Chip mounting equipment and semiconductor device manufacturing method

Abstract

This invention provides a chip mounting apparatus and a method for manufacturing a semiconductor device, improving mounting accuracy. The chip mounting apparatus includes a rotation mechanism that rotates a rotating shaft supporting a holding portion for holding a bare chip, and a control device. The rotation mechanism includes a drive unit, a first gear mounted on the drive unit, a second gear mounted on the rotating 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 holding portion by a predetermined rotation angle using the rotation mechanism. Each time the rotation angle is rotated, a camera is used to capture an image of the surface of the holding portion in contact with the bare chip. Based on the captured image, the rotation amount of the holding portion is calculated, and a rotation amount command value and an offset of the rotation amount for each rotation angle are calculated as mapping data. This mapping data is then calculated corresponding to a rotation number that is a common multiple of the number of teeth of the first gear, the second gear, and the transmission mechanism.

Description

Technical Field

[0001] This disclosure relates to chip mounting apparatus, such as a chip mounting apparatus that can be applied to rotate bare chips in a horizontal plane. Background Technology

[0002] In the semiconductor chip assembly process, there are assembly processes that involve dividing a wafer into individual semiconductor chips (hereinafter referred to as bare chips), individually mounting them onto wiring substrates or lead frames (hereinafter referred to as substrates), and sealing them.

[0003] There are several methods for chip mounting technology that mounts individual bare chips onto a substrate. One method involves using the chucks of a pick-up head to pick up individual bare chips from a tape (hereinafter referred to as a dicing tape) in a diced state and place them onto an intermediate stage. After positioning on the intermediate stage, the chucks of a placement head pick up and place them onto the substrate. Another method is a direct pick-up method, in which individual bare chips picked up from the dicing tape using the chucks of a placement head are directly placed onto the substrate.

[0004] In addition, for example, when there is a rotational offset of the bare die picked up from the wafer or intermediate stage, or when there is a rotational offset of the substrate, sometimes the placement head rotates the collet to tilt and correspond to the bare die or substrate before picking it up.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: JP Japanese Patent Application Publication No. 2012-59933 Summary of the Invention

[0008] In rotating mechanisms that rotate collets, for example, where the drive motor and rotating shaft transmit power via gears or belts, the number of teeth on these components is generally not set to be the same. When gears or belts with different numbers of teeth are used, even if the driven rotating shaft rotates one revolution, as long as the positional relationship of the gear teeth is not the same, a shift will occur in that coordinate.

[0009] The subject of this disclosure is to provide a technique for correcting the offset between a command value and the actual amount of rotation in a rotating mechanism.

[0010] If we were to briefly summarize the representative aspects of this disclosure, the following would be a brief overview.

[0011] That is, the chip mounting apparatus includes a rotation mechanism that rotates a rotating shaft supporting a holding portion for holding a bare chip, and a control device. The rotation mechanism includes a drive unit, a first gear mounted on the drive unit, a second gear mounted on the rotating 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 holding portion by a predetermined rotation angle using the rotation mechanism. Each time the rotation angle is rotated, an image is captured by a camera device of the surface of the holding portion in contact with the bare chip. Based on the captured image, the rotation amount of the holding portion is calculated, and a rotation amount command value and a rotation amount offset for each rotation angle are calculated as mapping data. The mapping data is then calculated in correspondence with 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.

[0012] Invention Effects

[0013] According to this disclosure, installation accuracy can be improved. Attached Figure Description

[0014] Figure 1 This is a conceptual diagram of the chip mounting machine in the above observation embodiment.

[0015] Figure 2 It is used for explanation Figure 1 The diagram shows the function of the camera in the chip mounting machine.

[0016] Figure 3 It is used for explanation Figure 1 The diagram shows the control system of the alignment mechanism in a chip mounting machine.

[0017] Figure 4 It is used for explanation Figure 1 The diagram shows the operation of a chip mounting machine.

[0018] Figure 5 It is used for explanation Figure 4 A side view of the rotating mechanism of the mounting head is shown.

[0019] Figure 6 It is used for explanation Figure 5 A diagram showing the accuracy problem of the mechanical mechanism of the rotating mechanism.

[0020] Figure 7 It is a graph showing the relationship between the command value and the actual rotation amount.

[0021] Figure 8 This is a diagram showing the markings on the collet.

[0022] Figure 9 This is a schematic side view of the main parts of the chip mounting machine in the first variant.

[0023] Figure 10 This is a cross-sectional view showing a portion of the mounting head.

[0024] Figure 11 This is a diagram illustrating the θ offset of the bottom surface of the collet of the chip placement machine in the second variation.

