TW201941316A - Die bonding device and method of manufacturing semiconductor device - Google Patents

Abstract

Provided is a technique capable of reducing defects in a product in a bonding process. A die bonding apparatus comprises: a photographing apparatus for photographing dies or substrates so as to determine the position of the dies or the substrates and detect the appearances of the dies and the substrates; and a control unit for controlling the photographing apparatus. Moreover, the control unit photographs the plurality of dies or substrates by using the photographing apparatus, generates an averaging image by averaging light and shade values of each pixel of the plurality of photographed images, generates a binary coded image due to a threshold value of the averaging image, and determines whether or not an abnormality occurs by using blob labeling of the binary coded image so as to perform a surface inspection.

Description

Sticky crystal device and manufacturing method of semiconductor device

This case relates to a die attach device, which can be applied to, for example, a die attach device having an appearance inspection function.

A part of the manufacturing process of a semiconductor device includes a process of combining packages by mounting a semiconductor wafer (hereinafter referred to as a die) on a wiring board or a lead frame (hereinafter referred to as a substrate), and a part of the process of combining packages by a semiconductor wafer ( (Hereinafter referred to as a wafer) to divide (cut) the die, and to mount the divided die on a substrate. The manufacturing apparatus used in the bonding process is a die bonder such as a die bonder.

The die attach device is a device that uses solder, gold plating, and resin as bonding materials to bond (mount and adhere) the crystal grains to the substrate or the bonded crystal grains. In a die-bonding machine that bonds crystal grains to the surface of a substrate, for example, a suction nozzle called a chuck is used to pick up the crystal grains from a wafer, transfer the crystal grains to the substrate, apply thrust, and heat the bonding material. The operation (work) for joining is repeated.
[Prior technical literature]
[Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2008-98348

(Problems to be solved by the invention)

When a wafer is diced to manufacture a die, cracks or injuries may occur in the die extending from the cut section to the inside due to cutting resistance during dicing and the like. In addition, there may be cases where a foreign substance adheres due to a paste residue or the like from the polishing tape attached to the surface of the wafer. In addition, foreign matter adhering to the crystal grains may be attached to other crystal grains via a chuck. That is, foreign matter adhesion and the like occur before and during the bonding process.
The object of this case is to provide a technology capable of reducing the defective rate of the products of the joining process.
Other problems and novel features can be clearly understood from the description of the explanatory drawings and the drawings.

(Means for solving problems)

The summary of the representative in this case is briefly explained as follows.
That is, the sticky crystal device has:
The imaging device takes in the aforementioned crystal grains or the substrate in order to perform positioning and appearance inspection of the die or the substrate; and the control unit controls the aforementioned imaging device.
The control unit captures a plurality of the crystal grains or the substrate by the imaging device, averages the shade values of each pixel of the plurality of captured images, and generates an averaged image, and generates an averaged image based on the averaged image. The binary image of the critical value determines the presence or absence of an abnormality based on the binary large object mark of the aforementioned binary image, and performs a surface inspection.

[Effect of the invention]

According to the above-mentioned sticking crystal device, the defective rate of the products of the bonding process can be reduced.

In the sticking device of the embodiment, the surface of the crystal grains and the substrate is inspected before the sticking of the crystals, and the surface of the crystal grains and the substrate is checked after the bonding of the crystals. This can reduce the defective rate of the product. In the die attach device according to another embodiment, the sensitivity of the surface inspection of the die and / or the substrate is improved. This can reduce the defective rate of the product.

Hereinafter, examples and comparative examples will be described using drawings. However, in the following description, the same constituent elements are denoted by the same reference numerals, and overlapping descriptions may be omitted. In addition, in order to make the description clearer than the actual form, the drawings may schematically show the width, thickness, shape, and the like of each part, but this is merely an example and does not limit the interpreter of the present invention.

[Example]

FIG. 1 is a schematic top view of the die attacher 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 a die supply section 1, a picking section 2, an intermediate stage section 3, a joint section 4, a transfer section 5, a substrate supply section 6, a substrate carry-out section 7, and a control section that monitors and controls the operation of each section 8. The Y-axis direction is the front-back direction of the die attach machine 10, and the X-axis direction is the left-right direction. The die supply unit 1 is placed on the front side of the die attacher 10, and the joint portion 4 is placed on the inside.

