Abstract: A power module has a copper layer composed of copper or a copper alloy on a surface of a circuit layer to which a semiconductor device is bonded, and a solder layer that is formed by using a solder material is formed between the circuit layer and the semiconductor device. An average crystal grain size which is measured by EBSD measurement in a region having a thickness of up to 30 ?m from the surface of the circuit layer in the solder layer is 10 ?m or less, the solder layer has a composition that contains Sn as a main component, 0.01 to 1.0% by mass of Ni, and 0.1 to 5.0% by mass of Cu, and a thermal resistance increase rate when a power cycle is loaded 100,000 times is less than 10% in a power cycle test.

Abstract: In a power module according to the present invention, a copper layer composed of copper or a copper alloy is provided at a surface of a circuit layer onto which a semiconductor element is bonded, and a solder layer formed by using a solder material is formed between the circuit layer and the semiconductor element. An alloy layer containing Sn as a main component, 0.5% by mass or more and 10% by mass or less of Ni, and 30% by mass or more and 40% by mass or less of Cu is formed at the interface between the solder layer and the circuit layer, the thickness of the alloy layer is set to be within a range of 2 ?m or more and 20 ?m or less, and a thermal resistance increase rate is less than 10% after loading a power cycles 100,000 times under a condition where an energization time is 5 seconds and a temperature difference is 80° C. in a power cycle test.

Abstract: In a power module according to the present invention, a copper layer composed of copper or a copper alloy is provided at a surface of a circuit layer onto which a semiconductor element is bonded, and a solder layer formed by using a solder material is formed between the circuit layer and the semiconductor element. An alloy layer containing Sn as a main component, 0.5% by mass or more and 10% by mass or less of Ni, and 30% by mass or more and 40% by mass or less of Cu is formed at the interface between the solder layer and the circuit layer, the thickness of the alloy layer is set to be within a range of 2 ?m or more and 20 ?m or less, and a thermal resistance increase rate is less than 10% after loading a power cycles 100,000 times under a condition where an energization time is 5 seconds and a temperature difference is 80° C. in a power cycle test.

Abstract: A power module is provided with a copper layer composed of copper or a copper alloy on a surface of a circuit layer to which a semiconductor device is bonded, and a solder layer that is formed by using a solder material is formed between the circuit layer and the semiconductor device. An average crystal grain size which is measured by EBSD measurement in a region having a thickness of up to 30 ?m from the surface of the circuit layer in the solder layer is 10 ?m or less, the solder layer has a composition that contains Sn as a main component, 0.01 to 1.0% by mass of Ni, and 0.1 to 5.0% by mass of Cu, and a thermal resistance increase rate when a power cycle is loaded 100,000 times is less than 10% in a power cycle test.