KR20210031811A - Die bonding device and method of manufacturing semiconductor device - Google Patents

Abstract

An objective of the present invention is to provide a technology capable of inspecting the appearance of a paste-type adhesive that a change in a shape occurs after application. In a registration operation before mass production, a die bonder is configured to measure time from an operation of applying a paste-type adhesive to a metal frame to an operation of imaging the paste-type adhesive during mass production and image the paste-type adhesive applied to the metal frame to acquire a reference inspection image after applying the paste-type adhesive to the metal frame and waiting for the measured time.

Description

A die bonding device and a method of manufacturing a semiconductor device {DIE BONDING DEVICE AND METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE}

The present disclosure relates to a die bonding apparatus, and is applicable to, for example, a die bonder having a function of applying a paste-type adhesive.

Part of the manufacturing process of a semiconductor device includes a process of assembling a package by mounting a semiconductor chip (hereinafter, simply referred to as “die”) on a wiring board or lead frame (organic substrate such as metal, glass, epoxy, etc.). Part of the process includes 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 mounting the divided die on a substrate. A semiconductor manufacturing apparatus used in the bonding process is a die bonder.

The die bonder is an apparatus for bonding (mounting and bonding) a die onto a substrate or an already bonded die using a resin paste, solder, gold plating, or the like as a bonding material. In a die bonder that bonds a die to the surface of a substrate, for example, a suction nozzle called a collet is used to absorb and pick up the die from the wafer, convey it onto the substrate, and apply a pressing force to heat the bonding material. By doing so, the operation (operation) of performing bonding is repeatedly performed.

When using a resin as a bonding material, a resin paste such as Ag epoxy and acrylic is used as an adhesive (hereinafter referred to as a paste adhesive). The paste-type adhesive that adheres the die to the lead frame, etc. is enclosed in a syringe, and the syringe It moves up and down with respect to the lead frame, and paste-type adhesive is injected and applied. That is, a predetermined amount of a paste adhesive is applied to a predetermined position by a syringe enclosed with a paste adhesive, and a die is pressed and baked onto the paste adhesive to be adhered. A recognition camera is installed in the vicinity of the syringe, and it is checked whether or not the paste-type adhesive applied by the recognition camera is applied in a predetermined position and in a predetermined amount by a predetermined amount.

Japanese Patent Publication No. 2013-197277

In order to improve the adhesion of the mold resin to the substrate, which seals the die mounted on a substrate such as a lead frame, which is a metal frame, a shell pattern treatment is performed on the substrate. However, after application of the paste adhesive, bleeding of the paste adhesive occurs due to fine irregularities formed on the substrate, and a shape change occurs in the applied paste adhesive. For this reason, it becomes difficult to inspect the applied paste adhesive.

An object of the present disclosure is to provide a technique capable of inspecting the appearance of a paste-type adhesive in which a shape change occurs after application.

Other problems and novel features will become apparent from the description of the present specification and the accompanying drawings.

A brief overview of representative ones of the present disclosure is as follows.

That is, in the registration operation before mass production, the die bonder measures the time from the operation of applying the paste-type adhesive to the metal frame at the time of mass production to the operation of imaging the paste-type adhesive, and applies the paste-type adhesive to the metal frame. After application, the measured time is waited, and the paste-like adhesive applied to the metal frame is imaged to obtain a reference inspection image.

According to the die bonding apparatus, it is possible to inspect the appearance of a paste-type adhesive in which a shape change occurs after application.

1: is a figure explaining the application|coating of a paste adhesive.
Fig. 2 is a diagram for explaining a problem in the case of applying a paste-type adhesive to a lead frame on which a shell pattern has been processed.
Fig. 3 is a view for explaining a problem in the case of applying a paste-type adhesive to a lead frame on which a shell pattern has been processed.
4 is a diagram illustrating an outline of an embodiment.
5 is a diagram illustrating a method of inspecting a paste adhesive in the first embodiment.
6 is a diagram illustrating a method of inspecting a paste adhesive in the first embodiment.
Fig. 7 is a diagram explaining a method of inspecting a paste adhesive according to a first modified example.
8 is a diagram illustrating a method of inspecting a paste adhesive according to a second embodiment.
9 is a diagram illustrating a method of inspecting a paste adhesive according to a second embodiment.
10 is a diagram illustrating a method of inspecting a paste adhesive according to a second embodiment.
11 is a diagram illustrating an example of a method for predicting a shape.
Fig. 12 is a diagram explaining a method of inspecting a paste adhesive according to a second modified example.
13 is a diagram illustrating a method of inspecting a paste adhesive according to a third embodiment.
14 is a conceptual diagram viewed from above of the die bonder of the embodiment.
15 is a configuration diagram of an optical system of the die bonder of FIG. 14.
16 is a block diagram showing a schematic configuration of a control system of the die bonder of FIG. 14.
17 is a flowchart showing a method of manufacturing a semiconductor device.

Hereinafter, embodiments, modifications, and examples will be described with reference to the drawings. However, in the following description, the same constituent elements are denoted by the same reference numerals, and repetitive description may be omitted. In addition, in order to make the explanation more clear, the drawings may be schematically expressed with respect to the width, thickness, shape, etc. of each part compared to the actual mode, but are only examples and do not limit the interpretation of the present invention.

First, the application of the paste-type adhesive will be described with reference to FIG. 1. FIG. 1(a) is a diagram showing a captured image of a paste-type adhesive applied on the tabs of a lead frame in which tabs are arranged in a grid pattern, and FIG. 1(b) is a binarization of FIG. 1(a). It is a figure showing an image.

