US 5,521,030 A · Process for making holographic embossing tools

Abstract

A method for producing durable embossing tools is disclosed. An anisotropic etching process, such as ion etching, is used to etch a relief pattern into a hard substrate. A transfer layer is formed overlaying a generally smooth, seamless surface region of a substrate. A desired relief pattern is formed in the transfer layer, by exposing a photoresist, embossing, or the like. The substrate having the photoresist thereon is subjected to an anisotropic etch. The anisotropic etch continues until the transfer layer is completely removed and the relief pattern is formed in the upper surface of the embossing tool. The relative etch rates between the transfer layer and the surface region of the embossing tool are selected to provide the desired depth modulation in the surface of the embossing tool. An embossing tool produced according to the invention has a relatively hard surface and may thus be used for the mass production of holographic images without significant degradation of the pattern. Because the embossing tool can be made from an extremely hard material such as chromium or hardened steel, materials which previously could not be economically embossed with holograms, such as aluminum or steel, may now be embossed by an embossing tool made according to this invention.

Claims15

Dependent claims

A method of making a tool for embossing holograms comprising:

providing a durable substrate having a smooth surface;
forming a transfer layer overlying the surface of the substrate;
forming a surface relief pattern in the surface of the transfer layer that corresponds to a holographic image;
etching said transfer layer and said substrate anisotropically using a beam-based etching process in a manner that causes the direction of said anisotropic etch on each point being etched to vary continuously during said etching;
and
continuing said etching until said surface relief pattern of the hologram has been etched from said transfer layer into said substrate.

3 more elements

A method of making an embossing substrate for embossing holograms comprising:

providing a substrate having a smooth surface;
forming a transfer layer overlaying the surface of the substrate;
forming a surface relief pattern corresponding to a holographic image in the surface of the transfer layer;
anisotropically etching the transfer layer and the surface of the substrate with a relatively thin ion beam while simultaneously moving said substrate and said relatively thin ion beam relative to each other to cause the angle of incidence of the etch beam and the direction of the etch on each point to change continuously while the transfer layer and substrate are being etched;
and
continuing said anisotropic etching until said holographic image pattern in said transfer layer has been etched into said substrate.

3 more elements

Dependencies are inferred from the claim text.

Process for making holographic embossing tools

Life of this patent

Process for making holographic embossing tools

Life of this patent

Abstract

Claims15