KR20220161174A - Die bonding device and manufacturing method of semiconductor device - Google Patents

Abstract

Provided is the technology capable of distinguishing and recognizing cracks and scratches. A die bonding device includes an imaging device which captures an image of a die, an illumination device which irradiates light at a predetermined angle with respect to an optical axis of the imaging device, and a control unit which controls the imaging device and the illumination device. The control unit is configured to change an irradiation direction of illumination light from the lighting device in a horizontal direction to capture multiple images of the dies with the imaging device, and, based on a change in brightness of a scratch formed on the die in the captured image, to discriminate whether it is a crack or a scratch.

Description

Die bonding device and manufacturing method of semiconductor device {DIE BONDING DEVICE AND MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE}

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.

Part of the manufacturing process of a semiconductor device includes a step of assembling a package by 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 board). In part, there is a process of dividing dies from a semiconductor wafer (hereinafter simply referred to as a wafer) (dicing process) and a bonding process of mounting the divided dies on a substrate. A semiconductor manufacturing device used in the bonding process is a die bonding device such as a die bonder.

In a process prior to the bonding process, for example, a dicing process, there are cases where scratches occur on the die. For example, in Japanese Unexamined Patent Publication No. 2020-13841 (Patent Document 1), when an abnormality on the surface of a die is detected by image pickup with a camera by a dark field method in which oblique light is emitted to brightly illuminate an object, the abnormality A technique for judging from a captured image whether the scratch is caused by a foreign material is disclosed. The scratches on the surface of the die include scratches (scratches) only on the surface layer that occur in the protective film layer formed of polyimide-based resin or the like, and scratches that pass through the protective film layer and reach the silicon layer. In this specification, the former is referred to as a scratch, and the latter is referred to as a crack.

Japanese Unexamined Patent Publication No. 2020-13841

Since the cracks reach the circuit area of the die, devices with cracks must be treated as defective. On the other hand, in the case of scratches only on the surface layer of the protective film layer, the circuit area is not destroyed, and depending on the type of semiconductor product, there are cases where a device having only scratches is treated as a good product. However, in the case of small scratches that can be observed only with a microscope or the like, rather than simply visually destructive scratches, the technique disclosed in Patent Document 1 detects scratches on the surface of the die by imaging with a camera. , it is difficult to determine from a captured image whether the flaw is due to a crack or a scratch.

An object of the present disclosure is to provide a technique capable of distinguishing and recognizing cracks and scratches. Other problems and novel features will become clear from the description of the present specification and accompanying drawings.

A brief outline of representative ones of the present disclosure is as follows.

That is, the die bonding device includes an imaging device that captures an image of a die, a lighting device that irradiates light at a predetermined angle with respect to an optical axis of the imaging device, and a control unit that controls the imaging device and the lighting device. to provide The control unit changes the irradiation direction of the illumination light from the lighting device in the horizontal direction, captures a plurality of images of the die by the imaging device, and based on a change in brightness of a scratch formed on the die in the captured image, , configured to identify whether it is a crack or a scratch.

According to the present disclosure, cracks and scratches can be distinguished and recognized.

1 is a schematic top view showing a configuration example of a die bonder in an embodiment.
FIG. 2 is a diagram explaining a schematic configuration when viewed from the direction of arrow A in FIG. 1 .
Fig. 3 is a schematic sectional view showing a main part of the die supply section shown in Fig. 1;
Fig. 4 is a block diagram showing a schematic configuration of a control system of the die bonder shown in Fig. 1;
FIG. 5 is a flowchart for explaining a die bonding process in the die bonder shown in FIG. 1;
6 is a diagram showing the arrangement of a lighting device of a substrate recognition camera.
FIG. 7 is a schematic view illustrating movement of the lighting device shown in FIG. 6 .
8 is a conceptual diagram explaining scratches and cracks.
Fig. 9(a) is a diagram showing a case where illumination light is irradiated from a right oblique upward direction with respect to scratches. Fig. 9(b) is a diagram showing a case where illumination light is irradiated from above obliquely on the front side with respect to scratches.
Fig. 10(a) is a view showing a case where illumination light is irradiated from a right-angled upward direction in a direction perpendicular to the crack direction. Fig. 10(b) is a diagram showing a case where illumination light is irradiated from above at an angle on the front side in a direction parallel to the direction of crack cracking.
Fig. 11 is a diagram showing the irradiation direction of illumination light and the brightness of scratches when there are scratches on the die.
Fig. 12 is a diagram showing the irradiation direction of illumination light and the brightness of flaws when there is a crack in the die.
Fig. 13 is a diagram explaining a lighting device according to a first modified example.
14 is a diagram explaining a lighting device according to a second modified example.
Fig. 15 is a diagram explaining a lighting device according to a third modified example.

