Semiconductor manufacturing apparatus and semiconductor device manufacturing method

Abstract

To provide a technique capable of improving the accuracy of positioning.SOLUTION: A semiconductor manufacturing apparatus includes an imaging device having a first camera that images a substrate having a tab area on which a die is to be mounted and a reference mark, a second camera that images the reference mark, and a lens unit, and a coaxial illumination device. The lens unit includes a first lens that functions as an objective lens for the first camera, a second lens that functions as an objective lens for the second camera, and a beam splitter that splits reflected light from an object into the first lens and the second lens.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present disclosure relates to semiconductor manufacturing equipment and is applicable, for example, to a die bonder that handles dies or substrates having position recognition marks. [Background technology]

[0002] As part of the manufacturing process of a semiconductor device, dies separated from a wafer are picked up and bonded to a substrate. For example, images of the dies and substrate are taken with a camera, and the dies and substrate are positioned based on the images. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2022-98312 Summary of the Invention [Problem to be solved by the invention]

[0004] For example, in the above-mentioned positioning, the edge of a position recognition mark formed on a substrate or die may be used as the reference position, but in this case, it may be difficult to obtain the position of the edge (reference position) with high accuracy.

[0005] An object of the present disclosure is to provide a technique that can improve the accuracy of positioning. Other objects and novel features will become apparent from the description of this specification and the accompanying drawings. [Means for solving the problem]

[0006] A brief summary of representative aspects of this disclosure is as follows. That is, the semiconductor manufacturing apparatus includes an imaging device having a first camera that images a substrate having a tab area on which a die is to be mounted and a reference mark, a second camera that images the reference mark, a lens unit, and a coaxial illumination device. The lens unit includes a first lens that functions as an objective lens for the first camera, a second lens that functions as an objective lens for the second camera, and a beam splitter that splits reflected light from an object into the first lens and the second lens. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to improve the accuracy of positioning. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic top view showing an example of the configuration of a die bonder according to an embodiment. [Figure 2] FIG. 2 is a diagram illustrating the schematic configuration when viewed from the direction of arrow A in FIG. [Figure 3] FIG. 3 is a block diagram showing a schematic configuration of a control system of the die bonder shown in FIG. [Figure 4] FIG. 4 is a flowchart showing a method for manufacturing a semiconductor device using the die bonder shown in FIG. [Figure 5] FIG. 5 is a diagram showing an example of an optical system in a bonding section. [Figure 6] FIG. 6 is a diagram showing the position recognition marks and bonding centers provided on the substrate. [Figure 7] FIG. 7 is a cross-sectional view of a substrate having leads. [Figure 8] FIG. 8 is a diagram showing the relationship between the lead and the lighting device shown in FIG. [Figure 9] FIG. 9 is a diagram illustrating a lighting device according to an embodiment. [Figure 10] FIG. 10 is a diagram illustrating the teaching operation. [Figure 11] FIG. 11 is a diagram illustrating the production operation. [Figure 12]FIG. 12 is a diagram showing the arrangement of the optical system of the bonding unit in the first modified example. [Figure 13] FIG. 13 is a diagram showing the arrangement of the optical system of the bonding unit in the second modified example. [Figure 14] FIG. 14 is a diagram showing the arrangement of the optical system of the bonding unit in the third modified example. [Figure 15] FIG. 15 is a diagram showing the arrangement of the optical system of the bonding unit in the fourth modified example. [Figure 16] FIG. 16 is a diagram showing the arrangement of an optical system in a bonding section in the fifth modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments and modifications will be described with reference to the drawings. However, in the following description, the same components will be assigned the same reference numerals, and repeated description may be omitted. Note that, to clarify the description, the drawings may show the width, thickness, shape, etc. of each part more schematically than in the actual embodiment. Furthermore, the dimensional relationships and ratios of each element between multiple drawings do not necessarily match.

[0010] The configuration of a die bonder, which is one embodiment of a mounting device, will be described with reference to Figures 1 and 2. Figure 1 is a schematic top view showing an example of the configuration of the die bonder in the embodiment. Figure 2 is a diagram illustrating the schematic configuration as seen from the direction of arrow A in Figure 1.

[0011] The die bonder 1 broadly comprises a wafer supply unit 10, a pickup unit 20, an intermediate stage unit 30, a bonding unit 40, a transport unit 50, a substrate supply unit 60, a substrate unloading unit 70, and a control unit (control device) 80. The Y2-Y1 direction is the front-to-rear direction of the die bonder 1, the X2-X1 direction is the left-to-right direction, and the Z1-Z2 direction is the up-to-down direction. The wafer supply unit 10 is located on the front side of the die bonder 1, and the bonding unit 40 is located on the rear side.

