JP7223310B2 - Holding member, transfer member, method for manufacturing transfer member, and method for manufacturing light-emitting substrate - Google Patents

Description

The present invention relates to a holding member, a transfer member having the holding member, a method for manufacturing the transfer member, and a method for manufacturing a light emitting substrate using the transfer member.

2. Description of the Related Art In recent years, so-called micro-LED displays, which use a light-emitting substrate in which a plurality of micro-light-emitting diode (LED) chips are arranged on a circuit board having a circuit, have been developed. Micro LED displays are superior to liquid crystal displays and the like in terms of brightness, power consumption, response speed, reliability, etc., and are attracting attention as next-generation lightweight and thin displays.

Conventionally, when manufacturing light-emitting substrates used in micro-LED displays, a plurality of micro-light-emitting diode chips formed by dicing a wafer are arranged one by one on a circuit board by a pick-and-place process. In such a light-emitting substrate manufacturing method, the pick-and-place process is repeated millions of times or more, and the process of arranging the micro-light-emitting diode chips on the circuit board takes a long time, thereby increasing the manufacturing cost. end up That is, the light-emitting substrate can only be manufactured with low productivity.

Therefore, as disclosed in Japanese Unexamined Patent Application Publication No. 2002-100000, it was considered to dispose the micro-light-emitting diode chips from the wafer to the circuit board by means of an adhesive stamp. Since the adhesive stamp of Patent Document 1 can hold a plurality of micro light emitting diode chips, a plurality of micro light emitting diode chips can be arranged on a circuit board in one pick-and-place process. Therefore, the time required for the process of disposing the micro LED chip on the circuit board can be shortened, and the manufacturing cost can be reduced.

Japanese Patent Application Publication No. 2017-531915

By the way, the adhesive stamp of Patent Literature 1 loses its adhesive force when the pick-and-place process is repeated. As the adhesive strength of the adhesive stamp decreases, the reliability of the adhesive stamp holding the micro-light emitting diode chip during the pick-and-place process decreases. For this reason, a step of imparting adhesive strength to the adhesive stamp and a step of exchanging the adhesive stamp are required, which makes it difficult to improve the productivity of manufacturing the light-emitting substrate.

Therefore, the inventors of the present invention conducted a study to make it possible to arrange the micro light emitting diode chips from the wafer to the circuit board without repeating the pick and place process, and furthermore, to collectively assemble the micro light emitting diode chips on the circuit board. A holding member for holding a micro light emitting diode chip, a transfer member for a micro light emitting diode chip having the holding member, a method for manufacturing the transfer member, and a manufacturing method for a light emitting substrate using the transfer member I found a way. SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to improve the productivity of a light emitting substrate having a plurality of micro light emitting diode chips arranged thereon.

A holding member of the present invention is a holding member that holds a plurality of light emitting diode chips,
a substrate;
a plurality of protrusions regularly arranged two-dimensionally on one surface of the substrate;
and an adhesive layer having adhesiveness provided at the tip of the projecting portion.

In the holding member of the present invention, the substrate may have an area of 176 cm ² or more in plan view.

In the holding member of the present invention, the substrate may be transparent.

In the holding member of the present invention, the substrate may have positioning marks.

In the holding member of the present invention, the coefficient of linear expansion of the base material may be 10×10 ⁻⁵ /K or less.

In the holding member of the present invention, the projection may have a Young's modulus of 10 GPa or less.

In the holding member of the present invention, the adhesiveness of the adhesive layer may be lowered by heating, cooling, or ultraviolet irradiation.

The transfer member of the present invention is
a holding member according to any one of the above;
and a plurality of light-emitting diode chips held by the respective protrusions via the adhesive layer.

The method for manufacturing a transfer member of the present invention comprises:
a step of contacting a chip substrate having diced light-emitting diode chips with any of the holding members described above to hold the plurality of light-emitting diode chips on the plurality of projections in the first region of the holding member;
moving the holding member relative to the chip substrate;
The chip substrate is brought into contact with the holding member, and the plurality of light emitting diode chips different from the plurality of light emitting diode chips are protruded in a second region different from the first region of the holding member. and holding it on the part.

In the method of manufacturing a transfer member according to the present invention, in the step of moving the holding member relative to the chip substrate, the position at which the holding member is moved relative to the chip substrate is a positioning mark of at least one of the chip substrate and the holding member. may be determined based on

In the transfer member manufacturing method of the present invention, the pitch of the array of the plurality of protrusions of the holding member may be an integral multiple of the pitch of the array of the diced light emitting diode chips of the chip substrate.

In the method for manufacturing a light-emitting substrate of the present invention, the light-emitting diode chips of the above-described transfer member are electrically connected to the circuit of the circuit board, and the plurality of light-emitting diode chips are removed from the holding member of the transfer member. A step of collectively transferring to the circuit board is provided.

In the method for manufacturing a light-emitting substrate of the present invention,
The step of transferring the light emitting diode chip from the transfer member to the circuit board includes:
pressing the transfer member against the circuit board to electrically connect the light emitting diode chip to the circuit;
and peeling the light emitting diode chip from the adhesive layer.

In the method for manufacturing a light-emitting substrate of the present invention, the step of transferring the light-emitting diode chips from the transfer member to the circuit board includes removing the adhesiveness of the adhesive layer before the step of peeling the light-emitting diode chips from the adhesive layer. may further include the step of lowering the

ADVANTAGE OF THE INVENTION According to this invention, the productivity of the light emitting board in which several light emitting diode chips are arrange|positioned can be improved.

