WO2023098503A1

WO2023098503A1 - Shielding structure, package body, board-level architecture, radiator, and electronic device

Info

Publication number: WO2023098503A1
Application number: PCT/CN2022/133199
Authority: WO
Inventors: 熊振兴; 熊建波; 赵才军; 梁晓彤; 赵亚涛
Original assignee: 华为技术有限公司
Priority date: 2021-11-30
Filing date: 2022-11-21
Publication date: 2023-06-08
Also published as: CN116207079A

Abstract

The present application relates to the field of electronic devices, and provides a shielding structure, a package body, a board-level architecture, a radiator, and an electronic device, which can reduce the impact of an external force on the package body while reducing the electromagnetic noise generated by the package body. The shielding structure comprises: at least one shielding unit group. Each shielding unit group comprises at least one shielding unit. Each shielding unit comprises a non-Newtonian fluid material and a conductive layer provided on the surface of the non-Newtonian fluid material.

Description

Shielding structure, package body, board-level structure, heat sink and electronic equipment

This application claims the priority of the Chinese patent application submitted to the State Intellectual Property Office on November 30, 2021, with the application number 202111449159.8 and the application name "A shielding structure, package, board-level architecture, heat sink and electronic equipment" , the entire contents of which are incorporated in this application by reference.

technical field

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

Background technique

Bare Die packaging refers to a chip packaging method that directly exposes the die (Die). The periphery of the Die is no longer wrapped with a cover, but a layer of thermally conductive material (for example, Thermal Interface Materials (TIM) is covered on the die. )). When the package and heat sink obtained by bare Die package are packaged on a printed circuit board (PCB) to form a board-level structure, the Die in the package can directly transfer heat to the heat sink through the heat-conducting material, and the maximum The junction-to-case thermal resistance of the package is reduced to a certain extent. Compared with the traditional lid (lid) package, the bare Die package can improve the heat dissipation efficiency by more than 10°C. Therefore, with the sharp increase of package power consumption, bare die packages have gradually become mainstream.

However, although the bare Die package improves the heat dissipation effect of the package, it also lacks the shielding and support of the cover. On the one hand, the electromagnetic noise generated by the package will deteriorate. , it is easy to cause the thermal conductive material to be crushed, thus causing damage to the package.

Contents of the invention

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

In the first aspect, the embodiment of the present application provides a shielding structure, including at least one set of shielding unit groups, each shielding unit group includes at least one shielding unit, and each shielding unit includes a non-Newtonian fluid material and is arranged on the surface of the non-Newtonian fluid material the conductive layer.

The non-Newtonian fluid materials used in this application are solid at normal temperature. When the non-Newtonian fluid material is static or slowly compressed, the molecules in the non-Newtonian fluid material are separated from each other and have weak connection force with each other. The non-Newtonian fluid material is bendable and easy to deform. When the non-Newtonian fluid material is subjected to high-speed impact, the connection force between the molecules in the material of the non-Newtonian fluid material is strengthened, the material becomes hard, and a large force is required to make it deform significantly. Due to its conductivity, the conductive layer, on the other hand, because the conductive layer of the shielding structure has conductivity, can be electrically connected to the heat sink, so it can absorb part of the electromagnetic radiation emitted by the package and reduce the electromagnetic noise generated by the package. .

Therefore, when the shielding structure provided by the present application is used for board-level architecture packaging, for example, the shielding structure is provided at the gap between the package body (obtained based on the bare Die package) and the bottom of the heat sink, or at the periphery of the package body, The shielding structure is added between the PCB and the radiator. On the one hand, if the heat sink is steadily and slowly applied to the shielding structure when installing the heat sink, the non-Newtonian fluid material of the shielding structure is soft and easily deformed, so that the heat sink can be installed on the PCB normally. Ensure that the heat sink is in full contact with the package to ensure heat dissipation from the package. And when the packaged board-level structure falls, or improper force is used when installing the heat sink, due to the support of the shield structure, the bottom of the heat sink will first give the shield structure a high-speed impact. At this time, the shielding structure will give a greater resilience to the bottom of the heat sink, and the non-Newtonian fluid material of the shielding structure will become hard and not easily deformed, thereby preventing the package from being subjected to significant pressure and reducing the possibility of the package being damaged . On the other hand, since the conductive layer of the shielding structure has conductivity, it can absorb part of the electromagnetic radiation emitted by the package and reduce the electromagnetic noise generated by the package.

In a possible implementation manner, the thickness of the conductive layer is less than or equal to 0.2 mm.

Wherein, the thickness of the conductive layer may be the thickness of the thickest part of the conductive layer, or 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 a possible implementation manner, the shielding unit further includes an adhesive layer, and the adhesive layer is used to fix the shielding unit at a target position.

By setting the sticking layer, the shielding unit can be flexibly set, so that it can be easily fixed at the target position. Wherein, the target position may be a position where a shielding unit needs to be used. For example, the target location may be on a support frame of a package, on the bottom of a heat sink, on a support, on a shield, and the like.

In one possible implementation, the non-Newtonian fluid material includes polyurethane or polyborosiloxane.

For example, the non-Newtonian fluid material can be prepared by using polyurethane (PU) as the base material and polyborosiloxane (PBDMS) as the modification group. By adjusting the ratio of polyborosiloxane, the density of non-Newtonian fluid materials can be adjusted.

In a possible implementation manner, when the compression ratio of the non-Newtonian fluid material under normal conditions is less than or equal to the first threshold, the shear stress of the non-Newtonian fluid material is less than or equal to 0.3 MPa.

