TWI725498B - Die-bonding device and manufacturing method of semiconductor device - Google Patents

Abstract

The subject of the present invention is to provide a technique that can reduce the defect rate of products in the joining process. The solution is that the die-bonding device is equipped with: In order to perform positioning and appearance inspection of the die or substrate, an imaging device that captures the aforementioned die or substrate; and Control the control unit of the aforementioned imaging device. The control unit uses the imaging device to capture a plurality of the crystal grains or the substrate, and averages the shade values of the pixels of the captured images to generate an averaged image, and generates a threshold based on the averaged image The binary image of the value is determined based on the Blob (binary large object) Labeling of the binary image, and the surface inspection is performed.

Description

Die bonding device and manufacturing method of semiconductor device

This case is about the die bonding device, for example, it can be applied to the die bonding device with visual inspection function.

As part of the manufacturing process of semiconductor devices, there is a process of mounting a semiconductor chip (hereinafter referred to as a die) on a wiring board or a lead frame (hereinafter referred to as a substrate) to be assembled and packaged, and part of the process of assembling and packaging includes a semiconductor wafer ( Hereinafter referred to as wafer) to divide (dicing) the die, and to mount the divided die on the substrate. The manufacturing equipment used in the bonding process is a die bonder and other die bonder.

The die bonding device is a device in which solder, gold plating, and resin are used as bonding materials to bond (mount and bond) the die on the substrate or the die that has been bonded. In a die bonder that bonds die, for example, to the surface of a substrate, a suction nozzle called a chuck is used to suck and pick up the die from the wafer, transport it to the substrate, apply thrust, and heat the bonding material. The action (work) for joining will be repeated. [Prior Technical Literature] [Patent Literature]

[Patent Document 1] JP 2008-98348 A

(The problem to be solved by the invention)

When dicing a wafer to produce a die, due to cutting resistance during dicing, etc., cracks or damage may occur in the die extending from the cross section to the inside of the die. In addition, foreign matter may adhere due to residual paste from the polishing tape attached to the surface of the wafer. In addition, foreign matter adhering to the die may also be attached to other die via the chuck. That is, the adhesion of foreign matter etc. occurs before and during the joining process. The subject of this case is to provide a technology that can reduce the defect rate of products in the joining process. Other issues and novel features can be clearly understood from the description of this explanatory drawing and the accompanying drawings. (Means to solve the problem)

A brief description of the representative persons in this case is as follows. That is, the die bonding device is equipped with: An imaging device that captures the aforementioned die or the aforementioned substrate in order to perform positioning and appearance inspection of the die or substrate; and The control unit controls the aforementioned imaging device. The control unit uses the imaging device to capture a plurality of the crystal grains or the substrate, and averages the shade values of the pixels of the captured images to generate an averaged image, and generates an averaged image based on the averaged image. For the binary image of the threshold value, the presence or absence of an abnormality is determined based on the binary large object mark of the above-mentioned binary image, and the surface inspection is performed. [Effects of the invention]

According to the above-mentioned die bonding device, the defect rate of products in the joining process can be reduced.

In the die bonding device of the embodiment, the surface inspection of the die and the substrate is performed before the die bonding, and the surface inspection of the die and the substrate is performed after the die bonding. In this way, the defective rate of products can be reduced. The die bonding device of other embodiments improves the sensitivity of the surface inspection of the die and/or the substrate. In this way, the defective rate of products can be reduced.

Hereinafter, examples and comparative examples will be described with reference to the drawings. However, in the following description, the same constituent elements are given the same reference numerals, and overlapping descriptions may be omitted. In addition, in order to make the description clearer, the drawings sometimes schematically show the width, thickness, shape, etc. of each part compared to the actual form, but after all, it is only an example and does not limit the interpreter of the present invention. [Example]

Fig. 1 is a schematic top view of the die bonder of the embodiment. Fig. 2 is a diagram illustrating the operation of the pickup head and the bonding head when viewed from the direction of arrow A in Fig. 1.

The die bonder 10 is roughly divided into: die supply unit 1, pickup unit 2, intermediate platform unit 3, bonding unit 4, conveying unit 5, substrate supply unit 6, substrate delivery unit 7, and a control unit that monitors and controls the actions of each unit 8. The Y-axis direction is the front-rear direction of the die bonder 10, and the X-axis direction is the left-right direction. The die supply part 1 will be arranged on the front side of the die bonder 10, and the bonding part 4 will be arranged on the inside.

