Mounting method, mounting device, and mounting program

Abstract

The mounting method comprises a first imaging step of obtaining a first image by capturing a die main surface including an alignment mark installed on a semiconductor die that is a mounting target through an NCF which is a covering member covering the alignment mark; a first extraction step of extracting an alignment mark from the first image; a waiting step of waiting until a predetermined time elapses if the extraction of the alignment mark fails as a result of the first extraction step; a second imaging step of obtaining a second image by capturing the die main surface again after the waiting step; and a second extraction step of extracting an alignment mark from the second image.

Description

Technology Field

[0001] The present invention relates to a mounting method, a mounting device, and a mounting program. Background Technology

[0002] Bonding, which is one of the processes for manufacturing a semiconductor device, mounts a semiconductor die, which is a mounting target diced to a predetermined size, onto a substrate, which is a target object. Bonding includes the operation of holding the semiconductor die so that it can be detachably held, the operation of transporting the held semiconductor die to a predetermined position, and the operation of fixing the transported semiconductor die to the substrate.

[0003] Patent Document 1 discloses a technology relating to the operation of fixing a semiconductor die to a substrate. The technology of Patent Document 1 accurately aligns the position of a semiconductor die held in a mounting tool with respect to a substrate to be bonded to the semiconductor die.

[0004] There are also cases where a semiconductor die is bonded to a substrate while the bonding surface of the semiconductor die with electrodes installed is placed in contact with the bonding surface of the substrate with electrodes installed. This type of bonding is also called a flip-chip bond. In a flip-chip bond, the electrodes of the semiconductor die are bonded to the electrodes of the substrate by solder. Patent documents 2 and 3 disclose a technique for forming a flux for solder bonding on the bonding surface of a mounting object. Prior art literature

[0005] Japanese Patent Publication No. 2017-157682, International Publication No. 2023-002557, International Publication No. 2023-017620 The problem to be solved

[0006] When fixing a mounting object to a target object, it is important to accurately determine the position of the mounting object relative to the target object. The mounting object is equipped with alignment marks to define its position. The area containing the alignment marks is captured by a camera. The position of the mounting object is determined using the image obtained through the capture.

[0007] However, even if alignment marks are imprinted on the image obtained by imaging, there may be cases where the alignment marks cannot be extracted from the image. If the extraction of alignment marks fails, the position of the mounting object relative to the target object cannot be accurately determined. Consequently, the mounting object for which alignment marks could not be extracted may be treated as a defective product. In other words, a mounting object that is actually a good product ends up being treated as a defective product.

[0008] The present invention provides a mounting method, a mounting device, and a mounting program that reduce the number of mounting objects that are treated as defective products. means of solving the problem

[0009] A mounting method in one embodiment of the present invention comprises: a first imaging step of obtaining a first image by imaging a main surface of an object including an alignment mark installed on the object through a covering member that covers the alignment mark; a first extraction step of extracting an alignment mark from the first image; a waiting step of waiting until a predetermined time elapses if the extraction of the alignment mark fails as a result of the first extraction step; a second imaging step of obtaining a second image by imaging the main surface of the object again after the waiting step; and a second extraction step of extracting an alignment mark from the second image.

[0010] According to this implementation method, if the extraction of alignment marks from the first image obtained in the first imaging step fails, the process waits for a predetermined amount of time to elapse, after which the image is acquired again and the alignment marks are extracted from the said image. Factors that hinder the extraction of alignment marks may be resolved over time. Therefore, even if the extraction of alignment marks fails as a result of the first extraction step, the extraction of alignment marks may succeed as a result of the second extraction step. In that case, it is possible to determine a product as good based on the result of the second extraction step, rather than a product as defective based on the result of the first extraction step. As a result, the number of objects that are treated as defective despite being good can be reduced.

[0011] In the above-described mounting method, the object may be a semiconductor die. During the standby step, heat may be applied to the semiconductor die. This step further increases the possibility of eliminating factors that hinder the extraction of alignment marks.

[0012] In the above-described mounting method, if the alignment mark is successfully extracted as a result of the first extraction step, the object may be provided to the next manufacturing process. According to this step, the object from which the alignment mark has been successfully extracted can be provided to the next manufacturing process.

[0013] In the above-described implementation method, if the alignment mark is successfully extracted as a result of the second extraction step, the object is provided to the next manufacturing process, and if the alignment mark is not extracted, the object does not need to be provided to the next manufacturing process. According to this step, from the failure to extract the alignment mark in the first extraction step, it is possible to obtain an object that can be provided to the next manufacturing process.

