Chip on film flexible circuit board and display device

Patent metadata

Field	Value
Publication number	US-9713249-B2
Application number	US-201314235955-A
Country	US
Kind code	B2
Filing date	Dec 12, 2013
Priority date	Apr 27, 2013
Publication date	Jul 18, 2017
Grant date	Jul 18, 2017

Abstract

A Chip on Film (COF) flexible circuit board and a display device using the COF flexible circuit board are provided. The circuit board includes: a substrate; a plurality of conductive terminals arranged separately in parallel over the substrate, each of the plurality of conductive terminals including a wide line and a narrow line; and a anisotropic conductive adhesive region provided over the substrate. A connection site of the wide line and the narrow line is located in an overlapping area of the anisotropic conductive adhesive region and the substrate. The embodiments of the invention can reduce the probability of the circuit board being broken and the undesirable phenomena such as open circuit.

First claim

What is claimed is:

1. A Chip on Film (COF) flexible circuit board, comprising:
a substrate;
a plurality of conductive terminals arranged separately in parallel over the substrate, each of the plurality of conductive terminals including a wide line and a narrow line connected with each other; and
an anisotropic conductive adhesive region provided over the substrate;
wherein a connection site of the wide line and the narrow line is provided within an overlapping area of the anisotropic conductive adhesive region and the substrate, which is away from an edge of the anisotropic conductive adhesive region and an edge of the substrate, and a space area is provided between adjacent wide lines, the wide lines have a width larger than a width of the space area; and
a dummy pad of anti-fracture provided at a side of the substrate, wherein the dummy pad includes a wide portion and a narrow portion, a heat pressing position line is preset on the substrate, and the wide portion has a width so that it at least extends to the heat pressing position line.

2. A display device, comprising a display panel, wherein the display panel is coupled to a COF flexible circuit board by anisotropic conductive adhesive, wherein the COF flexible circuit board comprises:
a substrate;
a plurality of conductive terminals arranged separately in parallel over the substrate, each of the plurality of conductive terminals including a wide line and a narrow line connected with each other; and
an anisotropic conductive adhesive region provided over the substrate;
wherein a connection site of the wide line and the narrow line is provided within an overlapping area of the anisotropic conductive adhesive region and the substrate, which is away from an edge of the anisotropic conductive adhesive region and an edge of the substrate, and a space area is provided between adjacent wide lines, the wide lines have a width larger than a width of the space area; and
a dummy pad of anti-fracture provided at a side of the substrate, wherein the dummy pad includes a wide portion and a narrow portion, a heat pressing position line is preset on the substrate, and the wide portion has a width so that it at least extends to the heat pressing position line.

3. The display device according to claim 2 , wherein a ratio of the width of the wide lines and the width of the space area is about 5.5:4.5.

4. The COF flexible circuit board according to claim 1 , wherein a conductive terminal joint area is disposed between several adjacent wide lines, and an end of the conductive terminal joint area is located in the overlapping area of the anisotropic conductive adhesive region and the substrate.

5. The COF flexible circuit board according to claim 1 , wherein the anisotropic conductive adhesive region comprises an anisotropic conductive adhesive attaching region, and an anisotropic conductive adhesive overflowing region formed around the anisotropic conductive adhesive attaching region, and
the connecting site of the wide line and the narrow line is located in the anisotropic conductive adhesive attaching region.

6. The COF flexible circuit board according to claim 1 , wherein the width of the space area is about four times larger than a diameter of conductive particles in the anisotropic conductive adhesive region.

7. The Chip on Film (COF) flexible circuit board according to claim 1 , wherein a ratio of the width of the wide lines and the width of the space area is about 5.1:4.9 to 5.9:4.1.

8. The Chip on Film (COF) flexible circuit board according to claim 1 , wherein a ratio of the width of the wide lines and the width of the space area is about 5.5:4.5.

9. The COF flexible circuit board according to claim 1 , wherein a conductive terminal joint area is disposed between several adjacent wide lines, and an end of the conductive terminal joint area is located in the overlapping area of the anisotropic conductive adhesive region and the substrate.

10. The COF flexible circuit board according to claim 9 , wherein the anisotropic conductive adhesive region comprises an anisotropic conductive adhesive attaching region, and an anisotropic conductive adhesive overflowing region formed around the anisotropic conductive adhesive attaching region, and
both the connecting site of the wide line and the narrow line and an end of the conductive terminal joint area are located in the anisotropic conductive adhesive attaching region.

11. The COF flexible circuit board of claim 9 , wherein, among adjacent conductive terminal joint areas with respect to one conductive terminal joint area, at least one adjacent conductive terminal joint area having a length different from a length of the one conductive terminal joint area is provided.

12. The COF flexible circuit board according to claim 11 , wherein different lengths of the conductive terminal joint areas are arranged alternately.

13. The COF flexible circuit board according to claim 7 , wherein a conductive terminal joint area is disposed between several adjacent wide lines, and an end of the conductive terminal joint area is located in the overlapping area of the anisotropic conductive adhesive region and the substrate.

14. The COF flexible circuit board according to claim 8 , wherein a conductive terminal joint area is disposed between several adjacent wide lines, and an end of the conductive terminal joint area is located in the overlapping area of the anisotropic conductive adhesive region and the substrate.

15. The COF flexible circuit board of claim 10 , wherein, among adjacent conductive terminal joint areas with respect to one conductive terminal joint area, at least one adjacent conductive terminal joint area having a length different from a length of the one conductive terminal joint area is provided.

16. The COF flexible circuit board according to claim 15 , wherein different lengths of the conductive terminal joint areas are arranged alternately.

17. The display device according to claim 2 , wherein a ratio of the width of the wide lines and the width of the space area is about 5.1:4.9 to 5.9:4.1.

18. The display device according to claim 2 , wherein a conductive terminal joint area is disposed between several adjacent wide lines, and an end of the conductive terminal joint area is located in the overlapping area of the anisotropic conductive adhesive region and the substrate.

19. The display device according to claim 2 , wherein the anisotropic conductive adhesive region comprises an anisotropic conductive adhesive attaching region, and an anisotropic conductive adhesive overflowing region formed around the anisotropic conductive adhesive attaching region, and
the connecting site of the wide line and the narrow line is located in the anisotropic conductive adhesive attaching region.

20. The display device according to claim 2 , wherein, among adjacent conductive terminal joint areas with respect to one conductive terminal joint area, at least one adjacent conductive terminal joint area having a length different from a length of the one conductive terminal joint area is provided.

Assignees

• Hefei Boe Optoelectronics Tech
• Boe Technology Group Co Ltd
• Hefei Optoelectronics Tech Co Ltd

Inventors

• Cheng Liang
• Li Yang
• Qi Peng
• Huang Yang
• Gong Xiaowei
• Sun Lian
• Nie Chunyang
• Wang Min

Classifications

• H05K1/028 Primary

  Bending or folding regions of flexible printed circuits (H05K1/0283 takes precedence) · CPC title

• H05K1/117

  Pads along the edge of rigid circuit boards, e.g. for pluggable connectors · CPC title

• H05K2201/09727

  Varying width along a single conductor; Conductors or pads having different widths · CPC title

• H05K1/0296

  Conductive pattern lay-out details not covered by sub groups H05K1/02 - H05K1/0295 (H05K1/11 takes precedence; lay-out adapted to mounted component configuration H05K1/18) · CPC title

• H05K2201/10136

  Liquid Crystal display [LCD] · CPC title