TW202418410A - Die bonder and buffer devices for die bonder - Google Patents

Abstract

The present invention discloses a die bonder and buffer devices for the die bonder. The present invention includes a rotary die stage that is rotated with an axis as the center by a rotary drive unit. The rotary die stage includes a die support part for supporting a die. The die support part is sequentially located at a first transfer position, a die inspection position and a second transfer position according to the rotation of the rotary die stage. The present invention further includes a die visual unit configured by a single camera module to catch a first side of the die transferred from the die support part to the die inspection position, and catch a second side of the die picked up by a bonding head from the second transfer position.

Description

Die bonding machine and buffer device for die bonding machine

An embodiment of the present invention relates to a die bonding machine used in performing a die bonding process.

To manufacture semiconductor devices, various processes need to be performed, one of which is the process of assembling a package. Generally, the process of assembling a package includes a dicing process to cut a semiconductor wafer into multiple individual dies, and a die bonding process to mount the dies obtained by the dicing process on a substrate such as a lead frame or a printed circuit board (PCB). Here, the equipment used to perform the die bonding process is a die bonding machine.

A die bonding machine as a bonding device includes a die supply device and a die bonding device. The die supply device supplies a die to be loaded on a substrate to the die bonding device, and the die bonding device loads the die from the die supply device on the substrate. To this end, the die supply device includes a die transfer unit that picks up and transfers the die from a pick-up position, and the die bonding device includes a bonding unit that picks up the die supplied by the die supply device and moves it to a bonding position and applies pressure for loading on the substrate.

The die transfer unit includes a transfer head configured to transfer the die from the pick-up position to the destination position while moving back and forth between the pick-up position and the destination position by vertical and horizontal movement. In view of this, conventional die bonding machines are limited in shortening the time required for the die transfer step for supplying the die to the die bonding device.

A visual inspection is performed on the top or bottom of a die during a series of processes of transferring the die from a pickup position to a bonding position. However, such a visual inspection has complicated the transfer path of the die or caused a delay in the transfer of the die in a conventional die bonding machine. [Prior Art Literature] [Patent Literature]

(Patent Document 1) Korean Public Patent Gazette No. 10-2017-0042955 (2017.04.20) (Patent Document 2) Korean Public Patent Gazette No. 10-2019-0019286 (2019.02.27) (Patent Document 3) Korean Public Patent Gazette No. 10-2391432 (2022.04.27)

An embodiment of the present invention is to provide a die bonding machine which is more advantageous in terms of improving efficiency, mainly by increasing the speed of the die bonding process.

The technical problems to be solved are not limited to these, and those skilled in the art will be able to clearly understand other technical problems not mentioned from the following description.

According to an embodiment of the present invention, a buffer device of a die bonding machine can be provided, comprising: a rotating die stage, which is rotated by a rotating drive unit and has a die supporting portion arranged along a peripheral area around a rotation center, the die supporting portion being sequentially located at a first transfer position, a die inspection position, and a second transfer position to transfer the die; and a die visual unit, which shoots the first side of the die transferred to the die inspection position through the die supporting portion through a first shooting path directly facing the die, and shoots the second side of the die picked up from the second transfer position by the bonding unit through a second shooting path passing through the interior of the rotating die stage.

The rotating grain stage may have a hollow region surrounded by a peripheral region, and through portions communicating with the hollow region are respectively provided between the grain supporting portions.

It may be that the first photographing path is provided for directly photographing the first side of the die transferred to the die inspection position, and the second photographing path is provided for photographing the second side of the die picked up from the second transfer position using the hollow area and the through portion.

It can be that the grain vision unit includes a first camera module and a second camera module, the first camera module and the second camera module are configured to face the grain inspection position around the rotating grain stage, the first shooting path will directly incident the image of the first side of the grain transmitted to the grain inspection position on the first camera module, the grain vision unit also includes: a mirror module, which is used to reflect the image of the second side of the grain picked up from the second transmission position to the second camera module in the hollow area, and the second shooting path reflects the image of the second side to the second camera module according to the position of the through part.

The crystal grain visual unit may further include: a position adjustment module, which moves the mirror module in a direction parallel to the crystal grain picked up from the second transfer position to adjust the position of the mirror module relative to the crystal grain picked up from the second transfer position. The second shooting path using the mirror module may be a right angle.

The die support portion and the through portion may be arranged at the same configuration angle along the peripheral region, the rotation drive unit rotates the rotating die stage by the configuration angle unit and moves the die support portion by the configuration angle unit, and the first transfer position, the die inspection position, and the second transfer position are set so that the die support portion that moves by the configuration angle unit can exist in sequence. There may be three or more die support portions.

The rotating grain stage may include: a rotating shaft providing a rotation center; a rotating member provided on the rotating shaft; a supporting member extending from the rotating member along the length direction of the rotating shaft and arranged at intervals around the rotation center to form a peripheral area; and a grain stage provided at the front end portion of each of the supporting members and having a grain supporting portion respectively, the grain supporting portions being arranged along the peripheral area and having a hollow area surrounded by the peripheral area, and each of the spaces formed between the grain stages is a through portion.

The rotating die stage may be configured such that the die support portion supports the die by adsorption. Each of the die support portions may be formed to have a receiving groove aligned with the die.

According to an embodiment of the present invention, a buffer device of a die bonding machine can be provided, comprising: a rotating die stage, which is rotated by a rotating driving unit and has a die supporting portion arranged along a peripheral area around a rotation center, the die supporting portion being sequentially located at a first transfer position, a die inspection position, and a second transfer position to transfer the die; and a die visual unit, which photographs the first side of the die transferred to the die inspection position through the die supporting portion through a first photographing path directly facing the first side, and photographs the second side of the die picked up from the second transfer position through the bonding unit through a second photographing path passing through the interior of the rotating die stage, the rotating die stage having a hollow area surrounded by the peripheral area, and two die supporting portions are respectively arranged between the die supporting portions and the second side of the die. The through portion is connected to the hollow area, the first shooting path is provided for directly shooting the first side of the grain transmitted to the grain inspection position, the second shooting path is provided for shooting the second side of the grain picked up from the second transmission position using the hollow area and the through portion, the grain visual unit includes a single camera module, the camera module is configured to face the grain inspection position around the rotating grain stage, the first shooting path will directly incident the image of the first side of the grain transmitted to the grain inspection position on the camera module, the grain visual unit also includes: a mirror module, which is used to reflect the image of the second side of the grain picked up from the second transmission position in the hollow area to the camera module, and the second shooting path reflects the image of the second side to the camera module according to the position of the through portion. At this time, a single camera module may be able to switch the focus to a first focus for photographing a first side of a die transferred to a die inspection position or a second focus for photographing a second side of a die picked up from a second transfer position.