[0014] In the above-described mounting method, the object may be a substrate. In the waiting step, a time may be set during which the influence of the flux applied to the substrate on the second image is reduced. According to this process, the number of substrates judged as defective can be reduced.

[0015] A mounting device of another form of the present invention comprises a bonding head that detachably holds a semiconductor die having a die alignment mark installed thereon, a camera that captures the die surface on which the die alignment mark is formed or the substrate surface on which the substrate alignment mark is formed through a covering member that covers the die alignment mark or the substrate alignment mark, and a controller that controls the camera and the bonding head. The controller performs a first capturing operation to obtain a first image by capturing the die surface or the substrate surface, a first extraction operation to extract the die alignment mark or the substrate alignment mark from the first image, a waiting operation to wait until a predetermined time elapses if the extraction of the die alignment mark or the substrate alignment mark fails as a result of the first extraction operation, a second capturing operation to obtain a second image by capturing the die surface or the substrate surface again after the waiting operation, and a second extraction operation to extract the die alignment mark or the substrate alignment mark from the second image.

[0016] A mounting program, which is another form of the present invention, is for a mounting device comprising a bonding head that detachably holds a semiconductor die having a die alignment mark installed thereon, and a camera that captures the die surface on which the die alignment mark is formed or the substrate surface on which the substrate alignment mark is formed through a covering member that covers the die alignment mark or the substrate alignment mark. The mounting program enables a computer to function as a first imaging function unit that obtains a first image by capturing the die surface or the substrate surface, a first extraction function unit that extracts the die alignment mark or the substrate alignment mark from the first image, a standby function unit that waits until a predetermined time elapses if the extraction of the die alignment mark or the substrate alignment mark fails as a result of the operation of the first extraction function unit, a second imaging function unit that obtains a second image by capturing the die surface or the substrate surface again after the operation of the standby function unit, and a second extraction function unit that extracts the die alignment mark or the substrate alignment mark from the second image.

[0017] The number of objects that are treated as defective despite being good products can be reduced by the mounting device and mounting program, just as with the mounting method. Effects of the invention

[0018] According to the mounting method, mounting device, and mounting program of the present invention, the number of objects treated as defective products can be reduced. Brief explanation of the drawing

[0019] FIG. 1 is a diagram showing the configuration of a mounting device to which the mounting method and mounting program of the present embodiment are applied. Figure 2 is a cross-sectional view showing an enlarged view of a semiconductor die. FIG. 3a is an example of a reference alignment mark. FIG. 3b is an example of an image in which the alignment mark was successfully extracted. FIG. 3c is an example of an image in which the alignment mark was not extracted. FIG. 4 is a flowchart showing the main steps of the implementation method of the present embodiment. FIG. 5a is a cross-sectional view of a semiconductor die in which no foreign matter is present that hinders the extraction of alignment marks. FIG. 5b is a cross-sectional view of a semiconductor die in which foreign matter is present that hinders the extraction of alignment marks. Figure 6 is a diagram showing the physical configuration of the controller. Figure 7 is a functional block diagram of the controller. FIG. 8a is a cross-sectional view illustrating the case where the extraction of alignment marks fails due to flux. FIG. 8b is a cross-sectional view illustrating the case where the extraction of alignment marks succeeds. Figure 9 is a flowchart showing the main steps of a modified implementation method. Specific details for implementing the invention

[0020] Hereinafter, embodiments for implementing the present invention will be described in detail with reference to the attached drawings. In the description of the drawings, the same reference numerals are used for identical elements, and redundant descriptions are omitted.

[0021] As shown in FIG. 1, a mounting device (1) attaches a semiconductor die (2) (object) to a substrate (3). The mounting device (1) has a pickup unit (11), a bonding unit (12), and a controller (13). The pickup unit (11) lifts the semiconductor die (2) from a pickup stage (11S). Then, the pickup unit (11) transfers the semiconductor die (2) to a bonding unit (12). The bonding unit (12) mounts the received semiconductor die (2) onto a substrate (3) on a bonding stage (12S). The controller (13) controls the operation of the pickup unit (11) and the operation of the bonding unit (12) described above.

[0022] The pickup unit (11) has a guide rail (11G), a pickup stage (11S), a pickup head (11H), and a camera (11C). The guide rail (11G) is a body for reciprocating the pickup head (11H) in a predetermined direction. The guide rail (11G) extends, for example, from an area where pickup is performed to a bonding unit (12).

