CN116075142A

CN116075142A - Circuit module with electromagnetic shielding structure and terminal equipment thereof

Info

Publication number: CN116075142A
Application number: CN202111297229.2A
Authority: CN
Inventors: 冯竹; 温淏然
Original assignee: Huawei Device Co Ltd
Current assignee: Huawei Device Co Ltd
Priority date: 2021-11-02
Filing date: 2021-11-02
Publication date: 2023-05-05

Abstract

The application relates to the technical field of circuits, in particular to a circuit module with an electromagnetic shielding structure and terminal equipment thereof, wherein the circuit module with the electromagnetic shielding structure comprises: a circuit board; the electronic components are arranged on the circuit board; the electromagnetic shielding structure comprises an electromagnetic shielding cover and at least one electromagnetic shielding wall for partitioning, the electromagnetic shielding cover is arranged on the circuit board, and the plurality of electronic components are arranged between the electromagnetic shielding cover and the circuit board; one side of the electromagnetic shielding wall is connected with the electromagnetic shielding cover, and the other side of the electromagnetic shielding wall is connected with the copper exposure area of the circuit board and the preset part of at least one electronic component and extends to the reference ground, so that the electromagnetic shielding structure can conduct partition shielding on a plurality of electronic components. Thus, electromagnetic signals generated by the electronic components are conducted to the reference ground through the electromagnetic shielding structure, and the problem that electromagnetic interference is formed by signals generated between the electronic components is solved.

Description

Circuit module with electromagnetic shielding structure and terminal equipment thereof

Technical Field

The present disclosure relates to the field of circuit technologies, and in particular, to a circuit module with an electromagnetic shielding structure and a terminal device thereof.

Background

With the continuous perfection of functions of terminal devices and the continuous development of miniaturization of terminal devices, it is a necessary requirement to realize more electronic component arrangements on circuit boards with limited areas of terminal devices.

However, as the integration level of the terminal device is continuously improved, signals sent by electronic components on a circuit board of the terminal device become more and more complex, and electromagnetic interference between different signals (for example, coupling between an electromagnetic field generated when electronic components such as an inductor operate and an electromagnetic field generated when a communication module such as a bluetooth communication module operates) also becomes more and more serious.

Disclosure of Invention

To overcome the above technical problems, a first aspect of the embodiments of the present application provides a circuit module with an electromagnetic shielding structure, the circuit module includes:

a circuit board;

the electronic components are arranged on the circuit board;

the electromagnetic shielding structure comprises an electromagnetic shielding cover and at least one electromagnetic shielding wall for partitioning, the electromagnetic shielding cover is arranged on the circuit board, and the plurality of electronic components are arranged between the electromagnetic shielding cover and the circuit board;

one side of the electromagnetic shielding wall is connected with the electromagnetic shielding cover, and the other side of the electromagnetic shielding wall is connected with the copper exposure area of the circuit board and at least one preset part of the electronic components and extends to the reference ground, so that the electromagnetic shielding structure can shield a plurality of electronic components in a partitioned manner; the preset part comprises at least one grounding end of the electronic component or at least one electromagnetic shielding layer of the electronic component.

Thus, electromagnetic signals generated by the electronic components are conducted to the reference ground through the electromagnetic shielding structure, and the problem that electromagnetic interference is formed by signals generated between the electronic components is solved.

In a possible implementation of the first aspect, the ground pins of the plurality of electronic components include any one or more of a resistor ground pin, a capacitor ground pin, and an inductor ground pin.

In a possible implementation of the first aspect, the circuit board includes at least a first partition and a second partition.

In a possible implementation manner of the first aspect, the material of the electromagnetic shielding structure is a metal, an alloy or a conductive polymer material.

In a possible implementation of the first aspect, the circuit module further includes a dielectric layer, where the dielectric layer is disposed between the electromagnetic shielding structure and the circuit board.

In a possible implementation manner of the first aspect, the dielectric layer is not disposed on all of the first electronic components in the plurality of electronic components, and the electromagnetic shielding structure extends and fills a portion where the dielectric layer is not disposed.

In a possible implementation manner of the first aspect, the first electronic component includes any one or two of a first heat generating electronic component and a first height limiting electronic component.

In a possible implementation of the first aspect, the first heat-generating electronic component includes any one or more of a charging module and a system on a chip;

the first height limiting electronic component comprises any one or more of a system on a chip, a Bluetooth chip and a storage chip.

In one possible implementation of the first aspect, the electronic component with the electromagnetic shielding layer includes any one or more of a radio frequency chip, a power chip, and a memory chip.

