KR102557337B1 - Zero stiffness pad for transferring device, method of manufacturing the same and zero stiffness pad group including zero stiffness pad for transferring device - Google Patents

Abstract

An embodiment of the present invention includes a non-rigid pad for element transfer, a method for manufacturing a non-rigid pad for element transfer, and a non-rigid pad for element transfer, which provide a uniform contact pressure between a target substrate to which an element is to be transferred and an element. To provide a non-rigid pad group for element transfer. Here, the non-rigid pad for element transfer includes a base plate and a plurality of pillars, one end of which is connected to and protrudes from one surface of the base plate and is bent and deformed when an external force is applied, and a transfer to which a plurality of elements to be transferred to the target substrate are adhered It is disposed between the film and a pressing part that provides a pressing force so that the plurality of elements are transferred to the target substrate, and when the pressing force of the pressing part is provided, it is bent and deformed so that a uniform contact pressure is provided between the plurality of elements and the target substrate.

Description

ZERO STIFFNESS PAD FOR TRANSFERRING DEVICE, METHOD OF MANUFACTURING THE SAME AND ZERO STIFFNESS PAD GROUP INCLUDING ZERO STIFFNESS PAD FOR TRANSFERRING DEVICE}

The present invention relates to a non-rigid pad for element transfer, a method for manufacturing the non-rigid pad for element transfer, and a group of non-rigid pads for element transfer including the non-rigid pad for element transfer, and more particularly, to a target substrate on which elements are to be transferred. It relates to an element transfer non-rigid pad for providing a uniform contact pressure between a device and an element, a method for manufacturing the element transfer non-rigid pad, and an element transfer non-rigid pad group including the element transfer non-rigid pad.

Production equipment used in the semiconductor process, flexible electronics process, display process, MEMS process, LED process, solar cell process, etc. requires a device that transfers thin film elements.

Existing thick-walled devices have undergone a transfer process of picking or placing using vacuum chuck technology, but when vacuum chuck technology is applied to thin-walled devices, vacuum chuck technology generates Since the device is damaged due to the pressure applied, it is generally not applicable to thin film devices of 5 microns or less. As another method, there is a method of transferring an element using an electrostatic chuck technology, but when applied to a thin element, damage to the element may occur due to static electricity.

For the above reasons, there is a known technology for attaching or transporting a thin film element having a very thin thickness using van der Waals force acting at the nanoscale, and controlling such van der Waals force It is possible to transfer the thin film element using a transfer device capable of At this time, if the surface of the transfer device is very hard, the thin film device cannot be adhered and transferred because the transfer device and the device do not come into good contact with each other due to a slight difference in thickness between the devices or curvature existing in the substrate. Therefore, in order to transfer such a thin film element, a transfer device using a material having a very low modulus of elasticity, a polymer or rubber material is used. For example, a flexible stamp is widely used.

Typically, the transfer device may be of a roll type and a plate type.

In the roll-type transfer device, a roller is positioned on a substrate, and an adhesive layer is provided on an outer circumferential surface of the roller to adhere micro devices, so that micro devices can be transferred.

In the plate-type transfer device, micro devices may be transferred by providing an adhesive layer provided on the lower surface of a pressure plate positioned above a substrate to adhere the micro devices.

Meanwhile, in a roll-type transfer device or a plate-type transfer device, in order for a plurality of micro devices to be picked from a source substrate to an adhesive layer or to place a plurality of micro devices adhered to an adhesive layer to a target substrate, a plurality of micro devices and It is important that a uniform contact pressure is applied between the adhesive layers.

However, due to tolerances in the transfer device, such as processing errors and assembly tolerances of rollers or pressure plates, and factors such as uneven height of micro devices or warpage of the substrate, uniform contact pressure between the adhesive layer and the micro devices is not generated. this comes into existence

1 is an exemplary diagram for explaining problems of a conventional roll-type transfer process.

As shown in (a) of FIG. 1, when the target substrate 10 is bent, when the terminals of the elements 20 and 21 are temporarily bonded to the electrodes 11 and 12 of the target substrate 10, the target Corresponding to the bending of the substrate 10, the transfer film 30 is also bent. In this state, when the pressing part 40 such as a roller presses the transfer film 30 (see FIG. 1(b)), a desired contact pressure is generated between the element 20 and the electrode 11 in the central part. However, little or no contact pressure is generated between the element 21 and the electrode 12 at the edge. Therefore, as shown in (c) of FIG. 1 , there is a problem in that the element 21 at the edge of the transfer film 30 may not be transferred to the target substrate 10 .

And, if the pressing force of the pressing unit 40 is increased to transfer the edge element 21 to the target substrate 10, even if the edge element 21 is transferred to the target substrate 10, the center Since an excessively large contact pressure is applied to the portion, the element 20 in the central portion may be pressed and damaged.

Therefore, there is a need for a technique capable of overcoming non-uniformity of contact pressure between a device and a target substrate caused by various errors.

Republic of Korea Patent Registration No. 1241964 (Announced on March 11, 2013)

In order to solve the above problems, a technical problem to be achieved by the present invention is to manufacture a non-rigid pad for device transfer and a non-rigid pad for device transfer so that a uniform contact pressure is provided between the target substrate and the device to which the device is transferred. An object of the present invention is to provide a non-rigid pad group for element transfer including a method and a non-rigid pad for element transfer.

The technical problem to be achieved by the present invention is not limited to the above-mentioned technical problem, and other technical problems not mentioned can be clearly understood by those skilled in the art from the description below. There will be.

In order to achieve the above technical problem, one embodiment of the present invention is a base plate; And a transfer film including a plurality of pillars, one end of which is connected to one surface of the base plate and protrudes and is bent and deformed when an external force is applied, and a plurality of elements to be transferred to a target substrate are adhered to the transfer film, and the plurality of elements are attached to the target Disposed between pressing parts that provide a pressing force to be transferred to a substrate, and when the pressing force of the pressing part is provided, it is bent and deformed so that a uniform contact pressure is provided between the plurality of elements and the target substrate. A non-rigid pad is provided.