FIG. 1 is an exploded perspective view showing a display device using a light emitting substrate with micro light emitting diode chips. FIG. 2 is a plan view of a light emitting substrate with micro light emitting diode chips. 3 is an enlarged view of a part of the light emitting substrate of FIG. 2. FIG. FIG. 4 is a vertical cross-sectional view of a light emitting substrate with micro light emitting diode chips. FIG. 5 is a longitudinal sectional view of the transfer member. FIG. 6 is a vertical cross-sectional view of the holding member. FIG. 7 is a plan view of the holding member. FIG. 8 is a plan view showing a chip substrate with diced micro light emitting diode chips. FIG. 9 is a diagram for explaining the process of holding the micro light emitting diode chip on the holding member. FIG. 10 is a diagram for explaining the process of holding the micro light emitting diode chip on the holding member. FIG. 11 is a diagram for explaining the process of holding the micro light emitting diode chip on the holding member. FIG. 12 is a diagram for explaining the process of holding the micro light emitting diode chip on the holding member. FIG. 13 is a diagram for explaining the process of holding the micro light emitting diode chip on the holding member. FIG. 14 is a diagram for explaining the process of holding the micro light emitting diode chip on the holding member. FIG. 15 is a diagram for explaining the process of holding the micro light emitting diode chip on the holding member. FIG. 16 is a diagram for explaining the process of transferring the micro light-emitting diode chips from the transfer member to the circuit board. FIG. 17 is a diagram for explaining the process of transferring the micro light emitting diode chip from the transfer member to the circuit board. FIG. 18 is a diagram for explaining the process of transferring the micro light emitting diode chips from the transfer member to the circuit board. FIG. 19 is a diagram for explaining a modified example of the holding member.

An embodiment of the present invention will be described below with reference to the drawings. In the drawings attached to this specification, for the convenience of illustration and ease of understanding, the scale and the ratio of vertical and horizontal dimensions are changed and exaggerated from those of the real thing.

In addition, "sheet surface (plate surface, film surface)" refers to the target sheet-shaped member (plate-shaped, film-shaped) when viewed as a whole and broadly. member, film-like member).

Furthermore, the terms used herein to specify shapes and geometric conditions and their degrees, such as "parallel", "perpendicular", "identical", length and angle values, etc., are not strictly defined. It shall be interpreted to include the extent to which similar functions can be expected without being bound by the meaning.

FIG. 1 is an exploded perspective view schematically showing the display device 1. FIG. The display device 1 displays an image or the like on the display surface 5 . In the example shown in FIG. 1 , the display device 1 has a light emitting substrate 10 and a diffusion layer 7 arranged to face the light emitting substrate 10 . The surface of the diffusion layer 7 opposite to the side facing the light emitting substrate 10 is the display surface 5 of the display device 1 . The display device 1 is a so-called micro LED display that uses light emitted from one or more light emitting diodes as one pixel. In the illustrated example, the light emitted by the light emitting substrate 10 is diffused by the diffusion layer 7 . However, the diffusion layer 7 can be omitted.

The light emitting substrate 10 emits light forming an image displayed on the display surface 5 . 2 is a plan view showing a part of the light emitting substrate 10, FIG. 3 is a plan view showing an enlarged part of the light emitting substrate 10 of FIG. 2, and FIG. 4 is a part of the light emitting substrate 10. It is a vertical cross-sectional view showing the. As shown in FIG. 2, the light-emitting substrate 10 includes a circuit board 11 and a plurality of micro light-emitting diode chips (also simply referred to as "light-emitting diode chips") 50 regularly arranged two-dimensionally on the circuit board 11. have. The circuit board 11 has positioning means for positioning the transfer member 20 having the micro light emitting diode chips 50 in the step of transferring the micro light emitting diode chips 50 from the transfer member 20 to be described later. In the example shown in FIG. 2, the positioning means are a plurality of cross-shaped positioning marks M1. However, the cross-shaped positioning mark M1 is merely an example, and various positioning marks M1 such as a square, a triangle, and a circle can be used. Moreover, as shown in FIG. 3, the circuit board 11 has a circuit 13 . Furthermore, each micro light emitting diode chip 50 has two electrodes 51, as shown in FIG. Micro light emitting diode chip 50 is electrically connected to circuit 13 through electrode 51 . By controlling the current flowing through the circuit 13 and applying a voltage between the two electrodes 51, any micro light emitting diode chip 50 can be caused to emit light. The combination of light emitted by the micro light emitting diode chips 50 can form an image displayed by the display device 1 .

The wavelength of the light emitted from the micro light emitting diode chip 50 is determined by the semiconductor material or the like that constitutes the micro light emitting diode chip 50 . The micro light emitting diode chip 50 includes, for example, a GaAs-based compound semiconductor, an InP-based compound semiconductor, a GaN-based compound semiconductor, or the like. The dimensions of the micro light emitting diode chip 50 in plan view can be, for example, a rectangular shape with a side of 3 μm or more and 1000 μm or less, and the thickness of the micro light emitting diode chip 50 can be, for example, 10 μm or more and 500 μm or less.

In the illustrated example, the micro light emitting diode chip 50 includes a first light emitting diode chip 50R that emits red light with a wavelength range of 620 nm to 680 nm, and a second light emitting diode chip that emits green light with a wavelength range of 530 nm to 570 nm. 50G, and a third light emitting diode chip 50B that emits blue light with a wavelength range of 440 nm to 480 nm. The first light-emitting diode chip 50R, the second light-emitting diode chip 50G, and the third light-emitting diode chip 50B arranged near each other form one pixel of the display device 1. FIG. Therefore, the light emitting substrate 10 can emit light for forming an image displayed in full color.

