Die bonding apparatus and method for manufacturing semiconductor device

Abstract

To provide a technology capable of distinguishing and recognizing a crack and a scratch.SOLUTION: A die bonding device includes an imaging device for imaging a die, an illumination device for radiating light at an angle at which the die is inclined at a prescribed angle to an optical axis of the imaging device, and a control part for controlling the imaging device and the illumination device. The control part is configured so as to change a horizontal radiation direction of the illumination light from the illumination device to image the die multiple times and distinguish whether a crack or a scratch is on the basis of a change in brightness of a scar formed on the die in a picked-up image.SELECTED DRAWING: Figure 7

Description

[Technical field]

[0001] The present disclosure relates to a die bonding apparatus and is applicable to, for example, a die bonding apparatus that performs surface inspection of a die. [Background technology]

[0002] Part of the manufacturing process for semiconductor devices is the process of mounting a semiconductor chip (hereinafter simply referred to as a die) on a wiring board or a lead frame (hereinafter simply referred to as a substrate) to assemble a package, and part of the process of assembling the package is the process of dividing the die from a semiconductor wafer (hereinafter simply referred to as a wafer) (dicing process) and the bonding process of mounting the divided die on the substrate. The semiconductor manufacturing equipment used in the bonding process is a die bonding device such as a die bonder.

[0003] In a process prior to the bonding process, for example, a dicing process, scratches may occur on the die. For example, JP 2020-13841 A (Patent Document 1) discloses a technology that uses a dark field method in which oblique illumination is applied to brightly project an object, and when an abnormality on the die surface is detected by imaging with a camera, it is determined from the captured image whether the abnormality is due to a scratch or a foreign object. Scratches on the die surface include scratches (scratches) that occur only on the surface of a protective film layer formed of a polyimide resin or the like, and scratches that penetrate the protective film layer and reach the silicon layer. In this specification, the former is called a scratch, and the latter is called a crack. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2020-13841 A Summary of the Invention [Problem to be solved by the invention]

[0005] Since the cracks reach the circuit area of ​​the die, elements with cracks should be treated as defective. On the other hand, scratches that only occur on the surface of the protective film layer do not destroy the circuit area, and depending on the type of semiconductor product, elements with only scratches may be treated as non-defective. However, in the case of small scratches that can only be observed with a microscope, rather than scratches that destroy the shape and are easily visible to the naked eye, when scratches on the surface of the die are detected by imaging with a camera using the technology shown in Patent Document 1, it is difficult to determine from the captured image whether the scratches are due to cracks or scratches.

[0006] An object of the present disclosure is to provide a technique capable of distinguishing and recognizing a crack from a scratch. Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0007] A brief summary of representative aspects of this disclosure is as follows. That is, the die bonding apparatus includes an imaging device that images a die, an illumination device that irradiates the die with light at a predetermined angle with respect to the optical axis of the imaging device, and a control unit that controls the imaging device and the illumination device. The control unit is configured to capture a plurality of images of the die with the imaging device by changing the horizontal irradiation direction of the illumination light from the illumination device, and to identify whether a scratch formed on the die is a crack or a scratch based on a change in brightness of the scratches formed on the die in the captured images. Effect of the Invention

[0008] According to the present disclosure, cracks and scratches can be distinguished and recognized. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic top view showing an example of the configuration of a die bonder in an embodiment. [Diagram 2]FIG. 2 is a diagram for explaining a schematic configuration when viewed from the direction of arrow A in FIG. [Diagram 3] FIG. 3 is a schematic cross-sectional view showing a main part of the die supply section shown in FIG. [Figure 4] FIG. 4 is a block diagram showing a schematic configuration of a control system of the die bonder shown in FIG. [Diagram 5] FIG. 5 is a flow chart illustrating the die bonding process in the die bonder shown in FIG. [Figure 6] FIG. 6 is a diagram showing the arrangement of lighting devices for the board recognition camera. [Figure 7] FIG. 7 is a schematic diagram illustrating the movement of the lighting device shown in FIG. [Figure 8] FIG. 8 is a conceptual diagram for explaining scratches and cracks. [Figure 9] Fig. 9(a) is a diagram showing a case where illumination light is irradiated onto a scratch from diagonally above on the right side, and Fig. 9(b) is a diagram showing a case where illumination light is irradiated onto a scratch from diagonally above on the front side. [Figure 10] Fig. 10(a) is a diagram showing a case where illumination light is irradiated from diagonally above the right side in a direction perpendicular to the crack direction, and Fig. 10(b) is a diagram showing a case where illumination light is irradiated from diagonally above the front side in a direction parallel to the crack direction. [Figure 11] FIG. 11 is a diagram showing the irradiation direction of the illumination light and the brightness of the scratch when there is a scratch on the die. [Figure 12] FIG. 12 is a diagram showing the irradiation direction of the illumination light and the brightness of the flaw when there is a crack in the die. [Figure 13] FIG. 13 is a diagram illustrating a lighting device according to a first modified example. [Figure 14] FIG. 14 is a diagram illustrating an illumination device in the second modified example. [Figure 15] FIG. 15 is a diagram illustrating an illumination device according to a third modified example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the embodiments and modifications will be described 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 order to clarify the description, the drawings may show the width, thickness, shape, etc. of each part in a schematic manner compared to the actual embodiment, but these are merely examples and do not limit the interpretation of the present invention.

