Display device and method of manufacturing the same

Abstract

Disclosed are a display device and a manufacturing method thereof, wherein the display device includes a display module and a circuit board. The display module includes: a base substrate including a display area and a non-display area adjacent to the display area; and a first pad placed on the base substrate and overlapping the non-display area. The circuit board includes a first board and a second pad placed on the first board and contacting the first pad, wherein the second pad is provided with a first metal layer of a single material.

Description

[0001] This application claims priority to and the benefit of Korean Patent Application No. 10-2018-0111525, filed on September 18, 2018, which is hereby incorporated by reference herein in its entirety. Technical Field

[0002] One or more aspects of the embodiments of the present disclosure herein relate to a display device, and more particularly, to a display device and a method for manufacturing the display device. Background Art

[0003] Various display devices that may be used in multimedia devices such as televisions, mobile phones, tablet computers, navigation devices, and / or game consoles are being developed.

[0004] The display device includes a display panel for displaying an image. The display panel includes a plurality of gate lines, a plurality of data lines, and a plurality of pixels connected to the plurality of gate lines and the plurality of data lines. The display panel can be connected (or combined) to a circuit board for providing electrical signals (required for image display) to the gate lines and / or data lines.

[0005] The circuit board can be connected to the display panel using an anisotropic conductive film scheme or an ultrasonic scheme. Of the two schemes, the connection scheme using the ultrasonic scheme between the display panel and the circuit board can further enhance connectivity and reduce (eg, simplify) the manufacturing process compared to the anisotropic conductive film scheme. Summary of the invention

[0006] One or more aspects of embodiments of the present disclosure are directed to a display device in which a circuit board and a display panel are bonded using an ultrasonic bonding scheme and a method of manufacturing the display device.

[0007] An embodiment of the inventive concept provides a display device, comprising: a display module, comprising a base substrate and a first pad, the base substrate comprising a display area and a non-display area adjacent to the display area, the first pad being located on the base substrate and overlapping the non-display area; a circuit board comprising a first board and a second pad, the second pad being located on the first board and contacting the first pad, wherein the second pad is provided with a first metal layer composed of a single material.

[0008] In an embodiment, the first pad may include: a first sub-metal layer on the base substrate; a second sub-metal layer on the first sub-metal layer; and a third sub-metal layer on the second sub-metal layer and contacting the second pad.

[0009] In embodiments, at least a portion of the second sub-metal layer may contact the second pad.

[0010] In an embodiment, the thickness of the second sub-metal layer may be greater than the thickness of each of the first sub-metal layer and the third sub-metal layer.

[0011] In an embodiment, the first sub-metal layer and the third sub-metal layer may be composed of the same material.

[0012] In an embodiment, the first sub-metal layer and the third sub-metal layer may be composed of titanium, and the second sub-metal layer may be composed of aluminum.

[0013] In an embodiment, the first metal layer may be composed of copper.

[0014] In an embodiment, the display device may further include a resin between the base substrate and the first plate, the resin surrounding the first pad and the second pad.

[0015] In an embodiment, the circuit board may further include: a third pad separated from the second pad on a plane of the circuit board and electrically connected to the second pad; and a driving circuit board including a second board and a driving pad located on the second board and electrically connected to the third pad.

[0016] In an embodiment, the display device may further include an anisotropic conductive film that electrically connects the third pad with the driving pad, wherein the anisotropic conductive film includes: an adhesive film located between the first plate and the second plate; and conductive particles located in the adhesive film and configured to electrically connect the third pad with the driving pad.

[0017] In an embodiment, the third pad may include: a second metal layer on the first plate; and an auxiliary metal layer on the second metal layer and configured to electrically contact the conductive particles, wherein the second metal layer may be composed of the same material as that of the first metal layer.

[0018] In an embodiment, the auxiliary metal layer may be composed of antimony.

[0019] In an embodiment, the third pad may be provided with a second metal layer composed of a single material, and the third pad may contact the driving pad.

[0020] In an embodiment, the circuit board may be a flexible board.

[0021] In an embodiment, each of the first pad and the second pad may be provided in plural.

[0022] In an embodiment of the inventive concept, a method for manufacturing a display device includes: arranging a first pad on a display substrate and arranging a second pad on a circuit board; bringing the first pad into contact with the second pad; applying pressure on the circuit board in a thickness direction of the display substrate; and generating ultrasonic vibrations at an interface between the first pad and the second pad when the pressure is applied, wherein the second pad is provided with a metal layer composed of a single material.

[0023] In an embodiment, the manufacturing method may further include placing a resin between the display substrate and the circuit board such that the resin surrounds the first pad and the second pad.

[0024] In an embodiment, the first pad may include: a first sub-metal layer, located on the display substrate and composed of a first metal material; a second sub-metal layer, located on the first sub-metal layer and composed of a second metal material; and a third sub-metal layer, located on the second sub-metal layer, the third sub-metal layer contacting the second pad and composed of the first metal material.

[0025] In embodiments, at least a portion of the second pad may directly contact the second sub-metal layer.

