TWI492317B - The method of detecting the relative position of the grain adapter and the bonding tool and the semiconductor grain - Google Patents

Description

Method for detecting relative position of die bonder and bonding tool and semiconductor die

The present invention relates to a construction of a die bonder and a method of detecting the relative position of a bonding tool to a semiconductor die adsorbed at the front end of the bonding tool.

As a device for bonding a semiconductor die to a circuit board such as a lead frame, a die bonder is often used. The die bonder lowers the semiconductor die held by the front end of the bonding tool toward the surface of the circuit substrate adsorbed and fixed on the bonding stage, and bonds the semiconductor die to the circuit substrate.

In the die bonder, the semiconductor die must be pressed to the circuit substrate in a state where the position of the semiconductor die adhered to the bonding tool is aligned with the bonding position of the circuit substrate. Therefore, when the semiconductor die is transferred by the bonding tool, the image obtained by adsorbing on the back surface of the semiconductor die of the bonding tool is used, and the relative positions of the semiconductor die and the circuit substrate are aligned according to the alignment mark on the back surface of the semiconductor die. Method (for example, refer to Patent Document 1).

However, in the method described in Patent Document 1, when the image is acquired, it is necessary to temporarily stop the transfer of the semiconductor crystal grains, and there is a problem that the working time becomes long. Therefore, it is proposed that a reference member having a mirror and a rectangular through-hole is fixed to a transfer head of a semiconductor die through an L-shaped connecting member, and when the semiconductor die is transported by the transfer head, there is no need to temporarily stop the transfer. Obtaining a first image data of the semiconductor die and a second image data of the imaging reference member, and superimposing the two image data to detect the position of the semiconductor die relative to the reference member, The detection result corrects the method in which the semiconductor die is mounted on the circuit board (for example, refer to Patent Document 2).

Patent Document 1: Japanese Patent Laid-Open Publication No. 2010-40738

Patent Document 2: Japanese Patent Laid-Open Publication No. 2007-115851

However, in the conventional technique described in Patent Document 2, since it is necessary to arrange the reference member at a position that does not interfere with the bonding, it is necessary to make the optical path of the reference member to the camera and the optical path of the semiconductor die adsorbed to the tip end of the transfer head different light paths. . On the other hand, in order to simultaneously capture the image of the reference member and the image of the semiconductor die adsorbed on the front end of the transfer head, it is necessary to form the optical path by combining the two optical paths. Further, it is necessary to make the optical path length of the reference member to the camera equal to the optical path length of the semiconductor die surface to the camera so that the reference member coincides with the focus of the image of the semiconductor die. Therefore, it is necessary to use a half mirror or a cymbal in a large amount in the optical system, which may cause a problem that the configuration of the optical system becomes complicated.

Further, in the conventional technique described in Patent Document 2, since the reference member is attached to the transfer head by the connecting member, the reference member vibrates due to the reciprocating movement of the transfer head, and thus the detection error causes the position of the semiconductor die. The problem of the case of offset (refer to Patent Document 2, paragraph 0096).

Accordingly, an object of the present invention is to effectively detect the positional deviation of a bonding tool and a semiconductor die with a simple configuration.

The die bonder of the present invention comprises: a bonding tool; a light source; a camera; and a reflector; the bonding tool has a base for adsorbing the front end of the semiconductor die, a base thicker than the front end adsorption surface, and a connection between the adsorption surface and the base and opposite to Inclined surface of the center line of the long side direction; light The source system is disposed on the adsorption surface side of the bonding tool; the camera simultaneously obtains an image of the image of the semiconductor die adsorbed on the adsorption surface and the image of the reflector and the inclined surface of the bonding tool; the reflector is adjacent to the base of the bonding tool, and is adsorbed The surface is disposed above the focal depth of the camera and disposed in the longitudinal direction of the bonding tool, and does not move relative to the bonding tool, and reflects light from the light source to at least the adsorption surface side of the bonding tool.

Preferably, the die attachor of the present invention further includes an image processing unit; the image processing unit processes the image of the reflector obtained by the camera, the image of the inclined surface of the bonding tool obtained by the camera, and the semiconductor crystal obtained by the camera. The image of the particle is used to detect the relative position of the bonding tool to the semiconductor die.

In the die bonder of the present invention, preferably, the reflector is a crank for holding the bonding tool, or a ring attached to the bonding tool or a portion adjacent to the base of the bonding tool, and has a long side with respect to the bonding tool. A reflecting surface perpendicular to the center line; the reflecting surface is an end surface of the adsorption side of the crank, or an end surface of the adsorption side of the ring, or an end surface of the segment.

In the die bonder of the present invention, preferably, the position of the bonding tool and the semiconductor die is the position on the adsorption surface of the center line in the longitudinal direction of the bonding tool and the position on the adsorption surface of the center of the semiconductor die. Either or both of the offset, or the angle of inclination of the semiconductor die relative to the reference axis of the adsorption face.

In the die bonder of the present invention, preferably, the die attachor further includes: a moving mechanism; and a control unit; the moving mechanism moves the bonding tool; and the control unit moves the bonding tool by the moving mechanism, and the bonding tool picks up the position from the semiconductor die When the predetermined position is reached between the bonding position and the bonding position, the light source is illuminated, and the image of the semiconductor die adsorbed on the adsorption surface and the image of the inclined surface of the bonding tool and the image of the reflector are simultaneously acquired by the camera while moving the bonding tool.