[0011] Fig. 1 is a schematic top view showing the configuration of a die bonder in an embodiment, and Fig. 2 is a diagram illustrating the schematic configuration when viewed from the direction of arrow A in Fig. 1.

[0012] The die bonder 10 broadly comprises a die supply unit 1, a pickup unit 2, an intermediate stage unit 3, a bonding unit 4, a transport unit 5, a substrate supply unit 6, a substrate unloading unit 7, and a control unit 8 that monitors and controls the operation of each unit. The Y-axis direction is the front-rear direction of the die bonder 10, and the X-axis direction is the left-right direction. The die supply unit 1 is disposed on the front side of the die bonder 10, and the bonding unit 4 is disposed on the back side. Here, one or more product areas (hereinafter referred to as package areas P) that will eventually become one package are printed on the substrate S.

[0013] The die supply unit 1 has a wafer holder 12 that holds a wafer 11, and a push-up unit 13, shown by a dotted line, that pushes up a die D from the wafer 11. The die supply unit 1 moves in the XY directions by a driving means (not shown), and moves the die D to be picked up to the position of the push-up unit 13.

[0014] The pickup unit 2 has a pickup head 21 that picks up the die D, a pickup head Y drive unit 23 that moves the pickup head 21 in the Y direction, various drive units (not shown) that raise and lower, rotate and move the collet 22 in the X direction, and a wafer recognition camera 24. The pickup head 21 has a collet 22 that suction-holds the pushed-up die D at its tip, picks up the die D from the die supply unit 1 and places it on the intermediate stage 31. The pickup head 21 has various drive units (not shown) that raise and lower, rotate and move the collet 22 in the X direction.

[0015] The intermediate stage unit 3 has an intermediate stage 31 on which a die D is temporarily placed, and a stage recognition camera 32 for recognizing the die D on the intermediate stage 31.

[0016] The bonding unit 4 has a bonding head 41, a Y drive unit 43, and a substrate recognition camera 44. The bonding head 41 has a collet 42 that suctions and holds the die D at its tip, similar to the pickup head 21. The Y drive unit 43 moves the bonding head 41 in the Y-axis direction. The substrate recognition camera 44 captures an image of a position recognition mark (not shown) in the package area P of the substrate S and recognizes the bonding position. The bonding unit 4 picks up the die D from the intermediate stage 31 and bonds it on the package area P of the substrate S being conveyed, or bonds it by stacking it on a die already bonded on the package area P of the substrate S. With this configuration, the bonding head 41 corrects the pickup position and posture based on the imaging data of the stage recognition camera 32, and picks up the die D from the intermediate stage 31. Then, the bonding head 41 bonds the die D on the package area P of the substrate, or by stacking it on a die already bonded on the package area P of the substrate S, based on the imaging data of the substrate recognition camera 44.

[0017] The transport section 5 has a substrate transport claw 51 that grips and transports the substrate S, and a transport lane 52 along which the substrate S moves. The substrate S moves by driving a nut (not shown) of the substrate transport claw 51 provided on the transport lane 52 by a ball screw (not shown) provided along the transport lane 52. With this configuration, the substrate S moves from the substrate supply section 6 along the transport lane 52 to the bonding position, and after bonding, moves to the substrate unloading section 7 and hands the substrate S over to the substrate unloading section 7.

[0018] The control unit 8 includes a memory that stores a program (software) that monitors and controls the operation of each part of the die bonder 10, and a central processing unit (CPU) that executes the program stored in the memory.