The light emitting substrate 10 is manufactured by placing the micro light emitting diode chips 50 on the circuit board 11 where the circuit 13 is formed. In order to manufacture the light emitting substrate 10 on which the plurality of micro light emitting diode chips 50 are arranged with high productivity, a holding member 30 and a transfer member 20 having the holding member 30 as shown in FIG. 5 are used.

An embodiment of the holding member 30 and the transfer member 20 having the holding member will be described below with reference to FIGS. 5 to 7. FIG.

FIG. 5 is a longitudinal sectional view showing part of the transfer member 20. As shown in FIG. The transfer member 20 is a member that enables the plurality of micro light emitting diode chips 50 to be collectively transferred onto the circuit board 11 . It is preferable that the dimension of the transfer member 20 in plan view is equal to or larger than the dimension of the circuit board 11 in plan view so that the micro light-emitting diode chips 50 can be arranged on the entire circuit board 11 with only one transfer.

The transfer member 20 has a holding member 30 and a plurality of micro light emitting diode chips 50 held by the holding member 30 . The plurality of micro light emitting diode chips 50 are arranged on the transfer member 20 so as to be held at positions corresponding to positions on the circuit board 11 to which the micro light emitting diode chips 50 are to be transferred. ing. In other words, the arrangement intervals and arrangement pattern of the plurality of micro light emitting diode chips 50 on the transfer member 20 are the same as the arrangement intervals and arrangement pattern in which the plurality of micro light emitting diode chips 50 are to be arranged on the circuit board 11 . there is Also, in the illustrated example, a first light emitting diode chip 50 R is held by the holding member 30 as the micro light emitting diode chip 50 .

The holding member 30 is a member capable of holding a plurality of micro light emitting diode chips 50 . 6 is a longitudinal cross-sectional view of a portion of the retaining member 30 of the present invention, and FIG. 7 is a plan view of a portion of the retaining member 30. As shown in FIG. As shown in FIGS. 6 and 7, the holding member 30 includes a base material 31, protrusions 33 provided on one surface of the base material 31, and an adhesive layer 35 provided at the tip of each protrusion 33. and have

The base material 31 is a member that appropriately supports the plurality of protrusions 33 . The base material 31 has positioning means for positioning the chip substrate 40 having the micro light emitting diode chip 50 and the holding member 30 in the step of holding the micro light emitting diode chip 50 on the holding member 30 to be described later. In the example shown in FIG. 2, the positioning means are cross-shaped positioning marks M2. However, the cross-shaped positioning mark M2 is merely an example, and various positioning marks M2 such as a square, triangle, and circle can be used. A plurality of positioning marks M2 are provided on one surface of the base material 31 for each area that partitions the holding member 30 at regular intervals. Moreover, in order to facilitate observation of the positioning mark M2, the substrate 31 is preferably transparent.

In addition, the term “transparent” means having transparency to the extent that one side of the base material can be seen through the other side through the base material, for example, 30% or more, more Preferably, it means having a visible light transmittance of 70% or more. The visible light transmittance is the transmittance at each wavelength when measured within the measurement wavelength range of 380 nm to 780 nm using a spectrophotometer ("UV-3100PC" manufactured by Shimadzu Corporation, compliant with JIS K 0115). is specified as the mean of

The area of the base material 31 in plan view is larger than that of the chip substrate 40 having a plurality of micro light-emitting diode chips 50, which will be described later. Specifically, it is preferable that the area of the substrate 31 in plan view is 176 cm ² or more. Moreover, it is preferable that the dimension of the base material 31 in plan view is equal to or larger than the dimension of the circuit board 11 in plan view so that the dimension of the transfer member 20 in plan view is equal to or larger than the dimension in plan view of the circuit board 11 .

The thickness of the base material 31 is preferably 0.5 mm or more and 3 mm or less in consideration of transparency, appropriate supportability of the protrusions 33, and the like. Further, in order to prevent deformation of the base material 31 in the manufacturing process of the light emitting substrate 10, which will be described later, it is preferable that the base material 31 has high rigidity. Moreover, it is preferable that the base material 31 is not easily deformed by heat. Specifically, the coefficient of linear expansion of the base material 31 is preferably 10×10 ⁻⁵ /K or less, more preferably 5×10 ⁻⁵ /K or less. Examples of materials for the base material 31 include acrylic resin and glass.

The projecting portion 33 is a portion that holds the micro light-emitting diode chip 50 via an adhesive layer 35, which will be described later. The projecting portion 33 is provided at a position where the holding member 30 holds the micro light emitting diode chip 50 on the base material 31 . That is, the protruding part 33 is provided at a position corresponding to the position on the circuit board 11 where the micro light emitting diode chip 50 is arranged. The dimension of the projection 33 in plan view is preferably equal to or less than the dimension of the micro light emitting diode chip 50 . In the illustrated example, the dimensions of the protrusion 33 in plan view are equal to the dimensions of the micro light emitting diode chip 50 .

The protrusions 33 are regularly arranged two-dimensionally on one surface of the base material 31 . The regular two-dimensional arrangement of the protrusions 33 corresponds to a plurality of micro light-emitting diode chips 50 regularly arranged two-dimensionally on the circuit board 11 . In other words, the arrangement interval and arrangement pattern of the protrusions 33 are the same as the arrangement interval and arrangement pattern of the plurality of micro light emitting diode chips 50 to be arranged on the circuit board 11 . The protrusions 33 are arranged at a pitch p1x in the first direction d1, and arranged at a pitch p1y in a second direction d2 non-parallel to the first direction d1. In the illustrated example, the first direction d1 and the second direction d2 are orthogonal to each other. The pitches p1x and p1y are, for example, 50 μm or more and 870 μm or less.