First, the die supply unit 1 supplies die D mounted on the substrate P. The die supply unit 1 includes a wafer holding table 12 that holds a wafer 11, and an ejection unit 13 shown by dotted lines that ejects the die D from the wafer 11. The die supply unit 1 is moved in the XY direction by a driving means not shown, and the picked up die D is moved to the position of the jacking unit 13.

The pickup part 2 has: Pickup head 21 for picking up die D; The Y driving part 23 of the pickup head that moves the pickup head 21 in the Y direction; and Each drive part not shown in figure which raises, lowers, rotates, and moves the chuck 22 in the X direction. The pick-up head 21 has a chuck 22 (also refer to FIG. 2) for sucking and holding the raised die D at the front end, and picks up the die D from the die supply unit 1 and places it on the intermediate platform 31. The pick-up head 21 has each drive part which is not shown in figure which raises and lowers, rotates, and moves the chuck 22 in the X direction.

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

The bonding part 4 picks up the die D from the intermediate stage 31 and joins it on the substrate P being transported, or joins in the form of being laminated on the die bonded on the substrate P. The joint 4 has: The bonding head 41 is provided with a chuck 42 that sucks and holds the die D at the front end similarly to the pick-up head 21 (refer also to FIG. 2); Y driving part 43, which moves the bonding head 41 in the Y direction; and The substrate recognition camera 44 picks up the position recognition mark (not shown) of the substrate P and recognizes the bonding position. With such a configuration, the bonding head 41 corrects the pickup position and posture based on the imaging data of the platform recognition camera 32, picks up the die D from the intermediate platform 31, and bonds the die D to the substrate based on the imaging data of the substrate recognition camera 44 P.

The transport section 5 is provided with: a substrate transport tray 51 on which one or a plurality of substrates P (four in FIG. 1) are placed, and a tray rail 52 on which the substrate transport tray 51 moves. The first having the same structure is provided in parallel. , The second conveying department. The substrate transport tray 51 is moved by a ball screw (not shown) provided along the tray rail 52 to drive a nut (not shown) provided on the substrate transport tray 51. With such a configuration, the substrate transport tray 51 places the substrate P on the substrate supply section 6, moves to the bonding position along the tray rail 52, and after bonding, moves to the substrate unloading section 7, and delivers the substrate P to the substrate unloading section 7. The first and second conveying parts are driven independently of each other. While the die D is bonded to the substrate P placed on one of the substrate conveying trays 51, the other substrate conveying tray 51 conveys the substrate P and returns to the substrate. The supply unit 6 prepares for placing a new substrate P and the like.

Next, the structure of the crystal grain supply unit 1 will be described with reference to FIGS. 3 and 4. Fig. 3 is an external perspective view showing the configuration of a crystal grain supply unit. Fig. 4 is a schematic cross-sectional view showing a main part of a crystal grain supply part.

The die supply unit 1 includes a wafer holding table 12 that moves in the horizontal direction (XY direction), and a jack-up unit 13 that moves in the vertical direction. The wafer holding table 12 has: The expansion ring 15 holding the wafer ring 14; and The dicing tape 16 held on the wafer ring 14 with plural dies D adhered is positioned on the horizontal support ring 17. The jacking unit 13 is arranged inside the support ring 17.

The die supply unit 1 lowers the expansion ring 15 holding the wafer ring 14 when the die D is pushed up. As a result, the dicing tape 16 held on the wafer ring 14 will be stretched, and the spacing of the die D will be enlarged. The lifting unit 13 lifts the die D from below the die D, so that the pick-up of the die D is improved. Promote. A film-like adhesive material called a die attach film (DAF) 18 is attached between the wafer 11 and the dicing tape 16. In the wafer 11 having the die attach film 18, dicing is performed on the wafer 11 and the die attach film 18. Therefore, in the peeling process, the wafer 11 and the die attach film 18 are peeled from the dicing tape 16.

The die bonding machine 10 has: Wafer recognition camera 24 for recognizing the posture of die D on wafer 11; A platform recognition camera 32 that recognizes the posture of the die D placed on the intermediate platform 31; and The board recognition camera 44 recognizes the mounting position on the bonding platform BS. It is necessary to correct the posture deviation between the recognition cameras to be the platform recognition camera 32 that participates in the pickup of the bonding head 41 and the substrate recognition camera 44 that participates in the bonding of the bonding head 41 toward the mounting position. In this embodiment, the wafer recognition camera (first imaging device) 24 is used to detect the damage or foreign matter of the die D, and the substrate recognition camera (second imaging device) 44 is used to detect the substrate P and the bonded substrate P Grain damage or foreign matter.

