TW202135642A - Manufacturing method for die bonding device and semiconductor device characterized by improving the uniformity of photographic conditions of photographed objects - Google Patents

Abstract

To provide the technology that can improve the uniformity of photographic conditions of multiple photographed objects. The die bonding device is equipped with: a delivery route used to deliver substrates; multiple photographic devices fixedly arranged above the delivery route in a row along the width direction of the substrate; and a control portion which is constituted to obtain pictures by using photographing devices to photograph a row of bonding zones located on the substrates along the width direction, generates synthetic pictures based on the obtained pictures and identifies the photographed objects of the bonding zones based on the synthetic pictures. The photographing field of each photographing device is repeated on the substrate and the repeated photographing field is constituted to be greater than the bonding zone.

Description

Die bonding device and manufacturing method of semiconductor device

The present disclosure relates to a die bonding device, and for example, it can be applied to a die bonder that recognizes the bonding area of a camera with a plurality of numbers.

A part of the manufacturing process of a semiconductor device includes a process of mounting a semiconductor chip (hereinafter, simply referred to as a die) on a wiring board or lead frame, etc. (hereinafter referred to as a substrate) to assemble a package, and a part of a process of assembling a package There are a process of dividing a die from a semiconductor wafer (hereinafter, simply referred to as a wafer) (a dicing process), and a bonding process of placing the divided die on a substrate. The semiconductor manufacturing equipment used in the bonding process is a die bonding device such as a die bonder.

The die bonder is a device that uses resin paste, solder, and gold plating as bonding materials to bond (place and bond) the die on the substrate or the bonded die. For example, in a die bonder that bonds dies to the surface of a substrate, a suction nozzle called a chuck installed at the front end of the bonding head is repeatedly used to suck and pick up the die from the wafer, and Place it on a specific position on the substrate, apply a pressing force, and heat the bonding material to perform the bonding action (work).

When resin is used as a bonding material, resin paste such as Ag epoxy and acrylic is used as an adhesive (hereinafter referred to as a paste adhesive). The paste-like adhesive for bonding the die to the substrate is enclosed in a syringe, and the syringe moves up and down with respect to the substrate to inject the paste-like adhesive and apply it. That is, by applying a specific amount of paste-like adhesive to a specific position with a syringe enclosed with a paste-like adhesive, the die is crimped and baked to be bonded to the paste-like adhesive. . Install an identification camera near the syringe, and use the identification camera to confirm the position where the paste-like adhesive is applied for positioning. Furthermore, confirm whether the applied paste-like adhesive has a specific shape and only A specific amount is applied to a specific location.

Furthermore, a recognition camera is installed near the bonding head, and the recognition camera is used to confirm the position of the substrate to which the die is bonded for positioning. Furthermore, it is confirmed whether the die to be bonded is bonded at a specific position. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2013-197277 A

[The problem to be solved by the invention]

When a single imaging device using a non-telecentric lens is used to capture a plurality of imaging objects, the imaging object far below the imaging device becomes oblique imaging and looks at the side surface of a solid shape. The subject of this disclosure is to provide a technology that can improve the uniformity of the imaging conditions of a plurality of imaging objects. Other topics and novel features are obvious from the description of this manual and the attached drawings. [Means to solve the problem]

A brief description of the outline of the representative content in this disclosure is as follows. That is, the die bonding device includes: a conveying path for conveying a substrate; a plurality of imaging devices fixedly arranged above the conveying path in a row along the width direction of the substrate; and a control unit, It is configured to use the plurality of imaging devices to image a row of multiple junction regions located on the substrate along the width direction to obtain a plurality of images, to generate a composite image based on the acquired plurality of images, and to recognize the above based on the composite image. For the imaging target in the bonding area, the imaging field of view of each imaging device overlaps on the substrate, and the repeated imaging field is configured to be larger than the bonding area. [Effects of Invention]

With the above-mentioned die bonding device, the uniformity of imaging conditions for a plurality of imaging objects can be improved.

Hereinafter, implementation types, modified examples, and embodiments are described using drawings. However, in the following description, the same reference numerals are given to the same constituent elements, and repetitive descriptions may be omitted. In addition, in order to make the description clearer, although there are diagrams that illustrate the width, thickness, shape, etc. of each part more than the actual state, this is only an example and is not intended to limit the interpretation of the present invention.

First, using FIGS. 1 to 3, the technique discussed by the inventors will be explained. Fig. 1(a) is an oblique view showing a normal field optical system, and Fig. 1(b) is an oblique view showing a wide field optical system.

In the sequence of positioning, bonding (die bonding or paste coating), and inspection of the substrate S, as shown in Figure 1(a), when using a low-resolution imaging device CML with a normal field of view optical system Since only an area slightly larger than one joining area AA is captured, only the number of joining areas AA and image recognition are required. Here, as an example, an example in which the substrate S has six bonding areas AA in one row and five bonding areas is shown. A low-resolution camera device is a camera device that can capture images with sufficient resolution only in an area slightly larger than a junction area, for example, a camera device with a resolution of about 300,000 to about 1.3 million pixels.

Therefore, as shown in FIG. 1(a), it is necessary to repeatedly move the imaging device CML in the width direction (Y-axis direction) of the substrate S, and perform imaging and image recognition of other bonding areas in the row, and Carry out the action of processing based on the identification of its portrait. In addition, after imaging in one row, the substrate S is moved in the substrate conveying direction (X-axis direction) to perform imaging in the next row.

Therefore, a moving mechanism for moving the supporting member (not shown) of the imaging device CML in the width direction of the substrate S is required, and the supporting mechanism of the imaging device CML becomes complicated and large, and becomes expensive. Furthermore, since it takes time to move in the width direction of the imaging device CML, and the waiting time for imaging until the shaking of the imaging device CML due to the vibration generated by the movement of the support member subsides, it is impossible to bond the die Speed up. Or, in order to prevent vibration, a vibration prevention mechanism is required, and die bonding becomes expensive. Furthermore, if there is a mechanism section that moves back and forth above the junction area and below the imaging device, it is necessary to consider the timing at which the mechanism section does not block the imaging field of view. By ensuring this imaging timing, it is impossible to increase the speed of die bonding.