The protruding portion 33 protrudes in the normal direction of the plate surface of the base material 31 . The length L by which the protrusion 33 protrudes from the base material 31 is preferably greater than the thickness of the micro LED chip 50, and is, for example, 0.1 μm or more and 100 μm or less. Moreover, the projecting portion 33 has flexibility. Specifically, the Young's modulus of the projecting portion 33 is preferably 10 GPa or less, more preferably 5 GPa or less. Such a protruding portion 33 is made of acrylic resin, for example, and can be formed using a photolithography technique or an imprint technique.

The adhesive layer 35 is provided at the tip of the protrusion 33 so that the protrusion 33 can hold the micro LED chip 50 . The adhesive layer 35 has adhesiveness. The adhesiveness of the adhesive layer 35 can be reduced, for example, by heating, cooling, or UV irradiation. In addition, in this specification, stickiness is a sticky property, and is not distinguished from adhesiveness. As the material of the adhesive layer 35, for example, an acrylic adhesive is used. The thickness of the adhesive layer 35 is, for example, 0.1 μm or more and 100 μm or less.

Next, a method for holding the micro light emitting diode chip 50 on the holding member 30, that is, a method for manufacturing the transfer member 20 will be described with reference to FIGS. 8 to 15. FIG. In the following description, as an example, a method of holding the first light emitting diode chip 50R on the holding member 30 will be described.

First, as shown in FIG. 8, a chip substrate 40 having a plurality of micro light emitting diode chips 50 (first light emitting diode chips 50R) diced on one surface is prepared. The chip substrate 40 may be the diced wafer itself, or may be a substrate obtained by temporarily transferring the micro light emitting diode chips 50 from the diced wafer. The chip substrate 40 has a chip base 41 and a plurality of micro light emitting diode chips 50 arranged on the chip base 41 . Moreover, the chip substrate 40 has positioning means for positioning with the holding member 30 . In the example shown in FIG. 8, the positioning means are a plurality of cross-shaped positioning marks M3. However, the cross-shaped positioning mark M3 is merely an example, and various positioning marks M3 such as a square, triangle, and circle can be used.

Each micro light emitting diode chip 50 has two electrodes 51 provided on the side of the chip substrate 41 . Also, the micro light emitting diode chips 50 are arranged on the chip substrate 41 at a pitch p2x in the first direction d1, and arranged at a pitch p2y in a second direction d2 non-parallel to the first direction d1. That is, the micro light emitting diode chips 50 are formed by dicing the wafer in the first direction d1 and the second direction d2. In the illustrated example, the first direction d1 and the second direction d2 are orthogonal to each other. The pitches p2x and p2y are, for example, 5 μm or more and 200 μm or less.

Here, an integral multiple of the array pitch p2x of the micro light emitting diode chips 50 of the chip substrate 40 in the first direction d1 is the array pitch p1x of the plurality of protrusions 33 of the holding member 30 in the first direction d1. . Similarly, an integral multiple of the array pitch p2y in the second direction d2 of the micro light emitting diode chips 50 of the chip substrate 40 is the array pitch p1y of the plurality of projections 33 of the holding member 30 in the second direction d2. . Since the arrangement interval and arrangement pattern of the protrusions 33 are the same as the arrangement interval and arrangement pattern of the plurality of micro light emitting diode chips 50 arranged on the circuit board 11, the micro light emitting diode chips 50 on the chip substrate 40 are arranged at the same intervals and pattern. An integer multiple of the array pitch p2x in one direction d1 is an integer multiple of the array pitch in the first direction d1 of the micro light emitting diode chip 50 (first light emitting diode chip 50R) on which the circuit board 11 is arranged. An integer multiple of the array pitch p2y in the direction d2 is an integer multiple of the array pitch of the micro light emitting diode chips 50 (first light emitting diode chips 50R) on the circuit board 11 in the second direction d2.

Next, as shown in FIG. 9, the surface of the chip substrate 41 of the chip substrate 40 on which the micro light-emitting diode chips 50 are arranged and the surface of the substrate 31 of the holding member 30 on which the protruding portions 33 are arranged. , face each other. After that, the chip substrate 40 and the holding member 30 are positioned. Positioning is performed based on the positioning means of the base material 31 of the holding member 30 and the positioning means of the chip substrate 40 . As a specific example, positioning is performed by aligning the positioning mark M2 of the base material 31 with the positioning mark M3 of the chip substrate 40 in the first region R1 of the holding member 30 . Whether the positioning marks M2 and M3 match can be confirmed, for example, by a camera 80 arranged on the side opposite to the surface on which the projecting portions 33 of the holding member 30 are arranged. Since the base material 31 is transparent, it is possible to check the positioning marks M2 and M3 through the base material 31 from the side opposite to the surface on which the projections 33 of the holding member 30 are arranged.

The chip substrate 40 and the holding member 30 may be positioned by only one of the positioning means of the base material 31 of the holding member 30 and the positioning means of the chip substrate 40 .

Next, as shown in FIG. 10, the chip substrate 40 and the holding member 30 are brought closer to each other so that the chip substrate 40 is brought into contact with the holding member 30 . When the chip substrate 40 contacts the holding member 30 , the micro LED chips 50 of the chip substrate 40 come into contact with the adhesive layer 35 provided at the tips of the projections 33 in the first region R<b>1 of the holding member 30 . The micro LED chip 50 is adhered to the adhesive layer 35 so that the protrusions 33 hold the micro LED chip 50 through the adhesive layer 35 . That is, the micro light emitting diode chip 50 is held on the plurality of projecting portions 33 within the first region R1 of the holding member 30 from the chip substrate 40 .

