Display device

Abstract

An embodiment of the present invention provides a display device, comprising: a substrate including a display area in which an image is displayed and a non-display area arranged outside the display area; a pad portion arranged in the non-display area on the substrate and including a plurality of pads separated by a predetermined distance; and a flexible printed circuit board coupled to the pad portion, wherein the flexible printed circuit board may include a plurality of leads, each of the plurality of pads may be coupled to each of the plurality of leads, each of the plurality of pads may include a contact pad electrode contacting each of the plurality of leads, and the contact pad electrode may include a dummy electrode surrounding an edge of a lower surface of each of the plurality of leads.

Description

[0001] This application claims the priority benefit of Korean Patent Application No. 10-2019-0037996 filed on April 1, 2019, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0002] The present disclosure relates to a display device and a method for manufacturing the same. Background Art

[0003] The display device includes a substrate and a plurality of signal lines and transistors disposed on the substrate. In addition, a flexible printed circuit film applying various signals for driving the display device may be bonded to the pad of the substrate.

[0004] Anisotropic conductive film (ACF) is used to bond a flexible printed circuit film. Anisotropic conductive film is a film such as a resin film in which conductive particles are arranged in an insulating layer, and the anisotropic conductive film is conductive in its thickness direction and insulating in its surface direction. In this case, the lead and pad of the flexible printed circuit film are bonded by the conductive particles, and the actual bonding area of ​​the pad and the lead is smaller than the area of ​​the pad and the lead.

[0005] The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art. Summary of the invention

[0006] The present invention has been made in an effort to provide a display device and a method of manufacturing the same, which can perform an ultrasonic bonding process to bond a flexible printed circuit film to a substrate.

[0007] According to an exemplary embodiment of the present invention, a display device includes a substrate including a display area and a non-display area, a pad portion having a plurality of pads separated by a predetermined distance from each other, and a flexible printed circuit board having a plurality of leads is disposed in the non-display area. Each of the plurality of pads is coupled to a corresponding lead among the plurality of leads, and each of the plurality of pads includes a contact pad electrode contacting a lower surface of the corresponding lead among the plurality of leads and a dummy electrode surrounding an edge of a lower surface of the corresponding lead among the plurality of leads.

[0008] The contact pad electrode includes the same material as the plurality of lead lines.

[0009] A lower surface of each of the plurality of leads is uneven.

[0010] Each of the plurality of pads includes an inspection portion configured to inspect a lower surface of a corresponding lead among the plurality of leads, and the opening of the contact pad electrode corresponds to the inspection portion.

[0011] Each of the plurality of pads extends in a direction perpendicular to an edge portion of the substrate, and the flexible printed circuit board is connected to the pad portion on the edge portion of the substrate.

[0012] The display device also includes: a semiconductor layer, which is arranged on a substrate; a gate insulating layer, which is arranged on the semiconductor layer; a gate electrode and a first capacitor electrode, which are arranged on the gate insulating layer and separated from each other; a capacitor insulating layer, which is arranged on the gate electrode and the first capacitor electrode; a second capacitor electrode, which is arranged on the capacitor insulating layer and overlapped with the first capacitor electrode; an interlayer insulating layer, which is arranged on the capacitor insulating layer and the second capacitor electrode; a source electrode and a drain electrode, which are arranged on the interlayer insulating layer and separated from each other; a planarization film, which is arranged on the source electrode and the drain electrode; and a light emitting diode, which is arranged on the planarization film and connected to the drain electrode.

[0013] The display device further includes a cutout surrounding each of the plurality of pads. The cutout penetrates the interlayer insulating layer and the capacitor insulating layer.

[0014] The planarization film covers the cutout and covers the side surfaces of the contact pad electrodes.

[0015] Each of the plurality of pads further includes a gate pad electrode disposed between the substrate and the contact pad electrode.

[0016] The display device further includes a plurality of pad contact holes that penetrate the interlayer insulating layer and the capacitor insulating layer to expose the gate pad electrode and are spaced apart from each other in a direction along which the pad portion extends. The capacitor insulating layer and the interlayer insulating layer are disposed between the gate pad electrode and the contact pad electrode. The contact pad electrode contacts the gate pad electrode through the plurality of pad contact holes.

[0017] Each of the plurality of pads further includes a capacitor pad electrode between a gate pad electrode including the same material as the gate electrode and a contact pad electrode including the same material as the second capacitor electrode and the contact pad electrode also including the same material as the source and drain electrodes.

[0018] The display device further includes a plurality of pad contact holes that penetrate the interlayer insulating layer to expose the capacitor pad electrode and are spaced apart from each other in a direction along which the pad portion extends. The capacitor insulating layer is disposed between the gate pad electrode and the capacitor pad electrode. The interlayer insulating layer is disposed between the capacitor pad electrode and the contact pad electrode. The contact pad electrode contacts the capacitor pad electrode through the plurality of pad contact holes.

[0019] The plurality of pads include a first pad and a second pad adjacent to each other, the first pad further including a gate pad electrode disposed between the substrate and the contact pad electrode, and the second pad further including a capacitor pad electrode disposed between the substrate and the contact pad electrode.

[0020] The contact pad electrode further includes protrusions provided on the left side, the right side, and the lower side of the contact pad electrode in a plan view.