[0012] The wafer supply unit 10 includes a wafer cassette lifter 11, a wafer holder 12, a peeling unit 13, and a wafer recognition camera 14.

[0013] A wafer cassette lifter 11 moves a wafer cassette (not shown), which stores multiple wafer rings WR, up and down to the wafer transport height. A wafer correction chute (not shown) aligns the wafer rings WR supplied from the wafer cassette lifter 11. A wafer extractor (not shown) removes wafer rings WR from the wafer cassette and supplies them to the wafer holder 12, or removes them from the wafer holder 12 and stores them in the wafer cassette.

[0014] A wafer W is adhered (attached) to a dicing tape DT, and the wafer W is divided into multiple dies D. The dicing tape DT is held by a wafer ring WR. The wafer W is, for example, a semiconductor wafer or a glass wafer, and the dies D are semiconductor chips or glass chips. A film-like adhesive material DF called a die attach film (DAF) may be attached between the wafer W and the dicing tape DT. The adhesive material DF hardens when heated.

[0015] The wafer holder 12 is moved in the X1-X2 and Y1-Y2 directions by a drive unit (not shown), and moves the die D to be picked up to the position of the peeling unit 13. The wafer holder 12 also rotates the wafer ring WR in the XY plane by a drive unit (not shown). The peeling unit 13 is moved in the vertical direction by a drive unit (not shown). The peeling unit 13 peels the die D from the dicing tape DT.

[0016] The wafer recognition camera 14 recognizes the pick-up position of the die D to be picked up from the wafer W and inspects the surface of the die D.

[0017] The pickup unit 20 has a pickup head 21 and a pickup head table 23. The pickup head 21 is provided with a collet unit 22 that suction-holds the peeled die D at its tip. The pickup head 21 picks up the die D from the wafer supply unit 10 and places it on the intermediate stage 31. The pickup head table 23 moves the pickup head 21 in the Z1-Z2 direction, the Y1-Y2 direction, and the X1-X2 direction. The pickup head table 23 may also rotate the pickup head 21.

[0018] The intermediate stage unit 30 has an intermediate stage 31 on which the die D is placed, and a stage recognition camera 34 for recognizing the die D on the intermediate stage 31. The intermediate stage 31 has suction holes that adsorb the placed die D. The placed die D is temporarily held on the intermediate stage 31. The intermediate stage 31 is both a placement stage on which the die D is placed and a pickup stage on which the die D is picked up.

[0019] The bonding section 40 includes a bond head 41, a bond head table 43, a substrate recognition camera 44, and a bond stage 46. The bond head 41 is provided with a collet 42 that suction-holds a die D at its tip. The bond head table moves the bond head 41 in the Z1-Z2, Y1-Y2, and X1-X2 directions. The bond head table 43 may also rotate the bond head 41. The substrate recognition camera 44 captures an image of the substrate S and recognizes the bond position. Here, the substrate S may be, for example, a wiring board, a lead frame, or a glass substrate. The substrate S has multiple product areas (hereinafter referred to as package areas P) that will eventually become a single package. The substrate S also has position recognition marks (not shown) for the package areas P. The bond stage 46 is raised when the die D is placed on the substrate S and supports the substrate S from below. The bond stage 46 has a suction port (not shown) for vacuum-adsorbing the substrate S, and is capable of fixing the substrate S. The bond stage 46 also has a heating unit (not shown) for heating the substrate S.

[0020] With this configuration, the bond head 41 corrects the pickup position and posture based on the image data of the stage recognition camera 34, and picks up the die D from the intermediate stage 31. Then, the bond head 41 bonds the die D onto the package area P of the substrate S based on the image data of the substrate recognition camera 44, or bonds the die D by stacking it on top of a die that has already been bonded onto the package area P of the substrate S.

[0021] The transport unit 50 has transport claws 51 that grip and transport the substrate S, and a transport lane 52 along which the substrate S moves. The substrate S moves in the X1 direction by driving a nut (not shown) of the transport claws 51 provided on the transport lane 52 with a ball screw (not shown) provided along the transport lane 52. With this configuration, the substrate S moves from the substrate supply unit 60 along the transport lane 52 to the bonding position, and after bonding, moves to the substrate unloading unit 70 and hands the substrate S over to the substrate unloading unit 70.

[0022] The substrate supply unit 60 removes the substrate S, which has been stored in a transport jig and carried in, from the transport jig and supplies it to the transport unit 50. The substrate unloading unit 70 stores the substrate S, which has been carried in by the transport unit 50, in the transport jig.

[0023] Next, the control unit 80 will be described with reference to Fig. 3. Fig. 3 is a block diagram showing a schematic configuration of a control system of the die bonder shown in Fig. 1.

