Patent Publication Number: US-2022223450-A1

Title: Apparatus for producing semiconductor device, and method for producing semiconductor device

Description:
TECHNICAL FIELD 
     The present specification discloses an apparatus for producing a semiconductor device and a method for producing a semiconductor device in which a semiconductor device is produced with a semiconductor chip installed on a substrate. 
     DESCRIPTION OF RELATED ART 
     In the related art, a technique for installing a semiconductor chip on a substrate to produce a semiconductor device is widely known. In such a technique for producing a semiconductor device, it is required to reliably install a semiconductor chip at a target position. Therefore, a technique in which a bonding head is provided with a bonding tool for bonding a semiconductor chip and a camera for capturing an image of a substrate, a relative position of the bonding tool with respect to the substrate is determined on the basis of the image captured by the camera, and the semiconductor chip is installed at a target position is proposed in the related art. 
     According to such a technique, the semiconductor chip can be more reliably installed at the target position. Here, to accurately calculate the relative position of the bonding tool with respect to the substrate on the basis of the captured image, an accurate value of an offset amount between the bonding tool and the camera (hereinafter referred to as a “camera offset amount”) is required. However, the camera offset amount often fluctuates due to distortion of a producing apparatus (particularly, distortion of a drive system of the bonding head), temperature change, or the like, and it is difficult to acquire an accurate value of the camera offset amount. As a result, in the related art, positional accuracy of the semiconductor chip may decrease. 
     REFERENCE LIST 
     Patent Literature 
     
         
         Patent Literature 1: Japanese Patent No. 6256486 
         Patent Literature 2: Japanese Patent Application Publication No. 2004-146776 
       
    
     SUMMARY 
     Technical Problem 
     Patent Literature 1 and Patent Literature 2 disclose a technique in which a two-vertical-field-of-view camera capable of simultaneously capturing images of both a chip held by a bonding tool and a substrate is provided, and on the basis of the images obtained by the two-vertical-field-of-view camera, a bonding head is driven such that an inspection chip is located at a target position of the substrate and a required correction amount is calculated from an actual position of the mounted chip. 
     According to Patent Literature 1 and Patent Literature 2, a position error of the chip can be reduced to some extent. However, Patent Literature 1 and Patent Literature 2 require an expensive two-vertical-field-of-view camera, which may lead to an increase in cost. Further, in Patent Literature 1, a dedicated substrate to which an alignment mark is attached is required for calculating the correction amount. Further, in Patent Literature 2, a procedure for calculating the correction amount is very complicated and takes time. 
     Therefore, the present specification discloses an apparatus for producing a semiconductor device and a method for producing a semiconductor device in which, when a semiconductor chip is installed, positional accuracy is further improved in a simpler procedure. 
     Solution to Problem 
     An apparatus for producing a semiconductor device disclosed in the present specification includes: a stage on which a substrate is mounted; a bonding head capable of moving to a discretionary point relative to the stage; a position detecting means for detecting a position of the bonding head; a bonding tool that is attached to the bonding head and holds a chip; a first camera that is attached to the bonding head and captures an image of a mounting surface, which is an upper surface of the stage or an upper surface of the substrate mounted on the stage, from above; and a controller, wherein the controller is configured to execute for each of one or more points: a mounting process of mounting the chip on the mounting surface by moving the bonding head to the discretionary point and then driving the bonding tool; an inspection image acquisition process of acquiring, as an inspection image, an image of the mounting surface after the chip has been mounted thereon captured by the first camera; a correction amount calculation process of calculating, as an area correction amount, a correction amount for a camera offset amount, which is an offset amount of the first camera with respect to the bonding tool, on the basis of a position of the chip in the inspection image; and a storage process of associating the calculated area correction amount and a position of the discretionary point detected by the position detecting means and then storing the associated information in a storage device. 
     In this case, in the correction amount calculation process, the controller may calculate the area correction amount on the basis of a difference between an actual position of the chip in the inspection image and an ideal position of the chip, which is obtained from the camera offset amount in design, in the inspection image. 
     Further, in this case, the apparatus for producing a semiconductor device may further include a second camera that captures an image of the bonding tool from below, the controller may be configured to execute a tool image acquisition process of acquiring, as a tool image, an image of the chip held by the bonding tool, which is captured by the second camera, prior to the mounting process, and the controller may calculate a chip offset amount which is an offset amount of a center of the bonding tool with respect to a center of the chip on the basis of the tool image, and may calculate the ideal position of the chip in the inspection image on the basis of the chip offset and the camera offset amount in design. 
