ELECTRONIC DEVICE WITH STACKED CIRCUIT BOARDS

Description

Background

[0001] The present disclosure relates generally to the field of semiconductor packaging. More particularly, the present disclosure relates to an electronic device with stacked printed circuit boards (PCBs).

[0002] US 2019 / 280368 A1 describes a microwave antenna apparatus and a semiconductor package module.

[0003] US 2021 / 210400 A1 describes an underfill structure for chip-on-wafer-on-substrate packages and methods of forming the same.

[0004] US 2020 / 083151 A1 describes packages with Si-substrate-free interposer and a method for forming same.

[0005] KR 2018 0064743 A describes a fan-out semiconductor package.

[0006] US 2019 / 109115 A1 describes a microelectronic interposer for a microelectronic package.

[0007] US 2021 / 183794 A1 describes a package structure and method of fabricating the same.

[0008] US 11 127 650 B2 describes a semiconductor device package including a thermal dissipation element and method of manufacturing the same.

[0009] EP 2 940 729 A1 describes an electronic assembly comprising a base carrier structure.

[0010] US 2020 / 203309 A1 describes method for packaging semiconductor dies.

[0011] US 2021 / 020574 A1 discloses a structure including a bridge die. The bridge die includes a semiconductor substrate and an interconnect structure over the semiconductor substrate.

[0012] Increased miniaturization of components, greater packaging density of integrated circuits ("ICs"), higher performance, and lower cost are ongoing goals of the computer industry. To support the electronic devices with higher functionality and better performance, more and more signal balls are integrated into one single chip package, which leads to the increase of the overall package size.

[0013] PCB designer are facing the same problem. As known in the art, PCBs are flat structures that present bonding pads on the surfaces for the fixation of circuit components. The flat structure of the PCBs imposes a constraint to the shape of the electronic device.Summary

[0014] One object of the present disclosure is to provide an electronic device with stacked printed circuit boards in order to solve the above-mentioned prior at shortcomings or deficiencies. An electronic device according to the invention is defined in the independent claim. The dependent claims define preferred embodiments thereof.

[0015] The electronic device includes a main printed circuit board (PCB) assembly comprising a bottom PCB and a semiconductor package mounted on an upper surface of the bottom PCB. The semiconductor package includes a substrate and a semiconductor die mounted on a top surface of the substrate. The semiconductor die and the top surface of the substrate are encapsulated by a molding compound. A top PCB is mounted on the semiconductor package through first connecting elements.

[0016] Preferably, the semiconductor package comprises a flip-chip die, a wire-bonding die, or a fan-out die.

[0017] The semiconductor die has an active surface and a rear surface coupled to the top surface of the substrate, wherein the semiconductor die comprises through silicon vias.

[0018] The the electronic device further includes a middle re-distribution layer (RDL) structure disposed between the semiconductor die and the top PCB. The active surface of the semiconductor die is directly connected to the middle RDL structure through second connecting elements. The middle RDL structure comprises dielectric layers and interconnect structures.

[0019] The electronic device further includes a memory component mounted on the middle RDL structure. Preferably, the memory component is electrically connected to the substrate via the interconnect structures of the middle RDL structure and the through silicon vias of the semiconductor die.

[0020] Preferably, the electronic device further includes a heat sink mounted on the middle RDL structure around the memory component.

[0021] Preferably, the memory component is High-Bandwidth Memory (HBM) comprising dynamic random-access memory (DRAM) dies stacked on one another, which are vertically interconnected by through silicon vias.

[0022] Preferably, the electronic device further includes a plurality of through mold vias (TMVs) disposed in the molding compound. The TMVs penetrate through an entire thickness of the molding compound, thereby forming terminals on a top surface of the semiconductor package.

[0023] Preferably, the top PCB is mounted on the terminals.

[0024] Preferably, the substrate is a re-distribution layer (RDL) substrate.

[0025] The electronic device further includes a top PCB assembly mounted on the semiconductor package through third connecting elements.

[0026] The top PCB assembly comprises a PCB and two components mounted on opposite sides of the PCB.

[0027] Preferably, the components comprise a memory device, an antenna device or an RF device.

[0028] Another aspect of the disclosure that does not belong to the present invention provides that the active surface of the semiconductor die directly faces the memory component or the substrate.

[0029] Preferably, the memory component is High-Bandwidth Memory (HBM) comprising dynamic random-access memory (DRAM) dies stacked on one another, which are vertically interconnected by through silicon vias.

[0030] The semiconductor die and the top surface of the substrate are encapsulated by a first molding compound. Preferably, the memory component is encapsulated by a second molding compound.

[0031] Preferably, the electronic device further includes a plurality of first through mold vias (TMVs) disposed in the first molding compound. The first TMVs penetrate through an entire thickness of the first molding compound.

