Abstract: A coolant passageway (2) of a heat sink (1) has a coolant lead-in part (21), a coolant lead-out part (22), coolant-contact parts (23), coolant-transit parts (25), and connecting parts (24). The coolant-contact parts (23) are disposed spaced apart from one another along a coolant path leading from the coolant lead-in part (21) to the coolant lead-out part (22) and are configured such that they bring the coolant into contact with a cooling-wall part. The coolant-transit parts (25) are disposed between adjacent coolant-contact parts (23) and are configured such that the coolant can transit from upstream-side coolant-contact parts (23) to downstream-side coolant-contact parts (23) in the coolant paths. The connecting parts (24) are interposed between the coolant-transit parts (25) and the coolant-contact parts (23) and have a passageway cross-sectional area that is smaller than those of the coolant-contact parts (23) and the coolant-transit parts (25).

Abstract: A coolant passageway (2) of a heat sink (1) has a coolant lead-in part (21), a coolant lead-out part (22), coolant-contact parts (23), coolant-transit parts (25), and connecting parts (24). The coolant-contact parts (23) are disposed spaced apart from one another along a coolant path leading from the coolant lead-in part (21) to the coolant lead-out part (22) and are configured such that they bring the coolant into contact with a cooling-wall part. The coolant-transit parts (25) are disposed between adjacent coolant-contact parts (23) and are configured such that the coolant can transit from upstream-side coolant-contact parts (23) to downstream-side coolant-contact parts (23) in the coolant paths. The connecting parts (24) are interposed between the coolant-transit parts (25) and the coolant-contact parts (23) and have a passageway cross-sectional area that is smaller than those of the coolant-contact parts (23) and the coolant-transit parts (25).

Abstract: During edgewise bending that is carried out on an aluminum alloy bus bar made of an aluminum alloy rectangular wire, an edgewise bending portion is heated to a temperature between 100 and 250° C. inclusive, and within 5 minutes after the heating, edgewise bending is carried out. In the aluminum alloy bus bar, the ratio A/B of Vickers hardness A in a heated portion to Vickers hardness B in a non-heated portion is at least 0.8. If necessary, flatwise bending is further carried out on the aluminum alloy bus bar, forming the bus bar into a predetermined shape.

Abstract: During edgewise bending that is carried out on an aluminum alloy bus bar made of an aluminum alloy rectangular wire, an edgewise bending portion is heated to a temperature between 100 and 250° C. inclusive, and within 5 minutes after the heating, edgewise bending is carried out. In the aluminum alloy bus bar, the ratio A/B of Vickers hardness A in a heated portion to Vickers hardness B in a non-heated portion is at least 0.8. If necessary, flatwise bending is further carried out on the aluminum alloy bus bar, forming the bus bar into a predetermined shape.