In an embodiment of the present invention, the base plate may be in close contact with the transfer film, and the other end of the pillar may be disposed to face the pressing part.

In an embodiment of the present invention, the other end of the pillar may be in close contact with the transfer film, and the base plate may be disposed to face the pressing part.

On the other hand, in order to achieve the above technical problem, one embodiment of the present invention is a base plate; And a plurality of pillars, one end of which is connected to one surface of the base plate and protrudes to be bent and deformed when an external force is applied, disposed below the target substrate, and a plurality of elements adhered to the transfer film are transferred to the target substrate Provided is a non-rigid pad for element transfer, characterized in that, when the pressing force of the pressing part is provided, the bending deformation is applied so that a uniform contact pressure is provided between the plurality of elements and the target substrate.

In an embodiment of the present invention, the base plate may adhere to the target substrate.

In an embodiment of the present invention, the other end of the pillar may be in close contact with the target substrate.

On the other hand, in order to achieve the above technical problem, one embodiment of the present invention is a base plate; In addition, a transfer film having one end connected to one side of the base plate and protruding to include a plurality of pillars that are bent and deformed when an external force is applied, and a plurality of elements to be transferred to a target substrate are adhered, and the plurality of elements are attached to the target substrate It is disposed between a pressing part that provides a pressing force to be transferred to and a lower portion of the target substrate, and is bent and deformed when the pressing force of the pressing part is provided so that a uniform contact pressure is provided between the plurality of elements and the target substrate It provides a non-rigid pad for element transfer, characterized in that.

In an embodiment of the present invention, two of the element transfer non-rigid pads may be stacked.

In an exemplary embodiment of the present invention, each of the element transfer non-rigid pads stacked and disposed may have the same relative positions of the base plate and the pillar.

In an embodiment of the present invention, the relative positions of the base plate and the column of any one of the element transfer non-rigid pads among the element transfer non-rigid pads that are stacked and arranged are the other element transfer non-rigid pads. It may be opposite to the base plate and the column of.

In an embodiment of the present invention, the base plate and the pillar are formed of at least one of silicone rubber, urethane rubber, fluororubber, EPDM (ethylene propylene diene rubber), NBR (nitrile-butadiene rubber), and PMMA (polymethyl methacrylate) It can be.

In an embodiment of the present invention, the cross-sectional shape of the pillar perpendicular to the axial direction is formed asymmetrically so that the direction of bending deformation of the pillar can be controlled.

In an embodiment of the present invention, a plurality of pillars may be grouped to form a pillar group, and pillars belonging to each of the pillar groups may be disposed such that bending deformation directions are symmetrical to each other.

In an embodiment of the present invention, the pressing unit is a roller, and the pillars may be disposed at a high column density from the center of the base plate to the front and rear ends of the base plate based on the moving direction of the pressing unit.

In an embodiment of the present invention, the pillar is bent in one direction to form an eccentric shape, and when an external force is applied to the pillar, the pillar may be initially bent and bent in the eccentric direction.

In an embodiment of the present invention, the pillar has a first straight portion formed along the axial direction from one end of the pillar, and a bent portion formed eccentrically by being bent in one direction and connected to one end of the first straight line portion; It may have a second straight portion connected to the other end of the bent portion and formed along an axial direction.

In an embodiment of the present invention, the pillar has a first extension extending obliquely in one direction from one end of the pillar, and one end connected to the first extension and extending obliquely in the opposite direction to the first extension It may have a second extension part.

In an embodiment of the present invention, the other end of the second extension part may be formed with a curved surface.

On the other hand, in order to achieve the above technical problem, one embodiment of the present invention is a method of manufacturing a non-rigid pad for element transfer, using a 3D printer process or a LIGA process to form a mold corresponding to the non-rigid pad for element transfer. Mold manufacturing step to manufacture; And it provides a method of manufacturing a non-rigid pad for element transfer, characterized in that it comprises a molding step of molding a non-rigid pad for element transfer by injecting a molding liquid into the mold and curing it.

In an embodiment of the present invention, the molding liquid is at least one of silicone rubber, urethane rubber, fluororubber, EPDM (ethylene propylene diene rubber) and NBR (Nitrile-butadiene rubber), and the molding liquid is cured at room temperature (Room Temperature Vulcanization) or high temperature curing (High Temperature Vulcanization).

On the other hand, in order to achieve the above technical problem, an embodiment of the present invention is an element transfer device having a base plate and a plurality of pillars that are bent and deformed when an external force is applied by protruding and connecting one end to one surface of the base plate. A rigid pad is included, and the non-rigid pad for element transfer is formed between a transfer film on which a plurality of elements to be transferred to a target substrate are adhered, and a pressing part providing a pressing force so that the plurality of elements are transferred to the target substrate. The above are stacked and arranged, and when the pressing force of the pressing part is provided, the first bending deformation occurs so that a uniform first contact pressure is provided between the plurality of elements and the target substrate, and when the pressing force of the pressing part increases and is provided, 2 It provides a non-rigid pad group for element transfer, characterized in that the second contact pressure greater than the first contact pressure is uniformly provided between the plurality of elements and the target substrate through secondary bending deformation.

On the other hand, in order to achieve the above technical problem, an embodiment of the present invention is an element transfer device having a base plate and a plurality of pillars that are bent and deformed when an external force is applied by protruding and connecting one end to one surface of the base plate. A rigid pad is included, and three or more of the non-rigid pads for element transfer are stacked and disposed under a target substrate to which a plurality of elements attached to a transfer film are to be transferred, and the plurality of elements are transferred to the target substrate. When the pressing force of the pressing unit is provided, a first bending deformation is performed so that a uniform first contact pressure is provided between the plurality of elements and the target substrate, and when the pressing force of the pressing unit is increased and provided, a second bending deformation is performed to provide a uniform first contact pressure between the plurality of elements. It provides a non-rigid pad group for element transfer characterized in that a second contact pressure greater than the first contact pressure is uniformly provided between the and the target substrate.

