Connection film and display panel including same

Abstract

Disclosed are a connection film for connecting a substrate and a plurality of light-emitting diodes, and a display panel including same. The connection film may include a sheet having a black-based color and a plurality of conductive adhesive members provided on the sheet at intervals.

Description

Connecting film and display panel including the same

[0001] The present disclosure relates to a connecting film connecting a light-emitting diode and a substrate and a display panel including the same.

[0002] To mount a component on a substrate, a conductive connection material is placed between the component and the substrate. Connection materials include anisotropic conductive films (ANFs) containing numerous conductive balls and conductive adhesives. While conductive adhesives are less expensive than ACFs, they lack optical performance and are therefore unsuitable for use as a material for connecting light-emitting diodes to the substrate of a display panel.

[0003] The present disclosure provides a low-cost and easy-to-manufacture connecting film and a display panel including the same.

[0004] According to one or more embodiments, the connecting film, which connects the substrate and the plurality of light-emitting diodes, may include a sheet having a black series color and a plurality of conductive adhesive members provided at intervals on the sheet.

[0005] The above plurality of conductive adhesive members may be provided on the sheet in a grid pattern.

[0006] The area of ​​each of the plurality of conductive adhesive members may be smaller than the area of ​​the substrate pad provided on the substrate and smaller than the area of ​​the electrode pad provided on the light-emitting diode.

[0007] The area of ​​each of the plurality of conductive adhesive members may be 30% to 80% of the smallest area among the area of ​​the substrate pad and the area of ​​the electrode pad.

[0008] Each of the plurality of conductive adhesive members may have a curing temperature of less than 200 degrees. Each of the plurality of conductive adhesive members may have a resistance value after curing in the range of 0.1 ohm to 20 ohm.

[0009] Each of the above-described plurality of conductive adhesive members may include an epoxy resin and conductive materials dispersed in the epoxy resin. The conductive materials may be gold (Au), silver (Ag), carbon (C), copper (Cu), nickel (Ni), aluminum (Al), indium (In), or tin (Sn).

[0010] The above sheet may have optical properties in the range of 0.1 to 30.

[0011] According to one or more embodiments, the connecting film may further include a plurality of openings in the sheet. The connecting film may further include an insulating resin having a gray color and disposed in the plurality of openings, and a reflective member disposed along an edge of the insulating resin and having a size smaller than the size of the conductive adhesive member.

[0012] The above reflective member may include a plurality of glass balls.

[0013] The above insulating resin may have a luminance characteristic of 1 < RGB < 100.

[0014] According to one or more embodiments, a display panel may include a substrate, a connecting film attached to the substrate, and a light emitting diode connected to the substrate by the connecting film.

[0015] The above-mentioned connecting film may include a sheet having a black series color; and a conductive adhesive member provided at intervals on the sheet and electrically connecting a plurality of substrate pads of the substrate and a plurality of electrode pads of the light-emitting diode to each other.

[0016] According to one or more embodiments, the display panel may further include a plurality of openings in the sheet. The connecting film may further include a reflective member including an insulating resin having a gray color and a plurality of glass balls surrounding side surfaces of the light emitting diode, the insulating resin being disposed in the plurality of openings.

[0017] FIG. 1 is a cross-sectional view illustrating a display panel according to one or more embodiments.

[0018] FIG. 2 is a plan view illustrating a connecting film according to one or more embodiments.

[0019] FIG. 3 is a cross-sectional view of a connecting film according to one or more embodiments taken along line AA' shown in FIG. 2.

[0020] FIG. 4 is a drawing showing a substrate having a first substrate pad and a second substrate pad according to one or more embodiments.

[0021] FIG. 5 is a drawing showing a light emitting diode provided with a first electrode pad and a second electrode pad according to one or more embodiments.

[0022] FIG. 6 is a drawing showing an example in which a conductive adhesive member of a connecting film according to one or more embodiments is transformed from a non-conductive state to a conductive state by heat compression.

[0023] FIGS. 7 to 10 are drawings showing a manufacturing process of a connecting film according to one or more embodiments.

[0024] FIG. 11 is a plan view showing an example of attaching a connecting film to a substrate according to one or more embodiments.

[0025] FIG. 12 is a cross-sectional view showing an example of attaching a connecting film to a substrate according to one or more embodiments.

[0026] FIG. 13 is a plan view showing an example of transferring a light-emitting diode onto a connecting film according to one or more embodiments.

[0027] FIG. 14 is a cross-sectional view showing a light emitting diode transferred onto a connecting film according to one or more embodiments.

[0028] FIG. 15 is a cross-sectional view illustrating a display panel according to one or more embodiments.

[0029] Figure 16 is an enlarged view showing part B shown in Figure 15.

[0030] FIG. 17 is a cross-sectional view showing a connecting film according to one or more embodiments.

[0031] FIG. 18 is a drawing showing an example of providing a touch screen to a display panel according to one or more embodiments.

[0032] FIG. 19 is a cross-sectional view illustrating a display panel according to one or more embodiments.

[0033] FIG. 20 is a cross-sectional view of a connecting film according to one or more embodiments.

[0034] FIGS. 21 to 27 are drawings showing a manufacturing process of a connecting film according to one or more embodiments.

[0035] FIG. 28 is a cross-sectional view showing a light emitting diode transferred onto a connecting film according to one or more embodiments.

[0036] FIG. 29 is a cross-sectional view illustrating a display panel according to one or more embodiments.

[0037] FIG. 30 is a block diagram illustrating a display device according to one or more embodiments.

[0038] Hereinafter, various embodiments will be described in more detail with reference to the accompanying drawings. One or more embodiments described herein may be variously modified. Specific embodiments may be depicted in the drawings and further described in the detailed description. However, the specific embodiments disclosed in the accompanying drawings are merely intended to facilitate understanding of various embodiments. Therefore, the technical concepts disclosed in the accompanying drawings are not intended to be limited by the specific embodiments disclosed in the accompanying drawings, but should be understood to include all equivalents or alternatives falling within the spirit and technical scope of the present disclosure.