Hereinafter, embodiments and modified examples will be described using drawings. However, in the following description, the same reference numerals are given to the same constituent elements, and repetitive explanations are omitted in some cases. In addition, in order to make explanation clearer, although the width, thickness, shape, etc. of each part are schematically shown compared with an actual embodiment, it is an example only and does not limit the interpretation of this invention. .

1 is a schematic top view showing the configuration of a die bonder in an embodiment. FIG. 2 is a diagram explaining a schematic configuration when viewed from the direction of arrow A in FIG. 1 .

The die bonder 10 is largely divided into a die supply unit 1, a pick-up unit 2, an intermediate stage unit 3, a bonding unit 4, a transfer unit 5, and a substrate supply unit 6. and a substrate carrying out unit 7 and a control unit 8 that monitors and controls the operation of each unit. The Y-axis direction is the front-back 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 rear side. Here, on the substrate S, one or a plurality of product areas (hereinafter referred to as package areas P), which ultimately become one package, are printed.

The die supply unit 1 has a wafer holder 12 for holding the wafer 11 and a lifting unit 13 indicated by a dotted line for pushing the die D up from the wafer 11 . The die supply unit 1 is moved in the XY direction by a drive unit (not shown) to move the die D to be picked up to the position of the lifting unit 13 .

The pick-up unit 2 includes a pick-up head 21 that picks up the die D, a Y drive part 23 of the pick-up head that moves the pick-up head 21 in the Y direction, and a collet 22 that lifts, rotates, and It has each drive part (not shown) which moves in a direction, and the wafer recognition camera 24. The pick-up head 21 has a collet 22 that adsorbs and 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 pick-up head 21 has drive units (not shown) that lift, rotate, and move the collet 22 in the X direction.

The intermediate stage unit 3 has an intermediate stage 31 for temporarily loading the die D, and a stage recognition camera 32 for recognizing the die D on the intermediate stage 31 .

The bonding unit 4 has a bonding head 41 , a Y drive unit 43 , and a substrate recognition camera 44 . Like the pick-up head 21, the bonding head 41 includes a collet 42 for adsorbing and holding the die D at its tip. 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) of the package area P of the substrate S, and recognizes the bonding position. The bonding section 4 picks up the die D from the intermediate stage 31 and bonds it onto the package area P of the substrate S being transported or stacks it on the die already bonded onto the package area P of the substrate S. bonding in the form With such a configuration, the bonding head 41 corrects the pick-up 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 stacks the die on the package area P of the substrate or on the die already bonded on the package area P of the substrate S based on the image data of the substrate recognizing camera 44. Bond D.

The conveyance section 5 has substrate conveyance claws 51 for holding and conveying the substrate S, and conveyance lanes 52 for moving the substrate S. The substrate S is moved by driving a nut (not shown) of a substrate carrying claw 51 provided in the transfer lane 52 with a ball screw (not shown) provided along the transfer lane 52 . With this configuration, the substrate S is moved from the substrate supply unit 6 to the bonding position along the transfer lane 52, and after bonding, moves to the substrate carrying unit 7, and the substrate S is transported to the substrate carrying unit 7. hand over S.

The control unit 8 includes a memory for storing a program (software) for monitoring and controlling the operation of each unit of the die bonder 10 and a central processing unit (CPU) for executing the program stored in the memory.

Next, the configuration of the die supply unit 1 will be described using FIG. 3 . Fig. 3 is a schematic sectional view showing a main part of the die supply section shown in Fig. 1;

The die supply unit 1 includes a wafer holding table 12 that moves in the horizontal direction (XY direction) and a lifting unit 13 that moves in the vertical direction. The wafer holding table 12 includes an expander ring 15 holding the wafer ring 14 and a dicing tape 16 held by the wafer ring 14 and to which a plurality of dies D are bonded horizontally. It has a support ring 17 for positioning. The lifting unit 13 is disposed inside the support ring 17 .

