Mounting device, lighting system adjustment method, and semiconductor device manufacturing method

Abstract

To provide a technique capable of improving recognition accuracy of a workpiece.SOLUTION: A mounting apparatus comprises: an illumination system which emits light in a light amount based on an illumination value; an image pickup device which images a workpiece irradiated with the light by the illumination system; and a control unit which performs output control of the illumination system and image processing of the image captured by the image pickup device. The control unit is configured to set the illumination value to a prescribed value when a recognition error of the workpiece occurs, acquire an acquired image by imaging the workpiece irradiated by the illumination system by the image pickup device, acquire a pattern image that is the most similar to a template image by retrieving the acquired image, calculate the matching concordance ratio between the most similar pattern image and the template image, change the prescribed value, and obtain the illumination value having the highest matching concordance ratio.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to a mounting apparatus and is applicable to, for example, a die bonder equipped with a camera that recognizes a die or a substrate. [Background technology]

[0002] Part of the manufacturing process for semiconductor devices is the process of assembling a package by mounting a semiconductor chip (hereinafter simply referred to as a die) on a wiring board or lead frame (hereinafter simply referred to as a substrate), and part of the process of assembling the package is the process of separating the die from a semiconductor wafer (hereinafter simply referred to as a wafer) (dicing process) and the bonding process of mounting the separated die on a substrate. The semiconductor manufacturing equipment used in the bonding process is a mounting device such as a die bonder.

[0003] Generally, the positioning of dies and substrates (hereinafter simply referred to as workpieces) in die bonders is performed by irradiating the workpieces with light from an illumination system (illumination device) and processing the images captured by a camera. Therefore, the recognition accuracy of the workpieces is greatly affected by the amount of light (illumination output) of the illumination system. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2017-147258 Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present disclosure is to provide a technology that can improve the accuracy of workpiece recognition. Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0006] A brief summary of representative aspects of this disclosure is as follows. That is, the mounting apparatus includes an illumination system that emits a light amount based on an illumination value, an imaging device that images a workpiece illuminated with light by the illumination system, and a control unit that controls the output of the illumination system and performs image processing on the image captured by the imaging device. When a workpiece recognition error occurs, the control unit is configured to set the illumination value to a predetermined value, capture an image of the workpiece illuminated by the illumination system using the imaging device to obtain an acquired image, search the acquired images to obtain a pattern image that is most similar to the template image, calculate a matching rate between the most similar pattern image and the template image, and change the predetermined value to find the illumination value that maximizes the matching rate. [Effects of the Invention]

[0007] According to the present disclosure, the accuracy of workpiece recognition can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic top view showing an example of the configuration of a die bonder according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating the schematic configuration when viewed from the direction of arrow A in FIG. [Figure 3] FIG. 3 is a block diagram showing a schematic configuration of a control system of the die bonder shown in FIG. [Figure 4] FIG. 4 is a diagram showing an optical system of a wafer supply unit in the die bonder shown in FIG. [Figure 5] FIG. 5 is a diagram showing an example of a unique portion (selected region). [Figure 6] FIG. 6 is a diagram showing examples of a registered image and a similar image. [Figure 7] FIG. 7 is a conceptual diagram illustrating the transfer of recipe data. [Figure 8] FIG. 8 shows an image of a die and an image of a template. [Figure 9]FIG. 9 is a diagram illustrating the inter-pattern distance difference and the inter-pattern angle difference. [Figure 10] FIG. 10 is a diagram showing the relationship between the illumination value and the degree of match in this embodiment. [Figure 11] FIG. 11 is a flowchart for explaining automatic adjustment of illumination values ​​in this embodiment. [Figure 12] FIG. 12 is a flowchart for explaining automatic adjustment of illumination values ​​in this embodiment. [Figure 13] FIG. 13 is a flowchart for explaining automatic adjustment of illumination values ​​in this embodiment. [Figure 14] FIG. 14 is a diagram showing the relationship between the illumination value and the degree of match in the first and second modified examples. [Figure 15] FIG. 15 is a diagram showing the relationship between the illumination value and the degree of coincidence in the third modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments and modifications will be described with reference to the drawings. However, in the following description, the same components will be assigned the same reference numerals, and repeated description may be omitted. Note that, to clarify the description, the drawings may show the width, thickness, shape, etc. of each part more schematically than the actual embodiment, but these are merely examples and do not limit the interpretation of the present invention.

[0010] The configuration of a die bonder, which is an example of a mounting device, will be described with reference to FIGS. 1 and 2. FIG.

[0011] The die bonder 10 is broadly divided into a die supply unit 1, a pickup unit 2, an intermediate stage unit 3, a bonding unit 4, a transport unit 5, a substrate supply unit 6, a substrate unloading unit 7, and a control unit 8 that monitors and controls the operation of each unit. The Y-axis direction is the front-to-back direction of the die bonder 10, and the X-axis direction is the left-to-right direction. The die supply unit 1 is located on the front side of the die bonder 10, and the bonding unit 4 is located on the back side. Here, one or more product areas (hereinafter referred to as package areas P) that will eventually become a single package are printed on the substrate S.

[0012] The die supply unit 1 has a wafer holder 12 that holds a wafer 11, and a push-up unit 13, indicated by a dotted line, that pushes up a die D from the wafer 11. The wafer holder 12 moves in the X and Y directions by a driving means (not shown), and moves the die D to be picked up to the position of the push-up unit 13. The push-up unit 13 moves in the vertical direction by a driving means (not shown). The wafer 11 is adhered to a dicing tape 16 and is divided into multiple dies D. The wafer 11 is held by a wafer ring (not shown). In addition, a film-like adhesive material called a die attach film (DAF) is attached between the wafer 11 and the dicing tape 16.

