JP2014036068A - Die bonder, and method of detecting position of bonding tool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect a position of a bonding tool itself with high accuracy.SOLUTION: A die bonder 10 includes: a bonding tool 24; a stroboscope 34; a camera 32; and a shank 20. The bonding tool 24 comprises: a front-end suction surface 27 sucking a semiconductor die 30; a bottom that is thicker than the front-end suction surface 27; and an inclined plane connecting between the suction surface 27 and the bottom, and inclined to a longitudinal direction center line. The stroboscope 34 is arranged to the suction surface 27 side of the bonding tool 24. The camera 32 simultaneously acquires an image of the shank 20 and an image of the inclined plane of the bonding tool 24. The shank 20 is adjacent to the bottom of the bonding tool 24, and does not move relatively to the bonding tool 24, and reflects light from the stroboscope 34 to at least the suction surface 27 side of the bonding tool 24.

Description

  The present invention relates to a die bonder structure and a bonding tool position detection method.

  A die bonder is often used as an apparatus for bonding a semiconductor die to a circuit board such as a lead frame. The die bonder lowers the semiconductor die sucked and held at the tip of the bonding tool toward the surface of the circuit board sucked and fixed on the bonding stage, and bonds the semiconductor die onto the circuit board.

  In the die bonder, it is necessary to press the semiconductor die against the circuit board in a state where the position of the semiconductor die attracted by the bonding tool is matched with the bonding position of the circuit board. Therefore, the semiconductor die picked up by the bonding tool is recognized by the camera, and thereby the position of the semiconductor die picked up by the bonding tool is detected, while the bonding position of the circuit board on which the semiconductor die is mounted is detected by another camera. A method of recognizing and aligning a semiconductor die at a bonding position based on the result and bonding the semiconductor die to that position is used (for example, see Patent Document 1).

  Also, after bonding the semiconductor die to the circuit board, a method of detecting the difference between the position where the semiconductor die is actually bonded and the bonding position on the circuit board, and correcting the alignment between the camera and the bonding tool based on this difference. Used (see, for example, Patent Document 2).

  On the other hand, in the die bonder, the circuit board is heated to bring the bonding metal such as solder on the circuit board into a molten state, and after pressing the heated semiconductor die by adsorbing it onto the bonding tool, the semiconductor die is cooled, A method of joining the semiconductor die and the circuit board with solidified solder is often used, but the position of the bonding tool may change due to heating, making it impossible to bond the semiconductor die to the bonding position accurately. is there.

  In this case, as described in Patent Document 1, even if the semiconductor die sucked by the bonding tool is recognized by the camera, the bonding position of the semiconductor die is only shifted from the center of the bonding tool. It is difficult to distinguish whether the position of the semiconductor layer changes with temperature, and there is a problem that the bonding accuracy of the semiconductor die is lowered. Also, even if you try to acquire an image of the bonding tool tip without adhering the semiconductor die to the tip of the bonding tool, it is difficult to acquire the image due to contamination due to bonding, and it is possible to accurately detect changes in the position of the bonding tool itself. There is a problem that the bonding accuracy of the semiconductor die is lowered.

  In addition, the method described in Patent Document 2 is a method of feeding back a positional deviation amount after bonding once, so it is effective when the positional deviation amount is small. For example, after the die bonder is continuously operated, it is stopped for a certain period of time. In the case where the temperature change is large and the amount of positional deviation is large as in the case, it is not effective, and there is a problem that position adjustment is required by trial bonding.

JP 2010-40738 A JP-A-4-299542

  Accordingly, an object of the present invention is to accurately detect the position of the bonding tool itself.

  The die bonder of the present invention includes a bonding tool, a light source, a camera, and a reflector. The bonding tool includes a suction surface at a tip that sucks a semiconductor die, a root thicker than the suction surface at the tip, and a suction surface. And an inclined surface that is inclined with respect to the longitudinal center line, the light source is disposed on the suction surface side of the bonding tool, and the camera is an image of the reflector and an image of the inclined surface of the bonding tool. And the reflector is adjacent to the base of the bonding tool, 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. And

  The die bonder of the present invention further includes an image processing unit, which processes the image of the reflector acquired by the camera and the image of the inclined surface of the bonding tool acquired by the camera, and determines the position of the bonding tool. It is also suitable as detecting.