In a second aspect, an embodiment of the present application further provides a terminal device, where the terminal device includes any one of the circuit modules having an electromagnetic shielding structure in the first aspect.

Drawings

Fig. 1 (a) shows a perspective view of a mobile phone 1';

fig. 1 (b) shows an exploded view of a mobile phone 1';

FIG. 1 (c) shows an exploded view of a handset 1' provided with a conformal shielding structure;

FIG. 1 (d) shows an exploded view of another mobile phone 1' provided with a split-cavity shielding structure, according to some embodiments of the present application;

FIGS. 2 (a) to 2 (b) show cross-sectional views of the circuit module along section A-A in FIG. 1 (c) where two electronic components 52-1 'to 52-4' are located;

FIG. 2 (c) shows a cross-sectional view of the circuit module in which the electronic components 52-1 'to 52-4' are located, taken along section A-A in FIG. 1 (c);

FIG. 2 (d) shows a cross-sectional view of the circuit module in which the electronic components 52-1 'to 52-4' are located, taken along section A-A in FIG. 1 (d);

fig. 3 shows an exploded view of a mobile phone 1;

FIG. 4 (a) shows a cross-sectional view of a circuit module in which electronic components 52-1 'through 52-4' are located, taken along section A-A on the right side of FIG. 3, according to some embodiments of the present application;

FIG. 4 (B) shows a cross-sectional view of a circuit module with electronic components 52-1 'through 52-4' taken along section B-B on the right side of 3 (a), according to some embodiments of the present application;

FIG. 4 (C) shows a cross-sectional view of a circuit module with electronic components 52-1 'through 52-4' taken along section C-C in the right side of 3 (a), according to some embodiments of the present application;

fig. 5 shows an exploded view of a mobile phone 1.

FIG. 6 (a) shows a cross-sectional view of a circuit module in which electronic components 52-1 'through 52-4' are located, taken along section A-A in FIG. 5, according to some embodiments of the present application;

FIG. 6 (B) shows a cross-sectional view of the circuit module in which the electronic components 52-1 'through 52-4' are located, taken along section B-B in FIG. 5, according to some embodiments of the present application;

FIG. 6 (C) shows a cross-sectional view of the circuit module in which the electronic components 52-1 'through 52-4' are located, taken along section C-C in FIG. 5, according to some embodiments of the present application;

FIG. 7 (a) illustrates a schematic diagram of a structure for cavity-splitting shielding of a high heat-generating device, according to some embodiments of the present application;

FIG. 7 (b) illustrates a side view of a method of patterned masking two adjacent high heat generating devices, according to some embodiments of the present application;

FIG. 8 illustrates a side view of a circuit module with electromagnetic shielding structure in a circuit board to reduce the height of a height-limited area, according to some embodiments of the present application;

fig. 9 (a) to 9 (e) are schematic views showing a process of forming the circuit module of fig. 4 (a) by processing the patterned shielding structure using the sacrificial layer scheme;

FIGS. 10 (a) to 10 (d) are schematic views showing still another process of forming the circuit module of FIG. 4 (a) by laser cutting, ablating or cleaning;

fig. 11 (a) to 11 (d) are schematic views illustrating another process of forming the circuit module of fig. 4 (a).

Reference numerals illustrate:

1' -mobile phone; 2' -backshell; 3' -frame; 4' -display screen; a 5' -circuit module; a 50' -circuit board; 52-1' -electronic components; 52-2' -electronic components; 52-3' -electronic components; 52-4' -electronic components; a 53' -dielectric layer; a 54' -shielding layer; 531' -copper exposure region; 531 "-copper exposure area;

1-a mobile phone; 2-a rear shell; 3-frame; 4-displaying a screen; 52-1-electronic components; 52-2-electronic components; 52-3-electronic components; 52-4-electronic components; 541-electromagnetic shield; 542-electromagnetic shielding walls; 501-exposing a copper area; 60-sacrificial layer; 70-groove.

Detailed Description

Illustrative embodiments of the present application include, but are not limited to, a circuit module having an electromagnetic shielding structure and a terminal device thereof.