[0013] The pickup unit 2 has a pickup head 21 that picks up the die D, a pickup head Y drive unit 23 that moves the pickup head 21 in the Y direction, various drive units (not shown) that raise and lower, rotate, and move the collet 22 in the X direction, and a wafer recognition camera 24 that recognizes the posture of the die D on the wafer 11. The pickup head 21 has a collet 22 that suction-holds the pushed-up die D at its tip, picks up the die D from the die supply unit 1, and places it on the intermediate stage 31. The pickup head 21 has various drive units (not shown) that raise and lower, rotate, and move the collet 22 in the X direction.

[0014] The intermediate stage unit 3 has an intermediate stage 31 on which the die D is temporarily placed, and a stage recognition camera 32 for recognizing the die D on the intermediate stage 31.

[0015] The bonding unit 4 includes a bond head 41, a Y-axis drive unit 43, and a substrate recognition camera 44. The bond head 41, like the pickup head 21, includes a collet 42 that suction-holds the die D at its tip. The Y-axis drive unit 43 moves the bond head 41 in the Y-axis direction. The substrate recognition camera 44 captures an image of a position recognition mark (not shown) in the package area P of the substrate S to recognize the bonding position. The bonding unit 4 picks up a die D from the intermediate stage 31 and bonds the die onto the package area P of the substrate S being conveyed, or bonds the die by stacking it on top of a die already bonded onto the package area P of the substrate S. With this configuration, the bond head 41 corrects the pickup position and posture based on the image data captured by the stage recognition camera 32 and picks up the die D from the intermediate stage 31. Then, the bond head 41 bonds the die D onto the package area P of the substrate based on the image data of the substrate recognition camera 44, or by stacking it on top of a die already bonded onto the package area P of the substrate S.

[0016] The transport unit 5 has substrate transport claws 51 that grip and transport the substrate S, and a transport lane 52 along which the substrate S moves. The substrate S moves by driving a nut (not shown) of the substrate transport claws 51 provided on the transport lane 52 with a ball screw (not shown) provided along the transport lane 52. With this configuration, the substrate S moves from the substrate supply unit 6 along the transport lane 52 to the bonding position, and after bonding, moves to the substrate unloading unit 7 and hands the substrate S over to the substrate unloading unit 7.

[0017] Next, the control unit 8 will be described with reference to FIG.

[0018] The control system 80 includes a control unit (control device) 8, a drive unit 86, a signal unit 87, and an optical system 88. The control unit 8 broadly includes a control and arithmetic unit 81 mainly composed of a CPU (Central Processing Unit), a storage device 82, an input / output device 83, a bus line 84, and a power supply unit 85. The storage device 82 includes a main storage device 82a composed of RAM (Random Access Memory) that stores processing programs and the like, and an auxiliary storage device 82b composed of an HDD (Hard Disk Drive), SSD (Solid State Drive), or the like that stores control data, image data, and the like required for control.

[0019] The input / output device 83 includes a monitor 83a that displays the device status and other information, a touch panel 83b that inputs operator instructions, a mouse 83c that operates the monitor, and an image capture device 83d that captures image data from an optical system 88. The input / output device 83 also includes a motor control device 83e that controls a drive unit 86 that includes an XY table (not shown) of the die supply unit 1 and the ZY drive axis of the bond head table, and an I / O signal control device 83f that captures or controls signals from a signal unit 87 that includes various sensors and switches and volumes that control the brightness of the lighting device 26 (described later). The optical system 88 includes a wafer recognition camera 24, a stage recognition camera 32, and a substrate recognition camera 44. The control / arithmetic unit 81 captures and calculates necessary data via a bus line 84, controls the pickup head 21, and sends information to the monitor 83a, etc.

[0020] The control unit 8 stores image data captured by the wafer recognition camera 24, stage recognition camera 32, and substrate recognition camera 44 in the storage device 82 via the image capture device 83d. Based on the stored image data, software is programmed to position the die D and the package area P of the substrate S and inspect the surfaces of the die D and substrate S using the control and calculation device 81. Based on the positions of the package area P of the die D and substrate S calculated by the control and calculation device 81, the software drives the driver 86 via the motor control device 83e. This process positions the die on the wafer, and the driver units of the pickup unit 2 and bonding unit 4 operate to bond the die D onto the package area P of the substrate S. The wafer recognition camera 24, stage recognition camera 32, and substrate recognition camera 44 used digitize light intensity and color. The wafer recognition camera 24, stage recognition camera 32, and substrate recognition camera 44 are also referred to as imaging devices.

[0021] Next, a die bonding step, which is one step in the method for manufacturing a semiconductor device, will be described.

[0022] In the die bonding process of this embodiment, first, a wafer ring incorporating a wafer is prepared and carried into die bonder 10 (P1 process). Control unit 8 places the wafer ring on wafer holder 12 and transports wafer holder 12 to a reference position where die D is picked up (P2 process). Next, substrate S is prepared and carried into die bonder 10 (P3 process). Control unit 8 places substrate S on transport lane 52 in substrate supply unit 6. Control unit 8 moves substrate transport claws 51, which grip and transport substrate S, to a bonding position (P4 process).

