US-20260129771-A1 - CIRCUIT BOARD AND DISPLAY DEVICE

US20260129771A1US 20260129771 A1US20260129771 A1US 20260129771A1US-20260129771-A1

Abstract

A circuit board and a display device are disclosed. The circuit board includes: a base substrate including a device area; a plurality of first pads located on a side of the base substrate and in the device area, where a material of the first pads includes Cu; an oxidation protection layer located on a side away from the base substrate, of the first pads, where the plurality of first pads are bonded to a plurality of electronic components through the oxidation protection layer; a material of the oxidation protection layer includes CuaMgbXc, where X includes one or any combination of Al, Sn, Pb, Au, Ag, In, Zn, Bi, Ga, V, W, Y, Zr, Mo, Nb, Pt, Co or Sb.

Inventors

Kun Zhao
Qi Qi
Zhongpeng Tian
Ce Ning
Zhengliang Li
Nianqi YAO
Jiayu HE
Hehe HU
Jie Huang
Feifei Li

Assignees

BOE TECHNOLOGY GROUP CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20230427
Priority Date: 20220512

Claims (14)

1 . A circuit board, comprising: a base substrate comprising a device area; a plurality of first pads located on a side of the base substrate and in the device area, wherein a material of the first pads comprises Cu; an oxidation protection layer located on a side away from the base substrate, of the first pads, wherein the plurality of first pads are bonded to a plurality of electronic components through the oxidation protection layer; a material of the oxidation protection layer comprises Cu a Mg b X c , wherein X comprises one or any combination of Al, Sn, Pb, Au, Ag, In, Zn, Bi, Ga, V, W, Y, Zr, Mo, Nb, Pt, Co or Sb.
2 . The circuit board according to claim 1 , wherein a thickness of the oxidation protection layer is in a range of 100 Å to 1000 Å.
3 . The circuit board according to claim 1 , wherein in the material of the oxidation protection layer, a sum of a mass fraction of Mg and a mass fraction of X accounts for 5% to 90%.
4 . The circuit board according to claim 3 , wherein a mass fraction of Cu accounts for 20% to 95%, the mass fraction of Mg accounts for 5% to 80%, and the mass fraction of X accounts for 10% to 40%.
5 . The circuit board according to claim 3 , wherein an atomic ratio of Cu, Mg and X is 61:10:29.
6 . The circuit board according to claim 1 , wherein the first pad comprises: a first metal layer located between the base substrate and the oxidation protection layer, and a second metal layer between the first metal layer and the oxidation protection layer; wherein a material of the first metal layer is same as the material of the oxidation protection layer, and a material of the second metal layer comprises Cu.
7 . The circuit board according to claim 1 , wherein the base substrate further comprises a bonding area, the bonding area comprises a plurality of second pads located on the base substrate, the plurality of second pads are configured to be bonded to a printed circuit; the second pads and the first pads are located on a same film layer, and a side away from the base substrate, of the second pads comprises the oxidation protection layer.
8 . The circuit board according to claim 7 , further comprising a first wiring layer located between the first pads and the base substrate, wherein the first wiring layer comprises a first sub-metal layer, a first sub-wiring layer and a second sub-metal layer which are stacked; wherein the first pads are electrically connected to the second sub-metal layer, and the second pads are electrically connected to the second sub-metal layer; a material of the first sub-metal layer and a material of the second sub-metal layer comprise molybdenum-niobium alloy, and a material of the first sub-wiring layer comprises copper.
9 . The circuit board according to claim 8 , wherein the device area further comprises: a first passivation layer located between the first wiring layer and the first pads, a first planarization layer between the first passivation layer and the first pads, a second planarization layer located on a side away from the base substrate, of the oxidation protection layer and covering an area between the plurality of first pads, and a first connection portion located on the oxidation protection layer.
10 . The circuit board according to claim 9 , wherein the bonding area further comprises: a second passivation layer located between the first wiring layer and the second pads, a third planarization layer between the second passivation layer and the second pads, a fourth planarization layer located on the side away from the base substrate, of the oxidation protection layer and covering an area between the plurality of second pads, and a second connection portion located on the oxidation protection layer; wherein the third planarization layer and the first planarization layer are arranged in a same layer, the fourth planarization layer and the second planarization layer are arranged in a same layer, and the second passivation layer and the first passivation layer are arranged in a same layer.
11 . The circuit board according to claim 9 , wherein the plurality of first pads are divided into a plurality of groups of first pads, each of the groups of the first pads comprises a cathode pad and an anode pad arranged in pairs; the circuit board further comprises a second wiring layer arranged in a same layer as the plurality of first pads, and a side away from the base substrate, of the second wiring layer comprises the oxidation protection layer, and the second wiring layer is configured to realize a series connection or parallel connection of the plurality of groups of the first pads, and the second wiring layer is further configured to be electrically connected to the first wiring layer by a through hole penetrating the first planarization layer and the first passivation layer.