On the other hand, this is not repeated every time the substrate is joined after the conveyance. As shown in Figure 1(b), when the wide-field optical system of the high-resolution imaging device CMH is used, all the joining areas (all protrusions) of the substrate S Collecting the pieces together) or imaging and recognizing the bonding area in at least one row in the width direction of the substrate, the processing time becomes efficient, and the above-mentioned problem can be solved. Here, a high-resolution imaging device refers to an imaging device that can capture at least all areas divided into a column in the width direction of the substrate S at a time with sufficient resolution, for example, an imaging device with a resolution of about 5 million pixels or more. One row includes a plurality of joint areas, for example, includes 4 joint areas.

However, the wide-field optical system (wide-field camera) has the following problems. To solve this problem, use Fig. 2 and Fig. 3 to explain. Fig. 2(a) is a conceptual diagram of a wide-field optical system using microlenses, and Fig. 2(b) is a conceptual diagram of a wide-field optical system using telecentric lenses. Fig. 3(a) is a diagram showing the image of the three-dimensional shape of the paste, and Fig. 3(b) is a diagram showing the spectral lines on the paste when the substrate is viewed in a wide area with a microlens.

(1) Ensuring telecentricity Even if the magnification of the microlens is simply reduced, it becomes a wide area, but the more it deviates from the center of the field of view, the more it is viewed obliquely from above, as shown in Figure 2(a), although the imaging object OBC in the center of the field of view In the OBL, the side surface is not visible, but in the OBL on the left side, the right side can be seen, and in the OBR on the right side, the left side can be seen, and the side surface of the stereoscopic shape can be seen. Furthermore, the magnification is changed by the height of the imaging object OBL, and it is difficult to perform such alignment when the height changes. For example, the paste applied on the substrate or the die laminated on the substrate have different heights due to different positions.

These problems can be solved by using a telecentric lens. Since the telecentric lens collects parallel light, the side of all the imaging objects cannot be seen. However, in this case, as shown in Figure 2(b), a lens with a diameter larger than the desired field of view is generally required. For example, to ensure a field of view of 100mm square, for example, a diagonal diameter of 141mm or more is required. The distance becomes longer. Mounting such a large lens on a die bonding device is not ideal from the viewpoint of efficiency.

(2) Uniform illumination in the field of view When a non-telecentric lens is used to ensure a wide area, one side of the field of view becomes a state of obliquely viewing from above. Because the direction of this is opposite in the right and left ends, or the upper and lower ends of the field of view, the direction of illumination is likely to become uneven. Furthermore, even when irradiating parallel light using telecentric light, it is difficult to obtain a uniformly irradiated image within the imaging field of view. For example, as shown in FIG. 3(a), the paste adhesive PA applied to the substrate in the shape of a cross is higher in the center part and lower in the front end part. Viewing the substrate coated with paste adhesive as shown in Figure 3(a) with a microlens in a wide area, as shown in Figure 3(b), because the center of the imaging field of view is viewed from directly above The part is brighter, and the peripheral part is obliquely viewed, so it is darker. Furthermore, because the height of the paste-like adhesive is uneven, the spectral lines on the paste-like adhesive PA move. Here, the center of the field of view of the camera is at the center of the image in Figure 3(b). The substrate S has six tabs TB as bonding regions in a row, which means seven rows. The four rows of tabs TB on the right side of the substrate S are coated with a paste-like adhesive PA.

Next, an embodiment that solves the above-mentioned problem will be described using FIGS. 4 to 5. Fig. 4(a) is a top view for the multiplexing of the imaging device of the implementation type, and Fig. 4(b) is a side view when viewed from the direction of arrow A in Fig. 4(a). Fig. 5 is a diagram illustrating the lighting device used in the imaging device of the implementation type, Fig. 5(a) is a cross-sectional view of the lighting device, and Fig. 5(b) is a side view.

As an implementation form for solving the above-mentioned problems, multiplexing (three-dimensional) of the imaging device is performed. For example, as shown in FIG. 4, above the substrate S, a plurality of imaging devices CM1 to CM4 are arranged in a row in the width direction (Y-axis direction) of the substrate S and fixedly arranged. Here, each of the imaging devices CM1 to CM4 is an imaging device with a resolution equal to or higher than that of the imaging device CML, and it is not possible to image the entire area of one column in the width direction of the substrate S with sufficient resolution at one time. Furthermore, even if each of the imaging devices CM1 to CM4 uses a telecentric lens, it is better to use a non-telecentric lens such as a micro lens. The imaging devices CM1 to CM4 are at the same height with a certain interval in the horizontal direction. The optical axes of the imaging devices CM1 to CM4 are parallel to each other and perpendicular to the substrate S. In addition, even if the optical axes of the imaging devices CM1 to CM4 are allowed to be out of focus in the imaging field of view, they may be slightly inclined from the vertical line to the substrate S.

In this embodiment, each of the imaging devices CM1 to CM4 is the imaging object in the imaging junction area AA11 to AA14. In addition, the imaging fields IA1 to IA4 of each of the imaging devices CM1 to CM4 do not overlap. Furthermore, by moving the substrate S in the conveying direction (Y-axis direction), the remaining rows of imaging objects are sequentially imaged. By multiplying the imaging device, the imaging can be performed just above the imaging object, and the uniformity of the illumination within the imaging field of view can be improved for inspection. Furthermore, by multiplexing the imaging device, there is no need to move the imaging device, and the same processing efficiency as the wide-field optical system can be achieved.

Here, the substrate S is, for example, as shown in (a) (b), and has a rectangular shape and a flat plate shape, and has many bonding areas AA11 to AA14, AA21 to AA24, and ･･･ in the vertical and horizontal directions. The substrate S is configured such that the length in the conveying direction (X-axis direction) is longer than the length in the width direction (Y-axis direction).