Preferably, the die attachor of the present invention further includes: a moving mechanism; and a control unit; the moving mechanism moves the bonding tool; and the control unit changes the position of the bonding tool by the moving mechanism, and detects the image according to the image processing unit The position of the bonding tool and the semiconductor die corrects the position of the bonding tool.

The position detecting method of the present invention detects the relative position of the bonding tool and the semiconductor die in the die bonder, and includes: an image obtaining step; and a relative position detecting step; the die bonder is provided with a bonding tool and a configuration a light source on the adsorption surface side of the bonding tool, a reflector that does not move relative to the bonding tool, and reflects light from the light source to the adsorption surface side of the bonding tool, and simultaneously acquires the semiconductor die adsorbed on the adsorption surface. a camera for capturing an image of an image and a reflector and an image of an inclined surface of the bonding tool, the bonding tool having a base for adsorbing the front end of the semiconductor die, a base thicker than the front end of the adsorption surface, and connecting the adsorption surface and the base with respect to the longitudinal direction The inclined surface of the center line is inclined, and the reflector is adjacent to the base of the bonding tool, and is disposed in the longitudinal direction of the bonding tool from the depth of focus of the camera from the adsorption surface, and includes a reflection perpendicular to the center line of the longitudinal direction of the bonding tool. Image acquisition step, by which the image of the semiconductor die adsorbed on the adsorption surface is simultaneously obtained by the camera The image of the reflector and the image of the inclined surface of the bonding tool; the relative position detection step, the image of the reflector obtained from the camera, the image of the inclined surface of the bonding tool obtained by the camera, and the image of the semiconductor die obtained by the camera Detecting the relative position of the bonding tool to the semiconductor die.

In the position detecting method of the present invention, preferably, the position of the bonding tool and the semiconductor die is a position on the adsorption surface of the center line in the longitudinal direction of the bonding tool and the position on the adsorption surface of the center of the semiconductor die. Either or both of the offset, or the angle of inclination of the semiconductor die relative to the reference axis on the adsorption face.

In the position detecting method of the present invention, preferably, the die bonder further includes a moving mechanism for moving the bonding tool; and the image capturing step of moving the bonding tool by the moving mechanism, and the bonding tool reaches from the pickup position of the semiconductor die When the predetermined position between the joint positions is made, the light source is caused to emit light, and the image of the semiconductor crystal grain adsorbed on the adsorption surface and the image of the reflector and the inclined surface of the bonding tool are simultaneously acquired by the camera while moving the bonding tool.

The present invention achieves an effect of effectively detecting the positional deviation of the bonding tool and the semiconductor die with a simple configuration.

10‧‧ ‧ die bonder

11‧‧‧ Guide rail

12‧‧‧X direction moving mechanism

13‧‧‧Y direction moving mechanism

15‧‧‧ Bonding head

16‧‧‧Z direction moving mechanism

17‧‧‧θ direction moving mechanism

20‧‧‧ crank

21,23‧‧‧ end face

22‧‧‧ Ring

24‧‧‧ Bonding tools

25‧‧‧ base

26‧‧‧Slanted surface

27‧‧‧Adsorption surface

28‧‧‧ Section

29‧‧‧Under

30‧‧‧Semiconductor grains

32‧‧‧ camera

33‧‧ Sight

34‧‧‧flash

35‧‧‧Mirror

36‧‧‧ Picking up the stage

37‧‧‧Joining stage

38‧‧‧Track

40‧‧‧Image Processing Department

41,51‧‧‧CPU

42,52‧‧‧ memory

43‧‧·Image acquisition program

44‧‧‧ Relative position detection program

45,55‧‧‧Control data

46, 56‧‧‧ data bus interface

47‧‧‧ camera interface

48‧‧‧Flash interface

49, 59‧‧‧ data bus

50‧‧‧Control Department

53‧‧‧Location Control Program

54‧‧‧correction program

57‧‧‧Mobile agency interface

60‧‧‧Communication line

71~76‧‧‧Arrows

81~89‧‧‧Image

90‧‧‧Long-side direction centerline

91‧‧‧Circular outline line

92‧‧‧ four-corner shape baseline

93‧‧‧Y direction guideline

94‧‧‧X direction baseline

95‧‧‧Y direction measuring line

96‧‧‧X direction measuring line

97,98‧‧ Center

D‧‧‧Focus depth

L1~L3‧‧‧Light path length

△X, △Y, △θ‧‧‧ offset

Fig. 1 is a system diagram showing the configuration of a control system of a die bonder in an embodiment of the present invention.

Fig. 2 is a view showing the details of the bonding tool and the crank of the die bonder in the embodiment of the present invention.

Fig. 3 is an explanatory view showing the operation of the die bonder in the embodiment of the present invention.

4(a) and 4(b) are explanatory views showing the structure of the bonding tool and the crank of the die bonder and the image captured by the camera in the embodiment of the present invention.

5(a) and 5(b) are explanatory views showing the steps of performing binarization processing on the image shown in Fig. 4.

Fig. 6 is an explanatory view showing an image obtained by binarizing the image shown in Fig. 4.

Fig. 7 (a) and (b) are explanatory views showing the structure of the bonding tool and the ring of the die bonder and the image captured by the camera in another embodiment of the present invention.