[0025] The annotations in the attached figures are explained as follows:

[0026] 14: Control device

[0027] 100: Chip placement machine (chip placement device)

[0028] 204: Upward-view camera (video recording device)

[0029] 205: Platform recognition camera (video recording device)

[0030] 308: Theta-axis motor (drive unit)

[0031] 402: Collet (holding part)

[0032] 403: Shaft (rotating shaft)

[0033] 408: Rotating mechanism

[0034] 411a: Gear (First Gear)

[0035] 411b: Gear (Second Gear)

[0036] 411c: Belt (transmission mechanism)

[0037] D: Bare chip Detailed Implementation

[0038] This disclosure relates to a technique in a chip mounting apparatus such as a chip mounter that picks up a bare chip and places it on a substrate or stage. When the attachment head or the stage for placing the bare chip has a theta rotation mechanism, the offset between the commanded value and the actual rotation amount is corrected. For example, correction data for the theta rotation of the attachment head or stage is created in advance using a camera device. This automatically corrects the theta rotation offset caused by the rotation mechanism during mounting. As a result, mounting accuracy is improved without affecting productivity.

[0039] Hereinafter, embodiments and variations will be described using the accompanying drawings. However, in the following description, the same reference numerals will sometimes be used to refer to the same constituent elements, and repeated descriptions will be omitted. Furthermore, in order to make the description clearer, the width, thickness, shape, etc. of the parts in the drawings are sometimes schematically shown compared to the actual form, but this is only an example and does not limit the interpretation of this disclosure.

[0040]

Example

[0041] First, use Figure 1 The basic structure of the chip mounting machine in the embodiment is explained. Figure 1 This is a conceptual diagram of the chip mounting machine in the embodiment, viewed from above.

[0042] The chip placement machine 100 generally includes a wafer supply unit 11, a workpiece supply / transfer unit 12, a chip placement unit 13, and a control device 14. The Y-axis direction is the front-to-back direction of the chip placement machine 100, and the X-axis direction is the left-to-right direction. The wafer supply unit 11 is located near the front of the chip placement machine 100, and the chip placement unit 13 is located at the far side.

[0043] The wafer supply section 11 includes a wafer cassette lift 111 and a pick-up device 112. Wafer rings 211 (described later) are moved from outside the chip mounter 100 into the wafer supply section 11. Figure 2 Additionally, the workpiece supply / transfer unit 12 includes a stacker loader 121, a frame feeder 122, and an unloader 123. The substrate S (described later) is moved from outside the chip mounting machine 100 into the workpiece supply / transfer unit 12. Figure 2 Additionally, the chip mounting section 13 includes a pre-forming section 131 and a mounting head 132.

[0044] exist Figure 1 In the middle, the wafer box elevator 111 has a wafer ring 211 filled with wafers (see reference). Figure 2 A wafer cassette (not shown) sequentially supplies wafer rings 211 to a pick-up device 112. The pick-up device 112 includes a wafer holding stage 112a for holding the wafer rings 211 and a push-up unit 112b for pushing bare wafers from the wafers W held on the wafer rings 211. The wafer holding stage 112a is capable of utilizing a collet 402 (see reference 402). Figure 4 The bare chip D (see reference) is picked up from the dicing tape 212 held in the wafer ring 211 as the pick-up target. Figure 4 The wafer ring 211 is moved using a drive unit (not shown) in a manner that allows the wafer ring 211 to move.

[0045] The stacker loader 121 will attach the substrate S (refer to) to the bare chip D. Figure 2 The substrate S is supplied to the frame feeder 122. The frame feeder 122 transports the substrate S to the unloading machine 123 via two processing positions. This will be described later. Figure 2 As shown, the two processing positions are processing position 232 of the preforming section 131 and processing position 233 of the mounting head 132. The unloading machine 123 holds the transported substrate S. The substrate S is moved out of the chip mounting machine 100 from the unloading machine 123.

[0046] The preforming section 131 is equipped with a chip adhesive application device, which applies chip adhesive to the substrate S transported by the frame feeder 122. The mounting head 132 picks up the bare chip D, which is to be picked up, from the pick-up device 112 and raises it, moving the bare chip D to point P2 (see reference) on the frame feeder 122. Figure 4 Then, the mounting head 132 lowers the bare chip D at point P2 after the movement, and mounts the bare chip D onto point P2 on the substrate S coated with chip adhesive. Furthermore, if a thin film of adhesive is pre-attached to the back side (adhesive surface) of the bare chip, no chip adhesive application device is provided in the pre-forming section 131, and no chip adhesive is applied to the substrate S.

[0047] Also used Figure 2 Explain the basic functions of the camera used in the chip mounting machine 100. Figure 2 It is used for explanation Figure 1 The diagram shows the function of the camera in the chip mounting machine. Figure 2 (a) is in Figure 1 The diagram viewed from arrow A. Figure 2 (b) is a view taken from above. Furthermore, in Figure 2 The image shows the camera and its captured images in the chip mounter 100. Therefore, illustrations and descriptions of functional parts (other components, wiring) that are not relevant to the description are omitted.