[0026] In an embodiment, the second pad may be composed of copper. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings are included to provide a further understanding of the inventive concept and are incorporated in and constitute a part of this specification. The accompanying drawings illustrate example embodiments of the inventive concept and together with the description serve to explain the principles of the inventive concept. In the drawings:

[0028] Figure 1 is a perspective view of an embodiment of the inventive concept;

[0029] Figure 2 is an exploded perspective view of a display device according to an embodiment of the inventive concept;

[0030] Figure 3 is a cross-sectional view of a display module according to an embodiment of the inventive concept;

[0031] Figure 4 is a plan view of a display device according to an embodiment of the inventive concept;

[0032] Figure 5A is an equivalent circuit diagram of a pixel according to an embodiment of the inventive concept;

[0033] Figure 5B is a partial cross-sectional view showing a portion of a display device according to an embodiment of the inventive concept;

[0034] Figure 6 According to the embodiment of the invention concept Figure 4 A cross-sectional view taken along line II' shown in FIG.

[0035] Figure 7 shows a combination between a first pad and a second pad according to an embodiment of the inventive concept;

[0036] Figure 8 yes Figure 6 An enlarged view of the area AA shown in FIG.

[0037] Fig.9A According to the embodiment of the invention concept Figure 4 A cross-sectional view taken along line II-II' shown in FIG.

[0038] Fig. 9B According to another embodiment of the invention Figure 4 A cross-sectional view taken along line II-II' shown in FIG.

[0039] Fig.10 is a flow chart illustrating a bonding process between a first pad and a second pad according to an embodiment of the inventive concept; and

[0040] FIG. 11A to FIG. 11C is a diagram showing ultrasonic bonding between a first pad and a second pad. DETAILED DESCRIPTION

[0041] It will be understood that when an element or layer is referred to as being “on,” “connected to” or “coupled to” another element or layer, it can be directly “on,” directly connected to or directly coupled to the other element or layer, or intervening elements or layers may be present.

[0042] The same reference numerals in the drawings refer to the same elements throughout. In addition, in the drawings, in order to effectively describe the technical content, the thickness, ratio and size of the elements may be exaggerated, and the embodiments of the present disclosure are not limited to the statements provided.

[0043] The term "and / or" includes any and all combinations of one or more of the listed items.

[0044] Expressions such as “at least one of,” “one of,” and “selected from,” when preceding a list of elements, modify the entire list of elements and do not modify the individual elements of the list.

[0045] Additionally, when describing embodiments of the present invention, the use of "may" refers to "one or more embodiments" of the present invention.

[0046] Terms such as "first" and "second" can be used to describe various components, but these components should not be limited by the terms. Terms are used only for the purpose of distinguishing one component from another component. For example, a first component may be referred to as a second component, or similarly, a second component may be referred to as a first component without departing from the scope of the present invention. Unless the context clearly indicates otherwise, the singular forms "a", "an", and "the" are also intended to include plural forms.

[0047] Additionally, terms such as "below," "above," and "upper" are used to explain the relationship of items shown in the drawings. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the drawings.

[0048] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the example embodiments belong. It will be further understood that terms (such as those defined in common dictionaries) should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and will not be interpreted in an ideal or overly formal sense unless explicitly defined as such herein.

[0049] It will also be understood that when the terms "comprises," "includes" and / or variations thereof are used in this specification, it indicates the presence of the stated features, integers, steps, operations, elements, components or combinations thereof, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components or combinations thereof.

[0050] Hereinafter, embodiments will be described in more detail with reference to the accompanying drawings.

[0051] Figure 1 is a perspective view of an embodiment of the inventive concept. Figure 2 is an exploded perspective view of a display device according to an embodiment of the inventive concept.

[0052] about Figure 1 , the display device DD can display the image IM on the display surface DD-IS. According to the inventive concept, a display device DD provided with a flat display surface DD-IS is shown, but the embodiments of the inventive concept are not limited thereto. Without limitation, the display device DD may include a curved display surface or a stereoscopic display surface. The stereoscopic display surface includes a plurality of display areas configured to indicate different directions, for example, a polygonal columnar display surface.

[0053] According to an embodiment of the inventive concept, the display device DD may be a flexible display device. However, the embodiment of the inventive concept is not limited thereto, and the display device DD according to the inventive concept may be a rigid display device.

[0054] According to the present embodiment, the electronic module, the camera module and / or the power module, etc. may be arranged (placed) in a bracket and / or a housing, etc. together with the display device DD to form a mobile phone terminal. The display device DD in the embodiment of the inventive concept may be applied to large electronic devices such as televisions and / or monitors, and / or small or medium-sized electronic devices such as tablets, vehicle navigators, game consoles and / or smart watches.

[0055] The display surface DD-IS may be parallel to a surface defined by the first direction DR1 and the second direction DR2. The direction perpendicular to the display surface DD-IS (i.e., the thickness direction of the display device DD) is indicated by a third direction DR3. The front surface (or top surface) and the rear surface (or bottom surface) of each component, element or unit described below are distinguished by the third direction DR3 (e.g., the rear (or bottom) surface and the front (or top) surface are arranged sequentially in the third direction DR3). However, the first direction to the third direction DR1, DR2 and DR3 shown in the embodiment are only examples, and the directions indicated by the first direction to the third direction DR1, DR2 and DR3 may be converted into opposite directions.

[0056] like Figure 1 As shown in FIG. 1 , the display surface DD-IS includes a display area DD-DA on which an image IM is displayed and a non-display area DD-NDA adjacent to the display area DD-DA. The non-display area DD-NDA is an area on which no image is displayed. Figure 1 , application icons and watch widgets are shown as examples of image IM.

