Thermal interconnects for integrated circuits.

Abstract

An electronic device (10) is provided having a printed circuit board (PCB) (100) having one or more thermal vias (110) filled with a thermally conductive material (120), the electronic device (10) further having a package (200), the package (200) having a substrate (210) and a die (220) having an active side (230) having an integrated circuit and a heat removal side (250), the heat removal side (250) of the die (220) being in thermal conductive connection with the one or more thermal vias (110) through solder balls (300). The present disclosure also relates to related devices and methods.

Description

[Technical field]

[0001] The present disclosure relates to electronic devices, particularly for high frequency communications. [Background technology]

[0002] Modern electronic equipment are becoming more and more powerful, but require increasingly tight integration. Highly integrated electronics entails stronger requirements regarding tolerances and compactness (e.g., size or small area) for, for example, connections. Summary of the Invention

[0003] Books Disclosure It is an object of the present invention to provide techniques that allow improved connections for electronic devices, and in particular connections that allow for the transfer of heat away from the active surface or side of an integrated circuit that includes a die.

[0004] An electronic device is disclosed that includes a printed circuit board (PCB). The PCB includes one or more thermal vias filled with a thermally conductive material. The electronic device further includes a package including a substrate and a die. The die has an active side having an integrated circuit and a heat removal side. The heat removal side of the die is connected to the one or more thermal vias through solder balls. Thermally Conductive Connection It is in this state.

[0005] Further described is a package for an electronic device. The package comprises a substrate and a die. The die has an active side having an integrated circuit and a heat removal side. The heat removal side is connected to a printed circuit board via a thermally conductive connection through solder balls. circuit The thermal via is adapted to be connected or connectable to one or more thermal vias of a printed circuit board (PCB).

[0006] Print the package circuitA method of soldering to a substrate is contemplated. The printed circuit board includes one or more thermal vias filled with a thermally conductive material. The package includes a substrate and a die, the die having an active side having an integrated circuit and a heat removal side. The method includes soldering solder balls to provide a thermally conductive connection to the heat removal side of the die with the one or more thermal vias.

[0007] The approach described herein allows for compact placement of electronic components with good heat removal characteristics. This is particularly useful for multi-element configurations, such as antenna arrays having multiple antennas and / or subarrays of antennas. Heat can be considered to be transferable from the active side and / or material of the die, through the solder balls, and through the thermal vias.

[0008] The die may be considered as having and / or consisting of and / or implemented as and / or serving by a block or mass of semiconductor material, for example based on and / or having and / or consisting of Si and / or Ge and / or Ga and / or As and / or S and / or combinations thereof, in particular GaN or SiGe or GaAs, if applicable, and / or which may have one or more doped zones, and / or may have an integrated circuit such as a functional electronic circuit (e.g., performing a function and / or group of functions, e.g., processing signals, e.g., signals from and / or to one or more antennas, and / or controlling one or more antennas). The integrated circuit and / or the active side may generate heat during operation, for example when connected to and / or supplied with power. Heat generated on the active side may be conducted away from the die on the heat removal side. In general, the heat removal side may be located opposite the active side. The active side and / or the heat removal side may be parallel to each other. The active side and / or the heat removal side represent the largest outer surface of the die, and in some cases, it may be considered that the active side and the heat removal side may have the same area size. In general, the die may have multiple surfaces, e.g., one of which may be associated with and / or served by the active side, and / or one of which may be associated with and / or served by the heat removal side. The number of surfaces of the die may be six (or more, e.g., having a surface side cut into an angled surface), in some examples. The die may comprise and / or be embedded in and / or be embedded in a substrate. The substrate may generally include and / or represent, e.g., a laminate and / or a mold (or a mold compound), and / or a glass, or a similar material, and may be a different substrate or substrate. MaterialThe layers may be the same or different materials. The heat removal side of the die may not include a substrate and / or the active side may be in contact with and / or intended to be in contact with a substrate. In some cases, the die may be a flip chip die assembled on a substrate. The package may include a die assembled to and / or embedded in a substrate and / or including a mask on the heat removal side of the die, the mask defining and / or providing and / or leaving uncovered connection points for solder balls.

