Alignment method and element transfer apparatus

Abstract

The present invention provides an alignment method and an element transfer apparatus that enable high-precision positioning of an element support substrate and an element transfer substrate. [Solution] This alignment method comprises: an imaging step of imaging a first alignment mark 12 formed on the semiconductor chip support substrate 10 and a second alignment mark 22 formed on the semiconductor chip transfer substrate 20 while the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 are facing each other at the transfer position; a position detection step of detecting the positions of the first alignment mark 12 and the second alignment mark 22 based on the images of the first alignment mark 12 and the second alignment mark 22; and an alignment step of aligning the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 based on the positions of the first alignment mark 12 and the second alignment mark 22.

Description

Technical Field

[0001] This invention relates to an element transfer method and an element transfer device, and particularly to an alignment method and an element transfer device for aligning an element support substrate and an element transfer target substrate.

Background Art

[0002] Conventionally, an alignment method for aligning an element support substrate and an element transfer target substrate has been known (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a transfer method (alignment method) for transferring an LED chip (element) held on a transfer substrate (element support substrate) to a transfer target substrate (element transfer target substrate). In this transfer method, first, the position of the transfer substrate or the transfer target substrate is confirmed by a camera. Next, based on the position of the transfer substrate or the transfer target substrate confirmed by the camera, the transfer target substrate is moved horizontally or rotated around an axis along the vertical direction, and alignment (alignment) of the transfer substrate and the transfer target substrate is performed. Thereafter, laser light is irradiated from a laser light irradiation unit toward the LED chip held on the transfer substrate, and the LED chip is transferred to the transfer target substrate.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Here, although not explicitly stated in Patent Document 1, in the conventional alignment method described in Patent Document 1, the element transfer substrate is moved so that the alignment marks formed on the element transfer substrate are within the camera's field of view, and the alignment marks are imaged by the camera. Then, the alignment correction amount for the element transfer substrate is obtained based on the imaged alignment marks. Next, the element support substrate is moved so that the alignment marks formed on the element support substrate are within the camera's field of view, and the alignment marks are imaged by the camera. Then, the alignment correction amount for the element support substrate is obtained based on the imaged alignment marks. Subsequently, the element support substrate and the element transfer substrate are moved to the transfer position, and alignment is performed to position the element support substrate and the element transfer substrate so that their transfer target positions overlap, based on the alignment correction amount of the element support substrate and the alignment correction amount of the element transfer substrate.

[0006] However, in the conventional alignment method described above, the element support substrate and the element transfer substrate move to the transfer position after the alignment correction amount has been obtained. As a result of this movement, further positional errors (deviations from the desired position) of the element support substrate and the element transfer substrate that are not included in the alignment correction amount may occur. Therefore, even if the element support substrate and the element transfer substrate are aligned based on the obtained alignment correction amounts for the element support substrate and the element transfer substrate, there is a problem in that it is not possible to align the element support substrate and the element transfer substrate with high accuracy.

[0007] This invention was made to solve the above-mentioned problems, and one of its objectives is to provide an alignment method and an element transfer apparatus that can accurately align an element support substrate and an element transfer substrate. [Means for solving the problem]

[0008] To achieve the above objective, the alignment method according to the first aspect of this invention comprises: an imaging step of imaging a first alignment mark formed on an element support substrate and a second alignment mark formed on an element transfer substrate while the element support substrate on which the element is supported and the element transfer substrate on which the element is transferred are facing each other at the transfer position; a position detection step of detecting the positions of the first alignment mark and the second alignment mark based on the images of the first alignment mark and the second alignment mark captured in the imaging step; and an alignment step of performing alignment to align the element support substrate and the element transfer substrate based on the positions of the first alignment mark and the second alignment mark detected in the position detection step.

[0009] In this first phase alignment method, as described above, during the imaging process, the element support substrate on which the element is supported and the element transfer substrate on which the element is transferred are facing each other at the transfer position, and the first alignment mark formed on the element support substrate and the second alignment mark formed on the element transfer substrate are imaged. As a result, there is no need to move the element support substrate and the element transfer substrate to the transfer position after obtaining the alignment correction amount. Therefore, no positional errors occur due to the movement of the element support substrate and the element transfer substrate after obtaining the alignment correction amount. Consequently, the element support substrate and the element transfer substrate can be aligned with high precision.

[0010] In the alignment method according to the first aspect described above, preferably, the imaging step includes imaging the first alignment mark and the second alignment mark via the element support substrate or the element transfer substrate using an imaging unit, when viewed from the direction in which the first alignment mark and the second alignment mark are imaged. With this configuration, even if the first alignment mark and the second alignment mark overlap with the element support substrate or the element transfer substrate when viewed from the imaging unit, the first alignment mark formed on the element support substrate and the second alignment mark formed on the element transfer substrate can be imaged by the imaging unit.

[0011] In this case, preferably, the position detection step detects the positions of the first alignment mark and the second alignment mark based on a single image in which the first alignment mark and the second alignment mark are simultaneously captured within the depth of field of the imaging unit and in the same field of view. With this configuration, since the first alignment mark and the second alignment mark are simultaneously captured within the depth of field of the imaging unit, it is easy to obtain a focused image of the same field of view necessary to acquire the respective alignment correction amounts.