[0021] According to an exemplary embodiment of the present invention, a manufacturing method of a display device is provided as follows. A plurality of pixels and a plurality of spare pads are formed on a substrate. Each of the plurality of spare pads includes a data pad electrode. A flexible printed circuit board including a plurality of leads is aligned with the plurality of spare pads so that the data pad electrode is associated with a corresponding lead among the plurality of leads. Ultrasonic vibrations are applied to form a plurality of contact pad electrodes from the data pad electrodes and the corresponding leads associated with each other. Each of the contact pad electrodes contacts a corresponding lead among the plurality of leads. The contact pad electrode includes a material included in the data pad electrode and a material included in the plurality of leads. Each of the plurality of spare pads extends in a first direction perpendicular to an edge portion of the substrate to which the flexible printed circuit board is combined. The application of ultrasonic vibrations is performed in the first direction.

[0022] The application of ultrasonic vibration further forms a dummy electrode around the edge of the lower surface of each of the plurality of leads.

[0023] A lower surface of each of the plurality of lead lines contacting a corresponding contact pad electrode of the plurality of contact pad electrodes is uneven.

[0024] The manufacturing method of the display device further includes performing an inspection on a lower surface of each of the plurality of lead lines through the opening of each of the plurality of contact pad electrodes.

[0025] A data pad electrode and a corresponding contact pad electrode are formed on the interlayer insulating layer, and the data pad electrode includes a step.

[0026] The thickness of the data pad electrode formed on the interlayer insulating layer is thicker than the thickness of the corresponding contact pad electrode formed on the interlayer insulating layer.

[0027] According to an embodiment, a bonding area between a flexible printed circuit film and a substrate may be increased by performing an ultrasonic bonding process to bond the flexible printed circuit film to the substrate. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 A display device according to an exemplary embodiment of the present invention is schematically shown.

[0029] Figure 2 Schematically shows an exemplary embodiment of the present invention. Figure 1 A cross-sectional view of one pixel of the display device shown in FIG.

[0030] Figure 3 Schematically shows an exemplary embodiment of the present invention. Figure 1 The pad portion of the display device shown in .

[0031] Figure 4 Schematically shows a schematic diagram of an exemplary embodiment of the present invention along Figure 3 A cross-sectional view taken along line IV-IV'.

[0032] Figure 5 The exemplary embodiment according to the present invention is shown along Figure 3 A cross-sectional view taken along line V-V'.

[0033] Figures 6 to 8 A bonding process for bonding a flexible printed circuit board to a pad according to an exemplary embodiment of the present invention is schematically illustrated.

[0034] Fig. 9 and Fig.10 A cross-sectional scanning electron microscope (SEM) photograph of a pad portion in a bonding process for bonding a flexible printed circuit board to the pad portion according to an exemplary embodiment of the present invention is shown.

[0035] Fig.11 and Fig.12 A cross-sectional view of a cushion according to an exemplary embodiment of the present invention is schematically shown.

[0036] Fig.13 A cross-sectional view of a cushion according to an exemplary embodiment of the present invention is schematically shown.

[0037] Fig.14 A pad portion of a display device according to an exemplary embodiment of the present invention is schematically illustrated.

[0038] Fig.15 The exemplary embodiment according to the present invention is shown along Fig.14 A cross-sectional view taken along line XV-XV'.

[0039] Fig.16 A pad portion of a display device according to an exemplary embodiment of the present invention is schematically illustrated. DETAILED DESCRIPTION

[0040] Hereinafter, the present invention will be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. As those skilled in the art will appreciate, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

[0041] In order to clearly describe the present invention, parts irrelevant to the description are omitted, and like reference numerals denote like elements throughout the specification.

[0042] In addition, in the drawings, the size and thickness of each element are arbitrarily shown for ease of description, and the present invention is not necessarily limited to the size and thickness shown in the drawings. In the drawings, the thickness of layers, films, panels, regions, etc. are exaggerated for clarity. In the drawings, the thickness of some layers and regions are exaggerated for ease of description.

[0043] It will be understood that when an element such as a layer, film, region, or substrate is referred to as being "on" another element, it may be directly on the other element, or there may be intervening elements. Conversely, when an element is referred to as being "directly on" another element, there are no intervening elements. In addition, in the specification, the words "on..." or "above..." mean being disposed on or below a target portion, and do not necessarily mean being disposed on the upper side of the target portion based on the direction of gravity.

[0044] In addition, unless explicitly described to the contrary, the word “comprise” and variations such as “comprising”, will be understood to imply the inclusion of stated elements but not the exclusion of any other elements.

[0045] Furthermore, throughout the specification, the phrase "on a plane" means observing a target portion from the top, and the phrase "on a section (or on a cross section)" means observing a section formed by vertically cutting the target portion from the side.

[0046] Now refer to Figure 1 A display device according to an exemplary embodiment of the present invention is described.

[0047] Figure 1 A display device according to an exemplary embodiment of the present invention is schematically shown.

[0048] Reference Figure 1 , the display device 1000 according to the present embodiment includes a substrate 100 including a display area DA and a non-display area NA disposed around the display area DA.

[0049] The substrate 100 may include glass or plastic. In addition, the substrate 100 may be a flexible substrate including materials excellent in heat resistance and durability such as polyethylene naphthalate (PEN), polycarbonate (PC), polyarylate (PAR), polyetherimide (PEI), polyethersulfone (PES) and polyimide (PI). However, the present invention is not limited thereto, and the substrate 100 may include a flexible substrate made of various flexible materials.