[0019] Next, the configuration of the die supply section 1 will be described with reference to Fig. 3. Fig. 3 is a schematic cross-sectional view showing the main part of the die supply section shown in Fig. 1.

[0020] The die supply unit 1 includes a wafer holder 12 that moves horizontally (XY directions) and a push-up unit 13 that moves up and down. The wafer holder 12 has an expand ring 15 that holds a wafer ring 14, and a support ring 17 that horizontally positions a dicing tape 16 that is held by the wafer ring 14 and has multiple dies D attached thereto. The push-up unit 13 is disposed inside the support ring 17.

[0021] When the die D is pushed up, the die supply unit 1 lowers the expand ring 15 holding the wafer ring 14. As a result, the dicing tape 16 held by the wafer ring 14 is stretched, and the interval between the dies D is widened, and the push-up unit 13 pushes up the dies D from below, improving the pick-up property of the dies D. In addition, as the wafer is thinned, the adhesive that bonds the dies to the substrate changes from liquid to film, and a film-like adhesive material called a die attachment film (DAF) 18 is attached between the wafer 11 and the dicing tape 16. In the wafer 11 having the die attachment film 18, dicing is performed on the wafer 11 and the die attachment film 18. Therefore, in the peeling process, the wafer 11 and the die attachment film 18 are peeled off from the dicing tape 16.

[0022] The die bonder 10 has a wafer recognition camera 24 that recognizes the posture of the die D on the wafer 11, a stage recognition camera 32 that recognizes the posture of the die D placed on the intermediate stage 31, and a board recognition camera 44 that recognizes the mounting position on the bonding stage BS. The recognition cameras that must correct the posture deviation are the stage recognition camera 32 involved in picking up by the bonding head 41, and the board recognition camera 44 involved in bonding to the mounting position by the bonding head 41. In this embodiment, a surface inspection of the die D is performed using a lighting device described later together with the wafer recognition camera 24, stage recognition camera 32, and board recognition camera 44.

[0023] Next, the control unit 8 will be described with reference to FIG. 4. FIG. 4 is a block diagram showing a schematic configuration of the control system of the die bonder shown in FIG. 1. The control system 80 includes the control unit 8, a drive unit 86, a signal unit 87, and an optical system 88. The control unit 8 mainly includes a control / arithmetic unit 81 mainly composed of a CPU, a storage unit 82, an input / output unit 83, a bus line 84, and a power supply unit 85. The storage unit 82 includes a main storage unit 82a composed of a RAM storing processing programs and the like, and an auxiliary storage unit 82b composed of an HDD, an SSD, or the like storing control data and image data required for control. The input / output unit 83 includes a monitor 83a displaying the device status and information, a touch panel 83b for inputting an operator's instructions, a mouse 83c for operating the monitor, and an image capture unit 83d for capturing image data from the optical system 88. The input / output device 83 also has a motor control device 83e which controls drive units 86 such as the XY table (not shown) of the die supply unit 1 and the ZY drive shaft of the bonding head table, and an I / O signal control device 83f which takes in or controls signals from a signal unit 87 such as various sensor signals and switches for lighting devices, etc. The optical system 88 includes the wafer recognition camera 24, the stage recognition camera 32, and the substrate recognition camera 44. The control / arithmetic unit 81 takes in necessary data via the bus line 84, performs calculations, and controls the pickup head 21, etc., and sends information to the monitor 83a, etc.

[0024] The control unit 8 stores image data captured by the wafer recognition camera 24, the stage recognition camera 32, and the substrate recognition camera 44 in the storage device 82 via the image capture device 83d. Using software programmed based on the stored image data, the control and calculation device 81 is used to position the package area P of the die D and the substrate S, and to inspect the surfaces of the die D and the substrate S. Based on the positions of the package area P of the die D and the substrate S calculated by the control and calculation device 81, the software drives the drive unit 86 via the motor control device 83e. This process positions the die on the wafer, and the pickup unit 2 and the bonder 4 are operated by the drive units to bond the die D onto the package area P of the substrate S. The wafer recognition camera 24, the stage recognition camera 32, and the substrate recognition camera 44 used are grayscale or color cameras, etc., and convert light intensity into numerical values. The wafer recognition camera 24, the stage recognition camera 32, and the substrate recognition camera 44 are also called imaging devices.

[0025] Next, a die bonding step, which is one step in the method for manufacturing a semiconductor device, will be described with reference to Fig. 5. Fig. 5 is a flow chart for explaining the die bonding step in the die bonder shown in Fig. 1.