[0039] In this disclosure, terms including ordinal numbers such as “first,” “second,” etc. may be used to describe various components, but these components are not limited by the aforementioned terms. The aforementioned terms are used solely for the purpose of distinguishing one component from another. In this disclosure, terms such as “comprises” or “has” should be understood to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification, but do not preemptively exclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. When a component is referred to as being “connected” or “connected” to another component, it should be understood that it may be directly connected or connected to the other component, but that other components may also be present in between. On the other hand, when a component is referred to as being “directly connected” or “directly connected” to another component, it should be understood that there are no other components present in between. In this disclosure, the term "identical" may encompass not only complete matching but also differences that take into account the scope of processing errors. If a detailed description of a related known function or configuration is deemed likely to unnecessarily obscure the gist of this disclosure, the detailed description will be abbreviated or omitted.

[0040] Below, with reference to the attached drawings, an embodiment of the present disclosure is described in detail so that those skilled in the art can easily implement the present disclosure. However, the embodiment of the present disclosure may be implemented in various different forms and is not limited to the embodiment of the present disclosure described herein.

[0041] Hereinafter, with reference to the drawings, a display module and a display device including the same according to one or more embodiments are described.

[0042] FIG. 1 is a cross-sectional view illustrating a display panel according to one or more embodiments. FIG. 2 is a plan view illustrating a connecting film according to one or more embodiments.

[0043] According to one or more embodiments, the display panel (10) may be a flat display panel or a curved display panel having a screen having a predetermined curvature.

[0044] Referring to FIG. 1, the display panel (10) may include a substrate (30), a connection film (50) provided on the substrate (30), and a plurality of light-emitting diodes (40) electrically and physically connected to the substrate (30) by the connection film (50).

[0045] According to one or more embodiments, a plurality of light emitting diodes (40) are provided on the substrate (30), but for convenience of explanation, only one light emitting diode (40) is illustrated in FIG. 1 on the substrate (30).

[0046] According to one or more embodiments, the substrate (30) may be a glass substrate, a substrate made of a flexible synthetic resin series (e.g., polyimide (PI), polyethylene terephthalate (PET), polyethersulfone (PES), polyethylene naphthalate (PEN), polycarbonate (PC), etc.), or a ceramic substrate.

[0047] According to one or more embodiments, a TFT layer including a TFT (thin film transistor) may be provided on a first surface (30a) of the substrate (30). The TFT provided on the TFT layer may be, for example, an LTPS TFT (low-temperature polycrystalline silicon TFT), an LTPO (low-temperature polycrystalline oxide) TFT, an oxide TFT, a Si TFT (poly silicon, a-silicon), an organic TFT, or a graphene TFT. The TFT may also be applied by manufacturing only a P-type (or N-type) MOSFET in a Si wafer CMOS process.

[0048] According to one or more embodiments, the TFT layer of the substrate (30) may be formed integrally with the first surface (30a) of the substrate (30), or may be manufactured in the form of a separate film and attached to the first surface (30a) of the substrate (30).

[0049] According to one or more embodiments, the second side (30b) of the substrate (30) may be provided with a power supply circuit for supplying power to the TFT circuit, a data drive driver, a gate drive driver, or a timing controller for controlling each drive driver.

[0050] According to one or more embodiments, the first side (30a) of the substrate (30) may be divided into an active region and a non-active region. The active region may be a region occupied by a TFT layer among the entire area of ​​the first side (30a) of the substrate (30). The non-active region may be a region excluding the active region among the entire area of ​​the first side (30a) of the substrate (30). The edge region of the substrate (30) may be the outermost region of the substrate. For example, the edge region of the substrate (30) may include a region corresponding to a side surface of the substrate, a portion of the first side (30a) of the substrate (30) adjacent to each side surface, and a portion of the second side (30b) of the substrate (30). A plurality of side wirings may be arranged in the edge region of the substrate (30) to electrically connect a TFT circuit on the first side (30a) of the substrate (30) and a driving circuit on the second side (30b) of the substrate (30).

[0051] According to one or more embodiments, the substrate (30) may omit the TFT layer on which the TFT circuit is formed. In this case, a plurality of micro IC chips that function as the TFT circuit may be mounted on the first surface (30a) of the substrate (30). In this case, the plurality of micro ICs may be electrically connected to a plurality of light-emitting diodes (40) arranged on the first surface (30a) of the substrate (30) via wiring.

[0052] According to one or more embodiments, the substrate (30) may have a plurality of pixels arranged on the TFT layer. Each pixel may be driven by a TFT circuit. One pixel may include at least two light-emitting diodes (40) that emit light of different colors. In the present disclosure, one light-emitting diode (40) may be referred to as one sub-pixel.

[0053] According to one or more embodiments, the light emitting diode (40) may be an inorganic light emitting diode having a size of 100 μm or less. The inorganic light emitting diode may be a micro LED or a mini LED.

[0054] According to one or more embodiments, the light emitting diode (40) may be formed in the form of a flip chip in which a first electrode pad (41) (e.g., an anode electrode pad) and a second electrode pad (42) (e.g., a cathode electrode pad) are arranged on opposite sides of the light emitting surface.

[0055] According to one or more embodiments, the connection film (50) may be laminated to the first side (30a) of the substrate (30) prior to transferring the plurality of light emitting diodes (40) to the substrate (30).

[0056] According to one or more embodiments, the connecting film (50) can electrically and physically connect the substrate (30) and the plurality of light-emitting diodes (40). For example, the connecting film (50) includes a conductive material so as to electrically connect the electrode pads (first electrode pad (41) and second electrode pad (42)) of the light-emitting diode (40) and the electrode pads (first substrate pad (31) and second substrate pad (32)) of the substrate (30) corresponding to the electrode pads of the diode (40).

