Lapping and polishing method and apparatus for planarizing photoresist and metal microstructure layers

A method for lapping a workpiece including a microstructure layer formed of photoresist or metal, comprising the steps of:

• (a) furnishing a lapping machine with a lapping plate having a lapping surface made of a soft metal;
• (b) conditioning the lapping plate to furnish the lapping plate surface with a rough ridged surface;
• (c) conditioning the lapping plate by embedding diamonds from a diamond lapping slurry into the lapping surface;
• (d) mounting the workpiece on a mounting plate made of a material selected from the group of materials consisting of steel and glass, mounting glass support pieces on the mounting plate around the workpiece, and placing weights on the mounting plate to provide contact pressure between the workpiece and the glass support pieces and the lapping plate surface;
• and
• (e) lapping the workpiece to remove material therefrom by rotating the lapping plate surface against the workpiece while periodically applying a diamond lapping slurry onto the lapping plate and continuously embedding diamonds from the lapping slurry into the lapping surface.

A method for lapping a workpiece including a microstructure layer formed of photoresist or metal, comprising the steps of:

• (a) furnishing a lapping machine with a lapping plate having a lapping surface made of a soft metal;
• (b) conditioning the lapping plate using a diamond embedded conditioning ring placed on the lapping surface to furnish the lapping plate surface with a rough ridged surface;
• (c) conditioning the lapping plate by spraying a diamond lapping slurry onto the lapping plate surface and embedding diamonds from the lapping slurry into the surface using a ceramic conditioning ring placed on the lapping plate ahead of the diamond slurry spray;
• (d) mounting a workpiece to be lapped onto the lapping plate;
• and
• (e) lapping the workpiece to remove material therefrom by rotating the lapping plate surface against the workpiece while periodically spraying a diamond lapping slurry onto the lapping plate and continuously embedding diamonds from the lapping slurry into the lapping surface using the ceramic conditioning ring.

A lapping apparatus for lapping a workpiece including a microstructure layer formed of photoresist or metal, comprising:

• (a) a lapping machine with a lapping plate having a lapping surface made of a soft metal and wherein the lapping plate is conditioned such that the lapping plate surface has a rough ridged surface and such that diamonds from a diamond lapping slurry are embedded into the rough ridged surface;
• (b) mounting means for mounting the workpiece to be lapped onto the lapping plate for lapping the workpiece;
• (c) means for periodically applying a diamond lapping slurry onto a location on the lapping plate while lapping the workpiece to remove material therefrom;
• and
• (d) conditioning means for continuously embedding diamonds from the lapping slurry into the lapping surface while lapping the workpiece, the conditioning means placed on the lapping plate between the location on the lapping plate where the diamond lapping slurry is applied and the workpiece.

A lapping apparatus for lapping a workpiece including a microstructure layer formed of photoresist or metal, comprising:

• (a) a lapping machine with a lapping plate having a lapping surface made of a soft metal and wherein the lapping plate is conditioned such that the lapping plate surface has a rough ridged surface and such that diamonds from a diamond lapping slurry are embedded into the rough ridged surface;
• (b) mounting means for mounting the workpiece to be lapped onto the lapping plate for lapping the workpiece including a mounting plate made of a material selected from the group of materials consisting of steel and glass upon which the workpiece is mounted along with glass support pieces of equal thickness mounted on the mounting plate around the workpiece, and weights on the mounting plate to provide contact pressure between the workpiece and the glass support pieces and the lapping plate surface;
• (c) means for periodically applying a diamond lapping slurry onto the lapping plate while lapping the workpiece to remove material therefrom;
• and
• (d) means for continuously embedding diamonds from the lapping slurry into the lapping surface while lapping the workpiece.

A method of forming metal microstructures, comprising the steps of:

• (a) applying a photoresist in a layer onto a substrate base;
• (b) exposing the photoresist in a pattern to radiation to render the photoresist dissolvable in a pattern;
• (c) removing the dissolvable photoresist;
• (d) depositing a first layer of metal onto the substrate base into the area from which the photoresist has been removed to form a photoresist-metal layer;
• and
• (e) planarizing the photoresist-metal layer by:
• (1) mounting the substrate base on a lapping machine with a lapping plate having a lapping surface made of a soft metal wherein the lapping plate is conditioned such that the lapping plate surface has a rough ridged surface and such that diamonds from a diamond lapping slurry have been embedded into the rough ridged surface, and
• (2) lapping the photoresist-metal layer to remove material therefrom by rotating the lapping plate surface against the photoresist-metal layer while periodically applying a diamond lapping slurry onto the lapping plate and placing a conditioning device on the lapping plate to continuously embed diamonds from the lapping slurry into the lapping surface.

A method of forming metal microstructures, comprising the steps of:

• (a) applying a photoresist in a layer onto a substrate base;
• (b) exposing the photoresist in a pattern to radiation to render the photoresist dissolvable in a pattern;
• (c) removing the dissolvable photoresist;
• (d) depositing a first layer of metal onto the substrate base into the area from which the photoresist has been removed to form a photoresist-metal layer;
• and
• (e) planarizing the photoresist-metal layer by:
• (1) mounting the substrate base on a lapping machine by mounting the substrate base on a mounting plate, mounting glass support pieces on the mounting plate around the substrate base, and by placing weights on the mounting plate to provide contact pressure between the photoresist-metal layer and the glass support pieces and a lapping plate surface, wherein the lapping plate surface is made of a soft metal and wherein the lapping plate is conditioned such that the lapping plate surface has a rough ridged surface and such that diamonds from a diamond lapping slurry have been embedded into the rough ridged surface, and
• (2) lapping the photoresist-metal layer to remove material therefrom by rotating the lapping plate surface against the photoresist-metal layer while periodically applying a diamond lapping slurry onto the lapping plate and continuously embedding diamonds from the lapping slurry into the lapping surface.

A method of forming microstructures, comprising the steps of:

• (a) providing a first preformed sheet of photoresist material which can be exposed to radiation to affect its susceptibility to a developer;
• (b) exposing the photoresist sheet in a pattern to radiation which will change its susceptibility to a developer;
• and
• (c) removing the material of the photoresist sheet to reduce the thickness of the sheet to a desired thickness by:
• (1) mounting the photoresist sheet on a lapping machine with a lapping plate having a lapping surface made of a soft metal wherein the lapping plate is conditioned such that the lapping plate surface has a rough ridged surface and such that diamonds from a diamond lapping slurry have been embedded into the rough ridged surface, and
• (2) lapping the photoresist sheet to remove material therefrom by rotating the lapping plate surface against the photoresist sheet while periodically applying a diamond lapping slurry onto the lapping plate and placing a conditioning device on the lapping plate to continuously embed diamonds from the lapping slurry into the lapping surface.