Laser-based method and system for processing targeted surface material and article produced thereby

Abstract

A laser-based method and system for processing targeted surface material and article produced thereby are provided. The system processes the targeted surface material within a region of a workpiece while avoiding undesirable changes to adjacent non-targeted material. The system includes a primary laser subsystem including a primary laser source for generating a pulsed laser output including at least one pulse having a wavelength and a pulse width less than 1 ns. A delivery subsystem irradiates the targeted surface material of the workpiece with the pulsed laser output including the at least one pulse to texture the targeted surface material. The pulsed laser output has sufficient total fluence to initiate ablation within at least a portion of the targeted surface material and the pulse width is short enough such that the region and the non-targeted material surrounding the material are substantially free of slag.

1 - 57 . (canceled)  
   
   
       58 . An article of manufacture comprising: 
 at least one surface material having discernible indicia formed thereon during at least one step of manufacturing the article, the indicia being formed by a method of selectively irradiating targeted surface material within a region of a workpiece with a pulsed laser output, the indicia being at least semi-permanent and useable during a subsequent step of manufacturing the article;    the region and non-targeted material surrounding the region are substantially slag-free; and    surface roughness is increased within at least a portion of the region during the at least one step of manufacturing, thereby reducing reflection of energy used for reading the indicia.    
   
   
       59 . The article as claimed in  claim 58 , wherein high reflectance contrast is obtained between the region and a background of the region over a wide range of viewing angles.  
   
   
       60 . The article as claimed in  claim 58 , wherein a surface of the background of the region has a strong specular reflection component.  
   
   
       61 . The article as claimed in  claim 58 , wherein reflectance contrast between the discernible indicia and a background of the region exceeds 30:1 over an angular viewing range of at least 20 degrees.  
   
   
       62 . The article as claimed in  claim 58 , wherein the indicia include an alphanumeric indicium having a font dimension 0.3 mm or finer.  
   
   
       63 . The article as claimed in  claim 58 , wherein the indicia include a two-dimensional matrix code.  
   
   
       64 . The article as claimed in  claim 58 , wherein the indicia are useable for one or more steps of manufacturing the article in addition to identification.  
   
   
       65 . The article as claimed in  claim 58 , wherein the indicia are distinguishable from a background of the region with a roughness measurement obtained by at least one of SEM (scanning electron microscope) data, and AFM (atomic force microscope) data.  
   
   
       66 . The article as claimed in  claim 58 , wherein DIN 4768 roughness measurement standards may be utilized to compare roughness of a portion of the indicia with a background of the region.  
   
   
       67 . The article as claimed in  claim 58 , wherein the indicia are distinguishable from a background of the region with a measurement of image contrast.  
   
   
       68 . The article as claimed in  claim 58 , wherein the indicia are machine readable.  
   
   
       69 . The article as claimed in  claim 58 , wherein the indicia appear as a sequence of non-overlapping dots that form a dot matrix code.  
   
   
       70 . The article as claimed in  claim 58 , wherein the indicia are usable in at least one of traceability, component identification, and sorting.