According to an embodiment of the present invention, the non-stiffness pad for element transfer has a zero stiffness region where a specific load occurs in a specific deformation section, so that the pressing part cannot provide a uniform pressing force due to various error factors. However, the non-rigid pad for element transfer can apply a uniform contact pressure between the element and the target substrate, and through this, the element can be transferred more stably and effectively.

The effects of the present invention are not limited to the above effects, and should be understood to include all effects that can be inferred from the detailed description of the present invention or the configuration of the invention described in the claims.

It is an exemplary diagram for explaining problems of the conventional roll-type transfer process of FIG. 1 .
2 is a perspective view showing a non-rigid pad for element transfer according to an embodiment of the present invention.
FIG. 3 is a graph showing the shape deformation of the non-rigid pad for element transfer of FIG. 2 and the resultant displacement-load relationship.
FIG. 4 is an exemplary view showing a first application example of the non-rigid pad for element transfer of FIG. 2 .
5 is an exemplary view showing a moment of inertia, a cross-sectional area, a critical load, and a critical displacement according to the cross-sectional shape of the column of FIG.
FIG. 6 is a graph showing another shape of a column of the non-rigid pad for element transfer of FIG. 2 and a displacement-load relationship according thereto.
FIG. 7 is a perspective view illustrating another shape of a pillar of the non-rigid pad for element transfer of FIG. 2 .
FIG. 8 is an exemplary diagram for explaining a bending deformation direction of the element transfer non-rigid pad of FIG. 7 .
9 is a graph showing a displacement-load relationship according to shape deformation of the non-rigid pad for element transfer of FIG. 7 .
10 is an exemplary diagram for explaining a bending deformation direction according to another shape of a pillar of a non-rigid pad for element transfer according to an embodiment of the present invention.
FIG. 11 is another exemplary view for explaining a bending deformation direction according to another shape of a pillar of the non-rigid pad for element transfer of FIG. 2 .
FIG. 12 is an exemplary diagram for explaining the arrangement of pillars of the non-rigid pad for element transfer of FIG. 2 .
FIG. 13 is an exemplary diagram for explaining the arrangement of pillars of the non-rigid pad for element transfer of FIG. 2 .
FIG. 14 is an exemplary diagram for explaining a working example of the non-rigid pad for element transfer of FIG. 13 .
FIG. 15 is a graph showing another example of the first application example of the non-rigid pad for element transfer of FIG. 2 and the resulting displacement-load relationship.
FIG. 16 is an exemplary view showing a second application example of the non-rigid pad for element transfer of FIG. 2 .
FIG. 17 is an exemplary view showing a third application example of the non-rigid pad for element transfer of FIG. 2 .
FIG. 18 is a graph showing an application example of an element transfer non-rigid pad group composed of the element transfer non-rigid pad of FIG. 2 and a displacement-load relationship according thereto.

Hereinafter, the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in many different forms and, therefore, is not limited to the embodiments described herein. And in order to clearly explain the present invention in the drawings, parts irrelevant to the description are omitted, and similar reference numerals are attached to similar parts throughout the specification.

Throughout the specification, when a part is said to be “connected (connected, contacted, combined)” with another part, it is not only “directly connected”, but also “indirectly connected” with another member in between. ”Including cases where it is. In addition, when a certain component is said to "include", this means that it may further include other components without excluding other components unless otherwise stated.

Terms used in this specification are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, terms such as “include” or “have” are intended to designate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, but one or more other features It should be understood that the presence or addition of numbers, steps, operations, components, parts, or combinations thereof is not precluded.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

2 is a perspective view showing a non-rigid pad for element transfer according to an embodiment of the present invention, and FIG. 3 is a graph showing shape deformation of the non-rigid pad for element transfer of FIG. 2 and displacement-load relationship accordingly.

As shown in FIGS. 2 and 3 , the element transfer non-rigid pad 100 may include a base plate 110 and a pillar 120 .

The base plate 110 may be formed flat, and the pole 120 may have one end 121 connected to one surface of the base plate 110 and protruded. The pillar 120 may be bent and deformed when an external force is applied, and the external force may be provided to the other end 122 of the pillar 120 . Here, the bending deformation of the column 120 may mean including buckling.

The base plate 110 and the pillar 120 may include at least one of silicone rubber, urethane rubber, fluororubber, ethylene propylene diene rubber (EPDM), nitrile-butadiene rubber (NBR), polymethyl methacrylate (PMMA), and epoxy-based negative photoresist. can be formed into one.

The method of manufacturing the non-rigid pad for device transfer may directly manufacture the non-rigid pad for device transfer using a photolithography process using a UV light source, a 3D printer process, or a LIGA process using X-rays. In this case, at least one of silicon rubber, PMMA, and epoxy-based negative photoresist may be used as the material of the non-rigid pad for device transfer.

As another method, a method for manufacturing a non-rigid pad for element transfer includes a mold manufacturing step of manufacturing a mold having a shape corresponding to the non-rigid pad for element transfer using a 3D printer process or a LIGA process, and injecting a molding liquid into the mold and curing to form a non-rigid pad for device transfer.

The molding fluid injected into the mold is at least one of silicone rubber, urethane rubber, fluororubber, EPDM, and NBR, and the molding fluid may be room temperature vulcanization or high temperature vulcanization.

In the element transfer non-rigid pad 100 according to the present invention, as shown in FIG. 3, after the pillar 120 is bent by the first displacement d1, the second displacement d2 greater than the first displacement d1. ), the same load (F) can be generated in the first displacement (d1) and second displacement (d2) sections. That is, it may have a zero stiffness region in which the same load (F) is maintained in the first displacement (d1) and second displacement (d2) sections.