[0048] The chip recognition camera 201 captures the patterned surface of the chip W mounted on the chip ring 211, which is mounted on the chip ring 211, from the pickup device 112. Then, the control device 14 uses known image processing such as pattern recognition to calculate the center position of a bare chip D, calculates the offset between the center position of the bare chip D and the center position of the collet 402 and the center position of the push unit 112b, and corrects the position of the bare chip D by eliminating the offset.

[0049] Similarly, the pre-forming camera 202 captures images of the designated bare die bonding positions (mounting points) of the substrate S transported to the processing position 232 in the pre-forming section 131. Then, the control device 14 uses known image processing such as pattern recognition to correct the positional offset of the syringe that injects resin paste in a manner that applies resin paste to the bare die bonding position, and applies the resin paste.

[0050] Similarly, the substrate recognition camera 203 captures the designated bare chip bonding position of the substrate S transported to the processing position 233 of the mounting head 132. Then, the control device 14 uses known image processing such as pattern recognition to correct the positional offset of the collet 402, etc., in a way that the bare chip D is mounted at the center position of the bare chip bonding position, thereby mounting the bare chip D.

[0051] The next substrate S is moved from the stacker loader 121 at intervals of the spacing 251 between the processing position 232 of the preform 131 and the processing position 233 of the mounting head 132, and is transported to the unloader 123.

[0052] The chip recognition camera 201, the pre-formed camera 202, and the substrate recognition camera 203 are, for example, camera devices using CCD or CMOS camera elements.

[0053] Next, use Figure 3 Explain the alignment mechanism and position offset correction. Figure 3 This is a diagram illustrating the control system of the alignment mechanism in the embodiment.

[0054] 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 part of the control device 14.

[0055] The chip recognition camera 201 captures the patterned surface of the chip W and outputs the captured image data to the image processing device 301.

[0056] The image processing device 301 uses known image processing techniques such as pattern recognition to analyze the input image data, and extracts the offsets of the X, Y, and θ coordinates using alignment marks at specified locations on the wafer W and the bare chip D. Then, the image processing device 301 calculates a position correction amount in a manner that brings the center of the picked-up bare chip D to the center position of the picked-up chip, and outputs the calculated position correction amount to the position control device 302.

[0057] The position control device 302 outputs control signals 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 signals to move the XY stage 213 to correct the X and Y coordinates.

[0058] The position control device 302 outputs a control signal to the θ-axis drive unit 305 of the mounting head 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, causing the collet 402 to rotate to correct the θ (rotational) coordinate.

[0059] The substrate recognition camera 203 captures the upper surface (surface) of the substrate S and outputs the captured image data to the image processing device 301.

[0060] The image processing device 301 analyzes the input image data using known image processing methods such as pattern recognition, and extracts the offsets of the X, Y, and θ coordinates using alignment marks at a specified location on the substrate S. Then, the image processing device 301 calculates the position correction amount based on the center of the picked-up bare chip D reaching the center of the mounting position on the substrate S, and outputs the calculated position correction amount to the position control device 302.

[0061] The position control device 302 outputs control signals to the X-axis drive unit 303 and Y-axis drive unit 304 of the placement head 132 based on the input position correction amount. The X-axis drive unit 303 and Y-axis drive unit 304 control the X-axis motor 306 and Y-axis motor 307 respectively based on the input control signals to move the placement head to correct the X and Y coordinates.

[0062] In the above embodiment, the position correction of the pickup device 112 and the mounting head 132 was described. The same applies to the preforming section 131 below. Furthermore, the image processing device 301 and the position control device 302 are a single unit that controls all pickup devices 112, preforming sections 131, and mounting heads 132.

[0063] use Figure 4 and Figure 5 illustrate Figure 1 The detailed structure and operation of the chip mounting machine are shown. Figure 4 It is used for explanation Figure 1 The diagram shows the operation of a chip mounting machine. Figure 5 It is used for explanation Figure 4 A side view of the rotating mechanism of the mounting head is shown.

[0064] like Figure 4 As shown, the wafer W attached to the dicing tape 212 has multiple bare chips D after being diced. A chuck 402 provided in the placement head 420 picks up the bare chips D from the wafer W and places them on the substrate S. A wafer recognition camera 201 captures images of the bare chips D. A substrate recognition camera 203 captures images of the substrate S. A tilting camera 204, acting as an imaging device, captures images of the back of the chuck 402 or the back of the bare chip (not shown) being picked up by the chuck 402. The placement head 420 has a rotation mechanism 408 that corrects for any deviation in the rotation direction of the picked-up bare chips D. The rotation mechanism 408 is, for example, composed of a pulley / belt 411 for transmitting the rotational driving force of the θ-axis motor 308 (which serves as a drive unit) to the shaft 403 on which the chuck 402 is mounted.

[0065] like Figure 5As shown, the pulley / belt section 411 consists of a gear 411a mounted on the rotating shaft of the θ-axis motor 308, a gear 411b mounted on the shaft 403, and a timing belt 411c serving as a transmission mechanism for transmitting the rotation of gear 411a to gear 411b. The rotation center 409 of gear 411b is located at the center 410 (point P1) of the shaft 403, which serves as the rotating shaft.

