Abstract:
A bonding structure with a buffer layer, and a method of forming the same are provided. The bonding structure comprises a first substrate with metal pads thereon, a protection layer covered on the surface of the substrate, a first adhesive metal layer formed on the metal pads, a buffer layer coated on the protection layer and the metal pads, a first metal layer covered on the buffer layer, and a second substrate with electrodes and a bonding layer thereon. The first metal layer, the electrodes and the bonding layer are bonded to form the bonding structure. Direct bonding can be performed through surface activation or heat pressure. The method uses fewer steps and is more reliable. The temperature required for bonding the structure is lower. The bonding density between the contacted surfaces is increased to a fine pitch. The quality at the bonding points is increased because fewer contaminations between the contacted surfaces are generated.
Abstract:
An IC chip/substrate assembly bonded together by a non-conductive adhesive and a method for forming the assembly. The assembly consists of an IC chip that has bumps formed on an active surface, a substrate that has bond pads formed on a top surface, wherein at least one of the IC chip and the substrate has dummy bumps formed in-between the bumps or the bond pads, and a non-conductive adhesive disposed in between and bonding the IC chip and the substrate together in a face-to-face relationship with the bumps in electrical communication with the bond pads.
Abstract:
A method for bonding an IC chip by a non-conductive adhesive that contains between about 5 weight % and about 25 weight % of a non-conductive filler is described. The filler particles in the filler material must have a hardness that is higher, and preferably at least two times higher, than the metal material forming the bump. Moreover, the filler particles must be non-electrically conductive such that electrical shorts between a plurality of bumps on the IC chip do not occur. The concentration of the filler in the adhesive must be high enough so as to reduce the CTE of the adhesive to match that of the IC chip and the substrate, and low enough so as not to impede the electrical communication between the bumps on the IC chip and the bond pads on 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:
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.