Die Bonding Apparatus and Method of Manufacturing Semiconductor Device

Abstract

To provide a technique for improving mounting accuracy.SOLUTION: A die bonding device includes a control device and a rotating mechanism that rotates a rotating shaft supporting a holding unit for holding a die. The rotating mechanism includes a drive unit, a first gear attached to the drive unit, a second gear attached to the rotating shaft, and a transmission mechanism that transmits rotation of the first gear to the second gear. The control device rotates the holding unit to a predetermined rotation angle by the rotating mechanism, captures an image of the surface of the holding unit in contact with the die with an imaging device for each rotation angle, calculates the amount of rotation of the holding unit on the basis of the captured image, calculates the amount of deviation between a rotation amount command value and the rotation amount for each rotation angle, sets the amount of deviation as mapping data, and calculates the mapping data for the number of rotations that is the common multiple of the number of teeth of the first gear, the second gear, and the transmission mechanism.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a die bonding apparatus, and is applicable to, for example, a die bonding apparatus that rotates a die in a horizontal plane.

Background Art

[0002] In the process of assembling semiconductor chips, there is an assembly process such as dividing a wafer on which a plurality of semiconductor chips are formed in a batch in a wafer process into individual semiconductor chips (hereinafter referred to as dies), and individually bonding and encapsulating them to a wiring board or a lead frame or the like (hereinafter referred to as a substrate).

[0003] There are several methods for die bonding technology for bonding individual dies to a substrate. As one method, individual dies are picked up from an adhesive tape (hereinafter referred to as a dicing tape) on which dies are arranged in a state where the wafer is divided by a collet of a pick-up head and placed on an intermediate stage, positioned at the intermediate stage, and then picked up by a collet of a bonding head and placed on the substrate. Further, as another method, there is a direct pick-up method in which individual dies picked up from the dicing tape by a collet of a bonding head are directly placed on the substrate.

[0004] Also, for example, when there is a rotational deviation in the die picked up from the wafer or the intermediate stage, or when there is a rotational deviation in the substrate, the bonding head may rotate the collet according to its inclination before picking up and then pick up.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] In a rotation mechanism for rotating a collet or the like, for example, when the driving unit motor and the rotating shaft transmit power by gears or belts, it is basically not necessary to make their number of teeth the same. When using gears or belts with different numbers of teeth, even if the driven-side rotating shaft makes one full rotation, as long as the tooth positional relationship does not become the same, there will be a deviation in its coordinates.

[0007] An object of the present disclosure is to provide a technique for correcting the deviation between a command value and an actual rotation amount in a rotation mechanism.

Means for Solving the Problems

[0008] The outline of typical ones among the present disclosure is briefly described as follows. That is, the die bonding apparatus includes a rotation mechanism for rotating a rotating shaft that supports a holding portion for holding a die, and a control device. The rotation mechanism includes a driving unit, a first gear attached to the driving unit, a second gear attached to the rotating shaft, and a transmission mechanism for transmitting the rotation of the first gear to the second gear. The control device rotates the holding portion to a predetermined rotation angle by the rotation mechanism, images the surface in contact with the die of the holding portion by an imaging device for each rotation angle, calculates the rotation amount of the holding portion based on the captured image, and calculates the deviation amount between the rotation amount command value and the rotation amount for each rotation angle as mapping data, and is configured to perform the calculation of the mapping data for a number of rotations that is the least common multiple of the number of teeth of the first gear, the second gear, and the transmission mechanism.

Effects of the Invention

[0009] According to the present disclosure, the mounting accuracy can be improved.

Brief Description of the Drawings

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0011] The present disclosure relates to a technique for correcting a deviation between a command value and an actual rotation amount of a rotation amount when an attachment head that picks up a die and places it on a substrate, a stage, or the like, and the attachment head has a θ rotation mechanism, or when a stage on which the die is placed has a θ rotation mechanism, in a die bonding apparatus such as a die bonder. For example, correction data for θ rotation of the attachment head or the stage is created in advance using an imaging device. As a result, a θ rotation deviation caused by the rotation mechanism during mounting is automatically corrected. As a result, the productivity is not reduced and the mounting accuracy is improved.

[0012] Hereinafter, examples and modified examples will be described with reference to the drawings. However, in the following description, the same reference numerals may be assigned to the same components, and repeated descriptions may be omitted. Note that, for the purpose of making the description clearer, the drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the actual embodiment, but this is merely an example and does not limit the interpretation of the present disclosure.

Example

[0013] First, the basic configuration of the die bonder in the example will be described with reference to FIG. 1. FIG. 1 is a conceptual diagram of the die bonder in the example as viewed from above.

[0014] The die bonder 100 generally includes a wafer supply unit 11, a work supply and transfer unit 12, a die bonding unit 13, and a control device 14. The Y-axis direction is the front-rear direction of the die bonder 100, and the X-axis direction is the left-right direction. The wafer supply unit 11 is arranged on the front side of the die bonder 100, and the die bonding unit 13 is arranged on the back side.

