JP2020004812A - Die bonder and manufacturing method of semiconductor device - Google Patents

Abstract

To solve the problem that it is difficult to detect all surfaces of a coating area of a paste-like adhesion agent in the case where a brightness of a substrate surface and a brightness of a coating part of the paste-like adhesion agent are close.SOLUTION: A die bonder includes steps of; (a) imaging a state of a pre-coating of an adhesion agent of a substrate by setting an illumination device to a first state, and imaging the state of a post-coating of the adhesion agent on the substrate; (b) imaging the state of the pre-coating of the adhesion agent of the substrate by setting the illumination device to a second state, and imaging the state of the post-coating of the adhesion agent on the substrate; (c) calculating binary data of a difference between an imaging image in the state of the post-coating imaged in the first state of the illumination device and the imaging image of the state of the pre-coating, and calculating the binary data of the difference between the imaging image in the state of the post-coating imaged in the second state of the illumination device and the imaging image in the state of the pre-coating; and (e) synthesizing the binary data calculated in the first state of the illumination device with the binary data calculated in the second state, and obtaining a coating pattern of the adhesion agent.SELECTED DRAWING: Figure 19

Description

  The present disclosure relates to a die bonder, and is applicable to, for example, a die bonder including a preform portion.

  A part of a semiconductor device manufacturing process includes a process of mounting a semiconductor chip (hereinafter, simply referred to as a die) on a wiring board, a lead frame or the like (hereinafter, simply referred to as a substrate) and assembling a package. Some of the steps include a step of dicing a die from a semiconductor wafer (hereinafter simply referred to as a wafer) (dicing step) and a bonding step of mounting the split die on a substrate. A semiconductor manufacturing apparatus used in the bonding step is a die bonder.

  A die bonder is a device for bonding (mounting and bonding) a die onto a substrate or an already bonded die using solder, gold plating, or resin as a bonding material. In a die bonder for bonding a die to, for example, the surface of a substrate, a die is suctioned from a wafer using a suction nozzle called a collet, picked up, transferred onto the substrate, applied with a pressing force, and heated with a bonding material. Thus, the operation (work) of performing bonding is repeatedly performed.

  When a resin is used as a joining material, a resin paste such as Ag epoxy and acrylic is used as an adhesive (hereinafter, referred to as a paste adhesive). A paste adhesive for bonding the die to a lead frame or the like is enclosed in a syringe. The syringe moves up and down with respect to the lead frame to eject and apply the paste adhesive. That is, a predetermined amount of the paste adhesive is applied to a predetermined position by a syringe in which the paste adhesive is sealed, and a die is pressed onto the paste adhesive to be bonded.

  A recognition camera is attached near the syringe, and it is checked whether a predetermined amount of the paste adhesive applied by the recognition camera is applied to a predetermined position.

JP 2013-197277 A

If the brightness of the board surface is close to the brightness of the area where the paste adhesive is applied, such as when applying a paste adhesive such as epoxy resin to the surface of a metal-plated board, cover the entire area of the paste adhesive application area. Difficult to detect.
An object of the present disclosure is to provide a die bonder capable of improving a detection rate of an application pattern of a paste adhesive applied to a substrate.
Other problems and novel features will be apparent from the description of this specification and the accompanying drawings.

The outline of a typical one of the present disclosure will be briefly described as follows.
That is, the die bonder (a) takes an image of a state before the application of the adhesive on the substrate with the lighting device in the first state, an image of the state after the application of the adhesive on the substrate, and (b) (C) imaging the state before the application of the adhesive on the substrate and imaging the state after the application of the adhesive on the substrate; Calculating binarized data of a difference between a captured image of the state after application captured in the state and a captured image of the state before application, and (d) calculating the binary image of the illumination device in the second state after the application. Binary data of the difference between the captured image in the state and the captured image in the state before the application is obtained, and (e) the binary data obtained in the first state of the lighting device and the binary data obtained in the second state. The obtained binarized data is synthesized to obtain the adhesive application pattern.

  According to the die bonder, it is possible to improve the detection rate of the application pattern of the paste adhesive applied to the substrate.

It is a figure explaining application of a paste adhesive. It is a figure explaining the application pattern of paste adhesive. It is a figure explaining the application state of a paste adhesive. It is a figure explaining the problem at the time of applying a paste adhesive to the surface of the board | substrate by which metal plating was performed. It is a figure showing an optical system of an embodiment. FIG. 6 is a diagram illustrating image processing using the optical system of FIG. 5. It is a figure explaining why it is better to separate lighting of two lights. It is a top view showing arrangement of a lighting installation of a 2nd modification. It is a perspective view showing arrangement of oblique illumination of the lighting installation of a 3rd modification. It is a typical perspective view showing the lighting device of the 4th modification. It is a typical perspective view showing the lighting device of the 5th modification. It is a schematic side view which shows the illumination device of a 6th modification. It is a schematic side view which shows the illumination device of a 7th modification. It is a typical perspective view showing the lighting device of the 8th modification. FIG. 3 is a conceptual diagram of the die bonder of the embodiment as viewed from above. FIG. 16 is a configuration diagram of an optical system of the die bonder in FIG. 15. It is a block diagram of the preform part optical system of FIG. FIG. 16 is a block diagram illustrating a schematic configuration of a control system of the die bonder in FIG. 15. It is a flowchart explaining the acquisition method of the inspection image of a paste adhesive. 20 is a flowchart illustrating the inspection image processing of FIG. 19. 6 is a flowchart illustrating a method for manufacturing a semiconductor device.

