JP7704534B2 - Die bonding apparatus and method for manufacturing semiconductor device - Google Patents

Description

This disclosure relates to a die bonding apparatus and is applicable, for example, to a die bonding apparatus that rotates a die in a horizontal plane.

The semiconductor chip assembly process involves dividing a wafer, on which multiple semiconductor chips have been collectively formed in a wafer process, into individual semiconductor chips (hereafter referred to as dies), which are then individually bonded to a wiring board or lead frame (hereafter referred to as a board) and sealed.

There are several methods of die bonding technology for bonding individual dies to a substrate. In one method, the individual dies are picked up by the collet of a pick-up head from an adhesive tape (hereafter referred to as dicing tape) on which the dies are arranged after the wafer has been divided, and placed on an intermediate stage. After positioning on the intermediate stage, the dies are picked up by the collet of a bonding head and placed on the substrate. Another method is the direct pick-up method, in which individual dies are picked up by the collet of a bonding head from the dicing tape and placed directly on the substrate.

Also, for example, if there is a rotational misalignment in the die being picked up from the wafer or intermediate stage, or if there is a rotational misalignment in the substrate, the bonding head may rotate the collet to match the inclination before picking up the die.

JP 2012-59933 A

In a rotating mechanism that rotates a collet or the like, for example, if the drive motor and the rotating shaft transmit power using gears or belts, the number of teeth is generally not the same. If gears or belts with different numbers of teeth are used, even if the driven rotating shaft rotates once, there will be a deviation in the coordinates unless the positional relationship of the teeth is the same.

The objective of this disclosure is to provide a technology that corrects the discrepancy between a command value and the actual amount of rotation in a rotation mechanism.

A brief summary of representative aspects of this disclosure is as follows.
That is, the die bonding apparatus includes a rotation mechanism that rotates a rotation shaft that supports a holder that holds a die, and a control device. 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. The control device is configured to rotate the holder to a predetermined rotation angle by the rotation mechanism, capture images of the surface of the holder that contacts the die with the image capture device for each rotation angle, calculate the amount of rotation of the holder based on the captured images, and calculate the deviation between a rotation amount command value and the amount of rotation for each rotation angle to obtain mapping data, and calculate the mapping data for a number of rotations that is a common multiple of the numbers of teeth of the first gear, the second gear, and the transmission mechanism.

This disclosure makes it possible to improve mounting accuracy.

FIG. 2 is a conceptual diagram showing a die bonder in an embodiment as viewed from above. 2 is a schematic diagram for explaining a function of a camera in the die bonder shown in FIG. 1 . 2 is a diagram for explaining a control system of an alignment mechanism in the die bonder shown in FIG. 1 . 2 is a schematic diagram for explaining the operation of the die bonder shown in FIG. 1 . 5 is a side view for explaining a rotation mechanism of the bonding head shown in FIG. 4. 6 is a diagram for explaining a problem of precision of the mechanical mechanism of the rotation mechanism shown in FIG. 5 . FIG. 4 is a diagram showing the relationship between a command value and an actual rotation amount. FIG. 13 is a diagram showing a marker provided on a collet. FIG. 11 is a schematic side view of a main part of a die bonder in a first modified example. FIG. 2 is a cross-sectional view showing a part of a bonding head. 13A and 13B are diagrams for explaining a θ deviation of the bottom surface of a collet of a die bonder in a second modified example.

This disclosure relates to a technology for correcting the deviation between the command value for the amount of rotation and the actual amount of rotation in a die bonding device such as a die bonder that is equipped with an attachment head that picks up a die and places it on a substrate or stage, when the attachment head has a θ rotation mechanism, or when the stage on which the die is placed has a θ rotation mechanism. For example, an imaging device is used to create correction data for the θ rotation of the attachment head or stage in advance. This automatically corrects the deviation in θ rotation caused by the rotation mechanism during mounting. As a result, mounting accuracy is improved without reducing productivity.