[0012] Furthermore, when the alignment correction amount for the element support substrate and the alignment correction amount for the element transfer substrate are acquired at different timings, temperature changes may occur in the imaging unit that images the first and second alignment marks, and in the moving mechanism that moves the element support substrate and the element transfer substrate, between the timing when the alignment correction amount for the element support substrate is acquired and the timing when the alignment correction amount for the element transfer substrate is acquired. In this case, the temperature change causes a misalignment of the imaging unit and a deviation in the accuracy of the movement amount of the moving mechanism. As a result, errors due to the influence of temperature changes occur in the alignment correction amounts of the element support substrate and the element transfer substrate, making it impossible to accurately align the element support substrate and the element transfer substrate. Therefore, by simultaneously acquiring the alignment correction amount for the element support substrate and the alignment correction amount for the element transfer substrate, as in the first surface alignment method, the influence of temperature changes on the alignment correction amount can be suppressed, and the element support substrate and the element transfer substrate can be accurately aligned.

[0013] In the alignment method according to the first aspect described above, preferably, the imaging unit includes a lens having multiple focal lengths, and the imaging step includes a step of using the lens having multiple focal lengths to adjust the focus or focal length of the imaging unit so that the distance between the element support substrate and the element transfer substrate is within the depth of field of the lens having multiple focal lengths. With this configuration, even when the distance between the element support substrate and the element transfer substrate is relatively large and does not fall within the depth of field of one focal length of the lens, the alignment marks of the element support substrate and the alignment marks of the element transfer substrate can be simultaneously imaged using the lens having multiple focal lengths. As a result, even when the distance between the element support substrate and the element transfer substrate is relatively large, the imaging unit can simultaneously capture a focused image with the element support substrate and the element transfer substrate within the depth of field of the lens having multiple focal lengths.

[0014] In the alignment method according to the first aspect described above, preferably, the imaging step includes imaging the first and second alignment marks that overlap with the element when viewed from the direction in which the first and second alignment marks are imaged, using an imaging unit capable of capturing infrared light images. With this configuration, even if the first and second alignment marks overlap with the element and therefore cannot be imaged by an imaging unit capable of capturing visible light images, the first and second alignment marks can be imaged by an imaging unit capable of capturing infrared light images.

[0015] An element transfer apparatus according to the second aspect of this invention comprises: an imaging unit that images a first alignment mark formed on an element support substrate and a second alignment mark formed on an element transfer substrate, with the element support substrate on which the element is supported and the element transfer substrate on which the element is transferred facing each other; a position detection unit that detects the positions of the first alignment mark and the second alignment mark based on the images of the first alignment mark and the second alignment mark captured by the imaging unit; and an alignment unit that performs alignment to position the element support substrate and the element transfer substrate based on the positions of the first alignment mark and the second alignment mark detected by the position detection unit.

[0016] In this second type of element transfer apparatus, as described above, the imaging unit captures the first alignment mark formed on the element support substrate and the second alignment mark formed on the element transfer substrate while the element support substrate, on which the element is supported, and the element transfer substrate, on which the element is transferred, are facing each other at the transfer position. This eliminates the need to move the element support substrate and the element transfer substrate to the transfer position after acquiring the alignment correction amount. Therefore, no positional errors occur due to the movement of the element support substrate and the element transfer substrate after acquiring the alignment correction amount. As a result, the element support substrate and the element transfer substrate can be aligned with high precision. [Effects of the Invention]

[0017] According to the present invention, as described above, it is possible to provide an alignment method and an element transfer apparatus that can accurately align an element support substrate and an element transfer substrate. [Brief explanation of the drawing]

[0018] [Figure 1] This is a schematic diagram showing the overall configuration of a semiconductor chip transfer apparatus according to the first embodiment (when the alignment marks are located on a surface other than the top surface of the semiconductor chip). [Figure 2]It is a plan view of a semiconductor chip support substrate according to the first embodiment. [Figure 3] It is a schematic diagram showing the overall configuration of a semiconductor chip transfer device according to the first embodiment (when the alignment mark is on the upper surface of the semiconductor chip). [Figure 4] It is a plan view of a semiconductor chip support substrate according to the first embodiment. [Figure 5] It is a flowchart for explaining the alignment method according to the first to third embodiments. [Figure 6] It is a schematic diagram showing the overall configuration of a semiconductor chip transfer device according to the second embodiment. [Figure 7] It is a plan view of a semiconductor chip support substrate according to the second embodiment. [Figure 8] It is a schematic diagram showing the overall configuration of a semiconductor chip transfer device according to the third embodiment. [Figure 9] It is a plan view of a semiconductor chip support substrate according to the third embodiment. [Figure 10] It is a plan view of a semiconductor chip support substrate according to the first modification. [Figure 11] It is a schematic diagram showing a captured image of an alignment mark according to the second modification. [Figure 12] It is a schematic diagram showing the overall configuration of a semiconductor chip transfer device according to the third modification. [Figure 13] It is a plan view of a semiconductor chip support substrate according to the third modification. [Embodiments for Carrying Out the Invention]

[0019] Hereinafter, embodiments embodying the present invention will be described based on the drawings.