  In the die bonder of the present invention, the reflector is a shank that holds the bonding tool, a ring attached to the bonding tool, or a step adjacent to the base of the bonding tool, and is perpendicular to the longitudinal center line of the bonding tool. It has a reflecting surface, and the reflecting surface is preferably an end surface on the suction surface side of the shank, an end surface on the suction surface side of the ring, or an end surface of the stepped portion.

  The die bonder of the present invention further includes a control unit, and the control unit corrects the position of the bonding tool based on a difference between the position of the bonding tool detected by the image processing unit and a preset reference position. Is also suitable.

  A bonding tool position detection method for a die bonder according to the present invention includes an image acquisition step and a position detection step. The die bonder includes a tip suction surface for sucking a semiconductor die, a root thicker than the tip suction surface, and a suction The bonding tool has a slanted surface that connects the surface and the base and is inclined with respect to the longitudinal center line, and is relatively moved between the light source disposed on the suction surface side of the bonding tool and the bonding tool. A reflector that reflects light from the light source to the suction surface side of the bonding tool, and a camera that simultaneously obtains an image of the reflector and an image of the inclined surface of the bonding tool, and the reflector is the root of the bonding tool. The image acquisition process includes a reflector image and a bonding tool by a camera, including a reflective surface that is adjacent to and perpendicular to the longitudinal centerline of the bonding tool. The position of the bonding tool from the image of the reflector acquired by the camera and the image of the inclined surface of the bonding tool acquired by the camera. Features.

  The die bonder bonding tool position correction method of the present invention includes an image acquisition step, a position detection step, and a position correction step. The die bonder includes a tip suction surface for sucking a semiconductor die, and a tip suction surface. A bonding tool having a thick root, an adsorption surface and an inclined surface that is inclined with respect to the longitudinal center line, a light source disposed on the adsorption surface side of the bonding tool, and the bonding tool And a reflector that reflects light from the light source toward the suction surface side of the bonding tool and a camera that simultaneously acquires an image of the reflector and an image of the inclined surface of the bonding tool. The body includes a reflective surface adjacent to the base of the bonding tool and perpendicular to the longitudinal centerline of the bonding tool. And the image of the inclined surface of the bonding tool at the same time, the position detection step detects the position of the bonding tool from the image of the reflector acquired by the camera and the image of the inclined surface of the bonding tool acquired by the camera, The position correction step is characterized in that the position of the bonding tool is corrected based on the difference between the position of the bonding tool detected in the position detection step and a preset reference position.

  The present invention has an effect that the position of the bonding tool itself can be accurately detected.