The following describes the embodiments and modified examples with reference to the drawings. However, in the following description, the same components are given the same reference numerals and repeated description may be omitted. Note that in the drawings, the width, thickness, shape, etc. of each part may be shown diagrammatically compared to the actual embodiment in order to make the description clearer, but these are merely examples and do not limit the interpretation of this disclosure.

First, the basic configuration of the die bonder in the embodiment will be described with reference to Figure 1. Figure 1 is a conceptual diagram of the die bonder in the embodiment as seen from above.

The die bonder 100 is broadly composed of a wafer supply unit 11, a work supply and transport 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 disposed on the front side of the die bonder 100, and the die bonding unit 13 is disposed on the back side.

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

In FIG. 1, the wafer cassette lifter 111 has a wafer cassette (not shown) filled with wafer rings 211 (see FIG. 2), and sequentially supplies the wafer rings 211 to the pickup device 112. The pickup device 112 includes a wafer holder 112a that holds the wafer ring 211, and a push-up unit 112b that pushes up a die from the wafer W held by the wafer ring 211. The wafer holder 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 a collet 402 (see FIG. 4).

The stack loader 121 supplies the substrate S (see FIG. 2) to which the die D is to be bonded to the frame feeder 122. The frame feeder 122 transports the substrate S to the unloader 123 via two processing positions on the frame feeder 122. As shown in FIG. 2, which will be described later, the two processing positions are a processing position 232 of the preform section 131 and a processing position 233 of the bonding head section 132. The unloader 123 stores the transported substrate S. The substrate S is transported from the unloader 123 to the outside of the die bonder 100.

The preform section 131 is provided with a die adhesive applicator, and applies a die adhesive to the substrate S transported by the frame feeder 122. The bonding head section 132 picks up the die D to be picked up from the pickup device 112, rises, and moves the die D to a point _P2 (see FIG. 4) on the frame feeder 122. The bonding head section 132 then lowers the die D at the moved point _P2 , and mounts the die D at the point _P2 on the substrate S to which the die adhesive has been applied. Note that, if a film-like adhesive is attached to the back surface (adhesive surface) of the die in advance, the preform section 131 is not provided with a die adhesive applicator, and the die adhesive is not applied to the substrate S.

Furthermore, the basic functions of the camera used in the die bonder 100 will be explained using 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 from the arrow A in FIG. 1, and FIG. 2(b) is a view from above. Note that FIG. 2 explains the camera in the die bonder 100 and the captured image. For this reason, illustrations and explanations of functional parts that are not relevant to the explanation (other components, wiring) are omitted.

The wafer recognition camera 201 captures an image of 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. The control device 14 then 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 and the center of the collet 402 and the center position of the push-up unit 112b, and corrects the position of the die D to eliminate the deviation.

Similarly, the preform camera 202 captures an image of a predetermined die-attaching position (bonding point) of the substrate S that has been transported 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 by well-known image processing such as pattern recognition so that the resin paste is applied to the die-attaching position, and applies the resin paste.

Similarly, the substrate recognition camera 203 captures an image of a predetermined die attachment position of the substrate S that has been transported to the processing position 233 in the bonding head unit 132. The control device 14 then performs positional correction of the collet 402, etc., by well-known image processing such as pattern recognition, so that the die D is mounted at the center position of the die attachment position, and mounts the die D.

The next substrate S is loaded from the stack loader 121 while maintaining a 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 transported to the unloader 123.

The wafer recognition camera 201, the preform camera 202, and the substrate recognition camera 203 are, for example, imaging devices using a CCD imaging element or a CMOS imaging element.

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.

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.

The wafer recognition camera 201 captures an image of the pattern surface (front surface) of the wafer W and outputs the captured image data to the image processing device 301.

The image processing device 301 analyzes the input image data using well-known image processing such as pattern recognition, and extracts the deviations in the X, Y, and θ coordinates using alignment marks at predetermined locations on the wafer W and die D. The image processing device 301 then calculates the amount of position correction so that the center of the die D to be picked up is located at the central pickup position, and outputs the calculated amount of position correction to the position control device 302.