[0024] The control system 8 includes a control unit (control device) 80, a drive unit 86, a signal unit 87, and an optical system 88. The control unit 80 is broadly configured as a computer including a control and arithmetic unit 81 mainly composed of a CPU (Central Processing Unit), a storage unit 82, an input / output device 83, a bus line 84, and a power supply unit 85. The storage unit 82 has a main storage unit 82a and an auxiliary storage unit 82b. The main storage unit 82a is configured with a RAM (Random Access Memory) that stores processing programs and the like. The auxiliary storage unit 82b is configured with an HDD (Hard Disk Drive) or SSD (Solid State Drive) that stores control data, image data, and the like required for control. An external storage device can be connected to the control unit 80.

[0025] The input / output device 83 includes a monitor 83a that displays the device status and other information, a touch panel 83b that inputs operator instructions, a pointing device such as a mouse 83c that operates the monitor 83a, and an image capture device 83d that captures image data from the optical system 88. The input / output device 83 also includes a motor control device 83e and an I / O signal control device 83f. The motor control device 83e controls the drive unit 86 for the XY table (not shown) of the wafer supply unit 10, the pickup head table 23, and the bond head table 43. The I / O signal control device 83f captures signals from various sensors in the signal unit 87 and controls switches and volumes that control the brightness of the lighting devices in the signal unit 87 and valves that control vacuum suction. The optical system 88 includes a wafer recognition camera 14, a stage recognition camera 34, and a substrate recognition camera 44. The wafer recognition camera 14, the stage recognition camera 34, and the substrate recognition camera 44 digitize light intensity and color. The control and calculation device 81 takes in necessary data via a bus line 84, performs calculations, controls the pickup head 21 and the like, and sends information to the monitor 83a and the like.

[0026] The control unit 80 stores image data captured by the wafer recognition camera 14, the stage recognition camera 34, and the substrate recognition camera 44 in the storage device 82 via the image capture device 83d. Using software programmed based on the stored image data, the control and calculation device 81 positions the die D and the package area P of the substrate S and performs an appearance inspection of the die D and the substrate S. Based on the positions of the package area P of the die D and the substrate S calculated by the control and calculation device 81, the software moves the drive unit 86 via the motor control device 83e. Through this process, the die on the wafer is positioned, and the pickup head table 23 and the bond head table 43 are operated to bond the die D onto the package area P of the substrate S.

[0027] The control unit 80 can be configured by installing the above-mentioned program stored in an external storage device into a computer. Examples of external storage devices include HDDs, USB memory, and SSDs. The auxiliary storage device 82b and the external storage device are configured as computer-readable recording media. Hereinafter, these will be collectively referred to as recording media. When the term recording media is used in this specification, it may refer to only the auxiliary storage device 82b alone, only the external storage device alone, or both. Note that programs and data may be provided to a computer and from a computer to an external device using communication means such as the Internet or a dedicated line, without using an external storage device.

[0028] A part of the manufacturing process of a semiconductor device using the die bonder 1 (a method for manufacturing a semiconductor device) will be described with reference to Fig. 4. Fig. 4 is a flowchart showing a method for manufacturing a semiconductor device using the die bonder shown in Fig. 1. In the following description, the operation of each part constituting the die bonder 1 is controlled by a control unit 80.

[0029] (Wafer loading process: process S1) A wafer cassette containing wafer rings WR is loaded into wafer cassette lifter 11. The loaded wafer rings WR are then supplied (carried in) to wafer holder 12.

[0030] (Substrate loading process: Process S2) The transport jig storing the substrate S is loaded into the substrate supply section 60. In the substrate supply section 60, the substrate S stored in the transport jig is taken out of the transport jig. Then, the substrate S is supplied (carried in) to the bonding section 40 via the transport section 50.

[0031] (Pickup process: process S3) After step S1, the wafer holder 12 is moved so that the desired die D can be picked up from the dicing tape DT. The die D is photographed by the wafer recognition camera 14, and the die D is positioned and its surface inspected based on the image data acquired by the photograph. The image data is processed to calculate the amount of deviation (in the X, Y, and θ directions) of the die D on the wafer holder 12 from the die position reference point of the die bonder, and the die is positioned accordingly. Note that the die position reference point is previously held at a predetermined position on the wafer holder 12 as the initial setting for the device. The image data is processed to inspect the surface of the die D.

[0032] The positioned die D is peeled off from the dicing tape DT by the peeling unit 13 and the pickup head 21. The die D peeled off from the dicing tape DT is attracted to and held by a collet part 22 provided on the pickup head 21, and is transported to and placed on the intermediate stage 31.