The application of the paste-type adhesive to the lead frame, which is a metal frame, is performed, for example, in a preform portion provided before the bonding portion. First, the preform part uses a recognition camera to position the lead frame LF to which the paste-type adhesive is to be applied. Positioning is performed by pattern matching or the like, similar to the bonding head. Next, the preform part is ejected from the nozzle at the tip of the syringe in which the paste adhesive PA is enclosed, and is applied along the trajectory of the nozzle. The syringe is driven in the XYZ axis according to the shape to be applied, and is applied by drawing a free trajectory such as a x mark shape or a cross shape according to the trajectory. Finally, the preform part inspects the state of the paste adhesive PA after application using a recognition camera (appearance inspection is performed). The presence or absence of the paste-type adhesive (PA), the application area, and the application shape (shortage, protrusion), etc. are checked as necessary. In addition to the method of counting the number of pixels after separating the paste region by the binarization process shown in Fig. 1B, the inspection is performed by a method of comparing by difference, a score by pattern matching, and the like. Hereinafter, the application pattern of the paste-type adhesive PA will be described as having a x-marked shape.

As shown in Fig. 1(a), there are shortages (interruption of Fig. 1(a)), protrusion (lower end of Fig. 1(a)) and the like depending on the application state of the paste-type adhesive. In addition, the upper end of FIG. 1A is a case in which the paste-type adhesive is applied in a normal state.

In order to improve the adhesion to the mold resin that seals the lead frame as the substrate to which the die is bonded, the lead frame is subjected to a shell pattern treatment. A problem in the case of applying a paste-type adhesive to the lead frame on which the shell pattern has been processed will be described with reference to FIGS. 2 and 3. FIG. 2(a) is a diagram showing a captured image immediately after applying a paste-type adhesive to the surface of a lead frame on which the shell pattern has been processed, and FIG. 2(b) is a predetermined time from FIG. 2(a). It is a figure which shows the captured image in the passed state, FIG. 2(c) is a conceptual cross-sectional view taken along line AA in FIG. 2(b), and FIG. 2(d) is 2(a) of FIG. It is a figure showing a valued image, and FIG. 2(e) is a figure showing the binarized image of FIG. 2(b). Fig. 3 is a diagram showing a picked-up image of a paste-type adhesive applied on tabs of a lead frame in which tabs are arranged in a grid pattern.

When the paste-type adhesive PA is applied to the tab TB serving as the die mounting portion of the lead frame LF in which the shell pattern has been processed, as shown in Fig. 2(b)(c), with the passage of time Paste adhesive (PA) spreads thinly. The surface of the lead frame LF on which the shell pattern has been treated is not flat, and there are fine irregularities. The paste-type adhesive PA applied so as to penetrate into these irregularities spreads. In this specification, this bleeding is referred to as bleed (BO). In the initial stage, the bleed (BO) spreads thinly in a uniform direction with the elapsed time. In addition, even in the case where the viscosity of the paste-type adhesive is small, even in the case where the viscosity of the paste-type adhesive is small, even in a lead frame that has not been subjected to the shell pattern treatment, the paste-type adhesive spreads with elapsed time.

In the case of visual inspection immediately after applying the paste adhesive PA, the inspection is terminated before the bleed BO spreads. However, if for some reason a re-inspection or inspection is required after a predetermined period of time has elapsed, it is necessary to consider the change of the bleed (BO).

In bleed, there is a seepage of solvent and a seepage of the paste itself. In the case of seeping out of the paste itself, it is judged as defective when there is a change in bleed (BO). In this case, it can be detected by the binarized image of Fig. 2(e) after a predetermined time elapses after application and the binarized image of Fig. 2(d) immediately after application registered in advance.

On the other hand, bleed (BO) hardly affects the applied amount of the paste-type adhesive (PA), and when the presence of bleed (BO) itself is not bad, a certain amount of time has elapsed after the application of the paste-type adhesive (PA). After that, if an appearance inspection is performed using an image captured with a recognition camera installed above the applied paste adhesive PA, even if an attempt is made to measure the amount of the paste adhesive PA, it is accurate due to the influence of the bleed (BO). The amount of paste (area/applied shape) cannot be detected. If the captured image is binarized as it is, since the bleed BO is also regarded as a paste-coated area, as shown in Fig. 2E, it is impossible to separate the paste portion PST from the bleed BO. In the current inspection system, which is only capable of two-dimensional inspection, it is judged as excessive coating.

A case where inspection is required after a predetermined time has elapsed from the application of the paste adhesive PA will be described with reference to FIG. 3.

In FIG. 3, a paste-type adhesive PA is sequentially applied from a tab at the upper right of the lead frame LF in which the tabs are arranged in a grid pattern in a downward direction, and the paste adhesive PA is applied to the tab at the lower right. After application, the paste-type adhesive PA is sequentially applied from the uppermost position in the second row from the right to the downward direction, and then, similarly, in the third row and the fourth row. Accordingly, the paste-type adhesive (PAS) applied to the topmost tab in the first row has the largest elapsed time after application, and the paste-type adhesive (PAE) applied to the bottommost tab in the fourth row has the shortest elapsed time after application.

As shown in FIG. 3, when the appearance inspection of the paste-type adhesive applied to all the tabs in four rows after application of four rows, that is, after application of the paste-type adhesive (PAE), is performed, as shown in FIG. ) Spread varies from tap to tap. In general, since the visual inspection of the paste adhesive is performed for each row, the diffusion of bleed BO differs for each tab in the paste adhesive of the tab applied at the beginning of the row and the paste adhesive of the tab applied last in the row.