In order to solve the problem of electromagnetic interference between different signals emitted by electronic components on a circuit board of a terminal device, which is mentioned in the background art, the illustrative embodiments of the present application include, but are not limited to, a circuit module having an electromagnetic shielding structure and a terminal device thereof. Specifically, the circuit module with electromagnetic shielding structure includes: a circuit board; the electronic components are arranged on the circuit board; the electromagnetic shielding structure comprises an electromagnetic shielding cover and at least one electromagnetic shielding wall for partitioning, the electromagnetic shielding cover is arranged on the circuit board, and the plurality of electronic components are arranged between the electromagnetic shielding cover and the circuit board; one side of the electromagnetic shielding wall is connected with the electromagnetic shielding cover, and the other side of the electromagnetic shielding wall is connected with the copper exposure area of the circuit board and the preset part of at least one electronic component and extends to the reference ground, so that the electromagnetic shielding structure can shield a plurality of electronic components in a partitioning way; the preset part comprises at least one grounding end of the electronic component or at least one electromagnetic shielding layer of the electronic component.

It is understood that the circuit board in embodiments of the present application may include a printed circuit board (Printed Circuit Board, PCB) or a package carrier or the like.

The circuit module with the electromagnetic shielding structure provided in the embodiment of the application may be applied to a mobile phone, a vehicle-mounted device (may also be referred to as a car machine), a tablet computer, a notebook computer, an ultra-mobile personal computer (ultra-mobile personal computer, UMPC), a handheld computer, a netbook, a personal digital assistant (personal digital assistant, PDA), a wearable terminal device, a virtual reality device, and other terminal devices, which is not limited in any way. For easy understanding, the technical scheme of the application is described by taking a mobile phone as an application scene.

Fig. 1 (a) shows a perspective view of a mobile phone 1'. Fig. 1 (b) shows an exploded view of the handset 1'. As shown in the left side of fig. 1 (b), the mobile phone 1' includes a rear case 2', a frame 3', a display screen 4', and a circuit module 5' which are sequentially disposed. In the structure of the installed mobile phone 1', the rear case 2', the frame 3', and the display screen 4' are sequentially and fixedly connected, and the circuit module 5 'is arranged in the structure surrounded by the rear case 2', the frame 3', and the display screen 4'. The structure on the right side of fig. 1 (b) is an enlarged view of a part E ' of the structure on the left side of fig. 1 (b), and as shown on the right side of fig. 1 (b), a plurality of electronic components 52-1' to 52-n ' (only the electronic components 52-1' to 52-4' are shown in fig. 1 b) are provided on a circuit board 50' (Printed Circuit Board, PCB) of the circuit module 5'.

It is understood that the electronic component may be a self-shielding device, which refers to a chip, such as a radio frequency chip, a power chip, a memory chip, etc., with an electromagnetic shielding structure (which may be referred to as a shielding layer hereinafter) on the surface of the device itself. The electromagnetic shielding structure can be made of metal such as copper, silver, stainless steel, alloy or conductive polymer material. The electromagnetic shielding structure can be processed by adopting methods such as sputtering, electroplating and the like.

The electronic component may also be a high heat-generating (heat-dissipating) device, which is a device that generates higher heat by itself when the device is in operation, so that its temperature rises, such as a System on Chip (SoC), a charging module, or the like.

The electronic component may also be a height limiting device, which refers to a device that has a certain height requirement on a partial area of the circuit board when the product is assembled, such as an SoC, a bluetooth chip, a memory chip, etc., but is not limited thereto.

In some embodiments, a solution to the electromagnetic interference problem between the electronic components in the circuit module 5' is: a conformal shielding (Conformal Shielding) structure is arranged on an electronic component, and the scheme is to perform indiscriminate shielding on a passive device and an active device on a circuit board by utilizing an electromagnetic shielding structure with an electromagnetic shielding function. The passive devices may be resistors, capacitors, inductors, and the like, and the active devices are electronic elements that require a power source to perform a specific function.

For example, fig. 1 (c) shows an exploded view of a handset 1' provided with a conformal shielding structure. Fig. 1 (c) differs from fig. 1 (b) in that, as shown on the right side of fig. 1 (c), electromagnetic shielding structures, i.e., shielding layers 54', are provided on the electronic components 52-1' to 52-4 '. Specifically, the dielectric layer 53 'and the shielding layer 54' are sequentially stacked on the electronic components 52-1 'to 52-4'. It will be appreciated that the dielectric layer 53' serves to provide physical isolation between the electronic components and the shield layer 54' and to avoid shorting the shield layer 54' to the components.

Fig. 2 (a) to 2 (b) show cross-sectional views of the circuit module in which the two electronic components 52-1 'to 52-4' are located along the section A-A in fig. 1 (c).

As shown in fig. 2 (a), the circuit module 5' includes a circuit board 50', electronic components 52-1' to 52-4' provided on the circuit board 50', a dielectric layer 53', and a shielding layer 54'.

