CN116207079A

CN116207079A - Shielding structure, packaging body, board-level framework, radiator and electronic equipment

Info

Publication number: CN116207079A
Application number: CN202111449159.8A
Authority: CN
Inventors: 熊振兴; 熊建波; 赵才军; 梁晓彤; 赵亚涛
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2023-06-02
Also published as: WO2023098503A1

Abstract

The application provides a shielding structure, a packaging body, a board level framework, a radiator and electronic equipment, relates to the field of electronic equipment, and can reduce electromagnetic noise generated by the packaging body and reduce impact of external force on the packaging body. Wherein, shielding structure includes: at least one shielding unit group, each shielding unit group comprises at least one shielding unit, and each shielding unit comprises a non-Newtonian fluid material and a conductive layer arranged on the surface of the non-Newtonian fluid material.

Description

Shielding structure, packaging body, board-level framework, radiator and electronic equipment

Technical Field

The application relates to the field of electronic equipment, in particular to a shielding structure, a packaging body, a board-level framework, a radiator and electronic equipment.

Background

Bare Die packaging refers to a manner of chip packaging in which a Die (Die) is directly exposed, the Die periphery no longer being covered by a lid, but rather a layer of thermally conductive material (e.g., thermally conductive interface material (Thermal Interface Materials, TIM)) is covered over the Die. When the package body obtained by adopting the bare Die package and the radiator are packaged on a printed circuit board (printed circuit board, PCB) to form a board-level framework, the Die in the package body can directly transfer heat to the radiator through a heat conducting material, so that the crusting thermal resistance of the package body is reduced to the greatest extent. Compared with the traditional cover (lid) package, the bare Die package can improve the heat dissipation efficiency by more than 10 ℃. Therefore, with the proliferation of package power consumption, bare Die packaging is becoming a mainstream.

However, the bare Die package improves the heat dissipation effect of the package body, but at the same time, due to lack of shielding and supporting of the cover, on one hand, the problem of deterioration of electromagnetic noise generated by the package body to the outside occurs, and on the other hand, in the case of mounting a radiator or falling down, the situation of crushing of the heat conducting material easily occurs, thereby causing damage to the package body.

Disclosure of Invention

The application provides a shielding structure, a packaging body, a board level framework, a radiator and electronic equipment, which can reduce the impact of external force on the packaging body while reducing electromagnetic noise generated by the packaging body.

In a first aspect, embodiments of the present application provide a shielding structure including at least one shielding element group, each shielding element group including at least one shielding element, each shielding element including a non-newtonian fluid material and a conductive layer disposed on a surface of the non-newtonian fluid material.

The non-newtonian fluid materials used in the present application exhibit a solid state at ambient temperature. When the non-Newtonian fluid material is in a static state or is slowly compressed, molecules in the non-Newtonian fluid material are separated from each other, and weak connecting force is provided between the molecules, so that the non-Newtonian fluid material can be bent and is easy to deform. When the non-Newtonian fluid material is subjected to high-speed impact, the connection force between molecules in the material of the non-Newtonian fluid material is enhanced, the material is hardened, and a large force is required to enable the material to be obviously deformed. On the other hand, the conductive layer of the shielding structure is conductive and can be electrically connected with the radiator, so that part of electromagnetic radiation emitted by the packaging body can be absorbed, and electromagnetic noise generated by the packaging body is reduced.

Therefore, when the shielding structure provided by the application is used for a board level architecture package, for example, the shielding structure is arranged at a gap between a package body (obtained based on a bare Die package) and the bottom of a heat sink, or the shielding structure is added between a PCB and the heat sink at the periphery of the package body. On the one hand, if when the radiator is installed, the radiator is stably and slowly applied with pressure to the shielding structure, the non-Newtonian fluid material of the shielding structure is softer and is easy to deform, so that the radiator can be normally installed on a PCB, the radiator and the packaging body are ensured to be fully contacted, and the heat dissipation of the packaging body is ensured. When the packaged board-level structure falls down or the radiator is mounted with improper force, the bottom of the radiator can firstly impact the shielding structure at high speed due to the support of the shielding structure. At this time, the shielding structure can give the radiator bottom with great resilience force, and shielding structure's non-Newtonian fluid material hardens, is difficult for taking place deformation to avoid the encapsulation body to receive obvious pressure, reduce the possibility that the encapsulation body is damaged. On the other hand, the conductive layer of the shielding structure has conductivity, so that part of electromagnetic radiation emitted by the packaging body can be absorbed, and electromagnetic noise generated by the packaging body is reduced.

In one possible implementation, the thickness of the conductive layer is less than or equal to 0.2 millimeters.

The thickness of the conductive layer may be the thickness of the thickest portion of the conductive layer, or may be the average thickness of the conductive layer. By setting the thickness of the conductive layer to be less than or equal to 0.2 mm, the presentation of the mechanical properties of the non-newtonian fluid material can be ensured.

In one possible implementation, the shielding element further comprises an adhesive layer for securing the shielding element in the target position.

By arranging the adhesive layer, the shielding unit can be flexibly arranged, and the shielding unit is convenient to fix at a target position. Wherein the target position may be a position where the shielding unit needs to be used. For example, the target location may be on a support frame of the package, a bottom of the heat sink, on a support, on a shield, etc.

In one possible implementation, the non-newtonian fluid material comprises polyurethane or polyborosiloxane.

For example, the non-newtonian fluid material may be prepared with Polyurethane (PU) as the substrate and Polyborosiloxane (PBDMS) as the modifying group. The compactness of the non-Newtonian fluid material can be regulated by regulating the proportion of the polyborosiloxane.