In the case of performing the entire tap inspection after application to a plurality of tabs such as one row or multiple rows, the time from application to inspection varies for each tab, and the spread of bleed (BO) varies from tab to tab, and the inspection result is the position of the tab. It changes according to.

Next, an outline of an embodiment solving the above problem will be described with reference to FIG. 4. FIG. 4A is a diagram showing a captured image immediately after applying a paste adhesive to the surface of the lead frame, and FIG. 4B is a captured image after a predetermined time has elapsed from FIG. 4A. 4(c) is a diagram showing the binarized image of FIG. 4(a), and FIG. 4(d) is a diagram showing the binarized image of FIG. 4(b) 4(e) is a diagram showing the binarized image of FIG. 4(a), and FIG. 4(f) shows the binarized image with the bleed change removed from FIG. 4(b). It is a drawing.

In the first embodiment, the registration timing of the reference inspection image as a reference is matched with the inspection timing in continuous operation during mass production, and as shown in Fig. 4D, inspection is performed by image recognition including bleed. Make a judgment. On the other hand, in the second embodiment, the original coating amount (shape) is predicted from the spread of bleed, and as shown in Fig. 4F, the change in bleed is removed to perform inspection determination. In the third embodiment, inspection determination is made by separating the bleed from the paste portion by illumination. Hereinafter, each inspection method will be described in detail.

(First embodiment)

A method of inspecting a paste-type adhesive in the first embodiment will be described with reference to FIGS. 5 and 6. 5 is a flowchart illustrating a method of acquiring a reference inspection image. FIG. 6(a) is a diagram showing a captured image immediately after applying a paste-type adhesive to the surface of the lead frame, and FIG. 6(b) is a captured image after A minutes have elapsed from FIG. 6(a). Fig. 6(c) is a diagram showing a captured image after B minutes has elapsed from Fig. 6(a), and Fig. 6(d) is a binarization of Fig. 6(a) Fig. 6(e) is a diagram showing the binary image of Fig. 6(b), and Fig. 6(f) is a diagram showing an image, It is a drawing.

As described above, in the first embodiment, the registration timing of the reference inspection image as a reference is matched with the inspection timing at the time of mass production, and inspection determination is performed by image recognition including bleed. The inspection method described below is performed by a control device provided in the die bonder controlling a recognition camera or the like as an imaging device.

First, a registration (image acquisition) operation will be described with an actual recognition timing.

(Step S1: Acquisition of mass production conditions (recognition timing))

Actually, a futile operation (step S11) is performed without application, and the timing (time) from application in the continuous operation at the time of mass production to the visual inspection (recognition) imaged with the recognition camera is measured (step S12). As described in FIG. 3, after applying the paste adhesive PA to the plurality of tabs TB of the lead frame LF, from the first paste adhesive PAS to the last paste adhesive ( In the case of sequential visual inspection until PAE), the time from each application to the visual inspection is measured. Thereby, the timing of visual inspection at the time of mass production is acquired.

(Step S2: Acquisition of a reference inspection image)

Actually, the paste adhesive PA is applied once to the tab TB of the lead frame LF serving as the first substrate, and settings such as lighting are determined (step S21). At the same time as the application, measurement of the elapsed time is started. Wait until the elapsed time being measured reaches the time (actual measurement time) measured in step S12 (step S22), that is, paste-type adhesive (PA) using a recognition camera at the actual recognition timing, which is the timing of visual inspection in mass production. A reference inspection image of is acquired, stored in a storage device provided in the control device, and registered (step S23). For example, when the time measured in step S12 is A minutes, the captured image in FIG. 6B is registered as a reference inspection image, and when the time measured in step S12 is B minutes, The captured image is registered as a reference inspection image. When the time measured in step S11 is one, one inspection image is acquired, and when the time measured in step S11 is a plurality, a plurality of reference inspection images at each time is acquired. Thereby, a reference inspection image at the visual inspection timing at the time of mass production is acquired.

In mass production, inspections and judgments are performed in continuous operation. In the visual inspection after the application of the paste-type adhesive PA to the tab TB of the lead frame LF as the second substrate, an image was acquired using a recognition camera, and compared with the reference inspection image registered in step S23, the application was normally performed. Whether or not it is determined. For example, when the captured image of the visual inspection during mass production is binarized and the time measured in step S12 is A minutes, the time measured in step S12 is compared with the binarized image shown in Fig. 6E. In the case of this B minute, it is compared with the binarized image shown in Fig. 6F.

In the first embodiment, since the recognition registration timing takes into account the change in the two-dimensional shape of the paste-type adhesive, it is possible to distinguish between the initial application amount and the change over time, and the registration of the reference inspection image and inspection in the appearance inspection during mass production. Correct inspection determination becomes possible by matching the conditions of the image acquisition timing. That is, the registration timing of the reference inspection image and the acquisition timing of the inspection image during mass production (continuous operation) are matched to detect a shape change of the applied paste adhesive. Thereby, stabilization of the determination of the presence or absence of an abnormality in the applied paste adhesive is achieved, and correct inspection determination becomes possible. Further, by automating the registration timing of the reference inspection image (the device is adapted to mass production conditions), it becomes possible to eliminate the difference caused by the operator, and the operation rate can also be improved.

