A method for mounting a head stack assembly (HSA) circuit assembly is disclosed. A flexible circuit substrate may be coupled to a stiffener. The stiffener may be a metal, such as aluminum, or some other stiff and durable material. The flexible circuit substrate may be made of an organic material and may have a series of electronic leads embedded in the flexible circuit substrate. The flexible substrate may be coupled to the stiffener by an adhesive or laminated onto the stiffener. The stiffener may be mounted onto the actuator arm by soldering or by laser welding.