregularities. Therefore, even if the orientation adjustment step S4 is performed, the technical significance of performing the imaging step S2 to form multiple images thereafter is not lost.

[0095] In addition, the structures and methods according to the above-described embodiments can be modified as appropriate without departing from the scope of the present invention. [Explanation of symbols]

[0096] 2: Test equipment 4: Base (4a: top surface, 4b: opening) 6: Cassette 8: Transport unit (8a, 8b: clamping mechanism) 10: Temporary rail 11: Chip unit 12: Frame holding unit (12a: frame support part, 12b: frame holding part, 12c: drive mechanism) 13: Chip 14: Moving Block 15: Dicing tape 16:Y-axis direction movement mechanism 17: Ring frame 18: Y-axis guide rail 20: Screw shaft 22: Power source 24: X-axis direction moving frame (24a: through hole) 26:X-axis direction movement mechanism 28: X-axis guide rail 30:Screw shaft 32: Power source 34: Raising mechanism (34a: Suction cylinder) 36: Z-axis direction movement mechanism 38: Z-axis guide rail 40:Screw shaft 42: Z-axis movement base 44: Power source 46:Y-axis direction movement mechanism 48: Y-axis guide rail 50:Screw shaft 52: Y-axis direction movement base 54: Power source 56: Lifting mechanism 58: Arm (58a: Mounting part) 60: Holding mechanism (60a: Mounted part, 60b: Support part, 60c: Suction tube) 62: Vibration isolation table 64: Moving mechanism (64a: XY stage, 64b: mounting part) 66: Camera 68: Camera 70: Test unit 72: Support member 74: Indenter 76: Measuring instrument 78:Z-axis direction movement mechanism 80: Z-axis guide rail 82: Screw shaft 84: Z-axis movement base 86: Power source 88: Controller (88a: memory, 88b: processor)

Claims

1. A test method for a test specimen, comprising: an imaging step of imaging the imaged surface of the test piece using light passing through an optical system; a load measuring step of measuring the load at break of the test piece by pressing the test piece with an indenter while increasing the load applied to the test piece after the imaging step, In the imaging step, a plurality of images are formed by imaging the imaged surface in each of a plurality of states in which a first distance between the focus of the optical system and a specific point included in the imaged surface in a first direction parallel to the optical axis of the optical system is different from one another.

2. In the imaging step, a partial imaging step of forming a plurality of partial images by partially imaging the imaged surface in each of a plurality of states in which the first distances are equal to one another and a second distance between the focal point of the optical system and the specific point included in the imaged surface in a second direction orthogonal to the first direction is different from one another; 2. The testing method according to claim 1, wherein the steps of: altering the first interval; and altering the second interval are repeated alternately.

3. The testing method according to claim 1 or 2, further comprising an orientation adjustment step of adjusting the orientation of the test piece before the imaging step.

4. A test strip testing device comprising: a holding mechanism for holding the test piece; a camera for capturing an image of the imaged surface of the test piece held by the holding mechanism using light passing through an optical system; a moving mechanism for relatively moving the focal point of the optical system and the holding mechanism along a first direction parallel to the optical axis of the optical system; a support member for supporting the test piece; an indenter for pressing the test piece supported by the support member; a measuring device for measuring a load applied to the test piece when the indenter presses the test piece; a controller for controlling the camera and the moving mechanism to form a plurality of images by capturing images of the imaged surface in a plurality of states in which a first distance between the focal point of the optical system in the first direction and a specific point included in the imaged surface is different from one another; and A test device comprising:

Images