[0032] Preferably, the electronic device further includes a plurality of second through mold vias (TMVs) disposed in the second molding compound, wherein the second TMVs penetrate through an entire thickness of the second molding compound.

[0033] Preferably, the semiconductor die, the memory component, and the top surface of the substrate are encapsulated by a unified molding compound.

[0034] These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.Brief Description of the Drawings

[0035] The accompanying drawings are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention. In the drawings: FIG. 1 is a schematic, cross-sectional diagram showing an exemplary electronic device with stacked printed circuit boards (PCBs) in accordance with one embodiment of the disclosure that does not belong to the present invention; FIG. 2 is a schematic, cross-sectional diagram showing an exemplary electronic device with stacked PCBs in accordance with another embodiment of the disclosure that belongs to the present invention; FIG. 3 is a schematic, cross-sectional diagram showing an exemplary electronic device with stacked PCBs in accordance with another embodiment of the disclosure that belongs to the present invention; FIG. 4 is a schematic, cross-sectional diagram showing an exemplary electronic device with stacked PCBs in accordance with another embodiment of the disclosure that does not belong to the present invention; FIG. 5 is a schematic, cross-sectional diagram showing an exemplary electronic device with stacked PCBs in accordance with another embodiment of the disclosure that does not belong to the present invention; and FIG. 6 is a schematic, cross-sectional diagram showing an exemplary electronic device with stacked PCBs in accordance with another embodiment of the disclosure that does not belong to the present invention. Detailed Description

[0036] In the following detailed description of embodiments of the invention, reference is made to the accompanying drawings, which form a part hereof, and in which is shown by way of illustration specific preferred embodiments in which the disclosure may be practiced.

[0037] The present invention is defined only by the appended claims.

[0038] It will be understood that when an element or layer is referred to as being "on", "connected to" or "coupled to" another element or layer, it can be directly on, connected or coupled to the other element or layer or intervening elements or layers may be present. In contrast, when an element is referred to as being "directly on," "directly connected to" or "directly coupled to" another element or layer, there are no intervening elements or layers present. Like numbers refer to like elements throughout. As used herein, the term "and / or" includes any and all combinations of one or more of the associated listed items.

[0039] Packaging of an integrated circuit (IC) chip can involve attaching the IC chip to a substrate (e.g., a packaging substrate) which, among other things, provides mechanical support and electrical connections between the chip and other electronic components of a device. Substrate types include, for example, cored substrates, including thin core, thick core (laminate bismaleimide-triazine resin (BT resin) or FR-4 type fibrous board material), and laminate core, as well as coreless substrates. Cored package substrates, for example, can be built up layer by layer around a central core, with layers of conductive material (usually copper) separated by layers of insulating dielectric, with interlayer connections being formed with through holes or microvias (vias).

[0040] High Bandwidth Memory (HBM) is a high-speed computer memory interface for 3D-stacked synchronous dynamic random-access memory (SDRAM). HBM achieves higher bandwidth while using less power in a substantially smaller form factor than DDR4 or GDDR5. This is achieved by stacking up to eight dynamic random-access memory (DRAM) dies and an optional base die which can include buffer circuitry and test logic. The stack is often connected to the memory controller on a GPU or CPU through a substrate, such as a silicon interposer. Alternatively, the memory die could be stacked directly on the CPU or GPU chip. Within the stack the die are vertically interconnected by through-silicon vias (TSVs) and microbumps. The HBM DRAM uses wide-interface architecture to achieve high-speed, low-power operation.

[0041] FIG. 1 is a schematic, cross-sectional diagram showing an exemplary electronic device 1 with stacked printed circuit boards (PCBs) in accordance with one embodiment of the disclosure, that does not belong to the present invention.

[0042] Preferably, the electronic device 1 may serve as a three-dimensional (3D) assembly including at least two vertically stacked PCBs respectively mounted on opposite sides of a semiconductor package. As shown in FIG. 1, the electronic device 1 comprises a main PCB assembly 10 including, but not limited to, a bottom PCB PB and a semiconductor package CP mounted on an upper surface S1 of the bottom PCB PB. Preferably, for example, the semiconductor package CP may comprise a substrate 100 and a semiconductor die 101, such as a logic die, mounted on a top surface (die-attach surface) 100a of the substrate 100. The semiconductor die 101 may comprise a flip-chip die, a wire-bonding die, or a fan-out die. The semiconductor die 101 may be connected to the top surface 100a of the substrate 100 via a plurality of connecting elements 111 such as bumps or metal pillars, but not limited thereto. The semiconductor die 101 and the top surface 100a of the substrate 100 may be encapsulated by a molding compound 120 such as epoxy resin.

