JP5344145B2 - Method for aligning electronic component and substrate in bonding apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a bonding device for conducting positional alignment by considering not only an amount of displacement between a substrate recognition camera and a chip recognition camera, but also an amount of displacement between the substrate recognition camera and a bonding head for accurate mounting. <P>SOLUTION: A bonding device includes a bonding head 3, a bonding stage 5, a head moving means 9, the chip recognition camera 6, the substrate recognition camera 7, and a camera moving means 9 for moving the substrate recognition camera independently of the bonding head. A head camera 8 moving integrally with the bonding head, a first target mark 10 for positioning in a field of view of the chip recognition camera, and a second target mark 11 provided on the bonding stage are provided. The positional alignment of an electronic component 1 and a substrate 2 is conducted by sandwiching the first target mark to grasp the amount of displacement of both cameras, recognizing the first target mark and the second target mark with the substrate recognition camera and the head camera to grasp the amount of displacement, and further considering these amounts of displacement. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

The present invention relates to an improvement of a method of aligning an electronic component and a substrate in the bonding apparatus, and more particularly, head recognizes a deviation amount of the electronic component recognition camera and the board recognition camera, the position of the board recognition camera and the bonding head The present invention relates to a method for grasping the displacement amount of the recognition camera and aligning the electronic component and the substrate by taking these displacement amounts into consideration.

  Conventionally, a bonding apparatus for aligning and bonding electronic components to a substrate has been provided with an electronic component recognition camera and a substrate recognition camera. The electronic component recognition camera and the board recognition camera may be displaced from the reference position due to changes in temperature conditions and the like. For this reason, the amount of deviation between the electronic component recognition camera and the board recognition camera is grasped, and alignment is performed in consideration of the amount of deviation.

  In addition, as shown in Patent Document 1, in order to improve the productivity of the bonding apparatus, the bonding head and the substrate recognition camera can be moved in the same direction by separate moving means. When the substrate recognition camera and the bonding head are moved by separate moving means, it is expected that the amount of movement between the substrate recognition camera and the bonding head will also shift due to a change in temperature conditions.

  In recent years, bonding devices are required to have high precision in mounting electronic components on a substrate, and therefore, it is necessary to align the electronic component and the substrate in consideration of the amount of displacement between the substrate recognition camera and the bonding head. I came.

Japanese Patent No. 3555488

The present invention not only mounts the electronic component on the substrate by taking into account the displacement amount between the substrate recognition camera and the electronic component recognition camera, but also reduces the displacement amount between the substrate recognition camera and the bonding head. In addition, an object is to provide a method for aligning an electronic component and a substrate in a bonding apparatus that enables high-precision mounting by aligning and mounting the electronic component on the substrate .

In order to solve the above problems, the present invention employs the following means as a method for aligning an electronic component and a substrate in a bonding apparatus.
First, a bonding head for holding an electronic component, a bonding stage for supporting a substrate on which the electronic component is mounted, a head moving means for moving the bonding head with respect to the bonding stage, and a lower part of the bonding head moving path. A first camera for recognizing an electronic component held on the bonding head, a second camera for recognizing a substrate supported on the bonding stage, and a camera moving means for moving the second camera independently of the bonding head And a bonding apparatus provided with
Second, the electronic device is recognized by the first camera, the substrate is recognized by the second camera, and the electronic component and the substrate are aligned and bonded.
Third, a head camera that can move integrally with the bonding head by the head moving means, a first target mark that can be positioned within the field of view of the first camera, and a second target mark provided on the bonding stage And provide.
Fourthly, the first camera and the second camera are opposed to each other with the first target mark interposed therebetween to grasp the amount of deviation between them, and the first target mark and the second target mark are respectively determined by the second camera and the head camera. It is characterized in that the amount of deviation between the two is recognized and the electronic component and the substrate are aligned in consideration of the obtained amount of deviation.

  In the present invention, the first camera and the second camera are opposed to each other with the first target mark interposed therebetween to grasp the amount of deviation between them, and the first target mark and the second target mark are respectively detected by the second camera and the head camera. It recognizes and recognizes the amount of deviation between the two, and performs positioning of the electronic component and the board in consideration of the amount of deviation thus grasped, so that not only the amount of deviation between the first camera and the second camera but also the second By taking into account the amount of deviation between the camera and the head camera, it has become possible to perform highly accurate positioning that also takes into account the amount of deviation between the second camera that recognizes the substrate and the amount of bonding head.

