Element transfer method and element transfer apparatus

Abstract

To provide an element transfer method that enables transferring elements while suppressing damage to the elements caused by deformation of an adhesive layer, even for elements with relatively small thickness.SOLUTION: The semiconductor chip transfer method (element transfer method) comprises: a placement process for placing elements on a first substrate having elasticity via an adhesive layer having elasticity; an extension process for extending the adhesive layer in a direction parallel to the surface of the element; and a transfer process for transferring the elements to a second substrate by irradiating the first substrate with laser light from the side opposite to where the elements are placed on the first substrate in a state that the adhesive layer is stretched during the extension process.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to an element transferring method and an element transferring apparatus, and more particularly to an element transferring method and an element transferring apparatus for transferring elements by irradiating them with laser light. [Background technology]

[0002] BACKGROUND ART Conventionally, there is known an element transfer method in which an element is transferred by irradiating it with laser light (see, for example, Patent Document 1).

[0003] The above-mentioned Patent Document 1 discloses a laser transfer method for transferring an article attached to a substrate to another substrate. In the above-mentioned Patent Document 1, a blistering layer that deforms when irradiated with laser light and an adhesive layer are provided between the substrate and the article, and the article is held by the adhesive layer. In the above-mentioned Patent Document 1, laser light is irradiated from the upper surface side of the substrate toward the blistering layer adjacent to the adhesive layer, and the blistering layer deforms, causing the adhesive layer to deform into a downward convex shape. As a result, the article is peeled off from the adhesive layer and transferred to another substrate. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Special Publication No. 2014-515883 Summary of the Invention [Problem to be solved by the invention]

[0005] In a conventional element transfer method such as that described in Patent Document 1, if the thickness of the article (element) is relatively small, deformation of the adhesive layer (sticky layer) during transfer causes bending stress to be applied to the element, which may result in damage to the element. Therefore, there is a demand for an element transfer method and element transfer device that can transfer elements while suppressing damage to the elements, even when the element is relatively thin.

[0006] The present invention has been made to solve the above-mentioned problems, and one object of the present invention is to provide an element transfer method and element transfer device that are capable of transferring elements while suppressing damage to the elements caused by deformation of the adhesive layer, even in the case of elements with a relatively small thickness. [Means for solving the problem]

[0007] In order to achieve the above object, an element transfer method according to a first aspect of the present invention includes an arrangement step of arranging an element on a first substrate having elasticity via a stretchable adhesive layer; a stretching step of stretching the adhesive layer in a direction along the surface of the element; and a transfer step of irradiating laser light toward the first substrate from the side opposite to the side on which the element is arranged of the first substrate, while the adhesive layer has been stretched in the stretching step, to transfer the element to a second substrate.

[0008] In the element transfer method according to this first aspect, as described above, while the adhesive layer is stretched, laser light is irradiated toward the first substrate from the side opposite to the side on which the element is placed, thereby transferring the element to the second substrate. As a result, the adhesive layer is stretched, thereby reducing the height of the portion of the adhesive layer deformed by the laser light irradiation, and therefore reducing the bending stress imparted to the element by the deformed adhesive layer. Furthermore, as the adhesive layer is stretched, the element is subjected to a force along the direction in which the adhesive layer is stretched. Here, the force applied to the element along the direction in which the adhesive layer is stretched assists in the peeling of the element from the adhesive layer, thereby facilitating the peeling of the element from the adhesive layer. As a result, even in the case of elements with relatively small thicknesses, the element can be transferred while suppressing damage to the element due to deformation of the adhesive layer.

[0009] In the element transfer method according to the first aspect, the stretching step preferably includes a step of stretching the first substrate and the adhesive layer by sandwiching the first substrate and the adhesive layer together with a clamping unit that sandwiches the first substrate and the adhesive layer together, at least one end and the other end of the first substrate and the adhesive layer, as viewed from a direction perpendicular to the surface of the first substrate, and moving the clamping units apart from each other in a direction along the surface of the element. This configuration ensures that the first substrate and the adhesive layer are stretched simultaneously by the clamping unit, thereby preventing a decrease in the force applied to the element in the direction in which the adhesive layer is stretched, compared to when the first substrate is not stretched. As a result, the element can be easily peeled off.

[0010] In the element transfer method according to the first aspect, the stretching step preferably includes a step of stretching the adhesive layer by pressing the first substrate against a holding substrate arranged on the side opposite to the side on which the elements are arranged, and the transfer step includes a step of irradiating a laser beam toward the holding substrate from the side opposite to the side on which the elements are arranged of the first substrate, with the adhesive layer stretched in the stretching step, to transfer the elements to the second substrate. With this configuration, the elements can be positioned at a predetermined position by contacting the first substrate with the holding substrate, thereby preventing a decrease in the accuracy of the element transfer position. Furthermore, by pressing the holding substrate against the first substrate to stretch the adhesive layer, stretching the adhesive layer and positioning the elements can be performed simultaneously. As a result, the time required for the element transfer step can be reduced.

[0011] In the element transfer method according to the first aspect, the transfer step preferably includes a step of transferring the element to the second substrate by irradiating the first substrate with laser light from the side opposite to the side on which the element is placed, while the adhesive layer is stretched in the stretching step, and moving the laser light relative to the first substrate along the stretching direction of the adhesive layer. This configuration ensures that the direction in which the element peels and the direction in which the adhesive layer is stretched coincide with each other, so that the force applied to the element along the stretching direction of the adhesive layer can more efficiently promote peeling of the element. As a result, the element can be easily peeled.

[0012] The element transfer method according to the first aspect preferably further includes a holding step of bringing the first substrate into contact with a holding substrate, which is arranged on the side of the first substrate opposite to the side on which the elements are arranged and is held substantially parallel to the second substrate, while the adhesive layer is stretched in the stretching step. The transfer step includes a step of irradiating a laser beam toward the holding substrate from the side of the first substrate opposite to the side on which the elements are arranged, while the first substrate and the holding substrate are in contact in the holding step, to transfer the elements to the second substrate. With this configuration, the first substrate and the second substrate on which the elements are arranged are substantially parallel, so that even when multiple elements are arranged on the first substrate, the multiple elements are positioned substantially parallel to the second substrate. As a result, it is possible to suppress a decrease in the transfer position accuracy of the elements while suppressing variation in the transfer position accuracy for each element.

