JP2020136361A - Mounting device and manufacturing method of semiconductor device - Google Patents

Abstract

To provide a mounting device capable of reducing the influence of vibration in strobe exposure recognition imaging.SOLUTION: A mounting device includes an imaging device that moves relative to an imaging target and picks up the imaging target, and a lighting device that irradiates the imaging target with light. The lighting device is configured to emit strobe light a plurality of times in a period of half or less of a vibration period within an exposure time of the imaging device.SELECTED DRAWING: Figure 7

Description

The present disclosure relates to a mounting device, and is applicable to, for example, a mounting device using strobe lighting.

In an electronic component mounting device, in order to mount an electronic component with high accuracy, while the electronic component is sucked and held by a suction nozzle and moved to a mounting portion, the electronic component is subjected to an image pickup device such as a CCD or CMOS. An image is taken by a digital camera having a CMOS, the captured image information is converted into an electric signal, and image processing is performed to obtain a measured value. Then, based on this measured value, the mounting position is corrected while the electronic component is moving, and the electronic component is mounted on the printed circuit board. For imaging of electronic components with this camera, it is necessary to use a lighting device having a predetermined amount of light or more in order to obtain a highly accurate image with few errors. Generally, a flash with a strobe or a halogen lamp Means such as continuous lighting by the above are used (for example, Patent Document 1).
In the exposure of a recognition camera using strobe illumination (strobe exposure), high-speed operation can be captured by shortening the exposure time to about several tens of μs, and recognition processing is possible.

Japanese Unexamined Patent Publication No. 2000-124683

In a device in which multiple axes operate at the same time, if other axes operate during recognition imaging, the position of the image captured will be different between the static position and the vibrating image due to the effect of operating vibration. There is. Strobe exposure has an electronic circuit configuration that focuses on emitting a large amount of light in a short time due to high-speed processing, and there is a limit to the maximum emission time for extending the lighting time of the strobe, and the natural vibration of the device (for example, number It is difficult to emit light for more than one cycle (10 Hz, several tens of ms, etc.) and take an image.
An object of the present disclosure is to provide a mounting device capable of reducing the influence of vibration in strobe exposure recognition imaging.
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 mounting device includes an image pickup device that moves relative to the image pickup target object and images the image pickup target object, and an illumination device that irradiates the image pickup target object with light. The lighting device is configured to emit strobe light a plurality of times at a cycle of 1/2 or less of the vibration cycle within the exposure time of the imaging device.

According to the mounting device, the influence of vibration can be reduced in strobe exposure.

FIG. 1 is a diagram showing a configuration of an imaging system of the first embodiment. FIG. 2 is a diagram showing an operation timing when an image is taken in a short time after the axis operation of the image pickup system of FIG. 1 is stopped. FIG. 3 is a diagram showing the light emission timing of the imaging system of FIG. FIG. 4 is a diagram showing an operation timing when an image is taken with a recognition waiting time from the axis operation stop of the image pickup system of FIG. 1 to the start of recognition. FIG. 5 is a diagram showing operation timings when imaging is performed a plurality of times after the axis operation of the imaging system of FIG. 1 is stopped. FIG. 6 is a diagram showing the configuration of the imaging system of the second embodiment. FIG. 7 is a diagram showing the operation timing of the imaging system of FIG. FIG. 8 is a diagram showing the light emission timing of the imaging system of FIG. FIG. 9 is a diagram showing a configuration of an imaging system of the first modification. FIG. 10 is a top view showing an outline of the flip chip bonder of the embodiment. FIG. 11 is a diagram illustrating the operation of the pickup flip head and the transfer head when viewed from the direction of arrow A in FIG. FIG. 12 is a diagram illustrating the operation of the bonding head when viewed from the direction of arrow B in FIG. FIG. 13 is a schematic cross-sectional view showing a main portion of the die supply portion of FIG. FIG. 14A is a diagram showing the configuration of the undervision camera, and FIG. 14B is a diagram showing the configuration of the bond camera. FIG. 15 is a diagram showing a configuration of a normal exposure imaging system. FIG. 16 is a diagram showing the operation timing of the imaging system of FIG. FIG. 17 is a diagram illustrating the operation of the bonding head when viewed from the direction of arrow B in FIG. FIG. 18 is a diagram showing images of a bond camera and an undervision camera. FIG. 19 is a flowchart showing a bonding method carried out by the flip chip bonder of the embodiment.

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.

<First Embodiment>
An imaging system for strobe exposure will be described with reference to FIGS. 1 to 5. FIG. 1 is a diagram showing a configuration of an imaging system of the first embodiment. FIG. 2 is a diagram showing an operation timing when an image is taken in a short time after the axis operation of the image pickup system of FIG. 1 is stopped. FIG. 3 is a diagram showing the light emission timing of the imaging system of FIG. FIG. 4 is a diagram showing an operation timing when an image is taken with a recognition waiting time from the axis operation stop of the image pickup system of FIG. 1 to the start of recognition. FIG. 5 is a diagram showing operation timings when imaging is performed a plurality of times after the axis operation of the imaging system of FIG. 1 is stopped.

As shown in FIG. 1, the strobe exposure imaging system 100S includes a controller 101, strobe lighting power supplies 107a and 107b, an illumination device 103, an imaging device 104 having a camera 104a and a lens 104b, and a recognition processing device 105. , Equipped with.

The controller 101 outputs an image pickup trigger signal to the camera 104a, and the camera 104a receives the image pickup trigger signal and starts exposure, and at the same time, outputs a light trigger signal (strobe trigger) so that the light turns on at the light emission delay time set from the start of exposure. Output to strobe lighting power supplies 107a and 107b. The strobe illumination power supplies 107a and 107b receive the illumination trigger signal from the camera 104a and supply the illumination emission current to the illumination device 103. The lighting device 103 is composed of pseudo-coaxial lighting 103a, side lighting 103b, and the like. The illuminating device 103 arranges a large number of light emitting diodes in a matrix and illuminates the work 108 to be imaged by the surface emitting light source.