Hereinafter, some of the representative modified examples and other embodiments of the embodiment will be exemplified. In the description of the following modified examples and other embodiments, it is assumed that the same reference numerals as those of the above-described embodiments may be used for portions having the same configuration and function as those described in the above-described embodiments. In addition, as for the description of such a part, it is assumed that the description in the above-described embodiment can be appropriately used within a range not technically contradictory. In addition, a part of the above-described embodiment, a plurality of modified examples, and all or part of the other embodiments may be appropriately and complexly applied within a range not technically contradictory.

(1st modification)

The change with time after application of the paste adhesive PA may be detected. A method of acquiring a reference inspection image in a modified example of the first embodiment (first modified example) will be described with reference to FIG. 7. 7 is a flowchart illustrating a method of acquiring a reference inspection image.

After step S2 in Fig. 5, a reference inspection image of the paste adhesive PA applied to the tab TB of the lead frame LF as the first substrate is acquired using a recognition camera and the reference inspection image is acquired. The time is acquired (step S24). It is determined whether or not the diffusion of bleed is saturated based on the previously acquired reference inspection image and the latest reference inspection image (step S25). Steps S24 and S25 are repeated, and the saturation time at which the diffusion of bleed is saturated is obtained (step S26).

That is, with the passage of time after application, a reference inspection image is acquired a plurality of times, for example, as shown in Figs. 6A to 6C. Using these reference inspection images, changes over time and saturation time are confirmed. When the inspection is not performed after coating and before the device is stopped, a determination is made at the time of restarting mass production based on the time from application to the inspection after restarting the device (referred to herein as the device stop time). When the device stop time is within the saturation time, it is determined using a reference inspection image corresponding to the device stop time. If the device stop time is longer than the saturation time, it is determined using a reference inspection image corresponding to the saturation time.

(2nd embodiment)

A method of inspecting a paste-type adhesive in the second embodiment will be described with reference to FIGS. 8 to 11. Fig. 8 is a flowchart for explaining registration of the spread of bleed. 9 is a flowchart for explaining an appearance inspection at the time of construction start. Fig. 10 is a diagram for explaining prediction of the applied amount (shape) of a paste adhesive immediately after application. FIG. 10A is a diagram showing a captured image immediately after applying a paste-type adhesive to the surface of the lead frame, and FIG. 10B is a captured image after A minutes have elapsed from FIG. 10A. Fig. 10(c) is a diagram showing a captured image in a state where B minutes have elapsed from Fig. 10(a). FIG. 10(d) is a diagram showing a captured image in a state that A minute has elapsed from FIG. 10(a), and FIG. 10(e) is a diagram showing the binary image of FIG. 10(d) , FIG. 10(f) is a binarized image calculated immediately after application from the binarized image of FIG. 10(d). FIG. 10(g) is a diagram showing a captured image after B minutes from FIG. 10(a), and FIG. 10(h) is a diagram showing the binary image of FIG. 10(g) , FIG. 10(i) is a binarized image calculated immediately after application from the binarized image of FIG. 10(h). 11 is a diagram for describing an example of a method for predicting a shape.

As described above, in the second embodiment, the original coating amount (shape) is predicted from the diffusion of the lead, and the change in bleed is removed to perform inspection determination. Hereinafter, it demonstrates in detail.

As shown in Fig. 8, by performing an imitation operation (registration operation), the speed at which the bleed spreads for each type is investigated and converted into a database. Hereinafter, the imitation operation will be described.

The lead frame LF as the first substrate is conveyed to the place where the paste adhesive PA is applied (step S31), and an illumination value is determined (step S32). Next, the paste adhesive PA is applied to the tab TB of the lead frame LF serving as the first substrate, and measurement of the passage of time is started (step S33). Immediately after application, the paste-type adhesive PA is imaged using a recognition camera, the image is introduced, and a time stamp is acquired (step S34), and the area and shape of the area of the paste-type adhesive applied from the captured image At least one of them is measured (step S35). Thereafter, steps S34 and S35 are repeated every predetermined time until diffusion of bleed is saturated.

In the continuous operation at the start of construction, as shown in Fig. 9, the lead frame LF as the second substrate is conveyed to the place where the paste adhesive PA is applied (step S41), and the paste adhesive PA is transferred. It is applied to the tab TB of the lead frame LF serving as the second substrate (step S42). The pasty adhesive PA is applied and measurement of the lapse of time is started (step S43). After application, the paste adhesive PA is imaged using a recognition camera at a predetermined timing to introduce an image, and a time stamp is acquired (step S44).

The area and shape of the region of the paste adhesive PA immediately after application are predicted based on the elapsed time calculated from the time stamp acquired in step S44 and the image acquired during the imitation operation (step S45). At this time, the image acquired in step S44 is inspected by normal image processing. For example, when the elapsed time from application is A minutes, as shown in Fig. 10(e), for an image obtained by binarizing the detected application area, it is determined according to the elapsed time acquired by mimicry. Based on the amount of shrinkage, shrinkage treatment is performed to calculate the area and shape immediately after application. Thereby, the predicted image at the time of application shown in Fig. 10(f) is generated, and the amount of application at the time of application is predicted, and the result is obtained. When the elapsed time from application is B minutes, as shown in Fig. 10(h), based on the amount of contraction determined according to the elapsed time acquired by the imitating operation for the image obtained by binarizing the detected application area. Then, a shrinkage treatment is performed to calculate the area and shape immediately after application. Thereby, the predicted image at the time of application shown in Fig. 10(i) is generated, and the amount of application at the time of application is predicted, and the result is obtained.