[0023] Following the P2 step, the control unit 8 moves the wafer holder 12 on which the wafer 11 is placed at a predetermined pitch and holds it horizontally, thereby placing the die D to be picked up first at the pick-up position (P5 step).

[0024] Following step P5, the control unit 8 photographs the main surface (top surface) of the die D to be picked up using the wafer recognition camera 24, and calculates the amount of positional deviation of the die D to be picked up from the above-mentioned pickup position from the acquired image. Based on this amount of positional deviation, the control unit 8 moves the wafer holder 12 on which the wafer 11 is placed, and accurately positions the die D to be picked up at the pickup position (step P6). Then, the control unit 8 photographs the main surface (top surface) of the die D to be picked up using the wafer recognition camera 24, and performs surface inspection of the die D from the acquired image (step P7).

[0025] Following step P4, the control unit 8 images the board S using the board recognition camera 44 and positions the board S based on the captured image (step P8). Then, the control unit 8 images the board S using the board recognition camera 44 and performs a surface inspection of the package area P of the board S based on the acquired image (step P9).

[0026] Following step P8, the control unit 8 causes the pickup head 21 including the collet 22 to pick up the die D from the dicing tape 16 and place it on the intermediate stage 31 (step P10). Thereafter, the die D are peeled off one by one from the dicing tape 16 according to the same procedure. Once all the dies D except for the defective ones have been picked up, the dicing tape 16 and the wafer ring, etc., which have held the dies D in the outer shape of the wafer 11, are carried out.

[0027] Following step P10, the control unit 8 detects any misalignment of the die placed on the intermediate stage 31 by capturing an image using the stage recognition camera 32. If there is any misalignment, the control unit 8 corrects the misalignment by driving the intermediate stage 31 in a plane parallel to the mounting surface having the mounting position using a drive device (not shown) provided on the intermediate stage 31 (step P11). Then, the control unit 8 captures an image of the die placed on the intermediate stage 31 using the stage recognition camera 32, and performs a surface inspection of the die D from the captured image (step P12).

[0028] Following step P12, the control unit 8 picks up the die D from the intermediate stage 31 using the bond head 41 including the collet 42 and bonds it to the package area P of the substrate S or to a die already bonded to the package area P of the substrate S (step P13).

[0029] Following step P13, after bonding the die D, the control unit 8 inspects the die D and the substrate S by using the substrate recognition camera 44 to check whether the bond position is accurate (step P14). At this time, the center of the die and the center of the tab are determined, and it is inspected whether the relative positions are correct. Then, the control unit 8 images the die D and the substrate S using the substrate recognition camera 44, and performs a surface inspection of the die D and the substrate S from the acquired image (step P15).

[0030] Thereafter, following the same procedure, the dies D are bonded one by one to the package area P of the substrate S. When bonding of one substrate is completed, the substrate S is moved to the substrate unloading section 7 by the substrate transport claws 51, and the substrate S is handed over to the substrate unloading section 7 (process P16). Then, the substrate S is unloaded from the die bonder 10 (process P17).

[0031] As described above, the die D is mounted on the substrate S via the die attach film and then carried out from the die bonder. Thereafter, the die D is electrically connected to the electrodes of the substrate S via Au wires in a wire bonding process. To manufacture a stacked package, the substrate S on which the die D is mounted is then carried into the die bonder, and a second die D is stacked on the die D mounted on the substrate S via the die attach film 18. After being carried out from the die bonder, the second and subsequent dies D are electrically connected to the electrodes of the substrate S via Au wires in a wire bonding process. The second and subsequent dies D are peeled from the dicing tape 16 using the method described above, then carried to a bonding position and stacked on top of the die D. After the above process is repeated a predetermined number of times, the substrate S is carried to a molding process, and the multiple dies D and Au wires are sealed with molding resin (not shown), completing the stacked package.

[0032] Next, the optical system of the pickup unit 2 will be described with reference to FIG.

[0033] An objective lens 25 is attached to the wafer recognition camera 24, and an image of the main surface of the die D is captured through this objective lens 25. An illumination device 26 is disposed between the objective lens 25 and the die D. The illumination light from the surface illumination light 261 is reflected by the half mirror 262 to the same optical axis as the wafer recognition camera 24 and illuminates the die D. The light illuminated onto the die D along the same optical axis as the wafer recognition camera 24 is reflected by the die D, and the specularly reflected light of the light is transmitted through the half mirror 262 to reach the wafer recognition camera 24, forming an image of the die D. In other words, the illumination device 26 functions as a coaxial epi-illumination (coaxial illumination). The illumination device 26 is connected to an output controller 27, which functions as a light control device. The output controller 27 controls the illumination output (light intensity) of the illumination device 26 based on the illumination value (LV) from the control unit 8. The illumination device 26 and the output controller 27 constitute an illumination system.

[0034] The optical system of the intermediate stage section 3 (stage recognition camera 32 and its lighting device) and the optical system of the bonding section 4 (substrate recognition camera 44 and its lighting device) are configured in the same manner as the optical system of the pickup section 2 (wafer recognition camera 24 and lighting device 26).

[0035] Next, a die positioning method will be described with reference to FIGS.

[0036] The die positioning algorithm mainly uses template matching, and is calculated using the commonly known normalized correlation formula. The result is the matching agreement rate (matching score). Template matching can be performed using a tracing operation for reference learning or a continuous starting operation.