[0057] According to one or more embodiments, the connection film (50) may include an adhesive material. When a plurality of light-emitting diodes (40) transferred to the substrate (30) are thermally compressed, the connection film (50) may melt, and the lower portions of the plurality of light-emitting diodes (40) may be inserted into the connection film (50). When the connection film (50) is cured through the curing process, the plurality of light-emitting diodes (40) may be physically and firmly fixed to the first surface (30a) of the substrate (30).

[0058] According to one or more embodiments, the connecting film (50) may include a plurality of conductive adhesive members (51) and sheets (53).

[0059] According to one or more embodiments, the plurality of conductive adhesive members (51) may have a spacing and size that do not cause a short circuit between each other after thermal compression. The plurality of conductive adhesive members (51) may be arranged continuously at a constant spacing. The plurality of conductive adhesive members (51) may have a size smaller than the first substrate pad (31) and the second substrate pad (32) of the substrate (30), and the first electrode pad (41) and the second electrode pad (42) of the light-emitting diode (40), respectively.

[0060] According to one or more embodiments, the conductive adhesive member (51) may be patterned on the sheet (53). For example, a plurality of conductive adhesive members (51) may be provided in a grid pattern on the sheet (53) as shown in FIG. 2. The conductive adhesive members (51-1, 51-2) adjacent to each other in the column direction may be arranged at a first pitch (P1). The conductive adhesive members (51-1, 51-3) adjacent to each other in the row direction may be arranged at a second pitch (P2). The first pitch (P1) may be the same as the second pitch (P2), but is not limited thereto.

[0061] According to one or more embodiments, a plurality of conductive adhesive members (51) may correspond to one substrate pad of the substrate (30) so as to achieve good electrical connection between the substrate (30) and the light emitting diode (40). In this case, the first pitch (P1) and the second pitch (P2) may be set to be smaller than the column-direction pitch and the row-direction pitch of the plurality of substrate pads (31, 32) provided on the substrate (30).

[0062] According to one or more embodiments, the area of ​​the conductive adhesive member (51) may be determined based on the minimum area (S) among the areas of the first substrate pad (31) and the second substrate pad (32) of the substrate (30), and the areas of the first electrode pad (41) and the second electrode pad (42) of the light emitting diode (40). For example, the area of ​​the conductive adhesive member (51) may have a range of 30% to 80% of the minimum area (S).

[0063] According to one or more embodiments, the conductive adhesive member (51) may be formed in a square shape as shown in FIG. 2 when viewed from a plan view. However, the shape of the conductive adhesive member (51) is not limited to a square, and may have various shapes such as a triangle, circle, oval, star shape, etc.

[0064] FIG. 3 is a cross-sectional view of a connecting film according to one or more embodiments taken along the line AA' shown in FIG. 2, showing a gap (G1) between adjacent conductive adhesive members. FIG. 4 is a view showing a substrate provided with a first substrate pad and a second substrate pad according to one or more embodiments, showing a gap (G2) between the first substrate pad and the second substrate pad. FIG. 5 is a view showing a light-emitting diode provided with a first electrode pad and a second electrode pad according to one or more embodiments, showing a gap (G3) between the first electrode pad and the second electrode pad.

[0065] According to one or more embodiments, the first spacing (G1, see FIG. 3) of adjacent conductive adhesive members (51) may be determined based on a minimum spacing (G0) among the second spacing (G2, see FIG. 4) of the first substrate pad (31) and the second substrate pad (32) of the substrate (30) and the third spacing (G3, see FIG. 5) of the first electrode pad (41) and the second electrode pad (42) of the light-emitting diode (40). For example, the first spacing (G1) of adjacent conductive adhesive members (51) may have a range of 1% to 30% of the minimum spacing (G0).

[0066] FIG. 6 is a drawing showing an example in which a conductive adhesive member of a connecting film according to one or more embodiments is transformed from a non-conductive state to a conductive state by heat compression.

[0067] According to one or more embodiments, the conductive adhesive member (51) may have a curing temperature of less than 200 degrees in consideration of the heat resistance characteristic limit. The conductive adhesive member (51) may have a range of a resistance value (R) after curing in a range of 0.1 ohm to 20 ohm. If the resistance value (R) after curing of the conductive adhesive member (51) is less than 0.1 ohm, material dispersibility is not satisfied, and if the resistance value (R) after curing of the conductive adhesive member (51) exceeds 20 ohm, current loss may occur, making it difficult to use the conductive adhesive member (51).

[0068] According to one or more embodiments, the conductive adhesive member (51) may include an epoxy resin (52a) and conductive materials (52b) dispersed in the epoxy resin (52a), as shown in FIG. 6. The epoxy resin (52a) may physically connect the first substrate pad (31) and the second substrate pad (32) of the substrate (30) and the first electrode pad (41) and the second electrode pad (42) of the light-emitting diode (40) to each other through a thermal compression and curing process. The conductive materials (52b) may be a material having high conductivity. For example, the conductive materials (52b) may be gold (Au), silver (Ag), carbon (C), copper (Cu), nickel (Ni), aluminum (Al), indium (In), or tin (Sn). The conductive materials (52b) may be dispersed and arranged at intervals within the epoxy resin (52a) so as to not mostly contact each other, as shown in FIG. 6. The conductive adhesive member (51) that is pressed during thermal compression can become electrically conductive. In this case, the conductive materials (52b) of the conductive adhesive member (51) that is pressed can become electrically conductive by coming into contact or clumping together with the gaps between them becoming narrower.

[0069] According to one or more embodiments, the sheet (53) may be made of an insulating material. For example, the sheet (53) may be a thermoplastic material (styrene butadiene, or polyvinyl butylene) or a thermosetting material (epoxy resin, polyurethane, or acrylic resin).