8(a) and 8(b) are explanatory views showing the structure of a bonding tool of a die bonder and an image captured by a camera according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the die bonder 10 of the present invention includes a bonding head 15 to which a bonding tool 24 is attached via a crank 20, a guide rail 11 for guiding the bonding head 15 in the Y direction, and a bonding head 15 to move in the Y direction. The Y-direction moving mechanism 13, the X-direction moving mechanism 12 for moving the guide rail 11 and the bonding head 15 in the X direction, the camera 32 provided on the lower side of the bonding head 15, the light source 34, the flash unit 34, and the image processing of the connection camera 32 and the flash unit 34 The unit 40 and the control unit 50 that connects the X and Y direction moving mechanisms 12 and 13. The bonding tool 24 has an adsorption surface 27 for adsorbing the semiconductor crystal grains 30 at the tip end, and the flash lamp 34 is provided with a mirror 35 for directing the light of the light toward the bonding tool 24. The bonding head 15 includes a Z-direction moving mechanism 16 that moves the bonding tool 24 in the Z direction, and a θ-direction moving mechanism 17 that rotationally moves the bonding tool 24 in the θ direction. Each of the moving mechanisms 16 and 17 is connected to the control unit 50. . The control unit 50 moves the bonding tools 24 in the respective directions of X, Y, Z, and θ by operating the respective moving mechanisms 12, 13, 16, and 17 in the X, Y, Z, and θ directions. Further, as shown by the coordinate axis in Fig. 1, the horizontal direction of the paper surface is the Y direction, the upper and lower directions of the paper surface are the Z direction, the direction perpendicular to the paper surface is the X direction, and the rotation direction around the Z axis is the θ direction.

As shown in FIG. 1, the image processing unit 40 is a computer having a CPU 41 for processing signals and data therein and a memory 42 for storing data or programs. The memory 42 stores therein an image acquisition program 43, a relative position detection program 44, and a control data 45 which will be described later. Further, the image processing unit 40 includes a camera interface 47 and a flash interface 48 that are connected to the camera 32 and the flash unit 34. Further, the image processing unit 40 is provided with a data bus interface 46 for performing data communication with the control unit 50 of another computer. The CPU 41, the memory 42, the interfaces 47, 48, and the data bus interface 46 are connected by a data bus 49 inside the image processing unit 40.

As shown in FIG. 1, the control unit 50 is the same as the image processing unit 40, and is internally A computer 51 having a memory 51 for processing signals and data, and a computer 52 for storing data or programs, through the data bus interface 56, the communication line 60, the data bus interface 46 of the image processing unit 40, and the CPU 41 of the image processing unit 40, The memory 42 is connected. The memory 52 stores therein a position control program 53, a correction program 54, and a control data 55 which will be described later. Further, the control unit 50 includes a moving mechanism interface 57 that connects the moving mechanisms 12, 13, 16, and 17 in the X, Y, Z, and θ directions. The CPU 51, the memory 52, the moving mechanism interface 57, and the data bus interface interface 56 are connected by a data bus 59 inside the control unit 50.

Each of the moving mechanisms 12, 13, 16, 17 of the X, Y, Z, and θ of the die bonder 10 of the present embodiment outputs a signal indicating the position of each of the X, Y, Z, and θ directions of the tip end of the bonding tool 24, respectively. The control unit 50 obtains the positions of the X, Y, Z, and θ directions of the tip end of the bonding tool 24 from the signals of the respective moving mechanisms 12, 13, 16, and 17.

As shown in FIG. 2, the bonding tool 24 has a base portion 25 that adsorbs the front end adsorption surface 27 of the semiconductor die 30, is thicker than the front end adsorption surface 27, and connects the adsorption surface 27 and the base portion 25 and is inclined with respect to the longitudinal direction center line 90. The inclined surface is an inclined curved surface 26. The front end adsorption surface 27 is a plane perpendicular to the center line 90 of the longitudinal direction of the bonding tool 24 in a size substantially the same as the size of the semiconductor die 30. Therefore, the back surface of the semiconductor crystal grain 30 adsorbed on the adsorption surface 27 also becomes a plane perpendicular to the center line 90 of the longitudinal direction of the bonding tool 24.

The base portion 25 of the bonding tool 24 is thicker than the front end suction surface 27, and is fixed to the cylindrical shape of the crank 20. The inclined curved surface 26 is a curved surface that expands in a funnel shape from the adsorption surface 27 toward the base portion 25. Further, the crank 20 has a cylindrical shape in which the outer peripheral surface of the base portion 25 of the bonding tool 24 is fitted to the inner peripheral side, and the lower end side or the end surface 21 on the side of the suction surface 27 is the longitudinal direction of the bonding tool 24 or the bonding tool 24 The longitudinal direction of the center line 90 is perpendicular to the plane, and the surface is processed into a mirror surface. Crank 20 and bonding tool The fitting 24 is so as not to move relative to the bonding tool 24, and is disposed adjacent to the base 25.

As shown in FIG. 2, the camera 32 is disposed at a position where the focus is adhered to the back surface of the semiconductor die 30 of the bonding tool 24 (the lower side in the Z direction) when the bonding tool 24 is moved to a predetermined position directly above, and is adjusted to be adjusted. A clear image of the back side of the semiconductor die 30 can be obtained. That is, the camera 32 is adjusted so that the optical path length L1 of the lens of the camera 32 and the back surface of the semiconductor die 30 becomes the focal length of the lens of the camera 32.