[0026] (Wafer loading: process P1) In the die bonding process of the embodiment, first, control unit 8 removes wafer ring 14 holding wafer 11 from a wafer cassette, places it on wafer holder 12, and transports wafer holder 12 to a reference position where die D is picked up. Next, control unit 8 performs fine adjustment based on an image acquired by wafer recognition camera 24 so that the placement position of wafer 11 accurately coincides with the reference position.

[0027] (Die transport: Process P2) Next, the control unit 8 moves the wafer holder 12 on which the wafer 11 is placed by a predetermined pitch and holds it horizontally to place the first die D to be picked up at the pick-up position. The wafer 11 is inspected in advance for each die by an inspection device such as a prober, and map data indicating whether each die is good or bad is generated and stored in the storage device 82 of the control unit 8. The map data is used to determine whether the die D to be picked up is good or bad. If the die D is bad, the control unit 8 moves the wafer holder 12 on which the wafer 11 is placed by a predetermined pitch, places the next die D to be picked up at the pick-up position, and skips the defective die D.

[0028] (Die positioning: Process P3) The control unit 8 photographs the main surface (top surface) of the die D to be picked up by the wafer recognition camera 24, and calculates the amount of positional deviation of the die D to be picked up from the above-mentioned pick-up position from the acquired image. The control unit 8 moves the wafer holder 12 on which the wafer 11 is placed based on the amount of positional deviation, and accurately places the die D to be picked up at the pick-up position.

[0029] (Die surface inspection: process P4) Next, the control unit 8 performs a surface inspection of the die D from the image acquired by the wafer recognition camera 24. Here, if the control unit 8 determines that there is no problem with the surface of the die D, it proceeds to the next process (process P9 described below), but if it determines that there is a problem, it performs skip processing or stops due to an error. The skip processing skips processes P9 and onward for the die D, moves the wafer holder 12 on which the wafer 11 is placed at a predetermined pitch, and places the next die D to be picked up at the pick-up position.

[0030] (Board loading: process P5, board transport: process P6) The control unit 8 causes the board supply unit 6 to place the board S on the transport lane 52. The control unit 8 causes the board transport claws 51, which grip and transport the board S, to move to the bonding position.

[0031] (Board positioning: process P7) The control unit 8 captures an image of the substrate S with the substrate recognition camera 44 and positions the substrate S based on the captured image.

[0032] (Substrate surface inspection: process P8) Next, the control unit 8 performs a surface inspection of the package area P of the board S from the image acquired by the board recognition camera 44. Here, the control unit 8 judges whether there is a problem in the surface inspection, and if it judges that there is no problem in the surface of the package area P of the board S, it proceeds to the next process (process P9 described below). If the control unit 8 judges that there is a problem in the surface inspection, it visually checks the surface image, or further performs a high-sensitivity inspection or an inspection with changed lighting conditions, and if there is a problem, it performs a skip process, and if there is no problem, it performs the process of the next process. The skip process skips process P10 and subsequent processes for the relevant tab of the package area P of the board S, and registers the defect in the board process start information.

[0033] (Pickup: Process P9, Place on intermediate stage: Process P10) The control unit 8 causes the die supply unit 1 to accurately position the die D to be picked up at the pick-up position, and then causes the pick-up head 21 including the collet 22 to pick up the die D from the dicing tape 16 and place it on the intermediate stage 31.

[0034] (Die position inspection: process P11) The control unit 8 detects a misalignment (rotational misalignment) of the die placed on the intermediate stage 31 by capturing an image using the stage recognition camera 32. If there is a misalignment, the control unit 8 corrects the misalignment by rotating the intermediate stage 31 in a plane parallel to the mounting surface having the mounting position using a rotation drive device (not shown) provided on the intermediate stage 31.

[0035] (Die surface inspection: process P12) The control unit 8 performs a surface inspection of the die D from the image acquired by the stage recognition camera 32. Here, if the control unit 8 determines that there is no problem with the surface of the die D, it proceeds to the next process (process P13 described below), but if it determines that there is a problem, it performs skip processing or stops due to an error. In skip processing, the die is placed on a defective product tray (not shown) or the like, and processes P13 and after for the die D are skipped, the wafer holder 12 on which the wafer 11 is placed is moved at a predetermined pitch, and the next die D to be picked up is placed at the pick-up position.