Use Figure 5 to explain the control system. Fig. 5 is a block diagram showing a schematic configuration of a control system of the die bonder of Fig. 1. The control system 80 includes a control unit 8, a drive unit 86, a signal unit 87 and an optical system 88. The control unit 8 is roughly different and mainly includes: a control and arithmetic device 81 composed of a CPU (Central Processor Unit), a memory device 82, an input/output device 83, a bus line 84, and a power supply unit 85. The storage device 82 is a main storage device 82a composed of RAM for storing processing programs and the like, and an auxiliary storage device 82b composed of HDD for storing control data or image data necessary for control. The input/output device 83 has: a monitor 83a for displaying device status or information, a touch panel 83b for inputting instructions from an operator, a mouse 83c for operating the monitor, and an image capture for capturing image data from the optical system 88入装置83d. In addition, the I/O device 83 is a motor control device 83e having a drive unit 86 such as an XY stage (not shown) that controls the die supply unit 1 or a ZY drive shaft of the bonding head stage, and various sensors are taken in. A signal or an I/O signal control device 83f that takes in a signal or controls it from a signal unit 87 such as a switch of a lighting device or the like. The optical system 88 includes a wafer recognition camera 24, a table recognition camera 32, and a substrate recognition camera 44. The control/calculating device 81 takes in necessary data via the bus line 84, calculates, and transmits the information to the control of the pickup 21 and the like, or the monitor 83a and the like.

The control unit 8 stores the image data captured by the wafer recognition camera 24 and the substrate recognition camera 44 in the memory device 82 via the image capturing device 83d. According to the saved image data, the positioning of the die D and the substrate P is performed by using the control and arithmetic device 81 through programmed software. Based on the positions of the die D and the substrate P calculated by the control and arithmetic device 81, the drive unit 86 is actuated via the motor control device 83e by software. According to this process, the positioning of the die on the wafer is performed, and the driving part of the pickup part 2 and the bonding part 4 are operated to bond the die D to the substrate P. The wafer recognition camera 24 and the substrate recognition camera 44 used are gray scale, color, etc., to digitize the light intensity.

Next, the wafer identification camera will be explained using FIG. 6. 6 is a diagram for explaining the optical system of the wafer supply unit, showing the arrangement of the illumination unit that irradiates the light for image shooting to the wafer recognition camera and the die to be picked up. The platform recognition camera 32 and the substrate recognition camera 44 are the same as the wafer recognition camera 24. The imaging unit ID of the wafer recognition camera 24 is connected to one end of the lens barrel BT, and an objective lens (not shown) is mounted on the other end of the lens barrel BT. The composition of the face portrait. Between the lens barrel BT and the die D on the line connecting the imaging unit ID and the die D, an illuminating unit LD having a surface emitting illumination (light source) SL and a half mirror (semi-transmissive mirror) HM inside is arranged. The irradiated light from the surface-emission illumination SL is reflected by the half mirror HM on the same optical axis as the imaging unit ID, and is irradiated to the die D. The scattered light irradiated to the die D with the same optical axis as the imaging unit ID is reflected by the die D, and the specularly reflected light passes through the half mirror HM to reach the imaging unit ID, forming an image of the die D. That is, the illuminating unit LD has a function of coaxial epi-illumination (coaxial illumination).

The lighting system is not limited to coaxial lighting, but can also be dome lighting, oblique light ring lighting, oblique light strip lighting, transparent lighting, etc. It is also possible to construct a system with a plurality of combinations of these lighting according to the subject. The color of the light source is white, etc. in addition to a single color. The light source can be adjusted by linear change, for example, the light quantity can be adjusted by the pulse dimming load of LED.

FIG. 7 is a flowchart illustrating the die bonding process of the semiconductor manufacturing apparatus of the embodiment. Fig. 8 is a flowchart illustrating processing when there is a problem with the surface inspection. In the die bonding process of the embodiment, first, the control unit 8 takes out the wafer ring 14 holding the wafer 11 from the cassette and places it on the wafer holding table 12, and transfers the wafer holding table 12 to the die. The reference position for picking of D (wafer loading (process P1)). Next, the control unit 8 performs fine adjustments from the image obtained by the wafer recognition camera 24 so that the placement position of the wafer 11 can be accurately aligned with the reference position.