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 and Y coordinates.

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, and rotates the collet 402 to correct the θ (rotation) coordinate.

The substrate recognition camera 203 captures an image of the top surface (surface) of the substrate S and outputs the captured image data to the image processing device 301.

The image processing device 301 analyzes the input image data using well-known image processing such as pattern recognition, and extracts the deviations in the X, Y, and θ coordinates using alignment marks at predetermined locations on the substrate S. The image processing device 301 then calculates the amount of position correction so that the center of the die D to be picked up is located at the center of the mounting position on the substrate S, and outputs the calculated amount of position correction to the position control device 302.

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 and Y coordinates.

In the above embodiment, position correction for the pickup device 112 and the bonding head unit 132 was described. The same applies to the preform unit 131 below. The image processing device 301 and the position control device 302 are a single unit that controls all of the pickup device 112, the preform unit 131, and the bonding head unit 132.

The detailed configuration and operation of the die bonder shown in FIG. 1 will be described with reference to FIG. 4 and FIG. 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.

As shown in FIG. 4, the wafer W attached to the dicing tape 212 has a plurality of divided dies D. The collet 402 provided on the bonding head 420 picks up the die D in the wafer W by suction and places it on the substrate S. The wafer recognition camera 201 captures the die D. The substrate recognition camera 203 captures the substrate S. The under-vision camera 204 as an imaging device captures 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 driving 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 attached.

5, the pulley/belt unit 411 is composed of a gear 411a attached to the rotating shaft of the θ-axis motor 308, a gear 411b attached to the shaft 403, and a timing belt 411c serving as a transmission mechanism for transmitting the rotation of the gear 411a to the gear 411b. The center of rotation 409 of the gear 411b is located at the center 410 (point P ₁ ) of the shaft 403 serving as the rotation axis.

The rotation mechanism 408 of the bonding head 420 transmits the power of the θ-axis motor 308 to the rotating shaft 403 as a driven part via gears 411a, 411b and a timing belt 411c, and the number of teeth of the gears 411a, 411b is changed to increase the precision of the rotation resolution. 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 done because in the event of a malfunction, the driving part side may not be able to stop. In addition, the bonding head 420 as a whole requires a lifting mechanism, a vacuum suction mechanism, a rotation mechanism, and a load mechanism, and in order to reduce the number of parts in order to make it smaller, the encoder is mounted only on the driving part side. Therefore, the control device 14 only recognizes the absolute position of the gear 411a on the driving part side.

The problem of accuracy of the mechanical mechanism of the rotation mechanism 408 will be explained using Figures 6 and 7. Figure 6 is a diagram for explaining the problem of accuracy of the mechanical mechanism of the rotation mechanism shown in Figure 5. Figure 6(a) is a diagram showing the positions of the teeth of the drive side gear, the driven side gear, and the belt. Figure 6(b) is a diagram showing the positions of the teeth of the drive side gear and the belt when the driven side gear rotates once from the state shown in Figure 6(a). Figure 7 is a diagram showing the relationship between the command value and the actual amount of rotation.

As shown in FIG. 6, even if the driven gear 411b rotates once as designed, the positions of the teeth of the belt 411c and the driving gear 411a are different. Here, arrows a, b, and c indicate the positions of specific teeth of the gears 411a, 411b, and timing belt 411c, respectively. Since the gear 411b rotates once, the arrow b points in almost the same direction in FIG. 6(a) and FIG. 6(b), and the position of the specific teeth is almost the same. The arrow a of the gear 411a points in almost the opposite direction in FIG. 6(a) and FIG. 6(b), and the specific teeth are located on almost the opposite side during rotation. The arrow c of the timing belt 411c is located in a completely different position in FIG. 6(a) and FIG. 6(b).