The die supply unit 1 lowers the expand ring 15 holding the wafer ring 14 when the die D is pushed up. As a result, the dicing tape 16 held by the wafer ring 14 is stretched, the gap between the dies D is increased, and the die D is pushed up from below the die D by the lifting unit 13, The pickup property of D is improved. In addition, as the thickness is reduced, the adhesive for bonding the die to the substrate changes from a liquid to a film, and the film-like adhesion between the wafer 11 and the dicing tape 16 is called a die attach film (DAF) 18. The material is pasted. In the wafer 11 having the die attach film 18 , dicing is performed on the wafer 11 and the die attach film 18 . Therefore, in the separation process, the wafer 11 and the die attach film 18 are separated from the dicing tape 16 .

The die bonder 10 includes a wafer recognition camera 24 for recognizing the posture of the die D on the wafer 11 and a stage recognition camera 32 for recognizing the posture of the die D loaded on the intermediate stage 31; It has a board recognition camera 44 that recognizes the mounting position on the bonding stage BS. What must be corrected for the posture misalignment between the recognition cameras is the stage recognition camera 32 involved in pickup by the bonding head 41 and the board recognition camera 44 involved in bonding to the mounting position by the bonding head 41. )to be. In this embodiment, surface inspection of the die D is performed using a lighting device described later together with the wafer recognition camera 24, the stage recognition camera 32, and the substrate recognition camera 44.

Next, the control unit 8 will be described using FIG. 4 . Fig. 4 is a block diagram showing a schematic configuration of a control system of the die bonder shown in Fig. 1; The control system 80 includes a control unit 8, a drive unit 86, a signal unit 87, and an optical system 88. The control unit 8 is largely divided into 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. have The storage device 82 includes a main storage device 82a composed of RAM for storing processing programs and the like, and a secondary storage device composed of a HDD, SSD, etc., for storing control data and image data necessary for control. (82b). The input/output device 83 includes a monitor 83a for displaying device status and information, a touch panel 83b for inputting operator instructions, a mouse 83c for operating the monitor, and an optical system 88. It has an image acquisition device 83d that acquires image data. In addition, the input/output device 83 includes a motor control device 83e that controls a drive unit 86 such as an XY table (not shown) of the die supply unit 1 or a ZY drive shaft of a bonding head table, and various sensor signals and It has an I/O signal control device 83f that acquires or controls signals from a signal unit 87 such as a switch of a lighting device or the like. The optical system 88 includes a wafer recognition camera 24 , a stage recognition camera 32 , and a substrate recognition camera 44 . The control/arithmetic unit 81 acquires necessary data via the bus line 84, calculates it, and sends information to the control of the pickup head 21 or the like or to the monitor 83a or the like.

The controller 8 stores image data captured by the wafer recognition camera 24, the stage recognition camera 32, and the substrate recognition camera 44 via the image acquisition device 83d in the storage device 82. The positioning of the package area P of the die D and the substrate S and the surface inspection of the die D and the substrate S are performed using the control/arithmetic unit 81 by software programmed based on the stored image data. Based on the positions of the die D and the package area P of the substrate S calculated by the control/arithmetic unit 81, the driving unit 86 is moved via the motor control unit 83e by software. By this process, the positioning of the die on the wafer is performed, and the die D is bonded onto the package area P of the substrate S by operating the pickup unit 2 and the drive unit of the bonding unit 4. The used wafer recognition camera 24, stage recognition camera 32, and substrate recognition camera 44 are gray scale or color cameras, and digitize light intensity. The wafer recognition camera 24, stage recognition camera 32, and substrate recognition camera 44 are also referred to as imaging devices.

Next, a die bonding process, which is one process of a semiconductor device manufacturing method, will be described with reference to FIG. 5 . FIG. 5 is a flowchart for explaining a die bonding process in the die bonder shown in FIG. 1;

(Wafer Loading: Process P1)

In the die bonding process of the embodiment, first, the control unit 8 takes out the wafer ring 14 holding the wafer 11 from the wafer cassette and places it on the wafer holder 12, and then the wafer holder ( 12) is conveyed to the reference position where die D is picked up. Next, the control unit 8 performs fine adjustment from the image acquired by the wafer recognition camera 24 so that the arrangement position of the wafer 11 exactly coincides with the reference position.