     Further, after the mounting process is executed, the controller may execute the inspection image acquisition process without moving the bonding head horizontally. 
     Further, the position detecting means may include a position sensor installed in a drive system of the bonding head. 
     There is provided a method for producing a semiconductor device disclosed in the present specification in which steps are executed for each of one or more points, the steps including: a step of moving a bonding head, to which a bonding tool and a first camera are attached, to discretionary point on a stage; a step of mounting the chip held by the bonding tool on a mounting surface, which is an upper surface of the stage or an upper surface of the substrate mounted on the stage; a step of acquiring, as an inspection image, an image of the mounting surface after the chip has been mounted thereon captured by the first camera; a step of calculating, as an area correction amount, a correction amount for a camera offset amount, which is an offset amount of the first camera with respect to the bonding tool, on the basis of a position of the chip in the inspection image; and a step of associating the calculated area correction amount and a position of the discretionary point and then storing the associated information in a storage device. 
     Another apparatus for producing a semiconductor device disclosed in the present specification includes: a stage on which a substrate is mounted; a bonding head capable of moving relative to the stage; a bonding tool that is attached to the bonding head and bonds a chip to the substrate; a first camera that is attached to the bonding head and captures an image of a mounting surface, which is an upper surface of the stage or an upper surface of the substrate mounted on the stage, from above; and a controller, wherein the controller is configured to execute for each of one or more points: a first mounting process of mounting a reference chip on the mounting surface by moving the bonding head to a discretionary point and then driving the bonding tool; a reference image acquisition process of acquiring, as a reference image, an image of the mounting surface after the reference chip has been mounted thereon captured by the first camera; a second mounting process of mounting an inspection chip on the reference chip by positioning the bonding head on the basis of the reference image such that the inspection chip is allowed to be mounted directly above the reference chip and then driving the bonding tool; an inspection image acquisition process of acquiring, as an inspection image, an image of the mounting surface after the inspection chip has been mounted thereon captured by the first camera; a correction amount calculation process of calculating, as an area correction amount, a correction amount for a camera offset amount, which is an offset amount of the first camera with respect to the bonding tool, on the basis of a positional deviation between the reference chip and the inspection chip in the inspection image; and a storage process of associating the calculated area correction amount and a position of the discretionary point and then storing the associated information in a storage device. 
     Advantageous Effects of Invention 
     According to the apparatus for producing a semiconductor device and the method for producing a semiconductor device disclosed in the present specification, when a semiconductor chip is installed, positional accuracy is further improved in a simpler procedure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view showing a configuration of a producing apparatus. 
         FIG. 2  is a flowchart showing a flow when a semiconductor chip is bonded to a target position on a substrate. 
         FIG. 3  is a view showing an example of a tool image. 
         FIG. 4  is a view showing an example of a mounting surface image. 
         FIG. 5  is a conceptual view showing a state in which a camera offset error occurs. 
         FIG. 6  is a flowchart showing a flow of acquisition of an area correction amount. 
         FIG. 7A  is a conceptual view showing a flow of acquisition of an area correction amount. 
         FIG. 7B  is a conceptual view showing a flow of acquisition of an area correction amount. 
         FIG. 7C  is a conceptual view showing a flow of acquisition of an area correction amount. 
         FIG. 8  is a partially enlarged view of an inspection image. 
         FIG. 9  is a flowchart showing another acquisition procedure of an area correction amount. 
         FIG. 10  is a flowchart showing another acquisition procedure of an area correction amount. 
         FIG. 11A  is a conceptual view showing a state of the acquisition procedure according to the flowcharts of  FIGS. 9 and 10 . 
         FIG. 11B  is a conceptual view showing a state of the acquisition procedure according to the flowcharts of  FIGS. 9 and 10 . 
         FIG. 11C  is a conceptual view showing a state of the acquisition procedure according to the flowcharts of  FIGS. 9 and 10 . 
         FIG. 12A  is a conceptual view showing a state of the acquisition procedure according to the flowcharts of  FIGS. 9 and 10 . 
         FIG. 12B  is a conceptual view showing a state of the acquisition procedure according to the flowcharts of  FIGS. 9 and 10 . 
         FIG. 12C  is a conceptual view showing a state of the acquisition procedure according to the flowcharts of  FIGS. 9 and 10 . 
         FIG. 13  is a view showing an example of the inspection image. 