In one possible implementation, the shear stress of the non-newtonian fluid material is less than or equal to 0.3 megapascals when the compression ratio of the non-newtonian fluid material in the normal state is less than or equal to the first threshold.

Wherein the first threshold is a strain limit for the non-newtonian fluid material to enter the dense region. For example, the first threshold is 0.4, then when the strain of the non-newtonian fluid material exceeds 0.4 (e.g., the volume of the non-newtonian fluid material is compressed by more than 40% of the original volume in the volume dimension), the intermolecular connection force within the material of the non-newtonian fluid material increases, and the material hardens and is not easily deformed. The strain interval exceeding the first threshold is referred to as the dense region. The non-Newtonian fluid material entering the compact region is hard, has larger shearing stress, and often needs larger external force to overcome the shearing stress of the non-Newtonian fluid material so as to continuously deform the non-Newtonian fluid material.

In packaging board level architecture, the heat spreader needs to be in sufficient contact with the package to facilitate heat dissipation by the package. Then, when the heat sink approaches the package by pressing the shielding unit, if the shielding unit generates a larger shearing stress to resist the external force given by the heat sink, the user may need to apply a larger pressure on the heat sink to compress the shielding unit, so that the heat sink approaches the package. If the pressure applied by the user is smaller than the shearing stress of the shielding unit, poor contact between the heat spreader and the package may be caused.

A non-newtonian fluid material having a shear stress of less than or equal to 0.3 mpa is selected to make the shielding element prior to entering the dense region. On the one hand, the package board-level architecture is convenient for users, and on the other hand, good contact between the radiator and the package body is ensured.

In one possible implementation, the conductive layer completely coats the surface of the non-newtonian fluid material.

By means of the complete coating, the strain of the non-Newtonian fluid material is limited in the coating range of the conductive layer, and the problem that the shape change mode of the non-Newtonian fluid material in a normal state cannot support the radiator is avoided.

In one possible implementation manner, when the shielding unit group includes a plurality of shielding units, the plurality of shielding units are arranged in an annular shape, and a distance between two adjacent shielding units is less than or equal to a quarter of a target wavelength, where the target wavelength is a wavelength of electromagnetic waves to be suppressed by the shielding structure.

In one possible implementation, the shielding structure further includes a shielding case corresponding to each shielding element in the first shielding element group, the shielding element being disposed on top of the corresponding shielding case, the shielding case being for shielding electromagnetic waves, the first shielding element group being one of at least one group of shielding element groups.

The shielding cover can be made of a conductive material, and the shielding effect of the shielding structure on electromagnetic noise is further enhanced by arranging the shielding cover.

In one possible implementation, the shielding structure further includes a support corresponding to each shielding element of the second shielding element group, the shielding element being disposed on top of the corresponding support, the support being for supporting the corresponding shielding element, the second shielding element group being one of the at least one shielding element group.

The supporting piece can be made of conductive materials, and the supporting piece is arranged to further enhance the shielding effect of the shielding structure on electromagnetic noise while guaranteeing the supporting effect of the shielding unit.

In one possible implementation, the shielding structure further includes a support and an insulating layer corresponding to each shielding element in the second shielding element group; the shielding unit comprises a first subunit and a second subunit, and the second shielding unit group is one of at least one shielding unit group;

the insulating layer is located the bottom of support, and first subunit is located the support top, and the second subunit is located support and insulating layer side.

When the shielding structure is packaged in a board level architecture, other power supply circuit modules may be provided on the PCB. By providing an insulating layer, a short circuit can occur and the package can be burned out. And, by dividing each shielding unit in the second shielding unit group into a first subunit and a second subunit, the area of the shielding unit receiving electromagnetic wave radiation is increased, thereby further increasing the electromagnetic shielding effect.

In one possible implementation, the surface resistance of the conductive layer is less than or equal to 0.1 Ω.

The surface resistance of the conductive layer can be measured by a universal meter. The smaller the surface resistance of the conductive layer is, the stronger the electromagnetic absorption capability of the conductive layer is. The surface resistance of the conductive layer can be limited within 0.1 omega, so that the electromagnetic shielding effect of the shielding structure is enhanced.

In one possible implementation, the conductive layer is a metal film structure, a woven wire mesh structure, or a conductive cloth structure. The metal film structure can be a metal film which is electroplated, and the conductive cloth structure can be a structure obtained by electroplating a layer of metal film on the fiber cloth. The flexible structures such as a metal film structure, a woven metal wire mesh structure or a conductive cloth structure are adopted, so that the appearance of the conductive layer on the mechanical properties of the non-Newtonian fluid material is reduced.

In a second aspect, embodiments of the present application provide a package comprising a substrate, a Die, a support frame, a plastic package, and a shielding structure as described in the first aspect or any of the alternatives of the first aspect; the Die is arranged on the substrate, the supporting frame is arranged at the edge position of the substrate and surrounds the periphery of the Die, and the substrate, the Die and the supporting frame are molded by the plastic package body; the shielding structure is arranged on the supporting frame.

In a third aspect, embodiments of the present application provide a heat sink, where the bottom of the heat sink is provided with a shielding structure according to the first aspect or any of the alternatives of the first aspect.

In a fourth aspect, embodiments of the present application provide a board-level architecture comprising a package as described in the second aspect, a shielding structure as described in the first aspect or any of the alternatives of the first aspect, or a heat sink as described in the third aspect; the shielding structure is used for shielding electromagnetic radiation generated by the packaging body and reducing impact of external force on the packaging body.

For example, a board level architecture may comprise a PCB and a package as described in the second aspect. Because the shielding structure is arranged on the packaging body, electromagnetic radiation generated by the packaging body can be shielded, and impact of external force on the packaging body is reduced.

