Embodiments of the present invention relate generally to the manufacture of semiconductor devices. In particular, embodiments of the present invention relate to package on package (PoP) devices and methods for manufacturing such devices.
Package on package (PoP) stacking is an important system in package (SiP) solution in the area of mobile applications. In the mobile applications world, the height of stacked packages is an important driver for new applications. Reducing the height of packages may allow for them to fit in thinner mobile devices or at new positions within the mobile device (e. g. under battery, double sided assembly of a board, etc.). Accordingly, future system integration applications are currently driving to further reduce the thickness of PoP solutions.
One current PoP solution may include the use of embedded wafer level ball grid array (eWLB) or embedded panel level ball grid array (ePLB) technologies. Such a PoP device based on eWLB technology is illustrated in the cross-sectional view in
The substrate 135 mounted over the mold layer 115 may include any number of active or passive components 140. In some instances, a second mold layer 116 may also encase the components. A second die 120 may also be mounted to the second substrate 135. The second die 120 may be any die, such as a power management integrated circuit (PMIC) or a memory component, such as a high bandwidth memory (HBM). However, mounting the substrate 135 to the mold layer 115 increases the thickness of the PoP device. For example, the substrate 135 needs to be electrically and mechanically coupled to the vias 125 in the mold layer 115 by solder bumps 126. The solder bumps 126 have a stand-off height T that increases the thickness of the package. For example, the solder bumps 126 may have a stand-off height T that is approximately 50 μm or greater. In addition to the increase in height attributable to the solder bumps 126, the assembly process provides additional drawbacks that prevent further reduction of the thickness of eWLB/ePLB based PoP devices. Specifically, the substrate 135 needs to be attached with the solder bumps 126 after the lower package is formed. Therefore, the mold layer 115 of the eWLB/ePLB (which may also be referred to as a reconstituted wafer or panel) needs to be able to withstand the stresses of package assembly. Accordingly, the mold layer 115 needs to be relatively thick. As such, the overall package thickness needs to be increased in order to assemble the PoP device.
Accordingly, there is a need in the art for packaging technologies that allow for the formation of thin PoP devices.
Described herein are systems that include a semiconductor package and methods of forming such semiconductor packages. In the following description, various aspects of the illustrative implementations will be described using terms commonly employed by those skilled in the art to convey the substance of their work to others skilled in the art. However, it will be apparent to those skilled in the art that the present invention may be practiced with only some of the described aspects. For purposes of explanation, specific numbers, materials and configurations are set forth in order to provide a thorough understanding of the illustrative implementations. However, it will be apparent to one skilled in the art that the present invention may be practiced without the specific details. In other instances, well-known features are omitted or simplified in order not to obscure the illustrative implementations.
Various operations will be described as multiple discrete operations, in turn, in a manner that is most helpful in understanding the present invention, however, the order of description should not be construed to imply that these operations are necessarily order dependent. In particular, these operations need not be performed in the order of presentation.
In order to decrease the overall thickness of the package, embodiments of the invention include a mold layer and a substrate that are stacked without the need for solder bumps to electrically and mechanically couple the two together. Instead of forming a reconfigured wafer or panel and then attaching the substrate to the mold layer with solder bumps, embodiments of the invention mount the substrate directly to the mold layer during the molding process. As such, the extra stand-off height needed for the solder bumps is eliminated. By way of example, the elimination of solder bumps may reduce the thickness of the package by approximately 50 μm or more. Additionally, mounting the substrate directly to the mold layer allows for a thinner mold layer to be formed. Since the substrate provides mechanical stability during subsequent processing (e.g., during handling and through mold via formation) the thickness of the mold layer may be decreased relative to the mold layers used in typical eWLB/ePLB processes. Therefore, embodiments of the invention are able to provide PoP devices that have reduced thicknesses because the solder bumps between the mold layer and the substrate are eliminated, and because the thickness of the mold layer may be reduced.
Embodiments of the invention include a plurality of different configurations that may be used separately or in combination, depending on the needs of the device. Some exemplary configurations according to embodiments of the invention are illustrated in
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According to an embodiment, a redistribution layer 230 may be formed over a surface of the mold layer 215. The redistribution layer 230 may include one or more dielectric film layers 234 and conductive traces and vias 232. Additional embodiments may also include solder resists (not shown) formed over a surface of the redistribution layer 230 in order to prevent solder bumps 219 from shorting between contacts. The conductive traces and vias 232 provide electrical routing from the die 210 to the solder bumps. The conductive traces may also electrically couple through mold vias 225, to the die 210 and/or the solder bumps 219.