  Hereinafter, embodiments, modifications, comparative examples, and examples will be described with reference to the drawings. However, in the following description, the same components are denoted by the same reference numerals, and repeated description may be omitted. In addition, in order to make the description clearer, the width, thickness, shape, and the like of each part may be schematically illustrated as compared with the actual mode. However, the drawings are merely examples, and the interpretation of the present invention is not described. There is no limitation.

  First, application of the paste adhesive will be described with reference to FIGS. FIG. 1 is a diagram illustrating the application of a paste adhesive. 2A and 2B are diagrams for explaining a paste-like adhesive application pattern. FIG. 2A is a cross mark shape, FIG. 2B is a round shape, and FIG. 2C is a cross mark shape. FIG. 2D shows a frame shape in which a Y shape is combined therebetween. FIGS. 3A and 3B are diagrams for explaining the application state of the paste adhesive, FIG. 3A shows a normal state, FIG. 3B shows an insufficiency state, and FIG. FIG. 3D shows an excessive state. In FIGS. 3 and 4, the black part is the substrate serving as the background, and the white part is the paste adhesive.

  As shown in FIG. 1A, the paste-like adhesive is applied by injecting the paste-like adhesive from the nozzle NZL at the tip of the syringe SYR in which the paste-like adhesive is sealed, and applying the paste according to the locus of the nozzle NZL. The syringe SYR is driven in the XYZ axes according to the shape to be applied, and applies a free locus as shown in FIG. In addition, as shown in FIG. 1B, there is a stamp-shaped one obtained by processing the shape of the nozzle tip. Hereinafter, the application pattern of the paste-like adhesive is described as having a cross-shaped shape in FIG. 2A.

  The die bonder has an inspection function for inspecting a state after application of the paste adhesive. As shown in FIG. 3, depending on the application state of the paste adhesive, there are insufficient (FIG. 3 (b)), protruding (FIG. 3 (c)) and excessive (FIG. 3 (d)). FIG. 3A shows a case where the paste adhesive is applied in a normal state. The inspection is performed by comparing the area and the shape of the application area of the paste-like adhesive with a shape that is close to an ideal shape or that stores a reference application shape.

  Next, a problem when a paste-like adhesive such as an epoxy resin is applied to the surface of a substrate on which metal plating such as palladium plating has been performed will be described with reference to FIG. 4A and 4B are diagrams for explaining a problem in the case of applying a paste-like adhesive to the surface of a metal-plated substrate. FIG. 4A is an oblique illumination image, and FIG. FIG. 4 (c) is a diagram showing reflection of oblique illumination, FIG. 4 (d) is a diagram showing reflection of coaxial illumination, and FIG. FIG. 4F is a diagram in which the image of the coaxial illumination is binarized.

  In many cases, the plating surface is not uniform, and the brightness of the plating surface is not uniform but varies. The state when the epoxy resin is applied thereto will be inspected. Epoxy resins come in a variety of types and mixtures, including transparent, colored transparent, milky white, gray, and those containing metal particles. In addition, since the surface is mirror-reflected because it is a liquid, there are some which transmit light. If the color or the reflectance (brightness) of the plating surface of the substrate surface is close to the reflectance (brightness) of the epoxy resin applied portion, the following phenomenon is caused, and it is difficult to detect the entire surface of the paste adhesive application area. Here, the brightness depends on the reflectance and the reflection angle. Further, regardless of the presence or absence and type of metal plating, the material of the substrate, and the like, there is a similar problem when the reflectance of the substrate and the paste adhesive is close, particularly when the reflectance on the substrate side is slightly low.

  Since the application area is a liquid surface, illumination causes specular reflection, and a bright line or a dark portion corresponding to the position of the illumination is generated. For example, as shown in FIG. 4A, in an image acquired by oblique illumination, a bright line BI appears around the application area, and a dark part DP appears at the center of the application area. This is because, as shown in FIG. 4C, the incident direction of the illumination is low in the oblique illumination OL. On the other hand, as shown in FIG. 4B, in an image acquired by the coaxial illumination CL, a bright line BI appears at the center of the application area, and a dark part DP appears around the application area. This is because, as shown in FIG. 4D, the incident direction of the illumination is high in the coaxial illumination CI.