[0020] [First Embodiment] A semiconductor chip transfer apparatus 100 and a method for transferring a semiconductor chip 1 according to the first embodiment will be described. The semiconductor chip transfer apparatus 100 is an example of an "element transfer apparatus" in the claims. The semiconductor chip 1 is an example of an "element" in the claims. The control unit 60 is an example of an "alignment unit" in the claims.

[0021] (Semiconductor chip transfer equipment) As shown in Figure 1, the semiconductor chip transfer apparatus 100 according to this first embodiment is configured to transfer a semiconductor chip 1 supported on a semiconductor chip support substrate 10 to a semiconductor chip transfer substrate 20 by a laser lift-off method.

[0022] The semiconductor chip transfer apparatus 100 comprises a support substrate holding section 30, a substrate to be transferred holding section 40, a moving mechanism 50, a control section 60, an imaging section 70, a position detection section 80, and a laser irradiation section (not shown). In the drawings, the left-right direction (one direction in the horizontal plane) of the semiconductor chip transfer apparatus 100 is defined as the X direction. The up-down direction (vertical direction) of the semiconductor chip transfer apparatus 100 is defined as the Z direction. The upward direction is defined as the Z1 direction, and the downward direction is defined as the Z2 direction. The direction perpendicular to the X and Z directions (the other direction in the horizontal plane) of the semiconductor chip transfer apparatus 100 is defined as the Y direction.

[0023] As shown in Figure 2, the semiconductor chip 1 is a thin, rectangular element with sides of approximately several hundred micrometers to tens of millimeters, such as a memory chip. Note that the semiconductor chip 1 is not limited to thin elements like memory chips, but may be other types of semiconductor elements. Furthermore, multiple semiconductor chips 1 are arranged on the semiconductor chip support substrate 10. The pitch between multiple semiconductor chips 1 is relatively small. For example, if the semiconductor chip 1 has a rectangular shape, the pitch between multiple semiconductor chips 1 is smaller than the length of the side of the semiconductor chip 1 along the X direction. Although Figure 2 shows two semiconductor chips, in reality, many semiconductor chips may be arranged in a matrix.

[0024] As shown in Figure 1, the semiconductor chip transfer apparatus 100 transfers a semiconductor chip 1, supported on a semiconductor chip support substrate 10, to a semiconductor chip transfer substrate 20 using the laser lift-off method. The transfer accuracy of the semiconductor chip 1 is greatly affected by the accuracy of the superposition of the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20. Therefore, the first alignment mark 12 formed on the semiconductor chip support substrate 10 is imaged by the imaging unit 70 to obtain the alignment correction amount of the semiconductor chip support substrate 10. Similarly, the second alignment mark 22 formed on the semiconductor chip transfer substrate 20 is imaged by the imaging unit 70 to obtain the alignment correction amount of the semiconductor chip transfer substrate 20. Based on the obtained alignment correction amounts, alignment is performed to align the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20.

[0025] The semiconductor chip support substrate 10 is formed from a material that transmits laser light, such as a glass substrate, an SiO2 (silicon dioxide) substrate, or a sapphire substrate. The semiconductor chip support substrate 10 supports the semiconductor chip 1 via an adhesive layer 2. The adhesive layer 2 is also called a transfer material.

[0026] The adhesive layer 2 is positioned on the Z2-side surface 10a of the semiconductor chip support substrate 10. Multiple semiconductor chips 1 are held on the Z2-side surface 2a of the adhesive layer 2. Multiple semiconductor chips 1 are arranged on the semiconductor chip support substrate 10 via the adhesive layer 2. The adhesive layer 2 is made of a material that decomposes and generates gas components when irradiated with laser light. By generating gas components, the adhesive layer 2 deforms into a convex shape that protrudes toward the Z2 side. For example, polyimide or silicon can be used as the adhesive layer 2. Due to the deformation of the adhesive layer 2, the contact area between the semiconductor chip 1 and the adhesive layer 2 decreases, causing the semiconductor chip 1 to peel off from the adhesive layer 2 and be transferred to the semiconductor chip transfer substrate 20.

[0027] As shown in Figure 1, the semiconductor chip transfer substrate 20 is a substrate for manufacturing semiconductor products by transferring, for example, a large number of semiconductor chips 1 from a semiconductor chip support substrate 10 onto the semiconductor chip transfer substrate 20. The semiconductor chip transfer substrate 20 has an adhesive layer 21 formed thereon for bonding the transferred semiconductor chips 1. The adhesive layer 21 is also called a catch layer.

[0028] The support substrate holding portion 30 holds the semiconductor chip support substrate 10 on which the semiconductor chip 1 is supported. The support substrate holding portion 30 holds the semiconductor chip support substrate 10 with the surface 10a supporting the semiconductor chip 1 facing downwards. The support substrate holding portion 30 has an opening 31. The first alignment mark 12 formed on the semiconductor chip support substrate 10 held by the support substrate holding portion 30 is imaged by the imaging portion 70 through the opening 31. The support substrate holding portion 30 is configured to be movable relative to the transfer substrate holding portion 40 in at least the X and Y directions by a moving mechanism 50.

