JP2020155737A - Semiconductor manufacturing device and manufacturing method of semiconductor device - Google Patents

Abstract

To provide a technique capable of avoiding an input into a camera by reflecting a light of an irradiation even if a flatness level of a front surface of a wafer or a die cannot be maintained.SOLUTION: A semiconductor manufacturing device comprises: an imaging device that images a die; an illumination device that irradiates the die with a light to an optical axis of the imaging device at a prescribed angle; and a control part that controls the imaging device and the illumination device. The predetermined angle is an angle that is not entered into the imaging device even if the light irradiated from the illumination device is directly reflected by the die when the die is flat. The control part is structured so that at least one of the imaging device, the illumination device, and the die is moved so that the light irradiated from the illumination device is not entered into the imaging device directly reflected in the die when the die is not flat.SELECTED DRAWING: Figure 7

Description

The present disclosure relates to semiconductor manufacturing equipment and is applicable to, for example, a die bonder including a camera that recognizes a die.

A part of the manufacturing process of a semiconductor device includes a process of mounting a semiconductor chip (hereinafter, simply referred to as a die) on a wiring board, a lead frame, etc. (hereinafter, simply referred to as a substrate) and assembling a package. Partly, there is a step of dividing a die from a semiconductor wafer (hereinafter, simply referred to as a wafer) (dying step) and a bonding step of mounting the divided die on a substrate. The semiconductor manufacturing equipment used in the bonding process is a die bonder.

A die bonder is a device that uses solder, gold plating, or resin as a bonding material to bond (mount and bond) a die onto a substrate or a die that has already been bonded. In a die bonder that bonds a die to the surface of a substrate, for example, the die is sucked from a wafer using a suction nozzle called a collet, picked up, transported onto the substrate, and a pressing force is applied and the bonding material is heated. By doing so, the operation (work) of performing bonding is repeated. The collet is a holder having suction holes, sucking air, and sucking and holding the die, and has the same size as the die.

Before picking up the die from the wafer or after bonding the die to the substrate or the like, an image is taken by a camera using a lighting device in order to inspect the wafer or the die for scratches such as cracks and foreign matter.

JP-A-2017-117916

In general, the dark field method is better when inspecting minute scratches. The surface of the wafer is close to a mirror surface, and oblique light illumination, which is an illumination method in which light is applied diagonally, is preferable for inspecting by the dark field method. In the dark field type inspection, it is required that the wafer or die surface as the background reflects the illumination light and prevents it from being input to the camera. When the flatness of the surface of the wafer or die can be maintained, even if the light from the illumination is reflected and not input to the camera, the flatness of the surface of the wafer or die can be maintained due to warpage of the wafer or die. If not, the light from the illumination may be reflected and input to the camera.
An object of the present disclosure is to provide a technique capable of reflecting the illumination light and preventing it from being input to the camera even when the flatness of the surface of the wafer or die cannot be maintained.
Other challenges and novel features will become apparent from the description and accompanying drawings herein.

The following is a brief outline of the representative ones of the present disclosure.
That is, the semiconductor manufacturing apparatus controls the imaging device that images the die, the lighting device that irradiates the die with light at a predetermined angle with respect to the optical axis of the imaging device, and the imaging device and the lighting device. It has a part and. The predetermined angle is an angle that does not enter the imaging device even if the light emitted from the lighting device is directly reflected by the die when the die is flat. The control unit is at least one of the imaging device, the lighting device, and the die so that when the die is not flat, the light emitted from the lighting device is directly reflected by the die and does not enter the imaging device. It is configured to move one.

According to the above-mentioned semiconductor manufacturing apparatus, it is possible to reflect the illumination light and prevent it from being input to the camera even when the flatness of the surface of the wafer or die cannot be maintained.

It is a figure which shows the coaxial illumination schematically. It is a figure which shows the oblique light illumination schematically. It is a figure which shows the state of the incident light and the reflected light of oblique light illumination schematically. It is a figure which shows typically the state of the incident light and the reflected light when it is smaller than the incident angle of FIG. This is an example of a captured image using the oblique light bar illumination of FIG. It is a figure explaining the problem of oblique lighting. It is a figure explaining the technique of embodiment. It is a flowchart explaining the 1st method. It is a flowchart explaining the 2nd method. It is a figure explaining the case which the region of direct light reflection cannot be removed even if the field of view is moved. It is a schematic top view which shows the structural example of the die bonder of an Example. 11 is a diagram illustrating a schematic configuration when viewed from the direction of arrow A in FIG. 11. It is an external perspective view which shows the structure of the die supply part of FIG. It is the schematic sectional drawing which shows the main part of the die supply part of FIG. It is a figure which shows the arrangement of the lighting apparatus of a substrate recognition camera. It is a block diagram which shows the schematic structure of the control system of the die bonder of FIG. It is a flowchart explaining the die bonding process in the die bonder of FIG. It is a flowchart which showed mainly the process of taking an image by a wafer recognition camera. It is a flowchart which showed mainly the process of taking an image by a substrate recognition camera. It is a figure explaining the measuring method of the warp position (specular reflection region) of a die. The oblique light illumination of FIG. 7 is a diagram for explaining the influence of oblique light illumination located on a mirror surface object with respect to the optical axis. It is a schematic perspective view which shows the substrate recognition camera and the lighting apparatus in the 1st modification. It is a schematic perspective view which shows the substrate recognition camera and the lighting apparatus in the 2nd modification. It is a schematic perspective view which shows the wafer recognition camera and the lighting apparatus in the 3rd modification.

Hereinafter, embodiments and examples will be described with reference to the drawings. However, in the following description, the same components may be designated by the same reference numerals and repeated description may be omitted. In addition, in order to clarify the description, the drawings may schematically represent the width, thickness, shape, etc. of each part as compared with the actual embodiment, but this is just an example, and the interpretation of the present invention is used. It is not limited.

