JP7793354B2 - Measurement method - Google Patents

Description

The present invention relates to a measurement method for measuring the strength of a chip having a top surface, a bottom surface, and a side surface.

Grinding the backside of a semiconductor wafer generates grinding strain on the backside of the wafer. Furthermore, dicing with a cutting blade after grinding generates cutting strain on the side of the semiconductor device chip.

The three-point bending method specified in SEMI standard G86-0303 is commonly used to measure the strength of semiconductor device chips. However, until now, only manual testing equipment was available on the market, and workers had to remove the desired chip from a wafer divided into chips, set it in the testing equipment, and measure its strength, which was time-consuming.

In addition, depending on how the worker picks up and places the chips, there is a risk of damage to the chips that cannot be seen with the naked eye. If the way the chips are picked up and placed varies from chip to chip, it becomes difficult to make accurate strength comparisons.

The applicant of this application therefore developed a testing device that picks up chips from a wafer and measures the strength of the picked-up chips (see, for example, Patent Document 1).

Japanese Patent Application Laid-Open No. 2020-094833

The testing equipment shown in Patent Document 1 has a camera that measures the side of the chip whose strength is to be measured, and takes an image of the side before destroying the chip. However, the imaging position within the chip is fixed, and the equipment only measures the same position on each of the chips being compared.

On the other hand, the strength of a chip will be affected by the presence of a chip directly below the pressing position of the indenter compared to when there is no chip directly below the pressing position of the indenter. However, since the chip is broken into small pieces after destruction, it is difficult to detect where the chip was formed on the broken chip.

There is a need to accumulate information on the relationship between the position where the indenter presses and chipping of the chip before destroying the chip.

The object of the present invention is to provide a measurement method that can accumulate information on the relationship between the position where the indenter presses and chipping of the chip.

In order to solve the above-mentioned problems and achieve the object, the measurement method of the present invention is a measurement method for measuring the strength of a chip having an upper surface, a lower surface, and a side surface, and is characterized by comprising: a chip mounting step in which the chip is mounted on a pair of supports arranged at a predetermined distance and the lower surface of the chip is supported by the supports; a chip breaking step in which an indenter arranged above the chip mounted on the supports and between the pair of supports is moved toward the chip supported by the supports, pressing the upper surface of the chip with the indenter to break it, and detecting the load at which the indenter breaks the chip with a load measuring instrument; a side surface imaging step in which the side surface of the chip corresponding to the position on the top surface of the chip where the indenter presses before the indenter breaks the chip; and a chipping detection step in which, after the side surface imaging step, chipping on the lower surface of the chip is detected based on the image of the side surface of the chip and the distance between the chip and the position on the chip where the indenter presses.

In the above-described measurement method, the chip may be rectangular, the indenter may be bar-shaped and extend in a direction perpendicular to the direction in which the pair of support portions are aligned, and the side surface imaging step may image at least two side surfaces of the chip that face each other and intersect with the extension direction of the indenter.

The measuring method of the present invention is a method for measuring the strength of a chip having an upper surface, a lower surface, and a side surface, and includes a chip placing step of placing the chip on a pair of supports arranged at a predetermined interval and supporting the lower surface of the chip with the supports; a chip breaking step of moving an indenter arranged above the chip placed on the supports and between the pair of supports toward the chip supported by the supports, pressing the upper surface of the chip with the indenter to break it, and detecting the load when the indenter breaks the chip with a load measuring device; and a chip breaking step of detecting the upper surface of the chip before the indenter breaks it. and a chipping detection step of detecting chipping on the underside of the chip based on the image of the side of the chip after the side imaging step is performed, wherein after the chipping detection step is performed and before the indenter destroys the chip, the chip is placed on the support part so that the indenter will press the position corresponding to the maximum chipping detected in the chipping detection step, and in the chip destroying step, the indenter presses the position corresponding to the maximum chipping .

In the measurement method, the chip is rectangular, the indenter is bar-shaped and extends in a direction perpendicular to the direction in which the pair of support portions are aligned, and the side imaging step may image at least two side surfaces of the chip that face each other and intersect the extension direction of the indenter .

The present invention has the advantage of being able to store information relating to the position where the indenter presses and chipping of the chip.

FIG. 1 is a perspective view showing a part of a configuration example of a test apparatus for carrying out a measurement method according to the first embodiment. FIG. 2 is a perspective view of the main part of the testing device shown in FIG. FIG. 3 is a perspective view of a wafer unit including a wafer divided into chips to be measured by the test device shown in FIG. FIG. 4 is a perspective view of a chip to be measured in the measurement method according to the first embodiment. FIG. 5 is a cross-sectional view schematically showing a push-up unit and the like of the testing device shown in FIG. 6 is a perspective view of a support unit of the strength measuring mechanism of the testing apparatus shown in FIG. 1. FIG. FIG. 7 is a flowchart showing the flow of the measurement method according to the first embodiment. 8 is a cross-sectional view schematically showing a state in which the periphery of the chip to be measured on the tape of the wafer unit is suction-held on the upper surface of the tape holding portion of the push-up unit in the pickup step of the measurement method shown in FIG. FIG. 9 is a cross-sectional view schematically showing a state in which the chip to be measured is pushed up by the push-up portion of the push-up unit in the pick-up step of the measuring method shown in FIG. FIG. 10 is a cross-sectional view that schematically shows a state in which the chip to be measured is held by suction on the lower surface of the holder in the pick-up step of the measurement method shown in FIG. FIG. 11 is a perspective view schematically showing a state in which the back surface of the chip held by the holder by suction is faced to the downward imaging camera in the back surface imaging step of the measurement method shown in FIG. FIG. 12 is a perspective view schematically showing a state in which the holder holding the chip by suction is lowered in the backside imaging step of the measuring method shown in FIG. FIG. 13 is a side view schematically showing a state in which the side surface held by the holder by suction and the side imaging unit are made to face each other in the side imaging step of the measuring method shown in FIG. FIG. 14 is a diagram schematically showing an image acquired in the side image capturing step of the measurement method shown in FIG. FIG. 15 is a diagram schematically showing a captured image in which chipping is detected in the chipping detection step of the measurement method shown in FIG. FIG. 16 is a cross-sectional view schematically showing the chip mounting step of the measurement method shown in FIG. FIG. 17 is a cross-sectional view schematically showing a state in which the back surface of the chip is pressed by the indenter and comes into contact with the upper end of the support protrusion of the support portion in the chip destruction step of the measurement method shown in FIG. FIG. 18 is a cross-sectional view schematically showing a state in which the chip is destroyed in the chip destruction step of the measurement method shown in FIG. FIG. 19 is a cross-sectional view schematically showing a chip mounting step of a measurement method according to a modified example of the first embodiment. FIG. 20 is a cross-sectional view schematically showing a state in which the maximum chipping on the back surface of the side surface of the chip is positioned below the tip of the indenter in the chip destruction step of the measurement method according to a modified example of the first embodiment.

Modes for carrying out the present invention (embodiments) will be described in detail with reference to the drawings. The present invention is not limited to the contents described in the following embodiments. Furthermore, the components described below include those that would be easily imagined by a person skilled in the art and those that are substantially identical. Furthermore, the configurations described below can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications to the configuration can be made without departing from the spirit of the present invention.

[Embodiment 1]
A measurement method according to a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view showing a portion of an example configuration of a test apparatus for carrying out the measurement method according to the first embodiment. FIG. 2 is a perspective view of a main part of the test apparatus shown in FIG. 1. FIG. 3 is a perspective view of a wafer unit including a wafer divided into chips to be measured by the test apparatus shown in FIG. 1. FIG. 4 is a perspective view of a chip to be measured by the measurement method according to the first embodiment. FIG. 5 is a cross-sectional view schematically showing a push-up unit and the like of the test apparatus shown in FIG. 1. FIG. 6 is a perspective view of a support unit of a strength measurement mechanism of the test apparatus shown in FIG. 1. FIG. 7 is a flowchart showing the flow of the measurement method according to the first embodiment.