[0050] Elements for displaying images are provided in the display area DA to display images. The non-display area NA does not display images, and the non-display area NA includes elements and / or wirings for generating and / or transmitting various signals to be applied to the display area DA. Figure 1, four edge regions including the left and right edge regions and the upper and lower edge regions are shown as the non-display region NA. The present invention is not limited thereto. In an exemplary embodiment, only the edge region of one side of the substrate 100 (i.e., only the lower edge region of the substrate 100) may be used as the non-display region NA. Although the display region DA is shown as a quadrilateral, the display region DA may have various shapes such as a circle, an ellipse, and a polygon in addition to the quadrilateral.

[0051] A plurality of pixels PX are arranged in a display area DA of the substrate 100, for example, in a matrix form. Signal lines such as a plurality of gate lines (not shown), a plurality of data lines (not shown) and a plurality of drive voltage lines (not shown) are arranged in the display area DA. The gate lines may extend substantially in a row direction, and the data lines may extend substantially in a column direction intersecting the row direction. In addition, the drive voltage lines may extend substantially in a column direction. Each pixel PX is connected to a corresponding gate line and a corresponding data line to receive a gate signal and a data signal from these signal lines. In addition, each pixel PX may be connected to a corresponding drive voltage line to receive a drive voltage.

[0052] The driving part 300 for generating and / or processing various signals for driving the display device 1000 and the pad part PP including a pad for receiving a signal from the outside are disposed in the non-display area NA of the substrate 100 .

[0053] The driving part 300 may include a data driving part for applying a data signal to the data line, a gate driving part for applying a gate signal to the gate line, and a signal control part for controlling the data driving part and the gate driving part. The driving part 300 may be mounted as a chip between the display area DA and the pad part PP. In this case, the driving part 300 may include a data driving part and a signal control part, and the gate driving part may be integrated in the non-display area NA at the left edge / right edge of the substrate 100.

[0054] The flexible printed circuit film (or referred to as a flexible printed circuit board) 400 includes a first end coupled to the pad portion PP and a second end connected to, for example, an external printed circuit board to receive signals such as image data and receive a power supply voltage such as a driving voltage ELVDD and a common voltage. In an exemplary embodiment, the first end and the second end may be opposite to each other.

[0055] Now refer to Figure 2 To describe Figure 1 The structure of a pixel of the display device shown in .

[0056] A plurality of layers, lines, and elements are disposed on the substrate 100. Although a large number of pixels are arranged in the display area DA of the substrate 100, in order to simplify the drawings, Figure 2Only one pixel is shown in FIG. Each pixel includes a plurality of transistors, but for ease of description, one transistor will be mainly described.

[0057] Figure 2 Schematically shows Figure 1 A cross-sectional view of one pixel of the display device shown in FIG.

[0058] Reference Figure 2 The buffer layer 110 is disposed on the substrate 100. The buffer layer 110 may be made of silicon nitride (SiN x ) or a single layer of silicon nitride (SiN x ) and silicon oxide (SiO x ) is formed by a double layer of the substrate 100. The buffer layer 110 is used to prevent the penetration of unnecessary components such as impurities or moisture while making the surface flat. Depending on the type of the substrate 100 and process conditions, the buffer layer 110 may be omitted.

[0059] The semiconductor layer 120 is disposed on the buffer layer 110. The semiconductor layer 120 may include a source region and a drain region doped with impurities and a channel region disposed between the source region and the drain region. The semiconductor layer 120 may include polycrystalline silicon or an oxide semiconductor.

[0060] The gate insulating layer 131 is disposed on the semiconductor layer 120 and the buffer layer 110, and the gate electrode 140 and the first capacitor electrode C1 separated from each other are disposed on the gate insulating layer 131. The gate electrode 140 and the first capacitor electrode C1 may include the same material. The gate electrode 140 overlaps the semiconductor layer 120. In this case, the gate electrode 140 overlaps the channel region of the semiconductor layer 120.

[0061] The capacitor insulating layer 132 is disposed on the gate electrode 140, the first capacitor electrode C1, and the gate insulating layer 131. The gate insulating layer 131 and the capacitor insulating layer 132 may include inorganic insulating materials such as silicon nitride and silicon oxide. In an exemplary embodiment, the gate insulating layer 131 and the capacitor insulating layer 132 may include different inorganic insulating materials. For example, the gate insulating layer 131 and the capacitor insulating layer 132 may include silicon nitride and silicon oxide, respectively. The present invention is not limited thereto. For example, the gate insulating layer 131 and the capacitor insulating layer 132 may include the same inorganic insulating material.

[0062] The second capacitor electrode C2 is disposed on the capacitor insulating layer 132. The second capacitor electrode C2 overlaps the first capacitor electrode C1 and forms a storage capacitor Cst, and the capacitor insulating layer 132 is disposed as a dielectric between the second capacitor electrode C2 and the first capacitor electrode C1.

[0063] The interlayer insulating layer 150 is disposed on the second capacitor electrode C2 and the capacitor insulating layer 132. The interlayer insulating layer 150 may include an inorganic insulating material such as silicon nitride and silicon oxide.