If there is a variation in the inherent teeth of the gears 411a, 411b and the timing belt 411c, or if there is a slight center misalignment of the rotating mechanism 408 such as the gears 411a, 411b, a slight deviation occurs in the θ angle of the gear 411b on the driven side. Therefore, even if the rotation amount of the gear 411b on the driven side rotates once and the specified angle (command value) of the gear 411b on the driven side is the same, it will not be the same angle as the previous rotation. For example, a deviation occurs at the specified angles of 90 degrees and 360 + 90 degrees. In other words, due to the accuracy problem of the mechanical mechanism of the rotating mechanism 408, even if you want to rotate the die D at a specified angle, there will be an excess or deficiency. Therefore, as shown in Figure 7, the measured value is wavy with respect to the ideal value, and a displacement waveform exists at a period when the meshing of the gears 411a, 411b and the timing belt 411c is the same. In FIG. 7, the gear 411a on the driving side rotates five times, the gear 411b on the driven side rotates three times, and the timing belt 411c rotates two times to achieve the same meshing.

In this embodiment, during the tracing operation, the displacement (deviation) of the rotation amount of the rotation mechanism 408 of the bonding head 420 is measured and mapped, and during continuous operation, any excess or deficiency in the rotation amount is corrected. In addition to mapping one rotation of the collet 402 of the bonding head 420, at least one cycle of the combination of the gears and timing belt as a mechanical factor is mapped.

As a tracing operation, the gear 411a on the driving side, the gear 411b on the driven side, and the timing belt 411c are rotated for a number of rotations that is a common multiple of the number of teeth, and the displacement amount between the specified angle of the gear 411b and the actual rotation amount is measured for each predetermined angle, and the measurement result is stored as mapping data. In other words, the deviation amount of the rotation amount for all mutual positional relationships of each part that constitutes the rotation mechanism 408 is measured in advance, and the measurement result is stored and recorded in the storage device of the control device 14. Here, as the mapping data, not only data for one direction of rotation but also data for the opposite direction of rotation is obtained. The 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 is set to, for example, the least common multiple. This reduces the number of measurements and the amount of mapping data. The calculation of the mapping data may be performed for a number of rotations that is the least common multiple, and averaged for each of the above-mentioned predetermined angles. This improves accuracy.

During continuous operation, the deviation amount after rotation to the specified position (specified angle) is predicted 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, and the correction amount is determined based on the mapping data obtained by the tracing operation to correct the command rotation amount. In other words, during continuous operation, the offset amount obtained for each command angle is fed back to rotate. For example, the feedback increases or decreases the command value so that the graph of command value vs. 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 position of each part that constitutes the rotation mechanism 408, and the deviation amount is fed back. Then, before inputting the command value of the rotation amount, the correction amount of the arrival position is calculated in advance in consideration of the deviation amount predicted from the arrival position, and the correction amount is determined in advance and corrected.

In addition, if the rotation mechanism 408 is rotated manually when the power is cut off, the absolute position will be lost, so a brake is applied to prevent rotation when the power is cut off, and remeasurement is always performed automatically when starting up.

An example of a method for measuring the displacement of the rotation amount during a scanning operation is described with reference to Figure 8. Figure 8 shows a marker provided on the collet.

The image processing device 301 captures an image of 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. 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 shape and size of the die.

The image processing device 301 outputs a rotation amount command value to the rotation mechanism 408 via the position control device 302, and the rotation mechanism 408 rotates the collet 402 according to the rotation amount command value. The image processing device 301 rotates the collet 402 at a predetermined angle, such as the minimum resolution unit of the rotation mechanism 408, via the position control device 302. The image processing device 301 captures images of the two markers 402a and 402b at a predetermined angle using the undervision camera 204.