It is a distribution diagram showing the composition of the control system of the die bonder in the embodiment of the present invention. It is explanatory drawing which shows the detail of the bonding tool and shank of the die bonder in embodiment of this invention. It is explanatory drawing which shows operation | movement of the die bonder in embodiment of this invention. It is explanatory drawing which shows the structure of the bonding tool and shank of the die bonder in embodiment of this invention, and the image caught with the camera. It is explanatory drawing which shows the process of binarizing the image shown in FIG. It is explanatory drawing which shows the image which binarized the image shown in FIG. It is explanatory drawing which shows the structure of the bonding tool and ring of the die bonder in other embodiment of this invention, and the image caught with the camera. It is explanatory drawing which shows the structure of the bonding tool of the die bonder in other embodiment of this invention, and the image caught with the camera.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the die bonder 10 of this embodiment includes a bonding head 15 to which a bonding tool 24 is attached via a shank 20, a guide rail 11 that guides the bonding head 15 in the Y direction, and the bonding head 15 as Y A Y-direction moving mechanism 13 that moves in the direction, an X-direction moving mechanism 12 that moves the guide rail 11 and the bonding head 15 in the X direction, a camera 32 provided below the bonding head 15, and a circuit board 31. A camera 39 provided above the suction-fixed bonding stage 37, a strobe 34 as a light source, an image processing unit 40 to which the cameras 32 and 39 and the strobe 34 are connected, an X and Y direction moving mechanism 12, The control part 50 to which 13 is connected is provided. The bonding tool 24 has an adsorption surface 27 that adsorbs the semiconductor die 30 at the tip, and the strobe 34 includes a reflecting mirror 35 that directs emitted 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 rotates the bonding tool 24 in the θ direction. Are respectively connected to the control unit 50. The controller 50 moves the bonding tool 24 in the X, Y, Z, and θ directions by operating the moving mechanisms 12, 13, 16, and 17 in the X, Y, Z, and θ directions. It is configured. 1, the horizontal direction on the paper is the Y direction, the vertical direction of the paper is the Z direction, the vertical direction to the paper 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 that includes a CPU 41 that internally processes signals and data, and a memory 42 that stores data and programs. The memory 42 stores therein an image acquisition program 43, a position detection program 44, and control data 45 described later. In addition, the image processing unit 40 includes a camera interface 47 and a strobe interface 48 for connecting to the cameras 32 and 39 and the strobe 34. Further, the image processing unit 40 includes a data bus interface 46 for performing data communication with the control unit 50 which is another computer. The CPU 41, the memory 42, the interfaces 47 and 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, like the image processing unit 40, the control unit 50 is a computer that includes a CPU 51 that internally processes signals and data, and a memory 52 that stores data and programs, and a data bus interface 56. Are connected to the CPU 41 and the memory 42 of the image processing unit 40 via the communication line 60 and the data bus interface 46 of the image processing unit 40. The memory 52 stores therein a position control program 53, a position correction program 54, and control data 55, which will be described later. In addition, the control unit 50 includes a moving mechanism interface 57 for connecting to 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 56 are connected by a data bus 59 inside the control unit 50.

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

  As shown in FIG. 2, the bonding tool 24 connects the tip suction surface 27 that sucks the semiconductor die 30, the root 25 that is thicker than the tip suction surface 27, and the suction surface 27 and the root 25. And an inclined curved surface 26 that is an inclined surface inclined with respect to the line 90. The suction surface 27 at the tip is substantially the same size as the semiconductor die 30 and is a plane perpendicular to the longitudinal center line 90 of the bonding tool 24.

  The base 25 of the bonding tool 24 is thicker than the suction surface 27 at the tip and is a cylindrical shape fixed to the shank 20, and the inclined curved surface 26 is a curved surface that spreads in a funnel shape from the suction surface 27 toward the root 25. Further, the shank 20 has a cylindrical shape in which the outer peripheral surface of the base 25 of the bonding tool 24 is fitted on the inner peripheral side, and the end surface 21 on the lower side or the suction surface 27 side is in the longitudinal direction of the bonding tool 24. Alternatively, the surface of the bonding tool 24 is a plane perpendicular to the longitudinal center line 90 and the surface thereof is mirror-finished. Since the shank 20 is engaged with the bonding tool 24, the shank 20 does not move relative to the bonding tool 24 and is disposed at a position adjacent to the root 25.

  As shown in FIG. 2, the camera 32 is focused on the back surface (the lower surface in the Z direction) of the semiconductor die 30 adsorbed by the bonding tool 24 when the bonding tool 24 moves to a predetermined position directly above. It is arranged so as to fit, and is adjusted so that a sharp image of the back surface of the semiconductor die 30 can be acquired. That is, the camera 32 is adjusted so that the optical path length L1 between 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 shank 20 are arranged in the longitudinal direction away from the suction surface 27 that sucks the semiconductor die 30, and from the lens of the camera 32 to the bonding tool 24. The optical path lengths to the inclined curved surface 26 and the end surface 21 of the shank 20 are optical path lengths L2 and 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 die 30, the optical path lengths L2 and L3 are longer than the length obtained by adding the focal depth D to the optical path length L1, respectively. . For this reason, when the camera 32 acquires the image of the inclined curved surface 26 of the bonding tool 24 and the image of the end surface 21 of the shank 20, the inclined curved surface 26 of the bonding tool 24 and the end surface 21 of the shank 20 are out of focus. The acquired image of the inclined curved surface 26 and the image of the end surface 21 are slightly blurred images.

