JP6952623B2 - Manufacturing method of die bonding equipment and semiconductor equipment - Google Patents

Description

The present disclosure relates to a die bonding apparatus, and is applicable to, for example, a die bonder including a camera that recognizes a substrate.

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. Part of the process includes a step of dividing a die from a semiconductor wafer (hereinafter, simply referred to as a wafer) (dying step) and a die bonding step of mounting the divided die on a substrate. The semiconductor manufacturing apparatus used in the die bonding process is a die bonding apparatus such as 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 the wafer using a suction nozzle called a collet and picked up (pickup process), transported onto the substrate, and a pressing force is applied. The operation (work) of bonding by heating the bonding material (bonding process) is repeated.

At the time of the pick-up process and the bonding process described above, the die or the substrate is imaged by an image pickup device according to each process, and positioning and inspection are performed by image processing based on the captured image.

Japanese Unexamined Patent Publication No. 2012-59765

The substrate is carried into a die bonding apparatus, die bonded, and then transported. That is, the substrate is conveyed from the upstream to the downstream of the die bonding apparatus. In a die bonding apparatus that requires high accuracy, it is naturally necessary to manage vibration and airflow inside the apparatus with high accuracy. However, in a die bonding device having a drive unit and a heat generating unit, it is physically difficult to eliminate these effects. In particular, the image captured by the imaging device is remarkably susceptible to these effects.

The image captured by the image pickup device is used for positioning. If the position when actually working is deviated from the position at the time when this image is captured, the captured image is inappropriate for positioning and cannot be used. Therefore, the image for positioning cannot be acquired until the substrate transfer is completed and the vibration becomes small within a predetermined magnitude. Therefore, the tact time of die bonding becomes long. Further, due to the optical fluctuation due to the influence of heat, a time-uncertain factor is included in the captured image, and the positioning accuracy is not improved.
An object of the present disclosure is to provide a die bonding apparatus capable of detecting the influence of at least one of vibration and heat.
Other challenges and novel features will become apparent from the description and accompanying drawings herein.

The following is a brief overview of the representative ones of the present disclosure.
That is, the die bonding apparatus is arranged in the imaging region of the imaging apparatus in the vicinity of the substrate or the die and the imaging apparatus having the first CMOS image sensor and sequentially reading out the line exposure, and the first CMOS imaging device is provided. It includes a first reference line extending in a direction orthogonal to the horizontal pixel line of the element, and a control device for controlling the image pickup device. The control device detects vibration or fluctuation due to heat haze based on an image of the first reference line imaged by the image pickup device with the same exposure as the substrate or the die.

According to the above die bonding apparatus, it is possible to detect the influence of vibration or fluctuation due to heat haze.

It is a figure explaining that the image pickup apparatus is affected by vibration. It is a figure explaining an example which prohibits imaging at a vibration generation timing and avoids the influence of vibration. It is a figure explaining an example of confirming the presence or absence of vibration. It is a figure explaining the relationship between a vibration period and an exposure time. It is a figure explaining the method of detecting the vibration of 1st Embodiment. It is a flowchart explaining the method of detecting the vibration of 1st Embodiment. It is a figure which shows the example of the image of the emission line when there is vibration. It is a figure explaining the method of detecting the vibration of the 2nd Embodiment. It is a captured image explaining the method of detecting the vibration of the 2nd Embodiment. It is a flowchart explaining the method of detecting the vibration of the 2nd Embodiment. It is a figure explaining the method of detecting the fluctuation by the heat haze of the third embodiment. It is a figure explaining the method of detecting the fluctuation by the heat haze of the third embodiment. It is a flowchart of a copy operation. It is a flowchart of a continuous construction start operation. It is a schematic top view which shows the structural example of the die bonder of an Example. FIG. 15 is a diagram illustrating a schematic configuration when viewed from the direction of arrow A in FIG. It is an external perspective view which shows the structure of the die supply part of FIG. It is the schematic cross-sectional view which shows the main part of the die supply part of FIG. 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.