[0029] The substrate holding unit 40 holds the semiconductor chip transfer substrate 20, onto which the semiconductor chip 1 supported on the semiconductor chip support substrate 10 is transferred, from below (Z2 side).

[0030] The moving mechanism 50 moves the semiconductor chip support substrate 10, the semiconductor chip transfer substrate 20, and the imaging unit 70 relative to each other. Specifically, the moving mechanism 50 moves the support substrate holding unit 30, the transfer substrate holding unit 40, and the imaging unit 70 individually. The moving mechanism 50 moves the support substrate holding unit 30, the transfer substrate holding unit 40, and the imaging unit 70 relative to each other in at least the X and Y directions. The moving mechanism 50 moves the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 so that they are facing each other at the transfer position where the semiconductor chip is transferred. Here, the transfer position refers to the position of the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 where, after the alignment of the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 is completed, the semiconductor chip 1 supported by the semiconductor chip support substrate 10 can be transferred to the semiconductor chip transfer substrate 20. For example, the separation distance L between the semiconductor chip support substrate 10 and the semiconductor chip substrate 20 at the transfer position is approximately several tens of micrometers to several hundred micrometers. At the transfer position, the alignment camera 71 cannot be placed between the semiconductor chip support substrate 10 and the semiconductor chip substrate 20. The moving mechanism 50 may move the support substrate holding section 30 and the substrate to be transferred holding section 40 without moving the imaging section 70. Alternatively, the moving mechanism 50 may move the support substrate holding section 30 and the imaging section 70 without moving the substrate to be transferred holding section 40. The moving mechanism 50 moves the support substrate holding section 30 and the imaging section 70 relative to each other, and the imaging section 70 captures the first alignment mark 12 formed on the semiconductor chip support substrate 10. The moving mechanism 50 also moves the substrate to be transferred holding section 40 and the imaging section 70 relative to each other, and the imaging section 70 captures the second alignment mark 22 formed on the semiconductor chip substrate 20. The moving mechanism 50 may move all of the components included in the imaging unit 70, namely the alignment camera 71, the visible light source 72, and the mirror 73, or it may move only the alignment camera 71 and the mirror 73 while keeping the visible light source 72 stationary.

[0031] The imaging unit 70 comprises an alignment camera 71, a visible light source 72, and a mirror 73. The imaging unit 70 simultaneously images the first alignment mark 12 formed on the semiconductor chip support substrate 10 and the second alignment mark 22 formed on the semiconductor chip transfer substrate 20, while the semiconductor chip support substrate 10 on which the semiconductor chip 1 is supported and the semiconductor chip transfer substrate 20 on which the semiconductor chip 1 is transferred are facing each other at the transfer position. The imaging unit 70 images the first alignment mark 12 and the second alignment mark 22 through the semiconductor chip support substrate 10 or the semiconductor chip transfer substrate 20, viewed from the direction (Z direction) in which the first alignment mark 12 and the second alignment mark 22 are imaged. The imaging unit 70 adjusts the illuminance and angle of the visible light source 72 and the angle and position of the mirror 73 so that images necessary for detecting the positions of the first alignment mark 12 and the second alignment are obtained. The imaging unit 70 adjusts the focal length of the alignment camera 71 and captures images of the first alignment mark 12 and the second alignment mark 22.

[0032] The position detection unit 80 detects the positions of the first alignment mark 12 and the second alignment mark 22 based on a single image simultaneously captured by the imaging unit 70 within the depth of field and the same field of view 71a (see Figure 2). The position detection unit 80 includes, for example, a processor such as a CPU (Central Processing Unit) and memory such as ROM (Read Only Memory) and RAM (Random Access Memory), and performs various controls by executing a program (software). Alternatively, the position detection unit 80 may be configured by hardware with a dedicated processor (processing circuit). The position detection unit 80 may also perform image processing on the images of the first alignment mark 12 and the second alignment mark 22 captured by the imaging unit 70 using lens distortion correction and filter functions.

[0033] The control unit 60 performs alignment of the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 based on the positions of the first alignment mark 12 and the second alignment mark 22 detected by the position detection unit 80. Specifically, based on the positions of the first alignment mark 12 and the second alignment mark 22 detected by the position detection unit 80, the control unit 60 controls the movement mechanism 50 that moves the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20. The control unit 60 includes, for example, a processor such as a CPU (Central Processing Unit) and memory such as ROM (Read Only Memory) and RAM (Random Access Memory), and performs various controls by executing a program (software). Alternatively, the control unit 60 may be configured by hardware with a dedicated processor (processing circuit).

[0034] (Alignment method) Next, with reference to Figure 5, the alignment method according to the first embodiment will be described.

[0035] In step S1, the control unit 60 controls the moving mechanism 50 to bring the semiconductor chip support substrate 10 on which the semiconductor chip 1 is supported and the semiconductor chip transfer substrate 20 on which the semiconductor chip 1 is transferred from the semiconductor chip support substrate 10 to face each other at the transfer position.

[0036] In step S2, the imaging unit 70 simultaneously images the first alignment mark 12 formed on the semiconductor chip support substrate 10 and the second alignment mark 22 formed on the semiconductor chip transfer substrate 20 (imaging step).

