Back to results
US 6,596,395 B1Granted
Balls of single crystal silicon and method of making the same
AssigneeNtn Corporation
InventorKatsutoshi Muramatsu
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeNtn Corporation
InventorKatsutoshi Muramatsu
Estimating the term…
Silicon balls of single crystal silicon for use in semiconductir circuit substrates or the like, which have been lapped to satisfy necessary requirements and a method of making the same. The silicon ball of single crystal silicon is a lapped ball of single crystal silicon having a sphericity of not greater than 0.08 μm and also having a residue stress layer of not greater than 5 μm in a depth from a processing surface thereof on one side in negative and positive directions. The method of making the silicon balls makes use of a pair of lapping tables 2 and 3 supported in face-to-face relation with each other. One or both of the lapping tables 2 and 3 is prepared from finely divided abrasive particles hardened by the use of a resinous bonding material. Workpieces W of single crystal silicon are sandwiched between the lapping tables 2 and 3 and are lapped to provide the lapped balls.
A lapped ball of single crystal silicon having a sphericity of not greater than 0.08 μm and also having a residue stress layer of not greater than 5 μm in depth.
A method of making lapped balls of single crystal silicon by the use of a pair of lapping tables each prepared by hardening abrasive particles with a resinous bonding material and supported in face-to-face relation with each other, said method comprising a step of lapping workpieces of single crystal silicon between the lapping tables, to produce a single crystal silicon ball substantially free from crystal strain and residue stress in a region 3 μm depthwise of a surface layer thereof.
A polished ball of single crystal silicon having a sphericity of not greater than 0.5 μm and a surface roughness of not greater than 0.5 nmRa and free from crystal strains and residue stresses in a region 3 μm depthwise of a surface layer thereof.
A method of making polished balls of single crystal silicon with the use of a pair of polishing tables, one or both of said polishing tables comprising a polishing cloth and one or both of said polishing tables having a workpiece rolling grooves defined therein, said polishing tables being supported in face-to-face relation with each other, said method comprising polishing workpieces of single crystal silicon between the polishing tables, to produce a single crystal silicon ball substantially free from crystal strain and residue stress in a region 3 μm depthwise of a surface layer thereof.
A method of making polished balls of single crystal silicon with the use of a pair of polishing tables, one of said polishing tables comprising a polishing cloth and the other of said polishing tables comprising a resinous table, one or both of said polishing tables having a workpiece rolling grooves defined therein, said polishing tables being supported in face-to-face relation with each other, said method comprising polishing workpieces of single crystal silicon between the polishing tables, to produce a single crystal silicon ball substantially free from crystal strain and residue stress in a region 3 μm depthwise of a surface layer thereof.
Dependencies are inferred from the claim text.