When inspecting die cracks in the dark field of oblique illumination, the relative positional relationship between the illumination, the camera (imaging device), and the die is important for keeping the detection rate high. As will be described later, in oblique light illumination, the illumination device is arranged so that the incident angle is as vertical as possible to the die surface, and the angle is such that the light directly reflected from the incident angle (direct light) does not enter the camera. It is better to do it. Beyond that, the light from the light source mirror-reflected on the die surface becomes direct light and enters the camera. Therefore, the die surface has a bright field of view in the crack inspection. It becomes difficult to secure the contrast between the crack and the background, and as a result, the detection rate is deteriorated.

The incident angle of the illumination will be described with reference to FIGS. 1 to 4. FIG. 1 is a diagram schematically showing coaxial illumination. FIG. 2 is a diagram schematically showing oblique illumination. FIG. 3 is a diagram schematically showing the state of incident light and reflected light of oblique light illumination. FIG. 4 is a diagram schematically showing the state of incident light and reflected light when the angle of incidence is smaller than that of FIG. FIG. 5 is an example of a captured image using the oblique light bar illumination of FIG.

As shown in FIG. 1, in coaxial illumination, the illumination device CEI is configured such that light illuminates the surface of the die D along the optical axis OA and half mirror HM of the camera CMR and lens LNS. Here, the optic axis OA is substantially perpendicular to the surface of the die D, and the incident angle is approximately 0 degrees. Therefore, when an image is taken with a camera CMR using the illumination device CEI, the surface of the die D has a bright field of view with respect to cracks, the reflectance is close, the contrast is difficult to obtain, and as a result, the detection sensitivity does not improve.

As shown in FIG. 2, in oblique light illumination, the illumination device OBL is configured such that light irradiates the surface of the die D at a predetermined angle with respect to the optical axis OA of the camera CMR and the lens LNS. Here, the angle of incidence with respect to the optical axis is θ. When an image is taken with a camera CMR using an illumination device OBL, the surface of the die D has a dark field of view with respect to cracks, the reflectance is different, and contrast is easily obtained. The closer the incident angle of this lighting device OBL is to vertical (the smaller the θ), the larger the contrast difference between the crack and the background, and the easier it is to classify on the image (binarization, etc.), resulting in detection sensitivity. Will improve.

At this time, as shown in FIG. 3, the light RL mirror-reflected on the surface of the die D to be inspected is arranged so as not to directly enter the lens LNS. The incident angle at this time is θ1. However, if the incident angle of the illuminating device OBL is made too close to the vertical direction, the light RL mirror-reflected on the surface of the die D enters the lens LNS as shown in FIG. Assuming that the incident angle at this time is θ2, 0 <θ2 <θ1. Therefore, as shown in FIG. 5, the reflected area RA has a bright field of view, which deteriorates the detection sensitivity. Therefore, the positional relationship between the lighting device, the camera, and the die is important.

Next, the problem of oblique lighting will be described with reference to FIG. FIG. 6A is a diagram schematically showing the state of incident light and reflected light of oblique light illumination on the stacked dies. FIG. 6B is an enlarged view of the stacked and stacked dies of FIG. 6A. FIG. 6C is an example of a captured image of the stacked die of FIG. 6A.

The above-mentioned positional relationship between the illumination, the camera, and the die is established when the surface of the die is flat to some extent. However, the flatness cannot be maintained depending on the type of die to be laminated such as NAND flash. For example, as shown in FIG. 6B, in the case of the method of stacking the dies D1, D2, D3, and D4 while stacking them, the unsupported region NSA of the lower layer may warp. As a result, as shown in FIG. 6A, even if the incident angle of the irradiation light of the lighting device OBL is θ1, which is the same as in FIG. 3, the light directly reflected in the warped region WA of the die D4 (reflection angle is high). (Changed light) RL1 enters the lens LNS, and as shown in FIG. 6 (c), it becomes an unsupported region NSA (warped region WA) bright field of the lower layer, which deteriorates the detection sensitivity.

Next, the technique of the embodiment for solving the above problems will be described with reference to FIG. 7. FIG. 7A is a diagram schematically showing the state of incident light and reflected light of oblique light illumination on the stacked dies. FIG. 7B is an example of an image taken by capturing the stacked stacked dies of FIG. 7A at the center of the field of view. FIG. 7 (c) is an example of an image taken by capturing the stacked stacked dies of FIG. 7 (a) at a position deviated from the center of the field of view.

In the embodiment, at least one of the camera CMR, the illumination device OBL, and the die D is moved so that the reflected light on the curved surface of the die D is not taken into the lens LNS.
For example, as shown in FIG. 7A, by moving the camera CMR and the lighting device OBL in the same direction (in the direction of the arrow) at the same time, the light RL1 reflected by the curved surface of the die D is not captured by the lens. To. Here, as for the positional relationship between the initial (before moving) lighting device OBL, camera CMR, and die D (those whose flatness is maintained), as shown in FIG. 3, a bright field of view does not appear on the surface of the die D. The position.

That is, as shown by the broken line in FIG. 7A, the lighting device OBL, the camera CMR, and the die D are arranged, and the center of the die D is placed at the center of the field of view VF (optical axis OA) of the camera CMR. When the die D has a warp, the light RL1 directly reflected in the warped region of the die D enters the lens LNS and has a bright field of view as shown in FIG. 7B.

On the other hand, as shown in FIG. 7A, the camera CMR and the oblique illumination device OBL are moved to shift the center of the field of view VF (optical axis OA) from the center of the die D, so that the warped region WA of the die D The directly reflected light RL1 does not enter the lens LNS, and as shown in FIG. 7C, the bright field of view does not appear.

It is preferable to move the camera CMR and the lighting device OBL at the same time. This is because it is easy to maintain the positional relationship between the camera CMR and the lighting device OBL. Only the lighting device OBL may be moved or only the camera CMR may be moved so that the bright field of view does not appear in the region where the die is not warped.