[0037] In the first embodiment, the imaging step includes imaging the first alignment mark 12 and the second alignment mark 22 through the semiconductor chip support substrate 10 using a single alignment camera 71, viewed from the direction (Z direction) in which the first alignment mark 12 and the second alignment mark 22 are imaged. The alignment camera 71 includes a lens having a single focal length. Visible light passes through the semiconductor chip support substrate 10 and the adhesive layer 2. That is, visible light passes through to the adhesive layer 2 (Z direction) as viewed from the alignment camera 71. As shown in Figure 2, the alignment camera 71 obtains a single image in visible light in which a pair of identical cross-shaped first alignment marks 12 and cross-shaped second alignment marks 22 are simultaneously imaged at different positions (separated in the X-axis and Y-axis directions) within the same field of view 71a. As shown in Figure 3, even when the first alignment mark 12 is on the upper surface (Z1 side) of the semiconductor chip 1, visible light is transmitted to the adhesive layer 2 (Z direction) as seen from the alignment camera 71, so an image of the first alignment mark 12 and the second alignment mark 22 in visible light can be obtained. In this case, as shown in Figure 4, a single image is obtained in which a pair of identical cross-shaped first alignment marks 12 and second alignment marks 22 are simultaneously captured in visible light in the same field of view 71a at different positions (separated in the X and Y directions). Note that the shape of the alignment marks may be square or grid-like. Also, the first alignment mark 12 and the second alignment mark 22 may have different shapes.

[0038] In step S3, the position detection unit 80 detects the position information of the first alignment mark 12 and the second alignment mark 22 based on the images of the first alignment mark 12 and the second alignment mark 22 captured by the imaging unit 70 (position detection step). For example, the position detection unit 80 uses image processing techniques such as pattern matching to compare the image information of the first alignment mark 12 and the second alignment mark 22 that has been previously recorded in the position detection unit 80 with the images of the first alignment mark 12 and the second alignment mark 22 captured by the imaging unit 70. Through pattern matching, the center point and orientation of each are automatically detected from the images of the first alignment mark 12 and the second alignment mark 22 captured by the imaging unit 70. The position detection unit 80 then detects the coordinates of the first alignment mark 12 and the second alignment mark 22 captured by the imaging unit 70 on the XY plane, as well as their rotation angles relative to the X or Y axis, by comparing them with the position information of the alignment camera 71 at the time of imaging. The position detection unit 80 may also perform image processing on the captured images of the first alignment mark 12 and the second alignment mark 22 using lens distortion correction or filtering functions.

[0039] Furthermore, in the first embodiment, the position detection step includes detecting the positions of the first alignment mark 12 and the second alignment mark 22 based on a single image obtained by simultaneously capturing the first alignment mark 12 and the second alignment mark 22 within the depth of field of the imaging unit 70 and in the same field of view 71a. In other words, the first alignment mark and the second alignment mark 22 can be captured simultaneously without changing their positions in the Z direction.

[0040] In step S4, the control unit 60 performs alignment (positioning) of the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20. A specific example of alignment is described below. The control unit 60 registers the target position of the semiconductor chip support substrate 10. Here, the target position of the semiconductor chip support substrate 10 refers to the position where the semiconductor chip support substrate 10 is placed when the semiconductor chip 1 is transferred from the semiconductor chip support substrate 10 to the semiconductor chip transfer substrate 20. Based on the position information of the first alignment mark 12 obtained in step S3, the control unit 60 detects the position of the semiconductor chip support substrate 10. The control unit 60 obtains the alignment correction amount of the semiconductor chip support substrate 10 (the difference from the detected position to the target position). Similarly, the control unit 60 registers the target position of the semiconductor chip transfer substrate 20. Here, the target position of the semiconductor chip transfer substrate 20 refers to the position where the semiconductor chip transfer substrate 20 is placed when the semiconductor chip 1 is transferred from the semiconductor chip support substrate 10 to the semiconductor chip transfer substrate 20. Based on the position information of the second alignment mark 22 obtained in step S3, the control unit 60 detects the position of the semiconductor chip transfer substrate 20. The control unit 60 acquires the alignment correction amount of the semiconductor chip transfer substrate 20 (the difference from the calculated position to the target position). Then, based on the acquired alignment correction amount of the semiconductor chip support substrate 10 and the correction amount of the semiconductor chip transfer substrate 20, the control unit 60 performs alignment to align the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 (alignment process). Note that the alignment correction amount of the semiconductor chip support substrate 10 and the correction amount of the semiconductor chip transfer substrate 20 are acquired simultaneously because they are based on images simultaneously captured in the same field of view 71a of the alignment camera 71.

[0041] (Effects of the first embodiment) Next, the effects of the first embodiment will be described.

[0042] In the first embodiment, with the above configuration, the imaging unit 70 simultaneously images the first alignment mark 12 formed on the semiconductor chip support substrate 10 and the second alignment mark 22 formed on the semiconductor chip transfer substrate 20, while the semiconductor chip support substrate 10 on which the semiconductor chip 1 is supported and the semiconductor chip transfer substrate 20 on which the semiconductor chip 1 is transferred are facing each other at the transfer position. As a result, there is no need to move the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 to the transfer position after acquiring the alignment correction amount. Therefore, no positional errors occur due to the movement of the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 after acquiring the alignment correction amount. As a result, the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 can be aligned with high precision.