Next, the control unit 8 moves the wafer holding table 12 on which the wafer 11 is placed at a predetermined pitch and maintains it horizontally, thereby arranging the first picked die D at the pickup position (die transfer (process) P2)). The wafer 11 is inspected for each die by an inspection device such as a probe in advance, and map data indicating good or bad is generated for each die and stored in the memory device 82 of the control unit 8. The judgment of whether the die D to be picked up is a good product or a defective product is based on the map data. When the die D is a defective product, the control unit 8 moves the wafer holding table 12 on which the wafer 11 is placed at a predetermined pitch, and arranges the die D to be picked up at the pickup position, skipping the defective product.的晶粒 D.

The control unit 8 photographs the main surface (upper surface) of the die D to be picked up by the wafer recognition camera 24, and calculates the displacement amount of the die D to be picked up from the pickup position from the acquired image. The control unit 8 moves the wafer holding table 12 on which the wafer 11 is placed based on this displacement, and accurately arranges the die D to be picked at the pickup position (die positioning (process P3)).

Next, the control unit 8 performs surface inspection of the die D from the image obtained by the wafer recognition camera 24 (process P4). The details of the surface inspection (visual inspection) of the crystal grains will be described later. Here, the control unit 8 judges whether there is a problem by surface inspection (process P41), and when it is determined that there is no problem on the surface of the crystal grain D, proceed to the next process (process P9 described later), but when it is determined that there is a problem , For all the crystal grains, any one of the three selections is processed (Process P42).

Case 1, visually confirm the surface image (process P43), skip processing (process P45) when there is a problem, and perform sub-process processing when there is no problem. The skip process is step P9 where the die D is skipped, the wafer holding table 12 on which the wafer 11 is placed is moved at a predetermined pitch, and the die D to be picked up next is arranged at the pickup position.

In case 2, after washing the die D (process P46) by a washing device such as air blowing, the processing of case 1 is performed.

In case 3, after washing the die D (process P47) with a washing device such as air blowing, the surface inspection is performed again (process P48). Use surface inspection to determine whether there is a problem (process P49). When it is determined that there is no problem on the surface of the die D, proceed to the next process (process P9), but when it is determined that there is a problem, proceed to case 1 for all the crystal grains. Or any treatment of 2 (Engineering P4A).

The control section 8 places the substrate P on the substrate transport tray 51 in the substrate supply section 6 (substrate loading (process P5)). The control unit 8 moves the substrate transport tray 51 on which the substrate P is placed to the bonding position (substrate transport (process P6)).

The substrate is picked up by the substrate recognition camera 44 to perform positioning (substrate positioning (process P7)).

Next, the control unit 8 performs the surface inspection of the substrate P from the image obtained by the substrate recognition camera 44 (process P8). The details of the substrate surface inspection will be described later. Here, the control unit 8 judges whether there is a problem by surface inspection (process P41), and when it is determined that there is no problem on the surface of the substrate P, proceed to the next process (process P9 described later), but when it is determined that there is a problem, For all the substrates, any one of the three selections is processed (Process P42).

Case 1 (Case 1), visually confirm the surface image (process P43), skip the process (process P45) when there is a problem, and perform the next process when there is no problem. The skip process is to skip the substrate P and register the fault information of the substrate start after the TAB (Tape Automated Bonding, TAB) process PA.

In Case 2 (Case 2), the substrate P is cleaned (process P46) by a cleaning device such as air ejection, and then the processing of Case 1 is performed.

In case 3 (Case 3), the substrate P is cleaned (process P47) by a cleaning device such as an air jet, and then the surface inspection is performed again (process P48). Use surface inspection to determine whether there is a problem (process P49). When it is determined that there is no problem on the surface of the substrate P, proceed to the next process (process P9), but when it is determined that there is a problem, perform case 1 or 2 for all substrates Any treatment (Engineering P4A).

The control unit 8 correctly arranges the die D to be picked up at the pickup position, picks up the die D from the dicing tape 16 by the pickup head 21 including the chuck 22, and places it on the intermediate platform 31 (die handling ( Engineering P9)). The control unit 8 detects the posture deviation (rotational deviation) of the die placed on the intermediate platform 31 by capturing images by the platform recognition camera 32. When there is a posture deviation, the control unit 8 uses a rotation drive device (not shown) provided on the intermediate platform 31 to rotate the intermediate platform 31 on a plane parallel to the mounting surface with the installation position to correct the posture deviation. .

The control unit 8 picks up the die D from the intermediate platform 31 by the bonding head 41 including the chuck 42, and adheres the die to the substrate P or the die that has been bonded to the substrate P (die attach ((engineering PA)) .

The control unit 8 checks whether the bonding position of the die D is correct after bonding the die D (inspection of the relative position of the die and the substrate (process PB)). At this time, in the same way as the alignment of the crystal grains described later, the center of the crystal grains and the center of the automatic tape bonding are obtained, and it is checked whether the relative position is correct.