     
    
    
     DESCRIPTION OF THE EMBODIMENTS 
     Hereinafter, a configuration of an apparatus for producing a semiconductor device  10  will be described with reference to the drawings.  FIG. 1  is a schematic view showing a configuration of the producing apparatus  10 . The producing apparatus  10  produces a semiconductor device by bonding a plurality of semiconductor chips  110  to a substrate  100 . 
     The producing apparatus  10  includes a pickup unit  12 , a bonding head  14 , a stage  16 , and a controller  18 . The pickup unit  12  has a push-up pin  20  that pushes up the semiconductor chip  110  mounted on a dicing tape  120 , and a pickup head  22  that holds the pushed-up semiconductor chip  110  on its bottom surface. The pickup head  22  is rotatable about a rotation axis O extending in a horizontal direction. When the pickup head  22  rotates 180 degrees, the picked-up semiconductor chip  110  can be inverted 180 degrees in a thickness direction. As a result, the surface of the semiconductor chip  110  which is adhered to the dicing tape  120  faces upward. 
     The bonding head  14  is moved in the horizontal direction parallel to an upper surface of the stage  16  by an XY drive mechanism (not shown). The XY drive mechanism includes a drive source (a motor or the like) and a sensor that detects a moving position (for example, an encoder or the like). The bonding head  14  is provided with a bonding tool  24  that adsorbs and holds the semiconductor chip  110 . The bonding tool  24  can be raised and lowered in a vertical direction orthogonal to the horizontal direction by a Z-axis drive mechanism (not shown) and can rotate around an axis A extending in the vertical direction. 
     Further, the bonding head  14  is also provided with a first camera  26 . The first camera  26  is attached to the bonding head  14  in a posture in which an optical axis thereof extends downward and captures an image of the upper surface of the stage  16  or an upper surface of the substrate  100  mounted on the stage  16  (hereinafter referred to as a “mounting surface”). Since both the bonding tool  24  and the first camera  26  are fixed to the bonding head  14 , they both move together with the bonding head  14 . 
     An offset amount of the optical axis of the first camera  26  with respect to a central axis of the bonding tool  24  will be referred to below as a “camera offset amount Ocm.” A value of the camera offset amount Ocm in design is stored in advance in a memory of the controller  18  as a basic camera offset amount Ocm_b. However, a slight error may occur between an actual camera offset amount Ocm and the basic camera offset amount Ocm_b due to distortion of a drive system, a temperature change, and the like. Therefore, in the present example, an area correction amount C for correcting the error between the actual camera offset amount Ocm and the basic camera offset amount Ocm_b is calculated prior to a bonding process of the semiconductor chip  110 , which will be described later. 
     The stage  16  vacuum-adsorbs and supports the substrate  100  conveyed by a conveying mechanism (not shown). A second camera  28  disposed in a posture in which an optical axis thereof extends upward is provided in the vicinity of the stage  16 . The second camera  28  captures an image of a bottom surface of the bonding tool  24  and the semiconductor chip  110  held by the bonding tool  24 . 
     The controller  18  controls driving of each part of the producing apparatus  10  and includes, for example, a processor that executes various operations and a memory that stores various programs and data. The controller  18  drives the pickup unit  12  and the bonding head  14  to bond a plurality of semiconductor chips  110  onto the substrate  100 . Further, in order to improve positional accuracy of the bonding, the controller  18  calculates the above-mentioned area correction amount C for each of a plurality of points Pi (i=1, 2, . . . , imax) and stores the calculated area correction amount C, which will be described later. 
     Next, a flow of bonding the semiconductor chip  110  to the target position on the substrate  100  will be described with reference to  FIG. 2 . When the semiconductor chip  110  is bonded to the substrate  100 , the controller  18  first drives the bonding head  14  and the pickup unit  12  to hold the semiconductor chip  110  on the bottom surface of the bonding tool  24  (S 10 ). Subsequently, the controller  18  moves the bonding head  14  such that the bonding tool  24  is in a field of view of the second camera  28 , and then the second camera  28  captures an image of the bottom surface of the bonding tool  24  holding the semiconductor chip  110  (S 12 ). Hereinafter, the captured image of the bottom surface of the bonding tool  24  is referred to as a “tool image  40 .”  FIG. 3  is a view showing an example of the tool image  40 . 
     As shown in  FIG. 3 , the tool image  40  shows the bottom surface of the bonding tool  24  and the semiconductor chip  110  adsorbed and held on the bottom surface. The controller  18  calculates a tilt of the semiconductor chip  110  with respect to an X-axis on the basis of the tool image  40  and rotates the bonding tool  24  around the axis A to correct the tilt (that is, to make a side of the semiconductor chip  110  parallel to the X-axis). Further, the obtained tool image  40  is temporarily stored in the memory of the controller  18 . 