[0057] In some embodiments, the display area DD-DA has a rectangular shape and is surrounded by the non-display area DD-NDA. However, embodiments of the inventive concept are not limited thereto, and the shape of the display area DD-DA and the shape of the non-display area DD-NDA may be designed differently. For example, the non-display area DD-NDA may be disposed (e.g., placed) adjacent to only one side of the display area DD-DA, or may be omitted.

[0058] about Figure 2 , the display device DD may include a window member WM, a display module DM, a circuit board FB and a container member BC.

[0059] The window member WM is disposed on the top of the display module DM and may transmit the image IM provided from the display module DM through the transmission area TA. The window member WM includes the transmission area TA and the non-transmission area NTA. The transmission area TA may have Figure 1 In some embodiments, the image IM displayed in the display area DD-DA of the display device DD may be viewed from the outside through the transmissive area TA of the window member WM.

[0060] The non-transmission area NTA may have Figure 1The shape of the non-display area DD-NDA shown in FIG. 4 corresponds to the shape of the non-display area DD-NDA shown in FIG. 4 . The non-transmission area NTA may have a relatively low optical transmittance compared to the transmission area TA. However, the technical spirit of the inventive concept is not limited thereto, and in some embodiments, the non-transmission area NTA may not be included.

[0061] The window member WM may be formed of glass, sapphire and / or plastic, etc. Although shown as having a single layer, the window member WM may include a plurality of layers. The window member WM may include a base layer overlapped with the non-transmission area NTA, and may include at least one printed layer disposed on the rear surface of the base layer. The printed layer may have a specified color. For example, the printed layer may be disposed in black and / or a color other than black.

[0062] The display module DM may be disposed between the window member WM and the container member BC. The display module DM includes a display panel DP and an input sensing unit ISU.

[0063] The display panel DP may generate an image and transmit the generated image to the window member WM. According to an embodiment of the inventive concept, the display panel DP may be an organic light emitting display panel, a liquid crystal display panel, or a quantum dot light emitting display panel, but is not particularly limited. For example, the organic light emitting display panel includes an organic light emitting element. The liquid crystal display panel includes a liquid crystal module. The quantum dot light emitting display panel includes quantum dots or quantum rods.

[0064] Hereinafter, the display panel DP according to an embodiment of the inventive concept will be described as an organic light emitting display panel. However, the technical spirit of the inventive concept is not limited thereto, and various suitable display panels may be applied to the inventive concept.

[0065] The input sensing unit ISU may be disposed between the window member WM and the display panel DP. The input sensing unit ISU senses input applied from the outside. The input applied from the outside may be provided in various suitable ways. The external input may include various suitable types (or kinds) of external input, such as from a part of the user's body, a stylus, light, heat, and / or pressure. In addition, the external input may be not only input generated from contact with a part of the body (such as a user's finger), but may also be input from a touch in a proximal or adjacent space.

[0066] The input sensing unit ISU may be directly disposed on the display panel DP. For example, the input sensing unit ISU in the embodiment may be manufactured with the display panel DP through a continuous process. However, the technical spirit of the inventive concept is not limited thereto, and the input sensing unit ISU may be disposed as a separate panel to be combined with the display panel DP. As another example, the input sensing unit ISU may be omitted.

[0067] The circuit board FB may be connected (or coupled) to one end of the display panel DP to provide a driving signal to the display panel DP. The driving signal may be a signal for displaying an image on the display panel DP. Figure 2 , only a structure in which the circuit board FB is connected to the display panel DP is shown, but the embodiments of the inventive concept are not limited thereto. For example, the display device DD may further include a touch circuit board connected to the input sensing unit ISU. The touch circuit board may provide a touch drive signal to the input sensing unit ISU. In an embodiment of the present disclosure, a combination scheme in which the circuit board FB is connected to the display panel DP may be substantially the same as a scheme in which the touch circuit board is connected to the input sensing unit ISU.

[0068] The container member BC can be combined with the window member WM. The container member BC provides the rear surface of the display device DD and is combined with the window member WM to define the internal space. The container member BC may include a material having a relatively high hardness property. For example, the container member BC may include a plurality of frames and / or a plurality of plates composed of glass, plastic and / or metal. The container member BC can stably (or appropriately) protect the components of the display device DD accommodated in the internal space from external impacts.

[0069] Although it is described above that the container member BC includes a material having a high hardness property, the embodiments of the inventive concept are not limited thereto. For example, the container member BC may include a flexible material, and the display device DD according to the embodiments of the inventive concept may have a flexible (e.g., foldable and / or bendable) property. As a result, the components included in the display device DD may also have a flexible property.

[0070] Figure 3 is a cross-sectional view of a display module according to an embodiment of the inventive concept.

[0071] about Figure 3 , the display panel DP includes: a base substrate SUB; a circuit element layer DP-CL, which is disposed on the base substrate SUB; a display element layer DP-OLED; and an insulating layer TFL. The input sensing unit ISU may be directly disposed on the insulating layer TFL. In this specification, when component A is described as being "directly disposed" on component B, this means that no adhesive layer is disposed between component A and component B.

[0072] The base substrate SUB may include at least one plastic film. For example, the base substrate SUB may include a glass substrate, a metal substrate, an organic / inorganic composite material substrate, and / or a plastic substrate as a flexible substrate, etc. Figure 1 The display area DD-DA and the non-display area DD-NDA described may be respectively Figure 3The display panel area DP-DA and the non-display panel area DP-NDA defined on the base substrate SUB shown in FIG.

