Beam lead formation method
AssigneeSharp Kabushiki Kaisha
InventorMituo Matunami
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Abstract
The present disclosure is directed toward a method for making semiconductor devices having beam leads for electrical connections to external terminals. An undercoating metal film is deposited directly or via a protective film on a semiconductor wafer on which interconnections are formed together with electrode pad or contact areas. After subsequent deposition of an upper metal film, beam leads are formed in a desired pattern in a manner to contact with and extend from the electrode areas. The final step is to apply physical force to the semiconductor wafer such that the undercoating metal film serving also as a portion of the beam leads is forcibly spaced away from the major surface of the semiconductor wafer.
Claims10
A method of making semiconductor devices having a predetermined number of beam leads for electrical connections to external terminals, said method comprising the steps of:
- preparing a semiconductor wafer including one or more circuit elements thereon;
- forming a predetermined number of electrode pads to which the corresponding beam leads are connected;
- depositing over the surface of the semiconductor wafer except the electrode pads an undercoating metal film which does not adhere strongly to the wafer surface;
- forming in a desired pattern a metal film which adheres closely to the electrode pads and the undercoating metal film and forms the aforementioned beam leads;
- applying physical force to the semiconductor wafer in order to cause the undercoating metal film to be spaced away from the surface;
- and
- dividing the semiconductor wafer into a plurality of semiconductor devices.
A method of making semiconductor devices having a predetermined number of beam leads for electrical connections to external terminals, said method comprising the steps of;
- preparing a semiconductor wafer including one or more circuit elements thereon;
- forming a predetermined number of electrode pads to which the corresponding beam leads are to be connected;
- depositing a heat-resisting protective film over the semiconductor wafer;
- depositing over the surface of the protective film a first undercoating metal film which does not adhere strongly to the wafer surface;
- removing the protective film and the undercoating metal film over the area of the electrode pads;
- depositing an auxiliary electrode metal film over the undercoating metal film and the surface of the electrode
- depositing a second metal film on the auxiliary electrode metal film and extending to the electrode pads, said first undercoating metal film and the second metal film forming the beam leads;
- applying physical force to the semiconductor wafer in order to cause the first undercoating metal film to be spaced away from the wafer surface;
- and
- dividing the semiconductor wafer into a plurality of semiconductor devices.
A method of making semiconductor devices having a predetermined number of beam leads for electrical connections to external terminals, said method comprising the steps of:
- preparing a semiconductor wafer including one or more circuit elements thereon;
- forming a predetermined number of electrode pads to which the corresponding beam leads are to be connected;
- depositing a heat-resisting protective film over the semiconductor wafer, except for the electrode pads;
- depositing a metal film over the heat-resisting film and the electrode pads;
- removing said metal film from the heat-resisting protective film except that portion corresponding to the electrode pads;
- depositing an additional multi-layered metal film over the electrode pads;
- annealing the semiconductor wafer;
- applying a first undercoating metal film to the surface of the semiconductor wafer except for the electrode pads, which does not adhere strongly to the wafer surface;
- depositing a second film on the first undercoated metal film and the electrode pads;
- applying physical force to the semiconductor wafer in order to cause the first undercoating metal film to be spaced away from the wafer surface;
- and
- dividing the semiconductor wafer into a plurality of semiconductor devices.
Dependencies are inferred from the claim text.