[0015] The wafer supply unit 11 includes a wafer cassette lifter 111 and a pickup device 112. A wafer ring 211 (see FIG. 2) described later is carried into the wafer supply unit 11 from outside the die bonder 100. Further, the work supply and transfer unit 12 includes a stack loader 121, a frame feeder 122, and an unloader 123. A substrate S (see FIG. 2) described later is carried into the work supply and transfer unit 12 from outside the die bonder 100. The die bonding unit 13 includes a preform unit 131 and a bonding head unit 132.

[0016] In FIG. 1, the wafer cassette lifter 111 has a wafer cassette (not shown) filled with a wafer ring 211 (see FIG. 2), and sequentially supplies the wafer ring 211 to the pickup device 112. The pickup device 112 includes a wafer holding table 112a that holds the wafer ring 211 and a pushing-up unit 112b that pushes up the die from the wafer W held by the wafer ring 211. The wafer holding table 112a moves the wafer ring 211 by a drive unit (not shown) so that the die D (see FIG. 4) to be picked up can be picked up from the dicing tape 212 held by the wafer ring 211 by the collet 402 (see FIG. 4).

[0017] The stack loader 121 supplies the substrate S (see FIG. 2) to which the die D is to be adhered to the frame feeder 122. The frame feeder 122 conveys the substrate S to the unloader 123 via two processing positions on the frame feeder 122. Here, as shown in FIG. 2 to be described later, the two processing positions are the processing position 232 of the preform unit 131 and the processing position 233 of the bonding head unit 132. The unloader 123 stores the conveyed substrate S. The substrate S is carried out of the die bonder 100 from the unloader 123.

[0018] The preform unit 131 is provided with a die adhesive application device, and applies a die adhesive to the substrate S conveyed by the frame feeder 122. The bonding head unit 132 picks up the die D to be picked up from the pickup device 112 and rises, and moves the die D to the point P2 (see FIG. 4) on the frame feeder 122. Then, the bonding head unit 132 lowers the die D at the moved point P2, and mounts the die D on the point P2 on the substrate S to which the die adhesive has been applied. When a film-like adhesive is pre-attached to the back surface (adhesive surface) of the die, the preform unit 131 is not provided with a die adhesive application device, and the die adhesive is not applied to the substrate S.

[0019] Furthermore, the basic functions of the camera used in the die bonder 100 will be described with reference to FIG. 2. FIG. 2 is a schematic diagram for explaining the functions of the camera in the die bonder shown in FIG. 1. FIG. 2(a) is a view seen from arrow A in FIG. 1, and FIG. 2(b) is a top view. In FIG. 2, the camera in the die bonder 100 and its captured image are described. For this reason, illustration and description of functional parts (other components, connections) not related to the description are omitted.

[0020] The wafer recognition camera 201 images the pattern surface (front surface) of the wafer W mounted on the wafer ring 211 mounted on the pickup device 112 from above the pickup device 112. Then, the control device 14 calculates the center position of one die D by well-known image processing such as pattern recognition, calculates the deviation between the center position of the die D, the center of the collet 402, and the center position of the pick-up unit 112b, and corrects the position of the die D so as to eliminate the deviation.

[0021] Similarly, the preform camera 202 images a predetermined die bonding position (bonding point) of the substrate S conveyed to the processing position 232 in the preform section 131. Then, the control device 14 corrects the positional deviation of the syringe that injects the resin paste so that the resin paste is applied to the die bonding position by well-known image processing such as pattern recognition, and applies the resin paste.

[0022] Also, similarly, the substrate recognition camera 203 images a predetermined die bonding position of the substrate S conveyed to the processing position 233 in the bonding head section 132. Then, the control device 14 corrects the positional deviation of the collet 402 and the like so that the die D is mounted at the center position of the die bonding position by well-known image processing such as pattern recognition, and mounts the die D.

[0023] The next substrate S is carried in from the stack loader 121 while maintaining the interval of the pitch 251 between the processing position 232 of the preform section 131 and the processing position 233 of the bonding head section 132, and is conveyed to the unloader 123.

[0024] The wafer recognition camera 201, the preform camera 202, and the substrate recognition camera 203 are imaging devices using, for example, a CCD image sensor or a CMOS image sensor.

[0025] Next, the alignment mechanism and position deviation correction will be described with reference to FIG. 3. FIG. 3 is a diagram for explaining the control system of the alignment mechanism in the embodiment.

[0026] The alignment mechanism includes an image processing device 301, a position control device 302, an X-axis drive unit 303, a Y-axis drive unit 304, a θ-axis drive unit 305, an X-axis motor 306, a Y-axis motor 307, and a θ-axis motor 308. Here, the image processing device 301 and the position control device 302 constitute a part of the control device 14.

[0027] The wafer recognition camera 201 images the pattern surface (front surface) of the wafer W and outputs the captured image data to the image processing device 301.

[0028] The image processing device 301 analyzes the input image data by well-known image processing such as pattern recognition, and extracts the deviations in the X coordinate, Y coordinate, and θ coordinate by the alignment marks at predetermined positions on the wafer W and the die D. Then, the image processing device 301 calculates a position correction amount so that the center of the die D to be picked up comes to the center position of the pickup, and outputs the calculated position correction amount to the position control device 302.