As a shape prediction method, a simple image expansion process or image contraction process may be employed. The number of contractions or expansions relative to the elapsed time is determined from the data acquired during the simulation operation. Image expansion processing or image contraction processing is performed in eight or four orientations. As shown in Fig. 11, a starting point is provided at each bent point (marked by) of the penlight trajectory of the x-marked shape, and the amount of change per time in the outward direction with respect to the outline indicated by the arrow during the imitating operation is obtained, You may use it for prediction calculations. The amount of change may be predicted only by the area.

Inspection and determination are performed based on the area and shape predicted in step S45, and the area and shape in the image immediately after application during the imitation operation (step S45). For example, the inspection is performed by comparing the area or shape of the predicted application area of the paste-type adhesive PA and the application shape that is used as a reference at the time of the imitation operation, and the like. The area of the coating area is extracted by counting pixels of a specific brightness (extraction from histogram data, etc.), blob detection, or the like. In the comparison of the shape of the coating area, reference data that can be compared with data after binarization is acquired and held by an imitating operation, and the reference data is compared with the data of the expected shape by differential processing or the like.

In the inspection method of the second embodiment, it is assumed that the speed and direction at which the bleed spreads within a certain time after application is confirmed in advance and reproduced according to the determined calculation formula. Therefore, the upper limit time for uniformly and continuously spreading of the bleed is also measured in advance by the mimic operation, and after the upper limit time has elapsed, a process of invalidating the measurement result is also performed.

In the second embodiment, since the bleed advances in a certain amount within a certain time, the application state of the paste excluding the bleed portion can be confirmed.

(2nd modification)

A method of inspecting a paste adhesive in a modified example of the second embodiment (a second modified example) will be described with reference to FIGS. 8 and 12. 12 is a flowchart for explaining an appearance inspection at the time of construction start.

In the inspection method of the paste-type adhesive in the second modification, the captured image or shape for each elapsed time during the imitating operation is compared with the captured image or shape acquired at the start of mass production. It is the same as steps S41 to S44 at the time of the imitating operation and the start of construction in the second embodiment.

During the imitating operation, the captured image or shape data is held for each elapsed time after application of the paste adhesive PA to the tab TB of the lead frame LF serving as the first substrate (steps S34 and S35). The elapsed time from application of the paste adhesive PA to the tab TB of the lead frame LF serving as the second substrate to the inspection in the continuous operation at the time of starting construction is measured (step S43). From the value of the elapsed time, select which image to compare with during the imitation operation. That is, the image or shape data at the time of the imitation operation corresponding to the elapsed time is acquired (step S45a). Inspection and determination are performed based on the image acquired in step S44 or shape data based thereon and the image or shape data acquired in step S45a (step S46a).

(3rd embodiment)

In the second embodiment, the original application amount (shape) is predicted from the spread of bleed, and the change in bleed is removed to perform inspection determination, but in the third embodiment, the bleed is separated from the paste portion by illumination. A method of inspecting a paste adhesive in the third embodiment will be described with reference to FIG. 13. 13 is a diagram illustrating an imaging device and a lighting device in a third embodiment.

As shown in Fig. 2C, since the paste portion (PST) and the bleed portion (BO) are three-dimensionally different, the bleed portion (BO) is separated from the arm and the paste portion (PST) as light. Bleed (BO) is imprinted darkly on the surface of the substrate in most cases after application (similar to the state in which concrete appears dark after rain). Therefore, when the difference processing between the image before application and the image after application is performed, the bleed BO is necessarily captured as a cancer (negative image). Therefore, if the differential processing is performed in the negative cut-out mode, the bleed (BO) component can be excluded. However, it cannot be said that the paste portion PST becomes bright. This is a characteristic of liquid surface reflection, and when collimated light is irradiated with incident illumination, the peripheral portion of the paste portion PST may become dark. Therefore, as shown in Fig. 13, it is used in combination with a four-beam illumination (preferably a ring or a square type) so that the periphery of the paste portion PST is always bright.

As shown in FIG. 13, the illumination device ID in 3rd embodiment is equipped with the coaxial illumination CL and the quadrature illumination OL which are incident illuminations. The coaxial illumination CL is composed of an illumination LS and a half mirror HM, and irradiates light along an optical axis of the imaging device CAM. The oblique illumination OL irradiates light obliquely with respect to the optical axis. Since the application area of the paste adhesive PA is a liquid surface, specular reflection occurs due to illumination, and a bright line or dark portion corresponding to the position of the illumination is generated. For example, a bright line appears around the coating area and a dark portion appears in the center of the coating area in an image acquired by the oblique illumination OL. This is because the incident direction of the illumination is low in the incident light illumination OL. On the other hand, in the image acquired by the coaxial illumination CL, a bright line appears in the center of the coating area, and dark portions appear around the coating area. This is because the incident direction of the illumination is high in the coaxial illumination CL. By using the coaxial illumination CL and the four-beam illumination together together, the dark part can be removed.

<Example>

The configuration of a die bonder as the die bonding apparatus of the embodiment will be described with reference to FIGS. 14 to 16. 14 is a schematic view from above of a die bonder of an embodiment. 15 is a configuration diagram of an optical system of the die bonder of FIG. 14. Fig. 16 is a block diagram showing a schematic configuration of a control system of the die bonder of Fig. 14;

The die bonder 10 is largely divided into a wafer supply unit 1, a work supply/transport unit 2, and a die bonding unit 3.

The wafer supply unit 1 includes 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 the desired die D can be picked up from the wafer ring 16.