[0066] The rotation mechanism 408 of the placement head 420 transmits power from the θ-axis motor 308 to the rotating shaft 403, which is the driven part, using gears 411a and 411b and a timing belt 411c. The rotational resolution is refined by changing the number of teeth on gears 411a and 411b. The θ-axis motor 308 is primarily driven by a servo motor or a pulse motor equipped with an encoder. Using an encoder only on the driven side is generally not recommended as the drive side may become unstoppable in case of a malfunction. Furthermore, the placement head 420 requires a lifting mechanism, a vacuum suction mechanism, a rotation mechanism, and a load-bearing mechanism. To reduce the number of parts and minimize its size, the encoder is only mounted on the drive side. Therefore, the control device 14 only identifies the absolute position of gear 411a on the drive side.

[0067] use Figure 6 as well as Figure 7 This section explains the accuracy of the mechanical mechanism of the rotating mechanism 408. Figure 6 It is used for explanation Figure 5 A diagram showing the accuracy problem of the mechanical mechanism of the rotating mechanism. Figure 6 (a) is a diagram showing the positions of the gear on the driving side, the gear on the driven side, and the teeth of the belt. Figure 6 (b) shows the gear on the driven side. Figure 6 (a) shows the position of the gear and belt teeth on the drive side when the state has rotated one revolution. Figure 7 It is a graph showing the relationship between the command value and the actual rotation amount.

[0068] like Figure 6 As shown, even if the driven gear 411b rotates one revolution as designed, the positions of the teeth on the belt 411c and the drive gear 411a are different. Here, arrows a, b, and c indicate the specific positions of the teeth on each of the gears 411a, 411b, and timing belt 411c. Because gear 411b rotates one revolution, therefore, in… Figure 6 (a) and Figure 6 In (b), arrows b point in almost the same direction, and the positions of specific gear teeth are basically the same. Arrow a of gear 411a is... Figure 6 (a) and Figure 6In (b), the teeth are basically oriented in opposite directions, with specific teeth located almost on opposite sides relative to each other during rotation. Arrow c on timing belt 411c... Figure 6 (a) and Figure 6 (b) is located in a completely different position.

[0069] If there is an inherent tooth deviation in gears 411a, 411b and timing belt 411c, or a small center offset in the rotating mechanism 408 such as gears 411a, 411b, the θ angle of the driven gear 411b will have a small offset. Therefore, even if the specified angle (command value) of the driven gear 411b is set to the same value for one revolution, the rotation amount of one revolution of the driven gear 411b will not be the same as before one revolution. For example, offsets will occur at specified angles of 90 degrees and 360+90 degrees. That is, due to the precision problem of the mechanical mechanism of the rotating mechanism 408, the bare chip D may rotate too much or too little when desired. Therefore, as Figure 7 As shown, the measured values ​​fluctuate relative to the ideal values, with a displacement waveform existing periodically around the time when the meshing of gears 411a, 411b, and timing belt 411c occurs at the same time. Figure 7 In the process, when the gear 411a on the drive side rotates 5 times, the gear 411b on the driven side rotates 3 times, and the timing belt 411c rotates 2 times, the meshing becomes the same.

[0070] In this embodiment, during the simulation, the displacement (offset) of the measured rotation amount is mapped relative to the rotation mechanism 408 of the placement head 420, and corrections are made for excessive or insufficient rotation amount during continuous operation. The mapping is performed not only for one revolution of the collet 402 of the placement head 420, but also for at least one cycle of the combination of gears and timing belts, which are key components of the mechanism.

[0071] As a simulation operation, rotations are performed at a number of rotations that are common multiples of the number of teeth of the drive-side gear 411a, the driven-side gear 411b, and the timing belt 411c. Each time a predetermined angle is rotated, the displacement between a specified angle and the actual rotation amount of gear 411b is measured, and the measurement result is retained as mapping data. That is, the offset of the rotation amount relative to the relative positional relationships of all components constituting the rotating mechanism 408 is measured, and the measurement result is stored and recorded in the storage device of the control device 14. Here, as mapping data, not only data in one direction of rotation but also data in the opposite direction are acquired. For example, the common multiple of the number of teeth of the drive-side gear 411a, the driven-side gear 411b, and the timing belt 411c is the least common multiple. This reduces the number of measurements and the amount of mapping data. Alternatively, the mapping data can be calculated corresponding to multiple rotations that are least common multiples, and averaged for each of the aforementioned predetermined angles. This improves accuracy.