Wherein the conformal shielding (Conformal Shielding) structure formed by the shielding layer 54' can electromagnetically shield the electronic components 52-1' to 52-4 '. Specifically, a dielectric layer 53' provided on the circuit board 50' covers the electronic components 52-1' to 52-4', a shielding layer 54' is provided on the dielectric layer 53', and both ends of the shielding layer 54' are connected to two copper-exposed regions 531' on the circuit board 50 '. The upper surfaces of the electronic components 52-1' to 52-4' are at a height h1 from the upper surface of the circuit board 50', and the upper surface of the dielectric layer 53' is at a height h2 from the upper surface of the circuit board 30 '. Fig. 2 (b) differs from fig. 2 (a) in that in fig. 2 (b) the height h1 and the height h2 are equal, whereas in fig. 2 (a) the height h1 is smaller than the height h2.

However, the conformal shielding structure has the following disadvantages: only all electronic components in the conformal shielding structure (also called a shielding body) can be shielded indiscriminately, and the problem of electromagnetic interference among electronic components in the same cavity cannot be solved.

The solution to the problem of electromagnetic interference between electronic components within the same cavity in the circuit module 5' is to perform cavity-division shielding (Compartment Shielding) on the electronic components, which may be differential shielding of different electronic components in the circuit board by using an electromagnetic shielding structure with an electromagnetic shielding function. For example, an electronic component requiring electromagnetic shielding is shielded by an electromagnetic shielding structure, and an electronic component not requiring electromagnetic shielding is exposed and is not electromagnetically shielded. For example, fig. 1 (c) shows an exploded view of a mobile phone 1' provided with a split-cavity shielding structure.

Fig. 2 (c) shows a cross-sectional view of the circuit module in which the electronic components 52-1 'to 52-4' are located, taken along the section A-A in fig. 1 (c). As shown in fig. 2 (c), the electronic components 52-1' and 52-2' are electromagnetically shielded only by the electromagnetic shielding structure formed of the shielding layer 54', and the electronic components 52-3' and 52-4' are not electromagnetically shielded. Specifically, the shielding layer 54' is disposed on the circuit board 50', the electronic components 52-1' and 52-2' are disposed between the shielding layer 54' and the circuit board 50', and two ends of the shielding layer 54' are respectively connected to two copper leakage areas 531' on the circuit board 50 '.

For another example, the embodiment of the application performs the isolation between different chambers of the accommodating chamber of the electronic component through the electromagnetic shielding wall (also called as metal partition wall, cavity-separating shielding rib and the like), namely the cavity-separating shielding (compartment shielding) structure. Specifically, unlike the above-mentioned split-cavity shield, the electromagnetic shield wall partitions the electronic component accommodation chamber into at least a first chamber and a second chamber, one end of the electromagnetic shield wall is connected with the electronic shield, and the other end of the electromagnetic shield wall is connected with (a) a copper exposure area on the circuit board, (b) a grounding end of the electronic component or an electromagnetic shield layer of the electronic component. Thus, electromagnetic radiation signals generated by the electronic components of different chambers are directly conducted to the reference ground through the shielding layer, mutual interference is avoided, and the problem of electromagnetic interference between different signals sent by the electronic components of the first chamber and the electronic components of the second chamber is solved.

For example, fig. 1 (d) shows an exploded view of another mobile phone 1' provided with a split-cavity shielding structure, according to some embodiments of the present application. Fig. 2 (d) shows a cross-sectional view of the circuit module in which the electronic components 52-1 'to 52-4' are located, taken along the section A-A in fig. 1 (d). As shown in fig. 2 (d), fig. 2 (d) is different from fig. 2 (c) in that the shielding layer 54' in fig. 2 (d) includes an electromagnetic shield 541' and an electromagnetic shield wall 542', both ends of the electromagnetic shield 541' are respectively connected to copper exposing areas 531' on both sides of the circuit board 50', one end of the electromagnetic shield wall 542' is connected to the electromagnetic shield 541', and the other end of the electromagnetic shield wall 542' is connected to the copper exposing areas 531″ to divide the electronic component accommodating chamber between the shielding layer 54' and the circuit board 50' into two chambers which electromagnetically shield the electronic components 52-1' and 52-2' and the electronic components 52-3' and 52-4', respectively.

The electromagnetic shielding wall in the cavity-dividing shielding structure is used for directly transmitting electromagnetic signals in different cavities to the reference ground of the circuit board through the shielding layer, and the electromagnetic signals in different cavities cannot interfere with each other.