[0037] First, the tracing operation will be explained using Figures 5 and 6. The control unit 8 transports the reference sample to the pickup position. The control unit 8 acquires an image PCr of the reference sample using the wafer recognition camera 24. For example, the operator of the die bonder selects at least one unique portion UA ​​as shown in Figure 5 from within the image using a human interface (touch panel 83b or mouse 83c). It is preferable to select multiple unique portions UA. The control unit 8 stores at least one positional relationship (coordinates) between the selected unique portion (selected area) UA and the reference sample in the storage device 82. The control unit 8 stores the image of the selected area UA shown in Figure 5 in the storage device 82 as the template image PT shown in Figure 6. It is preferable to store multiple template images PT. The reference work image and its coordinates are stored in the storage device.

[0038] Next, continuous operation will be explained using FIG. 6. The control unit 8 transports a product wafer as a component for production to a pickup position. The control unit 8 captures an image of the product wafer with the wafer recognition camera 24 and acquires an image PCn of the product die. As shown in FIG. 6, the control unit 8 compares the template image PT saved during the copying operation with the acquired image PCn of the product die, searches for the image PTn of the most similar part, and calculates the coordinates of the searched image PTn. The control unit 8 compares these coordinates with the coordinates measured using the reference sample and calculates the position of the product die (the offset between the image PTn and the template image PT).

[0039] In a manufacturing line, multiple manufacturing machines of the same model are installed, and conditions are set in advance for each product type on one machine, recipe data is created based on the conditions, and the recipe data is then imported to other machines to process under the same conditions. This method minimizes the time required for production startup and enables processing under the same conditions on multiple machines.

[0040] Next, a method of setting conditions in advance in one device (first device) in a manufacturing line and transferring the created recipe data to another device (second device) will be described with reference to FIG.

[0041] The first die bonder 10_1 as the first device and the second die bonder 10_2 as the second device have the same configuration as the die bonder 10. A wafer recognition camera 24 and an illumination device 26 are mounted on the die bonders 10_1 and 10_2.

[0042] The images used for die positioning, as described above, as well as image-related parameters, coordinates, lighting values ​​(LV), etc. are stored for each product type as a group of recipe data for starting the manufacturing of each product. This group of data is called recipe data (RCP).

[0043] Methods for transferring recipe data (RCP) between devices include using an external storage medium 28 such as a USB memory or CD-ROM, connecting devices via a communication means such as a wired LAN or wireless LAN, and connecting the first die bonder 10_1 and the second die bonder 10_2 via a wired LAN or wireless LAN via a host computer.

[0044] It is assumed that the control unit 8 creates recipe data (RCP) in the first die bonder 10_1, and the created recipe data (RCP) is transferred to the second die bonder 10_2. The transferred recipe data (RCP) includes a template image PT, coordinate data, illumination value (LV), etc., which are used for template matching obtained by the above-mentioned tracing operation.

[0045] The control unit 8 of the second die bonder 10_2 illuminates the product using an illumination device 26 or the like based on the illumination value (LV) of the recipe data (RCP) received from the first die bonder 10_1, and captures an image of the product to which the transferred recipe data (RCP) is applied using a wafer recognition camera 24 or the like of the second die bonder 10_2. At this time, if the illumination value (LV) of the recipe data (RCP) is not an optimal illumination value, the second die bonder 10_2 may not be able to obtain an image similar to that of the first die bonder 10_1. Furthermore, even if the illumination value (LV) of the recipe data (RCP) is an optimal illumination value (LV), the second die bonder 10_2 may not be able to obtain an image similar to that of the first die bonder 10_1 due to differences in the illumination systems, cameras, and lenses of the first die bonder 10_1 and the second die bonder 10_2. For example, as shown in Figure 7, the lighting output of the lighting system may differ from one another, causing the product to appear differently, resulting in a recognition error (the image may not be clear enough for accurate recognition).

[0046] In other words, when template matching processing is performed by the control unit 8 of the second die bonder 10_2 using the transplanted recipe data, these machine differences may cause a decrease in the matching rate even for similar products, reducing durability (robustness) against unexpected changes in the production process and causing a case where image algorithms such as die positioning cannot be processed normally. If the matching rate falls below a predetermined value, a recognition error is detected. This predetermined value is, for example, 70 to 80%.

[0047] Furthermore, the control unit 8 of the first die bonder 10_1 illuminates the product using the illumination device 26 or the like based on the illumination value (LV) of the recipe data (RCP), and repeatedly captures images of the same product using the wafer recognition camera 24 or the like. If the number of repetitions increases, the first die bonder 10_1 may not be able to capture the same image as before due to deterioration over time of the illumination device 26 or the like of the first die bonder 10_1. For example, a change in illumination output may cause the product to appear differently, resulting in a recognition error. In other words, when template matching processing is performed using the first die bonder 10_1 using the recipe data (RCP), even for similar products, the matching agreement rate may decrease due to changes in illumination output, etc., and a recognition error may occur.

[0048] In order to deal with such problems in the optical system including the illumination system (illumination device), an outline of a method for determining the optimum illumination value will be explained with reference to FIGS.

[0049] When the control unit 8 performs the above-mentioned continuous operation in the second die bonder 10_2 to which the recipe data (RCP) is transferred or the first die bonder 10_1 that has undergone a change over time (hereinafter referred to as the adjustment target device), if a die recognition error occurs, the following processing is performed. Also, if the lighting device 26 or the like of the second die bonder 10_2 that has undergone the following processing undergoes a change over time and a die recognition error occurs, the following processing is performed. It may be performed when no recognition error occurs (before the recognition error occurs).