The measurement method according to the first embodiment is carried out by the test apparatus 1 shown in Figures 1 and 2. The test apparatus 1 shown in Figures 1 and 2 is an apparatus that picks up a test piece, a chip 14 shown in Figure 4, from the tape 15 of the wafer unit 17 shown in Figure 3, takes an image of at least the chip 14, and destroys the imaged chip 14 to measure the flexural strength (equivalent to strength) of the chip 14.

(wafer unit)
3, the wafer unit 17 includes a wafer 10 divided into a plurality of chips 14, a tape 15 to which the wafer 10 is attached, and an annular frame 16 to which the outer periphery of the tape 15 is attached to house the wafer 10 within an opening. The wafer 10 is a disk-shaped semiconductor wafer, an optical device wafer, or the like, with a substrate 11 made of silicon, sapphire, gallium, or the like.

The wafer 10 has devices 13 formed in areas defined by a plurality of planned division lines 12 formed in a grid pattern on the surface 11-1 of the substrate 11. In embodiment 1, the wafer 10 has a disk-shaped tape 15 with an annular frame 16 attached to its outer periphery, attached to the back surface 11-2 behind the surface 11-1, and is supported by the annular frame 16 to form a wafer unit 17.

The wafer 10 is also cut along the planned division lines 12 to separate it into individual chips 14. That is, the wafer 10 has cut grooves 18 formed between the chips 14, penetrating the wafer 10 itself. As shown in FIG. 4, the chip 14 is composed of a portion of the substrate 11 and a device 13, and has a rectangular planar shape. The chip 14 has a surface 11-1 (corresponding to the top surface in embodiment 1), a back surface 11-2 (corresponding to the bottom surface in embodiment 1) behind the surface 11-1, and multiple side surfaces 11-3 extending from the surface 11-1 to the back surface 11-2.

In embodiment 1, the wafer 10 has devices 13 formed on the surface 11-1 of the substrate 11. However, in the present invention, if the test device 1 is used to evaluate the appropriateness of the processing conditions for the so-called post-processing step of dividing the wafer 10 into individual chips 14, the devices 13 do not need to be formed on the surface 11-1.

(Test equipment)
As shown in FIG. 1, the testing apparatus 1 includes a cassette mounting table 3 provided on an apparatus main body 2 and on which a cassette 4 containing a plurality of wafer units 17 is placed, a transfer unit 5 for transferring the wafer units 17 into and out of the cassette 4, a pair of temporary placement rails 6 on which the wafer units 17 transferred out of the cassette 4 or the wafer units 17 before being transferred into the cassette 4 are temporarily placed, a frame fixing unit 7, a moving mechanism 30 for moving the frame fixing unit 7 in the Y-axis direction and the X-axis direction, a push-up unit 40, an imaging camera 50, a pickup mechanism 60, a holder moving unit 70 (shown in FIG. 2), an imaging device 100, a strength measuring mechanism 200, and a control unit 400.

The cassette 4 is a storage container that stores multiple wafer units 17 at intervals in the Z-axis direction, which is parallel to the vertical direction, and is provided with an opening 8 for inserting and removing the wafer units 17. The cassette 4 is placed on the upper surface of the cassette mounting table 3, which raises and lowers the cassette 4 in the Z-axis direction.

A pair of temporary placement rails 6 are provided on both widthwise ends of the opening 8 of the cassette 4 placed on the cassette placement table 3 on the apparatus main body 2, and extend linearly in the Y-axis direction, which is parallel to the horizontal direction. The pair of temporary placement rails 6 are arranged parallel to each other and spaced apart along the X-axis direction, which is perpendicular to the Y-axis direction and parallel to the horizontal direction. The annular frame 16 of the wafer unit 17 is temporarily placed on the pair of temporary placement rails 6.

The carry-in/out unit 5 is movable in the Y-axis direction by a movement mechanism (not shown). The carry-in/out unit 5 carries the wafer unit 17 out of the cassette 4 and temporarily places it on the temporary placement rails 6, then carries the wafer unit 17 to the upper surface of the lowered frame support member 22 of the frame fixing unit 7 and places it on the upper surface of the frame support member 22. The carry-in/out unit 5 also carries the wafer unit 17 from the upper surface of the lowered frame support member 22 of the frame fixing unit 7 into the cassette 4 via the temporary placement rails 6.

(frame fixing unit)
The frame fixing unit 7 holds and fixes the annular frame 16 arranged around the wafers 10 on the tape 15 of the wafer unit 17. The frame fixing unit 7 is installed on a moving table 21. The frame fixing unit 7 includes an annular frame support member 22, an annular frame pressing member 23 arranged above and fixed to the frame support member 22, and an elevating mechanism (not shown) that raises and lowers the frame support member 22.

Before being raised, the upper surface of the frame support member 22 is flush with the upper surface of the temporary placement rail 6, and the annular frame 16 of the wafer unit 17 is placed on it. When the annular frame 16 of the wafer unit 17 is placed on the upper surface of the frame support member 22, the frame fixing unit 7 uses the lifting mechanism to raise the frame support member 22, sandwiching the annular frame 16 between the frame holding member 23 and the frame support member 22. The frame fixing unit 7 sandwiches the annular frame 16 between the frame holding member 23 and the frame support member 22, holding and fixing the annular frame 16 arranged around the wafer 10 on the tape 15, and fixing the wafer unit 17.

(Moving mechanism)
The movement mechanism 30 includes an X-axis movement mechanism 31 that is provided on the apparatus main body 2 and moves the movement table 21 in the X-axis direction, and a Y-axis movement mechanism 32 that is provided on the movement table 21 that is moved in the X-axis direction by the X-axis movement mechanism 31 and moves the frame fixing unit 7 in the Y-axis direction. The X-axis movement mechanism 31 moves the movement table 21, i.e., the frame fixing unit 7, in the X-axis direction between a position aligned with the pair of temporary placement rails 6 in the Y-axis direction and a position spaced apart from the pair of temporary placement rails 6. Each movement mechanism 31, 32 includes well-known ball screws 33, 34 that are provided rotatably about their axes, well-known motors 35, 36 that rotate the ball screws 33, 34 about their axes, and well-known guide rails 37, 38 that support the movement table 21 or the frame fixing unit 7 movably in the X-axis or Y-axis direction.

(Thrust-up unit)
The push-up unit 40 is disposed below the frame fixing unit 7, which is positioned by the X-axis movement mechanism 31 at a position away from the pair of temporary placement rails 6. The push-up unit 40 is provided in the recess 9 of the device main body 2, and pushes up one of the chips 14 via the tape 15 of the wafer unit 17 fixed by the frame fixing unit 7, which is positioned by the X-axis movement mechanism 31 at a position away from the pair of temporary placement rails 6.

The push-up unit 40, as a whole, is connected to an elevation mechanism (not shown) comprised of a motor or the like, and moves up and down along the Z-axis direction. As shown in FIG. 5 , the push-up unit 40 has a hollow cylindrical tape holding section 41 and a rectangular prism-shaped push-up section 42 located inside the tape holding section 41. The top surface 48 of the tape holding section 41 is formed flat and parallel to the horizontal direction, and serves as a tape holding surface that suction-holds the tape 15 around the chip 14 to be measured. The top surface 48 of the tape holding section 41 has multiple suction grooves 44 formed concentrically along the circumferential direction of the tape holding section 41. Each suction groove 44 is connected to a suction source 47, such as an ejector, via a suction path 45 and an on-off valve 46 formed inside the push-up unit 40.

The push-up section 42 has a rectangular top planar shape that is the same size as the chip 14. The push-up section 42 includes a first push-up member 42-1 formed in the shape of a rectangular cylinder, a second push-up member 42-2 formed in the shape of a rectangular cylinder and housed within the first push-up member 42-1, and a third push-up member 42-3 formed in the shape of a rectangular cylinder and housed within the second push-up member 42-2. The first push-up member 42-1, second push-up member 42-2, and third push-up member 42-3 are each connected to an elevation unit (not shown) comprised of a motor or the like, and move up and down along the Z-axis direction.

The first push-up member 42-1 and the second push-up member 42-2 are raised by the lifting unit, pushing up the outer edge of the chip 14 to be measured via the tape 15. The third push-up member 42-3 is raised by the lifting unit, pushing up the center of the chip 14 via the tape 15 inside the first push-up member 42-1 and the second push-up member 42-2.