Here, since the projecting portion 33 has flexibility, specifically, the Young's modulus of the projecting portion 33 is 10 GPa or less, more preferably 5 GPa or less. The protrusion 33 of the holding member 30 can deform in a direction perpendicular to the contact surface between the chip substrate 40 and the protrusion 33 . Therefore, the contact pressure for bringing the chip substrate 40 into contact with the projecting portion 33 is uniformly applied to each projecting portion 33 that is in contact with the chip substrate 40 . In other words, it is possible to avoid a part of the protrusion 33 contacting the micro LED chip 50 of the chip substrate 40 with high contact pressure. When a portion of the protrusion 33 contacts the micro LED chip 50 with high contact pressure, the adhesive force between the protrusion 33 and the micro LED chip 50 will cause the other protrusion 33 and the other micro LED chip 50 to contact each other. , the resulting transfer member 20 may be difficult to handle, and the high contact pressure may destroy the micro-light emitting diode chip 50 . For this reason, it is preferable to avoid a portion of the protruding portion 33 from contacting the micro LED chip 50 with a high contact pressure.

11 is a plan view showing a state in which the chip substrate 40 shown in FIG. 10 is brought into contact with the plurality of projecting portions 33 in the first region R1 of the holding member 30. FIG. Since the chip substrate 40 and the holding member 30 are positioned and the dimension of the projection 33 in plan view is equal to the dimension of the micro light emitting diode chip 50, one projection in the first region R1 33 can hold one micro light emitting diode chip 50 . Further, as shown in FIG. 11, the arrangement pitch p1x of the plurality of projections 33 of the holding member 30 in the first direction d1 is an integral number of the arrangement pitch p2x of the micro LED chips 50 of the chip substrate 40 in the first direction d1. Since it is doubled (five times in the illustrated example), one micro light emitting diode chip 50 can be held against all protrusions 33 within the first region R1 in the first direction d1. Similarly, the arrangement pitch p1y of the plurality of projections 33 of the holding member 30 in the second direction d2 is an integral multiple of the arrangement pitch p2y of the micro light emitting diode chips 50 of the chip substrate 40 in the second direction d2 (the example shown in the figure). Therefore, one micro LED chip 50 can be held by each of the protrusions 33 in the first region R1 in the second direction d2.

Thereafter, as shown in FIG. 12 , after the chip substrate 40 and the holding member 30 are separated, the holding member 30 is moved relative to the chip substrate 40 . The position after the holding member 30 is moved relative to the chip substrate 40 is determined by the positioning means of the base material 31 and the positioning means of the chip substrate 40 . For example, positioning is performed by aligning the positioning mark M2 of the base material 31 with the positioning mark M3 of the chip substrate 40 in the second region R2 of the holding member. It should be noted that the second region R2 of the holding member 30 is a region different from the first region R1, and is a region adjacent to the first region R1 in the first direction d1 in the illustrated example.

Next, as shown in FIG. 13, the chip substrate 40 and the holding member 30 are brought close to each other to bring the chip substrate 40 into contact with the holding member 30 . When the chip substrate 40 contacts the holding member 30 , the micro light emitting diode chips 50 of the chip substrate 40 come into contact with the adhesive layer 35 provided at the tips of the plurality of projections 33 in the second region R<b>2 of the holding member 30 . The micro LED chips 50 contacting the adhesive layer 35 in the second region R2 are different from the micro LED chips 50 contacting the adhesive layer 35 in the first region R1. A plurality of protrusions 33 hold a plurality of micro LED chips 50 via an adhesive layer 35 . That is, the micro light emitting diode chip 50 is held on the plurality of projections 33 within the second region R2 of the holding member 30 from the chip substrate 40 .

14 is a plan view showing a state in which the chip substrate 40 shown in FIG. 13 is brought into contact with the plurality of projecting portions 33 in the second region R2 of the holding member 30. FIG. The chip substrate 40 and the holding member 30 are positioned, the dimensions of the protrusions 33 in plan view are equal to the dimensions of the micro light emitting diode chip 50, and the pitch of the arrangement of the protrusions 33 of the holding member 30 Since p1x and p1y are integral multiples of the pitches p2x and p2y of the arrangement of the micro-LED chips 50 on the chip substrate 40, one micro-LED chip 50 is provided for each protrusion 33 in the second region R2. can be retained.

As described above, by repeating the step of relatively moving the holding member 30 with respect to the chip substrate 40 and the step of holding the micro light-emitting diode chip 50 on the projecting portion 33 in a certain region, a plurality of holding members 30 can be obtained. A micro LED chip 50 can be held on each protrusion 33 of the region via an adhesive layer 35 . As shown in FIG. 15, by moving the holding member 30 relative to the chip substrate 40 in the first direction d1 and the second direction d2, the protrusions 33 are provided with micro light emitting diodes over the entire area of the holding member 30. As shown in FIG. A chip 50 can be held. Through the above steps, the transfer member 20 having the holding member 30 and the plurality of micro light emitting diode chips 50 as shown in FIG. 5 is manufactured.

In the above example, the method of holding the first light emitting diode chip 50R as the micro light emitting diode chip 50 on the holding member 30 has been described. Each can be held by separate holding members 30 .

Next, a method of arranging the micro light-emitting diode chips 50 on the circuit board 11 using the transfer member 20, that is, a method of manufacturing the light-emitting board 10 will be described with reference to FIGS. 16 to 18. FIG. In the following description, as an example, a method of arranging the first light emitting diode chip 50R on the circuit board 11 will be described.

