Semiconductor package

A semiconductor package and die assembly with a package having an exterior surface and an interior space, the interior space defined by a first side wall, and a second side wall that opposes the first side wall. Also part of the assembly is a package floor and a package ceiling. The package floor includes package floor conductors. The package ceiling opposes the package floor and includes package ceiling conductors in the package ceiling. One or more semiconductor dies are on the floor of the package floor. Electrical conductors electrically connect the one or more floor dies to the package floor conductors. One or more semiconductor dies are located on the package ceiling. Electrical conductors are configured to electrically connect the one or more ceiling dies to the package ceiling conductors. An air space is located between the package floor and the package ceiling.

FIELD OF THE INVENTION

The innovation relates to semiconductor package, and in particular to a semiconductor package having components on the floor and ceiling of an interior space of the package.

RELATED ART

Prior art package designs are shown inFIGS. 1 and 2. These package designs, while acceptable for certain applications, suffer from several drawbacks. One such drawback is that because all the components are located on the floor of the package interior. This invention allows an optimized used of the internal available real estate. Passive components such as inductors capacitors and resistors can be located on the floor of the package.

In addition, the heat dissipation from the electrical components is an important aspect of package and component design. Excess heat can limit operating parameters and degrade lifetime of the device before failure when all the components are located on one side of the package.

Yet another limiting factor is the limited space associated with many electronic devices. As electronic devices are made to be smaller and smaller, the area on a PCB and on a package is likewise limited. The prior art package shown inFIGS. 1 and 2do not improve component density, which is one way to maximize electrical processing capability per package and PCB area.

SUMMARY

To overcome the drawbacks of the prior art and provide additional benefit, disclosed herein is a semiconductor package and die assembly. In one embodiment, the assembly includes a package having an exterior surface and an interior space. The interior space defined by a first side wall, and a second side wall that opposes the first side wall. Also part of the assembly is a package floor and a package ceiling. The package floor includes package floor conductors in the package floor. The package ceiling opposes the package floor and includes package ceiling conductors in the package ceiling. One or more floor dies are on the floor of the package floor, and the floor dies comprising semiconductor dies. Electrical conductors electrically connect the one or more floor dies to the package floor conductors. One or more ceiling dies that comprise semiconductor dies are located on the package ceiling. Electrical conductors are also part of the assembly and are configured to electrically connect the one or more ceiling dies to the package ceiling conductors.

In one embodiment, the assembly further comprises an air space located between the package floor and the package ceiling, the air space extending from the first side wall to the second side wall. It is also contemplated that the assembly may comprise wall conductors located in the first side wall, the second side wall or both, such that the wall conductors are electrically connecting the package ceiling conductors to the package floor conductors. In one embodiment, the wall conductors comprise RF and DC interconnection via. The assembly may also include a high frequency connector on the side wall or ceiling. The high frequency connector may be located in either the first side wall or the second side wall, or third side wall or a fourth side wall. The assembly may also include an upper heat sink located on the package ceiling. In one configuration, the assembly further comprises heat conductors in the package ceiling that connect to the heat sink. The package ceiling may be further configured as a heat sink.

Also disclosed is a semiconductor package comprising a package floor having an upper surface and a lower surface. The package floor includes package floor conductors in the package floor or on the upper surface of the package floor. One or more side walls extend upward from the package floor and a package ceiling is supported by the side walls. The package ceiling has an exterior surface and an interior surface, the interior surface opposes the upper surface of the package floor and connects to the one or more package walls. The package ceiling includes package ceiling conductors in or the interior surface of the package ceiling. One or more floor dies comprising semiconductor dies are located on the package floor. Also part of this configuration are one or more electrical conductors electrically connecting at least one of the package floor conductors to at least one of the package ceiling conductors.

In one embodiment, the one or more side walls are at an outer edge of the package floor. The semiconductor package may further comprise a high frequency connector in at least one of the one or more side walls. In one embodiment, the electrical conductors that electrically connect at least one of the package floor conductors to at least one of the package ceiling conductors comprise RF and DC interconnection vias. Also part of this embodiment is an optional heat sink on or in the package ceiling. In one embodiment, the semiconductor package has an air space located between the package floor and the package ceiling. This air space may extend from a first side wall to a second side wall.

