Method for manufacturing printed wiring board

Abstract

A method for manufacturing a printed wiring board including providing a starting material including an insulating resin substrate having first and second surfaces, irradiating laser upon the first surface of the insulating resin substrate such that a first opening portion having an opening on the first surface is formed, irradiating laser upon the second surface of the insulating resin substrate such that a second opening portion having an opening on the second surface and communicated to the first opening portion is formed and that a penetrating-hole having the first and second opening portions is formed, forming a first conductor on the first surface of the insulating resin substrate, forming a second conductor on the second surface of the insulating resin substrate, and forming a through hole conductor structure in the penetrating-hole to electrically connecting the first conductor and the second conductor.

What is claimed is: 
     
         1 . A method for manufacturing a printed wiring board, comprising:
 providing a starting material comprising an insulating resin substrate having a first surface and a second surface;   irradiating laser upon the first surface of the insulating resin substrate such that a first portion of a penetrating-hole is formed with an opening on the first surface of the insulating resin substrate;   irradiating laser upon the second surface of the insulating resin substrate such that a second portion of the penetrating-hole is formed with an opening on the second surface of the insulating resin substrate, connects to the first portion and is set off from the first portion;   forming a first conductor on the first surface of the insulating resin substrate;   forming a second conductor on the second surface of the insulating resin substrate; and   forming a through-hole conductor structure formed in the penetrating-hole of the insulating resin substrate to electrically connecting the first conductor and the second conductor.   
     
     
         2 . The method according to  claim 1 , wherein the starting material comprises a plurality of metal foils laminated on the first and second surfaces of the insulating resin substrate, respectively. 
     
     
         3 . The method according to  claim 1 , wherein the forming of the through-hole conductor structure comprises forming an electroless plated film on inner walls of the first portion and second portion of the penetrating-hole and forming an electrolytic plated layer over the electroless plated film. 
     
     
         4 . The method according to  claim 1 , wherein the irradiating laser upon the first surface of the insulating resin substrate comprises forming the first portion having an axis of the center of gravity, and the irradiating laser upon the second surface of the insulating resin substrate comprises forming the second portion having an axis of the center of gravity such that the axis of the center of gravity of the first portion is out of alignment with the axis of the center of gravity of the second portion. 
     
     
         5 . The method according to  claim 4 , wherein the axis of the center of gravity of the first portion is out of alignment with the axis of the center of gravity of the second portion by a distance in a range of 5 μm to 30 μm. 
     
     
         6 . The method according to  claim 1 , wherein the insulating resin substrate has a thickness which is in a range of 100 μm to 500 μm. 
     
     
         7 . The method according to  claim 1 , wherein the penetrating-hole is formed such that the penetrating-hole has a neck portion connecting the first portion and second portion of the penetrating-hole and that the first portion and second portion of the penetrating-hole taper from the openings on the first surface and second surface of the insulating resin substrate toward the neck portion. 
     
     
         8 . The method according to  claim 7 , wherein the first portion and second portion of the penetrating-hole have a diameter on the first surface and second surface of the insulating resin substrate in a range of 75 μm to 300 μm, respectively, and the neck portion of the penetrating-hole has a diameter in arrange of 50 μm to 250 μm. 
     
     
         9 . The method according to  claim 1 , wherein the penetrating-hole is formed in a plurality such that the plurality of penetrating-holes is formed at a pitch in a range of 100 μm to 400 μm. 
     
     
         10 . The method according to  claim 1 , wherein the forming of the first conductor includes forming a first through-hole land on the first surface of the insulating resin substrate, the forming of the second conductor includes forming a second through-hole land on the second surface of the insulating resin substrate, and the forming of the through-hole conductor structure includes forming the through-hole conductor structure connecting the first through-hole land on the first surface of the insulating resin substrate and the second through-hole land on the second surface of the insulating resin substrate on end portions of the through-hole conductor structure, respectively. 
     
     
         11 . The method according to  claim 1 , wherein the irradiating laser upon the first surface of the insulating resin substrate comprises forming the first opening portion having a sidewall extending from the opening on the first surface of the insulating resin substrate toward the second surface of the insulating resin substrate, the irradiating laser upon the second surface of the insulating resin substrate comprises forming the second opening portion having a sidewall extending from the opening on the second surface of the insulating resin substrate toward the first surface of the insulating resin substrate such that the second opening portion is connected to the first opening portion to form a neck portion connecting the first opening portion and the second opening portion, and the neck portion is defined by an intersection line of the sidewalls of the first and second opening portions and is formed such that the neck portion is not parallel to at least one of the first surface and second surface of the insulating resin substrate. 
     
