Patent attributes
Provided is a method for manufacturing a liquid cooling jacket including a jacket body and a sealing body joined to the jacket body. The method includes steps of: preparing; placing; first primary joining with a rotary tool; and second primary joining with the rotary tool. The rotary tool includes a base end pin and a distal end pin. The distal end pin includes a flat surface and a protrusion protruding from the flat surface. In the first primary joining and the second primary joining, friction stirring is performed in a state where the jacket body and the sealing body are brought in contact with the flat surface of the distal end pin and the base end pin and only the jacket body is brought in contact with a distal end surface of the protrusion.