Next, the control unit 8 performs surface inspection of the die D and the substrate P (engineering PC) from the image obtained by the substrate recognition camera 44. The details of the surface inspection of the die D and the substrate P will be described later. Here, the control unit 8 judges whether there is a problem by a surface inspection (process P41), and when it is determined that there is no problem on the surface of the substrate P to which the die D is bonded, proceed to the next process (process P9 described later), but When it is determined that there is a problem, any one of three selections is performed for all the substrates (Process P42).

Case 1, visually confirm the surface image (process P43), skip processing (process P45) if there is a problem, and perform sub-process processing if there is no problem. In the skip process, the defective registration of the board construction information is performed.

In case 2, the cleaning process of the substrate P (process P46) is performed by a cleaning device such as air ejection, and then the process of case 1 is performed.

In case 3, the substrate P is cleaned (process P47) by a cleaning device such as air ejection, and then the surface inspection is performed again (process P48). Use surface inspection to determine whether there is a problem (process P49). When it is determined that there is no problem on the surface of the substrate P, proceed to the next process (process P9), but if it is determined to be a problem, perform case 1 or Any treatment of 2 (Engineering P4A).

In addition, when the bonded product is laminated, any one of Examples 1 to 3 is implemented in each layer.

After that, the die D is bonded to the substrate P one by one according to the same procedure. When the bonding of one substrate is completed, the substrate transport tray 51 is moved to the substrate unloading section 7 (substrate transport (process PD)), and the substrate P is delivered to the substrate unloading section 7 (substrate unloading (process PE)).

After that, the die D is peeled off from the dicing tape 16 one by one according to the same procedure (Process P9). Except for defective products, if all the dies D are picked up, the dicing tape 16 and the wafer ring 14 that hold the dies D in the shape of the wafer 11 are unloaded to the wafer cassette (Engineering PF).

In addition, at least one of the processes P4, P8, and PC may not be performed. Immediately before the die bonding, by inspecting the surface of the die and/or the substrate, the incidence of product defects can be reduced. Immediately after the die is bonded, by inspecting the surface of the die and the substrate, the incidence of product defects can be reduced. By inspecting the surface of the die and the substrate immediately before the die bonding, and checking the surface of the die and the substrate immediately after the die bonding, it is possible to distinguish whether the process of occurrence of defects such as cracks is a die-bonding process.

Use Figure 9 to 13 to illustrate the method of crystal grain positioning. Fig. 9 is a flowchart for explaining the imitation operation. Fig. 10 is a diagram showing an example of a unique part (selection field). Fig. 11 is a flowchart for explaining the continuous construction operation. Fig. 12 is a diagram showing examples of registered portraits and similar portraits. FIG. 13 is a diagram showing an example of obtaining the center of a crystal grain from the positional relationship of a pattern, FIG. 13(A) is a registered image, and FIG. 13(B) is an image of a crystal grain to be aligned.

The grain positioning algorithm mainly uses template matching, and is set as an operation in the well-known normalized correlation equation. The result is used as the agreement rate. Model matching is an imitative action with reference learning and an action for continuous start-up.

First, explain the imitation action. The control unit 8 transports the reference sample to the pickup position (step S1). The control unit 8 uses the wafer recognition camera 24 to obtain the image PCr of the reference sample (step S2). The operator of the die bonder will use the user interface (touch panel 83b or mouse 83c) to select the unique part UA as shown in FIG. 10 from the portrait (step S3). The control unit 8 stores the positional relationship (coordinates) between the selected unique part (selection area) UA and the reference sample in the memory device 82 (step S4). The control unit 8 saves the image (model image) PT of the selected field in the memory device 82 (step S5). The workpiece image (registered image) used as the reference and its coordinates are stored in the memory device 82.

By preparing a plurality of registered images, as shown in FIG. 13, the center of the crystal grain is calculated from the relative relationship with each position of the registered image that is consistent with the check, and the positioning is performed. The substrate positioning is also performed by using the unique part of the substrate to calculate the center position of the automatic bonding of the tape with the die.