[0013] According to a second aspect of the present invention, an element transfer device includes a laser light irradiation unit that irradiates laser light toward a stretchable first substrate, on which elements are arranged via a stretchable adhesive layer, from the side opposite to the side on which the elements are arranged of the first substrate, and an extension unit that stretches the adhesive layer in a direction along the surface of the elements, and the laser light irradiation unit is configured to irradiate laser light toward the first substrate while the adhesive layer is stretched, thereby transferring the elements to the second substrate.

[0014] In the device transfer device according to this second aspect, as described above, the laser light irradiation unit is configured to irradiate laser light toward the first substrate while the adhesive layer is stretched, thereby transferring the element to the second substrate. As a result, the adhesive layer is stretched, thereby reducing the height of the portion of the adhesive layer deformed by the laser light irradiation, and therefore reducing the bending stress imparted to the element by the deformed adhesive layer. Furthermore, as the adhesive layer is stretched, the element is subjected to a force along the direction in which the adhesive layer is stretched. Here, the force applied to the element along the direction in which the adhesive layer is stretched assists the element's peeling from the adhesive layer, thereby facilitating the peeling of the element from the adhesive layer. As a result, even if the element is relatively fragile, such as an element with a relatively small thickness, the element can be peeled from the adhesive layer while preventing damage to the element. As a result, a device transfer device can be provided that transfers elements while preventing damage to the element due to deformation of the adhesive layer.

[0015] In the device transfer device according to the second aspect, the stretching unit preferably includes a clamping unit that clamps the first substrate and the end of the adhesive layer together when viewed from a direction perpendicular to the surface of the first substrate, and is configured to stretch the first substrate and the adhesive layer by moving the clamping unit relative to the device, and the laser light irradiating unit is configured to irradiate laser light toward the first substrate while the first substrate and the adhesive layer are stretched, thereby transferring the device to the second substrate. This configuration ensures that the first substrate and the adhesive layer are stretched simultaneously, thereby preventing a decrease in the force applied to the device along the stretching direction of the adhesive layer compared to when the first substrate is not stretched. As a result, the device can be easily peeled off. [Effects of the Invention]

[0016] As described above, the element transfer method and element transfer apparatus of the present invention can transfer elements while suppressing damage to the elements caused by deformation of the adhesive layer, even in the case of elements with a relatively small thickness. [Brief explanation of the drawings]

[0017] [Figure 1]1 is a schematic diagram showing the overall configuration of a semiconductor chip transfer device according to a first embodiment. [Figure 2] FIG. 1 is a plan view showing a state in which a semiconductor chip according to a first embodiment is arranged on a transfer substrate. [Figure 3] 1 is a cross-sectional view of a semiconductor chip transfer apparatus according to a first embodiment. [Figure 4] 3 is a plan view showing a state in which a decompression groove and a decompression hole are provided in the holding substrate according to the first embodiment. FIG. [Figure 5] 5A and 5B are diagrams illustrating the state of the adhesive layer and the semiconductor chip when irradiated with laser light according to the first embodiment. [Figure 6] 5A and 5B are diagrams showing trajectories of laser light moving relative to the semiconductor chip according to the first embodiment. [Figure 7] 4 is a flowchart for explaining a process of the semiconductor chip transfer method according to the first embodiment. [Figure 8] 2A to 2C are schematic views for explaining some of the steps of the semiconductor chip transfer method according to the first embodiment. [Figure 9] 10 is a flowchart for explaining a process of a semiconductor chip transfer method according to a second embodiment. [Figure 10] 10A to 10C are schematic views for explaining some of the steps of a semiconductor chip transfer method according to a second embodiment. [Figure 11] 10A and 10B are diagrams showing trajectories of laser light moving relative to a semiconductor chip according to a modified example. [Figure 12] FIG. 10 is a plan view for explaining a holding substrate according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the accompanying drawings.

[0019] [First embodiment] The configuration of a semiconductor chip transfer apparatus 100 according to a first embodiment of the present invention will be described with reference to Figures 1 to 5. The semiconductor chip transfer apparatus 100 is an example of the "element transfer apparatus" in the claims.

[0020] (Semiconductor chip transfer device) As shown in Fig. 1, a semiconductor chip transfer device 100 is configured to transfer a semiconductor chip 1 arranged on a transfer substrate 10 to a transfer target portion 20 by a laser lift-off method. The transfer substrate 10 is an example of a "first substrate" in the claims. The transfer target portion 20 is an example of a "second substrate" in the claims.

[0021] The semiconductor chip transfer apparatus 100 includes an extension unit 30, a transfer substrate holding unit 40, a drive mechanism 50, a control unit 60, a laser light irradiation unit 70, a holding substrate 80, and a pressure reduction mechanism 90. The extension unit 30 includes a first clamping unit 31 and a second clamping unit 32. In FIG. 1, the left-right direction (one direction in a 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 of the semiconductor chip transfer apparatus 100 (the other direction in a horizontal plane) is defined as the Y direction. The first clamping unit 31 and the second clamping unit 32 are each an example of a "clamping unit" in the claims.

[0022] As shown in Fig. 2, a plurality of semiconductor chips 1 are arranged in a matrix (rows and columns) at predetermined intervals on the transfer substrate 10. The transfer substrate 10 has, for example, a rectangular shape. The semiconductor chip 1 is, for example, a thin element, such as a memory, having a rectangular shape with a side length of several tens of micrometers to several millimeters and a thickness of several micrometers to 30 micrometers. The semiconductor chip 1 is an example of an "element" in the claims.

[0023] 3, the holding substrate 80 is formed of a material that transmits the laser light L, such as an SiO2 (silicon dioxide) substrate or a sapphire substrate. The transfer substrate 10 is formed of a resin material that transmits the laser light L and has elasticity, such as PO (polyolefin) or PVC (polyvinyl chloride). The semiconductor chip 1 is disposed on the transfer substrate 10 via an adhesive layer 2. The adhesive layer 2 is also called a transfer material.

