Abstract: A boring cutter body (5) is inserted into a circular hole (3) and is rotated and moved in an axial direction, whereby screw-shaped groove parts (11) are formed by using a tool bit (9) provided on a tip end of an outer peripheral portion, and broken surfaces (15) are formed by breaking tips of ridge parts generated by formation of the groove parts (11). Moreover, the groove parts (11) are processed through electric discharge machining using a wire electrode (17) provided to the boring cutter body (5) behind the tool bit (9) in the rotating direction, thereby forming finely roughened portions (41) having more finely roughened shapes than the broken surfaces (15).

Abstract: A semiconductor module includes a plurality of semiconductor elements, a first tabular electrode coupled to one face side of the plurality of semiconductor elements, a second tabular electrode coupled to the other face side of the plurality of semiconductor elements, and a molding material that encapsulates the plurality of semiconductor elements between the first electrode and the second electrode. A protrusion extending toward the second electrode is provided in a circumferential edge portion of the first electrode, and the protrusion surrounds the molding material.

Abstract: There are provided a process of forming a recess groove having a depth shallower than and a width larger than the notch groove for fracturing at a portion of fracturing and splitting in the permanent magnet; a process of forming the notch groove for fracturing the permanent magnet in a groove bottom of the recess groove formed in the recess-groove forming process; and a process of fracturing and splitting the permanent magnet along the notch groove so as to obtain magnet pieces.

Abstract: A semiconductor module includes a plurality of semiconductor elements, a first tabular electrode coupled to one face side of the plurality of semiconductor elements, a second tabular electrode coupled to the other face side of the plurality of semiconductor elements, and a molding material that encapsulates the plurality of semiconductor elements between the first electrode and the second electrode. A protrusion extending toward the second electrode is provided in a circumferential edge portion of the first electrode, and the protrusion surrounds the molding material.

Abstract: There are provided a process of forming a recess groove having a depth shallower than and a width larger than the notch groove for fracturing at a portion of fracturing and splitting in the permanent magnet; a process of forming the notch groove for fracturing the permanent magnet in a groove bottom of the recess groove formed in the recess-groove forming process; and a process of fracturing and splitting the permanent magnet along the notch groove so as to obtain magnet pieces.

Abstract: A boring cutter body (5) is inserted into a circular hole (3) and is rotated and moved in an axial direction, whereby screw-shaped groove parts (11) are formed by using a tool bit (9) provided on a tip end of an outer peripheral portion, and broken surfaces (15) are formed by breaking tips of ridge parts generated by formation of the groove parts (11). Moreover, the groove parts (11) are processed through electric discharge machining using a wire electrode (17) provided to the boring cutter body (5) behind the tool bit (9) in the rotating direction, thereby forming finely roughened portions (41) having more finely roughened shapes than the broken surfaces (15).