[0036] (Die bonding: process P13) The control unit 8 picks up a die D from the intermediate stage 31 by a bonding head 41 including a collet 42 and bonds the die to a package area P of the substrate S or to a die already bonded to a package area P of the substrate S.

[0037] (Inspection of the relative position between the die and the substrate: process P14) After bonding the die D, the control unit 8 inspects whether the bonding position is accurate by capturing images of the die D and the substrate S with the substrate recognition camera 44. At this time, the center of the die and the center of the tab are obtained, and it is inspected whether the relative positions are correct.

[0038] (Surface inspection of die and substrate: process P15) Next, the control unit 8 performs a surface inspection of the die D and the substrate S from the image acquired by the substrate recognition camera 44. If the control unit 8 determines that there is no problem with the surface of the die D, it proceeds to the next process (process P9 described below), but if it determines that there is a problem, it performs a skip process or stops due to an error. In the skip process, it registers a defect in the substrate processing start information.

[0039] (Board transport: process P16, board unloading: process P17) Thereafter, following the same procedure, the dies D are bonded one by one to the package areas P of the substrate S. When bonding for one substrate is completed, the substrate transport claws 51 move the substrate S to the substrate unloading section 7 and deliver the substrate S to the substrate unloading section 7.

[0040] (Wafer unloading: process P18) Thereafter, the dies D are peeled off one by one from the dicing tape 16 following the same procedure (step P9). When picking up all the dies D except for the defective ones is completed, the dicing tape 16 and the wafer ring 14 that have been holding the dies D in the shape of the wafer 11 are unloaded into a wafer cassette.

[0041] The surface inspection for cracks may be performed at least at one of the die supply unit 1, the intermediate stage unit 3, and the bonding unit 4, which are the locations where die position recognition is performed, but it is more preferable to perform it at all locations. If it is performed at the die supply unit 1, cracks can be detected early. If it is performed at the intermediate stage unit 3, cracks that could not be detected at the die supply unit 1 or cracks that occurred after the pick-up process (cracks that did not become apparent before the bonding process) can be detected before bonding. Also, if it is performed at the bonding unit 4, cracks that could not be detected at the die supply unit 1 and the intermediate stage unit 3 (cracks that did not become apparent before the bonding process) or cracks that occurred after the bonding process can be detected before bonding when the next die is stacked, or before the substrate is discharged.

[0042] Next, illumination for surface inspection will be described with reference to Fig. 6 and Fig. 7. Fig. 6 is a diagram showing the arrangement of the illumination device of the board recognition camera. Fig. 7 is a schematic diagram explaining the movement of the illumination device in Fig. 6.

[0043] As shown in FIG. 6, the substrate recognition camera 44 is disposed perpendicular to the surface of the die D. In other words, the optical axis is perpendicular to the surface of the die D. The illumination device 45 is an oblique illumination device, and irradiates the die D at a predetermined angle (θ) with respect to the optical axis. The incident angle (θ) of this illumination light IL is preferably less than 45 degrees, and more preferably 5 to 15 degrees. Also, as shown in FIG. 7, the illumination device 45 can rotate within a horizontal plane with the optical axis as the central axis. Here, a scratch K is shown on the surface of the die D in FIG. 7.

[0044] Here, scratches and cracks will be explained with reference to Fig. 8. Fig. 8 is a conceptual diagram for explaining scratches and cracks.

[0045] The scratch Ks is generated as if some kind of collision object CLL scrapes the surface. It depends on the collision pressure at this time, but it is thought that the collision object CLL moves on the surface of the die D in an area close to the surface of the die D and collides while bouncing slightly. The crack Kc is generated, for example, by pressure PRS applied from the bottom of the die D, so that it grows in accordance with the stacking structure of the die D or the crystal direction of the silicon, and is likely to form in a direction close to the direction along the side of the die D.

[0046] In other words, the scratch Ks is a broken line-shaped scratch (scratch) that is relatively shallow. The scratch Ks is one of the scratches K on the surface of the die D that occurs near the surface layer of a protective film layer formed of a polyimide resin or the like. On the other hand, the crack Kc is a continuous linear scratch that is deeper than the scratch Ks. The crack Kc penetrates the protective film layer and reaches the silicon layer. The scratch Ks is generated on the wafer surface during certain processes such as the backgrinding process.