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 explanation, 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.

First, the problem of the image captured by the imaging device will be described.
The influence of vibration will be described with reference to FIGS. 1 to 4. FIG. 1 is a diagram illustrating that the image pickup apparatus is affected by vibration. FIG. 2 is a diagram for explaining an example in which imaging is prohibited at the vibration generation timing to avoid the influence of vibration, and FIG. 2 (A) is a diagram when there is a difference in movement amount and speed, and FIG. 2 (B). ) Is a diagram when there is a retry operation or an operation in an N cycle cycle (for example, wafer unloading, cleaning of various parts, etc.). FIG. 3 is a diagram illustrating an example of confirming the presence or absence of vibration. FIG. 4 is a diagram for explaining the relationship between the vibration cycle and the exposure time, FIG. 4 (A) is a diagram when the vibration cycle is relatively fast with respect to the exposure time, and FIG. 4 (B) is a diagram with respect to the exposure time. It is a figure when the vibration cycle is relatively fast.

The vibration generated by the transport operation is transmitted not only directly to the substrate but also to the main body of the die bonding apparatus. Further, the vibration generated for picking up not only in the transport operation but also in the picking process is mechanically transmitted to the die bonding apparatus. For example, the vibration acceleration at the time of pickup is about 9.8 to 147 [m / s ² ].

Cameras used for positioning alignment include a first camera CA1 attached to a first drive unit DU1 such as an XY table and a second camera CA2 attached to a fixed position in the apparatus. The first camera CA1 or the second camera CA2 is affected by the vibration generated by the operation of the first drive unit DU1 (arrow E1), causing blurring in the captured image of the first camera CA1 or the second camera CA2, and the positioning accuracy. May worsen. Alternatively, the influence of vibration generated by the operation of the second drive unit DU2 and the third drive unit DU3 that drive the driven unit (for example, the pickup head or the bonding head) HD of another unit (for example, the pickup unit or the bonding unit). In response to (arrow E2), the captured image of the first camera CA1 or the second camera CA2 may be blurred, and the positioning accuracy may be deteriorated.

In order not to be affected by such vibrations, measures to reduce vibrations by driving a table or, as shown in FIG. 2, prohibit imaging at the vibration generation timing (for example, a predetermined period from the vibration generation timing). Timing control such as (imaging (exposure) after statically indeterminate delay (tDLY)) is required. However, as shown in FIG. 2A, when there is a difference in the amount of movement and the speed, it is difficult to confirm whether the statically indeterminate time is sufficient. Further, as shown in FIG. 2B, when there is a retry operation or an operation in an N cycle cycle, it takes time and effort to confirm whether the statically indeterminate time is sufficient in accordance with the retry operation. Also, since not all movements are affected, it is important to know exactly how much the camera field of view is affected by each vibration trigger. Since the operation parameters, timing, speed, delay due to each processing, etc. of the device differ each time depending on the type of construction to be started and the retry processing, it is desirable to be able to determine whether or not the device is affected by vibration for each imaging.

As shown in FIG. 3, there is a method of attaching an acceleration sensor AS or the like to the third camera CA3 in order to confirm the presence or absence of vibration, but with this method, the amplitude and frequency of the vibration generated in the third camera CA3 main body can be determined. Even if it can be grasped, it is difficult to grasp the amplitude on the image of the blur generated in the image in the visual field, and it is difficult to confirm whether it is actually affected by the positioning alignment.

Therefore, it suffices if the presence or absence of vibration can be confirmed from the image in the camera. If the image is blurred due to vibration, it can be detected. However, as shown in FIG. 4 (A), if the vibration cycle is relatively fast with respect to the exposure time, it can be seen that the image IMA is blurred and vibrates, but as shown in FIG. 4 (B), the exposure time On the other hand, if the vibration cycle is relatively slow, the image IMB does not blur, so it is unknown. Therefore, depending on the relationship between the exposure time and the vibration frequency, a camera that controls the shutter at a batch timing, for example, a camera using a CCD image sensor (hereinafter referred to as a CCD camera) or a CMOS image sensor with a global shutter (simultaneous exposure batch read). It cannot be reliably detected by the camera used (hereinafter referred to as a CMOS camera).