  Next, the operation of the die bonder 10 of this embodiment will be described. As shown in FIG. 3, the control unit 50 of the die bonder 10 shown in FIG. 1 executes a position control program 53 to drive the moving mechanisms 12, 13, 16, 17 in the X, Y, Z, and θ directions to pick up. The bonding tool 24 is moved onto the diced wafer placed on the stage 36, and the semiconductor die 30 is sucked onto the suction surface 27 at the tip of the bonding tool 24. The semiconductor die 30 is heated by a heater (not shown). Then, the control unit 50 moves the bonding head 15 onto the bonding stage 37 as shown by a locus 38 shown in FIG. The circuit board 31 attracted and fixed on the bonding stage 37 is heated by a heater (not shown) incorporated in the bonding stage 37, and the bonding metal such as solder on the circuit board 31 is in a molten state. Here, the control unit 50 lowers the bonding head 15 onto the circuit board 31 that is sucked and fixed onto the bonding stage 37, and presses the heated semiconductor die 30 sucked by the bonding tool 24 onto the circuit board 31. After that, the semiconductor die 30 is cooled, and the semiconductor die 30 and the circuit board 31 are joined with the solidified solder.

  When the bonding of the semiconductor die 30 is completed, the image processing unit 40 acquires an image of the circuit board 31 and the semiconductor die 30 bonded thereon by the camera 39 provided on the circuit board 31. The amount of deviation between the actual bonding position and the bonding position of the circuit board 31 is detected. If there is a position shift, the position of the bonding tool 24 is corrected by the shift amount. In this case, a moving average of the positional deviation may be obtained, and the deviation correction direction may be determined based on the tendency of the moving average value to change.

  When bonding is continuously performed by the die bonder 10 by repeating the series of steps as described above, the position of the bonding tool 24 is gradually moved from the preset reference position at each correction as the temperature of the die bonder 10 increases. To go. When the temperature of the die bonder 10 reaches a substantially constant temperature, the correction amount becomes substantially zero, and the position of the bonding tool 24 does not move.

  When the die bonder 10 is stopped for a certain time, for example, 30 minutes or one hour after bonding is performed at a constant temperature, the position of the bonding tool 24 returns to the original reference position due to a decrease in the temperature of the die bonder 10. Come on. When the bonding is resumed, it is located between the position immediately after the stop and the initial reference position. Since this intermediate position changes variously depending on the stop time of the die bonder 10, bonding temperature conditions, etc., for example, the temperature of somewhere in the die bonder 10 is measured, and the intermediate position of the bonding tool 24 is predicted based on the result. It is difficult.

  Therefore, the control unit 50 and the image processing unit 40 detect an intermediate position of the bonding tool 24 as described below.

  First, the CPU 51 of the control unit 50 executes the position control program 53 in a state where the semiconductor die 30 is not attracted to the bonding tool 24, and the bonding head 15 is placed at the center position of the camera 32 lens as shown in FIG. , The bonding tool 24 is moved to a predetermined position directly above the camera 32, and a trigger signal for causing the strobe 34 to emit light is output. This trigger signal is transmitted to the image processing unit 40 through the data bus interfaces 56 and 46 and the communication line 60. The predetermined position is a position set in the position control program 53 in advance.

  When this trigger signal is input, the CPU 41 of the image processing unit 40 executes the image acquisition program 43. The CPU 41 outputs a command for causing the strobe 34 to emit light. In response to this command, a flash signal is output from the flash interface 48 to the flash 34, and the flash 34 emits light. Further, when the trigger signal is input, the image processing unit 40 captures an image from the camera 32 through the camera interface 47 in synchronization with the light emission of the strobe 34. The captured image is stored in the memory 42 of the image processing unit 40.