  Even if the image acquired by the camera is binarized, the image is affected by the background, and only the application area cannot be extracted. In addition, the boundary between the light and dark parts is close to the brightness of the substrate surface, and these cannot be extracted by the binarization processing. For example, as shown in FIG. 4E, the image of oblique illumination is binarized, and as shown in FIG. 4F, the image of oblique illumination is binarized, and only the application area is extracted. I can't.

  Next, an embodiment for solving the above problem will be described with reference to FIGS. FIG. 5 is a diagram illustrating an optical system according to the embodiment. 6A and 6B are diagrams for explaining image processing using the optical system of FIG. 5, FIG. 6A is a diagram showing image processing using oblique illumination, and FIG. 6B is a diagram using coaxial illumination. FIG. 6C is a diagram illustrating image processing, and FIG. 6C is a diagram obtained by combining FIGS. 6A and 6B.

In an embodiment, the illumination device includes a plurality of lighting conditions, it acquires an image after coating and prior to application of the paste-like adhesive according to each lighting conditions, performs differential processing. The application area is obtained by binarization processing from the image obtained by performing the difference processing of each lighting state. The obtained application areas are combined as a logical sum for each lighting state. This makes it possible to increase the application area detection rate (detected application area / actual application area).

  For example, as shown in FIG. 5, using the oblique illumination OL of the illumination device ID, the image before and after the application is acquired by the camera CAM as an imaging device, subjected to differential image processing, and further binarized (FIG. 6A). . Further, as shown in FIG. 5, images before and after application are acquired by the camera CAM using the coaxial illumination CL of the illumination device ID, subjected to differential image processing, and further binarized (FIG. 6 (a)). As shown in FIG. 6C, the difference image of FIG. 6A and the difference image of FIG. 6B are combined.

  The influence of the non-uniform background pattern is removed by the absolute value difference image processing, and the processing is performed on a plurality of images in the lighting state, and by combining the images, the application area of the paste adhesive PA is extracted. By changing the illumination state (for example, switching between coaxial illumination and oblique illumination) such as changing the irradiation position of the illumination, it is possible to move the bright line or dark portion of the paste adhesive PA. By performing difference processing on the moved images and synthesizing them, an application area of the paste adhesive PA can be extracted.

  Next, the reason why it is better to divide a plurality of lighting states (for example, to turn on the lighting) will be described with reference to FIG. FIG. 7 is a diagram for explaining the reason why it is better to separate the lighting of the two lights, and FIG. 7A is an image when a liquid is applied to a plane having a flat brightness. FIG. 7B is a graph showing the lightness distribution, in which the horizontal axis represents coordinates [× 100] and the vertical axis represents lightness [× 100]. FIG. 7C is a graph showing the difference with respect to the brightness before the application, in which the horizontal axis represents the coordinates [× 100] and the vertical axis represents the brightness offset [× 100].

  It is assumed that the bright and dark portions when the liquid is applied to a flat surface have a sinusoidal distribution. Further, it is assumed that the light portion and the dark portion are slightly moved by changing the position of the illumination. As shown in FIG. 7A, A is before switching of the illumination position, and B is after switching. The brightness distribution is as shown in the graph of FIG. 7B, where the horizontal axis is the X coordinate and the vertical axis is the brightness. The solid line BA is the brightness of A, the solid line BB is the brightness of B, the broken line BC is the brightness of simultaneous lighting before and after the movement, and the solid line BD is the brightness before application.

  FIG. 7C shows a difference (lightness offset) with respect to the lightness (BD) before application in FIG. 7B. The brightness offset is represented by the vertical axis, and the X coordinate is represented by the horizontal axis. The offset of the simultaneous lighting becomes a broken line E, and a region where the offset cannot be sufficiently obtained occurs in a half cycle. On the other hand, each difference is calculated, and the graph superimposed after the absolute value calculation is a solid line F. It can be seen that the solid line F has no region where the offset cannot be sufficiently obtained as compared with the broken line E.

  Hereinafter, some typical modified examples of the embodiment will be exemplified. In the following description of the modified example, the same reference numerals as those in the above-described embodiment may be used for parts having the same configurations and functions as those described in the above-described embodiment. As for the description of such portions, the description in the above-described embodiment can be appropriately used within a technically consistent range. Further, a part of the above-described embodiment and all or a part of the plurality of modified examples may be appropriately combined and applied within a technically consistent range.

  In the embodiment, the switching of the illumination is described by taking the coaxial illumination and the oblique illumination as an example. However, the illumination state may be switched in the following modified example. Each switching is selected, and a difference image before and after the application in each illumination is acquired. An image is acquired for each switching before application, and the same switching is sequentially performed after application to acquire an image again. For example, in the illumination in the first state, images before and after application of the paste adhesive are acquired, and the influence of the pattern of the background substrate due to the differential image processing is removed. In the illumination in the second state, images before and after application of the paste adhesive are acquired, and the influence of the pattern of the background substrate due to the differential image processing is removed. The difference processing by the multiple illumination in the first state and the second state is combined to reduce the influence of the bright line or dark portion reflected on the liquid surface of the paste adhesive. The lighting state is not limited to the two lighting states of the first state and the second state, and may be three or more lighting states.