[0043] Preferably, for example, additional components 103 and 105 may be mounted on the surfaces of the bottom PCB PB. The additional components 103 and 105 may comprise active or passive components such as IC chips, capacitors, resistors or inductors. Although the semiconductor die 101 is shown to be mounted on the top surface 100a of the substrate 100 in a flip-chip manner, it is understood that alternatively the semiconductor die 101 may be mounted on the substrate 100 by using wire-bonding techniques. Preferably, the semiconductor package CP may include a fan-out die.

[0044] Preferably, the semiconductor package CP may include one or more logic dies, including, but not limited to, a central processing unit (CPU), a graphics processing unit (GPU), a system-on-a-chip (SOC), a field-programmable gate array (FPGA), a microcontroller unit (MCU), a power management integrated circuit (PMIC) die, a radio frequency (RF) die, a sensor die, a micro-electro-mechanical-system (MEMS) die, a signal processing die (e.g., digital signal processing (DSP) die), or the like, or any combinations thereof.

[0045] Preferably, for example, the substrate 100 may be a wiring substrate and may be formed of polymer materials such as bismaleimide triazine (BT) laminates and / or build-up films known in the art. Preferably, the substrate 100 may be a re-distribution layer (RDL) substrate comprising dielectric layers and conductive layers, and may have a thinner thickness compared to conventional package substrates. It is to be understood that the substrate 100 may be a single layer or a multi-layer structure.

[0046] Preferably, for example, the substrate 100 may comprise a plurality of connection pads 100p disposed on or near the top surface 100a of the substrate 100. Preferably, for example, the substrate 100 may comprise a plurality of conductive traces 100t interconnecting the plurality of connection pads 100p with a plurality of ball pads 100s distributed on or near a bottom surface 100b of the substrate 100. Solder balls SB are disposed on the ball pads 100s, respectively. Preferably, at least one passive device PE may be mounted on the bottom surface 100b of the substrate 100 using surface mount technique (SMT).

[0047] Preferably, a plurality of through mold vias (TMVs) 122 may be disposed in the molding compound 120. The TMVs 122 penetrate through the entire thickness of the molding compound 120, thereby forming terminals 122t on the top surface S2 of the semiconductor package CP. Preferably, for example, a PCB assembly 50 and a PCB 60 may be mounted on the corresponding terminals 122t on the top surface S2 of the semiconductor package CP through connecting elements 502 and 602, respectively. Preferably, for example, the connecting elements 502 and 602 may comprise solder balls or any suitable conducive joints known in the art. Preferably, for example, the PCB assembly 50 may comprise a PCB 52 and components 503 and 505 such as, memory devices, antenna devices or radio-frequency (RF) devices mounted on opposite sides of the PCB 52. Preferably, the PCB assembly 50 is physically separated from the PCB 60 and disposed on the top surface S2 of the semiconductor package CP in a side-by-side manner.

[0048] It is advantageous to use the present disclosure because by connecting some signals to the PCB assembly 50 and the PCB 60 through the TMVs 122, the bottom ball count and the size of the semiconductor package CP can both be reduced.

[0049] FIG. 2 is a schematic, cross-sectional diagram showing an exemplary electronic device 2 with stacked PCBs in accordance with the invention, wherein like regions, layers or elements are designated by like numeral numbers or labels. Preferably, the electronic device 2 may serve as a 3D assembly including at least two vertically stacked PCBs respectively mounted on opposite sides of a semiconductor package. As shown in FIG. 2, likewise, the electronic device 2 comprises a main PCB assembly 10 including a bottom PCB PB and a semiconductor package CP mounted on an upper surface S1 of the bottom PCB PB. The semiconductor package CP comprises a substrate 100 and a semiconductor die 101, such as a logic die, mounted on a top surface (die-attach surface) 100a of the substrate 100. The semiconductor die 101 is connected to the top surface 100a of the substrate 100 via a plurality of through silicon vias (TSVs) 110 that penetrates through the entire thickness of the semiconductor die 101. The peripheral sidewalls of the semiconductor die 101 and the top surface 100a of the substrate 100 are encapsulated by a molding compound 120 such as epoxy resin.

[0050] Preferably, for example, additional components 103 and 105 may be mounted on the surfaces of the bottom PCB PB. The additional components 103 and 105 may comprise active or passive components such as IC chips, capacitors, resistors or inductors.

[0051] Preferably, the semiconductor package CP may include one or more logic dies, including, but not limited to, a central processing unit (CPU), a graphics processing unit (GPU), a system-on-a-chip (SOC), a field-programmable gate array (FPGA), a microcontroller unit (MCU), a power management integrated circuit (PMIC) die, a radio frequency (RF) die, a sensor die, a micro-electro-mechanical-system (MEMS) die, a signal processing die (e.g., digital signal processing (DSP) die), or the like, or any combinations thereof.