It is better for multiple cameras to have the same lighting system. For example, as shown in FIG. 5(a), between the imaging devices CM1 to CM4 and the substrate S, an illuminating device LD provided with a surface emitting illumination (light source) SL and a half mirror (half-transmissive mirror) HM inside is arranged. The irradiated light from the surface-emitting illumination SL is reflected by the half mirror HM on the same optical axis as the imaging devices CM1 to CM4, and is irradiated to the imaging target in the bonding area AA11 to AA14 of the substrate S. The scattered light irradiated to the imaging object in the junction area AA11~AA14 with the same optical axis as the imaging device CM1~CM4 is reflected by the imaging object in the junction area AA11~AA14, and the regular reflection light is transmitted through and semi-reflected The mirror HM reaches the imaging devices CM1 to CM4, and forms the image of the imaging target in the joining areas AA11 to AA14. That is, the illuminating device LD has the function of coaxial epi-illumination (coaxial illumination).

As shown in Figure 5(b), the length in the Y-axis direction of the surface-emitting illumination SL and the half mirror HM is configured to be a little wider than the entire imaging field of view of the imaging devices CM1 to CM4 in the width direction of the substrate S, and the surface emits light. The illumination SL is divided into light-emitting areas SL1 to SL4 that are slightly wider than the respective imaging fields of the imaging devices CM1 to CM4, and each can be turned on/off. The light-emitting area of the coaxial lighting device is divided, and each camera device CM1 ~ CM4 can be dimmed. Accordingly, the uniformity of illumination in all areas of the imaging field of view of the imaging devices CM1 to CM4 can be improved. In addition, as will be described later, when each of the imaging fields of the imaging devices CM1 to CM4 overlaps, the light emitting regions SL1 to SL4 also overlap.

Next, the repetition of the imaging field of view of the plural imaging devices will be described using FIGS. 6 to 8. Fig. 6 is a top view explaining the repetition of the imaging field of view of a plurality of imaging devices. Fig. 7 is a side view when viewed from the direction of arrow A in Fig. 6. Fig. 8 is a diagram illustrating the amount of repetition of the imaging field of view.

In the above-mentioned embodiment, the imaging field of view IA1 to IA4 of each of the imaging devices CM1 to CM4 is not overlapped. However, when multiple imaging devices are performed, the distance between the various products (the distance between the joining areas) and the distance between the imaging devices do not have to be the same, so as shown in Figure 6 and Figure 7, the imaging field is repeated to a certain extent. Better.

In FIGS. 6 and 7, as an example, four imaging devices are provided, and six bonding areas are provided in a row of the substrate S, and the distance between the imaging devices is larger than the distance between the bonding areas. Therefore, the imaging field of view of adjacent imaging devices is overlapped, for example, it is assumed that the imaging field of view of one imaging device includes two or more imaging objects. Accordingly, each of the imaging devices CM1 to CM4 is an imaging device with a resolution higher than that of the imaging device CML. Although each of the imaging devices CM1 to CM4 is an imaging device that cannot image the entire area in the width direction of the substrate S with sufficient resolution at a time, even if it can image the entire area in the width direction of the substrate S with sufficient resolution at a time Regional camera devices are also available. Here, the substrate S is, for example, as shown in FIG. 6, is rectangular and flat, and has many bonding areas AA11 to AA16, AA21 to AA26, and ･･･ in the vertical and horizontal directions. The substrate S is configured such that the length in the conveying direction (X-axis direction) is longer than the length in the width direction (Y-axis direction).

If the overlapping area OVL of the imaging field of view is the size that includes the maximum size of the imaging object (it is sufficient if the maximum product size is maintained). According to this, all the photographic objects capture the whole of the photographic objects in any photographing field of view. As shown in Fig. 8, if the overlapping area OVL is the size of the captured object OB2, for example, for a sub-straight substrate, if the overlapping amount is the largest protrusion size, all the protrusions are among the protrusions. The panorama is reflected in any one's field of vision.

For the synthesis of the plural camera images, the description will be given using Figs. 9-15. Figure 9 is a diagram illustrating image mosaic and coordinate matching. Figure 10 is a schematic diagram illustrating image mosaic and coordinate conversion using a calibration plate. Fig. 11 is a diagram illustrating distortion. Fig. 12 is a diagram showing conversion determinants of affine conversion and projection conversion. FIG. 13 is a diagram illustrating image mosaic and coordinate conversion of the target model by the substrate. Fig. 14 is an image of a state where a paste-like adhesive is applied to the tabs of the multi-lead frame using a plurality of camera devices. Fig. 14(a) is an image taken without temporal variation, and Fig. 14(b) is an image with A camera image of a situation that has been mutated over time. Fig. 15 is a diagram for explaining the space re-correction, Fig. 15(a) is a diagram showing the state before the space re-correction, and Fig. 15(b) is a diagram showing the state after the space re-correction.

In order to suppress the amount of repetition, the control unit CNT synthesizes images captured by a plurality of imaging devices by image mosaic or the like. In general image mosaic, in order to smoothly join the plural images together, the alignment of the image may be lost in the original condition.

Therefore, in the implementation type, in the synthesis of images captured by multiple cameras, (A) When the die bonding device is shipped or adjusted, perform image mosaic and coordinate conversion using the calibration board. (B) During the fine adjustment of the die bonding device or during continuous operation, the image mosaic caused by the target model of the substrate and the coordinate conversion caused by the target model arranged on the chute are performed.

The above (A) will be described using FIGS. 9 to 12. As shown in Fig. 9, the control unit CNT is projected as a coordinate mark CMRK which is a scale covering all the imaging fields of the multiplexed imaging device during the adjustment of the bonding device, and is reflected in the coordinate mark CMRK of the OVL range of the overlapping area. With the same intersection IP as the reference, the image is coordinated by projection conversion or affine conversion, etc., to obtain an image (composite image) that sequentially joins the images between the imaging devices. Here, the coordinate mark CMRK prepares a calibration plate as an adjustment jig, and it is marked on the flat plate for the user, and the coordinate mark CMRK is, for example, a grid-shaped one. When the coordinates are converted, it is necessary to ensure the mark of the positional relationship of the whole space. In the case of the coordinate mark CMRK that covers the entire synthetic field of view shown in Figure 9, the overall spatial positional relationship can be guaranteed during coordinate conversion such as projection conversion, and the image space coordinates can be matched with the actual space coordinates at the interval of each intersection.