Wherein, the first threshold is the strain limit value of the non-Newtonian fluid material entering the dense region. For example, if the first threshold is 0.4, then when the strain of the non-Newtonian fluid material exceeds 0.4 (for example, in the volume dimension, the volume of the non-Newtonian fluid material is compressed by more than 40% of the initial volume), the molecules in the material of the non-Newtonian fluid material The connection force between them is enhanced, the material becomes hard, and it is not easy to deform. The strain region above the first threshold is called the dense region. The non-Newtonian fluid material entering the dense region is relatively hard and has a large shear stress. It often requires a greater external force to overcome the shear stress of the non-Newtonian fluid material in order to continue to deform the non-Newtonian fluid material.

When packaging the board-level structure, the heat sink needs to be in full contact with the package to facilitate heat dissipation from the package. Then, when the heat sink is close to the package by squeezing the shielding unit, if the shielding unit generates a large shear stress to resist the external force given by the heat sink, it may cause the user to apply greater pressure on the heat sink to compress The shielding unit makes the heat sink approach the package body. If the pressure applied by the user is less than the shear stress of the shielding unit, it may cause poor contact between the heat sink and the package.

A non-Newtonian fluid material whose shear stress is less than or equal to 0.3 MPa before entering the dense region is selected to make the shielding unit. On the one hand, it is convenient for users to package the board-level structure, on the other hand, it ensures good contact between the heat sink and the package.

In a possible implementation manner, the conductive layer completely covers the surface of the non-Newtonian fluid material.

Through the way of complete covering, the strain of the non-Newtonian fluid material is limited within the covering range of the conductive layer, avoiding that the shape change of the non-Newtonian fluid material under normal conditions cannot play a role in supporting the radiator.

In a possible implementation, when the shielding unit group includes multiple shielding units, the multiple shielding units are arranged in a ring, and the distance between two adjacent shielding units is less than or equal to a quarter of the target wavelength, and the target wavelength The wavelength of electromagnetic waves to be suppressed by the shielding structure.

In a possible implementation, the shielding structure further includes a shielding case corresponding to each shielding unit in the first shielding unit group, the shielding unit is arranged on the top of the corresponding shielding case, the shielding case is used for shielding electromagnetic waves, the first shielding The cell group is one of at least one set of masked cell groups.

Wherein, the shielding cover may be made of conductive material, and the shielding effect of the shielding structure on electromagnetic noise is further enhanced by providing the shielding cover.

In a possible implementation manner, the shielding structure further includes a support corresponding to each shielding unit in the second shielding unit group, the shielding unit is arranged on the top of the corresponding support, and the support is used to support the corresponding shielding unit, The second shielding unit group is one of at least one group of shielding unit groups.

Wherein, the supporting member may also be made of a conductive material, and by providing the supporting member, while ensuring the supporting effect on the shielding unit, the shielding effect of the shielding structure on electromagnetic noise is further enhanced.

In a possible implementation, the shielding structure further includes a support and an insulating layer corresponding to each shielding unit in the second shielding unit group; the shielding unit includes a first subunit and a second subunit, and the second shielding unit group being one of at least one set of shielded cell sets;

The insulating layer is located at the bottom of the support, the first subunit is located at the top of the support, and the second subunit is located at the sides of the support and the insulating layer.

When the shielding structure is packaged in a board-level framework, other power circuit modules may be arranged on the PCB. By providing an insulating layer, a short circuit can occur and the package can be burned. Moreover, by dividing each shielding unit in the second shielding unit group into a first subunit and a second subunit, the area where the shielding unit receives electromagnetic wave radiation is increased, thereby further increasing the electromagnetic shielding effect.

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

The surface resistance of the conductive layer can be measured by a multimeter. The smaller the surface resistance of the conductive layer is, the stronger the electromagnetic absorption capacity of the conductive layer is. In this application, the surface resistance of the conductive layer can be limited within 0.1Ω, so as to enhance the electromagnetic shielding effect of the shielding structure.

In a possible implementation manner, the conductive layer is a metal film structure, a woven wire mesh structure or a conductive cloth structure. Wherein, the metal thin film structure may be an electroplated metal film, and the conductive cloth structure may be a structure obtained by electroplating a layer of metal thin film on the fiber cloth. By adopting flexible structures such as a metal film structure, a woven wire mesh structure, or a conductive cloth structure, the performance of the conductive layer on the mechanical properties of non-Newtonian fluid materials is reduced.

In the second aspect, the embodiment of the present application provides a package, including a substrate, a die, a support frame, a plastic package, and the shielding structure as described in the first aspect or any optional mode of the first aspect; the Die is arranged in On the substrate, the support frame is arranged on the edge of the substrate and surrounds the Die, and the plastic package plastically seals the substrate, the Die and the support frame; the shielding structure is arranged on the support frame.

In a third aspect, the embodiment of the present application provides a radiator, the bottom of the radiator is provided with the shielding structure as described in the first aspect or any optional manner of the first aspect.

In the fourth aspect, the embodiment of the present application provides a board-level architecture, including the package as described in the second aspect, the shielding structure as described in the first aspect or any optional mode of the first aspect, or the shielding structure as described in the third aspect The heat sink and the shielding structure are used to shield the electromagnetic radiation generated by the package and reduce the impact of external force on the package.

For example, a board-level architecture may include a PCB and a package as described in the second aspect. Since the package is provided with a shielding structure, it can shield the electromagnetic radiation generated by the package and reduce the impact of external force on the package.

