Display device

Abstract

A display device having a display panel including a first land portion is provided. A flexible printed circuit board is configured to be attached to the display panel. The flexible printed circuit board includes a second land portion configured to be electrically connected to the first land portion. The first land portion includes a plurality of first signal lands, a first test land, and a first alignment land having a first shape. The second land portion includes a second alignment land having a second shape. The second alignment land includes a first portion and a second portion spaced apart from each other. The first shape and the second shape are configured to form a predetermined alignment mark when the flexible printed circuit board is attached to the display panel at a predetermined position.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to Korean Patent Application No. 10-2020-0084341, filed on July 8, 2020, with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] One or more exemplary implementations relate to display devices. Background Technology

[0004] A display device is an electronic device that displays images. A display device includes a display panel that generates images and a driver integrated circuit that drives the display panel. The display panel may include a display area and a peripheral area located outside the display area. Scan lines and data lines are formed in the display area and are insulated from each other. Multiple pixel circuits are connected to the scan lines and data lines. Light is emitted from a pixel corresponding to each pixel circuit, and an image is generated by this light.

[0005] The peripheral area is the region from which light is not emitted and where no image is displayed. Driver integrated circuits and the like can be located in the peripheral area. Furthermore, circuit boards connected to application processors and the like can be located in the peripheral area. The pad portion can be located in the peripheral area of ​​the display panel and can be used to connect the circuit board to the display panel. The pad portion can be exposed to the outside for connecting the circuit board. When the circuit board is attached to the pad portion, it must be attached in the correct position, and an attachment defect test can be performed to confirm that the circuit board is correctly connected to the pad portion. Summary of the Invention

[0006] One or more exemplary embodiments include a display device in which a circuit board is correctly connected to a display panel at a predetermined location. Furthermore, since the pad areas where the circuit board and the display panel are attached to each other can be dead zones in the display device, one or more exemplary embodiments provide a display device that can reduce the area of ​​the pad areas. However, these aspects are exemplary, and the scope of the inventive concept is not limited thereto.

[0007] Other aspects will be set forth in part in the description which follows, and in part will be apparent from the description, or may be learned by practice of exemplary embodiments of the inventive concept presented.

[0008] One or more exemplary embodiments include a display device having a display panel including a first pad portion. A flexible printed circuit board is configured to be attached to the display panel. The flexible printed circuit board includes a second pad portion configured to be electrically connected to the first pad portion. The first pad portion includes a plurality of first signal pads, a first test pad, and a first alignment pad having a first shape. The second pad portion includes a second alignment pad having a second shape. The second alignment pad includes a first portion and a second portion spaced apart from each other. The first shape and the second shape are configured to form predetermined alignment marks when the flexible printed circuit board is attached to the display panel at a predetermined location.

[0009] Each of the first and second portions of the second alignment pad may overlap with a portion of the first alignment pad.

[0010] The second pad portion may further include a plurality of second signal pads corresponding to a plurality of first signal pads, and a second test pad arranged spaced apart from the second alignment pad and corresponding to the first test pad.

[0011] The second test pad can be arranged on a plane between the second alignment pad and multiple second signal pads.

[0012] The second test pad and the first and second portions of the second alignment pad can have shapes that are isolated from each other.

[0013] The second test pad and the first and second portions of the second alignment pad may be spaced apart from each other, and a portion of the first alignment pad may be positioned on a plane between the first portions of the second test pad and the second alignment pad, and between the first and second portions of the second alignment pad. Each of the second test pad and the second alignment pad may include a test terminal.

[0014] The second test pad may include two or more test terminals, and each of the first and second portions of the second aligned pad may include a test terminal.

[0015] When current is applied to one of the test terminals of the second test pad and the second alignment pad, and the other of the test terminals of the second test pad and the second alignment pad is grounded, the first alignment pad and the second alignment pad can form a path for current flow.

[0016] The first alignment pad can be electrically connected to the first test pad.

[0017] The first alignment pad may include a main body portion extending from the first test pad in a first direction and a branch portion protruding from the main body portion in a second direction intersecting the first direction.

[0018] The first portion of the second alignment pad may include a protrusion that is positioned on a plane on the opposite side of the branch portion of the first alignment pad relative to the main body portion.

[0019] Multiple first signal pads and multiple second signal pads may be arranged in a first direction, a first portion of a second alignment pad may include a portion extending in the first direction, and a second portion of the second alignment pad may be spaced apart from the first portion in a second direction intersecting the first direction.

[0020] Multiple first signal pads and multiple second signal pads may be arranged in a first direction, a first portion of a second alignment pad may include a portion extending in a second direction intersecting the first direction, and a second portion of the second alignment pad may be spaced apart from the first portion in the first direction.

[0021] Multiple first signal pads and multiple second signal pads may be arranged in a first direction, one of the multiple first signal pads and one of the multiple second signal pads may extend in a second direction intersecting the first direction, and another of the multiple first signal pads and another of the multiple second signal pads may extend upward in a third direction different from the first direction and the second direction.

[0022] The length of multiple first signal pads can be greater than the length of multiple second signal pads.

[0023] The display device may also include a conductive adhesive component between the first pad portion and the second pad portion.

[0024] The display device may also include multiple pixel circuits, each of which includes a thin-film transistor and a storage capacitor. Multiple first signal pads are electrically connected to the multiple pixel circuits, and a first test pad is electrically open-circuited with the multiple pixel circuits.

[0025] Other aspects, features, and advantages beyond those described above will become apparent from the details, claims, and drawings used to implement the following exemplary embodiments.

[0026] These general and specific exemplary implementations can be implemented using systems, methods, computer programs, or any combination thereof. Attached Figure Description

[0027] The above and other aspects, features, and advantages of exemplary embodiments of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings, wherein:

[0028] Figure 1 This is a plan view illustrating an exemplary embodiment of a display device according to a concept of the present invention;

[0029] Figure 2 This is an equivalent circuit diagram of a pixel circuit included in a display device according to an exemplary embodiment of the present invention.

[0030] Figure 3 It is along Figure 1 The cross-sectional view taken along line III-III' shows a portion of a display device according to an exemplary embodiment of the concept of the present invention;

[0031] Figure 4 This is a plan view illustrating an exemplary embodiment of a display device according to a concept of the present invention;

[0032] Figure 5 It is along Figure 4 A cross-sectional view taken along line V-V' shows a portion of a display device according to an exemplary embodiment of the concept of the present invention;

[0033] Figures 6A to 6C This is a plan view showing a first pad portion of a display panel and a second pad portion of a flexible printed circuit board according to an exemplary embodiment of the concept of the present invention;

[0034] Figure 7A This is a perspective view showing a portion of a first pad portion of a display panel and a portion of a second pad portion of a flexible printed circuit board according to an exemplary embodiment of the concept of the present invention; and

[0035] Figure 7B This is an illustrative representation of an exemplary embodiment based on the concept of the present invention. Figure 7A An exploded perspective view of the first pad portion and a portion of the second pad portion. Detailed Implementation

[0036] Reference will now be made in detail to embodiments, examples of which are illustrated in the accompanying drawings, wherein the same reference numerals always denote the same elements. In this respect, the exemplary embodiments may take different forms and should not be construed as limited to the description set forth herein. Therefore, exemplary embodiments are described below only by reference to the accompanying drawings to illustrate aspects of this specification. As used herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. Throughout the disclosure, the expression “at least one of a, b, or c” means only a, only b, only c, both a and b, both a and c, both b and c, all of a, b, and c, or variations thereof.