[0064] The source electrode 161 and the drain electrode 162 separated from each other are disposed on the interlayer insulating layer 150. The source electrode 161 and the drain electrode 162 are connected to the semiconductor layer 120 through contact holes disposed in the gate insulating layer 131, the capacitor insulating layer 132, and the interlayer insulating layer 150. Here, the portion of the semiconductor layer 120 connected to the source electrode 161 and the portion of the semiconductor layer 120 connected to the drain electrode 162 are the source region and the drain region, respectively. The source electrode 161 and the drain electrode 162 may be a single-layer film or a multi-layer film including titanium (Ti), aluminum (Al), or silver (Ag). For example, the source electrode 161 and the drain electrode 162 may have a three-layer film structure of titanium (Ti) / aluminum (Al) / titanium (Ti).

[0065] The gate electrode 140, the source electrode 161, and the drain electrode 162 form a transistor together with the semiconductor layer 120, and a channel of the transistor is formed in a channel region of the semiconductor layer 120 overlapping the gate electrode 140. Figure 2 The transistor shown in can be a driving transistor in a pixel of a display device. Since the gate electrode 140 is disposed above the semiconductor layer 120, the transistor can be a top-gate transistor. The structure of the transistor is not limited thereto, and various changes can be made, for example, the transistor can be a bottom-gate transistor in which the gate electrode is disposed below the semiconductor layer.

[0066] The planarization film 170 is disposed on the source electrode 161, the drain electrode 162, and the interlayer insulating layer 150. The planarization film 170 may include an organic material, and an upper surface of the planarization film 170 may be planarized.

[0067] The light emitting diode LD and the pixel defining layer 190 are disposed on the planarization film 170. The light emitting diode LD emits light according to a signal received from the transistor. The light emitting diode LD includes a first electrode 180, a light emitting member 181, and a second electrode 182.

[0068] The first electrode 180 is disposed on the planarization film 170, and is electrically connected to the drain electrode 162 through a contact hole formed in the planarization film 170. The first electrode 180 functions as an anode of the light emitting diode LD.

[0069] The first electrode 180 may include a reflective material, and may include at least one of magnesium (Mg), silver (Ag), gold (Au), calcium (Ca), lithium (Li), chromium (Cr), aluminum (Al), and alloys thereof.

[0070] The pixel defining layer 190 is disposed on the planarization film 170 and is provided with an opening overlapping the first electrode 180. The pixel defining layer 190 may include an organic material.

[0071] The light emitting member 181 is disposed on the first electrode 180 overlapping the opening of the pixel defining layer 190. For example, the light emitting member 181 is disposed in the opening of the pixel defining layer 190. The light emitting member 181 may include at least one of a light emitting layer, a hole injection layer (HIL), a hole transport layer (HTL), an electron transport layer (ETL), and an electron injection layer (EIL). When the light emitting member 181 includes all of them, the hole injection layer is disposed on the first electrode 180 as an anode, and the hole transport layer, the light emitting layer, the electron transport layer, and the electron injection layer may be sequentially stacked on the hole injection layer. Here, the light emitting layer may include an organic material or may include an inorganic material.

[0072] The second electrode 182 is disposed on the pixel defining layer 190 and the light emitting member 181. The second electrode 182 may include a transparent material. The second electrode 182 may include indium tin oxide (In-Sn-O, ITO), indium gallium oxide (In-Ga-O, IGO) or indium zinc oxide (In-Zn-O, IZO). In addition, the second electrode 182 may include a thin silver-magnesium alloy, a thin silver-lithium alloy, silver (Ag), magnesium (Mg) or calcium (Ca). The second electrode 182 serves as a cathode of the light emitting diode LD.

[0073] The capping layer 191 is disposed on the second electrode 182. The capping layer 191 allows light generated from the light emitting member 181 to be efficiently emitted toward the outside.

[0074] The encapsulation layer 200 is disposed on the cover layer 191. The encapsulation layer 200 can encapsulate the light emitting diode LD to prevent moisture or oxygen from penetrating from the outside. The encapsulation layer 200 includes a first inorganic layer 201, an organic layer 202, and a second inorganic layer 203. The first inorganic layer 201 is disposed on the cover layer 191 and may include an inorganic material. The organic layer 202 is disposed on the first inorganic layer 201 and may include an organic material. In addition, the upper surface of the organic layer 202 may be planarized. The second inorganic layer 203 is disposed on the organic layer 202 and may include an inorganic material. In addition, the encapsulation layer 200 may further include at least one organic layer and at least one inorganic layer sequentially disposed on the second inorganic layer 203. In this case, the organic layer and the inorganic layer may be alternately disposed.

[0075] The touch sensing layer may be provided on the encapsulation layer 200. When an object approaches the touch sensing layer or actually touches the touch sensing layer, the touch sensing layer may sense a touch. Here, the touch includes not only when an external object such as a user's finger directly touches the touch sensing layer, but also when the external object approaches the touch sensing layer or hovers in a state where the external object approaches the touch sensing layer.

[0076] In the following, reference will be made to Figures 3 to 5 describe Figure 1 The pad portion of the display device shown in .

[0077] Figure 3 Schematically shows Figure 1 The pad portion of the display device shown in . Figure 4 Schematically shows the Figure 3 A cross-sectional view taken along line IV-IV'. Figure 5 Shown along Figure 3 A cross-sectional view taken along line V-V'.

[0078] Reference Figures 3 to 5 , one end of the flexible printed circuit film 400 is bonded to the pad portion PP.