Optionally, the board level architecture may comprise a PCB, a package and a shielding structure as described in the first aspect or any of the alternatives of the first aspect.

Optionally, the board level architecture may comprise a PCB, a package and a heat sink as described in the third aspect. The radiator is provided with the shielding structure, so that electromagnetic radiation generated by the packaging body can be shielded, and impact of external force on the packaging body is reduced.

Optionally, the board level architecture may comprise a PCB, a shielding structure as described in the first aspect or any of the alternatives of the first aspect, a package as described in the second aspect and a heat sink as described in the third aspect.

Optionally, the board level architecture may include a plastic package structure that encapsulates the board level architecture, protecting the stability of the various components in the board level architecture.

In a fifth aspect, embodiments of the present application provide an electronic device, including a shielding structure as described in the first aspect or any of the alternatives of the first aspect, a package as described in the second aspect, a board level architecture as described in the fourth aspect, or a heat sink as described in the third aspect.

Drawings

Fig. 1 is a schematic structural diagram of a package provided in an embodiment of the present application;

fig. 2 is a schematic structural diagram of a board-level architecture according to an embodiment of the present application;

fig. 3 is a schematic view of a scenario in which a heat spreader crushes a heat conductive layer according to an embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of a shielding unit according to an embodiment of the present application;

FIG. 5 is a schematic diagram showing the relationship between the shear stress and the strain of a non-Newtonian fluid material according to an embodiment of the present disclosure;

FIG. 6 is a schematic representation of the relationship between resiliency and compression ratio of a non-Newtonian fluid material provided in an embodiment of the present application;

fig. 7 is a schematic structural diagram ii of a shielding unit according to an embodiment of the present application;

fig. 8 is a schematic diagram of a partial structure of a shielding structure according to an embodiment of the present application;

fig. 9 is a schematic partial structure diagram of a shielding structure according to an embodiment of the present application;

fig. 10 is a schematic diagram of a partial structure of a shielding structure according to an embodiment of the present application;

fig. 11 is a schematic structural diagram II of a board-level architecture according to an embodiment of the present application;

fig. 12 is a schematic diagram of a first shape of a first shielding unit set according to an embodiment of the present application;

fig. 13 is a second schematic shape diagram of a first shielding unit set according to an embodiment of the present application;

fig. 14 is a schematic structural diagram III of a board-level architecture according to an embodiment of the present application;

fig. 15 is a schematic structural diagram of a board-level architecture according to an embodiment of the present disclosure;

fig. 16 is a schematic view of a scenario in which a support is disposed on a PCB according to an embodiment of the present application;

fig. 17 is a schematic diagram of a board-level architecture according to an embodiment of the present disclosure;

fig. 18 is a schematic structural diagram of a board-level architecture according to an embodiment of the present disclosure;

Fig. 19 is a schematic structural diagram seventh of a board-level architecture according to an embodiment of the present application;

fig. 20 is a schematic structural diagram eight of a board-level architecture according to an embodiment of the present disclosure;

fig. 21 is a schematic structural diagram nine of a board-level architecture according to an embodiment of the present application;

fig. 22 is a schematic diagram of a noise test result based on the board-level architecture shown in fig. 11 according to an embodiment of the present application;

FIG. 23 is a schematic view of drop test results based on the board-level architecture shown in FIG. 11 according to an embodiment of the present disclosure;

fig. 24 is a schematic structural diagram of a package body provided with a shielding structure according to an embodiment of the present application;

fig. 25 is a schematic structural diagram of a radiator with a shielding structure according to an embodiment of the present application.

Detailed Description

With the proliferation of package power consumption, bare Die packaging has become a mainstream. The package body based on the bare Die package may have a structure as shown in fig. 1, including a substrate, die, a support frame, and a plastic package body (not shown in fig. 1). The Die is soldered on a substrate, and metal wires are disposed in the substrate, so that signals on bumps (bumps) of the Die can be transferred to corresponding Ball Grid Array (BGA) pins on the substrate. A support frame (commonly referred to as Ring) is provided around Die at the edge of the substrate for package protection and enhanced heat dissipation. The substrate, die and the supporting frame are protected by the plastic package body in a packaging mode, so that the mechanical performance of the package body is enhanced, and the reliability of the package body is guaranteed. For example, the encapsulation may be performed by a molding process. Of course, although not shown, small packages such as capacitors, inductors, etc. may be disposed on the substrate, so as to improve the reliability of signals of the whole package.

Because Die is the heat source of the package, a layer of heat conducting layer is generally covered on Die. So that the heat energy can be transferred to the radiator through the heat conducting layer when the board-level framework packaging is carried out later, and the heat dissipation is enhanced. The thermally conductive layer may be TIM1.5 or other thermally conductive interface material, among others.

As shown in fig. 2, in packaging a board level architecture, BGA pins of a package are typically soldered to corresponding areas on a PCB. And then aligning the heat radiator with the packaging body, and fixing the heat radiator on the PCB by using screws.

In one example, to ensure good contact between the heat spreader and the package, and ensure heat dissipation, a boss may be further disposed at the bottom of the heat spreader, and the heat spreader is fixed on the PCB board by using screws after aligning the boss of the heat spreader with the heat conductive layer of the package during packaging.

In practical tests, it was found that, although the package based on the bare Die package can improve the heat dissipation efficiency by more than 10 ℃ compared with other packages (for example, the package based on the lid package), the electromagnetic noise is increased by 5-10 dB. And when the radiator is installed, if the force is improper or the packaged board-level framework falls, the situation that the heat conducting layer is crushed easily occurs. For example, as shown in fig. 3, in the case of installation, dropping, or the like, the heat sink may be inclined to one side so that the boss of the heat sink presses the edge of the heat conductive layer with a large impact force, resulting in the edge of the heat conductive layer being crushed. After the heat conduction layer is crushed, the Die cannot dissipate heat smoothly, so that the Die works in a high-temperature environment, the service life and reliability of the Die are shortened, and the Die is easy to damage.