The image processing device 301 performs image processing such as binarization on the captured image of the die D to calculate and determine the center of gravity positions of the two markers 402a and 402b. The image processing device 301 calculates (measures) the actual amount of rotation (actual rotation amount) of the collet 402 based on the center of gravity positions of the two markers 402a and 402b, i.e., based on the angle (θ) between the line passing through the two center of gravity positions and the reference line. The image processing device 301 stores and saves (records) the deviation (displacement) 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 device 301 or the position control device 302.

The mapping data is recorded for the number of rotations that is the least common multiple of the number of teeth of the driving gear 411a, the driven gear 411b, and the timing belt 411c. For example, if the numbers of teeth of the driving gear 411a, the driven gear 411b, and the timing belt 411c are 6, 18, and 66, respectively, the common multiple is 198, so the driving gear 411a, the driven gear 411b, and the timing belt 411c make 33 rotations, 11 rotations, and 3 rotations, respectively. Therefore, the positional relationship of the teeth of the driven gear 411b is the same every 11 rotations, so 11 rotations of the driven gear 411b are recorded.

Next, the procedure during continuous operation, that is, the procedure in which the bonding head 420 picks up the die D from the wafer W and mounts it on the substrate S, which is part of the manufacturing process of the semiconductor device, will be briefly explained using FIG. 4.

The wafer recognition camera 201 captures an image of 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 processes the captured image of the die D to calculate the center position (Xd, Yd, θd) of the die D.

The board recognition camera 203 captures an image of a predetermined die attachment position on the board S and outputs the captured image to the image processing device 301. The image processing device 301 processes the captured image of the board S to calculate the center position (Xm, Ym, θm) of the mounting position on the board S.

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 center of gravity position O. At this time, the image processing device 301 calculates the θ correction amount 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 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 wafer W.

In this manner, the collet 402 of the bonding head 420 moves onto the wafer W (point P ₀ ) and picks up the die D based on the images captured by the wafer recognition camera 201 and the substrate recognition camera 203. After picking up, the collet 402 of the bonding head 420 moves to point P ₂ .

At point _P2 , the center of rotation (Xp, Yp, θp) of the collet 402 is aligned with the center of the mounting position (Xm, Ym, θm) and the die D picked up from the wafer W is mounted on the substrate S.

According to the embodiment, it is possible to correct the rotational deviation caused by the mechanical nature of the rotation mechanism, thereby improving the rotational accuracy of bonding and improving the bonding accuracy.

<Modification>
Below, some representative modified examples of the embodiment are illustrated. In the following description of the modified examples, the same reference numerals as those in the above embodiment may be used for parts having the same configuration and function as those described in the above embodiment. The description of such parts may be appropriately cited within the scope of technical inconsistency. Furthermore, a part of the above embodiment and all or a part of the modified examples may be appropriately applied in a composite manner within the scope of technical inconsistency.

(First Modification)
The die bonder in the first modified 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 modified example.

The die bonder 100 in the first modified example is a device that first places a die D picked up by a pick-up head 220 on a holding portion (holding position) of an intermediate stage 330, then picks up the placed die D again by a bonding head 420, and bonds and mounts the die D on a substrate S that has been transported to the bonding position.

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.

In this modified example, the recognition cameras that must be corrected for posture misalignment are the stage recognition camera 205, which is involved in picking up by the bonding head 420, and the board recognition camera 203, which is involved in bonding to the bonding position by the bonding head 420.

The die bonder 100 also includes an under-vision camera 204 that is provided between the intermediate stage 330 and the bonding stage 430. The under-vision camera 204 observes from directly below the state of the die D or collet 402 that is being adsorbed while the bonding head 420 is moving.

Next, the procedure by 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 explained using FIG. 9.

The stage recognition camera 205 captures an image of 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.

The board recognition camera 203 captures an image of a predetermined die attachment position on the board S and outputs the captured image to the image processing device 301. The image processing device 301 processes the captured image of the board S to calculate the center position (Xm, Ym, θm) of the mounting position on the board S.

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 that time, the image processing device 301 calculates the θ correction amount based on the rotational deviation of the die D, the rotational deviation of the substrate S, and the mapping data of the θ rotation. 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.