[0070] According to one or more embodiments, the sheet (53) may be formed of a pigment or dye having a black color with high optical density and low reflectivity to secure a black appearance. For example, the sheet (53) may absorb light emitted from a plurality of light-emitting diodes (40) provided on the substrate (30) to improve crosstalk between adjacent light-emitting diodes (40) and absorb external light to improve contrast ratio. For example, the sheet (53) may be formed of a material having a reflectivity of about 9% or less in the entire wavelength range of visible light (e.g., 390 nm to 700 nm).

[0071] According to one or more embodiments, the sheet (53) may be formed of a material having an optical characteristic (L: Luminosity) in the range of 0.1 to 30. If the optical characteristic of the material forming the sheet (53) is less than 0.1, curing is not smooth, making production difficult. If the optical characteristic (L) of the material forming the sheet (53) exceeds 30, there is a problem of lowering the black quality.

[0072] According to one or more embodiments, the sheet (53) may be formed of a material having adhesive strength. The adhesive strength (T) of the material forming the sheet (53) may range from 0.1 g (gram) to 1 g (gram). If the adhesive strength of the material forming the sheet (53) is less than 0.1 g, the adhesive strength is weak, making it difficult to physically fix the light emitting diode (40) to the substrate (30). If the adhesive strength of the material forming the sheet (53) is greater than 1 g, the adhesive strength is too strong, making it difficult to repair the light emitting diode (40). For example, in order to repair the light emitting diode (40), the substrate (30) may be heated to deform the cured connection film (50) so that it has fluidity so that a defective light emitting diode mounted on the substrate (30) can be separated from the substrate (30).

[0073] According to one or more embodiments, the sheet (53) may be made of a material having both the optical properties (L) range (0.1 to 30) described above and the adhesive strength (T) range (0.1 g to 1 g) described above.

[0074] According to one or more embodiments, the thickness of the sheet (53) may be such that, when the light-emitting diode (40) transferred to the substrate (30) is thermally compressed, the first electrode pad (41) and the second electrode pad (42) of the light-emitting diode (40) can be electrically connected to the first substrate pad (31) and the second substrate pad (32) of the substrate (30), respectively. For example, the thickness of the sheet (53) may be about 35 μm or less.

[0075] According to one or more embodiments, the sheet (53) may be formed to surround the lower side surfaces of a plurality of light-emitting diodes (40). Since the sheet (53) has a black color, it can absorb light emitted from the light-emitting diodes (40) to minimize or improve crosstalk between adjacent light-emitting diodes (40). In this case, the sheet (53) may function as a black matrix.

[0076] Hereinafter, a manufacturing process of a connecting film (50) according to one or more embodiments is described. FIGS. 7 to 10 are drawings showing a manufacturing process of a connecting film according to one or more embodiments.

[0077] Referring to FIG. 7, a plurality of conductive adhesive members (51) can be printed on a support plate (21) by an imprint method. A plurality of conductive adhesive members (51) can be provided on an imprinting stamp (23) in a predetermined pattern (e.g., a grid pattern). The imprinting stamp (23) can print a plurality of conductive adhesive members (51) in a grid pattern on the upper surface (21a) of the support plate (21) while rotating in one direction. By using the imprint method, a connection film (50) including a plurality of conductive adhesive members (51) of a fine size can be manufactured on a large area.

[0078] A plurality of conductive adhesive members (51) can be formed in a grid pattern on the support plate (21) by a slit coating method in which pigment is coated on the support plate (21) using a slit nozzle in addition to the imprint method, an inkjet printing method, or a 3D printing method using a three-dimensional printer.

[0079] Referring to Fig. 8, a plurality of conductive adhesive members (51) can be patterned on a support plate (21) and then cured to have a predetermined hardness. Next, a sheet (53) having a black color is laminated to the upper surface (21a) of the support plate (21). In this case, when the sheet (53) is laminated to the upper surface (21a) of the support plate (21), the sheet (53) can have fluidity due to the heat provided to the sheet (53). The sheet (53) can cover the plurality of conductive adhesive members (51). A portion of the sheet (53) can flow between the plurality of cured conductive adhesive members (51).

[0080] Referring to FIG. 9, a plurality of conductive adhesive members (51) can be combined with a sheet (53) while maintaining a grid pattern on the sheet (53). When the plurality of conductive adhesive members (51) and the sheet (53) are cured, they can be formed as one body to form a connecting film (50).

[0081] Referring to Fig. 10, after the connection film (50) is separated from the support plate (21), a first protective film (71) and a second protective film (72) can be attached to both sides of the connection film (50) to protect the connection film (50). The connection film (50) can be stored and transported with the first protective film (71) and the second protective film (72) attached.

[0082] Hereinafter, an example of electrically and physically connecting a plurality of light-emitting diodes (40) to a substrate (30) using a connecting film (50) is described with reference to the drawings.

[0083] Fig. 11 is a plan view showing an example of attaching a connecting film to a substrate according to one or more embodiments. Fig. 12 is a cross-sectional view showing an example of attaching a connecting film to a substrate according to one or more embodiments.

[0084] Referring to FIGS. 11 and 12, a connecting film (50) may be laminated to a first surface (30a) of a substrate (30) in a direction in which a plurality of conductive adhesive members (51) face the first substrate pads (31) and the second substrate pads (32) of the substrate (30) before transferring a plurality of light-emitting diodes (40) to the substrate (30). In this case, a plurality of conductive adhesive members (51) may correspond to the first substrate pads (31) and the second substrate pads (32) of the substrate (30), as shown in FIG. 11. A plurality of conductive adhesive members (51) corresponding to the first substrate pads (31) and the second substrate pads (32) of the substrate (30) may contact the first substrate pads (31) and the second substrate pads (32) of the substrate (30), as shown in FIG. 12.

[0085] A plurality of conductive adhesive members (51) are arranged at a constant first interval (G1). Accordingly, a short circuit is not caused between the first substrate pad (31) and the second substrate pad (32) of the substrate (30) by the corresponding plurality of conductive adhesive members (51a).