In other words, while the non-rigid pad 100 for element transfer is compressed and deformed by an external force, the load does not increase in a specific displacement section. This means that contact pressure can be constantly applied between the element and the target substrate if an appropriate amount of force is provided from the pressing part so that the element transfer non-rigid pad 100 is deformed within a specific deformation range.

Therefore, in the process of controlling the processing error of the configuration that provides the pressing force to the transfer film, the thickness error of the transfer film, the assembly error between various components including the pressing unit, or the pressing force applied to the device, such as the pressing unit Even if a uniform pressing force is not provided to the transfer film due to a load control error, etc., a non-rigid pad 100 for element transfer is provided and an appropriate pressing force so that the non-rigid pad 100 for element transfer is deformed within a specific displacement range. When providing, a uniform contact pressure can be generated between the device and the target substrate. The pressing unit 40 may include a roller or a flat plate-shaped stamp. Hereinafter, for convenience of description, a case in which the pressing unit 40 is a roller is taken as an example.

FIG. 4 is an exemplary view showing a first application example of the non-rigid pad for element transfer of FIG. 2 .

As shown in FIG. 4, the element transfer non-rigid pad 100 includes a transfer film 30 to which a plurality of elements 20 to be transferred to the electrode 11 of the target substrate 10 are adhered, and a plurality of elements ( 20) may be disposed between the pressing parts 40 that provide pressing force to be transferred to the target substrate 10.

The element transfer non-rigid pad 100 arranged in this way is bent and deformed when the pressing force of the pressing unit 40 is applied so that a uniform contact pressure can be provided between the plurality of elements 20 and the target substrate 10. .

As shown in (a) and (b) of FIG. 4, in the non-rigid pad 100 for element transfer, the other end of the pillar 120 is in close contact with the transfer film 30, and the base plate 110 is the pressing portion. (40). This arrangement may be applied when it is difficult to place the element transfer non-rigid pad 100 under the target substrate 10 .

As shown in the drawing, the non-rigid pad 100 for element transfer may be pressed by the pressing part 40 in a state disposed on the transfer film 30, or may be provided to cover the outer circumferential surface of the pressing part 40. .

And, as shown in (a') and (b') of FIG. 4, in the non-rigid pad 100 for element transfer, the base plate 110 adheres to the transfer film 30, and the other side of the pillar 120 The end may be disposed to face the pressing part 40 .

Meanwhile, it is preferable that the pitch P1 between the pillars 120 of the non-rigid pad 100 for element transfer is smaller than the pitch P2 between the elements 20 and 20 . In addition, it is preferable that the cross-sectional area of the pillars 120 of the non-rigid pad 100 for element transfer is smaller than the pitch P2 between elements 20 and 20 .

In addition, the element transfer non-rigid pad 100 has a force required to generate bending deformation as the cross-sectional area of the pillar 120 is wide, the length of the pillar 120 is short, or the modulus of elasticity of the pillar 120 is large. this can grow Therefore, by adjusting the cross-sectional area of the column 120, adjusting the length of the column 120, or adjusting the modulus of elasticity by changing the material of the column 120, the critical displacement and , the critical load can be controlled.

5 is an exemplary view showing a moment of inertia, a cross-sectional area, a critical load, and a critical displacement according to the cross-sectional shape of the column of FIG.

5 (a) shows the moment of inertia (I), cross-sectional area (A), critical load (Pcr), and critical displacement (Dcr) when the cross section of the column is rectangular, and in (b) of FIG. 5, the column The moment of inertia, cross-sectional area, critical load, and critical displacement are shown when the cross-section of is an ellipse, and in (c) of FIG. there is.

According to this, when the horizontal length (b) and vertical length (h) of the cross section of the pillar 120 are the same, the value obtained by dividing the moment of inertial (I) according to the cross-sectional shape of the pillar 120 by the cross-sectional area (A) As (I/A) is smaller, the critical displacement can be reduced. That is, it can be seen that the critical displacement coefficients decrease to 1/12, 1/16, and 1/24 in the order of rectangle, ellipse, and rhombus, respectively.

In addition, when the horizontal length (b) and the vertical length (h) of the cross section of the column 120 are the same, it can be seen that the critical load is determined according to the moment of inertia (I). That is, it can be seen that the critical load coefficients decrease to π ² /12, π ³ /64, and π ² /48 in the order of rectangle, ellipse, and rhombus, respectively.

Therefore, by appropriately selecting the cross-sectional shape of the pillar 120, the critical displacement and critical load resulting from the bending deformation of the pillar 120 can be controlled.

On the other hand, E is the elastic modulus of the material of the column 120, AR is the aspect ratio (Aspect Ratio), the ratio (L / h) of the vertical length (h) of the cross section to the length (L) of the column 120, K is the column is the Column Effective Length Factor.

In addition, as the aspect ratio AR of the pillar 120 increases, the critical displacement and critical load at which bending deformation occurs may decrease.

6 is a graph showing another shape of the column of the non-rigid pad for element transfer of FIG. 2 and the resulting displacement-load relationship, wherein the column 120a in (a) of FIG. 6 has an eccentricity of 50 μm, The pillar 120b of (b) may have an eccentricity of 100 μm, and the pillar 120c of FIG. 6 (c) may have an eccentricity of 200 μm.

As shown in FIG. 6 , the other ends 122 of each of the pillars 120a, 120b, and 120c may all be formed in the same convex shape. In this way, when the other ends 122 of each of the pillars 120a, 120b, and 120c are formed in the same convex shape, the restraint due to the degree of eccentricity of each of the pillars 120a, 120b, and 120c is small and almost similar. It can have a no-stiffness section.

FIG. 7 is a perspective view showing another shape of a pillar of the non-rigid pad for element transfer of FIG. 2 , and FIG. 8 is an exemplary view for explaining a direction of bending deformation of the non-rigid pad for element transfer of FIG. 7 .

As shown in FIGS. 7 and 8 , the initial state of the pillar 120 may be bent in one direction to form an eccentric shape.

