本发明之半导体设备用接合线具有Cu合金芯材、及形成于其表面之Pd被覆层，可同时实现高温下之球接合部之接合可靠性提高、及耐力比(=最大耐力/0.2%耐力)：1.1~1.6。 借由使导线中包含赋予高温环境下之连接可靠性之元素而提高高温下之球接合部之接合可靠性，进而，借由于对接合线之垂直于导线轴之方向之芯材剖面测定结晶方位之结果中，将导线长度方向之结晶方位中相对于导线长度方向之角度差为15度以下之结晶方位<100>之方位比率设为30%以上，且将接合线之垂直于导线轴之方向之芯材剖面中之平均结晶粒径设为0.9~1.5μm，而将耐力比设为1.6以下。

The bonding wire for a semiconductor device of the present invention has a Cu alloy core material and a Pd coating layer formed on the surface of the bonding wire, and can simultaneously realize improved reliability for the bonding of the ball joint portion at high temperature and the proof stress ratio (=maximum proof stress/0.2% proof stress) of 1.1~1.6. By incorporating elements that impart bonding reliability in a high temperature environment, the bonding reliability of the ball joint portion at high temperature is increased. Furthermore, in a result of measuring crystallization orientation on the core material cross section perpendicular to the wire axis of the bonding wire, the orientation ratio of the wire in the length direction with respect to the <100> crystallization orientation within the angular difference range of less than 15 degrees in the wire length direction is set to 30% or more, and the average grain size of the core material cross section perpendicular to the wire axis of the bonding wire is set to be 0.9~1.5[mu]m. Further, the proof stress ratio is set to be 1.6 or less.