[0037] Because this disclosure allows for various modifications and multiple implementations, specific exemplary embodiments will be illustrated in the accompanying drawings and described in detail in the written description. Hereinafter, the effects and features of the inventive concept, as well as methods for implementing the effects and features of the inventive concept, will be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the inventive concept are illustrated. However, this disclosure may be implemented in many different forms and should not be construed as limited to the exemplary embodiments set forth herein.

[0038] One or more exemplary embodiments of the inventive concept will now be described in more detail with reference to the accompanying drawings. Regardless of the drawing numbers, those parts that are the same or corresponding to each other are presented with the same reference numerals, and redundant descriptions are omitted.

[0039] It should be understood that although this document may use terms such as "first," "second," etc., to describe various components, these components should not be limited by these terms. These terms are only used to distinguish one component from another.

[0040] Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, as used herein.

[0041] It should also be understood that the terms “comprising” and / or “including” as used herein specify the presence of the described features or elements, but do not exclude the presence or addition of one or more other features or elements.

[0042] It should be understood that when a layer, region, or element is said to be formed on or disposed on another layer, region, or element, it may be formed directly or indirectly on or disposed on another layer, region, or element. For example, there may be an intermediate layer, region, or element. However, when a layer, region, or element is said to be directly formed on or disposed on another layer, region, or element, there may be no intermediate layer, region, or element.

[0043] For ease of illustration, the dimensions of the components in the accompanying drawings may be enlarged. In other words, since the dimensions and thicknesses of the components in the accompanying drawings are arbitrarily shown for ease of illustration, the following exemplary embodiments are not limited thereto.

[0044] When an exemplary implementation can be implemented differently, a particular process sequence can be performed differently from the described sequence. For example, two consecutively described processes can be performed substantially simultaneously, or in the reverse order of the described sequence.

[0045] In this disclosure, "A and / or B" may include "A", "B" or "A and B". Furthermore, in this disclosure, "at least one of A and B" may include "A", "B" or "A and B".

[0046] In the exemplary embodiments described below, when layers, regions, or elements are referred to as “connections,” it should be understood that they may be directly connected, or there may be intermediate portions between layers, regions, or elements. For example, when layers, regions, or elements are referred to as “electrical connections,” they may be directly electrically connected, or layers, regions, or elements may be indirectly electrically connected thereto, and there may be intermediate portions.

[0047] The x-axis, y-axis, and z-axis are not limited to the three axes of a Cartesian coordinate system and can be interpreted in a broader sense. For example, the x-axis, y-axis, and z-axis can be perpendicular to each other, or they can represent different directions that can intersect each other at various angles and are not perpendicular to each other.

[0048] Figure 1 This is a schematic plan view of a display device 1 according to an exemplary embodiment of the concept of the present invention.

[0049] Reference Figure 1 In an exemplary embodiment, the display device 1 may include a display panel 10, which includes a driver integrated circuit 20 and a first pad portion 30.

[0050] The display panel 10 may include a display area DA and a peripheral area PA disposed outside the display area DA. The display panel 10 may provide an image by means of an array of multiple pixels PX arranged in the display area DA. Each pixel PX may include a light-emitting element that emits light of a certain color (e.g., red, green, or blue light), and the display panel 10 may provide an image by using the light emitted by the light-emitting element.

[0051] like Figure 1As shown in the exemplary embodiments, the display area DA may have a rectangular shape defined in a plane along the x-axis (hereinafter referred to as the "X direction") and the y-axis (hereinafter referred to as the "Y direction"). The thickness direction of the display device 1 may extend along the z-axis (hereinafter referred to as the "Z direction") perpendicular to the X and Y directions. The display area DA has a relatively long side extending in the Y direction and a relatively short side extending in the X direction. However, the exemplary embodiments of the inventive concept are not limited thereto. For example, in another exemplary embodiment, the display area DA may have a rectangular shape having a relatively long side extending in the X direction and a relatively short side extending in the Y direction. However, in other exemplary embodiments, the display area DA may be another polygon, such as a square shape, or an elliptical shape, or a circular shape, or an irregular shape, etc.

[0052] The peripheral region PA is the area that does not generate an image and can be a non-display area. The peripheral region PA can completely or partially surround the display area DA. For example, as Figure 1 As shown in the exemplary embodiment, the peripheral region PA may surround all four sides of the display region DA. However, in another exemplary embodiment, the display region DA may extend to at least one edge of the display panel 10, and the peripheral region PA may not surround one or more sides of the display region DA. The driver integrated circuit 20 may be disposed in the peripheral region PA. For example, in Figure 1 In the exemplary embodiment shown, the driver integrated circuit 20 may be disposed on the lower portion of the peripheral region PA (e.g., in the Y direction). However, the exemplary embodiments of the present invention are not limited thereto, and in other exemplary embodiments, the driver integrated circuit may be disposed in other portions of the peripheral region PA. In the exemplary embodiments, the driver integrated circuit 20 may be mounted using a chip-on-glass (COG) method, a chip-on-film (COF) method, or a chip-on-plastic (COP) method. However, the exemplary embodiments of the present invention are not limited thereto. The driver integrated circuit 20 generates an electrical signal in response to driving power and signals received from the outside, and provides the generated electrical signal to the pixel circuit PC as described below (in Figure 2 Each of the following (in Chinese).

[0053] Furthermore, the first pad portion 30 can be located within the peripheral region PA. For example, as... Figure 1As shown in the exemplary embodiment, the first pad portion 30 may be disposed on the lower portion (e.g., in the Y direction) of the peripheral region PA and may be spaced apart (e.g., in the Y direction) from the driver integrated circuit 20. The first pad portion 30 is an area such as a printed circuit board (PCB) to which it can be electrically connected. The first pad portion 30 may include a plurality of first signal pads 31, first test pads 32, and first alignment pads 33. Figure 1 As shown in the exemplary embodiment, the display panel 10 may have two first signal pads 31. However, in other exemplary embodiments, the number of multiple first signal pads 31 may vary.

[0054] Multiple first signal pads 31 can be electrically connected to the driver integrated circuit 20 via wires, conductive layers, etc., and electrical signals from the PCB can be transmitted to the driver integrated circuit 20 via the multiple first signal pads 31. A first test pad 32 can be used to verify that the display panel 10 and the PCB are correctly connected to each other. For example, unlike the multiple first signal pads 31, the first test pad 32 can be insulated from the first signal pads 31 and can be not electrically connected to the driver integrated circuit 20. For example, there can be an electrical open circuit between the first test pad 32 and the driver integrated circuit 20, and therefore, the first test pad 32 can be electrically open to the pixel circuit PC. A first alignment pad 33 can be used to align the PCB with the display panel 10, such that the PCB can be attached to the display panel 10 at a predetermined location that provides an increased level of adhesion and sufficient electrical connection between the PCB and the display panel 10. Figure 1 As shown in the exemplary embodiment, the first alignment pad 33, the first test pad 32, and the first signal pad 31 can be arranged in the X direction. However, the exemplary embodiment of the present invention is not limited thereto, and the first alignment pad 33, the first test pad 32, and the first signal pad 31 can be arranged differently in the peripheral region PA.

[0055] Figure 2 This is an equivalent circuit diagram of a pixel circuit included in a display device according to an exemplary embodiment of the present invention.