     
         12 . The method according to  claim 2 , wherein the forming of the first conductor includes forming a first through-hole land on the first surface of the insulating resin substrate, the forming of the second conductor includes forming a second through-hole land on the second surface of the insulating resin substrate, and the forming of the through-hole conductor structure includes forming the through-hole conductor structure connecting the first through-hole land on the first surface of the insulating resin substrate and the second through-hole land on the second surface of the insulating resin substrate on end portions of the through-hole conductor structure, respectively. 
     
     
         13 . The method according to  claim 2 , wherein the irradiating laser upon the first surface of the insulating resin substrate comprises forming the first opening portion having a sidewall extending from the opening on the first surface of the insulating resin substrate toward the second surface of the insulating resin substrate, the irradiating laser upon the second surface of the insulating resin substrate comprises forming the second opening portion having a sidewall extending from the opening on the second surface of the insulating resin substrate toward the first surface of the insulating resin substrate such that the second opening portion is connected to the first opening portion to form a neck portion connecting the first opening portion and the second opening portion, and the neck portion is defined by an intersection line of the sidewalls of the first and second opening portions and is formed such that the neck portion is not parallel to at least one of the first surface and second surface of the insulating resin substrate. 
     
     
         14 . The method according to  claim 3 , wherein the forming of the first conductor includes forming a first through-hole land on the first surface of the insulating resin substrate, the forming of the second conductor includes forming a second through-hole land on the second surface of the insulating resin substrate, and the forming of the through-hole conductor structure includes forming the through-hole conductor structure connecting the first through-hole land on the first surface of the insulating resin substrate and the second through-hole land on the second surface of the insulating resin substrate on end portions of the through-hole conductor structure, respectively. 
     
     
         15 . The method according to  claim 3 , wherein the irradiating laser upon the first surface of the insulating resin substrate comprises forming the first opening portion having a sidewall extending from the opening on the first surface of the insulating resin substrate toward the second surface of the insulating resin substrate, the irradiating laser upon the second surface of the insulating resin substrate comprises forming the second opening portion having a sidewall extending from the opening on the second surface of the insulating resin substrate toward the first surface of the insulating resin substrate such that the second opening portion is connected to the first opening portion to form a neck portion connecting the first opening portion and the second opening portion, and the neck portion is defined by an intersection line of the sidewalls of the first and second opening portions and is formed such that the neck portion is not parallel to at least one of the first surface and second surface of the insulating resin substrate. 
     
     
         16 . The method according to  claim 4 , wherein the forming of the first conductor includes forming a first through-hole land on the first surface of the insulating resin substrate, the forming of the second conductor includes forming a second through-hole land on the second surface of the insulating resin substrate, and the forming of the through-hole conductor structure includes forming the through-hole conductor structure connecting the first through-hole land on the first surface of the insulating resin substrate and the second through-hole land on the second surface of the insulating resin substrate on end portions of the through-hole conductor structure, respectively. 
     
     
         17 . The method according to  claim 4 , wherein the irradiating laser upon the first surface of the insulating resin substrate comprises forming the first opening portion having a sidewall extending from the opening on the first surface of the insulating resin substrate toward the second surface of the insulating resin substrate, the irradiating laser upon the second surface of the insulating resin substrate comprises forming the second opening portion having a sidewall extending from the opening on the second surface of the insulating resin substrate toward the first surface of the insulating resin substrate such that the second opening portion is connected to the first opening portion to form a neck portion connecting the first opening portion and the second opening portion, and the neck portion is defined by an intersection line of the sidewalls of the first and second opening portions and is formed such that the neck portion is not parallel to at least one of the first surface and second surface of the insulating resin substrate. 
     
     
         18 . The method according to  claim 1 , wherein the forming of the first portion of the penetrating-hole comprises tapering the first portion of the penetrating-hole from the opening on the first surface of the insulating resin substrate, and the forming of the second portion of the penetrating-hole comprises tapering the second portion of the penetrating-hole from the opening on the second surface of the insulating resin substrate. 
     
     
         19 . The method according to  claim 2 , wherein the forming of the first portion of the penetrating-hole comprises tapering the first portion of the penetrating-hole from the opening on the first surface of the insulating resin substrate, and the forming of the second portion of the penetrating-hole comprises tapering the second portion of the penetrating-hole from the opening on the second surface of the insulating resin substrate. 
     
     
         20 . The method according to  claim 3 , wherein the forming of the first portion of the penetrating-hole comprises tapering the first portion of the penetrating-hole from the opening on the first surface of the insulating resin substrate, and the forming of the second portion of the penetrating-hole comprises tapering the second portion of the penetrating-hole from the opening on the second surface of the insulating resin substrate.