As shown in FIG. 2, the lighting device 103 lights the strobe by single light after the light emission delay time (Td4) from the image pickup trigger signal. The controller 101 inputs an image pickup trigger signal to the camera 104a, and after the exposure delay time (Td1), the camera 104a opens the shutter for the set exposure time (Tex1) to expose the work 108 to be imaged through the lens 104b. Take an image. After the imaging of the camera 104a is completed (after the transfer waiting time (Td2) after the end of exposure), the camera 104a transfers the image data to the recognition processing device 105, and after the completion waiting time (Td3), the recognition processing device 105 transfers the image data. The amount of misalignment is calculated based on.

Assuming that the time from the issuance of the imaging trigger signal to the completion of the recognition calculation is the recognition time (Tr), Tr is as follows.
Tr = Td1 + Tex1 + Td2 + Ttr + Td3 + Trc
Here, Ttr is the image transfer time, and Trc is the recognition calculation time.

As shown in FIG. 3, the exposure time (Tex1), which is the time when the camera shutter is open, is
Tex1 = Td4 + Tem + Tm
Is. Here, Tim is the light emission time, and Tm is the exposure margin time. The emission delay time, emission time, and emission intensity are variable values, and the exposure margin time is a fixed value, for example, the following values.
Light emission time = 5 to 107.4 μs (in 0.2 μs increments)
Emission delay time = 10 to 112.4 μs (in 0.2 μs increments)
Exposure margin time = 5 μs (fixed value)
Emission intensity (light intensity) = 512 gradations For strobe exposure, the exposure time (Tex1) can be set extremely short, such as about 20 μs, and the emission time, which is the actual exposure time, can also be set extremely short, such as about 10 μs. However, it becomes recognizable and can be speeded up. Here, the moving recognition imaging means that the work 108 to be imaged is moving while the imaging device 104 is stationary, or the imaging device 104 is moving while the work 108 to be imaged is stationary. This is recognition imaging when both the imaging device 104 and the work 108 to be imaged are moving.

As described above, in a device in which a plurality of axes operate at the same time, when other axes operate during recognition imaging, the image captured due to the influence of the operating vibration is vibrating with the image at the stationary position. The position may shift with.

If the image is taken in a short time after the shaft operation is stopped, recognition deviation due to vibration will occur. As shown in FIG. 2, the average value of the displacement during exposure is the recognition position (black circle in FIG. 2), and in FIG. 2, it is located at the negative displacement, and recognition deviation occurs. That is, the position may shift when an image is taken with one strobe light emission during vibration.

As shown in FIG. 3, by making the actual exposure time, that is, the light emission time (Tem) longer than the vibration cycle, it is possible to average the vibration caused by the vibration in the captured image and reduce the influence of the vibration. is there. For example, when the strobe light emission time is about 10 ms and the vibration cycle is 10 ms or less (vibration frequency is 100 Hz or more), it is possible to reduce the influence of vibration. However, during exposure and imaging while moving, the strobe illuminance is increased, so that the lighting power output becomes a high current, and the power capacity is insufficient, so that light cannot be emitted for a long time. The light emission time is about 100 μs at the longest, and if the vibration cycle is 100 μs or less (vibration frequency is 10 kHz or more), it is possible to reduce the influence of vibration.

As shown in FIG. 4, it is conceivable to provide a recognition waiting time (Trw) from the stop of the shaft operation to the start of the recognition and wait for the vibration to subside before the exposure. As a result, it is possible to reduce the influence of vibration even when the vibration cycle is long. However, it is necessary to set a long recognition waiting time (Trw) in consideration of a long vibration cycle, and it takes time for recognition.

As shown in FIG. 5, after the axis operation is stopped, it is conceivable to perform imaging and recognition calculation a plurality of times (N times) and perform averaging processing thereof. As a result, it is possible to reduce the influence of vibration without providing a long recognition waiting time. However, the recognition time (Tr2) is less than N times the recognition time (Tr) in the cases of FIGS. 2 and 3, and recognition takes time. In the case of FIG.
Tr2 = N × Tr- (N-1) Td4
Will be. Here, N = 2.

Since the strobe exposure of the first embodiment described above emits light only once during the exposure time, it is hereinafter referred to as a strobe single exposure.

<Second embodiment>
The strobe exposure imaging system of the second embodiment will be described with reference to FIGS. 6 to 8. FIG. 6 is a diagram showing the configuration of the imaging system of the second embodiment. FIG. 7 is a diagram showing the operation timing of the imaging system of FIG. 8 is a diagram showing the light emission timing of the imaging system of FIG. 6, FIG. 8A is a case where the light emission intensity is set to 1 / N, and FIG. 8B is a case where the light emission time is set to 1 / N. Is.

As shown in FIG. 6, the configuration of the imaging system 100 of the second embodiment is the same as that of the imaging system 100S of FIG.

As shown in FIGS. 6 and 7, the controller 101 outputs an imaging trigger signal to the camera 104a. The camera 104a starts exposure after the exposure delay time (Td1) from the image pickup trigger signal, and outputs a continuous lighting trigger signal (strobe trigger) to the strobe lighting power supplies 107a and 107b after the emission delay time (Td4) set from the start of exposure. To do. The strobe lighting power supplies 107a and 107b cause the light emitting diode of the lighting device 103 to emit light with a light emission delay time (Td4), a light emission time (Tem), a light amount (light emission intensity), and a light emission cycle (Tep) set in advance from the illumination trigger signal. .. The camera 104a opens the shutter for the set exposure time (Tex2) to expose, and images the work 108 to be imaged through the lens 104b. After the imaging of the camera 104a is completed (after the transfer waiting time (Td2) after the end of exposure), the camera 104a transfers the image data to the recognition processing device 105, and after the completion waiting time (Td3), the recognition processing device 105 transfers the image data. The amount of misalignment is calculated based on. The camera 104a outputs a plurality of trigger signals for the input of one imaging trigger signal.

