Patent ID: 11962057
Assignee: 3D GLASS SOLUTIONS, INC.
Field: Materials, metallurgy (Chemistry)
Classification: CPC H  C | IPC C  H

Claim 0:
1. A method of making an empty substrate integrated waveguide (ESIW) device including antenna and RF signal launch elements comprising the steps of:
forming an ESIW pattern, an ESIW supports RF signal launch, a perimeter ground patterns and one or more edges of a waveguide on a wafer comprising lithium ions;
annealing the exposed pattern in the presence of silver ions at a temperature that enables silver ions to coalesce into silver nanoparticles, and increasing the temperature to between 520° C.-620° C. to allow lithium oxide to form around the silver nanoparticles;
coating a topside of the wafer with a photoresist; exposing and developing a pattern to protect the waveguide pattern while leaving the ground pattern exposed;
spinning on a blanket photoresist on a backside of the wafer and etching exposed ground ceramic portions in an HF bath;
removing the photoresist leaving one or more ground pattern openings and a ceramic waveguide;
electroplating copper on the open ground pattern until all ground openings are filled;
coating a backside of the wafer with photoresist; exposing and developing a rectangular element with one or more small etch release features;
depositing 200 Å to 2,000 Å of titanium metal to form a first titanium layer, followed by a 1 μm deposition of copper onto the backside of the wafer;
removing the photoresist leaving a rectangular copper element to form a bottom of the ESIW structure that is electrically connected to the ground pattern copper and waveguide launching element;
exposing and developing a rectangular element in photoresist that is oversized over the ceramic ESIW pattern with the one or more etch release features;
electroplating copper on the exposed copper areas with between 5-50 μm of copper to improve the rigidity of the ESIW structure;
depositing 200 Å to 2,000 Å of titanium metal to form a second titanium layer followed by a 0.5 um to 1 μm deposition of copper onto the topside of the wafer;
coating the top side of the wafer with a photoresist; exposing and developing a top side ESIW pattern;
using a standard photoresist stripper, copper etchant and titanium etchant to remove the photoresist and to etch any exposed deposition metal, leaving the electroplated copper ESIW patterns;
placing wafer in a 0.5% to 50% HF ultrasonic bath; and
washing the wafer to remove the HF to obtain the empty substrate integrated waveguide device including antenna and RF signal launch elements.