[0029] The position control device 302 outputs a control signal to the X-axis drive unit 303 and the Y-axis drive unit 304 of the pickup device 112 based on the input position correction amount. The X-axis drive unit 303 and the Y-axis drive unit 304 control the X-axis motor 306 and the Y-axis motor 307 respectively based on the input control signal, and move the XY table 213 to correct the X coordinate and the Y coordinate.

[0030] The position control device 302 outputs a control signal to the θ-axis drive unit 305 of the bonding head unit 132 based on the input position correction amount. The θ-axis drive unit 305 controls the θ-axis motor 308 based on the input control signal, rotates the collet 402, and corrects the θ (rotation) coordinates.

[0031] The substrate recognition camera 203 images the upper surface (front surface) of the substrate S and outputs the captured image data to the image processing device 301.

[0032] The image processing device 301 analyzes the input image data by well-known image processing such as pattern recognition, and extracts the deviations of the X coordinate, Y coordinate, and θ coordinate by the alignment marks at predetermined positions on the substrate S. Then, the image processing device 301 calculates a position correction amount so that the center of the die D to be picked up comes to the center position of the mounting position of the substrate S, and outputs the calculated position correction amount to the position control device 302.

[0033] The position control device 302 outputs control signals to the X-axis drive unit 303 and the Y-axis drive unit 304 of the bonding head unit 132 based on the input position correction amount. The X-axis drive unit 303 and the Y-axis drive unit 304 control the X-axis motor 306 and the Y-axis motor 307 respectively based on the input control signals, and move the bonding head to correct the X coordinate and the Y coordinate.

[0034] In the above-described embodiment, the position correction for the pickup device 112 and the bonding head unit 132 has been described. Hereinafter, the same applies to the preform unit 131. Also, the image processing device 301 and the position control device 302 are a set, and control all of the pickup device 112, the preform unit 131, and the bonding head unit 132.

[0035] The detailed configuration and operation of the die bonder shown in FIG. 1 will be described with reference to FIGS. 4 and 5. FIG. 4 is a schematic diagram for explaining the operation of the die bonder shown in FIG. 1. FIG. 5 is a side view for explaining the rotation mechanism of the bonding head shown in FIG. 4.

[0036] As shown in FIG. 4, the wafer W attached to the dicing tape 212 has a plurality of diced dies D. The collet 402 provided on the bonding head 420 sucks and picks up the die D in the wafer W and places it on the substrate S. The wafer recognition camera 201 images the die D. The substrate recognition camera 203 images the substrate S. The under vision camera 204 as an imaging device images the back surface of the collet 402 or the back surface of the die (not shown) being picked up by the collet 402. The bonding head 420 has a rotation mechanism 408, which corrects the deviation in the rotation direction of the picked-up die D. The rotation mechanism 408 is composed of, for example, a θ-axis motor 308 as a drive unit and a pulley-belt unit 411 for transmitting the rotational driving force of the θ-axis motor 308 to the shaft 403 on which the collet 402 is mounted.

[0037] As shown in FIG. 5, the pulley-belt unit 411 is composed of a gear 411a attached to the rotation shaft of the θ-axis motor 308, a gear 411b attached to the shaft 403, a timing belt 411c as a transmission mechanism for transmitting the rotation of the gear 411a to the gear 411b, and the like. The rotation center 409 of the gear 411b is located at the center 410 (point P1) of the shaft 403 as the rotation axis.

[0038] The rotation mechanism 408 of the bonding head 420 transmits the power of the θ-axis motor 308 to the rotation shaft 403 as a driven part by the gears 411a, 411b and the timing belt 411c, and improves the rotation resolution by changing the number of teeth of the gears 411a, 411b. The θ-axis motor 308 is mainly driven by a servo motor or a pulse motor equipped with an encoder. The method of mounting the encoder only on the driven part side is not usually used because the driving part side may not be able to stop in case of a failure. Also, as a whole, the bonding head 420 requires an up-down mechanism, a vacuum suction mechanism, a rotation mechanism, and a load mechanism. To miniaturize it, the encoder is mounted only on the driving part side to reduce the number of parts. Therefore, the control device 14 recognizes only the absolute position of the gear 411a on the driving part side.

[0039] The problem of the accuracy of the mechanical mechanism of the rotation mechanism 408 will be described with reference to FIGS. 6 and 7. FIG. 6 is a diagram for explaining the problem of the accuracy of the mechanical mechanism of the rotation mechanism shown in FIG. 5. FIG. 6(a) is a diagram showing the positions of the teeth of the driving-side gear, the driven-side gear, and the belt. FIG. 6(b) is a diagram showing the positions of the teeth of the driving-side gear and the belt when the driven-side gear rotates one revolution from the state shown in FIG. 6(a). FIG. 7 is a diagram showing the relationship between the command value and the actual rotation amount.