As shown in FIG. 10, the control unit CNT uses, for example, three imaging devices to divide the field of view to capture images of a large calibration plate CP having a grid-like pattern. The three imaging devices have overlapping areas OV12 and OV23 with a certain degree of field overlap due to adjacent imaging devices. The intersection IP of the grid pattern in the repeating areas OV12 and OV13 is indicated by black dots.

First, the control unit CNT converts the pixel coordinates of the image of the other imaging device based on either one of the adjacent imaging devices using affine conversion or projection conversion. Here, the reference portrait takes portrait IV1, and the conversion portrait takes portrait IV2 as an example. The conversion is to calculate the affine conversion or projection conversion by aligning the coordinates of the intersection IP (black point coordinates) in the converted images with the coordinates of the intersection IP (black point coordinates) in the corresponding reference image Convert the parameters of the ranks. Here, generally speaking, the transformation matrix of affine transformation is expressed in equation (1) of FIG. 12, and the determinant of projection transformation is expressed in equation (2) of FIG. 12. The calculation of the conversion row and column generally only needs to be a three-point coordinate, which is not an unambiguous conversion. It can be converted more accurately by performing the conversion on each part of the grid-like grid, so it is better to perform the conversion for each grid.

The reference image IV1 has the distortion represented by the barrel type or spool type as shown in Fig. 11. First, use all the intersection IPs of the correction plate CP entering the field of view to convert the meta image into a right angle to the upright It is better to perform distortion correction on the image aligned with the coordinate system (first distortion correction). Accordingly, other than the overlapping areas OV12 and OV23 are also incorporated into the composite image by simple magnification adjustment.

Because the coordinate alignment is carried out by the pixel coordinate system, the converted coordinates of the portrait IV2 are required to be integer values, but the pixels converted by affine conversion or projection conversion do not necessarily have to be suitable for this place, and there are also post-conversions. When the coordinates of is the middle value. At this time, each coordinate system of the converted image is corrected by the shade value represented by the nearest neighbor interpolation method, bilinear interpolation method, bicubic interpolation method, etc. from the shade value of the closest converted coordinate system.

The above (B) will be described using FIGS. 13 to 15. Because the conversion in the adjustment before production operation is in the image space in the field of view, the intersection IP of the correction plate CP representing the coordinate reference is arranged in a large number and evenly spaced, so it is easier to align the image space and the actual coordinate space. In this regard, in continuous operation or simple adjustment, image synthesis and coordinate alignment are performed without using the correction plate CP. As long as the images are combined, it is only necessary to know the positions that show the same place, so the target mark TM for positioning on the substrate is used. Since the positioning target mark TM is used as the positioning process of the tab at the time of joining (adhesive or pasting), the template model has been registered, so use this. As shown in Fig. 13, when a plurality of protrusions enter the overlapping areas OV12 and OV23 of the image, the positioning target mark TM of the adjacent protrusions is used to ensure a punctuation of more than three points. In the case where only one protrusion enters the overlapping area, a three-point positioning target mark TM is registered in advance on one protrusion and registered as a template image model.

With this method, although it can be synthesized by the coordinate alignment between the images, it cannot be aligned with the actual space. Even if any image is aligned as a reference, the alignment with the coordinate space is not performed in advance, and when it is combined as it is, as shown in Fig. 11, it is an image adjacent to the image IV1 of the reference image IV2 and the image IV3 adjacent to the image IV2 are affected by the distortion of the image IV1. When the deviation caused by the distortion is adjacent to the image IV1 in order, the image IV3 at the farthest position is the most enlarged. In order to suppress the amount of enlargement, a mark SMRK is set at the known coordinates of the chute SCT, and the coordinates of the set mark SMRK are measured again from the image, and then the combined image is returned together. Because the distortion of the image here depends on the lens of the imaging device, the conversion (first distortion correction) at the time of the initial conversion is performed after the implementation of the image synthesis. In order to align the overall coordinates, the mark on the chute SCT is used. SMRK is better. That is, the control unit CNT uses the coordinate mark CMRK to correct the actual space and the image space, and then grasps the coordinates of the mark SMRK separately provided on the chute SCT as the conveyance path. Here, the chute SCT is located outside the both ends of the substrate S in the width direction.

As described above, the coordinate mark CMRK is aligned before the production operation by the die bonding device, and is aligned as an adjustment operation. However, since the start of construction, due to the self-heating and saturation of the imaging devices, or the deviation of the heat distribution between the imaging devices, as shown in Figure 14(b), the imaging field of view of each imaging device has slightly different The diachronic displacement of the person. Here, the image in the imaging field of view IA2 of the camera device CM2 deviates to the right from the image in the imaging field of view IA1 of the camera device CM1. That is, the imaging device CM2 is shifted to the right. Furthermore, the place surrounded by the quadrangular frame indicates the vicinity of the lower left corner of each protruding piece. This deviation cannot be ignored in a bonding device that requires micrometer precision. Even during construction, the slight deviation needs to be corrected. Hereinafter, the method of correcting this slight deviation will be described using FIG. 15.

As described above, when a deviation between the imaging devices occurs during continuous construction, there may be a difference in the pitch between the protrusions of the substrate S having a known pitch. The control unit CNT detects the inherent displacement caused by the heat of the imaging device and other factors by periodically measuring the known tab pitch. Furthermore, even if the control unit CNT periodically measures the distance between the marks SMRK on the known chute SCT, it can also detect the inherent displacement caused by the heat of the imaging device.

When detecting the displacement, the control unit CNT uses a feature mark such as a positioning target mark TM on the substrate S. And again calculate the projection conversion ranks or the affine conversion ranks for synthesizing and transforming the image. At this time, the calculated projection conversion ranks or affine conversion ranks can be used to join images, but as shown in Fig. 15(a), there may be cases where the image space and the actual space cannot be matched. Therefore, the control unit CNT uses the mark SMRK on the chute SCT measured initially, and performs conversion again based on its coordinates. In this way, a composite image as shown in Figure 15(b) is obtained.