With the wafer unit 17, including the annular frame 16 held by the frame fixing unit 7, positioned above the push-up unit 40, the suction grooves 44 on the upper surface 48 of the tape holding section 41 are sucked by the suction source 47, and the tape 15 around the chip 14 to be measured is held by suction on the upper surface 48 of the tape holding section 41. The push-up unit 40 suction-holds the tape 15 around the chip 14 to be measured on the upper surface 48 of the tape holding section 41, and the push-up members 42-1, 42-2, and 42-3 of the push-up section 42 are raised, pushing the chip 14 above the tape 15 and peeling the outer edge of the chip 14 from the tape 15. The dimensions of the push-up unit 40 are adjusted appropriately depending on the size of the chip 14.

In embodiment 1, when the push-up unit 40 pushes up the chip 14, the lifting mechanism starts raising the first push-up member 42-1, the second push-up member 42-2, and the third push-up member 42-3 simultaneously at the same speed, and the second push-up member 42-2 is raised above the first push-up member 42-1, and the third push-up member 42-3 is raised above the second push-up member 42-2, and then each of them stops rising. In other words, when the push-up unit 40 pushes up the chip 14, the first push-up member 42-1, the second push-up member 42-2, and the third push-up member 42-3 start rising simultaneously at the same speed, and the first push-up member 42-1, the second push-up member 42-2, and the third push-up member 42-3 stop rising in order.

(imaging camera)
The imaging camera 50 is disposed above the frame fixing unit 7, which is positioned by the X-axis moving mechanism 31 at a position away from the pair of temporary placement rails 6. The imaging camera 50 forms a captured image by capturing an image of the chip 14 and the surroundings of this chip 14 that are pushed up by the push-up portion 42 of the push-up unit 40 of the wafer 10 of the wafer unit 17, which includes the annular frame 16 held by the frame fixing unit 7, which is positioned by the X-axis moving mechanism 31 at a position away from the pair of temporary placement rails 6.

The imaging camera 50 includes an imaging element (i.e., pixel) that captures an image of the chip 14 pushed up by the push-up portion 42 of the push-up unit 40 of the wafer 10 of the wafer unit 17, which includes an annular frame 16 held by the frame fixing unit 7, and the area around this chip 14. The imaging element is, for example, a CCD (Charge-Coupled Device) imaging element or a CMOS (Complementary MOS) imaging element.

The imaging camera 50 photographs the chip 14 and the surrounding area of the chip 14 being pushed up by the push-up portion 42 of the push-up unit 40 of the wafer 10 of the wafer unit 17, which includes the annular frame 16 held by the frame fixing unit 7, to obtain images for purposes such as aligning the push-up unit 40 with the chip 14 being measured and being pushed up by the push-up unit 40 of the wafer 10, and outputs the obtained images to the control unit 400.

(Pickup mechanism)
The pickup mechanism 60 picks up the chips 14 pushed up by the push-up unit 40 from the wafer 10 of the wafer unit 17. The pickup mechanism 60 includes a moving base 61 that is moved in the Y-axis direction and the Z-axis direction by a holder moving unit 70, an arm 62 that extends in the X-axis direction from the moving base 61 in a direction away from the holder moving unit 70, and a holder 63 that is connected to the tip of the arm 62 via an elevator part 64 and that holds the chips 14.

The holder 63 has a lower surface 65 that faces the push-up portion 42 of the push-up unit 40, sandwiching the wafer unit 17 fixed by the frame fixing unit 7, which is positioned away from the pair of temporary placement rails 6 by the X-axis movement mechanism 31. The planar shape of the lower surface 65 is formed into a rectangle of the same size as the chip 14. The lower surface 65 has a suction groove 69 formed therein, which is connected to a suction source 68, such as an ejector, via a suction path 66 and an on-off valve 67, etc.

With the chip 14 pushed up by the push-up portion 42 in contact with the lower surface 65 of the holder 63, the suction groove 69 is sucked by the suction source 68, suction-holding the chip 14 to the lower surface 65. The holder 63 suction-holds the chip 14 pushed up by the push-up portion 42 of the push-up unit 40 to the lower surface 65, and is raised by the holder movement unit 70 to pick up the chip 14 suction-held on the lower surface 65 from the tape 15.

In addition, in embodiment 1, the test device 1 may be provided with a load cell, which is a measuring means, on the upper surface side of the push-up unit 40, for measuring the load applied to the chip 14 when it is picked up from the tape 15. The load cell outputs the measurement results to the control unit 400. Note that in the present invention, the load cell, which is a measuring means, may also be provided on the lower surface 65 side of the holder 63 of the pickup mechanism 60.

The lifting unit 64 is provided at the tip of the arm 62, has a holder 63 attached to its lower end, and is raised and lowered along the Z-axis direction relative to the arm 62 by a cylinder or the like (not shown). When the lifting unit 64 lowers, it brings the underside 65 of the holder 63 closer to the wafers 10 of the wafer unit 17, which includes the annular frame 16 held by the frame fixing unit 7, and when it rises, it moves the underside 65 of the holder 63 away from the wafers 10 of the wafer unit 17.

(Holder moving unit)
The holder moving unit 70 moves the holder 63 along the Z-axis direction and the Y-axis direction. The holder moving unit 70 moves the holder 63 among a pickup position where the chip 14 is picked up from the tape 15, a backside imaging position where the backside 11-2 of the chip 14 held by the holder 63 is imaged by the downward imaging camera 102 of the imaging device 100, an imaging position where the side surface 11-3 of the chip 14 held by the holder 63 is imaged by the side surface imaging camera 121 of the imaging device 100, and a measurement position where the chip 14 is placed on a pair of support portions 205 (shown in FIG. 6 ) of the support unit 210 of the strength measurement mechanism 200 and the flexural strength of the chip 14 is measured by the strength measurement mechanism 200. The holder moving unit 70 moves the holder 63 among the pickup position, the backside measurement position, and the measurement position, thereby transporting the chip 14 picked up by the holder 63 to the support unit 210 of the strength measurement mechanism 200.

As shown in Figure 2, the holder movement unit 70 includes a second Y-axis movement mechanism 71 that is mounted on the device main body 2 and moves the moving table 73 in the Y-axis direction, and a Z-axis movement mechanism 72 that is mounted on the moving table 73 that is moved in the Y-axis direction by the second Y-axis movement mechanism 71 and moves the moving base 61, i.e., the pickup mechanism 60, in the Z-axis direction.

The second Y-axis movement mechanism 71 moves the moving table 73, i.e., the pickup mechanism 60, along the Y-axis from a pickup position where the upper surface 48 of the tape holding portion 41 of the push-up unit 40 and the lower surface 65 of the holder 63 face each other in the Z-axis direction toward the strength measurement mechanism 200. Each movement mechanism 71, 72 includes well-known ball screws 74, 75 rotatable about their axes, well-known motors 76, 77 that rotate the ball screws 74, 75 about their axes, and well-known guide rails 78, 79 that support the moving table 73 or pickup mechanism 60 for movement in the Y-axis or Z-axis direction.

(imaging device)
The imaging device 100 captures images of the front surface 11-1, back surface 11-2, and side surface 11-3 of the chip 14. As shown in Figures 1 and 2, the imaging device 100 includes a lower imaging unit 101 arranged adjacent to the push-up unit 40 in the Y-axis direction on the device body 2, a chip inversion mechanism 110 that inverts the chip 14 upside down, and a lateral imaging unit 120.

The lower imaging unit 101 is equipped with a lower imaging camera 102 that captures images of the chip 14 held by the holder 63 of the pickup mechanism 60 from below. The lower imaging camera 102 is positioned so as to overlap the movement path of the holder 63, which is parallel to the Y-axis direction, caused by the holder movement unit 70.

The lower imaging camera 102 faces the chip 14 held by the holder 63 along the Z-axis direction, with the lifting section 64 lowered from the arm 62 and held by suction on a support column 103 erected from the device main body 2, and images the chip 14 from below. This prevents vibrations of the arm 62 caused by the operation of the holder movement unit 70, etc., from being transmitted to the chip 14, improving the accuracy of imaging of the chip 14 by the lower imaging camera 102.

