CN111867238A

CN111867238A - Printed circuit board assembly and electronic device

Info

Publication number: CN111867238A
Application number: CN202010872781.9A
Authority: CN
Inventors: 江超
Original assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Current assignee: Guangdong Oppo Mobile Telecommunications Corp Ltd
Priority date: 2020-08-26
Filing date: 2020-08-26
Publication date: 2020-10-30

Abstract

The present disclosure relates to a printed circuit board assembly and an electronic device, the printed circuit board assembly including: the shielding cover is arranged on one side of the circuit board and forms an accommodating cavity with the circuit board in a surrounding manner; the shielding cover comprises a shielding layer, a first insulating layer and a second insulating layer, wherein the first insulating layer is arranged on one side of the shielding layer, the first insulating layer deviates from at least one group of conducting layers and the second insulating layer on one side of the shielding layer, the second insulating layer is arranged on one side of the conducting layers deviating from the first insulating layer, and the conducting layers are electrically connected with the circuit board. The printed circuit board assembly provided by the disclosure can reduce the number of layers of the printed circuit board, reduce the thickness of the printed circuit board and save the manufacturing cost of the printed circuit board.

Description

Printed circuit board assembly and electronic device

Technical Field

The present disclosure relates to the technical field of electronic devices, and particularly to a printed circuit board assembly and an electronic device.

Background

A Printed Circuit Board (PCB) is an important electronic component, is a support for an electronic component, and is a carrier for electrical connection of the electronic component. With the increasing integration of mobile phones, designers have pursued larger battery space and smaller motherboard area while reducing the size of mobile phones, wherein controlling the occupied thickness of the PCB becomes one of the key factors in the design of electronic devices such as mobile phones.

In the prior art, under the condition that devices are very dense on a PCB, in order to complete the electrical communication of each device as required, a higher layer number needs to be used, so that the manufacturing cost of the PCB is greatly improved, and the plate thickness is increased due to the improvement of the layer number of the PCB, which is inconsistent with the increasingly light and thin background of a product, so that the user experience is influenced, and the market competitiveness of the product is seriously reduced.

It is to be noted that the information disclosed in the above background section is only for enhancement of understanding of the background of the present disclosure, and thus may include information that does not constitute prior art known to those of ordinary skill in the art.

Disclosure of Invention

An object of the present disclosure is to provide a printed circuit board assembly and an electronic device, which can reduce the number of layers of a printed circuit board, reduce the thickness of the printed circuit board, and save the manufacturing cost of the printed circuit board.

According to an aspect of the present disclosure, there is provided a printed circuit board assembly including:

a circuit board;

the shielding cover is arranged on one side of the circuit board and forms an accommodating cavity with the circuit board in an enclosing way; wherein,

the shielding cover comprises a shielding layer, a first insulating layer and a second insulating layer, wherein the first insulating layer is arranged on one side of the shielding layer, the first insulating layer deviates from at least one group of conducting layers and the second insulating layer on one side of the shielding layer, the second insulating layer is arranged on one side of the conducting layer deviating from the first insulating layer, and the conducting layers are electrically connected with the circuit board.

According to the printed circuit board assembly, the shielding cover and the circuit board are enclosed to form the accommodating cavity, the cavity is used for accommodating elements arranged on the circuit board, the shielding cover is provided with the shielding layer and can play a shielding role on the elements arranged in the accommodating cavity, the shielding cover further comprises at least one group of conducting layers and a second insulating layer, and partial routing on the circuit board can be transferred to the shielding cover through the conducting layers arranged on the shielding cover and electrically connected with the circuit board so as to share routing pressure on the circuit board, so that the number of layers of the circuit board can be relatively reduced; therefore, the printed circuit board assembly provided by the disclosure can reduce the number of layers of the printed circuit board on the premise that the shielding cover ensures the shielding effect, reduce the thickness of the printed circuit board and save the manufacturing cost of the printed circuit board.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosure.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and together with the description, serve to explain the principles of the disclosure. It is to be understood that the drawings in the following description are merely exemplary of the disclosure, and that other drawings may be derived from those drawings by one of ordinary skill in the art without the exercise of inventive faculty.

Fig. 1 is a schematic diagram of a factor circuit board assembly provided by an embodiment of the present disclosure;

FIG. 2 is an enlarged view of a portion of FIG. 1;

fig. 3 is a schematic diagram of a factor circuit board assembly provided by another embodiment of the present disclosure;

fig. 4 is a schematic structural diagram of an electronic device according to an embodiment of the present disclosure.

