Abstract: A variety of improved approaches for packaging integrated circuits are described. In one described approach, a multiplicity of dice are mounted on a carrier (e.g., a plastic carrier). Each die has a plurality of wire bonded contact studs secured to its associated I/O pads. An encapsulant is applied over the carrier to cover the dice and at least portions of the contact studs to form an encapsulant carrier structure. After the encapsulant has been applied, a first surface of the encapsulant and the contact studs are ground such that exposed portions of the contact studs are smooth and substantially co-planar with the encapsulant. In some embodiments, a redistribution layer is formed over the encapsulant carrier structure and solder bumps are attached to the redistribution layer. A contact encapsulant layer is applied over the encapsulant carrier structure to provide extra mechanical support for the resulting packages.

Abstract: A variety of improved approaches for packaging integrated circuits are described. In one described approach, a multiplicity of die cavities are formed in a plastic carrier. In some preferred embodiments, the die cavities are formed by laser ablation. A multiplicity of dice are placed on the carrier, with each die being placed in an associated die cavity. Each of the dice preferably has a multiplicity of I/O bumps formed thereon. An encapsulant is applied over the carrier to form an encapsulant layer that covers the dice and fills portions of the cavities that are not occupied by the dice. In some preferred embodiments, the encapsulant is an epoxy material applied by screen printing and the dice are not physically attached to the carrier prior to the application of the encapsulant. In these embodiments, the epoxy encapsulant serves to secure the dice to the carrier.

Abstract: A variety of improved approaches for packaging integrated circuits are described. In one described approach, a multiplicity of dice are mounted on a carrier (e.g., a plastic carrier). Each die has a plurality of wire bonded contact studs secured to its associated I/O pads. An encapsulant is applied over the carrier to cover the dice and at least portions of the contact studs to form an encapsulant carrier structure. After the encapsulant has been applied, a first surface of the encapsulant and the contact studs are ground such that exposed portions of the contact studs are smooth and substantially co-planar with the encapsulant. In some embodiments, a redistribution layer is formed over the encapsulant carrier structure and solder bumps are attached to the redistribution layer. A contact encapsulant layer is applied over the encapsulant carrier structure to provide extra mechanical support for the resulting packages.

Abstract: Arrangements for plating a single surface of a thin foil are described. In one aspect, a metal foil is wrapped tightly at least partially around a plating solution drum. The drum is partially immersed in a plating solution such that the waterline of the metal plating solution is below a break point where the metallic foil strip begins to unwind from the plating solution drum. With this arrangement, one side of the metallic foil strip is exposed to the metal plating solution, while the opposing back side of the metallic foil strip does not come in substantial contact with the metal plating solution. In this manner, the exposed side of the foil is plated while the back surface of the foil is not plated. The drum may be rotated to convey the foil through the plating solution.

Abstract: In a method aspect, a multiplicity of ICs are attached to routing on a structurally supportive carrier (such as a wafer). The dice are encapsulated and then both the dice and the encapsulant layer are thinned with the carrier in place. A second routing layer is formed over the first encapsulant layer and conductive vias are provided to electrically couple the first and second routing layers as desired. External I/O contacts (e.g. solder bumps) are provided to facilitate electrical connection of the second routing layer (or a subsequent routing layer in stacked packages) to external devices. A contact encapsulant layer is then formed over the first encapsulant layer and the second routing layer in a manner that embeds the external I/O contacts at least partially therein. After the contact encapsulant layer has been formed, the carrier itself may be thinned significantly and singulated to provide a number of very low profile packages. The described approach can also be used to form stacked multi-chip packages.

Abstract: A leadframe suitable for use in the packaging of at least two integrated circuit dice into a single integrated circuit package is described. The leadframe includes a plurality of leads. Each of a first set of the plurality of leads has a first side and a second side substantially opposite the first side of the lead. Additionally, each of the first and second sides of the first set of leads each include at least two solder pads. Each solder pad on a lead of the first set of leads is isolated from other solder pads on the same side of the lead with at least one recessed region adjacent the solder pad. In various embodiments, I/O pads from at least two dice are physically and electrically connected to the opposing sides of the leads.

Abstract: One aspect of the invention pertains to an arrangement for forming exposed die packages. The arrangement includes a semiconductor wafer having multiple integrated circuit dice whose back surfaces cooperate to form the back surface of the wafer. A thermally conductive adhesive layer is deposited on the back surface of the wafer. The metal foil is attached to the wafer with the adhesive layer. Methods of forming exposed die packages using the above arrangement are also described.

