Product having through-hole and laser processing method

Abstract

A processing method of forming a through-hole in a workpiece by means of a pulsed laser beam includes the steps of providing a removable sacrifice layer on the workpiece, forming a through-hole in the workpiece by the laser beam in a state where the sacrifice layer is provided, and removing the sacrifice layer from the workpiece after the step of forming the through-hole.

1 - 4 . (canceled) 
     
     
         5 . A product having a through-hole made by a pulsed laser, wherein
 (θ×d 0.68 )/φ≦4.0 is satisfied where φ (μm) denotes a diameter of said pulsed laser, θ (°) denotes a taper angle of said through-hole and d (μm) denotes a thickness of said product.   
     
     
         6 . A product having a through-hole made by a pulsed laser, wherein
 said through-hole is straight-like in shape.   
     
     
         7 . A product having a through-hole made by a pulsed laser, wherein
 a wall surface of said through-hole has no curved portion that is inwardly convex at one end of said through-hole such that the diameter of said through-hole expands as approaching an opening at said one end.   
     
     
         8 . The product having the through-hole according to  claim 7 , wherein
 no protruded portion is present at a peripheral edge of an opening of said through-hole.   
     
     
         9 . The product having the through-hole according to  claim 7 , wherein
 both surfaces where said through-hole opens have no attachment of scattered fragments due to laser ablation.