Optionally, the board-level architecture may include a PCB, a package body, and the shielding structure as described in the first aspect or any optional manner of the first aspect.

Optionally, the board-level structure may include a PCB, a package body, and a heat sink as described in the third aspect. Since the shielding structure is arranged on the radiator, the electromagnetic radiation generated by the package can be shielded, and the impact of external force on the package can be reduced.

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

Optionally, the board-level architecture may include a plastic encapsulation structure, which plastic-seals the board-level architecture to protect the stability of each component in the board-level architecture.

In the fifth aspect, the embodiment of the present application provides an electronic device, including the shielding structure as described in the first aspect or any optional mode of the first aspect, the package as described in the second aspect, and the package as described in the fourth aspect. The aforementioned board-level architecture or the heat sink as described in the third aspect.

Description of drawings

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

FIG. 2 is a structural schematic diagram 1 of a board-level architecture provided by an embodiment of the present application;

Fig. 3 is a schematic diagram of a scene where a heat sink crushes a heat conduction layer according to an embodiment of the present application;

FIG. 4 is a first structural schematic diagram of a shielding unit provided by an embodiment of the present application;

5 is a schematic diagram of the relationship between shear stress and strain of a non-Newtonian fluid material provided in the embodiment of the present application;

Fig. 6 is a schematic diagram of the relationship between the rebound force and the compression ratio of a non-Newtonian fluid material provided by the embodiment of the present application;

FIG. 7 is a second structural schematic diagram of a shielding unit provided in an embodiment of the present application;

FIG. 8 is a partial structural schematic diagram 1 of a shielding structure provided by an embodiment of the present application;

Fig. 9 is a partial structural schematic diagram II of a shielding structure provided by the embodiment of the present application;

FIG. 10 is a schematic diagram of a partial structure of a shielding structure provided in the embodiment of the present application III;

FIG. 11 is a schematic structural diagram II of a board-level architecture provided by an embodiment of the present application;

Fig. 12 is a first schematic diagram of the shape of a first shielding unit group provided by the embodiment of the present application;

Fig. 13 is a second schematic diagram of the shape of a first shielding unit group provided by the embodiment of the present application;

FIG. 14 is a schematic structural diagram III of a board-level architecture provided by an embodiment of the present application;

FIG. 15 is a structural schematic diagram 4 of a board-level architecture provided by an embodiment of the present application;

FIG. 16 is a schematic diagram of a scene where a support is provided on a PCB according to an embodiment of the present application;

FIG. 17 is a schematic structural diagram five of a board-level architecture provided by an embodiment of the present application;

FIG. 18 is a sixth structural diagram of a board-level architecture provided by the embodiment of the present application;

FIG. 19 is a schematic structural diagram VII of a board-level architecture provided by an embodiment of the present application;

FIG. 20 is a schematic structural diagram eighth of a board-level architecture provided by an embodiment of the present application;

FIG. 21 is a schematic structural diagram of a board-level architecture provided in the embodiment of the present application (9);

Figure 22 is a schematic diagram of a noise test result based on the board-level architecture shown in Figure 11 provided by the embodiment of the present application;

FIG. 23 is a schematic diagram of a drop test result based on the board-level architecture shown in FIG. 11 provided by the embodiment of the present application;

FIG. 24 is a schematic structural diagram of a package provided with a shielding structure provided in an embodiment of the present application;

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

Detailed ways

With the sharp increase in power consumption of packages, bare die packages have gradually become mainstream. The structure of the package based on the bare Die package may be as shown in FIG. 1 , including a substrate, a Die, a supporting frame and a plastic package (not shown in FIG. 1 ). Wherein, the Die is welded on the substrate, and the substrate is provided with metal traces, which can transmit the signal on the bump of the Die to the corresponding Ball Grid Array (BGA) pin on the substrate. A support frame (generally called a Ring) is provided around the die at the edge of the substrate for package protection and enhanced heat dissipation. The substrate, Die and support frame are packaged and protected by a plastic package to enhance the mechanical properties of the package and ensure the reliability of the package. Exemplarily, it can be sealed by molding process. Of course, although not shown, some small packages such as capacitors and inductors may also be arranged on the substrate to improve the reliability of the signal of the entire package.

Since Die is the heat source of the package, a layer of heat conduction layer is usually covered on Die. In order to facilitate subsequent board-level structure packaging, heat energy can be transferred to the heat sink through the heat conduction layer to enhance heat dissipation. Wherein, the heat conduction layer can be TIM1.5 or other heat conduction interface materials.

As shown in FIG. 2 , when packaging a board-level structure, generally the BGA pins of the package are soldered to corresponding areas on the PCB. Then align the heat sink with the package body, and fix the heat sink on the PCB with screws.

In one example, in order to ensure good contact between the heat sink and the package body and ensure the heat dissipation effect, a boss can also be provided at the bottom of the heat sink. Screws secure the heatsink to the PCB.

In the actual test, it is found that although the package based on the bare Die package can improve the heat dissipation efficiency by more than 10°C compared with other packages (for example, the package based on the lid package), it also increases the electromagnetic noise by 5-10dB . And when installing the heat sink, if the force is not appropriate, or the packaged board-level structure falls, it is easy to cause the heat conduction layer to be crushed. For example, as shown in FIG. 3 , the heat sink may tilt to one side during installation, drop, etc., so that the boss of the heat sink presses the edge of the heat conduction layer with a large impact force, causing the edge of the heat conduction layer to be crushed. After the heat conduction layer is crushed, the Die cannot dissipate heat smoothly, making the Die work in a high-temperature environment, reducing the service life and reliability of the Die, and easily damaged.