According to an embodiment of the present invention, a buffer device of a die bonding machine can be provided, comprising: a rotating die stage, which is rotated by a rotating driving unit, and has a die support portion arranged along a peripheral area around a rotation center, the die support portion being sequentially located at a first transfer position, a die inspection position, and a second transfer position to transfer the die; and a die visual unit, which transmits the die through the die support portion. The first side of the die to the die inspection position is photographed through the first photographing path directly facing it, and the second side of the die picked up from the second transfer position by the bonding unit is photographed through the second photographing path passing through the interior of the rotating die stage, the rotating die stage having a hollow area surrounded by a peripheral area, and through parts connected to the hollow area are respectively arranged between the die supporting parts, and the first photographing path provides In order to directly photograph the first side of the grain transmitted to the grain inspection position, the second shooting path is provided to photograph the second side of the grain picked up from the second transmission position using the hollow area and the through part, the through parts are provided to form a pair of two and are opposite to each other with the rotation center as the center, the grain inspection position is set to be opposite to the second transmission position, the grain visual unit includes a first camera module and a second camera module, the first camera module and the second camera module are configured to face the grain inspection position around the rotating grain stage, the first shooting path will directly incident on the first camera module the image of the first side of the grain transmitted to the grain inspection position, and the second shooting path will incident on the second camera module the image of the second side of the grain picked up from the second transmission position according to the position of the through parts that form a pair of two. At this time, the crystal grain visual unit may further include: a position adjustment module, which enables the first camera module and the second camera module to move in a direction parallel to the crystal grain to be photographed.

According to an embodiment of the present invention, a die bonding machine can be provided, comprising: a die transfer unit, which transfers a die from a pick-up position to a first transfer position; a bonding unit, which picks up a die from a second transfer position and loads it on a substrate; and a buffer device between the die transfer unit and the bonding unit, wherein the buffer device comprises: a rotating die stage, which is rotated by a rotating drive unit and has a die arranged along a peripheral area around a rotation center. A grain supporting part, which is sequentially located at a first conveying position, a grain inspection position and a second conveying position to convey the grain; and a grain visual unit, which shoots the first side of the grain conveyed to the grain inspection position through the grain supporting part through a first shooting path directly facing the grain, and shoots the second side of the grain picked up from the second conveying position through the bonding unit through a second shooting path passing through the interior of the rotating grain stage.

In the die bonding machine according to the embodiment of the present invention, the rotating die stage may have a hollow area surrounded by a peripheral area, and through parts communicating with the hollow area are respectively provided between the die supporting parts.

In the die bonding machine according to the embodiment of the present invention, the first shooting path may be provided for directly shooting the first side of the die transferred to the die inspection position, and the second shooting path may be provided for shooting the second side of the die picked up from the second transfer position using the hollow area and the through part.

In the grain bonding machine according to the embodiment of the present invention, the rotation center of the rotating grain stage may be arranged in the horizontal direction, and the grain transfer unit includes: a transfer head, which transfers the grain at the picking position or the first transfer position according to the swinging movement centered on the horizontal axis parallel to the rotation center; and a swinging drive module, which provides power for the swinging movement to the transfer head.

According to an embodiment of the present invention, a die bonding machine can be provided, comprising: a wafer stage, supporting a wafer holding a die; a wafer stage driving unit, moving the wafer stage in a horizontal direction to selectively position the die at a pick-up position; a die transfer unit, transferring the die from the pick-up position to a first transfer position; a buffer device, receiving the die from the first transfer position and transferring the die to a second transfer position; and a bonding unit, picking up the die from the second transfer position and transferring the die to a second transfer position. The buffer device comprises: a rotating crystal stage, having a peripheral area around a horizontal axis and a hollow area surrounded by the peripheral area, crystal support parts arranged along the peripheral area and through parts respectively arranged between the crystal support parts to communicate with the hollow area are arranged at the same configuration angle, the rotating crystal stage rotates with the horizontal axis as the center by a unit of the configuration angle, and the crystal support parts and the through parts are sequentially located at a first transfer position, a crystal inspection position, and a crystal inspection position. position and a second transmission position; a rotation drive unit that rotates the rotating die stage by a unit of a configuration angle; a die visual unit that includes a first camera module and a second camera module, the first camera module photographing the first side of the die that is transmitted to the die inspection position through the die support portion through a first shooting path, and the second camera module photographing the second side of the die that is picked up from the second transmission position through the bonding unit through a second shooting path, the first camera module and the second The camera module is configured to face the grain inspection position around the rotating grain stage, and the first shooting path directly incidents the image of the first side of the grain transmitted to the grain inspection position on the first camera module. The grain visual unit also includes: a mirror module, which is used to reflect the image of the second side of the grain picked up from the second transmission position to the second camera module in the hollow area, and the second shooting path reflects the image of the second side to the second camera module according to the position of the through part.

The solution to the technical problem will be more specific and clear through the following embodiments, drawings, etc. In addition, various solutions other than the solutions mentioned below can be additionally proposed.

According to the embodiments of the present invention, the die transfer speed can be increased, and the upper and lower sides of the die can be inspected by a simple structure without delaying the die transfer, thereby greatly improving the unit per hour (UPH).

According to the embodiments of the present invention, a buffer device including a rotating die stage which is lightweight, compact, simple in structure and easy to manufacture can be provided.

The effects of the invention are not limited to these, and those skilled in the art will be able to clearly understand other effects not mentioned from this specification and the attached drawings.

Hereinafter, with reference to the attached drawings, embodiments of the present invention are described in detail so that a person having ordinary knowledge in the technical field to which the present invention belongs can easily implement it. However, the present invention can be implemented in various different forms and is not limited to the embodiments described here.

When describing the embodiments of the present invention, if a specific description of a related well-known function or structure is judged to be unnecessarily obscuring the gist of the present invention, the specific description will be omitted, and parts with similar functions and effects will use the same figure labels throughout the entire drawings.

At least part of the terms used in the specification are defined in consideration of the functions in the specification and may be changed according to the user, the intention of the user, custom, etc. Therefore, the terms should be interpreted based on the content throughout the specification. In addition, in the specification, when it is said that a certain constituent element is included, unless there is a special record to the contrary, this does not exclude other constituent elements and means that other constituent elements may also be included. In addition, when it is said that a certain part is connected (or combined) with other parts, this includes not only the case of direct connection (or combination) but also the case of indirect connection (or combination) through other parts.

On the other hand, in the drawings, the size or shape of components, the thickness of lines, etc. may be expressed slightly exaggerated for easier understanding.

The die bonding machine according to the embodiment of the present invention can be used in the die bonding process to load the die on a substrate such as a lead frame, a PCB, etc. Here, the die loaded on the substrate can be assigned grades according to the working performance, etc. In addition, these die can also be loaded on the bonding area on the substrate, or can be loaded on other die already loaded on the substrate.

The structure and operation of the die bonding machine according to the first embodiment of the present invention are shown in FIGS. 1 to 11 .

1 , a die bonding machine according to a first embodiment of the present invention includes: a die supply device 100 for supplying a die 20 to be loaded on a substrate 30; a die bonding device 200 for loading the die 20 on the substrate 30 (i.e., selectively loading the die 20 on a bonding area on the substrate or on other die already loaded on the substrate); a buffer device 300 disposed between the die supply device 100 and the die bonding device 200; and a control unit (not shown) for controlling the operation of the die supply device 100, the die bonding device 200 and the buffer device 300.