[0043] Furthermore, if the alignment correction amount for the semiconductor chip support substrate 10 and the alignment correction amount for the semiconductor chip transfer substrate 20 are acquired at different timings, temperature changes may occur in the imaging unit 70 that images the first alignment mark 12 and the second alignment mark 22, and in the moving mechanism 50 that moves the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20, between the timing when the alignment correction amount for the semiconductor chip support substrate 10 is acquired and the timing when the alignment correction amount for the semiconductor chip transfer substrate 20 is acquired. In this case, the temperature change may cause a misalignment of the imaging unit 70 and a deviation in the accuracy of the movement amount of the moving mechanism 50. As a result, errors due to the temperature change occur in the alignment correction amounts of the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20, making it impossible to accurately align the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20. Therefore, in the first embodiment, by simultaneously acquiring the alignment correction amount of the semiconductor chip support substrate 10 and the alignment correction amount of the semiconductor chip transfer substrate 20, the influence of temperature changes on the alignment correction amount can be suppressed, thereby enabling accurate positioning of the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20.

[0044] In the first embodiment, the imaging unit 70 images the first alignment mark 12 and the second alignment mark 22 through the semiconductor chip support substrate 10, as viewed from the direction (Z direction) in which the first alignment mark 12 and the second alignment mark 22 are imaged. As a result, even if the first alignment mark 12 and the second alignment mark 22 and the semiconductor chip support substrate 10 overlap as viewed from the imaging unit 70, the imaging unit 70 can image the first alignment mark 12 formed on the semiconductor chip support substrate 10 and the second alignment mark 22 formed on the semiconductor chip transfer substrate 20.

[0045] The position detection unit 80 detects the positions of the first alignment mark 12 and the second alignment mark 22 based on a single image simultaneously captured within the depth of field of the imaging unit 70 and within the same field of view 71a of the alignment camera 71. As a result, since the first alignment mark 12 and the second alignment mark 22 are simultaneously captured within the depth of field of the imaging unit 70, it is easy to obtain a focused image of the same field of view 71a of the alignment camera 71, which is necessary for acquiring the respective alignment correction amounts.

[0046] [Second Embodiment] Next, a semiconductor chip transfer apparatus 100a according to the second embodiment will be described. The semiconductor chip transfer apparatus 100a is an example of an "element transfer apparatus" in the claims. The single-lens, two-focal-length lens 76 is an example of a "lens having multiple focal lengths" in the claims. Components identical to those in the first embodiment are shown in the figures with the same reference numerals, and their descriptions are omitted.

[0047] As shown in Figure 6, in the semiconductor chip transfer apparatus 100a according to this second embodiment, the imaging unit 70 includes a single-lens, two-focus lens 76. The imaging unit 70 adjusts its focus position or focal length so that the separation distance L between the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 is within the depth of field of the single-lens, two-focus lens 76. Specifically, the imaging unit 70 adjusts its focus position or focal length so that the first alignment mark 12 formed on the semiconductor chip support substrate 10 and the second alignment mark 22 formed on the semiconductor chip transfer substrate 20 are within the depth of field of the single-lens, two-focus lens 76.

[0048] (Alignment method) Next, with reference to Figure 5, the alignment method according to the second embodiment will be described.

[0049] In step S1, similar to the alignment method according to the first embodiment, the control unit 60 positions the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 facing each other at the transfer position.

[0050] In step S2a, the imaging process includes a single-lens, two-focus lens 76, as shown in Figure 6, and includes a step of adjusting the focus position or focal length of the imaging unit 70 so that the separation distance L between the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 is within the depth of field of the single-lens, two-focus lens 76. The separation distance L refers to the separation distance between the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 in the Z direction. Specifically, in the second embodiment, as shown in Figure 6, even when the separation distance L between the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 is relatively large, the focus position or focal length of the alignment camera 71 is adjusted so that it is within the depth of field of the single-lens, two-focus lens 76. Therefore, a single alignment camera 71 captures in-focus images of the first alignment mark 12 and the second alignment mark 22 through the semiconductor chip support substrate 10. As a result, as shown in Figure 7, a single image is obtained in which a pair of identical cross-shaped first alignment marks 12 and a cross-shaped second alignment mark 22 are simultaneously captured in visible light within the same field of view 71a at different positions (separated in the X-axis and Y-axis directions). Note that the shape of the alignment marks may be square or grid-like. Also, the first alignment mark 12 and the second alignment mark 22 may have different shapes.

[0051] Similar to the alignment method according to the first embodiment described above, in step S3, the position detection unit 80 detects the position information of the first alignment mark 12 and the second alignment mark 22. In step S4, the control unit 60 performs alignment (positioning) of the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20.

[0052] (Effects of the second embodiment) Next, the effects of the second embodiment will be described.

[0053] In the second embodiment, with the above configuration, the imaging unit 70 includes lenses having multiple focal lengths, and the imaging process uses a single-lens, two-focal-length lens 76 to adjust the focus or focal length of the imaging unit so that the separation distance L between the conductor chip support substrate 10 and the semiconductor chip transfer substrate 20 is within the depth of field of the single-lens, two-focal-length lens 76. As a result, even when the separation distance L between the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 is relatively large, the imaging unit 70 can simultaneously capture a focused image with both the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 within the depth of field of the single-lens, two-focal-length lens 76.