First, the die supply unit 1 supplies the die D mounted on the substrate P. The die supply unit 1 includes a wafer holding table 12 that holds the wafer 11, and a jacking unit 13 shown by a dotted line for lifting up 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 jack unit 13.

The pickup section 2 has:
A pick-up head 21 that picks up the die D;
A Y drive unit 23 for moving the pickup head 21 in the Y direction; and various drive units (not shown) for raising, lowering, rotating, and moving the chuck 22 in the X direction.
The pick-up head 21 is a chuck 22 (see also FIG. 2) that holds and holds the jacked-up crystal grains D at the front end, picks up the crystal grains D from the crystal grain supply unit 1, and places them on the intermediate stage 31. The pick-up head 21 includes drive units (not shown) for raising, lowering, rotating, and moving the chuck 22 in the X direction.

The intermediate stage unit 3 includes an intermediate stage 31 on which the die D is temporarily placed, and a platform identification camera 32 for identifying the die D on the intermediate stage 31.

The bonding portion 4 picks up the die D from the intermediate stage 31 and is bonded to the transferred substrate P, or is bonded in a form laminated on the die that has been bonded to the substrate P.
The joint 4 has:
The bonding head 41 is provided with a chuck 42 (also referred to in FIG. 2) for holding and holding the crystal grain D to the tip end in the same manner as the picking head 21;
The Y driving section 43 moves the bonding head 41 in the Y direction, and the substrate recognition camera 44 picks up a position identification mark (not shown) of the substrate P and recognizes the bonding position.
With this 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 transfer unit 5 is a first structure including a substrate transfer tray 51 on which one or a plurality of substrates P (four in FIG. 1) are placed, and a tray rail 52 in which the substrate transfer tray 51 is moved. 2. The second transfer section. The substrate transfer tray 51 is moved by driving a nut (not shown) provided on the substrate transfer tray 51 with a ball screw (not shown) provided along the tray rail 52.
With this configuration, the substrate transfer tray 51 mounts the substrate P on the substrate supply unit 6 and moves to the bonding position along the tray rail 52. After the bonding, the substrate transfer tray 51 is moved to the substrate transfer unit 7 and the substrate P is transferred to the substrate transfer unit. 7. The first and second transfer units are driven independently of each other, and while the die D is bonded to the substrate P placed on one substrate transfer tray 51, the other substrate transfer tray 51 is to carry out the substrate P and return 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 part 1 is demonstrated using FIG.3 and FIG.4. FIG. 3 is an external perspective view showing a configuration of a crystal grain supply unit. FIG. 4 is a schematic cross-sectional view showing a main part of a crystal grain supply unit.

The die supply unit 1 includes a wafer holding table 12 that moves in the horizontal direction (XY direction), and a jacking unit 13 that moves in the vertical direction.
The wafer holding table 12 has:
An expansion ring 15 that holds the wafer ring 14; and a dicing tape 16 that is held on the wafer ring 14 and has a plurality of dies D adhered thereto are positioned on a 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 by the wafer ring 14 is stretched, and the interval between the crystal grains D is widened. The ejection unit 13 ejects the crystal grains D from below the crystal grains D, thereby improving the pick-up property of the crystal grains D. Promotion. A thin film-shaped 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 sticky crystal machine 10 is provided with:
A wafer recognition camera 24 that recognizes the orientation of the die D on the wafer 11;
A platform recognition camera 32 that recognizes the posture of the die D placed on the intermediate platform 31; and a substrate recognition camera 44 that recognizes the mounting position on the bonding platform BS.
It is necessary to correct the posture deviation between the recognition cameras. The platform recognition camera 32 participating in the pickup of the bonding head 41 and the substrate recognition camera 44 participating in the bonding of the bonding head 41 toward the mounting position. In this embodiment, a wafer recognition camera (first imaging device) 24 is used to check for damage or foreign matter on the die D, and a substrate recognition camera (second imaging device) 44 is used to detect the substrate P and the substrate P bonded to the substrate P. Grain injuries or foreign bodies.