[0024] The adhesive layer 2 is disposed on the Z2-side surface 10a of the transfer substrate 10. The semiconductor chip 1 is disposed on the Z2-side surface 2a of the adhesive layer 2. The adhesive layer 2 is formed from a stretchable material that decomposes to generate gas components when irradiated with laser light L from the laser light irradiation unit 70. The generation of the gas components causes the adhesive layer 2 to deform into a convex shape protruding toward the Z2 side (see FIG. 6). The adhesive layer 2 is formed from, for example, polyimide or silicon.

[0025] The holding substrate 80 is disposed on the Z1-side surface 10b of the transfer substrate 10. The holding substrate 80 is held so as to be approximately parallel to the transfer substrate 20 (transfer substrate holding unit 40). The holding substrate 80 is provided with a decompression groove 80a having an opening on the surface facing the transfer substrate 10, and a decompression hole 80b, which is a through-hole having openings on the Z1-side surface of the decompression groove 80a and the Z1-side surface of the holding substrate 80. The decompression hole 80b is connected to the decompression mechanism 90, for example, by a hollow pressure-resistant hose. When the decompression mechanism 90 is operated, it draws air from the opening on the side of the pressure-resistant hose opposite the decompression mechanism 90 and exhausts air from a location different from the location where the pressure-resistant hose is connected. In other words, the decompression mechanism 90 can decompress a closed space by connecting the pressure-resistant hose to the closed space. The decompression mechanism 90 is, for example, a decompression pump. As shown in FIG. 4, the decompression groove 80a is provided inside the outer periphery of the holding substrate 80 so as to follow the outer periphery. One decompression hole 80b is provided on the X1 side of the holding substrate 80 at a position overlapping with the decompression groove 80a when viewed from the Z-axis direction. The decompression groove 80a and the decompression hole 80b are provided outside the arrangement area of ​​the semiconductor chip 1 when viewed from the Z-axis direction.

[0026] As shown in FIGS. 1 and 3 , the extension unit 30 includes a first clamping unit 31 and a second clamping unit 32, which clamp an end of the transfer substrate 10, on which the semiconductor chip 1 is arranged, via the adhesive layer 2, together with an end of the adhesive layer 2. The first clamping unit 31 includes a pair of clamping portions 31a and 31b. The second clamping unit 32 includes a pair of clamping portions 32a and 32b. The first clamping unit 31 clamps the transfer substrate 10 and the adhesive layer 2 by relatively moving the pair of clamping portions 31a and 31b toward each other by the drive mechanism 50. The second clamping unit 32 clamps the transfer substrate 10 and the adhesive layer 2 by relatively moving the pair of clamping portions 32a and 32b toward each other by the drive mechanism 50. The first clamping unit 31 and the second clamping unit 32 clamp the transfer substrate 10 and the adhesive layer 2, respectively, so that the transfer substrate 10 is held with the surface on which the semiconductor chip 1 is arranged facing downward (Z2 direction). The extension unit 30 is arranged outside the irradiation range of the laser light L irradiated from the laser light irradiation unit 70.

[0027] As shown in FIG. 1, the first clamping unit 31, the second clamping unit 32 and the holding substrate 80 are configured to be movable relative to the transferred substrate holding unit 40 (transferred unit 20) in the X, Y and Z directions by a driving mechanism 50.

[0028] As shown in FIG. 3, the transferred portion 20 is a substrate onto which a large number of semiconductor chips 1 arranged on a transfer substrate 10 are transferred, for example, during the manufacturing process of a semiconductor product. The transferred portion 20 includes an adhesive layer 20a for adhering the transferred semiconductor chips 1 and a transferred substrate 20b on which the adhesive layer 20a is arranged. The adhesive layer 20a is also called a catch layer. The transferred portion 20 may also have wiring formed thereon that can be electrically connected to the transferred semiconductor chips 1. The transferred portion 20 has a rectangular shape in a plan view.

[0029] The transferee substrate holding unit 40 holds the transferee substrate 20b, onto which the semiconductor chip 1 arranged on the transfer substrate 10 is transferred, from below (Z2 side). The transferee substrate holding unit 40 is configured to be movable relative to the first clamping unit 31, the second clamping unit 32, and the holding substrate 80 in the X, Y, and Z directions by a drive mechanism 50 (see FIG. 1). By performing one or both of the movement of the first clamping unit 31, the second clamping unit 32, and the holding substrate 80 by the drive mechanism 50 and the movement of the transferee substrate holding unit 40, it is possible to adjust the relative position of the semiconductor chip 1 arranged on the transfer substrate 10 with respect to the transferee unit 20.

[0030] 1, the control unit 60 is configured with a processor such as a CPU (Central Processing Unit) and performs various controls by executing a program (software). The control unit 60 arbitrarily selects a semiconductor chip 1 in the transfer area and controls the laser light emitting unit 70 to irradiate laser light L, thereby transferring the selected semiconductor chip 1 to the transfer target unit 20. To irradiate the laser light L onto the selected semiconductor chip 1, the control unit 60 rotates a galvanometer mirror 72 to reflect the laser light L at an arbitrary angle. The control unit 60 also controls the operation of the drive mechanism 50, the operation of the pressure reducing mechanism 90, and the opening and closing of the slit 74.

[0031] The laser light irradiation unit 70 is configured to irradiate the transfer substrate 10 with laser light L. The laser light irradiation unit 70 includes a laser light source 71, a galvanometer mirror 72, and an fθ lens 73. The laser light source 71 is a light source that emits laser light L. The galvanometer mirror 72 is rotatable about two intersecting axes as rotation axes, and reflects the laser light L at an arbitrary angle. The fθ lens 73 focuses the laser light L reflected by the galvanometer mirror 72 onto the surface of the transfer region of the transfer substrate 10.

[0032] A slit 74 is provided between the laser light source 71 and the galvanometer mirror 72. The size of the opening of the slit 74 is adjusted to adjust the area SA (see FIG. 5) of the spot region of the laser light L. The area SA of the spot region means the area on the adhesive layer 2 of the laser light L that has passed through the holding substrate 80 and the transfer substrate 10 and is irradiated onto the adhesive layer 2.