DETAILED DESCRIPTION

To overcome the drawbacks of the prior art and provide additional benefit, a new package and device configuration is disclosed. As shown inFIG. 3, the package300includes numerous elements. At the top of the package is an optional heat sink304that may be part of the package300or connected to the package to establish a thermal path316for heat from the interior of the package. The heat sink may be made of metal or any other thermally conductive material in any configuration. Below the heat sink304is a package ceiling308that may include one or more heat paths312configured to conduct heat from the package interior or components to the heat sink.

Below the package ceiling308are package side walls320which support the package ceiling308and heat sink304. In this embodiment, the left hand side wall includes electrical conductors324that conduct electrical signals from the package ceiling308to the lower portion of the package334. In this example embodiment, the side wall conductors324include signal conductors and a ground path. One or more of the side wall conductors324terminate in a solder pad at the bottom of the package, which in turn connects to a printed circuit board330or any other support surface for the package300. Another of the side wall conductors324may connect to the package floor338to electrically connect the package ceiling308to the package floor338. One or more additional electrical connections between the package308and the PCB330may exist as would be understood by one of ordinary skill in the art. Such connections may be solder balls, or solder pads, or any other type connections.

In this embodiment, the right hand side wall322of the package300includes a connector340that includes a conductor pin344that electrically connects to the ceiling308or the floor338. In the example embodiment the connector is a G3PO connector, but in other embodiments, different types of connectors may be incorporated, either standard or custom. Other types of high speed or high frequency interfaces may be used other than a connector type configuration. Although shown as one connector340, it is contemplated that each package300may incorporate multiple connectors or capability to electrically connect to multiple connectors. The connector pin or any portion of the connector can connect whether to the ceiling or the floor based on the package and circuit design.

The bottom of the package300is defined by the Lid circuit substrate338, which is also part of the package. The package ceiling and lid338may comprise any material capable of forming a package. In this example embodiment, the package ceiling308and the floor338include one or more electrical conductor in or on one or more surfaces or areas of the package. Thus the ceiling308, side walls324, and floor338may be configured with electrical conductors.

An interior space350is defined by the ceiling308, side walls,324,322, and the floor338. The floor338includes a floor surface334to which one or more floor components354, such as surface mount components, and/or one or more floor dies358, are connected. The floor components354and floor dies358may be connected to the floor surface338by solder, epoxy, resin or any other means. In this embodiment, bond wires360electrically connect the floor die358to the floor surface334. In other embodiments, other types of electrical connections may occur between the components354and the floor dies358and/or floor components354to the floor surface334. The floor components354and the floor dies358electrically connect the one or more electrical conductors in or on the floor338.

The ceiling308includes a ceiling surface362to which one or more ceiling components, such as surface mount components, and/or one or more ceiling dies368are connected. The ceiling components364and floor dies368may be connected to the ceiling surface362by solder, epoxy, resin or any other means. In this embodiment, bond wires370electrically connect the ceiling die368to the ceiling surface362. In other embodiments, other types of electrical connections may occur between the ceiling components364and the ceiling dies368to the ceiling surface362. The ceiling components364and the ceiling dies368electrically connect the one or more electrical conductors in or on the ceiling308. Any type component or element may connect to the floor or ceiling.

It is also contemplated that the electrical connections between the electrical components, whether located on the floor or ceiling, may comprise any type of electrical connection. For example the electrical devices (dies or packages) may be connected to the floor or ceiling with, or other elements within the device with a flip-chip arrangement, solder bumps, wire bonding, flat package through-hole package, surface mount, chip carrier, pin grid array, flat package, small outline package, chip-scale package, ball grid array, transistor, diode, small pin count IC packages, multi-chip packages, down bonding, or any other attachment scheme.

Between the floor surface334and the ceiling surface362is an air gap or air space350. In one embodiment, the air gap extends from side wall324to side wall320without interruption. In one embodiment, the air gap350extends without interruption between the dies368,358. The air gap is shown in a different perspective inFIG. 5. The benefit to the air gap is it provides isolation for high frequency signals and minimizes the negative impacts on the high frequency signals. It also provides for a reworkable assembly in case there are error or failures that need the root cause to be determined. Alternative embodiments would include potting compounds or RF absorbing compounds that encapsulate either the floor or ceiling components.