[0050] 8, two images of the template image PT included in the recipe data (RCP) are referred to as template images A1 and A2. Also, a product image captured by the wafer recognition camera 24 in the apparatus to be adjusted is referred to as acquired image B. Of acquired image B, two images most similar to template images A1 and A2 are referred to as pattern images C1 and C2. Pattern images C1 and C2 are collectively referred to as pattern image C.

[0051] The matching rate (hereinafter referred to as the matching rate (MR)) between the pattern image C and the template image PT is, for example, the average value of the matching rate (MR1) between the first pattern image C1 and the first template image A1 and the matching rate (MR2) between the second pattern image C2 and the second template image A2.

[0052] The control unit 8 of the device to be adjusted recognizes the die while changing the illumination value (LV) and searches for the illumination value (LVm) that provides the highest degree of match. If there are multiple illumination values ​​(LVm) that provide the highest degree of match, the one with the smallest inter-pattern distance difference (PD) is adopted. Here, the inter-pattern distance difference (PD) is the difference between the distance (dA) between the first template image A1 and the second template image A2 and the distance (dC) between the first pattern image C1 and the second pattern image C2, as shown in FIG. 9. If there are multiple illumination values ​​(LVm) that provide the highest degree of match and the inter-pattern distance difference (PD) is the same, the one with the smallest inter-pattern angle difference (PA) is adopted. Here, the inter-pattern angle difference (PA) is the difference between the angle (θA) of the line connecting the first template image A1 and the second template image A2 and the angle (θC) of the line connecting the first pattern image C1 and the second pattern image C2, as shown in FIG. 9.

[0053] Then, the control unit 8 determines the illumination value (LVm) that gives the highest degree of match as the optimum illumination value, and sets the optimum illumination value as the illumination value (LV) of the recipe data.

[0054] The method for automatically adjusting the illumination value will be described in detail with reference to FIGS.

[0055] As shown in FIG. 10, the control unit 8 searches for the illumination value (LVm) that maximizes the degree of match between the pattern image C and the template image PT by increasing the illumination value (LV) in increments of a predetermined check interval (CI) within a predetermined range (SR). Here, the predetermined range (SR) is from the minimum illumination value (LVmin) to the maximum illumination value (LVmax). The illumination value (LV) has 256 gradations from 0 to 255, for example (LVmin = 0, LVmax = 255). CI = 1. The degree of match at the illumination value (LVm) that maximizes the degree of match is referred to as MRm. Alternatively, the control unit 8 may search for the illumination value (LVm) that maximizes the degree of match between the pattern image C and the template image PT by decreasing the illumination value (LV) in increments of a predetermined value from the maximum illumination value (LVmax) to the minimum illumination value (LVmin). Furthermore, the predetermined range (SR) may not be between the minimum illumination value (LVmin) and the maximum illumination value (LVmax), but may be between an illumination value greater than the minimum illumination value (LVmin) and an illumination value less than the maximum illumination value (LVmax).

[0056] The control unit 8 starts automatic adjustment of the illumination value for die recognition (START) as shown in Fig. 11. First, the control unit 8 changes the illumination value (LV) to the check illumination value (CLV) (step S21). The check illumination value (CLV) is a variable for storing the illumination value (LV) currently being checked. Here, the initial value of the check illumination value (CLV) is 0.

[0057] Next, the control unit 8 presets (sets) the imaging conditions of the wafer recognition camera 24 (step S22).

[0058] Next, the control unit 8 causes the wafer recognition camera 24 to capture an image of the die, and acquires the captured image (acquired image B) (step S23).

[0059] Next, the control unit 8 recognizes the die from the acquired image B (step S24). That is, the control unit 8 searches for the pattern image C that is most similar to the template image PT, and calculates the degree of match (MR) between the pattern image C and the template image PT. The control unit 8 further calculates the inter-pattern distance difference (PD) and the inter-pattern angle difference (PA). Here, the inter-pattern distance difference (PD) is also called the rational distance measurement value (RD), and the inter-pattern angle difference (PA) is also called the rational angle measurement value (RA). In this step, a recognition error is prevented from occurring even if the degree of match (MR) is low.

[0060] Next, the control unit 8 acquires the die recognition result (step S25). That is, the control unit 8 stores the degree of match (MR), the inter-pattern distance difference (PD), and the inter-pattern angle difference (PA) in the storage device 82. Then, the process proceeds to step S26 shown in FIG.

[0061] 12, the control unit 8 determines whether there is any problem with the die recognition result (step S26). Here, if there is no problem with the recognition result, it is called the recognition result OK. In other words, the control unit 8 determines whether the degree of match (MR) is equal to or greater than a predetermined value (MRt).

[0062] If the judgment condition in step S26 is met (YES), the control unit 8 judges whether the degree of match (MR) is higher than the degree of match (MRh) stored in the high score structure (HS) (step S27). Here, the high score structure (HS) is a structure for storing data of the illumination value (LVm) that results in the highest degree of match, and the contents of the structure are the illumination value (LVh), the degree of match (MRh), the measured value of rationality distance (RDh), and the measured value of rationality angle (RAh). The initial value of the degree of match (MRh) is 0.

[0063] If the determination condition in step S27 is met (YES), the control unit 8 stores the data in the high score structure (HS) (step S28). The control unit 8 stores the MR, RD, and RA calculated in step S24 in MRh, RDh, and RAh. The control unit 8 stores the LV set in step S21 in LVh. Then, the control unit 8 proceeds to step S35 shown in FIG. 13.