[0009] The heat removal side of the die can be considered to include a metal layer. Thermally Conductive Connection The metal layer may be directly contactable and / or may provide the possibility of a thermally conductive connection, for example to provide a thermally conductive connection to the die. The solder balls may be considered to be connected and / or connectable and / or solderable and / or solderable to the metal layer. The metal layer may be considered to define the outer surface of the die, particularly at the heat removal side. The solder balls may generally be located or disposed on and / or in contact with and / or at the heat removal side of the die. Generally, the heat removal side may be at least partially or completely accessible and / or contactable to the solder balls.

[0010] In general, the metallic material or metallic layer may include and / or consist of one or more metals and / or metal alloys. The metallic material and / or layer may include and / or consist of copper and / or aluminum and / or gold and / or silver (which may be considered thermally conductive materials and / or metals). The connection is generally made by, for example, force fit and / or friction lock and / or form fit and / or integral joining (e.g., soldering and / or welding and / or melting and / or lamination). Contact with The device may comprise and / or provide the possibility of physically connecting to the device, including Thermally Conductive Connectionmay be a connection between connected layers and / or devices and / or components, allowing for heat transfer via conduction, e.g., such that conduction is the predominant (at least 10 times, or 100 times) mode of heat transfer. Thermally Conductive Connection may be provided indirectly, e.g., between components and / or elements that are not in direct physical contact, in which case Thermally Conductive Connection between intermediate elements and / or components Thermally Conductive Connection The thermally conductive connection may be provided and / or facilitated by a series and / or layers of. The thermally conductive connection may be electrically conductive and / or may be provided by and / or between metallic materials. The solder balls may be thermally conductive and / or metallic materials, such as solder alloys and / or solder materials that may have a lower melting point than the metallic layers or materials to which they are contacted and / or soldered. The solder balls may be implemented as solder bumps and / or microbumps and / or may be acted upon and / or intended and / or coined or flattened. In general, the solder balls and / or solder balls may be surrounded and / or embedded in an underfill material, which may be non-conductive. The underfill material may be disposed to surround the solder balls after they are soldered to the die and / or PCB.

[0011] A printed circuit board (PCB) can comprise one or more layers. Vias can be thought of as through holes that pass through one or more layers and can be provided, for example, by drilling the layers individually or in groups, or by providing holes in the individual layers (e.g., before combining and / or laminating them), or by drilling vias / through holes after combining and / or laminating the layers to form a base PCB, or by being formed during a lamination process. ThermalThe vias may be intended to provide thermally conductive heat transfer and may be or can be filled with a thermally conductive material, for example a thermally conductive metallic material. The thermal vias may include a wall coating, for example a metal layer, which may for example prevent the thermally conductive material from seeping into the PCB material and / or improve the contact and / or adhesion of the thermally conductive material. The vias may include and / or be covered by a metal layer (or multiple metal layers, for example on both ends of the via) that provides a connection area for a solder ball or a thermal interface material. In general, a PCB may include multiple layers, which may be of different materials, and the layers may be connected and / or bonded and / or stacked, for example, based on lamination and / or soldering and / or gluing. At least one of these layers may be non-thermally conductive and / or flame-retardant and / or may play the role of a substrate layer. In general, a PCB may include one or more copper layers and / or substrate layers. Material The layers may include a thermally insulating layer and / or a flame retardant layer and / or a solder mask layer and / or a screen layer. The layers may include copper and / or fiberglass and / or epoxy and / or phenolic or other materials. The thermal vias are formed by at least one thermally non-conductive layer, e.g., a substrate. Material layer and / or fiberglass layer and / or flame retardant layer. Thermal A via can be considered to be in thermally conductive contact if the data filled with the thermally conductive contact is in thermally conductive contact. The thermal via can be connected and / or connectable and / or intended to be connected to a heat sink, which is attached or attachable to a PCB, e.g., a cooling body.

[0012] It may be considered that the solder balls may be in direct contact with the metal layer on the heat removal side of the die and / or may be in direct contact with the semiconductor material of the die, facilitating good heat removal from the die through the thermally conductive material.

