Patent ID: 8043711

Claim:
An aluminum alloy clad sheet for a heat exchanger comprising a core layer, a sacrificial layer formed on one surface of the core layer, and a filler layer comprising an Al—Si based alloy formed on the other surface of the core layer, wherein the core layer comprises 0.5 to 1.1 mass % Si, 0.5 to 1.1 mass % Cu, at least 0.05 mass % and less than 0.6 mass % Mn, 0.05 to 0.25 mass % Ti, up to 0.45 mass % Mg, and the remainder of Al and inevitable impurities, the sacrificial layer comprises in excess of 0.5 mass % and up to 1.1 mass % Si, 0.001 to 1.7 mass % Mn, 3.0 to 6.0 mass % Zn, and the remainder of Al and inevitable impurities, the core layer has a crystal grain size after brazing heat treatment at 595° C. for 3 minutes of at least 50 μm and less than 300 μm the filler layer has a thickness of 20 to 55 μm, and the sacrificial layer has a thickness of 25 to 50 μm, and grains of intermetallic compounds selected from the group consisting of Al—Mn, Al—Mn—Si, Al—Fe, Al—Fe—Si, and Al—Mn—Fe—Si-based intermetallic compounds having a grain diameter of at least 0.65 μm are present in the core layer and are distributed such that those having a grain diameter of 0.65 to 15 μm are present in the core layer in an amount not exceeding 5×10 3 grains per mm 2 , and those having a grain diameter in excess of 15 μm are present in the core layer in an amount not exceeding 50 grains per mm 2 .