[0064] If the determination condition in step S27 is not met (NO), the control unit 8 determines whether the matching degree (MR) is the same as the matching degree (MRh) stored in the high score structure (HS) (step S29).

[0065] If the judgment condition in step S29 is met (YES), the control unit 8 determines whether the rationality distance measurement value (MD) calculated in step S24 is smaller than the rationality distance measurement value (MDh) stored in the high score structure (HS) (step S30).

[0066] If the determination condition in step S30 is met (YES), the control unit 8 stores the data in the high score structure (step S31). The control unit 8 stores the MR, RD, and RA calculated in step S24 in MRh, RDh, and RAh. Then, the control unit 8 proceeds to step S35 shown in FIG. 17.

[0067] If the judgment condition in step S30 is not met (NO), the control unit 8 determines whether the rationality distance measurement value (MD) calculated in step S24 is the same as the rationality distance measurement value (MDh) stored in the high score structure (HS) (step S32).

[0068] If the judgment condition in step S32 is met (YES), the control unit 8 determines whether the measurement value (MA) of the rationality angle calculated in step S24 is less than or equal to the measurement value (MAh) of the rationality angle stored in the high score structure (HS) (step S33).

[0069] If the determination condition in step S33 is met (YES), the control unit 8 stores the data in the high score structure (step S34). The control unit 8 stores the MR, RD, and RA calculated in step S24 in MRh, RDh, and RAh. Then, the control unit 8 proceeds to step S35 shown in FIG. 17.

[0070] If the judgment conditions in step S26 are not met (NO), if the judgment conditions in step S29 are not met (NO), if the judgment conditions in step S32 are not met (NO), and if the judgment conditions in step S33 are not met (NO), the control unit 8 proceeds to step S35 shown in Figure 13.

[0071] 13, the control unit 8 determines whether the check illumination value (CLV)≧the maximum illumination value (LVmax) (step S35), where LVmax=255.

[0072] If the determination condition in step S35 is not satisfied (NO), the control unit 8 adds the check interval (CI) to the check illumination value (CLV) (CLV←CLV+CI) (step S36).

[0073] Subsequently, the control unit 8 determines whether the check illumination value (CLV) is greater than the maximum illumination value (LVmax) (step S37).

[0074] If the determination condition in step S37 is satisfied (YES), the control unit 8 sets the check illumination value (CLV) to the maximum illumination value (LVmax) (step S38), and then the control unit 8 returns to step S21 shown in FIG.

[0075] If the determination condition in step S37 is not satisfied (NO), the control unit 8 returns to step S21 shown in FIG.

[0076] If the determination condition in step S35 is met (YES), the control unit 8 determines whether or not there is one or more recognition results that are OK (JDG) (step S39).

[0077] If the determination conditions in step S39 are met (YES), the control unit 8 determines that the automatic adjustment result is successful (automatic adjustment result OK) (step S40). The control unit 8 may display the automatic adjustment result OK on the monitor 83a. Then, the automatic adjustment of the illumination value for die recognition is completed (END).

[0078] If the determination condition in step S39 is not met (NO), the control unit 8 determines that the automatic adjustment result is a failure (automatic adjustment result NG) (step S41). The control unit 8 may display the automatic adjustment result NG on the monitor 83a. Then, the automatic adjustment of the illumination value for die recognition is terminated (END).

[0079] According to the embodiment, one or more of the following advantages can be obtained.

[0080] (1) Even if a recognition error occurs due to the lighting value, the lighting value can be automatically adjusted by the control unit, eliminating the need for manual adjustment by performing die recognition again. This eliminates the need to measure the light intensity using an illuminance meter (light quantity meter) installed on the workpiece or adjust the lighting output by capturing the reflected light from a reflective jig installed on the workpiece with a camera. This reduces the downtime of production equipment (die bonders, etc.), thereby improving the productivity of the production equipment.

[0081] (2) The system searches for lighting values ​​that provide a high degree of match using actual parts (workpieces) and equipment (lighting systems, cameras, lenses, etc.), making it possible to determine the optimal lighting values ​​for those parts and equipment. This allows production to be carried out with optimal brightness, improving the quality and reliability of production equipment.

[0082] (3) Since manual adjustment is no longer necessary, differences between operators are eliminated, and variations due to human factors are eliminated, allowing optimal lighting values ​​to be set.

[0083] (4) Because the lighting value recipe can be automatically generated, the lighting value of the recipe data created by another production device can be changed to the optimal lighting value for each production device.

[0084] (5) The lighting value recipe can be automatically generated, reducing variations between production devices.

[0085] <Modification> Below, several representative modified examples of the embodiment are given. In the following description of the modified examples, the same reference numerals as those in the above-described embodiment may be used for parts having the same configurations and functions as those described in the above-described embodiment. Furthermore, the description of such parts may be appropriately cited within the scope of not being technically inconsistent. Furthermore, a part of the above-described embodiment and all or part of the multiple modified examples may be appropriately applied in a composite manner within the scope of not being technically inconsistent.

[0086] (First Modification) A method for automatically adjusting the illumination value in the first modified example will be described with reference to Fig. 14. The black circles "●" shown in Fig. 14 indicate search locations.

