NOVELTY - A solder joint material comprises a copper-based metal material (1) mainly comprising copper, a surface-treated layer (2) provided on the copper-based metal material and comprising an amorphous layer comprising oxygen and a metal with a higher oxygen affinity than copper, and a tin-based solder plating layer provided on the surface-treated layer.    USE - Solder joint material is used for solar cell modules (claimed). Can also be used as die-bonding material for semiconductor device having various structures, lead materials, sealing materials, joint materials of insulating substrates, diodes of alternators, insulated gate bipolar transistor modules, front-end modules (e.g. radiofrequency modules), vehicle power modules, LEDs, metal oxide semiconductor FETs, ceramic substrates, etc.    ADVANTAGE - The solder joint material is excellent in solder bondability and joint reliability after soldering. The amorphous layer serves as barrier layer which inhibits bonding between copper and oxygen. Since formation/growth of highly brittle intermetallic compound (Cu6Sn5) layer at a copper/solder interface is suppressed by providing the surface-treated layer, it is possible to improve strength reliability and bending fatigue properties of the solder joints. Since joint reliability is excellent, decrease in power generation efficiency is suppressed when applied to a solar cell module. Copper diffusion to the surface of surface-treated layer and oxygen ingress into a copper raw material, which cause oxidation of copper raw material, are suppressed or reduced by the amorphous layer. This allows growth of an oxide film on the surface of the copper-based metal material to be suppressed during storage.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) soldering component (10);    (2) solar cell module; and    (3) manufacture of solder joint material.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic cross-sectional view of the soldering component.    Copper-based metal material (1)    Surface-treated layer (2)    Soldering component (10)