Abstract: The present inventions relate generally to methods for packaging integrated circuits using thin foils that form electrical interconnects for the package. The foil includes a base layer (such as copper) with an optional plating layer (such as silver) suitable for improving adhesion of the bonding wires (or other connectors) to the foil. The base layer (or the plated surface if the foil is preplated) of the foil is patterned by laser ablation to define components (e.g. contacts) of a device area. The patterning is arranged to ablate entirely through selected portions of the plating layer and part, but not all, of the way through corresponding underlying portions of the base layer. In some embodiments, the metallic foil is partially etched after the laser ablation in order to deepen the trenches that define the patterning of the foil. Multiple dice may then be attached to die attach pad areas of the plated foil and electrically coupled to electrical contacts.

Abstract: A leadframe suitable for use in the packaging of at least two integrated circuit dice into a single integrated circuit package is described. The leadframe includes a plurality of leads. Each of a first set of the plurality of leads has a first side and a second side substantially opposite the first side of the lead. Additionally, each of the first and second sides of the first set of leads each include at least two solder pads. Each solder pad on a lead of the first set of leads is isolated from other solder pads on the same side of the lead with at least one recessed region adjacent the solder pad. In various embodiments, I/O pads from at least two dice are physically and electrically connected to the opposing sides of the leads.

Abstract: Arrangements for plating a single surface of a thin foil are described. In one aspect, a metal foil is wrapped tightly at least partially around a plating solution drum. The drum is partially immersed in a plating solution such that the waterline of the metal plating solution is below a break point where the metallic foil strip begins to unwind from the plating solution drum. With this arrangement, one side of the metallic foil strip is exposed to the metal plating solution, while the opposing back side of the metallic foil strip does not come in substantial contact with the metal plating solution. In this manner, the exposed side of the foil is plated while the back surface of the foil is not plated. The drum may be rotated to convey the foil through the plating solution.

Abstract: Methods for minimizing warpage of a welded foil carrier structure used in the packaging of integrated circuits are described. Portions of a metallic foil are ultrasonically welded to a carrier to form a foil carrier structure. The ultrasonic welding helps define a panel in the metallic foil that is suitable for packaging integrated circuits. Warpage of the thin foil can be limited in various ways. By way of example, an intermittent welding pattern that extends along the edges of the panel may be formed. Slots may be cut to define sections in the foil carrier structure. Materials for the metallic foil and the carrier may be selected to have similar coefficients of thermal expansion. An appropriate thickness for the metallic foil and the carrier may be selected, such that the warpage of the welded foil carrier structure is limited when the foil carrier structure is subjected to large increases in temperature. Foil carrier structures for use in the above methods are also described.

Abstract: A leadframe suitable for use in the packaging of at least two integrated circuit dice into a single integrated circuit package is described. The leadframe includes a plurality of leads. Each of a first set of the plurality of leads has a first side and a second side substantially opposite the first side of the lead. Additionally, each of the first and second sides of the first set of leads each include at least two solder pads. Each solder pad on a lead of the first set of leads is isolated from other solder pads on the same side of the lead with at least one recessed region adjacent the solder pad. In various embodiments, I/O pads from at least two dice are physically and electrically connected to the opposing sides of the leads.

Abstract: A method of packaging integrated circuit dice into exposed die packages is described. The method includes depositing a metallic layer onto the back surface of an integrated circuit wafer such that it covers the back surface. The method additionally includes applying a protective layer over the metallic layer such that the protective layer covers the metallic layer. The method further includes singulating the wafer to produce individual dice. Each die may then be electrically connected to a lead frame. The die and portions of the lead frame may then be encapsulated with a molding compound. The protective layer inhibits the molding compound from contacting the metallic layer on the back surface of the die. The protective layer is then removed from the metallic layer. As a result, an individual IC package is produced that includes a die having a metallic layer exposed on the back surface of the die.

Abstract: An improved method and apparatus for packaging integrated circuits are described. More particularly, a method and apparatus for use in securing a plurality of integrated circuit dice to a lead frame panel are described. Each integrated circuit die includes an active surface having a multiplicity of solder bumps. The lead frame panel includes an array of device areas, each including a plurality of leads. The method includes positioning a plurality of dice into designated positions on a carrier such that the active surfaces of the dice are facing upwards. The carrier includes a carrier frame including an associated array of carrier device areas. A lead frame panel may be positioned over the carrier such that the solder bumps on the active surfaces of the dice are adjacent and in contact with the associated leads of the associated device areas.