Hereinafter, embodiments of the present invention will be described together with examples according to the drawings.
FIG. 1 is a perspective view showing an outline of a semiconductor chip bonding apparatus which is an embodiment of a bonding apparatus according to the present invention, which is an apparatus for aligning and bonding a semiconductor chip 1 as an electronic component to a substrate 2. .

  The semiconductor chip bonding apparatus according to the embodiment includes a bonding head 3, a semiconductor chip supply unit 4, a bonding stage unit 5 that supports the substrate 2, a bottom camera 6 that recognizes the semiconductor chip 1, and a top that recognizes the substrate 2. The camera 7 includes a head camera 8 that can move integrally with the bonding head 3, a moving device 9 that moves the bonding head 3 and the top camera 7, and a first target mark 10 and a second target mark 11. .

  The bonding head 3 is a member for sucking and holding the semiconductor chip 1 and moving it by the moving device 9 to bond the semiconductor chip 1 to the substrate 2. The bonding head 3 includes a Z-axis drive mechanism 32 that controls the vertical movement, It has a θ-axis drive mechanism (not shown) that controls rotation, and is mounted on a movable table 18 of a moving device 9 that moves in the Y direction (left and right direction in FIG. 1).

  The semiconductor chip supply unit 4 includes a chip tray 12 on which a large number of semiconductor chips 1 are arranged, a supply stage 13 on which the chip tray 12 is placed, and an X that enables the supply stage 13 to move in the X direction (front-rear direction in FIG. 1). A shaft drive table 14 is provided.

  The bonding stage 5 includes a bonding stage 15 that supports the substrate 2, an X-axis drive table 16 that enables the bonding stage 15 to move in the X direction, and a second that is installed outside the mounting portion of the substrate 2 on the bonding stage 15. A target mark 11 is provided. Therefore, the second target mark 11 moves only in the X direction integrally with the bonding stage 15.

  The moving device 9 for the bonding head 3 and the top camera 7 is provided with a movable table 18 on which the bonding head 3 is mounted and a movable table 19 on which the top camera 7 is mounted on one magnet track 17. The movable tables 18 and 19 are linear sliders that can be independently driven in the Y direction (direction orthogonal to the X direction, left and right in FIG. 1). The moving device 9 serves as a head moving means and a camera moving means in the present invention. In the embodiment, one moving device 9 is used as the head moving device and the camera moving device in this way, but two independent moving devices may be provided.

  The bottom camera 6 is a camera that recognizes the semiconductor chip 1 attracted and held by the bonding head 3, and is installed below the moving path of the bonding head 3 between the semiconductor chip supply unit 4 and the bonding stage 15. The bottom camera 6 is a camera corresponding to the first camera for recognizing an electronic component in the present invention.

  The top camera 7 is a camera that recognizes the substrate 2 supported on the bonding stage 15, and can move to the moving device 9 in the same direction as the moving direction of the bonding head 3, and moves independently of the bonding head. It is so fitted. The top camera 7 is a camera corresponding to the second camera for recognizing the substrate in the present invention.

  The head camera 8 is a camera for grasping the amount of deviation from the top camera 7, and substantially grasps the amount of deviation between the bonding head 3 and the top camera 7. The head camera 8 is fixed to the body 33 of the bonding head 3 so as to be movable integrally with the bonding head 3.

  The first target mark 10 is provided with a specific mark at the same position on both the front and back surfaces, and the bottom camera 6 and the top camera 7 and the bottom camera 6 and the head camera 8 sandwich the first target mark 10 by the approach mechanism 20. Is configured to be able to enter and retreat in the X direction so that can be positioned on the same axis. As the specific mark, a cross shape, which is the most common reference position designation mark, is used in the embodiment. The intersection of the cross shape is the mark center 31 of the first target mark 10.

  The second target mark 11 uses a cross shape having the same mark center 34 as the first target mark 10, but is provided only on the surface and fixed to the bonding stage 15. Different from the target mark 10. Therefore, the second target mark 11 can move in the X direction integrally with the bonding stage 15.