[0079] A plurality of pads P are spaced apart from each other at predetermined intervals in the pad portion PP. Each pad P has a substantially rectangular planar shape and extends in a first direction perpendicular to an edge of the substrate 100 where the pad portion PP is provided. For example, one end of the flexible printed circuit film 400 is connected to an edge of the substrate 100. The flexible printed circuit film 400 includes a circuit film 410 and a plurality of leads 420 provided on one surface of the circuit film 410. The plurality of leads 420 may correspond to the plurality of pads P. In an exemplary embodiment, each of the plurality of leads 420 may correspond to a corresponding one of the plurality of pads P, and each of the plurality of leads 420 may be coupled to a corresponding one of the plurality of pads P in the pad portion PP.

[0080] Each pad P includes a gate pad electrode 141, a capacitor pad electrode 143, and a contact pad electrode 165. In the following description of the relationship between the pad portion PP and the display area DA, reference may also be made to Figure 1 and Figure 2 .

[0081] The buffer layer 110 is disposed on the substrate 100, and the gate pad electrode 141 is disposed on the buffer layer 110. The gate pad electrode 141 may include the same material as the gate electrode 140 disposed in the display area DA. The gate pad electrode 141 and the gate electrode 140 may be formed simultaneously by the same process. The present invention is not limited thereto, and the gate pad electrode 141 and the gate electrode 140 may be formed separately by different processes. In addition, although not shown, the gate insulating layer 131 may be disposed between the gate pad electrode 141 and the buffer layer 110.

[0082] The capacitor insulating layer 132 is disposed on the gate pad electrode 141 and the buffer layer 110, and the capacitor pad electrode 143 is disposed on the capacitor insulating layer 132. Although not shown, the gate pad electrode 141 contacts the capacitor pad electrode 143 through a contact hole formed in the capacitor insulating layer 132 outside the pad portion PP. The capacitor pad electrode 143 may include the same material as the second capacitor electrode C2 disposed in the display area DA. The capacitor pad electrode 143 may be formed by the same process as the second capacitor electrode C2. However, the present invention is not limited thereto, and the capacitor pad electrode 143 and the second capacitor electrode C2 may be separately formed by different processes.

[0083] The interlayer insulating layer 150 is disposed on the capacitor pad electrode 143 and the capacitor insulating layer 132. The interlayer insulating layer 150 includes a plurality of pad contact holes 155 overlapping the capacitor pad electrode 143. The plurality of pad contact holes 155 expose the capacitor pad electrode 143. In an exemplary embodiment, the capacitor pad electrode 143 is exposed by the plurality of pad contact holes 155. To simplify the description, the capacitor pad electrode 143 is exposed by three pad contact holes 155. However, the present invention is not limited thereto, and the number of the plurality of pad contact holes 155 may be different from three. The plurality of pad contact holes 155 are separated from each other by a predetermined distance in a first direction along which each of the pads P extends. In addition, a cutout 133 overlapping the buffer layer 110 is disposed in the interlayer insulating layer 150 and the capacitor insulating layer 132. In an exemplary embodiment, the cutout 133 penetrates the interlayer insulating layer 150 and the capacitor insulating layer 132 to expose the buffer layer 110. The cutout 133 is disposed to surround each of the pads P.

[0084] The contact pad electrode 165 is disposed on the interlayer insulating layer 150 and the capacitor pad electrode 143. The contact pad electrode 165 contacts the capacitor pad electrode 143 and a corresponding lead in the lead 420, which may be referred to as the lead 420. The contact pad electrode 165 fills the pad contact hole 155 and contacts the capacitor pad electrode 143 through the pad contact hole 155. The contact pad electrode 165 is connected to the dummy electrode 168 surrounding the edge of the lower surface of the lead 420. The contact pad electrode 165 and the dummy electrode 168 connected to each other may be referred to as a connection pad CP. Here, the lower surface of the lead 420 is a surface in contact with the contact pad electrode 165. The contact pad electrode 165 may include the same material as the source electrode 161 and the drain electrode 162 disposed in the display area DA and the same material as the lead 420. Specifically, the portion of the contact pad electrode 165 contacting the lead 420 may include the same material as the source electrode 161 and the drain electrode 162 and the same material as the lead 420. The dummy electrode 168 may also include the same material as the source electrode 161 and the drain electrode 162 and the same material as the lead 420 .

[0085] The lower surface of the lead 420 contacts the contact pad electrode 165. The lead 420 may include gold (Au) or silver (Ag), and the lower surface of the lead 420 has a protrusion-recess shape such as a bump. For example, the lower surface of the lead 420 may be uneven to increase the contact area between the lead 420 and the contact pad electrode 165. The lower surface of the lead 420 may partially include the same material as the source electrode 161 and the drain electrode 162.

[0086] Each pad P includes an inspection portion 145. The inspection portion 145 is a region where electrodes (i.e., the gate pad electrode 141, the capacitor pad electrode 143, and the contact pad electrode 165) are not present. For example, the inspection portion 145 may be defined by an opening OP of the contact pad electrode 165. Under the opening OP, the interlayer insulating layer 150 and the capacitor insulating layer 132 are provided and may be formed of an oxide material that allows light to pass therethrough. Therefore, the lower surface of the lead 420 may be inspected from the lower surface of the substrate 100 through the inspection portion 145.