The effect of heat will be described below.
In the bonding step, the substrate is heated to about 80 to 160 [° C.] in order to cure the die attach film. Therefore, there is air turbulence in the die bonder due to heating or the like. Further, an air flow is generated in the die bonder due to a transfer operation or a pickup operation.

In particular, when positioning, in the die bonding device, the camera, which is an imaging device, images the target (board or die) to be positioned, and the image captured by the image processing device is image-processed to perform image processing on the target reference position (alignment mark). Is being extracted. However, the part imaged by the camera is close to the heat source, and the airflow moves violently. Therefore, the camera is affected by optical fluctuations due to the movement of the air flow. Further, in order to acquire a bright image, the brightness of the illumination is often increased to take an image, but the heat generated by the irradiation of the illumination light cannot be ignored.

<First Embodiment>
Next, the first embodiment, which is an example of solving the above-mentioned problems, will be described with reference to FIGS. 5 to 7. In the first embodiment, the presence or absence of vibration is detected from the captured image, and if there is vibration, imaging is performed again. 5A and 5B are views for explaining a method of detecting vibration of the first embodiment, FIG. 5A is a perspective view showing a configuration for detecting vibration, and FIG. 5B is an image taken when there is vibration. It is an image. FIG. 6 is a flowchart for determining the presence or absence of vibration. FIG. 7 is a diagram showing an image of a bright line when there is vibration.

In the first embodiment, it is detected whether the image is vibrating at each imaging. A rolling shutter CMOS camera (line exposure sequential readout imaging device) is used as the camera CA. As shown in FIG. 5A, a reference line BL orthogonal to the horizontal pixel line of the CMOS image sensor constituting the camera CA is provided in the image pickup area IA of the camera CA.

Since the rolling shutter becomes a shutter sequentially in the vertical direction for each horizontal line on the image, as shown in FIG. 5B, if the image IBL of the captured reference line BL loses its linearity, the camera CA It can be determined that it is vibrating. In addition, since the wave pattern drawn by the image IBL of the captured reference line BL becomes a vibration waveform as it is, the amplitude and frequency can be determined, and from the result, even if the captured image is affected by the vibration, the alignment accuracy is correct. It is possible to judge whether it can affect the frequency. Since this method has directivity in the measurement direction of the vibration waveform, it is preferable to use this method when the vibration direction is clarified. In this embodiment, in addition to vibration, the influence of fluctuation due to heat haze can also be confirmed.

The determination of the presence or absence of vibration or fluctuation will be described with reference to FIG.
First, the camera CA captures an object including the reference line BL, and the image is acquired (step S1). Next, the x-coordinate of the brightest pixel of the first line is obtained from the acquired image, and this is designated as Lx (1) (step S2). Next, the x-coordinate of the brightest pixel on the second line is obtained from the acquired image, and this is designated as Lx (2) (step S3). Similarly, the x-coordinate of the brightest pixel of the N-line (final line) eye is obtained from the acquired image, and it is defined as Lx (N) (step S4).

As shown in FIG. 7, for example, the x-coordinate of the brightest pixel on the i-line is Lx (i) = 6, the x-coordinate of the brightest pixel on the i + 8th line is Lx (i + 8) = 7, and the x-coordinate of the brightest pixel on the i + 15th line is the most. The x-coordinate of the bright pixel is Lx (i + 15) = 4.

Next, the maximum value (MAX (Lx (1) to Lx (N))) is obtained from the x-coordinates (Lx (1) to Lx (N)) of the brightest pixel of each line, and the brightest of each line is obtained. The minimum value (MIN (Lx (1) to Lx (N))) is obtained from the x-coordinates (Lx (1) to Lx (N)) of the pixel, and the difference (DEV) between the maximum value and the minimum value is obtained (step). S5). It is determined whether the difference (DEV) is equal to or greater than a predetermined threshold value (TH) (step S6). If YES, it is determined that there is vibration or fluctuation, and the process returns to step S1. If NO, it is determined that there is no vibration or fluctuation, and an alignment process such as target recognition is performed using the captured image (step S7).