[0052] Preferably, for example, the substrate 100 may be a wiring substrate and may be formed of polymer materials such as bismaleimide triazine (BT) laminates and / or build-up films known in the art. Preferably, the substrate 100 may be a re-distribution layer (RDL) substrate comprising dielectric layers and conductive layers, and may have a thinner thickness compared to conventional package substrates. It is to be understood that the substrate 100 may be a single layer or a multi-layer structure.

[0053] Preferably, for example, the substrate 100 may comprise a plurality of connection pads 100p disposed on or near the top surface 100a of the substrate 100. Preferably, for example, the substrate 100 may comprise a plurality of conductive traces 100t interconnecting the plurality of connection pads 100p with a plurality of ball pads 100s distributed on or near a bottom surface 100b of the substrate 100. Solder balls SB are disposed on the ball pads 100s, respectively. Preferably, at least one passive device PE may be mounted on the bottom surface 100b of the substrate 100 using surface mount technique (SMT).

[0054] The semiconductor die 101 is mounted on the top surface 100a of the substrate 100. The semiconductor die 101 has a top surface (or active surface) 101a and a passive rear surface 101b. The circuit elements such as transistors are fabricated on or near the top surface 101a of the semiconductor die 101. The passive rear surface 101b of the semiconductor die 101 is coupled to the top surface 100a of the substrate 100 by using methods known in the art, for example, SMT or adhesion. That is, the semiconductor die 101 is mounted on the top surface 100a of the substrate 100 with a "face-up" configuration. Preferably, the semiconductor die 101 may be electrically connected to the substrate 100 and the solder balls SB on the bottom surface 100b of the substrate 100 through the TSVs 110, which are mainly for power / ground connection of the semiconductor die 101 or HBM. Preferably, for example, the TSVs 110 may be power or ground TSVs for transmitting power or ground signals.

[0055] The electronic device 2 further comprises a middle re-distribution layer (RDL) structure 200 on the semiconductor die 101. The middle RDL structure 200 comprises dielectric layers 210 and interconnect structures 220. The interconnect structures 220 are electrically connected to a plurality of RDL pads 230. The top surface 101a of the semiconductor die 101 is electrically connected to the middle RDL structure 200 through connecting elements BP such as micro-bumps, metal pillars, or the like. Preferably, the gap between the middle RDL structure 200 and the top surface 101a of the semiconductor die 101 may be filled with an underfill material UF such as an epoxy resin, but is not limited thereto. Preferably, a plurality of through mold vias (TMVs) 122 may be disposed in the molding compound 120. The TMVs 122 may be electrically connected to the interconnect structures 220 of the middle RDL structure 200.

[0056] A PCB assembly 50 and a PCB 60 are mounted on the corresponding RDL pads 230 of the middle RDL structure 200. The PCB assembly 50 comprises a PCB 52 and components 503 and 505 mounted on opposite sides of the PCB 52 through connecting elements 502 and 602, respectively. Preferably, for example, the connecting elements 502 and 602 may comprise solder balls or any suitable conducive joints known in the art. Preferably, the PCB assembly 50 is physically separated from the PCB 60 and disposed on the middle RDL structure 200 with the PCB 60 in a side-by-side manner.

[0057] A memory component 300 is directly mounted on the middle RDL structure 200 and is disposed between the PCB 60 and the PCB assembly 50. The memory component 300 protrudes from top surfaces of the PCB 60 and the PCB assembly 50. Preferably, the memory component 300 may comprise a High-Bandwidth Memory (HBM) including multiple DRAM dies 301 stacked on one another and the stacked DRAM dies 301 are vertically interconnected by through silicon vias (TSVs) 310 and microbumps BT. Preferably, the memory component 300 may further comprise a DRAM base 302 which can include buffer circuitry and test logic. Preferably, the DRAM base 302 may include a DRAM controller.

[0058] Preferably, the memory component 300 may be aligned with the underlying semiconductor die 101 and disposed at or near the center of the semiconductor die 101 when viewed from above. That is, the center of the memory component 300 may be aligned with the center of the semiconductor die 101. When viewed from above, the memory component 300 completely overlaps with the underlying semiconductor die 101. Preferably, the DRAM base 302 is electrically coupled to the middle RDL structure 200 and signals such as power or ground may be transmitted to the solder balls SB on the bottom surface 100b of the substrate 100 via the shorter conductive path comprised at least of the interconnect structures 220 of the middle RDL structure 200, the connecting elements BP, the TSVs 110 of the semiconductor die 101, and the conductive traces 100t of the substrate 100. Optionally, some of the power or ground signals may be transmitted to the solder balls SB on the bottom surface 100b of the substrate 100 via the connecting elements BP, the interconnect structures 220 of the middle RDL structure 200, the TMVs 122, and the conductive traces 100t of the substrate 100.