[0033] The die D on the intermediate stage 31 is photographed by the stage recognition camera 34, and the die D is positioned and its surface inspected based on the image data acquired by photographing. The image data is processed to calculate the amount of deviation (in the X, Y, and θ directions) of the die D on the intermediate stage 31 from the die position reference point of the die bonder, and the die is positioned accordingly. Note that the die position reference point is previously held at a predetermined position on the intermediate stage 31 as the initial setting of the device. The image data is processed to inspect the surface of the die D.

[0034] After transporting the die D to the intermediate stage 31, the pickup head 21 is returned to the wafer supply unit 10. Following the procedure described above, the next die D is peeled off from the dicing tape DT, and thereafter, the dies D are peeled off one by one from the dicing tape DT following the same procedure.

[0035] (Bond process: Process S4) The substrate S is transported to the bond stage 46 by the transport unit 50. The substrate S placed on the bond stage 46 is imaged by the substrate recognition camera 44, and image data is acquired by the image capture. The image data is processed to calculate the amount of deviation (X, Y, and θ directions) of the substrate S from the substrate position reference point of the die bonder 1. Note that the substrate position reference point is previously held at a predetermined position of the bonding unit 40 as the initial setting of the device.

[0036] The suction position of the bond head 41 is corrected based on the amount of deviation of the die D on the intermediate stage 31 calculated in step S3, and the die D is suctioned by the collet unit 42. The bond head 41, which has suctioned the die D from the intermediate stage 31, bonds the die D to a predetermined location on the substrate S supported by the bond stage 46. The substrate recognition camera 44 photographs the die D bonded to the substrate S, and based on the image data acquired by photographing, an inspection is performed to determine whether the die D has been bonded to the desired position (inspection of the relative position of the die D and the substrate S), etc.

[0037] After bonding the die D to the substrate S, the bond head 41 is returned to the intermediate stage 31. Following the procedure described above, the next die D is picked up from the intermediate stage 31 and bonded to the substrate S. This is repeated until a die D is bonded to all the package areas P of the substrate S.

[0038] (Substrate unloading process: Process S5) The transfer section 50 transfers the substrate S with the die D bonded thereto from the bonding section 40 to the substrate transfer section 70. In the substrate transfer section 70, the substrate S is taken out and stored in a transfer jig, and then the substrate S is transferred out. The transfer jig storing the substrate S is transferred out of the die bonder 1.

[0039] As described above, the die D is mounted on the substrate S and is carried out from the die bonder 1. Thereafter, for example, a transport jig storing the substrate S on which the die D is mounted is transported to a wire bonding process, where the electrodes of the die D are electrically connected to the electrodes of the substrate S via Au wires or the like. Then, the substrate S is transported to a molding process, where the die D and the Au wires are sealed with molding resin (not shown), thereby completing a semiconductor package.

[0040] Next, the optical system of the bonding section 40 will be described with reference to Fig. 5. Fig. 5 is a diagram showing an example of the optical system of the bonding section.

[0041] The board recognition camera 44 serving as an imaging device includes a first camera 441, a second camera 442, and a lens unit 443 to which the first camera 441 and the second camera 442 are attached. The first camera 441 and the second camera 442 are configured to capture an image of the main surface (front surface, upper surface) of the board S or the main surface of the die D bonded to the board S through the lens unit 443. An illumination device 45 is disposed between the lens unit 443 and the board S, etc. The first camera 441 and the illumination device 45 are disposed directly above the package area P of the board S, which is the object to be photographed (subject).

[0042] Lens unit 443 includes first lens 443a and second lens 443b. Lens unit 443 further includes half mirror (beam splitter) 443c provided between first lens 443a and illumination device 45, and mirror 443d provided between second camera 442 and second lens 443b. Each component of lens unit 443 may be housed in a lens barrel (cylinder), and first camera 441 and second camera 442 may be fixed to the lens barrel.

[0043] For example, the first camera 441 is a camera that photographs the subject at low magnification (low resolution). The second camera 442 is a camera that photographs the subject at high magnification (high resolution). Here, low magnification means a magnification that can obtain a sufficient field of view necessary for positioning. High magnification means a magnification that can obtain a pixel resolution that can detect the edge of a reference lead, which will be described later, with high accuracy. Note that the first camera 441 may be a camera that photographs the subject at high magnification (high resolution), and the second camera 442 may be a camera that photographs the subject at low magnification (low resolution).

[0044] The first lens 443a is an objective lens provided between the first camera 441 and the half mirror 443c. The second lens 443b is an objective lens provided between the mirror 443d and the half mirror 443c. The half mirror 443c splits the light (optical axis OA) incident from the Z2 side to the Z1 side into transmitted light (optical axis OA1) toward the Z1 side and reflected light (optical axis OA2) toward the X1 side. The mirror 443d reflects the reflected light from the half mirror 443c toward the Z1 side.

