Patent ID: 8110051

Claim:
A method of producing a high-strength aluminum alloy fin material for heat exchangers having a tensile strength before brazing of at most 240 MPa and a tensile strength after brazing of 150 MPa or more, comprising: pouring a melt comprising 0.8-1.4 wt % of Si, 0.15-0.7 wt % of Fe, 1.5-3.0 wt % of Mn and 0.5-2.5 wt % of Zn, further having Mg as an impurity limited to at most 0.05 wt % and the remainder comprising impurities and Al; continuously casting a slab having a thickness of from 5 to 10 mm and winding the slabs into rolls, followed immediately by; cold rolling to a sheet having a thickness of from 0.05 to 0.4 mm; inter annealing at a temperature of from 350 to 500° C.; and cold rolling at a cold reduction rate of from 10 to 50% to a final sheet thickness of from 40 to 200 μm.