[0087] When the flexible printed circuit film 400 is bonded to the pad part PP, an ultrasonic bonding process is performed, in which case the above-mentioned surface concavities and convexities such as bumps may be formed on the lower surface of the lead 420 by ultrasonic vibration. The lower surface of the lead 420 may be inspected by the inspection part 145, and the roughness amount of the lower surface of the lead 420 may be inspected to determine the bonding degree of the pad P and the lead 420. In an exemplary embodiment, as the roughness amount increases, the bonding degree increases.

[0088] In the following, reference will be made to Figures 6 to 8 and Figure 4A method for manufacturing a display device according to an exemplary embodiment of the present invention is described. In addition, in the description of the relationship between the pad portion PP and the display area DA, reference may also be made to Figure 1 and Figure 2 .

[0089] Figures 6 to 8 A bonding process for bonding a flexible printed circuit board to a pad according to an embodiment of the present invention is schematically illustrated.

[0090] Reference Figure 6 and Figure 7 , a plurality of spare pads Plow are formed on the substrate 100. The spare pads Plow are formed in the non-display area NA of the substrate 100. For example, the spare pads Plow may be formed in the pad portion PP. In this case, a plurality of pixels PX and wirings are formed in the display area DA of the substrate 100.

[0091] A plurality of backup pads Plow are formed to be spaced apart from each other by a predetermined distance. Each backup pad Plow has a substantially rectangular planar shape and extends in a first direction perpendicular to an edge of the substrate 100 where the pad portion PP is provided. For example, the flexible printed circuit film 400 is connected to an edge of the substrate 100.

[0092] Each standby pad Plow includes a gate pad electrode 141, a capacitor pad electrode 143, and a data pad electrode 163. The structure of the data pad electrode 163 of the standby pad Plow according to the present embodiment is the same as that of the data pad electrode 163. Figures 3 to 5 The structure of the pad P shown in FIG. 1 is different, and the rest of the structures are the same. Therefore, the description of the same structure will be omitted.

[0093] The data pad electrode 163 is disposed on the interlayer insulating layer 150 and contacts the capacitor pad electrode 143 through the pad contact hole 155. The data pad electrode 163 may include the same material as the source electrode 161 and the drain electrode 162 disposed in the display area DA.

[0094] Reference Figure 8 and Figure 4 After each lead 420 is associated with each spare pad Plow, the flexible printed circuit film 400 is bonded to the pad portion PP. For example, each lead 420 may be aligned with the corresponding spare pad Plow. When the flexible printed circuit film 400 is bonded to the pad portion PP, an ultrasonic bonding process is performed. While performing the ultrasonic bonding process, pressure such as ultrasonic pressure waves is applied in a direction perpendicular to the upper surface of the substrate 100, and the spare pad Plow is bonded in a first direction (such as the first direction) along which it extends. Figure 8 Ultrasonic vibration is performed.

[0095] The data pad electrode 163 forms a step through the pad contact hole 155. In other words, the data pad electrode 163 and the interlayer insulating layer 150 form concavoconvexities on the capacitor pad electrode 143. These concavoconvexities are formed in the extending direction of the backup pad Plow so as to increase the friction between the lead wire 420 and the data pad electrode 163 in the ultrasonic bonding process.

[0096] Since the data pad electrode 163 and the lead line 420 are rubbed against each other due to the ultrasonic bonding process, concavities and convexities are formed on the lower surface of the lead line 420, the material of the lead line 420 and the material of the data pad electrode 163 are mixed, and the mixture thereof contacts the lead line 420 to form the contact pad electrode 165. That is, the pad P including the contact pad electrode 165 is formed. Therefore, the contact pad electrode 165 may include the same material as the source electrode 161 and the drain electrode 162 disposed in the display area DA and the same material as the lead line 420.

[0097] Due to the ultrasonic bonding process, e.g. Figure 4 The thickness of the contact pad electrode 165 disposed on the interlayer insulating layer 150 between the upper surface of the interlayer insulating layer 150 and the upper surface of the contact pad electrode 165 (ie, the thickness D1) indicated in FIG. Figure 7 The thickness (i.e., thickness D2) of the data pad electrode 163 disposed on the interlayer insulating layer 150 indicated in FIG. 1 is small between the upper surface of the interlayer insulating layer 150 and the upper surface of the data pad electrode 163. In addition, due to the ultrasonic bonding process, the concavities and convexities of the data pad electrode 163 and the interlayer insulating layer 150 formed on the capacitor pad electrode 143 are eliminated, and the dummy electrode 168 surrounding the edge of the lower surface of the lead 420 can be formed.

[0098] After the ultrasonic bonding process, the lower surface of the lead 420 may be inspected by the inspection part 145. The bonding degree between the pad P and the lead 420 may be determined by inspecting the roughness of the lower surface of the lead 420 through the inspection part 145 from the lower surface of the substrate 100.

[0099] When the conventional anisotropic conductive film is used to bond the flexible printed circuit film 400 , bonding of the pad P and the lead 420 is performed by conductive balls included in the anisotropic conductive film so that the actual bonding area of ​​the pad P and the lead 420 is smaller than that of the pad P and the lead 420 .

[0100] When the pad P and the lead 420 are bonded by performing an ultrasonic bonding process while bonding the flexible printed circuit film 400 as in the present embodiment, the lead 420 and the contact pad electrode 165, which are not conductive balls, are directly bonded, so that it is possible to increase the bonding area of ​​the pad P and the lead 420. For example, the entire surface of the capacitor pad electrode 143 exposed by the pad contact hole 155 may contact the lead 420.