1, 2, etc., the die 20 may be moved from the pick-up position P1 to the bonding position P3 via the first transfer position P21, the die inspection position P23, and the second transfer position P22 in sequence. The die supply device 100 may transfer the die 20 from the pick-up position P1 to the first transfer position P21, and the die bonding device 200 may transfer the die 20 from the second transfer position P22 to the bonding position P3. The buffer device 300 may transfer the die 20 from the first transfer position P21 to the second transfer position P22 via the die inspection position P23. The buffer device 300 may receive the transfer of the die 20 from the die supply device 100 at the first transfer position P21, and transfer it to the die bonding device 200 at the second transfer position P22.

Thus, compared with the direct method of directly transferring the die 20 from the pick-up position P1 to the joining position P3, the multi-stage method of transferring the die 20 from the pick-up position P1 to the transfer positions P21 and P22, and then transferring from the transfer positions P21 and P22 to the joining position P3 can ensure increased productivity. As the die 20 becomes thinner or larger, the time required to supply the die 20 (the die picking time using the die ejector 120 and the transfer head 131 described later) increases, so that the die supply operation speed can be greatly slowed down compared to the die loading operation speed. The multi-stage method of transferring the die 20 can prevent the decrease in productivity even in such an environment.

2 and the like, the die supply device 100 includes: a wafer stage 110 for supporting a wafer 10; a wafer stage driving unit (not shown) for moving the wafer stage 110 in a horizontal direction (e.g., X direction and Y direction); a die ejector 120 for selectively separating a die 20 on the wafer 10 supported by the wafer stage 110 from the wafer 10; and a die transport unit 130 for transporting the die 20 separated by the die ejector 120.

1, 2, etc., a wafer 10 includes individualized dies 20 through a dicing process performed before a die bonding process, and further includes a dicing tape 11 to which the dies 20 are attached, and a ring-shaped wafer frame 12 for holding the dicing tape 11. The dicing tape 11 may be held by the wafer frame 12 by attaching the edge portion to the bottom of the wafer frame 12. The individualized dies 20 may be arranged on the central portion of the dicing tape 11.

The wafer stage 110 includes a ring-shaped stage base 111, a support ring 112 protruding from the stage base 111, and a wafer expander 113 provided around the support ring 112. The support ring 112 uniformly supports the center portion and the edge portion of the extendable dicing tape 11 from below. The wafer expander 113 moves the wafer frame 12 downward in the up-down direction corresponding to the vertical direction (Z direction), so that the dicing tape 11 supported by the support ring 112 is extended as a whole, and the space between the dies 20 attached to the dicing tape 11 is expanded. The function of the wafer expander 113 can improve the accuracy and efficiency of the die separation work through the die ejector 120.

The wafer expander 113 may include frame clamps for clamping or releasing the wafer frame 12 at multiple positions and a clamp lifting module for moving the frame clamps in the up and down direction (Z direction). The clamp lifting module may be disposed on the stage base 111.

The wafer stage driving unit can move the stage base 111 in the horizontal direction to move the wafer stage 110 to the target position. For example, the wafer stage driving unit can selectively position the die 20 on the wafer 10 supported by the wafer stage 110 at the pickup position P1 by moving the wafer stage 110 in the horizontal direction. To this end, the die supply device 100 can include a wafer vision unit (not shown) for detecting the die to be loaded on the substrate 30 among the die 20 on the wafer 10 supported by the wafer stage 110, and the wafer stage driving unit can work to move the wafer stage 110 in the horizontal direction according to the detection result of the wafer vision unit so that the die 20 to be loaded on the substrate 30 is correctly positioned at the pickup position P1.

The die ejector 120 is provided inside the wafer stage 110 and is configured to be below the wafer 10 supported by the wafer stage 110 and opposite to the pick-up position P1. The die ejector 120 may include: a tape adsorption module that utilizes vacuum to adsorb the cutting tape 11; and an ejection module that pushes the die 20 located at the pick-up position P1 upward in the up-down direction by a push-up operation. In order to separate the die 20 located at the pick-up position P1 from the wafer 10, the die ejector 120 may push up the die 20 at the pick-up position P1 through the ejection module while the cutting tape 11 is adsorbed on the tape adsorption module, so that the cutting tape 11 is peeled off from the die 20 at the pick-up position P1.

2 to 4 , the die transfer unit 130 includes a transfer head 131 for picking up the die 20 pushed up by the die ejector 120. The first transfer position P21 is located above the wafer stage 110, higher than the pick-up position P1, and is separated from the pick-up position P1 in the horizontal direction (e.g., X direction). The die transfer unit 130 is configured to transfer the die 20 from the pick-up position P1 to the first transfer position P21 while the transfer head 131 moves back and forth between the pick-up position P1 and the first transfer position P21 through a swinging motion at a certain angle.

Specifically, the die transport unit 130 may further include a swing axis 132 provided in a horizontal direction (e.g., Y direction) above the pickup position P1 and a swing drive module 133 for providing a driving force required for the swing movement to the transport head 131, so that the transport head 131 may swing around the swing axis 132. In addition, the die transport unit 130 may further include a linear actuator 134 to move the transport head 131 in a direction that is spaced apart from and close to the swing axis 132. For example, the linear actuator 134 may move the transport head 131 in a radial direction around the swing axis 132.

The swing drive module 133 may include a rotary motor that rotates the swing shaft 132 in two directions. The linear actuator 134 may include a moving body that performs linear motion and has a first end and a second end, the first end (fixed end) is provided on the swing shaft 132, and the second end (free end) holds the moving body. The conveying head 131 may be provided at the second end (moving body) of the linear actuator 134. The conveying head 131 may pick up and hold the die 20 by adsorption.

In the observed die transfer unit 130, in order to transfer the die 20 from the pickup position P1 to the first transfer position P21, the transfer head 131 located at the pickup position P1 can approach the die 20 at the pickup position P1 through the linear actuator 134 in a pickup posture with the suction front end opposite to the pickup position P1, and pick up the die 20 at the pickup position P1. At this time, the top of the die 20 is suctioned to the suction front end of the transfer head 131. After picking up the die 20, the transfer head 131 can rise through the linear actuator 134 to avoid interference with the die ejector 120, and then rotate and move to the first transfer position P21 through the swing drive module 133, so as to be located at the first transfer position P21. If the transfer head 131 is configured to transfer the die 20 from the pickup position P1 to the first transfer position P21 by swinging motion, the transfer speed of the rising die 20 can be ensured compared to the prior art die transfer method that uses vertical and horizontal movements.