On the other hand, as shown in FIG. 2, the inclined curved surface 26 of the bonding tool 24 and the end surface 21 of the crank 20 are separated from the adsorption surface 27 of the adsorption semiconductor die 30 in the longitudinal direction, from the lens of the camera 32 to the bonding tool 24. The optical path length of the inclined curved surface 26 and the end surface 21 of the crank 20 is the optical path length L2, L3. On the other hand, since the focal depth D of the lens of the camera 32 is slightly longer than the thickness of the semiconductor crystal 30, the optical path lengths L2 and L3 are longer than the length of the optical path length L1 plus the depth of focus D, respectively. Therefore, by the camera 32 simultaneously capturing the image of the back side of the semiconductor die 30 and the image of the inclined curved surface 26 of the bonding tool 24 and the image of the end face 21 of the crank 20, the inclined curved surface 26 of the bonding tool 24 and the end face 21 of the crank 20 are obtained. In a state in which the focus is inconsistent, the image of the oblique curved surface 26 and the image of the end surface 21 are more or less blurred.

Next, the operation of the die bonder 10 of the present embodiment will be described. As shown in FIG. 3, the control unit 50 of the die bonder 10 executes the position control program 53 to drive the respective moving mechanisms 12, 13, 16, 17 in the X, Y, Z, and θ directions to place the bonding tool 24 on the pickup. The wafer on the wafer 36 is moved over the wafer 36 to adsorb the semiconductor die 30 to the front end adsorption surface 27 of the bonding tool 24. Next, as shown in the trajectory 38 of FIG. 3, the bonding head 15 is moved onto the bonding stage 37, and the bonding head 15 is lowered onto the circuit substrate adsorbed and fixed on the bonding stage 37 to form the semiconductor die. 30 is bonded to the circuit substrate. This is the basic action of the die bonder 10.

The CPU 51 of the control unit 50 executes the position control program 53 to signal the moving mechanisms 12, 13, 16, 17 from X, Y, Z, and θ while the bonding tool 24 is moving from the pickup stage 36 to the bonding stage 37. The position of each of the X, Y, Z, and θ directions at the front end of the bonding tool 24 is detected. As shown in FIG. 2, the bonding tool 24 comes to a predetermined position directly above the camera 32, and becomes the center line 90 of the long side direction of the bonding tool 24. After the state coincides with the center position of the lens of the camera 32, a trigger signal for causing the flash lamp 34 to emit light is output. The trigger signal is transmitted to the image processing unit 40 via the data bus interface interfaces 56, 46 and the communication line 60. Further, the predetermined position is set in advance in the position control program 53.

After the trigger signal is input to the CPU 41 of the image processing unit 40, the image acquisition program 43 is executed. The CPU 41 outputs an instruction to cause the flash 34 to emit light. With this instruction, the illuminating signal is output from the flash interface 48 to the flash 34, and the flash 34 emits light. Further, after the trigger signal is input, the image processing unit 40 extracts the image from the camera 21 through the camera interface 47 in synchronization with the light emission of the flash lamp 34. Then, the captured image is stored in the memory 42 of the image processing unit 40. Further, the image capturing is performed while moving the bonding tool 24 (without stopping the movement).

After the flash lamp 34 emits light, the light from the flash lamp 34, like the arrows 71, 73, 75 shown in Fig. 4(a), enters the inclined curved surface 26 of the bonding tool 24 from the side of the adsorption surface 27 of the bonding tool 24, and the semiconductor crystal. The back surface of the pellet 30 and the end surface 21 of the crank 20. A portion of the light incident on the end face 21 of the crank 20 is reflected toward the longitudinal direction of the bonding tool 24 or in the direction along the center line 90 of the longitudinal direction of the bonding tool 24 (arrow in the Z direction) as shown by the arrow 72 shown in FIG. On the side, as shown in Fig. 2, the camera 32 is injected into the lower side of the bonding tool 24 (on the side of the adsorption surface 27). Therefore, in the present embodiment, the crank 20 is a reflector, and the end surface 21 of the crank 20 is a reflecting surface. In addition, the semiconductor die 30 is injected. One of the light on the back side or the lower side (the side on the negative side in the Z direction) is reflected toward the longitudinal direction of the bonding tool 24 or along the length of the bonding tool 24 as indicated by an arrow 75 as shown in Fig. 4(a). The direction of the center line 90 in the lateral direction (the negative side in the Z direction) is incident on the camera 32 on the lower side of the bonding tool 24 (on the side of the adsorption surface 27).

On the other hand, as shown by an arrow 73 in Fig. 4, the light incident on the inclined curved surface 26 of the bonding tool 24 is reflected in the horizontal direction or the like and the long side of the bonding tool 24 as shown by an arrow 74 shown in Fig. 4(a). The direction is different or the direction is different from the direction along the center line 90 of the longitudinal direction of the bonding tool 24.