The recognition time (Tr3) is as follows, as in the first embodiment.
Tr3 = Td1 + Tex2 + Td2 + Ttr + Td3 + Trc
However, the exposure time (Tex2) of the second embodiment is longer than the exposure time (Tex1) of the first embodiment, and therefore the recognition time (Tr3) of the second embodiment is the recognition time (Tr) of the first embodiment. It is longer than (Tex2-Tex1).

As shown in FIG. 8, the exposure time (Tex2) is
Tex2 = Tem × (N-1) + Td4 + Tem + Tm
Is. The light emission cycle is 10 ms or more due to the restrictions of the current strobe. For example
Light emission cycle = 10 ms
Emission delay time = 10 μs
Light emission time = 50 μs
Exposure margin time = 5 μs
N = 4
Then
Tex2 = 10ms x (4-1) + 10μs + 50μs + 5μs = 30.11ms
Will be.

Since the strobe exposure of the second embodiment described above has a plurality of light emission within the exposure time, it is hereinafter referred to as strobe multiple exposure.

In order to prevent overexposure, the total exposure light amount of the strobe multiple exposure of the second embodiment is set to be the same as the light amount of the strobe single exposure of the first embodiment. The amount of light emitted by one strobe is adjusted by adjusting the light emission time and the light emission intensity. For example, as shown in FIG. 8A, when one flash of strobe multiple exposure that emits N times in one exposure time is the same as the flash time of one strobe exposure, the strobe multiple exposure is used. The intensity of one flash is set to 1 / N of the intensity of one exposure of the strobe. As shown in FIG. 8B, when the intensity of one strobe multiple exposure that emits N times in one exposure time is the same as the intensity of one exposure of a strobe, the one emission time is set. Set to 1 / N. Further, for example, when the flash time of one strobe multiple exposure is set to five times the flash time of the strobe single exposure, the flash intensity of one strobe multiple exposure is reduced to 1/5 N of the flash intensity of the strobe single exposure. To do.

As shown in FIG. 7, the strobe is turned on a plurality of times (4 times in this example) within one exposure time. Images for multiple strobe lights are exposed multiple times on one image, and the vibration components are averaged in one image. For this purpose, strobe exposure is performed a plurality of times with a period of 1/2 or less of the vibration period (Top) within the time (exposure time) when the shutter of the camera is opened. This makes it possible to reduce recognition deviation due to vibration caused by shaft movement, vibration caused by other shaft movement, vibration caused by disturbance, and the like.

In the second embodiment, the strobe is fired a plurality of times during one imaging and averaged by multiple exposures, so that disturbances such as vibration after the operation axis is stopped and vibration caused by axis operation other than the recognition target axis are disturbed. It is possible to reduce the impact. Further, it is possible to shorten the time for starting recognition after the recognition target operation axis stops. Further, since only one imaging and data transfer are required, the transfer time and the processing time of the recognition calculation can be shortened, and the speed can be made higher than that of a normal strobe single exposure multiple times. In addition, the strobe illumination capable of emitting light with sufficient illuminance for an extremely short time shortens the actual exposure time (exposure time while emitting light), and recognition during movement is also possible.

<Modification example>
Hereinafter, some typical modifications of the embodiment 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 configurations and functions 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 technically consistent range. 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. 9 is a diagram showing a configuration of an imaging system of the first modification.

In the second embodiment, the trigger signal for performing the strobe light emission a plurality of times is generated by the camera 104a, but it may be generated by a pulse generator outside the camera 104a. The camera 104a of the imaging system 100A of the first modification outputs the input imaging trigger signal to the pulse generation circuit 109, and the pulse generation circuit 109 outputs a predetermined number of trigger signals at predetermined intervals based on the input imaging trigger signal. Output.

(Second modification)
In the second embodiment, when the flash time of one strobe multiple exposure is the same as the flash time of the strobe single exposure, the flash intensity of one strobe multiple exposure is set to 1 / of the flash intensity of the strobe single exposure. Although it is set to N, the emission intensity of one strobe multiple exposure may be the same as the emission intensity of one strobe exposure. As a result, in the appearance inspection for detecting foreign matter, even when recognizing a dark object whose illuminance is insufficient by one exposure, it is possible to secure and recognize the brightness by strobe exposure a plurality of times.

(Third variant)
The imaging system 100S of the first embodiment and the imaging system 100 of the second embodiment may be combined. The imaging system of the third modification includes a strobe single exposure function of the imaging system 100S (strobe single exposure mode) and a strobe multiple exposure function of the imaging system 100 (strobe multiple exposure mode).

In the image pickup system of the third modification, in the strobe single exposure mode, the camera 104a outputs a single-shot trigger signal based on the image pickup trigger signal from the controller 101, and operates in the same manner as the image pickup system 100S. In the strobe multiple exposure mode, the camera 104a outputs a continuous trigger signal based on the image pickup trigger signal from the controller 101, and operates in the same manner as the image pickup system 100.

Hereinafter, an example applied to the flip chip bonder, which is an example of the mounting device of the above-described embodiment, will be described. The flip chip bonder is used for manufacturing, for example, a fan-out type wafer level package (FOWLP), which is a package for forming a rewiring layer in a wide area exceeding the chip area.