To solve this problem, the present application provides a shielding structure, which includes at least one shielding unit group, and each shielding unit group includes at least one shielding unit. As shown in FIG. 4 , the shielding unit includes a non-Newtonian fluid material and a conductive layer disposed on the surface of the non-Newtonian fluid material.

Non-Newtonian fluid materials refer to fluid materials that do not satisfy Newton's experimental law of viscosity, and the relationship between shear stress and shear rate is not linear. When the shear rate is low, the shear stress of the fluid is basically unchanged; when the shear rate exceeds a critical value, the shear stress increases with the increase of the shear rate, and the viscosity of the fluid will increase with the pressure or shear As the stress increases, the volume of the material expands.

In the embodiment of the present application, the non-Newtonian fluid material is solid at room temperature. When the non-Newtonian fluid material is in a normal state (static or slowly compressed state), the molecules in the material of the non-Newtonian fluid material are separated from each other and have a weak connection force with each other. The non-Newtonian fluid material is bendable and easy to deformation. When the non-Newtonian fluid material is subjected to high-speed impact, the connection force between the molecules in the material of the non-Newtonian fluid material is strengthened, the material becomes hard, and a large force is required to make it deform significantly.

Exemplarily, under the action of an external force, the relationship between the shear stress and the strain of the non-Newtonian fluid material for different shear rates (unit: mm/s) can be shown in FIG. 5 . In general, when the strain of the non-Newtonian fluid material exceeds a first threshold (for example, 0.4 as shown in Figure 5), the connection force between molecules in the material of the non-Newtonian fluid material is enhanced, and the material becomes hard, exceeding 0.4 The strain interval is called the dense region. In the dense region, when the strain of the non-Newtonian fluid material increases, the non-Newtonian fluid material will generate greater shear stress.

It can be seen that when the non-Newtonian fluid material produces a shear rate of 100 mm/s, the pressure exceeding 1 MPa can cause the strain of the non-Newtonian fluid material to exceed the first threshold and enter the dense region. For a non-Newtonian material to continue to deform appreciably, more pressure needs to be applied.

Therefore, when the shielding structure provided by this application is used for board-level architecture packaging, for example, the shielding structure is provided at the gap between the support frame and the bottom of the radiator, or the shielding structure is added between the PCB and the radiator on the periphery of the package. shielding structure. On the one hand, if the radiator is installed to apply pressure to the shielding structure steadily and slowly, the non-Newtonian fluid material of the shielding structure is soft and easily deformed, so that the radiator can be normally installed on the PCB, Make sure that the boss of the heat sink is in full contact with the heat conduction layer of the package. And when the packaged board-level structure falls, or improper force is used when installing the heat sink, due to the support of the shield structure, the bottom of the heat sink will first give the shield structure a high-speed impact. At this time, the shielding structure will give a greater resilience to the bottom of the radiator, and the non-Newtonian fluid material of the shielding structure will become hard and not easily deformed, thereby avoiding obvious pressure on the heat conducting layer and reducing the possibility of the heat conducting layer being crushed .

On the other hand, since the conductive layer of the shielding structure is conductive and can be electrically connected to the heat sink, it can absorb part of the electromagnetic radiation emitted by the package and reduce the electromagnetic noise generated by the package.

In the embodiment of the present application, the conductive layer may be a flexible structure such as a metal film structure, a woven wire mesh structure or a conductive cloth structure, which does not affect the presentation of the mechanical properties of the non-Newtonian fluid material. Wherein, the metal thin film structure may be an electroplated metal thin film, and the conductive cloth structure may be a metal thin film electroplated on the fiber cloth.

In order 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 0.2 mm.

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

In one example, the conductive layer can be arranged on the side surface of the Newtonian fluid material when the shielding unit is packaged in the board-level structure, and the side surface is the side facing the package body, so as to absorb the heat produced by the package body. Electromagnetic radiation.

Optionally, as shown in FIG. 4 , the conductive layer may also completely cover the surface of the non-Newtonian fluid material. Through the way of complete covering, the strain of the non-Newtonian fluid material is limited within the covering range of the conductive layer, so as to prevent the shape change of the non-Newtonian fluid material from being unable to support the heat sink under normal conditions.

In one example, the non-Newtonian fluid material can be made of polyurethane or polyborosiloxane. For example, polyurethane (PU) is used as the base material, and polyborosiloxane (PBDMS) is used as the modification component. By adjusting the ratio of polyborosiloxane, the density of non-Newtonian fluid materials can be adjusted.

As shown in Figure 6, it is the relationship between the resilience and compression ratio of non-Newtonian fluid materials under different densities under normal conditions. The compression ratio refers to the strain in the thickness or volume of the non-Newtonian fluid material. For example, taking the thickness as an example, the compression ratio of 40% refers to the ratio of the compressed thickness to the initial thickness, which means that the non-Newtonian fluid material is compressed by 40% on the basis of the initial thickness under the action of external force. The rebound force refers to the force generated by the non-Newtonian fluid material on the unit area when the non-Newtonian fluid material is compressed, and the direction of the rebound force is opposite to that of the external force.

For example, in Figure 6, when the non-Newtonian fluid material with a density of 0.55 is compressed by 30%, the non-Newtonian fluid material will produce a rebound force of 100 Newton (N) to resist the external force, that is to say, a greater external force needs to be applied to The non-Newtonian fluid material continues to be compressed.

