Abstract: A printed circuit board includes: a first insulating layer; a first circuit layer disposed on one surface of the first insulating layer; a second insulating layer disposed on the first insulating layer and covering at least a portion of the first circuit layer; a via conductor passing through the second insulating layer and connected to the first circuit layer; a via land connected to the via conductor in an upper portion of the via conductor; and a second circuit layer disposed on the second insulating layer and connected to the via land. The via conductor and the via land have a first interface where the via conductor and the via land are in contact with each other.

Abstract: The present invention relates to an air-circulation type shock buffering footwear which can absorb and alleviate a shock applied on a foot, allow the air ventilation through the inside and give a pleasant and comfortable feeling to the wearer for many hours. The inventive shoe comprises the first and second air rooms formed respectively in the front and rear of and on the underside of the middle sole layer, said first and second air rooms communicating with each other through passages; a plurality of sucking holes formed in the inner sole layer to communicate with throughholes of the first air room; the first and second buffering members respectively incorporated in the first and second air rooms for both alleviating shock and circulating the air; the first check valve disposed in the front of the second air room to open or close the passages; and the second check valve disposed in the rear of the second check valve to communicate with the outside so as to discharge the air.