(Die Transfer: Process P2)

Next, the control unit 8 pitch-moves the wafer holding table 12 on which the wafer 11 is mounted, and horizontally holds the wafer holder 12 at a predetermined pitch, thereby arranging the first die D to be picked up at the pick-up position. The wafer 11 is previously inspected for each die by an inspection device such as a prober, and map data indicating good or bad for each die is generated and stored in the storage device 82 of the control unit 8 . Determination of whether the die D to be picked up is a good product or a defective product is performed based on the map data. When the die D is a defective product, the control unit 8 pitch-moves the wafer holder 12 on which the wafer 11 is placed, at a predetermined pitch, and places the die D to be picked up next to the pick-up position, thereby removing the defective product. Skip die D.

(Die Positioning: Process P3)

The control unit 8 photographs the principal surface (upper surface) of the die D to be picked up by the wafer recognition camera 24, and calculates the amount of displacement of the die D to be picked up from the pick-up position from the acquired image. The control unit 8 moves the wafer holding table 12 on which the wafer 11 is placed based on the amount of displacement, and accurately places the die D to be picked up at the pick-up position.

(Die Surface Inspection: Step P4)

Next, the control unit 8 inspects the surface of the die D from the image acquired by the wafer recognition camera 24 . Here, the control unit 8 proceeds to the next step (step P9 described later) when it is determined that there is no problem with the surface of the die D, but when it is determined that there is a problem, skip processing or error stop is performed. In the skip processing, steps P9 and after of the die D are skipped, the wafer holder 12 on which the wafer 11 is mounted is pitch-moved at a predetermined pitch, and the die D to be picked up next is placed at the pick-up position.

(Substrate loading: process P5, substrate transfer: process P6)

The control unit 8 loads the substrate S onto the transfer lane 52 from the substrate supply unit 6 . The controller 8 moves the substrate transport claw 51 that grips and transports the substrate S to the bonding position.

(Substrate Positioning: Process P7)

The control unit 8 captures an image of the substrate S with the substrate recognition camera 44 and determines the position of the substrate S based on the captured image.

(Substrate surface inspection: process P8)

Next, the control unit 8 inspects the surface of the package area P of the substrate S from the image acquired by the substrate recognition camera 44 . Here, the control unit 8 determines whether or not there is a problem in the surface inspection, and when it is determined that there is no problem on the surface of the package area P of the substrate S, the control unit 8 proceeds to the next step (step P9 to be described later). When it is determined that there is a problem in the surface inspection, the control unit 8 visually confirms the surface image, performs a more highly sensitive inspection or an inspection with different lighting conditions, etc., and skips if there is a problem, When there is no problem, the process of the next process is performed. In the skip processing, steps P10 and subsequent steps for the corresponding tab of the package area P of the substrate S are skipped, and defects are registered in the substrate start-up information.

(pickup: process P9, mid-stage load: process P10)

The control unit 8 accurately arranges the die D to be picked up at the pick-up position by the die supply unit 1, and then the die D is placed in the dicing tape 16 by the pick-up head 21 including the collet 22. is picked up from and loaded on the intermediate stage 31.

(Die Position Inspection: Process P11)

The controller 8 detects a posture misalignment (rotational misalignment) of the dies loaded on the intermediate stage 31 by capturing an image with the stage recognition camera 32 . When there is a posture shift, the control unit 8 rotates the intermediate stage 31 in a plane parallel to the mounting surface having the mounting position by means of a swing drive device (not shown) provided on the intermediate stage 31 to correct the posture shift. correct the

(Die surface inspection: step P12)

The control unit 8 inspects the surface of the die D from the image acquired by the stage recognition camera 32 . Here, the controller 8 proceeds to the next step (step P13 described later) when it is determined that there is no problem with the surface of the die D, but when it is determined that there is a problem, skip processing or error stop is performed. In the skip processing, the die is loaded on a defective product tray (not shown), skipping steps P13 and later of die D, the wafer holder 12 on which the wafer 11 is loaded is pitch-moved at a predetermined pitch, and then picked up next. Place die D at the pick-up location.

(Die Bonding: Process P13)

The control unit 8 picks up the die D from the intermediate stage 31 by the bonding head 41 including the collet 42, and the die D is bonded to the package area P of the substrate S or to the package area P of the substrate S. Bond the die to the die.