[0056] Reference Figure 2 In an exemplary implementation, display device 1 is in ( Figure 1The light-emitting element (LED) may include a light-emitting element and a pixel circuit PC. The light-emitting element may include a light-emitting diode, such as an organic light-emitting diode (OLED). However, exemplary embodiments of the present invention are not limited thereto, and the light-emitting element may be various other light-emitting elements. An OLED may be electrically connected to the pixel circuit PC and may receive a driving voltage and emit light through the pixel circuit PC. The light-emitting element emits light through a light-emitting region, and the light-emitting region may be defined as a pixel PX (in...). Figure 1 middle).

[0057] The pixel circuit PC may include multiple thin-film transistors and a storage capacitor. In an exemplary embodiment, the pixel circuit PC may include a first thin-film transistor T1, a second thin-film transistor T2, and a storage capacitor Cap.

[0058] The second thin-film transistor T2 can be a switching thin-film transistor. The second thin-film transistor T2 can be connected to the scan line SL and the data line DL. The second thin-film transistor T2 can transmit the data voltage (e.g., the data signal) input from the data line DL to the first thin-film transistor T1 based on the switching voltage (e.g., the switching signal) input from the scan line SL.

[0059] A storage capacitor Cap is connected to a second thin-film transistor T2 and a drive voltage line PL. The storage capacitor Cap can store a voltage corresponding to the difference between the voltage received from the second thin-film transistor T2 and a first power supply voltage ELVDD applied to the drive voltage line PL. The storage capacitor Cap may include at least a first storage plate Cap1 and a second storage plate Cap2. However, exemplary embodiments of the present invention are not limited thereto.

[0060] The first thin-film transistor T1 can be a driving thin-film transistor. The first thin-film transistor T1 can be connected to a driving voltage line PL and a storage capacitor Cap. The first thin-film transistor T1 can control the driving current flowing from the driving voltage line PL to the organic light-emitting diode (OLED) in response to the voltage value stored in the storage capacitor Cap. The OLED can emit light with a certain brightness according to the driving current. The opposite electrode (e.g., the cathode) of the OLED can receive a second power supply voltage ELVSS.

[0061] exist Figure 2In an exemplary embodiment, the pixel circuit PC includes two thin-film transistors and one storage capacitor. However, the exemplary embodiments of the present invention are not limited thereto. For example, in other exemplary embodiments, the pixel circuit PC may include three or more thin-film transistors and / or two or more storage capacitors. For example, in an exemplary embodiment, the pixel circuit PC may include seven thin-film transistors and one storage capacitor. The number of thin-film transistors and storage capacitors can vary depending on the design of the pixel circuit PC. However, for ease of description, an embodiment in which the pixel circuit PC includes two thin-film transistors and one storage capacitor will be described below.

[0062] Figure 3 This is an illustrative representation of an exemplary embodiment based on the concept of the present invention. Figure 1 A cross-sectional view of a portion of the display device. Figure 3 It can correspond to the edge of the display device Figure 1 The sectional view taken from line III-III' in the figure.

[0063] refer to Figure 3 In an exemplary embodiment, substrate 100 may have a multilayer structure including a base layer and an inorganic layer. The base layer may include a polymer resin. For example, substrate 100 may include a base layer and a barrier layer. The base layer may include a polymer resin, and the barrier layer may include an inorganic insulating layer. For example, substrate 100 may include a first base layer 101, a first barrier layer 102, a second base layer 103, and a second barrier layer 104 sequentially stacked (e.g., in the Z direction). In an exemplary embodiment, the first base layer 101 and the second base layer 103 may include at least one compound selected from polyethersulfone, polyacrylate, polyetherimide, polyethylene naphthalate, polyethylene terephthalate, polyphenylene sulfide, polyarylate, polyimide, polycarbonate, cellulose acetate propionate, etc. The first barrier layer 102 and the second barrier layer 104 may include an inorganic insulating material, such as at least one compound selected from silicon oxide, silicon oxynitride, and silicon nitride. However, exemplary embodiments of the present invention are not limited thereto.

[0064] The buffer layer 111 can be disposed on the substrate 100. For example, as Figure 3 As shown in the exemplary embodiment, the lower surface of the buffer layer 111 can directly contact the upper surface of the second barrier layer 104. However, the exemplary embodiments of the present invention are not limited thereto. The buffer layer 111 can reduce or block foreign materials, moisture, or ambient air penetrating the lower portion of the substrate 100, and can provide a flat surface on the substrate 100. In the exemplary embodiment, the buffer layer 111 may include an inorganic insulating material, such as at least one compound selected from silicon oxide, silicon oxynitride, and silicon nitride, and may have a single-layer structure or a multi-layer structure including the above materials.

[0065] The pixel circuit PC can be disposed on the buffer layer 111. For example, as... Figure 3 As shown in the exemplary embodiment, the pixel circuit PC can be directly disposed on the buffer layer 111. The pixel circuit PC may include a thin-film transistor (TFT) and a storage capacitor (Cap).

[0066] A thin-film transistor (TFT) may include a semiconductor layer Act, a gate electrode GE overlapping a channel region of the semiconductor layer Act (e.g., in the Z direction), and a source electrode SE and a drain electrode DE respectively connected to a source region and a drain region of the semiconductor layer Act. A first gate insulating layer 112 may be disposed between the semiconductor layer Act and the gate electrode GE (e.g., in the Z direction). A second gate insulating layer 113 and an interlayer insulating layer 114 may be disposed between the gate electrode GE and the source electrode SE and / or between the gate electrode GE and the drain electrode DE (e.g., in the Z direction).

[0067] The storage capacitor Cap can be configured to overlap with the thin-film transistor TFT. For example... Figure 3 As shown in the exemplary embodiments, the storage capacitor Cap may include a first capacitor plate CE1 and a second capacitor plate CE2 that overlap each other (e.g., in the Z direction). In some exemplary embodiments, the gate electrode GE of the thin-film transistor TFT may include the first capacitor plate CE1 of the storage capacitor Cap. A second gate insulating layer 113 may be disposed between the first capacitor plate CE1 and the second capacitor plate CE2.

[0068] In exemplary embodiments, the semiconductor layer Act may include polycrystalline silicon. For example, in some exemplary embodiments, the semiconductor layer Act may include amorphous silicon. In some exemplary embodiments, the semiconductor layer Act may include an oxide of at least one material selected from the group consisting of indium (In), gallium (Ga), tin (Sn), zirconium (Zr), vanadium (V), hafnium (Hf), cadmium (Cd), germanium (Ge), chromium (Cr), titanium (Ti), and zinc (Zn). The semiconductor layer Act may include a channel region, and source and drain regions doped with impurities.

[0069] The first gate insulating layer 112 may include an inorganic insulating material, such as at least one compound selected from silicon oxide, silicon oxynitride, and silicon nitride, and may have a single-layer structure or a multi-layer structure including the above materials.

[0070] The gate electrode GE or the first capacitor plate CE1 may include a low-resistance conductive material, such as at least one compound selected from molybdenum (Mo), aluminum (Al), copper (Cu) and / or titanium (Ti), and may be a single layer or multiple layers of the above materials.

[0071] The second gate insulating layer 113 may include an inorganic insulating material, such as at least one compound selected from silicon oxide, silicon oxynitride, and silicon nitride, and may have a single-layer structure or a multi-layer structure including the above materials.