Next, as shown in FIG. 4(b), an annular image 81 (image of the reflector) having a high luminance (white) reflected from the light of the flash lamp 34 toward the end surface 21 of the camera 32 is captured in the field of view of the camera 32, from the flash. The light of 34 does not reflect a circular image 82 having a low brightness (black or gray) to the inclined curved surface 26 of the bonding tool 24 of the camera 32, and the semiconductor crystal grains reflected from the flash lamp 34 in the circular image 82 are reflected to the camera 32. The four corner image 84 of the high brightness (white) on the back side of 30. The video processing unit 40 simultaneously acquires the three images 81, 82, and 84 by the camera 32 and stores them in the memory 42. Further, the image 83 at the leading end of the bonding tool 24 shown by a broken line in Fig. 4(b) is blocked by the image of the semiconductor die 30, and the camera 32 cannot capture it.

As explained above, the focus of the camera 32 is adjusted to coincide with the back side of the semiconductor die 30, so that the image 84 on the back side of the semiconductor die 30 is a clear image. However, the end surface 21 of the crank 20 and the inclined curved surface 26 of the bonding tool 24 are offset from the back surface of the semiconductor die 30 in the Z direction by more than the focal depth D of the camera 32, so that the annular image 81 of the end face 21 having a high brightness (white) is The circular image 82 of the oblique curved surface 26 having a low brightness (black or gray) is a blurred image.

The CPU 41 of the image processing unit 40 executes the relative position detecting program 44. In the following description, the brightness of the image is described as 256 gray levels (brightness 0 to brightness 255). Obtained by camera 32 As shown in FIG. 5(a), the image includes an annular image 81 of the brightness 255 of the end surface 21 (image of the reflector), and a circular image 82 of the brightness 0 of the inclined curved surface 26 of the bonding tool 24 (image of the inclined surface). A four-corner image 84 of the brightness 255 of the back side of the semiconductor die 30. As described above, the annular image 81 and the circular image 82 are blurred images because the focus of the camera 32 is shifted. Therefore, as shown in FIG. 5(a), the brightness of the image 81 is the brightness 255 as shown by the line a in the outer peripheral portion. However, as the circular image 82 is approached, a part of the black image 82 is mixed due to the blur of the focus, such as the line b. The brightness shown is reduced little by little. Then, after entering the area of the image 82, the brightness is rapidly lowered, and in the inner area of the image 82, the brightness becomes near zero. Next, as indicated by line c, the state of luminance 0 continues to the image 84 on the back side of the semiconductor die 30. The focus of camera 32 coincides with the back side of semiconductor die 30, so image 84 has a sharp outline. Further, the back surface of the semiconductor die 30 reflects the light of the flash lamp 34, and thus the luminance is 255. Therefore, the brightness of the image, as indicated by line d, rises substantially vertically from brightness 0 to brightness 255 at the edge of image 84. Next, in the area of the image 84, as shown by the line e, it is fixed to the brightness 255.

As shown in FIG. 5(a), the CPU 41 of the image processing unit 40 uses the preset binarization threshold to obtain the four-corner shape of the circular outline line 91 and the image 84 of the image 82 as shown in FIG. 5(b). Baseline 92. The binarization threshold is determined in advance by a test or the like as a reference condition such as a state of light of the flash lamp 34 and a photographing position, and a circular line having a diameter substantially the same as that of the base portion 25 of the bonding tool 24 can be obtained as The circular shape reference line 91 of the image 82. The image 81 and the image 82 are images of the inclined curved surface 26 of the bonding tool 24 and the end surface 21 of the crank 20 which are arranged concentrically. Therefore, the change of the brightness of each region from the line a to the line e in FIG. 5 is a winding bonding tool. The center line of the long side direction of 24 is the object. Therefore, the brightness variation between the image 81 and the image 82 is changed even in the case where the condition of the light of the flash lamp 34, the photographing position, and the like is shifted by the reference condition. The line, as shown in Fig. 5(a), is a left-right object (targeting the center line in the longitudinal direction of the bonding tool 24), so that the binarization threshold is used as shown in Fig. 5(b). The circular outer shape reference line 91' is formed concentrically with the outer side of the bonding tool 24 having a diameter smaller than the outer shape of the base portion 25 of the bonding tool 24. Therefore, even when the condition of the light of the flash lamp 34, the photographing position, and the like are shifted from the reference condition, the centers of the circular outer shape reference lines 91, 91' coincide with the positions of the center line of the longitudinal direction of the bonding tool 24.

In addition, the focus on the back side of the semiconductor die 30 is uniform, and the brightness of the edge of the image 84 changes substantially vertically. Therefore, even if the condition of the light of the flash lamp 34, the photographing position, and the like are shifted from the reference condition, the four-corner shape of the image 84 The size of the reference line 92 hardly changes.

That is, in the present embodiment, the annular image 81 of the end face 21 of the light reflecting the flash lamp 34 has a high luminance, and conversely, the circular image 82 of the inclined curved surface 26 of the light which does not reflect the flash 34 is low in luminance, and the luminance difference is extremely large. Therefore, the position of the end face 21 and the inclined curved surface 26 of the bonding tool 24 in the longitudinal direction is greater than or equal to the depth of focus D from the back surface of the semiconductor die 30, and even if a clear image cannot be obtained, the luminance difference between the respective images 81 and 82 can be made large. The circular shape reference line 91 of the outer shape and the concentric circle of the joining tool 24 is taken out. Moreover, the quadrilateral outline reference line 92 can be reliably taken out using the sharp edges of the image 84 on the back side of the semiconductor die 30.