[0087] In the embodiment, the control unit 8 recognizes the illumination value (LV) by increasing it by one within a predetermined range (SR) and searches for the illumination value (LVm) that maximizes the degree of match between the template image PT and the pattern image C. As shown in the upper graph of FIG. 14 , the control unit 8 in the first modified example is configured to search for the illumination value (LV) within the predetermined range (SR) from the minimum illumination value (LVmin) to the maximum illumination value (LVmax) while leaving a predetermined check interval (CI). In other words, the control unit 8 is configured to search for the illumination value (LV) from the minimum illumination value (LVmin) to the maximum illumination value (LVmax) while increasing the check interval (CI) by a predetermined value. The check interval (CI) is configurable. The first modified example has a faster search speed than the embodiment. Alternatively, the illumination value (LV) may be searched from the maximum illumination value (LVmax) to the minimum illumination value (LVmin) while leaving a predetermined interval. In addition, instead of searching between the minimum illumination value (LVmin) and the maximum illumination value (LVmax), the search may be performed between an illumination value greater than the minimum illumination value (LVmin) and an illumination value smaller than the maximum illumination value (LVmax).

[0088] (Second Modification) A method for automatically adjusting the illumination value in the second modified example will be described with reference to FIG.

[0089] As shown in the upper graph of FIG. 14, the control unit 8 in the second modified example searches the illumination value (LV) from the minimum illumination value (LVmin) to the maximum illumination value (LVmax) at predetermined check intervals (CI), as in the first modified example. The control unit 8 then obtains the illumination value (LVm) with the highest degree of match. The control unit 8 then searches around the illumination value (LVm) with the highest degree of match shown in the upper graph of FIG. 14, i.e., within a predetermined range (LVs to LVe) including LVm, while increasing the illumination value (LV) by 1, as shown in the lower graph of FIG. 14. Here, LVs = LVm - CI and LVe = LVm + CI, where LVm and CI are shown in the upper graph of FIG. 14. The control unit 8 sets the initial illumination value (LV) to LVs and the maximum illumination value (LVmax) to LVe, and executes the process according to the flowcharts shown in FIGS. 11 to 13. The second modified example has a faster search speed than the embodiment, and can achieve the same level of accuracy as the embodiment. Note that the search may be performed while decreasing the illumination value (LV) by one within a predetermined range (LVs to LVe).

[0090] (Third Modification) A method for automatically adjusting illumination values ​​in the third modified example will be described with reference to Fig. 15. The black circles "●" shown in Fig. 15 indicate search locations.

[0091] In the third modified example, the control unit 8 obtains the currently registered illumination value (LVr) with the highest degree of match, as shown in the upper graph of FIG. 15. Here, the currently registered illumination value (LVr) with the highest degree of match is, for example, the illumination value included in the imported recipe data RCP, or the illumination value set before the recognition error occurred. Then, as in the second modified example, the control unit 8 searches around the illumination value (LVr) with the highest degree of match shown in the upper graph of FIG. 15, i.e., within a predetermined range (LVs to LVe) including LVr, while increasing the illumination value (LV) by 1, as shown in the lower graph of FIG. 15. Here, LVs = LVr - SI and LVe = LVr + SI, and SI may be in the same range as CI shown in FIG. 14 or may be in a range larger than CI shown in FIG. 14. The third modified example has a faster search speed than the embodiment, and can obtain the same level of accuracy as the embodiment. The search may be performed while decreasing the illumination value (LV) by 1 within the predetermined range (LVs to LVe).

[0092] The invention made by the present inventors has been specifically described above based on embodiments and modifications, but it goes without saying that the present disclosure is not limited to the above embodiments and modifications, and various modifications are possible.

[0093] For example, in the embodiment, an example has been described in which two template images A1 and A2 and two pattern images C1 and C2 are used, but the number of each of the template image and the pattern image may be one, or three or more.

[0094] In addition, although the embodiment has been described using the example of die recognition in the die supply unit, the present invention can also be applied to die recognition in the intermediate stage unit, recognition of the substrate before bonding, recognition of the die and substrate after bonding, recognition of the die or collet by an undervision camera, etc. Note that the illumination value for recognizing the die and substrate after bonding is determined to be the optimum value for the die.

[0095] Furthermore, although the embodiment has been described taking the coaxial illumination as an example, the illumination device may be an oblique ring illumination, an oblique bar illumination, or a combination of the coaxial illumination and these.

[0096] Furthermore, in the embodiment, die appearance inspection recognition is performed after die position recognition, but die position recognition may be performed after die appearance inspection recognition.

[0097] Furthermore, although a DAF is attached to the back surface of the wafer in the embodiment, the DAF may be omitted.

[0098] In addition, although the embodiment includes one pickup head and one bonding head, there may be two or more of each. Also, although the embodiment includes an intermediate stage, there may be no intermediate stage. In this case, the pickup head and bonding head may be combined.

[0099] In addition, although bonding is performed with the front side of the die facing up in the embodiment, it is also possible to flip the die over after picking it up and bond it with the back side facing up. In this case, there is no need to provide an intermediate stage. This device is called a flip-chip bonder.