(First modification)
In the first modification, the illumination device obtains a plurality of illumination states by switching the color of illumination (wavelength of illumination light). The colors of the illuminating light are three primary colors of red, green, and blue, as well as white, infrared, and ultraviolet. When light other than visible light is used, a camera having light receiving sensitivity at the wavelength is used. The difference between the spectral reflection characteristics of the plating surface of the substrate and the surface of the paste adhesive is utilized.

(Second modification)
In the second modification, the illumination device switches the irradiation direction of the oblique illumination to obtain a plurality of illumination states. FIG. 8 is a plan view showing the arrangement of the illumination device according to the second modification.

  As shown in FIG. 8, the illumination device includes a plurality of oblique illuminations OL1 to OL8. The oblique illuminations OL1, OL3, OL5, and OL7 are arranged such that light is incident from the vicinity of the corner of the substrate S to the vicinity of the center of the substrate S, and the oblique illuminations OL2, OL4, OL6, and OL8 face each of the four sides of the substrate S. It is arranged so that light is incident from the position near the center of the substrate S. The control unit 8 controls the oblique illuminations OL1 to OL8 so as to be separately lit for each irradiation direction.

  The first state and the second state are configured by changing the oblique illumination that is turned on and the oblique illumination that is turned off. For example, as the first state of illumination, the oblique illuminations OL1, OL3, OL5, and OL7 are turned on, and the oblique illuminations OL2, OL4, OL6, and OL8 are turned off. As the second state of illumination, the oblique light illuminations OL1, OL3, OL5, and OL7 are turned off, and the oblique light illuminations OL2, OL4, OL6, and OL8 are turned on.

  The lighting state is not limited to the two lighting states of the first state and the second state, and may be three or more lighting states. For example, the oblique light OL1 is turned on to turn off the other oblique light as the first state, the oblique light OL2 is turned on to turn off the other oblique light as the second state,..., The eighth state is the oblique light OL8 may be turned on and other oblique illumination may be turned off.

(Third modification)
In the third modification, the lighting device has a plurality of oblique illuminations and switches the oblique illuminations to obtain a plurality of illumination states. FIG. 9 is a perspective view showing the arrangement of oblique illumination of the illumination device of the third modification.

  As shown in FIG. 9, the illumination device includes a plurality of oblique illuminations OL1 to OL3 having different irradiation angles. The control unit 8 controls the oblique illuminations OL1 to OL3 so as to be separately turned on for each irradiation angle. For example, the oblique light OL1 is turned on and the oblique light OL2 and OL3 are turned off as the first state, and the oblique light OL2 is turned on and the oblique light OL1 and OL3 are turned off as the second state. In the second state, the oblique light OL3 may be turned on and the oblique light OL1 and OL2 may be turned off. Note that the third state may also be provided to turn on the oblique light illumination OL3 and turn off the oblique light OL1 and OL2.

(Fourth modification)
In the fourth modification, the illumination device moves the oblique illumination to obtain a plurality of illumination states. FIG. 10 is a schematic perspective view showing a lighting device according to a fourth modification.

  In the case of the second modification, the oblique illumination of the lighting device is fixed and arranged. However, as shown in FIG. 10, the fourth modification includes bar type oblique illumination (oblique bar illumination) BLD1 to BLD4. The control unit 8 controls the oblique light bar illuminations BLD1 to BLD4 to rotate in the horizontal direction indicated by the arrow. For example, in the first state, the oblique bar illuminations BLD1 to BLD4 are arranged so as to face four sides of the substrate S, and in the second state, the oblique bar illuminations BLD1 to BLD4 are rotated and arranged at the four corners of the substrate S. The second state is not limited to the one that rotates 45 degrees with respect to the first state, and may be any angle greater than 0 degrees and less than 90 degrees. When the angle is smaller than 45 degrees, three or more states may be provided.

(Fifth modification)
In the fifth modified example, the oblique ring illumination area is divided, and the lighting positions are switched to obtain a plurality of illumination states. FIG. 11 is a schematic perspective view showing a lighting device according to a fifth modification.

  In the embodiment, the second modified example and the third modified example, the oblique light bar lighting device is used. In the fifth modified example, as shown in FIG. 11, a ring-type oblique light (oblique light illumination) RLD is used. In the regions R1 to R8, dimming of lighting and extinguishing is enabled for each region. The control unit 8 controls the oblique light ring illumination RLD so that each of the regions R1 to R8 is separately lit.