[0073] In some embodiments, the circuit element layer DP-CL includes at least one intermediate insulating layer and a circuit element. The intermediate insulating layer may include at least one intermediate inorganic film and at least one intermediate organic film. The circuit element may include a signal line and / or a pixel driving circuit, etc.

[0074] In some embodiments, the display element layer DP-OLED includes a plurality of organic light emitting diodes. The display element layer DP-OLED may further include an organic film such as a pixel defining layer. According to another embodiment, when the display panel is provided using a liquid crystal display panel, the display element layer may be provided using a liquid crystal layer.

[0075] The insulating layer TFL encapsulates the display element layer DP-OLED. For example, the insulating layer TFL may include a thin film encapsulation layer. The insulating layer TFL may protect the display element layer DP-OLED from foreign substances such as moisture, oxygen and / or dust particles. Figure 3 The middle insulating layer TFL is shown to overlap the display panel area DP-DA and the non-display panel area DP-NDA, but embodiments of the inventive concept are not limited thereto. For example, the insulating layer TFL may not overlap the non-display panel area DP-NDA.

[0076] Figure 4 is a plan view of a display device according to an embodiment of the inventive concept. Figure 5A is an equivalent circuit diagram of a pixel according to an embodiment of the inventive concept. Figure 5B is a partial cross-sectional view illustrating a portion of a display device according to an embodiment of the inventive concept.

[0077] about Figure 4 , the display device DD includes: a display panel DP; a circuit board FB electrically connected to the display panel DP; and a driving circuit board PB electrically connected to the circuit board FB.

[0078] The display panel DP may include: a gate driving circuit GDC; a plurality of signal lines SGL; a plurality of first pads (also referred to as pads) PD1 overlapped with the first pad area SA; and a plurality of pixels PX.

[0079] A plurality of pixels PX are disposed on the display panel area DP-DA. Each of the plurality of pixels PX includes an organic light emitting diode and a pixel driving circuit PXC connected to the organic light emitting diode (see FIG. Figure 5A). The gate driving circuit GDC, the signal line SGL, the first pad PD1 and / or the pixel driving circuit PXC may be included in a substrate disposed on the base substrate SUB. Figure 3 The circuit element layer DP-CL is shown in FIG.

[0080] exist Figure 5A , any one gate line GL, any one data line DL, a power line PL, and a pixel PX connected thereto are shown. However, the configuration of the pixel PX may not be limited to Figure 5A The configuration shown in the figure can be modified according to the desired actual application.

[0081] The pixel PX may include an organic light emitting diode ED and a pixel driving circuit PXC.

[0082] The organic light emitting diode ED may be a front surface light emitting diode or a rear surface light emitting diode. As a pixel driving circuit PXC configured to drive the organic light emitting diode ED, the pixel PX includes a first transistor T1 (or a switching transistor), a second transistor T2 (or a driving transistor), and a capacitor Cap (or a storage capacitor). The first power supply voltage ELVDD is provided to the second transistor T2, and the second power supply voltage ELVSS is provided to the organic light emitting diode ED. The second power supply voltage ELVSS may be lower than the first power supply voltage ELVDD.

[0083] The first transistor T1 outputs a data signal to be applied to the data line DL in response to a gate signal applied to the gate line GL. The capacitor Cap is charged with a voltage corresponding to the data signal received from the first transistor T1. The second transistor T2 is connected to the organic light emitting diode ED. The second transistor T2 controls a driving current ID flowing through the organic light emitting diode ED in response to the amount of charge stored in the capacitor Cap.

[0084] The equivalent circuit described above is only an example, and the embodiments of the present disclosure are not limited thereto. For example, the pixel PX may further include a plurality of transistors and a greater number of capacitors.

[0085] Refer again Figure 4 The gate driving circuit GDC generates a plurality of gate signals and sequentially outputs the gate signals to a plurality of gate lines GL. In addition, the gate driving circuit GDC may also output another control signal to the pixel driving circuit PXC of the pixel PX.

[0086] The gate driving circuit GDC may include a plurality of thin film transistors provided by the same process as that of the pixel driving circuit PXC of the pixel PX (eg, a low temperature polysilicon (LTPS) process and / or a low temperature polycrystalline oxide (LTPO) process).

[0087] The signal line SGL may overlap the display panel area DP-DA and the non-display panel area DP-NDA, and be disposed on the base substrate SUB. The signal line SGL may include a gate line GL, a data line DL, a power line PL, and a control signal line CSL. Each of the gate lines GL is connected to a corresponding pixel among the pixels PX, and each of the data lines DL is connected to a corresponding pixel among the pixels PX. The power line PL is connected to the pixel PX. The control signal line CSL may provide a control signal to the gate drive circuit GDC.

[0088] The circuit board FB may be connected to one end of the display panel DP and one end of the driving circuit board PB. According to an embodiment, the circuit board FB may be provided with a flexible printed circuit board. Figure 2 As shown in , the circuit board FB may be bent along one side of the display panel DP to be disposed on the rear surface of the display panel DP.

[0089] Although in Figure 4 , the circuit board FB is illustrated as being separated from the display panel DP and the driving circuit board PB, but the circuit board FB may be connected to a portion of the non-display panel area DP-NDA of the display panel DP and a portion of the driving circuit board PB.

