Printed circuit board

A printed circuit board, comprising:

• a plurality of insulating layers;
• a plurality of wiring layers respectively disposed on or within the plurality of insulating layers;
• a plurality of vias, each via among the plurality of vias penetrating through at least one of the plurality of insulating layers, and each via among the plurality of vias connecting to at least one of the plurality of wiring layers;
• a glass substrate having a first surface and a second surface opposing each other in a first direction, a first side surface and a second side surface opposing each other in a second direction perpendicular to the first direction, and a third side surface and a fourth side surface opposing each other in a third direction perpendicular to the first and second directions, the glass substrate is at least partially disposed between the plurality of insulating layers in the first direction;
• and
• a protection material covering the first to fourth side surfaces of the glass substrate,
• wherein each of the first surface and the second surface of the glass substrate has a peripheral portion connected to the first to fourth side surfaces and a central portion surrounded by the peripheral portion, and
• the protection material is spaced apart from central portions of the first surface and the second surface of the glass substrate, respectively.