Also, the pillar 120 may have a first straight portion 125 , a second straight portion 126 , and a bent portion 127 .

The first straight portion 125 may be formed along the axial direction of the pillar 120 from one end 121 of the pillar 120 .

The bent portion 127 may be formed eccentrically by having one end connected to the first straight portion 125 and bent in one direction.

The second straight portion 127 may be connected to the other end of the bent portion 127 and may be formed along the axial direction. The second straight portion 126 may be formed on the same central axis as the first straight portion 15 . Accordingly, the bent portion 127 may be formed to be bent in one direction between the first straight portion 125 and the second straight portion 126, and may be formed to be eccentric in one direction.

The pillars 120 may be formed to be symmetrical to each other with respect to the center (C). That is, the bent portion 127 may be formed symmetrically with respect to the center C, and the first straight portion 125 and the second straight portion 126 may be formed to have the same length. However, the pillars 120 are not necessarily limited to be formed symmetrically with respect to the center (C).

When a load F is applied to the pillar 120, the pillar 120 may initially be bent and bent in an eccentric direction, and the bending direction B of the pillar 120 may be controlled using this. That is, when the bent part 127 is formed to be eccentric in one direction, when the load F is applied by the pressing part 40, the bent part 127 may be bent and deformed in the initially eccentric direction. When viewed as a whole through the column 120 may be bent in one direction. That is, as shown in FIG. 7 , when the pillar 120 is initially formed eccentrically to the right, when a load F is applied, the pillar 120 may be bent in the right direction.

In addition, since the pillar 120 is bent in one direction and formed in an eccentric shape, bending deformation may proceed slowly, and a non-rigidity characteristic may be stably implemented without a negative stiffness section appearing.

9 is a graph showing a displacement-load relationship according to shape deformation of the non-rigid pad for element transfer of FIG. 7 . 9 is made of room temperature curing type (RTV) silicone rubber, and when a vertical load is applied to each pillar having a bent part formed with a curve (Cs1) of 8.21 degrees and a bent part formed with a curve (Cs2) of 8.27 degrees, each pillar It shows the displacement and load relationship of

As shown in FIG. 9, both the column having a bent portion formed by a curve Cs1 of 8.21 degrees and the column having a bent portion formed by a curve Cs2 of 8.27 degrees are uniform without a negative stiffness section after the displacement of 0.6 mm. It can be seen that there is a non-stiffness characteristic that generates a single load.

10 is an exemplary view for explaining a bending deformation direction according to another shape of a pillar of a non-rigid pad for element transfer according to an embodiment of the present invention.

As shown in FIG. 10 , the pillar 120 may have a first extension 128 and a second extension 129 .

The first extension part 128 may obliquely extend in one direction from one end of the pillar 120 .

The second extension part 129 may have one end connected to the first extension part 128 and may be formed to obliquely extend in the opposite direction to the first extension part 128 . In the pillar 120 of this embodiment, the first straight part and the second straight part may be omitted from the pillar of FIG. 7 . In this case, the total height of the column 120 can be lowered, and the bending deformation can proceed more slowly, so that the non-rigidity characteristic can be implemented more stably. The first extension part 128 and the second extension part 129 may be formed symmetrically with each other and have the same length, but are not necessarily limited thereto.

Even in this embodiment, since the pillar 120 is formed eccentrically from the beginning, the bending deformation direction B can be controlled. That is, as shown in (a) of FIG. 10, when the pillar 120 is formed to be eccentric in one direction, when the load F is applied, the pillar 120 may initially be bent in the eccentric direction. . That is, when the pillar 120 is initially formed eccentrically to the right as in (a) of FIG. 10, when a load F is applied, the pillar 120 may be bent in the right direction ((a) of FIG. 10). ') reference).

Similarly, when the post 120 is initially formed eccentrically to the left as in (b) of FIG. 10, when a load F is applied, the post 120 may be bent to the left ((b' of FIG. 10). ) reference).

And, as shown in (c) of FIG. 10, the pillars 120a, 120b, 120c, and 120d have an asymmetric cross-sectional shape perpendicular to the axial direction, so that the bending deformation direction B may be controlled. The cross-sectional shape of the pillar may be formed asymmetrically by adding or subtracting any one or more of a semi-ellipse, a quadrangle, a triangle, and a trapezoid.

In addition, the other end of the second extension part 129 may be formed as a curved surface. Through this, even if the aspect ratio (AR) of the pillar 120 is small, no stiffness can be stably implemented without generating a negative stiffness section.

FIG. 11 is another exemplary view for explaining a direction of bending deformation according to another shape of a pillar of the non-rigid pad for element transfer of FIG. 2 .

As shown in FIG. 11, an inclined surface 123 may be formed at one end of the pillar 120, and the bending deformation direction B of the pillar 120 may be controlled through the formation direction of the inclined surface 123. there is.

That is, as shown in (a) of FIG. 11, when the inclined surface 123 formed at one end of the pillar 120 is inclined in one direction, when the load F is applied, the pillar 120 is inclined to the inclined surface ( 123) may be bent and deformed in the opposite direction. That is, when the inclined surface 123 is formed inclined in the right direction as shown in (a) of FIG. 11, when a load F is applied, the pillar 120 may be bent and deformed in the left direction ((a' in FIG. 11). ) reference).

Similarly, when the inclined surface 123 is formed inclined in the left direction as shown in (b) of FIG. 11, when a load F is applied, the pillar 120 may be bent in the right direction ((b' in FIG. 11). ) reference).

FIG. 12 is an exemplary diagram for explaining the arrangement of pillars of the non-rigid pad for element transfer of FIG. 2 .

As shown in (a) of FIG. 12 , a plurality of pillars of the non-rigid pad 100 for element transfer may be grouped to form a pillar group G1. In addition, the pillars 120a and 120b belonging to each pillar group G1 may be arranged such that bending deformation directions Ba and Bb are symmetrical to each other.

