Liquid crystal display device and a manufacturing method thereof

A manufacturing method of a liquid crystal display device, the liquid crystal display device, comprising:

• an upper substrate, comprising:
• a substrate;
• a color filter, formed on a surface of the substrate facing a lower substrate;
• and
• a black matrix, formed in the same layer with the color filter;
• a lower substrate, cell-assembled with the upper substrate and comprising:
• a base substrate;
• a gate metal bus, a gate insulating layer, a source/drain metal bus and a first insulating protection layer, which are formed on the base substrate sequentially at a periphery of a display area of the liquid crystal display device;
• a transparent electrode, formed on the first insulating protection layer at the periphery of the display area of the liquid crystal display device;
• and
• a second insulating protection layer, covering the transparent electrode at the periphery of the display area of the liquid crystal display device;
• and
• a seal agent, provided at the periphery of the display area of the liquid crystal display device,
• wherein an upper portion of the seal agent is attached to the substrate and directly contacts the substrate and a lower portion thereof is attached to the second insulating protection layer,
• wherein the gate insulating layer directly contacts the source/drain metal bus, the manufacturing method, comprising following steps:
• Step A:
• sequentially forming a gate metal bus, a gate insulating layer, a source/drain metal bus and a first insulating protection layer on a base substrate at a periphery of a display area of the liquid crystal display device, wherein, a first through hole passing through the gate insulating layer and the first insulating protection layer is formed above the gate metal bus to expose a part of the gate metal bus;
• Step B:
• on the base substrate obtained after the step A, forming a second through hole above the source/drain metal bus, which penetrates through the first insulating protection layer to expose a part of the source/drain metal bus;
• Step C:
• on the base substrate obtained after the step B, forming a transparent electrode connecting the gate metal bus and the source/drain metal bus through the first through hole and the second through hole above the first insulating protection layer at the periphery of the display area of the liquid crystal display device;
• Step D:
• forming a second insulating protection layer on the base substrate obtained after the step C which covers the transparent electrode, so that obtaining a lower substrate;
• and
• Step E:
• using a seal agent to adhere an upper substrate comprising a color filter and a black matrix at the same layer and the second insulating protection layer, and using an ultraviolet ray mask to irradiate and cure the seal agent,
• wherein the gate insulating layer directly contacts the source/drain metal bus,
• wherein, the step D comprises following steps:
• Step D1:
• sequentially depositing insulating material and a photoresist over the first insulating protection layer and the transparent electrode;
• Step D2:
• exposing the photoresist on the insulating material using the ultraviolet light mask, and developing the photoresist;
• Step D3:
• under protection of the exposed and developed photoresist, etching the insulating material to form the second insulating protection layer;
• and
• Step D4:
• removing a residual photoresist.