[0023] A pickup stage (11S) is configured to accommodate a plurality of semiconductor dies (2) that are objects. The pickup stage (11S) may additionally be equipped with a desired function required for the pickup operation of the semiconductor dies (2) by the pickup head (11H). For example, the pickup stage (11S) may be equipped with a function to push up the semiconductor dies (2) that are the object of the pickup operation.

[0024] The pickup head (11H) is connected to the guide rail (11G). The pickup head (11H) moves back and forth along the guide rail (11G). The pickup head (11H) has the function of holding the semiconductor die (2) in a detachable manner. The function of holding the semiconductor die (2) in a detachable manner may be realized by a known structure.

[0025] The camera (11C) captures a predetermined area of ​​the semiconductor die (2) selected as a pickup target. The image obtained by capturing is output to, for example, a controller (13).

[0026] The bonding unit (12) has a guide rail (12G), a bonding stage (12S), a bonding head (12H), and a camera (12C).

[0027] The guide rail (12G) is a body for reciprocating the bonding head (12H) in a predetermined direction. The guide rail (12G) extends, for example, from a pickup unit (11) to a bonding stage (12S) where the bonding operation is performed.

[0028] The bonding stage (12S) is on which the substrate (3) on which the semiconductor die (2) is mounted is placed. The bonding stage (12S) may additionally be equipped with desired functions required for mounting. For example, the bonding stage (12S) may be equipped with a function to maintain the position of the substrate (3).

[0029] The bonding head (12H) is connected to the guide rail (12G). The bonding head (12H) reciprocates along the guide rail (12G). The bonding head (12H) also has the function of holding the semiconductor die (2) in a detachable manner. The function of holding the semiconductor die (2) in a detachable manner may be realized by a known structure. For example, the bonding head (12H) has a vacuum suction mechanism as a detachment mechanism. In addition, the bonding head (12H) has the function of pressing the semiconductor die (2) against the substrate (3) with a predetermined force. In addition, the bonding head (12H) may have a built-in heater (121) and have the function of providing heat to the semiconductor die (2).

[0030] The camera (12C) captures a specific area of ​​the semiconductor die (2) held in the bonding head (12H). The image obtained by this capture may be used to obtain relative position information between the semiconductor die (2) and the substrate (3).

[0031] The controller (13) controls the operation of the bonding unit (12) and the pickup unit (11). Details of the controller (13) will be explained in detail in the following paragraph.

[0032] Here, attention is paid to the semiconductor die (2). Between the time the semiconductor die (2) is lifted from the pickup stage (11S) and mounted on the substrate (3), the die front side (2a) (target front side) and the die back side (2b) are reversed. It is assumed that the die front side (2a) has the function of being electrically connected to the substrate (3). That is, when the semiconductor die (2) is attached to the substrate (3), the die front side (2a) faces the substrate front side (3a). Then, the die back side (2b) can be defined as the side that does not face the substrate front side (3a) when the semiconductor die (2) is attached to the substrate (3).

[0033] The semiconductor die (2) lined up on the pickup stage (11S) has its die front side (2a) facing upward and its die back side (2b) facing the stage front side. Accordingly, the pickup unit (11) holds the die front side (2a). Then, the pickup unit (11) rotates 180 degrees. As a result, the die back side (2b) faces upward. Then, the bonding unit (12) holds the die back side (2b). Then, the pickup unit (11) removes the die front side (2a). As a result, the semiconductor die (2) is in a state where the die front side (2a) faces downward. Then, the bonding unit (12) mounts the die front side (2a) of the semiconductor die (2) to a predetermined position on the substrate (3). This series of mounting operations is called a flip-chip process or flip-chip bonding.

[0034] As described above, the flip-chip process includes a picking operation of the semiconductor die (2), a mounting operation of the semiconductor die (2), and a transfer operation of the semiconductor die (2). These operations require position information of the semiconductor die (2). For example, in the mounting operation of the semiconductor die (2), the relative position information of the semiconductor die (2) with respect to the substrate (3) is used to accurately mount the semiconductor die (2) at a predetermined position on the substrate (3).

[0035] Position information of the semiconductor die (2) is obtained using an alignment mark (2M) (die alignment mark) installed on the semiconductor die (2). Specifically, an area including the alignment mark (2M) is captured by a camera (12C). By processing the image obtained by the capture by a controller (13), position information of the semiconductor die (2) can be obtained.