[0090] The circuit board FB may include a first board FCB and a plurality of second pads PD2 disposed on the first board FCB. The second pads PD2 may be disposed in a second pad area FA1 defined in the first board FCB. When the circuit board FB and the display panel DP are combined, the first pad area SA and the second pad area FA1 may overlap each other.

[0091] The second pads PD2 may be electrically and respectively coupled to the first pads PD1 disposed in the first pad area SA. As a result, a plurality of driving signals transmitted from the second pads PD2 may be transmitted to the display panel DP through the first pads PD1.

[0092] According to an embodiment of the inventive concept, the first pad PD1 (hereinafter, the first pad) of the display panel DP may be respectively bonded to the second pad PD2 (hereinafter, the second pad) of the circuit board FB based on an ultrasonic bonding scheme. The ultrasonic bonding scheme may refer to a process in which two metal materials are directly bonded by pressure and ultrasonic vibration. As a result, the first pad PD1 may contact the second pad PD2, and the first pad PD1 and the second pad PD2 may be bonded to each other.

[0093] The second pads PD2 may be electrically connected to each other.

[0094] In the related display panel, the second pad of the circuit board may include at least two laminated metal layers. When the second pad is provided with two or more metal layers, the process cost increases, and ultrasonic bonding may not be easily performed between the metal layers of the second pad and the metal layers of the first pad in contact.

[0095] According to an embodiment of the inventive concept, the second pad PD2 included in the circuit board FB may be provided with a first metal layer composed of a single material. Here, the second pad PD2 according to an embodiment of the inventive concept may be provided with a metal material for easily (or suitably) ultrasonically bonding with the metal layer included in the first pad PD1. Therefore, the overall process cost can be reduced, and ultrasonic bonding between the first pad PD1 and the second pad PD2 becomes easier. Figure 6 A detailed description thereof is provided.

[0096] In some embodiments, the circuit board FB may include a first board FCB and a plurality of third pads PD3 disposed on the first board FCB. In the circuit board FB, a third pad area FA2 overlapping the driving pad area PA of the driving circuit board PB is defined, and the third pad PD3 may be disposed on the first board FCB to overlap the third pad area FA2. When the circuit board FB is combined with the driving circuit board PB, the third pad area FA2 may overlap the driving pad area PA defined in the driving circuit board PB.

[0097] The third pad PD3 may be separated from the second pad PD2 on a plane (e.g., along the second direction DR2), and the driving chip DC is interposed between the third pad PD3 and the second pad PD2. The driving chip DC may be electrically connected to the second pad PD2 and the third pad PD3. The driving chip DC receives a driving signal output from the driving circuit board PB through the third pad PD3, and outputs a data signal to be provided to the pixel PX based on the received driving signal. The data signal may be transmitted to the first pad PD1 through the second pad PD2. The first pad PD1 may transmit the data signal from the driving chip DC to the data lines DL from among the signal lines SGL, respectively.

[0098] Although the driving chip DC is described herein as being disposed on the circuit board FB, the technical spirit of the inventive concept is not limited thereto. As another example, the driving chip DC may be mounted on the base substrate SUB of the display panel DP.

[0099] The driving circuit board PB may generate all driving signals and power supply signals required to drive the input sensing unit ISU, and may provide the generated driving signals and power supply signals to the display panel DP and the input sensing unit ISU. The driving circuit board PB may include a second board PCB and a driving pad PDd (hereinafter, driving pad) disposed on the second board PCB. The driving pad PDd may be disposed in a driving pad area PA defined in the second board PCB.

[0100] According to an embodiment of the inventive concept, the third pad PD3 included in the circuit board FB may be provided with a second metal layer composed of a single material. The second metal layer of the third pad PD3 may include the same material as the first metal layer of the second pad PD2 (may be composed of the same material as the first metal layer of the second pad PD2). For example, the third pad PD3 may be provided with a metal material for easily (or suitable for) ultrasonic bonding with the metal layer included in the driving pad PDd (may be composed of a metal material for easily (or suitable for) ultrasonic bonding with the metal layer included in the driving pad PDd). Therefore, the overall process cost can be reduced, and ultrasonic bonding between the third pad PD3 and the driving pad PDd can be made easier.

[0101] Although the third pad PD3 and the driving pad PDd are described here as being combined based on an ultrasonic bonding scheme, the technical spirit of the inventive concept is not limited thereto. For example, according to another embodiment, the third pad PD3 and the driving pad PDd may be electrically connected via an adhesive member. In this case, the third pad PD3 and the driving pad PDd may be electrically connected via conductive particles PI( Fig.9A ) electrical connection. Fig.9A and Fig. 9B A more detailed description thereof will be provided.

[0102] about Figure 5B , showing the Figure 5A A partial cross-sectional view of a display panel corresponding to an equivalent circuit of a pixel shown in FIG. 1 . The circuit element layer DP-CL, the display element layer DP-OLED and the insulating layer TFL are sequentially disposed on the base substrate SUB.

[0103] Figure 4 The circuit board FB shown in FIG. 1 may be disposed on a portion of the base substrate SUB, and the portion does not overlap the display element layer DP-OLED. The second pad PD2 included in the circuit board FB may be connected to the first pad PD1 included in the circuit element layer DP-CL.