According to an embodiment of the invention, the through mold vias 225 may be a conductive material that extends through a thickness of the mold layer 215. In the illustrated embodiment, the through mold vias 225 are shown having tapered sidewalls. Embodiments of the invention may include tapered sidewalls when a laser drilling process is used to form the openings in which the through mold vias 225 are formed. However, it is to be appreciated that the shape of the through mold vias does not need to include continuously tapered sidewalls. As will be described in greater detail below, alternative fabrication processes may be used that produce through mold vias that have alternative sidewall shapes. The through mold vias 225, provide electrical pathways from one surface of the mold layer 215 to the opposite surface of the mold layer 215. This enables a substrate 250 to be mounted above the mold layer 215. According to an embodiment, the active side of the embedded die 210 may oriented so that it faces away from the substrate 250.
According to an embodiment, the substrate 250 is mounted directly to a surface of the mold layer 215 without the need for solder bumps. As illustrated, contacts 227 in the substrate 250 may be in direct contact with a surface of the through mold vias 225. According to an embodiment, the adhesion between the substrate 250 and the mold layer 215 is sufficiently strong enough to provide a mechanical bond between the two layers. The adhesion between the two layers is sufficiently strong because the substrate 250 may be bonded to the mold layer 215 during the molding process used to form the mold layer, as will be described in greater detail below. Additional embodiments of the invention may further increase the adhesion between the substrate 250 and the mold layer 215 by including mechanical anchors (not shown) on the substrate 250. For example, the substrate 250 may also include ridges, grooves, pockets, or the like in order to further increase the adhesion between the two layers.
According to an embodiment, the substrate 250 may include conductive traces and vias 257 formed in one or more dielectric layers 252. By way of example, the dielectric layers may be a polyimide, polybenzoxazole (PBO), ABF, or epoxy based material. The conductive traces and vias 257 may provide electrical routing from the contacts 227 to one or more components 220/240 mounted to the substrate 250. The components 220 are illustrated as being mounted to conductive traces with solder bumps 221. For example, the components 220 may be flip-chip mounted to the substrate 250. In one embodiment the components 220 may be a die or the like. For example, the components may be a memory device, such as a high bandwidth memory (HBM) device, a power management integrated circuit (PMIC), or the like. Other components 240 are illustrated as being directly mounted to the substrate 250 without solder bumps. The additional components 240 may be active or passive components. For example, active electronic components may include one or more semiconductive dies with integrated circuitry, such as transistors, diodes, or the like, and passive electronic components may include resistors, capacitors, integrated passive devices (IPDs), or the like.
Accordingly, the packaged device according to the embodiment illustrated in
As mentioned above, additional embodiments of the invention may also include through mold vias that do not have continuously tapered sidewalls throughout the entire thickness of the mold layer 215. A package according to such an embodiment is illustrated and described with respect to
As illustrated in
The use of conductive balls 228 provides several benefits. One benefit is that the laser drilled openings for the vias 225 do not need to be as deep. As such, the throughput can be increased because the reduced drill depth reduces the time needed to form the via openings. Additionally, the shallower openings are easier to fill with conductive material. Accordingly, the yield may be increased because the openings are more likely to be properly filled with conductive material. Furthermore, the shallower drill depth allows for the vias 225 to be formed with a tighter pitch. Reducing the pitch allows for a decrease in the size of the package.
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The ability to form packages according to embodiments of the invention is made possible by using a molding process that simultaneously mounts the substrate to the mold layer as the mold layer is being formed. A process flow for forming such packages according to an embodiment of the invention is illustrated and described with respect to
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After the dice 310 are mounted on the mold carrier 394, the mold carrier 394 may be placed in the molding tool. In one embodiment, the molding tool may include a supporting portion 392 for supporting the mold carrier 394 and a top portion 391 for holding the substrate 350. For example, the substrate 350 may be held in place with a vacuum. While the illustrated embodiment depicts a molding tool with two components, it is to be appreciated that any suitable molding tool that can support the mold carrier 394 and attach the substrate may be used. It is to be appreciated that the substrate 350 illustrated in
According to an embodiment, a molding compound 315 may be dispensed over the mold carrier 394 and the dice 310. By way of example, the molding compound 315 may be any suitable compound (e.g., liquid, granular, pellet, sheet, etc.). After the molding compound 315 is dispensed, the top portion 391 of the molding tool may be pressed into the molding compound 315, as indicated by the arrow. Pressing the top portion 391 of the molding tool brings the substrate 350 into contact with the molding compound. After a curing process, the substrate 350 may be adhered to the solidified mold layer 315.