[0033] As shown in FIG. 5, the laser light irradiation unit 70 (see FIG. 1) intermittently irradiates the semiconductor chip 1 with laser light L, for example. The control unit 60 (see FIG. 1) controls the irradiation position of the laser light L so that the areas SA of the spot regions of the laser light L do not overlap each other. In the first embodiment, the control unit 60 moves the irradiation position of the laser light L relative to the transfer substrate 10 to control the irradiation position of the laser light L so that the laser light L is irradiated from one end side 1a (see FIG. 3) of the semiconductor chip 1 in the X-axis direction to the other end side 1b (see FIG. 3). The control unit 60 controls the irradiation position of the laser light L so that the laser light L is irradiated in a meandering manner by repeating movement in the X-axis direction and movement in the Y-axis direction from one end side to the other end side of the semiconductor chip 1 in the X-axis direction, for example, along the dashed arrowed line shown in FIG. 5. The laser power of all the intermittently irradiated laser light L is the same. The area SA of the spot region of the laser light L is smaller than the area 1A of the semiconductor chip 1. The spot area of ​​the laser light L has, for example, a rectangular shape with a side length of several μm or more and several tens of μm or less.

[0034] (Semiconductor chip transfer method) Next, the semiconductor chip transfer method of the first embodiment will be described with reference to FIGS.

[0035] 7, in step S1 in the first embodiment, the control unit 60 (see FIG. 1) stretches the transfer substrate 10 and the adhesive layer 2. Specifically, the control unit 60 clamps one end of the transfer substrate 10 in the X-axis direction and one end of the adhesive layer 2 in the X-axis direction with the first clamping unit 31, and clamps the other end of the transfer substrate 10 in the X-axis direction and the other end of the adhesive layer 2 in the X-axis direction with the second clamping unit 32, and stretches the transfer substrate 10 and the adhesive layer 2 by separating the first clamping unit 31 and the second clamping unit 32 from each other in a direction along the surface of the semiconductor chip 1.

[0036] Step S1 is outlined in FIGS. 8(a) and 8(b). As shown in FIG. 8(a), the control unit 60 (see FIG. 1) causes the drive mechanism 50 to relatively move the pair of clamping portions 31a and 32b of the first clamping unit 31 in the Z-axis direction (direction of the arrow) so that they approach each other, thereby clamping one end of the transfer substrate 10 in the X-axis direction and one end of the adhesive layer 2 in the X-axis direction together. The control unit 60 also causes the drive mechanism 50 to relatively move the pair of clamping portions 32a and 32b of the second clamping unit 32 in the direction of the arrow so that they approach each other, thereby clamping the other end of the transfer substrate 10 in the X-axis direction and the other end of the adhesive layer 2 in the X-axis direction together. The first clamping unit 31 and the second clamping unit 32 before clamping are indicated by dashed lines, and the first clamping unit 31 and the second clamping unit 32 after clamping are indicated by solid lines. 8(b), the control unit 60 stretches the transfer substrate 10 and the adhesive layer 2 by separating a first clamping unit 31, which clamps one end of the transfer substrate 10 in the X-axis direction and one end of the adhesive layer 2 in the X-axis direction, from a second clamping unit 32, which clamps the other end of the transfer substrate 10 in the X-axis direction and the other end of the adhesive layer 2 in the X-axis direction, from each other in a direction along the surface of the semiconductor chip 1 (X-axis direction). The first clamping unit 31 and the second clamping unit 32 before separation are indicated by dashed lines, and the first clamping unit 31 and the second clamping unit 32 after separation are indicated by solid lines. In the first embodiment, at the time of step S1, the holding substrate 80 is disposed on the side of the transfer substrate 10 opposite to the side on which the semiconductor chip 1 is disposed, without contacting the transfer substrate 10.

[0037] In step S2, in the first embodiment, the control unit 60 (see FIG. 1) brings the transfer substrate 10 and the holding substrate 80 into contact with each other. Specifically, the control unit 60 causes the drive mechanism 50 to move the first clamping unit 31 and the second clamping unit 32 relative to the holding substrate 80 in the Z-axis direction, thereby bringing the stretched transfer substrate 10 into contact with the holding substrate 80. When the transfer substrate 10 and the holding substrate 80 come into contact with each other, the openings of the decompression grooves 80a formed in the holding substrate 80 are blocked by the transfer substrate 10. An outline of step S2 is shown in FIG. 8(c). As shown in FIG. 8(c), the control unit 60 moves the first clamping unit 31 and the second clamping unit 32 toward the holding substrate 80 in the Z-axis direction (the direction of the arrow), thereby bringing the transfer substrate 10 and the holding substrate 80 into contact with each other. When the transfer substrate 10 and the holding substrate 80 come into contact with each other, the semiconductor chip 1 is positioned at a predetermined position. The first clamping unit 31 and the second clamping unit 32 before movement are shown by dashed lines, and the first clamping unit 31 and the second clamping unit 32 after movement are shown by solid lines.

[0038] In step S3, the control unit 60 (see FIG. 1) adsorbs the transfer substrate 10 to the holding substrate 80. Specifically, with the openings of the decompression grooves 80a blocked by the transfer substrate 10, the control unit 60 operates the decompression mechanism 90 to reduce the pressure in the spaces within the decompression grooves 80a and the decompression holes 80b, thereby adsorbing the transfer substrate 10 to the holding substrate 80. An outline of step S3 is shown in FIG. 8(d). In FIG. 8(d), the air pressure in the spaces within the decompression grooves 80a and the decompression holes 80b is lower than atmospheric pressure.

[0039] In step S4, the control unit 60 (see FIG. 1) irradiates the semiconductor chip 1 with laser light L to transfer the semiconductor chip 1. Specifically, while the transfer substrate 10 and the adhesive layer 2 are stretched, the control unit 60 irradiates the laser light L from the Z1 side (opposite to the surface 10a of the transfer substrate 10 on which the semiconductor chip 1 is arranged) via the adhesive layer 2 toward the transfer substrate 10 on which the semiconductor chip 1 is arranged. The laser light L then passes through the holding substrate 80 and the transfer substrate 10 and irradiates the adhesive layer 2, thereby peeling the semiconductor chip 1 from the transfer substrate 10 and transferring the semiconductor chip 1 from the transfer substrate 10 to the transferee 20. That is, the transfer is performed by the laser lift-off method. Note that, as shown in FIG. 5, the entire semiconductor chip 1 is peeled and transferred by intermittently irradiating the laser light L having a spot area smaller than the area of ​​the semiconductor chip 1 multiple times. Furthermore, as shown in FIGS. 3 and 5, the control unit 60 controls the laser light L to move along the direction in which the transfer substrate 10 and the adhesive layer 2 are stretched (the X-axis direction). The situation when the semiconductor chip 1 is transferred will be described later.