[0101] Fig. 9 and Fig.10 A cross-sectional scanning electron microscope (SEM) photograph of a pad portion in a bonding process for bonding a flexible printed circuit board to the pad portion according to an exemplary embodiment of the present invention is shown.

[0102] Reference Fig. 9 , as referenced Figure 4 As depicted, the contact pad electrode 165 is connected to the dummy electrode 168 surrounding the edge of the lower surface of the lead 420 .

[0103] Fig.10 FIG. 1 shows a partially enlarged cross-sectional SEM photograph of a pad portion in a bonding process for bonding a flexible printed circuit board to a pad portion according to an embodiment of the present invention, referring to FIG. Fig.10 , the portion of the contact pad electrode 165 indicated by the arrow disposed between the lead 420 and the capacitor pad electrode 143 is a portion including the same material as the lead 420 and the materials of the source electrode 161 and the drain electrode 162. That is, the portion of the contact pad electrode 165 contacting the lead 420 may include the same material as the source electrode 161 and the drain electrode 162 and the same material as the lead 420.

[0104] In the following, reference will be made to Figures 11 to 16 The pad according to an exemplary embodiment of the present invention is described. Here, Fig.11 and Fig.12 ; Fig.13 , Fig.14 and Fig.15 ;as well as Fig.16 Different embodiments are shown.

[0105] Fig.11 and Fig.12 A cross-sectional view of a cushion according to an exemplary embodiment of the present invention is schematically shown. Fig.11 Schematically shows the Figure 4 A cross-sectional view taken along the extension direction of the pad P is shown in FIG. Fig.12 Schematically shows the Figure 5 A cross-sectional view of two adjacent pads P is shown in FIG.

[0106] Reference Fig.11 and Fig.12 , only the structure of the planarization film 170 of the pad portion according to this embodiment is different from Figure 4 and Figure 5 The structure of the pad portion shown in FIG. 1 is different, and the rest of the structures are the same. The description of the same structure will be omitted.

[0107] The planarization film 170 covers the cutout 133 and covers the side surface of the contact pad electrode 165. When the flexible printed circuit film 400 is bonded to the pad portion PP, the metal particles forming the electrode of each pad P and the metal particles forming each lead 420 can be prevented from being attached to the contact pad electrode 165 by the planarization film 170, thereby preventing adjacent pads P from being short-circuited.

[0108] Fig.13 A cross-sectional view of a cushion according to an exemplary embodiment of the present invention is schematically shown. Fig.13 Schematically shows the Figure 4 A cross-sectional view taken along the extending direction of the pad P is shown in FIG.

[0109] Reference Fig.13 , only the structure of the electrode included in the pad portion of this embodiment is different from Figure 4 The structure of the electrode of the pad portion shown in FIG. 1 is different, and the remaining structures are the same. Therefore, the description of the same structure will be omitted.

[0110] Each pad P includes a gate pad electrode 141 and a contact pad electrode 165. That is, different from Figure 4 , the capacitor pad electrode 143 does not exist in the pad P according to the present embodiment. Therefore, the pad contact hole 155 is provided in the interlayer insulating layer 150 and the capacitor insulating layer 132, and overlaps with the gate pad electrode 141. For example, the pad contact hole 155 penetrates the interlayer insulating layer 150 and the capacitor insulating layer 132 to expose the gate pad electrode 141. However, the present invention is not limited thereto, and may be Figure 4 In the exemplary embodiment of FIG. 1 , the gate pad electrode 141 is omitted. That is, each pad P may include a capacitor pad electrode 143 and a contact pad electrode 165 .

[0111] in addition, Fig.11 and Fig.12 The planarization film 170 shown in FIG. 1 may be applied to Fig.13 The pad portion of this exemplary embodiment.

[0112] Fig.14 A pad portion of a display device according to an exemplary embodiment of the present invention is schematically illustrated. Fig.15 Shown along Fig.14 A cross-sectional view taken along line XV-XV'.

[0113] Reference Fig.14 and Fig.15 , the structures of the electrodes included in the pads adjacent to each other are different. That is, only the structure of the electrodes included in the pad portion according to the present embodiment is different from Figures 3 to 5 The structure of the electrode of the pad portion shown in FIG. 1 is different, and the remaining structures are the same. Therefore, the description of the same structure will be omitted.

[0114] The first pad P1 and the second pad P2 of the pad part PP are separated from each other by a predetermined distance. The structure of the electrode included in the first pad P1 and the structure of the electrode included in the second pad P2 are different from each other. The first pad P1 includes a gate pad electrode 141 and a contact pad electrode 165, and the second pad P2 includes a capacitor pad electrode 143 and a contact pad electrode 165.

[0115] Different from Figures 3 to 5 In the pad P shown in FIG. 1 , there is no capacitor pad electrode 143 in the first pad P1. Therefore, the first pad contact hole 155-1 is provided in the interlayer insulating layer 150 and the capacitor insulating layer 132 and overlaps the gate pad electrode 141. For example, the first pad contact hole 155-1 penetrates the interlayer insulating layer 150 and the capacitor insulating layer 132 to expose the gate pad electrode 141. Figures 3 to 5 In the pad P shown in FIG. 1 , there is no gate pad electrode 141 in the second pad P2. Therefore, the second pad contact hole 155-2 is provided in the interlayer insulating layer 150 and overlaps the capacitor pad electrode 143. For example, the second pad contact hole 155-2 penetrates the interlayer insulating layer 150 to expose the capacitor pad electrode 143.