[0040] As shown in FIG. 6, even if the gear 411b on the driven part side is rotated one revolution in design, the positions of the teeth of the belt 411c and the gear 411a on the driving part side are different. Here, the arrows a, b, and c indicate the positions of specific teeth of the gear 411a, the gear 411b, and the timing belt 411c, respectively. Since the gear 411b is rotated one revolution, the arrow b faces almost the same direction in FIGS. 6(a) and 6(b), and the positions of the specific teeth are almost the same. The arrow a of the gear 411a faces almost the opposite direction in FIGS. 6(a) and 6(b), and the specific tooth is located almost on the opposite side during rotation. The arrow c of the timing belt 411c is located at completely different positions in FIGS. 6(a) and 6(b).

[0041] If there are inherent tooth variations in the gears 411a, 411b, and the timing belt 411c, or if there is a slight misalignment of the rotation mechanism 408 such as the gears 411a and 411b, a slight deviation will occur in the θ angle of the gear 411b on the driven part side. Therefore, even if the rotation amount of the gear 411b on the driven part side rotates one revolution and the specified angle (command value) of the gear 411b on the driven part side is made the same, it will not be the same angle as before one revolution. For example, a deviation will occur between the specified angles of 90 degrees and 360 + 90 degrees. That is, due to the problem of the accuracy of the mechanical mechanism of the rotation mechanism 408, even if it is desired to rotate the die D at a specified angle, an overshoot or undershoot will occur. Therefore, as shown in FIG. 7, the measured value fluctuates with respect to the ideal value, and there is a displacement waveform at the cycle of the timing when the meshing of the gears 411a, 411b, and the timing belt 411c becomes the same. In FIG. 7, the driving-side gear 411a rotates 5 revolutions, the driven-side gear 411b rotates 3 revolutions, and the timing belt 411c rotates 2 revolutions to achieve the same meshing.

[0042] In this embodiment, during the imitation operation, for the rotation mechanism 408 of the bonding head 420, the displacement (deviation amount) of the rotation amount is measured and mapped, and during continuous operation, the excess or deficiency of the rotation amount is corrected. Not only the mapping for one rotation of the collet 402 of the bonding head 420, but also the mapping for at least one cycle of the combination of the gear and the timing belt is performed as a mechanism factor.

[0043] As the imitation operation, it is rotated by the number of rotations that is the least common multiple of the number of teeth of the gear 411a on the drive side, the gear 411b on the driven side, and the timing belt 411c. The displacement amount between the specified angle and the actual rotation amount of the gear 411b is measured for each predetermined angle, and the measurement result is held as mapping data. That is, the deviation amount of the rotation amount is measured in advance for all the mutual positional relationships of the respective components constituting the rotation mechanism 408, and the measurement result is stored and recorded in the storage device of the control device 14. Here, as the mapping data, not only the data in one rotation direction but also the data in the reverse direction is acquired. The least common multiple of the number of teeth of the gear 411a on the drive side, the gear 411b on the driven side, and the timing belt 411c is, for example, the least common multiple. Thereby, the number of measurements can be reduced and the amount of mapping data can be reduced. The calculation of the mapping data may be performed for the number of rotations that are a plurality of least common multiples and averaged for each of the above-mentioned predetermined angles. Thereby, the accuracy can be improved.

[0044] During continuous operation, based on the measured displacement amount and the positional relationship (absolute position) of each tooth of the gears 411a, 411b and the timing belt 411c, the amount of deviation after rotation to the specified position (specified angle) is predicted, and the correction amount is determined based on the mapping data obtained by the tracking operation to correct the commanded rotation amount. That is, during continuous operation, the offset obtained for each commanded angle is fed back and rotated. The feedback, for example, increases or decreases the command value so that the graph of the command value - actual rotation amount becomes linear as shown in FIG. 7. In other words, the correction amount is determined based on the mapping data of the deviation amount of the rotation amount and the absolute positions of the respective components constituting the rotation mechanism 408, and the deviation amount is fed back. Then, in view of the deviation amount predicted from the arrival position before the command value of the rotation amount is input, the correction amount of the arrival position is calculated in advance, and the correction amount is determined and corrected in advance.

[0045] Note that if the rotation mechanism 408 is manually rotated when the power is turned off, the absolute position will be lost. Therefore, when the power is turned off, it is made impossible to rotate by the brake, or remeasurement is always automatically performed at startup.

[0046] An example of a method for measuring the displacement of the rotation amount during the tracking operation will be described with reference to FIG. 8. FIG. 8 is a diagram showing markers provided on the collet.

[0047] The image processing device 301 images the bottom surface (the surface that adsorbs the die D) of the collet 402 from below the collet 402 by the under vision camera 204. Markers 402a and 402b are provided at two locations on the bottom surface of the collet 402. The two markers 402a and 402b are, for example, circular. Here, the collet 402 has a rectangular shape that matches the die shape and size.