Detailed Description

Example embodiments will now be described more fully with reference to the accompanying drawings. Example embodiments may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the concept of example embodiments to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and thus their detailed description will be omitted.

Although relative terms, such as "upper" and "lower," may be used in this specification to describe one element of an icon relative to another, these terms are used in this specification for convenience only, e.g., in accordance with the orientation of the examples described in the figures. It will be appreciated that if the device of the icon were turned upside down, the element described as "upper" would become the element "lower". When a structure is "on" another structure, it may mean that the structure is integrally formed with the other structure, or that the structure is "directly" disposed on the other structure, or that the structure is "indirectly" disposed on the other structure via another structure.

The terms "a," "an," "the," "said," and "at least one" are used to indicate the presence of one or more elements; the terms "comprising" and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements; the terms "first," "second," and the like are used merely as labels, and are not limiting on the number of their objects.

The inventors have found that the connection of the inner boards of a multilayer printed circuit board to the inner board is typically achieved by making inner layer metallization holes in the inner board. Specifically, according to the conventional blind via hole burying manufacturing process, two or more inner layer boards to be connected are generally pressed, then through holes are drilled in the inner layer boards, then electroplating is carried out to form inner layer metalized holes, the inner layer boards are connected with the inner layer boards, then an upper outer layer board and a lower outer layer board are pressed above and below the inner layer boards, and the multilayer PCB board with the conductive blind via holes is manufactured.

However, the conventional buried blind hole manufacturing process needs secondary pressing, and when the number of layers of the multilayer PCB is large, the production efficiency is low. In addition, the inlayer blind hole is processed before the pressfitting promptly, because the processing of blind hole needs through heavy copper and electroplating process, and it must lead to the breathing of inner plating, when the number of piles of multilayer PCB board is more, leads to this kind of phenomenon more serious to the in-process counterpoint degree of difficulty that leads to follow-up pressfitting and outer circuit to process promotes, has improved the manufacturing cost of PCB board.

The disclosed embodiments provide a Printed Circuit Board Assembly (PCBA), as shown in fig. 1, including: a Printed Circuit Board (PCB) 10 and a shielding cover 20, wherein the shielding cover 20 is disposed on one side of the PCB 10 and encloses an accommodating cavity with the PCB 10; the shielding cover 20 includes a shielding layer 210, a first insulating layer 220 disposed on one side of the shielding layer 210, and at least one set of a conductive layer 230 and a second insulating layer 240 disposed on one side of the first insulating layer 220 away from the shielding layer 210, the second insulating layer 240 is disposed on one side of the conductive layer 230 away from the first insulating layer 220, and the conductive layer 230 is electrically connected to the circuit board 10. The PCB is soldered and assembled with electronic components by mounting the PCB on a SMT (surface mount Technology) board and then performing DIP (dual inline-pin package) assembly.

According to the printed circuit board assembly provided by the present disclosure, the shielding cover 20 and the circuit board 10 enclose a containing cavity, the cavity is used for containing components arranged on the circuit board 10, the shielding cover 20 has the shielding layer 210, and can shield the components arranged in the containing cavity, the shielding cover 20 further includes at least one group of conductive layer 230 and a second insulating layer 240, through the conductive layer 230 arranged on the shielding cover 20, and the conductive layer 230 is electrically connected with the circuit board 10, part of routing on the circuit board 10 can be transferred onto the shielding cover 20 to share routing pressure on the circuit board, so that the number of layers of the circuit board 10 can be relatively reduced; therefore, the printed circuit board assembly provided by the present disclosure can reduce the number of layers of the circuit board 10, reduce the thickness of the circuit board 10, and save the manufacturing cost of the circuit board 10 on the premise that the shielding cover 20 ensures the shielding effect thereof.

In addition, utilize the ascending space of printed circuit board assembly thickness direction, transfer the partial line of circuit board 10 to shielding lid 20 on, utilize shielding lid 20 to walk the line, can reduce printed circuit board assembly's whole thickness to can make the thickness of adopting the printed circuit board assembly's that this disclosure provided electronic equipment do thinner relatively, with the market competition who improves the product.

Specifically, the shield cover 20 further includes: a third insulating layer disposed on a side of the shielding layer 210 away from the first insulating layer 220, and at least one conductive layer and a second insulating layer disposed on a side of the third insulating layer away from the shielding layer 210. At least one group of conducting layers and second insulating layers are also formed on the side, away from the first insulating layer 220, of the shielding layer 210, so that the shielding cover 20 forms a double-sided board, more conducting layers can be formed on the shielding cover 20, more wires on the circuit board 10 are transferred to the shielding cover 20, more wire pressure on the circuit board is shared, and the number of layers of the circuit board 10 can be further relatively reduced.

