Aluminum alloy backboard manufacturing method, backboard and sputtering target material

The invention relates to the technical field of sputtering target materials, in particular to an aluminum alloy back plate manufacturing method which comprises the following steps: providing an aluminum bar, and cutting off the aluminum bar; obtaining an aluminum column from the cut part of the aluminum bar, heating the aluminum column, and forging the aluminum column; calendering the aluminum column to form a plate blank; the multiple plate blanks are evenly spaced and enter an oven to be heated through a conveying belt; hoisting the plate blank, and putting the plate blank into a water tank for water cooling; and cutting and trimming the plate blank, and machining and polishing the surface of the plate blank. According to the technical scheme, through plastic processing of forging and calendaring, coarse crystal grains in the aluminum bar raw material can be crushed, so that the crystal grains are micronized, the hardened crystal grains are uniform, and the phenomenon of low local hardness can be avoided; t