US-20260130023-A1 - DISPLAY PANEL AND METHOD MANUFACTURING THEREOF

US20260130023A1US 20260130023 A1US20260130023 A1US 20260130023A1US-20260130023-A1

Abstract

A display panel includes a substrate, an LED array disposed on the front side of the substrate, a driving circuit disposed on the front side of the substrate and connected to the LED array, a connecting line and a transparent conductive layer disposed on the back side of the substrate. The connecting line is spaced apart with a side surface of the substrate thereby defining a cutting area. The transparent conductive layer extends from the cutting area and at least partially covering the connecting line. The display panel further includes a first passivation layer and a conductive layer. The first passivation layer is disposed on the transparent conductive layer and the connecting line. The side surfaces of the first passivation layer, the transparent conductive layer, and the substrate are aligned. The conductive layer penetrates the first passivation layer to connect the transparent conductive layer to the driving circuit.

Inventors

Bin-Cheng LIN
Bo-Ru JIAN
Chi-Sheng Liao
Ta-Wen Liao

Assignees

AUO Corporation

Dates

Publication Date: 20260507
Application Date: 20251229
Priority Date: 20220630

Claims (15)

1 . A display panel comprising: a substrate having a front surface and a back surface opposite to each other; a light-emitting diode (LED) array disposed on the front surface of the substrate; a driving circuit disposed on the front surface of the substrate and being coupled to the LED array; a connecting line disposed on the back surface of the substrate, wherein the connecting line is spaced from a side surface of the substrate by a distance such that a cutting area is defined; a transparent conductive layer disposed on the back surface of the substrate, wherein the transparent conductive layer is extended from the cutting area and at least partially covers the connecting line, and a side surface of the transparent conductive layer aligns the side surface of the substrate; a first passivation layer covering a portion of the transparent conductive layer on the connecting line, wherein the first passivation layer does not extend into the cutting area; and a conductive layer, wherein an end of the conductive layer is coupled to the transparent conductive layer, and another end of the conductive layer is coupled to the driving circuit.
2 . The display panel of claim 1 , wherein the connecting line comprises a first region adjacent the cutting area, a third region, and a second region between the first region and the third region, the transparent conductive layer covers the first region and the second region, and the first passivation layer is disposed on the first region and the third region.
3 . The display panel of claim 2 , further comprising: a driving circuit board; and a conductor material connecting the transparent conductive layer on the second region to the driving circuit board.
4 . The display panel of claim 1 , further comprising: a repairing metal embedded in the connecting line and covered by the first passivation layer.
5 . The display panel of claim 1 , further comprising: a repairing metal embedded in the connecting line and the transparent conductive layer and covered by the first passivation layer.
6 . The display panel of claim 1 , further comprising: a transparent insulating layer disposed between the connecting line and the substrate.
7 . The display panel of claim 6 , wherein the transparent conductive layer directly contacts the transparent insulating layer, at the cutting area.
8 . The display panel of claim 1 , wherein the transparent conductive layer directly contacts the substrate, at the cutting area.
9 . A method of manufacturing a display panel, comprising: forming a light-emitting diode (LED) array and a driving circuit coupled to the LED array on a front surface of a substrate; flipping the substrate and forming a patterned metal layer on a back surface of the substrate, the patterned metal layer comprising a connection line and a test pad spaced apart from each other thereby defining a cutting area between the connection line and the test pad; forming a transparent conductive layer on the back surface of the substrate, wherein the transparent conductive layer interconnects the connection line and the test pad; performing an electrical testing comprising using a probe contacting the transparent conductive layer on the test pad; and after the performing the electrical testing, cutting the substrate along the cutting area, to obtain the display panel.
10 . The method of manufacturing the display panel of claim 9 , wherein a side surface of the substrate and a side surface of the transparent conductive layer are aligned, after the cutting the substrate along the cutting area.
11 . The method of manufacturing the display panel of claim 9 , further comprising: after performing an electrical testing and prior to the cutting the substrate along the cutting area, forming a first passivation layer on the transparent conductive layer.
12 . The method of manufacturing the display panel of claim 11 , wherein a side surface of the substrate and a side surface of the transparent conductive layer, and a side surface of the first passivation layer are aligned, after the cutting the substrate along the cutting area.
13 . The method of manufacturing the display panel of claim 11 , wherein when a defect is found after performing the electrical testing, the method further comprises repairing the defect before the first passivation layer is formed.
14 . The method of manufacturing the display panel of claim 11 , further comprising: forming a second passivation layer on the first passivation layer; forming a protection layer on the second passivation layer; forming an opening penetrating the first passivation layer, the second passivation layer, and the protection layer to expose the transparent conductive layer; filling a conductor material in the opening; and connecting a driving circuit board to the conductor material.
15 . The method of manufacturing the display panel of claim 9 , further comprising: after cutting the substrate along the cutting area, forming a conductive layer connecting the transparent conductive layer at the back surface of the substrate to the driving circuit at the front surface of the substrate.