[0036] FIG. 2 is a cross-sectional view showing an enlarged view of the mounting operation of a semiconductor die (2). A plurality of bump electrodes (21) are installed on the die surface (2a) of the semiconductor die (2). An alignment mark (2M) is also installed on the die surface (2a). Additionally, a non-conductive film called NCF (Non Conductive Film) (hereinafter referred to as "NCF (22)") is installed on the die surface (2a). The NCF (22) (covering member) is attached to the entire die surface (2a). Accordingly, the bump electrodes (21) and the alignment mark (2M) are covered by the NCF (22).

[0037] Then, when capturing an image using a camera (12C), the alignment mark (2M) is visible through the NCF (22). Ideally, there is no foreign matter between the film surface (22a) of the NCF (22) and the die surface (2a) of the semiconductor die (2). In the absence of foreign matter, the edge of the alignment mark (2M) appearing in the image is the external shape of the alignment mark (2M) itself.

[0038] However, there may be foreign matter between the film surface (22a) of the NCF (22) and the die surface (2a) of the semiconductor die (2). Examples of foreign matter include bubbles or fine dust. For example, if bubbles (2B) are present on the edge of the alignment mark (2M), the edge of the alignment mark (2M) appearing in the image will differ from the external shape of the alignment mark (2M) itself.

[0039] For example, the shape exemplified in FIG. 3a is defined as a reference alignment mark (2D). Then, in the process of obtaining position information, an area having the same shape as this reference alignment mark (2D) is searched from the image. From the image (D1) shown in FIG. 3b, an area having the same shape as the reference alignment mark (2D) can be extracted. However, from the image (D1) shown in FIG. 3c, an area having the same shape as the reference alignment mark (2D) may not be extracted. If an area having the same shape as the reference alignment mark (2D) cannot be extracted, position information of the semiconductor die (2) is not obtained, and therefore the semiconductor die (2) cannot be accurately mounted in a predetermined area of ​​the substrate (3). As a result, if an area having the same shape as the reference alignment mark (2D) cannot be extracted, the semiconductor die (2) is treated as a defective product.

[0040] The mounting method, mounting device, and mounting program of the present embodiment prevent a good semiconductor die (2) from being treated as a defective product because an alignment mark (2M) cannot be extracted from an image. In addition, the mounting method, mounting device, and mounting program of the present embodiment can be applied to all processes in which an alignment mark (2M) is captured through the NCF (22) in the process of manufacturing a semiconductor device.

[0041] Managerial Method

[0042] With reference to FIG. 4, the mounting method of the present embodiment will be described. The mounting method is executed by a controller (13). Specifically, the mounting method includes controlling a camera (12C) by the controller (13), processing image data provided from the camera (12C), and controlling a pickup unit (11) or a bonding unit (12) based on the result of the processing.

[0043] First, the controller (13) captures the die surface (2a) by controlling the camera (12C) (S11). As a result of executing step S11, the controller (13) receives a first image (D1) from the camera (12C).

[0044] Next, the controller (13) extracts an alignment mark (2M) from the first image (D1) (S12). As a result of executing step S12, either "successful extraction of the alignment mark (2M)" or "failure to extract the alignment mark (2M)" is obtained. Any method may be used for image processing to extract the alignment mark (2M). For example, as shown in FIG. 5a, if there are no bubbles or dust extending across the edge of the alignment mark (2M) between the semiconductor die (2) and the NCF (22), the controller (13) can succeed in extracting the alignment mark (2M) from the first image (D1). In this regard, for example, as shown in FIG. 5b, if there is a bubble or dust across the edge of the alignment mark (2M) between the semiconductor die (2) and the NCF (22), the controller (13) may fail to extract the alignment mark (2M) from the first image (D1).

[0045] Next, the controller (13) determines whether the extraction of the alignment mark (2M) was successful (S13). If, as a result of executing step S13, the “extraction of the alignment mark (2M) was successful” (S13: YES), the controller (13) transfers the semiconductor die (2) to the next process (S14). For example, if this mounting method is executed in the process of mounting the semiconductor die (2) onto the substrate (3) by the bonding unit (12), the next process of bonding the semiconductor die (2) to the substrate (3) may be executed. On the other hand, if, as a result of executing step S13, the “extraction of the alignment mark (2M) failed” (S13: NO), the next step S15 is executed.

[0046] Next, the controller (13) waits until a predetermined amount of time has elapsed (S15). As described in the explanation of step S12, if there are bubbles or dust across the edge of the alignment mark (2M), the extraction of the alignment mark (2M) from the first image (D1) may fail. Foreign matter that hinders the extraction of the alignment mark (2M) may disappear over time. Specifically, if there are bubbles (2B) across the edge of the alignment mark (2M) between the semiconductor die (2) and the NCF (22), these bubbles (2B) may disappear over time.

