Abstract: A composite bump structure and methods of forming the composite bump structure. The composite bump structure comprises a polymer body of relatively low Young's Modulus compared to metals covered by a conductive metal coating formed at the input/output pads of an integrated circuit element or substrate. The composite bump is formed using material deposition, lithography, and etching techniques. A layer of soldering metal can be formed on the composite bumps if this is desired for subsequent processing. A base metal pad covering the integrated circuit element input/output pad can be used to provide added flexibility in location of the composite bump. The composite bump can be formed directly on the input/output pad or on the base metal pad.

Abstract: A tape automated bonding (TAB) process in which a tape-carrier through its finger leads is bonded to composite bumps on an IC chip wherein the composite bumps are constructed by a polymeric material layer and at least one metal layer. The polymeric material layer has a lower rigidity (or a lower Young's modules) than those of the metal layers. Structural damages during the bonding process that is frequently caused by a rigid metal bump is eliminated. The TAB bonding process can be carried out by using either an all-metal lead frame, a plated metal lead frame, or a polymer reinforced metal lead frame. The polymer/metal composite bumps constructed on the IC chip require a smaller bonding force when bonded in a thermal bonder.

Abstract: This invention provides a bonded structure and a method of forming the bonded structure for joining a lead array to the conducting bonding pads of an integrated circuit element. The invention uses an anisotropic conductive film with tape automated bonding to form the bonded structure. The invention also uses integrated circuit elements having composite bumps as input/output pads. The composite bumps comprise a polymer body covered by a conductive metal coating. The invention provides a low cost method of tape automated bonding which uses lower temperature and pressure in the bonding process and provides a bond which is automatically encapsulated after the bonding has been completed. The lower temperature and pressure improve the dimensional stability of the elements of the bonded structure and the automatic encapsulation provides improved reliability.

Abstract: This invention provides a bonded structure and a method of forming the bonded structure for joining a lead array to the conducting bonding pads of an integrated circuit element. The invention uses an anisotropic conductive film with tape automated bonding to form the bonded structure. The invention also uses integrated circuit elements having composite bumps as input/output pads. The composite bumps comprise a polymer body covered by a conductive metal coating. The invention provides a low cost method of tape automated bonding which uses lower temperature and pressure in the bonding process and provides a bond which is automatically encapsulated after the bonding has been completed. The lower temperature and pressure improve the dimensional stability of the elements of the bonded structure and the automatic encapsulation provides improved reliability.

Abstract: A composite bump structure and methods of forming the composite bump structure. The composite bump structure comprises a polymer body of relatively low Young's Modulus compared to metals covered by a conductive metal coating formed at the input/output pads of an integrated circuit element or substrate. The composite bump is formed using material deposition, lithography, and etching techniques. A layer of soldering metal can be formed on the composite bumps if this is desired for subsequent processing. A base metal pad covering the integrated circuit element input/output pad can be used to provide added flexibility in location of the composite bump. The composite bump can be formed directly on the input/output pad or on the base metal pad.

Abstract: This invention provides a connection structure and methods of forming the connection structure which combines the advantages of composite bumps and conductive films formed of conductive particles in a non-conductive binder. The conductive film provides conductive particles in a non-conductive binder which can be placed on the input/output pads of an integrated circuit element or substrate. The conductive particles contact composite bumps comprised of a polymer body, having a relatively low Young's Modulus, and a conductive metal coating to form the connection structure. The relatively low Young's Modulus of the composite bumps greatly reduce the recoil forces during bonding. Because of the low recoil forces the connection can be formed with reduced bonding force and forces tending to separate the connection once formed are reduced. The non-conductive binder is cured to form the adhesive between the integrated circuit element and the substrate.

Abstract: A bonded structure comprising the physical and electrical connections between an integrated circuit element and substrate using a composite bump comprised of a single polymer body of low Young's Modulus, a conductive barrier metal coating covering the polymer body and a soldering metal coating covering the conductive barrier metal coating. When the bonded structure is formed the composite bump is deformed and the low Young's Modulus of the polymer body allows a very reliable bonded structure with very low bonding force. Due to the low Young's Modulus there is little stress tending to break the solder joint after the bonded structure is formed. The bond is formed using a soldering process so that the soldering metal forms a conductive adhesive between the composite bumps and either the substrate input/output pads or the integrated circuit element input/output pads.

Abstract: A composite bump structure and methods of forming the composite bump structure. The composite bump structure comprises a polymer body of relatively low Young's Modulus compared to metals covered by a conductive metal coating formed at the input/output pads of an integrated circuit element or substrate. The composite bump is formed using material deposition, lithography, and etching techniques. A layer of soldering metal can be formed on the composite bumps if this is desired for subsequent processing.