In addition, since the thickness of the substrate P (the height of the upper surface of the substrate P) causes the magnification to change, calibration becomes difficult when the height is changed. The method of reducing the influence of the thickness of the substrate will be explained using FIGS. 16 and 17.

Fig. 16 is a diagram illustrating a method of changing the height of the calibration plate. Fig. 16(a) shows a state where the substrate is transported and placed on the bonding table and arranged, and Fig. 16(b) shows a cross section of the calibration plate moving up and down picture. Fig. 17 is a diagram illustrating the marks placed on the chute, Fig. 17(a) is a cross-sectional view showing the state where the substrate is conveyed and placed on the bonding table, and Fig. 17(b) is on the chute where the mark is placed View, Figure 17(b) is a cross-sectional view of a chute with a mark set in another example.

In order to correspond to the height displacement, the control unit CNT slightly moves the correction plate CP up and down to obtain a projection conversion row for each height. The control unit CNT calculates the thickness of the known substrate or the height of the paste, calculates the position of the calibration pattern or the predicted height of the inspection view position from the thickness of the crystal grains, etc., and automatically selects which projection conversion row to use for each height. The control unit CNT is in the overlapping area between the adjacent imaging devices to identify the same point on the substrate and measure the height. The control unit CNT automatically selects the projection conversion rank to be used from the measured value.

Specifically, at the time of correction by the first calibration plate CP, as shown in FIG. 16(b), the bonding table AS provided with the calibration plate CP is moved up and down, and the calibration plate is measured at every height of the bonding table AS The coordinates of the intersection of CP. The up and down mechanism of the bonding table is configured to be able to move up and down in units of μm.

Furthermore, it is preferable that the mark SMRK provided on the chute SCT is set to the same height as the height of the upper surface of the substrate P. As shown in Figs. 17(a) and (b), for example, holes (cavities) of different depths and diameters are formed in the chute SCT. Even if the hole with the mark SMRK is shown in Figure 17(c), it can be set individually for each depth. If the mark SMRK is the same as the upper surface of the substrate P and the height, it may be a hole.

If implemented, it has one or more of the following effects. (a) Since each imaging object can be viewed from almost directly above, it is possible to prevent the height direction of an image produced by a simple low-magnification optical system from tilting at the edge of the field of view. (b) Since the inherent displacement caused by the heat of the imaging device can be detected, the correction of the imaging device can be implemented during the operation of the die bonder, so the influence of the temporal displacement of the imaging device can be reduced. (c) Since it can correspond to the height displacement, it will not be affected by the change in thickness due to the type of the substrate, so the impact of different types can be reduced. (d) By at least any one of the above (a) to (c), it is possible to stabilize the positioning accuracy and stabilize the inspection.

(Modification) Hereinafter, a representative modification example of the implementation form is illustrated. In the description of the following modification examples, the parts having the same configuration and function as those described in the above-mentioned embodiment are assumed to be able to use the same symbols as those in the above-mentioned embodiment. Moreover, the description of such a part is assumed to be capable of appropriately quoting the description in the above-mentioned embodiment within a technically non-contradictory range. Furthermore, it is possible to appropriately and compoundly apply all or a part of a part of the above-mentioned embodiment and a plurality of modifications within the scope of no technical contradiction.

FIG. 18 is a perspective view explaining the multiplexing of the imaging device in the modified example. In the embodiment, although an example is described in which a plurality of imaging devices are used to image objects in one column in the width direction of the substrate S, even if the plurality of imaging devices are arranged in the length direction of the substrate S, the plurality of imaging devices are arranged as Grid-shaped, multiple rows of imaging objects can also be captured.

For example, as shown in Fig. 18, four rows of camera device groups CM10~CM40 are arranged, and each camera device group has four camera devices CM1 to CM4 of the implementation type arranged in a row, and 16 camera devices are arranged as Lattice. Here, on the substrate S, six imaging target portions in one row are arranged in five rows, and imaging fields of adjacent imaging devices overlap.

As shown in Fig. 18, since not only the entire imaging object in the first row of the substrate S but also the entire imaging object in the second row and subsequent rows can be scanned in parallel, the synthesized image can be recognized, so it is compared with the implementation type. The state can reduce the number of times of moving the substrate S and imaging. [Example]

The following description is directed to an embodiment to which the above-mentioned implementation type is applied. Fig. 19 is a top view showing the outline of the die bonder in the embodiment. Fig. 20 is a diagram illustrating the operation of the pickup head and the bonding head when viewed from the direction of arrow A in Fig. 19.

The die bonder 10 roughly has a die supply part 1, a pickup part 2, an intermediate stage part 3, a preform part 9, a bonding part 4, a conveying part 5, a substrate supply part 6, which supplies the die D mounted on the substrate S, The board carrying-out part 7, and the control part 8 which monitors and controls the operation of each part. The Y axis direction is the front and back direction of the die bonder 10, and the X axis direction is the left and right direction. The die supply part 1 is arranged on the front side of the die bonder 10, and the bonding part 4 is arranged on the deep side. Here, a plurality of product regions (hereinafter referred to as package regions P) that become the final package is formed on the substrate S. For example, when the substrate S is a lead frame, the package area P has a tab on which the die D is placed.

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

The pick-up part 2 has a pick-up head 21 for picking up the die D, a Y-drive part 23 for the pick-up head that moves the pick-up head 21 to the Y-axis direction, and each of the unillustrated pick-up heads that lift, rotate, and move the chuck 22 in the X-axis direction. The drive unit and the wafer recognition camera 24 that grasps the pickup position of the die D picked up from the wafer 11. The pick-up head 21 has a chuck 22 (also refer to FIG. 14) for sucking and holding the pushed-up die D at the front end, and picks up the die D from the die supply unit 1 and places it on the intermediate platform 31. The pick-up head 21 has each drive part (not shown) which raises and lowers, rotates, and moves the chuck 22 in the X direction.