[0072] During continuous operation, based on the measured displacement and the positional relationship (absolute position) of the teeth of gears 411a, 411b and timing belt 411c, the offset after rotation to a specified position (specified angle) is anticipated. The commanded rotation amount is then corrected based on the mapping data obtained through simulated motion. That is, during continuous operation, the offset obtained for each commanded angle is fed back and rotated. Feedback is, for example, as follows: Figure 7 The command value is increased or decreased in a way that makes the curve of command value versus actual rotation a linear shape, as shown. In other words, the correction amount is determined based on the mapping data of the rotation offset and the absolute position of each component constituting the rotation mechanism 408, and the offset is fed back. Moreover, the correction amount for the reached position is calculated in advance, taking into account the offset expected from the reached position before the command value of the rotation is input, and the correction amount is determined and corrected in advance.

[0073] Furthermore, if the rotating mechanism 408 is manually rotated when the power is off, the absolute position will disappear. Therefore, the brake can be used to prevent it from rotating when the power is off, or the remeasurement can be performed automatically during startup.

[0074] use Figure 8 This illustrates an example of a method for measuring the displacement of rotation during a simulated motion. Figure 8 This is a diagram showing the markings on the collet.

[0075] The image processing device 301 uses a low-angle camera 204 to capture an image of the bottom surface of the collet 402 (the surface where the bare chip D is attached) from below. Two markings 402a and 402b are provided on the bottom surface of the collet 402. These markings 402a and 402b are, for example, circular. Here, the collet 402 is a rectangular shape matching the dimensions of the bare chip.

[0076] The image processing device 301 outputs a rotation amount command value to the rotating mechanism 408 via the position control device 302, and the rotating mechanism 408 rotates the collet 402 according to the rotation amount command value. The image processing device 301, via the position control device 302, causes the collet 402 to rotate by a predetermined angle, which is the minimum resolution unit of the rotating mechanism 408, each time. Each time the predetermined angle is rotated, the image processing device 301 uses the upward-view camera 204 to capture images of two markings 402a and 402b.

[0077] The image processing device 301 performs image processing such as binarization on the captured image of the bare chip D, and calculates and determines 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 angle (θ) formed by the straight line passing through the two centroid positions and the reference straight line, the image processing device 301 calculates (measures) the actual rotation amount (actual rotation amount) of the collet 402. The image processing device 301 saves (records) the offset (displacement amount) between the rotation amount command value (command angle) and the actual rotation amount (measurement result) as mapping data to the storage device of the image processing device 301 or the position control device 302.

[0078] Mapping data is recorded corresponding to the number of rotations that is the least common multiple of the number of teeth on the drive-side gear 411a, driven-side gear 411b, and timing belt 411c. For example, if the number of teeth on the drive-side gear 411a, driven-side gear 411b, and timing belt 411c are set to 6, 18, and 66 respectively, then the least common multiple is 198. Therefore, the drive-side gear 411a, driven-side gear 411b, and timing belt 411c rotate 33 times, 11 times, and 3 times respectively. Thus, the positional relationship of the teeth on the driven-side gear 411b becomes the same every time it rotates 11 times, thereby recording 11 times corresponding to the number of rotations 11 on the driven-side gear 411b.

[0079] Next, during continuous operation, that is, as part of the semiconductor device manufacturing process, the mounting head 420 picks up the bare die D from the wafer W, using... Figure 4 The order of mounting on substrate S is briefly explained.

[0080] The chip recognition camera 201 captures the surface of the bare chip D, the target of the chip W, and outputs the captured image to the image processing device 301. The image processing device 301 performs image processing on the captured image of the bare chip D, thereby calculating the center position (Xd, Yd, θd) of the bare chip D.

[0081] The substrate recognition camera 203 captures images of the designated bare chip bonding positions on the substrate S and outputs the captured images to the image processing device 301. The image processing device 301 performs image processing on the captured images of the substrate S to calculate the center position (Xm, Ym, θm) of the substrate S mounting position.

[0082] The position control device 302 also aligns the center position of the bare chip D calculated by the image processing device 301 with the rotation center (Xp, Yp, θp) of the collet 402. Here, the rotation center (Xp, Yp, θp) is the center of gravity position O. At this time, based on the offset in the rotation direction of the bare chip D, the offset in the rotation direction of the substrate S, and the mapping data of θ rotation, the image processing device 301 calculates the θ correction amount. Based on this θ correction amount, the position control device 302 performs θ correction on the collet 402 and picks up the bare chip D, which is the picking target, from the wafer W.

[0083] In this manner, the collet 402 of the placement head 420 moves toward the wafer W (point P0) and picks up the bare die D based on images captured by the die recognition camera 201 and the substrate recognition camera 203. After picking up, the collet 402 of the placement head 420 moves to point P2.

[0084] At point P2, align the rotation center (Xp, Yp, θp) of the collet 402 with the center of the mounting position (Xm, Ym, θm) and mount the bare chip D picked up from the wafer W onto the substrate S.

[0085] According to the embodiment, the rotational offset caused by the mechanical reasons of the rotating mechanism can be corrected, thereby improving the rotational accuracy of the mounting and improving the mounting accuracy.