FIG. 10 is a top view showing an outline of the flip chip bonder of the embodiment. FIG. 11 is a diagram illustrating the operation of the pickup flip head and the transfer head when viewed from the direction of arrow A in FIG. FIG. 12 is a diagram illustrating the operation of the bonding head when viewed from the direction of arrow B in FIG. FIG. 13 is a schematic cross-sectional view showing a main portion of the die supply portion of FIG.
As shown in FIG. 10, the flip chip bonder 10 is roughly classified into a die supply unit 1, a first pickup unit 2a, a second pickup unit 2b, a first transfer stage unit 3a, and a second transfer stage unit 3b. A first bonding unit 4a, a second bonding unit 4b, a transport unit 5, a substrate supply unit 6K, a substrate carry-out unit 6H, and a control device 7 for monitoring and controlling the operation of each unit are provided. The second pickup section 2b, the second transfer stage section 3b, and the second bonding section 4b are the first pickup section 2a and the first transfer stage section with respect to a line extending in the Y-axis direction through the die D to be picked up, respectively. It is arranged in a mirror object with 3a and the first bonding portion 4a, is configured in the same manner, and operates in the same manner. The code "b" of each component of the second pickup section 2b, the second transfer stage section 3b, and the second bonding section 4b is each element of the first pickup section 2a, the first transfer stage section 3a, and the first bonding section 4a. Corresponds to the code "a" of.

First, the die supply unit 1 supplies the die D to be mounted on the substrate P, which is an example of the work. The die supply unit 1 includes a wafer holding base 12 for holding the divided wafer 11, a push-up unit 13 for pushing up the die D from the wafer 11, and a wafer ring supply unit 18. The die supply unit 1 moves in the XY direction by a driving means (not shown), and moves the die D to be picked up to the position of the push-up unit 13. The wafer ring supply unit 18 has a wafer cassette (not shown) in which the wafer ring 14 is housed, and sequentially supplies the wafer ring 14 to the die supply unit 1 and replaces it with a new wafer ring. The wafer cassette in which the wafer ring 14 is housed is supplied to the wafer ring supply unit 18 from the outside of the flip chip bonder 10. The die supply unit 1 moves the wafer ring 14 to the pickup point so that the desired die D can be picked up from the wafer ring 14. The wafer ring 14 is a jig to which the wafer 11 is fixed and can be attached to the die supply unit 1.

The first pickup unit 2a is located on the substrate supply unit 6K side with respect to the die D to be picked up. The first pickup unit 2a has a pickup flip head 21a that picks up and reverses the die D, a drive unit 23a that moves the collet 22a (see FIG. 11) up and down, rotates, reverses, and moves in the X-axis direction, and the die D at the tip. A pickup head 25a having a collet 26a (see FIG. 11) that attracts and holds the pickup head 25a, and a drive unit 27a that moves the pickup head 25a up and down and moves in the X-axis direction are provided. A wafer recognition camera 24 is provided directly above the die D to be picked up, and is shared by the first pickup unit 2a and the second pickup unit 2b. With such a configuration, as shown in FIG. 11, the pickup flip head 21a picks up the die D based on the imaging data of the wafer recognition camera 24, rotates the pickup flip head 21a by 180 degrees, and bumps the die D. The die D is turned upside down and turned toward the lower surface so that the die D is passed to the pickup head 25a. The pickup head 25a receives the inverted die D from the pickup flip head 21a and places it on the first transfer stage portion 3a.

The first transfer stage unit 3a includes transfer stages 31a1 and 31a2 on which the die D is temporarily placed, an undervision camera (first imaging device) 34a, and an undervision correction mark 35a. The transfer stages 31a1 and 31a2 can be moved in the Y-axis direction by a drive unit (not shown).

The first bonding portion 4a is located on the substrate supply portion 6K side with respect to the die D to be picked up. The first bonding portion 4a picks up the die D from the transfer stages 31a1 and 31a2 and bonds the die D onto the conveyed substrate P. The first bonding portion 4a includes a bonding head 41a, a bond head table 45a for moving the bonding head 41a in the Z-axis direction, a gantry table (Y beam) 43a for moving the bond head table 45a in the Y-axis direction, and a gantry table. A pair of X beams (not shown) that move 43a in the X-axis direction, and a bond camera (second imaging device) 44a that captures a position recognition mark (not shown) of the substrate P and recognizes the bonding position. Be prepared. The gantry table 43a extends in the Y-axis direction so as to straddle the mounting stage BS (see FIG. 12), and both ends thereof are supported by a pair of X beams so as to be movable in the X-axis direction. When the die D is bonded to the substrate P, the substrate P is attracted and fixed to the mounting stage BS. The bond camera 44a is provided on the bond head table 45a. As shown in FIG. 12, the bonding head 41a includes bonding heads 41a1, 41a2, 41a3, 41a4 each having collets 42a1, 42a2, 42a3, 42a4 that attract and hold four dies D at their tips.
With such a configuration, the bonding head 41a picks up the die D from the transfer stages 31a1 and 31a2, and the undervision camera 34a and the bond camera 44a image the position where the bonding head holds the die D. The bonding positioning correction position is calculated based on this imaging data, and the bonding head is moved to bond the die D to the substrate P.

The transport unit 5 includes transport rails 51 and 52 in which the substrate P moves in the X-axis direction. The transport rails 51 and 52 are provided in parallel. With such a configuration, the substrate P is carried out from the board supply section 6K, moved to the bonding position along the transport rails 51 and 52, moved to the board carry-out section 6H after bonding, and the board P is moved to the board carry-out section 6H. hand over. While the die D is being bonded to the substrate P, the substrate supply unit 6K carries out a new substrate P and stands by on the transport rails 51 and 52. The substrate P is carried into the substrate supply unit 6K from the outside of the flip chip bonder 10, and the substrate P on which the die D is placed is carried out of the flip chip bonder 10 from the substrate carry-out unit 6H.

The control device 7 includes a program (software) for monitoring and controlling the operation of each part of the flip chip bonder 10, a storage device (memory) for storing data, and a central processing unit (CPU) for executing the program stored in the memory. , Equipped with. The control device 7 includes the controller 101 of the embodiment, the recognition processing device 105, and the like.