[0047] Therefore, if the controller (13) fails to extract the alignment mark (2M), it waits for a predetermined amount of time (S15). During this waiting period, the controller (13) does not output a command to move the bonding unit (12) or a command to move the field of view of the camera (12C). In other words, the controller (13) maintains the state of the field of view of the camera (12C) during the imaging operation of step S11. If the foreign substance is a bubble (2B), it may disappear over time during this waiting period. If the foreign substance is dust, it does not disappear over time during this waiting period. As a result, among the cases where the alignment mark (2M) failed to be extracted in step S12, there may be cases where the alignment mark (2M) is successfully extracted when imaging and extraction are performed again.

[0048] Additionally, in step S15, additional operations may be performed while waiting for a predetermined amount of time to elapse. For example, an operation to apply heat to the semiconductor die (2) may be performed as needed (S151). More specifically, heat is applied to the NCF (22) through the semiconductor die (2) using a heater (121) built into the bonding head (12H). The disappearance of the bubble (2B) may also be promoted by this heat.

[0049] Next, the controller (13) captures the die surface (2a) again after a predetermined amount of time has elapsed. In step S16, the state of the camera (12C)'s field of view is maintained during the period in which the predetermined amount of time has elapsed. Therefore, when the die surface (2a) is captured again in step S16, a second image (D2) is obtained that has the same field of view as the image obtained in step S11. Furthermore, the "same field of view" described here does not require that the area of ​​the die surface (2a) or the area not of the die surface (2a) included in the image strictly correspond to the first image and the second image. That is, the "same field of view" described here means that the alignment mark (2M) included in the first image and the alignment mark (2M) included in the second image are identical.

[0050] Next, the controller (13) extracts an alignment mark (2M) from the second image (D2) (S17). This step S17 is identical to step S12 in that the data used for extraction is different. Therefore, as a result of executing this step S17, either "the extraction of the alignment mark (2M) was successful" or "the extraction of the alignment mark (2M) failed" is obtained.

[0051] Then, the controller (13) determines whether the extraction of the alignment mark (2M) was successful (S18). If, as a result of executing step S18, the “extraction of the alignment mark (2M) was successful” (S18: YES), the controller (13) transfers the semiconductor die (2) to the next process (S14). In this case, the product that was judged to be defective because the extraction of the alignment mark (2M) failed as a result of the first imaging and extraction process is provided to the next manufacturing process as a good product. On the other hand, if, as a result of executing step S18, the “extraction of the alignment mark (2M) failed” (S18: NO), the semiconductor die (2) is not transferred to the next process (S19). For example, the controller (13) may not perform bonding to the substrate (3) and may dispose of the semiconductor die (2) held in the bonding head (12H) as a defective product in a designated box, etc.

[0052] Controller and Program

[0053] Next, a controller (13) and a mounting program (P) that execute the mounting method are described. By executing the mounting program (P), the controller (13) executes the mounting method shown in the flow of FIG. 4.

[0054] Referring to FIG. 6, the hardware configuration of the controller (13) is described. The controller (13) is configured by a computer (50). The computer (50) has a processor (51), which is a CPU (Central Processing Unit), a main memory (52), an auxiliary memory (53), an external communication unit (54), an input unit (55), and an output unit (56). The controller (13) is configured by one or more computers (50) configured by these hardware and software such as programs.

[0055] When the controller (13) is configured by multiple computers (50), these computers (50) may be connected locally or connected via a communication network such as the Internet or an intranet. Through this connection, one controller (13) is logically established.

[0056] The processor (51) executes an operating system or applications and programs. The main memory (52) is composed of ROM (Read Only Memory) and RAM (Random Access Memory). The secondary memory (53) is a storage medium composed of a hard disk and flash memory, etc. The secondary memory (53) generally stores a larger amount of data than the main memory (52). The input unit (55) is composed of a keyboard, mouse, touch panel, and microphone for voice input, etc.

[0057] The auxiliary storage unit (53) stores the implementation program (P) and data required for processing in advance. The implementation program (P) executes each functional element of the controller (13) on the computer (50). For example, the implementation program (P) is read by the processor (51) or the main memory unit (52) and operates at least one of the processor (51), the main memory unit (52), the auxiliary storage unit (53), the external communication unit (54), the input unit (55), and the output unit (56). For example, the implementation program (P) performs the reading and writing of data in the main memory unit (52) and the auxiliary storage unit (53).

