Printed circuit board and method for manufacturing same

Patent metadata

Field	Value
Publication number	US-2016353582-A1
Application number	US-201514848517-A
Country	US
Kind code	A1
Filing date	Sep 9, 2015
Priority date	May 27, 2015
Publication date	Dec 1, 2016
Grant date	—

Abstract

The present disclosure relates to a method for manufacturing a printed circuit board. The method includes the steps as follows. First, a substrate including a base layer and a copper foil layer on a surface of the base layer is provided. Second, a conductive layer is formed on portions of the copper foil layer. Third, portions of the copper foil layer exposed from the conductive layer are removed by an etching process, and the conductive layer is thinner by the etching process. The reserved portions of the copper foil layer and the conductive layer forms a conductive pattern to obtain a printed circuit board without plating wires. A printed circuit board without plating wires made by the above method is also provided.

First claim

What is claimed is:

1 . A method of manufacturing a printed circuit board comprising:
providing a substrate comprising a base layer and a first copper foil layer formed on one side of the base layer; electroplating a first conductive layer on a portion of a surface of the first copper foil layer; electroplating a first surface treatment patterned layer on a portion of the surface of the first conductive layer; etching another portion which is not covered with the first conductive layer, of the first copper foil layer; and reducing a thickness of yet another portion of the first conductive layer which is not covered with the first surface treatment patterned layer.

2 . The method of manufacturing a printed circuit board of claim 1 , wherein the first conductive layer is thicker than the first copper foil layer.

3 . The method of manufacturing a printed circuit board of claim 1 , wherein the first surface treatment patterned layer is made of nickel-gold (Ni—Au), nickel-platinum-gold (Ni—Pt—Au), or nickel-palladium-gold (Ni—Pd—Au).

4 . The method of manufacturing a printed circuit board of claim 1 , wherein the method further comprises:
forming a first solder mask er on the surface of the first conductive layer which is not covered with the face treatment patterned layer, the first solder mask layer covers a portion of the surfaces of the first surface treatment patterned layer and the base layer at the same side, the first surface treatment patterned layer exposed from the first solder mask layer becomes a connective portion for electrically connection.

5 . The method of manufacturing a printed circuit board of claim 1 , wherein the method prior to electroplate the first conductive layer further comprises:
drilling a through hole through the base layer from the first copper foil layer to a second copper foil layer opposite to the first copper foil layer and formed on another side of the base layer; and forming a seed layer on the wall of the through hole and on the surfaces of the first copper foil layer and the second copper foil layer.

6 . The method of manufacturing a printed circuit board of claim 5 , wherein the thickness of the first conductive layer is greater than the sum of the thicknesses of the first copper foil layer and the seed layer.

7 . The method of manufacturing a printed circuit board of claim 5 , wherein the method for electroplating the first conductive layer further comprises:
electroplating a second conductive layer on a portion of the surface of the seed layer located on the second copper foil layer, and electroplating a third conductive layer on the surface of the seed layer located on the wall of the through hole, each of the seed layer, the first copper foil layer, and the second copper foil layers which are not covered with the first conductive layer or the second conductive layers are formed as a removable plating wire.

8 . The method of manufacturing a printed circuit board of claim 7 , wherein the thickness of the second conductive layer is greater than the sum of the thicknesses of the second copper foil layer and the seed layer positioned on the second copper foil layer.

9 . The method of manufacturing a printed circuit board of claim 7 , wherein the second conductive layer has the same thickness as the first conductive layer.

10 . The method of manufacturing a printed circuit board of claim 7 , wherein the method for etching the first copper foil layer which not covered with the first conductive layer further comprises:
etching the seed layer which is not covered with the first conductive layer or the second conductive layer, and etching the second copper foil layer which is not covered with the second conductive layer, wherein after etching, the first copper foil layer, the seed layer positioned on the first copper foil layer, and the first conductive layer positioned on the seed layer are formed as a first conductive pattern, and the second copper foil layer, the seed layer positioned on the second copper foil layer, and the second conductive layer positioned on the seed layer are formed as a second conductive pattern.

11 . A printed circuit board comprising:
a base layer; a first conductive pattern comprising:
a first copper foil layer formed on one side of the base layer; and
a first conductive layer formed on a portion of a surface of the first copper foil layer; and
a first surface treatment patterned layer formed on a portion of a surface of the first conductive pattern,
wherein the first conductive pattern which is covered with the first surface treatment patterned layer has sidewalls tilted with respect to the base layer at an oblique angle, the first conductive pattern covered with the first surface treatment patterned layer having a cross section that is trapezoidal shaped, and a width gradually decreasing in a direction from the base layer to the first conductive layer.

12 . The printed circuit board of claim 11 , wherein the thickness of the first conductive layer is greater than the thickness of the first copper foil layer.

13 . The printed circuit board of claim 11 , wherein the thickness of the first conductive pattern which is covered with the first surface treatment patterned layer is greater than the thickness of the first conductive pattern which is not covered with the first surface treatment patterned layer.

14 . The printed circuit board of claim 11 , wherein the first surface treatment patterned layer is made of nickel-gold (Ni—Au), nickel-platinum-gold (Ni—Pt—Au), or nickel-palladium-gold (Ni—Pd—Au).

15 . The printed circuit board of claim 11 , wherein the printed circuit board further comprises a first solder mask layer, the first solder mask layer covers the surface of the first conductive pattern which is not covered with the first surface treatment patterned layer and part of the surfaces of the first surface treatment patterned layer and the base layer at the same side, and the first surface treatment patterned layer exposed from the first solder mask layer becomes a first connective portion.

16 . The printed circuit board of claim 15 , wherein the first connective portion is a bonding pad or a conductive finger.

17 . The printed circuit board of claim 11 , wherein the printed circuit board further comprises:
a second conductive pattern opposite to the first conductive pattern and formed on another side of the base layer, the second conductive pattern comprises:
a second copper foil layer opposite to the first copper foil layer; and
a second conductive layer formed on a portion of a surface of the second foil layer; and
a second surface treatment patterned layer formed on a portion of a surface of the second conductive pattern; and a through hole covered with a third conductive layer to be formed as a conductive through hole for connecting the first conductive pattern and the second conductive pattern,
wherein the second conductive pattern which is covered with the second surface treatment patterned layer has sidewalls tilted with respect to the base layer at an oblique angle, the second conductive pattern covered with the second surface treatment patterned layer having a cross section that is trapezoidal shaped, and a width gradually decreased in a direction from the base layer to the second conductive layer.

18 . The printed circuit board of claim 17 , wherein the thickness of the second conductive pattern which is covered with the second surface treatment patterned layer is greater than the thickness of the second cond

Assignees

• Fukui Prec Component (Shenzhen) Co Ltd
• Hongqisheng Prec Electronics (Qinhuangdao) Co Ltd
• Zhen Ding Tech Co Ltd

Inventors

• Su Wei-Shuo

Classifications

• H05K2201/09736

  Varying thickness of a single conductor; Conductors in the same plane having different thicknesses · CPC title

• H05K3/427

  initial plating of through-holes in metal-clad substrates · CPC title

• H05K3/244 Primary

  Finish plating of conductors, especially of copper conductors, e.g. for pads or lands (selective plating methods H05K3/243; finish plating of conductors made by printing techniques H05K3/246; solder as finish H05K3/3465) · CPC title

• H05K2201/0338

  Layered conductor, e.g. layered metal substrate, layered finish layer or layered thin film adhesion layer · CPC title

• H05K2203/0723

  Electroplating, e.g. finish plating · CPC title