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According to additional embodiments of the invention, the molding process may also be used to embed conductive balls into the mold layer when the substrate is attached. A process according to such an embodiment is illustrated and described with respect to
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According to additional embodiments of the invention, the molding process may also be used to embed one or more components into the mold layer when the substrate is attached. A process according to such an embodiment is illustrated and described with respect to
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After the formation of the mold layer 515 with the additional components 540 embedded therein, the processing may proceed in substantially the same manner described above with respect to
According to additional embodiments of the invention, a molding process may also be used that includes a die that is attached to the bottom surface the substrate prior to the molding process. A process according to such an embodiment is illustrated and described with respect to
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After the formation of the conductive via bars 676 and the conductive pillars 662, 675 are exposed, the processing may proceed in substantially the same manner described above with respect to
Depending on its applications, computing device 700 may include other components that may or may not be physically and electrically coupled to the board 702. These other components include, but are not limited to, volatile memory (e.g., DRAM), non-volatile memory (e.g., ROM), flash memory, a graphics processor, a digital signal processor, a crypto processor, a chipset, an antenna, a display, a touchscreen display, a touchscreen controller, a battery, an audio codec, a video codec, a power amplifier, a global positioning system (GPS) device, a compass, an accelerometer, a gyroscope, a speaker, a camera, and a mass storage device (such as hard disk drive, compact disk (CD), digital versatile disk (DVD), and so forth).
The communication chip 706 enables wireless communications for the transfer of data to and from the computing device 700. The term “wireless” and its derivatives may be used to describe circuits, devices, systems, methods, techniques, communications channels, etc., that may communicate data through the use of modulated electromagnetic radiation through a non-solid medium. The term does not imply that the associated devices do not contain any wires, although in some embodiments they might not. The communication chip 706 may implement any of a number of wireless standards or protocols, including but not limited to Wi-Fi (IEEE 802.11 family), WiMAX (IEEE 802.16 family), IEEE 802.20, long term evolution (LTE), Ev-DO, HSPA+, HSDPA+, HSUPA+, EDGE, GSM, GPRS, CDMA, TDMA, DECT, Bluetooth, derivatives thereof, as well as any other wireless protocols that are designated as 3G, 4G, 5G, and beyond. The computing device 700 may include a plurality of communication chips 706. For instance, a first communication chip 706 may be dedicated to shorter range wireless communications such as Wi-Fi and Bluetooth and a second communication chip 706 may be dedicated to longer range wireless communications such as GPS, EDGE, GPRS, CDMA, WiMAX, LTE, Ev-DO, and others.
The processor 704 of the computing device 700 includes an integrated circuit die packaged within the processor 704. In some implementations of the invention, the integrated circuit die of the processor includes one or more devices that are assembled in an ePLB or eWLB based PoP package that that includes a mold layer directly contacting a substrate, in accordance with implementations of the invention. The term “processor” may refer to any device or portion of a device that processes electronic data from registers and/or memory to transform that electronic data into other electronic data that may be stored in registers and/or memory.
The communication chip 706 also includes an integrated circuit die packaged within the communication chip 706. In accordance with another implementation of the invention, the integrated circuit die of the communication chip includes one or more devices that are assembled in an ePLB or eWLB based PoP package that that includes a mold layer directly contacting a substrate, in accordance with implementations of the invention.
The above description of illustrated implementations of the invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific implementations of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize.
These modifications may be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific implementations disclosed in the specification and the claims. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.
Embodiments of the invention include a semiconductor package, comprising: a die embedded within a mold layer; a substrate positioned above the mold layer, wherein a surface of the substrate directly contacts a surface of the mold layer, and wherein an active side of the die faces away from the substrate; and a through mold via formed through the mold layer, wherein the through mold via is electrically coupled to a contact formed on the surface of the substrate that is contacting the mold layer.
Additional embodiments of the invention include a semiconductor package, further comprising: a conductive structure that electrically couples the through mold via to the contact, and wherein the conductive structure is embedded in the mold layer.
Additional embodiments of the invention include a semiconductor package, wherein the conductive structure is a solder ball.
Additional embodiments of the invention include a semiconductor package, wherein the solder ball has a core.
Additional embodiments of the invention include a semiconductor package, wherein the core is a polymer core or a copper core.
