Patent ID: 7585360

Claim:
A metal plating solution comprising diamond powder dispersed and suspended therein at a concentration of 0.01 to 160 g per liter, wherein; (i) said diamond powder have an element composition consisting mainly of carbon in the range of 72 to 89.5% by weight, hydrogen in the range of 0.8 to 1.5%, nitrogen in the range of 1.5 to 2.5% of, and oxygen in the range of 10.5 to 25.0%, (ii) and, 80% or more by number average and/or 70% or more by weight average of particles of said diamond powder are in the range of 2 nm to 50 nm in diameters thereof, (iii) and, said particles of said powder exhibit a strongest peak of the intensity of the Bragg angle at 43.9° (2θ±2°), strong and characteristic peaks at 73.5° (2θ±2°) and 95° (2θ±2°), a warped halo at 17° (2θ±2°), and no peak at 26.5°, by X-ray diffraction (XRD) spectrum analysis using Cu—Kα radiation, (iv) and, the specific surface area of said powder is not smaller than 1.50×10 5 m 2 /kg, and substantially all of the surface carbon atoms of said particles are bonded with hetero atoms, and total absorption space of said powder is 0.5 m 3 /kg or more, when dried.