     If the tool image  40  is obtained, the controller  18  moves the bonding head  14  upward from the substrate  100  (S 14 ). In that state, the controller  18  drives the first camera  26  to capture an image of the mounting surface (that is, the upper surface of the substrate  100 ) (S 16 ). Hereinafter, the image obtained by the first camera  26  is referred to as a “mounting surface image  42 .”  FIG. 4  is a view showing an example of the mounting surface image  42 . 
     If the mounting surface image  42  is obtained, the controller  18  calculates a relative positional relationship between the semiconductor chip  110  and a target position Ptg on the basis of the mounting surface image  42 , the tool image  40 , and the camera offset amount Ocm (S 18 ). 
     This calculation principle will be described with reference to  FIG. 4 . For a final offset amount Os which is an offset amount of the target position Ptg with respect to a center Pcp of the semiconductor chip  110 , Os=Ocp+Ocm+Otg. Here, Ocp is an offset amount of a central axis Ptl of the bonding tool  24  with respect to the center Pcp of the semiconductor chip  110  (hereinafter referred to as a “chip offset amount Ocp”). This chip offset amount Ocp can be calculated by the tool image  40  being analyzed. Further, Ocm is an offset amount of an optical axis position Pcm of the first camera  26  with respect to the central axis Ptl of the bonding tool  24 , that is, the camera offset amount Ocm. This camera offset amount Ocm can be calculated on the basis of the basic camera offset amount Ocm_b stored in advance and the area correction amount C which will be described later. 
     Further, Otg is an offset amount of the target position Ptg with respect to the optical axis position Pcm of the first camera  26  (hereinafter referred to as a “target offset amount Otg”). This target offset amount Otg can be calculated by the mounting surface image  42  being analyzed. That is, as shown in  FIG. 4 , usually, the substrate  100  has a substrate side mark  102  as a reference for positioning. In the example illustrated in  FIG. 4 , the substrate side mark  102  is a cross-shaped mark and is provided near four corners of the substrate  100 . The first camera  26  captures an image of the mounting surface at an angle of view including the substrate side mark  102 . Therefore, the substrate side mark  102  is included in the mounting surface image  42 . The target position Ptg in the mounting surface image  42  can be specified with the substrate side mark  102  as a reference. Further, a center position of the mounting surface image  42  can be regarded as the optical axis position Pcm of the first camera  26 . The target offset amount Otg can be obtained from the offset amount of the target position Ptg in the mounting surface image  42  with respect to the center position of the mounting surface image  42  (the optical axis position Pcm of the first camera  26 ). 
     If the relative positional relationship between the center Pcp of the semiconductor chip  110  and the target position Ptg, that is, the final offset amount Os, can be calculated, the controller  18  moves the bonding head  14  by the final offset amount Os. As a result, the semiconductor chip  110  held by the bonding tool  24  is located directly above the target position Ptg. In this state, the controller  18  lowers the bonding tool  24  to bond the semiconductor chip  110  to the target position Ptg. 
     As is clear from the above description, in the present example, the chip offset amount Ocp, the camera offset amount Ocm, and the target offset amount Otg are used for positioning the semiconductor chip  110 . In other words, to accurately position the semiconductor chip  110 , accurate values of the chip offset amount Ocp, the camera offset amount Ocm, and the target offset amount Otg are required. Here, the accurate values of the chip offset amount Ocp and the target offset amount Otg can be calculated from the tool image  40  and the mounting surface image  42 . 
     On the other hand, it is not possible to find the camera offset amount Ocm from the tool image  40  and the mounting surface image  42 , and it is necessary to store an accurate value of the camera offset amount Ocm in advance. Here, as described above, the memory of the controller  18  stores the value of the camera offset amount Ocm in design, that is, the basic camera offset amount Ocm_b. However, an error (hereinafter referred to as a “camera offset error”) may occur between the actual camera offset amount Ocm and the basic camera offset amount Ocm_b due to distortion of a drive system of the bonding head  14  and the like. 