[0058] The implementation program (P) may be provided after being recorded on a recording medium of a type such as a CD-ROM, DVD-ROM, or semiconductor memory, for example. The implementation program (P) may also be provided as a data signal through a communication network.

[0059] As shown in FIG. 7, the controller (13) operates as a plurality of functional components by having the processor (51) sequentially process the implementation program (P) and data deployed in the memory (52M), which is the main memory (52). As functional components, the controller (13) has a head control unit (131), a camera control unit (132), an alignment mark extraction unit (133), an extraction result determination unit (134), and a waiting time setting unit (135).

[0060] The head control unit (131) outputs a head command C131 that controls the operation of the pickup unit (11) and the bonding unit (12). The head command C131 may include a command regarding movement of the pickup head (11H) or the bonding head (12H) in a predetermined direction, a command regarding pickup operation of the semiconductor die (2) by the pickup head (11H), a command regarding transfer operation of the semiconductor die (2) from the pickup head (11H) to the bonding head (12H), and a command regarding bonding operation of the semiconductor die (2) to the substrate (3) by the bonding head (12H).

[0061] Additionally, the head control unit (131) may generate and output a head command C131 using the output of the extraction result determination unit (134). For example, when the extraction result determination unit (134) determines that "the extraction of the alignment mark (2M) was successful," it may output a head command C131 that executes the next operation. That is, the head control unit (131) executes step S14 in the mounting method.

[0062] The camera control unit (132) outputs a camera command C132 that controls the operation of the camera (12C). The camera command C132 may include commands regarding operations to move, enlarge, and reduce the field of view of the camera (12C), and commands regarding imaging operations by the camera (12C). That is, the camera control unit (132) executes steps S11 and S16 in the implementation method.

[0063] In addition, the camera control unit (132) may also generate and output a camera command C132 using the output of the extraction result determination unit (134). For example, if the extraction result determination unit (134) determines that "the extraction of the alignment mark (2M) failed," it may output a camera command C132 to induce the camera (12C) to perform an imaging operation again after a predetermined time has elapsed.

[0064] The alignment mark extraction unit (133) reads a first image (D1) or a second image (D2) from memory (52M) and performs a process to extract an alignment mark (2M) from the read first image (D1) or second image (D2). That is, the alignment mark extraction unit (133) performs steps S12 and S17 in the mounting method. Then, the alignment mark extraction unit (133) may attach additional information such as "the alignment mark (2M) was successfully extracted" or "the alignment mark (2M) was not extracted" to the first image (D1) or second image (D2) and output it to memory (52M). In addition, when the alignment mark extraction unit (133) "the alignment mark (2M) was successfully extracted," it may also perform a process to obtain position information of the semiconductor die (2) and output the position information to memory (52M).

[0065] The extraction result determination unit (134) reads the first image (D1) or the second image (D2) with additional information attached from the memory (52M) and determines whether the content of the additional information is "successful extraction of the alignment mark (2M)" or "failure to extract the alignment mark (2M)." That is, the extraction result determination unit (134) executes steps S13 and S18 in the mounting method. When the content of the additional information indicates that "successful extraction of the alignment mark (2M)" has been achieved, the extraction result determination unit (134) outputs information that permits the execution of the next manufacturing process. This information is read into the head control unit (131) via the memory (52M). When the content of the additional information indicates that "failure to extract the alignment mark (2M)" has been achieved, the extraction result determination unit (134) outputs information that prohibits the execution of the next manufacturing process. This information is read into the waiting time setting unit (135) via memory (52M).

[0066] The standby time setting unit (135) maintains the state of the camera (12C), pickup unit (11), and bonding unit (12) based on information that prohibits the execution of the next manufacturing process stored in the memory (52M). That is, the standby time setting unit (135) executes step S15 in the mounting method.

[0067] <Effects of Action>

[0068] The mounting method comprises a first imaging step (S11) for obtaining a first image (D1) by imaging a die surface (2a) including an alignment mark (2M) installed on a semiconductor die (2) that is a target object through an NCF (22) which is a covering member covering the alignment mark (2M); a first extraction step (S12) for extracting the alignment mark (2M) from the first image (D1); a waiting step (S15) for waiting until a predetermined time elapses if the extraction of the alignment mark (2M) fails as a result of the first extraction step (S12); a second imaging step (S16) for obtaining a second image (D2) by imaging the die surface (2a) again after the waiting step (S15); and a second extraction step (S17) for extracting the alignment mark (2M) from the second image (D2).

