Abstract: A metal layer such as copper, silver or nickel is coated on a surface of reinforcement particles (aluminum oxide or silicon carbide powder) by electroless plating technique. The metal-coated reinforcement particles with an appropriate volume fraction are inserted into the gap between two metal plates or two metal matrix composite (MMC) plates. The reinforcement particles are stirred into the metal plates or the MMC plates by friction stir welding (FSW) to form a butt weld metal containing reinforcement particles. Or the metal-coated reinforcement particles deposited on the surface of the metal plates or the MMC plates and then are stirred into base material of the metal plates. The metal-coated reinforcement particles are uniformly distributed in a weld metal by such stirring, the coated metal layer on the surface of the reinforcement particles form an alloy with metallurgical bonding.

Abstract: Disclosed is a method of realizing thermosonic wire bonding between metal wires and copper pads by depositing a thin film to surfaces of semiconductor chips with copper pads, where a thin film that provides the effect of self-passivation to prevent oxidization of the copper pads located thereunder is deposited on surfaces of the copper pads to provide sufficient protection to the chips with copper pads thereby preventing copper from oxidizing at elevated temperature during packaging, due to die sawing, die mounting or curing and thermosonic wire bonding, which would result in failure of bonding metal wires to the copper pads, poor bondability between the metal wires and the copper pads, or low bonding strength of the bonds.

Abstract: Disclosed is a method of realizing thermosonic wire bonding between metal wires and copper pads by depositing a thin film to surfaces of semiconductor chips with copper pads, where a thin film that provides the effect of self-passivation to prevent oxidization of the copper pads located thereunder is deposited on surfaces of the copper pads to provide sufficient protection to the chips with copper pads thereby preventing copper from oxidizing at elevated temperature during packaging, due to die sawing, die mounting or curing and thermosonic wire bonding, which would result in failure of bonding metal wires to the copper pads, poor bondability between the metal wires and the copper pads, or low bonding strength of the bonds.

Abstract: Discloses is a method of realizing direct bonding between metal wires and copper pads by means of thermosonic wire bonding using a shielding gas spraying device, where a shielding gas is provided between metal wires and a chip with copper pads during thermosonic wire bonding to form a gas shielding zone around a wire bonding zone of a thermosonic wire bonder, to effectively prevent oxidization of the chips with copper pads at elevated temperature of a heating stage of the thermosonic wire bonder; thus, the provision of the shielding gas spraying device according to this invention allows the metal wires to be directly bonded to the chips with copper pads by means of thermosonic wire bonding process, and overcomes the problem caused by the copper oxide film, thereby meeting the demand of high bondability required by the semiconductor packaging industry, and significantly improving the bonding strength and reliability of the metal wires and chip with copper pads.