     This will be described with reference to  FIG. 5 .  FIG. 5  is a conceptual view showing a state in which the camera offset error occurs. The drive system of the bonding head  14  may be mechanically distorted. For example, as shown in  FIG. 5 , bending may occur in an X guide rail  15   x  that guides the movement of the bonding head  14  in the X direction. In this case, a relative position of the first camera  26  with respect to the bonding tool  24  may change depending on the position of the bonding head  14 , and a camera offset error may occur. Further, the optical axis of the first camera  26  or the central axis of the bonding tool  24  may be tilted due to the bending of the X guide rail  15   x . In this case, a relative position of the optical axis of the first camera  26  with respect to the central axis of the bonding tool  24  in the mounting surface image  42  changes, and the camera offset error occurs. Such a camera offset error varies depending on the position of the bonding head  14 . For example, a bending amount of the X guide rail  15   x  described above tends to increase as it approaches a center of the X guide rail  15   x , and thus the camera offset error also tends to increase as it approaches the center of the X guide rail  15   x.    
     To accurately position the semiconductor chip  110 , it is necessary to accurately correct the camera offset error that varies depending on the position of the bonding head  14 . Therefore, in the present example, prior to the bonding of the semiconductor chip  110 , the area correction amount C for correcting the camera offset error is acquired for each of the plurality of points Pi. The acquisition of this area correction amount C will be described below. 
       FIG. 6  is a flowchart showing a flow of the acquisition of the area correction amount C.  FIGS. 7A to 7C  are conceptual views showing the flow of the acquisition of the area correction amount C. The process shown in  FIG. 6  is performed prior to bonding the semiconductor chip  110 . Further, the memory of the controller  18  stores coordinate values of a plurality of points Pi in advance. The number, a disposition interval, a disposition range, and the like of the plurality of points Pi are not particularly limited. For example, usually, a plurality of target positions is set on one substrate  100 , and the semiconductor chips  110  are installed on the plurality of target positions. The plurality of points Pi may be the same as the plurality of target positions. 
     When the area correction amount C is acquired, the controller  18  first initializes a parameter i and sets i=1 (S 30 ). Subsequently, the controller  18  drives the pickup unit  12  and the bonding head  14  to hold an inspection chip  130  at a tip end of the bonding tool  24  (S 32 ). Here, the inspection chip  130  is not particularly limited as long as it can be handled by the bonding tool  24 . Therefore, the inspection chip  130  may be, for example, the semiconductor chip  110  that is actually bonded. Further, the inspection chip  130  may be a dedicated chip specially provided for calculating the area correction amount C. In this case, any alignment mark may be attached to the inspection chip  130 . 
     Next, the controller  18  drives the bonding head  14  and the second camera  28  to acquire the tool image  40  (S 34 ). Specifically, as shown in  FIG. 7A , the controller  18  moves the bonding head  14  such that the bonding tool  24  is located directly above the second camera  28 , and then causes the second camera  28  to capture an image of the bonding tool  24  and the inspection chip  130  held by the bonding tool  24 . In a case in which the inspection chip  130  is tilted with respect to the X-axis, the controller  18  rotates the bonding tool  24  around the axis A to eliminate the tilt. Further, the tool image  40  obtained by this capturing is temporarily stored in the memory of the controller  18 . 
     Next, the controller  18  moves the bonding head  14  to the point Pi (S 36 ). This movement is controlled on the basis of a detection result of a position sensor (for example, an encoder or the like) mounted on the drive system of the bonding head  14 . If the bonding head  14  reaches the point Pi, the controller  18  lowers the bonding tool  24  to mount the inspection chip  130  on the mounting surface, as shown in  FIG. 7B  (S 38 ). Here, as described above, the mounting surface may be the upper surface of the stage  16  or the upper surface of the substrate  100  mounted on the stage  16 . In either case, a special alignment mark is not required on the mounting surface. In other words, in the case of the present example, it is not necessary to prepare a dedicated substrate  100  or the like to acquire the area correction amount C. 
     If the inspection chip  130  can be mounted on the mounting surface, the controller  18  drives the first camera  26  to capture an image of the mounting surface and the inspection chip  130  mounted on the mounting surface, as shown in  FIG. 7C  (S 40 ). Hereinafter, the captured image of the mounting surface and the inspection chip  130  will be referred to as an “inspection image  44 .” 
     If the inspection image  44  is obtained, the controller  18  calculates the area correction amount C on the basis of the inspection image  44  and the tool image  40  (S 42 ). This will be described with reference to  FIG. 8 .  FIG. 8  is a partially enlarged view of the inspection image  44 . 