Next, the continuous operation will be explained. The control part 8 conveys the member for continuous operation (wafer for product) to a pick-up position (step S11). The control unit 8 uses the wafer recognition camera 24 to obtain the image PCn of the product die (step S12). As shown in FIG. 10, the control unit 8 compares the template image PT stored in the simulation action with the acquired image PCn of the product die, and calculates the coordinates of the image PTn of the most similar part (step S13). The coordinates are compared with the coordinates measured on the reference sample, and the position of the product crystal grain (the shift between the image PTn and the template image PT) is calculated (step S14). Use FIG. 14 to explain the appearance inspection and recognition of the crystal grains (exception of abnormalities such as cracks, foreign objects, flaws, and voids). FIG. 14 is a diagram explaining the method of detecting an abnormality, FIG. 14(A) is a diagram explaining the binarization method, and FIG. 14(B) is a diagram explaining the image difference method.

The abnormality on the surface of the die is detected by methods such as binarization or image difference method. In the binarization method, an image PC2 that is binarized with an image PCa of crystal grains with foreign matter FO and cracked CR is generated, and abnormal parts (foreign matter FO and cracked CR) are detected. In the image difference method, an image PCa-n obtained by the difference between the image PCa of the crystal grain with the foreign matter FO and the crack CR and the image PCn of the good crystal grain is generated, and the foreign matter and the crack are detected.

The problems related to the above-mentioned technique will be explained using FIGS. 15 and 16. FIG. 15 is a diagram showing the shading values of a camera image with a large abnormal portion in the coordinate direction one-dimensionally. FIG. 16 is a diagram showing the shading values of a camera image with a small abnormal part in the coordinate direction one-dimensionally.

Whether it is binarization or difference processing, for the image that should be in a good product, the presence of foreign matter or injury can be judged by checking the change in shade. As shown in Fig. 15, it is easy to detect when the shade value of the abnormal part is substantially different from normal. However, as shown in FIG. 16, when the actual area of the abnormal part is small or the original brightness of the abnormal part is close to the normal part, the change is small. The inspection of images with small brightness changes (less brightness deviation) may be difficult to distinguish due to the noise of the image itself. For example, if the foreign matter has a small change in density, it will be swallowed by random noise in the image, making judgment difficult.

17 and 18 are used to explain the detection of the abnormal part of the embodiment. Fig. 17 is a flowchart showing the surface inspection of the embodiment. FIG. 18 is a diagram explaining the detection of an abnormal portion, FIG. 18(A) is a comparative example, and FIG. 18(B) is a diagram showing an embodiment.

When inspecting the damage or foreign matter of the die or the substrate (subject), a plurality of images of the subject are taken (step S21). The shading values of the pixels of the images taken in the plural images are averaged to generate an averaged image (step S22). A binarized image in which the averaged image is binarized with a critical value is generated (step S23). It is determined whether there is a foreign object marked by the binary large object of the binary image (step S23).

For one shot of the subject (comparative example), as shown in Figure 18 (A), when the density change caused by the foreign object is large, it can be detected, but when the density change caused by the foreign object is small, the image will be imaged. Random noise is swallowed and difficult to distinguish.

The averaging image of the embodiment can bring the random noise close to the true value (the average value of the subject's density) (noise suppression). Since the averaged image with suppressed noise is smaller than the image processed with one image (comparative example), the random noise is smaller, so it is possible to judge abnormalities (wounds, foreign objects) with small changes in density. As shown in Figure 18(B), once the random noise is suppressed, the judgment threshold can be closer to the average value of the image, so the sensitivity limit can be improved as a result.

According to the embodiment, it is possible to improve the sensitivity limit for detecting abnormalities of the surface of the object (die and substrate) that can be captured by the camera, such as scratches, foreign objects, pores, cracks, etc.

By dividing the image into multiple times, the changes in shades or coordinates caused by sunburn or vibration can also be averaged, so the sensitivity limit of the inspection can be improved.

The main cause of random noise is photon noise or noise that occurs randomly like text by an amplifier during A/D conversion. Random noise can be measured by increasing the number of measurements, averaging, and suppressing the instability of the value, which is close to the value originally intended to be measured. This makes it easy to recognize slight changes in the image due to wounds, foreign objects, and the like.

The photon noise is that the more the total number of photons taken in, the smaller the relative noise ratio. Noise reduction can also be achieved by extending the exposure time. However, in the imaging of a digital camera represented by a CCD or CMOS sensor, the following problems will occur if the exposure time is extended. (a) The dark current noise (fixed pattern noise) increases, but it cannot be distinguished. (b) Affected by interference light, the impact of interference light on the imaging environment must be removed. The embodiment can also suppress these problems.

Immediately before the die bonding, by inspecting the die and/or substrate with high sensitivity, the incidence of product defects can be further reduced. Immediately after the die is bonded, by inspecting the die and substrate with high sensitivity, the incidence of product defects can be further reduced.