Further, instead of moving the camera CMR and / or the lighting device OBL, the subject to be imaged may be moved. For example, the dicing tape is moved when the die is warped on the dicing tape, or the substrate is moved on the bond stage.

Further, when moving the camera CMR and the lighting device OBL, it is preferable that the direction is opposite to the brightly shining surface. When moving the subject, it is preferable to move the subject in the same direction as the brightly shining surface. Further, it is preferable that the field of view has about twice the die size.

Change the camera position, lighting position, or subject position in consideration of the warp of the die. In order to maintain the inspection sensitivity, it is preferable to set the incident angle as long as it does not receive the direct light reflected from the mirror surface, and the position can be adjusted according to the deformation of the subject. Therefore, in the inspection sensitivity of the die crack inspection, the die warp. It is possible to minimize the deterioration due to the influence of.

The oblique light illumination is usually configured as a face-to-face pair, and for example, a two-direction oblique light bar illumination or a four-direction oblique light bar illumination is used. The oblique illumination of FIG. 7A will be described with reference to FIG. 21 regarding the influence of the oblique illumination (hereinafter referred to as the opposite oblique illumination) located on the optical axis OA on the mirror surface. FIG. 21A is a diagram schematically showing the state of incident light and reflected light of the opposite oblique light illumination to the warped die before the field of view is moved. FIG. 21B is a diagram schematically showing the state of incident light and reflected light of the opposite oblique light illumination on the die without warpage. FIG. 21C is a diagram schematically showing the state of incident light and reflected light of the opposite oblique light illumination on the die having a warp before and after the field of view movement.

When the field of view of the oblique light illumination that is a face-to-face pair is moved according to the above description, as shown in FIG. 21 (b), the light directly reflected by the die D without warpage (hereinafter referred to as specular light) is generated. It is incident on the camera, and as a result, the die D appears white. However, as shown in FIG. 21 (c), the warped die D is less affected because the inclination of the reflected light is also large. Further, when the illumination is in four directions, the light source in the orthogonal direction is originally not affected by this warp.

Next, a method for moving the field of view relative to the imaged object will be described with reference to FIGS. 8 and 9. FIG. 8 is a flowchart illustrating the first method. FIG. 9 is a flowchart illustrating the second method.

The first method is a method of moving the field of view relative to the die D after confirming whether there is direct reflection of the irradiation light due to the warp. Relative visual field movement and re-examination when direct light reflections occur. The moving direction of the field of view is determined from the position on the die where the directly reflected light is generated. Suitable for use with dies on wafers where the warping position is unknown. Here, the relative field of view movement means that the field of view of the camera CMR with respect to the die D is moved by moving at least one of the camera CMR and the die D. Due to the relative field of view movement, the center of the field of view of the camera CMR and the center of the die D are deviated.

As shown in FIG. 8, after die positioning (step S12) by member transfer (step S11), pattern matching, etc., the surface illuminance of the die D is confirmed using an illuminance meter built in the camera CMR, and the surface illuminance of the die D is directly confirmed. The presence or absence of specular reflection of light (direct reflection of illuminance light) is confirmed (step S13). If there is specular reflection of the direct light of the light source, the relative field of view is moved (step S14). If there is no specular reflection of the direct light of the light source, the die D is inspected for cracks and foreign matter (step S15). It should be noted that the die crack inspection may be activated first, and then it may be confirmed whether or not there is direct reflection of the light source light. Further, a illuminometer different from the camera CMR may be installed to check the surface illuminance of the die D.

The second method is a method in which the warp direction is determined when the dies are laminated, and the movement amount offset is determined by following the number of stacking stages of the dies first, and the relative visual field movement is performed in advance. ..

As shown in FIG. 9, after die positioning (step S12) by member transfer (step S11), pattern matching, etc., relative visual field movement is performed based on the number of stages of the positioning die (step S24). The lower die has less warp, and the upper die has more warp, so the amount of movement increases as it goes up. Then, the die D is inspected for cracks and foreign matter (step S25). In this method, the movement amount may be readjusted by further adding a confirmation process for checking whether the light source light is directly reflected.

Even if the relative visual field is moved, the area of direct light reflection may not be completely removed. This will be described with reference to FIG. FIG. 10A is an captured image before moving the visual field. FIG. 10B is an captured image after moving the field of view.

As shown in FIG. 10A, a white-filled region (non-inspectable region) appears in a ring shape before the visual field is moved. As shown in FIG. 10B, before the visual field is moved, the white-filled area (non-inspectable area) is reduced, but remains in the corner of the die. The area painted in white is treated as a mask each time, and the field of view is relatively moved to secure the inspection area as a whole. For example, by masking the inspectable area of FIG. 10 (a) for inspection, the inspectable area at the corner of the die can be secured as an inspection area, and by masking the inspectable area of FIG. 10 (b), FIG. The non-inspectable area of 10 (a) can be secured as an inspection area. Therefore, the entire die can be secured as an inspection area.

FIG. 11 is a schematic top view showing the configuration of the die bonder of the embodiment. FIG. 12 is a diagram illustrating a schematic configuration when viewed from the direction of arrow A in FIG.

The die bonder 10 is roughly divided into a die supply unit 1 for supplying a die D for mounting a product area (hereinafter referred to as a package area P) which is one or a plurality of final packages on a printed circuit board S, and a pickup unit 2. , An intermediate stage unit 3, a bonding unit 4, a transport unit 5, a substrate supply unit 6, a substrate carry-out 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 arranged on the front side of the die bonder 10, and the bonding unit 4 is arranged on the back side.

First, the die supply unit 1 supplies the die D to be mounted on the package area P of the substrate S. The die supply unit 1 includes a wafer holding table 12 for holding the wafer 11, and a pushing unit 13 indicated by a dotted line for pushing the die D from the wafer 11. The die supply unit 1 is moved in the XY direction by a driving means (not shown), and the die D to be picked up is moved to the position of the push-up unit 13.