  When the stroboscope 34 emits light, light from the stroboscope 34 is inclined from the end surface 21 of the shank 20 and the inclined curved surface of the bonding tool 24 from the suction surface 27 side of the bonding tool 24 as indicated by arrows 71, 73, 75 shown in FIG. 26, is incident on the suction surface 27 of the bonding tool 24. A part of the light incident on the end face 21 of the shank 20 is in the longitudinal direction of the bonding tool 24 or in the direction along the longitudinal center line 90 of the bonding tool 24 (Z As shown in FIG. 2, the light is reflected toward the camera 32 on the lower side of the bonding tool 24 (on the suction surface 27 side). Therefore, in this embodiment, the shank 20 is a reflector, and the end surface 21 of the shank 20 is a reflecting surface.

  On the other hand, the light incident on the inclined curved surface 26 of the bonding tool 24 as indicated by an arrow 73 in FIG. 4A corresponds to the longitudinal direction of the bonding tool 24 such as the horizontal direction as indicated by an arrow 74 in FIG. Reflected in a different direction or in a direction different from the direction along the longitudinal centerline 90 of the bonding tool 24. Further, since the suction surface 27 of the bonding tool 24 is soiled by bonding, the light incident on the suction surface 27 of the bonding tool 24 is irregularly reflected on the surface as shown by an arrow 75 in FIG. Similar to the light incident on the inclined curved surface 26 as indicated by an arrow 76, the light is reflected in a direction different from the longitudinal direction of the bonding tool 24 or a direction different from the direction along the longitudinal center line 90 of the bonding tool 24.

  Then, as shown in FIG. 4B, in the visual field 33 of the camera 32, the lightness (white) ring-shaped image 81 (reflector) of the end face 21 where the light from the strobe 34 reflects toward the camera 32 is reflected. ), A light image (black or gray) of the inclined curved surface 26 of the bonding tool 24 in which the light from the strobe 34 does not reflect toward the camera 32, and similarly, the light from the strobe 34 is reflected by the camera 32. A low-lightness (black or gray) circular image 83 of the suction surface 27 of the bonding tool 24 that does not reflect toward the screen is captured. The image processing unit 40 simultaneously acquires these three images 81, 82, and 83 by the camera 32 and stores them in the memory 42.

  As described above, the focus of the camera 32 is adjusted to match the back surface of the semiconductor die 30, and the shank 20 is displaced from the back surface of the semiconductor die 30 in the Z direction by a depth greater than the focal depth D of the camera 32. The ring-shaped image 81 and the circular image 82 of the end surface 21, the inclined curved surface 26 of the bonding tool 24 are blurred images. Further, although the suction surface 27 of the bonding tool 24 is in the depth of focus D of the camera 32, the light is not reflected toward the camera, so that the image 83 is an image having a low brightness (black or gray) as with the image 82. It has become.

  The CPU 41 of the image processing unit 40 executes a position detection program 44. In the following description, the brightness of the image will be described as 256 gradations (brightness 0 to brightness 255). As shown in FIG. 5A, the image acquired by the camera 32 includes a ring-shaped image 81 (reflector image) with a lightness of 255 on the end face 21 and a circular lightness with a lightness of 0 on the inclined curved surface 26 of the bonding tool 24. An image 82 (an image of an inclined surface) and a circular image 83 of lightness 0 of the suction surface 27 of the bonding tool 24 are included. As described above, the ring-shaped image 81 and the circular image 82 are blurred because the camera 32 is out of focus. Therefore, as shown in FIG. 5 (a), the brightness of the image 81 is 255 at the outer peripheral portion as shown by the line a. However, as the circular image 82 approaches, the brightness of the black image 82 increases. The part is mixed and the brightness gradually decreases as shown by the line b. Then, when entering the area of the image 82, the brightness rapidly decreases, and in the inner area of the image 82, the brightness is close to zero. The inner area of the image 83 continues to have a lightness of 0 as indicated by the line c.