[0059] FIG. 3 is a schematic, cross-sectional diagram showing an exemplary electronic device 3 with stacked PCBs in accordance with still another embodiment of the invention, wherein like regions, layers or elements are designated by like numeral numbers or labels. One difference between the electronic device 3 in FIG. 3 and the electronic device 2 in FIG. 2 is that a heat sink 80 is mounted on the middle RDL structure 200 around the memory component 300 to improve thermal performance and the robustness of the electronic device 3. Preferably, the heat sink 80 may have an annular shape and surround the memory component 300, but not limited thereto.

[0060] FIG. 4 is a schematic, cross-sectional diagram showing an exemplary electronic device 4 with stacked PCBs in accordance with still another embodiment of the disclosure, which does not form part of the present invention, wherein like regions, layers or elements are designated by like numeral numbers or labels. Preferably, the electronic device 4 may serve as a 3D assembly including at least two vertically stacked PCBs respectively mounted on opposite sides of a semiconductor package. As shown in FIG. 4, likewise, the electronic device 4 comprises a main PCB assembly 10 including, but not limited to, a bottom PCB PB and a semiconductor package CP mounted on an upper surface S1 of the bottom PCB PB. The semiconductor package CP comprises a substrate 100 and a semiconductor die 101, such as a logic die, mounted on a top surface 100a of the substrate 100. The semiconductor die 101 is connected to the top surface 100a of the substrate 100 via a plurality of TSVs 110 that penetrates through the entire thickness of the semiconductor die 101. The peripheral sidewalls of the semiconductor die 101 and the top surface 100a of the substrate 100 are encapsulated by a molding compound 120 such as epoxy resin.

[0061] Preferably, for example, additional components 103 and 105 may be mounted on the surfaces of the bottom PCB PB. The additional components 103 and 105 may comprise active or passive components such as IC chips, capacitors, resistors or inductors.

[0062] Preferably, the semiconductor package CP may include one or more logic dies, including, but not limited to, a central processing unit (CPU), a graphics processing unit (GPU), a system-on-a-chip (SOC), a field-programmable gate array (FPGA), a microcontroller unit (MCU), a power management integrated circuit (PMIC) die, a radio frequency (RF) die, a sensor die, a micro-electro-mechanical-system (MEMS) die, a signal processing die (e.g., digital signal processing (DSP) die), or the like, or any combinations thereof.

[0063] Preferably, for example, the substrate 100 may be a wiring substrate and may be formed of polymer materials such as BT laminates and / or build-up films known in the art. Preferably, the substrate 100 may be a RDL substrate comprising dielectric layers and conductive layers, which have thinner thickness compared to conventional package substrates. It is to be understood that the substrate 100 may be a single layer or a multi-layer structure.

[0064] Preferably, for example, the substrate 100 may comprise a plurality of connection pads 100p disposed on or near the top surface 100a of the substrate 100. Preferably, for example, the substrate 100 may comprise a plurality of conductive traces 100t interconnecting the plurality of connection pads 100p with a plurality of ball pads 100s distributed on or near a bottom surface 100b of the substrate 100. Solder balls SB are disposed on the ball pads 100s, respectively. Preferably, at least one passive device PE may be mounted on the bottom surface 100b of the substrate 100 using SMT.

[0065] The semiconductor die 101 is mounted on the top surface 100a of the substrate 100. The semiconductor die 101 has a top surface (or active surface) 101a and a passive rear surface 101b. The circuit elements such as transistors are fabricated on or near the top surface 101a of the semiconductor die 101. The passive rear surface 101b of the semiconductor die 101 is coupled to the top surface 100a of the substrate 100 by using methods known in the art, for example, SMT or adhesion. That is, the semiconductor die 101 is mounted on the top surface 100a of the substrate 100 with a "face-up" configuration. Preferably, the semiconductor die 101 may be electrically connected to the substrate 100 and the solder balls SB on the bottom surface 100b of the substrate 100 through the TSVs 110, which are mainly for power / ground connection of the semiconductor die 101 or HBM. Preferably, for example, the TSVs 110 may be power or ground TSVs for transmitting power or ground signals.

[0066] The electronic device 4 comprises a middle RDL structure 200 on the semiconductor die 101. The middle RDL structure 200 comprises dielectric layers 210 and interconnect structures 220. The interconnect structures 220 are electrically connected to a plurality of RDL pads 230. The top surface 101a of the semiconductor die 101 is electrically connected to the middle RDL structure 200 through connecting elements BP such as micro-bumps, metal pillars, or the like. Preferably, the gap between the middle RDL structure 200 and the top surface 101a of the semiconductor die 101 may be filled with an underfill material UF such as an epoxy resin, but is not limited thereto. Preferably, a plurality of TMVs 122 may be disposed in the molding compound 120. The TMVs 122 may be electrically connected to the interconnect structures 220 of the middle RDL structure 200.

