Ceramic substrate material, method for production and utilisation of the same and antenna or antenna array

A method for producing a ceramic substrate material with a first layer and optionally a further layer is specified. The first layer of a first layer consists of at least a first component of a crystalline ceramic material and / or a glass material as matrix and a second component of a further crystalline ceramic material which is present in the matrix. An etching step is performed, wherein in the first layer, cladding regions of the crystals and / or crystal agglomerates of the second component are selectively etched to produce a void structure in the first layer. The present invention further relates to a corresponding ceramic substrate material,