1 , a wafer 10 including dies 20 individualized by a dicing process is housed in a cassette 40. Of course, the cassette 40 may be configured to accommodate a plurality of wafers 10. The die supply device 100 may further include a load port 140 for loading the cassette 40 and a wafer transfer unit 150 for loading the wafer 10 taken out from the cassette 40 on the load port 140 onto the wafer stage 110. In order to load the taken-out wafer 10 onto the wafer stage 110, the taken-out wafer 10 may be moved in a horizontal direction (e.g., in the X direction) along a wafer transfer rail 160, and the wafer stage 110 may be moved toward the side of the wafer 10 moving along the wafer transfer rail 160 by the aforementioned wafer stage drive unit (e.g., in the Y direction).

The second transfer position P22 is higher than the first transfer position P21. The die 20 transferred from the first transfer position P21 to the second transfer position P22 remains in a horizontal state. Referring to FIG. 1 , FIG. 7 , etc., the die bonding device 200 includes a bonding unit 210 for picking up the die 20 transferred to the second transfer position P22 and loading it on the substrate 30, and a bonding stage 220 for supporting the substrate 30 at the bonding position P3.

The bonding unit 210 includes a bonding head 211 for picking up the die 20 from the second transfer position P22 and a bonding head driving module for moving the bonding head 211. The bonding head driving module may be composed of a bonding head vertical driving module 212 for moving the bonding head 211 in the vertical direction and a bonding head horizontal driving module 213 for moving the bonding head 211 in the horizontal direction (e.g., Y direction). The bonding head 211 of the bonding unit 210 may move between the second transfer position P22 and the bonding position P3 which are spaced apart from each other in the horizontal direction (e.g., Y direction). The bonding unit 210 can transfer the die 20 from the second transfer position P22 to the bonding position P3 by means of the bonding head 211 picking up the die 20 and the bonding head driving module (refer to 212, 213) moving the bonding head 211 in the vertical and horizontal directions, and can apply pressure to the die 20 for loading the die 20 onto the substrate 30.

The bonding head 211 may include a bonding tool for picking up and holding the die 20 by suction and a heater for heating the die 20 held by the bonding tool to a bonding temperature. The bonding head 211 may be configured to transfer the heat of the heater to the die 20 through the bonding tool. The bonding head vertical drive module 212 may be connected to the bonding head 211, and the bonding head horizontal drive module 213 may be connected to the bonding head vertical drive module 212. The bonding stage 220 may heat the supported substrate 30 to a bonding temperature.

The substrate 30 is stored in a magazine. The substrate 30 is supplied from the first magazine 50 to the bonding position P3, and is stored in the second magazine 55 after the loading of the die 20 is completed. The die bonding device 200 may further include a substrate conveying unit 230. The substrate conveying unit 230 may convey the substrate 30 from the first magazine 50 to the bonding stage 220, and may convey the substrate 30 from the bonding stage 220 to the second magazine 55. The substrate 30 may be moved more accurately along the guidance of the substrate conveying guide rail 240 between the first magazine 50 and the second magazine 55 which are spaced apart from each other in the horizontal direction (e.g., X direction). The substrate conveying unit 230 may include one or more grippers 231 for holding or releasing the substrate 30, and a gripper driving module 232 for moving the gripper 231 in the horizontal direction (e.g., X direction).

2, 9, 10, etc., the buffer device 300 includes a rotating die stage (refer to 310, 330, 340), a rotating driving unit 320, and a die visual unit 350. The buffer device 300 can be disposed above the wafer stage 110 by means of a mounting structure.

The rotating crystal stage has a horizontal axis A parallel to the swing axis 132 (eg, Y direction) as the rotation center. The rotating crystal stage has a peripheral region 301 centered on the horizontal axis A and a hollow region 302 surrounded by the peripheral region 301 . A crystal support portion 341 and a through portion 303 are provided in the peripheral region 301 .

The peripheral region 301 is provided around the hollow region 302. The hollow region 302 is provided inside the peripheral region 301 and is composed of an empty space. The grain supporting portions 341 support the grains 20 respectively. The grain supporting portions 341 are arranged at intervals along the peripheral region 301 to be separated from each other. The through portions 303 are provided to communicate with the hollow regions 302 respectively between the grain supporting portions 341. The grain supporting portions 341 and the through portions 303 are arranged at the same intervals along the peripheral region 301 according to a configuration angle set in advance (hereinafter, referred to as a setting angle). For example, if four die supporting portions 341 are provided, four through portions 303 are also provided, so the setting angle in this case is 45 degrees, and the four die supporting portions 341 and the four through portions 303 are alternately arranged at intervals of 45 degrees.

The rotating die stage can rotate only in one direction with the horizontal axis A as the center. The rotating die stage is rotated by the rotation drive unit 320 in units of a set angle. For example, if there are four die support portions 341 and thus four through portions 303, the rotation drive unit 320 rotates the rotating die stage in units of 45 degrees. Of course, according to the step rotation of the rotating die stage, the die support portions 341 move together with the through portions 303 in units of a set angle.

The die support portion 341 and the through portion 303 can be positioned at the first transfer position P21 and the second transfer position P22 in sequence by rotating the set angle unit, and can be positioned at the die inspection position P23 in sequence in the process of moving from the first transfer position P21 to the second transfer position P22. The rotational movement of the die support portion 341 and the through portion 303 is repeated, so that the die support portion 341 and the through portion 303 can repeat the process of passing through the first transfer position P21, the die inspection position P23, and the second transfer position P22 in sequence. Of course, the first transfer position P21, the die inspection position P23, and the second transfer position P22 are set to have a configuration structure in which the die support portion 341 and the through portion 303 can exist in sequence.

Such a rotating die stage includes a rotating shaft 310 disposed on a horizontal axis A, a rotating member 331 provided on the rotating shaft 310, a supporting member 332 provided on the rotating member 331, and a die stage 340 supported by the supporting member 332. In FIG. 9 , reference numeral 330 is a rotating frame, and the rotating frame 330 includes a rotating member 331 and a supporting member 332.

The rotating shaft 310 is rotated by a set angle unit through the rotating drive unit 320. The rotating component 331 may be formed to have a disc structure. The rotating drive unit 320 may be arranged behind (or in front of) the rotating component 331, and the rotating shaft 310 may be arranged between the rotating drive unit 320 and the rotating component 331. The rotating drive unit 320 may include a rotating motor connected to the rotating shaft 310.

The support member 332 extends from the rotating member 331 in a horizontal direction (e.g., Y direction) parallel to the length direction of the rotating shaft 310. The support members 332 are arranged at intervals around the horizontal axis A to be separated from each other to form a peripheral area 301. The support members 332 may protrude forward (or backward) of the rotating member 331. The die stages 340 are provided at the front end portions of the support members 332. The die stages 340 have die supporting portions 341. The die stages 340 are arranged on the outer side of the die supporting portions 341, one of the inner side facing the horizontal axis A and the outer side opposite thereto.