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

The preforming unit 9 includes a syringe 91, a driver 93 that moves the syringe 91 in the Y direction and the Z direction, and an adhesive recognition camera 94 as an imaging device that grasps the application position of the syringe 91 and the like. Here, the adhesive recognition camera 94 is, for example, the multiplexed imaging devices CM1 to CM4 of the implementation type, and the imaging devices CM1 to CM4 are respectively configured to perform imaging using the illumination device LD. The preforming section 9 applies a paste-like adhesive such as epoxy resin to the substrate S conveyed by the conveying section 5 with a syringe 91. The syringe 91 is enclosed with a paste-like adhesive, and is configured to be applied by pushing the paste-like adhesive from the tip of the nozzle to the substrate S by air pressure. For example, in the case of a multi-lead frame in which a plurality of unit lead frames are arranged in a row in a horizontal row on the substrate S, a paste-like adhesive is applied to each protrusion of the unit lead frame.

The bonding part 4 picks up the die D from the intermediate platform 31 and bonds it to the encapsulation area P coated with the paste-like adhesive of the substrate S being conveyed. The bonding portion 4 includes the bonding head 41 of the chuck 42 (also refer to FIG. 20) that sucks and holds the die D at the tip end, the Y movable portion 43 that moves the bonding head 41 in the Y-axis direction, and the photographic substrate. The position identification mark (not shown) of the package area P of S, and the substrate identification camera 44 for identifying the bonding position. Here, the board recognition camera 44 is, for example, the multiplexed imaging devices CM1 to CM4 of the implementation type, and the imaging devices CM1 to CM4 are respectively configured to perform imaging using the illumination device LD. With such a configuration, the bonding head 41 corrects the pickup position and posture based on the photographic data of the platform recognition camera 32, picks up the die D from the intermediate platform 31, and bonds the die D to the substrate based on the photographic data of the substrate recognition camera 44.

The conveying section 5 has a substrate conveying claw 51 for picking and conveying the substrate S and a conveying path 52 for moving the substrate S. The substrate S is moved by driving a nut (not shown) of the substrate conveying claw 51 provided on the conveyance passage 52 by a ball wheel rod (not shown) provided along the conveyance passage 52. With such a configuration, the substrate S is moved from the substrate supply part 6 to the bonding position along the conveyance path 52, and after bonding, it moves to the substrate unloading section 7 and delivers the substrate S to the substrate unloading section 7.

Next, the structure of the crystal grain supply unit 1 will be described with reference to FIG. 21. Fig. 21 is a schematic cross-sectional view showing the main part of the crystal grain supply part of Fig. 19.

The die supply unit 1 includes a wafer holding table 12 that moves in the horizontal direction (XY axis direction), and a peeling unit 13 that moves in the vertical direction. The wafer holding table 12 includes an expansion ring 15 for holding the wafer ring 14 and a support ring 17 for positioning the dicing tape 16 fixed to the wafer ring 14 horizontally. In the wafer 11, the die D diced into a mesh shape is bonded and fixed to the dicing tape 16. The peeling unit 13 is arranged inside the support ring 17.

When the die supply unit 1 pushes on the die D, the expansion ring 15 holding the wafer ring 14 is lowered. As a result, the dicing tape 16 held on the wafer ring 14 is elongated, and the interval between the die D is widened. When the dicing tape 16 is pushed up from below the die D by the peeling unit 13, the dicing tape 16 is moved horizontally, and Improve the pick-up of Die D.

As shown in FIG. 22, 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 and arithmetic device 81 mainly composed of a CPU (Central Processor Unit), a memory device 82, an input/output device 83, a bus line 84, and a power supply unit 85. The memory device 82 has a main memory device 82a constituted by a RAM storing processing programs and the like, and an auxiliary memory device 82b constituted by an HDD storing control data or images and other data required for control. The input and output device 83 has a screen 83a for displaying device status or information, a touch panel 83b for inputting instructions from an operator, a mouse 83c for operating the screen, and an image capturing device for capturing image data from the optical system 88 83d. Furthermore, the input and output device 83 has a motor control device 83e that controls the XY stage (not shown) of the die supply unit 1 or the drive unit 86 of the ZY drive shaft of the head stage, and signals from various sensors or illumination The signal part 87 of the switch of the device etc. captures or controls the signal I/O signal control device 83f. The optical system 88 includes a wafer identification camera 24, an adhesive identification camera 94, a platform identification camera 32, and a substrate identification camera 44 shown in FIG. The control and arithmetic device 81 captures required data via the bus line 84, performs calculations, and controls the pickup 41, etc., or sends information to the screen 83a, etc.

The control unit 8 stores the image data captured by the optical system 88 in the memory device 82 through the image capturing device 83d. According to the software programmed according to the saved image data, use the control and calculation device 81 to perform positioning of the die D and the substrate S, inspection of the coating pattern of the paste adhesive, and surface inspection of the die D and the substrate S . According to the positions of the die D and the substrate S calculated by the control and arithmetic device 81, the drive unit 86 is moved by software via the motor control device 83e. Through this process, the positioning of the die D on the wafer 11 is performed, and the die supply part 1 and the driving part of the die bonding part 4 are operated to bond the die D to the substrate S. The recognition camera used in the optical system 88 is a grayscale, color camera, etc., and the light intensity is digitized.

Next, a method of manufacturing a semiconductor device using the die bonder related to the embodiment will be described with reference to FIG. 23. FIG. 23 is a flowchart showing a method of manufacturing a semiconductor device using the die bonder of FIG. 19;

(Step S51: Wafer and substrate loading process) The wafer ring 14 holding the dicing tape 16 attached to the die D divided from the wafer 11 is stored in a wafer cassette (not shown), and carried into the die bonder 10. The control unit 8 supplies the wafer ring 14 from the wafer cassette filled with the wafer ring 14 to the die supply unit 1. In addition, the substrate S is prepared and carried into the die bonder 10. The control section 8 mounts the substrate S on the substrate conveying claw 51 by the substrate supply section 6.