In response to this problem, the present application provides a shielding structure comprising at least one shielding element group, each shielding element group comprising at least one shielding element. As shown in fig. 4, the shielding unit includes a non-newtonian fluid material and a conductive layer disposed on a surface of the non-newtonian fluid material.

Non-newtonian fluid materials refer to fluid materials that do not satisfy newtonian viscosity laws of experiment, where the relationship between shear stress and shear rate is not linear. At lower shear rates, the shear stress of the fluid is substantially unchanged; when the shear rate exceeds a critical value, the shear stress increases as the shear rate increases, the viscosity of the fluid increases as the pressure or shear stress experienced increases, and the volume of the material expands.

In embodiments of the present application, the non-newtonian fluid material exhibits a solid state at ambient temperature. When the non-Newtonian fluid material is in a normal state (static state or slowly compressed state), molecules in the non-Newtonian fluid material are separated from each other, and have weak connecting force, so that the non-Newtonian fluid material can be bent and is easy to deform. When the non-Newtonian fluid material is subjected to high-speed impact, the connection force between molecules in the material of the non-Newtonian fluid material is enhanced, the material is hardened, and a large force is required to enable the material to be obviously deformed.

By way of example, the relationship between shear stress and strain of the non-newtonian fluid material can be shown in fig. 5 for different shear rates (in millimeters per second mm/s) under external forces. In general, when the strain of the non-newtonian fluid material exceeds a first threshold (e.g., 0.4 as shown in fig. 5), the intermolecular connection force within the material of the non-newtonian fluid material is enhanced, the material hardens, and a strain interval exceeding 0.4 or more is referred to as a dense region. In the dense region, the non-newtonian fluid material will generate greater shear stress as the strain of the non-newtonian fluid material increases.

It can be seen that when the non-newtonian fluid material produces a shear rate of 100mm/s, a pressure exceeding 1MPa may cause the strain of the non-newtonian fluid material to exceed the first threshold and enter the compaction zone. If the non-newtonian fluid material continues to deform significantly, then a greater pressure needs to be applied.

Therefore, when the shielding structure provided by the application is used for board-level architecture packaging, the shielding structure is arranged at a gap between the supporting frame and the bottom of the radiator, or the shielding structure is added between the PCB and the radiator at the periphery of the packaging body. On the one hand, if when the radiator is installed, the radiator is enabled to stably and slowly apply pressure to the shielding structure, the non-Newtonian fluid material of the shielding structure is softer and is easy to deform, so that the radiator can be normally installed on a PCB, and the boss of the radiator is enabled to be fully contacted with the heat conducting layer of the packaging body. When the packaged board-level structure falls down or the radiator is mounted with improper force, the bottom of the radiator can firstly impact the shielding structure at high speed due to the support of the shielding structure. At this time, the shielding structure can be given with great resilience force with the radiator bottom, and shielding structure's non-Newtonian fluid material hardens, is difficult for taking place deformation to avoid the heat conduction layer to receive obvious pressure, reduce the possibility that the heat conduction layer is crushed.

On the other hand, the conductive layer of the shielding structure has conductivity and can be electrically connected with the radiator, so that part of electromagnetic radiation emitted by the packaging body can be absorbed, and electromagnetic noise generated by the packaging body can be reduced.

In the embodiment of the application, the conductive layer can be a flexible structure such as a metal film structure, a woven metal wire mesh structure or a conductive cloth structure, and the mechanical properties of the non-Newtonian fluid material are not affected. The metal film structure can be a plated metal film, and the conductive cloth structure can be a plated metal film on the fiber cloth.

To ensure the presentation of the mechanical properties of the non-newtonian fluid material, the thickness of the conductive layer is set to be thin, for example, the thickness of the conductive layer may be set to be less than or equal to 0.2mm.

Alternatively, in order to enhance the electromagnetic shielding effect of the shielding structure, the surface resistance of the conductive layer may be set to 0.1 Ω or less in order to enhance the electromagnetic absorption capability of the conductive layer.

In one example, the conductive layer may be provided at the design time on a side surface of the newtonian fluid material, which is the side facing the package when the shielding element is packaged in a board level architecture, in order to absorb electromagnetic radiation generated by the package.

Alternatively, as shown in FIG. 4, the conductive layer may also completely coat the surface of the non-Newtonian fluid material. By means of the complete coating mode, the strain of the non-Newtonian fluid material is limited in the coating range of the conductive layer, and the problem that the shape change mode of the non-Newtonian fluid material cannot support the radiator in a normal state is avoided.

In one example, the non-newtonian fluid material can be prepared from polyurethane or polyborosiloxane. For example, polyurethane (PU) is used as a substrate and Polyborosiloxane (PBDMS) is used as a modifying component. The compactness of the non-Newtonian fluid material is regulated by regulating the proportion of the polyborosiloxane.

As shown in fig. 6, is a relationship between the rebound force and the compression ratio of the non-newtonian fluid material at different densities in the normal state. Where compression ratio refers to the strain that occurs in thickness or volume of a non-newtonian fluid material. For example, a compression ratio of 40% refers to a ratio of the compressed thickness to the original thickness, meaning that the non-newtonian fluid material is compressed by 40% based on the original thickness upon application of an external force. The rebound force refers to a force generated by the non-newtonian fluid material per unit area when the non-newtonian fluid material is compressed, the direction of the rebound force being opposite to the direction of the external force.