[0048] The image processing apparatus 301 outputs a rotation amount command value to the rotation mechanism 408 via the position control apparatus 302, and the rotation mechanism 408 rotates the collet 402 according to the rotation amount command value. The image processing apparatus 301 rotates the collet 402 at predetermined angles such as the minimum resolution unit of the rotation mechanism 408 via the position control apparatus 302. The image processing apparatus 301 images two markers 402a and 402b at predetermined angles by the under vision camera 204.

[0049] The image processing apparatus 301 performs image processing such as binarization on the captured image of the die D to calculate and obtain the centroid positions of the two markers 402a and 402b respectively. The image processing apparatus 301 calculates (measures) the actual rotation amount (actual rotation amount) of the collet 402 based on the centroid positions of the two markers 402a and 402b, that is, based on the angle (θ) formed by the straight line passing through the two centroid positions and the reference straight line. The image processing apparatus 301 stores (records) the deviation amount (displacement amount) between the rotation amount command value (command angle) and the actual rotation amount (measurement result) as mapping data in the storage device of the image processing apparatus 301 or the position control apparatus 302.

[0050] The recording of the mapping data is performed for the number of rotations equal to the least common multiple of the number of teeth of the gear 411a on the driving side, the gear 411b on the driven side, and the timing belt 411c. For example, if the number of teeth of the gear 411a on the driving side, the gear 411b on the driven side, and the timing belt 411c are 6, 18, and 66 respectively, the least common multiple is 198. Therefore, the gear 411a on the driving side, the gear 411b on the driven side, and the timing belt 411c rotate 33 times, 11 times, and 3 times respectively. Thus, since the tooth positional relationship becomes the same every 11 rotations of the gear 411b on the driven side, the number of rotations of the gear 411b on the driven side for 11 rotations is recorded.

[0051] Next, during continuous operation, that is, the procedure in which the bonding head 420, which is a part of the semiconductor device manufacturing process, picks up the die D from the wafer W and mounts it on the substrate S will be briefly described with reference to FIG. 4.

[0052] The wafer recognition camera 201 images the surface of the die D to be picked up on the wafer W and outputs the captured image to the image processing device 301. The image processing device 301 calculates the center position (Xd, Yd, θd) of the die D by processing the image of the captured die D.

[0053] The substrate recognition camera 203 images a predetermined die bonding position on the substrate S and outputs the captured image to the image processing device 301. The image processing device 301 calculates the center position (Xm, Ym, θm) of the mounting position of the substrate S by processing the image of the captured substrate S.

[0054] Furthermore, the position control device 302 aligns the rotation center (Xp, Yp, θp) of the collet 402 with the center position of the die D calculated by the image processing device 301. Here, the rotation center (Xp, Yp, θp) is the centroid position O. At this time, based on the deviation in the rotation direction of the die D, the deviation in the rotation direction of the substrate S, and the mapping data of the θ rotation, the image processing device 301 calculates the θ correction amount. The position control device 302 performs θ correction on the collet 402 based on the θ correction amount to pick up the die D to be picked up from the wafer W.

[0055] In this way, the collet 402 of the bonding head 420 moves to a position on the wafer W (point P0) based on the images captured by the wafer recognition camera 201 and the substrate recognition camera 203 and picks up the die D. After picking up, the collet 402 of the bonding head 420 moves to point P2.

[0056] At point P2, the die D picked up from the wafer W is mounted on the substrate S by aligning the rotation center (Xp, Yp, θp) of the collet 402 with the center (Xm, Ym, θm) of the mounting position.

[0057] According to the embodiment, since the rotational deviation caused by the mechanics of the rotation mechanism can be corrected, the rotational accuracy of bonding can be improved, and the bonding accuracy can be improved.

[0058] <Modification Example> Hereinafter, some representative modification examples of the embodiments will be illustrated. In the description of the following modification examples, for parts having the same configuration and function as those described in the above-described embodiments, the same reference numerals as those in the above-described embodiments may be used. And for the description of such parts, within a range where there is no technical contradiction, the description in the above-described embodiments may be appropriately incorporated. Also, a part of the above-described embodiments and all or part of a plurality of modification examples may be appropriately and comprehensively applied within a range where there is no technical contradiction.

[0059] (First Modification Example) The die bonder in the first modification example will be described with reference to FIG. 9. FIG. 9 is a schematic side view of the main part of the die bonder in the first modification example.

[0060] The die bonder 100 in the first modification example is a device that places the die D picked up by the pickup head 220 once on the holding part (holding position) of the intermediate stage 330, picks up the placed die D again by the bonding head 420, and bonds and mounts it on the substrate S conveyed to the bonding position.

[0061] The die bonder 100 includes a wafer recognition camera 201 that recognizes the posture of the die D on the wafer W, a stage recognition camera 205 that recognizes the posture of the die D placed on the intermediate stage 330, and a substrate recognition camera 203 that recognizes the mounting position of the substrate S on the bonding stage 430.

[0062] In this modification example, it is necessary to correct the posture deviation between the recognition cameras for the stage recognition camera 205 involved in the pickup by the bonding head 420 and the substrate recognition camera 203 involved in the bonding to the bonding position by the bonding head 420.