  As shown in FIG. 5A, the CPU 41 of the image processing unit 40 uses a preset binarization threshold to draw a round outline 91 of the image 82 as shown in FIG. get. As for the binarization threshold, when conditions such as the light state of the strobe 34 and the photographing position are the reference conditions, a circular line having a diameter substantially the same as the outline of the root 25 of the bonding tool 24 is a round outline of the image 82. It is determined in advance by a test or the like so that it can be acquired as 91. Since 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 shank 20 that are concentrically arranged, the change in brightness of each region indicated by the line a to the line c in FIG. Symmetric about the longitudinal centerline of the tool 24. Therefore, even when conditions such as the light state of the strobe 34 and the photographing position deviate from the reference conditions, the change curve of the brightness between the image 81 and the image 82 is as shown by the alternate long and short dash line b ′ in FIG. Since it becomes left-right symmetric (symmetric around the longitudinal center line of the bonding tool 24), the round outline 91 ′ obtained using the binarization threshold shown in FIG. It becomes a concentric circle with the outer shape of the bonding tool 24 having a smaller diameter than the outer shape. For this reason, even when conditions such as the light state of the strobe 34 and the photographing position deviate from the reference conditions, the centers of the round outlines 91 and 91 ′ coincide with the position of the longitudinal center line of the bonding tool 24.

  That is, in the present embodiment, the ring-shaped image 81 of the end face 21 that reflects the light of the strobe 34 has high brightness, and conversely, the circular image 82 of the inclined curved surface 26 that does not reflect the light of the strobe 34 has lightness. Is low and the brightness difference is very large. Therefore, the longitudinal positions of the bonding tool 24 of the end surface 21 and the inclined curved surface 26 are separated from the back surface of the semiconductor die 30 by the depth of focus D, and the brightness of the images 81 and 82 can be obtained even if a sharp image cannot be acquired. By utilizing the fact that the difference is large, it is possible to reliably extract the circular outline 91 concentric with the outline of the bonding tool 24.

  As shown in FIG. 6, the image processing unit 40 superimposes the outer contour line 92 of the bonding tool 24 at the reference position on the circular outer contour line 91, and the X direction center line 94 and the Y direction center of the circular outer contour line 91. The position of the center 97, which is the intersection of the line 93 and the center lines 94, 93, is determined. Then, the image processing unit 40 determines the position of the center 97 of the circular outline 91 and the center 98 of the outline 92 that is the position of the center of the bonding tool 24 at the reference position (the X-direction centerline 96 and the Y of the outline 92). Deviation amounts ΔX and ΔY in the X and Y directions with respect to the position of the direction center line 95) are obtained.

  The circular outline 91 is concentric with the outline inside the end face 21 of the shank 20 that is not displaced relative to the bonding tool 24, and is also concentric with the outline of the bonding tool 24. The position of the center 97 of the outline 91 is the center position of the longitudinal center line 90 of the bonding tool 24 shown in FIG. 4A, and indicates the center position of the bonding tool 24 when the bonding tool 24 is in the intermediate position. It is. Therefore, the deviation amounts ΔX and ΔY in the X and Y directions between the center 97 of the circular outline 91 and the center 98 of the outline 92 are the deviation amounts in the X and Y directions from the reference position at the center of the bonding tool 24. It becomes.

  The reference position of the center of the bonding tool 24 is the position of the bonding tool 24 when the die bonder 10 is in the initial state and the temperature is room temperature, and is a preset position. The absolute coordinates in the die bonder 10 are known. Therefore, the absolute coordinates in the die bonder 10 of the bonding tool 24 at the intermediate position can be detected by acquiring the above-described deviation amounts ΔX and ΔY.

  When the image processing unit 40 detects the shift amounts ΔX and ΔY in the X and Y directions with respect to the reference position of the bonding tool 24 at the intermediate position, the image processing unit 40 transmits the data to the control unit 50 through the data bus interfaces 46 and 56 and the communication line 60. To do. The CPU 51 of the control unit 50 executes the position correction program 54, corrects the position of the tip of the bonding tool 24 detected by the moving mechanisms 12 and 13 by the received deviation amounts ΔX and ΔY in the X and Y directions, and performs bonding. The semiconductor die 30 can be bonded to the exact position of the circuit board above the stage 37.