(Step S52: Pick up the project) The control unit 8 moves the wafer ring 14 by using the wafer holding table 12 to pick up the desired die D from the wafer ring 14, and performs positioning and surface based on the data captured by the wafer recognition camera 24 Inspection of. The control part 8 peels the die D from the dicing tape by the peeling unit 13.

The control unit 8 picks up the peeled die D from the wafer 11 by the picker 21. In this way, the die D peeled off from the dicing tape 16 is sucked and held by the chuck 22 of the pick-up head 21, and is conveyed to the next process (step BS13). Moreover, when the die D is returned to the die supply unit 1 from the chuck 22 which is transported to the next process, the following die D is peeled off from the dicing tape 16 in the above order, and then in the same order, the die D is peeled off from the dicing tape 16 one by one.

(Step S53: Joining process) The control unit 8 obtains an image of the surface of the substrate S before coating by the adhesive recognition camera 94 to confirm the surface to which the paste-like adhesive should be applied. If there is no problem on the surface to be coated, the control unit 8 applies a paste-like adhesive from the syringe 91 to the substrate S transported by the transport unit 5. When the substrate S is a multiple lead frame, a paste-like adhesive is applied to all the tabs. The control unit 8 uses the adhesive recognition camera 94 to reconfirm whether the paste-like adhesive is applied correctly after application, and inspect the applied paste-like adhesive. If there is no problem in coating, the control unit 8 conveys the substrate S to the bonding stage BS by the conveyance unit, and performs positioning based on the image data photographed by the substrate recognition camera 44.

The control unit 8 places the die D picked up from the wafer 11 by the pickup head 21 on the intermediate stage 31, and the die D is picked up again from the intermediate stage 31 by the bonding head 41 and bonded to the positioned substrate S. The control unit 8 checks whether or not the die D is bonded to a desired position based on the image data captured by the substrate recognition camera 44.

(Step S54: Board unloading process) The control unit 8 takes out the substrate S to which the die D is bonded from the substrate conveying claw 51 by the substrate unloading unit 7. The substrate S is carried out from the die bonder 10.

In the above, although the invention created by the present inventors has been specifically described based on the implementation types, embodiments, and modifications, the present invention is not limited to the foregoing implementation types, modifications, and embodiments, and various modifications can of course be made.

For example, in the embodiment, although the example of applying a paste-like adhesive on the substrate with the preformed part is described, the adhesive for bonding the die to the substrate is used even if the adhesive is bonded to the wafer 11 and diced A film-like adhesive material called a die-attach film (DAF) between the adhesive tapes 16 may be used to replace the paste-like adhesive applied by the syringe 91. DAF is suitable for a laminated package composed of a large number of die placed on the die on the substrate S.

Furthermore, in the embodiment, although it is described that an intermediate platform part 3 is provided between the die supply part 1 and the bonding part 4, the die D picked up from the die supply part 1 by the pickup head 21 is placed in the middle. The stage 31 uses the bonding head 41 to pick up the die D again from the intermediate stage 31 and bond it to the transferred substrate S. However, even if the bonding head 41 is used to bond the die D picked up from the die supply unit 1 to the substrate S is also possible.

10: Die Bonder (Die Bonding Device) AA: Joint area CM1~CM4: Camera device CNT: Control Department S: substrate SCT: Chute (transport path)

[Fig. 1(a)] is an oblique view showing a normal field optical system, and [Fig. 1(b)] is an oblique view showing a wide field optical system. [Figure 2(a)] is a conceptual diagram of a wide-field optical system using micro lenses, [Figure 2(b)] is a conceptual diagram of a wide-field optical system using telecentric lenses. [Fig. 3(a)] is a diagram showing the image of the three-dimensional shape of the paste, [Fig. 3(b)] is a diagram showing the spectral lines on the paste when the substrate is viewed in a wide area with a microlens. [Fig. 4(a)] is a top view for the multiplexing of the camera device of the implementation type, [Fig. 4(b)] is a side view when viewed from the direction of arrow A in Fig. 4(a). Fig. 5 is a diagram for explaining the lighting device used in the imaging device of the implementation type. [FIG. 6] It is a top view explaining the repetition of the imaging field of view of a plurality of imaging devices. [Fig. 7] is a side view when viewed from the direction of arrow A in Fig. 6. [Fig. [Fig. 8] A diagram for explaining the amount of overlap of the imaging field of view. [Figure 9] is a diagram illustrating image mosaic and coordinate matching. [Figure 10] is a schematic diagram illustrating image mosaic and coordinate conversion using the calibration plate. [Fig. 11] is a diagram explaining distortion. [FIG. 12] A diagram showing the conversion determinants of affine conversion and projection conversion. [Figure 13] is a diagram illustrating the image mosaic and coordinate conversion of the target model by the substrate. [Fig. 14] A diagram illustrating the influence of the temporal displacement of the imaging device. [Fig. 15] is a diagram for explaining space re-correction. [Figure 16] is a diagram showing how to change the height of the calibration plate. [Fig. 17] A diagram for explaining the marks provided on the chute. Fig. 18 is a perspective view explaining the multiplexing of the imaging device in the modified example. [Fig. 19] is a top view showing the outline of the die bonder in the embodiment. [Fig. 20] is a diagram explaining the operation of the pickup head and the bonding head when viewed from the direction of arrow A in Fig. 19; [Fig. 21] is a schematic cross-sectional view showing the main part of the crystal grain supply part of Fig. 19. [Fig. [FIG. 22] A block diagram illustrating the schematic configuration of the control system of the die bonder of FIG. 19. [FIG. 23] A flowchart showing a method of manufacturing a semiconductor device.