[0067] A memory package 30 is directly mounted on the middle RDL structure 200. The memory package 30 comprises a memory component 300 comprising a HBM including multiple DRAM dies 301 stacked on one another and the stacked DRAM dies 301 are vertically interconnected by TSVs 310 and microbumps BT. Preferably, the memory component 300 may further comprise a DRAM base 302 which can include buffer circuitry and test logic. Preferably, the DRAM base 302 may include a DRAM controller. Preferably, the memory component 300 is packaged by a molding compound 320.

[0068] Preferably, the memory component 300 may be aligned with the underlying semiconductor die 101 and disposed at or near the center of the semiconductor die 101 when viewed from above. That is, the center of the memory component 300 may be aligned with the center of the semiconductor die 101. When viewed from above, the memory component 300 completely overlaps with the underlying semiconductor die 101. Alternatively, the memory component 300 may not be aligned with the underlying semiconductor die 101.

[0069] Preferably, the DRAM base 302 is electrically coupled to the middle RDL structure 200 and signals such as power or ground may be transmitted to the solder balls SB on the bottom surface 100b of the substrate 100 via the shorter conductive path comprised at least of the interconnect structures 220 of the middle RDL structure 200, the connecting elements BP, the TSVs 110 of the semiconductor die 101, and the conductive traces 100t of the substrate 100. Optionally, some of the power or ground signals may be transmitted to the solder balls SB on the bottom surface 100b of the substrate 100 via the connecting elements BP, the interconnect structures 220 of the middle RDL structure 200, the TMVs 122, and the conductive traces 100t of the substrate 100.

[0070] A PCB assembly 50 and a PCB 60 are mounted on the memory package 30 in a side-by-side manner. The PCB assembly 50 and the PCB 60 are electrically connected to the corresponding RDL pads 230 of the middle RDL structure 200 via the TMVs 322 in the molding compound 320. The PCB assembly 50 comprises a PCB 52 and components 503 and 505 mounted on opposite sides of the PCB 52, respectively.

[0071] FIG. 5 is a schematic, cross-sectional diagram showing an exemplary electronic device 5 with stacked PCBs in accordance with still another embodiment of the disclosure, which does not form part of the present invention, wherein like regions, layers or elements are designated by like numeral numbers or labels. Preferably, the electronic device 5 may serve as a 3D assembly including at least two vertically stacked PCBs respectively mounted on opposite sides of a semiconductor package. As shown in FIG. 5, likewise, the electronic device 5 comprises a main PCB assembly 10 including, but not limited to, a bottom PCB PB and a semiconductor package CP mounted on an upper surface S1 of the bottom PCB PB. Preferably, for example, the semiconductor package CP may comprise a substrate 100 and a semiconductor die 101, such as a logic die, mounted on a top surface 100a of the substrate 100. The semiconductor die 101 may be connected to the top surface 100a of the substrate 100 via a plurality of TSVs 110 that penetrates through the entire thickness of the semiconductor die 101. The peripheral sidewalls of the semiconductor die 101 and the top surface 100a of the substrate 100 may be encapsulated by a molding compound 120 such as epoxy resin.

[0072] Preferably, for example, additional components 103 and 105 may be mounted on the surfaces of the bottom PCB PB. The additional components 103 and 105 may comprise active or passive components such as IC chips, capacitors, resistors or inductors.

[0073] Preferably, the semiconductor package CP may include one or more logic dies, including, but not limited to, a central processing unit (CPU), a graphics processing unit (GPU), a system-on-a-chip (SOC), a field-programmable gate array (FPGA), a microcontroller unit (MCU), a power management integrated circuit (PMIC) die, a radio frequency (RF) die, a sensor die, a micro-electro-mechanical-system (MEMS) die, a signal processing die (e.g., digital signal processing (DSP) die), or the like, or any combinations thereof.

[0074] Preferably, for example, the substrate 100 may be a wiring substrate and may be formed of polymer materials such as BT laminates and / or build-up films known in the art. Preferably, the substrate 100 may be a RDL substrate comprising dielectric layers and conductive layers, which have thinner thickness compared to conventional package substrates. It is to be understood that the substrate 100 may be a single layer or a multi-layer structure.