  As described above, the die bonder 10 of the present embodiment uses the brightness difference between the image 81 of the end face 21 of the shank 20 holding the bonding tool 24 and the image 82 of the inclined curved surface 26 of the bonding tool 24. Since the center position of the longitudinal center line 90 of the bonding tool 24 is detected, the end surface 21 and the inclined curved surface 26 are displaced from the back surface of the semiconductor die 30 by more than the focal depth D, and the images 81 and 82 are not sharp. However, it is possible to reliably detect the absolute coordinates in the die bonder 10 of the bonding tool 24 at the intermediate position. Further, the intermediate position of the bonding tool 24 can be accurately detected with a simple configuration in which the end surface 21 of the shank 20 is mirror-finished to be a reflecting surface. Further, since the position of the bonding tool itself can be accurately detected, the semiconductor die 30 is moved from the first bonding to the accurate position of the circuit board 31 on the bonding stage 37 in the restart after the die bonder 10 is temporarily stopped. Can be bonded.

  In the present embodiment, the inclined surface of the bonding tool 24 has been described as the 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, and from the strobe 34. Any shape may be used as long as it does not reflect light in the direction along the longitudinal center line 90. For example, it may be a tapered surface that obliquely connects the suction surface 27 and the root 25. .

  Next, another embodiment of the present invention will be described with reference to FIGS. Parts similar to those of the embodiment described with reference to FIG. 1 to FIG. In the embodiment shown in FIG. 7, a ring 22 that is fitted and fixed to the outer periphery of the root 25 of the bonding tool 24 is attached to the lower side of the shank 20 of the embodiment described with reference to FIGS. 1 to 6. . The lower end surface 23 of the ring 22 is mirror-finished so that light from the strobe 34 can be reflected. In the present embodiment, the ring 22 is a reflector, the end surface 23 is a reflecting surface, and the ring 22 is disposed adjacent to the root 25.

  As shown in FIG. 7B, in this embodiment, the camera 32 has a slightly blurred image 86 of the end surface 23 of the ring-shaped ring 22 with a high brightness (white) and a slightly curved surface of the bonding tool 24 slightly blurred. 26 images 82 of low brightness (black or gray) and sharp and low brightness (black or gray) bonding surfaces 24 of the bonding tool 24 are acquired, and an image 86 of the end surface 23 and an inclined curved surface 26 image are acquired. A circular outline 91 with respect to 82 is extracted, and absolute coordinates in the die bonder 10 of the bonding tool 24 at an intermediate position are detected. The effect of this embodiment is the same as that of the embodiment described above with reference to FIGS.

  In another embodiment shown in FIG. 8A, the base 25 of the bonding tool 24 is stepped, and the lower surface 29 below the stepped portion 28 is mirror-finished so that light from the strobe 34 can be reflected. It is a thing. In the present embodiment, the step portion 28 of the bonding tool 24 is a reflector, the lower surface 29 of the step portion 28 is a reflecting surface, and the lower surface 29 is disposed adjacent to the root 25.

  As shown in FIG. 8B, in the present embodiment, the camera 32 has an image 88 of the lower surface 29 of the ring-shaped step portion 28 having a slightly blurred high brightness (white) and a slightly inclined tilt of the bonding tool 24. A low brightness (black or gray) image 82 of the curved surface 26 and a sharp and low brightness (black or gray) image 83 of the suction surface 27 of the bonding tool 24 are obtained, and an image 88 of the lower surface 29 and the inclined curved surface 26 are acquired. A circular outline 91 with the image 82 is extracted, and the absolute position in the die bonder 10 of the bonding tool 24 at the intermediate position is detected. The effect of this embodiment is the same as that of the embodiment described above with reference to FIGS.