[0072] The second capacitor plate CE2 may include at least one compound selected from Al, platinum (Pt), palladium (Pd), silver (Ag), magnesium (Mg), gold (Au), nickel (Ni), neodymium (Nd), iridium (Ir), chromium (Cr), calcium (Ca), Mo, Ti, tungsten (W), and Cu, and may have a single-layer structure or a multi-layer structure including the above materials.

[0073] The interlayer insulation layer 114 may include an inorganic insulating material, such as at least one compound selected from silicon oxide, silicon oxynitride and silicon nitride, and may have a single-layer structure or a multi-layer structure including the above materials.

[0074] The source electrode SE or drain electrode DE may include at least one compound selected from Al, Pt, Pd, Ag, Mg, Au, Ni, Nd, Ir, Cr, Ca, Mo, Ti, W, and Cu, and may include a single-layer structure or a multi-layer structure containing the above materials. For example, the source electrode SE or drain electrode DE may have a three-layer structure of Ti layer / Al layer / Ti layer.

[0075] The pixel circuit PC, including the aforementioned thin-film transistor (TFT) and storage capacitor (Cap), can be electrically connected to the pixel electrode 210.

[0076] The planarization layer 115 can be disposed above the first gate insulating layer 112, the second gate insulating layer 113, and the interlayer insulating layer 114. For example, as Figure 3 As shown in the exemplary embodiment, the lower surface of the planarization layer 115 can directly contact the upper surface of the interlayer insulating layer 114, as well as the upper and lateral side surfaces of the source electrode SE and the drain electrode DE. The planarization layer 115 can be disposed above the thin-film transistor TFT of the pixel circuit PC. For example, the planarization layer 115 can be disposed between the thin-film transistor TFT of the pixel circuit PC and the pixel electrode 210 (e.g., in the Z direction). The planarization layer 115 may include an organic insulating material. For example, the planarization layer 115 may include an organic insulating material, such as at least one compound selected from acrylic acid, benzocyclobutene (BCB), polyimide, and hexamethyldisiloxane (HMDSO). The organic insulating material of the planarization layer 115 may be a photosensitive organic insulating material.

[0077] Pixel electrodes 210 can be disposed on the planarization layer 115. For example, as Figure 3As shown in the exemplary embodiment, the lower surface of the pixel electrode 210 can directly contact the upper surface of the planarization layer 115. The pixel electrode 210 can be electrically connected to the pixel circuit PC through contact holes formed in the planarization layer 115. For example, as Figure 3 As shown in the exemplary embodiment, the pixel electrode 210 can directly contact the source electrode SE through a contact hole formed in the planarization layer 115 to be electrically connected to the pixel circuit PC.

[0078] In an exemplary embodiment, the pixel electrode 210 may include a reflective film comprising Ag, Mg, Al, Pt, Pd, Au, Ni, Nd, Ir, Cr, or compounds thereof. The pixel electrode 210 may include a reflective layer comprising the aforementioned materials and a transparent conductive film above and / or below the reflective layer. The transparent conductive film may include at least one compound selected from indium tin oxide (ITO), indium zinc oxide (IZO), zinc oxide (ZnO), indium oxide, indium gallium oxide (IGO), aluminum zinc oxide (AZO), etc. In an exemplary embodiment, the pixel electrode 210 may have a three-layer structure of sequentially stacked (e.g., in the Z direction) ITO layer / Ag layer / ITO layer.

[0079] A pixel defining layer 117 may be disposed on the pixel electrode 210. The pixel defining layer 117 may cover the lateral edge of the pixel electrode 210 and may include an opening 117OP that overlaps with the central portion of the pixel electrode 210.

[0080] The pixel defining layer 117 can prevent arcing or the like at the lateral edge of the pixel electrode 210 by increasing the distance between the lateral edge of the pixel electrode 210 and the opposing electrode 230 disposed above the pixel electrode 210. In an exemplary embodiment, the pixel defining layer 117 may include an organic insulating material, such as at least one compound selected from polyimide, polyamide, acrylic resin, BCB, HMDSO, and phenolic resin. The pixel defining layer 117 can be formed by a method such as spin coating. However, exemplary embodiments of the present invention are not limited thereto.

[0081] An intermediate layer 220 is formed on the pixel defining layer 117 to correspond to the pixel electrode 210. In an exemplary embodiment, the intermediate layer 220 may include a high molecular weight organic material or a low molecular weight organic material that emits light of a certain color.

[0082] The relative electrode 230 can be disposed on the intermediate layer 220. For example, as Figure 3As shown in the exemplary embodiment, the lower surface of the intermediate layer 220 can directly contact the upper surface of the pixel electrode 210, and the upper surface of the intermediate layer 220 can directly contact the lower surface of the opposing electrode 230. The opposing electrode 230 can be made of a conductive material with a relatively low work function. For example, in the exemplary embodiment, the opposing electrode 230 may include a (semi-)transparent layer comprising Ag, Mg, Al, Ni, Cr, Li, Ca, or alloys thereof. Optionally, the opposing electrode 230 may further include a layer containing at least one compound selected from ITO, IZO, ZnO, and In2O3 on the (semi-)transparent layer comprising the above-described materials. In the exemplary embodiment, the opposing electrode 230 may include Ag and Mg. In the exemplary embodiment, the opposing electrode 230 may be integrally formed to completely cover the display area DA (in Figure 1 (in the middle), and can be extended to multiple pixels (PX).

[0083] The stacked structure of pixel electrode 210, intermediate layer 220, and opposing electrode 230 can form a light-emitting diode, such as an organic light-emitting diode (OLED). An OLED can emit red, green, or blue light, and the light-emitting area of ​​each OLED corresponds to a pixel PX. Since the opening 117OP of the pixel defining layer 117 defines the size and / or width of the light-emitting area, the size and / or width of the pixel PX can depend on the size and / or width of the corresponding opening 117OP of the pixel defining layer 117.

[0084] The capping layer 250 can be disposed on the opposing electrode 230. For example, as... Figure 3 As shown in the exemplary embodiments, the lower surface of the capping layer 250 can directly contact the upper surface of the opposing electrode 230. In the exemplary embodiments, the capping layer 250 may include lithium fluoride (LiF). Optionally, the capping layer 250 may include an inorganic insulating material such as silicon nitride and / or an organic insulating material. However, the exemplary embodiments of the present invention are not limited thereto. For example, in some exemplary embodiments, the capping layer 250 may be omitted.

[0085] The thin-film encapsulation layer 300 can be disposed on the cover layer 250. The organic light-emitting diode (OLED) can be covered by the thin-film encapsulation layer 300. For example... Figure 3 As shown in the exemplary embodiments, the thin-film encapsulation layer 300 may include a first inorganic encapsulation layer 310 and a second inorganic encapsulation layer 330, and an organic encapsulation layer 320 disposed between the first inorganic encapsulation layer 310 and the second inorganic encapsulation layer 330 (e.g., in the Z direction). However, the exemplary embodiments of the present invention are not limited thereto, and in other exemplary embodiments, the number and arrangement of the inorganic and organic encapsulation layers may vary.