  The first state and the second state are configured by changing the light-on area and the light-off area. For example, as the first state of illumination, the regions R1, R2, R3, and R4 are turned on, and the regions R5, R6, R7, and R8 are turned off. As the second state of illumination, the regions R1, R2, R3, and R4 are turned off, and the regions R5, R6, R7, and R8 are turned on.

  The lighting state is not limited to the two lighting states of the first state and the second state, and may be three or more lighting states. For example, the area R1 is turned on and the other areas are turned off as the first state, the area R2 is turned on and the other oblique illumination is turned off as the second state, and the area R8 is turned on as the eighth state. Alternatively, other oblique illumination may be turned off.

(Sixth modification)
In the sixth modification, a plurality of illumination states are obtained by switching between parallel light and diffused light in coaxial illumination. FIG. 12 is a schematic side view showing a lighting device according to a sixth modification, FIG. 12 (a) is a side view showing a state in which coaxial illumination emits parallel light, and FIG. It is a side view which shows the state which irradiates light.

  As shown in FIG. 12A, the coaxial illumination CL1 is provided with lenses LN1, LN2 and a half mirror HM1 on the light emitting surface of the illumination LS1, and outputs parallel light, and as shown in FIG. 12B. And a coaxial illumination that outputs diffused light by installing a diffusion plate DP1 and a half mirror HM2 on the light emitting surface of the illumination LS2. The control unit 8 controls lighting and extinguishing of the illuminations LS1 and LS2, and switches between the oblique illumination in the first state of FIG. 12A and the oblique illumination in the second state of FIG. 12B.

(Seventh modification)
In the seventh modification, a plurality of illumination states are obtained by switching between parallel light and diffused light in oblique illumination. FIG. 13 is a schematic side view showing a lighting device of a seventh modified example. FIG. 13A is a side view showing a state where oblique illumination irradiates parallel light, and FIG. It is a side view which shows the state which irradiates light.

  As shown in FIG. 13 (a), a lens LN3 is installed on the light emitting surface of the oblique illumination OL to output parallel light, and as shown in FIG. 13 (b), a diffusing plate is provided on the light emitting surface of the oblique illumination OL. Installing DP2 and outputting diffused light. The control unit 8 controls switching between the lens LN3 and the diffusion plate DP2, and switches between the first state shown in FIG. 13A and the second state shown in FIG. 13B.

  Note that the seventh modification can be combined with the sixth modification to obtain four illumination states.

(Eighth modification)
In the eighth modification, a plurality of illumination states are obtained by switching the polarization direction and phase. FIG. 14 is a schematic perspective view showing a lighting device according to an eighth modification.

  A polarizing filter PF1 and a wave plate WP1 are installed between the illumination LS3 and the paste adhesive PA, and a polarizing filter PF2 and a wave plate WP2 are installed between the paste adhesive PA and the camera CAM. The control unit 8 controls the polarization filters PF1 and PF2 and the wave plates WP1 and WP2 so that they can be attached and detached by a motor, or controls the polarization filters PF1 and PF2 so that they can be rotated. Thereby, the light applied to the paste adhesive PA and the light condensed by the camera CAM are polarized (first state), not polarized (second state), or shifted in phase (third state). By changing the polarization direction (fourth state), images of the paste adhesive PA having different patterns can be obtained.

  An example in which the lighting device of the embodiment is applied will be described using an example. The lighting device may be any one of the first to eighth modifications or a combination thereof.

  The configuration of the die bonder according to the embodiment will be described with reference to FIGS. FIG. 15 is a conceptual diagram of the die bonder of the embodiment as viewed from above. FIG. 16 is a configuration diagram of the optical system of the die bonder of FIG. FIG. 17 is a configuration diagram of the optical system of the preform unit of FIG.

  The die bonder 10 roughly includes a wafer supply unit 1, a work supply / transport unit 2, and a die bonding unit 3.

  The wafer supply unit 1 has a wafer cassette lifter 11 and a pickup device 12. The wafer cassette lifter 11 has a wafer cassette (not shown) filled with the wafer ring 16 and sequentially supplies the wafer ring 16 to the pickup device 12. The pickup device 12 moves the wafer ring 16 and pushes up the die D so that a desired die D can be picked up from the wafer ring 16.

  The work supply / transport unit 2 includes a stack loader 21, a frame feeder 22, and an unloader 23, and transports a substrate S such as a lead frame in the direction of an arrow. The stack loader 21 supplies the substrate S to which the die D is bonded to the frame feeder 22. The frame feeder 22 transports the substrate S to the unloader 23 via two processing positions on the frame feeder 22. The unloader 23 stores the transported substrate S.