[0116] in addition, Fig.11 and Fig.12 The planarization film 170 shown in FIG. 1 may be applied to Fig.15 The pad portion of the present embodiment.

[0117] Fig.16 A pad portion of a display device according to an exemplary embodiment of the present invention is schematically illustrated.

[0118] Reference Fig.16 , only the structure of the contact pad electrode of the pad portion of this embodiment is different from Figures 3 to 5 The structure of the contact pad electrode of the pad portion shown in FIG. 1 is different, and the remaining structures are the same. Therefore, the description of the same structure will be omitted.

[0119] The contact pad electrode 165 includes, in a plan view, a plurality of protrusions 169 protruding from the contact pad electrode 165. The protrusions 169 protrude in a plan view to the left, right, and lower sides of the contact pad electrode 165. An imaginary center line passing through the center of the protrusion 169 disposed on the left side of the contact pad electrode 165 in a plan view does not intersect with an imaginary center line passing through the center of the protrusion 169 disposed on the right side of the contact pad electrode 165 in a plan view.

[0120] While the invention has been described in connection with what is presently considered to be practical exemplary embodiments, it will be understood that the invention is not limited to the disclosed embodiments, but on the contrary, the invention is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the claims.

Claims

1. A display device, comprising: A substrate including a display area for displaying an image and a non-display area disposed outside the display area; a pad portion having a plurality of pads spaced apart from each other by a predetermined distance; A driving part, arranged between the display area and the pad part; as well as Flexible printed circuit board with multiple leads, Wherein, each of the plurality of pads is coupled to a corresponding lead among the plurality of leads, and each of the plurality of pads comprises a contact pad electrode and a dummy electrode, wherein the contact pad electrode contacts a lower surface of the corresponding lead among the plurality of leads, and the dummy electrode surrounds an edge of the lower surface of the corresponding lead among the plurality of leads.

2. The display device according to claim 1, wherein: The contact pad electrode comprises the same material as the plurality of leads, and The lower surface of each of the plurality of leads is uneven.

3. The display device according to claim 2, wherein: Each of the plurality of pads further includes an inspection portion configured to inspect the lower surface of the corresponding lead of the plurality of leads, and wherein the opening of the contact pad electrode corresponds to the inspection portion, and Each of the plurality of pads extends in a first direction perpendicular to an edge portion of the substrate, and the flexible printed circuit board is connected to the pad portion on the edge portion of the substrate.

4. The display device according to claim 3, further comprising: A semiconductor layer is disposed on the substrate; A gate insulating layer, disposed on the semiconductor layer; a gate electrode and a first capacitor electrode, disposed on the gate insulating layer and separated from each other; a capacitor insulating layer, disposed on the gate electrode and the first capacitor electrode; a second capacitor electrode, disposed on the capacitor insulating layer and overlapping the first capacitor electrode; an interlayer insulating layer, disposed on the capacitor insulating layer and the second capacitor electrode; a source electrode and a drain electrode, disposed on the interlayer insulating layer and separated from each other; A planarization film, disposed on the source electrode and the drain electrode; a light emitting diode disposed on the planarization film and connected to the drain electrode; as well as a cutout surrounding each of the plurality of pads, The cutout penetrates the interlayer insulating layer and the capacitor insulating layer.

5. The display device according to claim 4, wherein: The planarization film covers the cutout and covers a side surface of the contact pad electrode.

6. The display device according to claim 5, wherein: Each of the plurality of pads further includes a gate pad electrode disposed between the substrate and the contact pad electrode, and The display device further includes: a plurality of pad contact holes penetrating the interlayer insulating layer and the capacitor insulating layer to expose the gate pad electrode and spaced apart from each other in the first direction, wherein the capacitor insulating layer and the interlayer insulating layer are arranged between the gate pad electrode and the contact pad electrode, and The contact pad electrode contacts the gate pad electrode through the plurality of pad contact holes.

7. The display device according to claim 5, wherein: Each of the plurality of pads further includes a gate pad electrode disposed between the substrate and the contact pad electrode, Each of the plurality of pads further includes a capacitor pad electrode between the gate pad electrode and the contact pad electrode, The gate pad electrode includes the same material as that of the gate electrode, The capacitor pad electrode includes the same material as that of the second capacitor electrode, and The contact pad electrode includes the same material as that of the source electrode and the drain electrode.

8. The display device according to claim 7, further comprising: a plurality of pad contact holes penetrating the interlayer insulating layer to expose the capacitor pad electrodes and spaced apart from each other in the first direction, Wherein, the capacitor insulating layer is arranged between the gate pad electrode and the capacitor pad electrode, The interlayer insulating layer is disposed between the capacitor pad electrode and the contact pad electrode, and The contact pad electrode contacts the capacitor pad electrode through the plurality of pad contact holes.

9. The display device according to claim 5, wherein: The plurality of pads include a first pad and a second pad adjacent to each other, The first pad further includes a gate pad electrode disposed between the substrate and the contact pad electrode, and The second pad also includes a capacitor pad electrode disposed between the substrate and the contact pad electrode.

10. The display device according to claim 5, wherein: The contact pad electrode further includes a plurality of protrusions disposed on the left side, the right side, and the lower side of the contact pad electrode in a plan view.

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