In the first embodiment, a rolling shutter CMOS camera is used to enable exposure with a time difference processing in a minute time, which is not possible with a batch exposure type camera (CCD camera or a CMOS camera with a global shutter). The presence or absence of vibration is confirmed by giving a time difference process, providing a reference line that should be captured in a straight line, and checking whether the line is a straight line. Here, the imaging timing excluding vibration is controlled on the premise that the subject and the camera are stationary. In this method, the lighting system is not limited to constant lighting and strobe lighting.

This makes it possible to confirm whether vibration or fluctuation that may affect the image is generated during image imaging. It is possible to measure the amplitude, frequency, and static time of the generated vibration or fluctuation as an image blur in the coordinate system in the image. By confirming that the captured image is not affected by vibration or fluctuation, the positioning alignment accuracy performed in the image processing can be guaranteed as a response to vibration or fluctuation. If it can be detected that it is affected by vibration or fluctuation, retry processing such as re-recognition can be incorporated, and the positioning alignment accuracy performed in image processing can be stabilized.

Further, when the deviation due to vibration does not reach one pixel or becomes a pixel boundary, the center of the line may be obtained by approximate calculation from the variance of the shading value.

<Second embodiment>
Next, a second embodiment, which is an example of solving the above-mentioned problems, will be described with reference to FIGS. 8 to 10. In the second embodiment, as in the first embodiment, the presence or absence of vibration is detected from the captured image, and if there is vibration, imaging is performed again. FIG. 8 is a diagram illustrating a method of detecting vibration of the second embodiment, FIG. 8 (A) is a perspective view showing a configuration for detecting vibration, and FIG. 8 (B) is a view of FIG. 8 (A). It is a figure which shows the structure of a camera. FIG. 9 is an image captured when there is vibration, FIG. 9 (A) is a diagram showing an image of the first reference line by the first CMOS image sensor, and FIG. 9 (B) is a diagram showing an image of the first reference line by the second CMOS image sensor. It is a figure which shows the image of the two reference lines, and FIG. 9C is the figure which superposed the image of FIG. 9A and the image of FIG. 9B. FIG. 10 is a flowchart for determining the presence or absence of vibration.

As shown in FIG. 8A, the first reference line BL1 and the second reference line BL2 extending in the direction orthogonal to the extending direction in the imaging area IA of the camera CAA of the second embodiment. Is provided.

As shown in FIG. 8B, the camera CAA includes a first CMOS image sensor IPD1, a second CMOS image sensor IPD2, a first prism PR1, and a second prism PR2. The incident light IL to the camera CAA is divided into a first incident light IL1 and a second incident light IL2 by the first prism PR1 and the second prism PR2, and the first incident light IL1 is incident on the first CMOS image sensor IPD1. The second incident light IL2 is incident on the second CMOS image sensor IPD2. The first CMOS image sensor IPD1 is arranged so that the direction of the horizontal pixel line of the first CMOS image sensor IPD1 (the direction of the arrow H1) and the direction in which the first reference line BL1 extends are orthogonal to each other. Further, the second CMOS image sensor IPD2 is arranged so that the direction of the horizontal pixel line of the second CMOS image sensor IPD2 (the direction of the arrow H2) and the direction in which the second reference line BL2 extends are orthogonal to each other.

As shown in FIG. 9A, when the image IBL1 of the first reference line BL1 imaged by the first image sensor IPD1 is distorted, the region WA1 of the first image IM1 imaged by the first image sensor IPD1 is The image becomes a distorted area due to vibration. As shown in FIG. 9B, when the image IBL2 of the second reference line BL2 imaged by the second image sensor IPD2 is distorted, the region WA2 of the second image IM2 imaged by the second image sensor IPD2 is The image becomes a distorted area due to vibration. Therefore, the difference between the first image IM1 and the second image IM2 appears in the first region DA1 and the second region DA2 shown by the broken line in FIG. 9C.