In the following, the basics of the bonding operation in the embodiment will be described.
First, the bonding head 3 is moved above the semiconductor chip supply unit 4 by the moving device 9. The bonding head 3 is positioned above a predetermined semiconductor chip 1 by the movement of the bonding head 3 in the Y direction by the moving device 9 and the movement of the semiconductor chip supply unit 4 in the X direction by the X-axis drive table 14. The bonding head 3 is lowered by the operation of the Z-axis drive mechanism 32, and holds a predetermined semiconductor chip 1 by suction.

  Thereafter, the bonding head 3 is raised by the Z-axis drive mechanism 32 and moved to a preset position above the bottom camera 6 by the moving device 9 as shown in FIGS. 1 and 2A. At this position, the bottom camera 6 recognizes the semiconductor chip 1 attracted to the bonding head 3, and as shown in FIG. 3A, how much the semiconductor chip center 26 is displaced with respect to the bottom camera visual field center 23. Is grasped (XY position, θ angle). 3A is the field of view of the bottom camera, the position of the semiconductor chip 1 in the field of view 22 of the bottom camera in FIG. 3A is positioned in the field of view 24 of the top camera described later. For comparison with the position of the mark 21, the position is converted into the position of the semiconductor chip 1 recognized from above.

  Next, the moving device 9 and the X-axis drive table 16 are operated, and the top camera 7 and the bonding stage 15 are moved. As shown in FIGS. 1 and 2B, the top camera 7 is positioned above the bonding position. To do. The top camera 7 recognizes the positioning mark 21 on the substrate 2, and how much the positioning mark center 29 is displaced with respect to the top camera visual field center 25 as shown in FIG. 3B (XY position, θ angle). ). In FIG. 3B, reference numeral 24 denotes the top camera view.

  The position above the bottom camera 6 where the bonding head 3 is located and each bonding position on the substrate 2 are set in advance, and the bonding head 3 holds the semiconductor chip 1 and is positioned above the bottom camera 6. , Moved in the Y direction, and located above the bonding position as shown in FIG. The amount of movement at that time is also set in advance.

  The amount of deviation in the Y direction grasped by the bottom camera 6 and the amount of deviation in the Y direction of the positioning mark 21 of the substrate 2 grasped by the top camera 7 are adjusted with respect to the preset movement amount of the bonding head 3. Then, the bonding head 3 is actually moved. Further, the movement amount of the bonding stage 15 is also set in advance, and the amount of deviation in the X direction grasped by the bottom camera 6 and the amount of deviation in the X direction of the positioning mark 21 of the substrate 2 grasped by the top camera 7 are adjusted. The bonding stage 15 is moved in the X direction. This movement amount correction is performed as shown in FIG.

  Thereby, the positioning mark center 29 on the substrate 2 and the semiconductor chip center 26 are aligned. The inclination of the semiconductor chip 1 and the substrate 2 is corrected according to the angle of deviation by rotating the bonding head 3 by θ angle.

  This correction operation will be specifically described with reference to FIG. In recognition of the bottom camera 6, as shown in FIG. 3A, the semiconductor chip center 26 (Cx, Cy) is 1 in the X direction and 1 in the Y direction counterclockwise with respect to the bottom camera visual field center 23. It is shifted by 10 °. On the other hand, in the recognition of the top camera 7, the positioning mark center 29 (Mx, My) is deviated by −1 in the X direction and 2 ° in the Y direction by 5 ° with respect to the top camera visual field center 25.

  In such a state, the movement amount when the Y coordinate (Cy) of the semiconductor chip center 26 is brought close to the Y coordinate (My) of the positioning mark center 29 is My-Cy. Move in the direction. Since the traveling direction of the bonding head 3 is a minus direction in terms of coordinates, the correction value is obtained as-(My-Cy).

  On the other hand, the movement amount when the X coordinate (Mx) of the positioning mark center 29 is brought close to the X coordinate (Cx) of the semiconductor chip center 26 is Cx−Mx, and the bonding stage 15 is moved in the X direction by this value. .

  3A and 3B, − (My−Cy) = − (2-1) = − 1 and Cx−Mx = 1 − (− 1) = 2, and the bonding head 3 is set in advance. Then, the bonding stage 15 is moved by 2 in the plus direction from a preset position. Further, the inclination of the semiconductor chip 1 and the substrate 2 is dealt with by rotating the bonding head 3 clockwise by 15 °.

