Printed circuit board and method for manufacturing the same

A printed circuit board comprising:

• a flexible substrate divided into first, second, and third regions;
• a first rigid substrate in the first region of the flexible substrate;
• and a second rigid substrate in the third region of the flexible substrate, wherein a left lateral surface of the flexible substrate is aligned with a left lateral surface of the first rigid substrate, and a right lateral surface of the flexible substrate is aligned with a right lateral surface of the second rigid substrate;
• and wherein the second region and at least one of the first and third regions are horizontally spaced apart such that a cavity is formed between an outer lateral surface of the at least one of the first and third regions and an outer lateral surface of the second region and wherein the flexible substrate comprises:
• a polyimide layer;
• a first conductive layer on a top surface of the polyimide layer;
• a second conductive layer on a bottom surface of the polyimide layer;
• a first protective layer on the first conductive layer to protect the first conductive layer;
• a second protective layer on the second conductive layer to protect the second conductive layer;
• and a first connection part through the polyimide layer and electrically connecting the first conductive layer to the second conductive layer:
• a first insulating layer buried in the flexible substrate and disposed on top and bottom surfaces of the flexible substrate, and a second insulating layer disposed on top surface and bottom surface of the first insulating layer:
• wherein the first insulating layer includes an impregnated substrate containing glass fiber, and the second insulating layer includes an insulating sheet made of only resin;
• and wherein an electronic device is buried in the at least one of the first and second rigid substrates.