(Inspection of relative position of die and board: Step P14)

After bonding the die D, the control unit 8 inspects whether the bonding position is correct by taking images of the die D and the substrate S using the substrate recognition camera 44 . At this time, the center of the die and the center of the tap are obtained, and it is checked whether the relative positions are correct.

(Surface Inspection of Die and Substrate: Step P15)

Next, the control unit 8 inspects the surfaces of the die D and the substrate S from the images acquired by the substrate recognition camera 44 . Here, the control unit 8 proceeds to the next step (step P9 described later) when it is determined that there is no problem with the surface of the die D, but when it is determined that there is a problem, skip processing or error stop is performed. In the skip processing, defects are registered in substrate start information.

(Substrate transfer: step P16, substrate unloading: step P17)

Thereafter, dies D are bonded to the package area P of the substrate S one by one according to the same procedure. When the bonding of one substrate is completed, the substrate S is moved to the substrate delivery unit 7 by the substrate carrying claw 51, and the substrate S is passed to the substrate delivery unit 7.

(Wafer Unloading: Process P18)

Thereafter, dies D are peeled from the dicing tape 16 one by one according to the same procedure (step P9). When all the dies D except for the defective products are picked up, the dicing tape 16 and the wafer ring 14 holding the dies D in the outer shape of the wafer 11 are unloaded from the wafer cassette.

The crack surface inspection may be performed at at least one of the die supply section 1, the intermediate stage section 3, and the bonding section 4, which are places where die position recognition is performed, but it is more preferable to perform the crack surface inspection at all locations. When performed in the die supply section 1, cracks can be quickly detected. If performed in the intermediate stage unit 3, cracks that could not be detected in the die supply unit 1 or cracks that occurred after the pick-up process (crack that did not materialize prior to the bonding process) can be detected before bonding. In addition, when performed in the bonding unit 4, cracks that could not be detected in the die supply unit 1 and intermediate stage unit 3 (crackes that did not materialize prior to the bonding process) or cracks generated after the bonding process are removed from the next die. It can be detected before bonding to laminate or before substrate ejection.

Next, illumination for surface inspection will be described using FIGS. 6 and 7 . 6 is a diagram showing the arrangement of a lighting device of a substrate recognition camera. FIG. 7 is a schematic diagram illustrating movement of the lighting device of FIG. 6 .

As shown in Fig. 6, the substrate recognition camera 44 is placed perpendicular to the surface of die D. That is, the optical axis is perpendicular to the surface of die D. The illumination device 45 is an oblique light illumination and illuminates the die D at a predetermined angle (incident angle θ) with respect to the optical axis. The incident angle θ of the illumination light IL is preferably less than 45 degrees, more preferably 5 to 15 degrees. Further, as shown in Fig. 7, the lighting device 45 can be rotated and moved in a horizontal plane with the optical axis as the central axis. Here, in FIG. 7, scratches K are shown on the surface of die D.

Here, scratches and cracks are described using FIG. 8 . 8 is a conceptual diagram explaining scratches and cracks.

Scratch Ks is created as any impactor CLL scrapes the surface. Depending on the collision pressure at this time, it is considered that the impact object CLL moves on the surface of the die D in a region close to the surface of the die D and collides while slightly bouncing. The crack Kc is likely to be formed in a direction close to the direction along the side of the die D, for example, when pressure PRS is applied from the bottom of the die D to grow in accordance with the laminated structure of the die D or the silicon crystal direction.

In other words, the scratches Ks are relatively shallow broken-line scratches (scratch scratches). Among the scratches K on the surface of the die D, scratches Ks occur near the surface layer such as a protective film layer formed of polyimide-based resin or the like. On the other hand, the crack Kc is a continuous linear scratch, and is deeper than the scratch Ks. The crack Kc penetrates the protective film layer and reaches the silicon layer. In addition, the scratch Ks is generated on the wafer surface in a specific process such as a back grinding process.