The work supply/transport unit 2 has a stack loader 21, a frame feeder 22, and an unloader 23, and conveys the lead frame LF (see Fig. 15) in the direction of an arrow. The stack loader 21 supplies the lead frame LF to which the die D is bonded to the frame feeder 22. The frame feeder 22 conveys the lead frame LF to the unloader 23 through two processing positions on the frame feeder 22. The unloader 23 stores the conveyed lead frame LF.

The die bonding portion 3 has a preform portion (paste application unit) 31 and a bonding head portion 32. The preform part 31 applies a paste adhesive PA such as an epoxy resin to the lead frame LF conveyed by the frame feeder 22 with a syringe 36 (see Fig. 15). The syringe 36 has a paste-type adhesive PA enclosed therein, and the paste-type adhesive PA is extruded from the tip of the nozzle to the lead frame LF by pneumatic pressure and applied thereto. When the lead frame LF is, for example, a multi-lead lead frame in which a plurality of unit lead frames are arranged in a horizontal line and continuously installed in series, a paste adhesive PA is applied to each tab of the unit lead frame. Here, the lead frame LF is subjected to a shell pattern treatment. The bonding head 32 picks up and raises the die D from the pickup device 12, and moves the die D to a bonding point on the frame feeder 22. Further, the bonding head unit 32 lowers the die D at the bonding point and bonds the die D on the lead frame LF to which the paste-type adhesive PA is applied.

The bonding head unit 32 includes a ZY drive shaft 60 that moves the bonding head 35 in the Z-axis direction (height direction) and moves in the Y-axis direction, and an X drive shaft 70 that moves in the X-axis direction. Have. The ZY drive shaft 60 is a Y-axis direction indicated by an arrow C, that is, a Y drive shaft 40 for reciprocating the bonding head 35 between a pickup position in the pickup device 12 and a bonding point, and a die D as a wafer. It has a Z drive shaft 50 which is raised and lowered for picking up from 14 or bonding to the lead frame LF. The X drive shaft 70 moves the entire ZY drive shaft 60 in the X direction, which is a direction in which the lead frame LF is conveyed.

As shown in Fig. 15, the optical system 88 includes an adhesive recognition camera 33 as an imaging device that grasps the application position of the syringe 36, and the lead frame LF to which the bonding head 35 has been conveyed. A substrate recognition camera 34 for grasping a bonding position to be bonded to, and a wafer recognition camera 15 for grasping a pickup position of the die D picked up by the bonding head 35 from the wafer 14 are provided. Each recognition camera captures an image using an illumination device that illuminates an object. The die D diced in a mesh shape on the wafer 14 is fixed to a dicing tape 17 fixed to the wafer ring 16.

With this configuration, the paste-type adhesive PA is applied at the correct position by the syringe 36, the die D is reliably picked up by the bonding head 35, and at the correct position of the lead frame LF. Bonded.

As shown in Fig. 16, the control system 80 includes a control device 8, a drive unit 86, a signal unit 87, and an optical system 88. The control device 8 is largely divided into a control/operation device 81 mainly composed of a CPU (Central Processor Unit), a storage device 82, an input/output device 83, a bus line 84, and , Has a power supply unit (85). The storage device 82 is a main memory device 82a composed of a RAM storing processing programs, etc., and an auxiliary storage device 82b composed of an HDD storing control data, image data, etc. necessary for control. Has. 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 optical system 88. It has an image introducing device 83d for introducing image data. Further, the input/output device 83 includes a motor control device 83e that controls a driving unit 86 such as an XY table (not shown) of the wafer supply unit 1 or a ZY drive shaft of the bonding head table, and various sensor signals. B. It has an I/O signal control device 83f for introducing or controlling a signal from a signal unit 87 such as a switch such as a lighting device. The optical system 88 includes a wafer recognition camera 15, an adhesive recognition camera 33, and a substrate recognition camera 34. The control/calculation device 81 introduces and calculates necessary data via the bus line 84, and sends information to the control of the bonding head 35 or the like, the monitor 83a, or the like.

The control device 8 stores the image data captured by the optical system 88 through the image introduction device 83d in the storage device 82. Using the software programmed based on the saved image data, the die D and the lead frame LF are positioned using the control/calculation unit 81, the paste-type adhesive PA is applied and the pattern is inspected. Surface inspection of the die D and the lead frame LF is performed. Based on the positions of the die D and the lead frame LF calculated by the control/calculation device 81, the drive unit 86 is moved through the motor control device 83e by software. By this process, the die D is positioned on the wafer 14, and the die D is bonded onto the lead frame LF by operating as a driving unit of the wafer supply unit 1 and the die bonding unit 3. . The recognition camera used in the optical system 88 is a gray scale, color, etc., and quantifies the light intensity.

Next, a method of manufacturing a semiconductor device using a die bonder according to an embodiment will be described with reference to FIG. 17. 17 is a flowchart showing a method of manufacturing a semiconductor device.

(Step S51: Wafer/substrate carrying process)

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

(Step S52: pickup process)

The control device 8 moves the wafer ring 16 to the pickup device 12 so that the desired die D can be picked up from the wafer ring 16 so that the die D is pushed up and peeled off. The resulting die D is picked up from the wafer 14 by the bonding head 35.