However, the above-mentioned cavity-dividing shielding structure has the following disadvantages: in order to set the grounding loop in the cavity-dividing shielding structure, a grounding copper pad and an avoiding area (such as a large-area copper exposing area 531 ") need to be reserved on the circuit board, and the area of the circuit board needs to be occupied. The circuit module with the electromagnetic shielding structure is further introduced to solve the technical problem that the cavity-dividing shielding structure occupies the area of the circuit board.

The embodiment of the application is different from the cavity-dividing shielding structure, in that the electromagnetic shielding wall divides the accommodating cavity of the electronic component into at least a first cavity and a second cavity, one end of the electromagnetic shielding wall is connected with the electromagnetic shielding cover, and the other end of the electromagnetic shielding wall is respectively connected with the preset part of the electronic component and the copper exposure area of the circuit board. The preset part can be a device shielding layer on a self-shielding electronic component or a grounding pin of the electronic component with the grounding pin, so that on one hand, electromagnetic signals generated by the electronic components of different chambers are directly conducted to the reference ground through grounding without mutual interference, and the problem of electromagnetic interference between different signals sent by the electronic components of the first chamber and the electronic components of the second chamber is solved. On the other hand, because the device shielding layer on the self-shielding electronic component or the grounding pin of the electronic component with the grounding pin is fully utilized, namely, the device shielding layer on the self-shielding electronic component or the grounding pin of the electronic component with the grounding pin is used as a part of the copper exposing area, the area of the circuit board occupied by the additional windowing copper exposing ground for forming the closed cavity-dividing shielding path in the cavity-dividing shielding structure is reduced, the area of the surface windowing copper exposing area of the circuit board and the avoiding distance between the surface windowing copper exposing area and peripheral devices are included, and the miniaturization of the electromagnetic shielding structure is realized.

For example, fig. 3 shows an exploded view of a mobile phone 1. The rear case 2, the frame 3 and the display screen 4 shown on the left side of fig. 3 are identical to the rear case 2', the frame 3' and the display screen 4 'shown on the left side of fig. 1 (d), and fig. 3 is different from fig. 1 (d) in that the circuit module 5 is different from the circuit module 5'. Namely, the shielding layer 54 in the circuit module 5 is respectively connected with the device shielding layer of the electronic component and the preset copper exposing area of the circuit board and extends to the reference ground, so that the area of the circuit board occupied by windowing copper exposing ground for forming a closed cavity-dividing shielding path in the cavity-dividing shielding structure is reduced. Specific exemplary structures will be described below.

For example, fig. 4 (a) shows a cross-sectional view of a circuit module where electronic components 52-1 'through 52-4' are located along section A-A on the right side of fig. 3, according to some embodiments of the present application. Fig. 4 (B) shows a cross-sectional view of a circuit module in which electronic components 52-1 'through 52-4' are located, taken along section B-B on the right side of 3 (a), according to some embodiments of the present application. Fig. 4 (C) shows a cross-sectional view of a circuit module in which electronic components 52-1 'through 52-4' are located along section C-C in the right side of 3 (a), according to some embodiments of the present application.

As shown in fig. 4 (a), the circuit module 5 includes four passive devices: the electronic components 52-1 to 52-4, wherein the electronic component 52-3 is a self-shielding device, i.e. a device shielding layer or electromagnetic shielding structure is included above the device. Dielectric layer 53 covers electronic component 52-1, electronic component 52-2, and electronic component 52-4 and surrounding areas thereof, and does not cover or partially cover the upper surface of electronic component 52-3.

The shielding layer 54 includes an electromagnetic shielding cover 541 and an electromagnetic shielding wall 542, the electromagnetic shielding wall 542 extends from the interior of the electromagnetic shielding cover 541 toward the circuit board 50, the bottom edge of the electromagnetic shielding wall 542 is disposed on the upper surface of the electronic component 52-3, and two ends of the electromagnetic shielding cover 541 are respectively connected with the copper exposing areas 502 on two sides of the circuit board 50.

As shown in fig. 4 (b), the surface layers of the circuit boards 50 on both sides of the electronic component 52-3 are provided with copper exposure areas 501, and the bottom edges of the electromagnetic shielding walls 541 are connected to the device shielding layer and the copper exposure areas 501 on the surface of the electronic component 52-3, so as to realize cavity-separated shielding and grounding.