[0047] Next, the mechanism by which the scratch Ks and crack Kc are visualized differently depending on the illumination direction will be described with reference to Figs. 9(a), 9(b), 10(a) and 10(b). Fig. 9(a) is a diagram showing a case where illumination light is irradiated onto the scratch from diagonally above the right side. Fig. 9(b) is a diagram showing a case where illumination light is irradiated onto the scratch from diagonally above the front side. Fig. 10(a) is a diagram showing a case where illumination light is irradiated from diagonally above the right side in a direction perpendicular to the crack direction. Fig. 10(b) is a diagram showing a case where illumination light is irradiated from diagonally above the front side in a direction parallel to the crack direction.

[0048] When observing using the dark field method, which uses illumination light IL to brighten scratches, the scratches are made visible by the reflection of light on the sides of (the inside of) the minute scratches. Since the sides of the scratch Ks are not continuous, each scratch has independent sides facing all directions (multiple directions). For this reason, each scratch is made visible almost independently of the direction of illumination light, and can be seen no matter what direction the illumination light is applied from.

[0049] On the other hand, crack Kc has a continuous linear scratch, so the side is also continuous, and the scratch becomes visible depending on the irradiation direction of the illumination light more than scratch Ks. Therefore, in the horizontal direction, the light hits the side by irradiating the illumination light from a direction different from the direction in which the crack Kc extends. If the illumination light is irradiated from a direction close to perpendicular to the direction in which the crack Kc extends, the light can be reflected efficiently. On the other hand, if the light is irradiated parallel to the crack direction of crack Kc in the horizontal direction, the light does not hit the side efficiently, and as a result, crack Kc is not very visible.

[0050] Next, a method for distinguishing between scratches Ks and cracks Kc will be described with reference to Fig. 11 and Fig. 12. Fig. 11 is a diagram showing the brightness of a scratch when the direction of illumination light applied to the scratch is changed. Fig. 12 is a diagram showing the brightness of a scratch when the direction of illumination light applied to the crack is changed.

[0051] As shown in FIG. 7, the control unit 8 rotates the horizontal irradiation direction of the illumination light IL by rotating the illumination device 45. Then, the control unit 8 captures a plurality of captured images by capturing images of the die D at predetermined angles or at arbitrary angular intervals in the horizontal direction of the illumination device 45 using the substrate recognition camera 44. At this time, as shown in FIG. 11 and FIG. 12, the brightness of the scratches Ks and the cracks Kc in the captured images both change, but the change in brightness of the cracks Kc is greater than the change in brightness of the scratches Ks. A threshold value (Bth) is determined based on a ratio to the highest brightness, and the control unit 8 determines that a crack Kc is below or equal to the threshold value (Bth), and that a scratch Ks is above or equal to the threshold value (Bth). As described above, the cracks Kc are likely to be formed in a direction close to the direction along the side of the die D, so the irradiation direction may be at least two directions, a direction approximately perpendicular to one side of the die D and a direction approximately perpendicular to that direction, as shown by the straight arrow in FIG. 7. Even if the crack Kc is formed in a direction other than the direction along the edge of the die D, it is possible to determine whether or not the crack is formed because the difference in brightness of the crack when irradiated from the two directions described above is greater than the difference in brightness of the scratch Ks.

[0052] According to this embodiment, the difference in reflection characteristics depending on the shape of the scratch Ks and the crack Kc is utilized, so that the scratch Ks and the crack Kc can be distinguished from each other. This improves the discrimination ability of the inspection function in the die bonder. Also, based on the judgment result, the crack Kc can be treated as defective and the scratch Ks as non-defective. This improves the yield of products assembled by the die bonder. Also, when a scratch Ks occurs, production can be continued without stopping the production operation of the device due to an error call, etc., and this improves the throughput.

[0053] The illumination devices of the wafer recognition camera 24 and the stage recognition camera 32 in the surface inspection have the same configuration as the illumination device 45. Note that the illumination devices of the wafer recognition camera 24, the stage recognition camera 32, and the substrate recognition camera 44 in the positioning and position inspection use, for example, coaxial illumination.

[0054] <Modification> Below, some representative modified examples of the embodiment are exemplified. In the following description of the modified examples, the same reference numerals as those in the above-mentioned embodiment may be used for parts having the same configuration and function as those described in the above-mentioned embodiment. The description of such parts may be appropriately cited within the scope of technical inconsistency. Furthermore, a part of the above-mentioned embodiment and all or a part of the multiple modified examples may be appropriately applied in a composite manner within the scope of technical inconsistency.

[0055] (First Modification) The illumination device in the first modified example will be described with reference to Fig. 13. Fig. 13 is a diagram for explaining the illumination device in the first modified example.