For example, in FIG. 6, a non-Newtonian fluid material having a density of 0.55, when compressed by 30%, would generate a 100N (N) spring-back force against an external force, i.e., a greater external force would be required to allow the non-Newtonian fluid material to continue to be compressed.

It will be appreciated that in packaging board level architectures, the heat spreader needs to be in sufficient contact with the package to facilitate heat dissipation by the package. Then, when the heat sink approaches the package by pressing the shielding unit, if the shielding unit generates a larger resilience force to resist the external force given by the heat sink, the user may need to apply a larger force on the heat sink to compress the shielding unit, so that the heat sink approaches the package. If the force applied by the user is smaller than the resilience force of the shielding unit, poor contact between the heat spreader and the package may be caused.

Thus, in one example, a non-newtonian fluid material having a shear stress of less than or equal to 0.3 megapascals (i.e., a resiliency force per unit area of less than or equal to 300N) may be selected to make the shielding element prior to entering the dense zone (e.g., prior to the compression ratio exceeding 40%). On the one hand, the package board-level architecture is convenient for users, and on the other hand, good contact between the radiator and the package body is ensured.

Optionally, as shown in fig. 7, the shielding structure further includes an adhesive layer for fixing the shielding structure at the target position.

For example, as shown in fig. 7 (a), an adhesive layer may be attached to the surface of the conductive layer. As shown in fig. 7 (b), the adhesive layer may be adhered to the surface of the non-newtonian fluid material, and the adhesive layer and the conductive layer may entirely encapsulate the non-newtonian fluid material.

Based on the difference in packaging positions, at least one set of shielding unit groups in the shielding structure may include a first shielding unit group representing a shielding unit group for being disposed on the package body and/or a second shielding unit group representing a shielding unit group for being disposed at the periphery of the package body.

Optionally, the shielding structure further includes a shielding case corresponding to each shielding unit in the first shielding unit group, and the shielding case has conductivity for shielding electromagnetic waves. A schematic partial structure of the shield can and the shielding unit may be shown in fig. 8, for example. Fig. 8 (a) is a side view, and fig. 8 (b) is a top view. Wherein the shielding units are arranged at the tops of the corresponding shielding covers.

Optionally, the shielding structure further includes a support corresponding to each shielding unit in the second shielding unit group, as shown in fig. 9, the shielding unit is disposed on top of the corresponding support, and the support is used to support the corresponding shielding unit.

Optionally, the shielding structure further includes a support and an insulating layer corresponding to each shielding element in the second shielding element group; as shown in fig. 10, the shielding unit includes a first sub-unit and a second sub-unit, the insulation layer is positioned at the bottom of the support, the first sub-unit is positioned at the top of the support, and the second sub-unit is positioned at the sides of the support and the insulation layer.

The specific product form of the shielding structure, and its application in board level architecture packaging, is described by way of example below in connection with several examples.

In one example, the shielding structure includes a set of shielding units (i.e., a first shielding unit set) disposed at a gap between a support frame of the package and a bottom of the heat sink.

Referring to fig. 11, a board level architecture is provided for the present application, including a PCB, a package, a heat spreader, and a shielding structure; the packaging body and the radiator are respectively fixed on the PCB, the packaging body is positioned between the radiator and the PCB, and the shielding structure is arranged at a gap between the supporting frame of the packaging body and the bottom of the radiator. Wherein the shielding structure comprises a first shielding unit.

The size of the shielding elements in the first shielding element group may be determined based on the usage scenario. For example, assume that the substrate size of the package is 65x65mm, the support frame peripheral dimension is consistent with the substrate, and the width is 6mm. The width of each shielding element in the first shielding element group may be 6mm. Of course, the width of each shielding element may be greater than 6mm or less than 6mm without affecting the mounting of the various components in the board level architecture. The shape of the cross section thereof may also be not limited to a rectangular shape, such as the cross-sectional shapes shown in fig. 7 to 11. But may also be curved, triangular, trapezoidal, or other irregular patterns.

The first shielding unit group may include one shielding unit. The shape of the shielding unit may be set based on the shape of the support frame. For example, as shown in fig. 12, if the supporting frame is rectangular, the shielding unit may be correspondingly configured in a rectangular shape. If the supporting frame is a ring, the shielding unit may be correspondingly arranged as a ring. If the supporting frame is in a hexagonal shape, the shielding unit can be correspondingly arranged in a hexagonal shape and the like.

Optionally, if the package body has a gap requirement, the first shielding unit group may also include a plurality of shielding units, where the plurality of shielding units are annularly arranged. The spacing d between two adjacent shielding units is less than or equal to one quarter of the target wavelength. Wherein the target wavelength is the wavelength corresponding to the electromagnetic wave to be suppressed.

For example, as shown in fig. 13, for a circular ring-shaped support frame, the first shielding unit group may include a plurality of fan-shaped shielding units constituting a circular ring. Assuming that the frequency of electromagnetic waves to be suppressed by the package is 29GHz, the interval between adjacent two fan-shaped shielding units is set to be one quarter of the corresponding wavelength of electromagnetic waves of 29 GHz. The first shielding unit group can effectively shield electromagnetic noise generated by the package body at the 29GHz electromagnetic wave frequency point, and meets the requirement of the package body on the seam.

It should be noted that, when the respective shielding units in the first shielding unit group are disposed at the gap between the support frame of the package and the bottom of the heat sink, the thickness of each shielding unit may be determined according to the width of the gap between the support frame of the package and the bottom of the heat sink.

