Method for manufacturing printed wiring board

Patent metadata

Field	Value
Publication number	US-9078343-B2
Application number	US-201113325105-A
Country	US
Kind code	B2
Filing date	Dec 14, 2011
Priority date	Feb 22, 2011
Publication date	Jul 7, 2015
Grant date	Jul 7, 2015

Abstract

A method for manufacturing a printed wiring board including forming a penetrating hole in a core substrate, forming a first conductor on a first surface of the substrate, forming a second conductor on a second surface of the substrate, and filling a conductive material in the hole such that a through-hole conductor is formed in the hole and the first and second conductors are connected via the through-hole conductor. The forming of the hole includes forming a first opening in the first surface, forming a second opening from the bottom of the first opening toward the second surface such that the second opening has a smaller diameter than the first opening, forming a third opening in the second surface, and forming a fourth opening from the bottom of the third opening toward the first surface such that the fourth opening has a smaller diameter than the third opening.

First claim

What is claimed is:

1. A method for manufacturing a printed wiring board, comprising:
preparing a core substrate;
forming a penetrating hole in the core substrate;
forming a first conductor on a first surface of the core substrate;
forming a second conductor on a second surface of the core substrate on an opposite side of the first surface of the core substrate; and
filling a conductive material in the penetrating hole such that a through-hole conductor is formed in the penetrating hole and the first conductor and the second conductor are connected via the through-hole conductor,
wherein the forming of the penetrating hole comprises forming a first opening portion in the first surface of the core substrate, forming a second opening portion from a bottom portion of the first opening portion toward the second surface such that the second opening portion forms a first bent portion connected to the first opening portion and has a diameter which is smaller than a diameter of the first opening portion, forming a third opening portion in the second surface of the core substrate, and forming a fourth opening portion from a bottom portion of the third opening portion toward the first surface such that the fourth opening portion forms a second bent portion connected to the third opening portion and a third bend portion connected to the second opening portion and has a diameter which is smaller than a diameter of the third opening portion, the first opening portion inclines at an angle θ 1 and the second opening portion inclines at an angle θ 2 such that θ 1 >θ 2 is satisfied with respect to an axis normal to the first and second surfaces, and the third opening portion inclines at an angle θ 3 and the fourth opening portion inclines at an angle θ 4 such that θ 3 >θ 4 is satisfied with respect to the axis normal to the first and second surfaces.

2. The method for manufacturing a printed wiring board according to claim 1 , wherein the forming of the first opening portion comprises tapering the first opening portion to become narrower from the first surface of the core substrate toward the second surface, the forming of the second opening portion comprises tapering the second opening portion to become narrower from the first surface of the core substrate toward the second surface, the forming of the third opening portion comprises tapering third opening portion to become narrower from the second surface of the core substrate toward the first surface, and the forming of the fourth opening portion comprises tapering the fourth opening portion to become narrower from the second surface of the core substrate toward the first surface.

3. The method for manufacturing a printed wiring board according to claim 2 , wherein the forming of the first opening portion and the forming of the second opening portion satisfy ΔW 1 >ΔW 2 , where ΔW 1 represents a ratio at which a diameter of the first opening portion becomes narrower in a direction from the first surface of the core substrate toward the second surface, and ΔW 2 represents a ratio at which a diameter of the second opening portion becomes narrower in a direction from the first surface of the core substrate toward the second surface, and the forming of the third opening portion and the forming of the fourth opening portion satisfy ΔW 3 >ΔW 4 , where ΔW 3 represents a ratio at which a diameter of the third opening portion becomes narrower in a direction from the second surface of the core substrate toward the first surface, and ΔW 4 represents a ratio at which a diameter of the fourth opening portion becomes narrower in a direction from the second surface of the core substrate toward the first surface.

4. The method for manufacturing a printed wiring board according to claim 1 , wherein the forming of the penetrating hole comprises irradiating laser such that the penetrating hole is formed.

5. The method for manufacturing a printed wiring board according to claim 4 , wherein the irradiating of the laser comprises setting a laser diameter for forming the second opening portion to be smaller than a laser diameter for forming the first opening portion, and setting a laser diameter for forming the fourth opening portion to be smaller than a laser diameter for forming the third opening portion.

6. The method for manufacturing a printed wiring board according to claim 4 , wherein the laser for forming the second opening portion has a pulse width which is set to be longer than a pulse width of the laser for forming the first opening portion, and the laser for forming the fourth opening portion has a pulse width which is set to be longer than a pulse width of the laser for forming the third opening portion.

7. The method for manufacturing a printed wiring board according to claim 4 , wherein the irradiating of the laser satisfies 1.5≦B/A ≦3, where A represents the pulse width of the laser for forming the first opening portion and the third opening portion, and B represents the pulse width of the laser for forming the second opening portion and the fourth opening portion.

8. The method for manufacturing a printed wiring board according to claim 4 , wherein the irradiating of the laser comprises taking at least two shots of the laser for forming the second opening portion and the fourth opening portion.

9. The method for manufacturing a printed wiring board according to claim 8 , wherein the irradiating of the laser comprises setting laser conditions for each shot of the laser for forming the second opening portion and the fourth opening portion to be substantially a same.

10. The method for manufacturing a printed wiring board according to claim 1 , wherein the forming of the penetrating hole comprises offsetting a straight line passing through the gravity center of the second opening portion and perpendicular to the first surface of the core substrate from a straight line passing through the gravity center of the fourth opening portion and perpendicular to the second surface of the core substrate.

11. The method for manufacturing a printed wiring board according to claim 1 , wherein the core substrate has a thickness which is 0.4mm or greater.

12. The method for manufacturing a printed wiring board according to claim 1 , wherein the forming of the penetrating hole satisfies 0.6 ≦Wmin/Wmax≦0.8, where Wmax represents the maximum diameter of the penetrating hole, and Wmin represents the minimum diameter of the penetrating hole.

13. The method for manufacturing a printed wiring board according to claim 1 , wherein at least one of the first opening portion and the second opening portion is formed such that at least one of the first opening portion and the second opening portion has the maximum diameter of the penetrating hole.

14. The method for manufacturing a printed wiring board according to claim 1 , wherein the fourth opening portion is formed such that the third bend portion forms the minimum diameter of the penetrating hole.

15. The method for manufacturing a printed wiring board according to claim 1 , wherein at least one of the first opening portion and the second opening portion is formed such that at least one of the first opening portion and the second opening portion has the maximum diameter of the penetrating hole, and the fourth opening portion is formed such that the third bend portion forms the minimum diameter of the penetrating hole.

16. The method for manufacturing a printed wiring board according to claim 1 , wherein at least one of the first opening portion and the second opening portion is formed such that at least one of the first opening portion and the second o

Assignees

• Yamauchi Tsutomo
• Kawai Satoru
• Ibiden Co Ltd

Inventors

• Yamauchi Tsutomo
• Kawai Satoru

Classifications

• H05K2201/09854

  Hole or via having special cross-section, e.g. elliptical · CPC title

• H05K2203/1572

  Processing both sides of a PCB by the same process; Providing a similar arrangement of components on both sides; Making interlayer connections from two sides · CPC title

• H05K2201/09827

  Tapered, e.g. tapered hole, via or groove · CPC title

• H05K2203/1476

  Same or similar kind of process performed in phases, e.g. coarse patterning followed by fine patterning · CPC title

• H05K3/0032 Primary

  of organic insulating material · CPC title