The pickup unit 2 includes a pickup head 21 that picks up the die D, a Y drive unit 23 of the pickup head that moves the pickup head 21 in the Y direction, and drive units (not shown) that move the collet 22 up / down, rotate, and move in the X direction. , Have. The pickup head 21 has a collet 22 (see also FIG. 12) that attracts and holds the pushed-up die D to the 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 drive units (not shown) that move the collet 22 up / down, rotate, and move in the X direction.

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

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 to be conveyed, or laminates it on the die already bonded on the package area P of the substrate S. Bond in shape. The bonding unit 4 includes a bonding head 41 having a collet 42 (see also FIG. 12) that attracts and holds the die D to the tip like the pickup head 21, a Y drive unit 43 that moves the bonding head 41 in the Y direction, and a substrate. A substrate recognition camera 44 that captures a position recognition mark (not shown) of the package area P of S and recognizes the bonding position, an XY drive unit 45 that drives the board recognition camera 44 in the X-axis direction and the Y-axis direction, Has.
With such a configuration, the bonding head 41 corrects the pickup position / orientation based on the image data of the stage recognition camera 32, picks up the die D from the intermediate stage 31, and bases the board based on the image data of the board recognition camera 44. Bond the die D to S.

The transport unit 5 has a substrate transport claw 51 that grips and transports the substrate S, and a transport lane 52 to which the substrate S moves. The substrate S moves by driving a nut (not shown) of the substrate transport claw 51 provided in the transport lane 52 with a ball screw (not shown) provided along the transport lane 52.
With such a configuration, the substrate S moves from the substrate supply unit 6 to the bonding position along the transport lane 52, and after bonding, moves to the substrate unloading unit 7 and passes the substrate S to the substrate unloading unit 7.

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 with reference to FIGS. 13 and 14. FIG. 13 is an external perspective view showing the configuration of the die supply portion of FIG. FIG. 14 is a schematic cross-sectional view showing a main portion of the die supply portion of FIG.

The die supply unit 1 includes a wafer holding table 12 that moves in the horizontal direction (XY direction) and a push-up unit 13 that moves in the vertical direction. The wafer holding table 12 has an expanding ring 15 for holding the wafer ring 14 and a support ring 17 for horizontally positioning the dicing tape 16 held on the wafer ring 14 and to which a plurality of dies D are adhered. The push-up unit 13 is arranged inside the support ring 17.

The die supply unit 1 lowers the expanding ring 15 holding the wafer ring 14 when the die D is pushed up. As a result, the dicing tape 16 held in the wafer ring 14 is stretched to widen the interval between the dies D, and the push-up unit 13 pushes up the die D from below the die D to improve the pick-up property of the die D. The adhesive that adheres the die to the substrate as it becomes thinner changes from a liquid to a film, and a film-like adhesive material called a die attach film (DAF) 18 is attached between the wafer 11 and the dicing tape 16. There is. 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 peeling step, the wafer 11 and the die attach film 18 are peeled from the dicing tape 16. In the following description, the existence of the die attach film 18 will be ignored.

The die bonder 10 includes a wafer recognition camera 24 that recognizes the posture and position of the die D on the wafer 11, a stage recognition camera 32 that recognizes the posture and position of the die D mounted on the intermediate stage 31, and a bonding stage BS. It has a board recognition camera 44 that recognizes the mounting position of the above. It is the stage recognition camera 32 involved in the pickup by the bonding head 41 and the substrate recognition camera 44 involved in bonding to the mounting position by the bonding head 41 that must correct the posture deviation between the recognition cameras. In this embodiment, the surface of the die D is inspected by using the illumination device described later together with the wafer recognition camera 24, the stage recognition camera 32, and the substrate recognition camera 44.

Next, the lighting for surface inspection will be described with reference to FIG. FIG. 15 is a diagram showing the arrangement of the lighting device of the substrate recognition camera.

The substrate recognition camera 44 is arranged perpendicular to the surface of the die D. That is, the optical axis is perpendicular to the surface of the die D. The oblique light illumination device 46 is bidirectional oblique illumination by the oblique light bar illumination devices 46a and 46b, and irradiates the die D at a predetermined angle (θ1) with respect to the optical axis. The substrate recognition camera 44 and the oblique illumination devices 46a and 46b are fixed to the movable portion 45a, the movable portion 45a can be moved in the X-axis direction by the X drive unit 45b, and the X drive unit 45b is movable in the Y-axis direction by the Y drive unit 45c. It is possible to move to. Here, the incident angle (θ1) is the same as in FIG. The control unit 8 moves the substrate recognition camera 44 and the oblique illumination device 46 by the XY drive unit 45, and shifts the center of the field of view from the center of the die D, so that the light directly reflected in the warped region of the die D is the substrate recognition camera. It is possible to prevent the bright field from appearing without entering 44.

The lighting devices of the wafer recognition camera 24 and the stage recognition camera 32 are the same as the lighting devices of the substrate recognition camera 44. However, the wafer recognition camera 24 and its illumination device and the stage recognition camera 32 and its illumination device do not have to be configured to be moved by a drive unit similar to the XY drive unit 45. The control unit 8 does not move the wafer recognition camera 24 and its illumination device, but moves the wafer holding table 12 or the intermediate stage 31 to shift the center of the field of view from the center of the die D, so that the control unit 8 directly in the warped region of the die D. The reflected light does not enter the wafer recognition camera 24 or the stage recognition camera 32, and the bright field of view can be prevented from appearing.

Next, the control unit 8 will be described with reference to FIG. FIG. 16 is a block diagram showing a schematic configuration of the control system of the die bonder of FIG.