The control system will be described using FIG. 5. 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 driving unit 86, a signal unit 87, and an optical system 88. The control unit 8 is roughly divided into a control / computing device 81 constituted by a CPU (Central Processor Unit), a memory device 82, an input / output device 83, a bus line 84, and a power supply unit 85. The memory device 82 includes a main memory device 82a composed of a RAM such as a memory processing program, and an auxiliary memory device 82b composed of an HDD such as control data or image data necessary for memory control. The input / output device 83 includes a monitor 83a that displays device status or information, a touch panel 83b for inputting an operator's instruction, a mouse 83c that operates the monitor, and an image acquisition device for acquiring image data from the optical system 88.入 装置 83d. In addition, the input / output device 83 is a motor control device 83e having a drive unit 86 that controls an XY stage (not shown) of the die supply unit 1 or a ZY drive shaft of the joint head stage, and takes various sensors. A signal or an I / O signal control device 83f that receives a signal or is controlled from a signal unit 87 such as a switch of a lighting device or the like. The optical system 88 includes a wafer identification camera 24, a platform identification camera 32, and a substrate identification camera 44. The control / calculation device 81 is a control that fetches necessary data via a bus line 84, performs calculation, and transmits information to the pickup head 21 or the like, or a monitor 83a or the like.

The control unit 8 stores the image data captured by the wafer identification camera 24 and the substrate identification camera 44 in the memory device 82 via the image pickup device 83d. According to the stored image data, the positioning of the crystal grain D and the substrate P is performed by the control software 81 using the programmed software. Based on the positions of the crystal grain D and the substrate P calculated by the control unit 81, the driving unit 86 is actuated via the motor control device 83e by software. According to this process, the positioning of the crystal grains on the wafer is performed, and the driving portions of the pickup section 2 and the bonding section 4 are operated to bond the crystal grains D to the substrate P. The wafer identification camera 24 and the substrate identification camera 44 to be used are gray scale, color, and the like, and the light intensity is quantified.

Next, a wafer identification camera will be described using FIG. 6. FIG. 6 is a diagram for explaining an optical system of a wafer supply unit, and illustrates an arrangement of an illumination unit that irradiates light for image capturing to a wafer recognition camera and a die to be picked up. The platform identification camera 32 and the substrate identification camera 44 are the same as the wafer identification camera 24.
The imaging unit ID of the wafer identification camera 24 is connected to one end of the lens barrel BT, and an objective lens (not shown) is attached to the other end of the lens barrel BT. Composition of face portrait.
Between the lens barrel BT and the crystal grain D on the line connecting the imaging unit ID and the crystal grain D is an illumination unit LD provided with a surface-emission illumination (light source) SL and a half mirror (transflective mirror) HM inside. The irradiation 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 crystal grain D. The scattered light irradiated to the crystal grain D with the same optical axis as the imaging unit ID is reflected by the crystal grain D, and the regular reflected light will pass through the half mirror HM to reach the imaging unit ID, forming an image of the crystal grain D. That is, the illumination unit LD has a function of coaxial epi-illumination (coaxial illumination).

The lighting system is not limited to coaxial lighting, and can also be dome lighting, oblique halo lighting, oblique light bar lighting, transmission lighting, etc. It is also possible to construct a system using a plurality of combinations of such illuminations depending on the subject. The light source color is white in addition to monochrome. The light source can be used to adjust the output of the linear shape, such as the use of the LED pulse dimming load to adjust the amount of light.

FIG. 7 is a flowchart illustrating a 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 removes the wafer ring 14 holding the wafer 11 from the wafer cassette, places the wafer ring 14 on the wafer holding table 12, and transfers the wafer holding table 12 to the die. Reference position for picking up D (wafer loading (process P1)). Next, the control unit 8 performs fine adjustment from the image acquired by the wafer recognition camera 24 so that the arrangement position of the wafer 11 can accurately match 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 keeps it horizontally, thereby arranging the first picked-up die D at the pick-up position (die transfer (engineering) 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 is stored in the memory device 82 of the control unit 8. The determination of whether the crystal grain D to be picked is a good product or a defective product is performed based on the map data. When the die D is defective, the control unit 8 moves the wafer holding table 12 on which the wafer 11 is placed at a predetermined pitch, arranges the next picked die D at the pickup position, and skips the defective product. Grain D.

