Leadframe with power and ground planes

摘要

A leadframe for use in an integrated circuit package is described. The leadframe comprises a plurality of electrically conductive leads, a die attach pad, and an electrically conductive ring or rings formed generally around the circumference of the die attach pad and between the die attach pad and leads. In one embodiment, at least one of the leads is formed integrally with each ring. The die attach pad may also be formed integrally with one or more leads. In another embodiment, the ring or rings are formed so that they are electrically isolated from the die attach pad, and the die attach pad, leads, and ring or rings are all formed in substantially the same plane. In some embodiments, the ring or rings are broken into electrically isolated sections. Each of the ring sections (and die attach pad, if appropriate) may be electrically connected to a voltage source outside the integrated circuit package (e.g., a power supply or ground). The leadframe is formed from a single sheet of material by, for instance, stamping or etching. The leadframe may be used in either ceramic or plastic packages. The leadframe reduces switching noise and crosstalk, allows more flexibility in placement of power and/or ground bond pads on the die, and allows provision of ground and power planes in an integrated circuit package that is thinner than previous integrated circuit packages containing both ground and power planes.