Next, Fig. 9(a), Fig. 9(b), Fig. 10(a) and Fig. 10(b) are shown for the mechanism in which the scratch Ks and the crack Kc are visualized differently according to the irradiation direction of the illumination. explain using Fig. 9(a) is a diagram showing a case where illumination light is irradiated from a right oblique upward direction with respect to scratches. Fig. 9(b) is a diagram showing a case where illumination light is irradiated from above obliquely on the front side with respect to scratches. Fig. 10(a) is a view showing a case where illumination light is irradiated from a direction perpendicular to the direction of crack cracking and from above at a right angle. Fig. 10(b) is a diagram showing a case where illumination light is irradiated from above at an angle on the front side in a direction parallel to the direction of crack cracking.

In the case of observation by a dark field method in which illumination light IL is emitted to brightly illuminate a flaw, visualization of the flaw is performed by reflection of light on the (inside) side surface of the fine flaw. Since the side surface of the scratch Ks is not continuous, the side surface of each scratch is independent and is oriented in all directions (multi-directional). For this reason, each scratch is visualized almost independent of the irradiation direction of the illumination light, and can be seen even when the illumination light is irradiated from any direction.

On the other hand, since the scratches of the crack Kc are continuously generated in a straight line, the side surface is also continuous, and the scratch is visualized more dependent on the irradiation direction of the illumination light than the scratch Ks. For this reason, in the horizontal direction, light strikes the side surface by irradiating illumination light from a direction different from the direction in which the crack Kc extends. When illumination light is irradiated from a direction close to the direction perpendicular to the direction in which the crack Kc extends, the light can be efficiently reflected. On the other hand, in the horizontal direction, when light is projected parallel to the crack direction of the crack Kc, the light does not efficiently reach the side surface, and as a result, the crack Kc is not very visible.

Next, a method for determining scratch Ks and crack Kc will be described using FIGS. 11 and 12 . Fig. 11 is a diagram showing the brightness of scratches when the irradiation direction of illumination light is changed with respect to the scratches. Fig. 12 is a diagram showing the brightness of scratches when the irradiation direction of illumination light is changed with respect to cracks.

As shown in FIG. 7 , the controller 8 rotates the illumination device 45 to rotate the horizontal irradiation direction of the illumination light IL. Then, the control unit 8 captures a plurality of captured images by capturing images of the die D at predetermined angles in the horizontal direction of the lighting device 45 or at arbitrary angular intervals using the substrate recognition camera 44 . At this time, as shown in Figs. 11 and 12, the brightness of both the scratch Ks and the crack Kc in the captured image changes, but the change in brightness in the crack Kc is greater than the change in brightness in the scratch Ks. Big. A threshold value (Bth) is determined by the ratio to the highest brightness, etc., and the control unit 8 judges that below or below the threshold value (Bth) as a crack Kc, and above or above the threshold value (Bth) as a scratch Ks. As described above, since the crack Kc tends to be formed in a direction close to the direction along the side of the die D, the irradiation direction is approximately perpendicular to at least one side of the die D, as indicated by the straight arrow in FIG. 7 . A direction and a direction substantially perpendicular to the direction may be used in two directions. Even if the crack Kc is formed in a direction different from the direction along the side of the die D, the difference in brightness of cracks by irradiation from the above two directions is greater than the difference in brightness of scratches Ks, so determination is possible.

According to this embodiment, since the difference in reflection characteristics depending on the shape of the scratch Ks and the crack Kc is used, it is possible to discriminate between the scratch Ks and the crack Kc. In this way, the discrimination ability of the inspection function in the die bonder can be improved. In addition, based on the determined result, the crack Kc can be treated as a defective product and the scratch Ks as a good product. Thereby, the yield of products assembled by the die bonder can be improved. In addition, in the case of scratch Ks, production can be continued without stopping the production operation of the device due to an error call or the like. Through this, the throughput can be improved.

The lighting devices of the wafer recognition camera 24 and the stage recognition camera 32 in the surface inspection have the same structure as the lighting device 45 . In addition, for example, coaxial illumination is used for illumination devices of the wafer recognition camera 24, the stage recognition camera 32, and the substrate recognition camera 44 in positioning and position inspection.

<Example of modification>

Hereinafter, some representative modifications of the embodiments will be illustrated. In the description of the modified example below, it is assumed that the same reference numerals as those in the above-described embodiment can be used for parts having the same configuration and function as those described in the above-described embodiment. And regarding the explanation of these parts, within the range which does not contradict technically, the description in the above-mentioned embodiment shall be used suitably. In addition, a part of the embodiment described above and all or part of a plurality of modified examples can be appropriately and complexly applied within a range that is not technically contradictory.

