described is a design and method for producing a sputtering target assembly with low deflection made from target material solder bonded to composite backing plate with coefficient of thermal expansion matching the target material . the composite backing plate is composite configuration composed of at least two different materials with different cte . the composite backing plate , after plastic deformation , if necessary , has a cte matching the target material and low and desirable deflection in the bonding process , and therefore , resulting in a low deflection and low stress target material bonded to composite backing plate assembly . the method includes manufacturing composite backing plate with a flat bond surface , heat treating of target blank and composite backing plate to achieve desirable shape of bond surfaces , solder bonding target to a backing plate , and slowly cooling the assembly to room temperature . matching cte in both target material and backing plate eliminates the problem of cte mismatch and prevents the assembly from deflection and internal stress .