For example, assuming that the width of the gap between the support frame of the package and the bottom of the heat sink is 1.8mm after the heat conductive layer of the package is sufficiently contacted with the boss of the heat sink, the thickness of the shielding unit may be set to 1.8mm. Alternatively, more than 1.8mm may be provided. For example, assume that the compression ratio of the non-newtonian fluid material enters the dense region at 40%. Then, the thickness h of the shielding unit may be set to 1.8.ltoreq.h.ltoreq.3 mm. When the radiator is installed, before the non-Newtonian fluid material in the shielding unit is compressed to a compression ratio exceeding 40%, the static resilience force of the non-Newtonian fluid material in the shielding unit is smaller than or equal to 0.3Mpa, so that the heat conducting layer of the packaging body and the boss of the radiator can be fully connected, and poor contact between the radiator and the heat conducting layer is avoided. The package body can be ensured to normally dissipate heat. And the conducting layer of the shielding unit is electrically connected with the radiator, so that the electromagnetic shielding effect can be further enhanced.

Referring to fig. 14, another board level architecture is provided for the present application, including a PCB, a package, a heat spreader, and a shielding structure; the packaging body and the radiator are respectively fixed on the PCB, the packaging body is positioned between the radiator and the PCB, and the shielding structure is arranged at a gap between the supporting frame of the packaging body and the bottom of the radiator. The shielding structure may include a first shielding unit and a shielding case as shown in fig. 8. As shown in fig. 14, the top of the shield can is covered on the support frame of the package and the bottom is supported on the PCB. The shielding structure is disposed between the top of the shield and the bottom of the heat sink. By providing a shield (conductive material) to ground on the PCB, electromagnetic noise of the package is further reduced.

Wherein the shield can include a top and a sidewall as shown in fig. 8. In one example, the shape of the top of the shield can may be designed based on the support frame shape of the package. For example, the top of the shield may be rectangular-shaped, circular, hexagonal-shaped, etc. The side wall may be a cylindrical structure based on the peripheral shape of the top of the shield. The side walls are supported at the top edges, i.e. the side walls and the top form a lid-like structure with an opening at the top. After the shielding cover is buckled on the packaging body, the top of the shielding cover can cover the supporting frame of the packaging body, the bottom of the side wall can be supported on the PCB, and the boss of the radiator can penetrate through the through hole to contact with the heat conducting layer of the packaging body.

For example, the support frame of the package exhibits a rectangular return shape, and then the top of the shield can also be provided with a rectangular return shape.

Alternatively, for packages having slit requirements, the shield may be a structure capable of covering a localized area of the support frame of the package. For example, the support frame of the package body is rectangular, and when the package board level structure is provided, a plurality of shielding cases can be arranged, and after each shielding case is buckled on the package body, the top of the shielding case forms the rectangular shape.

It will be appreciated that the thickness of each shielding element in the first set of shielding elements may be determined based on the width of the gap between the top of the shielding can and the heat sink in the packaging environment. The specific thickness setting may be described with reference to the example shown in fig. 11, and will not be described here.

The second example, the shielding structure includes a set of shielding units (i.e., a second shielding unit set), and the shielding structure is disposed between the PCB at the periphery of the package and the heat sink.

Referring to fig. 15, yet another board level architecture provided for the present application includes a PCB, a package, a heat spreader, and a shielding structure; the packaging body and the radiator are respectively fixed on the PCB, and the packaging body is positioned between the radiator and the PCB; the shielding structure may include a second shielding unit group and a support member as shown in fig. 9. The bottom of the support is supported on the PCB, and the shielding unit is disposed between the top of the support and the heat sink.

Alternatively, the support member may be made of conductive material, and grounded on the PCB. The thickness of the shielding unit may be determined according to the height of the support and the width of the gap between the bottom of the heat sink and the support after the package is sufficiently contacted with the heat sink. The thickness of shielding unit can guarantee that the heat conduction layer at the encapsulation body can fully contact with the boss of radiator, and when the condition that takes place high-speed impact, the shielding unit can support the pressure from the radiator, avoids the radiator to produce too big pressure to the heat conduction layer. The specific thickness setting may be described with reference to the example shown in fig. 11, and will not be described here.

The support may be located around the first region of the PCB. The first region is a region for soldering the package. For example, as shown in fig. 16, the schematic view of the planar area of the PCB may be the soldering area of one package on the PCB, or the soldering areas of multiple packages with high-density layout. The support may be an integral structure capable of encircling the first region, for example, as shown in fig. 16 (a) and (c). Correspondingly, the second shielding unit group can comprise a shielding unit with an integrated structure, and also can comprise a plurality of shielding units which are annularly arranged, and the distance between two adjacent shielding units is smaller than or equal to one quarter of the target wavelength.

Alternatively, as shown in (b) and (d) of fig. 16, the first region may be surrounded by a plurality of supporters, and accordingly, the second shielding unit assembly includes shielding units therein in one-to-one correspondence with the plurality of supporters. It will be appreciated that, as shown in fig. 16, in addition to the first area and the support, the PCB is designed with other soldering areas and routing designs of the package according to actual needs. It will be appreciated that when a plurality of support members are provided around the first region, the spacing between the support members is less than a quarter of the target wavelength in order to ensure the shielding effect of the support members and the shielding unit on electromagnetic noise generated by the package.

Optionally, referring to fig. 17, yet another board level architecture provided herein includes a PCB, a package, a heat spreader, and a shielding structure; the packaging body and the radiator are respectively fixed on the PCB, and the packaging body is positioned between the radiator and the PCB; the shielding structure may include a second shielding element group, a support member, and an insulating layer as shown in fig. 10.

Each shielding unit in the second shielding unit group comprises a first subunit and a second subunit, the insulating layer is located at the bottom of the supporting piece and arranged between the supporting piece and the PCB, the first subunit is located at the top of the supporting piece, the second subunit is located at the side edges of the supporting piece and the insulating layer, and the insulating layer is filled in the space of the supporting piece, the PCB and the insulating layer.

