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THERMOCOMPRESSION Introduction : •Thermocompression bonding : utilizes high temperature and high impact force, and the ball/wedge method. No ultrasonic is used during bonding. Use in special application such as bonding of GaAs devices •The joining together of two materials, without an intermediate material, by the application of pressure and heat in the absence of an electrical current. Ball\Wedge : The machine used to make ball/wedge bonds incorporates a 'flame-off' arm. At the end of each full bonding cycle an arc is struck between the arm and the end of the wire, producing a ball. The ball is deformed as it is welded to the IC (integrated circuit), the second bond (known as the wedge, capillary-wedge, termination bond or stitch bond) is then made to the substrate. The figure below shows a schematic representation of the geometry of a ball/wedge bond. Wirebonding Pressur e Temperature Ultrasonic energy Wire Pad Thermocompressio n High 300-500 oC No Au, Al, Au Ultrasonic Low 25 oC Yes Au, Al Al, Au Thermosonic Low 100-150 oC Yes Au Al, Au Table I Thermocompression bonding, the innovation under consideration, involves heating the semiconductor surface to about 200_C to 300_C and then simply pressing the wire to be bonded against the semiconductor chip surface at the appropriate place with a pressure from 5,000 to 10,000 lb/sq in. In a few seconds a bondwith excellent physical and electrical properties is formed. The machine that performs this task is called a thermocompression bonder. Group Members : -Mohd Amirull Ameer -Mazlini Bt Abdullah -Harold Fred Loduin -Mohd Rahmat -Zul Wang Gani Thermocompression Bonding Thermocompression bonding is used for bonding gold wire with heat, pressure and time. No ultrasonic energy is applied to the bond wire. This bonding process requires elevated temperatures during the bonding process when compared to "thermosonic bonding". The heat is supplied by a heated workholder, which holds the part being bonded. The bonding wedge is usually heated as well. The bonding machine supplies the pressure as it pushes down the wedge onto the wire. The time or duration is how long the bonding wedge sits on the wire. Step Of Thermocompression :