As shown in FIG. 13, the wafer holding table 12 includes an expanding ring 15 for holding the wafer ring 14 and a support ring 17 for horizontally positioning the dicing tape 16 held by the wafer ring 14 and to which a plurality of dies D are adhered. , A push-up unit 13 for pushing up the die D upward. In order to pick up the predetermined die D, the push-up unit 13 is moved in the vertical direction by a drive mechanism (not shown), and the die supply unit 1 is moved in the horizontal direction.

The configuration of the undervision camera and the bond camera will be described with reference to FIG. FIG. 14A is a diagram showing the configuration of the undervision camera, and FIG. 14B is a diagram showing the configuration of the bond camera.

The undervision camera 34a includes an image pickup device 344 having a camera body 344a and a lens 344b, and a lighting device 343 having a pseudo coaxial illumination 343a and a ring illumination 343b. The undervision camera 34a is provided facing upward so as to image the upper die D from directly below. The camera body 344a and the lighting device 343 are controlled in the same manner as the camera body 104a and the lighting device 103 of the imaging system 100 of the embodiment. That is, the undervision camera 34a can image the die D by the strobe single exposure or the strobe multiple exposure of the embodiment according to the instruction of the control device 7. The undervision camera 34b has the same configuration as the undervision camera 34a.

The bond camera 44a includes an image pickup device 444 having a camera body 444a and a lens 444b, and a lighting device 443 having a pseudo coaxial illumination 443a and a side illumination 443b. The bond camera 44a is provided facing downward so as to image the lower undervision correction mark 35a, the die D, and the substrate P from above. The camera body 444a and the lighting device 443 are controlled in the same manner as the camera 104a and the lighting device 103 of the imaging system 100 of the embodiment. That is, the bond camera 44a can image the undervision correction mark 35a, the die D, and the substrate P by the strobe single exposure or the strobe multiple exposure of the embodiment. The bond camera 44b has the same configuration as the bond camera 44a.

The wafer recognition camera 24 has the same configuration as the bond camera 44a, but images the wafer 11 (die D) by normal exposure, but like the undervision camera 34a and the bond camera 44a, strobe exposure and strobe multiple exposure It is also possible to replace it with a possible system.

A normal exposure imaging system in which exposure is controlled by a camera shutter using constantly lit illumination will be described with reference to FIGS. 15 and 16. FIG. 15 is a diagram showing a configuration of a normal exposure imaging system. FIG. 16 is a diagram showing the operation timing of the imaging system of FIG.

The normal exposure imaging system 100R includes a controller 101, illumination power supplies 102a and 102b, an illumination device 103, an imaging device 104 having a camera 104a and a lens 104b, and a recognition processing device 105.

The controller 101 outputs control signals such as illumination ON / OFF and illuminance setting to the illumination power supplies 102a and 102b, and the illumination power supplies 102a and 102b supply the illumination emission current to the illumination device 103. The lighting device 103 is composed of pseudo-coaxial lighting 103a, side lighting (ring lighting, 4-way bar lighting, etc.) 103b, and the like. The illuminating device 103 arranges a large number of light emitting diodes in a matrix and illuminates the work 108 to be imaged by the surface emitting light source.

The lighting device 103 is always lit or lit before recognition exposure. The controller 101 inputs an image pickup trigger signal to the camera 104a, and after the exposure delay time (Td1), the camera 104a opens the shutter for the set exposure time (Tex3) to expose the work 108 to be imaged through the lens 104b. Take an image. After the imaging of the camera 104a is completed (after the end of the exposure, after the transfer waiting time (Td2)), the camera 104a transfers the image data to the recognition processing device 105, and the recognition processing device 105 determines the amount of misalignment based on the image data. Is calculated.

The recognition time (Tr4) is as follows, as in the first embodiment.
Tr4 = Td1 + Tex3 + Td2 + Ttr + Td3 + Trc
However, the exposure time (Tex3) is longer than the exposure time (Tex1) of the first embodiment, and therefore the recognition time (Tr3) is longer than the recognition time (Tr) of the first embodiment (Tex3-Tex1). ..

As described above, in a device in which a plurality of axes operate at the same time, when other axes operate during recognition imaging, the image captured due to the influence of the operating vibration is vibrating with the image at the stationary position. The position may shift with. However, as shown in FIG. 16, by lengthening the exposure time, the captured image is averaged due to vibration, and it is possible to reduce the influence of vibration. By securing an exposure time of 10 ms or more, operating vibrations of 100 Hz or higher are averaged by imaging, and it is possible to reduce the influence of vibrations.

Next, undervision correction will be described with reference to FIGS. 17 and 18. FIG. 17 is a diagram illustrating the operation of the bonding head when viewed from the direction of arrow B in FIG. 10, and FIG. 17A shows a state in which the first bonding head and the corresponding undervision correction mark are imaged. 17 (b) is a diagram showing a state in which the second bonding head and the corresponding undervision correction mark are imaged, and FIG. 17 (c) is a diagram showing the third bonding head and the corresponding undervision. FIG. 17 (d) is a diagram showing a state in which the vision correction mark is imaged, and FIG. 17 (d) is a diagram showing a state in which the fourth bonding head and the corresponding undervision correction mark are imaged. FIG. 18 (a) is a diagram showing an image of an undervision correction mark captured by a bond camera, FIG. 18 (b) is a diagram showing an image of a die captured by an undervision camera, and FIG. 18 (c) is a diagram showing an image captured by a bond camera. It is an image of the reference mark on the substrate by. In the captured image of FIG. 18, the outer circumference is shown in black and the inside is shown in white for ease of explanation.