[0045] The number of pixels of first camera 441 and second camera 442 is, for example, 300,000 to 60,000,000 pixels. For example, if first camera 441 and second camera 442 have approximately the same number of pixels, the magnification of first lens 443a is set to be smaller than the magnification of second lens 443b. As a result, the resolution of first camera 441 is smaller than the resolution of second camera 442. If the number of pixels of first camera 441 is set to be smaller than the number of pixels of second camera 442, first lens 443a and second lens 443b are set to have approximately the same magnification. As a result, the resolution of first camera 441 is smaller than the resolution of second camera 442.

[0046] The illumination device 45 includes a surface-emitting illuminator (light source) 451 and a half mirror 452 inside a lens barrel. Illumination light from the surface-emitting illuminator 451 is reflected by the half mirror 452 to the same optical axis as the first camera 441 and the second camera 442, and illuminates the substrate S, etc. The light illuminating the substrate S along the same optical axis OA as the first camera 441 and the second camera 442 is reflected by the substrate S, etc., and the reflected light passes through the half mirror 452 to reach the first camera 441 and the second camera 442, forming an image of the substrate S, etc. In other words, the illumination device 45 has a function of coaxial epi-illumination (coaxial illumination).

[0047] Next, the reference position used for positioning etc. will be explained using Fig. 6. Fig. 6 is a diagram showing the position recognition mark and bonding center provided on the substrate.

[0048] A position recognition mark M is provided in each package area P of the substrate S. At least one position recognition mark M is provided outside the area (tab area) where the die D is mounted. When stacked bonding is performed, the position recognition mark M may be provided on the die D. The position recognition mark M is, for example, configured by a reference lead. When bonding a die, the bonding center C is determined by the distance (dx, dy) from the edge (edge, boundary, reference position) of the reference lead. B The coordinates of the reference lead are sometimes expressed. The reference lead is sometimes simply called the lead LE. The center C of the reference lead M Distance from bonding center C BThe reference position of the position recognition mark M may be the center line in the width direction of the lead, or the center or center of gravity of the position recognition mark M. Also, as a reference on the die D side, the bonding center C B Instead of the coordinates of the die D, the coordinates of the corners or centers of the bonding pads provided on the die D may be used.

[0049] In this case, the die bonder needs to grasp the coordinates of the reference position by measuring and detecting the width and center of the lead LE by image processing of the edges of the lead LE, etc. Regardless of whether the edge, center, or center line of the reference lead is used as the reference, the board recognition camera 44 needs to use a high-magnification lens to increase the pixel resolution in order to more accurately detect the positions of the edges of the lead LE, etc.

[0050] On the other hand, the substrate recognition camera 44 must use a low-magnification lens to have a wide field of view that includes at least one package area P in order to recognize (position) the bonding position and inspect the surface of the die or substrate S.

[0051] The first camera 441 is capable of photographing the die D and the substrate S at a low magnification, while the second camera 442 is capable of photographing the position recognition mark M at a high magnification. The first camera 441 is capable of photographing an area including at least the tab region and the position recognition mark M provided outside the tab region. The second camera 442 photographs the position recognition mark M. Therefore, the substrate recognition camera 44 can solve the two problems described above.

[0052] Next, a method for detecting the position of the edge of the lead LE more accurately will be described.

[0053] First, the leads LE and the lighting device will be described. Fig. 7 is a diagram showing a cross section of a substrate having leads. Fig. 8 is a diagram showing the relationship between the leads shown in Fig. 7 and the lighting device.

[0054] As shown in A of Figure 7, it is sufficient if the surface (top surface) of the lead LE is flush (same height) with the surface (top surface) of the substrate S, but the surface of the lead LE is not flush with the surface of the substrate S, and the surface of the lead may protrude or be recessed from the surface of the substrate S, or the side may be rounded. For example, as shown in B of Figure 7, the lead LE may be convex with respect to the surface of the substrate S, and the side may be curved.

[0055] Even when observing at high magnification in the state shown in B of Figure 7, if a coaxial illumination device with nearly parallel light is used as the illumination device 45, only the flat portion of the upper surface of the lead LE will be illuminated, as shown in A of Figure 8, and therefore only the flat portion of the upper surface of the lead LE can be observed.

[0056] An oblique light source may be used as the lighting device 45 so that light hits the side surface of the lead LE. However, since the reflected light from the lead LE contains a large amount of specular reflection components, only the edges of the lead LE are brightened, as shown in B of Fig. 8, and only the side surface of the lead LE is emphasized, making it difficult to detect the edges in image processing. This is because the shading distribution (brightness: BR) becomes a pair of pulses on the side surface of the lead LE, and it is preferable that the shading distribution be a rectangular wave.