[0063] Further, the die bonder 100 includes an under-vision camera 204 provided between the intermediate stage 330 and the bonding stage 430. The under-vision camera 204 observes the state of the die D or the collet 402 being adsorbed by the bonding head 420 during movement from directly below.

[0064] Next, a procedure in which the bonding head 420 picks up the die D from the intermediate stage 330 and mounts it on the substrate S will be briefly described with reference to FIG. 9.

[0065] The stage recognition camera 205 images the surface of the die D on the intermediate stage 330 and outputs the captured image to the image processing device 301. The image processing device 301 calculates the center position (Xd, Yd, θd) of the die D by processing the captured image of the die D.

[0066] The substrate recognition camera 203 images a predetermined die bonding position on the substrate S and outputs the captured image to the image processing device 301. The image processing device 301 calculates the center position (Xm, Ym, θm) of the mounting position of the substrate S by processing the captured image of the substrate S.

[0067] Furthermore, the position control device 302 aligns the rotation center (Xp, Yp, θp) of the collet 402 with the center position of the die D calculated by the image processing device 301. At this time, based on the deviation in the rotation direction of the die D, the deviation in the rotation direction of the substrate S, and the mapping data of the θ rotation, the image processing device 301 calculates the θ correction amount. The position control device 302 performs θ correction on the collet 402 based on the θ correction amount and picks up the die D to be picked up from the intermediate stage 330.

[0068] In this way, the collet 402 of the bonding head 420 moves to the intermediate stage 330 (point P3) based on the images captured by the stage recognition camera 205 and the substrate recognition camera 203 and picks up the die D. After picking up, the collet 402 of the bonding head 420 moves to point P2.

[0069] At the point P2, the die D picked up from the intermediate stage 330 is mounted on the substrate S by aligning the rotation center (Xp, Yp, θp) of the collet 402 with the center (Xm, Ym, θm) of the mounting position.

[0070] (Second Modification Example) Although the misalignment of the rotation mechanism has been described, misalignment may occur during the replacement of the collet. The misalignment during the replacement of the collet will be described with reference to FIGS. 10 and 11. FIG. 10 is a cross-sectional view showing a part of the bonding head. FIG. 11 is a diagram for explaining the θ misalignment of the bottom surface of the collet of the die bonder in the second modification example. FIG. 11(a) is a diagram showing an ideal image of the bottom surface when the rotation amount command value imaged by the under-vision camera is 0 degree. FIG. 11(b) is a diagram showing an example of an image of the bottom surface misaligned in the θ direction. FIG. 11(c) is a diagram showing an example of an image of the bottom surface misaligned in the X direction and the Y direction.

[0071] As shown in FIG. 10, the bonding head 420 has a collet 402 to be replaced according to the size of the die fixed and attached to a shaft 403 as a fixing part by a fixture 404. The collet 402 is composed of a mounting part 402c and a bottom part 402d for sucking the die D. Since there is always a mechanical gap between the shaft 403 and the mounting part 402c of the collet 402, when fixed by the fixture 404, the center of the collet 402 may not coincide with the rotation center. As shown in FIG. 11, misalignment may occur in the θ direction, the X direction, and the Y direction each time the replacement is performed.

[0072] In this modification example, for example, an under-vision camera is used to create correction data for the rotation center of the collet each time the collet is replaced, in addition to correcting the misalignment by the rotation mechanism in the embodiment. Thereby, the misalignment of the rotation center is automatically corrected during mounting. As a result, the productivity is not reduced and the mounting accuracy is improved.

[0073] A method for creating mapping data for correction when the rotation center position of the collet 402 varies depending on the rotation angle thereof will be described with reference to FIG. 4.

[0074] Similar to the embodiment, the image processing apparatus 301 images the bottom surface of the collet 402 (the surface that adsorbs the die D) from below the collet 402 using the under-vision camera 204. Similar to the embodiment, the image processing apparatus 301 outputs a rotation amount command value to the rotation mechanism 408 via the position control apparatus 302, and the rotation mechanism 408 rotates the collet 402 according to the rotation amount command value. Similar to the embodiment, the image processing apparatus 301 rotates the collet 402 at predetermined angles such as the minimum resolution unit of the rotation mechanism 408 via the position control apparatus 302. Similar to the embodiment, the image processing apparatus 301 images the markers 402a and 402b at predetermined angles using the under-vision camera 204.

[0075] Similar to the embodiment, the image processing apparatus 301 performs image processing such as binarization on the captured image of the die D to calculate and obtain the centroid positions of the two markers 402a and 402b. Based on the centroid positions of the two markers 402a and 402b, that is, based on the center point O of the straight line connecting the two centroid positions and the angle formed with the reference line, the image processing apparatus 301 calculates (measures) the rotation center Ot of the collet 402 and the actual rotation amount (actual rotation amount). The image processing apparatus 301 stores and saves (records) the deviation amount between the center point O and the rotation center Ot and the deviation amount (displacement amount) between the rotation amount command value (command angle) and the actual rotation amount (measurement result) as mapping data in the storage device of the image processing apparatus 301 or the position control apparatus 302.