The undervision correction mark 35a is provided on the side opposite to the substrate P with the undervision camera 34a interposed therebetween. As shown in FIG. 17, the undervision correction mark 35a is configured by irradiating the pinholes 35a1 to 35a4 of the plate 35a5 with light sources 35a6 to 35a9 such as LEDs arranged below the plate 35a5 that blocks light. A mark is formed by a point light source. Four of the four pinholes 35a1 to 35a4 are arranged at positions corresponding to the four collets 42a1 to 42a4. Therefore, the four pinholes 35a1 to 35a4 form four undervision correction marks. When referring to the four undervision correction marks individually, reference numerals 35a1 to 35a4 are used.

When the bond camera 44a captures the undervision correction mark 35a, the light emitted from the lighting device 443 of the bond camera 44a is incident on the undervision camera 34a so as not to affect the recognition of the undervision camera 34a. Lighting device 443 is turned off. As a result, the influence of the undervision camera 34a, which will be described later, on the imaging of the collet 42a can be reduced.

While the bond head 41a and the bond camera 44a move in the Y-axis direction, the bond camera 44a captures and recognizes the undervision correction mark 35a, and as shown in FIG. 18A, the initially registered undervision correction The deviation between the position of the mark 35a (mark initial position) and the position of the undervision correction mark 35a recognized by the bond camera 44a is recognized, and (dXmark, dYmark) is calculated. When the collet 42a is positioned at the center of the undervision camera 34a, the undervision correction mark 35a is imaged by the bond camera, the position is measured, and the initial mark position is registered. At the same time as the undervision correction mark 35a is imaged by the bond camera 44a, the undervision camera 34a images and recognizes the mounting surface of the die D attracted and held by the collet 42a, and as shown in FIG. The position of the die D is recognized and measured from the center of the camera 34a, and (dXdie, dYdie) is calculated. From the results of (dXmark, dYmark) and (dXdie, dYdie), the position of the die D adsorbed and held by the collet 42a with respect to the position of the undervision correction mark 35a is calculated.

As shown in FIG. 17, the die Ds attracted and held by the four collets 42a1 to 42a4 mounted on the bonding head 41a are moved onto the undervision camera 34a, the die D is imaged, the position is recognized, and the collet The undervision correction marks 35a1 to 35a4 corresponding to the positions recognized by the undervision camera 34a for each of 42a1 to 42a4 are recognized and imaged by the bond camera 44a at the same time as the die D is recognized and imaged by the undervision camera 34a. The details will be described below.

First, as shown in FIG. 17A, the die D attracted and held by the collet 42a1 of the first bonding head 41a1 is moved onto the undervision camera 34a, and the die D is imaged to recognize the position. The undervision correction mark 35a1 corresponding to the position recognized by the undervision camera 34a with respect to the die D attracted and held by the collet 42a1 is imaged by the bond camera 44a to recognize the position.

Next, as shown in FIG. 17B, the die D attracted and held by the collet 42a2 of the second bonding head 41a2 is moved onto the undervision camera 34a, and the die D is imaged to recognize the position. At the same time, the undervision correction mark 35a2 corresponding to the position recognized by the undervision camera 34a for the die D attracted and held by the collet 42a2 is imaged by the bond camera 44a to recognize the position.

Next, as shown in FIG. 17C, the die D attracted and held by the collet 42a3 of the third bonding head 41a3 is moved onto the undervision camera 34a, and the die D is imaged to recognize the position. At the same time, the undervision correction mark 35a3 corresponding to the position recognized by the undervision camera 34a for the die D attracted and held by the collet 42a3 is imaged by the bond camera 44a to recognize the position.

Next, as shown in FIG. 17D, the die D attracted and held by the collet 42a4 of the fourth bonding head 41a4 is moved onto the undervision camera 34a, and the die D is imaged to recognize the position. At the same time, the undervision correction mark 35a4 corresponding to the position recognized by the undervision camera 34a for the die D attracted and held by the collet 42a4 is imaged by the bond camera 44a to recognize the position.

After the position recognition of the die D by the undervision camera 34a is completed, as shown in FIG. 17, the bonding head 41a moves to the substrate P which is adsorbed and fixed to the mounting stage BS while adsorbing and holding the die D, and the substrate P Bond the die D to a predetermined position. At that time, the bond camera 44a images and recognizes the reference mark RM provided on the substrate P, and as shown in FIG. 18C, the position of the reference mark RM on the substrate P as seen from the center of the bond camera 44a is determined. Recognize and measure (dX _RM , dY _RM ) to calculate. When calculating the position to bond the die D from the position of the reference mark RM, the position of the die D adsorbed and held on the collet 42a with respect to the position of the undervision correction mark 35a obtained earlier is added to calculate the bond position. .. That is, (Xbond, Ybond) is calculated by subtracting each recognition result from the target positioning coordinates to be bonded.

Xbond ₌ dX RM -dXdie-dXmark
Ybond ₌ dY RM -dYdie-dYmark
As a result, the effects of the bonding head positioning error and the displacement of the bonding head positioning position due to operating vibration can be offset, and the position of the die D is always calculated with reference to the undervision correction mark 35a, and the reference mark RM is used. It is possible to adjust the bond position from. In this example, when the head is positioned at the position to be bonded by each collet, the reference mark RM is placed in the field of view that can be imaged by the bond camera, and the method of correcting the bond position by recognizing this is described. As a method of correcting the positioning position at the time of bonding, an image is taken with a bond camera based on an alignment mark provided in advance on the substrate to be bonded, a mark individually provided at each bonding position on the substrate, or a die that has already been bonded. The same effect can be obtained by performing recognition calculation and correcting the bond position together with the recognition result of the undervision correction mark.

Next, a bonding method (method for manufacturing a semiconductor device) carried out in the flip chip bonder of the embodiment will be described with reference to FIG. FIG. 19 is a flowchart showing a bonding method carried out by the flip chip bonder of the embodiment. The first pickup portion 2a, the first transfer stage portion 3a, and the first bonding portion 4a side will be mainly described, but the same applies to the second pickup portion 2b, the second transfer stage portion 3b, and the second bonding portion 4b side. The second pickup section 2b, the second transfer stage section 3b, and the second bonding section 4b operate in parallel within a range that does not interfere with the first pickup section 2a, the first transfer stage section 3a, and the first bonding section 4a.