As shown in fig. 1, the first insulating layer 220 is disposed on a side of the shielding layer 210 close to the circuit board 10. At this time, the shielding cover 20 forms a single panel, and at least one group of the conductive layer 230 and the second insulating layer 240 are formed only on one side of the shielding layer 210 close to the circuit board 10, so that the at least one group of the conductive layer 230 and the second insulating layer 240 are located in the accommodating cavity, and the overall thickness of the printed circuit board assembly can be reduced under the condition that the routing pressure on the circuit board is shared as much as possible and the number of layers of the circuit board 10 is relatively reduced. Of course, when the shielding cover 20 forms a single panel, at least one set of the conductive layer 230 and the second insulating layer 240 may also be disposed on a side of the shielding layer 210 facing away from the circuit board 10, which is not limited in this disclosure.

The at least one conductive layer 230 and the second insulating layer 240 may be one, two, three or more, which are not listed herein, and those skilled in the art can design the conductive layer according to actual needs, and the disclosure is not limited thereto. It should be noted that, when more conductive layers 230 and second insulating layers 240 are disposed, the routing pressure on the circuit board can be shared more, and the number of layers of the circuit board 10 is relatively reduced more.

Specifically, the printed circuit board assembly further includes: at least one first element 30 is disposed on the circuit board 10 and located in the cavity. As shown in fig. 1, three first components 30 are disposed on the circuit board 10, and the three first components 30 are spaced apart on the circuit board 10.

Specifically, the printed circuit board assembly further includes: at least one second element 40 is disposed on the shielding cover 20 and located in the cavity. As shown in fig. 3, two first components 30 are disposed on the circuit board 10, and the two first components 30 are spaced apart on the circuit board 10.

Wherein, the orthographic projections of the first element 30 and the second element 40 on the circuit board 10 have no overlapping part. By making the orthographic projections of the first element 30 and the second element 40 on the circuit board 10 have no overlapping part, namely the first element 30 and the second element 40 are completely arranged in a staggered manner, the height space of the printed circuit board assembly can be better utilized, the space utilization rate of the accommodating cavity is improved, and the increase of the overall height of the printed circuit board 10 is avoided under the condition that more elements are arranged.

Specifically, the orthographic projections of the first elements 30 and the second elements 40 on the circuit board 10 are alternately arranged. By alternating the orthographic projection of the first elements 30 and the orthographic projection of the second elements 40 on the circuit board 10, that is, alternating the positions of the first elements 30 and the second elements 40, it is possible to ensure that there is sufficient clearance between the elements on the circuit board 10 or the shield cover 20, while enabling more elements to be disposed.

The materials of the first insulating layer 220, the second insulating layer 240 and the third insulating layer include: phenolic paper laminates, epoxy paper laminates, polyester glass mat laminates, epoxy glass cloth laminates, polyester films, polyimide films, fluorinated ethylene propylene films, and the like; the material of the conductive layer 230 includes: copper, iron, aluminum, or alloys thereof; the shielding layer 210 may be formed of a metal material, such as copper, iron, aluminum, or an alloy thereof.

Specifically, the shield cover 20 is a copper-based circuit board including a copper substrate forming the shield layer 210, a first insulating layer 220, and at least one set of conductive layers 230. The copper-based circuit board is used as the shielding cover 20, the copper substrate can play a good shielding role, and the conducting layer 230 of the copper-based circuit board can share the wiring pressure on the circuit board, so that the number of layers of the circuit board 10 can be relatively reduced. The conductive layer 230 of the copper-based circuit board is made of copper.

Electronic equipment, such as a mobile phone and a tablet computer, has a plurality of frequency bands of related working signals, such as WiFi, bluetooth signals, GPS (Global Positioning System) signals, beidou signals, GPRS (General packet radio Service )/WCDMA (Wideband Code Division multiple access) signals, and inevitably has mutual interference of electromagnetic waves, which affects normal operation of the equipment; meanwhile, electromagnetic waves are radiated to the outside, and the battery radiation safety threat of a user is caused.

The copper substrate of the copper-based circuit board has a good shielding effect, the problems can be effectively solved by using the copper-based circuit board, the copper-based circuit board has the effects of preventing external space radiation and static discharge from interfering a Central Processing Unit (CPU), and the copper-based circuit board has the other effect of inhibiting the circuit from radiating outwards. The types of the shielding cover mainly include a detachable shielding cover and an integrated shielding cover, wherein the detachable shielding cover mainly consists of a shielding frame and a copper-based circuit board. The shielding frame is provided with welding pins which are welded with corresponding welding pads on the circuit board to play a role of a framework of the copper-based circuit board, and the copper-based circuit board covers the shielding frame to play a shielding role.