It can be understood that when packaging a board-level structure, the heat sink needs to be in sufficient contact with the package body to facilitate heat dissipation from the package body. Then, when the heat sink is close to the package by squeezing the shielding unit, if the shielding unit generates a large rebound force to resist the external force given by the heat sink, it may cause the user to exert a greater force on the heat sink to compress the shield. unit so that the heat sink is closer to the package. If the force applied by the user is smaller than the resilience of the shielding unit, it may cause poor contact between the heat sink and the package.

Therefore, in an example, before entering the dense region (for example, before the compression ratio exceeds 40%), the non-shear stress is less than or equal to 0.3 MPa (that is, the rebound force generated per unit area is less than or equal to 300N) can be selected. Newtonian fluid material is used to make the shielding unit. On the one hand, it is convenient for users to package the board-level structure, on the other hand, it ensures good contact between the heat sink and the package.

Optionally, as shown in FIG. 7 , the shielding structure further includes an adhesive layer, and the adhesive layer is used to fix the shielding structure at a target position.

For example, as shown in (a) of FIG. 7 , the adhesive layer can be pasted on the surface of the conductive layer. Alternatively, as shown in (b) of FIG. 7 , the adhesive layer can be adhered to the surface of the non-Newtonian fluid material, and the adhesive layer and the conductive layer will completely cover the non-Newtonian fluid material.

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

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 and is used for shielding electromagnetic waves. Exemplarily, a schematic diagram of a partial structure of the shielding case and the shielding unit may be shown in FIG. 8 . (a) in FIG. 8 is a side view, and (b) in FIG. 8 is a top view. Wherein, the shielding unit is arranged on the top of the corresponding shielding case.

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 arranged on the 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 unit in the second shielding unit group; as shown in FIG. 10 , the shielding unit includes a first subunit and a second subunit, and the insulating layer is located at At the bottom of the support, the first subunit is located at the top of the support, and the second subunit is located at the sides of the support and the insulating layer.

The specific product form of the shielding structure and the application of the shielding structure in board-level architecture packaging are exemplarily described below in combination with several examples.

Example 1, the shielding structure includes a set of shielding unit groups (ie, the first shielding unit group), which are arranged at the gap between the supporting frame of the package and the bottom of the heat sink.

Referring to Figure 11, a board-level architecture is provided for this application, including a PCB, a package, a heat sink and a shielding structure; the package and the heat sink are respectively fixed on the PCB, and the package is located between the heat sink and the PCB Between, the shielding structure is arranged at the gap between the supporting frame of the package and the bottom of the radiator. Wherein, the shielding structure includes a first shielding unit.

The size of the shielding units in the first shielding unit group may be determined based on usage scenarios. For example, assume that the size of the substrate of the package is 65x65mm, the outer dimension of the supporting frame is consistent with the substrate, and the width is 6mm. Each shielding unit in the first shielding unit group may have a width of 6mm. Of course, the width of each shielding unit can be greater than 6mm or less than 6mm without affecting the installation of various components in the board-level architecture. The shape of its cross section is also not limited to a rectangle, such as the cross-sectional shapes shown in FIGS. 7-11 . It can also be arc, triangle, trapezoid or other irregular figures.

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 supporting frame. For example, as shown in FIG. 12 , if the supporting frame is in the shape of a rectangle, the shielding unit can be correspondingly set in the shape of a rectangle. If the supporting frame is a ring, the shielding unit can be correspondingly set as a ring. If the supporting frame is in the shape of a hexagonal back, the shielding unit can be correspondingly set in a hexagonal back shape, etc.

Optionally, if the package has a gap requirement, the first shielding unit group may also include a plurality of shielding units, and the plurality of shielding units are arranged in a ring. The distance d between two adjacent shielding units is less than or equal to 1/4 of the target wavelength. The target wavelength is the wavelength corresponding to the electromagnetic wave to be suppressed.

For example, as shown in FIG. 13 , for a circular support frame, the first shielding unit group may include a plurality of fan-shaped shielding units to form a circular ring. Assuming that the electromagnetic wave frequency to be suppressed by the package body is 29 GHz, then the distance between two adjacent fan-ring shielding units is set to correspond to a quarter of the wavelength of the 29 GHz electromagnetic wave. In order to make the first shielding unit group meet the requirements of the package on the gap under the condition that the package can effectively shield the electromagnetic noise generated by the package at the electromagnetic wave frequency point of 29 GHz.

It should be noted that when each shielding unit in the first shielding unit group is arranged at the gap between the supporting frame of the package and the bottom of the heat sink, the thickness of each shielding unit can be determined according to the thickness of the supporting frame of the package and the bottom of the heat sink. The width of the gap between the bottoms is determined.

For example, assuming that the gap between the support frame of the package and the bottom of the heat sink is 1.8 mm wide after the thermal conduction layer of the package is fully in contact with the boss of the heat sink, the thickness of the shielding unit can be set to 1.8 mm. Alternatively, it can also be set to exceed 1.8mm. For example, assume that the compression ratio of a non-Newtonian fluid material enters the dense region at 40%. Then, the thickness h of the shielding unit can be set to be 1.8≦h≦3mm. Then, when the heat sink is installed, before the non-Newtonian fluid material in the shielding unit is compressed to a compression ratio exceeding 40%, since the static resilience of the non-Newtonian fluid material of the shielding unit is less than or equal to 0.3Mpa, the heat conduction of the package body The boss of the layer and the heat sink can be fully connected to avoid poor contact between the heat sink and the heat conduction layer. Ensure that the package body can dissipate heat normally. In addition, the conductive layer of the shielding unit is electrically connected to the radiator, which can further enhance the electromagnetic shielding effect.