[0086] Fig. 13 is a plan view illustrating an example of transferring a light-emitting diode onto a connecting film according to one or more embodiments. Fig. 14 is a cross-sectional view illustrating a light-emitting diode transferred onto a connecting film according to one or more embodiments.

[0087] Referring to Fig. 13, before transferring a plurality of light-emitting diodes (40) to a substrate (30), the first electrode pad (41) and the second electrode pad (42) of each light-emitting diode (40) are aligned with the first substrate pad (31) and the second substrate pad (32) of the corresponding substrate (30), respectively.

[0088] Once alignment is complete, the connecting film (50) transfers a plurality of light-emitting diodes (40) to the laminated substrate (30). In this case, as shown in Fig. 14, the first electrode pad (41) and the second electrode pad (42) of the light-emitting diode (40) mounted on the upper surface (50a) of the connecting film (50) can be positioned to correspond to the first substrate pad (31) and the second substrate pad (31) of the substrate (30), respectively. Here, the upper surface (50a) of the connecting film (50) is the same surface as the upper surface of the sheet (53).

[0089] Fig. 15 is a cross-sectional view showing a display panel according to one or more embodiments, showing an example of thermally compressing a light emitting diode toward a substrate. Fig. 16 is an enlarged view showing part B shown in Fig. 15.

[0090] Referring to Fig. 15, a plurality of light-emitting diodes (40) transferred to a substrate (30) can be thermally compressed toward the substrate (30) using a pressurizing device (90). In this case, the temperature of the heat emitted from the pressurizing device (90) can be 60 to 150 degrees, and the pressure can be 10 Mpa or less.

[0091] The pressurizing device (90) may have an area approximately corresponding to the substrate (30) and may have a heater including a heating coil built into the inside. The pressurizing device (90) may release high-temperature heat while pressing the light-emitting surface (45) of the light-emitting diode (40) at a predetermined pressure.

[0092] The sheet (53) of the connecting film (50) can have fluidity due to the heat emitted from the pressurizing device (90). Accordingly, the light emitting diode (40) can be inserted into the sheet (53) of the connecting film (50) having fluidity while being pressed toward the substrate (30) by the pressurizing device (90).

[0093] The first electrode pad (41) and the second electrode pad (42) of the light-emitting diode (40) can be in contact with a plurality of conductive adhesive members (51) of the corresponding connection film (50). In this case, the first electrode pad (41) and the second electrode pad (42) of the light-emitting diode (40) can be electrically connected to the first substrate pad (31) and the second substrate pad (32) of the corresponding substrate (30) through the plurality of conductive adhesive members (51) of the connection film (50).

[0094] Referring to Fig. 16, when the light-emitting diode (40) is thermally compressed toward the substrate (30) by the pressurizing device (90), the conductive adhesive member (51) of the connection film (50) is pressed by the first electrode pad (41) of the light-emitting diode (40) so that the entirety of the conductive adhesive member (51) or a portion (51b) of the conductive adhesive member (51) is pressed. In this case, the conductive materials (52b) dispersed inside the pressed conductive adhesive member (51) come into contact or clump together, so that the conductive adhesive member (51) can be made electrically conductive. In addition, other portions of the conductive adhesive member (51) that are not pressed by the first electrode pad (41) of the light-emitting diode (40) can generally maintain their shape.

[0095] When the connecting film (50) is cured after heat pressing, the sheet (53) of the fluid connecting film (50) shrinks, so that the light emitting diode (40) can be physically firmly fixed to the substrate (30).

[0096] FIG. 17 is a cross-sectional view showing a connecting film according to one or more embodiments.

[0097] Referring to FIG. 17, a connecting film (50') according to one or more embodiments may include a plurality of conductive adhesive members (51') and a sheet (53') on which a plurality of conductive adhesive members (51') are patterned. The conductive adhesive members (51') and the sheet (53') have the same characteristics as the conductive adhesive members (51) and the sheet (53) described above, and thus a detailed description thereof will be omitted.

[0098] The plurality of conductive adhesive members (51') illustrated in Fig. 17 may have a cross-section that is roughly arc-shaped, unlike the rectangular cross-section of the plurality of conductive adhesive members (51) illustrated in Fig. 3. In this case, the conductive adhesive members (51') may have a three-dimensional shape that is a dome shape.

[0099] FIG. 18 is a drawing showing an example of providing a touch screen to a display panel according to one or more embodiments.

[0100] Referring to FIG. 18, a display panel (10') according to one or more embodiments may further include a touch screen (80) disposed above a plurality of light emitting diodes (40). Accordingly, the display panel (10') may provide various functions, such as inputting various commands through a UI / UX displayed on the display panel (10') via the touch screen (80) or enlarging or reducing an image displayed on the display panel (10').

[0101] According to one or more embodiments, the touch screen (80) may include a protective film (81) mounted on a light-emitting surface (45) of a light-emitting diode (40), an optical film (83) disposed on the protective film (81), and a transparent electrode (ITO) (85) disposed between the protective film (81) and the optical film (83). The transparent electrode (85) may be a capacitive touch wiring.

[0102] Fig. 19 is a cross-sectional view illustrating a display panel according to one or more embodiments. Fig. 20 is a cross-sectional view of a connecting film according to one or more embodiments.

[0103] Referring to FIG. 19, the display panel (110) may include a substrate (130), a connection film (150) provided on the substrate (130), and a plurality of light-emitting diodes (140) electrically and physically connected to the substrate (130) by the connection film (150). The substrate (130) and the light-emitting diodes (140) have substantially the same configurations as the substrate (30) and the light-emitting diodes (40) described above, respectively. Therefore, a detailed description of the substrate (130) and the light-emitting diodes (140) is omitted.