[0040] In step S5, the control unit 60 (see FIG. 1) determines whether all of the semiconductor chips 1 arranged on the transfer substrate 10 have been transferred. If the answer is No in step S5, the process returns to step S4. If the answer is Yes in step S5, the process of the semiconductor chip transfer method ends.

[0041] (Situation during transfer of semiconductor chip) As shown in FIG. 6, when the adhesive layer 2 is irradiated with laser light L, the adhesive layer 2 is deformed into a convex shape that protrudes toward the Z2 side. The deformed portion B of the adhesive layer 2 pushes the semiconductor chip 1 in the Z2 direction, thereby peeling the semiconductor chip 1 from the adhesive layer 2 around the deformed portion B of the adhesive layer 2. Because only the periphery of the deformed portion B of the adhesive layer 2 is pushed out, the semiconductor chip 1 is subjected to bending stress in the area surrounded by the dashed line (see FIG. 6), which is near the boundary between the part that has peeled off from the adhesive layer 2 and the part that has not peeled off from the adhesive layer 2. This bending stress may damage the semiconductor chip 1. This bending stress increases as the height h of the deformed portion B of the adhesive layer 2 increases, and decreases as the height h of the deformed portion B of the adhesive layer 2 decreases. When the transfer substrate 10 and the adhesive layer 2 are irradiated with laser light L while they are stretched, the height h of the deformed portion B of the adhesive layer 2 becomes relatively small. Therefore, irradiating the transfer substrate 10 and the adhesive layer 2 while they are stretched with laser light L is particularly effective in suppressing damage to the semiconductor chip 1 due to deformation of the adhesive layer 2. Furthermore, the semiconductor chip 1 is subjected to a force along the stretching direction (X-axis direction) of the transfer substrate 10 and the adhesive layer 2, which promotes peeling from the adhesive layer 2. Therefore, the semiconductor chip 1 is peeled from the adhesive layer 2 even when the height h of the deformed portion B of the adhesive layer 2 is relatively small. Generally, when the height h of the deformed portion B of the adhesive layer 2 is small, the force with which the deformed portion B of the adhesive layer 2 pushes out the semiconductor chip 1 is reduced, making it difficult for the semiconductor chip 1 to peel from the adhesive layer 2. For these reasons, irradiating the transfer substrate 10 and the adhesive layer 2 while they are stretched with laser light L is particularly effective in transferring the semiconductor chip 1 while suppressing damage to the semiconductor chip 1 due to deformation of the adhesive layer 2. The deformed portion B of the adhesive layer 2 is also called a blister.

[0042] (Effects of the first embodiment) Next, the effects of the first embodiment will be described.

[0043] As described above, the first embodiment includes the following steps: a placement step of placing the semiconductor chip 1 on the stretchable transfer substrate 10 via the stretchable adhesive layer 2; a stretching step of stretching the adhesive layer 2 in a direction along the surface of the semiconductor chip 1; and a transfer step of irradiating the transfer substrate 10 with laser light L from the side of the transfer substrate 10 opposite to the side on which the semiconductor chip 1 is placed, with the adhesive layer 2 stretched in the stretching step, thereby transferring the semiconductor chip 1 to the transfer receiving portion 20. As a result, the height h of the portion of the adhesive layer 2 deformed by the irradiation of the laser light L is reduced by stretching the adhesive layer 2, thereby reducing the bending stress imparted to the semiconductor chip 1 by the deformed adhesive layer 2. Furthermore, as the adhesive layer 2 is stretched, the semiconductor chip 1 is subjected to a force in the direction in which the adhesive layer 2 is stretched. The force applied to the semiconductor chip 1 in the direction in which the adhesive layer 2 is stretched assists in the peeling of the semiconductor chip 1 from the adhesive layer 2, thereby facilitating the peeling of the semiconductor chip 1 from the adhesive layer 2. As a result, even in the case of a semiconductor chip 1 having a relatively small thickness, the semiconductor chip 1 can be transferred while preventing damage to the semiconductor chip 1 due to deformation of the adhesive layer 2.

[0044] Furthermore, in the first embodiment, as described above, the stretching step includes a step of stretching the transfer substrate 10 and the adhesive layer 2 by sandwiching the transfer substrate 10 and the adhesive layer 2 together with the stretching units 30, as viewed from a direction perpendicular to the surface of the transfer substrate 10, and separating the stretching units 30 from each other in a direction along the surface of the semiconductor chip 1. This allows the transfer substrate 10 and the adhesive layer 2 to be reliably stretched simultaneously by the stretching units 30, thereby suppressing a decrease in the force applied to the semiconductor chip 1 in the direction in which the adhesive layer 2 is stretched, compared to when the transfer substrate 10 is not stretched. As a result, the semiconductor chip 1 can be easily peeled off.

[0045] Furthermore, in the first embodiment, as described above, the transfer step includes a step of irradiating laser light L toward the transfer substrate 10 from the side opposite to the side on which the semiconductor chip 1 is placed, with the adhesive layer 2 stretched in the stretching step, and moving the laser light L relative to the transfer substrate 10 along the stretching direction of the adhesive layer 2 to transfer the semiconductor chip 1 to the transfer recipient 20. This causes the direction in which the semiconductor chip 1 peels to coincide with the direction in which the adhesive layer 2 is stretched, so that the force that the semiconductor chip 1 receives along the stretching direction of the adhesive layer 2 can more efficiently promote peeling of the semiconductor chip 1. As a result, the semiconductor chip 1 can be easily peeled off.

