Patent ID: 7537813

Claim:
An acoustic insulating glazing unit comprising: at least two substrate sheets, joined together around their periphery using a sealed joint/spacer frame, the sealed joint/spacer frame defining with the two substrate sheets a flat cavity that is filled with a gas; an interior frame arranged inside the flat cavity in a periphery of the flat cavity, wherein side walls of the interior frame and internal walls of the at least two substrate sheets define at least one microcavity having dimensions to form a zone of thermoviscous losses for acoustic waves entering from the flat cavity, wherein the interior frame includes an inner chamber and opening slots that are arranged in the side walls of the interior frame, the inner chamber configured to receive the acoustic waves escaping from the at least one microcavity through the opening slots, and wherein a height of the at least one microcavity from an upper wall of the interior frame to the opening slots is at least 6 mm, and the at least one microcavity has a width between 0.2 mm and 1 mm.