[0104] According to one or more embodiments, a plurality of light emitting diodes (140) may be electrically and physically connected to a substrate (130) by a connecting film (150). A lower portion of the light emitting diode (140), including a first electrode pad (141) and a second electrode pad (142), may be inserted into an insulating resin (155) having a gray color of the connecting film (150). The first electrode pad (141) and the second electrode pad (142) of the light emitting diode (140) may be electrically connected to the first substrate pad (131) and the second substrate pad (132) of the corresponding substrate (130) by a plurality of conductive adhesive members (151) of the connecting film (150). The light emitting diode (140) may be physically firmly fixed to the substrate (130) by the sheet (153) of the connecting film (150).

[0105] According to one or more embodiments, the side surface (147) of the light emitting diode (140) may be surrounded by a reflective member (157) of a connecting film (150) partially inserted into an insulating resin (155). The reflective member (157) may reflect light emitted from the side surface (147) of the light emitting diode (140) toward the light emitting surface (145) of the light emitting diode (140), thereby improving the light emitting efficiency of the light emitting diode (140) and minimizing the amount of light emitted toward an adjacent light emitting diode (140), thereby improving crosstalk.

[0106] Referring to FIG. 20, a connecting film (150) according to one or more embodiments may include a plurality of conductive adhesive members (151), a sheet (153) having a black color, an insulating resin (155) having a gray color, and a reflective member (157) arranged along an edge of the insulating resin (155).

[0107] A plurality of conductive adhesive members (151) can be provided in a grid pattern on the sheet (153). Since the plurality of conductive adhesive members (151) have the same characteristics as the conductive adhesive member (51) described above, a description thereof is omitted.

[0108] According to one or more embodiments, the sheet (153) of the connecting film (150) may have the same characteristics as the sheet (53) of the connecting film (50) described above. The sheet (153) may have a plurality of openings (153a). The plurality of openings (153a) provided in the sheet (153) may be filled with an insulating resin (155). The insulating resin (155) may have a luminance characteristic of 1 < RGB < 100 to improve reflection efficiency. This luminance characteristic of 1 < RGB < 100 may be a brightness range that can be obtained when red has a range of 1 to 100, green has a range of 1 to 100, and blue has a range of 1 to 100 in RGB mode, and red, green, and blue are each selected as colors corresponding to one value from 1 to 100 and the three selected colors are mixed.

[0109] The reflective member (157) may be arranged along the edge of the insulating resin (155). The reflective member (157) may be arranged at a position that can prevent the reflective member (157) from being caught between the first substrate pad (131) and the second substrate pad (132) of the substrate (130) and the first electrode pad (141) and the second electrode pad (142) of the light-emitting diode (140) corresponding thereto when the light-emitting diode (140) is thermally compressed to the substrate (130). For example, if the reflective member (157) is caught between the first substrate pad (131) and the second substrate pad (132) of the substrate (130) and the first electrode pad (141) and the second electrode pad (142) of the light-emitting diode (140) corresponding thereto, electrical connection between the substrate pads of the substrate (130) and the electrode pads of the light-emitting diode (140) may not be smooth.

[0110] The reflective member (157) may be designed to surround the side surface (147) of the light-emitting diode (140). The reflective member (157) may include a plurality of glass balls. The size of the reflective member (157) may be smaller than the size of the conductive adhesive member (151). For example, the size of the glass balls may be about 10% or less of the size of the conductive adhesive member (151).

[0111] FIGS. 21 to 26 are drawings showing a manufacturing process of a connecting film according to one or more embodiments.

[0112] Referring to FIG. 21, a plurality of conductive adhesive members (151) can be printed on a support plate (121) by an imprint method. A plurality of conductive adhesive members (151) can be provided on an imprinting stamp (123) in a predetermined pattern (e.g., a grid pattern). The imprinting stamp (123) can print a plurality of conductive adhesive members (151) in a grid pattern on the upper surface (121a) of the support plate (121) while rotating in one direction. Using the imprint method, a connecting film (150) including a plurality of conductive adhesive members (151) of a fine size can be manufactured on a large area. In addition to the imprint method, the plurality of conductive adhesive members (151) can be formed in a grid pattern on the support plate (121) by a slit coating method, an inkjet printing method, or a 3D printing method.

[0113] A plurality of adhesive members (151) printed on the support plate (121) can be cured to have a predetermined path through a curing process.

[0114] Referring to FIG. 22, a reflective member (157) is ejected from a first dispenser (200) onto some of the adhesive members (151-1) among a plurality of adhesive members (151). For example, the movement path of the first dispenser (200) may be a trajectory corresponding to the outer edge of the light-emitting diode (140), as shown in FIG. 23. The first dispenser (200) may move along the trajectory and eject the reflective member (157) into the space between the upper surface of the adhesive members (151-1) corresponding to the trajectory and the adhesive members (151-1) corresponding to the trajectory. In this case, the reflective member (157) may form an approximately rectangular band shape roughly corresponding to the outer shape of the light-emitting diode (140). The reflective member (157) may be ejected from the first dispenser (200) in a state mixed with a pigment having viscosity. Accordingly, the reflective member (157) discharged from the first dispenser (200) may be formed in a dam shape that maintains a predetermined height. Here, the pigment mixed with the reflective member (157) may be a transparent resin or a resin identical to the insulating resin (155).

[0115] Referring to Fig. 24, an insulating resin (155) can be discharged toward the support plate (121) through a second dispenser (300) into the inner space of the reflective member (157) and the square-shaped reflective member (157). The insulating resin (155) can be a resin having a gray series color with a luminance characteristic of 1 < RGB < 100 to improve the reflection efficiency of light emitted from the light emitting diode (140).

[0116] Insulating resin (155) can be discharged in a grid pattern at a constant pitch on the support plate (121). The pitch of a plurality of insulating resins (155) can correspond to the pitch of a plurality of light-emitting diodes (140) transferred in a grid arrangement to the substrate (130).

[0117] After discharging a plurality of insulating resins (155) onto the support plate (121), a curing process can be performed to harden the plurality of insulating resins (155).