[0075] Preferably, for example, the substrate 100 may comprise a plurality of connection pads 100p disposed on or near the top surface 100a of the substrate 100. Preferably, for example, the substrate 100 may comprise a plurality of conductive traces 100t interconnecting the plurality of connection pads 100p with a plurality of ball pads 100s distributed on or near a bottom surface 100b of the substrate 100. Solder balls SB are disposed on the ball pads 100s, respectively. Preferably, at least one passive device PE may be mounted on the bottom surface 100b of the substrate 100 using SMT.

[0076] Preferably, the semiconductor die 101 is mounted on the top surface 100a of the substrate 100 with a "face-down" configuration with its top surface (or active surface) 101a directly facing the substrate 100. Preferably, the semiconductor die 101 may be electrically connected to the substrate 100 and the solder balls SB on the bottom surface 100b of the substrate 100 via the TSVs 110, which are mainly for power / ground connection of the semiconductor die 101 or HBM. Preferably, for example, the TSVs 110 may be power or ground TSVs for transmitting power or ground signals.

[0077] Preferably, a memory component 300 such as HBM is directly mounted on the semiconductor die 101. Preferably, the memory component 300 may be electrically connected to the semiconductor die 101 through the connecting elements BM such as micro-bumps or metal pillars. Preferably, the memory component 300 may comprise multiple DRAM dies 301 stacked on one another. The stacked DRAM dies 301 are vertically interconnected by TSVs 310 and microbumps BT. Preferably, the memory component 300 may further comprise a DRAM base 302 which can include buffer circuitry and test logic. Preferably, the DRAM base 302 may include a DRAM controller. Preferably, the semiconductor die 101 and the memory component 300 may be packaged in one unified molding compound 320.

[0078] Preferably, the memory component 300 may be offset from the center of the underlying semiconductor die 101, That is, the center of the memory component 300 is not aligned with and is deviated from the center of the semiconductor die 101. Preferably, signals such as power or ground may be transmitted to the solder balls SB on the bottom surface 100b of the substrate 100 via the shorter conductive path comprised of the connecting elements BM, the TSVs 110 of the semiconductor die 101, and the conductive traces 100t of the substrate 100.

[0079] Preferably, for example, a PCB assembly 50 and a PCB 60 may be mounted on the memory package 30 in a side-by-side manner. Preferably, for example, the PCB assembly 50 and the PCB 60 may be electrically connected to the substrate 100 via the TMVs 322 in the molding compound 320. Preferably, for example, the PCB assembly 50 may comprise a PCB 52 and components 503 and 505 mounted on opposite sides of the PCB 52, respectively.

[0080] FIG. 6 is a schematic, cross-sectional diagram showing an exemplary electronic device 6 with stacked PCBs in accordance with yet another embodiment of the disclosure, which does not form part of the present invention, wherein like regions, layers or elements are designated by like numeral numbers or labels. Preferably, the electronic device 6 may serve as a 3D assembly including at least two vertically stacked PCBs respectively mounted on opposite sides of a semiconductor package.

[0081] As shown in FIG. 6, the electronic device 6 comprises a main PCB assembly 10 including, but not limited to, a bottom PCB PB and a semiconductor package CP mounted on an upper surface S1 of the bottom PCB PB. Preferably, for example, the semiconductor package CP may comprise a substrate 100 and a semiconductor die 101, such as a logic die, mounted on a top surface (die-attach surface) 100a of the substrate 100. The semiconductor die 101 may comprise a flip-chip die, a wire-bonding die, or a fan-out die. The semiconductor die 101 may be connected to the top surface 100a of the substrate 100 via a plurality of connecting elements 111 such as bumps or metal pillars, but not limited thereto. The semiconductor die 101 and the top surface 100a of the substrate 100 may be encapsulated by a molding compound 120 such as epoxy resin.

[0082] Preferably, for example, additional components 103 and 105 may be mounted on the surfaces of the bottom PCB PB. The additional components 103 and 105 may comprise active or passive components such as IC chips, capacitors, resistors or inductors. Although the semiconductor die 101 is shown to be mounted on the top surface 100a of the substrate 100 in a flip-chip manner, it is understood that alternatively the semiconductor die 101 may be mounted on the substrate 100 by using wire-bonding techniques. Preferably, the semiconductor package CP may include a fan-out die.

[0083] Preferably, the semiconductor package CP may include one or more logic dies, including, but not limited to, a central processing unit (CPU), a graphics processing unit (GPU), a system-on-a-chip (SOC), a field-programmable gate array (FPGA), a microcontroller unit (MCU), a power management integrated circuit (PMIC) die, a radio frequency (RF) die, a sensor die, a micro-electro-mechanical-system (MEMS) die, a signal processing die (e.g., digital signal processing (DSP) die), or the like, or any combinations thereof.