[0076] Similar to the embodiment, the recording of the mapping data is performed for a number of rotations that is a common multiple of the number of teeth of the gear 411a on the driving part side, the gear 411b on the driven part side, and the belt 411c.

[0077] For example, the image processing apparatus 301 performs rotation from a rotation amount command value of 0 degrees to 360 degrees for the number of rotations of the least common multiple described above, and performs image processing on the images captured by the under vision camera 204 after each rotation operation. Then, in addition to the deviation amount (displacement amount, △θ) between the rotation amount command value (command angle) and the actual rotation amount (measurement result) similar to the embodiment, the image processing apparatus 301 stores the error (△X) of the X coordinate and the error (△Y) of the Y coordinate in the storage device of the control device 14 as mapping data.

[0078] The procedure in which the bonding head 420 picks up the die D from the wafer W and mounts it on the substrate S is the same as in the embodiment.

[0079] As described above, the disclosure made by the present inventors has been specifically described based on the embodiments and modified examples. However, it goes without saying that the present disclosure is not limited to the above embodiments and modified examples and can be variously changed.

[0080] For example, in the embodiment, an example using the timing belt 411c as a transmission mechanism for transmitting the rotation of the gear 411a to the gear 411b has been described. However, the transmission mechanism may be a gear.

[0081] Further, in the embodiments and modified examples, the method for calculating θ has been described as a method using the centroids of two circular markers. However, instead of the circular markers, straight line markers that are parallel and perpendicular to one side formed by the end of the lower surface of the collet may be provided. θ may be obtained from the direction of this straight line by edge detection at a plurality of locations of this straight line, or a template model typified by pattern matching may be registered, and θ may be obtained from the detection result of that model or the direction formed between the detection results of a plurality of models.

[0082] In the embodiments and modified examples, an example in which the bonding head 420 performs rotation correction before picking up the die D has been described. However, the bonding head 420 may perform bonding after rotating and correcting the die at the time of bonding without performing rotation correction before picking up.

[0083] Also, in the embodiments and modified examples, an example of detecting the amount of deviation in the rotational direction in the position measurement of the die on the wafer or at the intermediate stage was described. However, when the amount of deviation in the rotational direction is detected in the position measurement of the die by under vision after the bonding head 420 picks up the die D, the bonding head 420 may perform rotational correction on the die and then perform bonding.

[0084] Also, in the embodiments and modified examples, an example of performing rotational correction was described. However, for products that require bonding at multiple types of rotation angles (for example, 90 degrees, 180 degrees) on a single substrate, each die to be bonded may be rotated to the required angle and rotational correction may be performed.

[0085] Also, in the embodiments and modified examples, rotational correction of the bonding head was described. However, it may also be applied to an intermediate stage having a rotation mechanism that rotates the pickup head or the holding unit. When applying it to the pickup head, an under vision camera as an imaging device is provided below the pickup head 220 between the pickup device 112 and the intermediate stage 330 in the first modified example. When applying it to the intermediate stage, the intermediate stage 330 in the first modified example is provided with a rotation mechanism similar to the rotation mechanism of the bond head 420 and a holding unit that holds the die rotated by the rotation mechanism, and the stage recognition camera 205 is used as the imaging device.

[0086] Also, in the first modified example, one pickup head and one bonding head are provided respectively, but two or more of each may be provided.

[0087] Also, in the embodiments and modified examples, bonding is performed with the surface of the die facing up. However, after picking up the die, the front and back of the die may be inverted and bonding may be performed with the back surface of the die facing up. In this case, the intermediate stage may not be provided. This device is called a flip chip bonder.

[0088] In addition, in the embodiment, an example in which the die is picked up from the wafer has been described, but it may be picked up from a tray or the like storing the product die.

Explanation of Signs

[0089] 14: Control device 100: Die bonder (die bonding device) 204: Under vision camera (imaging device) 205: Stage recognition camera (imaging device) 308: θ-axis motor (drive unit) 402: Collet (holding unit) 403: Shaft (rotating shaft) 408: Rotating mechanism 411a: Gear (first gear) 411b: Gear (second gear) 411c: Belt (transmission mechanism) D: Die

Claims

1. A holding part for holding a die, A rotating mechanism for rotating a rotating shaft that supports the holding part, An imaging device for imaging the holding part, A control device for controlling the rotating mechanism and the imaging device, Comprising, The rotating mechanism includes a driving part, a first gear attached to the driving part, a second gear attached to the rotating shaft, and a transmission mechanism for transmitting the rotation of the first gear to the second gear, The control device, Rotates the holding part by a predetermined rotation angle by the rotating mechanism, and images the surface of the holding part that contacts the die by the imaging device for each rotation angle, Calculates the rotation amount of the holding part based on the captured image, and calculates the deviation amount between the rotation amount command value for each rotation angle and the rotation amount as mapping data, The calculation of the mapping data is configured to be performed for a number of rotations that is a common multiple of the number of teeth of the first gear, the second gear, and the transmission mechanism, The predetermined rotation angle is the angle of the minimum resolution unit of the rotating mechanism. When calculating the mapping data, the rotating mechanism rotates the holding part at a rotation speed higher than one rotation, and the rotation directions are the first rotation direction and the second rotation direction opposite to the first rotation direction. A die bonding device.