Additional embodiments of the invention include a semiconductor package, wherein one or more components are mounted to the surface of the substrate that is contacting the mold layer, and wherein the one or more components are embedded in the mold layer.
Additional embodiments of the invention include a semiconductor package, wherein the die is mounted to the substrate with an adhesive layer.
Additional embodiments of the invention include a semiconductor package, wherein the die comprises one or more pillars that provide an electrical connection from the die to a surface of the mold layer that faces away from the substrate.
Additional embodiments of the invention include a semiconductor package, wherein one or more components are mounted to a surface of the substrate facing away from the mold layer, and wherein at least one of the components is electrically coupled to the through mold via by conductive traces and vias formed in the substrate.
Additional embodiments of the invention include a semiconductor package, wherein at least one of the components is a high bandwidth memory.
Embodiments of the invention include a method of forming semiconductor package, comprising: dispensing a molding material over a die positioned on a mold carrier; pressing a substrate into the molding material and curing the molding material to form a mold layer around the die, wherein the substrate is adhered to the mold layer; removing the mold carrier form the mold layer; forming a via opening in the mold layer; and depositing a conductive material in the via opening to form a through mold via that is electrically coupled to a contact formed on the substrate.
Additional embodiments of the invention include a method of forming semiconductor package, wherein the via opening exposes the contact formed on the substrate.
Additional embodiments of the invention include a method of forming semiconductor package, wherein a conductive structure is attached to the contact formed on the substrate prior to pressing the substrate into the molding material, and wherein the conductive structure is embedded in the mold layer after the molding material is cured.
Additional embodiments of the invention include a method of forming semiconductor package, wherein the via opening exposes the conductive structure, and wherein the conductive structure electrically couples the via to the contact formed on the substrate.
Additional embodiments of the invention include a method of forming semiconductor package, wherein the conductive structure is a solder ball.
Additional embodiments of the invention include a method of forming semiconductor package, wherein one or more components are attached to the substrate prior to pressing the substrate into the molding material, and wherein the one or more components are embedded in the mold layer after the molding material is cured.
Additional embodiments of the invention include a method of forming semiconductor package, wherein the via opening is formed with a laser drilling process.
Additional embodiments of the invention include a method of forming semiconductor package, wherein the laser is aligned for the drilling process by using the die as a reference.
Additional embodiments of the invention include a method of forming semiconductor package, further comprising: attaching a component to a surface of the substrate opposite from the surface adhered to the mold layer, wherein the component is electrically coupled to the through mold via by conductive traces and vias formed in the substrate.
Additional embodiments of the invention include a method of forming semiconductor package, wherein the component is a high bandwidth memory.
Embodiments of the invention include a method of forming semiconductor package, comprising: dispensing a molding material over a mold carrier; pressing a substrate that has a die attached to the surface of the substrate into the molding material and curing the molding material to form a mold layer around the die, wherein the substrate is adhered to the mold layer, and wherein the die is embedded in the mold layer; removing the mold carrier form the mold layer; forming a via opening in the mold layer; and depositing a conductive material in the via opening to form a through mold via that is electrically coupled to a contact formed on the substrate.
Additional embodiments of the invention include a method of forming semiconductor package, wherein a plurality of conductive pillars are mounted to a surface of the die facing away from the substrate.
Additional embodiments of the invention include a method of forming semiconductor package, further comprising: recessing the mold layer to expose a surface of the conductive pillars.
Embodiments of the invention include a semiconductor package, comprising: a die embedded within a mold layer; a substrate positioned over the mold layer, wherein a surface of the substrate directly contacts a surface of the mold layer, and wherein an active side of the die faces away from the substrate; a through mold via formed through the mold layer, wherein the through mold via is electrically coupled to a contact formed on the surface of the substrate by a conductive structure that is contacting the mold layer; and one or more components mounted to the surface of the substrate that is contacting the mold layer, and wherein the one or more components are embedded in the mold layer.
Additional embodiments of the invention include a semiconductor package, wherein the conductive structure is a solder ball with a core that is copper or a polymer.
Additional embodiments of the invention include a semiconductor package, further comprising: one or more components mounted to a surface of the substrate facing away from the mold layer, and wherein at least one of the components is electrically coupled to the through mold via by conductive traces and vias formed in the substrate, and wherein at least one of the components is a high bandwidth memory.
Filing Document | Filing Date | Country | Kind |
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PCT/US2015/000291 | 12/23/2015 | WO | 00 |