CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to, and the benefit of, Korean Patent Application No. 10-2020-0040855 filed on Apr. 3, 2020 in the Korean Intellectual Property Office, the contents of which in its entirety are herein incorporated by reference.

BACKGROUND

1. Field

The present disclosure relates to a display device.

2. Description of the Related Art

Display devices have increasingly become of importance with the development of multimedia, and various types of display devices, such as an organic light-emitting diode (OLED) display device, a liquid crystal display (LCD) device, or the like, have been used.

A display device, which is a device for displaying an image, includes a display panel such as an OLED display panel or an LCD panel. The display panel may include light-emitting elements such as light-emitting diodes (LEDs), and the LEDs may be classified into OLEDs using an organic material as a fluorescent material, and inorganic LEDs (ILEDs) using an inorganic material as a fluorescent material.

SUMMARY

Embodiments of the present disclosure provide a display device including a new pad electrode structure.

Embodiments of the present disclosure also provide a display device including a new pad electrode structure that uses inorganic light-emitting diodes (ILEDs).

However, embodiments of the present disclosure are not restricted to those set forth herein. The above and other embodiments of the present disclosure will become more apparent to one of ordinary skill in the art to which the present disclosure pertains by referencing the detailed description of the present disclosure given below. According to the aforementioned and other embodiments of the present disclosure, some layers in a display area and a pad area can be merged and formed together by the same process. A display device having a new pad structure that includes pad electrodes that consist of layers located in the display area and can thus protect wire pads from subsequent processes can be provided.

In addition, the display device does not require a separate mask process for forming pad electrodes on wire pads. Thus, the number of mask processes that need to be performed in the pad area can be reduced, and as a result, the efficiency of the fabrication of the display device can be improved.

However, aspects of the present disclosure are not restricted to the one set forth herein. The above and other aspects of the present disclosure will become more apparent to one of ordinary skill in the art to which the present disclosure pertains by referencing the detailed description of the present disclosure given below.

According to some embodiments of the present disclosure, a display device includes a first substrate including a display area and a pad area, a wire pad on the first substrate in the pad area, first banks on the first substrate in the display area and spaced apart from each other, electrodes on the first banks and spaced apart from each other, a pad electrode base layer directly on the wire pad, having a greater width than the wire pad, and covering sides of the wire pad, a first insulating layer covering parts of the electrodes and part of the pad electrode base layer, light-emitting elements on the first insulating layer in the display area, respective ends of one of the light-emitting elements being on different ones of the electrodes, contact electrodes on the electrodes and contacting first ends of the light-emitting elements, and a pad electrode upper layer on the first insulating layer in the pad area and directly contacting the pad electrode base layer, wherein the pad electrode base layer includes the same material as the electrodes, and wherein the pad electrode upper layer includes the same material as the contact electrodes.

The first insulating layer may define a pad opening exposing part of a top surface of the pad electrode base layer, wherein the pad electrode upper layer contacts the exposed part of the top surface of the pad electrode base layer through the pad opening.

The pad electrode base layer may include an alloy of aluminum, wherein the pad electrode upper layer includes ITO, IZO, or ITZO.

The pad electrode base layer may be on the same layer as the wire pad.

The first insulating layer may have a greater width than the pad electrode base layer, and may be partially on the same layer as the pad electrode base layer and the wire pad, in the pad area.

The display device may further include a second insulating layer partially on the light-emitting elements, wherein the contact electrodes are on the second insulating layer and are spaced apart from each other.

The contact electrodes may directly contact different electrodes through openings that penetrate the first insulating layer to expose parts of top surfaces of the electrodes.

The second insulating layer might not be in the pad area.

The display device may further include a first interlayer insulating layer on the first substrate, a first data conductive layer on the first interlayer insulating layer, and including source and drain electrodes, a second interlayer insulating layer on the first data conductive layer, and a second data conductive layer on the first interlayer insulating layer and including voltage lines, wherein the wire pad is directly on the second interlayer insulating layer.

The display device may further include a third interlayer insulating layer on the second data conductive layer and excluded from the pad area, wherein the first banks are on the third interlayer insulating layer in the display area.

The first banks may be directly on the third interlayer insulating layer, wherein the third interlayer insulating layer is omitted from area where the first banks are spaced apart from each other to thereby expose the second interlayer insulating layer, and wherein sides of the third interlayer insulating layer are aligned with sides of the first banks.

At least part of the electrodes may be directly on the second interlayer insulating layer.

Opposing sides of the first banks may be inclined, wherein the light-emitting elements are between the first banks.

The display device may further include a second bank overlapping the first banks in a thickness direction, located over the first insulating layer, and surrounding an area in which the light-emitting elements are located.

The display area may include a cut area that is surrounded by the second bank, and in which the light-emitting elements are not located, wherein the electrodes and the first insulating layer are in the cut area, but are disconnected by a cut part, and wherein cut surfaces of the electrodes are aligned with cut surfaces of the first insulating layer.

According to some embodiments of the present disclosure, a display device includes a first substrate including a display area and a pad area, a data conductive layer on the first substrate and including power supply lines, which are in the display area, and a wire pad, which is in the pad area, first banks on the first substrate in the display area, and spaced apart from each other, first and second electrodes on the first banks in the display area, a pad electrode base layer in the pad area to cover the wire pad, a first insulating layer on the first electrode, the second electrode, and the pad electrode base layer and defining openings, light-emitting elements on the first insulating layer, between the first banks, and having respective ends on the first and second electrodes, first and second contact electrodes on the first and second electrodes in the display area, and contacting first ends of the light-emitting elements, and a pad electrode upper layer on the first insulating layer in the pad area, and directly contacting the pad electrode base layer.

The first electrode, the second electrode, and the pad electrode base layer may include the same material, wherein the first contact electrode, the second contact electrode, and the pad electrode upper layer include the same material.

The pad electrode base layer may have a greater width than the wire pad, wherein the first insulating layer and the pad electrode base layer are partially on the same layer as the wire pad in the pad area.

The display device may further include a first interlayer insulating layer on the first substrate and directly contacting the data conductive layer, and a second interlayer insulating layer on the data conductive layer, wherein the wire pad is directly on the second interlayer insulating layer.

The second interlayer insulating layer may expose part of the first interlayer insulating layer, wherein the first banks are directly on the second interlayer insulating layer so that the second interlayer insulating layer is aligned with inner sides of the first banks, and wherein parts of the first and second electrodes are directly on the first interlayer insulating layer.