[0104] In some embodiments, the circuit element layer DP-CL includes at least one insulating layer and circuit elements. The circuit elements include signal lines and / or pixel driving circuits, etc. The circuit element layer DP-CL can be provided by a process of setting an insulating layer, a semiconductor layer and / or a conductive layer (a photolithography process for the insulating layer and / or a patterning process for the semiconductor layer and / or the conductive layer), and can be manufactured by coating and / or deposition, etc.

[0105] The circuit element layer DP-CL may include a buffer layer BFL as an inorganic layer, a first intermediate inorganic layer 10, a second intermediate inorganic layer 20, and an intermediate organic layer 30 as an organic layer. The buffer layer BFL may include a plurality of laminated inorganic layers. Figure 5BThe arrangement relationship among the first semiconductor pattern OSP1, the second semiconductor pattern OSP2, the first control electrode GE1, the second control electrode GE2, the first input electrode DE1, the first output electrode SE1, the second input electrode DE2 and the second output electrode SE2 is exemplarily shown. The first through holes CH1, CH2, CH3 and CH4 are also exemplarily shown.

[0106] The display element layer DP-OLED may include an organic light emitting diode OLED. The display element layer DP-OLED includes a pixel defining layer PDL. For example, the pixel defining layer PDL may be an organic layer.

[0107] The first electrode AE ​​is disposed on the intermediate organic layer 30. The first electrode AE ​​is connected to the second output electrode SE2 through the fifth through hole CH5 penetrating the intermediate organic layer 30. An opening portion OM is defined in the pixel defining layer PDL. The opening portion OM of the pixel defining layer PDL exposes at least a portion of the first electrode AE. The opening portion OM of the pixel defining layer PDL is referred to as a light emitting opening portion to be distinguished from other opening portions.

[0108] In some embodiments, on the top surface of the pixel defining layer PDL, a spacer may be provided to overlap a portion of the pixel defining layer PDL. The spacer may have a shape integral with the pixel defining layer PDL (e.g., the spacer may be integrally formed with the pixel defining layer PDL), or the spacer may be an insulating structure provided by another process.

[0109] The pixel PX may include a light emitting region PXA and a non-light emitting region NPXA adjacent to the light emitting region PXA. The non-light emitting region NPXA may surround the light emitting region PXA. In an embodiment, the light emitting region PXA is defined to correspond to a portion of the first electrode AE ​​exposed by the light emitting opening portion OM.

[0110] The hole control layer HCL may be disposed in the light emitting area PXA and the non-light emitting area NPXA together. The hole control layer HCL may include a hole transport layer and further include a hole injection layer. The light emitting layer EML is disposed on the hole control layer HCL. The light emitting layer EML may be disposed in an area corresponding to the light emitting opening portion OM. In other words, the light emitting layer EML may be disposed in each of a plurality of pixels, respectively. The light emitting layer EML may include an organic material and / or an inorganic material. The light emitting layer EML may generate a specified (or set) color light.

[0111] The electron control layer ECL is arranged on the light emitting layer EML. The electron control layer ECL may include an electron transport layer and also include an electron injection layer. The hole control layer HCL and the electron control layer ECL may be arranged together in a plurality of pixels using an open mask. The second electrode CE is arranged on the electron control layer ECL. The second electrode CE may have an integral shape (e.g., may be integrally formed) and may be arranged together on the electron control layer ECL included in each of the plurality of pixels.

[0112] The insulating layer TFL is disposed on the second electrode CE. The insulating layer TFL may be a single encapsulation layer or a plurality of thin films.

[0113] Figure 6 According to the embodiment of the invention concept Figure 4 A cross-sectional view taken along line II' is shown. Figure 7 A coupling between a first pad and a second pad according to an embodiment of the inventive concept is illustrated. Figure 8 yes Figure 6 An enlarged view of area AA is shown in FIG.

[0114] about Figure 6 , the base substrate SUB may face the first board FCB in the third direction DR3. The first pad PD1 and the second pad PD2 may face each other and contact each other in the third direction DR3.

[0115] As mentioned above about Figure 4 As described, the first pad PD1 and the second pad PD2 according to the inventive concept can be directly bonded by an ultrasonic bonding scheme. For example, the second pad PD2 can be provided with a first metal layer P2 composed of a single material (see Figure 7 ), and may be provided with a metal material that is easily (or suitable for) ultrasonically bonding with the first pad PD1.

[0116] In more detail, about Figure 7 , the first pad PD1 includes: a first sub-metal layer P1a disposed on the base substrate SUB; a second sub-metal layer P1b disposed on the first sub-metal layer P1a; and a third sub-metal layer P1c disposed on the second sub-metal layer P1b. The second pad PD2 composed of a single material may be disposed on the third sub-metal layer P1c, and the third sub-metal layer P1c may contact the second pad PD2.

[0117] According to an embodiment of the inventive concept, the first sub-metal layer P1a and the third sub-metal layer P1c may be provided with the same (same) material (e.g., may be composed of the same (same) material), and may each have a thickness smaller than that of the second sub-metal layer P1b. For example, each of the first sub-metal layer P1a and the third sub-metal layer P1c according to an embodiment of the inventive concept may be provided with titanium (Ti), and the second sub-metal layer P1b may be provided with aluminum (Al). In addition, the second pad PD2 may be provided with copper (Cu).

[0118] The first sub-metal layer P1a provided with titanium can be easily (or suitably) ultrasonically bonded with the base substrate SUB provided with a glass substrate and the second sub-metal layer P1b provided with aluminum. In addition, the third sub-metal layer P1c provided with titanium can be easily (or suitably) ultrasonically bonded with the second pad PD2 and the second sub-metal layer P1b provided with aluminum.