As shown in FIG. 6, the image processing unit 40 detects the position of the center 97 of the circular outline line 91 and the center 98 of the quadrangular outline line 92 from the processed image, and sets the center of the circular outline line 91. The X-direction reference line 94 in the X direction toward the field of view 33 of the camera 32 and the Y-direction reference line 93 passing through the center 97 of the circular outline line 91 and facing the Y direction of the field of view 33 of the camera 32. Further, the image processing unit 40 sets the center 98 passing through the quadrangular outline line 92 and the side of the X-direction reference line 94 close to the quadrangular outline line 92. The X-direction measuring line 96 is in the Y-direction measuring line 95 which passes through the center 98 of the quadrangular outline line 92 and the side of the Y-direction reference line 93 which is close to the quadrangular outline line 92. Next, the image processing unit 40 obtains shift amounts ΔX and ΔY in the X direction and the Y direction, respectively, between the position of the center 97 of the circular outer shape reference line 91 and the position of the center 98 of the quadrangular outer shape reference line 92. Further, the image processing unit 40 detects the angle difference between the X-direction reference line 94 and the X-direction measurement line 96 in the θ direction or the angle difference between the Y-direction reference line 93 and the Y-direction measurement line 95 in the θ direction, and detects the θ of the quadrangular outline line 92. The rotation angle of the direction is shifted by Δθ.

As described above, the circular outer shape reference line 91 is concentric with the inner side of the end surface 21 of the crank 20 which is not offset from the position of the bonding tool 24, and the outer line of the bonding tool 24 is also concentric, thus The position of the center 97 of the shape reference line 91 is the center position of the center line 90 of the longitudinal direction of the bonding tool 24 shown in Fig. 4(a), and the four-corner reference line 92 is the outer edge of the semiconductor die 30, so the four corners The center 98 of the outline line 92 becomes the center position of the semiconductor die 30. Therefore, the offset amounts ΔX and ΔY in the X and Y directions of the circular outer shape reference line 91 and the quadrangular outer shape reference line 92 are the X and Y directions of the center position of the bonding tool 24 and the center position of the semiconductor die 30. Each offset.

Similarly, the X-direction reference line 94 passing through the center 97 of the circular outline line 91 and facing the X direction of the field of view 33 of the camera 32 and the Y direction passing through the center 97 of the circular outline line 91 and toward the field of view 33 of the camera 32. The Y-direction reference line 93 is a reference line on the adsorption surface 27 of the bonding tool 24, and passes through the center 98 of the quadrangular outline line 92 and is parallel to the X-direction measurement line near the X-direction reference line 94 of the quadrangular outline line 92. The Y-direction measuring line 95 parallel to the side passing through the center 98 of the quadrangular outline line 92 and the Y-direction reference line 93 close to the quadrangular outline line 92 is indicative of the semiconductor die 30 with respect to the bonding tool 24. The line of the inclination angle of the reference line on the adsorption surface 27. Therefore, the θ direction of the four-corner shape reference line 92 obtained from the angular difference between the X-direction reference line 94 and the X-direction measurement line 96 in the θ direction or the angular difference between the Y-direction reference line 93 and the Y-direction measurement line 95 in the θ direction is obtained. The rotation angle shift Δθ is an inclination angle of the semiconductor crystal grain 30 with respect to the reference line on the adsorption surface 27 of the bonding tool 24. Further, the offset between the center position of the bonding tool 24 and the center position of the semiconductor die 30 in the X and Y directions and the inclination angle of the semiconductor die 30 with respect to the reference line on the adsorption surface 27 of the bonding tool 24 are bonding tools. The relative position of 24 to semiconductor die 30.

The image processing unit 40 detects the offsets ΔX, ΔY, and Δθ of the semiconductor die 30 with respect to the X, Y, and θ directions of the bonding tool 24, and then passes the data through the data bus interface 46, 56, and communication. The line 60 is sent to the control unit 50. The CPU 51 of the control unit 50 executes the correction program 54 to correct the position of the front end of the bonding tool 24 detected by each of the moving mechanisms 12, 13, 16, 17 during the movement of the bonding tool 24 to the bonding stage 37 shown in FIG. Each of the shift amounts ΔX, ΔY, and Δθ in the X, Y, and θ directions can bond the semiconductor die 30 to the circuit board on the bonding stage 37 at the correct position and direction.

As described above, the die bonder 10 of the present embodiment utilizes the difference in luminance between the image 81 of the end face 21 of the crank 20 of the bonding tool 24 and the image 82 of the inclined curved surface 26 of the bonding tool 24, and the back surface of the semiconductor die 30. The brightness difference between the image 84 and the image 82 of the inclined curved surface 26 of the bonding tool 24 detects the center position of the center line 90 in the longitudinal direction of the bonding tool 24, the center position of the semiconductor die 30, and thus the end face 21 and the inclined curved surface 26 from the semiconductor die. The back side offset of 30 is larger than the depth of focus D, and the relative position of the bonding tool 24 and the semiconductor die 30 can be surely detected even if the respective images 81, 82 are not clear. Therefore, the end surface 21 of the crank 20 can be processed into a mirror surface to form a reflecting surface, and the complex optical system can be used to effectively detect the half. The position of the conductor grains is shifted. Further, since the crank 20 holds the bonding tool 24 and does not move relative to the bonding tool 24, it is not necessary to stop the movement of the bonding tool 24 when acquiring the image of the bonding tool 24, the crank 20, and the semiconductor die 30, and the working time can be shortened. Further, since the crank 20 does not protrude from the bonding head 15, vibration does not occur due to the movement of the bonding head 15, and the positional deviation of the semiconductor crystal grains can be effectively detected with a simple configuration.

