Flexible printed circuit board and method for manufacturing same

Patent metadata

Field	Value
Publication number	US-9648753-B2
Application number	US-201314758753-A
Country	US
Kind code	B2
Filing date	Dec 31, 2013
Priority date	Dec 31, 2012
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

The present invention relates to a method for manufacturing a flexible printed circuit board and a flexible printed circuit board manufactured by using the same. A circuit pattern is formed with a conductive paste on one surface of a base material, and the circuit pattern is sintered at a temperature of 290° C. to 420° C. to manufacture the flexible printed circuit board. As such, manufacturing costs can be reduced and productivity can be improved through a simple yet convenient process. Also, the circuit pattern is formed without a plating process, such that the problem of circuit pattern separation occurring during the plating process can be addressed and product reliability can be improved.

First claim

What is claimed is:

1. A method for manufacturing a flexible printed circuit board, comprising:
screen printing a circuit pattern with conductive paste on one side of a flat polyamide film; and
sintering the circuit pattern at 290° C.˜420° C.;
wherein the conductive paste is a silver paste comprising a silver powder in an amount of from 73 wt % to 88 wt %, a polymer resin in an amount of from 5.9 wt % to 9.5 wt %, and a solvent in an amount of from 5.7 wt % to 18.0 wt %; the silver powder ranges in mean size from 0.5 to 1.2 μm, and the circuit pattern after the sintering has a specific resistivity in a range of from 4.0 μΩ·cm to 6.5 μΩ·cm.

2. The method of claim 1 , wherein the sintering of the circuit pattern is carried out at 310° C.˜410° C.

3. The method of claim 1 , wherein the sintering of the circuit pattern is carried out for a period of 10 min˜35 min.

4. The method of claim 1 , wherein the sintering is achieved by heating the circuit pattern for 20˜30 min.

5. The method of claim 1 , wherein the silver paste further comprises a dispersant in an amount of 0.35 wt %˜2.90 wt %.

Assignees

• Amogreentech Co Ltd

Inventors

• Kim Jong-Soo
• Lee Kyung-Hoon
• Yu Jeong-Sang
• Kwon O-Chung

Classifications

• H05K3/12 Primary

  using {thick film techniques, e.g.} printing techniques to apply the conductive material {or similar techniques for applying conductive paste or ink patterns} · CPC title

• H05K2201/0154

  Polyimide · CPC title

• H05K1/0287

  having an universal lay-out, e.g. pad or land grid patterns or mesh patterns · CPC title

• H05K1/118

  specially for flexible printed circuits, e.g. using folded portions · CPC title

• H05K1/092 Primary

  Dispersed materials, e.g. conductive pastes or inks · CPC title