[0057] Next, a lighting device suitable for the lead LE shown in Fig. 7B will be described with reference to Fig. 9. Fig. 9 is a diagram for explaining the lighting device in the embodiment.

[0058] As shown in A of FIG. 9, it is preferable to use the surface-emitting type coaxial lighting device shown in FIG. 5 as lighting device 45. Alternatively, as shown in B of FIG. 9, it is preferable to use a combination of coaxial lighting device 453 and dome lighting device 454 as lighting device 45. Coaxial lighting device 453 may be the surface-emitting type coaxial lighting device shown in FIG. 5, or it may be a collimated light type or a coaxial lighting device that emits nearly collimated light. Dome lighting device 454 has an opening in the center of the ceiling, and coaxial lighting device 453 is installed above the opening. Surface-emitting type coaxial lighting and dome lighting can increase the incident light NA of the lighting (the range of light that reaches a point on the subject) as seen from the subject, so light can also be directed to the side surfaces of the lead LE.

[0059] In this case, it is preferable to determine the NA of the incident light of the illumination in consideration of the following: It is sufficient to irradiate the illumination in a range wider than the NA of the incident light determined by these conditions.

[0060] (a) The horizontal distance from the edge of the lead LE to the position where bending begins (d shown in B in Figure 7). (b) The amount of inclination of the side surface of the lead LE (θ shown in B of Figure 7) (c) Light intensity of reflected light on the surface of the lead LE

[0061] An example of a positioning method will be described with reference to Figures 10 and 11. Figure 10 is a diagram illustrating a teaching operation, and Figure 11 is a diagram illustrating a production operation.

[0062] The positioning algorithm mainly uses pattern matching using a template model (search algorithm using template matching), and performs model matching such as calculations using the commonly known normalized correlation formula or geometric search. The result is the match rate. Template matching is used in both teaching operations for reference learning and production operations for product assembly.

[0063] Taking substrate positioning as an example, the teaching operation is an operation that is performed in advance of the die bonding process shown in FIG.

[0064] The control unit 80 photographs the reference substrate S with the first camera 441 of the substrate recognition camera 44 to obtain an image PCr as shown in Fig. 10. The control unit 80 photographs the position recognition mark M formed on the reference substrate S with the second camera 442 of the substrate recognition camera 44 to obtain an image.

[0065] The operator of the die bonder selects a unique area UA including a characteristic pattern from within the image PCr using a human interface (touch panel 83b or mouse 83c). Here, the characteristic pattern of the unique area UA is, for example, a position recognition mark M. Although an example of the position recognition mark M is shown as being cross-shaped, it is not limited to this. For example, a wiring (lead) having a characteristic pattern (e.g., an L-shaped pattern) among the wirings formed on the substrate S or a circular lead shown in FIG. 10 may be used as the position recognition mark M.

[0066] The control unit 80 stores the positional relationship (coordinates) between the selected unique area UA and the reference substrate S in the storage device 82. For example, B The position coordinates of the die-side references (see FIG. 6) such as

[0067] The control unit 80 stores an image of the unique area UA (hereinafter referred to as a template image PT) that serves as a reference and its coordinates in the storage device 82. For example, the template image PT includes an image of the position recognition mark M. The coordinates of the stored template image PT are calculated based on the image of the position recognition mark M, and are stored as the coordinates of the center C of the position recognition mark M. M The reference position is calculated based on the position coordinates of the reference lead and the lead width of the reference lead that constitutes the position recognition mark M (see FIG. 6).

[0068] Next, the production operation in the die bonding process shown in FIG. 4 will be described.

[0069] In step S4, the control unit 80 captures an image of the product board S using the first camera 441 of the board recognition camera 44, and acquires an image PCn shown in FIG.

[0070] As shown in FIG. 11, the control unit 80 compares the template image PT stored in the teaching operation with the acquired image PCn of the product substrate S, and calculates the coordinates of the image PTn of the most similar portion.

[0071] The control unit 80 compares the coordinates of the image PTn with the coordinates measured on the reference substrate S, and calculates the position of the product substrate S (the offset between the image PTn and the template image PT).

[0072] Next, the effects of this embodiment will be described.

[0073] Even if the image system used for positioning has a pixel resolution greater than the repeatability bonding accuracy, it is possible to achieve the positioning performance required for bonding accuracy through statistical calculations in image processing. However, this only achieves repeatability accuracy, and to accurately mount the die in the desired location, it is necessary to feed back the results of the deviation measured by a separate offline system after temporary bonding. While this system can guarantee bonding repeatability, it is difficult to detect the reference surface of the workpiece (for example, the edge of the reference lead (called the reference edge)) at a resolution below the pixel resolution. As a result, it is difficult to perform teaching operations that specify an offset from the reference surface.