Referring to Figure 14, another board-level architecture is provided for this application, including a PCB, a package, a heat sink and a shielding structure; the package and the heat sink are respectively fixed on the PCB, and the package is located between the heat sink and the PCB Between, the shielding structure is arranged at the gap between the supporting frame of the package and the bottom of the heat sink. Wherein, the shielding structure may be as shown in FIG. 8 , including a first shielding unit and a shielding case. As shown in FIG. 14 , the top of the shield cover is covered on the supporting frame of the package, and the bottom is supported on the PCB. The shielding structure is disposed between the top of the shielding case and the bottom of the heat sink. The electromagnetic noise of the package is further reduced by setting the shield (material with conductivity) to ground on the PCB.

Wherein, as shown in FIG. 8 , the shielding case may include a top and a side wall. In one example, the shape of the top of the shield can be designed based on the shape of the supporting frame of the package. For example, the top of the shield can be shaped like a rectangle, a ring, or a hexagon. The sidewall may be a cylindrical structure based on the peripheral shape of the top of the shield. The side wall is supported on the top edge, that is, the side wall and the top form a cover-like structure with an opening at the top. After the shielding cover is buckled on the package body, the top of the shield cover can cover the supporting frame of the package body, the bottom of the side wall can be supported on the PCB, and the boss of the radiator can pass through the through hole to contact the heat conduction layer of the package body.

For example, if the supporting frame of the package is in the shape of a rectangle, then the top of the shield can also be set in the shape of a rectangle.

Optionally, for a package with gap requirements, the shield cover may be a structure capable of covering a partial area of the support frame of the package. For example, if the supporting frame of the package is in the shape of a rectangle, multiple shields can be provided when packaging the board-level structure. After each shield is fastened on the package, the top of the shield forms a rectangle.

It can be understood that the thickness of each shielding unit in the first shielding unit group can be determined according to the gap width between the top of the shielding case and the heat sink in the packaging environment. For the specific thickness setting, refer to the relevant description in the example shown in FIG. 11 , which will not be repeated here.

Example 2: The shielding structure includes a set of shielding unit groups (ie, the second shielding unit group), and the shielding structure is arranged between the PCB and the radiator on the periphery of the package.

Referring to Figure 15, another board-level architecture provided by the present application includes a PCB, a package, a heat sink and a shielding structure; the package and the heat sink are respectively fixed on the PCB, and the package is located between the heat sink and the Between the PCBs; the shielding structure may be as shown in FIG. 9 , including a second shielding unit group and a support. The bottom of the support is supported on the PCB, and the shielding unit is arranged between the top of the support and the radiator.

Optionally, the supporting member can also be made of conductive material, which is grounded on the PCB. The thickness of the shielding unit can 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 when the package body is fully in contact with the heat sink. The thickness of the shielding unit can ensure that the thermal conduction layer of the package can fully contact the boss of the heat sink, and when a high-speed impact occurs, the shielding unit can support the pressure from the heat sink to prevent the heat sink from causing excessive damage to the heat conduction layer. pressure. For the specific thickness setting, refer to the relevant description in the example shown in FIG. 11 , which will not be repeated here.

The supports may be located around the first area of the PCB. The first area is an area for soldering the package. Exemplarily, a schematic diagram of a PCB plane area may be as shown in FIG. 16 , and the first area may be a soldering area of a package on the PCB, or may be a soldering area of multiple packages in a high-density layout. The supporting member may be an integral structure capable of surrounding the first region, for example, the supporting member shown in (a) and (c) of FIG. 16 . Correspondingly, the second shielding unit group may include a shielding unit with an integrated structure, or may include a plurality of shielding units arranged in a ring, and the distance between two adjacent shielding units is less than or equal to 1/4 of the target wavelength one.

Or, as shown in (b) and (d) in Figure 16, the first area can be surrounded by a plurality of support members, and correspondingly, the second shielding unit assembly includes shielding units corresponding to the plurality of support members one by one. unit. It can be understood that, as shown in FIG. 16 , in addition to the first region and the support member, other soldering regions and routing designs of packages are designed on the PCB according to actual needs. It can be understood that when a plurality of support members are arranged around the first area, in order to ensure the shielding effect of the support members and the shielding unit on the electromagnetic noise generated by the package, the distance between the support members should be less than a quarter of the target wavelength one.

Optionally, referring to FIG. 17, another board-level architecture provided by the present application includes a PCB, a package body, a heat sink and a shielding structure; the package body and the heat sink are respectively fixed on the PCB, and the package body is located on the heat sink Between the device and the PCB; the shielding structure can be shown in Figure 10, including a second shielding unit group, a support and an insulating layer.

Each shielding unit in the second shielding unit group includes a first subunit and a second subunit, the insulating layer is located at the bottom of the support and is arranged between the support and the PCB, the first subunit is located at the top of the support, and the second The subunits are located on the sides of the support and the insulating layer, and fill in the space of the support, PCB and insulating layer.

In one case, if a large power circuit module is additionally provided on the PCB, an insulating layer may be provided between the support member and the PCB to prevent short circuit and burn out of the package body.

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

Example 3: The shielding structure includes two shielding unit groups (respectively a first shielding unit group and a second shielding unit group), which are respectively arranged on the supporting frame of the package and between the PCB and the heat sink on the periphery of the package.

Referring to FIG. 18 , it is another board-level architecture provided by the present application, wherein the shielding structure includes a first shielding unit group, a second shielding unit group and a support. That is, the shielding structure used in the board-level architecture shown in FIG. 18 is a combination of the shielding structures in the board-level architecture shown in FIG. 11 and FIG. 15 .