In this way, the collet 402 of the bonding head 420 moves onto the intermediate stage 330 (point _P3 ) based on the images captured by the stage recognition camera 205 and the substrate recognition camera 203 to pick up the die D. After picking up, the collet 402 of the bonding head 420 moves to point _P2 .

At point _P2 , the center of rotation (Xp, Yp, θp) of the collet 402 is aligned with the center of the mounting position (Xm, Ym, θm) and the die D picked up from the intermediate stage 330 is mounted on the substrate S.

(Second Modification)
Although the misalignment of the rotation mechanism has been described, misalignment may occur when replacing the collet. The misalignment when replacing 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 modified example. Fig. 11(a) is a diagram showing an ideal image of the bottom surface when the rotation amount command value captured by the under-vision camera is 0 degrees. 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 and Y directions.

As shown in FIG. 10, the bonding head 420 has a shaft 403 as a fixed part, to which a collet 402, which is replaced depending on the size of the die, is fixed by a fixture 404. The collet 402 is composed of a mounting part 402c and a bottom part 402d that adsorbs 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 center of rotation. As shown in FIG. 11, deviations in the θ direction, X direction, and Y direction may occur each time the collet is replaced.

In this modified 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 caused by the rotation mechanism in the embodiment. This automatically corrects the misalignment of the rotation center during mounting. As a result, mounting accuracy is improved without reducing productivity.

The method of creating mapping data for correction when the rotation center position of the collet 402 varies depending on the rotation angle is explained using FIG. 4.

As in the embodiment, the image processing device 301 captures an image of 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. As in the embodiment, the image processing device 301 outputs a rotation amount command value to the rotation mechanism 408 via the position control device 302, and the rotation mechanism 408 rotates the collet 402 according to the rotation amount command value. As in the embodiment, the image processing device 301 rotates the collet 402 at a predetermined angle, such as the minimum resolution unit of the rotation mechanism 408, via the position control device 302. As in the embodiment, the image processing device 301 captures images of the markers 402a and 402b at a predetermined angle using the under-vision camera 204.

As in the embodiment, the image processing device 301 performs image processing such as binarization on the image of the captured die D to calculate and determine the center of gravity positions of the two markers 402a and 402b. The image processing device 301 calculates (measures) the rotation center Ot and the actual rotation amount (actual rotation amount) of the collet 402 based on the center of gravity positions of the two markers 402a and 402b, that is, based on the center point O of the line connecting the two center of gravity positions and the angle between the line and the reference line. The image processing device 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 device 301 or the position control device 302.

As in the embodiment, the mapping data is recorded for the number of rotations that is a common multiple of the number of teeth of the gear 411a on the driving side, the gear 411b on the driven side, and the belt 411c.

For example, the image processing device 301 rotates the rotation amount command value from 0 degrees to 360 degrees for the number of rotations of the common multiple mentioned above, and processes the image captured by the under-vision camera 204 after each rotation operation. Then, the image processing device 301 stores the deviation (displacement, △θ) between the rotation amount command value (command angle) and the actual rotation amount (measurement result) as in the embodiment, as well as the error in the X coordinate (△X) and the error in the Y coordinate (△Y) as mapping data in the storage device of the control device 14.

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.

The disclosure made by the present inventors has been specifically described above based on examples and modified examples, but it goes without saying that the present disclosure is not limited to the above examples and modified examples, and various modifications are possible.

For example, in the embodiment, an example was described in which a timing belt 411c is used as a transmission mechanism for transmitting the rotation of gear 411a to gear 411b, but the transmission mechanism may also be gears.

In addition, in the embodiment and modified examples, the method of calculating θ using the center of gravity of two circular markers has been described, but instead of circular markers, a straight line marker that is parallel to 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 detecting the edges of multiple points on the straight line, or a template model, as typified by pattern matching, may be registered and θ may be obtained from the detection results of this model or the direction formed between the detection results of multiple models.