The system ofFIG. 4is generally similar to the system ofFIG. 3. In the system ofFIG. 4, the right hand side wall404is generally similar to the left hand side wall320and does not include a connector as shown inFIG. 3. The other elements are generally similar and the discussion of those elements is not repeated.

FIG. 5is a perspective view of the device with lid lifted with the lower part of the package mounted on a PCB. In this embodiment, the package includes a lower section504and an upper section or lid508. The lower section includes a floor512, opposing side walls516A,516B, and opposing side walls520A,520B. The package floor512is arranged in accordance with typical and traditional packages with one or more floor conductors arranged on or as part of the package.

On the package floor512are one or more floor electrical components524, such as die, packages, or any other component, passive or active, are located on the floor of the package. The floor electrical components524may be connected to the floor conductors530to allow electrical communication with the floor electrical components524to the package. It is contemplated the package has one or more electrical conductors on the exterior of the package to allow for electrical signal propagation between the package exterior and the package interior.

The side walls516,520of the package504extend upward form the package floor512as shown. In this embodiment, the side walls516A,516B include side wall conductors534that extend upward. The conductors may be in the side wall516, or on the interior or exterior surface of the side walls. It is contemplated that one or more of the side walls516,520may include conductors. The side wall conductors534may connect to the floor conductors530, a package exterior conductor538, or directly to the floor electrical components524in the package504. The package exterior conductors538may extend around the entire package or only be at certain locations. The package may also or alternatively have solder bumps on the bottom of the package. Although shown for purposes of discussion with only four side wall conductors, it is contemplated that any additional number of conductive paths may be in the side walls516A,516B.

Also shown in the side walls520are one or more input/outputs540, such as high frequency connectors configured to provide input to or output from the package. It is contemplated that the input/outputs540connectors connect to one or more floor electrical components524within the package, side wall conductors534, or both. Example of the inputs/outputs540include but are not limited to GPPO and G3PO High Frequency Connectors.

Also shown is an interior side550of a package lid508. When assembled, the lid508would rotate downward to establish the interior side550of the lid facing the package floor512. On the package lid the interior surface550has one or more lid electrical components558which are connected by lid conductors563. The lid508contains the lid conductors562on or in the lid. The material that forms the lid may be any type material, which is typically an insulator which is used to form existing packages or circuit boards. On the lid508are one or more side wall conductor connection points564that align with or otherwise electrically connect to the side wall conductors534. It is contemplated that the lid conductors562may connect to the side wall conductor connection points564.

Also shown as part of the lid508is a two-layer design that includes a conductor layer570and a heat sink layer574. The lid electrical components558and lid conductors562are on or part of the conductor layer570. The heat sink layer574may be on top of or part of the conductive layer, or both, and is configured to draw heat out of the interior space of the package504and from the lid electrical components558. The heat sink layer574or material may be formed from a high thermal conductivity metal or any other material.

The lid508may be attached to the package side walls516,520in any manner including with screws, glue, adhesive, solder connections, or any other manner. The side walls may also be configured with heat sinks or fins. The interior of the package504may be filled with filler, such as epoxy, or the interior space between the walls, floor, and the lid may be open to allow for heat movement. In one embodiment, the interior is sealed from the exterior. In another embodiment, the interior is at least partially open to allow for heat flow and air flow between the interior and the exterior. In one embodiment, air flow is assisted through mechanical means such as a microfan or other device to promote air flow. The floor electrical components and the lid electrical components may comprise any type component such as SMD components, epoxy mounted components or any other type of component. The package504may be configured to mount to a printed circuit board, another package of this or another design, or any other device.

As shown, the package500includes the upper heat sink510which in this embodiment is made from a high thermal conductivity metal. The side walls504support the ceiling and heat sink510. The connector interface508is also shown in this figure. The coaxial connectors could be on one side or multiple sides.

The disclosed design includes many benefits over the prior design. One benefit is that this design, which locates components and/or dies on the floor and the ceiling, is a higher component/die density per unit of area than prior art designs which only located components/dies on the floor. Another benefit of this design is that in certain embodiments heat generating components and/or dies, or elements which generate the most heat, will be located on the ceiling, directly near or in contact with the ceiling heat sinks which is the optimal position.