There is provided a novel, environmentally friendly primer for use in the pretreatment steps in electroless plating, which can be easily used in fewer steps with a lower cost. A primer for forming a metallic plating film on a substrate by electroless plating, the primer including: a hyperbranched polymer having an ammonium group at a molecular terminal and a weight-average molecular weight of 500 to 5,000,000; and a metal fine particle.

A composite is obtained by press-molding a mixed powder comprising 20-50 vol % of a metal powder and 50-80 vol % of a diamond powder for which a first peak in a volumetric distribution of particle size lies at 5-25 m, and a second peak lies at 55-195 m, and a ratio between the area of a volumetric distribution of particle sizes of 1-35 m and the area of a volumetric distribution of particle sizes of 45-205 m is from 1:9 to 4:6, thereby obtaining a composite having a high thermal conductivity and a coefficient of thermal expansion close to that of semiconductor devices, which is easy to mold into a prescribed shape.

Laminated composite (10) comprising at least one electronic substrate (11) and an arrangement of layers (20, 30) made up of at least a first layer (20) of a first metal and/or a first metal alloy and of a second layer (30) of a second metal and/or a second metal alloy adjacent to this first layer (20), wherein the melting temperatures of the first and second layers are different, and wherein, after a thermal treatment of the arrangement of layers (20, 30), a region with at least one intermetallic phase (40) is formed between the first layer and the second layer, wherein the first layer (20) or the second layer (30) is formed by a reaction solder which consists of a mixture of a basic solder with an AgX, CuX or NiX alloy, wherein the component X of the AgX, CuX or NiX alloy is selected from the group consisting of B, Mg, Al, Si, Ca, Se, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ga, Ge, Y, Zr, Nb, Mo, Ag, In, Sn, Sb, Ba, Hf, Ta, W, Au, Bi, La, Ce, Pr, Nd, Gd, Dy, Sm, Er, Tb, Eu, Ho, Tm, Yb and Lu and wherein the melting temperature of the AgX, CuX or NiX alloy is greater than the melting temperature of the basic solder. The invention also relates to a method for forming a laminated composite (10) and to a circuit arrangement containing a laminated composite (10) according to the invention.

An aluminum-diamond composite that exhibits both high thermal conductivity and a coefficient of thermal expansion close to that of semiconductor devices, and that can suppress the occurrence of swelling, etc., of a surface metal layer portion even in actual use under a high load. An aluminum-diamond composite includes 65-80 vol % of a diamond powder having a roundness of at least 0.94, for which a first peak in a volumetric distribution of grain size lies at 5-25 m, and a second peak lies at 55-195 m, and a ratio between the area of the volumetric distribution of grain sizes of 1-35 m and the area of the volumetric distribution of grain sizes of 45-205 m is from 1:9 to 4:6; the balance being composed of a metal containing aluminum.