[0046] Furthermore, in the first embodiment, as described above, a holding step is further provided in which, with the adhesive layer 2 stretched in the stretching step, the transfer substrate 10 is brought into contact with a holding substrate 80, which is arranged on the side of the transfer substrate 10 opposite to the side on which the semiconductor chip 1 is arranged and is held substantially parallel to the transfer recipient 20. The transfer step includes a step of irradiating laser light L toward the holding substrate 80 from the side of the transfer substrate 10 opposite to the side on which the semiconductor chip 1 is arranged, with the transfer substrate 10 and the holding substrate 80 in contact in the holding step, to transfer the semiconductor chip 1 to the transfer recipient 20. As a result, the transfer substrate 10 on which the semiconductor chip 1 is arranged and the transfer recipient 20 become substantially parallel, so that even when multiple semiconductor chips 1 are arranged on the transfer substrate 10, the multiple semiconductor chips 1 are positioned substantially parallel to the transfer recipient 20. As a result, it is possible to suppress a decrease in the transfer position accuracy of the semiconductor chip 1 while suppressing variation in the transfer position accuracy for each semiconductor chip 1.

[0047] [Second embodiment] Next, a description will be given of a semiconductor chip transfer method according to the second embodiment. In the second embodiment, the transfer substrate 10 is pressed against the holding substrate 80, thereby stretching the transfer substrate 10 and the adhesive layer 2.

[0048] The configuration of the semiconductor chip transfer device 100 of the second embodiment is similar to that of the first embodiment.

[0049] A semiconductor chip transfer method according to the second embodiment will be described with reference to FIGS.

[0050] 9, in step S101, in the second embodiment, the control unit 60 (see FIG. 1) presses the transfer substrate 10 against the holding substrate 80, thereby stretching the transfer substrate 10 and the adhesive layer 2. Specifically, the control unit 60 clamps one end of the transfer substrate 10 in the X-axis direction and one end of the adhesive layer 2 in the X-axis direction together with the first clamping unit 31, and clamps the other end of the transfer substrate 10 in the X-axis direction and the other end of the adhesive layer 2 in the X-axis direction together with the second clamping unit 32, and moves the first clamping unit 31 and the second clamping unit 32 toward the holding substrate 80 (Z1 side). As a result, the transfer substrate 10 is pressed against the holding substrate 80, thereby stretching the transfer substrate 10 and the adhesive layer 2.

[0051] Step S101 is outlined in Figures 10(a) and 10(b). As shown in Figure 10(a), the control unit 60 (see Figure 1) causes the drive mechanism 50 to relatively move the pair of clamping portions 31a and 31b of the first clamping unit 31 in the Z-axis direction (direction of the arrow) so that they approach each other, thereby clamping one end of the transfer substrate 10 in the X-axis direction and one end of the adhesive layer 2 in the X-axis direction together. The control unit 60 also causes the drive mechanism 50 to relatively move the pair of clamping portions 32a and 32b of the second clamping unit 32 in the direction of the arrow so that they approach each other, thereby clamping the other end of the transfer substrate 10 in the X-axis direction and the other end of the adhesive layer 2 in the X-axis direction together. The first clamping unit 31 and the second clamping unit 32 before clamping are indicated by dashed lines, and the first clamping unit 31 and the second clamping unit 32 after clamping are indicated by solid lines. 10(b), the control unit 60 moves a first clamping unit 31, which clamps one end of the transfer substrate 10 in the X-axis direction and one end of the adhesive layer 2 in the X-axis direction, and a second clamping unit 32, which clamps the other end of the transfer substrate 10 in the X-axis direction and the other end of the adhesive layer 2 in the X-axis direction, in the direction of the arrow toward the holding substrate 80 (Z1 side), thereby pressing the transfer substrate 10 against the holding substrate 80. As a result, a force pulling the transfer substrate 10 and the adhesive layer 2 in the X-axis direction is generated, causing the transfer substrate 10 and the adhesive layer 2 to stretch. The first clamping unit 31 and the second clamping unit 32 before movement are indicated by dashed lines, and the first clamping unit 31 and the second clamping unit 32 after movement are indicated by solid lines. As shown in FIG. 10(b), by pressing the transfer substrate 10 against the holding substrate 80, the opening of the decompression groove 80a provided in the holding substrate 80 is blocked by the transfer substrate 10.

[0052] In step S102, the control unit 60 (see FIG. 1) adsorbs the transfer substrate 10 to the holding substrate 80. Specifically, with the openings of the decompression grooves 80a blocked by the transfer substrate 10, the control unit 60 operates the decompression mechanism 90 to reduce the pressure in the spaces within the decompression grooves 80a and the decompression holes 80b, thereby adsorbing the transfer substrate 10 to the holding substrate 80. An outline of step S102 is shown in FIG. 10(c). In FIG. 10(c), the air pressure in the spaces within the decompression grooves 80a and the decompression holes 80b is lower than atmospheric pressure.

[0053] In step S103, the control unit 60 (see FIG. 1) irradiates the semiconductor chip 1 with laser light L to transfer the semiconductor chip 1. Specifically, while the transfer substrate 10 and the adhesive layer 2 are stretched, the control unit 60 irradiates the laser light L via the adhesive layer 2 toward the transfer substrate 10 on which the semiconductor chip 1 is arranged, from the side (Z1 side) opposite to the surface 10a of the transfer substrate 10 on which the semiconductor chip 1 is arranged. The laser light L then passes through the holding substrate 80 and the transfer substrate 10 and irradiates the adhesive layer 2, whereby the semiconductor chip 1 is peeled off from the transfer substrate 10 and transferred from the transfer substrate 10 to the transferee 20. That is, the transfer is performed by the laser lift-off method. Note that, as shown in FIG. 5, the entire semiconductor chip 1 is peeled off and transferred by intermittently irradiating the laser light L having a spot area smaller than the area of ​​the semiconductor chip 1 multiple times. 3 and 5, the control unit 60 controls the laser light L to move in the direction of the arrow along the direction (X-axis direction) in which the transfer substrate 10 and the adhesive layer 2 are stretched. The situation during transfer of the semiconductor chip 1 is the same as in the first embodiment.

[0054] In step S104, the control unit 60 (see FIG. 1) determines whether all of the semiconductor chips 1 arranged on the transfer substrate 10 have been transferred. If the answer is No in step S104, the process returns to step S103. If the answer is Yes in step S104, the process of the semiconductor chip transfer method ends.

[0055] (Effects of the second embodiment) Next, the effects of the second embodiment will be described.