[0056] The illumination device 45 does not have to be rotated as in the embodiment. The illumination device 45 in the first modification is configured with a ring-shaped oblique illumination, and is configured to be divided into a plurality of regions 45a to 45h, each of which can be independently controlled to be turned on and off. The illumination device 45 may be turned on and off in a different direction to change the illumination light irradiation direction to observe the brightness of the scratch. FIG. 13 shows an example in which the ring-shaped oblique illumination is divided into eight regions, but is not limited to this. It is sufficient that the illumination light has at least two horizontal irradiation directions, a direction substantially perpendicular to one side of the die D and a direction substantially perpendicular to the direction, and the number of divisions may be four.

[0057] (Second Modification) The illumination device in the second modified example will be described with reference to Fig. 14. Fig. 14 is a diagram for explaining the illumination device in the second modified example.

[0058] The illumination device 45 does not have to be in the shape of a rotating locus or a circle. As shown in the figure, the illumination device 45 in the second modified example may be configured with two-directional bar illuminations 45j, 45k, and the bar illuminations 45j, 45k may be turned on to observe the change in brightness of the scratch at that time. The illumination light is irradiated in two directions in the horizontal direction: a direction approximately perpendicular to one side of the die D, and a direction approximately perpendicular to that direction. In the second modified example, the two-directional bar illumination has been described as an example, but four-directional bar illumination may also be used.

[0059] (Third Modification) The illumination device in the third modified example will be described with reference to Fig. 15. Fig. 15 is a diagram for explaining the illumination device in the third modified example.

[0060] The illumination device 45 in the third modified example has a constant incidence angle θ of the light incident direction on the die D, and changes the horizontal direction. The incidence angle (θ) may be changed as appropriate depending on the scratches Ks and cracks Kc. As described above, the incidence angle (θ) is preferably less than 45 degrees, and more preferably 5 to 15 degrees, so the incidence angle (θ) is changed within that range. The changed incidence angle (θ) is fixed and the horizontal incidence direction is changed. For example, first, the incidence angle (θ) is fixed to a first angle (θ1) (θ=θ1), the illumination device 45 is rotated in a horizontal plane to change the horizontal incidence direction, and the change in the brightness of the scratches is observed. Next, the incidence angle (θ) is fixed to a second angle (θ2) (θ=θ2), and the illumination device 45 is rotated in a horizontal plane to change the horizontal incidence direction, and the change in the brightness of the scratches is observed. Here, θ1<θ2. This allows the difference in brightness of the cracks Kc to be larger than in the embodiment.

[0061] (Fourth Modification) The illumination device 45 in the fourth modified example may change the wavelength of light for the die D. The wavelength of the light is preferably shorter than the green wavelength that has an absorption region in the surface protective film (e.g., polyimide film), and may be in the ultraviolet light region. This provides a larger difference in the amount of light that reaches the crack Kc below the protective film and the scratch Ks on the upper surface due to absorption by the surface protective film (e.g., polyimide film), and further increases the difference in brightness of the light reflected from the crack Kc and the scratch Ks.

[0062] In this case, the incident angle (θ) of the light may be greater than 45 degrees. This is because the path of the light that reaches under the protective film is made longer, which leads to a greater difference in the amount of light that reaches the crack Kc under the protective film and the scratch Ks on the surface, thereby making it possible to increase the difference in brightness of the respective reflected lights.

[0063] Furthermore, multiple captured images may be obtained by capturing images of the die D at two or more light incidence angles (θ), each of which is captured with normal white visible light at angles less than 45 degrees and with a wavelength shorter than green that has an absorption region in the surface protective film (e.g., polyimide film) at angles greater than 45 degrees, at predetermined angles or at any angle intervals in the horizontal direction of the illumination device 45. This makes it possible to distinguish between scratches Ks and cracks Kc without further reducing the detection rate of cracks Kc.

[0064] The invention made by the present inventors has been specifically described above based on embodiments and modifications. However, it goes without saying that the present disclosure is not limited to the above embodiments and modifications, and various modifications are possible.

[0065] For example, in the embodiment, the die appearance inspection recognition is performed after the die position recognition, but the die position recognition may be performed after the die appearance inspection recognition.

[0066] Also, in the embodiment, a DAF is attached to the back surface of the wafer, but the DAF may be omitted.