     In the present example, the area correction amount C is calculated on the basis of a difference between an actual position and an ideal position of the inspection chip  130  in the inspection image  44 . Here, the ideal position of the inspection chip  130  is a position in the inspection image  44  of the inspection chip  130  in a case in which the camera offset amount Ocm is equal to the basic camera offset amount Ocm_b, in other words, in a case in which the camera offset error is zero. In  FIG. 8 , the actual position of the inspection chip  130  is shown by a solid line, and the ideal position of the inspection chip  130  is shown by a two-dot chain line. 
     The ideal position is a position deviated from a center of the inspection image  44  (that is, the optical axis of the first camera  26 ) by L=Ocm_b+Ocp. The basic camera offset amount Ocm_b is stored in advance in the memory, as has been described repeatedly. Further, the chip offset amount Ocp can be obtained from the tool image  40 . 
     Further, the actual position of the inspection chip  130  can be calculated by image analysis of the inspection image  44 . For example, in a case in which an alignment mark is attached to the inspection chip  130 , the alignment mark is extracted using a technique such as pattern matching, and coordinates of the extracted alignment mark in the inspection image  44  only have to be specified. 
     If the actual position and the ideal position of the inspection chip  130  in the inspection image  44  can be calculated, the controller  18  calculates the difference between the two and calculates a value that cancels out a value of the difference as the area correction amount C. For example, as shown in  FIG. 8 , it is assumed that the ideal position of the inspection chip  130  is deviated by (−X1, −Y1) from the actual position of the inspection chip  130 . In this case, the controller  18  calculates a value (X1, Y1) for cancelling out this deviation as the area correction amount C. When the semiconductor chip  110  is bonded, a value obtained by adding this area correction amount C to the basic camera offset amount Ocm_b only has to be used as the camera offset amount Ocm. 
     If the area correction amount C can be calculated, the controller  18  associates the area correction amount C and a current position of the point Pi with each other and stores them in the memory (S 44 ). If the area correction amount C can be calculated for one point Pi, the parameter i is incremented (S 46 ), and then the process returns to step S 32 . Then, an area correction amount C at a new point Pi is calculated by the same procedure. The inspection chip  130  used to acquire the area correction amount C of the new point Pi may be a chip newly supplied from the pickup unit  12  or an inspection chip  130  already mounted on the mounting surface. Therefore, for example, one inspection chip  130  may be mounted on each of the plurality of points Pi. Further, as another form, a plurality of area correction amounts C may be sequentially acquired while one inspection chip  130  is sequentially mounted on the plurality of points Pi. In any case, if the area correction amount C can be calculated for all the points Pi (that is, if Yes in S 46 ), the process ends. 
     Here, as is clear from the above description, the error corrected by the area correction amount C is not an error based on an absolute position on the mounting surface, but a camera offset error between the first camera  26  and the bonding tool  24 . Therefore, in the present example, even in a case in which the inspection chip  130  is mounted to acquire the area correction amount C, it is not necessary to strictly control a relative position of the inspection chip  130  with respect to the mounting surface. As a result, a complicated procedure for positioning the inspection chip  130  is not necessary, and the area correction amount C can be obtained by a simple procedure. 
     Further, in calculating the area correction amount C, it is not necessary to strictly control the relative position of the inspection chip  130  with respect to the mounting surface, and thus it is not necessary to attach a special alignment mark or the like to the mounting surface. As a result, it is not necessary to prepare a special mounting surface for calculating the correction amount, and the cost and labor required for acquiring the correction amount can be reduced. Further, in the present example, it is not necessary to capture an image of the bonding tool  24  and the mounting surface at the same time, and thus an expensive two-vertical-field-of-view camera is not necessary and the cost can be further reduced. Further, in the present example, by calculating the area correction amount C for each of the plurality of points Pi and storing the calculated area correction amount C, it is possible to deal with the position-dependent error and further improve the positional accuracy of the bonding. 
     Next, another example of the acquisition procedure of the area correction amount C will be described with reference to  FIGS. 9 to 13 .  FIGS. 9 and 10  are flowcharts showing another acquisition procedure of the area correction amount C.  FIGS. 11 and 12  are conceptual views showing a state of the acquisition procedure according to the flowcharts of  FIGS. 9 and 10 . In this example, a reference chip  140  is used in addition to the inspection chip  130  to acquire the area correction amount C. The reference chip  140  is a chip that is mounted on the mounting surface prior to the inspection chip  130  and is used as a positioning target of the inspection chip  130 . A shape, size, and the like of the reference chip  140  are not particularly limited. The reference chip  140  may be provided with any alignment mark to make it easier to find a position of the reference chip  140  in image analysis. 