If the pillars 120 provided on the element transfer non-rigid pad 100 are all bent and deformed in the same direction, the pressing part 40 is in the form of a roller and moves in one direction 41 while the element transfer non-rigid pad ( 100), as well as when the pressing part is a stamp in the form of a flat plate, a pushing force can be generated in the transfer film 30 in the same plane direction by the non-rigid pad 100 for element transfer. Accordingly, displacement in the plane direction may occur in the transfer film 30 .

However, when the pillars 120a and 120b of each pillar group G1 are arranged so that the bending deformation directions Ba and Bb are symmetrical to each other, the displacement in the plane direction caused by the bending deformation of each pillar 120a and 120b is offset. Since it can be, the displacement of the transfer film 30 in the plane direction can be prevented.

The number of pillars included in the pillar group is not particularly limited, and various modifications may be possible.

That is, as shown in (b) of FIG. 12, the pillar group G2 may have four pillars 120a, 120b, 120c, and 120d, and in this case, each pillar 120a, 120b, 120c, and 120d The pillars 120a, 120b, 120c, and 120d may be arranged such that the bending deformation directions Ba, Bb, Bc, and Bd are symmetrical to each other so that displacement in the plane direction due to bending deformation of the columns 120a, 120b, 120c, and 120d is offset.

FIG. 13 is an exemplary view for explaining the arrangement of pillars of the element transfer non-rigid pad of FIG. 2 , and FIG. 14 is an example view for explaining a working example of the element transfer non-rigid pad of FIG. 13 .

As shown in FIG. 13, when the pressing unit 40 is in the form of a roller and sequentially presses the element transfer non-rigid pad 100 while moving in one direction 41, the element transfer non-rigid pad 100 may have a higher pillar density toward the front end part E1 and the rear end part E2 based on the moving direction of the pressing unit 40. In other words, in the moving direction of the pressing unit 40, the columns have a high column density from the center of the base plate 110 toward the front and rear ends E1 and E2 of the non-rigid pad 100 for element transfer. can be placed as That is, the columns 120c may be formed more densely as they go from the columns 120b to the columns 120a.

As described above, the cross-sectional shape of the column can be formed asymmetrically by adding or subtracting any one or more of a semi-ellipse, a rectangle, a triangle, and a trapezoid, and through this, a column group arranged so that the bending deformation direction is symmetrical can be formed. there is.

14(a) and (a′) show a working example in the case of using a non-rigid pad 100a for element transfer with constant intervals between pillars 120. In the case of using the element-transferring non-rigid pad 100a with constant spacing between the pillars 120, at the moment when the pressing part 40 starts to advance, the pressing force of the pressing part 40 causes the pillar ( 120) is pressed so that the rear end of the transfer film 30 and the target substrate 10 can be lifted (see FIG. 14(a)), and at the moment when the progress of the pressing unit 40 ends, the column of the rear end E2 The front end of the transfer film 30 and the target substrate 10 can be lifted by pressing the 120 (see FIG. 14(a')). In this case, the function of the non-rigid pad 100a for element transfer may not be properly implemented.

However, in the case of using the non-rigid pad 100 for element transfer having the pillar density as shown in FIG. 13, the pressing force of the pressing unit 40 at the moment when the pressing unit 40 starts moving causes the shear part E1 to The column 120 of the column 120 is not pressed much, and even at the moment when the progress of the pressing part 40 ends, the column 120 of the rear end portion E2 is not pressed much, so the front end of the transfer film 30 and the target substrate 10 or The rear end may not be lifted, and through this, the function of the non-rigid pad 100 for element transfer may be properly implemented. (See Fig. 14 (b) and (b')).

Meanwhile, two non-rigid pads for device transfer may be stacked to form two layers. When the element transfer non-rigid pads are stacked and disposed, an effect similar to that obtained when the length of the pillar 120 is increased may occur.

FIG. 15 is a graph showing another example of the first application example of the non-rigid pad for element transfer of FIG. 2 and the resulting displacement-load relationship.

15(a) and (b) show a case in which the two element transfer non-rigid pads 100a and 100b are stacked in the same relative positions of the base plates 110a and 110b and the pillars 120a and 120b. , it can be seen that, even in this case, the first load F1 is generated within the displacement range of the first displacement d1 and the second displacement d2.

And, as shown in (a') and (b') of FIG. 15, the base plate 110a of any one element transfer non-rigid pad 100a among the two element transfer non-rigid pads 100a and 100b, and Even when the relative position of the pillar 120a is opposite to that of the base plate 110b and the pillar 120b of the element transfer non-rigid pad 100b, the first displacement d1 and the second displacement d2 It can be seen that the first load (F1) is generated within the displacement section.

The first displacement (d1), the second displacement (d2) and the first load (F1) in (b') of FIG. 15 are the first displacement (d1), the second displacement (d2) and It can be almost similar to the first load (F1), and through this, the laminated form of the two stacked element transfer non-rigid pads (100a, 100b) does not greatly affect the deformation range and the size of the load can know

16 is an exemplary diagram illustrating a second application example of the element transfer non-rigid pad of FIG. 2 . In this embodiment, the arrangement position of the element transfer non-rigid pad may be different from that of the first embodiment described above, and other details are the same, so the repeated contents are omitted as much as possible.

As shown in FIG. 16, in this embodiment, a plurality of devices 20 to which the non-rigid pad 100 for device transfer is adhered to the transfer film 30 may be disposed under the target substrate 10 to be transferred. . When the pressing force of the pressing unit 40 is provided so that the plurality of elements 20 are transferred to the target substrate 10, the element transfer non-rigid pad 100 is bent and deformed so that the plurality of elements 20 and the target substrate 10 A uniform contact pressure can be provided between them.

In this arrangement, it is difficult to attach the non-rigid pad 100 for element transfer to the outer circumferential surface of the pressing part 40 because the diameter of the pressing part 40 is small, or it is difficult to attach the element transfer device between the pressing part 40 and the transfer film 30. It can be applied when it is difficult to apply the non-rigid pad 100 used.