The back surface 11-2 of the chip 14 may have minute irregularities, such as saw marks from grinding performed on the back surface 11-2 of the wafer 10 before division, and these irregularities affect the flexural strength of the chip 14. Therefore, when measuring the flexural strength of the chip 14, it is preferable to check the condition of the back surface 11-2 of the chip 14 beforehand. For this reason, the test device 1 has a lower imaging camera 102 positioned so as to overlap the movement path of the holder 63, so that the chip 14 can be placed on the lower imaging camera 102 while held by the holder 63, allowing the back surface 11-2 of the chip 14 to be imaged.

The downward imaging camera 102 is capable of detecting saw marks formed on the back surface 11-2 of the chip 14. The downward imaging camera 102 is composed of an imaging element (not shown) located at the bottom of a box-shaped housing, an interference objective lens located at the top of the housing and facing the chip 14 from below in the Z-axis direction, and an interferometer equipped with a light source and other components located inside the housing.

The downward imaging camera 102 generates interference fringes due to interference between white light emitted by a light source and light reflected from the back surface 11-2 of the chip 14. The light resulting from this interference is captured by an imaging element, which then captures an image containing the interference fringes. The imaging element is, for example, a CCD (Charge-Coupled Device) imaging element or a CMOS (Complementary MOS) imaging element. The downward imaging camera 102 outputs the image containing the interference fringes captured by the imaging element to the control unit 400. The control unit 400 can detect minute irregularities on the back surface 11-2 of the chip 14 based on the intensity of the interference fringes in the image containing the interference fringes captured by the imaging element of the downward imaging camera 102.

In embodiment 1, the downward imaging camera 102 is equipped with a Mirau-type interference objective lens, a Michelson-type or a Linnik-type interference objective lens.

The downward imaging camera 102 configured as described above images the back surface 11-2 of the chip 14 held by suction in the holder 63, and outputs the image containing interference fringes obtained by the image capture to the control unit 400. The downward imaging camera 102 may also image the front surface 11-1 of a chip 14 that has been inverted upside down by the chip inversion mechanism 110 and whose back surface 11-2 is held by suction in the holder 63, and output the image obtained by the image capture to the control unit 400.

The chip inversion mechanism 110 inverts the top and bottom of the front surface 11-1 and back surface 11-2 of the chip 14, i.e., turns the chip 14 upside down. The chip inversion mechanism 110 is aligned with the lower imaging unit 101 in the Y-axis direction and is positioned farther from the push-up unit 40 than the lower imaging unit 101. The chip inversion mechanism 110 includes a columnar chip support base 111 that supports the chip 14, and an inversion mechanism 112.

The chip support base 111 extends upward from the device main body 2 and is positioned in line with the lower imaging camera 102 in the Y-axis direction (i.e., overlapping with the movement path of the holder 63). The chip support base 111 has a flat upper surface that is parallel to the horizontal direction, and supports on its upper surface a chip 14 transported by the holder 63 of the pickup mechanism 60. The chip support base 111 is also connected to a rotary drive source (not shown), and is rotated by the rotary drive source around an axis parallel to the Z-axis direction.

The inversion mechanism 112 is disposed above the chip support base 111. The inversion mechanism 112 is configured to be able to rotate the base 113 by 180° around an axis parallel to the X-axis direction while holding the chip 14 at its tip.

When flipping the chip 14 upside down, the chip flipping mechanism 110 supports the chip 14 transported by the holder 63 of the pickup mechanism 60 on the upper surface of the chip support base 111, and rotates the base 113 180° from the position shown by the solid lines in Figures 1 and 2 relative to the upper surface of the chip support base 111 supporting the chip 14 to the position shown by the dotted lines in Figures 1 and 2. The chip flipping mechanism 110 suction-holds the chip 14 at its tip and rotates the base 113 180° to flip the chip 14 upside down.

The chip 14 inverted by the chip inversion mechanism 110 is held by suction by the holder 63 of the pickup mechanism 60, and the suction holding of the tip of the chip inversion mechanism 110 is stopped. In this way, the chip inversion mechanism 110 inverts the chip 14 upside down.

In addition, the test device 1 has a chip support base 111 located at a position that overlaps with the movement path of the holder 63, so the holder 63 can place the chip 14 on the upper surface of the chip support base 111.

The lateral imaging unit 120 images the chip 14 from the side, i.e., the side surface of the chip 14. The lateral imaging unit 120 is positioned next to the lower imaging unit 101 in the Y-axis direction, and in embodiment 1, is positioned between the lower imaging unit 101 and the chip inversion mechanism 110.

The lateral imaging unit 120 has a side imaging camera 121, which is a camera that images the side surface 11-3 of the chip 14. The side imaging camera 121 is positioned so that it can image the side surface 11-3 of the chip 14 held by suction in the holder 63 of the pickup mechanism 60. In embodiment 1, the side imaging camera 121 is positioned so that it faces the side surface 11-3 of the chip 14 held by suction in the holder 63 of the pickup mechanism 60 in the X-axis direction. The side imaging camera 121 has an imaging element that images the side surface 11-3 of the chip 14. The imaging element is, for example, a CCD (Charge-Coupled Device) imaging element or a CMOS (Complementary MOS) imaging element.

The side imaging camera 121 focuses on the side surface 11-3 of the chip 14 held by suction in the holder 63 of the pickup mechanism 60, captures an image of the side surface 11-3, and outputs the captured image to the control unit 400.

The lateral imaging unit 120 uses the side imaging camera 121 to image one side surface 11-3 of the chip 14 held by suction on the holder 63 of the pickup mechanism 60. The holder 63 then supports the chip 14 on the chip support base 111, which then rotates around its axis. The chip 14 on the chip support base 111 is then again held by suction on the holder 63, and the other side surface 11-3 of the chip 14 held by suction on the holder 63 is then imaged by the side imaging camera 121.

In this way, in embodiment 1, the lateral imaging unit 120 uses the side imaging camera 121 to capture images of all side surfaces 11-3 of the chip 14 (for example, the side surfaces 11-3 on all four sides of the chip 14), obtains an image 500 (shown in FIG. 14) that includes the thickness of the chip 14 and any chips 501 (shown in FIG. 14, hereinafter referred to as chipping) formed on the chip 14, and outputs the obtained image 500 to the control unit 400.

In embodiment 1, the side image capturing camera 121 captures images of all side surfaces 11-3 of the chip 14. However, in the present invention, when the chip 14 is supported by a pair of support parts 205 (shown in FIG. 6) of the strength measurement mechanism 200 (described later), it is sufficient to capture images of the two side surfaces 11-3 located at both ends in the Y-axis direction out of all side surfaces 11-3 of the chip 14, to obtain the captured image 500. When the chip 14 is supported by a pair of support parts 205 of the strength measurement mechanism 200, the two side surfaces 11-3 located at both ends in the Y-axis direction out of all side surfaces 11-3 of the chip 14 are two side surfaces of the chip 14 facing each other and intersecting the extension direction of the indenter 221 of the strength measurement mechanism 200 (described later).

The widthwise center of the imaging range of the side imaging camera 121 of the lateral imaging unit 120 is set to a predetermined position on the chip 14. In embodiment 1, the widthwise center of the imaging range of the side imaging camera 121 of the lateral imaging unit 120 is set to the widthwise center 11-4 (shown in FIG. 14) of the chip 14. That is, the widthwise center 502 (left-right direction in FIG. 14) of the image 500 captured by the side imaging camera 121 coincides with the widthwise center 11-4, which is a predetermined position on the chip 14. In embodiment 1, the widthwise center of the surface 11-1 of the chip 14 is the position pressed by the indenter 221 of the strength measuring mechanism 200 of the chip 14 supported by the support portion 205 of the support unit 210 positioned in the initial position.

Using the above-mentioned lower imaging unit 101 and side imaging unit 120, the imaging device 100 images the front surface 11-1, back surface 11-2, and side surface 11-3 of the chip 14 picked up by the holder 63. In the present invention, the side imaging camera 121 that images the side surface 11-3 of the chip 14 may be provided in a position that allows it to image the side surface 11-3 of the chip 14 supported on the upper surface of the chip support base 111, and may image the side surface 11-3 of the chip 14 supported on the upper surface of the chip support base 111.