AA11~AA16: Joint area

CM1~CM4: Camera device

CNT: Control Department

S: substrate

IA1, IA2: camera field of view

Claims (23)

A die bonding device, including: Transport path, which is used to transport substrates; A plurality of imaging devices are fixedly arranged above the conveying path in a row along the width direction of the substrate; and The control unit is configured to capture a row of multiple junction regions located on the substrate along the width direction by the multiple imaging device to obtain a multiple image, and generate a composite image based on the acquired multiple images, and based on the composite image And to identify the imaging object in the above-mentioned joint area, The imaging field of each imaging device is configured to be repeated on the substrate, and the repeated imaging field is set to be larger than the bonding area. Such as the die bonding device of claim 1, wherein The control unit is configured to generate the composite image based on coordinate marks located in the overlapping imaging field of view. Such as the die bonding device of claim 2, wherein The above-mentioned coordinate mark is a grid-like ruler covering all the field of view of the above-mentioned imaging device, The control unit is configured to project the coordinate mark, project the image based on the same intersection point of the coordinate mark reflected in the repeated imaging field of view, and join the images between the imaging devices to generate the composite image. Such as the die bonding device of claim 3, wherein The transport path has a plurality of reference marks on the outer sides of both ends in the width direction of the substrate, respectively, The above-mentioned substrate has a plurality of protrusions arranged at specific intervals, The control unit is configured to measure the interval between the protrusions or the interval between the reference marks with the imaging device, and to detect the displacement between the imaging devices. Such as the die bonding device of claim 4, wherein The above-mentioned substrate further has characteristic marks, The control unit is configured to detect the displacement between the imaging devices, and recalculate the projection conversion matrix for synthesizing and converting the image based on the characteristic mark. Such as the die bonding device of claim 5, wherein The control unit is configured to recalculate the projection conversion matrix based on the reference mark measured in advance, using the coordinates as a reference. Such as the die bonding device of claim 6, wherein The control unit is configured to finely move the substrate up and down to obtain a projection conversion row for each height, Calculate the predicted height of the alignment pattern position or the inspection view position from the thickness of the substrate, the height of the paste, or the thickness of the crystal grains, and select any one of the projection conversion ranks to be maintained at each height based on the calculated predicted height. Such as the die bonding device of claim 7, wherein The control unit is configured to recognize the same point on the substrate in the repeated imaging field of view between the adjacent imaging devices, measure the height, and select the height to be maintained at each height based on the measured height. Projection transformation ranks. The die bonding device of any one of claims 1 to 8, wherein It is further provided with a plurality of illuminating devices provided corresponding to each of the plurality of the above-mentioned imaging devices, The control unit is configured to independently dim a plurality of the lighting devices. The die bonding device of any one of claims 1 to 8, wherein The control unit is configured to transport the substrate in the longitudinal direction of the substrate, and image the plurality of bonding regions in the next row by the plurality of imaging devices. The die bonding device of any one of claims 1 to 8, wherein The imaging object is a paste-like adhesive applied on the substrate. Such as the die bonding device of claim 11, wherein The control unit is configured to perform an appearance inspection of the paste-like adhesive applied on the substrate by the imaging device. The die bonding device of any one of claims 1 to 8, wherein The imaging target is the substrate or the die on the die that has already been bonded. A method of manufacturing a semiconductor device includes: a process of loading a substrate into a die bonding device, the die bonding device is provided with: a transport path for transporting a substrate having a plurality of bonding regions; and a plurality of imaging devices along the above The width direction of the substrate is fixedly arranged above the conveying path in a row; and a plurality of illumination devices are arranged corresponding to each of the plurality of imaging devices; The device is configured such that the imaging field of view of each imaging device is repeated on the substrate, and the repeated imaging field of view is set to be larger than the bonding area; An image capturing a row of the plurality of joint regions located on the substrate along the width direction by the plurality of imaging devices to obtain a plurality of images, a composite image is generated based on the obtained plurality of images, and the joint region is identified based on the composite image The engineering of the object; and The process of transporting the substrate in the longitudinal direction of the substrate and imaging the plurality of bonding regions in the next row with the plurality of imaging devices. Such as the method of manufacturing a semiconductor device of claim 14, wherein The composite image is generated based on the coordinate markers located in the repeated imaging field of view. Such as the method of manufacturing a semiconductor device of claim 15, wherein The above-mentioned coordinate mark is a grid-like ruler covering all the field of view of the above-mentioned imaging device, The coordinate mark is projected, the image is projected and converted based on the same intersection point of the coordinate mark reflected in the repeated imaging field of view, and the images between the imaging devices are joined to generate the composite image. Such as the method of manufacturing a semiconductor device of claim 16, wherein The transport path has a plurality of reference marks on the outer sides of both ends in the width direction of the substrate, respectively, The above-mentioned substrate has a plurality of protrusions arranged at specific intervals, The interval between the protrusions or the interval between the reference marks is measured by the imaging device, and the displacement between the imaging devices is detected. Such as the method of manufacturing a semiconductor device of claim 17, wherein The above-mentioned substrate further has characteristic marks, In the case of detecting the displacement between the above-mentioned imaging devices, based on the above-mentioned feature markers, the projection conversion matrix for synthesizing and converting the image is recalculated. Such as the method of manufacturing a semiconductor device of claim 18, wherein Based on the reference mark measured in advance, the projection conversion matrix is recalculated based on its coordinates. Such as the method of manufacturing a semiconductor device of claim 19, wherein The above-mentioned substrate is slightly moved up and down, and the projection conversion ranks are calculated at each height, Calculate the predicted height of the alignment pattern position or the inspection view position from the thickness of the substrate, the height of the paste, or the thickness of the crystal grains, and select any one of the projection conversion ranks to be maintained at each height based on the calculated predicted height. Such as the method of manufacturing a semiconductor device of claim 20, wherein In the repeated imaging field of view between adjacent imaging devices, the same point on the substrate is identified, the height is measured, and the projection conversion row to be maintained at each height is selected according to the measured height. The method of manufacturing a semiconductor device according to any one of claims 14 to 21, wherein It also has a process of applying a paste-like adhesive to the above-mentioned substrate, The above-mentioned imaging target object is the above-mentioned paste-like adhesive which is applied. The method of manufacturing a semiconductor device according to any one of claims 14 to 21, wherein It is further equipped with the process of bonding the die to the above-mentioned substrate or the die that has been bonded, The above-mentioned imaging target object is the above-mentioned crystal grain coated.

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