Optionally, referring to FIG. 19 , it is another board-level architecture provided by the present application, wherein the shielding structure includes a first shielding unit group, a shielding case, a second shielding unit group and a support. That is, the shielding structure used in the board-level architecture shown in FIG. 19 is a combination of the shielding structures in the board-level architecture shown in FIG. 14 and FIG. 15 .

Optionally, referring to FIG. 20 , it is another board-level architecture provided by the present application, wherein the shielding structure includes a first shielding unit group, a second shielding unit group, an insulating layer and a support. That is, the shielding structure used in the board-level architecture shown in FIG. 20 is a combination of the shielding structures in the board-level architecture shown in FIG. 11 and FIG. 17 .

Optionally, referring to FIG. 21 , it is another board-level architecture provided by the present application, wherein the shielding structure includes a first shielding unit group, a shielding cover, a second shielding unit group, an insulating layer and a support. That is, the shielding structure used in the board-level architecture shown in FIG. 21 is a combination of the shielding structures in the board-level architecture shown in FIG. 15 and FIG. 17 .

It can be understood that a corresponding shielding structure is provided on the supporting frame of the package and between the PCB and the heat sink on the periphery of the package to achieve double-layer protection and enhance the electromagnetic shielding effect of the shielding structure and the protection of the package. intensity.

Taking the board-level architecture shown in FIG. 11 as an example, the effect of board-level architecture packaging using the shielding structure provided by the present application will be exemplarily described below.

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

Release the board-level frame with the shielding structure and the board-level frame without the shielding structure at the same time from a height of 75mm, so that the board-level frame drops, and test the pressure on the surface of the package (for example, the heat conduction layer) in each board-level frame . As shown in FIG. 23 , compared with the board-level architecture without the shielding structure, the pressure of the package in the board-level architecture with the shielding structure drops from 2102N to 1499N, which is 28% lower. Moreover, the heat conduction layer in the board-level structure provided with the shielding structure is not crushed, and the temperature of the board-level structure is in a safe temperature range during operation.

Through the above experiments, it can be seen that the shielding structure provided by the present application has the function of electromagnetic shielding and anti-seismic buffering function. On the one hand, using the shielding structure provided by this application to package the package in a board-level structure can effectively suppress the deterioration of electromagnetic noise caused by bare Die packaging, and can also reduce the impact of the heat sink on the heat conduction layer of the package , so as to reduce the probability of the heat conduction layer of the package being crushed. On the other hand, since the shielding structure of the present application can realize electromagnetic shielding while ensuring heat dissipation, it solves the problem of incompatibility between heat dissipation and electromagnetic shielding in high-density layout scenarios, and is beneficial to high-density layout scenarios of packages.

It is worth noting that in the embodiment of this application, the shielding structure can be an independent shielding product. When packaging the board-level structure, the device can be soldered on the PCB first, and then the shielding structure can be pasted, screwed, welded, etc. fixed in place. Then install the radiator with screws.

Optionally, each part in the shielding structure (shielding unit, shielding cover, support, insulating layer, etc.) may also be an independent product. When packaging the board-level structure, the shielding structure provided by the present application is formed by fixing various parts at corresponding positions by pasting, screwing, welding, and the like.

Optionally, each shielding unit in the first shielding unit group in the shielding structure may also be directly disposed on the package body. For example, as shown in FIG. 24 , the present application also provides a package provided with a shielding unit.

Since the package body provided by the present application has been fixed with the first shielding unit group when it leaves the factory. Then, when packaging the board-level structure, there is no need to add an additional assembly process for the first shielding unit group. It is only necessary to solder the device on the PCB according to the conventional packaging steps, and align the boss of the heat sink with the heat conduction of the device. layer, and then fixed on the PCB with screws.

Optionally, the shielding structure can also be fixed on the radiator. Since the heat sink provided by the present application has already fixed the shielding structure when it leaves the factory. Then, when packaging the board-level structure, there is no need to add an additional assembly process for the shielding structure, just follow the conventional packaging steps, after soldering the device on the PCB, align the boss of the heat sink with the heat-conducting layer of the device, and then It can be fixed on the PCB by screws.

Optionally, some parts of the shielding structure may also be fixed on the radiator. For example, the first shielding unit group and/or the second shielding unit group may be arranged on the heat sink. Exemplarily, as shown in Figure 25, it is a heat sink provided by the present application, the second area of the bottom of the heat sink is provided with a first shielding unit group, and the third area is provided with a second shielding unit group, wherein the second The area is the area where the bottom of the heat sink is opposite to the support frame on the package when the heat sink is mounted on the PCB. The third area is the area where the bottom of the heat sink is opposite to the support on the PCB when the heat sink is installed on the PCB.

Since the heat sink provided by the present application has already fixed the shielding structure or some parts of the shielding structure when it leaves the factory. Then, when packaging the board-level structure, the assembly process for the shielding structure can be reduced, and the assembly efficiency can be improved.

Of course, some parts in the shielding structure (for example, the support, the insulating layer, and the second shielding unit group) can also be fixed on the PCB. Since the PCB provided by the present application has already fixed the shielding structure or some parts of the shielding structure when it leaves the factory. Then, when packaging the board-level structure, the assembly process for the shielding structure can be reduced, and the assembly efficiency can be improved.

Based on the shielding structure described in the above-mentioned embodiments, the present application also provides an electronic device, including the above-mentioned shielding structure, a board-level structure, a PCB provided with a packaging structure, a package body provided with a packaging structure, or a heat sink provided with a packaging structure wait.