(Strength measurement mechanism)
The strength measuring mechanism 200 is a measuring mechanism that measures the flexural strength of the chip 14 picked up by the pickup mechanism 60. The strength measuring mechanism 200 is disposed adjacent to the imaging device 100 in the Y-axis direction, and in the first embodiment, is disposed on the side farther from the push-up unit 40 than the chip inverting mechanism 110. In the first embodiment, the strength measuring mechanism 200 is disposed at a position overlapping with the movement path of the holder 63.

The strength measurement mechanism 200 comprises a lower container 201, a support unit 210, a pressing unit 220, an upper container 240, an air supply unit 250, and a debris discharge unit. The lower container 201 is placed on the device main body 2 and is box-shaped with an opening on the top.

The support unit 210 supports the chip 14 that has been picked up by the holder 63 of the pickup mechanism 60 and whose front surface 11-1, back surface 11-2, and side surface 11-3 have been imaged by the imaging device 100. The support unit 210 is housed in the lower container 201 installed on the device main body 2, and is positioned so that it overlaps with the movement path of the holder 63. For this reason, the holder movement unit 70 moves the holder 63 from a position facing the push-up unit 40 in the Z-axis direction to a position facing the support unit 210 in the Z-axis direction.

As shown in FIG. 6, the support unit 210 includes a pair of support parts 205 that support the chip 14, and a support part movement mechanism 219 that changes the position of each support part 205 in the X-axis direction and the spacing 212 between the pair of support parts 205. The pair of support parts 205 are arranged with a predetermined spacing 212 between them in the X-axis direction. Each support part 205 includes a support base 211 and a contact member 214.

The support base 211 is formed in a rectangular parallelepiped shape. The support bases 211 of the pair of support sections 205 are spaced apart in the X-axis direction, with a gap 212 between them. The pair of support bases 211 are also arranged with the longitudinal direction of their upper surfaces aligned along the Y-axis direction. The chip 14 whose flexural strength is to be measured is placed on the upper surface of the pair of support bases 211 using a holder 63 or the like. In embodiment 1, the back surface 11-2 of the chip 14 is placed on the support base 211.

The support bases 211 each have columnar (rod-shaped) support protrusions 213 that protrude upward formed on adjacent edges of their top surface, and the top surface is covered with a contact member 214 except for the aforementioned edges. The support protrusions 213 are made of metal such as stainless steel, are arranged parallel to the Y-axis direction, and support the back surface 11-2 side of the chip 14. In embodiment 1, the cross-sectional shape of the top surface of the support protrusions 213 is formed as an upwardly convex curved surface.

The contact member 214 is made of a material (such as sponge rubber) that is more flexible than the support protrusion 213, and is formed in the shape of a plate with a constant thickness. The contact member 214 has a rectangular planar shape, and its thickness in an undeformed state is greater than the amount by which the upper end 213-1 of the support protrusion 213 protrudes from the top surface of the support base 211.

The contact member 214 supports the chip 14 with the back surface 11-2 of the chip 14 placed on its upper surface. Therefore, the upper surface of the contact member 214 supports the back surface 11-2 of the chip 14. In embodiment 1, the upper surface of the contact member 214 in an undeformed state is positioned approximately 1 mm above the upper end of the support protrusion 213. Therefore, the back surface 11-2 of the chip 14 placed on the support base 211 contacts the upper surface of the contact member 214 with a gap between it and the support protrusion 213. Furthermore, when the indenter 221 presses the chip 14, the contact member 214 deforms and comes into contact with the back surface 11-2 of the chip 14, supporting the back surface 11-2. Therefore, the upper end 213-1 of the support protrusion 213 is a support surface that supports the back surface 11-2 of the chip 14. That is, the support portion 205 includes the upper end 213-1 of the support protrusion 213, which is the support surface that supports the back surface 11-2 of the chip 14.

The support unit movement mechanism 219 moves each support base 211 in the X-axis direction and includes a ball screw 216 rotatably mounted on a fixed plate 215 fixed to the device body 2, a motor 217 that rotates the ball screw 216, and a guide rail 218 that supports each support base 211 movably in the X-axis direction. The support unit movement mechanism 219 can move the pair of support bases 211 in the same direction along the X-axis, or in opposite directions. In embodiment 1, when the chip 14 is placed, the support unit movement mechanism 219 positions the pair of supports 205 at an initial position where the center between the upper ends 213-1 of the pair of support protrusions 213 is located on the movement path of the holder 63. Note that in embodiment 1, the X-axis direction is the direction in which the pair of supports 205 are aligned, i.e., the direction in which the pair of supports 205 are lined up.

The pressing unit 220 presses the chip 14 supported by the support unit 210 with an indenter 221, measures the load acting on the pressing unit 220 when pressing the chip 14, and presses and destroys the chip 14 supported by the support unit 210. The pressing unit 220 is provided above the support unit 210.

As shown in Figures 1 and 2, the pressing unit 220 includes an indenter 221, an indenter moving unit 222, and a load measuring device 223.

The indenter 221 is positioned above the chip 14 placed on the support parts 205 of the support unit 210 and above the space between the pair of support parts 205 that support the back surface 11-2 of the chip 14. The indenter 221 is formed in a bar shape extending in the Z-axis direction, which is perpendicular to the X-axis direction in which the pair of support parts 205 are aligned. Thus, in embodiment 1, the Z-axis direction is the extension direction of the indenter 221. The indenter movement unit 222 moves the indenter 221 along the Z-axis direction relative to the chip 14 supported by the pair of support parts 205. The indenter movement unit 222 supports the indenter 221 at its lower end, positions the indenter 221 opposite the space between the pair of support parts 205 of the support unit 210 along the Z-axis direction, and moves the indenter 221 up and down along the Z-axis direction.

The load measuring instrument 223 measures the load with which the indenter 221 presses against the chip 14 supported by the support parts 205. In embodiment 1, the load measuring instrument 223 is moved up and down along the Z-axis direction together with the indenter 221 by the indenter movement unit 222. The load measuring instrument 223 is composed of a well-known load cell or the like, and measures the load with which the indenter 221 presses against the chip 14 supported by the pair of support parts 205, and outputs the measurement result to the control unit 400.

The upper container 240 has an opening at the bottom and is formed in a box shape that can accommodate the pair of support bases 211 of the support unit 210. The upper container 240 is also positioned below the load measuring instrument 223 and has an insertion hole through which the indenter 221 can pass. The upper container 240 is also formed with a size that allows it to enter the lower container 201. Therefore, when the indenter 221 and load measuring instrument 223 are moved downward by the indenter moving unit 222, the upper container 240 is inserted into the lower container 201 and covers the upper side of the support unit 210.

The air supply unit 250 sprays air onto the tip of the indenter 221. The air supply unit 250 includes a nozzle 251 that sprays air toward the indenter 221, and an air supply source 253 that supplies air to the nozzle 251 via an on-off valve 252.

The nozzle 251 is shaped like a pipe and is inserted into the nozzle insertion hole of the upper container 240, with its tip facing the tip of the indenter 221 inside the upper container 240. The air supply unit 250 blows air from the nozzle 251 onto the tip of the indenter 221 to remove foreign matter adhering to the tip of the indenter 221, the top surface of the contact member 214, etc.

The fragment discharge unit discharges chip 14 fragments 11-5 (shown in Figure 18) present inside the lower container 201.

When measuring the flexural strength of the chip 14, the strength measuring mechanism 200 positions the indenter 221 and load measuring device 223 upward using the indenter movement unit 222, and then places the chip 14 on a pair of support parts 205 in their initial position using a holder 63 or the like. At this time, both ends of the chip 14 are supported by the pair of support parts 205, and the center 11-4 overlaps with the center between the upper ends 213-1 of the support protrusions 213.

The strength measurement mechanism 200 lowers the indenter 221 using the indenter movement unit 222, presses the chip 14 with the indenter 221, measures the load (force in the Z-axis direction) applied to the indenter 221 pressing the chip 14 with the load measuring instrument 223, and destroys the chip 14 with the indenter 221 while outputting the measurement results to the control unit 400 as appropriate. The strength measurement mechanism 200 performs a three-point bending test using the pair of support parts 205 of the chip 14 and the indenter 221, measures the bending strength (transverse strength) of the chip 14 through this three-point bending test, and outputs the measurement results to the control unit 400.