In the embodiment and modified example, an example has been described in which rotation correction is performed before the bonding head 420 picks up the die D. However, it is also possible to perform rotation correction before picking up the die D, and have the bonding head 420 perform rotation correction on the die D during bonding before bonding.

In addition, in the embodiment and modified example, an example was described in which the amount of rotational deviation was detected when measuring the position of a die on a wafer or an intermediate stage. However, if a rotational deviation is detected when measuring the position of the die by under-vision after the bonding head 420 picks up the die D, the bonding head 420 may perform rotational correction of the die before bonding.

In addition, in the embodiment and modified example, an example of performing rotation correction has been described, but for products that require bonding at multiple rotation angles (e.g., 90 degrees, 180 degrees) on a single substrate, each die to be bonded may be rotated to the required angle and rotation correction may also be performed.

In addition, while the embodiment and modified examples have been described with regard to the rotation correction of the bonding head, this may also be applied to an intermediate stage having a rotation mechanism that rotates the pick-up head or the holder. When applied to a pick-up head, an under-vision camera is provided as an imaging device below the pick-up head 220, between the pick-up device 112 and the intermediate stage 330 in the first modified example. When applied to an intermediate stage, a rotation mechanism similar to that of the bond head 420 and a holder that holds the die rotated by the rotation mechanism are provided on the intermediate stage 330 in the first modified example, and a stage recognition camera 205 is used as the imaging device.

In addition, the first variant has one pickup head and one bonding head, but there may be two or more of each.

In the embodiment and modified examples, the die is bonded with its front side facing up, but after picking up the die, it may be flipped over and bonded with its back side facing up. In this case, there is no need to provide an intermediate stage. This device is called a flip chip bonder.

In addition, in the embodiment, the die is picked up from a wafer, but it is also possible to pick up the die from a tray that holds the product die.

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 part)
403: Shaft (rotating shaft)
408: Rotation mechanism 411a: Gear (first gear)
411b: Gear (second gear)
411c: Belt (transmission mechanism)
D: Die

Claims (18)