[0056] In the second embodiment, as described above, the stretching step includes a step of stretching the adhesive layer 2 by pressing the transfer substrate 10 against the holding substrate 80, which is arranged on the side of the transfer substrate 10 opposite to the side on which the semiconductor chip 1 is arranged, and the transfer step includes a step of irradiating laser light L toward the holding substrate 80 from the side of the transfer substrate 10 opposite to the side on which the semiconductor chip 1 is arranged, with the adhesive layer 2 stretched in the stretching step, to transfer the semiconductor chip 1 to the transfer portion 20. As a result, the semiconductor chip 1 can be positioned at a predetermined position by contacting the transfer substrate 10 and the holding substrate 80, thereby preventing a decrease in the transfer position accuracy of the semiconductor chip 1. Furthermore, by stretching the adhesive layer 2 by pressing the holding substrate 80 against the transfer substrate 10, the stretching of the adhesive layer 2 and the positioning of the semiconductor chip 1 can be performed simultaneously. As a result, the time required for the transfer step of the semiconductor chip 1 can be reduced.

[0057] [Variations] The embodiments disclosed herein should be considered to be illustrative and not restrictive in all respects. The scope of the present invention is defined by the claims rather than the above description of the embodiments, and further includes all modifications (variations) within the meaning and scope of the claims.

[0058] For example, in the first and second embodiments, the transfer substrate 10 and the adhesive layer 2 are stretched, but the present invention is not limited to this. For example, the transfer substrate 10 may not be stretched, and only the adhesive layer 2 may be stretched.

[0059] In the first and second embodiments, the extension section 30 sandwiches and holds the transfer substrate 10 and the adhesive layer 2 together, but the present invention is not limited to this. For example, the extension section 30 may hold the transfer substrate 10 and the adhesive layer 2 by suction force or the like, rather than sandwiching them together.

[0060] In the first and second embodiments, the first clamping unit 31 and the second clamping unit 32 clamp one end and the other end in the X-axis direction of the transfer substrate 10 and the adhesive layer 2, respectively. However, the present invention is not limited to this. For example, the first clamping unit 31 and the second clamping unit 32 may clamp one end and the other end in the Y-axis direction of the transfer substrate 10 and the adhesive layer 2, respectively. The first clamping unit 31 and the second clamping unit 32 may clamp any location on the end of the transfer substrate 10 and the adhesive layer 2, respectively.

[0061] In the first and second embodiments, the stretching unit 30 includes the first clamping unit 31 and the second clamping unit 32, but the present invention is not limited to this. For example, the stretching unit 30 may include three or more clamping units.

[0062] Furthermore, in the first embodiment, an example has been described in which the transfer substrate 10 and the holding substrate 80 are brought into contact with each other by moving the first clamping unit 31 and the second clamping unit 32, but the present invention is not limited to this. For example, the transfer substrate 10 and the holding substrate 80 may be brought into contact with each other by moving the holding substrate 80. Furthermore, the transfer substrate 10 and the holding substrate 80 may be brought into contact with each other by moving the first clamping unit 31, the second clamping unit 32, and the holding substrate 80, respectively.

[0063] In the second embodiment, the transfer substrate 10 is pressed against the holding substrate 80 by moving the first clamping unit 31 and the second clamping unit 32, but the present invention is not limited to this. For example, the holding substrate 80 may be pressed against the transfer substrate 10 by moving the holding substrate 80. Furthermore, the holding substrate 80 and the transfer substrate 10 may be pressed against each other by moving the first clamping unit 31, the second clamping unit 32, and the holding substrate 80, respectively.

[0064] In the first and second embodiments, the direction in which the transfer substrate 10 and the adhesive layer 2 are stretched and the direction in which the laser light L is moved from one end of the semiconductor chip 1 to the other are both in the X-axis direction, but the present invention is not limited to this. For example, the direction in which the transfer substrate 10 and the adhesive layer 2 are stretched and the direction in which the laser light L is moved from one end of the semiconductor chip 1 to the other may both be in the Y-axis direction. Furthermore, the direction in which the transfer substrate 10 and the adhesive layer 2 are stretched and the direction in which the laser light L is moved from one end of the semiconductor chip 1 to the other may be different directions. Furthermore, the laser light L does not need to be moved.

[0065] Furthermore, in the first embodiment, an example was shown in which the transfer substrate 10 and the holding substrate 80 were in contact with each other, but the present invention is not limited to this. For example, the transfer substrate 10 and the holding substrate 80 do not have to be in contact with each other. In that case, the holding substrate 80 is no longer necessary, and the step of adsorbing the transfer substrate 10 to the holding substrate 80 is no longer necessary.

[0066] In the first and second embodiments, the holding substrate 80 is held substantially parallel to the transferred portion 20, but the present invention is not limited to this. For example, the holding substrate 80 may be held so as not to be substantially parallel to the transferred portion 20.

[0067] In the first and second embodiments, the transfer substrate 10 is made of a resin material, but the present invention is not limited to this. For example, the transfer substrate 10 may be made of a material other than a resin material.

[0068] In the first and second embodiments, the first clamping unit 31 and the second clamping unit 32 clamp the ends of the transfer substrate 10 and the adhesive layer 2, respectively, but the present invention is not limited to this. For example, the first clamping unit 31 and the second clamping unit 32 may clamp a location other than the ends of the transfer substrate 10 and the adhesive layer 2, respectively.

[0069] In the first and second embodiments, the laser outputs of the intermittently irradiated laser beams L are all the same, but the present invention is not limited to this. For example, the control unit 60 may be configured to adjust the laser output of the laser beam L according to the degree to which the transfer substrate 10 and the adhesive layer 2 are stretched. Specifically, the control unit 60 may be configured to set the laser output of the laser beam L irradiated to the end portions of the transfer substrate 10 and the adhesive layer 2, where the degree of stretching is relatively large, to be relatively small, and to set the laser output of the laser beam L irradiated to the central portions of the transfer substrate 10 and the adhesive layer 2, where the degree of stretching is relatively small, to be relatively large.

[0070] In the first and second embodiments, the transfer substrate 10 and the transferee substrate 20b are rectangular, but the present invention is not limited to this. For example, the transfer substrate 10 and the transferee substrate 20b may both be circular or polygonal.