[0084] Preferably, for example, the substrate 100 may be a wiring substrate and may be formed of polymer materials such as bismaleimide triazine (BT) laminates and / or build-up films known in the art. Preferably, the substrate 100 may be a re-distribution layer (RDL) substrate comprising dielectric layers and conductive layers, and may have a thinner thickness compared to conventional package substrates. It is to be understood that the substrate 100 may be a single layer or a multi-layer structure.

[0085] Preferably, for example, the substrate 100 may comprise a plurality of connection pads 100p disposed on or near the top surface 100a of the substrate 100. Preferably, for example, the substrate 100 may comprise a plurality of conductive traces 100t interconnecting the plurality of connection pads 100p with a plurality of ball pads 100s distributed on or near a bottom surface 100b of the substrate 100. Solder balls SB are disposed on the ball pads 100s, respectively. Preferably, at least one passive device PE may be mounted on the bottom surface 100b of the substrate 100 using surface mount technique (SMT).

[0086] Preferably, the electronic device 6 may further comprise a middle re-distribution layer (RDL) structure 200 on the semiconductor die 101. Preferably, the middle RDL structure 200 may comprise dielectric layers 210 and interconnect structures 220. The interconnect structures 220 may be electrically connected to a plurality of RDL pads 230. Preferably, a plurality of through mold vias (TMVs) 122 may be disposed in the molding compound 120. The TMVs 122 may be electrically connected to the interconnect structures 220 of the middle RDL structure 200.

[0087] Preferably, for example, a PCB assembly 50 and a PCB 60 may be mounted on the corresponding RDL pads 230 of the middle RDL structure 200 through connecting elements 502 and 602, respectively. Preferably, for example, the PCB assembly 50 may comprise a PCB 52 and components 503 and 505 mounted on opposite sides of the PCB 52. Preferably, for example, the components 503 and 505 may comprise memory devices, antenna devices or radio-frequency (RF) devices. Preferably, for example, the connecting elements 502 and 602 may comprise solder balls or any suitable conducive joints known in the art. Preferably, the PCB assembly 50 is physically separated from the PCB 60 and disposed on the middle RDL structure 200 with the PCB 60 in a side-by-side manner.

[0088] Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the appended claims.

Claims

1. An electronic device, comprising: a main printed circuit board, in the following also referred to as PCB, assembly (10) comprising a bottom PCB (PB) and a semiconductor package (CP) mounted on an upper surface (S1) of the bottom PCB (PB), wherein the semiconductor package (CP) comprises a substrate (100) and a semiconductor die (101) mounted on a top surface (100a) of the substrate (100), wherein the semiconductor die (101) and the top surface (100a) of the substrate (100) are encapsulated by a molding compound (120); and a middle re-distribution layer, in the following also referred to as RDL, structure (200) disposed on the semiconductor die (101); and a memory component (300) mounted on the middle RDL structure (200); wherein the semiconductor die (101) has an active surface (101a) and a rear surface (101b) coupled to the top surface (100a) of the substrate (100), wherein the semiconductor die (101) comprises through silicon vias (110), wherein the active surface (101a) of the semiconductor die (101) is directly connected to the middle RDL structure (200) through connecting elements (BP), and wherein the middle RDL structure (200) comprises dielectric layers (210) and interconnect structures (220); characterized by a top PCB (60) and a top PCB assembly (50) mounted on the middle RDL structure (200), respectively; wherein the middle RDL structure (200) is disposed between the semiconductor die (101) and the top PCB (60); wherein the memory component (300) is directly mounted on the middle RDL structure (200), is disposed between the top PCB (60) and the top PCB assembly (50), and protrudes from top surfaces of the top PCB (60) and the top PCB assembly (50); and wherein the top PCB assembly comprises a PCB (52) and two components (503, 505) mounted on opposite sides of the PCB (52).

2. The electronic device according to claim 1, wherein the substrate (100) is a re-distribution layer, in the following also referred to as RDL, substrate.

3. The electronic device according to claim 1 or 2, wherein the memory component (300) is electrically connected to the substrate (100) via the interconnect structures (220) of the middle RDL structure (200) and the through silicon vias (110) of the semiconductor die (101).

4. The electronic device according to claim 3 further comprising: a heat sink (80) mounted on the middle RDL structure (200) around the memory component (300).

5. The electronic device according to claim 3 or 4, wherein the memory component (300) is High-Bandwidth Memory, in the following also referred to as HBM, comprising dynamic random-access memory, in the following also referred to as DRAM, dies (301) stacked on one another, which are vertically interconnected by through silicon vias (310).

6. The electronic device according to claim 5, further comprising: a plurality of through mold vias, in the following also referred to as TMVs, (122) disposed in the molding compound (120), wherein the TMVs (122) penetrate through an entire thickness of the molding compound (120), thereby forming terminals (122t) on a top surface (S2) of the semiconductor package (CP).