[0086] <Variation Example>

[0087] Hereinafter, several representative modifications of the embodiments are illustrated. In the following description of the modifications, the same reference numerals as those in the above embodiments may be used for parts having the same structure and function as those described in the above embodiments. Moreover, the descriptions in the above embodiments are appropriately referenced to the extent that they do not contradict each other. In addition, a part of the above embodiments and all or part of multiple modifications may be appropriately combined to the extent that they do not contradict each other.

[0088] (First variation)

[0089] use Figure 9 Explain the chip mounting machine in the first variation. Figure 9 This is a schematic side view of the main parts of the chip mounting machine in the first variant.

[0090] The chip mounting machine 100 in the first modification is an apparatus that temporarily places a bare chip D picked up by the pick-up head 220 in the holding part (holding position) of the intermediate stage 330, picks up the placed bare chip D again by the mounting head 420, mounts it, and installs it on the substrate S that has been transported to the mounting position.

[0091] The chip placement machine 100 includes: a chip recognition camera 201 for recognizing the orientation of the bare chip D on the chip W; a stage recognition camera 205 for recognizing the orientation of the bare chip D placed on the intermediate stage 330; and a substrate recognition camera 203 for recognizing the mounting position of the substrate S on the placement stage 430.

[0092] In this variation, the posture offset between the recognition cameras must be corrected for the stage recognition camera 205, which participates in the picking by the placement head 420, and the substrate recognition camera 203, which participates in the placement to the placement position by the placement head 420.

[0093] Additionally, the chip placement machine 100 includes a tilting-angle camera 204 located between the intermediate stage 330 and the placement stage 430. The tilting-angle camera 204 observes from directly below the state of the bare chip D or the collet 402 held by the placement head 420 during its movement.

[0094] Next, use Figure 9 This section briefly explains the sequence in which the mounting head 420 picks up the bare chip D from the intermediate stage 330 and mounts it onto the substrate S.

[0095] The platform recognition camera 205 captures images of the surface of the bare chip D on the intermediate platform 330 and outputs the captured images to the image processing device 301. The image processing device 301 performs image processing on the captured images of the bare chip D to calculate the center position (Xd, Yd, θd) of the bare chip D.

[0096] The substrate recognition camera 203 captures images of the designated bare chip bonding positions on the substrate S and outputs the captured images to the image processing device 301. The image processing device 301 performs image processing on the captured images of the substrate S to calculate the center position (Xm, Ym, θm) of the mounting location of the substrate S.

[0097] The position control device 302 also aligns the center position of the bare chip D calculated by the image processing device 301 with the rotation center (Xp, Yp, θp) of the collet 402. At this time, based on the offset in the rotation direction of the bare chip D, the offset in the rotation direction of the substrate S, and the mapping data of 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 this θ correction amount and picks up the bare chip D, which is the picking target, from the intermediate stage 330.

[0098] In this manner, the collet 402 of the placement head 420 moves towards the intermediate stage 330 (point P3) and picks up the bare die D based on images captured by the stage recognition camera 205 and the substrate recognition camera 203. After picking up, the collet 402 of the placement head 420 moves to point P2.

[0099] At point P2, align the rotation center (Xp, Yp, θp) of the collet 402 with the center of the mounting position (Xm, Ym, θm) to mount the bare chip D picked up from the intermediate stage 330 onto the substrate S.

[0100] (Second variation)

[0101] The text explains the offset of the rotating mechanism, but sometimes positional offset occurs when changing collets. (Using...) Figure 10 as well as Figure 11 This indicates a positional shift during collet replacement. Figure 10 This is a cross-sectional view showing a portion of the mounting head. Figure 11 This is a diagram illustrating the θ offset of the bottom surface of the collet of the chip placement machine in the second variation. Figure 11 (a) is a diagram showing an image of the ideal bottom surface when the rotation command value is 0 degrees as captured by a camera at an upward angle. Figure 11 (b) is a diagram showing an example of an image of the bottom surface offset in the θ direction. Figure 11 (c) is a diagram showing an example of an image of the bottom surface offset in the X and Y directions.

[0102] like Figure 10 As shown, regarding the placement head 420, the collet 402, which is changed according to the size of the bare die, is fixed and mounted on the shaft 403, which serves as the fixing part, using a fixing tool 404. The collet 402 consists of a mounting part 402c and a bottom part 402d that holds the bare die D. There is inevitably a mechanical gap between the shaft 403 and the mounting part 402c of the collet 402; therefore, if fixed using the fixing tool 404, the center of the collet 402 may not be aligned with the rotation center. Figure 11 As shown, each replacement will result in an offset relative to the θ direction, X direction, and Y direction.

[0103] In this variation, for example, by using a camera with an upward viewing angle, correction data for the rotation center of the collet is created each time the collet is changed, based on the correction for the offset caused by the rotating mechanism in the previous embodiment. This automatically corrects for the offset of the rotation center during installation. The result is improved installation accuracy without affecting productivity.

[0104] use Figure 4 This describes a method for creating corrected mapping data when the rotation center position of collet 402 changes due to the angle of its rotation.