[0013] The electronic device may be considered to act and / or comprise an antenna circuit. The antenna circuit may be connected or connectable and / or adapted to control and / or operate one or more antenna elements, for example, four or more, or eight or more, or sixteen or more antenna elements. Controlling and / or operating the antenna elements may be performed collectively, for example, as an antenna array and / or subarray, and / or may include transmitting and / or receiving signaling, providing power, and / or processing signaling. For example, a compact configuration for high-density antenna configuration, for example, having multiple antenna circuits in a small area, may be provided for high-frequency communication (e.g., carrier frequencies of 5 GHz or higher, or 10 GHz or higher, or 28 GHz or higher, or 60 GHz or higher, particularly 100 GHz or higher).

[0014] In some cases, the electronic device may act and / or comprise a processor arrangement. The processor arrangement may comprise processing circuitry, for example, one or more processors and / or controllers (for example, microcontrollers and / or DSPs, digital signal processors) and / or processor cores and / or ASICs (Application Specific Integrated Circuits) and / or memories, for example, RAM and / or EPROM and / or EEPROM. In particular, the memory may be located on and / or on and / or above the active side of the die, which may comprise the processing circuitry on the active side. Heat can be carried away via the solder balls, limiting the thermal load on the memory arrangement.

[0015] It may be considered that the electronic device may comprise and / or be connected or connectable to a second package, particularly a memory, on a side corresponding to the active side of the die. The active side may comprise and / or provide processing circuitry, which may be connected or connectable to the memory and / or integrated circuits of the second package (e.g., on the second die), for storing and / or retrieving information and / or data. The second package may serve and / or comprise memory and / or processing circuitry and / or antenna circuitry and / or power circuitry (e.g., one or more power amplifiers) and / or radio circuitry and / or communication circuitry.

[0016] An antenna circuit may be considered that comprises the device described herein. The antenna circuit may be adapted for control and / or operation and / or may be connected or connectable to one or more antenna elements jointly controllable by the antenna circuit. The antenna circuit may comprise one or more power amplifiers and / or one or more analog-to-digital converters (ADCs) and / or DACs (digital-to-analog converters), which may be connected or connectable to the same (e.g., multiple) antenna elements. The antenna circuit may comprise multiple antenna elements.

[0017] A wireless communication device comprising one or more devices, e.g., electronic devices and / or antenna circuitry, as described herein. device Wireless communication is also described. device terminal and / or user Device , or a base station or a network node or an access point or a transmit / receive point (TRP), etc. A wireless communication device or terminal for wireless communication comprising the processor apparatus and / or antenna circuitry as described herein may be considered. [Brief description of the drawings]

[0018] The drawings are provided to illustrate the concepts and approaches described herein and are not intended to limit the scope thereof.

[0019] [Figure 1] 1 illustrates a schematic diagram of an exemplary electronic device. [Diagram 2] 3 illustrates diagrammatically another exemplary electronic device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] The approach described herein facilitates cooling of the circuitry from the backside (heat rejection side) of the silicon (or other semiconductor material of the die). There may be plating (e.g., metal layer) on the heat rejection side (e.g., backside of Si). Solder balls may be connected to the die material, e.g., silicon, on the heat rejection side. The solder balls may be connected to thermal vias (e.g., stacked vias) through the PCB, e.g., terminating in plated areas on the PCB, e.g., thermally connected to a heat sink using a thermal interface material. By using this technique, tight tolerances (e.g., as may be required when building larger antenna arrays with AiP for mmW products) can be maintained, allowing both thermal and electrical interconnects in a small area. The distance between the thermal vias and the electrical connections in the PCB can be kept to the minimum distance allowed by the PCB technology, which is advantageous compared to coining type solutions. In package-on-package solutions (e.g., processor and memory located together, especially memory connected on top of the application processor), heat dissipation can be an issue since the memory can be heat sensitive. The approach makes it easy to remove heat from the processor through the backside of the die.