In one case, if a large power circuit module is additionally arranged on the PCB, an insulating layer can be arranged between the supporting piece and the PCB to prevent the package body from being burnt out due to short circuit.

In this example, by dividing each shielding element in the second shielding element group into the first subunit and the second subunit, the area of the shielding element that receives electromagnetic wave radiation is increased, thereby further increasing the electromagnetic shielding effect.

The third example, the shielding structure includes two shielding unit groups (a first shielding unit group and a second shielding unit group respectively), which are respectively disposed on the support frame of the package body, and between the PCB and the heat sink at the periphery of the package body.

Referring to fig. 18, yet another board level architecture is provided herein, wherein the shielding structure includes a first shielding element group, a second shielding element group, and a support. I.e. the shielding structure used in the board level architecture shown in fig. 18 is a combination of the shielding structures in the board level architectures shown in fig. 11 and 15.

Optionally, referring to fig. 19, a further board level architecture is provided herein, wherein the shielding structure includes a first shielding unit group, a shielding cage, a second shielding unit group, and a support. I.e. the shielding structure used in the board level architecture shown in fig. 19 is a combination of the shielding structures in the board level architectures shown in fig. 14 and 15.

Optionally, referring to fig. 20, a further board level architecture is provided herein, wherein the shielding structure includes a first shielding element group, a second shielding element group, an insulating layer and a support. I.e. the shielding structure used in the board level architecture shown in fig. 20 is a combination of the shielding structures in the board level architectures shown in fig. 11 and 17.

Optionally, referring to fig. 21, a further board level architecture is provided herein, wherein the shielding structure includes a first shielding element group, a shielding can, a second shielding element group, an insulating layer, and a support. I.e. the shielding structure used in the board level architecture shown in fig. 21 is a combination of the shielding structures in the board level architectures shown in fig. 15 and 17.

It can be understood that the corresponding shielding structures are arranged on the supporting frame of the packaging body and between the PCB at the periphery of the packaging body and the radiator, so that double-layer protection is realized, and the electromagnetic shielding effect of the shielding structure and the protection force to the packaging body are enhanced.

The effect of board level architecture packaging using the shielding structure provided in the present application will be exemplarily described below using the board level architecture shown in fig. 11 as an example.

After the package is packaged according to the board-level architecture structure shown in fig. 11, noise test and drop test are performed on the obtained board-level architecture. As shown in fig. 22, in the frequency band range of 20 to 30GHz, electromagnetic noise generated by the package is reduced by 10 to 20dB.

The board level structure provided with the shielding structure and the board level structure not provided with the shielding structure were simultaneously released from the height of 75mm so that the board level structure was dropped, and the pressure of the package surface (e.g., the heat conductive layer) in each board level structure was tested. As shown in fig. 23, the pressure of the package in the board-level architecture provided with the shielding structure was reduced by 28% from 2102N to 1499N, compared to the board-level architecture provided with no shielding structure. And the heat conduction layer is not crushed in the board-level framework provided with the shielding structure, and the temperature of the board-level framework is in a safe temperature range during working.

Through the experiment, the shielding structure provided by the application has the electromagnetic shielding function and the anti-seismic buffering function. On the one hand, the shielding structure provided by the application is utilized to carry out board-level framework packaging on the packaging body, so that the problem of electromagnetic noise degradation caused by bare Die packaging can be effectively restrained, and the impact force of the radiator on the heat conducting layer of the packaging body can be reduced, thereby reducing the probability of crushing the heat conducting layer of the packaging body. On the other hand, because the shielding structure can realize electromagnetic shielding under the condition of guaranteeing heat dissipation, the problem that heat dissipation and electromagnetic shielding cannot be compatible is solved in the scene of high-density layout, and the high-density layout scene of the packaging body is facilitated.

It should be noted that, in the embodiment of the present application, the shielding structure may be an independent shielding product, and when the board-level architecture is packaged, the device may be soldered on the PCB first, and then the shielding structure is fixed at a corresponding position by adopting modes of adhesion, screw installation, soldering, and the like. The heat sink is then mounted with screws.

Alternatively, the individual parts of the shielding structure (shielding element, shielding cage, support, insulation layer, etc.) may also be separate products. When the board-level framework is packaged, each part is fixed at the corresponding position in a mode of adhesion, screw installation, welding and the like, so that the shielding structure is formed.

Alternatively, the individual shielding elements of the first shielding element group in the shielding structure may also be arranged directly on the package. For example, as shown in fig. 24, the present application also provides a package provided with the shielding unit.

Since the package provided by the present application has already fixed the first shielding unit group at the time of shipment. When the board-level architecture is packaged, no additional assembly process is required for the first shielding unit group, and the device is welded on the PCB according to the conventional packaging steps, and the boss of the radiator is aligned with the heat conducting layer of the device and then fixed on the PCB through screws.

Alternatively, the shielding structure may be fixed to the heat sink. The radiator provided by the application is fixed with the shielding structure when leaving the factory. When the board-level architecture is packaged, no additional assembly process is required for the shielding structure, and the device is welded on the PCB according to the conventional packaging steps, and then the boss of the radiator is aligned with the heat conducting layer of the device and is fixed on the PCB through screws.

Alternatively, part of the parts of the shielding structure may be fixed to the heat sink. For example, the first shielding element group and/or the second shielding element group may be provided on the heat sink. As shown in fig. 25, for example, in the heat sink provided in the present application, a second area of the bottom of the heat sink is provided with a first shielding unit group, and a third area is provided with a second shielding unit group, where the second area is an area of the bottom of the heat sink opposite to the supporting frame on the package body when the heat sink is mounted on the PCB. The third area is an area of the heat sink bottom opposite the support on the PCB when the heat sink is mounted on the PCB.