[0069] The mounting device (1) is equipped with a bonding head (12H) that holds a semiconductor die (2) with an alignment mark (2M) installed so as to be detachable, a camera (12C) that captures an image of the die surface (2a) on which the alignment mark (2M) is formed through an NCF (22) which is a covering member that covers the alignment mark (2M), and a controller (13) that controls the camera (12C) and the bonding head (12H). The controller (13) performs a first imaging operation to obtain a first image (D1) by capturing the die surface (2a), a first extraction operation to extract an alignment mark (2M) from the first image (D1), a waiting operation to wait until a predetermined time elapses if the alignment mark (2M) is not extracted as a result of the first extraction operation, and after the waiting operation, a second imaging operation to obtain a second image (D2) by capturing the die surface (2a) again, and a second extraction operation to extract an alignment mark (2M) from the second image (D2).

[0070] The mounting program (P) is for a mounting device (1) equipped with a bonding head (12H) that holds a semiconductor die (2) with an alignment mark (2M) installed in a detachable manner, and a camera (12C) that captures the die surface (2a) on which the alignment mark (2M) is formed through a covering member that covers the alignment mark (2M). The implementation program (P) enables the computer to function as a first imaging function unit that obtains a first image (D1) by capturing the die surface (2a), a first extraction function unit that extracts an alignment mark (2M) from the first image (D1), a waiting function unit that waits until a predetermined time elapses if the extraction of the alignment mark (2M) fails as a result of the operation of the first extraction function unit, a second imaging function unit that obtains a second image (D2) by capturing the die surface (2a) again after the operation of the waiting function unit, and a second extraction function unit that extracts an alignment mark (2M) from the second image (D2).

[0071] According to the mounting method, mounting device (1), and mounting program (P), if the extraction of the alignment mark (2M) from the first image (D1) obtained in the first imaging step (S11) fails, the process is repeated until a predetermined amount of time has elapsed, after which the image is acquired again and the alignment mark (2M) is extracted from the image. An example of a factor that hinders the extraction of the alignment mark (2M), such as a bubble (2B), may disappear over time. Therefore, even if the extraction of the alignment mark (2M) fails as a result of the first extraction step (S12), the extraction of the alignment mark (2M) may succeed as a result of the second extraction step (S17). Then, from the semiconductor die (2) determined to be defective based on the result of the first extraction step (S12), a semiconductor die (2) determined to be good based on the result of the second extraction step (S17) can be obtained. As a result, the number of semiconductor dies (2) that are treated as defective despite being good products can be reduced.

[0072] In the waiting step (S15), heat is applied to the semiconductor die (2). According to the step (S151) of applying heat to the semiconductor die (2), the possibility of eliminating bubbles (2B), which are factors that hinder the extraction of alignment marks (2M), can be further increased.

[0073] As a result of the first extraction step (S12), if the alignment mark (2M) is successfully extracted, the semiconductor die (2) that is the target is provided to the next manufacturing process. According to this step (S12), the semiconductor die (2) from which the alignment mark (2M) has been successfully extracted can be provided to the next manufacturing process.

[0074] As a result of the second extraction step (S17), if the alignment mark (2M) is successfully extracted, the semiconductor die (2), which is the target object, is provided to the next manufacturing process. If the alignment mark (2M) is not extracted, the semiconductor die (2) is not provided to the next manufacturing process. According to this step (S17), from the failure to extract the alignment mark (2M) in the first extraction step (S12), it is possible to obtain that it can be provided to the next manufacturing process.

[0075] <Variation Example>

[0076] Examples of implementation methods, implementation devices, and implementation programs have been described above. The implementation methods, implementation devices, and implementation programs are not limited to the examples mentioned above and may be implemented in various forms.

[0077] In the embodiment, a case was exemplified in which the alignment mark (2M) cannot be extracted from an image captured through the NCF (22). The mounting method, mounting device, and mounting program can also be applied to other scenes in the process of manufacturing a semiconductor device. A flux (3F) for bonding between the substrate electrode (31) and the bump electrode (21) of the semiconductor die (2) may be applied to the substrate electrode (31) installed on the main surface (3a) of the substrate (3) and around the substrate electrode (31). The flux (3F) has a relatively high viscosity. Therefore, as shown in FIG. 8a, the flux (3F) immediately after application covers the entire surface of the alignment mark (2N) (substrate alignment mark), but the surface of the flux (3F) becomes curved due to the surface tension of the flux (3F). In this case, there may be partial differences in the thickness of the flux (3F) on the alignment mark (2N). Also, the substrate (3) is an example of an object.