[0119] Ultrasonic bonding between titanium and copper may have a higher bonding efficiency than ultrasonic bonding between aluminum and copper. Here, higher bonding efficiency may refer to a larger direct contact area between the two components. As a result, electrical characteristics between the first pad PD1 and the second pad PD2 may be improved.

[0120] about Figure 8 , showing an ultrasonic bonding process between a first pad PD1 and a second pad PD2. As the ultrasonic process between the second pad PD2 provided with copper (composed of copper) and the third sub-metal layer P1c provided with titanium (composed of titanium) proceeds, the second pad PD2 comes into contact with the third sub-metal layer P1c (e.g., the second pad PD2 contacts the third sub-metal layer P1c). According to an embodiment of the inventive concept, because the third sub-metal layer P1c is provided thin, at least a portion of the third sub-metal layer P1c may be removed during ultrasonic bonding between the third sub-metal layer P1c and the second pad PD2. As a result, at least a portion of the second pad PD2 may contact the second sub-metal layer P1b.

[0121] Fig.9A According to the embodiment of the invention concept Figure 4 A cross-sectional view taken along line II-II' is shown. Fig. 9B According to another embodiment of the invention Figure 4 A cross-sectional view taken along line II-II' is shown.

[0122] As mentioned above about Figure 4 As described above, the third pad area FA2 overlapping the driving pad area PA of the driving circuit board PB is defined in the circuit board FB. According to an embodiment of the inventive concept, the circuit board FB and the driving circuit board PB may be electrically coupled by an adhesive member AF.

[0123] about Fig.9A , the circuit board FB may include a first board FCB and a plurality of third pads PD3 disposed on the first board FCB. The third pads PD3 may be disposed on the first board FCB together with the second pads PD2. The driving circuit board PB may include a second board PCB and driving pads PDd (hereinafter, driving pads) disposed on the second board PCB and electrically connected to the third pads PD3, respectively.

[0124] Each of the third pads PD3 (hereinafter, third pad) may include a second metal layer P3 and an auxiliary metal layer SY. The second metal layer P3 according to an embodiment of the inventive concept may be provided with copper, and the auxiliary metal layer SY may be provided with antimony (Sb).

[0125] The auxiliary metal layer SY can prevent or reduce the second metal layer P3 from being oxidized from the outside. When the auxiliary metal layer SY is omitted, an oxide layer is provided on the surface of the second metal layer P3. For example, when the second metal layer P3 is provided with copper, a copper oxide CuO layer is provided on the surface of the second metal layer P3. However, since the conductivity of copper oxide is low, the electrical connection characteristics between the third pad PD3 and the driving pad PDd electrically connected through the adhesive member AF are reduced.

[0126] The auxiliary metal layer SY according to an embodiment of the inventive concept is disposed on the second metal layer P3 to prevent or reduce the second metal layer P3 from being oxidized externally. In an embodiment of the present disclosure, since the auxiliary metal layer SY is provided with antimony (Sb) having high conductivity, the electrical connection characteristics between the second metal layer P3 and the driving pad PDd can be improved.

[0127] like Fig.9A As shown in , the circuit board FB can be electrically connected to the driving circuit board PB through the adhesive member AF. The adhesive member AF can be provided with an anisotropic conductive film. For example, the adhesive member AF may include conductive particles PI provided in an adhesive film PF having adhesive properties. The conductive particles PI make the third pad PD3 and the driving pad PDd conductive, for example, make the third pad PD3 and the driving pad PDd electrically connected. In an exemplary embodiment, as shown in FIG. Fig.9A As shown in FIG. , the conductive particles PI are in electrical contact with the auxiliary metal layer SY.

[0128] Therefore, the driving signal transmitted to the driving pad PDd through the circuit element mounted on the second board PCB may be provided to the third pad PD3 through the adhesive member AF. The driving signal transmitted to the third pad PD3 may be transmitted to the first pad PD1.

[0129] about Fig. 9B , the circuit board FB and the driving circuit board PB according to another embodiment of the inventive concept may be electrically coupled through an ultrasonic bonding scheme.

[0130] like Fig. 9B As shown in , the third pad PD3a is disposed on the first board FCB. The third pad PD3a of the inventive concept may be provided with a second metal layer composed of a single material. For example, the third pad PD3a may be provided with (composed of) copper.

[0131] As described above, since the third pad PD3 a is provided with copper, the third pad PD3 a is oxidized from the outside to provide a copper oxide CuO layer on the third pad PD3 a.

[0132] However, the copper oxide CuO layer may be removed through an ultrasonic bonding process between the third pad PD3 a and the driving pad PDd. Through the ultrasonic bonding, the third pad PD3 a and the driving pad PDd may be in contact.

[0133] Therefore, the driving signal transmitted to the driving pad PDd through the circuit elements mounted on the second board PCB can be provided to the third pad PD3a composed of a single material through the interface IF between the driving pad PDd and the third pad PD3a.

[0134] Fig.10 is a flowchart illustrating a bonding process between a first pad and a second pad according to an embodiment of the inventive concept. FIG. 11A to FIG. 11C is a diagram showing the steps of ultrasonic bonding between a first pad and a second pad.

[0135] about Fig.10 , an ultrasonic bonding scheme between the display panel DP and the circuit board FB will be described.