  After the positioning of the semiconductor chip 1 and the substrate 2 in this way, the bonding head 3 is lowered and the semiconductor chip 1 is bonded to the substrate 2. However, if there is a mechanical shift between the bottom camera 6 and the top camera 7, the center positions of the bottom camera 6 and the bonding head 3 do not match, and the semiconductor chip 1 is recognized as an incorrect position. The positional relationship of the positioning marks 21 on the substrate 2 is also incorrect.

  In order to correct the mechanical misalignment between the bottom camera 6 and the top camera 7 as described above, a set position corresponding to the visual field center 25 of the top camera 7 corresponds to the visual field center 23 of the bottom camera 6 as shown in FIG. , The first target mark 10 is positioned between them, the amount of deviation between them is grasped, and the center of the top camera 7 (top camera field center 25) is set to the center of the bottom camera 6 (bottom camera field center 23). ) To obtain the correction amount for positioning to.

  As shown in FIG. 5, the top camera field center 25 (Tx, Ty) has a deviation amount of Tx = 1, Ty = −1 with respect to the mark center 31 of the first target mark 10, and the bottom camera field center 23 Assume that (Bx, By) is a deviation amount of Bx = 0 and By = 0 (there is no deviation between the mark center 31 of the first target mark 10 and the visual field center 23 of the bottom camera 6).

  When there is a deviation amount between the top camera 7 and the bottom camera 6 as described above, when the bottom camera 6 recognizes the semiconductor chip center 26 and the bonding head center 27 as shown in FIG. In relation to the positioning mark center 29, the semiconductor chip 1 is recognized as having the semiconductor chip 1 in the dotted line portion 28 although it exists in the solid line hatched portion in FIG. 6B.

  Therefore, in order to position the visual field center 25 of the top camera 7 at the visual field center 23 of the bottom camera 6, correction values are obtained by Bx-Tx and By-Ty in FIG. This can be done by correcting the position of 1.

  However, when the bonding head 3 and the top camera 7 are driven separately and there is a variation in the amount of movement of each, the correction cannot be solved only by correction by calibration of the top camera 7 and the bottom camera 6. In particular, when a linear slider is used for driving as in the embodiment, the accuracy error due to heat generation increases, and the amount of positional deviation between the top camera 7 and the bonding head center 27 may change due to movement.

  As shown in FIG. 7A, when the top camera 7 and the bonding head 3 are respectively aligned with the visual field center 23 of the bottom camera 6, a deviation occurs between the visual field center 25 of the top camera 7 and the center 27 of the bonding head 3. There is a case. The shift is not reproduced on the bonding stage 15 at the movement destination due to the independent movement by the movable tables 18 and 19 in the moving device 9, and the shift amount changes. Therefore, the bottom camera 6 shown in FIG. Even if the correction is made in consideration of the amount of deviation at the upper position of the semiconductor chip 1, as shown in FIG. 7 (B), the semiconductor chip 1 has the relationship with the positioning mark center 29 recognized by the top camera 7 as shown in FIG. ), It is recognized that the semiconductor chip 1 exists in the dotted line portion 30.

  Therefore, the head camera 8 and the top camera 7 provided integrally with the bonding head 3 recognize the first target mark 10 and the second target mark 11, grasp the amount of change caused by the movement, and use this as the bottom camera. 6 and the correction value by the calibration of the top camera 7 are added.

  Specifically, as shown in FIG. 8A, the first target mark 10 is observed with the top camera 7, and the shift amount between the visual field center 25 of the top camera 7 and the mark center 31 of the first target mark 10. Recognize Next, as shown in FIG. 8B, the top camera 7 moves above the bonding stage 15 and observes the second target mark 11, and the center of the top camera 7 and the mark center 34 of the second target mark 11. And the change values (Xt, Yt) in the X and Y directions are recognized.

  On the other hand, as shown in FIG. 8B, the head camera 8 also observes the first target mark 10 and determines the amount of deviation between the center of the head camera 8 and the mark center 31 of the first target mark 10. The amount of deviation between the bonding head center 27 and the mark center 31 of the first target mark 10 is recognized. Next, as shown in FIG. 8C, the head camera 8 moves above the bonding stage 15 and observes the second target mark 11, and the center of the head camera 8 and the mark center 34 of the second target mark 11. The amount of deviation between the bonding head center 27 and the mark center 34 of the second target mark 11 is recognized via the amount of deviation from the head, and the X direction of the bonding head center 27 of the bonding head 3 that moves together with the head camera 8 is recognized. And the change value (Xh, Yh) in the Y direction is grasped.