The determination of the presence or absence of vibration or fluctuation will be described with reference to FIG.
First, an object (for example, a substrate or a die) including the first reference line BL1 and the second reference line BL2 is imaged by the camera CAA, and the first CMOS image sensor IPD1 and the second CMOS image sensor IPD2 simultaneously perform the first image. The IM1 and the second image IM2 are acquired (step S11). Next, the camera CAA transfers the first image IM1 and the second image IM2 to the control device (step S12). The control device makes a difference between the first image IM1 imaged by the first CMOS image sensor IPD1 and the second image IM2 imaged by the second CMOS image sensor IPD2, and converts them into absolute values (step S13). The control device determines whether or not there is a region (for example, first region DA1 and second region DA2) having a brightness equal to or higher than a predetermined threshold value in the image (step S14). If YES, it is determined that there is vibration or fluctuation, and the process returns to step S11. If NO, it is determined that there is no vibration or fluctuation, and an alignment process such as target recognition is performed using either the first image IM1 or the second image IM2 (step S15).

According to the second embodiment, the measurement in the XY direction can be performed as compared with the first embodiment in which the vibration in only one direction can be measured. By using this method, the vector direction of vibration can also be detected.

<Third Embodiment>
The third embodiment, which is an example of the means for solving the above-mentioned problems, will be described with reference to FIGS. 11 to 14. In the third embodiment, when the fluctuation due to the heat haze is detected, the captured image is corrected instead of re-imaging as in the first embodiment and the second embodiment.

FIG. 11 is a diagram illustrating a method of detecting fluctuations due to the heat haze of the third embodiment, is an image of a die mounting area of a substrate and its surroundings, and is a diagram showing an image distorted due to fluctuations. FIG. 12 is a diagram illustrating a method of detecting fluctuations due to the heat haze of the third embodiment, and is an image showing the relationship between the alignment pattern and the reference line. FIG. 13 is a flowchart of the copying operation. FIG. 14 is a flowchart of the continuous construction start operation.

As shown in FIG. 11, when the image IAM of the alignment pattern is distorted due to fluctuations, the SP where the image IAM should be captured straight, such as the boundary line of the die mounting area near the image IAM, is also distorted due to the fluctuations. Therefore, if there is a fluctuation due to the heat haze when the image is taken by the camera, the alignment pattern moves due to the fluctuation. As mentioned above, it is not known that the camera with the global shutter has moved, but with the camera with the rolling shutter, it can be judged whether or not it is affected by whether or not the known straight line part is distorted. Here, a straight line as close as possible to the alignment pattern is used as the reference line so that the alignment pattern and the fluctuation of the heat haze of the reference line have the same waveform.

As shown in FIG. 12, the boundary of a known straight line portion is detected at multiple points, and the true value of the straight line is detected by the Hough transform or the approximation process by the least squares method (the approximate straight line ASL is derived). If it is detected that the approximate straight line ASL is distorted on the same horizontal line as the alignment pattern, the distortion offset is measured from the boundary position on the same horizontal line (in phase) as the arrayment mark, and the alignment result is positioned. Is corrected by the amount of the distortion offset, so that the influence of the fluctuation due to the heat haze can be eliminated. Hereinafter, details will be described with reference to FIGS. 13 and 14.

First, as a copying operation, as shown in FIG. 13, the alignment pattern AP and the reference line SLP used for positioning are imaged and an image is captured (step S21). The position of the alignment pattern AP is registered (step S22). At this time, if pattern matching is used for the positioning algorithm, the model image is also registered. The position of the reference line SLP orthogonal to the alignment pattern AP on the same horizontal line is registered (step S23).