In the present embodiment, the inclined surface of the bonding tool 24 is a funnel-shaped inclined curved surface 26, but the inclined surface is inclined with respect to the longitudinal center line 90 of the bonding tool 24 so that the light from the flash lamp 34 is not reflected along The surface in the direction of the longitudinal direction center line 90 may be any shape, and may be, for example, a tapered surface that connects the adsorption surface 27 and the base portion 25 obliquely.

Further, in the present embodiment, the positional shift amount is detected and corrected in the joining operation. However, the present invention is not only a correction in the joining operation, but also, for example, a training or teaching before the joining of the actual product. The positional deviation is measured in advance and the offset amount of the bonding tool 24 is set based on the result. In this case, the inclined curved surface 26 of the bonding tool 24, the crank 20, and the respective images 81, 82, 84 of the semiconductor die 30, which are stopped by the movement of the bonding tool 24 when the image is acquired, are not joined. The images 81, 82, and 84 acquired by the movement of the tool 24 are combined to set the offset amount and the offset amount.

Further, in the present embodiment, the position of the bonding tool 24 is corrected based on the relative position of the bonding tool 24 and the semiconductor die 30 adsorbed on the adsorption surface 27 of the bonding tool 24, but the center line 90 in the longitudinal direction of the bonding tool 24 is used. As a result of the position detection, the relative position between the bonding tool 24 and the pickup stage 36 or the bonding stage 37 is corrected, and the offset amount of the pickup position or the bonding position due to the temperature change of the die bonder 10 may be corrected. In this case, for example, a moving average of the positional deviation between the bonding tool 24 and the pickup stage 36 or the bonding stage 37 is obtained, according to which The tendency of the change in the moving average determines the direction in which the offset is corrected.

Next, another embodiment of the present invention will be described with reference to Figs. 7 and 8 . The same portions as those of the embodiment described with reference to FIGS. 1 to 6 are denoted by the same reference numerals to omit the description. The embodiment shown in Fig. 7 is a ring 22 which is attached and fixed to the outer periphery of the base portion 25 of the bonding tool 24 on the lower side of the crank 20 of the embodiment described with reference to Figs. 1 to 6 . The end face 23 on the lower side of the ring 22 is machined into a mirror surface that reflects light from the flash lamp 34. In the present embodiment, the ring 22 is a reflector, the end surface 23 is a reflection surface, and the ring 22 is disposed adjacent to the base portion 25.

As shown in Fig. 7(b), in the present embodiment, the camera 32 obtains the image 86 of the end face 23 of the ring 22 which is slightly blurred and has a high brightness (white), and the brightness of the inclined curved surface 26 of the bonding tool 24 which is slightly blurred. A low (black or gray) image 82, a high brightness (white) image 84 of the back side of the semiconductor die 30, an image 86 of the end face 23 and a circular outline line 91 of the image 82 of the inclined curved surface 26, and a sloped surface The image 82 of the image 82 and the quadrangular outline line 92 of the image 84 on the back side of the semiconductor die 30 detect the relative position of the bonding tool 24 to the semiconductor die 30. The effects of this embodiment are the same as those of the embodiment described above with reference to Figs. 1 to 6 .

In another embodiment shown in Fig. 8(a), the base portion 25 of the bonding tool 24 is segmented, and the lower surface 29 of the lower portion of the segment portion 28 is processed into a mirror surface to reflect light from the flash lamp 34. In the present embodiment, the segment portion 28 of the bonding tool 24 is a reflector, the lower surface 29 of the segment portion 28 is a reflecting surface, and the lower surface 29 is disposed adjacent to the base portion 25.

As shown in Fig. 8(b), in the present embodiment, the camera 32 obtains an image 88 of the lower surface 29 of the annular portion 28 having a slightly blurred brightness (white), and a slightly curved curved surface 26 of the bonding tool 24. An image 82 having a low brightness (black or gray) and an image 84 on the back side of the semiconductor die 30 having a high brightness (white) are taken out of the image 82 of the lower surface 29 and the image 82 of the inclined curved surface 26 The shape reference line 91, the image 82 of the inclined curved surface 26, and the quadrangular outline line 92 of the image 84 on the back side of the semiconductor die 30 detect the relative position of the bonding tool 24 and the semiconductor die 30. The effects of this embodiment are the same as those of the embodiment described above with reference to Figs. 1 to 6 .