First, as shown in FIG. 16, the surface of the circuit board 11 on which the circuit 13 is formed faces the surface of the transfer member 20 on which the micro light emitting diode chips 50 are held. After that, the circuit board 11 and the transfer member 20 are positioned. Positioning is performed based on, for example, positioning means of the circuit board 11 and positioning means of the transfer member 20 . As a specific example, the positioning is performed by aligning the positioning mark M1 of the circuit board 11 with the positioning mark M2 of the substrate 31 of the transfer member 20 . Whether the positioning marks M1 and M2 are aligned can be confirmed by a camera 90 arranged on the side of the transfer member 20 opposite to the side on which the micro light emitting diode chip 50 is held. Since the base material 31 is transparent, the positioning marks M1 and M2 can be confirmed through the base material 31 from the side opposite to the surface of the transfer member 20 on which the micro light emitting diode chips 50 are held.

The positioning mark M2 of the base material 31 used for positioning the circuit board 11 and the transfer member 20 may be the same as the positioning mark used for positioning the chip board 40 and the holding member 30. A positioning mark different from the positioning mark used for positioning the chip substrate 40 and the holding member 30 may be used.

Next, as shown in FIG. 17, the transfer member 20 is pressed against the circuit board 11 . Since the circuit board 11 and the transfer member 20 are positioned, the micro light emitting diode chip 50 is pressed against the position where the circuit 13 of the circuit board 11 is provided, and the micro light emitting diode chip 50 is attached to the circuit 13 of the circuit board 11. can be electrically connected. An anisotropic conductive adhesive layer (not shown) for bonding the micro light emitting diode chip 50 to the circuit board 11 is formed at the position of the circuit board 11 where the micro light emitting diode chip 50 is arranged.

Here, since the projecting portion 33 has flexibility, specifically, the Young's modulus of the projecting portion 33 is 10 GPa or less, more preferably 5 GPa or less. The projecting portion 33 of the holding member 30 can deform in a direction perpendicular to the pressing surface between the circuit board 11 and the projecting portion 33 . Therefore, the pressure for pressing the transfer member 20 against the circuit board 11 is uniformly applied to each projecting portion 33 pressed against the circuit board 11 . In other words, it is possible to avoid the micro LED chip 50 held by a part of the protrusion 33 from being pressed against the circuit board 11 with a high pressure. If the micro LED chip 50 held by a part of the protrusion 33 is pressed against the circuit board 11 with high pressure, the micro LED chip 50 may be destroyed by the high pressure. Therefore, it is preferable that the micro light-emitting diode chip 50 held by a part of the projecting portion 33 is prevented from being pressed against the circuit board 11 with a high pressure.

The anisotropic conductive adhesive layer is heated while the transfer member 20 is pressed against the circuit board 11 . By heating the anisotropic conductive adhesive layer, the circuit board 11 and the micro light emitting diode chip 50 are bonded together. Moreover, according to the anisotropic conductive adhesive layer, conductivity can be exhibited in the pressing direction. Therefore, each electrode 51 of the micro light emitting diode chip 50 can be electrically connected to the circuit 13 facing the pressing direction.

Here, since the substrate 31 of the transfer member 20 is hard to be deformed by heat, specifically, the coefficient of linear expansion of the substrate 31 is 10×10 ⁻⁵ /K or less, more preferably 5×10 ⁻⁵ /K or less. Therefore, even if the transfer member 20 is heated when the anisotropic conductive adhesive layer is heated, the circuit board 11 and the transfer member 20 are less likely to be misaligned. That is, the micro light emitting diode chip 50 can be accurately transferred from the transfer member 20 to the circuit board 11 .

Also, the adhesiveness of the adhesive layer 35 is reduced while the transfer member 20 is being pressed against the circuit board 11 . That is, the adhesive layer 35 is heated, cooled, or irradiated with ultraviolet rays. In addition, when the adhesiveness of the adhesive layer 35 is reduced by heating, the heat when heating the above-described anisotropic conductive adhesive layer may be used. By reducing the adhesiveness of the adhesive layer 35 , the micro light emitting diode chip 50 can be easily peeled off from the adhesive layer 35 .

After that, as shown in FIG. 18, the holding member 30 is separated from the circuit board 11 and the holding member 30 is removed. Through the above steps, the plurality of micro light-emitting diode chips 50 held by the holding member 30 of the transfer member 20 are electrically connected to the circuit 13 of the circuit board 11, and the holding member 30 of the transfer member 20 is transferred to the circuit board. 11 are collectively transcribed, that is, collectively transcribed.

In the above example, the method of collectively transferring the first light emitting diode chips 50R as the micro light emitting diode chips 50 to the circuit board 11 has been described. A process similar to this process is performed for another holding member 30 that holds the second light emitting diode chip 50G and yet another holding member 30 that holds the third light emitting diode chip 50B. , the light-emitting substrate 10 having the micro-light-emitting diode chips 50 arranged thereon is manufactured. That is, it is possible to obtain the light-emitting substrate 10 that can emit light in full color.

The protruding length L of the protruding portion 33 of the holding member 30 is larger than the thickness of the micro light emitting diode chip 50 . Therefore, even when the second light emitting diode chips 50G are transferred to the circuit board 11 after the first light emitting diode chips 50R are collectively transferred to the circuit board 11 using the transfer member 20, the second light emitting diode chips 50G are transferred to the circuit board 11. The transfer is less likely to be hindered by the first light emitting diode chip 50R transferred to the circuit board 11. FIG.