Also in this embodiment, the non-rigid pad 100 for element transfer may be disposed such that the base plate 110 adheres to the target substrate 10 or the other end of the pillar 120 adheres to the target substrate 10. And, the two may be stacked and arranged.

17 is an exemplary view showing a third application example of the element transfer non-rigid pad of FIG. 2 . In this embodiment, the arrangement positions of the element transfer non-rigid pads in the above-described first and second embodiments are mixed. can be applied in the form of

As shown in FIG. 17, in this embodiment, a non-rigid pad for device transfer may be disposed between the lower portion of the target substrate 10, the transfer film 30, and the pressing unit 40, respectively, and the pressing unit ( When the pressing force of 40) is provided, it is bent and deformed so that a uniform contact pressure can be provided between the plurality of elements 20 and the target substrate 10.

When the element transfer non-rigid pads 100a and 100b generate the same load in the same displacement section and a pressing force is provided by the pressing unit 40, the element transfer non-rigid pads 100a and 100b simultaneously Bending can be deformed.

In addition, when the element transfer non-rigid pads 100a and 100b generate the same load in different displacement sections and a pressing force is provided by the pressing unit 40, the element transfer non-rigid pads 100a and 100b ) can be sequentially subjected to bending deformation. For example, when the element transfer non-rigid pad 100a provided on the lower part of the target substrate 10 is subjected to bending deformation in a relatively smaller deformation range, as shown, it is provided on the lower part of the target substrate 10. The column 120a of the element transfer non-rigid pad 100a is first bent and deformed, and then the column 120b of the element transfer non-rigid pad 100b disposed between the pressing part 40 and the transfer film 30 This bending can be deformed. In this embodiment, since different non-rigid regions may appear in the respective element-transfer-use non-rigid pads 100a and 100b, there is an effect that the range of the non-rigid region can be widened.

In this embodiment as well, the element transfer non-rigid pads 100a and 100b may be disposed such that the positions of the base plates or pillars are reversed, or two may be stacked.

FIG. 18 is a graph showing an application example of an element transfer non-rigid pad group composed of the element transfer non-rigid pad of FIG. 2 and a displacement-load relationship according thereto.

The element transfer non-rigid pad group may include a plurality of element transfer non-rigid pads. In FIG. 18, a four-layer non-rigid pad group for element transfer having four element transfer non-rigid pads 100a, 100b, 100c, and 100d is shown, but this is for illustrative purposes only, and the element transfer non-rigid pad group In this case, three or more device transfer non-rigid pads may be stacked.

As shown in FIG. 18, the element transfer non-rigid pads 100a, 100b, 100c, and 100d included in the element transfer non-rigid pad group include base plates 110a, 110b, 110c, and 110d and respective pillars. (120a, 120b, 120c, 120d) may be disposed in the same direction, but are not limited thereto, and the relative positions of the base plates (110a, 110b, 110c, 110d) and pillars (120a, 120b, 120c, 120d) They may be arranged differently.

In the element transfer non-rigid pad group, when an external force is applied, element transfer non-rigid pads of some of the plurality of layers are subjected to primary bending deformation, and in the deformation section between the first displacement (d1) and the first displacement (d2). 1 load (F1) may occur. Thereafter, when the external force increases, the element transfer non-rigid pad of the other layer is subjected to secondary bending and a third load F3 is generated in the deformation section between the third displacement d3 and the fourth displacement d4. can

As is already known, the weaker the constraint condition of both ends of the column, the smaller the bending deformation load, and the stronger the constraint condition, the greater the bending deformation load. The reason why the element transfer non-rigid pad group has a plurality of non-rigid areas in which different loads are generated in different displacement ranges is the pillar part and the base plate that are in close contact between each element transfer non-rigid pad forming a multi-layer, or This may be due to the fact that the constraint condition of the end of the column may be changed due to the difference in frictional force between the base plates that are in close contact with each other, and thus the bending deformation load may be changed.

The device transfer non-rigid pad group may be disposed between the transfer film and the pressurizing unit, or disposed below the target substrate, or disposed between the transfer film and the pressurizing unit, and both below the target substrate.

In the state in which the element transfer non-rigid pad group is arranged as above, when the pressing force of the pressing part is applied, the element transfer non-rigid pads of some layers are subjected to primary bending deformation to provide a uniform first contact pressure between the element and the target substrate. can be made In addition, when the pressing force of the pressing part increases and is provided, the element transfer non-rigid pad of the other layer is subjected to secondary bending deformation so that the second contact pressure greater than the first contact pressure can be uniformly provided between the element and the target substrate. If this is used, some of the plurality of elements can be selectively transferred to the target substrate.

The above description of the present invention is for illustrative purposes, and those skilled in the art can understand that it can be easily modified into other specific forms without changing the technical spirit or essential features of the present invention. will be. Therefore, the embodiments described above should be understood as illustrative in all respects and not limiting. For example, each component described as a single type may be implemented in a distributed manner, and similarly, components described as distributed may be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included in the scope of the present invention.