[0100] Furthermore, although the embodiment has been described with reference to a semiconductor manufacturing device, the present invention can also be applied to a mounting device that mounts electronic components on a printed circuit board. [Explanation of symbols]

[0101] 8. Control section 24 Wafer recognition camera (imaging device) C···Pattern image D···Die (Work) PT···Template Image

Claims

1. an illumination system that emits an amount of light based on an illumination value; an imaging device that images a workpiece illuminated with light by the illumination system; a control unit configured to control the output of the lighting system based on the illumination value and to perform image processing of an image captured by the imaging device; Equipped with The control unit setting the illumination value to a first predetermined value, and capturing an image of the workpiece illuminated by the illumination system using the imaging device; Searching the acquired image to acquire a pattern image that is most similar to the template image; calculating a matching rate between the most similar pattern image and the template image; The first predetermined value is changed within a predetermined range to determine an illumination value that maximizes the matching rate, the template image includes a first template image and a second template image; the pattern image includes a first pattern image and a second pattern image; The control unit calculating an inter-pattern distance difference that is the difference between a first distance that is the distance between the first template image and the second template image and a second distance that is the distance between the first pattern image and the second pattern image; When there are multiple illumination values ​​that result in the highest matching coincidence rate, the mounting device is configured to be able to adopt the illumination value that results in the smaller inter-pattern distance difference.

2. 2. The mounting device of claim 1, A mounting apparatus, wherein the matching agreement rate is an average value of the matching rate between the first template image and the first pattern image and the matching rate between the second template image and the second pattern image.

3. 2. The mounting device of claim 1, The control unit calculating an inter-pattern angle difference that is the difference between a first angle that is the angle of a line connecting the first template image and the second template image and a second angle that is the angle of a line connecting the first pattern image and the second pattern image; A mounting apparatus configured to adopt an illumination value that results in a smaller inter-pattern angle difference when the inter-pattern distance difference is the same.

4. In the mounting device of claim 3, The control unit is configured to increase or decrease the first predetermined value by a second predetermined value to find an illumination value that maximizes the matching agreement rate.

5. The mounting device according to claim 4, The predetermined range is from the minimum value to the maximum value of the illumination value, and the second predetermined value is one check interval.

6. The mounting device according to claim 4, The predetermined range is from the minimum value to the maximum value of the illumination value, and the second predetermined value is equal to or greater than two check intervals.

7. 7. The mounting device of claim 6, increasing or decreasing the first predetermined value by the second predetermined value, and determining the illumination value at which the obtained matching coincidence rate is highest as the predetermined illumination value; a second predetermined range is set between an illumination value obtained by subtracting the second predetermined value from the predetermined illumination value and an illumination value obtained by adding the second predetermined value to the predetermined illumination value; The control unit is configured to increase or decrease the first predetermined value by one check interval within the second predetermined range to find the illumination value that maximizes the matching agreement rate.

8. In the mounting device of claim 3, The lighting value included in the imported recipe or used at the time of production is used as the predetermined lighting value, The control unit is configured to increase or decrease the first predetermined value by one check interval within a second predetermined range including the predetermined illumination value, thereby determining the illumination value that maximizes the matching agreement rate.

9. A lighting system that emits a light amount based on an illumination value; an imaging device that images a workpiece illuminated with light by the illumination system; a control unit configured to control the output of the lighting system based on the illumination value and to perform image processing of an image captured by the imaging device; Equipped with The control unit setting the illumination value to a first predetermined value, and capturing an image of the workpiece illuminated by the illumination system using the imaging device; Searching the acquired image to acquire a pattern image that is most similar to the template image; calculating a matching rate between the most similar pattern image and the template image; changing the first predetermined value within a predetermined range to find an illumination value that maximizes the matching coincidence rate; recipe data including the template image and coordinate data of the template image; The mounting apparatus is configured to be able to store the illumination value that results in the highest matching coincidence rate as an optimal illumination value in the recipe data.

10. 1. A method for adjusting an illumination system in an apparatus including an illumination system that emits a light amount based on an illumination value and an imaging device that images a workpiece illuminated with light by the illumination system, comprising: a carrying-in step of carrying in the workpiece; a recognition step of recognizing the workpiece by the imaging device; Including, The recognition step includes: setting an illumination value to a predetermined value, and capturing an image of the workpiece illuminated by the illumination system using the imaging device; Searching the acquired image to acquire a pattern image that is most similar to the template image; calculating a matching rate between the most similar pattern image and the template image; changing the predetermined value to find an illumination value that maximizes the matching rate; the template image includes a first template image and a second template image; the pattern image includes a first pattern image and a second pattern image; The recognition step includes: calculating an inter-pattern distance difference that is the difference between a first distance that is the distance between the first template image and the second template image and a second distance that is the distance between the first pattern image and the second pattern image; When there are multiple illumination values ​​that result in the highest matching coincidence rate, the illumination value that results in the smallest inter-pattern distance difference is adopted.

11. a carrying-in process of carrying a workpiece into a semiconductor manufacturing apparatus including an illumination system that emits light in an amount based on an illumination value and an imaging device that images the workpiece illuminated by the illumination system; a recognition step of recognizing the workpiece by the imaging device; Including, The recognition step includes: setting an illumination value to a predetermined value, and capturing an image of the workpiece illuminated by the illumination system using the imaging device; Searching the acquired image to acquire a pattern image that is most similar to the template image; calculating a matching rate between the most similar pattern image and the template image; changing the predetermined value to find an illumination value that maximizes the matching rate; the template image includes a first template image and a second template image; the pattern image includes a first pattern image and a second pattern image; The recognition step includes: calculating an inter-pattern distance difference that is the difference between a first distance that is the distance between the first template image and the second template image and a second distance that is the distance between the first pattern image and the second pattern image; When there are a plurality of illumination values ​​that result in the highest matching coincidence rate, the illumination value that results in the smallest inter-pattern distance difference is adopted.

Images