In this way, on the one hand, the occupied area of the circuit board in the cavity-splitting shielding is lower than that of the circuit board in the prior art, for example, as shown in fig. 1 (d), in the xyz coordinate system, the positive x-axis direction is the direction from back to front of the current illustrated orientation of the circuit module 5, the positive y-axis direction is the direction from left to right of the current illustrated orientation of the circuit module 5, the positive z-axis direction is the direction from bottom to top of the current illustrated orientation of the circuit module 5, the length of the copper exposure area 531 'along the positive x-axis direction is a, the length along the positive y-axis direction is b, and the area of the additionally occupied circuit board 50' is a multiplied by b, i.e. a is b. The structure at the lower right side of fig. 3 is an enlarged view of the exposed copper area 501 and the electronic component 52-3 in the upper right side of fig. 3, and as shown in the structure at the lower right side of fig. 3, assuming that the projection area of the electromagnetic shielding wall on the xy plane is the same as the projection area of the electromagnetic shielding wall on the xy plane in fig. 1 (d), the length of the exposed copper area 501 along the positive x-axis direction is a1 plus a2, that is, a1+a2, the length along the positive y-axis direction is b, and the area of the extra occupied circuit board 50' is a1+a2 multiplied by b, that is, (a 1+a2) b is smaller than a b, so that the occupied area of the circuit board in the cavity shielding is saved.

On the other hand, since the electronic component 52-3 is a self-shielding device, the upper surface of the electronic component 52-3 includes a high-conductivity material (e.g., copper), and there may be signal coupling between the device shielding layer formed by the high-conductivity material and the electromagnetic shielding structure of the electronic component, thereby affecting the performance of the electronic component 52-3 and other devices on the entire circuit board. By connecting the shielding layer 54 with the electromagnetic shielding structure of the electronic component 52-3, the insulating gap between the electromagnetic shielding structure of the electronic component and the device shielding layer is removed, the coupling between the electromagnetic shielding structure of the electronic component and the device shielding layer is avoided, and the performance of the electronic component is prevented from being affected.

As another example, fig. 5 shows an exploded view of a mobile phone 1. As shown in the left side of fig. 5, the rear case 2, the frame 3, and the display screen 4 in fig. 5 are identical in structure to the rear case 2', the frame 3', and the display screen 4 'shown in fig. 1 (d), and fig. 5 is different from fig. 1 (d) in that the circuit modules 5 and 5' are different in structure. Fig. 6 (a) shows a cross-sectional view of a circuit module in which electronic components 52-1 'through 52-4' are located, taken along section A-A in fig. 5, according to some embodiments of the present application. Fig. 6 (B) shows a cross-sectional view of a circuit module in which electronic components 52-1 'through 52-4' are located along section B-B in fig. 5, according to some embodiments of the present application. Fig. 6 (C) shows a cross-sectional view of the circuit module in which the electronic components 52-1 'through 52-4' are located, taken along section C-C in fig. 5, according to some embodiments of the present application.

As shown in fig. 6 (a), the circuit module 5 includes four active or passive devices: electronic components 52-1 through 52-4. In the current field of view, the left Pin (Pin) of the electronic component 52-1 is the signal Pin a, and the right Pin is the ground Pin b.

A dielectric layer 53 is provided between the shielding layer 54 and the circuit board 50 to cover the portion of the electronic component 52-1 (the signal pin a and its surrounding area) other than the ground pin b, the electronic component 52-2 to the electronic component 52-4.

Both ends of the electromagnetic shielding cover 541 are respectively connected with the copper exposing areas 502 at both sides of the circuit board 50, and the electromagnetic shielding wall 541 is connected with the ground pin of the electronic component 52-1 and the copper exposing areas 501 so as to realize cavity-separated shielding and grounding.

As shown in fig. 6 (b), the dielectric layer 53 covers the electronic component 52-3, and the shield layer 54 covers the dielectric layer 53.

As shown in fig. 6 (c), the electromagnetic shielding wall 541 is connected to the ground pin of the electronic component 52-1 and the exposed copper area 501, so as to realize the shielding and grounding of the cavity.

The embodiment of the application realizes cavity-division shielding by utilizing the ground pin of the electronic component 52-1 and the exposed copper area on the circuit board in the cavity-division path, and reduces the occupied area of the cavity-division shielding ground pad.

Compared with the cavity-splitting shielding structures of fig. 2 (c) to fig. 2 (d), the area of the circuit board occupied by the open window copper-exposing grounding for forming a closed path in the cavity-splitting shielding structure is reduced by grounding through the grounding pin of the electronic component, and the miniaturization of shielding is realized by the open window copper-exposing area and the avoidance distance between the copper-exposing area and peripheral devices.

Besides the cavity-dividing shielding structure, two electromagnetic shielding walls can exist in the circuit module at the same time, one end of each electromagnetic shielding wall is connected with the electronic shielding cover, the other end of one electromagnetic shielding wall is connected with the copper exposing area on the circuit board and the grounding end of the electronic component, and the other end of the other electromagnetic shielding wall is connected with the copper exposing area on the circuit board and the electromagnetic shielding layer of the electronic component, but the electromagnetic shielding structure is not limited to the electromagnetic shielding structure.