2. In the die bonding device according to Claim 1, The control device is configured to perform the calculation of the mapping data for a number of rotations that is the least common multiple of the common multiples. A die bonding device.

3. In the die bonding device according to Claim 1, The control device is configured to perform the calculation of the mapping data for a number of rotations that is a plurality of least common multiples, and average for each rotation angle. A die bonding device.

4. In the die bonding device according to Claim 1, The control device is configured to perform rotation correction of the holding part based on the mapping data each time a die is picked up or placed at a predetermined position. A die bonding device.

5. In the die bonding device according to Claim 4, The control device is configured to determine a correction amount based on the mapping data and the absolute position of the rotating mechanism. A die bonding device.

6. In the die bonding device according to Claim 5, The control device is configured to calculate in advance the correction amount of the arrival position based on the deviation amount predicted from the arrival position before inputting the command value of the rotation amount of the holding part. A die bonding device.

7. In the die bonding apparatus according to claim 1, the holding part includes two markers, the control device is configured to calculate the centroid positions of the two markers respectively based on the captured image, and calculate the actual rotation amount of the holding part based on the calculated centroid positions. A die bonding apparatus.

8. In the die bonding apparatus according to any one of claims 1 to 7, the holding part is a collet attached to an attachment head that picks up a die and places it at a predetermined position, the imaging device is provided below the attachment head. A die bonding apparatus.

9. In the die bonding apparatus according to claim 8, the attachment head is a bonding head that picks up a die from a wafer and places it on a substrate. A die bonding apparatus.

10. In the die bonding apparatus according to claim 8, further, an intermediate stage, a pickup head that picks up a die from a wafer and places it on the intermediate stage, and is provided with, the attachment head is a bonding head that picks up a die from the intermediate stage and places it on a substrate. A die bonding apparatus.

11. In the die bonding apparatus according to claim 8, the control device further, calculates the rotation center of the collet based on the captured image, calculates the deviation amount of the rotation center for each rotation angle, and registers it in the mapping data, A die bonding apparatus configured to correct the position of the collet based on the mapping data each time the attachment head picks up the die or places it at a predetermined position.

12. In the die bonding apparatus according to claim 11, the deviation amount of the rotation center registered in the mapping data is the deviation amount in the X direction, Y direction, and θ direction for each rotation angle. A die bonding apparatus.

13. In the die bonding apparatus according to claim 1, the rotating shaft is composed of a shaft, the transmission mechanism is composed of a timing belt or a gear. A die bonding apparatus.

14. In the die bonding apparatus according to claim 1, the holding part is provided on an intermediate stage that picks up and places a die from a wafer, the imaging device is provided above the intermediate stage. A die bonding apparatus.

15. A holding unit that holds a die, a rotation mechanism that rotates a rotation shaft supporting the holding unit, an imaging device that images the holding unit, and a control device that controls the rotation mechanism and the imaging device, wherein the rotation mechanism includes a drive unit, a first gear attached to the drive unit, a second gear attached to the rotation shaft, and a transmission mechanism that transmits the rotation of the first gear to the second gear, and the control device rotates the holding unit by a predetermined rotation angle by the rotation mechanism, images a surface of the holding unit that contacts the die by the imaging device for each rotation angle, calculates a rotation amount of the holding unit based on the captured image, calculates a deviation amount between a rotation amount command value for each rotation angle and the rotation amount, and stores the deviation amount as mapping data in a storage device, and is configured to perform the storage of the mapping data for a number of rotations that is a common multiple of the number of teeth of the first gear, the second gear, and the transmission mechanism, the predetermined rotation angle is an angle of a minimum resolution unit of the rotation mechanism, and when calculating the mapping data, the rotation mechanism rotates the holding unit at a rotation speed higher than one rotation, and the rotation directions are a first rotation direction and a second rotation direction opposite to the first rotation direction. A step of loading a wafer ring into a die bonding device. A step of performing rotation correction of the holding unit based on the mapping data each time a die is picked up or each time the die is placed at a predetermined position. A method for manufacturing a semiconductor device including the above.

16. In the method for manufacturing a semiconductor device according to claim 15, A method for manufacturing a semiconductor device including a step of picking up a die from a wafer and placing the picked-up die on a substrate.

17. In the method for manufacturing a semiconductor device according to claim 15, A step of picking up a die from a wafer and placing the picked-up die on an intermediate stage, and A step of picking up a die from the intermediate stage and placing the picked-up die on a substrate. A method for manufacturing a semiconductor device including the above.

18. In the method for manufacturing a semiconductor device according to claim 15, In the mapping data, a rotation center of the holding unit is calculated based on the captured image, and a deviation amount of the rotation center for each rotation angle is calculated and registered. A method for manufacturing a semiconductor device.

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