The control unit 8 captures the principal surface (upper surface) of the pick-up die D by the wafer recognition camera 24, and calculates the amount of displacement of the pick-up die D from the pick-up position from the acquired image. The control unit 8 moves the wafer holding table 12 on which the wafer 11 is placed based on the amount of displacement, and correctly arranges the pick-up die D at the pick-up position (die positioning (process P3)).

Next, the control unit 8 performs a surface inspection of the die D from the image acquired by the wafer recognition camera 24 (process P4). The details of the surface inspection (appearance inspection) of the crystal grains will be described later. Here, the control unit 8 determines whether there is a problem by surface inspection (process P41). When it is determined that there is no problem on the surface of the crystal grain D, it proceeds to the next process (process P9 described later), but determines that there is a problem. Then, any one of the three selections is performed for all the crystal grains (process P42).

Case 1, visually confirm the surface image (process P43), skip the process when there is a problem (process P45), and perform the sub-process when there is no problem. The skip process is performed after the process P9 of skipping the die D, and the wafer holding table 12 on which the wafer 11 is placed is moved at a predetermined pitch, and the next picked-up die D is arranged at the picking position.

In Example 2, the washing process of the crystal grains D was performed by a washing device such as air jet (Process P46), and then the process of Example 1 was performed.

Case 3: After the washing process of the crystal grains D is performed by a washing device such as an air jet (process P47), 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 grain D, proceed to the next process (process P9), but if it is determined that there is a problem, perform case 1 for all the grains. Or any of 2 treatments (Engineering P4A).

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

The substrate is captured by the substrate recognition camera 44 and positioned (substrate positioning (process P7)).

Next, the control unit 8 performs a surface inspection of the substrate P from the image acquired by the substrate recognition camera 44 (process P8). The details of the substrate surface inspection will be described later. Here, the control unit 8 determines whether there is a problem by surface inspection (process P41). When it is determined that there is no problem on the surface of the substrate P, it proceeds to the next process (process P9 described later), but when it is determined that there is a problem, Any one of the three selections is performed for all the substrates (process P42).

Case 1 (Case 1), visually confirm the surface image (process P43), skip the process when there is a problem (process P45), and perform the sub-process when there is no problem. The skip process is to skip the substrate PA to the process PA of Tape Automated Bonding (TAB), and then register the substrate operation information badly.

Case 2 was performed after the substrate P was cleaned (process P46) by a cleaning device such as an air jet, and then the process of Case 1 was performed.

In case 3 (Case 3), the substrate P was cleaned (process P47) by a cleaning device such as an air jet, and then the surface inspection was 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). Any of the processing (Engineering P4A).

The control unit 8 picks up the die D to be picked up at the picking position correctly, picks up the die D from the cutting tape 16 by the picking head 21 including the chuck 22, and places it on the intermediate platform 31 (die manipulation ( Process P9)). The control unit 8 detects the posture deviation (rotational deviation) of the crystal grains placed on the intermediate stage 31 by taking a picture with the stage recognition camera 32. When there is a posture deviation, the control unit 8 corrects the posture deviation by rotating the intermediate platform 31 on a plane parallel to the mounting surface having the mounting position by a rotation driving device (not shown) provided on the intermediate platform 31. .

The control unit 8 picks up the die D from the intermediate stage 31 through the bonding head 41 including the chuck 42 and sticks the die to the substrate P or the die that has been bonded to the substrate P (die attached ((Engineering PA)) .

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

Next, the control unit 8 performs surface inspection of the crystal grains D and the substrate P from the image acquired by the substrate recognition camera 44 (process PC). Details of the surface inspection of the crystal grain D and the substrate P will be described later. Here, the control unit 8 determines whether there is a problem by surface inspection (process P41). When it is determined that there is no problem on the surface of the substrate P to which the crystal grains D are bonded, the control unit 8 proceeds to the next process (process P9 described later), but When it is determined that there is a problem, any one of the three selections is performed for all the substrates (process P42).

Case 1, visually confirm the surface image (process P43). If there is a problem, skip the process (process P45). If there is no problem, perform the subprocess. In the skip process, defective board registration information is registered.