  The die bonding section 3 has a preform section (paste application unit) 31 and a bonding head section 32. The preform unit 31 applies a paste adhesive PA such as an epoxy resin to the substrate S conveyed by the frame feeder 22 with a syringe 36. In the case where the substrate S is, for example, a multiple lead frame in which a plurality of unit lead frames are arranged in a row and connected in series, a paste adhesive PA is applied to each tab of the unit lead frame. Here, the substrate S is plated with palladium. The bonding head 32 picks up the die D from the pickup device 12 and moves up, and moves the die D to a bonding point on the frame feeder 22. Then, the bonding head 32 lowers the die D at the bonding point, and bonds the die D onto the substrate S on which the paste adhesive PA has been applied.

  The bonding head unit 32 has a ZY drive shaft 60 that moves the bonding head 35 up and down in the Z-axis direction (height direction) and moves it in the Y-axis direction, and an X drive shaft 70 that moves it in the X-axis direction. The ZY drive shaft 60 picks up the die D from the wafer 14 and the Y drive shaft 40 that reciprocates the bonding head 35 between the pickup position in the pickup device 12 and the bonding point in the Y axis direction indicated by the arrow C. And a Z drive shaft 50 that moves up and down for bonding to the substrate S. The X drive shaft 70 moves the entire ZY drive shaft 60 in the X direction in which the substrate S is transported.

  As shown in FIG. 16, the optical system 88 includes a preform optical system 33 for grasping the application position of the syringe 36 and a bonding optical system for grasping the bonding position where the bonding head 35 bonds to the transported substrate S. 34, and a wafer optical system 15 for grasping the pickup position of the die D picked up by the bonding head 35 from the wafer 14. Each optical system has an illumination device and a camera for illuminating the object. For example, as shown in FIG. 17, the preform unit optical system 33 includes an illumination device ID having coaxial illumination CL and oblique illumination OL, and a preform recognition camera 33a. The dies D diced in a mesh on the wafer 14 are fixed to a dicing tape 17 fixed to a wafer ring 16.

  With this configuration, the paste adhesive PA is applied to the correct position by the syringe 36, the die D is reliably picked up by the bonding head 35, and bonded to the correct position of the substrate S.

  The control system 80 will be described with reference to FIG. FIG. 18 is a block diagram showing a schematic configuration of a control system of the die bonder of FIG. The control system 80 includes a control unit 8, a drive unit 86, a signal unit 87, and an optical system 88. The control unit 8 roughly includes a control / calculation device 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 includes a main storage device 82a including a RAM storing a processing program and the like, and an auxiliary storage device 82b including an HDD storing control data and image data necessary for control. And The input / output device 83 includes a monitor 83a for displaying device status and information, a touch panel 83b for inputting an operator's instruction, a mouse 83c for operating the monitor, and an image capturing device 83d for capturing image data from the optical system 88. And 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 wafer supply unit 1 and a ZY drive shaft of the bonding head table, and various sensor signals and illumination devices. And an I / O signal control device 83f for taking in or controlling a signal from a signal section 87 such as a switch. The optical system 88 includes a wafer recognition camera of the wafer section optical system 15, a preform recognition camera 33a of the preform section optical system 33, and a substrate recognition camera of the bonding section optical system. The control / arithmetic unit 81 fetches necessary data via the bus line 84, calculates the data, and sends information to the control of the bonding head 35 and the like and the monitor 83a and the like.

  The control unit 8 stores the image data captured by the optical system 88 via the image capturing device 83d in the storage device 82. The positioning and positioning of the die D and the substrate S, the inspection of the application pattern of the paste adhesive PA, and the surface inspection of the die D and the substrate S are performed by using the control / calculation device 81 by software programmed based on the stored image data. Based on the positions of the die D and the substrate S calculated by the control / arithmetic unit 81, the drive unit 86 is moved by software via the motor control unit 83e. By this process, the die D on the wafer 14 is positioned, and the die D is bonded on the substrate S by operating the wafer supply unit 1 and the driving unit of the die bonding unit 3. The recognition camera used in the optical system 88 is gray scale, color, or the like, and quantifies light intensity.

  By the way, a syringe 36 for applying a paste adhesive is attached to the preform portion 31 shown in FIG. As described above, the paste adhesive is sealed inside the syringe 36, and the paste adhesive is extruded from the nozzle tip onto the substrate S by air pressure and applied.

The preform recognition camera 33a checks whether the paste adhesive applied on the substrate S is applied at an appropriate position and in an appropriate amount.
To briefly explain this checking operation, the surface on which the paste adhesive PA is to be applied is checked by the preform recognition camera 33a. If there is no problem on the surface to be applied, the paste adhesive PA is applied from the syringe 36. After the application, the preform recognition camera 33a checks again whether the paste adhesive PA has been applied correctly. If there is no problem with the application, the die is mounted on the paste adhesive PA, and the bonding is completed.

  A method for obtaining an inspection image of the paste adhesive PA will be described with reference to FIGS. FIG. 19 is a flowchart illustrating a method for obtaining an inspection image of the paste-like adhesive. FIG. 20 is a flowchart illustrating the inspection image processing of FIG.