[0086] Each of the first inorganic encapsulation layer 310 and the second inorganic encapsulation layer 330 may include one or more inorganic insulating materials. For example, in an exemplary embodiment, the inorganic insulating material may include at least one compound selected from alumina, titanium oxide, tantalum oxide, hafnium oxide, zinc oxide, silicon oxide, silicon nitride, and silicon oxynitride. In an exemplary embodiment, the first inorganic encapsulation layer 310 and the second inorganic encapsulation layer 330 may be formed using a chemical vapor deposition method. However, the exemplary embodiments of the present invention are not limited thereto.

[0087] The organic encapsulation layer 320 may include a polymer-based material. Examples of polymer-based materials may include at least one compound selected from acrylic resins, epoxy resins, polyimides, and polyethylene. For example, the organic encapsulation layer 320 may include acrylic resins such as polymethyl methacrylate, polyacrylic acid, etc. In an exemplary embodiment, the organic encapsulation layer 320 may be formed by curing monomers or applying polymers. However, exemplary embodiments of the inventive concept are not limited thereto.

[0088] In an exemplary embodiment, optical functional layers such as a touch input layer, an anti-reflective layer, and a color filter layer, as well as a coating layer, may be disposed on the thin-film encapsulation layer 300.

[0089] Figure 4 This is a schematic plan view of a display device 1 according to an exemplary embodiment of the concept of the present invention. For ease of explanation, references to the above-mentioned devices will be omitted. Figure 1 The components and configurations described are the same as those described below, and the differences will be described primarily below.

[0090] Reference Figure 4 In an exemplary implementation, display device 1 may include a PCB. For example... Figure 4 As shown in the exemplary embodiments, the PCB can be a flexible PCB FPC with flexible properties. In the exemplary embodiments, the flexible PCB FPC can be connected to external systems such as an application processor (AP) and / or a power supply unit to supply control signals and / or power to the driver integrated circuit 20 and the display panel 10. Hereinafter, for ease of description, exemplary embodiments of the display device 1 including a flexible PCB FPC will be described. However, the exemplary embodiments of the inventive concept are not limited thereto.

[0091] The flexible PCB (FPC) can be attached to the peripheral area PA of the display panel 10 and can be spaced a certain distance from the driver integrated circuit 20. For example, as Figure 4As shown in the exemplary embodiments, the flexible PCB FPC can be disposed on the lower portion of the peripheral region PA (e.g., in the Y direction) and can be spaced apart from the driver integrated circuit 20 in the Y direction. However, the exemplary embodiments of the inventive concept are not limited thereto. In the exemplary embodiments, the flexible PCB FPC and the display panel 10 can be attached to each other using a conductive adhesive member. For example, the conductive adhesive member can be an anisotropic conductive film (ACF). However, the exemplary embodiments of the inventive concept are not limited thereto.

[0092] The flexible PCB FPC may include a second pad portion 40 corresponding to the first pad portion 30 of the display panel 10. For example, when the flexible PCB FPC is attached to the peripheral area PA of the display panel 10, the second pad portion 40 may overlap (e.g., in the Z direction) or be disposed adjacent to the first pad portion 30. The second pad portion 40 may include a plurality of second signal pads 41, second test pads 42, and second alignment pads 43, and the plurality of second signal pads 41, second test pads 42, and second alignment pads 43 of the second pad portion 40 may respectively correspond to the plurality of first signal pads 31, first test pads 32, and first alignment pads 33 of the first pad portion 30. For example, when a flexible PCB (FPC) is attached to the peripheral area PA of a display panel 10, the plurality of second signal pads 41, second test pads 42, and second alignment pads 43 of the second pad portion 40 may overlap with (e.g., in the Z direction) the plurality of first signal pads 31, first test pads 32, and first alignment pads 33, respectively, or may be disposed adjacent to the plurality of first signal pads 31, first test pads 32, and first alignment pads 33, respectively. The pads of the first pad portion 30 and the second pad portion 40 may include conductive material.

[0093] A flexible PCB FPC can be attached to a display panel 10 such that a second pad portion 40 overlaps with a first pad portion 30 (e.g., in the Z direction). A first alignment pad 33 and a second alignment pad 43 can be aligned with the flexible PCB FPC relative to the display panel 10 such that the flexible PCB FPC is attached to the display panel 10 at a predetermined location. For example, in an exemplary embodiment, the first alignment pad 33 and the second alignment pad 43 can at least partially overlap each other (e.g., in the Z direction). The first alignment pad 33 has a first shape and the second alignment pad 43 has a second shape. When the first alignment pad 33 and the second alignment pad 43 at least partially overlap each other, the first shape of the first alignment pad 33 and the second shape of the second alignment pad 43 form alignment marks with a specific shape on a plane (e.g., in a plane defined in the X and Y directions). In an exemplary embodiment, the specific shape can be a shape including at least one or more curved portions or portions extending in at least two or more directions, such as a cross shape, an X shape, a Y shape, and a T shape. Figure 4 As shown in the exemplary embodiment, the first alignment pad 33 and the second alignment pad 43 can form a cross-shaped alignment mark. However, the exemplary embodiments of the present invention are not limited thereto. By aligning the display panel 10 with the flexible PCB FPC at a predetermined position, such that the first alignment pad 33 and the second alignment pad 43 form certain alignment marks on a plane, and then attaching the display panel 10 to the flexible PCB FPC, the adhesion quality can be improved. Although Figure 4 The exemplary embodiment shown illustrates that a portion of the first alignment pad 33 overlaps with the second alignment pad 43. However, in some exemplary embodiments, the first alignment pad 33 may be positioned adjacent to the second alignment pad 43 to form an alignment mark, and the first alignment pad 33 may not overlap with the second alignment pad 43 when the display panel 10 is attached to the flexible PCB FPC at a predetermined position.

[0094] Figure 5 This is an illustrative representation of an exemplary embodiment based on the concept of the present invention. Figure 4 A cross-sectional view of a portion of the display device 1. According to an exemplary embodiment of the present invention, Figure 5 This can correspond to the edge of display device 1. Figure 4 The sectional view taken by line V-V' in the middle.

[0095] Reference Figure 5In an exemplary embodiment, the display panel 10 can be bonded to the flexible PCB FPC using a conductive adhesive component 50 (e.g., ACF). The conductive adhesive component 50 may include an adhesive resin 51 and a plurality of conductive balls 52 dispersed in the adhesive resin 51. The display panel 10 can be aligned with the flexible PCB FPC such that the first pad portion 30 and the second pad portion 40 overlap each other (e.g., in the Z direction). In an exemplary embodiment, the conductive adhesive component 50 may be disposed between the first pad portion 30 and the second pad portion 40 (e.g., in the Z direction), and the display panel 10 may be attached to the flexible PCB FPC via a thermoforming process.

[0096] In an exemplary embodiment, each of the plurality of conductive balls 52 may be a conductive particle and may include a metal such as at least one selected from Ni, iron (Fe), Cu, Al, Sn, Zn, Cr, cobalt (Co), Ag, Au, etc. The adhesive resin 51 may include an insulating polymer, such as epoxy resin or acrylic resin.

[0097] The pads of the first pad portion 30 and the pads of the second pad portion 40, which are corresponding to each other, can be connected to each other by a conductive adhesive member 50. For example, conductive balls 52 of the conductive adhesive member 50 can be disposed between a plurality of first signal pads 31 of the first pad portion 30 and a plurality of second signal pads 41 of the second pad portion 40. Therefore, the corresponding first signal pads 31 and second signal pads 41 can be electrically connected to each other by using conductive balls 52. Similarly, the first test pad 32 and the second test pad 42 can be electrically connected to each other via conductive balls 52 disposed between them (e.g., in the Z direction). Similarly, the first alignment pad 33 and the second alignment pad 43 can be electrically connected to each other via conductive balls 52 disposed between them (e.g., in the Z direction).