  As a result, the amount of deviation (X, Y) between the top camera 7 and the bonding head 3 is grasped by calculating X = Xt−Xh, Y = Yt−Yh, and added to the correction value. Thereby, the calibration of the bottom camera 6 and the top camera 7 and the calibration of the top camera 7 and the bonding head 3 are performed. In this way, the semiconductor chip 1 and the substrate 2 are accurately positioned and bonded.

Schematic perspective view showing the entire semiconductor chip bonding apparatus according to the present embodiment It is explanatory drawing which shows the alignment procedure of a board | substrate and a semiconductor chip, (A) shows semiconductor chip recognition, (B) shows board recognition, (C) shows a bonding state. 4A and 4B are explanatory diagrams showing correction of a shift amount between a substrate and a semiconductor chip, where FIG. 5A shows recognition of the shift amount of the semiconductor chip, FIG. 5B shows recognition of the shift amount of the positioning mark on the substrate, and FIG. The correction of the shift amount of the substrate is shown. Explanatory perspective view showing displacement amount recognition position between bottom camera and top camera Explanatory drawing showing the amount of deviation between the bottom camera and top camera It is explanatory drawing which shows the recognition error by the deviation | shift amount of a bottom camera and a top camera, (A) shows recognition of a semiconductor chip, (B) shows the difference of the recognition position and actual position of a semiconductor chip. It is explanatory drawing which shows the recognition error by the deviation | shift amount of a top camera and a bonding head, (A) shows the deviation | shift amount of both, (B) shows the difference of the recognition position and actual position of a semiconductor chip. It is explanatory explanatory drawing which shows the measurement procedure of the deviation | shift amount of a top camera and a bonding head, (A) shows the time of the 1st target mark recognition with a top camera, (B) shows the 2nd target mark recognition with a top camera, and The first target mark recognition by the head camera is shown, and (C) shows the second target mark recognition by the head camera. Explanatory drawing of measurement of displacement between top camera and bonding head

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Semiconductor chip 2 ... Board | substrate 3 ... Bonding head 4 ... Semiconductor chip supply part 5 ... Bonding stage part 6 ... Bottom camera 7 ... Top camera 8 ... Head camera DESCRIPTION OF SYMBOLS 9 ... Moving apparatus 10 ... 1st target mark 11 ... 2nd target mark 12 ... Chip tray 13 ... Supply stage 14, 16 ... X-axis drive table 15 ... Bonding stage 17 ... Magnet track 18, 19 ... Movable table 20 ... Approach mechanism 21 ... Positioning mark 22 ... Bottom camera field of view 23 ... Bottom camera field of view 24 ... Top camera field of view 25 ..Top camera visual field center 26... Semiconductor chip center 27... Bonding head center 28, 30. ... positioning mark center 31, 34 ... mark center 32 ... Z-axis drive mechanism 33 ... Body

Claims (1)

A bonding head for holding an electronic component, a bonding stage for supporting a substrate on which the electronic component is to be mounted, a head moving means for moving the bonding head relative to the bonding stage, and a bonding head installed below the bonding head moving path. A first camera for recognizing a held electronic component; a second camera for recognizing a substrate supported on a bonding stage; and a camera moving means for moving the second camera independently of a bonding head;
In a method of aligning an electronic component and a substrate in a bonding apparatus in which an electronic component is recognized by a first camera, a substrate is recognized by a second camera, and the electronic component and the substrate are aligned and bonded.
A head camera that can move integrally with the bonding head by the head moving means, a first target mark that can be positioned within the field of view of the first camera, and a second target mark provided on the bonding stage;
With the first target mark sandwiched between the first camera and the second camera,
In addition to grasping the amount of deviation between the two, the first target mark and the second target mark are recognized by the second camera and the head camera, respectively, and the amount of deviation between them is grasped. A method of aligning an electronic component and a substrate in a bonding apparatus, wherein the alignment of the substrate and the substrate is performed.

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