According to the structure of the rotating die stage, a rotating die stage can be provided, wherein the die support portions 341 are arranged along the peripheral region 301, the rotating die stage has a hollow region 302 surrounded by the peripheral region 301, the space formed between the die stages 340 is a through portion 303, and the die support portions 341 and the through portion 303 are arranged at intervals at a set angle along the peripheral region 301. In addition, by means of the hollow region 302 and the through portion 303, a rotating die stage that is lightweight, has a simple structure, and is easy to manufacture can be provided.

The rotating grain stage is constituted by a grain support portion 341 of the grain stage 340, which supports the grain 20 by suction. As shown in FIG. 11 , the grain support portion 341 is formed into a shape of a receiving groove that is aligned with the grain 20. The grain stage 340 supports the grain 20 in a state where the grain 20 is accommodated in the receiving groove. As an example, the receiving groove can be formed into a shape corresponding to the grain 20 and aligned with the direction of the grain 20. The grain stage 340 is provided with one or more suction holes 342 at the bottom of each grain support portion 341 (i.e., the receiving groove) for vacuum suction of the grain 20.

3 , the transfer head 131 moved from the pick-up position P1 to the first transfer position P21 changes from the pick-up position to the transfer position. The transfer head 131 can be in a vertical state in the pick-up position (the die picked up by the transfer head is in a horizontal state) (refer to FIG. 2 ), and can be in a state tilted at a predetermined angle relative to the vertical direction in the transfer position (for example, a horizontal state rotated 90 degrees from the pick-up position) (the die picked up by the transfer head is in a vertical state). The die stage 340 can receive the die 20 from the transfer head 131 at the first transfer position P21 (refer to FIG. 3 ), transfer the received die 20 to the second transfer position P22 by rotational movement of a set angle unit, and transfer the transferred die 20 to the bonding head 211 at the second transfer position P22 (refer to FIG. 7 ).

When the die stage 340 is located at the first transfer position P21, the die support portion 341 is opposite to the suction front end of the transfer head 131 in the transfer posture. At this time, the transfer head 131 approaches the die support portion 341 opposite to the suction front end through the operation of the linear actuator 134, and places the die 20 transferred from the pickup position P1 on the approaching die support portion 341. Through this, the die 20 is accommodated in the die support portion 341 in an aligned state, and the lower surface (second surface) is suctioned to the die support portion 341.

If the die stage 340 moves to the vertex of the peripheral area 301, it is located at the second transfer position P22. When the die stage 340 is located at the second transfer position P22, the die support portion 341 is opposite to the bonding tool of the bonding head 211 located at the second transfer position P22. At this time, the bonding head 211 approaches the die support portion 341 opposite to the bonding tool through the bonding head vertical drive module 212, and picks up the die 20 transferred from the first transfer position P21 by the approaching die support portion 341. At this time, the upper surface (first surface) of the die 20 is adsorbed on the bonding tool.

The die visual unit 350 includes a first camera module 351, a second camera module 352, and a mirror module 353. For visual inspection of the die 20, the die visual unit 350 obtains an image of the upper surface (first surface) of the die 20 transferred to the die inspection position P23 through the die support portion 341, and obtains an image of the lower surface (second surface) of the die 20 picked up from the second transfer position P22 by the bonding head 211.

The first camera module 351 and the second camera module 352 are provided around the rotating die stage. The first and second camera modules 351 and 352 are arranged around the rotating die stage to face the die inspection position P23 and are fixed in position by a separate frame or the like. The die inspection position P23 is located on the side of the rotating die stage, so the first and second camera modules 351 and 352 are also arranged on the side of the rotating die stage.

The structure in which the first and second camera modules 351 and 352 are arranged on the side of the rotating die stage can prevent the upper and lower dimensions of the buffer device 300 from increasing, and can prevent the die transfer path from being extended. If the camera module is arranged below the rotating die stage, the upper and lower dimensions of the buffer device 300 are increased to ensure the working distance (WD) of the camera module, and the rotating die stage and the pick-up position P1 are placed close to each other above the wafer stage 110 may be limited. If the upper and lower dimensions of the buffer device 300 increase and the rotating die stage moves away from the pick-up position P1 in the horizontal direction, and the height difference between the first transfer position P21 and the pick-up position P1 increases, etc., the die transfer path may be extended and the die transfer speed may be slowed down.

The mirror module 353 is disposed in the hollow area 302, and rotates about the horizontal axis A with respect to the rotating die stage, and its position is fixed by a separate frame and maintained in a stationary state. The mirror module 353 includes a mirror tilted relative to the second transfer position P22 and the die inspection position P23, and the mirror is provided to reflect the image from the second transfer position P22 side to the die inspection position P23 side.

The first camera module 351 may be opposite to the top of the die 20 transferred to the die inspection position P23 through the die support portion 341. In this regard, the top of the die 20 transferred to the die inspection position P23 may be directly exposed to the first camera module 351. Therefore, the die visual unit 350 may capture and obtain an image of the top of the die 20 through a first capturing path in which the image of the top of the die 20 transferred to the die inspection position P23 is directly incident on the first camera module 351.

According to the angle of rotation of the rotating die stage, the through portion 303 between the die support portions 341 can be located at the second transfer position P22 and the die inspection position P23. In a state where the bonding head 211 picks up the die 20 from the second transfer position P22, if the through portion 303 is located at the second transfer position P22 and the die inspection position P23, an image of the bottom of the die 20 picked up from the second transfer position P22 by the bonding head 211 can be mapped to the mirror of the mirror module 353, and the image mapped to the mirror can be reflected to the second camera module 352. In this regard, the bottom of the die 20 picked up from the second transfer position P22 can be exposed to the second camera module 352 through the hollow area 302 equipped with the mirror module 353 and the through portion 303 connected thereto. Therefore, the die visual unit 350 can capture and obtain an image of the bottom of the die 20 by causing the image of the bottom of the die 20 picked up from the second transfer position P22 to be incident on the second capturing path of the second camera module 352 through the reflection effect of the mirror module 353.

In order to improve the quality of the image taken on the bottom of the die 20 , the second shooting path (optical axis) taken by the second camera module 382 using the lens module 353 for the bottom of the die 20 picked up by the bonding head 211 is preferably refracted at a right angle as shown in FIG. 8 .

The first shooting path for the first camera module 351 and the second shooting path for the second camera module 352 may be different in length from each other. The first camera module 351 may be maintained in a state set to a first focus point that can obtain a clear image for the upper surface of the die 20 transferred to the die inspection position P23. The second camera module 352 may be maintained in a state set to a second focus point that can obtain a clear image for the lower surface of the die 20 picked up from the second transfer position P22 by the bonding head 211.

The entire bottom of the die 20 picked up by the bonding head 211 may not be mapped to the mirror module 353 depending on the size or the suction position relative to the bonding tool. Therefore, although not shown, the die visual unit 350 may further include a position adjustment module for precisely moving the mirror module 353 in the horizontal direction (e.g., X direction and Y direction) which is a direction parallel to the die 20 picked up by the bonding head 211 to adjust the position of the mirror module 353 relative to the die 20 picked up by the bonding head 211. According to this position adjustment module for the mirror module 353, the positional relationship of the mirror module 353 relative to the bottom of the die 20 picked up by the bonding head 211 can be easily changed, thereby providing a more accurate image of the bottom of the die 20 picked up by the bonding head 211 to the second camera module 352.