(Step S53: bonding process)

The control device 8 acquires an image of the surface of the lead frame LF before application by the adhesive recognition camera 33 and checks the surface to which the paste-type adhesive PA is to be applied. If there is no problem with the surface to be applied, the control device 8 applies the paste-type adhesive PA from the syringe 36 to the lead frame LF conveyed by the frame feeder 22. When the lead frame LF is a multi-lead lead frame, paste-type adhesive PA is applied to all tabs. The control device 8 determines whether or not the paste-type adhesive PA has been accurately applied after application, according to an inspection method of the first embodiment, the second embodiment and the third embodiment, and their modified examples. ), and inspect the applied paste adhesive (PA). If there is no problem in application, the control device 8 bonds the die D picked up by the bonding head 35 to the lead frame LF to which the paste-type adhesive PA has been applied.

(Step S54: Substrate carrying out process)

The control device 8 supplies the lead frame LF to which the die D is bonded by the frame feeder 22 to the unloader 23. The lead frame LF is taken out from the die bonder 10.

As described above, the invention made by the present inventors has been specifically described based on the embodiments, modifications and examples, but the present invention is not limited to the above embodiments, modifications and examples, and it is to be noted that various modifications are possible. There is no need.

For example, in the first embodiment, an example in which the application is not actually applied in step S11 but a futile operation has been described, but in step S11, it may be applied in practice.

In addition, in the second embodiment, an example in which the speed at which the bleed spreads for each type is investigated and converted into a database by performing an imitation operation (registration operation) has been described. A recognition camera may be provided, and the speed at which the bleed spreads for each type may be calculated from a paste-like inspection image applied to the passing lead frame and the conveyance speed of the lead frame to form a database. In addition, since the situation at the time of mass production can be continuously checked, it is possible to automatically correct the database or to detect abnormalities or change points in paste coating using data deviations.

In addition, in the embodiment, an example in which the die D picked up from the wafer 14 by the bonding head 35 is bonded to the lead frame LF has been described, but between the wafer 14 and the lead frame LF An intermediate stage is provided, the die D picked up from the wafer 14 is loaded with the pickup head on the intermediate stage, the die D is picked up again from the intermediate stage with the bonding head 35, and the lead frame has been conveyed. Bonding to (LF) may be carried out.

8: control device
10: die bonder (die bonding device)
33: adhesive recognition camera (imaging device)
35: bonding head
D: Die
LF: lead frame (substrate)
PA: Paste type adhesive

Claims (13)