[0054] [Third Embodiment] Next, a semiconductor chip transfer apparatus 100b according to a third embodiment will be described. Note that the semiconductor chip transfer apparatus 100b is an example of the "element transfer apparatus" in the claims. Components identical to those in the first embodiment are shown in the figure with the same reference numerals, and their descriptions are omitted.

[0055] As shown in Figure 8, in the semiconductor chip transfer apparatus 100b according to this third embodiment, the first alignment mark 12 and the second alignment mark 22 that overlap with the semiconductor chip 1 when viewed from the direction (Z direction) for imaging the first alignment mark 12 and the second alignment mark 22 are imaged by an imaging unit 70b capable of capturing infrared light images. The imaging unit 70b includes an alignment camera 71b, an infrared light source 72b, and a mirror 73b. The imaging unit 70b adjusts the infrared light source 72b and the mirror 73b so that images necessary for detecting the positions of the first alignment mark 12 and the second alignment mark 22 are obtained. The imaging unit 70b adjusts the focal length of the alignment camera 71b and images the first alignment mark 12 and the second alignment mark 22.

[0056] (Alignment method) Next, with reference to Figure 5, the alignment method according to the third embodiment will be described.

[0057] In step S1, similar to the alignment method according to the first embodiment, the control unit 60 positions the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20 facing each other at the transfer position.

[0058] In step S2b, as shown in Figure 8, the first alignment mark 12 and the second alignment mark 22, which overlap with the semiconductor chip 1 when viewed from the direction (Z direction) from which the alignment camera 71 images the first alignment mark 12 and the second alignment mark 22, are imaged by an imaging unit 70b capable of capturing infrared light images via the semiconductor chip support substrate 10. The alignment camera 71b includes a lens having a single focal length. Specifically, in the third embodiment, as shown in Figure 8, the first alignment mark 12 and the second alignment mark 22 on the lower surface (Z2 side) of the semiconductor chip 1 are captured simultaneously within the same field of view 71a of a single alignment camera 71b capable of capturing infrared light images. In this case, as shown in Figure 9, a single image is obtained in which a pair of identical cross-shaped first alignment marks 12 and a cross-shaped second alignment mark 22 are simultaneously captured by infrared light in the same field of view 71a at different positions (separated in the X-axis and Y-axis directions). Note that the shape of the alignment marks may be square or grid-like. Also, the first alignment mark 12 and the second alignment mark 22 may have different shapes.

[0059] Similar to the alignment method according to the first embodiment described above, in step S3, the position detection unit 80 detects the position information of the first alignment mark 12 and the second alignment mark 22. In step S4, the control unit 60 performs alignment (positioning) of the semiconductor chip support substrate 10 and the semiconductor chip transfer substrate 20.

[0060] (Effects of the third embodiment) Next, the effects of the third embodiment will be described.

[0061] In the third embodiment, as described above, the imaging step includes imaging the first alignment mark 12 and the second alignment mark 22 that overlap with the semiconductor chip 1 when viewed from the direction (Z direction) for imaging the first alignment mark 12 and the second alignment mark 22 using an imaging unit 70 capable of capturing infrared light images. As a result, even if the first alignment mark 12 and the second alignment mark 22 cannot be imaged by the imaging unit 70 capable of capturing visible light images because they overlap with the semiconductor chip 1, the first alignment mark 11 and the second alignment mark 22 can be imaged by the imaging unit 70b capable of capturing infrared light images.

[0062] [Differentiation] It should be noted that the embodiments disclosed herein are illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than by the description of the embodiments above, and further includes all modifications (exceptions) within the meaning and scope equivalent to the claims.

[0063] For example, in the first to third embodiments described above, an example was shown in which a semiconductor chip 1 is used as the element of the present invention, but the present invention is not limited thereto. An element other than a semiconductor chip 1 may also be used as the element of the present invention.

[0064] Furthermore, while the first to third embodiments described above show examples in which the positions of the first alignment mark 12 and the second alignment mark 22 are detected by the position detection unit 80, the present invention is not limited thereto. For example, the positions of the first alignment mark 12 and the second alignment mark 22 may be detected by the control unit 60 or the imaging unit 70.

[0065] Furthermore, while the first to third embodiments described above show examples in which alignment is performed based on a single image captured simultaneously in the same field of view 71a using visible or infrared light, with respect to one pair of first alignment marks 12 and second alignment marks 22, the present invention is not limited thereto. For example, as shown in the first modified example in Figure 10, alignment may be performed based on a single image captured simultaneously in the same field of view 71a using visible or infrared light, with respect to multiple pairs of first alignment marks 12 and second alignment marks 22.

[0066] Furthermore, in the first to third embodiments described above, examples were shown in which the first alignment mark 12 and the second alignment mark 22 are imaged via the semiconductor chip support substrate 10 when viewed from the direction (Z direction) in which the first alignment mark 12 and the second alignment mark 22 are imaged, but the present invention is not limited thereto. For example, the first alignment mark 12 and the second alignment mark 22 may be imaged via the semiconductor chip transfer substrate 20.

