Wiring board and method for manufacturing wiring board

A wiring board comprising:

• a base including a front surface, a rear surface, and a base through hole;
• a first metal plate joined with the front surface;
• a second metal plate joined with the rear surface;
• and
• a conductive line arranged in an inner space of the base through hole to electrically connect the first metal plate and the second metal plate, wherein the conductive line includes the first metal plate, the second metal plate, and a conductive material that electrically connects the first metal plate and the second metal plate,
• wherein the second metal plate includes a joined portion, which is joined with the base, and an extended portion, which extends from the joined portion to an opening of the base through hole,
• a plate material, which includes a through hole that is in communication with the base through hole, is arranged in the inner space, and
• the conductive material fills the through hole of the base material.

A method for manufacturing a wiring board including

• a base including a front surface, a rear surface, and a side surface;
• a first metal plate joined with the front surface;
• a second metal plate joined with the rear surface;
• and
• a conductive line configured to electrically connect the first metal plate and the second metal plate, wherein the conductive line is arranged in an inner space defined by an inner wall surface of a base through hole formed in the base, and the conductive line includes the first metal plate, the second metal plate, and a conductive material electrically connecting the first metal plate and the second metal plate,
• wherein at least one of the first metal plate and the second metal plate includes a joined portion, which is joined with the base, and a bent portion, which is bent and extended from the joined portion to cover the inner wall surface,
• the method comprising the steps of:
• joining the first metal plate with the front surface;
• joining the second metal plate with the rear surface to close one open end of the base through hole;
• applying solder paste to a front surface of the first metal plate at a portion corresponding to the other open end of the base through hole;
• forming a through hole in the second metal plate at a portion facing the inner space;
• and
• performing a reflow process on the solder paste to fill solder, which serves as the conductive material, into a space formed by the through hole and an inner side of the bent portion while removing gas from the through hole of the second metal plate.

A method for manufacturing a wiring board including

• a base including a front surface, a rear surface, and a side surface;
• a first metal plate joined with the front surface;
• a second metal plate joined with the rear surface;
• and
• a conductive line configured to electrically connect the first metal plate and the second metal plate, wherein the conductive line is arranged in an inner space defined by an inner wall surface of a base through hole formed in the base, and the conductive line includes the first metal plate, the second metal plate, and a conductive material electrically connecting the first metal plate and the second metal plate,
• the method comprising the steps of:
• arranging the second metal plate that includes a through hole on the rear surface, wherein the through hole of the second metal plate is in communication with the base through hole and has a smaller opening area than the base through hole;
• arranging a plate material that includes a through hole in the base through hole, wherein the through hole of the plate material is in communication with the through hole of the second metal plate and has a larger opening area than the through hole of the second metal plate;
• arranging the first metal plate that includes a through hole on the front surface, wherein the through hole of the first metal plate is in communication with the through hole of the plate material;
• and
• filling a space formed by the through hole of the second metal plate, the through hole of the first metal plate, and the through hole of the plate material with solder, which serves as the conductive material.