| 摘要 |
PROBLEM TO BE SOLVED: To provide a heat spreader capable of suppressing generation of voids more excellently than now, and capable of bonding with a solder excellent in thermal conductivity, bonding strength, and reliability.SOLUTION: The heat spreader is composed of a composite material containing a high thermal conduction metal and low thermal expansion particles, and includes bonding surfaces arranged by making each of one surface of the plurality of the low thermal expansion particles to be coincided at the same flat plane. Between the plurality of low thermal expansion particles arranged at the bonding surface, a recessed step in a range of greater than or equal to 8.0 μm and less than or equal to 25.0 μm from the bonding surface is provided on a substrate. The heat spreader is formed by coating the bonding surface with a layer to be coated. The center line average roughness Ra of an exposed surface of the layer to be coated is greater than or equal to 2.0 μm and less than or equal to 9.0 μm.SELECTED DRAWING: Figure 1 |