Next, as a continuous construction start operation, as shown in FIG. 14, the alignment pattern AP and the reference line SLP used for positioning are imaged and the images are captured (step S31). The position of the alignment pattern AP is measured from the image IMA of the captured arrayment pattern (step S32). From the measured alignment pattern, the position where the registered reference line should be located is calculated, a straight line is detected in the vicinity thereof, and an approximate straight line ASL is obtained (step S33). If there is a deviation in the position near the alignment pattern (when deformation of the straight line is detected due to fluctuations due to heat haze) compared to the front and back parts of the straight line (the part corresponding to above or below the alignment pattern in the drawing), the deviation is Measure (step S34). The measurement result is fed back to the positioning result of the alignment pattern, and the misalignment of the die is corrected (step S35).

An example in which the above-described embodiment is applied to a die bonder will be described below.

FIG. 15 is a top view showing an outline of the die bonder according to the embodiment. FIG. 16 is a diagram illustrating the operation of the pickup head and the bonding head when viewed from the direction of arrow A in FIG.

The die bonder 10 is roughly divided into a 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. It has 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 each drive unit (not shown) that moves the collet 22 up / down, rotates, and moves in the X direction. , Have. The pickup head 21 has a collet 22 (see also FIG. 2) 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 portion 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 the die D 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. 2) 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. It has 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.
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.

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. 17 and 18. FIG. 17 is a view showing an external perspective view of the die supply unit. FIG. 18 is a schematic cross-sectional view showing a main part of the die supply part.

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 that holds the wafer ring 14, and a support ring 17 that horizontally positions the dicing tape 16 held by 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 by 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.

The die bonder 10 has a wafer recognition camera 24 that recognizes the posture of the die D on the wafer 11, a stage recognition camera 32 that recognizes the posture of the die D mounted on the intermediate stage 31, and a mounting position on the bonding stage BS. It has a substrate recognition camera 44 for recognizing. 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 stage recognition camera 32 uses a CMOS camera with a rolling shutter, and the horizontal pixel line of the CMOS image sensor constituting the stage recognition camera 32 is located near the die place position of the intermediate stage 31 in the image pickup area of the stage recognition camera 32. An orthogonal emission line (an example of a reference line of the first embodiment or the second embodiment) is provided. Further, the substrate recognition camera 44 uses a CMOS camera with a rolling shutter, and a bright line (No. 1) orthogonal to the horizontal pixel line of the CMOS image pickup element constituting the substrate recognition camera 44 in the clamper portion of the bonding area in the image pickup area of the substrate recognition camera 44. An example of the reference line of one embodiment or the second embodiment) is provided.

The control unit 8 will be described with reference to FIG. FIG. 19 is a block diagram showing a schematic configuration of the control system. 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 and the like, and an HDD, an SSD or the like for storing control data, image data and 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 and a ZZ drive shaft of a bonding head table, various sensor signals, lighting devices, and the like. It has an I / O signal control device 83f that captures or controls a signal from a signal unit 87 such as a switch of the above. 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. The drive unit 86 is moved by software via the motor control device 83e based on the positions of the die D and the package area P of the substrate S calculated by the control / arithmetic unit 81. 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.

FIG. 20 is a flowchart illustrating a die bonding process in the die bonder of FIG.
In the die bonding step 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 holding table 12, and the wafer holding table 12 is picked up by the die D. It is conveyed to the reference position where it is performed (wafer loading (step P1)). Next, the control unit 8 makes fine adjustments so that the arrangement position of the wafer 11 exactly matches the reference position from the image acquired by the wafer recognition camera 24.

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 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 non-defective 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.

The control unit 8 captures the main 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 pickup position from the acquired image. The control unit 8 moves the wafer holding table 12 on which the wafer 11 is placed based on this amount of misalignment, and accurately arranges the die D to be picked up at the pickup position (die positioning (step P3)).

Next, the control unit 8 inspects the surface of the die D from the image acquired by the wafer recognition camera 24 (step P4). 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 die D, the process proceeds to the next step (step P9 described later), but it is determined that there is a problem. In that case, 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 step processing is performed. 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 is placed on the substrate S transport lane 52 by the substrate supply unit 6 (board loading (process 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)).