A holder for holding the die;
A rotation mechanism that rotates a rotation shaft that supports the holding portion;
An imaging device that images the holding portion;
a control device that controls the rotation mechanism and the imaging device;
Equipped with
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 rotation of the first gear to the second gear,
The control device includes:
The holding part is rotated by the rotation mechanism through a predetermined rotation angle, and an image of a surface of the holding part that contacts the die is captured by the imaging device for each of the rotation angles;
Calculating a rotation amount of the holding part based on the captured image, and calculating a deviation amount between a rotation amount command value and the rotation amount for each rotation angle, and setting the deviation amount as mapping data;
The calculation of the mapping data is performed for a number of rotations that is a common multiple of the numbers of teeth of the first gear, the second gear, and the transmission mechanism,
A die bonding apparatus in which the specified rotation angle is an angle of the minimum resolution unit of the rotation mechanism, and when calculating the mapping data, the rotation mechanism rotates the holding part a number of rotations greater than one rotation, and the rotation direction is a first rotation direction and a second rotation direction opposite to the first rotation direction. 2. The die bonding apparatus according to claim 1,
The control device is a die bonding apparatus configured to calculate the mapping data for a number of rotations that is the least common multiple of the common multiples. 2. The die bonding apparatus according to claim 1,
The control device is a die bonding device configured to calculate the mapping data for a number of rotations that is a least common multiple, and to average the mapping data for each rotation angle. 2. The die bonding apparatus according to claim 1,
The control device is a die bonding apparatus configured to perform rotation correction of the holding part based on the mapping data each time a die is picked up or placed in a predetermined position. 5. The die bonding apparatus according to claim 4,
The control device is configured to determine a correction amount based on the mapping data and an absolute position of the rotation mechanism. 6. The die bonding apparatus according to claim 5,
The control device is configured to calculate in advance the correction amount of the arrival position based on an amount of deviation predicted from the arrival position before a command value for an amount of rotation of the holding unit is input. 2. The die bonding apparatus according to claim 1,
The retaining portion includes two markers;
The control device is a die bonding apparatus configured to calculate a center of gravity position of each of the two markers based on the captured image, and to calculate an actual rotation amount of the holding portion based on the calculated center of gravity positions. 8. The die bonding apparatus according to claim 1,
The holding part is a collet attached to an attachment head that picks up a die and places it in a predetermined position,
The imaging device is a die bonding apparatus provided below the attachment head. 9. 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. The die bonding apparatus according to claim 8, further comprising:
The intermediate stage and
a pick-up head that picks up a die from a wafer and places it on the intermediate stage;
Equipped with
The attachment head is a bonding head that picks up a die from the intermediate stage and places it on a substrate. 9. The die bonding apparatus according to claim 8,
The control device further comprises:
Calculating a rotation center of the collet based on the captured image, calculating a deviation amount of the rotation center for each rotation angle, and registering the deviation amount in the mapping data;
The die bonding apparatus is 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 in a predetermined position. 12. The die bonding apparatus according to claim 11,
The amount of deviation of the rotation center registered in the mapping data is the amount of deviation in the X direction, the Y direction, and the θ direction for each rotation angle. 2. The die bonding apparatus according to claim 1,
The rotation axis is constituted by a shaft,
The die bonding apparatus, wherein the transmission mechanism is composed of a timing belt or gears. 2. The die bonding apparatus according to claim 1,
the holding unit is provided on an intermediate stage on which a die is picked up from a wafer and placed;
The imaging device is a die bonding device provided above the intermediate stage. The present invention relates to a die forming method and a control device for controlling a die forming apparatus, the die forming method and the die forming apparatus, the die forming method and the die forming apparatus comprising: a holding part for holding a die; a rotation mechanism for rotating a rotation shaft supporting the holding part; an imaging device for imaging the holding part; and a control device for controlling the rotation mechanism and the imaging device, the rotation mechanism including a drive part, a first gear attached to the drive part, a second gear attached to the rotation shaft, and a transmission mechanism for transmitting rotation of the first gear to the second gear. The control device rotates the holding part by a predetermined rotation angle using the rotation mechanism, images a surface of the holding part that comes into contact with the die using the imaging device for each rotation angle, and controls the rotation of the holding part based on the captured images. a step of calculating a deviation between a rotation amount command value and the rotation amount for each rotation angle and storing the deviation in a storage device as mapping data, storing the mapping data for a number of rotations that is a common multiple of the numbers of teeth of the first gear, the second gear, and the transmission mechanism, the predetermined rotation angle being an angle of a minimum resolution unit of the rotation mechanism, and carrying the wafer ring into a die bonding device in which the rotation mechanism rotates the holding part a number of rotations that is greater than one rotation when calculating the mapping data, the rotation mechanism rotating the holding part a number of rotations that is greater than one rotation, and the rotation direction is a first rotation direction and a second rotation direction that is opposite to the first rotation direction;
performing a rotation correction of the holder based on the mapping data every time a die is picked up or placed in a predetermined position;
A method for manufacturing a semiconductor device comprising the steps of: 16. The method of manufacturing a semiconductor device according to claim 15,
A method of manufacturing a semiconductor device comprising the steps of picking up a die from a wafer and placing the picked-up die on a substrate. 16. The method of manufacturing a semiconductor device according to claim 15,
picking up a die from the wafer and placing the picked up die on an intermediate stage;
picking up a die from the intermediate stage and placing the picked up die on a substrate;
A method for manufacturing a semiconductor device comprising the steps of: 16. The method of manufacturing a semiconductor device according to claim 15,
A manufacturing method for a semiconductor device, in which the mapping data includes a rotation center of the holding part calculated based on the captured image, and the amount of deviation of the rotation center for each rotation angle calculated and registered.

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