[0074] It is possible to solve the above-mentioned problem by increasing the magnification and improving pixel resolution, but increasing the magnification narrows the field of view, making it impossible to obtain a sufficient field of view for positioning.

[0075] It is possible to obtain both high magnification and a wide field of view using a zoom lens or twin-lens optical system. However, there are the following issues:

[0076] Zoom lenses can solve the above-mentioned problems because they allow for active changes in magnification, but in the case of zoom lenses with a drive system, the accuracy of field of view position reproducibility is affected when switching magnification. In other words, when returning to the original magnification after changing the magnification, mechanical movement errors are included, so coordinate reproducibility is not 100%. This results in variations in the offset between the template model and the reference edge used during positioning. It is also possible to solve the above-mentioned problems by using multiple cameras with different magnifications, but this could result in an arrangement in which one of the cameras loses perpendicularity to the workpiece (the optical axis becomes tilted).

[0077] According to this embodiment, at least one of the following effects is achieved.

[0078] (a) Since the cameras with two different magnifications are installed on the same optical axis, it is possible to maintain high reproducibility of the field of view position when switching.

[0079] (b) It is possible to detect the reference edge more accurately using a high-magnification optical system. This makes it possible to accurately detect the offset of the template model of the reference edge. This improves the detection accuracy of the reference edge.

[0080] (c) Positioning is possible using pattern matching with a wide-field (low magnification) optical system.

[0081] (d) Using the above method, it is possible to stably obtain the offset between the reference position for positioning specified at a high magnification and the model registered at a low magnification (the offset can be obtained accurately even if teaching is re-performed).

[0082] (e) Offline offset measurement is no longer necessary.

[0083] <Modification> Below, several representative modified examples of the embodiment are given. In the following description of the modified examples, the same reference numerals as those in the above-described embodiment may be used for parts having the same configurations and functions as those described in the above-described embodiment. Furthermore, the description of such parts may be appropriately cited within the scope of not being technically inconsistent. Furthermore, a part of the above-described embodiment and all or part of the multiple modified examples may be appropriately applied in a composite manner within the scope of not being technically inconsistent.

[0084] The arrangement of the mirrors and lenses in lens unit 443 may be changed. The arrangement of the camera may also be changed. Furthermore, the arrangement of the lighting device may also be changed. These will be described below.

[0085] (First Modification) The optical system in the first modified example will be described with reference to Fig. 12. Fig. 12 is a diagram showing the arrangement of the optical system in the bonding section in the first modified example.

[0086] In the first modified example, mirror 443d is provided on the Z1 side of first lens 443a. The arrangement of first lens 443a, second lens 443b, and half mirror 443c is the same as in the embodiment. First camera 441 is provided on the X1 side of mirror 443d. Second camera 442 is provided on the X1 side of second lens 443b. As in the embodiment, half mirror 443c splits light incident from the Z2 side to the Z1 side into transmitted light toward the Z1 side and reflected light toward the X1 side. Mirror 443d reflects the transmitted light from half mirror 443c toward the X1 side.

[0087] (Second Modification) The optical system in the second modified example will be described with reference to Fig. 13. Fig. 13 is a diagram showing the arrangement of the optical system in the bonding section in the second modified example.

[0088] In the second modified example, mirror 443d is not provided. The arrangement of first lens 443a, second lens 443b, and half mirror 443c is the same as in the embodiment. First camera 441 is provided on the Z1 side of first lens 443a. Second camera 442 is provided on the X1 side of second lens 443b. As in the embodiment, half mirror 443c splits light incident from the Z2 side to the Z1 side into transmitted light toward the Z1 side and reflected light toward the X1 side.

[0089] (Third Modification) The optical system in the third modified example will be described with reference to Fig. 14. Fig. 14 is a diagram showing the arrangement of the optical system in the bonding section in the third modified example.

[0090] In the third modified example, second lens 443b is provided between second camera 442 and mirror 443d. The other arrangements are the same as in the embodiment.

[0091] (Fourth Modification) The optical system in the fourth modified example will be described with reference to Fig. 15. Fig. 15 is a diagram showing the arrangement of the optical system in the bonding section in the fourth modified example.

[0092] In the fourth modified example, an illumination device 47 is inserted into the lens portion 443 in the second modified example. The illumination device 47 is an insertion-type coaxial illumination device having a light source 471 and a half mirror 472 provided between the half mirror 443c and the second lens 443b. The light source 471 may emit either parallel or diffused light.