The substrate recognition camera 44 captures the substrate S and the emission line to perform positioning (board positioning (step P7)). According to the determination method of the first embodiment or the second embodiment, it is determined from the image of the captured emission line whether or not it is vibrating, and if it is determined that it is not vibrating, positioning is performed. If it is determined that the board is vibrating, the substrate recognition camera 44 acquires the image again.

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 (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)). ((Step P10). The control unit 8 captures the die D and the emission line with the stage recognition camera 32 to detect the posture deviation (rotational deviation) of the die placed on the intermediate stage 31. (Step P11). When it is determined from the image of the captured emission line whether or not it is vibrating by the determination method of the first embodiment or the second embodiment, and it is determined that the dicing is not vibrating, the posture of the die is displaced (step P11). The stage recognition camera 32 acquires an image again when it is determined that the camera is vibrating. If the control unit 8 has a posture deviation, the rotation drive device provided in the intermediate stage 31 is used. By (not shown), the intermediate stage 31 is swiveled on a surface parallel to the mounting surface having the mounting position to correct the posture deviation.

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 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 die D, the process proceeds to the next step (step P13 described later), but it is determined that there is a problem. In that case, visually check the surface image, or perform a high-sensitivity inspection or an inspection with different lighting conditions, and if there is a problem, place the die on a defective tray (not shown) and skip it. If there is no problem, the next step is performed. In the skip process, 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 the die D to be picked up next is arranged 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)).

After bonding the die D, the control unit 8 inspects whether the bonding position is accurate by photographing the die D, the substrate S, and the emission line with the substrate recognition camera 44 (relative position inspection between the die and the substrate (step). P14)). According to the determination method of the first embodiment or the second embodiment, it is determined from the image of the captured emission line whether or not it is vibrating, and when it is determined that it is not vibrating, it is inspected whether or not the bonding position is accurate. .. If it is determined that the board is vibrating, the substrate recognition camera 44 acquires the image again. 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 inspects the surfaces of the die D and the substrate S from the image acquired by the substrate recognition camera 44 (step P15). 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 bonded die D, the process proceeds to the next step (step P9 described later), but there is a problem. If it is determined that, 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 processing is performed. I do. 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 except 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).

The invention made by the present inventor has been specifically described above based on Examples and Modifications, 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 second embodiment, an example in which a reference line is provided to determine the presence or absence of vibration has been described, but both the first CMOS image sensor IPD1 and the second CMOS image sensor IPD2 may have cells in a square lattice. For example, both images are compared by difference comparison, and if there is a mismatched region, the presence or absence of vibration can be known without providing a reference line.

Further, in the embodiment, the emission line has been described as an example as the reference line, but the emission line is not limited to the one that emits light, and may be a reflective one, a simple pattern, or a projection by a laser.

Further, in the examples, the method of determining the vibration according to the first embodiment or the second embodiment has been described, but the method of determining the fluctuation according to the third embodiment may be applied.

Further, in the embodiment, an example in which the first embodiment or the second embodiment is applied in the imaging by the stage recognition camera and the substrate recognition camera has been described, but the first embodiment or the second embodiment is used in the imaging by the wafer recognition camera. May be applied.
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.

10 ... Die bonder 1 ... Die supply unit 13 ... Push-up unit 2 ... Pickup unit 24 ... Wafer recognition camera 3 ... Intermediate stage unit 31 ... Intermediate stage 32 ... Stage Recognition camera 4 ・ ・ ・ Bonding part 41 ・ ・ ・ Bonding head 42 ・ ・ ・ Collet 44 ・ ・ ・ Board recognition camera 5 ・ ・ ・ Transfer part 51 ・ ・ ・ Board transfer claw 8 ・ ・ ・ Control part S ・ ・ ・ Board BS ・ ・ ・ Bonding stage D ・ ・ ・ Die P ・ ・ ・ Package area CA ・ ・ ・ Camera BL ・ ・ ・ Reference line IA ・ ・ ・ Imaging area IBL ・ ・ ・ Reference line image