FIG2 shows a state where the die ejector 120 peels off the dicing tape 11 from the die 20 located at the pickup position P1, and the transfer head 131 picks up the die 20 located at the pickup position P1. In addition, FIG2 shows a state where the rotating die stage rotates at a set angle and any one of the die stages 340 (refer to the first die stage 340a) is located at the first transfer position P21. As an example, in the case where four die stages 340 and the through portions 303 therebetween are provided, if any one of the die stages (refer to the first die stage 340a) is located at the first transfer position P21, any two of the remaining three die stages are located at the die inspection position P23 and the second transfer position P22, respectively.

FIG. 3 shows a state in which the transfer head 131 moves from the pick-up position P1 to the first transfer position P21 in order to transfer the picked-up die 20 to the die stage (refer to the first die stage 340 a ) located at the first transfer position P21 .

Fig. 4 shows a state where the transfer head 131 transfers the picked-up die 20 to the die stage (refer to the first die stage 340a) located at the first transfer position P21 and then returns to the pick-up position P1. In addition, Fig. 4 shows a state where the die stage (refer to the first die stage 340a) located at the first transfer position P21 receives the die 20 from the transfer head 131 and is supported by adsorption and then rotates the die stage to rotate at a set angle. As an example, in the case where four die stages 340 and four through portions 303 therebetween are provided, if the die stage 340 located at the first transfer position P21 receives the die 20 from the transfer head 131 and then rotates the die stage at a set angle (45 degrees), any three through portions 303 are located at the first transfer position P21, the die inspection position P23, and the second transfer position P22, respectively.

FIG. 5 shows that the rotating die stage is rotated at a set angle in the state of FIG. 4 , another die stage (refer to the second die stage 340 b ) is located at the first transfer position P21 , and the transfer head 131 transfers the die 20 to another die stage (refer to the second die stage 340 b ) located at the first transfer position P21 .

FIG6 shows that as the rotating die stage repeatedly rotates at a set angle, the die stage (refer to the first die stage 340a) receiving the die 20 from the transfer head 131 is located at the die inspection position P23, and the first camera module 351 photographs the top of the die 20 transferred to the die inspection position P23. In addition, FIG6 shows that another die stage (refer to the third die stage 340c) is located at the first transfer position P21, and the transfer head 131 transfers the die 20 to another die stage (refer to the third die stage 340c) located at the first transfer position P21.

FIG. 7 shows that as the rotating die stage repeatedly rotates at a set angle, the die stage (refer to the first die stage 340a) located at the die inspection position P23 moves and is located at the second transfer position P22, so that the die 20 is transferred from the die inspection position P23 to the second transfer position P22, thereby another die stage (refer to the second die stage 340b) supporting the die is located at the die inspection position P23. In addition, FIG. 7 shows a state in which the bonding head 211 picks up the die from the second transfer position P22. In addition, FIG. 7 shows a state in which another die stage (refer to the fourth die stage 340d) is located at the first transfer position P21, and the transfer head 131 transfers the die 20 to another die stage (refer to the fourth die stage 340d) located at the first transfer position P21.

FIG8 shows a state in which the bonding head 211 that picks up the die 20 from the die stage (refer to the first die stage 340a) at the second transfer position P22 rises and rotates the die stage at a set angle. At this time, the bottom of the die 20 picked up by the bonding head 211 is exposed to the second camera module 352 through the hollow area 302 configured with the mirror module 353 and the through portion 303 connected thereto. In addition, FIG8 shows a state in which the mirror module 353 reflects the image of the bottom of the die 20 to the second camera module 352, and the second camera module 352 obtains the image of the bottom of the die 20. In addition, FIG8 shows a state in which the transfer head 131 returns to the pick-up position P1 after transferring the picked-up die 20 to the die stage 340 at the first transfer position P21.

The above operations can be controlled by the control unit. The buffer device 300 can transfer the die 20 from the die supply device 100 to the die bonding device 200 while repeatedly performing the above operations, temporarily store the die 20, and obtain images for visual inspection of the top and bottom of the die 20.

As observed, the die stage 340 of the die bonding machine according to the first embodiment of the present invention is configured to rotate in units of a set angle along the circumferential direction centered on the horizontal axis A and is sequentially located at the first transfer position P21, the die inspection position P23 and the second transfer position P22, so that the die 20 can be transferred from the die supply device 100 to the die bonding device 200 without delay, and the die 20 can be temporarily stored during this process, thereby ensuring an increased working speed. In addition, the die bonding machine according to the first embodiment of the present invention constructed as observed utilizes the hollow area 302 as the internal space of the rotating die stage and obtains an image for visual inspection of the bottom of the die 20 picked up by the bonding head 211, thereby simply suppressing the increase in the volume of the buffer device 300 through the die visual unit 350 and obtaining a good image of the bottom of the die 20.

The main part of the die bonding machine according to the second embodiment of the present invention is shown in FIG12. As shown in FIG12, the die bonding machine according to the second embodiment of the present invention is different from the first embodiment of the present invention in that the die visual unit 350 is configured to be able to photograph the bottom of the die 20 without a mirror module (refer to 353 in FIG2).

For this purpose, in the die bonding machine according to the second embodiment of the present invention, the rotating die stage may be provided so that the die supporting parts 341 and the through parts 303 arranged at the same interval along the peripheral area 301 according to the set angle (for example, 45 degrees) have an even number, and the through parts 303 form a pair of two each and are opposite to each other with the horizontal axis (the rotation center of the rotating die stage) as the center. In addition, the second transfer position P22 and the die inspection position P23 may be set to be opposite to each other. The first camera module 354 and the second camera module 355 may be arranged around the rotating die stage so as to face the die inspection position P23 and also be opposite to the second transfer position P22 according to the positions of the through parts 303 forming a pair of two each.

FIG. 12( a ) shows a state where the first camera module 354 directly captures the top surface of the die 20 transferred to the die inspection position P23 via the first imaging path, and a state where the bonding head 211 picks up the die 20 transferred to the second transfer position P22 .

FIG. 12( b ) shows a state in which the bonding head 211 that picks up the die 20 from the second transfer position P22 rises from the state in FIG. 12( a ), the rotating die stage rotates by a set angle, and any two through portions 303 that are opposite to each other and form a pair are located at the die inspection position P23 and the second transfer position P22, respectively, and the second camera module 355 photographs the bottom of the die 20 picked up by the bonding head 211. At this time, the second camera module 355 photographs the bottom of the die 20 without a mirror module (refer to 353 in FIG. 2 ) through a second photographing path that passes through the through portions 303 located at the die inspection position P23 and the second transfer position P22, respectively, and the hollow area 302 connected to the two through portions 303.