Wherein, the electronic device may be a smart phone, a tablet computer, a vehicle-mounted device, an ultra-mobile personal computer (UMPC), a robot, a computer device, a server, a smart home appliance, and other electronic devices involving a package. The embodiment of the present application does not impose any limitation on the specific type of the electronic device.

In the description of the present application, it should be understood that the terms "first", "second", etc. are used for descriptive purposes only, and cannot be interpreted as indicating or implying relative importance or implicitly specifying the quantity of indicated technical features . Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of said features. In the description of the present application, "plurality" means two or more, unless otherwise specifically defined.

In the description of this application, it should be noted that unless otherwise specified and limited, the terms "installation" and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integrated Ground connection; it can be mechanical connection, electrical connection or mutual communication; it can be direct connection or indirect connection through an intermediary, and it can be the internal communication of two components or the interaction relationship between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application according to specific situations.

In the description of the present application, it should be understood that the orientations or positional relationships indicated by the terms "upper", "lower", "side", "front", "rear" are based on installation orientations or positional relationships, and are only In order to facilitate the description of the present application and simplify the description, it does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as limiting the present application.

In the description of this application, it should be noted that the term "and/or" is only an association relationship describing associated objects, which means that there can be three relationships, for example, A and/or B, which can mean: exist alone A, A and B exist at the same time, and B exists alone.

It should also be noted that, in the embodiment of the present application, the same component or the same component is represented by the same reference numeral, and for the same component in the embodiment of the present application, only one of the parts or components may be marked as an example in the figure It should be understood that, for other identical parts or components, the reference signs are also applicable.

Finally, it should be noted that: the above is only a specific implementation of the application, but the scope of protection of the application is not limited thereto, and any changes or replacements within the technical scope disclosed in the application shall be covered by this application. within the scope of the application. Therefore, the protection scope of the present application should be determined by the protection scope of the claims.

Claims

A shielding structure, characterized in that it includes at least one set of shielding unit groups, each shielding unit group includes at least one shielding unit, and each shielding unit includes a non-Newtonian fluid material and is arranged on the non-Newtonian fluid material conductive layer on the surface.
The shielding structure according to claim 1, wherein the thickness of the conductive layer is less than or equal to 0.2 mm.
The shielding structure according to claim 1 or 2, wherein the shielding unit further comprises an adhesive layer, and the adhesive layer is used to fix the shielding unit at a target position.
The shielding structure according to any one of claims 1-3, wherein the non-Newtonian fluid material comprises polyurethane or polyborosiloxane.
The shielding structure according to any one of claims 1-4, characterized in that, when the compression ratio of the non-Newtonian fluid material is less than or equal to the first threshold, the shear stress of the non-Newtonian fluid material is less than or equal to 0.3 MPa.
The shielding structure according to any one of claims 1-5, wherein the conductive layer completely covers the surface of the non-Newtonian fluid material.
The shielding structure according to any one of claims 1-6, wherein the shielding unit group includes a plurality of shielding units, the plurality of shielding units are arranged in a ring, and two adjacent shielding units The distance between the units is less than or equal to a quarter of the target wavelength, and the target wavelength is the wavelength of the electromagnetic wave to be suppressed by the shielding structure.
The shielding structure according to any one of claims 1-7, characterized in that, the shielding structure further comprises a shielding cover corresponding to each of the shielding units in the first shielding unit group, and the shielding units are arranged at Corresponding to the top of the shielding case, the shielding case is used for shielding electromagnetic waves, and the first shielding unit group is one of at least one group of the shielding unit groups.
The shielding structure according to any one of claims 1-8, characterized in that, the shielding structure further comprises a support corresponding to each shielding unit in the second shielding unit group, and the shielding unit is arranged on Corresponding to the top of the supporting member, the supporting member is used to support the corresponding shielding unit, and the second shielding unit group is one of at least one group of the shielding unit groups.
The shielding structure according to any one of claims 1-9, wherein the shielding structure further comprises a support and an insulating layer corresponding to each of the shielding units in the second shielding unit group; the shielding The unit includes a first subunit and a second subunit, and the second shielding unit group is one of at least one group of the shielding unit groups;

The insulating layer is located at the bottom of the support, the first subunit is located at the top of the support, and the second subunit is located at the sides of the support and the insulating layer.
The shielding structure according to any one of claims 1-10, characterized in that, the surface resistance of the conductive layer is less than or equal to 0.1Ω.
The shielding structure according to any one of claims 1-11, wherein the conductive layer is a metal film structure, a woven wire mesh structure or a conductive cloth structure.
A package, characterized in that it includes a substrate, a die, a support frame, a plastic package, and the shielding structure according to any one of claims 1-7;

The Die is disposed on the substrate, the support frame is disposed at the edge of the substrate and surrounds the Die, and the plastic package plastic-seals the substrate, the Die and the support frame; The shielding structure is arranged on the support frame.
A radiator, characterized in that the bottom of the radiator is provided with the shielding structure according to any one of claims 1-12.
A board-level architecture, characterized by comprising the package according to claim 13, the shielding structure according to any one of claims 1-12, or the heat sink according to claim 14;

The shielding structure is used to shield the electromagnetic radiation generated by the package and reduce the impact of external force on the package.
An electronic device, characterized in that it comprises the shielding structure according to any one of claims 1-12, the package body according to claim 13, the heat sink according to claim 14, or the heat sink according to claim 15 The board-level architecture described above.