Low thermal conducting spacer assembly for an insulating glazing unit and method of making same

A method of making an insulating unit having a low thermal edge, comprising the steps of:

• forming a metal spacer frame, the spacer frame having a base, a first upright leg connected to the base and a second upright leg connected to the base and spaced from the first upright leg, the base having an inner surface facing the space between the upright legs and a surface opposite to the inner surface defined as an outer surface, the outer surface being generally flat, the first and second upright legs and outer surface of the base having a generally U-shaped configuration with the first and second legs only interconnected by the base;
• providing a moisture and gas impervious sealant on an outer surface of the first and second upright legs wherein the spacer frame and sealant provide an edge assembly;
• selecting the metal and physical dimensions of the spacer frame and sealant, such that the edge assembly is provided with a RES-value of at least 10 measured using ANSYS program, and
• securing a first sheet by the sealant on the outer surface of the first upright leg and a second sheet by the sealant on the outer surface of the second upright leg, thereby providing a sealed compartment between the sheets, wherein the sheets have a center and wherein the spacer frame is out of physical contact with the sheets with the inner surface of the base of the spacer frame facing the center of the sheets, and the sealant between the outer surface of the first and second upright legs and the respective adjacent sheets has a high resistance to the passage of gas between the outer surface of the first and second upright legs and the respective adjacent sheets, wherein a thermal conducting path between the sheets of the unit is only through the edge assembly, thereby providing the spacer frame, sealant and sheets as a unit with a RES-value of at least 10 at marginal edges of the unit.