[0021] FIG. 1 shows a schematic of an electronic device 10 including a PCB 100. The PCB may include thermal vias 110 filled with a thermally conductive material 120. The vias 110 may be stacked through multiple layers 130 of the PCB. The electronic device may also include a package 200 having a substrate 210 and a die 220. The die 220 may include an active side 230 having integrated circuits such as processing circuits and / or antenna circuits. The die 220 may also include a heat removal side 250 opposite the active side. The heat removal side 250 may be covered by a metal layer. A mask 260 may be provided, which may be non-thermally and / or electrically conductive. An underfill 270 material may be used, for example, to increase the reliability of the solder joints. The mask may cover the heat removal side 250 and / or metal layers, but leave open contact points for the solder balls 300 to contact the metal layers and / or semiconductor material of the die 220. The solder balls 300 contact the metal layer 140 of the vias 110, which lead to the common metal layer 140 on the other side of the PCB (away from the package 200) and contact the thermal interface material 150, which may be connected to a heat sink 400. surface When the circuitry on side 230 operates, heat is generated, and this approach utilizes solder balls that connect to the semiconductor material of die 220 to allow the heat to be removed through the backside (heat removal side).

[0022] 2 shows a schematic diagram of another exemplary electronic device including a processor unit (having processing circuitry). The PCB 100 and heat sink configuration may be similar to that shown in FIG. 1. Package 500 may represent a package as shown in FIG. 1, in this case with substrate 510 and die 520, including active surface The circuitry on the side may represent processing circuitry, such as a processor or controller or ASIC, or other heat generating circuitry, such as radio circuitry and / or power circuitry. Thermally Conductive Connectionis provided by the solder balls 530. A second package 600, for example representing a memory, is placed on top of the first package 500. The second package 600 may comprise a substrate 610 and a die 620, and may be connected with the solder balls 630 on the substrate 610 and with the substrate 510 of the first package 500. The die 620 may be fully embedded in the substrate 610 and / or embedded from the top and bottom and / or may not be directly connected or connectable to the solder balls and / or the first package. Heat generated by the processing circuitry of the die 520 can be efficiently removed via the solder balls 530 that directly connect to the heat removal side of the die 520, so that the thermal impact on the second package is limited. The arrangement of FIG. 2 is particularly suitable for small and / or mobile terminals, for example radio devices for wireless communication such as terminals or user equipment, and / or IoT devices (Internet-of-Things).

[0023] Wireless communication may relate to radio communication using carrier frequency ranges of 100 MHz or higher, or 1 GHz or higher, or 10 GHz or higher, or 50 GHz or higher, or 75 GHz or higher, or 100 GHz or higher. The bandwidth for communication may be at least 5% of the carrier frequency, or at least 8% of the carrier frequency. Frequencies of 10 GHz or higher, or 30 GHz or higher may be considered mmW (mm wavelength).

[0024] The circuit may comprise an integrated circuit. The processing circuit may comprise one or more processors and / or controllers (e.g., microcontrollers), and / or ASICs (Application Specific Integrated Circuits) and / or FPGAs (Field Programmable Gate Arrays), etc. The processing circuit may be considered to comprise and / or be (operably) connected or connectable to one or more memories or memory arrangements. The memory arrangement may comprise one or more memories. The memory may be adapted to store digital information. Examples of memories include volatile and non-volatile memories, and / or Random Access Memory (RAM), and / or Read Only Memory (ROM), and / or Magnetic and / or Optical Memory, and / or Flash Memory, and / or Hard Disk Memory, and / or EPROM or EEPROM (Erasable Programmable ROM or Electrically Erasable Programmable ROM).

[0025] A wireless communication device (also referred to as a wireless device) may generally comprise and / or be adapted to utilize processing circuits and / or radio circuits, in particular transmitters and / or transceivers and / or receivers, to process (e.g., trigger and / or schedule) and / or transmit and / or receive signaling, such as data signaling and / or control signaling and / or reference signaling, and / or perform beam switching. A wireless device may be implemented as a terminal or UE, but in some cases may be implemented as a network node, in particular a base station or relay node or IAB node, in particular providing a mobile termination (MT) function for such. In general, a wireless device may comprise transmit or receive diversity, and / or may be adapted thereto, and / or antenna circuitry, and / or two or more independently operable or controllable antenna arrays or arrangements, and / or transmitter circuitry and / or antenna circuitry; and / or may be connectable thereto; and / or may be connectable thereto;and / or to use multiple antenna ports (e.g. simultaneously), e.g. to control transmission or reception using an antenna array, and / or to utilize and / or operate and / or control two or more transmission sources which may be connectable or connectable thereto or which it may comprise, Conformity The wireless device may comprise (and / or be connected or connectable to) and / or be adapted to control transmission and / or reception from multiple components and / or transmitters and / or transmission sources and / or TRPs.