In Example 2, the substrate P was cleaned (process P46) by a cleaning device such as an air jet, and then the processing in Example 1 was performed.

Case 3: After the substrate P is cleaned by a cleaning device such as an air jet (process P47), 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). If it is determined that there is a problem, perform case 1 or all of the grains. Any of 2 processes (Engineering P4A).

In addition, in the case of a laminated bonded product, any one of Examples 1 to 3 was implemented in each layer.

Thereafter, the crystal grains D are bonded to the substrate P one by one by the same procedure. When the bonding of one substrate is completed, the substrate transfer tray 51 is moved to the substrate transfer portion 7 (substrate transfer (process PD)), and the substrate P is transferred to the substrate transfer portion 7 (substrate unload (process PE)).

Thereafter, the crystal grains D are peeled from the dicing tape 16 one by one in accordance with the same procedure (process P9). Except for defective products, if all the dies D have been picked up, the dicing tape 16 and wafer ring 14 of the dies D will be unloaded toward the wafer cassette by the outer shape of the wafer 11 (process PF).

In addition, at least one of the processes P4, P8, and PC may not be performed. Immediately before die bonding, inspection of the surface of the die and / or substrate can reduce the incidence of product defects. Immediately after die bonding, the incidence of product defects can be reduced by inspecting the surface of the die and substrate. By inspecting the surface of the crystal grains and the substrate immediately before die-bonding, and inspecting the surface of the crystal grains and the substrate immediately after die-adhesion, it can be discriminated whether or not a process such as cracking is a stick-crystal process.

A method for crystal grain positioning will be described with reference to FIGS. 9 to 13. FIG. 9 is a flowchart for explaining an imitation operation. FIG. 10 is a diagram showing an example of a unique portion (selection area). FIG. 11 is a flowchart for explaining a continuous start operation. FIG. 12 is a diagram showing an example of a registered image and a similar image. FIG. 13 is a diagram showing an example in which the center of the crystal grain is obtained from the positional relationship of the 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 is mainly based on the use of template matching, and is set to be a commonly known normalized correlation operation. The result is used as the agreement rate. Model matching is a reference learning imitating action and continuous starting action.

First, a description will be given of the imitation action. The control unit 8 transfers the reference sample to the pickup position (step S1). The control unit 8 uses the wafer recognition camera 24 to obtain an image PCr of the reference sample (step S2). The operator of the die attach machine selects a unique portion UA as shown in FIG. 10 from the image through a user interface (touch panel 83b or mouse 83c) (step S3). The control unit 8 stores the positional relationship (coordinates) between the selected unique portion (selection area) UA and the reference sample in the memory device 82 (step S4). The control unit 8 stores an image (template image) PT of the selected area in the memory device 82 (step S5). The reference workpiece image (registered image) 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 grains is calculated from the relative relationship with the positions corresponding to the checked registered images, and positioning is performed. The substrate positioning is also performed using a unique portion of the substrate to calculate the center position of the auto-bonding of the tape on which the die is mounted.

Next, the continuous operation will be described. The control unit 8 transfers the continuous-working member (product wafer) to a pick-up position (step S11). The control unit 8 obtains an image PCn of the product die using the wafer recognition camera 24 (step S12). As shown in FIG. 10, the control unit 8 compares the template image PT stored in the imitation operation with the obtained image PCn of the product grains, and calculates the coordinates of the image PTn of the most similar part (step S13). The coordinates are compared with the coordinates measured in the reference sample, and the position of the crystal grains for the product (the offset between the image PTn and the template image PT) is calculated (step S14).
FIG. 14 is used to explain grain appearance inspection and identification (cracks, abnormalities such as foreign bodies, wounds, and pores). FIG. 14 is a diagram illustrating a method of abnormality detection, FIG. 14 (A) is a diagram illustrating a binarization method, and FIG. 14 (B) is a diagram illustrating a portrait difference method.