[0078] In this state, when the alignment mark (2N) is captured by the camera (12C), the extraction of the alignment mark (2N) may fail. This is because the difference in the thickness of the flux (3F) on the alignment mark (2N) may result in a difference in the refractive index, and ultimately cause distortion in the image of the alignment mark (2N) formed by the camera (12C).

[0079] Therefore, as shown in the flowchart of FIG. 9, if the extraction of the alignment mark (2N) in step S12 from the image obtained in step S11A fails (S13: NO), the process waits until a predetermined time elapses (S15). As this time elapses, the flux (3F) gradually flows over the main surface of the substrate (3a) and eventually converges to a state where it covers the entire alignment mark (2N) with approximately a constant thickness (see FIG. 8b). Then, in step S16A, the image obtained by capturing the main surface of the substrate (3a) is highly likely to show an alignment mark (2N) without distortion. If a process (S17) to extract the alignment mark (2N) is performed using such an image, the extraction of the alignment mark (2N) may be successful. In addition, the predetermined time set in step S15 may be set by experimentally determining the effect of flux (3F) on the image of the substrate surface (3a), or it may be set during production operation.

[0080] Even with variations, among those that failed to extract the alignment mark (2N) in the first imaging and extraction, there may be cases where the alignment mark (2N) is successfully extracted in the second imaging and extraction. As a result, the number of substrates (3) judged to be defective can be reduced. Explanation of the symbols

[0081] 1… Mounting device, 2… Semiconductor die (object), 2a… Die surface (object surface), 2M… Alignment mark (die alignment mark), 2N… Alignment mark (substrate alignment mark), 3… Substrate, 3a… Substrate surface, 11C, 12C… Camera, 12H… Bonding head, 13… Controller, 22… NCF (covering member), 50… Computer, D1… First image, D2… Second image, P… Mounting program.

Claims

Claim 1 A mounting method comprising: a first imaging step for obtaining a first image by imaging a surface of an object including an alignment mark installed on the object through a covering member covering the alignment mark; a first extraction step for extracting the alignment mark from the first image; a waiting step for waiting until a predetermined time elapses if the extraction of the alignment mark fails as a result of the first extraction step; a second imaging step for obtaining a second image by imaging the surface of the object again after the waiting step; and a second extraction step for extracting the alignment mark from the second image. Claim 2 A mounting method according to claim 1, wherein the object is a semiconductor die, and in the waiting step, heat is applied to the semiconductor die. Claim 3 A method of providing the object to the next manufacturing process when the extraction of the alignment mark is successful as a result of the first extraction step in claim 1. Claim 4 A method of implementation according to claim 1, wherein if the second extraction step results in the successful extraction of the alignment mark, the object is provided to the next manufacturing process, and if the extraction of the alignment mark fails, the object is not provided to the next manufacturing process. Claim 5 A mounting method according to claim 1, wherein the object is a substrate, and in the waiting step, a time is set during which the influence of the flux applied to the substrate on the second image is reduced. Claim 6 A mounting device comprising: a bonding head that holds a semiconductor die having a die alignment mark installed in a detachable manner; a camera that captures the die surface on which the die alignment mark is formed or the substrate surface on which a substrate alignment mark is formed through a covering member that covers the die alignment mark or the substrate alignment mark; and a controller that controls the camera and the bonding head, wherein the controller performs a first capturing operation to obtain a first image by capturing the die surface or the substrate surface; a first extraction operation to extract the die alignment mark or the substrate alignment mark from the first image; a waiting operation to wait until a predetermined time elapses if the extraction of the die alignment mark or the substrate alignment mark fails as a result of the first extraction operation; a second capturing operation to obtain a second image by capturing the die surface or the substrate surface again after the waiting operation; and a second extraction operation to extract the die alignment mark or the substrate alignment mark from the second image. Claim 7 A mounting program for a mounting device comprising a bonding head that detachably holds a semiconductor die having a die alignment mark installed thereon, and a camera that captures the die surface on which the die alignment mark is formed or the substrate surface on which the substrate alignment mark is formed through a covering member that covers the die alignment mark or the substrate alignment mark, wherein the computer functions as a first imaging function unit that obtains a first image by capturing the die surface or the substrate surface, a first extraction function unit that extracts the die alignment mark or the substrate alignment mark from the first image, a standby function unit that waits until a predetermined time elapses if the extraction of the die alignment mark or the substrate alignment mark fails as a result of the operation of the first extraction function unit, a second imaging function unit that obtains a second image by capturing the die surface or the substrate surface again after the operation of the standby function unit, and a second extraction function unit that extracts the die alignment mark or the substrate alignment mark from the second image.

Images