[0026] In this disclosure, for purposes of explanation and not limitation, specific details are set forth (such as particular network functions, processes, and signaling steps) to provide a thorough understanding of the techniques presented herein. It will be apparent to those skilled in the art that the concepts and aspects may be implemented in other variations and modifications that depart from these specific details.

[0027] For example, the concepts and variations are described in part in the context of Long Term Evolution (LTE) or LTE-Advanced (LTE-A) or New Radio mobile or wireless communications technologies, or in the context of 6G technologies, but this does not preclude use of the concepts and aspects in connection with additional or alternative mobile communications technologies, such as Global System for Mobile Communications (GSM) or IEEE standards such as IEEE 802.11ad or IEEE 802.11ay. It will be appreciated that although the variations described may relate to certain Technical Specifications (TS) of the 3rd Generation Partnership Project (3GPP), the techniques, concepts, and aspects may be implemented in connection with various Performance Management (PM) specifications.

[0028] Further, those skilled in the art will appreciate that the services, functions, and steps described herein may be implemented using software operating in conjunction with a programmed microprocessor, or using an application specific integrated circuit (ASIC), a digital signal processor (DSP), a field programmable gate array (FPGA), or a general purpose computer. Although the variations described herein are described in the context of methods and devices, it will also be understood that the concepts and aspects presented herein may be embodied in program products as well as systems comprising control circuitry, e.g., a computer processor and a memory coupled to the processor, where the memory is encoded with one or more programs or program products that perform the services, functions, and steps disclosed herein.

[0029] The advantages of the embodiments and variations presented herein will be fully understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction, and arrangement of the exemplary embodiments thereof without departing from the scope of the concepts and embodiments described herein or sacrificing all of their advantageous effects. The embodiments presented herein can be modified in many ways.

Claims

1. 1. An electronic device (10) having a printed circuit board (PCB) (100), the PCB (100) having one or more thermal vias (110) filled with a thermally conductive material (120), the electronic device (10) further comprising a package (200), the package (200) having a substrate (210) and a die (220), the die (220) having an active side (230) having an integrated circuit and a heat removal side (250), the heat removal side (250) of the die (220) being thermally conductively connected to the one or more thermal vias (110) through solder balls (300).

2. 1. A package (200) for an electronic device (10), the package having a substrate (210) and a die (220), the die (220) having an active side (230) having an integrated circuit and a heat removal side (250), the heat removal side adapted to be connectable to one or more thermal vias (110) of a printed circuit board (PCB) (100) via a thermally conductive connection through solder balls (300).

3. 1. A method of soldering a package to a printed circuit board (PCB) (100) having one or more thermal vias (110) filled with a thermally conductive material (120), the package having a substrate (210) and a die (220) having an active side (230) having an integrated circuit and a heat removal side (250), the method comprising soldering a solder ball (300) to provide a thermally conductive connection between the heat removal side (250) of the die (220) and the one or more thermal vias (110).

4. 4. The device or method of any one of claims 1 to 3, wherein the heat removal side (250) of the die (220) comprises a metal layer.

5. 5. The device or method of claim 1, wherein the solder balls are in direct contact with a metal layer on the heat removal side (250) of the die (220) and / or in direct contact with a semiconductor material of the die (220).

6. 6. A device or method according to any one of claims 1 to 5, wherein the electronic device acts as and / or comprises an antenna circuit.

7. 6. A device or method according to any one of claims 1 to 5, wherein the electronic device acts as and / or comprises a processor unit.

8. 8. A device or method according to any one of claims 1 to 7, wherein the electronic device comprises and / or is connected or connectable to a second package, in particular a memory, on a side corresponding to the active side of the die (220).

9. An antenna circuit comprising a device according to any one of claims 1 to 8.

10. A wireless communication device comprising a device according to any one of claims 1 to 9.

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