By the way, as described above, the adhesive stamp of Patent Document 1 is repeatedly used in the pick-and-place process from the wafer to the circuit board in the manufacturing process of the light-emitting substrate, so that the adhesive strength is reduced. It is difficult to increase the productivity of manufacturing a light emitting substrate by arranging light emitting diode chips on a circuit board. On the other hand, according to the holding member 30 of the present embodiment, the micro light emitting diode chips 50 are placed in a plurality of regions of the holding member 30 from the chip substrate 40 which is a substrate obtained by temporarily transferring the micro light emitting diode chips from the wafer itself or the wafer. can be retained. By pressing the transfer member 20 holding the micro light emitting diode chips 50 on the holding member 30 against the circuit board 11 , the micro light emitting diode chips 50 can be transferred to the circuit board 11 . Thus, in the manufacturing process of the light emitting substrate 10, holding and peeling of the micro light emitting diode chip 50 via the adhesive layer 35 of the holding member are performed only once. Therefore, since the adhesive strength of the adhesive layer 35 does not decrease during the manufacture of the light emitting substrate, the light emitting substrate 10 can be manufactured with high productivity. Furthermore, since the micro light-emitting diode chips 50 can be collectively transferred to the circuit board 11, the light-emitting substrate 10 can be easily manufactured, and the productivity of the light-emitting substrate 10 can be improved.

In addition, repeating the pick-and-place process using the adhesive stamp of Patent Document 1 means that the adhesive stamp is reciprocated between the wafer and the circuit board, so it takes time to produce the light-emitting substrate, which reduces productivity. it gets lower. On the other hand, according to the method of manufacturing the transfer member 20 and the method of manufacturing the light emitting substrate 10 of the present embodiment, the micro light emitting diode chip 50 is held by the holding member 30 by moving the holding member 30 relative to the chip substrate 40 . By pressing the transfer member 20 holding the micro light emitting diode chips 50 against the circuit board 11, the light emitting board 10 can be manufactured. The relative movement of the holding member 30 with respect to the chip substrate 40 is very small compared to the reciprocation between the adhesive stamp wafer and the circuit board. Therefore, according to the method for manufacturing the transfer member 20 and the method for manufacturing the light emitting substrate 10 of the present embodiment, the time for manufacturing the light emitting substrate 10 can be shortened. That is, the light emitting substrate 10 can be manufactured with high productivity.

Furthermore, in the holding member 30 of this embodiment, the base material 31 has the positioning mark M2. The positioning mark M2 and the positioning mark M3 of the chip substrate 40 allow the micro light emitting diode chip 50 to be held by the holding member 30 with high accuracy. Further, the micro light-emitting diode chip 50 can be transferred from the transfer member 20 to the circuit board 11 with high precision by the positioning mark M2 and the positioning mark M1 of the circuit board 11. FIG. That is, the light emitting substrate 10 can be manufactured with high productivity.

Further, in the present embodiment, the pitches p1x and p1y of the arrangement of the projecting portions 33 of the holding member 30 are integral multiples of the pitches p2x and p2y of the arrangement of the micro light emitting diode chips 50 on the substrate. Therefore, by positioning the chip substrate 40 and the holding member 30 , it is possible to manufacture the transfer member 20 in which one micro light-emitting diode chip 50 is arranged on each projecting portion 33 of the holding member 30 with high precision. By using this transfer member 20, the light emitting substrate 10 can be manufactured with high productivity.

Furthermore, in the holding member 30 of the present embodiment, the coefficient of linear expansion of the base material 31 is 10×10 ⁻⁵ /K or less, more preferably 5×10 ⁻⁵ /K or less. Since the base material 31 is less likely to be deformed by heat, even if the transfer member 20 is heated in the manufacturing process of the light emitting substrate 10, the circuit board 11 and the transfer member 20 are less likely to be misaligned. The micro light emitting diode chip 50 can be accurately transferred from the transfer member 20 to the circuit board 11 . That is, the light emitting substrate 10 can be manufactured with high productivity.

In addition, in the holding member 30 of the present embodiment, the Young's modulus of the protrusion is 10 GPa or less, more preferably 5 GPa or less. Since the protrusion 33 has flexibility, when the chip substrate 40 contacts the protrusion 33 in the manufacturing process of the transfer member 20, a part of the protrusion 33 contacts the micro LED chip 50 with a high contact pressure. It is possible to prevent the micro light emitting diode chip 50 from being broken. Further, when the transfer member 20 is pressed against the circuit board 11 in the manufacturing process of the light emitting substrate 10, part of the projecting portion 33 is pressed against the micro light emitting diode chip 50 with a high pressure, and the micro light emitting diode chip 50 is destroyed. can be avoided. That is, the transfer member 20 and the light emitting substrate 10 can be manufactured with high productivity.

As described above, the holding member 30 of the present embodiment is a holding member that holds a plurality of micro light-emitting diode chips 50, and is composed of a base material 31 and two-dimensional substrates arranged on one surface of the base material 31 regularly. It includes a plurality of arranged projecting portions 33 and an adhesive layer 35 having adhesiveness provided at the tip of the projecting portion 33 . According to such a holding member 30 , the adhesive layer 35 provided on each protruding portion 33 holds the micro light emitting diode chip 50 only once during the manufacturing process of the transfer member 20 . Further, in the manufacturing process of the light emitting substrate 10, the adhesive layer 35 provided on each protruding portion 33 is removed from the micro light emitting diode chip 50 only once. Therefore, the adhesive strength of the adhesive layer 35 is less likely to decrease during the manufacturing of the transfer member 20 and the light emitting substrate 10 , and the productivity of the transfer member 20 and the light emitting substrate 10 are less likely to decrease. That is, the transfer member 20 having the micro light emitting diode chips 50 arranged on the holding member 30 can be manufactured with high productivity. can be manufactured with

Various modifications can be made to the above-described embodiment.