Wherein, the pad generally sets up the components and parts installation face at PCB, and the pad generally need guarantee 0.7 mm's distance to the flange limit, and the pad width also need guarantee 0.6mm, and the pin of shielding frame will be in the same place with the pad welding.

In addition, the shield cover 20 may also be an aluminum-based circuit board, the shield layer may be formed of an aluminum substrate, and the conductive layer may also be formed of an aluminum material; alternatively, the shield cover 20 may also be an iron substrate, and the shield layer may be formed of the iron substrate; the present disclosure is not so limited.

As shown in fig. 2, the conductive layer 230 is electrically connected to the circuit board 10 through a pad 250. Each of the conductive layers 230 is electrically connected to the circuit board 10 through a pad 250, and the connection strength between the conductive layer 230 and the circuit board 10 can be improved through the pad 250, so as to improve the stability and reliability of the printed circuit board assembly.

Specifically, the shield cover 20 includes a bent portion having a bending radius greater than or equal to three times the thickness of the shield cover 20. As shown in fig. 1, both sides of the shielding cover 20 are respectively in an S shape, and include two bending portions, and a bending radius of the bending portions is greater than or equal to three times of the thickness of the shielding cover 20, so as to avoid a situation that the conductive layer 230 in the shielding cover 20 is broken, and improve the stability and reliability of the printed circuit board assembly. Of course, the bending radius of the bent portion may also be less than three times the thickness of the shielding cover 20, which is not limited by the present disclosure.

The shielding cover 20 may be circular, rectangular, trapezoidal, oval or irregular in shape, the middle of the whole is convex, and the sides around are fixedly connected with the circuit board to form a containing cavity.

The shielding cover 20 and the circuit board 10 may be fixedly connected by welding, bonding, clamping or using an intermediate connector, for example, the shielding bracket and the shielding cover are used together, and the side of the shielding cover is provided with a spring structure with a bump by punching holes on the side of the shielding bracket. The shield bracket is soldered to the circuit board by SMT (Surface Mounted Technology), and then the shield cover is manually fastened to the shield bracket. The present disclosure is not limited thereto, and all changes related to the connection mode between the shielding cover and the circuit board belong to the protection scope of the present disclosure.

The thickness of the shielding cover 20 is 0.3mm to 0.6mm, such as 0.3mm, 0.4mm, 0.5mm, 0.6mm, etc., which is not specifically listed here, and of course, the thickness of the shielding cover 20 may also be less than 0.3mm or greater than 0.6mm, which is not limited by this disclosure. In addition, the dimensions of the shield cover in the width and length directions may be determined according to the actual circuit board to be shielded, and are not limited herein.

The present disclosure also provides an electronic device including the printed circuit board assembly described above. For the advantages of the electronic device, please refer to the above discussion about the advantages of the pcb assembly, which is not repeated herein. The electronic device may be, for example, a mobile phone, a tablet computer, a notebook computer, a monitor, an electronic watch, etc., which are not listed here.

Illustratively, as shown in fig. 4, the electronic device includes a camera assembly 510, a bezel 520, the aforementioned printed circuit board assembly 530, a battery 540, a rear cover 550, and a display screen 560. The following description of the embodiments of the present disclosure will take an electronic device as an example.

Center frame 520 may include a frame that encloses a closed loop structure and a connecting plate that is located inside the loop structure, to which camera head assembly 510 may be connected. Of course, in practical applications, the camera may also be connected to a front board or a rear cover of the electronic device, and this is not particularly limited in the embodiments of the present disclosure. The printed circuit board assembly 530 is provided with a processing module, and the image sensor and the processing module in the camera assembly 510 are connected, for example, the image sensor and the processing module may be connected through a circuit board.

The display 560, the middle frame 520 and the rear cover 550 form a receiving space for receiving other electronic components or functional modules of the electronic device. Meanwhile, the display screen 560 forms a display surface of the electronic device for displaying information such as images, texts, and the like. The Display 560 may be a Liquid Crystal Display (LCD) or an Organic Light-Emitting Diode (OLED) Display.

A glass cover may be provided over the display screen 560. The glass cover plate may cover the display screen 560 to protect the display screen 560 and prevent the display screen 560 from being scratched or damaged by water.

