Method of manufacturing packaging substrate and packaging substrate manufactured thereby

A packaging substrate comprising a core layer and an upper layer located on the core layer,

• wherein the core layer includes a glass core including a first surface and a second surface facing each other, a plurality of core vias and a cavity portion passing through the glass core in a thickness direction, an electrically conductive layer formed on a surface of the glass core, an electronic element arranged in the cavity portion, and an insulating layer filling the core vias and the cavity portion,
• the cavity portion is open and recessed in a direction toward the first surface or the second surface of the glass core or passes through the first surface and the second surface to have a space where the electronic element is disposed, and
• the insulating layer includes a first insulating layer in which a first insulating film is laminated on the first surface and cured, a second insulating layer in which a second insulating film is laminated on the first insulating layer and cured, and a third insulating layer in which the second insulating film is laminated in a direction from the second surface to the first surface and cured,
• wherein a first boundary where the first insulating film and the second insulating film come into contact is formed between the first insulating layer and the second insulating layer, and
• a second boundary where the first insulating film and the second insulating film come into contact is formed between the second insulating layer and the third insulating layer, and the second boundary is formed in the core vias and the cavity portion.