Microwave heating structure

Claim 1

A multiple layer article of manufacture, for formation into a packaging structure for heating a foodstuff by microwave energy to an edible condition comprising: a layer of flexible electroconductive material supported on a substrate layer, said layer of flexible electroconductive material having a thickness which is normally substantially opaque to microwave radiation and having a plurality of apertures extending wholly through the thickness of said electroconductive material layer and effective to generate thermal energy in said plurality of apertures when said article is exposed to microwave energy and the foodstuff is in contact with or proximate to said plurality of apertures, said plurality of apertures comprising: a first plurality of elongate discrete closed-end apertures, and a second plurality of continuous apertures, each of which encloses a discrete rectangular island of said electroconductive material, said plurality of apertures being sized and arranged in said layer of flexible electroconductive material to generate sufficient thermal energy to effect a desired surface browning of the foodstuff while permitting sufficient microwave energy to penetrate said layer of flexible electroconductive material into the foodstuff to effect a desired degree of heating of the foodstuff, whereby the foodstuff may be provided in an edible condition, said substrate layer being formed of microwave energy transparent material and being in adhered structural supporting relationship with said flexible layer of electroconductive material to permit a package structure be formed from said article in which the foodstuff is positioned.