[0105] Similar to the embodiment, the image processing device 301 uses a low-angle camera 204 to capture an image of the bottom surface of the collet 402 (the surface where the bare chip D is attached) from below. Also similar to 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 this rotation amount command value. Similarly to the embodiment, the image processing device 301 uses the position control device 302 to rotate the collet 402 by a predetermined angle, such as the minimum resolution unit of the rotation mechanism 408, each time. Also similar to the embodiment, the image processing device 301 uses the low-angle camera 204 to capture images of markings 402a and 402b at each predetermined angle.

[0106] Similar to the embodiment, the image processing device 301 performs image processing such as binarization on the captured image of the bare chip D, and calculates and determines 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 that serves as the reference line, the image processing device 301 calculates (measures) the rotation center Ot of the collet 402 and the actual rotation amount (actual rotation amount). The image processing device 301 saves (records) the offset between the center point O and the rotation center Ot, and the offset between the rotation amount command value (command angle) and the actual rotation amount (measurement result) as mapping data to the storage device of the image processing device 301 or the position control device 302.

[0107] Similar to the embodiment, mapping data is recorded corresponding to the number of rotations that are a common multiple of the number of teeth of the gear 411a on the drive side, the gear 411b on the driven side, and the belt 411c.

[0108] For example, the image processing device 301 performs rotations corresponding to the aforementioned common multiples of rotations, setting the rotation amount command value to 0 degrees to 360 degrees, and performs image processing on the images captured by the upward-view camera 204 after each rotation action. Furthermore, in addition to storing the same rotation amount command value (command angle) and the offset (displacement, Δθ) between the actual rotation amount (measurement result) as in the embodiment, the image processing device 301 also stores the error of the X coordinate (ΔX) and the error of the Y coordinate (ΔY) as mapping data in the storage device of the control device 14.

[0109] The order in which the mounting head 420 picks up the bare chip D from the wafer W and mounts it onto the substrate S is the same as in the embodiment.

[0110] The above description, based on embodiments and variations, details the disclosure made by the inventors of the present invention. However, the disclosure is not limited to the above embodiments and variations, and various modifications are possible.

[0111] For example, in the embodiment, an example is described using a timing belt 411c as a transmission mechanism to transmit the rotation of gear 411a to gear 411b, but the transmission mechanism may also be a gear.

[0112] Furthermore, while the embodiments and variations describe a method for calculating θ using the centroids of two circular markers, it is also possible to replace the circular markers with a marker that forms a right angle with an edge parallel to the end of the lower surface of the collet. θ can also be determined from the direction of the line by detecting multiple edges of that line, or by registering a representative template model for pattern matching and determining θ from the detection results of that model or the direction formed between the detection results of multiple models.

[0113] The embodiments and variations illustrate an example of performing rotational correction before the placement head 420 picks up the bare die D. Alternatively, rotational correction can be performed without prior picking, and the bare die can be rotated and corrected during placement by the placement head 420 before placement.

[0114] Furthermore, the embodiments and variations illustrate an example of detecting the offset in the rotation direction when determining the position of a bare die on a wafer or intermediate stage. However, if the offset in the rotation direction is detected when the position of the bare die is determined by looking down after the placement head 420 picks up the bare die D, the bare die can be rotated and corrected before placement by the placement head 420.

[0115] In addition, examples of rotation correction have been described in the embodiments and variations, but for products that need to be mounted on a substrate at multiple rotation angles (e.g., 90 degrees, 180 degrees), rotation correction can also be performed while rotating each bare chip to the required angle.

[0116] Furthermore, while rotation correction of the placement head has been described in the embodiments and variations, it can also be applied to intermediate stages having a rotation mechanism that rotates the pickup head or holding portion. When applied to the pickup head, a low-angle camera serving as an imaging device is provided between the pickup device 112 and the intermediate stage 330, and below the pickup head 220, in the first variation. When applied to the intermediate stage, the intermediate stage 330 in the first variation is provided with the same rotation mechanism as the placement head 420, and a holding portion for holding the bare chip that rotates using the rotation mechanism; a stage recognition camera 205 is used as the imaging device.

[0117] In addition, the first variant has one pickup head and one mounting head, but it may also have two or more.

[0118] In addition, in the embodiments and variations, the surface of the bare chip is set to face upwards for mounting. However, it is also possible to flip the bare chip after picking it up, so that the back side of the bare chip faces upwards for mounting. In this case, an intermediate stage may not be required. This device is called a flip chip mounter.

[0119] In addition, while the example described in the embodiments is picking up a bare chip from a wafer, it can also be set up to pick it up from a tray or the like that containing the bare chips of the product.