By inspecting the die and substrate with high sensitivity immediately before or just after the die bonding, it is possible to distinguish whether the defective process such as cracks is a die-bonding process.

As mentioned above, the invention developed by the present inventors has been specifically described based on the embodiments and examples, but the present invention is not limited to the above-mentioned embodiments and examples, and of course various modifications can be implemented.

For example, in the embodiment, the wafer recognition camera is used to inspect the surface of the die. However, the platform recognition camera can also be used to detect the surface of the die. In addition, the embodiment illustrates the type in which the coaxial illumination is arranged between the objective lens and the crystal grain, but it may also be an insertion type in the lens. In addition, in the embodiment, the grain appearance inspection and recognition are performed after the die location recognition, but the grain location recognition may also be performed after the die appearance inspection and recognition. In the embodiment, the substrate appearance inspection recognition is performed after the substrate positioning recognition, but the substrate positioning recognition may also be performed after the substrate appearance inspection recognition. In addition, the embodiment illustrates an example in which the detection of abnormalities on the surface of the die is performed by binarization or the image difference method, but the histogram calculation of the image, spatial filter processing, and pattern matching processing may also be used. In addition, in the embodiment, DAF is attached to the back surface of the wafer, but DAF may be absent. In this case, an apparatus for applying an adhesive to the substrate is provided. In addition, in the embodiment, one pick-up head and one bonding head are each provided, but each is two or more. In addition, the embodiment is provided with an intermediate platform, but there may be no intermediate platform. In this case, the pickup head and the bonding head can also be used together. In addition, in the embodiment, the surface of the die is used as the upper bonding, but after picking up the die, the front and back of the die may be reversed, and the back side of the die may be used as the upper bonding. In this case, the intermediate platform may not be provided. This device is called a flip chip bonder.

10‧‧‧Crystal Bonding Machine 1‧‧‧Wafer Supply Department D‧‧‧grain 2‧‧‧Pickup Department 24‧‧‧Wafer recognition camera ID‧‧‧Camera Department LD‧‧‧Lighting Department 3‧‧‧Intermediate platform 31‧‧‧Intermediate platform 32‧‧‧Platform recognition camera 4‧‧‧Joint 41‧‧‧Joint head 42‧‧‧Chuck 44‧‧‧Substrate recognition camera 5‧‧‧Transportation Department BS‧‧‧Joint Platform P‧‧‧Substrate 8‧‧‧Control Department

Fig. 1 is a schematic top view showing the structure of the die bonder of the embodiment. Fig. 2 is a diagram illustrating the schematic configuration and operation of the die bonder of Fig. 1. Fig. 3 is an external perspective view showing the configuration of the crystal grain supply part of Fig. 1. Fig. 4 is a schematic cross-sectional view showing the main part of the crystal grain supply part of Fig. 3. Fig. 5 is a block diagram showing a schematic configuration of the control system. Fig. 6 is a diagram for explaining the optical system of the die supply unit. FIG. 7 is a flowchart illustrating the die bonding process of the semiconductor manufacturing apparatus of the embodiment. Fig. 8 is a flowchart illustrating processing when there is a problem with the surface inspection. Fig. 9 is a flowchart for explaining the imitation operation. Fig. 10 is a diagram showing an example of a unique part (selection field). Fig. 11 is a flowchart for explaining the continuous construction operation. Fig. 12 is a diagram showing examples of registered portraits and similar portraits. FIG. 13 is a diagram showing an example of obtaining the center of a crystal grain from the positional relationship of the pattern. Fig. 14 is a diagram illustrating a method of detecting an abnormality. FIG. 15 is a diagram showing the shading values of a camera image with a large abnormal portion in the coordinate direction one-dimensionally. FIG. 16 is a diagram showing the shading values of a camera image with a small abnormal portion in the coordinate direction one-dimensionally. Fig. 17 is a flowchart showing the surface inspection of the embodiment. Fig. 18 is a diagram explaining the detection of an abnormal part.