(control unit)
The control unit 400 controls each of the above-mentioned components of the test device 1, causing the test device 1 to perform an imaging operation to image the front surface 11-1, back surface 11-2 and side surface 11-3 of the chip 14, and a measurement operation for each chip 14 to measure the flexural strength of the chip 14.

The control unit 400 is a computer having an arithmetic processing device with a microprocessor such as a CPU (central processing unit), a storage device with memory such as ROM (read only memory) or RAM (random access memory), and an input/output interface device. The arithmetic processing device of the control unit 400 performs arithmetic processing in accordance with a computer program stored in the storage device, and outputs control signals for controlling the test device 1 to each of the above-mentioned units of the test device 1 via the input/output interface device.

The control unit 400 is also connected to a display unit 300 (shown in Figure 1), which is a display means having a display screen 301 that displays the status of the measurement operation, images, etc., and a touch panel 302 (shown in Figure 1), which is an input means used by the operator to input information, etc., into the control unit 400 of the testing device 1. The display unit 300 is composed of a liquid crystal display device or the like. The touch panel 302 is overlaid on the display screen 301 of the display unit 300.

(Measurement method)
The measurement method according to the first embodiment also includes an imaging operation of imaging the front surface 11-1, back surface 11-2, and side surface 11-3 of the chip 14 of the test device 1, and a measurement operation of measuring the flexural strength of the chip 14. The measurement method according to the first embodiment is a measurement method of imaging the front surface 11-1, back surface 11-2, and side surface 11-3 of the chip 14 and measuring the flexural strength of the chip 14, and includes a pickup step 1001, a back surface imaging step 1002, a side surface imaging step 1003, a chipping detection step 1004, a chip mounting step 1005, and a chip destruction step 1006, as shown in FIG.

The testing apparatus 1 starts the measurement method according to embodiment 1 when an operator places a cassette 4 containing multiple wafer units 17 on the cassette mounting table 3, operates the touch panel 302, inputs measurement conditions and the like into the control unit 400, and the control unit 400 receives an instruction from the operator to start the measurement operation. The measurement conditions include the positions of each chip 14 to be measured in each wafer unit 17.

In embodiment 1, the test apparatus 1 sequentially picks up the chips 14 to be measured one by one from each wafer unit 17. Note that in this specification, during the measurement operation, the operator may operate a touch panel or the like to select the chip 14 to be picked up from the tape 15 each time a chip 14 is picked up.

(Pickup step)
Fig. 8 is a cross-sectional view schematically showing a state in which the periphery of a chip to be measured on the tape of the wafer unit is held by suction on the upper surface of the tape holding part of the push-up unit in the pickup step of the measurement method shown in Fig. 7. Fig. 9 is a cross-sectional view schematically showing a state in which the chip to be measured is pushed up by the push-up part of the push-up unit in the pickup step of the measurement method shown in Fig. 7. Fig. 10 is a cross-sectional view schematically showing a state in which the chip to be measured is held by suction on the lower surface of the holder in the pickup step of the measurement method shown in Fig. 7.

Pickup step 1001 is a step in which the chip 14 to be measured is picked up from the tape 15 of the wafer unit 17. In pick-up step 1001, the control unit 400 of the testing apparatus 1 controls the carry-in/out unit 5 to carry the wafer unit 17 containing the chip 14 to be measured out of the cassette 4 and temporarily place it on a pair of temporary placement rails 6, and controls the carry-in/out unit 5 to place the annular frame 16 of the wafer unit 17 temporarily placed on the temporary placement rails 6 on the lowered frame support member 22 of the frame fixing unit 7.

In the pickup step 1001, the control unit 400 of the testing apparatus 1 controls the frame fixing unit 7 to raise the frame support member 22, sandwiching the periphery of the chip 14 to be measured on the annular frame 16, i.e., the tape 15, between the frame holding member 23 and the frame support member 22, and fixing the wafer unit 17 with the frame fixing unit 7. In the pickup step 1001, the control unit 400 of the testing apparatus 1 controls the movement mechanism 30 based on the measurement conditions to move the frame fixing unit 7, and positions the next chip 14 to be measured on the wafer unit 17 held by the frame fixing unit 7 above the push-up unit 40 and below the imaging camera 50.

In pickup step 1001, the test apparatus 1 causes the imaging camera 50 to capture an image of the area around the next chip 14 to be measured on the wafer unit 17, and uses the image captured by the imaging camera 50 to control the movement mechanism 30 to align the chip 14 to be measured with the push-up unit 40. In pickup step 1001, the test apparatus 1 causes the control unit 400 to control the push-up unit 40, lowering the push-up members 42-1, 42-2, and 42-3, and then raising the entire push-up unit 40, bringing the upper surface 48 of the tape holding portion 41 of the push-up unit 40 and the upper surfaces of the push-up members 42-1, 42-2, and 42-3 into contact with the tape 15.

Furthermore, in embodiment 1, in the pickup step 1001, the control unit 400 of the test apparatus 1 controls the holder moving unit 70 to position the holder 63 at the pickup position and bring the holder 63 facing the chip 14 to be measured along the Z-axis direction. In the pickup step 1001, the control unit 400 of the test apparatus 1 opens the on-off valve 46, as shown in FIG. 8, to suction and hold the tape 15 on the upper surface 48 of the tape holding portion 41 of the push-up unit 40, and supports the chip 14 to be measured via the tape 15 at the push-up portion 42 of the push-up unit 40.

In the pickup step 1001, the control unit 400 of the testing apparatus 1 controls the push-up unit 40 to raise the push-up members 42-1, 42-2, and 42-3 simultaneously at the same speed, as shown in FIG. 9. In the pickup step 1001, the control unit 400 of the testing apparatus 1 controls the push-up unit 40 to first stop the rise of the first push-up member 42-1 among the push-up members 42-1, 42-2, and 42-3, as shown in FIG. 9, then stops the rise of the second push-up member 42-2 at a position above the first push-up member 42-1, and stops the rise of the third push-up member 42-3 at a position above the second push-up member 42-2.

Thus, in embodiment 1, in the pickup step 1001, the test apparatus 1 pushes up the chip 14 to be measured via the tape 15 using the push-up members 42-1, 42-2, and 42-3, and sequentially peels off the chip 14 to be measured from the tape 15, starting from the outer edge and working inward. In the pickup step 1001, as shown in FIG. 10, the control unit 400 of the test apparatus 1 controls the holder moving unit 70 to lower the holder 63 and bring the lower surface 65 of the holder 63 into contact with the chip 14 to be measured.

In the pickup step 1001, the control unit 400 of the testing apparatus 1 opens the on-off valve 67, sucks the underside 65 of the holder 63 with the suction source 68, and holds the chip 14 by suction on the underside 65 of the holder 63. In the pickup step 1001, the control unit 400 of the testing apparatus 1 controls the holder movement unit 70 to raise the holder 63, pick up the chip 14 that was held by suction on the underside 65 of the holder 63 from the tape 15, and transport it off the tape 15.

(Backside imaging step)
Fig. 11 is a perspective view schematically showing a state in which the back surface of the chip held by suction in the holder is made to face the downward imaging camera in the back surface imaging step of the measurement method shown in Fig. 7. Fig. 12 is a perspective view schematically showing a state in which the holder holding the chip by suction is lowered in the back surface imaging step of the measurement method shown in Fig. 7. The back surface imaging step 1002 is a step in which the back surface 11-2 of the chip 14 to be measured is imaged to obtain an image including interference fringes.

In the backside imaging step 1002, the control unit 400 of the test apparatus 1 controls the holder moving unit 70 to move the holder 63 to the backside imaging position, and as shown in FIG. 11, positions the holder 63 above the lower imaging camera 102 in the Z-axis direction at the backside imaging position, so that the chip 14 held by suction on the lower surface 65 of the holder 63 faces the lower imaging camera 102 along the Z-axis. In the backside imaging step 1002, the control unit 400 of the test apparatus 1 controls the lifting unit 64 to lower the holder 63 as shown in FIG. 12, so that the lifting unit 64 is held by suction on the support column 103, and then causes the lower imaging camera 102 to image the lower surface 11-2 of the chip 14, thereby obtaining an image including an interference fringe of the lower surface 11-2.