For example, as shown in FIG. 19, the protrusion 33 may include a base 33a and a plurality of fine extensions 33b supported on the base 33a. As shown, each fine extension 33b is finer than the base 33a. The fine extensions 33b are two-dimensionally arranged on the base 33a. Since each fine extension 33b can bend, the fine extension 33b has higher flexibility than the base 33a. The projecting portion 33 having such a configuration allows the projecting portion 33 to have higher flexibility. Therefore, when holding the micro light emitting diode chip 50 on the holding member 30, it is possible to more effectively prevent a portion of the protruding portion 33 from contacting the micro light emitting diode chip 50 of the chip substrate 40 with a high contact pressure. be able to. Further, when the micro light emitting diode chip 50 is arranged on the circuit board 11 using the transfer member 20, the micro light emitting diode chip 50 held by a part of the projecting portion 33 is pressed against the circuit board 11 with a high pressure. can be avoided more effectively. That is, damage to the micro light emitting diode chip 50 is more effectively avoided.

Further, in the above-described embodiment, the projecting portion 33 is formed on the base material 31 using photolithography technology or imprint technology. However, the projecting portion 33 may be formed integrally with the base material 31 . The projecting portion 33 can be formed integrally with the base material 31 by dry etching the material forming the base material 31 or by imprinting the same material as the base material 31 on the base material 31 . . When the protruding portion 33 is formed integrally with the base material 31, no interface is formed between the protruding portion 33 and the base material 31, so that separation between the protruding portion 33 and the base material 31 can be effectively suppressed. can be done. Moreover, since the projecting portion 33 can be formed together with the base material 31, the cost for forming the projecting portion 33 can be reduced.

Furthermore, the projecting portion 33 may have adhesiveness. Since the protruding portion 33 has adhesiveness, the adhesive layer 35 provided at the tip of the protruding portion 33 can be omitted. Therefore, the cost of providing the adhesive layer 35 can be reduced.

Also, the adhesive layer 35 may be provided not only on the tips of the protrusions 33 but also between the protrusions 33 . Furthermore, the adhesive layer 35 may be provided on the entire surface of the holding member 30 on which the projecting portion 33 is formed. In this case, the adhesive layer 35 can be easily provided, for example, by coating the surface of the holding member 30 on which the projecting portion 33 is formed.

Note that the light-emitting substrate 10 described above may be used in, for example, a lighting device other than the display device 1 .

1 display device 5 display surface 7 diffusion layer 10 light emitting substrate 11 circuit substrate 13 circuit 20 transfer member 30 holding member 31 base material 33 protrusion 35 adhesive layer 40 chip substrate 50 micro light emitting diode chip 50R first light emitting diode chip 50G second light emission Diode chip 50B Third light emitting diode chip 51 Electrode R1 First region R2 Second region R3 Third region M1, M2, M3 Positioning marks P1x, P1y, P2x, P2y Pitch

Claims (14)

A holding member that holds a plurality of light emitting diode chips,
a substrate;
a plurality of protrusions regularly arranged two-dimensionally on one surface of the substrate;
and an adhesive layer having adhesiveness provided at the tip of the protrusion,
the length by which the protruding portion protrudes from the base material is greater than the thickness of the light emitting diode chip held by the holding member;
The retaining member, wherein the protrusion includes a base and a plurality of micro-extensions supported on the base . The holding member according to claim 1, wherein the substrate has an area of 176 cm ² or more in plan view. The holding member according to claim 1 or 2, wherein the base material is transparent. 4. A retaining member according to any one of the preceding claims, wherein the substrate has alignment marks. The holding member according to any one of claims 1 to 4, wherein the base material has a linear expansion coefficient of 10 × 10 ^-5 /K or less. The holding member according to any one of claims 1 to 5, wherein the projection has a Young's modulus of 10 GPa or less. The holding member according to any one of claims 1 to 6, wherein the adhesiveness of the adhesive layer is reduced by heating, cooling, or ultraviolet irradiation. a holding member according to any one of claims 1 to 7;
and a plurality of light-emitting diode chips held on each protrusion via the adhesive layer. A chip substrate having diced light-emitting diode chips is brought into contact with the holding member according to any one of claims 1 to 7, and a plurality of the light-emitting diode chips are arranged in a plurality of protrusions in the first region of the holding member. a step of holding on a part;
moving the holding member relative to the chip substrate;
The chip substrate is brought into contact with the holding member, and the plurality of light emitting diode chips different from the plurality of light emitting diode chips are protruded in a second region different from the first region of the holding member. A method of manufacturing a transfer member, comprising the step of holding on a part. 10. In the step of relatively moving the holding member with respect to the chip substrate, a position at which the holding member is relatively moved is determined based on a positioning mark of at least one of the chip substrate and the holding member. 3. A method of manufacturing the transfer member according to 1. 11. The method of manufacturing a transfer member according to claim 9, wherein the pitch of the arrangement of the plurality of protrusions of the holding member is an integral multiple of the pitch of the arrangement of the diced light emitting diode chips of the chip substrate. According to claim 8, the light emitting diode chips of the transfer member are electrically connected to a circuit of a circuit board, and a plurality of the light emitting diode chips are collectively mounted on the circuit board from the holding member of the transfer member. A method for manufacturing a light-emitting substrate, comprising a step of transferring. The step of transferring the light emitting diode chip from the transfer member to the circuit board includes:
pressing the transfer member against the circuit board to electrically connect the light emitting diode chip to the circuit;
13. The method of manufacturing a light-emitting substrate according to claim 12, comprising a step of peeling the light-emitting diode chip from the adhesive layer. 3. The step of transferring the light-emitting diode chip from the transfer member to the circuit board further includes reducing the adhesiveness of the adhesive layer before the step of peeling the light-emitting diode chip from the adhesive layer. 14. The method for producing a light-emitting substrate according to 13.

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