10: target substrate
20: element
30: transfer film
40: pressing part
100: non-rigid pad for element transfer
110: base plate
120: column

Claims (22)

base plate; and
It includes a plurality of pillars, one end of which is connected to one surface of the base plate and is formed to protrude and is bent and deformed when an external force is applied,
It is disposed between a transfer film on which a plurality of elements to be transferred to a target substrate are adhered, and a pressing unit that provides a pressing force so that the plurality of elements are transferred to the target substrate,
The element transfer non-rigid pad, characterized in that when the pressing force of the pressing part is provided, it is bent and deformed so that a uniform contact pressure is provided between the plurality of elements and the target substrate. According to claim 1,
The base plate is in close contact with the transfer film, and the other end of the pillar is disposed to face the pressing part. According to claim 1,
The non-rigid pad for element transfer, characterized in that the other end of the pillar is in close contact with the transfer film, and the base plate is disposed to face the pressing part. base plate; and
It includes a plurality of pillars, one end of which is connected to one surface of the base plate and is formed to protrude and bend when an external force is applied.
The element is disposed under the target substrate to be transferred,
When the pressing force of the pressing unit is provided so that the plurality of elements adhered to the transfer film are transferred to the target substrate, they are bent and deformed so that a uniform contact pressure is provided between the plurality of elements and the target substrate. stiff pad. According to claim 4,
The base plate is a non-rigid pad for element transfer, characterized in that in close contact with the target substrate. According to claim 4,
The non-rigid pad for element transfer, characterized in that the other end of the pillar is in close contact with the target substrate. base plate; and
It includes a plurality of pillars, one end of which is connected to one surface of the base plate and is formed to protrude and is bent and deformed when an external force is applied,
It is disposed between a transfer film on which a plurality of elements to be transferred to a target substrate are adhered and a pressing unit providing a pressing force so that the plurality of elements are transferred to the target substrate, and at a lower portion of the target substrate,
The element transfer non-rigid pad, characterized in that when the pressing force of the pressing part is provided, it is bent and deformed so that a uniform contact pressure is provided between the plurality of elements and the target substrate. The method of any one of claims 1, 4 and 7,
The element transfer non-rigid pad, characterized in that two elements transfer non-rigid pads are stacked and disposed. According to claim 8,
The element transfer non-rigid pads, characterized in that the relative positions of the base plate and the pillar are the same in each of the element transfer non-rigid pads that are stacked and arranged. According to claim 8,
The relative position of the base plate and the pillar of any one of the element transfer non-rigid pads among the element transfer non-rigid pads that are stacked is opposite to that of the base plate and pillar of the other element transfer non-rigid pads. A non-rigid pad for device transfer, characterized in that. The method of any one of claims 1, 4 and 7,
The base plate and the pillar are formed of at least one of silicone rubber, urethane rubber, fluorine rubber, EPDM (ethylene propylene diene rubber), NBR (Nitrile-butadiene rubber) and PMMA (polymethyl methacrylate) For element transfer, characterized in that formed non-rigid pad. The method of any one of claims 1, 4 and 7,
The element transfer non-rigid pad, characterized in that the cross-sectional shape perpendicular to the axial direction of the pillar is formed asymmetrically to control the direction of bending deformation of the pillar. The method of any one of claims 1, 4 and 7,
A plurality of the pillars are grouped to form a pillar group, and the pillars belonging to each pillar group are arranged so that bending deformation directions are symmetrical to each other. The method of any one of claims 1, 4 and 7,
The element transfer non-rigid pad, characterized in that the pressing part is a roller, and the pillars are arranged with a high pillar density from the center of the base plate to the front and rear ends based on the moving direction of the pressing part. The method of any one of claims 1, 4 and 7,
The element transfer non-rigid pad, characterized in that the pillar is bent in one direction and formed in an eccentric shape, and when an external force is applied to the pillar, the pillar is initially bent and bent in the eccentric direction. According to claim 15,
the pillar
A first straight portion formed along the axial direction from one end of the pillar;
A bending portion having one end connected to the first straight line portion and bent in one direction to be eccentrically formed;
A non-rigid pad for element transfer, characterized in that it has a second straight portion connected to the other end of the bent portion and formed along an axial direction. According to claim 15,
the pillar
A first extension part obliquely extending in one direction from one end of the pillar;
An element transfer non-rigid pad, characterized in that it has a second extension portion connected to the first extension portion and one end thereof and extending obliquely in an opposite direction to the first extension portion. According to claim 17,
The element transfer non-rigid pad, characterized in that the other end of the second extension portion is formed with a curved surface. A method of manufacturing the non-rigid pad for element transfer according to any one of claims 1, 4 and 7,
A mold manufacturing step of manufacturing a mold having a shape corresponding to the non-rigid pad for element transfer using a 3D printer process or a LIGA process; and
A method of manufacturing a non-rigid pad for element transfer, characterized in that it comprises a molding step of molding a non-rigid pad for element transfer by injecting a molding liquid into the mold and curing it. According to claim 19,
The molding liquid is at least one material of silicone rubber, urethane rubber, fluororubber, EPDM (ethylene propylene diene rubber), and NBR (Nitrile-butadiene rubber),
The method of manufacturing a rigid pad for element transfer, characterized in that the molding liquid is room temperature curing (Room Temperature Vulcanization) or high temperature curing (High Temperature Vulcanization). A non-rigid pad for element transfer having a base plate and a plurality of pillars that are bent and deformed when an external force is applied, one end of which is connected to and protrudes from one surface of the base plate,
At least three non-rigid pads for element transfer are stacked and disposed between a transfer film on which a plurality of elements to be transferred to a target substrate are adhered, and a pressing part that provides a pressing force so that the plurality of elements are transferred to the target substrate. ,
When the pressing force of the pressing unit is provided, a first bending deformation is performed so that a uniform first contact pressure is provided between the plurality of elements and the target substrate, and when the pressing force of the pressing unit is increased and provided, a second bending deformation is performed to achieve the plurality of A non-rigid pad group for element transfer, characterized in that a second contact pressure greater than the first contact pressure is uniformly provided between the element and the target substrate. A non-rigid pad for element transfer having a base plate and a plurality of pillars that are bent and deformed when an external force is applied, one end of which is connected to and protrudes from one surface of the base plate,
Three or more non-rigid pads for element transfer are stacked and disposed under a target substrate on which a plurality of elements adhered to a transfer film are to be transferred,
When the pressing force of the pressing unit is provided so that the plurality of elements are transferred to the target substrate, a first bending deformation is performed so that a uniform first contact pressure is provided between the plurality of elements and the target substrate, and the pressing force of the pressing unit increases. If provided, it is subjected to secondary bending deformation so that a second contact pressure greater than the first contact pressure is uniformly provided between the plurality of elements and the target substrate.

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