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 roughly divided into a control / arithmetic unit 81 mainly composed of a CPU (Central Processor Unit), a storage device 82, an input / output device 83, a bus line 84, and a power supply unit 85. The storage device 82 is an auxiliary device composed of a main storage device 82a composed of a RAM for storing a processing program or the like, and an HDD, an SSD or the like for storing control data, image data, or the like necessary for control. It has a storage device 82b. The input / output device 83 includes a monitor 83a for displaying the device status and information, a touch panel 83b for inputting operator instructions, a mouse 83c for operating the monitor, and an image capture device 83d for capturing image data from the optical system 88. And have. Further, 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, a ZZ drive shaft of the bonding head table, and an XY drive shaft of the substrate recognition camera. It has an I / O signal control device 83f that captures or controls signals from signal units 87 such as various sensor signals and switches such as lighting devices. 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 takes in necessary data via the bus line 84, calculates the data, controls the pickup head 21 and the like, and sends the information to the monitor 83a and the like.

The control unit 8 stores the 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 acquisition device 83d. Using the software programmed based on the stored image data, the control / arithmetic unit 81 is used to position the package area P of the die D and the substrate S, and to inspect the surface of the die D and the substrate S. 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 drive unit 86 is moved by software via the motor control device 83e. By this process, the die on the wafer is positioned and operated by the drive unit of the pickup unit 2 and the bonding unit 4 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 to be used are grayscale, color, or the like, and the light intensity is quantified.

Next, the die bonding process will be described with reference to FIGS. 17 to 19. FIG. 17 is a flowchart illustrating a die bonding process in the die bonder of FIG. FIG. 18 is a flowchart showing mainly a process of taking an image with a wafer recognition camera. FIG. 19 is a flowchart showing mainly a process of taking an image with a substrate recognition camera.

In the die bonding step of the embodiment, first, as shown in FIG. 17, the control unit 8 takes out the wafer ring 14 holding the wafer 11 from the wafer cassette, places it on the wafer holding table 12, and places it on the wafer holding table 12. 12 is conveyed to a reference position where the die D is picked up (wafer loading (step P1)). Next, the control unit 8 makes fine adjustments (alignment) from the image acquired by the wafer recognition camera 24 so that the arrangement position of the wafer 11 exactly matches the reference position.

Next, the control unit 8 arranges the first die D to be picked up at the pickup position by moving the wafer holding table 12 on which the wafer 11 is placed at a predetermined pitch and holding it horizontally (die transfer). (Step P2)). The pickup position of the die D is also the recognition position of the die D by the wafer recognition camera 24. The wafer 11 is inspected in advance for each die by an inspection device such as a prober, and map data indicating good or bad is generated for each die and stored in the storage device 82 of the control unit 8. Whether the die D to be picked up is a good product or a defective product is determined by the map data. When the die D is a defective product, the control unit 8 moves the wafer holding table 12 on which the wafer 11 is placed at a predetermined pitch, arranges the die D to be picked up next at the pickup position, and arranges the defective product. Die D is skipped.

Next, as shown in FIG. 18, the control unit 8 sets the illumination output of the wafer recognition camera 24 to a value for die positioning (step S31). The control unit 8 photographs the main surface (upper surface) of the die D to be picked up by the wafer recognition camera 24 and acquires an image (step S32). The amount of displacement of the die D to be picked up from the pickup position is calculated from the acquired image, and the position of the die D is measured (step S33). The control unit 8 moves the wafer holding table 12 on which the wafer 11 is placed based on this displacement amount, and accurately arranges the die D to be picked up at the pickup position (die positioning (step P3)).

Next, as shown in FIG. 18, the control unit 8 changes the illumination output of the wafer recognition camera 24 to a value for die crack inspection (step S41). The control unit 8 photographs the main surface of the die D to be picked up by the wafer recognition camera 24 and acquires an image (step S42). As will be described later, the control unit 8 confirms the surface shading of the die D from the acquired image and detects the presence or absence of a specular reflection region (step S43). When there is a specular reflection region, the control unit 8 moves the wafer holding table 12 in the direction of the specular reflection region (step S44). When the lighting device is placed on a drive table different from the wafer recognition camera 24, only the lighting device may be moved. If the illuminator is a bar-type oblique illumination, the influencing side may be turned off. The control unit 8 acquires the camera image again. In step S43, if there is no specular reflection region, die crack and foreign matter inspection (surface inspection) are performed (step P4). Here, the control unit 8 proceeds to the next step (step P9 described later) when it is determined that there is no problem on the surface of the die D, but when it is determined that there is a problem, the skip process or the error stop. In the skip process, steps P9 and subsequent steps of the die D are skipped, the wafer holding table 12 on which the wafer 11 is placed is moved by a predetermined pitch, and the die D to be picked up next is arranged at the pickup position.

The control unit 8 places the substrate S on the transport lane 52 in the substrate supply unit 6 (board loading (step P5)). The control unit 8 moves the substrate transfer claw 51 that grabs and conveys the substrate S to the bonding position (board transfer (process P6)).

Next, as shown in FIG. 19, the control unit 8 moves the substrate recognition camera 44 to the imaging position (bonding tab imaging position) of the package area P to be bonded (step S71). The control unit 8 sets the illumination output of the board recognition camera 44 to a value for board positioning (step S72). The control unit 8 photographs the substrate S with the substrate recognition camera 44 and acquires an image (step S73). The position is measured by calculating the amount of misalignment of the package area P of the substrate S from the acquired image (step S74). The control unit 8 moves the substrate S based on this amount of misalignment, and performs positioning for accurately arranging the package area P to be bonded at the bonding position (board positioning (process P7)).

