Joined assembly and production method thereof

A production method for a joined assembly including a wire bundle and a metallic member, comprising:

• using a bundle of a plurality of conductive wires as the wire bundle, the conductive wires being isolated from each other through inter-wire insulating layers made from insulating resin;
• holding a head portion of the wire bundle in contact with a metallic member connecting portion of the metallic member, the head portion being arranged on a first side of the wire bundle in a lengthwise direction of the wire bundle, the head extension extending from the head portion to a second side of the wire bundle away from the first side in the lengthwise direction, the conductive wires being kept adhered to each other through the inter-wire insulating layer within the head extension, and
• making an end-to-end joint which is created by fusion-joining the conductive wires within the head portion of the wire bundle to a portion of the metallic member connecting portion after the head extension is retained to the metallic member connecting portion, wherein
• the end-to-end joint is created by emitting an energy beam to fuse and weld the head portion of the wire bundle to the portion of the metallic member connecting portion and also to remove the inter-wire insulating layers from the head portion.