The display screen 560 may include a display area as well as a non-display area. Wherein the display area performs the display function of the display screen 560 for displaying information such as images, text, etc. The non-display area does not display information. The non-display area can be used for arranging functional modules such as a camera, a receiver, a proximity sensor and the like. In some embodiments, the non-display area may include at least one area located at an upper portion and a lower portion of the display area.

Display screen 560 may be a full-face screen. At this time, the display screen 560 may display information in full screen, so that the electronic device has a larger screen occupation ratio. The display screen 560 includes only a display area and does not include a non-display area.

The middle frame 520 may be a hollow frame structure. The material of the middle frame 520 may include metal or plastic. The printed circuit board assembly 530 is mounted inside the receiving space. For example, the printed circuit board assembly 530 may be mounted on the middle frame 520 and received in the receiving space together with the middle frame 520. A ground point is provided on the printed circuit board assembly 530 to achieve grounding of the printed circuit board assembly 530.

One or more of the functional modules such as a motor, a microphone, a speaker, a receiver, an earphone interface, a universal serial bus interface (USB interface), a sensing module, a gyroscope, and a processor may be integrated on the pcb assembly 530. Meanwhile, the display screen 560 may be electrically connected to the printed circuit board assembly 530.

Wherein, the sensor module can include degree of depth sensor, pressure sensor, gyroscope sensor, baroceptor, magnetic sensor, acceleration sensor, distance sensor, be close optical sensor, fingerprint sensor, temperature sensor, touch sensor, ambient light sensor and bone conduction sensor etc.. The Processor may include an Application Processor (AP), a modem Processor, a Graphics Processing Unit (GPU), an Image Signal Processor (ISP), a controller, a video codec, a Digital Signal Processor (DSP), a baseband Processor, and/or a Neural Network Processor (NPU), and the like. The different processing units may be separate devices or may be integrated into one or more processors.

A display control circuit is also provided on the printed circuit board assembly 530. The display control circuit outputs an electrical signal to the display screen 560 to control the display screen 560 to display information. The light emitting control unit and the color change control unit may be provided on the main board.

The battery 540 is mounted inside the receiving space. For example, the battery 540 may be mounted on the middle frame 520 and received in the receiving space together with the middle frame 520. The battery 540 may be electrically connected to the printed circuit board assembly 530 to enable the battery 540 to power the electronic device. The printed circuit board assembly 530 may be provided thereon with a power management circuit. The power management circuit is used to distribute the voltage provided by the battery 540 to the various electronic components in the electronic device.

The back cover 550 is used to form an outer contour of the electronic device. The rear cover 550 may be integrally formed. In the molding process of the back cover 550, structures such as a rear camera hole, a fingerprint recognition module mounting hole, etc. may be formed on the back cover 550. The light emitting element may be provided in a housing, a printed circuit board assembly (main board), a middle frame, or the like in the rear cover 550.

Other embodiments of the disclosure will be apparent to those skilled in the art from consideration of the specification and practice of the disclosure disclosed herein. This application is intended to cover any variations, uses, or adaptations of the disclosure following, in general, the principles of the disclosure and including such departures from the present disclosure as come within known or customary practice within the art to which the disclosure pertains. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the disclosure being indicated by the following claims.

Claims

1. A printed circuit board assembly, comprising:

a circuit board;

2. The printed circuit board assembly of claim 1, wherein the first insulating layer is disposed on a side of the shielding layer adjacent to the circuit board.

3. The printed circuit board assembly of claim 1, wherein the shield cover further comprises: the third insulating layer is arranged on one side, away from the first insulating layer, of the shielding layer, and the conducting layer and the second insulating layer are arranged on one side, away from the shielding layer, of the third insulating layer.

4. The printed circuit board assembly of claim 1, further comprising:

the at least one first element is arranged on the circuit board and is positioned in the cavity;

at least one second element is arranged on the shielding cover and positioned in the cavity.

5. The printed circuit board assembly of claim 4, wherein an orthographic projection of the first element and the second element on the circuit board has no overlapping portion.

6. A printed circuit board assembly according to claim 5, wherein the orthographic projections of the first and second elements on the circuit board alternate.

7. The printed circuit board assembly of claim 1, wherein the shield cover is a copper-based circuit board comprising a copper substrate, the first insulating layer, and at least one of the conductive layer and the second insulating layer, the copper substrate forming the shield layer.

8. The printed circuit board assembly of claim 1, wherein the conductive layer is electrically connected to the circuit board by a pad.

9. The printed circuit board assembly of claim 1, wherein the shielding cover comprises a bend having a bend radius greater than or equal to three times the thickness of the shielding cover.

10. An electronic device comprising the printed circuit board assembly of any one of claims 1-9.