Claims (8)

A die bonding device is characterized by comprising: a die supply part which holds a dicing tape to which the die is attached; a wafer recognition camera which recognizes the posture of the die on the dicing tape; and a bonding head, which The die is bonded to the substrate or the die that has been bonded to the substrate; the substrate recognition camera, which recognizes the bonding position; and the control section, which controls the wafer recognition camera and the substrate recognition camera, the control section , Is configured to capture the die on the dicing tape by the wafer recognition camera, and position the die, and capture a plurality of sheets of the dicing tape by the wafer recognition camera The crystal grain averages the shade values of the pixels of the plural images taken to generate an averaged image, and generates a binarized image based on the threshold of the averaged image, based on the binary large size of the binarized image The object mark is used to determine the presence or absence of the abnormality of the aforementioned crystal grains and perform a surface inspection. For example, the die bonding device of the first patent application, wherein the control unit is further configured to capture the die bonded to the substrate by the substrate recognition camera, and inspect the position of the die, and The substrate recognition camera is used to capture a plurality of bonded dies, and the shade values of the pixels of the captured images are averaged to generate an averaged image, and the second of the threshold values based on the averaged image is generated In the valued image, the presence or absence of the abnormality of the crystal grain is determined based on the binary large object mark of the binary image, and the surface inspection is performed. A die bonding device is characterized by comprising: a die supply part which holds a dicing tape to which the die is attached; a wafer recognition camera which recognizes the posture of the die on the dicing tape; and a bonding head, which The die is bonded to the substrate or the die that has been bonded to the substrate; the substrate recognition camera, which recognizes the bonding position; and the control section, which controls the wafer recognition camera and the substrate recognition camera, the control section , The system is configured to capture the die bonded to the substrate by the substrate recognition camera, perform inspection of the position of the die, and capture a plurality of bonded die by the substrate recognition camera , Averaging the shade values of the pixels of the plural images taken to generate an averaged image, and generate a binarized image based on the threshold of the averaged image, according to the binary large object mark of the binarized image To determine the presence or absence of abnormality of the aforementioned crystal grains, a surface inspection is performed. A die-bonding device is characterized by having: a die supply part that holds a dicing tape with die attached; a wafer recognition camera that recognizes the posture of the die on the dicing tape; and a pickup head, which The system picks up the aforementioned die; the intermediate platform, which mounts the aforementioned die that is picked up; the platform recognition camera, which recognizes the aforementioned die on the aforementioned intermediate platform; the bonding head, which is to be placed on the aforementioned intermediate platform The die is bonded to the substrate or the die that has been bonded to the substrate; a substrate recognition camera, which recognizes the bonding position; and a control section, which controls the wafer recognition camera, the platform recognition camera, and the substrate recognition camera, The control unit is configured to capture the crystal grains placed on the intermediate platform by the platform recognition camera, perform inspection of the position of the crystal grains, and capture a plurality of images by the platform recognition camera The crystal grains placed on the intermediate platform average the shade values of the pixels of the plurality of images taken to generate an averaged image, and generate a binarized image based on the threshold of the averaged image, based on The binary large object mark of the binarized image is used to determine the presence or absence of the abnormality of the crystal grain and perform a surface inspection. For example, the die bonding device of the fourth item in the scope of patent application, wherein the control unit is further configured as: the camera is recognized by the wafer

To capture the die on the dicing tape, and position the die, and use the wafer recognition camera to capture a plurality of the die on the dicing tape, and then draw each image of the captured image. The shade values of the elements are averaged to generate an averaged image, a binary image based on the threshold of the averaged image is generated, and the presence or absence of the abnormal crystal grain is determined based on the binary large object mark of the binary image. Surface inspection. For example, the die bonding device of item 5 of the scope of patent application, wherein the control unit is further configured to capture the bonded die by the substrate recognition camera, and perform inspection of the position of the die, and by The substrate recognition camera captures a plurality of the die bonded to the substrate, averages the shade values of the pixels of the captured images to generate an averaged image, and generates the second of the threshold values based on the averaged image In the valued image, the presence or absence of the abnormality of the crystal grain is determined based on the binary large object mark of the binary image, and the surface inspection is performed. For example, the die bonding device of claim 4, wherein the control unit is further configured to capture the bonded die by the substrate recognition camera, and perform the inspection of the position of the die, and by The aforementioned substrate recognition camera is used to pick up a plurality of bonded sheets of the aforementioned The crystal grain averages the shade values of the pixels of the plural images taken to generate an averaged image, and generates a binarized image based on the threshold of the averaged image, based on the binary large size of the binarized image The object mark is used to determine the presence or absence of the abnormality of the aforementioned crystal grains and perform a surface inspection. As for the die bonding device described in any one of items 1 to 7 in the scope of the patent application, the control unit is further configured to capture the substrate by the substrate recognition camera to perform positioning of the substrate, and Taking a plurality of the substrates by the substrate recognition camera, averaging the shading values of the pixels of the images captured by the plurality of images to generate an averaged image, and generating a binary image based on the threshold of the averaged image, According to the binary large object mark of the binary image, the presence or absence of foreign matter on the substrate is judged and the surface inspection is performed.

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