(First modified example)

The lighting device in the first modified example will be described with reference to FIG. 13 . Fig. 13 is a diagram explaining a lighting device according to a first modified example.

The lighting device 45 does not need to be rotated like in the embodiment. The lighting device 45 in the first modified example is constituted by ring-shaped oblique light illumination, and is divided into a plurality of regions 45a to 45h so as to be independently controllable on/off. By changing the lighting position of the lighting device 45, the irradiation direction of the illumination light may be changed to observe the brightness of the flaw. In FIG. 13, an example of dividing ring-shaped oblique illumination into eight areas is shown, but is not limited thereto. The irradiation direction in the horizontal direction of the illumination light may be at least two 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.

(Second modified example)

A lighting device according to the second modified example will be described with reference to FIG. 14 . 14 is a diagram explaining a lighting device according to a second modified example.

The lighting device 45 may not have a rotational trajectory shape or a circular shape. As shown in the figure, the lighting device 45 in the second modification is composed of two-direction bar lighting 45j and 45k, and each bar lighting 45j and 45k is turned on to change the brightness of the scratch at that time. may be observed. The irradiation direction in the horizontal direction of the illumination light is two directions: a direction substantially perpendicular to one side of the die D and a direction substantially perpendicular to the direction. In the second modified example, bar lighting in two directions has been described as an example, but bar lighting in four directions may be used.

(3rd modified example)

A lighting device in the third modified example will be described with reference to FIG. 15 . Fig. 15 is a diagram explaining a lighting device according to a third modified example.

In the lighting device 45 in the third modified example, the direction of light incident on the die D changes the horizontal direction while keeping the incident angle θ constant. Incident angle θ may be appropriately changed according to scratch Ks or crack Kc. As described above, since the angle of incidence θ is preferably less than 45 degrees, and more preferably 5 to 15 degrees, the angle of incidence θ is varied within that range. While fixing the changed incident angle θ, the incident direction in the horizontal direction is changed. For example, first, the angle of incidence θ is fixed to the first angle θ1 (θ=θ1), and the illumination device 45 is rotated in a horizontal plane to change the direction of incidence in the horizontal direction to change the brightness of the scratch. Observe. Next, the angle of incidence θ is fixed to the second angle θ2 (θ=θ2), and the lighting device 45 is rotated in a horizontal plane to change the direction of incidence in the horizontal direction to observe the change in brightness of the scratch. . Here, θ1<θ2. Thereby, the difference in brightness of crack Kc can be made larger than in the embodiment.

(Fourth modified example)

The illumination device 45 in the fourth modification may change the wavelength of light to die D. The wavelength of light is preferably a wavelength shorter than that of green, which has an absorption region in the surface protective film (for example, polyimide film), and may be in the ultraviolet light region. Thereby, a greater difference is given between the cracks Kc under the protective film and the scratches Ks on the upper surface by absorption of the surface protective film (e.g., polyimide film) in the amount of light to reach the surface, so that the reflected light from the cracks Kc and the scratches Ks The difference in brightness can be made larger.

Incidentally, the light incident angle θ in this case may be an angle larger than 45 degrees. This is because the path of the light reaching under the protective film is made longer, and a larger difference in the amount of light reaching the crack Kc under the protective film and the scratch Ks on the surface can be generated, so that the difference in brightness of each reflected light can be made larger. .

In addition, at an incident angle (θ) of two or more lights, normal white visible light is illuminated at an angle of less than 45 degrees, and with a wavelength shorter than green light having an absorption region in a surface protective film (eg, polyimide film) at an angle greater than 45 degrees. A plurality of captured images may be acquired by imaging the die D at every predetermined angle in the horizontal direction of the device 45 or at arbitrary angular intervals. Thereby, it is possible to discriminate the scratch Ks and the crack Kc without lowering the detection rate of the crack Kc.

In the above, the invention made by the present inventors has been specifically described based on the embodiments and modifications, but the present disclosure is not limited to the above embodiments and modifications, and various changes are possible.

For example, although the external appearance inspection recognition of the die is performed after the die position recognition in the embodiment, the die location recognition may be performed after the external appearance inspection recognition.

Further, in the embodiment, DAF is affixed to the back surface of the wafer, but DAF may not be present.