The abnormality on the surface of the crystal grain is detected by a method such as binarization or image difference method. In the binarization method, an image PC2 of binarized images PCa of grains having foreign matter FO and cracked CR is generated, and abnormal portions (foreign matter FO and cracked CR) are detected. In the image difference method, a difference image PCa-n obtained by obtaining an image PCa of a crystal grain having a foreign object FO and a crack CR and an image PCn of a good crystal grain is generated, and the foreign object and crack are detected.

The problems related to the above-mentioned method will be described with reference to FIGS. 15 and 16. FIG. 15 is a diagram showing the gradation values of a camera image with a large abnormal portion in the coordinate direction. FIG. 16 is a diagram showing the gradation values of a camera image with a small abnormal portion in the coordinate direction.

Regardless of the binarization process or the difference process, the presence or absence of foreign matter or injury is judged by checking the change in density for the image that should be produced when the product is good. As shown in FIG. 15, it is easy to detect when the shading value of the abnormal portion is normal and greatly different. However, as shown in FIG. 16, when the actual area of the abnormal portion is small, or when the original brightness of the abnormal portion approaches the normal portion, the change is small. Inspection of an image with a small change in brightness (less brightness deviation) is difficult to discern due to the noise held by the image itself. For example, if the change in the shade of a foreign object is small, it will be swallowed by the random noise of the image, making judgment difficult.

The detection of an abnormal portion in the embodiment will be described with reference to FIGS. 17 and 18. FIG. 17 is a flowchart showing a surface inspection of the embodiment. FIG. 18 is a diagram illustrating detection of an abnormal portion, FIG. 18 (A) is a comparative example, and FIG. 18 (B) is a diagram illustrating an example.

When inspecting a die or a substrate (object) for a wound or a foreign object, a plurality of images are taken of the object (step S21). The shading values of the pixels of the plurality of captured images are averaged to generate an averaged image (step S22). A binary image is generated by binarizing the averaged image with a threshold value (step S23). The presence or absence of a foreign object marked by a binary large object based on the binary image is determined (step S23).

For one-time imaging of a subject (comparative example), as shown in FIG. 18 (A), when the change in the shade caused by a foreign object is large, it can be detected, but when the change in the shade caused by a foreign object is small, it will be imaged. Random noise is swallowed and difficult to discern.

In the averaged image of the embodiment, the random noise can be approximated to the true value (average of the density of the subject) (the noise is suppressed). Since the averaged image with suppressed noise is smaller than the image processed by one image (comparative example), the random noise becomes smaller, so that it is possible to determine an abnormality (wound, foreign body) with less change in density. As shown in FIG. 18 (B), once the random noise is suppressed, the judgment threshold value can also 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 of the abnormality of the surface of an object (a crystal grain and a substrate) that can be imaged by a camera and inspected for a wound, a foreign body, a void, or a crack.

By dividing the image into multiple images, changes in shading or coordinates caused by sunburn or vibration can 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 through an amplifier during A / D conversion. Random noise can be increased by increasing the number of measurements, averaging, and destabilizing the value, which is close to the value that was originally intended to be measured. This makes it easy to discern slight changes in the image caused by injuries, foreign objects, and the like.

Photon noise is the larger the total number of photons taken, the smaller the relative noise ratio. Noise reduction is also possible by extending the exposure time. However, in the case of a digital camera such as a CCD or CMOS sensor, the following problems occur when the exposure time is extended.
(a) The dark current noise (fixed pattern noise) is increased, but it cannot be distinguished.
(b) The influence of interference light on the imaging environment must be removed. The embodiment can suppress such problems.

Immediately before die bonding, inspection of the die and / or substrate with high sensitivity can reduce the incidence of product defects. Immediately after sticking the crystals, by inspecting the crystal grains and the substrate with a high sensitivity, the incidence of product defects can be further reduced.

Immediately before or immediately after the die-bonding, by examining the crystal grains and the substrate with high sensitivity, it is possible to distinguish whether a bad process such as cracking is a sticky-crystal process.

