Structure and method for sealing through-hole, and transfer substrate for sealing through-hole

A sealing structure comprising:

• a set of base materials forming a sealed space;
• at least one through-hole which is formed in at least one of the set of base materials, and communicates with the sealed space;
• and a sealing member that seals the through-hole, wherein
• the sealing structure comprises an underlying metal film on a surface of the base material in which the through-hole is formed, the underlying metal film comprising a bulk-like metal including at least one of gold, silver, palladium and platinum, the underlying metal film being formed so as to surround the peripheral part of the through-hole,
• the sealing member seals the through-hole while being bonded to the underlying metal film,
• the sealing member comprises:
• a sealing material which is bonded to the underlying metal film, and includes a compressed product of a metal powder including gold having a purity of 99.9% by mass or more;
• and
• a lid-like metal film which is bonded to the sealing material, and comprises a bulk-like metal including gold at least at a surface that is in contact with the sealing material, the bulk-like metal having a thickness of not less than 0.01 μm and not more than 5 μm,
• the sealing material comprises:
• an outer periphery-side densified region that is in contact with the underlying metal film;
• and a center-side porous region that is in contact with the through-hole, and
• a horizontal length (l) of a pore in a radial direction at any cross-section of the densified region and a width (W) of the densified region satisfy the relationship of 1≤0.1 W.