|
Compliant bonding is used to connect gold wires to electrical components such as integrated circuit "chips". It was invented by Alexander Coucoulas in the 1960s.〔Alexander Coucoulas ("Bonding With A Compliant Medium" ). . October 13, 1970. Filed July 6, 1967.〕 The bond is formed well below the melting point of the mating gold surfaces and is therefore referred to as a solid-state type bond. The compliant bond is formed by transmitting heat and pressure to the bond region through a relatively thick indentable or ''compliant medium'', generally an aluminum tape (Figure 1).〔Coucoulas, A. (1970) “Compliant Bonding” Proceedings 1970 IEEE 20th Electronic Components Conference, pp. 380–89. PDF, (PDF2 )〕 == Comparison with other solid state bond methods == Solid-state or pressure bonds form permanent bonds between a gold wire and a gold metal surface by bringing their mating surfaces in intimate contact at about 300 °C which is well below their respective melting points of 1064 °C, hence the term solid-state bonds. Two commonly used methods of forming this type of bond are thermocompression bonding and thermosonic bonding. Both of these processes form the bonds with a hard faced bonding tool that makes direct contact to deform the gold wires against the gold mating surfaces (Figure 2). Since gold is the only metal that does not form an oxide coating which can interfere with making a reliable metal to metal contact, gold wires are widely used to make these important wire connections in the field of microelectonic packaging. During the compliant bonding cycle the bond pressure is uniquely controlled by the inherent flow properties of the aluminum compliant tape (Figure 3). Therefore if higher bond pressures are needed to increase the final deformation (flatness) of a compliant bonded gold wire, a higher yielding alloy of aluminum could be employed. The use of a compliant medium also overcomes the thickness variations when attempting to bond a multiple number of conductor wires simultaneously to a gold metalized substrate (Figure 4). It also prevents the leads from being excessively deformed since the compliant member deforms around the leads during the bonding cycle thus eliminating mechanical failure of a bonded wire due to excessive deformation from a hard faced tool (Figure 3) which is employed by thermocompression, and thermosonic bonding. File:Electroformed beam leaded integrated circuit.png|Figure 5. An array of beam leaded silicon integrated circuits showing the attached and extended electroformed beam leads around the perriphery of the silicon chip File:Integrated circuit wire bonded.png|Figure 6. Wires solid state bonded directly to the metallized pads of a silicon integrated circuit chip File:Solid state bonding a beam leaded chip with a hard faced tool.jpg|Figure 7. Hard faced bonding tool simultaneously bonding all of the extended beam leads File:Compliant bonding a beam leaded chip0002.jpg|Figure 8. Compliant bonding a beam leaded silicon integrated circuit showing the indented compliant member after bonding the "chip" 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Compliant bonding」の詳細全文を読む スポンサード リンク
|