(Side imaging step)
Fig. 13 is a side view schematically showing a state in which the side surface held by the holder and the lateral imaging unit face each other in the side imaging step of the measurement method shown in Fig. 7. Fig. 14 is a diagram schematically showing an image acquired in the side imaging step of the measurement method shown in Fig. 7.

The side imaging step 1003 is a step in which an image is taken of an area including the widthwise center 11-4 of the side surface 11-3 of the chip 14, which corresponds to the widthwise center of the surface 11-1 of the chip 14, before the indenter 221 destroys the chip 14 in the chip destruction step 1006, to obtain an image 500. The widthwise center of the surface 11-1 of the chip 14 and the widthwise center 11-4 of the side surface 11-3 of the chip 14 overlap in the thickness direction of the chip 14 and correspond to each other.

In side-surface imaging step 1003, the control unit 400 of the test apparatus 1 controls the holder moving unit 70, the imaging device 100, etc. to move the holder 63 toward the side-surface imaging position. In side-surface imaging step 1003, the control unit 400 of the test apparatus 1 controls the holder moving unit 70, the imaging device 100, etc. to sequentially bring the widthwise centers 11-4 of each side surface 11-3 of the chip 14 held by suction on the lower surface 65 of the holder 63 toward the side-surface imaging camera 121 along the X-axis direction, as shown in FIG. 13, and then causes the side-surface imaging camera 121 to image each side surface 11-3, thereby obtaining an image 500 including the centers 11-4 of each side surface 11-3, as shown in FIG. 14.

Note that if chipping 501 is formed on the chip 14, the captured image 500 will be an image that includes the chipping 501. Note that in Figure 14, the chipping 501 on the chip 14 is indicated by hatching, and everything other than the chipping 501 on the chip 14 is indicated by shading.

In embodiment 1, the side image capturing step 1003 involves sequentially facing the center 11-4 of each side surface 11-3 of the chip 14 to the side image capturing camera 121 along the X-axis direction, and then having the side image capturing camera 121 capture an image of each side surface 11-3. Thus, in embodiment 1, the side image capturing step 1003 causes the side image capturing camera 121 to capture an image of each side surface 11-3 of the chip 14, thereby acquiring an image 500 including the center 11-4 of each side surface 11-3, thereby capturing an image of the region of the side surface 11-3 of the chip 14 that corresponds to the center in the width direction of the surface 11-1 of the chip 14. Note that in embodiment 1, the side image capturing step 1003 captures images of all side surfaces 11-3 of the chip 14, but in the present invention, it is sufficient to capture images of at least the aforementioned two side surfaces 11-3 of the chip 14.

(Chipping detection step)
Fig. 15 is a diagram schematically showing an image of a chipping detected in the chipping detection step of the measurement method shown in Fig. 7. Chipping detection step 1004 is a step of detecting chipping 501 on the back surface 11-2 side of chip 14 based on image 500 of side surface 11-3 of chip 14 after side surface imaging step 1003 is performed.

In chipping detection step 1004, the control unit 400 of the test device 1 detects chipping 501 on the back surface 11-2 side from the captured images 500 acquired by the side surface imaging camera 121 capturing images of each side surface 11-3. In chipping detection step 1004, the control unit 400 of the test device 1 calculates the distance 503 between the center of gravity of the chipping 501 on the back surface 11-2 side of each captured image 500 and the center 502 of the captured image 500. Note that distance 503 is the distance between the chipping 501 on the back surface 11-2 side of the chip 14 and the center 11-4 of the chip 14. Note that, as with FIG. 14, FIG. 15 shows the chipping 501 of the chip 14 with diagonal lines, and everything other than the chipping 501 of the chip 14 with shading.

(Chip placing step)
7. Chip placing step 1005 is a step of placing back surface 11-2 of chip 14 on a pair of support portions 205 of support unit 210 of strength measurement mechanism 200, and supporting back surface 11-2 of chip 14 with support portions 205. In chip placing step 1005, control unit 400 of test apparatus 1 controls holder moving unit 70 to move holder 63 to the measurement position, and places back surface 11-2 of chip 14 on the pair of support portions 205 positioned in the initial position of support unit 210 of strength measurement mechanism 200.

(Chip destruction step)
Fig. 17 is a cross-sectional view schematically showing a state in which the back surface of the chip is pressed by an indenter and comes into contact with the upper end of the support protrusion of the support part in the chip breaking step of the measurement method shown in Fig. 7. Fig. 18 is a cross-sectional view schematically showing a state in which the chip is broken in the chip breaking step of the measurement method shown in Fig. 7.

The chip breaking step 1006 is a step in which the indenter 221 is moved toward the chip 14 supported by the support portion 205, the indenter 221 presses against the surface 11-1 of the chip 14 to break it, and the load measuring device 223 detects the load when the indenter 221 breaks the chip 14. In the chip breaking step 1006, the control unit 400 of the testing device 1 controls the strength measurement mechanism 200 to lower the indenter 221 using the indenter movement unit 222, bringing the tip of the indenter 221 into contact with the surface 11-1 side of the center 11-4 of the chip 14, and then, as shown in FIG. 17, the indenter 221 presses against the chip 14. The load (force in the Z-axis direction) applied to the indenter 221 by the pressure of the chip 14 is measured by the load measuring device 223, and the measurement result is output to the control unit 400 as appropriate.

In the chip destruction step 1006, the control unit 400 of the testing apparatus 1 controls the strength measurement mechanism 200 to further lower the indenter 221, destroying the chip 14 as shown in FIG. 18, and calculates the value of the die strength of the chip 14 based on the maximum load measured by the load measuring instrument 223, etc. In the chip destruction step 1006, the control unit 400 of the testing apparatus 1 associates and stores the image including the interference fringe of the back surface 11-2 captured by the downward imaging camera 102, each captured image 500 captured by the side imaging camera 121, the distance 503 between the center of gravity of the chipping 501 on the back surface 11-2 side of each captured image 500 detected in the chipping detection step 1004 and the center 11-4, the die strength measured by the strength measurement mechanism 200, and the position of the chip 14 being measured on the wafer 10.

When the indenter 221 presses the chip 14, foreign matter (such as chip fragments 141 scattered during fracture) may adhere to the indenter 221. This foreign matter may affect the accuracy of the measurement of the flexural strength, so it is preferable to remove it. In embodiment 1, after the chip 14 is fractured in the chip fracture step 1006, the strength measurement mechanism 200 opens the on-off valve 252 as shown in FIG. 18 and blows air onto the indenter 221 using the air supply unit 250, thereby removing the foreign matter adhered to the indenter 221. Note that the present invention does not limit the timing of removing foreign matter from the indenter 221, etc., using the air supply unit 250. For example, foreign matter is removed as needed after the measurement of the flexural strength of one chip 14 is completed and before the measurement of the flexural strength of the next chip 14 is performed.

The test device 1 sequentially picks up chips 14 specified in the measurement conditions from the wafer unit 17, captures images with the imaging device 100, and measures the flexural strength with the strength measurement mechanism 200. After picking up all chips 14 specified in the measurement conditions from the wafer unit 17, capturing images with the imaging device 100, and measuring the flexural strength, the test device 1 loads the wafer unit 17 fixed by the frame fixing unit 7 into the cassette 4, completing the measurement operation.

As described above, the measurement method according to embodiment 1 includes a side imaging step 1003 in which an image including the widthwise center 11-4 of the side surface 11-3 of the chip 14, which corresponds to the widthwise center of the surface 11-1 of the chip 14, is captured before the indenter 221 destroys the chip 14 in the chip destruction step 1006, and an image 500 is obtained.

Furthermore, the widthwise center 502 of the image 500 captured by the side-image capturing camera 121 coincides with the widthwise center 11-4 of the chip 14, and the widthwise center of the surface 11-1 of the chip 14 is the position pressed by the indenter 221 of the strength measuring mechanism 200 of the chip 14 supported by the support portion 205 of the support unit 210 positioned in the initial position.