[0118] Referring to Fig. 25, the sheet (153) may be provided with a plurality of openings (153a) corresponding to a plurality of insulating resins (155). After aligning the plurality of openings (153a) of the sheet (153) with the plurality of insulating resins (155) on the support plate (121), the sheet (153) may be attached to the support plate (121). A plurality of insulating resins (155) having a gray color may be inserted into a plurality of openings (153a) of the sheet (153) having a black color, thereby forming an integral part with the sheet (153). In this case, the shape of the plurality of openings (153a) may be substantially the same as the shape of the plurality of insulating resins (155).

[0119] Referring to Fig. 27, after the connection film (150) is separated from the support plate (121), a third protective film (171) and a fourth protective film (172) for protecting the connection film (50) can be attached to both sides of the connection film (150). The connection film (150) can be stored and transported with the third protective film (171) and the fourth protective film (172) attached.

[0120] Hereinafter, an example of electrically and physically connecting a plurality of light-emitting diodes (140) to a substrate (130) using a connecting film (50) is described with reference to the drawings.

[0121] FIG. 28 is a cross-sectional view showing a light emitting diode transferred onto a connecting film according to one or more embodiments.

[0122] Referring to Fig. 28, before transferring a plurality of light-emitting diodes (140) to a substrate (130), the first electrode pad (141) and the second electrode pad (142) of each light-emitting diode (140) are aligned with the first substrate pad (131) and the second substrate pad (132) of the substrate (130), respectively. The plurality of light-emitting diodes (140) may be aligned so that they are positioned on the inside of a reflective member (157) that forms a rectangular band shape when viewed on a corresponding plane.

[0123] Once alignment is complete, the connecting film (150) transfers a plurality of light-emitting diodes (140) to the laminated substrate (130). In this case, the first electrode pad (141) and the second electrode pad (142) of the light-emitting diode (140) mounted on the upper surface (150a) of the connecting film (150) can be positioned to correspond to the first substrate pad (131) and the second substrate pad (131) of the substrate (130), respectively. Here, the upper surface (150a) of the connecting film (150) is the same surface as the upper surface of the insulating resin (155).

[0124] FIG. 29 is a cross-sectional view illustrating a display panel according to one or more embodiments.

[0125] Referring to Fig. 29, a plurality of light-emitting diodes (140) transferred to a substrate (130) can be thermally compressed toward the substrate (130) using a pressurizing device (190). In this case, the temperature of the heat emitted from the pressurizing device (190) can be 60 to 150 degrees, and the pressure can be 10 Mpa or less.

[0126] The insulating resin (155) of the connection film (150) may have fluidity due to the heat emitted from the pressurizing device (190). Accordingly, the light emitting diode (140) may be inserted into the insulating resin (155) of the connection film (150) that has fluidity while being pressed toward the substrate (130) by the pressurizing device (190).

[0127] The first electrode pad (141) and the second electrode pad (142) of the light-emitting diode (140) can be in contact with a plurality of conductive adhesive members (151) of the corresponding connection film (150). In this case, the first electrode pad (141) and the second electrode pad (142) of the light-emitting diode (140) can be electrically connected to the first substrate pad (131) and the second substrate pad (132) of the corresponding substrate (130) through the plurality of conductive adhesive members (151) of the connection film (150).

[0128] In this case, the side surface (147) of the light-emitting diode (140) may be surrounded by or in contact with the reflective member (157) of the connecting film (150). Accordingly, light emitted from the side surface (147) of the light-emitting diode (140) may be reflected by the reflective member (157) of the connecting film (150) and emitted through the light-emitting surface (145) of the light-emitting diode (140).

[0129] Additionally, the lower part of the light-emitting diode (140) can be inserted into an insulating resin (155) having a gray color of the connecting film (150). The insulating resin (155) can improve light reflectance compared to a sheet (153) having a black color.

[0130] FIG. 30 is a block diagram illustrating a display device according to one or more embodiments.

[0131] Referring to FIG. 30, a display device (1) may include a display module (3) and a processor (5). The display module (3) may include a display panel (10) and a display driver integrated circuit (IC) (7) for controlling the display panel (10).

[0132] The processor (5) may be implemented as a digital signal processor (DSP), a microprocessor, a graphics processing unit (GPU), an artificial intelligence (AI) processor, a neural processing unit (NPU), or a time controller (TCON) that processes a digital image signal. However, the present invention is not limited thereto, and may include one or more of a central processing unit (CPU), a micro controller unit (MCU), a micro processing unit (MPU), a controller, an application processor (AP), a communication processor (CP), or an ARM processor, or may be defined by the relevant terminology. In addition, the processor (5) may be implemented as a system on chip (SoC) or large scale integration (LSI) having a built-in processing algorithm, or may be implemented in the form of an application specific integrated circuit (ASIC), or a field programmable gate array (FPGA).

[0133] The processor (5) can control hardware or software components connected to the processor (5) by running an operating system or application program, and can perform various data processing and calculations. In addition, the processor (5) can load commands or data received from at least one of the other components into volatile memory and process them, and store various data in non-volatile memory.

[0134] The display driver IC (7) may include an interface module (7a), a memory (7b) (e.g., a buffer memory), an image processing module (7c), or a mapping module (7d). The display driver IC (7) may receive, for example, image information including image data or an image control signal corresponding to a command for controlling the image data, from another component of the display device (1) through the interface module (7a). For example, according to one embodiment, the image information may be received from a processor (5) (e.g., a main processor (e.g., an application processor) or an auxiliary processor (e.g., a graphics processing unit) that operates independently of the function of the main processor).