The radiator provided by the application is fixed with the shielding structure or part of the shielding structure when leaving the factory. When the board-level architecture is packaged, assembly procedures for the shielding structure can be reduced, and assembly efficiency is improved.

Of course, part of the components (e.g., support, insulation layer, second shielding element group) in the shielding structure may also be fixed on the PCB. Because the PCB that this application provided has fixed shielding structure or shielding structure's part at the factory. When the board-level architecture is packaged, assembly procedures for the shielding structure can be reduced, and assembly efficiency is improved.

Based on the shielding structure of the foregoing embodiment, the present application further provides an electronic device, including the foregoing shielding structure, a board-level architecture, a PCB provided with a packaging structure, a package provided with a packaging structure, or a heat sink provided with a packaging structure, etc.

The electronic device may be an electronic device related to a package, such as a smart phone, a tablet computer, a vehicle-mounted device super mobile personal computer (ultra-mobile personal computer, UMPC), a robot, a computer device, a server, and an intelligent home appliance. The embodiment of the application does not limit the specific type of the electronic device.

In the description of the present application, it should be understood that the terms "first," "second," and the like are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or an implicit indication of the number of technical features being indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more of the described features. In the description of the present application, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically connected, electrically connected or can be communicated with each other; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the terms in this application will be understood by those of ordinary skill in the art as the case may be.

In the description of the present application, it should be understood that the terms "upper," "lower," "side," "front," "rear," and the like indicate an orientation or positional relationship based on installation, and are merely for convenience of description of the present application and to simplify the description, rather than to indicate or imply that the apparatus or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the present application.

In the description of the present application, it should be noted that the term "and/or" is merely an association relationship describing an association object, and indicates that three relationships may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone.

It should be further noted that, in the embodiments of the present application, the same reference numerals denote the same components or the same parts, and for the same parts in the embodiments of the present application, reference numerals may be given to only one of the parts or the parts in the drawings by way of example, and it should be understood that, for other same parts or parts, the reference numerals are equally applicable.

Finally, it should be noted that: the foregoing is merely a specific embodiment of the present application, but the protection scope of the present application is not limited thereto, and any changes or substitutions within the technical scope of the present disclosure should be covered in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A shielding structure comprising at least one shielding element group, each shielding element group comprising at least one shielding element, each shielding element comprising a non-newtonian fluid material and a conductive layer disposed on a surface of the non-newtonian fluid material.

2. The shielding structure of claim 1, wherein the thickness of the conductive layer is less than or equal to 0.2 millimeters.

3. The shielding structure according to claim 1 or 2, wherein the shielding unit further comprises an adhesive layer for fixing the shielding unit at a target position.

4. A shielding structure according to any one of claims 1-3, wherein the non-newtonian fluid material comprises polyurethane or polyborosiloxane.

5. The shielding structure of any of claims 1-4, wherein the non-newtonian fluid material has a shear stress less than or equal to 0.3 megapascals when the compression ratio is less than or equal to a first threshold.

6. The shielding structure of any one of claims 1-5, wherein the conductive layer completely encapsulates the surface of the non-newtonian fluid material.

7. The shielding structure according to any one of claims 1 to 6, wherein the shielding unit group includes a plurality of the shielding units, the plurality of the shielding units are arranged in a ring shape, and a distance between two adjacent shielding units is less than or equal to a quarter of a target wavelength, the target wavelength being a wavelength of electromagnetic waves to be suppressed by the shielding structure.

8. The shielding structure according to any one of claims 1 to 7, further comprising a shield case corresponding to each of the shielding elements in a first shielding element group, the shielding element being provided on top of the corresponding shield case, the shield case being for shielding electromagnetic waves, the first shielding element group being one of at least one of the shielding element groups.

9. The shielding structure according to any one of claims 1-8, further comprising a support corresponding to each of the shielding elements of a second shielding element group, the shielding elements being arranged on top of the corresponding support for supporting the corresponding shielding element, the second shielding element group being one of at least one of the shielding element groups.

10. The shielding structure according to any one of claims 1-9, further comprising a support and an insulating layer corresponding to each of the shielding elements in the second shielding element group; the shielding unit comprises a first subunit and a second subunit, and the second shielding unit group is one of at least one shielding unit group;

the insulation layer is located at the bottom of the supporting piece, the first subunit is located at the top of the supporting piece, and the second subunit is located at the side edges of the supporting piece and the insulation layer.

11. The shielding structure according to any one of claims 1 to 10, wherein a surface resistance of the conductive layer is less than or equal to 0.1 Ω.

12. The shielding structure according to any one of claims 1 to 11, wherein the conductive layer is a metal film structure, a woven wire mesh structure, or a conductive cloth structure.

13. A package comprising a substrate, a Die, a support frame, a plastic package, and the shielding structure of any of claims 1-7;

the Die is arranged on the substrate, the supporting frame is arranged at the edge position of the substrate and surrounds the periphery of the Die, and the plastic package body is used for plastic package of the substrate, the Die and the supporting frame; the shielding structure is arranged on the supporting frame.

14. A radiator, characterized in that the radiator bottom is provided with a shielding structure as claimed in any one of claims 1-12.

15. A board-level architecture comprising the package of claim 13, the shielding structure of any of claims 1-12, or the heat sink of claim 14;

the shielding structure is used for shielding electromagnetic radiation generated by the packaging body and reducing impact of external force on the packaging body.

16. An electronic device comprising the shielding structure of any one of claims 1-12, the package of claim 13, the heat sink of claim 14, or the board level architecture of claim 15.