Chemical machining of silica and glass
AssigneeRockwell International Corporation
InventorsWilliam S. DeForest, Henry V. Connelly, Jr.
Life of this patent
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Abstract
A method of chemical machining of glass and all single-crystal, polycrystalline and amorphous forms of silica and like materials susceptible to etching by acid fluoride etchants. Relatively high-rate precision machining of deep cuts is enabled by using etching masks which are both highly adherent to glass and silica surfaces and highly resistant to attack by concentrated hydrofluoric acid. The etching mask is preferably a deposited composite of a relatively thin layer of metal highly adherent to said surfaces covered by a relatively thicker layer of etch resistant metal. Preferably, the etching mask surface is then sealed with a wax or an additional electrodeposited sealing layer of etch resistant metal.
Claims13
A method of chemically machining relatively deep cuts in an object of a material of a type which is conventionally etchable by acid fluoride etchants, said method comprising:
- forming an etching mask which is both highly adherent to said material and highly resistant to acid fluoride etchants by depositing, in a vacuum chamber, a relatively thin layer of a first metal immediately on a surface of said object wherein said first metal is highly adherent to said material;
- selectively defining a region of said object for chemical machining by removing said etching mask from said surface in said region;
- covering said etching mask with a relatively thick, relatively stress-free layer of sealing material by electrodepositing a layer of a second metal immediately on said etching mask;
- then, after said step of forming said etching mask and said step of covering said etching mask with said layer of sealing material are completed, contacting said object in said region with acid fluoride etchant for a period of time sufficient to machine a cut in said object to a depth of at least about one mil;
- and
- removing said etching mask and said layer of sealing material.
A method of chemically machining relatively deep cuts in an object of a material of a type which is conventionally etchable by acid fluoride etchants, said method comprising:
- forming an etching mask which is both highly adherent to said material and highly resistant to acid fluoride etchants by depositing, in a vacuum chamber, a relatively thin layer of a first metal immediately on a surface of said object wherein said first metal is highly adherent to said material;
- selectively defining a region of said object for chemical machining by removing said etching mask from said surface in said region;
- covering said etching mask with a relatively thick, relatively stress-free layer of sealing material immediately on said etching mask;
- then, after said step of forming said etching mask and said step of covering said etching mask with said layer of sealing material are completed, contacting said object in said region with acid fluoride etchant for a period of time sufficient to machine a cut in said object to a depth of at least about one mil;
- and
- removing said etching mask and said layer of sealing material.
Dependencies are inferred from the claim text.