[0135] The display driver IC (7) can communicate with the sensor module through the interface module (7a). In addition, the display driver IC (7) can store at least a part of the received image information in the memory (7b), for example, on a frame basis. The image processing module (7c) can, for example, perform preprocessing or postprocessing (e.g., resolution, brightness, or size adjustment) on at least a part of the image data based on at least the characteristics of the image data or the characteristics of the display panel (10). The mapping module (7d) can generate a voltage value or a current value corresponding to the image data preprocessed or postprocessed through the image processing module (7c). According to one embodiment, the generation of the voltage value or the current value can be performed based at least in part on, for example, the properties of the pixels of the display panel (10) (e.g., the arrangement of the pixels (RGB stripe or pentile structure), or the size of each subpixel). At least some pixels of the display panel (10) may be driven based at least in part on, for example, the voltage value or current value, so that visual information (e.g., text, image, or icon) corresponding to the image data may be displayed through the display panel (10).

[0136] The display driver IC (7) can transmit a driving signal (e.g., a driver driving signal, a gate driving signal, etc.) to the display based on image information received from the processor (5).

[0137] The display driver IC (7) can display an image based on an image signal received from the processor (5). For example, the display driver IC (7) can display an image by generating a driving signal for a plurality of sub-pixels based on the image signal received from the processor (5) and controlling the light emission of the plurality of sub-pixels based on the driving signal.

[0138] According to one or more embodiments, the display module (3) may further include a touch circuit. The touch circuit may include a touch sensor and a touch sensor IC for controlling the same. The touch sensor IC may control the touch sensor to detect, for example, a touch input or a hovering input for a designated location of the display panel (10). For example, the touch sensor IC may detect a touch input or a hovering input by measuring a change in a signal (e.g., voltage, light quantity, resistance, or charge quantity) for a designated location of the display panel (10). The touch sensor IC may provide information (e.g., location, area, pressure, or time) about the detected touch input or hovering input to the processor (5). According to one embodiment, at least a portion of the touch circuit (e.g., the touch sensor IC) may be included as a part of the display driver IC (7), the display panel (10), or another component (e.g., a coprocessor) disposed externally to the display module (3).

[0139] According to one or more embodiments, the pixel driving method of the display module (3) may be an AM (active matrix) driving method or a PM (passive matrix) driving method.

[0140] According to one or more embodiments, the display device (1) may include a display module (3). The display module (3) may display various images. Here, the images may include still images and / or moving images. The display module (3) may display various images, such as broadcast content, multimedia content, etc. In addition, the display module (3) may also display a user interface and icons.

[0141] According to one or more embodiments, the display module (3) can be installed and applied in a wearable device, a portable device, a handheld device, and various electronic products or battlefields requiring a display.

[0142] According to one or more embodiments, the display device (1) may include a plurality of display modules (3). The plurality of display modules (3) may be physically connected to implement a large display (e.g., a large format display). The large display may be a monitor for a personal computer, a high-resolution television, a signage (or digital signage), or an electronic display by connecting a plurality of display modules in a grid arrangement.

[0143] While the present disclosure has been illustrated and described above with reference to various examples, it will be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.

Claims

1. In a connecting film connecting a substrate and a plurality of light-emitting diodes, A sheet having a black color series; and A connecting film comprising a plurality of conductive adhesive members provided at intervals on the above sheet.

2. In paragraph 1, A connecting film wherein the above-mentioned plurality of challenging adhesive members are provided on the sheet in a grid pattern.

3. In paragraph 1 or 2, The area of ​​each of the above-mentioned plurality of challenging adhesive members is: A connecting film having a smaller area than the substrate pad provided on the substrate and a smaller area than the electrode pad provided on the light-emitting diode.

4. In paragraph 3, The area of ​​each of the above-mentioned plurality of challenging adhesive members is: A connecting film having an area of ​​30% to 80% of the smallest area among the area of ​​the substrate pad and the area of ​​the electrode pad.

5. In paragraph 3, Each of the above multiple challenging adhesive members, The curing temperature is less than 200 degrees, An interconnecting film having a resistance value in the range of 0.1 ohm to 20 ohm after curing.

6. In paragraph 3, Each of the above multiple challenging adhesive members, Epoxy resin; and Containing conductive materials dispersed in the above epoxy resin; The above-mentioned challenging materials are gold (Au), silver (Ag), carbon (C), copper (Cu), nickel (Ni), aluminum (Al), indium (In), or tin (Sn), and the connecting film.

7. In paragraph 3, The above sheet is a connecting film having optical properties in the range of 0.1 to 30.

8. In paragraph 1 or 2, The above sheet further comprises a plurality of openings, Insulating resin having a gray color arranged in the above-mentioned plurality of openings; and A connecting film further comprising a reflective member arranged along an edge of the insulating resin and having a size smaller than that of the conductive adhesive member.

9. In paragraph 8, A contact film wherein the above reflective member comprises a plurality of glass balls.

10. In paragraph 8, The above insulating resin is a connecting film having a brightness characteristic of 1 < RGB < 100.

11. In the display panel, substrate; a connecting film attached to the above substrate; and A light emitting diode connected to the substrate by the above connecting film; The above connecting film, A sheet having a black color series; and Conductive adhesive members provided at intervals on the above sheet and electrically connecting a plurality of substrate pads of the substrate and a plurality of electrode pads of the light-emitting diode to each other; A display panel wherein the spacing range of adjacent conductive adhesive members is 1% to 30% of the minimum spacing between adjacent substrate pads and the spacing between adjacent electrode pads.

12. In paragraph 11, The above-mentioned plurality of challenging adhesive members are provided on the sheet in a grid pattern, The area of ​​each of the above-mentioned plurality of challenging adhesive members is: A display panel, wherein the area of ​​the substrate pad is 30% to 80% of the smallest area among the areas of the electrode pads.

13. In paragraph 11, Each of the above multiple challenging adhesive members, Epoxy resin; and A display panel comprising conductive materials included in the above epoxy resin.

14. In paragraph 11, The above sheet further comprises a plurality of openings, Insulating resin having a gray color arranged in the above-mentioned plurality of openings; and A display panel further comprising a reflective member including a plurality of glass balls surrounding side surfaces of the light emitting diode.

15. In paragraph 14, The above insulating resin is a display panel having a luminance characteristic of 1 < RGB < 100.

Images