Abstract:
An improved method of attaching a semiconductor die to an organic substrate and an improved semiconductor package are herein disclosed. The die package comprises a die secured to a printed circuit board (PCB) with an adhesive tape. The adhesive tape may be of ingle or multi-layer construction. In one embodiment, a tri-layer tape is disclosed having a carrier layer sandwiched between two identical adhesive layers. In one embodiment, a method is disclosed utilizing a pressure sensitive, thermoset adhesive tape. In another embodiment, a method is disclosed utilizing a B-stageable thermoset adhesive. In yet another embodiment, a method using a pressure sensitive adhesive is disclosed. In still yet another embodiment, a method is disclosed wherein the adhesive is a hybrid material having both thermoset and thermoplastic components.
Abstract:
Flip-chip semiconductor assemblies, each including integrated circuit (IC) dice and an associated substrate, are electrically tested before encapsulation using an in-line or in-situ test socket or probes at a die-attach station. Those assemblies using “wet” quick-cure epoxies for die-attachment may be tested prior to the epoxy being cured by pressing the integrated circuit (IC) dice against interconnection bumps on the substrate for electrical connection, while those assemblies using “dry” epoxies may be cured prior to testing. In either case, any failures in the dice or in the interconnections between the dice and the substrates can be easily fixed, and the need for the use of “known good dice” (KGD) rework procedures during repair is eliminated.
Abstract:
An apparatus and method is provided for forming a board-on-chip (BOC) package. An adhesive material including a carrier and microcapsules distributed in the carrier is used to bond a semiconductor component to a mounting surface in a BOC package. The microcapsules contain a hardener and/or a catalyst that, when combined with the carrier, initiate a bonding reaction. The contents of the microcapsules are released via application of an external influence, such as pressure or heat, when the bonding reaction is desired to begin. The use of microcapsules permits the formulation of adhesive blends with a substantially increased pot life, increased stability and reliability at high temperatures, and favorable low temperature reaction and bonding characteristics.
Abstract:
A method and apparatus for creating second order vibrational modes. The apparatus includes a signal generator, a piezoelectric transducer, a plurality of wave propagating beams and reflecting boards. An electric field applied by the signal generator to the piezoelectric transducer induces a unidirectional vibration of the transducer. The vibration is propagated through the beams and reflected by the reflecting boards in a closed polygonal loop. The final reflection direction is perpendicular to the original vibration. A circular or elliptical vibration of the apparatus results. The circular or elliptical vibrational energy can be imparted to the wire bond of an integrated circuit to add strength to the connection.
Abstract:
A method and apparatus for improved stencil/screen print quality is disclosed. The stencil or screen assists in application of a printable material onto a substrate, such as an adhesive to a semiconductor die of a semiconductor wafer during a lead-on-chip (LOC) packaging process. In one embodiment, the stencil includes a coating applied to at least one surface of a pattern of the stencil or screen to retard running of the printable material onto the surface. In another embodiment, the stencil or screen includes a second coating applied to at least one other surface of the pattern to promote spreading of the printable material onto the substrate.
Abstract:
A Z-axis electrical contact may be formed using a resinous deposit containing conductive particles which may align along surface regions to form an electrical conduction path over the resinous material. If the resinous material is thermoplastic, the material may be heated to mechanically bond to contact surfaces. Advantageously, the resinous material may be formed by forcing a resinous matrix containing conductive particles through an annular opening in a stencil. The resulting member allows surfaces to be contacted which may be irregular or may be covered by native oxide layers.
Abstract:
A semiconductor package structure for a ball grid array type package using a plurality of pieces of adhesive elastomer film to attach a semiconductor die to a substrate having conductive traces in order to alleviate thermal mismatch stress between the semiconductor die and the printed circuit board to which the packaged device is soldered, while maintaining the reliability of the packaged device itself.
Abstract:
A method for attaching a workpiece, for example a semiconductor die, to a workpiece holder, for example a lead frame die support, comprises the steps of interposing an uncured adhesive between the semiconductor die and the die support and preheating the adhesive from an ambient temperature to a preheat temperature of between about 150° C. and about 160° C. over a period of about 1.5 seconds. Next, the preheat temperature is maintained for about 1.5 seconds, then the adhesive is further heated to a temperature of between about 190° C. and about 200° C. over a period of about 1.0 second. The inventive method quickly cures the adhesive to secure the die to the support with acceptably low levels of voiding. An apparatus which can be adapted to perform the inventive method is further described.
Abstract:
A conductive plastic lead frame and method of manufacturing the same suitable for use in IC packaging. In a preferred embodiment, the lead frame is constructed of a plastic or polymer based lead frame structure with an intrinsic conductive polymer coating. In a second embodiment the lead frame is a composite plastic or polymeric material intermixed with an intrinsic conductive polymer coating.
Abstract:
A method and apparatus for attaching an integrated circuit die to a substrate. Specifically, substrates which are used for BOC/COB or F/C surface, mounting comprise protrusions on the surface of the substrate. The protrusions are configured to form barriers to hold an adhesive paste within the barriers. An integrated circuit die is disposed on the top of the barriers and coupled to the substrate by the adhesive paste.