In addition, although the pick-up head and the bonding head are each provided with one each in embodiment, two or more may be sufficient respectively. Further, although an intermediate stage is provided in the embodiment, the intermediate stage may not be present. In this case, the pickup head and bonding head may be used together.

Further, in the embodiment, bonding is performed with the front surface of the die facing up, but after the die is picked up, the front and back surfaces of the die may be reversed and bonding may be performed with the rear surface of the die facing up. In this case, it is not necessary to provide an intermediate stage. This device is called a flip chip bonder.

10: die bonder (die bonding device)
44: substrate recognition camera (imaging device)
45: lighting device
8: control unit
D: die
K: scratches
Kc: crack
Ks: Scratch

Claims (15)

an imaging device for imaging the die;
an illuminating device for irradiating light to the die at a predetermined angle with respect to an optical axis of the imaging device;
A controller for controlling the imaging device and the lighting device
to provide,
The control unit changes the irradiation direction of the illumination light from the lighting device in the horizontal direction, captures a plurality of images of the die by the imaging device, and based on a change in brightness of a scratch formed on the die in the captured image, , a die bonding device configured to identify whether it is a crack or a scratch. According to claim 1,
wherein the control unit is configured to recognize as a crack a case where there is an image in which the brightness of a scratch formed on the die is below a predetermined value. According to claim 2,
wherein the control unit is configured to recognize as a scratch a case where there is an image in which the brightness of the scratch formed on the die is equal to or greater than a predetermined value. According to claim 1,
The die bonding device configured to change the irradiation direction of the illumination light in the horizontal direction by rotating the lighting device in the horizontal direction. According to claim 1,
The lighting device is constituted by a ring lighting device formed of a plurality of areas capable of independently turning on and off,
The die bonding device configured to change the irradiation direction of the illumination light in a horizontal direction by lighting a specific area among the plurality of areas. According to claim 1,
The lighting device is composed of a plurality of bar lighting devices capable of independently turning on and off,
The die bonding device configured to change the irradiation direction in the horizontal direction of the illumination light by turning on a specific bar lighting device among the plurality of bar lighting devices. According to claim 4,
The die bonding device, wherein the control unit is configured to change the irradiation direction of the illumination light in the vertical direction and the horizontal direction by changing the incident angle of the lighting device and rotating it in the horizontal direction. According to claim 1,
Further comprising a die supply unit having a wafer ring holder for holding the dicing tape to which the die is attached,
The die bonding device in which the control unit captures an image of the die attached to the dicing tape using the imaging device and the lighting device. According to claim 1,
Further comprising a bonding head for bonding the die onto a substrate or a previously bonded die;
The die bonding device, wherein the control unit captures an image of a die bonded on the substrate or die using the imaging device and the lighting device. According to claim 1,
a pick-up head for picking up the die;
Intermediate stage where the picked up dies are loaded
more provided,
The die bonding device according to claim 1 , wherein the control unit images a die mounted on the intermediate stage using the imaging device and the lighting device. An imaging device that captures an image of a die, an illumination device that irradiates light at a predetermined angle with respect to an optical axis of the imaging device, and a control unit that controls the imaging device and the lighting device, the control unit comprising: , the irradiation direction of the illumination light from the lighting device in the horizontal direction is changed, the imaging device captures a plurality of images of the die, and a crack is recognized based on the brightness of a scratch formed on the die in the captured image. A substrate carrying step of carrying a substrate into a die bonding device to be used;
A wafer carrying step of carrying in a wafer ring holder for holding the dicing tape on which the die is attached;
A pick-up process of picking up the die;
A bonding process of bonding the picked-up die onto the substrate or a die already bonded to the substrate.
Method of manufacturing a semiconductor device comprising a. According to claim 11,
The pick-up process loads the picked-up dies on an intermediate stage,
The bonding process picks up the die loaded on the intermediate stage. According to claim 11,
The semiconductor device manufacturing method further includes a step of inspecting a surface of the die using the imaging device and the lighting device before the pick-up step. According to claim 11,
The semiconductor device manufacturing method further includes a step of inspecting a surface of the die by using the imaging device and the lighting device after the bonding step. According to claim 12,
The semiconductor device manufacturing method further includes a step of inspecting a surface of the die using the imaging device and the lighting device after the pick-up step and before the bonding step.

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