In addition, as the diversification of the structures of electronic components in circuit boards increases and the spacing between adjacent electronic components decreases, the heat dissipation requirements for the electronic components become more and more intense. Fig. 7 (a) illustrates a schematic diagram of a structure for cavity-splitting shielding of a high heat-generating device, and fig. 7 (b) illustrates a side view of a method for patterned shielding of two adjacent high heat-generating devices, according to some embodiments of the present application.

As shown in fig. 7 (a), fig. 7 (a) differs from fig. 4 (a) in that the electronic component 52-3 is a high-heat-generating device, and for the region to be insulated, a dielectric layer 53 is covered, for example, the electronic component 52-1, the electronic component 52-2, and the region of the electronic component 52-2 not covered with the dielectric layer 53 are covered, whereas the region of the upper surface of the high-heat-generating electronic component 52-3 not including the electrode is not covered with the dielectric layer 53, and the shielding layer 54 extends and fills the region of the electronic component 52-3 not covered with the dielectric layer 53.

As shown in fig. 7 (b), for a circuit board capable of conducting heat, a heat conducting layer 80 may be added on the shielding layer 54 at the same time of performing local patterned shielding, so that heat of a high-heat-generating device in the circuit board can be further conducted, and the material of the heat conducting layer 80 may be a heat conducting material such as heat conducting silicone grease.

The application implements the improvement which is different from the cavity-dividing shielding and the cavity-sharing shielding: the cavity-divided shielding structure can be used for coating the shielding layer only without coating the dielectric layer above the high-heat-generation electronic component, so that the situation that heat dissipation is poor after shielding processing due to the fact that the insulating material is contained above the high-heat-generation electronic component is reduced. For the shielding packaging system through heat dissipation, the heat resistance can be obviously reduced by removing the dielectric layer above the electronic components and adding the heat conduction silicone grease, and the heat dissipation of the high-heat-generation device is facilitated.

In this embodiment of the present application, since the thermal conductivity of the conductive material (such as a metal system) of the shielding layer is generally higher than that of the insulating material of the dielectric layer, compared with the thermal conductivity of the insulating material covered over the electronic component, covering the conductive material and covering the conductive material over the device alone can effectively conduct the heat of the high-heat-generation device, so as to enhance the heat dissipation of the circuit board.

It will be appreciated that the structure of other structures in the terminal equipment, such as structural members, cameras, other functional devices, etc., is also becoming more and more complex, which also makes the height of the individual modules in the circuit board increasingly challenging and decreasing. Fig. 8 illustrates a side view of a circuit module with electromagnetic shielding structure in a circuit board that reduces the height of a height-limited area, according to some embodiments of the present application.

As shown in fig. 8, the circuit module 5 includes four active or passive devices: the electronic components 52-1 to 52-4, wherein the region corresponding to the electronic component 52-3 is a high-limit region. For circuit boards (electronic components 52-3) requiring height limiting, the dielectric layer 53 is discontinuous, i.e., the electronic components 52-3 requiring height limiting are not covered with the dielectric layer 53 and are directly covered with the shielding layer 54, and for ensuring shielding effectiveness, the shielding layer 54 is continuous, i.e., the shielding layer 54 is entirely covered in the height limiting region and the non-height limiting region.

It will be appreciated that in some embodiments, for the structure of fig. 8, the thickness of dielectric layer 53 over the non-highest electronic component may be the sum of the difference between the height of the highest and non-highest devices and the thickness of shield layer 54, and that the thickness of dielectric layer 53 formed of insulating material over the electronic component is typically about 50um-200um over the highest device. For the cavity-divided shielding package of fig. 8, the dielectric layer 53 is typically processed using injection molding, spraying, printing, coating, or the like.

This embodiment may reduce the height of non-highest devices in a circuit board with local height limiting requirements by removing insulating material over the height limiting areas. By reducing the height of the circuit board occupied by the area above the device, the shielding miniaturization and flexible collocation of the circuit board and other components in the terminal electronic product are realized.

The circuit module with electromagnetic shielding function in the embodiment of the present application has more schemes in terms of process implementation, and the following exemplarily describes several process flow diagrams formed by the circuit module of fig. 4 (a).

Fig. 9 (a) to 9 (e) are schematic views showing a process of forming the circuit module of fig. 4 (a) by processing the patterned shielding structure using the sacrificial layer scheme, the process comprising the steps of:

step 1: as shown in fig. 9 (a), the circuit module 5 includes a circuit board 50, and a plurality of electronic components disposed on the circuit board 50: electronic component 52-1, electronic component 52-2, electronic component 52-3, and electronic component 52-4.