[0093] (Fifth Modification) The optical system in the fifth modified example will be described with reference to Fig. 16. Fig. 16 is a diagram showing the arrangement of the optical system in the bonding section in the fifth modified example.

[0094] In the fifth modified example, an illumination device 47 is inserted into the lens portion 443 in the second modified example. The illumination device 47 is an insertion-type coaxial illumination device having a light source 471 and a half mirror 472 provided between the half mirror 443c and the first lens 443a. The light source 471 may emit either parallel or diffused light.

[0095] The disclosure made by the present inventors has been specifically described above based on embodiments and modified examples, but it goes without saying that the present disclosure is not limited to the above embodiments and modified examples, and various modifications are possible.

[0096] A lens with a NA that can accurately detect the lead edge may be used, which makes it possible to irradiate the lead side surface with illumination light even when using a coaxial illumination device that emits parallel or nearly parallel light.

[0097] Although the embodiment has been described using a die attach film, a die attach film may be omitted by providing a preform unit that applies adhesive to the substrate. The preform unit includes a preform head that applies the paste adhesive and a preform table that drives the preform head vertically and horizontally.

[0098] In the embodiment, a die bonder has been described in which a die is picked up from a wafer supply unit by a pickup head and placed on an intermediate stage, and the die placed on the intermediate stage is bonded to a substrate by a bond head. However, the present invention is not limited to this, and can also be applied to a die bonder in which a die is picked up from a wafer supply unit by a bond head and bonded to a substrate.

[0099] For example, the present invention can be applied to a die bonder that does not have an intermediate stage and a pick-up head and that bonds a die from a wafer supply unit to a substrate with a bond head.

[0100] It is also applicable to a flip chip bonder that does not have an intermediate stage, picks up a die from a wafer supply unit, turns the flip pick-up head upside down, and transfers the die to the bond head, which then bonds the die to a substrate.

[0101] In the embodiment, a die bonder has been described as an example, but the present invention can also be applied to a mounting device that picks up a workpiece by suction and places the picked-up workpiece on a substrate or the like. [Explanation of symbols]

[0102] 1. Die bonder (semiconductor manufacturing equipment) 44 Circuit board recognition camera (imaging device) 441···First Camera 442···Second Camera 443 Lens part 443a···First lens 443b Second lens 443c···Half mirror (beam splitter) 45. Lighting equipment

Claims

1. an imaging device including a first camera that captures an image of a substrate having a tab area on which a die is to be placed and a reference mark, a second camera that captures an image of the reference mark, and a lens unit; a coaxial lighting device; Equipped with The lens portion is a first lens that functions as an objective lens of the first camera; a second lens that functions as an objective lens of the second camera; a beam splitter that splits the light reflected from the object into the first lens and the second lens;

2. 2. The semiconductor manufacturing apparatus of claim 1, the beam splitter is disposed to split the reflected light from the subject into vertically upward transmitted light and horizontally reflected light; The coaxial lighting device is provided on the substrate side of the lens unit in the semiconductor manufacturing device.

3. 2. The semiconductor manufacturing apparatus of claim 1, the beam splitter is disposed to split the reflected light from the subject into vertically upward transmitted light and horizontally reflected light; The coaxial lighting device is inserted into the lens portion of the semiconductor manufacturing device.

4. 2. The semiconductor manufacturing apparatus of claim 1, The coaxial lighting device is a semiconductor manufacturing device having a surface emitting light source.

5. 2. The semiconductor manufacturing apparatus of claim 1, The semiconductor manufacturing apparatus further comprises a dome lighting device provided closer to the substrate than the coaxial lighting device.

6. 2. The semiconductor manufacturing apparatus of claim 1, The reference mark is a semiconductor manufacturing device formed by a lead.

7. 2. The semiconductor manufacturing apparatus of claim 1, A semiconductor manufacturing apparatus comprising a control unit configured to position the substrate based on an image obtained by photographing the substrate with the first camera and an image obtained by photographing the reference mark with the second camera.

8. a step of photographing the substrate using the imaging device of a semiconductor manufacturing apparatus, the imaging device including a first camera that photographs a substrate having a tab area on which a die is to be placed and a reference mark, a second camera that photographs the reference mark, and a lens unit, and a coaxial illumination device, wherein the lens unit has a first lens that functions as an objective lens of the first camera, a second lens that functions as an objective lens of the second camera, and a beam splitter that splits reflected light from an object into the first lens and the second lens; a step of positioning the substrate based on an image obtained by photographing the substrate with the first camera and an image obtained by photographing the reference mark with the second camera; A method for manufacturing a semiconductor device comprising:

Images