Next, as shown in FIG. 17, 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 (step P8). Here, the control unit 8 determines whether or not there is a problem in the surface inspection, and if it is determined that there is no problem on the surface of the package area P of the substrate S, the process proceeds to the next step (step P9 described later), but there is a problem. If it is determined to be present, the surface image is visually confirmed, or a high-sensitivity inspection or an inspection with different lighting conditions is performed. If there is a problem, skip processing is performed, and if there is no problem, the next process is performed. Perform processing. In the skip process, steps P10 and subsequent steps to the corresponding tab of the package area P of the substrate S are skipped, and defects are registered in the substrate construction start information.

The control unit 8 accurately arranges the die D to be picked up at the pickup position by the die supply unit 1, and then picks up the die D from the dicing tape 16 by the pickup head 21 including the collet 22 (die handling (step P9)). , Placed on the intermediate stage 31 (step P10). The control unit 8 detects the posture deviation (rotational deviation) of the die placed on the intermediate stage 31 with the stage recognition camera 32 (die position inspection (step P11)). When there is a posture deviation, the control unit 8 corrects the posture deviation by turning the intermediate stage 31 on a surface parallel to the mounting surface having the mounting position by a turning drive device (not shown) provided on the intermediate stage 31.

The control unit 8 inspects the surface of the die D from the image acquired by the stage recognition camera 32 (step P12). Here, the control unit 8 proceeds to the next step (step P13 described later) when it is determined that there is no problem on the surface of the die D, but when it is determined that there is a problem, the skip process or the error stop. In the skip process, the die is placed on a defective tray (not shown), the steps P13 and subsequent steps of the die D are skipped, the wafer holding table 12 on which the wafer 11 is placed is moved by a predetermined pitch, and then the die is moved at a predetermined pitch. The die D to be picked up is placed at the pickup position.

The control unit 8 picks up the die D from the intermediate stage 31 by the bonding head 41 including the collet 42, and die-bonds the die D to the package area P of the substrate S or the die already bonded to the package area P of the substrate S (diatouch). ((Step P13)).

Next, as shown in FIG. 19, the control unit 8 moves the substrate recognition camera 44 to the imaging position of the die D after bonding (step S141). The control unit 8 sets the illumination output of the substrate recognition camera 44 to a value for die positioning (step S142). The control unit 8 photographs the die D with the substrate recognition camera 44 and acquires an image (step S143). The position of the die D is measured from the acquired image (step S144). After bonding the die D, the control unit 8 inspects whether the bonding position is accurate (relative position inspection between the die and the substrate (step P14)). At this time, the center of the die and the center of the tab are obtained in the same manner as the alignment of the die, and it is inspected whether the relative position is correct.

Next, the control unit 8 moves the substrate recognition camera 44 to the imaging position for die crack inspection (step S151). In the case of laminated products, the direction of offset is determined in advance as the upper tiers are stacked. In that case, since the warp direction is also determined, the presence or absence of reflection is confirmed by teaching the amount of visual field movement that does not have specular reflection in advance and moving to the position including the offset from the beginning at the time of inspection. It is also possible to reduce the number of times the subsequent visual field movement is activated. The control unit 8 changes the illumination output of the substrate recognition camera 44 to a value for die crack inspection (step S152). The control unit 8 photographs the die D with the substrate recognition camera 44 and acquires an image (step S153). As will be described later, the control unit 8 confirms the surface shading of the die D from the acquired image and detects the presence or absence of a specular reflection region (step S154). When there is a specular reflection region, the control unit 8 moves the substrate recognition camera 44 in the direction opposite to the specular reflection region (step S155). When the lighting device is placed on a table driven separately from the substrate recognition camera 44 as in the second modification described later, only the lighting device may be moved. If the illuminator is a bar-type oblique illumination, the influencing side may be turned off. The control unit 8 acquires the camera image again. In step S154, if there is no specular reflection region, die crack and foreign matter inspection (surface inspection of die D and substrate S) are performed (step P15). Here, the control unit 8 proceeds to the next step (step P9 described later) when it is determined that there is no problem on the surface of the die D, but when it is determined that there is a problem, the skip process or the error stop. In the skip process, defects are registered in the board construction start information.

After that, the 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 unloading portion 7 by the substrate transport claw 51 (board transport (process P16)), and the substrate S is passed to the substrate unloading portion 7 (board unloading (process P17). )).

After that, the dies D are peeled off from the dicing tape 16 one by one according to the same procedure (step P9). When the pickup of all the dies D other than the defective products is completed, the dicing tape 16 and the wafer ring 14 and the like holding the dies D in the outer shape of the wafer 11 are unloaded to the wafer cassette (step P18).

Next, a method of measuring the warp position (specular reflection region) of the die will be described with reference to FIG. FIG. 20A is an inspection image of the die. FIG. 20B is a reference image of the die. 20 (c) is a difference image between the inspection image of FIG. 20 (a) and the reference image of FIG. 20 (b). FIG. 20 (d) is a binarized image of the difference image of FIG. 20 (c). FIG. 20E is a diagram for explaining the determination of the presence or absence of warpage of the die.

The control unit 8 calculates the difference image between the inspection image of the die shown in FIG. 20 (a) and the reference image of the die shown in FIG. 20 (b). As shown in FIG. 20 (c), the area other than the specular reflection area of the difference image becomes black, the specular reflection area becomes white, and the boundary area becomes blurry. The control unit 8 binarizes the difference image based on a certain shade threshold value to obtain the image shown in FIG. 20 (d). At this time, four inspection areas as shown in FIG. 20 (e) are provided near the edge of the image. If a white area exists above a certain area threshold value in each inspection area, it is determined that there is a warp, and the warp direction is determined from the position of the white area. In this case, it is determined that the underside of the die is warped.

The surface inspection of the crack may be performed at at least one place of the die supply part, the intermediate stage, and the bonding stage where the die position recognition is performed, but it is more preferable to perform the surface inspection at all the places. If it is done in the die supply section, cracks can be detected quickly. If the intermediate stage is performed, cracks that could not be detected in the die supply unit or cracks that occurred after the pickup step (cracks that did not become apparent before the bonding step) can be detected before bonding. Further, if the bonding stage is performed, cracks that could not be detected in the die supply section and the intermediate stage (cracks that did not become apparent before the bonding process) or cracks generated after the bonding process are bonded by laminating the next die. It can be detected before or before the substrate is ejected.