[0098] In the following text, as referenced below Figure 7A and Figure 7B As described in the exemplary embodiment, a portion of the conductive adhesive member 50 disposed between the first test pad 32 and the second test pad 42 is a test bonding portion 53. The test bonding portion 53 may be part of an electrical path through which test current flows to identify whether the first pad portion 30 and the second pad portion 40 are correctly connected.

[0099] Figures 6A to 6C This is a schematic plan view illustrating a first pad portion of a display panel and a second pad portion of a flexible printed circuit board according to an exemplary embodiment of the concept of the present invention.

[0100] Figure 6AThis is a side-by-side view of the first pad portion 30 of the display panel 10 and the second pad portion 40 of the flexible PCB FPC when viewed from the top of the display device 1 in the Z direction. As described above, the first pad portion 30 and the second pad portion 40 may overlap each other (e.g., in the Z direction). The first pad portion 30 and the second pad portion 40 may be formed symmetrically from left to right.

[0101] Reference Figure 6A In an exemplary implementation, the first pad portion 30 may include a plurality of first signal pads 31, first test pads 32, and first alignment pads 33. Although Figure 6A An exemplary implementation shows a first test pad 32 and a first alignment pad 33, but in another exemplary implementation, there may be two or more first test pads 32 and / or first alignment pads 33.

[0102] Multiple first signal pads 31, first test pads 32, and first alignment pads 33 may be arranged in a first direction (e.g., the X direction). The multiple first signal pads 31 and first test pads 32 may extend longitudinally in a second direction (e.g., the Y direction) intersecting the first direction. Figure 6A As shown in the exemplary embodiments, the lengths (e.g., lengths in the Y direction) of the first signal pad 31 and the first test pad 32 may be substantially the same. However, the exemplary embodiments of the inventive concept are not limited thereto.

[0103] In an exemplary embodiment, the first alignment pad 33 may be located at the outermost lateral edge of the first pad portion 30 (e.g., the outermost lateral edge in the X direction), and the first test pad 32 may be located adjacent to the first alignment pad 33 (e.g., in the X direction). A plurality of first signal pads 31 may be located in the central portion of the region of the first pad portion 30 (e.g., in the X direction). The first test pad 32 may be located between the first alignment pad 33 and the plurality of first signal pads 31 (e.g., in the X direction). However, exemplary embodiments of the present invention are not limited thereto, and the arrangement of the first alignment pad 33, the plurality of first signal pads 31, and the first test pad 32 may vary. For example, in another exemplary embodiment, the first alignment pad 33 and the first test pad 32 may be located in the central portion of the region of the first pad portion 30.

[0104] In an exemplary embodiment, the first alignment pad 33 may include at least one curved portion or a portion extending in at least two or more directions. For example... Figure 6AAs shown in the exemplary embodiment, the first alignment pad 33 may include a main portion 33a extending longitudinally from the first test pad 32 in a first direction (e.g., the X direction) and a branch portion 33b extending from the main portion 33a in a second direction (e.g., the Y direction) intersecting the first direction. As a comparative example, when the first alignment pad includes a portion extending in only one direction, alignment can only be checked in that direction. However, according to the exemplary embodiment, since the first alignment pad 33 includes portions extending in at least two directions, alignment in both directions can be confirmed in a plane (e.g., in a plane defined in the X and Y directions).

[0105] The first alignment pad 33 can be electrically connected to the first test pad 32. For example, as Figure 6A As shown in the exemplary embodiment, the first test pad 32 and the first alignment pad 33 are arranged adjacent to each other, and the main body portion 33a of the first test pad 32 and the branch portion 33b of the first alignment pad 33 can be integrally formed.

[0106] The second pad portion 40 may include multiple second signal pads 41, second test pads 42, and second alignment pads 43. For example... Figure 6A As shown in the exemplary embodiment, the second pad portion 40 may include a second test pad 42 and a second alignment pad 43. However, the exemplary embodiments of the present invention are not limited thereto, and in other exemplary embodiments, there may be two or more second test pads 42 and / or two or more second alignment pads 43.

[0107] Similar to the first pad portion 30, a plurality of second signal pads 41, second test pads 42, and second alignment pads 43 of the second pad portion 40 may be arranged in a first direction (e.g., the X direction). The plurality of second signal pads 41 and the second test pads 42 may extend longitudinally in a second direction (e.g., the Y direction) intersecting the first direction. Each of the plurality of second signal pads 41 and the second test pad 42 may have substantially the same length in the second direction (e.g., the Y direction). The plurality of second signal pads 41 may overlap with the plurality of first signal pads 31. The plurality of second signal pads 41 may have an arrangement and shape substantially corresponding to the arrangement and shape of the plurality of first signal pads 31. The second test pads 42 may overlap with the first test pads 32. The second test pads 42 may have a shape and arrangement substantially corresponding to the shape and arrangement of the first test pads 32.

[0108] like Figure 6AAs shown in the exemplary embodiment, the second length L2 (e.g., length in the Y direction) of the plurality of second signal pads 41 of the second pad portion 40 may be smaller than the first length L1 (e.g., length in the Y direction) of the plurality of first signal pads 31 of the first pad portion 30. When the conductive adhesive member 50 is disposed on the first pad portion 30, and then the second pad portion 40 is attached to the first pad portion 30, it is easier to attach the entire area of ​​the second pad portion 40 to the first pad portion 30 because the second length L2 is smaller than the first length L1.

[0109] In an exemplary embodiment, the second alignment pad 43 may be disposed at the outermost lateral edge of the second pad portion 40 region, and the second test pad 42 may be arranged adjacent to (e.g., in the X direction) the second alignment pad 43. A plurality of second signal pads 41 may be arranged in the central portion of the second pad portion 40 region. The second test pad 42 may be disposed between the second alignment pad 43 and the plurality of second signal pads 41 (e.g., in the X direction). However, exemplary embodiments of the present invention are not limited to this arrangement, and as another example, the second alignment pad 43 and the second test pad 42 may be arranged in the central portion of the second pad portion 40 region.

[0110] The second alignment pad 43 may be spaced apart from the second test pad 42 (e.g., in the X direction). The second alignment pad 43 may include a first portion 43-1 and a second portion 43-2 spaced apart from each other (e.g., in the Y direction). In an exemplary embodiment, the first portion 43-1 includes a portion extending longitudinally in a first direction (e.g., the X direction), and the second portion 43-2 may be spaced apart from the first portion 43-1 in a second direction (e.g., the Y direction) intersecting the first direction. For example, the second test pad 42, the first portion 43-1 of the second alignment pad 43, and the second portion 43-2 of the second alignment pad 43 may be spaced apart from each other and may each have an isolated shape in a plane (e.g., in a plane defined in the X and Y directions) in which the second test pad 42, the first portion 43-1 of the second alignment pad 43, and the second portion 43-2 of the second alignment pad 43 do not contact each other. Based on this arrangement, as will be described later, the first portion 43-1 and the second portion 43-2 of the second test pad 42 and the second alignment pad 43 can be used as different electrodes in the adhesion defect test.

