Vapor chamber and method for producing vapor chamber

A vapor chamber having a working fluid in an internal space formed between a first metal sheet and a second metal sheet,

• wherein the first metal sheet comprises a recessed channel and at least one projecting part,
• wherein the recessed channel is provided at an inner surface of the first metal sheet,
• wherein the projecting part projects from the inner surface of the first metal sheet toward the second metal sheet, and a top face of the projecting part abuts the second metal sheet,
• wherein the vapor chamber includes at least one top face joining part and gap flow channel part,
• wherein the top face joining part joins part of the top face of the projecting part and the second metal sheet,
• wherein the top face of the projecting part and the second metal sheet are separated at the gap flow channel part,
• wherein the gap flow channel part is provided between a top face abutting part not joined to the second metal sheet in the top face of the first metal sheet, and an inner surface abutting part of the second metal sheet, such that the top face abutting part and the inner surface abutting part being spaced apart by the gap flow channels,
• wherein the gap flow channel part includes a gap enlarged part at a sealed part side, and
• wherein an average value of a gap width between the top face abutting part and the inner surface abutting part at the gap enlarged part is larger than an average value of the gap width at the gap flow channel part other than the gap enlarged part.