  The control unit 8 turns on only the coaxial illumination CL of the illumination device ID, and acquires an image (P1) of the surface of the substrate S before application by the preform recognition camera 33a (step S1). Acquire multiple images according to the required sensitivity.

  The control unit 8 turns on only the oblique illumination OL of the illumination device ID, and acquires an image (Q1) of the surface of the substrate S before application by the preform recognition camera 33a (step S2). Acquire multiple images according to the required sensitivity.

  The control unit 8 applies the paste adhesive PA to the substrate S using the syringe 36 (Step S3). If the substrate S is a multiple lead frame, paste adhesive PA is applied to all tabs.

  When acquiring a plurality of images, the control unit 8 performs an averaging operation on the plurality of images (P1) (Step S4), and performs an averaging operation on the plurality of images (Q1) (Step S5).

  The control unit 8 turns on only the coaxial illumination CL of the illumination device ID, and acquires the image (P2) after application by the preform recognition camera 33a (step S6). Acquire multiple images according to the required sensitivity.

  The control unit 8 turns on only the oblique illumination OL of the illumination device ID, and acquires the image (Q2) after application by the preform recognition camera 33a (step S7). Acquire multiple images according to the required sensitivity.

  When acquiring a plurality of images, the control unit 8 performs an averaging operation on the plurality of images (P2) (Step S8), and performs an averaging operation on the plurality of images (Q2) (Step S9).

  In the inspection image processing, as shown in FIG. 19, first, the control unit 8 performs a difference process between P1 and P2 to obtain difference data (ΔP) (step SA1). Next, the control unit 8 performs binarization processing of the difference data (ΔP) to obtain binarized data (ΔPB) (step SA2). Next, the controller 8 performs a difference process between Q1 and Q2 to obtain difference data (ΔQ) (step SA3). Next, the control unit 8 performs binarization processing of the difference data (ΔQ) to obtain binarized data (ΔQB) (step SA4). Next, the binarized data (ΔPB) and the binarized data (ΔQB) are combined to determine the application area of the paste adhesive PA (step SA5).

  The inspection is performed by comparing the area and shape of the application area of the paste adhesive PA with a shape close to an ideal shape or with a reference memorized application shape. The area of the application area is extracted by counting pixels of a specific brightness (such as extraction from histogram data) or by using blob detection. In comparison of the shape of the application area, reference data that can be compared with the data after binarization is copied or held in an ideal shape, and is compared with the reference data by difference processing or the like.

  Next, a method of manufacturing a semiconductor device using the die bonder according to the embodiment will be described with reference to FIG. FIG. 21 is a flowchart showing a method for manufacturing a semiconductor device.

  Step S11: The wafer ring 16 holding the dicing tape 17 to which the die D divided from the wafer 14 is attached is stored in a wafer cassette (not shown), and is loaded into the die bonder 10. The controller 8 supplies the wafer ring 16 from the wafer cassette filled with the wafer ring 16 to the wafer supply unit 1. Further, the substrate S is prepared and carried into the die bonder 10. The control unit 8 supplies the substrate S from the stack loader 21 to the frame feeder 22.

  Step S12: The controller 8 picks up the separated die D from the wafer 14.

  Step S13: The control section 8 applies the paste adhesive PA from the syringe 36 to the substrate S transported by the frame feeder 22. The control unit 8 inspects the paste adhesive PA applied in steps S1 to SA. The control unit 8 bonds the picked-up die D to the substrate S on which the paste adhesive PA is applied.

  Step S14: The controller 8 supplies the substrate S to which the die D has been bonded by the frame feeder 22 to the unloader 23. The substrate S is carried out from the die bonder 10.

  As described above, the invention made by the present inventors has been specifically described based on the embodiment, the modification, and the example. However, the invention is not limited to the embodiment, the modification, and the example. Needless to say, it can be changed.

  For example, in the embodiment, the example has been described in which the die D picked up from the wafer 14 by the bonding head 35 is bonded to the substrate S. However, an intermediate stage is provided between the wafer 14 and the substrate S, and the pickup head picks up from the wafer 14. The die D thus placed may be placed on the intermediate stage, and the die D may be picked up again from the intermediate stage by the bonding head 35 and bonded to the transported substrate S.

  Further, in the embodiment, the example in which the paste-like adhesive such as the epoxy resin is applied to the surface of the substrate on which the metal plating such as the palladium plating is applied is described, but the resin substrate and the resin paste may be applied in combination. This is effective when the reflectivity of the paste is close or particularly when the substrate side is slightly lower.