<Modification example>
Hereinafter, some typical modifications will be illustrated. In the following description of the modified example, the same reference numerals as those in the above-described embodiment may be used for the portions having the same configuration and function as those described in the above-described embodiment. As for the explanation of such a part, the explanation in the above-described embodiment can be appropriately incorporated within a range that is technically consistent. In addition, a part of the above-described embodiment and all or a part of the plurality of modifications can be applied in combination as appropriate within a technically consistent range.

(First modification)
FIG. 22 is a schematic perspective view showing the substrate recognition camera and the lighting device in the first modification.

In the case of the embodiment, the oblique light illumination device 46 is oblique light bar illumination in two directions, but as shown in FIG. 22, it may be oblique light bar illumination in four directions. In the oblique light illumination device 46, an oblique light bar illumination device (not shown) located on the opposite side of the oblique light bar illumination devices 46a to 46c, the oblique light bar illumination device 46c, and the substrate recognition camera 44 is attached to the side surface of the substrate recognition camera 44. It is composed of. The substrate recognition camera 44 is fixed to the movable portion 45a, the movable portion 45a can be moved in the X-axis direction by the X drive portion 45b, and the X drive portion 45b can be moved in the Y-axis direction by the Y drive portion 45c.

As shown in FIG. 22 (b), when the die D is staggered in the Y-axis direction and stacked, direct reflection occurs on the positive side (right side in the drawing) of the die D due to the warped region of the die D. The substrate recognition camera 44 and the oblique illumination device 46 are moved in the direction of the arrow (negative side of the Y-axis (left side in the drawing)) to image the die D.
As shown in FIG. 22 (c), when the die D is offset in the X-axis direction and stacked, direct reflection occurs on the negative side (right side in the drawing) of the die D due to the warped region of the die D. The control unit 8 moves the substrate recognition camera 44 and the oblique illumination device 46 in the direction of the arrow (the positive side of the X-axis (left side in the drawing)) to image the die D.

(Second modification)
FIG. 23 is a schematic perspective view showing the substrate recognition camera and the lighting device in the second modification.

In the case of the embodiment and the first modification, the oblique light illumination device 46 is configured to move in the same positional relationship as the substrate recognition camera 44, but as shown in FIG. 23, it moves independently of the substrate recognition camera 44. It may be configured to do so. The oblique bar illumination devices 46a to 46d of the oblique light illumination device 46 are fixed to the movable portion 47a, the movable portion 47a can be moved in the X-axis direction by the X drive unit 47b, and the X drive unit 47b is Y-axis by the Y drive unit 47c. It is movable in the direction. The substrate recognition camera 44 is fixed to the movable portion 45a, the movable portion 45a can be moved in the X-axis direction by the X drive portion 45b, and the X drive portion 45b can be moved in the Y-axis direction by the Y drive portion 45c.

(Third variant)
FIG. 24 is a schematic perspective view showing the wafer recognition camera and the lighting device in the third modification.

In the case of the embodiment, the illumination device of the wafer recognition camera 24 is the oblique light bar illumination in two directions as in the oblique light illumination device 46, but as shown in FIG. 24, the illumination device may be oblique light bar illumination in four directions. The oblique light illumination device 26 is composed of oblique light bar illumination devices 26a to 26d. The wafer holding base 12 is fixed to the X drive unit 19b, the X drive unit 19b is movable in the X axis direction, and the X drive unit 19b is movable in the Y axis direction by the Y drive unit 19c.
Further, the side affected by the reflected light of the multi-directional oblique bar illumination may be turned off.

The invention made by the present inventor has been specifically described above based on the embodiments and examples, but the present invention is not limited to the above examples and modifications, and can be variously modified. Not to mention.

For example, in the embodiment, an example in which a two-way oblique light bar illumination is used as the oblique light illumination device has been described, but a four-direction oblique light bar illumination may be used, or a one-way oblique light bar illumination may be used.

Further, in the embodiment, the warp position (specular reflection region) of the die is measured in advance by camera image recognition, but the warp direction is detected by using a sensor such as a laser displacement system, and the lighting device or the camera is based on the detection. May be made to work. Further, a grid-like pattern may be projected on the surface of the die, and the warp direction may be determined based on the degree of disorder of the grid.

Further, 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.

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

Further, in the embodiment, one pickup head and one bonding head are provided, but two or more of each may be provided. Further, although the intermediate stage is provided in the embodiment, the intermediate stage may not be provided. In this case, the pickup head and the bonding head may be used in combination.

Further, in the embodiment, the die is bonded with the front surface facing up, but after picking up the die, the front and back surfaces of the die may be inverted and the die may be bonded with the back surface facing up. In this case, the intermediate stage may not be provided. This device is called a flip chip bonder.

Further, although the bonding head is provided in the embodiment, the bonding head may not be provided. In this case, the picked-up die is placed in a container or the like. This device is called a pickup device. Further, the surface inspection of the crack in this case may be carried out in a container or the like on which the picked-up die is placed.