Claims

1. A chip mounting apparatus characterized by comprising: Possessing: a holding section that holds a bare chip; a rotation mechanism that rotates a rotation shaft that supports the holding section; an imaging device that images the holding section; and a control device that controls the rotation mechanism and the imaging device, the rotation mechanism possesses a drive section, a first gear installed to the drive section, a second gear installed to the rotation shaft, and a transmission mechanism that transmits rotation of the first gear to the second gear, the control device is configured to: rotate the holding section by a prescribed rotation angle by the rotation mechanism, and image the surface of the holding section that contacts the bare chip by the imaging device every time the rotation angle is rotated, calculate the rotation amount of the holding section based on the imaged image, and calculate the offset amount of the rotation amount command value for each rotation angle from the rotation amount as mapping data, calculate the mapping data corresponding to the 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 prescribed 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 section by a number of rotations that is more than one rotation, and the direction of rotation is a first rotation direction and a second rotation direction that is opposite to the first rotation direction.

2. The chip mounting device according to claim 1, wherein the control device is configured to calculate the mapping data corresponding to the number of rotations that is a least common multiple of the common multiple.

3. The chip mounting device according to claim 1, wherein the control device is configured to calculate the mapping data corresponding to a plurality of numbers of rotations that are least common multiples, and average for each rotation angle.

4. The chip mounting device according to claim 1, wherein the control device is configured to perform rotation correction of the holding section based on the mapping data every time a bare chip is picked up or every time it is placed at a prescribed position.

5. The chip mounting device according to claim 4, wherein 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 chip mounting device according to claim 5, wherein the control device is configured to calculate the correction amount of the arrival position based on the offset amount expected from the arrival position before an instruction value of the rotation amount of the holding section is input.

7. The chip mounting device according to claim 1, wherein the holding section possesses two marks, the control device is configured to calculate the center of gravity position of each of the two marks based on the imaged image, and calculate the actual rotation amount of the holding section based on the calculated center of gravity positions.

8. The chip mounting device according to any one of claims 1 to 7, wherein the holding section is a collet that is installed to an accessory head that picks up a bare chip and places it at a prescribed position, the imaging device is provided below the accessory head.

9. The chip mounting device according to claim 8, wherein the accessory head is a mounting head that picks up a bare chip from a wafer and places it on a substrate.

10. The die attach apparatus of claim 8, wherein Further possessing: an intermediate stage; and a pickup head that picks up the bare chip from the wafer and places it on the intermediate stage, the attachment head is a mounting head that picks up the bare chip from the intermediate stage and places it on a substrate.

11. The chip mounting apparatus according to claim 8, wherein the control device is further configured to: calculate the center of rotation of the collet based on the captured image, calculate the offset of the center of rotation each time the rotation angle is rotated, and register the offset to the mapping data, perform position correction of the collet based on the mapping data each time the attachment head picks up the bare chip or each time it is placed at a prescribed position.

12. The chip mounting apparatus according to claim 11, wherein the offset of the center of rotation registered to the mapping data is an offset in the X direction, the Y direction, and the θ direction for each of the rotation angles.

13. The chip mounting apparatus according to claim 1, wherein the rotation shaft is composed of a shaft rod, the transmission mechanism is composed of a timing belt or a gear.

14. The chip mounting apparatus according to claim 1, wherein the holding section is provided at an intermediate stage on which a bare chip picked up from a wafer is placed, the imaging device is provided above the intermediate stage.

15. A method of manufacturing a semiconductor device, characterized by including: a step of carrying a wafer ring to a chip mounting apparatus having a holding section that holds a bare chip, a rotation mechanism that rotates a rotation shaft that supports the holding section, an imaging device that captures the holding section, and a control device that controls the rotation mechanism and the imaging device, the rotation mechanism having a driving section, a first gear attached to the driving section, 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 being configured to rotate the holding section by a prescribed rotation angle by the rotation mechanism, capture a surface of the holding section that contacts the bare chip by the imaging device each time the rotation angle is rotated, calculate a rotation amount of the holding section based on the captured image, and save, as mapping data, an offset of the rotation amount from a rotation amount command value for each of the rotation angles to a storage device, the mapping data being saved in correspondence with 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; and a step of performing rotation correction of the holding section based on the mapping data each time a bare chip is picked up or each time a bare chip is placed at a prescribed position, the prescribed rotation angle is an angle of a minimum resolution unit of the rotation mechanism, in calculating the mapping data, the rotation mechanism rotates the holding section by a number of rotations that is more than one rotation, and the direction of rotation is a first rotation direction and a second rotation direction that is opposite to the first rotation direction.

16. The method of manufacturing a semiconductor device according to claim 15, including: a step of picking up a bare chip from a wafer and placing the picked-up bare chip on a substrate.

17. The method of manufacturing a semiconductor device according to Claim 15, wherein including: a step of picking up a bare chip from a wafer and placing the picked-up bare chip on an intermediate stage; and A process of picking up a bare chip from the intermediate stage and placing the picked up bare chip on a substrate.

18. The method according to claim 15, wherein The center of rotation of the holding portion is calculated based on the captured image, the amount of shift of the center of rotation each time the rotation angle is rotated is calculated, and the mapping data is registered.

Images