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

For example, in the embodiment, an example is described in which the surface of the die is inspected by a wafer recognition camera, but the surface of the die may be inspected by a platform recognition camera.
In the embodiment, the coaxial illumination is described as a type that is arranged between the objective lens and the crystal grains, but it can also be an in-lens type.
Moreover, in the embodiment, the appearance of the grain is inspected and identified after the identification of the grain, but the appearance of the grain may be identified after the inspection of the appearance of the grain. In the embodiment, the substrate appearance inspection is performed after the substrate positioning recognition, but the substrate positioning inspection may be performed after the substrate appearance inspection and identification.
The embodiment is an example in which the abnormality detection on the surface of the crystal grains is performed by binarization or image difference method, but it is also possible to use histogram calculation of the image, spatial filter processing, and pattern matching processing.
In the embodiment, the DAF is attached to the back of the wafer, but the DAF may be omitted. In this case, a device for applying an adhesive to the substrate is provided.
In the embodiment, one pickup head and one bonding head are provided, but the number is two or more. In the embodiment, the intermediate platform is provided, but the intermediate platform may not be provided. In this case, the pickup head and the bonding head may be used in combination.
In the embodiment, the surfaces of the crystal grains are bonded together, but the front and back surfaces of the crystal grains may be reversed after picking up the crystal grains, and the back surface of the crystal grains may be bonded upward. In this case, the intermediate platform is optional. This device is called a flip-chip adapter.

10‧‧‧ Sticky Crystal Machine

1‧‧‧ Wafer Supply Department

D‧‧‧ Grain

2‧‧‧Pick up department

24‧‧‧ Wafer Identification Camera

ID‧‧‧ Camera Department

LD‧‧‧Lighting Department

3‧‧‧Middle Platform Department

31‧‧‧ intermediate platform

32‧‧‧Platform identification camera

4‧‧‧ Junction

41‧‧‧Joint head

42‧‧‧Chuck

44‧‧‧ substrate identification camera

5‧‧‧Transportation Department

BS‧‧‧Joint Platform

P‧‧‧ substrate

8‧‧‧Control Department

FIG. 1 is a schematic top view showing the configuration of a die bonder of an embodiment.

FIG. 2 is a diagram illustrating a schematic configuration and operation of the die attacher of FIG. 1.

FIG. 3 is an external perspective view showing a configuration of a crystal grain supply unit in FIG. 1.

FIG. 4 is a schematic cross-sectional view showing a main part of the crystal grain supply unit of FIG. 3.

FIG. 5 is a block diagram showing a schematic configuration of a control system.

FIG. 6 is a diagram for explaining an optical system of a crystal grain supply unit.

FIG. 7 is a flowchart illustrating a 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 an imitation operation.

FIG. 10 is a diagram showing an example of a unique portion (selection area).

FIG. 11 is a flowchart for explaining a continuous start operation.

FIG. 12 is a diagram showing an example of a registered image and a similar image.

FIG. 13 is a diagram showing an example in which the center of a crystal grain is obtained from a positional relationship of a pattern.

FIG. 14 is a diagram illustrating a method for detecting an abnormality.

FIG. 15 is a diagram showing the gradation values of a camera image with a large abnormal portion in the coordinate direction.

FIG. 16 is a diagram showing the gradation values of a camera image with a small abnormal portion in the coordinate direction.

FIG. 17 is a flowchart showing a surface inspection of the embodiment.

FIG. 18 is a diagram illustrating detection of an abnormal portion.

Claims (8)