12 . The circuit board according to claim 8 , further comprising a protection layer located on a side away from the base substrate, of the oxidation protection layer, the protection layer exposes the oxidation protection layer, a material of the protection layer comprises silicon nitride or silicon oxide.
13 . A display device, comprising: the circuit board according to claim 1 , a printed circuit and a plurality of electronic components; the plurality of electronic components are electrically connected to the plurality of first pads of the circuit board through the oxidation protection layer, and the printed circuit is electrically connected to a plurality of second pads of the circuit board through the oxidation protection layer.
14 . The display device according to claim 13 , wherein each of the electronic components is a Mini LED or a Micro LED.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present disclosure is a National Stage of International Application No. PCT/CN2023/091200, filed on Apr. 27, 2023, which claims priority to Chinese Patent Application No. 202210516249.2, filed with the China National Intellectual Property Administration on May 12, 2022, and entitled “Circuit Board and Display Device”, the content of which is hereby incorporated by reference in its entirety. TECHNICAL FIELD The present disclosure relates to the field of display technology, and in particular to a circuit board and a display device. BACKGROUND SMT is a surface mounted technology (abbreviation for Surface Mounted Technology), which is the most popular technology and process in the electronic assembly industry. SMT is a technology of placing electronic components with pins on a base substrate with pads, and of soldering and assembling the electronic components on a surface of the base substrate through reflow soldering or dip soldering. In order to complete fixed connections between the electronic components and the pads, it is necessary to set solder on the pads to be electrically connected to the electronic components on the base substrate, or to set solder on pins of the electronic components, and then align the electronic components with the pads and make the electronic components with the pads be in contact. For example, at a high temperature of 230° C. to 260° C., the solder is melted and well moistened, and then quickly cooled down to achieve the fixed connections between the electronic components and the pads. SUMMARY Embodiments of the present disclosure provide a circuit board and a display device. The circuit board can avoid the problem of oxidation of the pads in the device area, ensuring reliable electrical connection between the electronic components and the circuit board, and improving product yield. A circuit board according to an embodiment of the present disclosure includes: a base substrate including a device area;a plurality of first pads located on a side of the base substrate and in the device area, where a material of the first pads includes Cu;an oxidation protection layer located on a side away from the base substrate, of the first pads, where the plurality of first pads are bonded to a plurality of electronic components through the oxidation protection layer; a material of the oxidation protection layer includes CuaMgbXc, where X includes one or any combination of Al, Sn, Pb, Au, Ag, In, Zn, Bi, Ga, V, W, Y, Zr, Mo, Nb, Pt, Co or Sb. Optionally, in the circuit board according to an embodiment of the present disclosure, a thickness of the oxidation protection layer is in a range of 100 Å to 1000 Å. Optionally, in the circuit board according to an embodiment of the present disclosure, in the material of the oxidation protection layer, a sum of a mass fraction of Mg and a mass fraction of X accounts for 5% to 90%. Optionally, in the circuit board according to an embodiment of the present disclosure, a mass fraction of Cu accounts for 20% to 95%, the mass fraction of Mg accounts for 5% to 80%, and the mass fraction of X accounts for 10% to 40%. Optionally, in the circuit board according to an embodiment of the present disclosure, an atomic ratio of Cu, Mg and X is 61:10:29. Optionally, in the circuit board according to an embodiment of the present disclosure, the first pad includes: a first metal layer located between the base substrate and the oxidation protection layer, and a second metal layer between the first metal layer and the oxidation protection layer; where a material of the first metal layer is same as the material of the oxidation protection layer, and a material of the second metal layer includes Cu. Optionally, in the circuit board according to an embodiment of the present disclosure, the base substrate further includes a bonding area, the bonding area includes a plurality of second pads located on the base substrate, the plurality of second pads are configured to be bonded to a printed circuit; the second pads and the first pads are located on a same film layer, and a side away from the base substrate, of the second pads includes the oxidation protection layer. Optionally, the circuit board according to an embodiment of the present disclosure, the circuit board according to an embodiment of the present disclosure, further including a first wiring layer located between the first pads and the base substrate, where the first wiring layer includes a first sub-metal layer, a first sub-wiring layer and a second sub-metal layer which are stacked; the first pads are electrically connected to the second sub-metal layer, and the second pads are electrically connected to the second sub-metal layer;a material of the first sub-metal layer and a material of the second sub-metal layer include molybdenum-niobium alloy, and a material of the first sub-wiring layer includes copper. Optionally, in the circuit board according to an embodiment of the pr