[0136] about Fig.10 and Fig.11A In the first operation S110, the first pad PD1 disposed on the base substrate SUB (hereinafter, display substrate or substrate) may be arranged to face the second pad PD2 disposed on the first board FCB in the third direction DR3. In this case, the first pad PD1 and the second pad PD2 may be separated in the third direction DR3.

[0137] In some embodiments, a first oxide layer OY1 is disposed on the first pad PD1, and a second oxide layer OY2 is disposed on the second pad PD2. The first oxide layer OY1 may be a titanium oxide layer resulting from a reaction with titanium, and the second oxide layer OY2 may be a copper oxide layer resulting from a reaction with copper.

[0138] The second pad PD2 according to an embodiment of the inventive concept may be provided with a metal layer composed of a single material, and the first pad PD1 may be provided with a plurality of sub-metal layers in which titanium and aluminum are alternately laminated.

[0139] about Fig.10 and Fig. 11B, in the second operation S120, the first oxide layer OY1 disposed on the first pad PD1 and the second oxide layer OY2 disposed on the second pad PD2 may contact each other. Then, a pressure PS may be applied to the first board FCB of the circuit board FB toward the display substrate SUB. When the pressure PS is applied, vibration according to an ultrasonic wave (UL) frequency may be applied to an interface between the first pad PD1 and the second pad PD2 (third operation S130). As a result, a surface of the first pad PD1 and a surface of the second pad PD2 may contact each other.

[0140] about Fig.10 and Fig. 11C Since ultrasonic vibration is applied between the first pad PD1 and the second pad PD2, the first oxide layer OY1 and the second oxide layer OY2 may be damaged. As a result, the first pad PD1 and the second pad PD2 may contact (eg, may be directly connected) to improve electrical characteristics.

[0141] In addition, according to an embodiment of the inventive concept, a resin RS may be disposed between the first board FCB and the display substrate SUB. For example, the resin RS may block (or reduce) external air from penetrating into the first pad PD1 and the second pad PD2. As a result, oxidation of the first pad PD1 and the second pad PD2 may be prevented or reduced.

[0142] According to embodiments of the inventive concept, electrical connection characteristics between a circuit board and a display panel may be improved.

[0143] The embodiments of the present disclosure have been described above with reference to the accompanying drawings and example embodiments. However, the present invention is not limited to the disclosed embodiments. Specific terms have been used herein, but the specific terms are only used for the purpose of describing the inventive concept and are not used to define the meaning of the inventive concept or to limit the scope of the inventive concept, and the scope of the inventive concept is disclosed in the claims and their equivalents. Therefore, it will be understood by those skilled in the art that various modifications and other equivalent embodiments may be made. Therefore, the substantive technical scope of the inventive concept will be defined by the technical spirit of the claims and their equivalents.

Claims

1. A display device, comprising: A display module, comprising a base substrate and a first pad, wherein the base substrate has a display area and a non-display area adjacent to the display area, and the first pad is located on the base substrate and overlaps the non-display area; A circuit board comprising a first board, a second pad located on the first board and contacting the first pad, and a third pad separated from the second pad on a plane of the circuit board and electrically connected to the second pad; as well as anisotropic conductive film, so that the third pad is electrically connected to the driving circuit board, wherein the second pad is provided with a first metal layer composed of a single material, and The third pad includes: a second metal layer located on the first plate; and an auxiliary metal layer located on the second metal layer and configured to electrically contact the anisotropic conductive film.

2. The display device according to claim 1, wherein: The first pad comprises: A first sub-metal layer, located on the base substrate; a second sub-metal layer, located on the first sub-metal layer; and The third sub-metal layer is located on the second sub-metal layer and contacts the second pad.

3. The display device according to claim 2, wherein: At least a portion of the second sub-metal layer contacts the second pad.

4. The display device according to claim 2, wherein: The second sub-metal layer has a thickness greater than a thickness of each of the first sub-metal layer and the third sub-metal layer.

5. The display device according to claim 2, wherein: The first sub-metal layer and the third sub-metal layer are made of the same material.

6. The display device according to claim 1, wherein: The driving circuit board includes a second board and a driving pad located on the second board and electrically connected to the third pad.

7. The display device according to claim 6, wherein: The anisotropic conductive film includes an adhesive film located between the first plate and the second plate, and conductive particles located in the adhesive film and configured to electrically connect the third pad and the driving pad.

8. The display device according to claim 7, wherein: Said The auxiliary metal layer is configured to electrically contact the conductive particles, The second metal layer is made of the same material as that of the first metal layer.

9. A method for manufacturing a display device, the method comprising the following steps: Arranging a first pad on the display substrate and arranging a second pad and a third pad separated from the second pad and electrically connected to the second pad on the circuit board; bringing the first pad into contact with the second pad; applying pressure on the circuit board in a thickness direction of the display substrate; When the pressure is applied, ultrasonic vibration is generated at the interface between the first pad and the second pad; as well as The third pad is electrically connected to the driving circuit board through an anisotropic conductive film, wherein the second pad is provided with a metal layer composed of a single material, and The third pad includes: a second metal layer located on the circuit board; and an auxiliary metal layer located on the second metal layer and configured to electrically contact the anisotropic conductive film.

10. The manufacturing method according to claim 9, further comprising: A resin is placed between the display substrate and the circuit board such that the resin surrounds the first pad and the second pad.

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