As a result, the measurement method according to embodiment 1 has the advantage of being able to store the captured image 500 acquired in the side image capturing step 1003, thereby storing the relative positional relationship between the position pressed by the indenter 221 and the chipping 501.

The measurement method according to embodiment 1 also includes a chipping detection step 1004 that detects chippings 501 on the back surface 11-2 side of the chip 14 based on the captured image 500. In chipping detection step 1004, the measurement method according to embodiment 1 calculates the distance 503 between the center of gravity of each chipping 501 on the back surface 11-2 side and the center 502 of the captured image 500, i.e., the distance between the chipping 501 on the back surface 11-2 side of the chip 14 and the center 11-4 of the chip 14. As a result, the measurement method according to embodiment 1 has the effect of being able to accumulate the distance 503 between the position pressed by the indenter 221 and the chipping 501 on the back surface 11-2 side.

[Modification]
A measurement method according to a modified example of the first embodiment of the present invention will be described with reference to the drawings. Fig. 19 is a cross-sectional view schematically showing a chip mounting step of the measurement method according to the modified example of the first embodiment. Fig. 20 is a cross-sectional view schematically showing a state in which the maximum chipping on the back surface of the side surface of the chip is positioned below the tip of the indenter in the chip breaking step of the measurement method according to the modified example of the first embodiment. In Figs. 19 and 20, the same parts as those in the first embodiment are denoted by the same reference numerals, and their description will be omitted.

The measurement method according to the modified example is the same as that according to the first embodiment, except for the differences in chipping detection step 1004, chip placement step 1005, and chip destruction step 1006. In chipping detection step 1004 of the measurement method according to the modified example, the test device 1 detects the largest chipping 501 (hereinafter referred to as the maximum chipping and designated by the reference symbol 501-1) among the chippings 501 on the back surface 11-2 side in the multiple captured images 500 acquired by the control unit 400 capturing images of the side surface 11-3. In the modified example, the maximum chipping 501-1 is the chipping 501 with the largest area in the multiple captured images 500.

In chip placement step 1005 of the measurement method according to the modified example, the control unit 400 of the test apparatus 1 controls the support portion movement mechanism 219 of the support unit 210 to move the pair of support portions 205 from their initial positions so that the largest chipping 501-1 detected in chipping detection step 1004 is located at the center between the upper ends 213-1 of the pair of support protrusions 213. In chip placement step 1005 of the measurement method according to the modified example, as shown in FIG. 19 , the control unit 400 of the test apparatus 1 controls the holder movement unit 70 and the chip support base 111 of the imaging device 100, etc., to place the back surface 11-2 of the chip 14 on the pair of support portions 205 so that the side surface 11-3 on which the largest chipping 501-1 is formed faces the imaging device 100, etc. in the Y-axis direction.

In this way, in the measurement method according to the modified example, in the chip placement step 1005, the maximum chipping 501-1 is positioned above the center between the upper ends 213-1 of the pair of support protrusions 213. After the chipping detection step 1004 is performed, the chip 14 is placed on the support portion 205 so that the indenter 221 presses the position corresponding to the maximum chipping 501-1 detected in the chipping detection step 1004 before the indenter 221 destroys the chip 14.

In chip breaking step 1006 of the measurement method according to the modified example, the control unit 400 of the test apparatus 1 controls the support portion moving mechanism 219 of the support unit 210 to move the pair of support portions 205 and position the pair of support portions 205 of the support unit 210 at their initial positions, as shown in FIG. 20 . The maximum chipping 501-1 is then positioned below the tip of the indenter 221. In chip breaking step 1006 of the measurement method according to the modified example, the control unit 400 of the test apparatus 1 controls the strength measurement mechanism 200 in the same manner as in embodiment 1 to break the chip 14 and measure the flexural strength of the chip 14. Thus, in chip breaking step 1006 of the measurement method according to the modified example, the indenter 221 presses against a position on the surface 11-1 of the chip 14 that corresponds to the maximum chipping 501-1 and overlaps with the maximum chipping 501-1 in the thickness direction, thereby breaking the chip 14.

The measurement method according to the modified example includes a side imaging step 1003 in which an image of an area including the widthwise center 11-4 of the side surface 11-3 of the chip 14, which corresponds to the widthwise center of the surface 11-1 of the chip 14, is captured and an image 500 is acquired before the indenter 221 destroys the chip 14 in the chip destruction step 1006. Therefore, similar to the first embodiment, by storing the image 500 acquired in the side imaging step 1003, it is possible to accumulate the relative positional relationship between the position where the indenter 221 presses and the chipping 501.

In addition, in the measurement method according to the modified example, in chip destruction step 1006, the indenter 221 is pressed against a position on the surface 11-1 of the chip 14 that corresponds to the maximum chipping 501-1 and overlaps with the maximum chipping 501-1 in the thickness direction, destroying the chip 14, thereby enabling accurate measurement of the flexural strength of the chip 14.

The present invention is not limited to the above-described embodiments. In other words, various modifications can be made without departing from the gist of the present invention. For example, in the present invention, the front surface 11-1 of the chip 14 may be placed on a pair of supports 205, and the back surface 11-2 may be pressed with an indenter 221 to destroy the chip 14, thereby measuring the flexural strength of the chip 14. In this case, the front surface 11-1 corresponds to the lower surface, and the back surface 11-2 corresponds to the upper surface.

1 Testing device 10 Wafer 11-1 Surface (upper surface, lower surface)
11-2 Back side (bottom side, top side)
11-3 Side surface 14 Tip 205 Support portion 212 Distance 221 Indenter 223 Load measuring instrument 500 Captured image 501 Chipping 501-1 Maximum chipping 1003 Side image capturing step 1004 Chipping detection step 1005 Tip placement step 1006 Tip breaking step X Direction in which a pair of support portions are aligned Z Direction of extension of indenter

Claims (4)

A method for measuring the strength of a chip having an upper surface, a lower surface, and a side surface, comprising:
a chip placing step of placing the chip on a pair of support parts arranged at a predetermined interval and supporting the lower surface of the chip with the support parts;
a chip breaking step of moving an indenter disposed above the chip placed on the supports and between the pair of supports toward the chip supported by the supports, pressing the top surface of the chip with the indenter to break it, and detecting the load when the indenter breaks the chip with a load measuring device;
a side surface imaging step of imaging the side surface of the chip corresponding to the position where the indenter presses the top surface of the chip before the indenter breaks the chip;
A measurement method comprising: after the side imaging step, a chipping detection step of detecting chipping on the underside of the chip based on an image of the side of the chip , and calculating the distance between the chipping and the position on the chip where the indenter presses . The chip is rectangular,
the indenter is bar-shaped and extends in a direction perpendicular to the direction in which the pair of support portions are aligned,
The measuring method according to claim 1 , wherein the side surface imaging step images at least two side surfaces of the tip that face each other and intersect with the extension direction of the indenter. A method for measuring the strength of a chip having an upper surface, a lower surface, and a side surface, comprising:
a chip placing step of placing the chip on a pair of support parts arranged at a predetermined interval and supporting the lower surface of the chip with the support parts;
a chip breaking step of moving an indenter disposed above the chip placed on the supports and between the pair of supports toward the chip supported by the supports, pressing the top surface of the chip with the indenter to break it, and detecting the load when the indenter breaks the chip with a load measuring device;
a side surface imaging step of imaging the side surface of the chip corresponding to the position where the indenter presses the top surface of the chip before the indenter breaks the chip;
a chipping detection step of detecting chipping on the underside of the chip based on an image of the side surface of the chip after the side surface imaging step is performed ,
After the chipping detection step is performed, the chip is placed on the support so that the indenter presses a position corresponding to the maximum chipping detected in the chipping detection step before the indenter breaks the chip;
In the chip breaking step, the position corresponding to the maximum chipping is pressed with the indenter. The chip is rectangular,
the indenter is bar-shaped and extends in a direction perpendicular to the direction in which the pair of support portions are aligned,
The measuring method according to claim 3 , wherein the side surface imaging step images at least two side surfaces of the tip that face each other and intersect with the extension direction of the indenter.