  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 shank, 21, 23 end face, 22 ring, 24 bonding tool, 25 Root, 26 Inclined curved surface, 27 Adsorption surface, 28 Step part, 29 Lower surface, 30 Semiconductor die, 31 Circuit board, 32, 39 Camera, 33 Field of view, 34 Strobe, 35 Reflecting mirror, 36 Pickup stage, 37 Bonding stage, 38 Trajectory, 40 Image processing unit, 41, 51 CPU, 42, 52 Memory, 43 Image acquisition program, 44 Position detection program, 45, 55 Control data, 46, 56 Data bus interface, 47 Camera interface, 48 Strobe interface 49, 59 Data bus, 50 control unit, 53 Position control program, 54 Position correction program, 57 Movement mechanism interface, 60 Communication line, 71-76 arrow, 81-89 image, 90 Longitudinal center line, 91, 91 ' , 92 outline, 93-96 center line, 97,98 center, D focal depth, L1-L3 optical path length, ΔX, ΔY deviation amount.

Claims (6)

A bonding tool,
A light source;
A camera,
A reflector,
Including
The bonding tool includes a suction surface at a tip that sucks a semiconductor die, a base thicker than the suction surface at a tip, an inclined surface that connects the suction surface and the root, and is inclined with respect to a longitudinal center line. With
The light source is disposed on the suction surface side of the bonding tool,
The camera simultaneously acquires 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, does not move relative to the bonding tool, and reflects light from the light source to at least the suction surface side of the bonding tool.
A die bonder characterized by that. The die bonder according to claim 1,
Furthermore, an image processing unit is included,
The image processing unit
Processing the image of the reflector acquired by the camera and the image of the inclined surface of the bonding tool acquired by the camera, and detecting the position of the bonding tool;
Die bonder characterized by. The die bonder according to claim 1 or 2,
The reflector is a shank that grips the bonding tool, a ring attached to the bonding tool, or a step adjacent to the root of the bonding tool, and is perpendicular to the longitudinal center line of the bonding tool. Having a reflective surface,
The reflecting surface is an end surface on the suction surface side of the shank, an end surface on the suction surface side of the ring, or an end surface of the step;
Die bonder characterized by. The die bonder according to claim 2 or 3,
And a control unit,
The controller corrects the position of the bonding tool based on a difference between the position of the bonding tool detected by the image processing unit and a preset reference position;
Die bonder characterized by. A bonding tool position detection method for a die bonder,
An image acquisition process;
A position detection process;
Including
The die bonder includes a suction surface at a tip that sucks a semiconductor die, a root thicker than the suction surface at the tip, and an inclined surface that connects the suction surface and the root and is inclined with respect to a longitudinal center line. The bonding tool, the light source disposed on the suction surface side of the bonding tool, and the bonding tool do not move relatively, and the light from the light source is reflected on the suction surface side of the bonding tool. A reflector, and a camera that simultaneously acquires an image of the reflector and an image of the inclined surface of the bonding tool, the reflector is adjacent to the root of the bonding tool, and the longitudinal direction of the bonding tool Including a reflective surface perpendicular to the centerline,
The image acquisition step simultaneously acquires an image of the reflector and an image of the inclined surface of the bonding tool by the camera,
The position detecting step detects the position of the bonding tool from the image of the reflector acquired by the camera and the image of the inclined surface of the bonding tool acquired by the camera;
A position detection method characterized by the above. A position correction method for a die bonder bonding tool,
An image acquisition process;
A position detection process;
A position correction process;
Including
The die bonder includes a suction surface at a tip that sucks a semiconductor die, a root thicker than the suction surface at the tip, and an inclined surface that connects the suction surface and the root and is inclined with respect to a longitudinal center line. The bonding tool, the light source disposed on the suction surface side of the bonding tool, and the bonding tool do not move relatively, and the light from the light source is reflected on the suction surface side of the bonding tool. A reflector, and a camera that simultaneously acquires an image of the reflector and an image of the inclined surface of the bonding tool, the reflector is adjacent to the root of the bonding tool, and the longitudinal direction of the bonding tool Including a reflective surface perpendicular to the centerline,
The image acquisition step simultaneously acquires an image of the reflector and an image of the inclined surface of the bonding tool by the camera,
The position detection step detects the position of the bonding tool from the image of the reflector acquired by the camera and the image of the inclined surface of the bonding tool acquired by the camera,
The position correction step is to correct the position of the bonding tool based on a difference between the position of the bonding tool detected in the position detection step and a preset reference position;
A position correction method characterized by the above.

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