When a semiconductor device is manufactured by the flip chip bonder 10, the wafer cassette in which the wafer ring 14 is housed is supplied to the wafer ring supply unit 18 from the outside of the flip chip bonder 10. Further, the substrate P is carried into the substrate supply unit 6K from the outside of the flip chip bonder 10. The board P on which the die D is mounted is carried out from the board carry-out portion 6H to the outside of the flip-chip bonder 10. The operation in the flip chip bonder 10 will be described below.

Step S1: The control device 7 moves the wafer holding table 12 so that the die D to be picked up is located directly above the push-up unit 13, and pushes up the die to be peeled off based on the imaging data of the wafer recognition camera 24. And position it on the collet 22a. The push-up unit 13 is moved so that the upper surface of the push-up unit 13 comes into contact with the back surface of the dicing tape 16. At this time, the control device 7 attracts the dicing tape 16 to the upper surface of the push-up unit 13. The control device 7 lowers the collet 22a while evacuating it, lands it on the die D to be peeled off, and adsorbs the die D. The control device 7 raises the collet 22a and peels the die D from the dicing tape 16. As a result, the die D is picked up by the pickup flip head 21a.

Step S2: The control device 7 moves the pickup flip head 21a.

Step S3: The control device 7 rotates the pickup flip head 21a by 180 degrees, inverts the bump surface (surface) of the die D to face the lower surface, inverts the bump (surface) of the die D to face the lower surface, and turns the die D. To the pickup head 25a.

Step S4: The control device 7 picks up the die D from the collet 22a of the pickup flip head 21a by the collet 26a of the pickup head 25a, and delivers the die D.

Step S5: The control device 7 inverts the pickup flip head 21a and turns the suction surface of the collet 22a downward.

Step S6: Before or in parallel with step S5, the control device 7 moves the pickup head 25a to the transfer stage 31a1.

Step S7: The control device 7 places the die D held by the pickup head 25a on the transfer stage 31a1.

Step S8: The control device 7 moves the pickup head 25a to the delivery position of the die D. The control device 7 repeats steps S1 to S8 a predetermined number of times (four times in the embodiment).

Step S9: After or in parallel with step S8, the control device 7 moves the transfer stage 31a1 to a transfer position with the bonding head 41a.

Step SA: The control device 7 images the die D held by the transfer stage 31a1 by the bond camera 44a, and collectively collects a plurality of (four in the embodiment) die D from the transfer stage 31a1 by the collet 42a of the bonding head 41a. And pick up, and the die D is delivered.

Step SB: The control device 7 moves the four dies D held by the collets 42a1, 42a2, 42a3, 42a4 of the bonding heads 41a1, 41a2, 41a3, 41a4 from the transfer stage 31a1 onto the substrate P. At this time, the undervision correction mark 35a is imaged while the bond camera 44a is moved, and the four dies D that are moving are imaged by the undervision camera 34a. The gantry table 43a moves in the X-axis direction, and the bonding head 41a moves in the Y-axis direction.

Step SC: The control device 7 images the substrate by the bond camera 44a, the data of the undervision correction mark 35a imaged by the bond camera 44a, the data of the die D imaged by the undervision camera 34a, and the substrate imaged by the bond camera 44a. Based on the above data, the four dies D picked up by the collets 42a1, 42a2, 42a3, 42a4 of the bonding heads 41a1, 41a2, 41a3, 41a4 from the transfer stage 31a1 are collectively placed on the substrate P.

Step SD: The control device 7 moves the bonding heads 41a1, 41a2, 41a3, 41a4 to the transfer position with the transfer stage 31a2.

Step SE: The control device 7 moves the transfer stage 31a1 to the delivery position with the pickup head 25a.

In the above flow, the transfer stage 31a1 is used, but the same applies when the transfer stage 31a2 is used.

In the flip chip bonder 10, by using a light emitting strobe for an extremely short time of about 10 μs in imaging the die and the substrate, exposure imaging (recognition by fly scan) is performed while the die and the substrate to be imaged are moving, and production is performed. Although it is possible to improve the performance, a single strobe exposure for an extremely short time may be affected by recognition deviation due to disturbance effects such as vibration, which may hinder high-precision bonding. In such a case, by strobe multiple exposure as in the case proposed in the present invention, the camera is exposed for 10 ms or more, the strobe is fired multiple times within the exposure time, the recognition deviation due to the vibration effect at the time of imaging is reduced, and the recognition correction error. It is possible to suppress deterioration of accuracy due to the inclusion of the above, and it is possible to provide a highly accurate bonding operation.

The inventions made by the present inventors have been specifically described above based on the embodiments and examples, but the present invention is not limited to the above embodiments and examples, and can be variously modified. Needless to say.

In the embodiment, an example in which the controller 101 outputs an imaging trigger signal to the camera 104a has been described, but the recognition processing device 105 outputs an exposure start command to the camera 104a, and the camera 104a that receives the exposure start command starts exposure and the camera. The lighting trigger signal may be output from the 104a to the strobe lighting power supplies 107a and 107b.

Further, in the embodiments and examples, an example in which the lighting device is composed of pseudo-coaxial lighting and ring lighting has been described, but any one of the pseudo-coaxial lighting and ring lighting, the other lighting, and a combination thereof. It may be composed of lighting.

Moreover, although four examples of the bonding head (mounting head) have been described in the examples, the present invention is not limited to this, and one or a plurality of bonding heads may be used.