[0071] In the first and second embodiments, the intervals between the irradiation positions of the intermittently irradiated laser light L are uniform on the semiconductor chip 1, but the present invention is not limited to this. For example, the intervals between the irradiation positions of the intermittently irradiated laser light L may be adjusted to be different between the end side and the center side of the semiconductor chip 1.

[0072] Furthermore, in the first and second embodiments, the spot area of ​​the laser light L is rectangular, but the present invention is not limited to this. For example, the spot area of ​​the laser light L may be circular.

[0073] In the first and second embodiments, an example was shown in which a thin element such as a memory was used as the semiconductor chip 1, but the present invention is not limited to this. For example, various semiconductor elements other than a memory may be used as the semiconductor chip 1.

[0074] In the first and second embodiments, the driving mechanism 50 is configured to be able to move all of the first clamping unit 31, the second clamping unit 32, the holding substrate 80, and the transferred substrate holding unit 40, but the present invention is not limited to this. For example, the driving mechanism 50 may be provided separately for the first clamping unit 31, the second clamping unit 32, the holding substrate 80, and the transferred substrate holding unit 40.

[0075] In the first and second embodiments, the laser light L moves in a meandering manner by repeating movement in the X-axis direction and movement in the Y-axis direction from one end side of the semiconductor chip 1 in the X-axis direction to the other end side thereof along the dashed line with an arrow shown in Fig. 5, but the present invention is not limited to this. For example, as shown in Fig. 11, the laser light L may be irradiated in a meandering manner by repeating movement in a diagonal direction that combines the X-axis direction and the Y-axis direction, movement in the X-axis direction, and movement in the Y-axis direction from one end side of the semiconductor chip 1 in the X-axis direction to the other end side thereof along the dashed line with an arrow. The laser light L may also be moved along any other route.

[0076] Furthermore, in the above-described first and second embodiments, an example was shown in which the irradiated laser light L passes through the holding substrate 80, but the present invention is not limited to this. For example, as in a modified example shown in FIG. 12, the holding substrate 81 may have an opening 81c in the center. In this case, the laser light L is irradiated onto the transfer substrate 10 through the opening 81c. The decompression groove 81a has the same configuration as the decompression groove 80a. The decompression hole 81b has the same configuration as the decompression hole 80b.

[0077] In addition, in the first and second embodiments, an example in which only one decompression hole 80b is provided has been shown, but the present invention is not limited to this. For example, a plurality of decompression holes 80b may be provided. In this case, the plurality of decompression holes 80b may be connected to a common decompression mechanism 90, or each may be connected to a decompression mechanism 90 that is provided individually.

[0078] In the first and second embodiments, the peeling of the semiconductor chip 1 from the adhesive layer 2 is assisted by stretching the stretchable adhesive layer 2, but the present invention is not limited to this. For example, the peeling of the semiconductor chip 1 from the adhesive layer 2 may be assisted by charging at least the transferred portion 20 out of the semiconductor chip 1 and the transferred portion 20. [Explanation of symbols]

[0079] 1. Semiconductor chip (element) 2 Adhesive layer 10 Transfer substrate (first substrate) 20 Transferred part (second substrate) 30 Stretching part (clamping part) 31 First clamping part (clamping part) 32 Second clamping part (clamping part) 70 Laser light irradiation unit 80 Holding board 100 Semiconductor chip transfer device (element transfer device) L laser light

Claims

1. a placement step of placing an element on a stretchable first substrate via a stretchable adhesive layer; a stretching step of stretching the adhesive layer in a direction along the surface of the element; a transfer step of irradiating laser light toward the first substrate from the side opposite to the side on which the element is placed on the first substrate while the adhesive layer is stretched in the stretching step, thereby transferring the element to a second substrate.

2. 2. The element transfer method of claim 1, wherein the stretching step includes a step of sandwiching the first substrate and the adhesive layer together with a clamping portion that sandwiches at least one end and the other end of the first substrate and the adhesive layer when viewed from a direction perpendicular to the surface of the first substrate, and stretching the first substrate and the adhesive layer by separating a plurality of the clamping portions from each other in a direction along the surface of the element.

3. the stretching step includes a step of stretching the adhesive layer by pressing the first substrate against a holding substrate that is arranged on an opposite side of the first substrate from a side on which the element is arranged, 2. The element transfer method according to claim 1, wherein the transfer step includes a step of irradiating the laser light toward the holding substrate from the side of the first substrate opposite to the side on which the element is placed, while the adhesive layer is stretched in the stretching step, thereby transferring the element to the second substrate.

4. 2. The element transfer method according to claim 1, wherein the transfer step includes a step of irradiating the laser light toward the first substrate from the side opposite to the side on which the element is placed, while the adhesive layer is stretched in the stretching step, and moving the laser light relative to the first substrate along the stretching direction of the adhesive layer to transfer the element to the second substrate.

5. a holding step of bringing the first substrate into contact with a holding substrate, which is arranged on the opposite side of the first substrate from the side on which the element is arranged and is held substantially parallel to the second substrate, in a state in which the adhesive layer is stretched in the stretching step; 2. The element transfer method according to claim 1, wherein the transfer step includes a step of irradiating the laser light toward the holding substrate from a side of the first substrate opposite to the side on which the element is arranged, while the first substrate and the holding substrate are in contact with each other in the holding step, thereby transferring the element to the second substrate.

6. a laser light irradiation unit that irradiates a laser light toward a first substrate having elasticity, the first substrate having elements arranged thereon via an elastic adhesive layer, from a side opposite to a side on which the elements are arranged; a stretching portion that stretches the adhesive layer in a direction along the surface of the element, The laser light irradiation unit is configured to irradiate the laser light toward the first substrate while the adhesive layer is stretched, thereby transferring the element to the second substrate.

7. the stretching unit includes a clamping unit that clamps together ends of the first substrate and the adhesive layer when viewed from a direction perpendicular to the surface of the first substrate, and is configured to stretch the first substrate and the adhesive layer by moving the clamping unit relative to the element; 7. The element transfer device according to claim 6, wherein the laser light irradiation unit is configured to irradiate the laser light toward the first substrate while the first substrate and the adhesive layer are stretched, thereby transferring the element to the second substrate.

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