Description

RELATED APPLICATIONS This is a Divisional of U.S. application Ser. No. 18/161,383, filed Jan. 30, 2023, which claims priority to Taiwanese Application Serial Number 111124607, filed Jun. 30, 2022, and U.S. Provisional Application Ser. No. 63/313,744, filed Feb. 25, 2022, the entirety of which is incorporated by reference herein in their entireties. BACKGROUND Field of Invention The present invention relates to a display panel and method of manufacturing the same. Description of Related Art With the development of the display technique, the desire to the narrow frame displays or frameless displays is increased. The decreasing area of the frame can satisfy the requirement of greater display area. However, the narrow frame displays or frameless displays face a challenge of narrow line width and high wiring density. For the forgoing reasons, there is a need for maintaining the yield of the display and satisfying narrow frame or frameless requirement of the display. SUMMARY An aspect of the disclosure provides a display panel. The display panel includes a substrate having a front surface and a back surface opposite to each other, a light-emitting diode (LED) array disposed on the front surface of the substrate, a driving circuit disposed on the front surface of the substrate and being coupled to the LED array, a connecting line disposed on the back surface of the substrate, a transparent conductive layer disposed on the back surface of the substrate, a first passivation layer covering a portion of the transparent conductive layer on the connecting line, and a conductive layer. The connecting line is spaced from a side surface of the substrate by a distance such that a cutting area is defined. The transparent conductive layer is extended from the cutting area and at least partially covers the connecting line, and a side surface of the transparent conductive layer aligns the side surface of the substrate. The first passivation layer does not extend into the cutting area. An end of the conductive layer is coupled to the transparent conductive layer, and another end of the conductive layer is coupled to the driving circuit. Another aspect of the disclosure provides a method of manufacturing a display panel. The method includes forming a light-emitting diode (LED) array and a driving circuit coupled to the LED array on a front surface of a substrate; flipping the substrate and forming a patterned metal layer on a back surface of the substrate, the patterned metal layer comprising a connection line and a test pad spaced apart from each other thereby defining a cutting area between the connection line and the test pad; forming a transparent conductive layer on the back surface of the substrate, wherein the transparent conductive layer interconnects the connection line and the test pad; performing an electrical testing comprising using a probe contacting the transparent conductive layer on the test pad; and after the performing the electrical testing, cutting the substrate along the cutting area, to obtain the display panel. The method of manufacturing the display panel and the display panel thereof include performing the electrical test to the metal layer and the transparent conductive layer right after the metal layer and the transparent conductive layer are patterned. The defect can be found and repaired after the electrical test is performed. Because there is no other layer covering the connecting line and the transparent conductive layer when the defect is detected and repaired, the position of the defect can be observed easily, and the repairing metal can be filled in the defect easily. The cutting area does not include the metal layer such that the thickness of the cutting area is reduced. It is to be understood that both the foregoing general description and the following detailed description are by examples, and are intended to provide further explanation of the invention as claimed. BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings, FIG. 1 and FIG. 2 are backside views of a display panel of different manufacturing stages according to some embodiments of the disclosure, respectively; FIGS. 3, 4, 6, 7, 8, 9, 11, and 12 are cross-sectional views, taken along line A-A of FIG. 1, of the different stages of manufacturing the display panel, according to some embodiments of the disclosure, respectively; FIG. 5 is a top view of FIG. 4; FIG. 10 is a top view illustrating the connecting line of FIG. 9; FIG. 13 is a cross-sectional view of some other embodiments of the display panel of the disclosure; FIG. 14 is a cross-sectional view of some other embodiments of the display panel of the disclosure; FIG. 15 is a cross-sectional