Depending on the size of the die 20, the adsorption position of the die 20 relative to the die stage 340 and/or the bonding head 211, the position of the first camera module 354 and/or the second camera module 355, etc., the top of the die 20 transferred to the die inspection position P23 via the die stage 340 may not be completely exposed to the first camera module 354, and the bottom of the die 20 picked up by the bonding head 211 may not be completely exposed to the second camera module 355. Therefore, although not shown in the figure, the die vision unit 350 of the die bonding machine according to the second embodiment of the present invention may further include a position adjustment module, which adjusts the positions of the first camera module 354 and the second camera module 355 relative to the die 20 to be photographed by quickly and accurately moving the first camera module 354 and the second camera module 355 in the horizontal direction (e.g., X direction and Y direction) which is a direction parallel to the die to be photographed (the die transferred to the die inspection position P23, the die picked up by the bonding head 211). According to such a position adjustment module for the camera module, the positions of the first camera module 354 and the second camera module 355 relative to the top and bottom of the grain 20 to be photographed can be changed quickly and easily, thereby providing the first camera module 354 and the second camera module 355 with more accurate images of the top and bottom of the grain 20 to be photographed.

FIG12(a) shows a state where the first camera module 354 and the second camera module 355 are moved so that the top of the die 20 transferred to the die inspection position P23 via the die stage 340 can be accurately photographed by the first camera module 354. FIG12(b) shows a state where the first camera module 354 and the second camera module 355 are moved so that the bottom of the die 20 picked up by the bonding head 211 can be accurately photographed by the second camera module 355.

The main part of the die bonding machine according to the third embodiment of the present invention is shown in FIG13. As shown in FIG13, the die bonding machine according to the third embodiment of the present invention is different from the first embodiment of the present invention only in that the die visual unit 350 is configured to obtain an image of the top and an image of the bottom of the die 20 using a single camera module 356.

It may be that in the die bonding machine according to the third embodiment of the present invention, the camera module 356 is arranged around the rotating die stage and facing the upper surface of the die 20 transferred to the die inspection position P23, and the mirror module 357 arranged in the hollow area 302 is provided to map the image of the lower surface of the die 20 picked up by the bonding head 211 and reflect it to the camera module 356. Of course, the mirror module 357 includes a mirror, which rotates with respect to the rotating die stage, and the position is fixed by a separate frame or the like to maintain a stationary state.

The camera module 356 is configured to convert the focus to a first focus that can obtain a clear image of the top of the die 20 transferred to the die inspection position P23 or a second focus that can obtain a clear image of the bottom of the die 20 picked up from the second transfer position P22 by the bonding head 211.

FIG. 13( a ) shows a state where the camera module 356 directly captures the top surface of the die 20 transferred to the die inspection position P23 with the first focal point via the first imaging path, and a state where the bonding head 211 picks up the die 20 transferred to the second transfer position P22 .

FIG. 13( b ) shows that the bonding head 211 that picks up the die 20 from the second transfer position P22 rises from the state of FIG. 13( a ), and the rotating die stage rotates by a set angle, so that any two through portions 303 are located at the die inspection position P23 and the second transfer position P22, respectively, and the camera module 356 that changes from the first focus to the second focus photographs the bottom of the die 20 picked up by the bonding head 211 using the lens module 357. At this time, the camera module 356 photographs the bottom of the die 20 through the second photographing path that passes through the through portions 303 located at the die inspection position P23 and the second transfer position P22, respectively, and the hollow area 302 connected to the two through portions 303.

The die bonding machine according to the third embodiment of the present invention photographs the top and bottom of the die 20 using a single camera module 356, and thus can perform visual inspection of the die 20 with a simpler structure.

The present invention is described above, but the present invention is not limited by the disclosed embodiments and the attached drawings, and various changes can be made by ordinary technical personnel within the scope of the technical concept of the present invention. In addition, the technical concept described in the embodiments of the present invention can also be implemented independently, or two or more can be combined and implemented.

10: Wafer 11: Cutting tape 12: Wafer frame 20: Die 30: Substrate 40: Crystal box 50: First material box 55: Second material box 100: Die supply device 110: Wafer table 111: Table base 112: Support ring 113: Wafer expander 120: Die ejector 130: Die transfer unit 131: Transfer head 132: Swing axis 133: Swing drive module 134: Linear actuator 140: Loading port 150: Transfer unit 160: Transfer rail 200: Die bonding device 210: Bonding unit 211: Bonding head 212: bonding head vertical drive module 213: bonding head horizontal drive module 220: bonding platform 230: substrate transfer unit 231: clamp 232: clamp drive module 240: transfer rail 300: buffer device 301: peripheral area 302: hollow area 303: through-portion 310: rotation axis 320: rotation drive unit 330: rotation frame 331: rotation component 332: support component 340: die stage 340a: first die stage 340b: second die stage 340c: third die stage 340d: Fourth die stage 341: Support part 342: Adsorption hole 350: Die visual unit 351: First camera module 352: Second camera module 353: Mirror module 356: Camera module 357: Mirror module A: Horizontal axis P1: Pickup position P21: First transfer position P22: Second transfer position P23: Die inspection position P3: Joining position

FIG. 1 is a conceptual plan view of a die bonding machine according to the first embodiment of the present invention. FIG. 2 to FIG. 8 are schematic diagrams showing the structure of supplying a die to a die bonding device and its operation in the die bonding machine according to the first embodiment of the present invention. FIG. 9 and FIG. 10 are a plan view and a partial cross-sectional view of a rotating die stage of the die bonding machine according to the first embodiment of the present invention, respectively. FIG. 11 is a three-dimensional view of the die stage shown in FIG. 9 and the like. FIG. 12 is a schematic diagram showing a portion of a die bonding machine according to the second embodiment of the present invention. FIG. 13 is a schematic diagram showing a portion of a die bonding machine according to the third embodiment of the present invention.

10: Wafer

11: Cutting belt

12: Wafer frame

20: Grain

110: Wafer table

111: Table base

112:Support ring

113: Wafer expander

120: Grain ejector

130: Chip transfer unit

131: Transmitter

132: Swing axis

133: Swing drive module

134: Linear actuator

210:Joining unit

211:Joint head

212:Joint head vertical drive module

213: Joint head horizontal drive module

302: Hollow area

303: The through part

340: Chip stage

340a: First chip stage

351: First camera module

352: Second camera module

353:Mirror module

P1: Pickup position

P21: First transmission position

P22: Second transmission position

P23: Grain inspection position

Claims (20)