10 ... Die bonder (semiconductor manufacturing equipment)
8 ... Control unit D ... Die S ... Board CMR ... Camera (imaging device)
OBL ・ ・ ・ Lighting device OA ・ ・ ・ Optical axis VF ・ ・ ・ Field of view

Claims (17)

An imaging device that captures the die and
An illumination device that irradiates the die with light at a predetermined angle with respect to the optical axis of the image pickup device.
A control unit that controls the imaging device and the lighting device,
With
The predetermined angle is an angle that does not enter the imaging device even if the light emitted from the lighting device is directly reflected by the die when the die is flat.
The control unit is at least one of the imaging device, the lighting device, and the die so that when the die is not flat, the light emitted from the lighting device is directly reflected by the die and does not enter the imaging device. A semiconductor manufacturing device configured to move one. In the semiconductor manufacturing apparatus of claim 1,
The positional relationship between the imaging device and the lighting device is fixed.
The control unit is a semiconductor manufacturing apparatus configured to move at least one of the imaging device and the die so that the die deviates from the center of the field of view of the imaging device. In the semiconductor manufacturing apparatus of claim 2,
When the control unit confirms the surface illuminance of the die and determines that the light emitted from the lighting device is directly reflected by the die and is incident on the image pickup device, the control unit of the image pickup device and the die. A semiconductor manufacturing apparatus configured to move at least one of them. In the semiconductor manufacturing apparatus of claim 2 or 3,
A means for detecting the warp of the die is provided.
When the control unit detects the warp, the control unit is a semiconductor manufacturing device that moves the field of view of the image pickup device to either the front-back direction or the front-back direction of the detected warp direction. In the semiconductor manufacturing apparatus of claim 2,
The die is a die laminated on the die.
The control unit is a semiconductor manufacturing apparatus configured to move the field of view of the imaging apparatus based on the number of stacked stages. In the semiconductor manufacturing apparatus of claim 5,
A semiconductor manufacturing apparatus that moves the field of view of the imaging device in the same direction as the offset direction of the die stacked on the die, either back and forth, or both front and back. In the semiconductor manufacturing apparatus of claim 2,
When the light emitted from the lighting device is directly reflected by the die and incident on the imaging device even if the field of view of the image pickup device is moved, the control unit receives the light emitted from the lighting device. A semiconductor manufacturing apparatus configured to shift the center of the field of view of the imaging device and the center of the die so that a region that is directly reflected by the die and is not incident on the imaging device covers the entire area of the die. In the semiconductor manufacturing apparatus of claim 2, further
A die supply unit having a wafer ring holder for holding the dicing tape to which the die is attached is provided.
The control unit is a semiconductor manufacturing apparatus that uses the imaging device and the lighting device to image the die attached to the dicing tape. In the semiconductor manufacturing apparatus of claim 2, further
A bonding head for bonding the die onto a substrate or a die that has already been bonded is provided.
The control unit is a semiconductor manufacturing apparatus that uses the imaging device and the lighting device to image a die bonded onto the substrate or die. In the semiconductor manufacturing apparatus of claim 2, further
A pickup head that picks up the die and
The intermediate stage on which the picked-up die is placed and
With
The control unit is a semiconductor manufacturing apparatus that uses the imaging device and the lighting device to image a die placed on the intermediate stage. (A) An image pickup device that images a die, an illumination device that irradiates the die with light at a predetermined angle with respect to an optical axis of the image pickup device, and a control unit that controls the image pickup device and the illumination device. The predetermined angle is an angle at which the light emitted from the lighting device does not enter the imaging device even if the light emitted from the lighting device is directly reflected by the die when the die is flat, and the control unit controls the die. Is configured to move at least one of the imaging device, the lighting device, and the die so that the light emitted from the lighting device is not directly reflected by the die and enters the imaging device when is not flat. The process of bringing the substrate into the semiconductor manufacturing equipment
(B) The process of carrying in the wafer ring holder that holds the dicing tape to which the die is attached, and
(C) The process of picking up the die and
(D) A step of bonding the picked-up die onto the substrate or a die already bonded to the substrate.
A method for manufacturing a semiconductor device including. In the method for manufacturing a semiconductor device according to claim 11,
In step (c), the picked-up die is placed on an intermediate stage.
The step (d) is a method for manufacturing a semiconductor device that picks up a die mounted on the intermediate stage. In the method for manufacturing a semiconductor device according to claim 11, further (f) before the step (c), the surface illuminance of the die is confirmed, and the light emitted from the illuminating device is directly reflected by the die to be said. When it is determined that the light is incident on the imaging device, the center of the die and the center of the field of view of the imaging device are set so that the light emitted from the lighting device is not directly reflected by the die and enters the imaging device. A method for manufacturing a semiconductor device, which comprises a step of staggering and inspecting the surface of the die. In the method for manufacturing a semiconductor device according to claim 11, further (g) after the step (d), the surface illuminance of the die is confirmed, and the light emitted from the lighting device is directly reflected by the die to perform the imaging. When it is determined that the light is incident on the device, the center of the field of view of the image pickup device and the center of the die are shifted so that the light emitted from the lighting device is not directly reflected by the die and enters the image pickup device. A method for manufacturing a semiconductor device, which comprises a step of inspecting the surface of the die. In the method for manufacturing a semiconductor device according to claim 11, after (g) the step (d), the center of the field of view of the imaging device is shifted from the center of the die by an amount based on the number of stages in which the die is laminated. A method for manufacturing a semiconductor device, which comprises a step of inspecting the surface of the die. In the method for manufacturing a semiconductor device according to claim 12, the surface illuminance of the die is confirmed and irradiated from the lighting device after (h) the step (c) and before the step (d). When it is determined that the light is directly reflected by the die and incident on the image pickup device, the image pickup device is used so that the light emitted from the lighting device is not directly reflected by the die and enters the image pickup device. A method for manufacturing a semiconductor device, which comprises a step of inspecting the surface of the die by shifting the center of the field of view and the center of the die. In the method for manufacturing a semiconductor device according to any one of claims 13, 14 and 16.
When the light emitted from the lighting device is directly reflected by the die and incident on the imaging device even if the field of view is moved from the center of the imaging device, the light emitted from the lighting device is said to be the same. A method for manufacturing a semiconductor device that captures images while shifting the center of the field of view of the imaging device and the center of the die so that a region that is directly reflected by the die and is not incident on the imaging device covers the entire area of the die.

Images