[0111] In an exemplary embodiment, when the first pad portion 30 and the second pad portion 40 overlap at a predetermined position, each of the first portion 43-1 and the second portion 43-2 of the second alignment pad 43 may overlap with a portion of the first alignment pad 33. A portion of the first alignment pad 33 may overlap with the space between the second test pad 42 and the first portion 43-1 of the second alignment pad 43, and with the space between the first portion 43-1 and the second portion 43-2 of the second alignment pad 43.

[0112] Furthermore, the first portion 43-1 of the second alignment pad 43 may include a protrusion P that extends longitudinally relative to the main body portion 33a of the first alignment pad 33 in a direction opposite to the branch portion 33b of the first alignment pad 33. For example, as Figure 6A As shown in the exemplary embodiment, when the first alignment pad 33 includes a branch portion 33b projecting downward from the body portion 33a in the Y direction, the first portion 43-1 of the second alignment pad 43 includes a protruding portion P projecting upward in the Y direction. When the first alignment pad 33 and the second alignment pad 43 overlap in the correct position, the protruding portion P of the first portion 43-1 of the second alignment pad 43 may not overlap with the first alignment pad 33 (e.g., in the Z direction).

[0113] By shaping and arranging the first alignment pad 33 and the second alignment pad 43, when the first pad portion 30 and the second pad portion 40 overlap at a predetermined position, the first alignment pad 33 and the second alignment pad 43 can form alignment marks of a specific shape. These alignment marks indicate that the flexible PCB FPC is attached to the display panel 10 at a predetermined position to provide enhanced adhesion. For example, the alignment marks may be cross-shaped alignment marks (e.g., in a plane defined in the X and Y directions). Checking the alignment marks allows the user to confirm that the alignment between the first pad portion 30 and the second pad portion 40 (e.g., in the X and Y directions) is correct and that the flexible PCB FPC is attached to the display panel 10 at the predetermined position. (See reference...) Figure 6B In an exemplary implementation, a plurality of first signal pads 31 are arranged in a first direction (e.g., the X direction). However, the plurality of first signal pads 31 may extend longitudinally in different directions from each other. Figure 6BAs shown in the exemplary embodiment, the first signal pads 31 disposed in the central portion (e.g., in the X direction) of the first pad portion 30 can extend in a second direction (e.g., the Y direction) intersecting the first direction. Conversely, the first signal pads 31 disposed at opposite lateral edges of the first pad portion 30 can extend upward in a third direction different from the first and second directions. For example, the third direction can be located in the same plane as the first and second directions, but it can also intersect both the first and second directions. For example, the third direction can extend in the same plane as the X and Y directions, and can be disposed between the X and Y directions.

[0114] The angle formed by the arrangement direction (e.g., the X direction) of the plurality of first signal pads 31 and the longitudinal extension direction of each of the plurality of first signal pads 31 in the central portion of the first pad portion 30 can be a first angle θ1. In an exemplary embodiment, the first angle θ1 can be approximately 90 degrees. On the other hand, the angle formed by the arrangement direction and the longitudinal extension direction of the first signal pads 31 arranged at opposite lateral edges of the first pad portion 30 can be a second angle θ2, which can be less than approximately 90 degrees.

[0115] In another exemplary embodiment, a plurality of first signal pads 31 may be configured such that the angle formed by the arrangement direction and the longitudinal extension direction of the first signal pads 31 decreases from the central portion of the first pad portion 30 toward the two lateral edges.

[0116] As described above, the angle formed by the arrangement direction and longitudinal extension direction of the plurality of first signal pads 31 can vary depending on the position (e.g., position in the X direction) of each of the plurality of first signal pads 31 on the first pad portion 30, and the plurality of second signal pads 41 can be formed to correspond respectively to the plurality of first signal pads 31. Therefore, it is easier to determine whether the alignment of the first pad portion 30 and the second pad portion 40 is a predetermined alignment in which the flexible PCB FPC is attached to the display panel 10 at a predetermined position. For example, the plurality of first signal pads 31 and the plurality of second signal pads 41 extend in the same direction, but at least some of them extend in different directions, and therefore, misalignment can be more easily identified.

[0117] Reference Figure 6CIn an exemplary embodiment, a plurality of second signal pads 41 of the second pad portion 40 may be arranged in a first direction (e.g., the X direction), and the second alignment pad 43 may include a first portion 43-1 and a second portion 43-2. ​​The first portion 43-1 may extend longitudinally in a second direction (e.g., the Y direction) intersecting the first direction, and the second portion 43-2 may be spaced apart from the first portion 43-1 in the first direction (e.g., the X direction). The first portion 43-1 of the second alignment pad 43 extends longitudinally in the second direction (e.g., the Y direction), and when the flexible PCB FPC is attached to the display panel 10 at a predetermined position, and the first pad portion 30 and the second pad portion 40 overlap each other, a portion of the first portion 43-1 that does not overlap with the first alignment pad 33 (e.g., in the Z direction) may be formed.

[0118] Furthermore, the first portion 43-1 and the second portion 43-2 of the second alignment pad 43 may overlap with a portion of the first alignment pad 33, and a portion of the first alignment pad 33 may overlap with the space between the first portion 43-1 and the second portion 43-2 and the space between the first portion 43-1 and the second test pad 42.

[0119] With this shape and arrangement, when the second alignment pad 43 overlaps with the first alignment pad 33 at a predetermined position, an alignment mark having, for example, a cross shape can be formed on a plane (e.g., in a plane defined in the X and Y directions), and this alignment mark can be used to align the first pad portion 30 with the second pad portion 40. Furthermore, the second alignment pad 43 includes a second portion 43-2 spaced apart from the first portion 43-1 in a second direction intersecting the longitudinal extension direction of the first portion 43-1, and therefore, alignment in at least two directions can be confirmed on a plane.

[0120] Furthermore, the first part 43-1 and the second part 43-2 are formed to be spaced apart from each other (e.g., in the X direction), and thus can be used as different electrodes during the adhesion defect test described below.

[0121] Figure 7A 7B is a perspective view schematically illustrating a portion of a first pad portion of a display panel and a portion of a second pad portion of a flexible printed circuit board according to an exemplary embodiment of the present invention, and 7B is schematically illustrating... Figure 7A An exploded perspective view of the first pad portion and a portion of the second pad portion.

[0122] Figure 7A The diagram shows the first pad portion 30 and the second pad portion 40 aligned with each other at a predetermined position, and that they are bonded together using a conductive adhesive member 50. Figure 4 The flexible PCB FPC is attached to ( Figure 4 The display panel 10 in the middle forms a predetermined alignment mark by aligning the first test pad 32 and the first alignment pad 33 of the first pad portion 30 and the second test pad 42 and the second alignment pad 43 of the second pad portion 40. Figure 7B yes Figure 7A An exploded view of the structure shown.

[0123] Reference Figure 7A and Figure 7B In an exemplary embodiment, a portion of the conductive adhesive component 50 may be disposed between the first test pad 32 and the second test pad 42 (e.g., in the Z direction), and the first test pad 32 may be attached to the second test pad 42. Hereinafter, for ease of description, this portion of the conductive adhesive component 50 will be referred to as the test bonding portion 53.

[0124] According to an exemplary embodiment of the present invention, the resistance of the test bonding portion 53 can be measured to determine whether the display panel 10 and the flexible PCB FPC are properly attached to each other. For example, if the measured resistance of the test bonding portion 53 is greater than a normal value, this may indicate adhesion failure, and if the measured resistance of the test bonding portion 53 is less than a normal value, this may indicate good adhesion. A method for measuring the resistance of the test bonding portion 53 will be described below.