A crystal sticking device is characterized by: Wafer supply unit, which is a dicing tape with die attached; A wafer recognition camera that recognizes the posture of the die on the dicing tape; The bonding head is used for bonding the foregoing crystal grains to the substrate or the crystal grains that have been bonded to the substrate; A substrate recognition camera that recognizes the posture of the aforementioned die to be bonded; and The control unit controls the wafer recognition camera and the substrate recognition camera, The control unit is configured as follows: The wafer identification camera is used to pick up the crystal grains on the dicing tape, to position the crystal grains, and The wafer recognition camera captures the crystal grains on the plurality of dicing tapes, averages the shade values of each pixel of the plurality of captured images to generate an averaged image, and generates a threshold based on the averaged image. The binary image with a value is determined based on the binary large object mark of the binary image to determine the presence or absence of the foreign matter of the crystal grains, and a surface inspection is performed. For example, the above-mentioned control unit is configured as follows: The bonded crystal grains are picked up by the substrate recognition camera, the position of the crystal grains is checked, and The substrate recognition camera captures a plurality of the bonded crystal grains, averages the shade values of each pixel of the plurality of captured images to generate an averaged image, and generates a second threshold value based on the averaged image. The valued image is determined based on the binary large object mark of the above-mentioned binary image to determine the presence or absence of the foreign matter of the crystal grains, and a surface inspection is performed. A crystal sticking device is characterized by: Wafer supply unit, which is a dicing tape with die attached; A wafer recognition camera that recognizes the posture of the die on the dicing tape; The bonding head is used for bonding the foregoing crystal grains to the substrate or the crystal grains that have been bonded to the substrate; A substrate recognition camera that recognizes the posture of the aforementioned die to be bonded; and The control unit controls the wafer identification camera and the substrate identification camera, The control unit is configured as follows: The bonded crystal grains are picked up by the substrate recognition camera, the position of the crystal grains is checked, and The substrate recognition camera captures a plurality of the bonded crystal grains, averages the shade values of each pixel of the plurality of captured images to generate an averaged image, and generates a second threshold value based on the averaged image. The valued image is determined based on the binary large object mark of the above-mentioned binary image to determine the presence or absence of the foreign matter of the crystal grains, and a surface inspection is performed. A crystal sticking device is characterized by: Wafer supply unit, which is a dicing tape with die attached; A wafer recognition camera that recognizes the posture of the die on the dicing tape; A picking head, which picks up the aforementioned crystal grains; An intermediate platform on which the aforementioned grains are placed; A platform recognition camera that recognizes the pose of the crystal grain on the intermediate platform; A bonding head for bonding the crystal grains placed on the intermediate platform to a substrate or crystal grains that have been bonded to the substrate; A substrate recognition camera that recognizes the posture of the aforementioned die to be bonded; and The control unit controls the wafer identification camera, the platform identification camera, and the substrate identification camera. The control unit is configured as follows: The platform recognition camera captures the crystal grains placed on the intermediate stage, checks the position of the crystal grains, and The platform recognition camera captures a plurality of the crystal grains placed on the intermediate platform, averages the shade values of each pixel of the plurality of captured images to generate an averaged image, and generates an averaged image based on the averaged image. The binary image of the critical value of is determined based on the binary large object mark of the binary image to determine the presence or absence of the foreign matter of the crystal grains, and the surface is inspected. For example, the above-mentioned control unit is configured as follows: The wafer identification camera に is used to pick up the crystal grains on the dicing tape, to position the crystal grains, and The wafer recognition camera captures the crystal grains on the plurality of dicing tapes, averages the shade values of each pixel of the plurality of 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 binary large object mark of the binary image to determine the presence or absence of the foreign matter of the crystal grains, and a surface inspection is performed. For example, for the crystal sticking device of the scope of application for patent No. 5, wherein the aforementioned control unit is further configured as: The bonded crystal grains are picked up by the substrate recognition camera, the position of the crystal grains is checked, and The substrate recognition camera captures a plurality of the bonded crystal grains, averages the shade values of each pixel of the plurality of captured images to generate an averaged image, and generates a second threshold value based on the averaged image. The valued image is determined based on the binary large object mark of the above-mentioned binary image to determine the presence or absence of the foreign matter of the crystal grains, and a surface inspection is performed. For example, the above-mentioned control unit is configured as follows: The bonded crystal grains are picked up by the substrate recognition camera, the position of the crystal grains is checked, and The substrate recognition camera captures a plurality of the bonded crystal grains, averages the shade values of each pixel of the plurality of captured images to generate an averaged image, and generates a second threshold value based on the averaged image. The valued image is determined based on the binary large object mark of the above-mentioned binary image to determine the presence or absence of the foreign matter of the crystal grains, and a surface inspection is performed. According to the crystal sticking device described in any one of claims 1 to 7, the aforementioned control unit is further configured as: The substrate is captured by the substrate recognition camera, and the positioning of the substrate is performed, and Capturing a plurality of substrates by the substrate recognition camera, averaging the shade values of each pixel of the captured images, to generate an averaged image, and generating a binary image based on a threshold value of the averaged image, The presence or absence of foreign matter on the substrate is determined based on the binary large object mark of the binary image, and a surface inspection is performed.