Step 2: as shown in fig. 9 (b), a sacrificial material is processed on the upper surface of the electronic component 52-3 in a region where a dielectric material is not required, to form a sacrificial layer 60. The sacrificial material may be: photoresist, water-soluble glue, and the like.

Step 3: as shown in fig. 9 (c), dielectric materials are coated on the upper surfaces of the circuit board 50, the electronic component 52-1, the electronic component 52-2, the electronic component 52-3 and the electronic component 52-4 to form a dielectric layer 53.

Step 4: as shown in fig. 9 (d), the sacrificial layer 60 is removed using an etching solution, forming a groove 70 to be coated with a conductive material.

Step 5: as shown in fig. 9 (e), a conductive material is coated on the circuit board 50, the dielectric layer 53, and the groove 70 to form the shielding layer 54.

Fig. 10 (a) to 10 (d) show still another process schematic for forming the circuit module of fig. 4 (a) by laser cutting, ablating or cleaning, the process schematic comprising the steps of:

step 1: as shown in fig. 10 (a), the structure is the same as that shown in fig. 9 (a), and will not be described again.

Step 2: as shown in fig. 10 (b), dielectric layers 53 are formed by coating insulating materials on the upper surfaces of the circuit board 50, the electronic component 52-1, the electronic component 52-2, the electronic component 52-3, and the electronic component 52-4.

Step 3: as shown in fig. 10 (c), the region of the upper surface of the electronic component 52-3 where the dielectric layer is not required to be coated is subjected to removal of an insulating material by laser cutting/ablation/cleaning or the like to form a groove 70 to be coated with a conductive material.

Step 4: as shown in fig. 10 (d), the steps similar to those shown in fig. 9 (d) will not be described again.

Fig. 11 (a) to 11 (d) show still another process schematic for forming the circuit module of fig. 4 (a), the process schematic including the steps of:

step 1: as shown in fig. 11 (a), the structure is the same as that shown in fig. 9 (a), and will not be described again here.

Step 2: as shown in fig. 11 (b), the dielectric layer 53 is processed into a desired pattern, for example, a hollowed-out region is formed at a position corresponding to the exposed copper region 501 of the circuit board 50.

Step 3: as shown in fig. 11 (c), the dielectric layer 53 processed into the desired pattern in the above step 2 is laminated to the surface of the circuit board 50

Step 4: as shown in fig. 11 (d), the steps similar to those shown in fig. 9 (d) will not be described again.

In the drawings, some structural or methodological features may be shown in a particular arrangement and/or order. However, it should be understood that such a particular arrangement and/or ordering may not be required. Rather, in some embodiments, these features may be arranged in a different manner and/or order than shown in the illustrative figures. Additionally, the inclusion of structural or methodological features in a particular figure is not meant to imply that such features are required in all embodiments, and in some embodiments, may not be included or may be combined with other features.

It should be noted that in the examples and descriptions of this patent, relational terms such as first and second, and the like are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises an element.

While the present application has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present application.

Claims

1. A circuit module having an electromagnetic shielding structure, the circuit module comprising:

a circuit board;

the electronic components are arranged on the circuit board;

2. The circuit module of claim 1, wherein the ground pins of the plurality of electronic components comprise any one or more of a resistor ground pin, a capacitor ground pin, and an inductor ground pin.

3. The circuit module of claim 1, wherein the circuit board comprises at least a first partition and a second partition.

4. The circuit module of claim 1, wherein the electromagnetic shielding structure is made of a metal, an alloy or a conductive polymer material.

5. The circuit module of claim 1, further comprising a dielectric layer disposed between the electromagnetic shield structure and the circuit board.

6. The circuit module of claim 5, wherein the dielectric layer is not disposed entirely on a first electronic component of the plurality of electronic components, and wherein the electromagnetic shield structure extends and fills a portion where the dielectric layer is not disposed.

7. The circuit module of claim 6, wherein the first electronic component comprises any one or both of a first heat generating electronic component and a first height limiting electronic component.

8. The circuit module of claim 7, wherein the first heat-generating electronic component comprises any one or more of a charging module and a system-on-a-chip;

9. The circuit module of claim 1, wherein the electronic component having the electromagnetic shielding layer comprises any one or more of a radio frequency chip, a power chip, and a memory chip.

10. A terminal device, characterized in that it comprises a circuit module according to any one of claims 1 to 9.