[0125] Each of the second test pad 42 and the second alignment pad 43 may include at least one test terminal. For example, as Figure 7B As shown in the exemplary embodiment, the first portion 43-1 and the second portion 43-2 of the second alignment pad 43 may respectively include a first test terminal TP1 and a second test terminal TP2. The second test pad 42 may include at least two or more test terminals, such as a third test terminal TP3 and a fourth test terminal TP4.

[0126] In an exemplary embodiment, a test current I can be applied to one of the first test terminal TP1 and the fourth test terminal TP4, and the other of the first test terminal TP1 and the fourth test terminal TP4 can be grounded. For ease of explanation, an embodiment in which the test current I is applied to the first test terminal TP1 and the fourth test terminal TP4 is grounded will be described. However, the exemplary embodiments of the present invention are not limited thereto. A path CP for the test current I can be formed between the first test terminal TP1 and the fourth test terminal TP4. As an example, the test current I can flow from the first test terminal TP1 to the first portion 43-1 of the second alignment pad 43, the first alignment pad 33, the first test pad 32, the test bonding portion 53, the second test pad 42, and reach the fourth test terminal TP4. Since the conductive adhesive member 50 is disposed between the first alignment pad 33 and the second alignment pad 43 and between the first test pad 32 and the second test pad 42, the test current I can flow through the conductive ball 52 of the conductive adhesive member 50.

[0127] In this state, the first voltage V1 at the second test terminal TP2 and the second voltage V2 at the third test terminal TP3 can be measured. The second portion 43-2 of the second alignment pad 43 and the first test pad 32 are electrically connected to each other via the conductive adhesive member 50 and the first alignment pad 33, but no current flows, so there is no voltage drop. Therefore, the voltage at the first position P1 of the first test pad 32 can be the same as the first voltage V1. The voltage at the second position P2 of the second test pad 42 can be the same as the second voltage V2.

[0128] Therefore, the first voltage V1 and the second voltage V2 at opposite sides of the test connection portion 53 can be measured, i.e., the first voltage V1 at the first position P1 and the second voltage V2 at the second position P2, and the test current I flowing through the test connection portion 53 can be identified. Therefore, the resistance R of the test connection portion 53 can be measured using the following equation.

[0129]

[0130] By using the resistance R of the test bonding portion 53, which is measured in this way, it is possible to determine whether there are adhesion defects between the display panel 10 and the flexible PCB FPC.

[0131] In another exemplary embodiment, when a test current I is applied to the first test terminal TP1 and the fourth test terminal TP4 is grounded, the voltage at each of the first test terminal TP1 and the fourth test terminal TP4 can be measured. In this way, the total resistance in the path CP of the test current I between the first test terminal TP1 and the fourth test terminal TP4 can be obtained, and since the total resistance includes the resistance R of the test bonding portion 53, adhesion defects can be inspected by using the total resistance.

[0132] According to an exemplary embodiment, an adhesion defect test can be performed to check whether the first pad portion 30 of the display panel 10 and the second pad portion 40 of the flexible PCB FPC are correctly connected to each other. According to an exemplary embodiment conceived in this invention, since the alignment pads are used for the adhesion defect test, the adhesion defect test can be performed using only one pad from each of the first pad portion 30 and the second pad portion 40. This significantly reduces the number of test pads that cannot be used as signal pads and increases the number of signal pads available in a limited pad portion area. Alternatively, by reducing the area of ​​the pad portions, the dead zone of the display device 1 can be significantly reduced.

[0133] While display devices have been primarily described, exemplary embodiments of the inventive concept are not limited thereto. For example, methods of manufacturing display devices also fall within the scope of the inventive concept.

[0134] According to exemplary embodiments of the present invention, the display device can provide relatively easy detection of whether the PCB is attached to the display panel in the correct position and whether the PCB and the display panel are correctly connected to each other. The display device can enhance the user's ability to correctly align the circuit board with the display panel. Furthermore, it is possible to implement a display device that can reduce the area of ​​the solder pads on the display panel. However, the scope of the present invention is not limited to these effects.

[0135] It should be understood that the exemplary embodiments of the inventive concept described herein should be understood in a descriptive sense only and not for limiting purposes. The description of features or aspects within each exemplary embodiment should generally be considered applicable to other similar features or aspects in other exemplary embodiments. Although one or more exemplary embodiments have been described with reference to the accompanying drawings, those skilled in the art will understand that various changes in form and detail may be made herein without departing from the spirit and scope defined by the appended claims.

Claims

1. A display device, including: Display panel, including the first pad portion; A flexible printed circuit board configured to be attached to the display panel, the flexible printed circuit board including a second pad portion configured to be electrically connected to a first pad portion; The first pad portion includes a plurality of first signal pads, a first test pad, and a first alignment pad having a first shape; and The second pad portion includes a second alignment pad having a second shape, the second alignment pad comprising a first portion and a second portion spaced apart from each other. The first shape and the second shape are configured to form predetermined alignment marks when the flexible printed circuit board is attached to the display panel at a predetermined position. When the flexible printed circuit board is attached to the display panel at the predetermined position, each of the first portion and the second portion of the second alignment pad overlaps with a portion of the first alignment pad.

2. The display device according to claim 1, wherein, The second pad portion also includes: Multiple second signal pads overlap with the multiple first signal pads, respectively; and The second test pad is spaced apart from the second alignment pad and overlaps with the first test pad. The second test pad is positioned between the second alignment pad and the plurality of second signal pads.

3. The display device according to claim 2, wherein, The second test pad and the first and second portions of the second alignment pad do not contact each other and have shapes that are isolated from each other.

4. The display device according to claim 2, wherein: The second test pad is spaced apart from the first and second portions of the second alignment pad; as well as A portion of the first alignment pad is positioned to overlap with a first space between the second test pad and the first portion of the second alignment pad, and a second space between the first portion and the second portion of the second alignment pad, when the flexible printed circuit board is attached to the display panel at the predetermined location.

5. The display device according to claim 2, wherein, Each of the second test pad and the second alignment pad includes a test terminal.

6. The display device according to claim 5, wherein: The first test terminal of the second test pad and the second alignment pad is configured to receive current, and the second test terminal of the second test pad and the second alignment pad is grounded; as well as The first alignment pad and the second alignment pad are configured to form an electrical path through which the current flows.

7. The display device according to claim 1, wherein, The first alignment pad includes: The main body extends longitudinally from the first test pad in a first direction; and The branch portion protrudes from the main body portion in a second direction intersecting the first direction. The first test pad is integrally formed with the main body portion and the branch portion of the first alignment pad.

8. The display device according to claim 7, wherein, The first portion of the second alignment pad includes a protruding portion positioned to overlap with the opposite side of the branch portion of the first alignment pad relative to the main body portion when the flexible printed circuit board is attached to the display panel at the predetermined position.

9. The display device according to claim 2, wherein: The plurality of first signal pads and the plurality of second signal pads are arranged in a first direction. The first signal pad among the plurality of first signal pads and the first second signal pad among the plurality of second signal pads extend in a second direction intersecting the first direction, and The second first signal pad among the plurality of first signal pads and the second second signal pad among the plurality of second signal pads extend upward in a third direction different from the first direction and the second direction.

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