Further, in the embodiment, an example in which the reversing mechanism is provided in the pickup flip head, the die is received from the pickup flip head by the transfer head, placed on the intermediate stage, and the intermediate stage is moved has been described, but the present invention is not limited to this. Instead, the die may be picked up and the inverted pickup flip head may be moved, or the picked-up die D may be placed on a stage unit capable of rotating the front and back of the die to move the stage unit. ..

Further, in the embodiment, an example applied to the flip chip bonder will be described, but the present invention is not limited to this, and a die bonder for bonding a semiconductor chip (die) to a substrate or the like, a packaged semiconductor device or the like is mounted on the substrate. It can also be applied to chip mounters (surface mounters) and the like.

100: Imaging system 101: Controller 103: Lighting device 104: Imaging device 105: Recognition processing device 107: Strobe lighting power supply 108: Work (imaging target)

Claims (17)

A first imaging device that moves relative to the first imaging object and images the first imaging object.
The first illumination device that irradiates the first imaging object with light,
With
The first lighting device is a mounting device configured to emit strobe light a plurality of times at a cycle of 1/2 or less of the vibration cycle within the exposure time of the first imaging device. In the mounting device of claim 1,
Further, the first lighting device is provided with a strobe lighting power supply that supplies a lighting emission current.
The first imaging device is configured to start exposure based on an imaging trigger signal and generate a strobe trigger signal to be supplied to the strobe lighting power source.
The strobe illumination power supply is an mounting device configured to periodically supply the illumination emission current to the first illumination device based on the strobe trigger signal. In the mounting device of claim 1, further
A strobe lighting power source that supplies a lighting emission current to the first lighting device,
A pulse generation circuit that generates a strobe trigger signal to be supplied to the strobe lighting power supply based on the trigger signal.
With
The first imaging device is configured to start exposure based on an imaging trigger signal and generate a strobe trigger signal to be supplied to the strobe lighting power source.
The strobe illumination power supply is an mounting device configured to periodically supply the illumination emission current to the first illumination device based on the strobe trigger signal. In the mounting device of claim 1, further
A second imaging device that moves relative to the second imaging object and images the second imaging object,
A second lighting device that irradiates the second imaging object with light,
With
The second lighting device is a mounting device configured to emit strobe light a plurality of times at a cycle of 1/2 or less of the vibration cycle within the exposure time of the second imaging device. In the mounting device of claim 4,
The first imaging object is a die.
Further, a first mounting head for conveying the die is provided.
The first imaging device is a mounting device configured to image the die held by the moving first mounting head from below. In the mounting device of claim 5,
The second imaging object is a correction mark.
The second imaging device is mounted on the first mounting head, and when the die held by the first mounting head on which the first imaging device moves is imaged, the correction mark is imaged from above. Mounting equipment to be. In the mounting device of claim 6,
The second imaging device is a mounting device configured to image the substrate on which the die is placed from above. In the mounting device of claim 7,
Further, a transfer stage for transporting the die is provided.
The second imaging device is a mounting device configured to image the die held by the transfer stage from above. In the mounting device of claim 4,
The first luminaire includes pseudo-coaxial illuminating and side illuminating.
The second lighting device is a mounting device including pseudo-coaxial lighting and side lighting. In the mounting apparatus of claim 8, further
Implementation stage and
When it extends in the first direction so as to straddle the mounting stage and both ends thereof are movably supported in the second direction, the first beam and
A second beam that extends in the first direction so as to straddle the mounting stage and is supported on the mounting stage at both ends so as to be movable in the second direction.
With
The first mounting head is a mounting device configured to be movable in the first direction and supported by the first beam. In the mounting apparatus of claim 10, further
A flip pickup head that picks up the die from the die supply unit and reverses it,
A pickup head that can freely move in the first direction and picks up the die picked up by the flip pickup head,
With
The transfer stage is freely movable in the second direction, and the die picked up by the pickup head is placed on the transfer stage.
The first mounting head is a mounting device configured to pick up the die mounted on the transfer stage and mount it on the substrate on the mounting stage. In the mounting device of claim 11,
The first imaging device is a mounting device configured such that when the first mounting head transports the die from the transfer stage to the mounting stage, the die is imaged from below. In the mounting device of claim 11,
The second imaging device is a mounting device configured such that the first mounting head images the correction mark from above when the die is conveyed from the transfer stage to the mounting stage. In the mounting device of claim 11,
Further, a second mounting head that is movable in the first direction and is supported by the second beam is provided.
The second mounting head is a mounting device configured to pick up a die mounted on a transfer stage different from the transfer stage and mount it on the substrate on the mounting stage. The first imaging device that images the die, the second imaging device that images the substrate, the first lighting device that irradiates the die with light, the second illumination device that irradiates the substrate with light, and the die are conveyed. The process of carrying the board into a mounting device including a mounting head
A first imaging step in which the first imaging device images the die from below while the die is being conveyed by the mounting head.
A second imaging step in which the second imaging device images the substrate from above,
A step of mounting the die on the substrate based on the data captured in the first imaging step and the second imaging step, and
With
In the first imaging step, the first lighting device flashes light a plurality of times in a cycle of 1/2 or less of the vibration cycle within the exposure time of the first imaging device to image the die.
The second imaging step is a method for manufacturing a semiconductor device in which the second lighting device emits strobe light a plurality of times at a cycle of 1/2 or less of the vibration cycle within the exposure time of the second imaging device to image the substrate. In the method for manufacturing a semiconductor device according to claim 15,
In the first imaging step, the first imaging device images the die, the second imaging device images the undervision correction mark, and the semiconductor recognizes and corrects the positioning position of the die with respect to the first imaging device. How to manufacture the device. In the method for manufacturing a semiconductor device according to claim 15, further
The process of bringing in the wafer ring and
The third imaging step of imaging the die in the wafer ring and
With
In the third imaging step, a method for manufacturing a semiconductor device that constantly illuminates during an exposure time to image the die.

Images