[0067] In addition, although the embodiment includes one pick-up head and one bonding head, there may be two or more of each. Also, although the embodiment includes an intermediate stage, there may be no intermediate stage. In this case, the pick-up head and the bonding head may be combined.

[0068] In the embodiment, the die is bonded with the front side facing up, but after picking up the die, it may be turned over and bonded with the back side facing up. In this case, the intermediate stage does not need to be provided. This device is called a flip chip bonder. [Explanation of symbols]

[0069] 10 Die bonder (die bonding device) 44 Circuit board recognition camera (imaging device) 45 Lighting equipment 8. Control section D...Die K...scar Kc... crack Ks...scratch

Claims

1. an imaging device for imaging the die; an illumination device that irradiates the die with light at a predetermined angle with respect to the optical axis of the imaging device; A control unit that controls the imaging device and the lighting device; Equipped with The control unit of the die bonding apparatus is configured to capture multiple images of the die using the imaging device while changing the horizontal irradiation direction of the illumination light from the illumination device, and to identify whether a scratch is a crack or a scratch based on changes in brightness of the scratches formed on the die in the captured images.

2. 2. The die bonding apparatus according to claim 1, The control unit is configured to recognize a scratch formed on the die as a crack when an image shows that the brightness of the scratch is below a predetermined value.

3. 3. The die bonding apparatus according to claim 2, The control unit is configured to recognize a scratch as a scratch when an image shows that the brightness of a scratch formed on the die is equal to or greater than a predetermined value.

4. 2. The die bonding apparatus according to claim 1, The control unit is configured to change a horizontal irradiation direction of illumination light by rotating the illumination device in a horizontal direction.

5. 2. The die bonding apparatus according to claim 1, The illumination device is configured as a ring illumination device formed of a plurality of regions that can be turned on and off independently, The control unit is configured to change the horizontal irradiation direction of the illumination light by lighting a specific area among the plurality of areas.

6. 2. The die bonding apparatus according to claim 1, The lighting device is configured by a plurality of bar lighting devices that can be turned on and off independently, The control unit is configured to change a horizontal irradiation direction of illumination light by turning on a specific bar illumination device among the plurality of bar illumination devices.

7. 5. The die bonding apparatus according to claim 4, The control unit is configured to change the incidence angle of the illumination device and rotate the illumination device horizontally to change the irradiation direction of the illumination light in the vertical and horizontal directions.

8. 2. The die bonding apparatus of claim 1, further comprising: a die supply unit having a wafer ring holder for holding a dicing tape to which the die is attached; The control unit of the die bonding apparatus captures an image of the die attached to the dicing tape using the imaging device and the lighting device.

9. 2. The die bonding apparatus of claim 1, further comprising: a bonding head for bonding the die onto a substrate or onto an already bonded die; The control unit is a die bonding apparatus that uses the imaging device and the illumination device to capture an image of a die bonded onto the substrate or die.

10. 2. The die bonding apparatus of claim 1, further comprising: A pick-up head for picking up the die; an intermediate stage on which the picked-up die is placed; Equipped with The control unit of the die bonding apparatus uses the imaging device and the lighting device to capture an image of a die placed on the intermediate stage.

11. (a) carrying a substrate into a die bonding apparatus including an imaging device for imaging a die, an illumination device for irradiating the die with light at a predetermined angle with respect to an optical axis of the imaging device, and a control unit for controlling the imaging device and the illumination device, the control unit being configured to change the horizontal irradiation direction of the illumination light from the illumination device to take a plurality of images of the die with the imaging device, and to recognize cracks based on brightness of scratches formed on the die in the captured images; (b) carrying in a wafer ring holder holding a dicing tape having a die attached thereto; (c) picking up the die; (d) bonding the picked up die onto the substrate or onto a die already bonded to the substrate; A method for manufacturing a semiconductor device comprising the steps of:

12. 12. The method of manufacturing a semiconductor device according to claim 11, The step (c) includes placing the picked-up die on an intermediate stage; The step (d) comprises picking up the die placed on the intermediate stage.

13. The method of manufacturing a semiconductor device according to claim 11, further comprising: (e) before the step (c), performing a surface inspection of the die using the imaging device and the illumination device.

14. The method of manufacturing a semiconductor device according to claim 11, further comprising: (f) after the step (d), performing a surface inspection of the die using the imaging device and the illumination device.

15. The method of manufacturing a semiconductor device according to claim 12, further comprising: (g) performing a surface inspection of the die using the imaging device and the illumination device after the step (c) and before the step (d).

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