[0067] Furthermore, while the first to third embodiments described above show examples of detecting the positions of the first alignment mark 12 and the second alignment mark 22 based on a single image simultaneously captured in the same field of view, the present invention is not limited thereto. For example, the positions of the first alignment mark 12 and the second alignment mark 22 may be detected based on multiple images simultaneously captured in different fields of view.

[0068] Furthermore, while the first to third embodiments described above show examples in which the first alignment mark 12 and the second alignment mark 22 are imaged at different positions, the present invention is not limited thereto. For example, as shown in the second modified example in Figure 11, the first alignment mark 12 and the second alignment mark 22 may be imaged at the same position as long as their shapes do not overlap when viewed from the alignment camera 71 or 71b. The same position refers to a position where the center of the first alignment mark 12 and the center of the second alignment mark 22 coincide.

[0069] Furthermore, although the first to third embodiments described above show examples of imaging using a single alignment camera 71, the present invention is not limited thereto. For example, imaging may be performed using multiple alignment cameras 71 or 71b.

[0070] Furthermore, while the second embodiment described above shows an example in which the first alignment mark 12 and the second alignment mark 22 are imaged using a single-lens, two-focal-length lens 76, the present invention is not limited thereto. For example, imaging may be performed using a lens with three or more focal lengths.

[0071] Furthermore, in the third embodiment described above, an example was shown in which the first alignment mark 12 and the second alignment mark 22 are imaged by an imaging unit 70b capable of capturing infrared light images using a lens having one focal length of the alignment camera 71b, but the present invention is not limited thereto. For example, as shown in the third modified example in Figure 12, the first alignment mark 12 and the second alignment mark 22 may be imaged by an imaging unit 70b capable of capturing infrared light images using lenses having multiple focal lengths. In this case, as shown in Figure 13, in this third modified example, a single image is obtained in which a pair of identical cross-shaped first alignment marks 12 and cross-shaped second alignment marks 22 are simultaneously imaged with infrared light in the same field of view 71a at different positions (separated in the X-axis and Y-axis directions). Note that the shape of the alignment marks may be square or grid-like. Also, the first alignment mark 12 and the second alignment mark 22 may have different shapes. [Explanation of Symbols]

[0072] 1. Semiconductor chip (device) 10 Semiconductor chip support substrate 10a surface (surface supporting the element) 12. First alignment mark 20 Semiconductor chip transfer substrates 22. Second alignment mark 30 Support board holding part 40 Substrate holding section 50 Moving mechanism 60 Control Unit (Alignment Unit) 70 Imaging Unit 71 Alignment Camera 71b Alignment camera (infrared light) 71a Field of view (field of view of the alignment camera) 72b Infrared Light Source 73b Miller 76. Single-lens dual-focal-length lens (a lens with multiple focal lengths) 80 Position detection unit 100, 100a, 100b Semiconductor chip transfer equipment (device transfer equipment)

Claims

1. The imaging step involves imaging a first alignment mark formed on the element support substrate and a second alignment mark formed on the element transfer substrate, with the element support substrate on which the element is supported and the element transfer substrate on which the element is transferred facing each other at the transfer position. A position detection step in which the positions of the first alignment mark and the second alignment mark are detected based on the images of the first alignment mark and the images of the second alignment mark captured in the imaging step, An alignment method comprising: an alignment step of performing alignment to align the element support substrate and the element transfer substrate based on the positions of the first alignment mark and the second alignment mark detected in the position detection step.

2. The aforementioned imaging step is, The alignment method according to claim 1, further comprising the step of imaging the first alignment mark and the second alignment mark via the element support substrate or the element transfer substrate using an imaging unit, viewed from a direction for imaging the first alignment mark and the second alignment mark.

3. The position detection step is, The alignment method according to claim 2, further comprising the step of detecting the positions of the first alignment mark and the second alignment mark based on a single image obtained by simultaneously capturing the first alignment mark and the second alignment mark within the depth of field of the imaging unit and in the same field of view.

4. The imaging unit includes lenses having multiple focal lengths. The aforementioned imaging step is, The alignment method according to claim 3, further comprising the step of using a lens having a plurality of focal lengths and adjusting the focus position or focal length of the imaging unit so that the distance between the element support substrate and the element transfer substrate is within the depth of field of the lens having a plurality of focal lengths.

5. The aforementioned imaging step is, The alignment method according to any one of claims 1 to 4, further comprising the step of imaging the first alignment mark and the second alignment mark that overlap with the element when viewed from the direction in which the first alignment mark and the second alignment mark are imaged, using an imaging unit capable of capturing infrared light images.

6. An imaging unit captures a first alignment mark formed on the element support substrate and a second alignment mark formed on the element transfer substrate, with the element support substrate on which the element is supported and the element transfer substrate on which the element is transferred facing each other at the transfer position. A position detection unit detects the positions of the first alignment mark and the second alignment mark based on the images of the first alignment mark and the images of the second alignment mark captured by the imaging unit, An element transfer apparatus comprising an alignment unit that performs alignment to align the element support substrate and the element transfer substrate based on the positions of the first alignment mark and the second alignment mark detected by the position detection unit.

Images