     The inspection chip  130  is mounted on the reference chip  140 . Likewise, a shape, size, and the like of the inspection chip  130  are not particularly limited. However, in a case in which the alignment mark is attached to a surface of the reference chip  140 , the inspection chip  130  may be a transparent chip made of a transparent material such as glass, polycarbonate, acrylic, polyester, or transparent ceramic. With such a configuration, the alignment mark of the reference chip  140  can be checked even if the inspection chip  130  is superposed on the reference chip  140 . Further, as in the reference chip  140 , any alignment mark may be provided on a surface of the inspection chip  130 . Further, the inspection chip  130  may have a size smaller than that of the reference chip  140 . With such a configuration, even in a case in which the inspection chip  130  is mounted on the reference chip  140  in a state in which the position of the inspection chip  13  is deviated with respect to that of the reference chip  140 , the inspection chip  130  is less likely to fall from the reference chip  140 . 
     In a case in which the area correction amount C is acquired, the controller  18  first initializes a parameter i and sets i=1 (S 50 ). Subsequently, the controller  18  drives the bonding head  14  and the pickup unit  12  to hold the reference chip  140  at a tip end of the bonding tool  24  (S 52 ). 
     Next, the controller  18  drives the bonding head  14  and the second camera  28  to acquire the tool image  40  (S 54 ). Specifically, as shown in  FIG. 11A , the controller  18  moves the bonding head  14  such that the bonding tool  24  is located directly above the second camera  28 , and then causes the second camera  28  to capture an image of the bonding tool  24  and the reference chip  140  held by the bonding tool  24 . The controller  18  calculates a tilt of the reference chip  140  with respect to the X-axis on the basis of the tool image  40  and rotates the bonding tool  24  around the axis A to eliminate the tilt. 
     Next, the controller  18  moves the bonding head  14  to the point Pi (S 56 ). This movement is controlled on the basis of a detection result of a position sensor (for example, an encoder or the like) mounted on the drive system of the bonding head  14 . If the bonding head  14  reaches the point Pi, the controller  18  lowers the bonding tool  24  to mount the reference chip  140  on the mounting surface, as shown in  FIG. 11B  (S 58 ). Here, the mounting surface may be the upper surface of the stage  16  or the upper surface of the substrate  100  mounted on the stage  16 . 
     If the reference chip  140  is mounted on the mounting surface, the controller  18  causes the bonding tool  24  to hold the inspection chip  130  (S 60 ). Then, the controller  18  drives the bonding head  14  and the second camera  28  to acquire the tool image  40  (S 62 ). That is, as shown in  FIG. 11C , the controller  18  moves the bonding head  14  such that the bonding tool  24  is located directly above the second camera  28 , and then causes the second camera  28  to capture an image of the bonding tool  24  and the inspection chip  130  held by the bonding tool  24 . The controller  18  calculates a tilt of the inspection chip  130  with respect to the X-axis on the basis of the tool image  40  and rotates the bonding tool  24  around the axis A to eliminate the tilt. Further, the controller  18  temporarily stores the tool image  40  in the memory. 
     Subsequently, the controller  18  moves the bonding head  14  to the point Pi (S 64 ) and then causes the first camera  26  to capture an image of the mounting surface on which the reference chip  140  is mounted, as shown in  FIG. 12A  (S 66 ). Hereinafter, the captured image of the mounting surface on which the reference chip  140  is mounted is referred to as a “reference image.” Next, the controller  18  moves the bonding head  14  such that the inspection chip  130  held by the bonding tool  24  is located directly above the reference chip  140  (S 68 ). That is, the controller  18  calculates a relative position between the reference chip  140  mounted on the mounting surface and the inspection chip  130  held by the bonding tool  24  on the basis of the reference image and the tool image  40  acquired in step S 62 . The procedure for calculating the relative position is the same as the procedure described with reference to  FIG. 5 , except that a basic camera offset amount Ocm_b is used as a camera offset amount Ocm. That is, the controller  18  calculates a chip offset amount Ocp, which is an offset amount of the bonding tool  24  with respect to the inspection chip  130 , on the basis of the tool image  40 . Further, the controller  18  calculates a target offset amount Otg, which is an offset amount of a target position (that is, the reference chip  140 ) with respect to the optical axis of the first camera  26  (that is, the center of the reference image), on the basis of the reference image. Then, the controller  18  calculates, as a final offset amount Os, a value obtained by adding the calculated chip offset amount Ocp, the target offset amount Otg, and the basic camera offset amount Ocm_b to each other. In a case in which an actual camera offset amount Ocm is the same as the basic camera offset amount Ocm_b, the calculated final offset amount Os is an offset amount of the reference chip  140  with respect to the inspection chip  130 . Therefore, in a case in which Ocm=Ocm_b, if the bonding head  14  is moved by the final offset amount Os, the inspection chip  130  is located directly above the reference chip  140 . 