An imaging device for imaging the paste-type adhesive applied on the substrate, and
A bonding head for mounting a die on the substrate to which the paste-type adhesive is applied,
A control device that performs an appearance inspection based on the image of the paste-type adhesive captured by the imaging device
And,
The control device,
In the registration operation before mass production,
Measuring the time from the operation of applying the paste-type adhesive to the substrate during mass production to the operation of imaging the paste-type adhesive with the imaging device,
A die, configured to wait for the measured time after applying the first paste adhesive to the first substrate, and to capture the first paste adhesive applied to the first substrate with the imaging device to obtain a reference inspection image Bonding device. The method of claim 1,
The control device,
At the time of mass production, after the second paste-type adhesive is applied to the second substrate, the second paste-type adhesive applied to the second substrate is imaged with the imaging device when the measured time elapses to obtain an inspection image,
A die bonding apparatus, configured to perform a visual inspection based on the inspection image and the reference inspection image. The method of claim 2,
The control device,
In the registration operation, the die bonding apparatus is configured to acquire a plurality of reference inspection images by imaging the first paste adhesive a plurality of times with the imaging device in accordance with the passage of time after the application of the first paste adhesive. An imaging device for imaging the paste-type adhesive applied on the substrate, and
A bonding head for mounting a die on the substrate to which the paste-type adhesive is applied,
A control device that performs an appearance inspection based on the image of the paste-type adhesive captured by the imaging device
And,
The control device,
Measuring the elapsed time after applying the first paste adhesive to the first substrate,
The first paste adhesive is imaged a plurality of times with the imaging device to acquire a plurality of images and an elapsed time at the time of capturing each of the plurality of images,
Based on each of the plurality of images, measuring the area or shape of the first paste adhesive in the elapsed time at the time of each imaging,
In mass production,
Measure the elapsed time after applying the second paste-type adhesive to the substrate,
The second paste adhesive is imaged with the imaging device to acquire an inspection image and a second elapsed time at the time of imaging the inspection image,
An estimated area or expected shape upon application of the second paste adhesive is calculated based on the area or shape of the first paste adhesive in the second elapsed time and the elapsed time at the time of imaging,
A die bonding apparatus configured to perform an appearance inspection based on the expected area or the expected shape. An imaging device for imaging the paste-type adhesive applied on the substrate, and
A bonding head for mounting a die on the substrate to which the paste-type adhesive is applied,
A control device that performs an appearance inspection based on the image of the paste-type adhesive captured by the imaging device
And,
The control device,
Measuring the elapsed time after applying the first paste adhesive to the first substrate,
A plurality of images or a plurality of shape data based on the plurality of images are acquired by imaging the first paste adhesive a plurality of times with the imaging device, and the elapsed time at the time of each imaging of the plurality of images is acquired. ,
In mass production,
Measuring the elapsed time after applying the second paste adhesive to the second substrate,
Acquiring an inspection image or second shape data based on the inspection image by imaging the second paste adhesive with the imaging device, and acquiring a second elapsed time when capturing the inspection image,
An image or shape data corresponding to the second elapsed time is selected from the acquired plurality of images or the plurality of shape data, and visual inspection is performed based on the selected image or shape data and the inspection image or the second shape data. Configured to, a die bonding device. An imaging device for imaging the paste-type adhesive applied on the substrate, and
A beam illumination device for irradiating light to the paste-type adhesive from an oblique direction,
An incident lighting device that irradiates light to the paste-type adhesive from an upward direction,
A bonding head for mounting a die on the substrate to which the paste-type adhesive is applied,
A control device that performs an appearance inspection based on the image of the paste-type adhesive captured by the imaging device
And,
The control device,
The first image is acquired by imaging the substrate to which the paste-type adhesive is not applied,
The substrate to which the paste-type adhesive has been applied is illuminated by both of the beam lighting device and the incident lighting device to capture an image to obtain a second image,
Differential processing of the second image is performed from the first image to calculate difference data,
Acquire inspection data by excluding negative numbers from the difference data,
A die bonding apparatus, configured to perform an appearance inspection based on the inspection data. The method according to any one of claims 1 to 6,
A wafer ring holder for holding the dicing tape to which the die is affixed,
Syringe for applying the paste-type adhesive on the substrate
Further comprising a die bonding device. Appearance based on an imaging device for imaging a paste-type adhesive applied on a substrate, a bonding head for mounting a die on the substrate to which the paste-type adhesive is applied, and an image of the paste-type adhesive captured by the imaging device A control device for performing an inspection is provided, and the control device includes an operation of applying the paste-type adhesive to the substrate during mass production in a registration operation before mass production to image the paste-type adhesive with the imaging device. After measuring the time until, after applying the first paste adhesive to the first substrate, waiting for the measured time, the first paste adhesive applied to the first substrate is imaged with the imaging device, and a reference inspection image A step of carrying a second substrate into the obtained die bonding device, and
A step of applying a second paste-type adhesive on the second substrate, and
After the second paste-type adhesive is applied to the second substrate and the measured time elapses, the second paste-type adhesive applied to the second substrate is imaged with the imaging device to obtain an inspection image, and the Process of performing visual inspection based on the inspection image and the reference inspection image
Containing, the manufacturing method of a semiconductor device. The method of claim 8,
The control device, in the registration operation, acquires a plurality of reference inspection images by imaging the first paste-type adhesive a plurality of times with the imaging device according to the lapse of time after the application of the first paste-type adhesive. The method of manufacturing the device. Appearance based on an imaging device for imaging a paste-type adhesive applied on a substrate, a bonding head for mounting a die on the substrate to which the paste-type adhesive is applied, and an image of the paste-type adhesive captured by the imaging device A control device for performing inspection is provided, wherein the control device measures an elapsed time after applying the first paste-type adhesive to the first substrate, and takes a plurality of images of the first paste-type adhesive with the imaging device. Acquires an image of the image and the elapsed time at the time of capturing each of the plurality of images, and measures the area or shape of the first paste-type adhesive in the time elapsed at the time of capturing based on each of the plurality of images A step of carrying a second substrate into one die bonding device, and
A step of applying a second paste-type adhesive on the second substrate, and
The elapsed time after applying the second paste adhesive to the second substrate is measured, and the second paste adhesive is imaged with the imaging device to determine an inspection image and a second elapsed time at the time of imaging the inspection image. Acquire, calculate the estimated area or expected shape upon application of the second paste adhesive based on the area or shape of the first paste adhesive in the second elapsed time and the elapsed time at the time of imaging, and the Process of performing an appearance inspection based on the expected area or the expected shape
Containing, the manufacturing method of a semiconductor device. Appearance based on an imaging device for imaging a paste-type adhesive applied on a substrate, a bonding head for mounting a die on the substrate to which the paste-type adhesive is applied, and an image of the paste-type adhesive captured by the imaging device A control device for performing inspection is provided, wherein the control device measures an elapsed time after applying the first paste-type adhesive to the first substrate, and takes a plurality of images of the first paste-type adhesive with the imaging device. A step of carrying a second substrate into a die bonding apparatus that acquires an image of the image or shape data based on the plurality of images and acquires the elapsed time at the time of capturing each of the plurality of images; and
A step of applying a second paste-type adhesive on the second substrate, and
Elapsed time after applying the second paste adhesive to the second substrate is measured, and the second paste adhesive is imaged with the imaging device to acquire an inspection image or second shape data based on the inspection image. In addition, a second elapsed time at the time of capturing the inspection image is acquired, a reference inspection image or shape data corresponding to the second elapsed time is selected from the acquired plurality of images or the plurality of shape data, and the selected image Or a process of performing an appearance inspection based on shape data and the inspection image or the second shape data.
Containing, the manufacturing method of a semiconductor device. An imaging device for photographing a paste-type adhesive applied on a substrate, a beam illumination device for irradiating light to the paste-type adhesive from an oblique direction, and a bonding head for mounting a die on the substrate to which the paste-type adhesive is applied; , A step of carrying a substrate into a die bonding device including a control device for performing an external appearance inspection based on the image of the paste-like adhesive captured by the imaging device; and
A step of applying the paste-type adhesive on the substrate, and
The substrate to which the paste-type adhesive is not applied is imaged to acquire a first image, the substrate to which the paste-type adhesive is applied is imaged to obtain a second image, and the second image is obtained from the first image. Step of performing difference processing to calculate difference data, acquiring inspection data by excluding negative numbers from the difference data, and performing visual inspection based on the inspection data
Containing, the manufacturing method of a semiconductor device. The method according to any one of claims 8 to 12,
A step of carrying in a wafer ring holder that holds the dicing tape to which the die is affixed;
A step of picking up the die from the dicing tape;
The process of loading the picked up die onto the substrate
The method of manufacturing a semiconductor device further comprising a.

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