1: Wafer supply unit 2: Work supply / transport unit 3: Die bonding unit 10: Die bonder 12: Pickup device 14: Wafer 15: Wafer optical system 16: Wafer ring 17: Dicing tape 32: Bonding head unit 33: Preform Optical system 34: Bonding unit optical system 35: Bonding head 88: Optical system 80: Control system 81: Control / arithmetic device 82: Storage device 83: Input / output device 84: Bus line 85: Power supply unit D: Die S: Substrate CAM : Camera ID: Illumination device CL: Coaxial illumination OL: Oblique illumination PA: Paste adhesive

Claims (16)

A syringe for applying a paste-like adhesive on the substrate,
A bonding head for mounting a die on the substrate to which the adhesive has been applied,
An illumination device attached to the vicinity of the syringe and irradiating the imaging target with light in the first state and the second state,
A recognition camera,
A control device for controlling the lighting device and the recognition camera,
With
The control device includes:
With the lighting device in the first state, the recognition camera takes an image of the substrate before applying the adhesive, and takes an image of the substrate after applying the adhesive on the substrate,
With the lighting device in the second state, an image of the substrate before the application of the adhesive is taken by the recognition camera, and an image of the state after the application of the adhesive on the substrate is taken,
Obtain binary data of the difference between the captured image of the state after application captured in the first state of the lighting device and the captured image of the state before application,
Obtain binarized data of the difference between the captured image of the state after application captured in the second state of the lighting device and the captured image of the state before application,
A die bonder for obtaining the application pattern of the adhesive by combining the binarized data obtained in the first state and the binarized data obtained in the second state of the lighting device. The die bonder according to claim 1,
A die bonder, wherein the substrate is a metal-plated lead frame. The die bonder according to claim 1 or 2,
The picked-up image is a die bonder which is an image obtained by averaging images obtained by a plurality of image pickups. The die bonder according to claim 1 or 2,
A die bonder wherein the first state of the lighting device is light irradiation by coaxial lighting and the second state is light irradiation by oblique lighting. The die bonder according to claim 1 or 2,
A die bonder in which the control device switches the wavelength of the illumination light to bring the illumination device into the first state and the second state. The die bonder according to claim 1 or 2,
The illumination device includes a plurality of oblique illuminations having different irradiation directions,
A die bonder in which the control device controls turning on and off of the oblique illumination to bring the lighting device into the first state and the second state. The die bonder according to claim 6,
A die bonder in which each of the oblique illuminations has a different horizontal irradiation direction. The die bonder according to claim 6,
A die bonder in which each of the oblique illuminations has a different irradiation direction in the vertical direction. The die bonder according to claim 1 or 2,
The illumination device includes a plurality of oblique illuminations having different irradiation directions,
A die bonder wherein the control device controls the movement of the oblique illumination to bring the illumination device into the first state and the second state. The die bonder according to claim 1 or 2,
The illumination device includes a ring-shaped oblique illumination having a plurality of regions,
A die bonder, wherein the control device controls lighting and extinguishing for each of the regions of the ring-shaped oblique illumination to bring the lighting device into the first state and the second state. The die bonder according to claim 1 or 2,
The lighting device is a lighting device that can emit parallel light and diffused light,
A die bonder in which the control device controls switching between the parallel light and the diffused light to bring the lighting device into the first state and the second state. The die bonder according to claim 11,
A die bonder, wherein the illumination device is a coaxial illumination having illumination for irradiating the parallel light and illumination for irradiating the diffused light. The die bonder according to claim 1 or 2,
The illumination device includes a polarizing filter or a wave plate,
A die bonder in which the control device controls the presence or absence or rotation of the polarizing filter or the switching of the presence or absence of the wave plate to bring the illumination device into the first state and the second state. (A) carrying in a wafer ring holder for holding a dicing tape to which a die is attached;
(B) a step of loading the substrate;
(C) picking up the die;
(D) applying a paste adhesive on the substrate;
(E) bonding the picked die onto the substrate;
Including
The step (d) includes:
(D1) imaging the state of the substrate before the application of the adhesive with the lighting device in the first state;
(D2) switching the lighting device to a second state to image a state before the application of the adhesive on the substrate;
(D3) switching the lighting device to the first state and capturing an image of the state after application of the adhesive on the substrate;
(D4) switching the lighting device to the second state and imaging the state after the application of the adhesive on the substrate;
(D5) obtaining a difference between a captured image of the first state of the lighting device after the application and a captured image of the state before the application, and obtaining binary data of the difference;
(D6) obtaining a difference between the captured image of the illumination device after the application in the second state and the captured image of the state before the application, and obtaining binary data of the difference;
(D7) combining the binarized data obtained in the first state and the binarized data obtained in the second state of the lighting device to obtain the adhesive application pattern;
A method for manufacturing a semiconductor device including: The method for manufacturing a semiconductor device according to claim 14,
In the step (c), the picked die is placed on an intermediate stage,
The step (e) is a method of manufacturing a semiconductor device for picking up a die placed on the intermediate stage. The method for manufacturing a semiconductor device according to claim 14,
A method of manufacturing a semiconductor device, wherein the substrate is a metal-plated lead frame.

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