Printed circuit board and manufacture method thereof

• US 9,510,446 B2
• Filed: 10/03/2014
• Issued: 11/29/2016
• Est. Priority Date: 04/05/2012
• Status: Expired due to Fees

• Current Assignee: Tyco Electronics AMP Korea Ltd. (TE Connectivity Limited)
• Original Assignee: Tyco Electronics AMP Korea Ltd. (TE Connectivity Limited)
• Inventors: Choi, Yang Yun, Youn, Maeng Goun
• Primary Examiner(s): Thompson, Timothy
• Assistant Examiner(s): PIZZUTO, CHARLES M
• Application Number:
  US14/506,170
• Publication Number:
  US 20150021072A1
• Time in Patent Office: 788 Days
• Field of Search: 174/257, 29/173
• US Class Current: 1/1
• CPC Class Codes: H05K 1/0207 using internal conductor planes parallel to the surface for thermal conduction, e.g. power planes
• CPC Class Codes: H05K 1/0209 External configuration of printed circuit board adapted for heat dissipation, e.g. lay-out of conductors, coatings
• CPC Class Codes: H05K 1/09 Use of materials for the conductive, e.g. metallic pattern
• CPC Class Codes: H05K 2201/0323 Carbon
• CPC Class Codes: H05K 2201/0338 Layered conductor, e.g. layered metal substrate, layered finish layer or layered thin film adhesion layer
• CPC Class Codes: H05K 2201/0355 Metal foils
• CPC Class Codes: H05K 2203/0723 Electroplating, e.g. finish plating
• CPC Class Codes: H05K 2203/073 Displacement plating, substitution plating or immersion plating, e.g. for finish plating
• CPC Class Codes: H05K 2203/1394 Covering open PTHs, e.g. by dry film resist or by metal disc
• CPC Class Codes: H05K 3/022 Processes for manufacturing precursors of printed circuits, i.e. copper-clad substrates
• CPC Class Codes: H05K 3/06 the conductive material being removed chemically or electrolytically, e.g. by photo-etch process semi-additive methods H05K3/108
• CPC Class Codes: H05K 3/244 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 H05K3/3457, e.g. by plating H05K3/3473
• CPC Class Codes: H05K 3/383 by microetching
• CPC Class Codes: H05K 3/427 initial plating of through-holes in metal-clad substrates
• CPC Class Codes: Y10T 29/302 Clad or other composite foil or thin metal making

Abstract

A printed circuit board is disclosed having a substrate with an insulating layer, aluminum foil layers disposed on both sides of the insulating layer, and a through-hole formed in the insulating layer and aluminum foil layers. A metal layer is disposed over an exposed surface of the insulating layer positioned along an inner surface of the through-hole. A zinc film is positioned on a surface of the aluminum foil. A metal film is disposed over the zinc film. A plating film is disposed on a surface of the metal film. A circuit pattern is etched through the aluminum foil and the plating film.

Claims

1. A printed circuit board comprising:

a substrate having

an insulating layer,

aluminum foil layers disposed on both sides of the insulating layer, and

a through-hole formed in the insulating layer and aluminum foil layers;

a metal layer disposed over an exposed surface of the insulating layer positioned along an inner surface of the through-hole;

a zinc film positioned on a surface of the aluminum foil;

a metal film disposed over the zinc film;

a plating film disposed on a surface of the metal film; and

a circuit pattern etched through the aluminum foil and the plating film.

2. The printed circuit board of claim 1, wherein the aluminum foil has a chemically etched surface roughness.

3. The printed circuit board of claim 1, further comprising a bonding material positioned between the aluminum foil and the insulating layer.

4. The printed circuit board of claim 3, wherein the bonding material comprises a polyimide-based or epoxy-based bonding sheet.

5. The printed circuit board of claim 3, wherein the metal layer is formed on an exposed surface of the bonding material along the inner surface of the through-hole.

6. The printed circuit board of claim 1, wherein the substrate is multilayered, having a plurality of insulating layers and aluminum foil disposed on both sides of each insulating layer.

7. The printed circuit board of claim 1, wherein the metal layer is a carbon plating layer.

8. The printed circuit board of claim 1, wherein the metal film is a nickel film.

9. The printed circuit board of claim 1, wherein the plating film has an electroplated structure.

10. The printed circuit board of claim 1, wherein the printed circuit board is mounted to an electrical part of a vehicle.

11. The printed circuit board of claim 1, wherein the metal film is further disposed over the metal layer.

12. A manufacturing method for a printed circuit board comprising the steps of:

(a) preparing an aluminum foil;

(b) bonding the aluminum foil to both sides of an insulating layer;

(c) forming a through-hole passing through the aluminum foil and the insulating layer;

(d) forming a metal layer by depositing metal on an exposed portion of an inner surface of the through-hole on the insulating layer;

(e) replacing a surface of the aluminum foil with a zinc (Zn) film;

(f) forming a metal film by performing plating with respect to surfaces of the metal layer and the Zn film; and

(g) forming a plating film on a surface of the metal film by plating.

13. The manufacturing method of claim 12, wherein the step (a) comprises forming roughness on the aluminum foil by etching.

14. The manufacturing method of claim 13, wherein the etching is performed by alkali-based or acid-based chemical processing.

15. The manufacturing method of claim 12, wherein the step (b) comprises bonding of the aluminum foil and the insulating layer using a bonding material that absorbs thermal expansion of the aluminum foil.

16. The manufacturing method of claim 15, wherein the bonding material comprises a polyimide-based or epoxy-based bonding sheet.

17. The manufacturing method of claim 15, wherein the bonding is performed by heating or pressurizing an upper portion and a lower portion of the aluminum foil.

18. The manufacturing method of claim 15, wherein the metal layer is formed on the exposed portion of the bonding material exposed in the inner surface of the through-hole.

19. The manufacturing method of claim 12, wherein the metal layer of the step (d) comprises a carbon plating layer.

20. The manufacturing method of claim 12, wherein the metal film of the step (f) is formed by electrolytic reduction plating.

21. The manufacturing method of claim 12, wherein the step (g) comprises forming the plating film using electroplating.

22. The manufacturing method of claim 12, further comprising a step (h) of forming a circuit pattern on a surface of the plating film.

23. The manufacturing method of claim 22, wherein the circuit pattern is formed by acid etching the plating film and the aluminum foil using a chloride based material.

24. The manufacturing method of claim 23, wherein the chloride based material comprises at least one of ferric chloride, copper chloride, and sodium hypochlorite.

25. The manufacturing method of claim 12, wherein a multilayer printed circuit board is formed by repeating the step (a) and the step (b).