Claims (13)

An image pickup device that has a first CMOS image sensor and sequentially reads out line exposures,
A first reference line that is located near the substrate or die and is located in the image pickup region of the image pickup device and extends in a direction orthogonal to the horizontal pixel line of the first CMOS image pickup device.
A control device that controls the image pickup device and
With
The control device is a die bonding device that detects fluctuations due to vibration or heat haze based on an image of the first reference line imaged by the image pickup device with the same exposure as the substrate or the die. In claim 1,
The control device is a die bonding device that determines that there is the vibration or the fluctuation when the image of the first reference line deviates by a predetermined value or more. In claim 2,
The control device is a die bonding device that redoes the imaging of the substrate or the die by the imaging device. In claim 1,
Further, it is provided with a second reference line which is arranged in the imaging region of the imaging apparatus in the vicinity of the substrate or the die and extends in a direction orthogonal to the extending direction of the first reference line.
The image pickup device further includes a second CMOS image pickup device having a horizontal pixel line in a direction orthogonal to the direction in which the second reference line extends.
The control device includes an image of the first CMOS image sensor and an image of the second CMOS image sensor on which the image pickup device captures the substrate or the die, the first reference line, and the second reference line with the same exposure. A die bonding device that detects fluctuations due to vibration or heat haze based on. In claim 4,
The control device differentiates the image of the first CMOS image sensor and the image of the second CMOS image sensor, converts them into absolute values, and determines that the image has the vibration or the fluctuation when the image has a brightness equal to or higher than a predetermined value. Die bonding equipment. In claim 5,
The control device is a die bonding device that redoes the imaging of the substrate or the die by the imaging device. In claim 1,
Further, an alignment pattern is provided in the vicinity of the first reference line.
The control device is a die bonding device that measures a deviation in a position of the first reference line facing the alignment pattern and feeds back the measurement result to a positioning result of the alignment pattern. In claim 1, further
Equipped with a pickup head to pick up the die
The control device is a die bonding device that uses the image pickup device to image the substrate and the first reference line provided in the vicinity of the substrate. In claim 1, the pickup head for further picking up the die and the pickup head
The intermediate stage on which the picked-up die is placed and
With
The control device is a die bonding device that uses the image pickup device to image the die mounted on the intermediate stage and the first reference line provided on the intermediate stage. (A) An image pickup device having a first CMOS image sensor that sequentially reads out line exposures, and horizontal pixels of the first CMOS image pickup device that are arranged in the image pickup region of the image pickup device in the vicinity of a substrate or a die. A process of preparing a die bonding apparatus including a first reference line extending in a direction orthogonal to the line, and
(B) The process of carrying in the wafer ring holder holding the dicing tape to which the die is attached, and
(C) The process of bringing in the substrate and
(D) The process of picking up the die and
(E) A step of bonding the picked-up die onto the substrate or a die that has already been bonded to the substrate.
With
Manufacture of a semiconductor device that detects vibration or fluctuation due to heat haze based on an image of the first reference line imaged by the image pickup device with the same exposure as the substrate or the die in the step (d) or the step (e). Method. In claim 10,
In the step (e), when the detected vibration or the fluctuation is equal to or more than a predetermined value, the imaging device manufactures the semiconductor device that images the substrate and the first reference line provided in the vicinity of the substrate again. Method. In claim 10,
In the step (e), when the detected fluctuation is equal to or higher than a predetermined value and there is a deviation at a position facing the alignment pattern of the first reference line, the deviation is measured and the measurement result is obtained from the alignment pattern. A method for manufacturing a semiconductor device that feeds back to a positioning result. In claim 10,
In the step (d), when the detected vibration or the fluctuation is equal to or more than a predetermined value, the imaging device again manufactures the die and the semiconductor device for imaging the first reference line provided in the vicinity of the die. Method.

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