10‧‧ ‧ die bonder

11‧‧‧ Guide rail

12‧‧‧X direction moving mechanism

13‧‧‧Y direction moving mechanism

15‧‧‧ Bonding head

16‧‧‧Z direction moving mechanism

17‧‧‧θ direction moving mechanism

20‧‧‧ crank

24‧‧‧ Bonding tools

27‧‧‧Adsorption surface

30‧‧‧Semiconductor grains

32‧‧‧ camera

34‧‧‧flash

35‧‧‧Mirror

40‧‧‧Image Processing Department

41,51‧‧‧CPU

42,52‧‧‧ memory

43‧‧·Image acquisition program

44‧‧‧ Relative position detection program

45,55‧‧‧Control data

46, 56‧‧‧ data bus interface

47‧‧‧ camera interface

48‧‧‧Flash interface

49, 59‧‧‧ data bus

50‧‧‧Control Department

53‧‧‧Location Control Program

54‧‧‧correction program

57‧‧‧Mobile agency interface

60‧‧‧Communication line

Claims (9)

A die bonder comprising: a bonding tool; a light source; a camera; and a reflector; the bonding tool having an adsorption surface for adsorbing the front end of the semiconductor die, a base portion thicker than the front end of the adsorption surface, and connecting the adsorption surface and the a base portion and an inclined surface inclined with respect to a center line of the longitudinal direction; the light source is disposed on the adsorption surface side of the bonding tool; and the camera simultaneously obtains an image of the semiconductor die adsorbed on the adsorption surface and an image of the reflector And an image of the inclined surface of the bonding tool; the reflector is adjacent to the base of the bonding tool, and is disposed in a longitudinal direction of the bonding tool and is separated from the adsorption surface by a depth of focus of the camera, and is not disposed The light is moved relative to the bonding tool to reflect at least the light from the light source to the side of the adsorption surface of the bonding tool. The die bonder of claim 1, further comprising an image processing unit; the image processing unit processes the image of the reflector obtained by the camera, and the image of the inclined surface of the bonding tool obtained by the camera And an image of the semiconductor die obtained by the camera to detect a relative position of the bonding tool and the semiconductor die. The die bonder of claim 1 or 2, wherein the reflective system holds a crank of the bonding tool, or a ring attached to the bonding tool or a portion adjacent to the base of the bonding tool a reflecting surface perpendicular to a center line of a longitudinal direction of the bonding tool; The reflecting surface is an end surface of the crank on the side of the adsorption surface, or an end surface of the ring on the side of the adsorption surface, or an end surface of the segment. The die bonder of claim 1 or 2, wherein a position of the bonding tool and the semiconductor die is a position on the adsorption face of a center line of a longitudinal direction of the bonding tool and the semiconductor crystal Either or both of the offset between the positions of the centers of the particles on the adsorption surface or the angle of inclination of the semiconductor grains with respect to the reference axis of the adsorption surface. The die bonder of claim 1 or 2, further comprising: a moving mechanism; and a control portion; the moving mechanism moves the bonding tool; the control portion moves the bonding tool by the moving mechanism, When the bonding tool reaches a predetermined position between the semiconductor die and the bonding position, the light source emits light, and while the bonding tool moves, the camera simultaneously acquires an image of the semiconductor die adsorbed on the adsorption surface and the image An image of the inclined surface of the bonding tool and an image of the reflector. The die bonder of claim 1 or 2, further comprising: a moving mechanism; and a control portion; the moving mechanism moves the bonding tool; and the control portion changes a position of the bonding tool by the moving mechanism And correcting the position of the bonding tool based on the relative position of the bonding tool and the semiconductor die detected by the image processing unit. A position detecting method for detecting a bonding tool and a semiconductor die in a die bonder a relative position, comprising: an image acquisition step; and a relative position detection step; the die bonder includes a bonding tool, a light source disposed on an adsorption surface side of the bonding tool, and does not move relative to the bonding tool and The light from the light source is reflected to the reflector on the adsorption surface side of the bonding tool, and the image of the semiconductor die adsorbed on the adsorption surface and the image of the reflector and the image of the inclined surface of the bonding tool are simultaneously obtained. In the camera, the bonding tool has a suction surface that adsorbs the front end of the semiconductor die, a base portion that is thicker than the front end of the adsorption surface, and an inclined surface that connects the adsorption surface and the base portion and is inclined with respect to a center line of the longitudinal direction. The body is adjacent to the base of the bonding tool, and is disposed apart from the focal depth of the camera in a longitudinal direction of the bonding tool, and includes a reflecting surface perpendicular to a center line of a longitudinal direction of the bonding tool; The image obtaining step is performed by the camera simultaneously acquiring an image of the semiconductor die adsorbed on the adsorption surface and an image of the reflector An image of the inclined surface of the bonding tool; the relative position detecting step, the image of the reflector obtained from the camera, the image of the inclined surface of the bonding tool obtained by the camera, and the image obtained by the camera An image of the semiconductor die, detecting the relative position of the bonding tool to the semiconductor die. The position detecting method of claim 7, wherein a position of the bonding tool and the semiconductor die is a position on the adsorption surface of the longitudinal direction center line of the bonding tool and a center of the semiconductor die Either or both of the offset between the positions on the adsorption surface or the angle of inclination of the semiconductor die relative to the reference axis of the adsorption surface. A position detecting method according to claim 7 or 8 wherein the die bonder advances a moving mechanism for moving the bonding tool in one step; the image capturing step of moving the bonding tool by the moving mechanism, the bonding tool making the light source from a picking position of the semiconductor die to a predetermined position between the bonding position When the bonding tool is moved, the image of the semiconductor die adsorbed on the adsorption surface and the image of the reflector and the inclined surface of the bonding tool are simultaneously acquired by the camera.