     If the inspection chip  130  is located directly above the reference chip  140 , the controller  18  drives the bonding tool  24  to mount the inspection chip  130  on the reference chip  140 , as shown in  FIG. 12B  (S 70 ). Subsequently, as shown in  FIG. 12C , the controller  18  causes the first camera  26  to capture an image of the mounting surface and acquires the inspection image  44  (S 74 ). 
     If the inspection image  44  is obtained, the controller  18  calculates the area correction amount C on the basis of the inspection image  44  (S 76 ). This will be described with reference to  FIG. 13 .  FIG. 13  is a view showing an example of the inspection image  44 . In  FIG. 13 , the reference chip  140  is shown by a two-dot chain line, and the inspection chip  130  is shown by a solid line. In the present example, the area correction amount C is calculated on the basis of a difference between a position of the inspection chip  130  and a position of the reference chip  140  in the inspection image  44 . That is, in the present example, the inspection chip  130  is positioned with respect to the reference chip  140  and mounted on the reference chip  140  with Ocm=Ocm_b. Therefore, in a case in which Ocm=Ocm_b, a center Pr (a white x mark) of the reference chip  140  and a center Pe (a black x mark) of the inspection chip  130  should match each other. On the contrary, in a case in which Ocm Ocm_b and an offset error occurs between the two, the inspection chip  130  deviates from the reference chip  140  by the amount of the offset error. Therefore, if the inspection image  44  is analyzed and the deviation amount of the inspection chip  130  with respect to the reference chip  140  is extracted, the area correction amount C for correcting the deviation can be obtained. 
     In the example of  FIG. 13 , the inspection chip  130  is deviated from the reference chip  140  by (X1, −Y1). Therefore, in this case, the area correction amount C for correcting the deviation is (−X1, Y1). 
     If the area correction amount C can be calculated, the controller  18  associates the area correction amount C and a coordinate value of the point Pi with each other and stores them in the memory (S 78 ). If the area correction amount C can be calculated for one point Pi, the parameter i is incremented (S 82 ), and then the process returns to step S 52 . Then, an area correction amount C at a new point Pi is acquired by the same procedure. The reference chip  140  and the inspection chip  130  used to acquire the area correction amount C of the new point Pi may be chips newly supplied from the pickup unit  12  or an reference chip  140  and an inspection chip  130  already mounted on the mounting surface. If the area correction amount C can be acquired for all the points Pi (that is, if Yes in step S 80 ), the process ends. 
     Here, as is clear from the above description, in the present example, the reference chip  140  mounted prior to the inspection chip  130  is used as a mounting target position of the inspection chip  130 . Therefore, it is not necessary to attach a special alignment mark or the like to the mounting surface. As a result, it is not necessary to prepare a special mounting surface for calculating the correction amount, and the cost and labor required for calculating the correction amount can be reduced. Further, in the present example, instead of a theoretical target position, the reference chip  140  actually mounted on the mounting surface is set as a target position. Therefore, the camera offset error and, furthermore, the area correction amount C can be calculated more accurately. 
     Further, in the present example, it is not necessary to capture an image of the bonding tool  24  and the mounting surface at the same time, and thus an expensive two-vertical-field-of-view camera is not necessary and the cost can be further reduced. Further, in the present example, by calculating the area correction amount C for each of the plurality of points Pi and storing the calculated area correction amount C, it is possible to deal with the position-dependent error and further improve the positional accuracy of the bonding. 
     REFERENCE SIGNS LIST 
     
         
         
           
               10  Apparatus for producing semiconductor device 
               12  Pickup unit 
               14  Bonding head 
               15   x  X guide rail 
               16  Stage 
               18  Controller 
               20  Push-up pin 
               22  Pickup head 
               24  Bonding tool 
               26  First camera 
               28  Second camera 
               40  Tool image 
               42  Mounting surface image 
               44  Inspection image 
               100  Substrate 
               102  Substrate side mark 
               110  Semiconductor chip 
               120  Dicing tape 
               130  Inspection chip 
               140  Reference chip 
             C Area correction amount 
             Ocm Camera offset amount 
             Ocm_b Basic camera offset amount 
             Os Final offset amount 
             Otg Target offset amount 
             Ocp Chip offset amount