A buffer device of a die bonding machine includes: a rotating die stage, which is rotated by a rotating driving unit and has a die support portion arranged along the peripheral area around the rotation center, the die support portion is sequentially located at a first transfer position, a die inspection position, and a second transfer position to transfer the die; and a die visual unit, which photographs the first side of the die transferred to the die inspection position through the die support portion through a first shooting path directly facing the first side, and photographs the second side of the die picked up from the second transfer position by the bonding unit through a second shooting path passing through the interior of the rotating die stage. The buffer device of the die bonding machine as described in claim 1, wherein, the rotating die stage has a hollow area surrounded by the peripheral area, and through parts communicating with the hollow area are respectively provided between the die supporting parts. The buffer device of the die bonding machine as described in claim 2, wherein, the first shooting path is provided for directly shooting the first surface of the die transferred to the die inspection position, the second shooting path is provided for shooting the second surface of the die picked up from the second transfer position using the hollow area and the through portion. The buffer device of the die bonding machine as described in claim 3, wherein, the die visual unit includes a first camera module and a second camera module, the first camera module and the second camera module are configured to face the die inspection position around the rotating die stage, the first shooting path directly incidents the image of the first surface of the die transferred to the die inspection position on the first camera module, the die visual unit further includes: a mirror module for reflecting the image of the second surface of the die picked up from the second transfer position to the second camera module in the hollow area, and the second shooting path reflects the image of the second surface to the second camera module according to the position of the through portion. The buffer device of the die bonding machine as described in claim 4, wherein, the die visual unit further comprises: a position adjustment module, which moves the mirror module in a direction parallel to the die picked up from the second transfer position to adjust the position of the mirror module relative to the die picked up from the second transfer position. A buffer device for a die bonding machine as described in claim 4, wherein the second shooting path using the mirror module is a right angle. The buffer device of the die bonding machine as described in claim 4, wherein, the die support portion and the through portion are arranged at the same configuration angle along the peripheral area, the rotary drive unit rotates the rotary die stage by the unit of the configuration angle and moves the die support portion by the unit of the configuration angle, the first transfer position, the die inspection position and the second transfer position are set so that the die support portion moving by the unit of the configuration angle can exist in sequence. A buffer device for a die bonding machine as described in claim 7, wherein the die supporting portion has three or more. The buffer device of the die bonding machine as described in claim 3, wherein, the die visual unit includes a single camera module, the camera module is configured to face the die inspection position around the rotating die stage, the first shooting path directly incidents the image of the first surface of the die transferred to the die inspection position on the camera module, the die visual unit also includes: a mirror module, which is used to reflect the image of the second surface of the die picked up from the second transfer position to the camera module in the hollow area, and the second shooting path reflects the image of the second surface to the camera module according to the position of the through portion. The buffer device of the die bonding machine as described in claim 9, wherein, the camera module is capable of converting the focus to a first focus for photographing the first side of the die transferred to the die inspection position or a second focus for photographing the second side of the die picked up from the second transfer position. The buffer device of the die bonding machine as described in claim 3, wherein, the through-portions are provided to form a pair of two each and are opposite to each other with the rotation center as the center, the die inspection position is set to be opposite to the second transfer position, the die visual unit includes a first camera module and a second camera module, the first camera module and the second camera module are configured to face the die inspection position around the rotating die stage, the first shooting path directly incidents the image of the first surface of the die transferred to the die inspection position on the first camera module, the second shooting path incidents the image of the second surface of the die picked up from the second transfer position on the second camera module according to the position of the through-portions forming a pair of two each. The buffer device of the die bonding machine as described in claim 11, wherein, the die visual unit further comprises: a position adjustment module, which moves the first camera module and the second camera module in a direction parallel to the die to be photographed. The buffer device of the die bonding machine as described in claim 2, wherein, the rotating die stage comprises: a rotating shaft providing the rotation center; a rotating member provided on the rotating shaft; a supporting member extending from the rotating member along the length direction of the rotating shaft and arranged at intervals around the rotation center to form the peripheral area; and a die stage provided at the front end portion of each of the supporting members and having the die supporting portion respectively, so that the die supporting portion is arranged along the peripheral area, having the hollow area surrounded by the peripheral area, and each of the spaces formed between the die stages is the through portion. The buffer device of the die bonding machine as described in claim 1, wherein, the rotating die table is configured such that the die supporting portion supports the die by adsorption. A buffer device for a die bonding machine as described in claim 14, wherein each of the die supporting portions is formed to have a receiving groove aligned with the die. A die bonding machine comprises: a die transfer unit, which transfers a die from a pickup position to a first transfer position; a bonding unit, which picks up the die from a second transfer position and loads it on a substrate; and a buffer device between the die transfer unit and the bonding unit, the buffer device comprises: a rotating die table, which is rotated by a rotating drive unit and has a die support portion arranged along a peripheral area around a rotation center, the die support portion being sequentially located at the first transfer position, the die inspection position and the second transfer position to transfer the die; and The die visual unit photographs the first side of the die transferred to the die inspection position through the die support portion through a first photographing path that is directly facing the die, and photographs the second side of the die picked up from the second transfer position through the bonding unit through a second photographing path that passes through the interior of the rotating die table. A die bonding machine as described in claim 16, wherein, the rotating die stage has a hollow area surrounded by the peripheral area, and through parts communicating with the hollow area are respectively provided between the die supporting parts. The die bonding machine as described in claim 17, wherein, the first shooting path is provided for directly shooting the first side of the die transferred to the die inspection position, the second shooting path is provided for shooting the second side of the die picked up from the second transfer position using the hollow area and the through portion. The die bonding machine as described in claim 16, wherein, the rotation center of the rotating die stage is arranged in the horizontal direction, the die transfer unit comprises: a transfer head, which transfers the die by being located at the pick-up position or the first transfer position according to a swinging motion centered on a horizontal axis parallel to the rotation center; and a swinging drive module, which provides power for the swinging motion to the transfer head. A die bonding machine includes: a wafer stage supporting a wafer holding a die; a wafer stage driving unit moving the wafer stage in a horizontal direction to selectively position the die at a pick-up position; a die transfer unit transferring the die from the pick-up position to a first transfer position; a buffer device receiving the die from the first transfer position and transferring the die to a second transfer position; and a bonding unit picking up the die from the second transfer position and loading it on a substrate; the buffer device includes: A rotating grain stage having an outer peripheral area around a horizontal axis and a hollow area surrounded by the outer peripheral area, grain support parts arranged along the outer peripheral area and through parts respectively arranged between the grain support parts to communicate with the hollow area are arranged at the same configuration angle, the rotating grain stage rotates with the horizontal axis as the center at the unit of the configuration angle, the grain support part and the through part are sequentially located at the first transfer position, the grain inspection position and the second transfer position; A rotating driving unit rotates the rotating grain stage at the unit of the configuration angle; The grain visual unit includes a first camera module and a second camera module. The first camera module photographs the first surface of the grain transmitted to the grain inspection position through the grain supporting portion through a first shooting path, and the second camera module photographs the second surface of the grain picked up from the second transmission position through the joint unit through a second shooting path. The first camera module and the second camera module are configured to face the grain inspection position around the rotating grain stage. The first shooting path directly incidents the image of the first surface of the grain transmitted to the grain inspection position on the first camera module. The crystal grain visual unit further includes: a mirror module, which is used to reflect the image of the second surface of the crystal grain picked up from the second transmission position to the second camera module in the hollow area, and the second shooting path reflects the image of the second surface to the second camera module according to the position of the through portion.

Images