3D Layered PCB Assembly with Cavity for EMI Shielding
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Solution Overview
Problem
There is a need to reduce the thickness of printed circuit board (PCB) assemblies in mobile terminals to achieve a slimmer profile, while maximizing space for embedding electronic components.
Innovation Solution
A high-density PCB assembly is designed with a main printed circuit board, a body printed circuit board having a cavity, and a cover printed circuit board, where electronic components are mounted in a layered configuration to minimize space and provide electromagnetic interference (EMI) shielding, allowing for the integration of more components within a thinner profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If electronic components are mounted on both sides of a single PCB, then component integration is improved, but EMI shielding becomes problematic and space utilization is limited
Solution Approach 1:
The PCB assembly is segmented into three separate boards (main PCB, body PCB with cavity, and cover PCB), allowing electronic components to be distributed across multiple isolated surfaces while maintaining EMI shielding through the cavity structure and ground layers on each board
Solution Approach 2:
The body PCB with its cavity structure acts as a container that holds the main PCB and cover PCB in a nested arrangement, creating a layered configuration where ground layers and cavities provide EMI shielding between component layers
2Object-affected harmful factors
If additional EMI shielding structures are added, then electromagnetic interference protection is improved, but PCB assembly thickness increases
Solution Approach 1:
The ground layers on each PCB serve dual functions: providing electrical grounding for components and acting as EMI shielding barriers, eliminating the need for separate shielding structures that would increase thickness
Solution Approach 2:
The cavity in the body PCB creates a nested structure that provides EMI shielding volume without adding external thickness, as the shielding is formed by the cavity walls and ground layers within the existing PCB footprint
3Length of stationary object
If PCB assembly thickness is reduced, then mobile terminal slimness is improved, but space for electronic components becomes limited
Solution Approach 1:
The design transitions from a single-plane component arrangement to a three-dimensional layered configuration with three PCBs stacked vertically, utilizing the thickness dimension to accommodate more components while maintaining overall assembly slimness
Solution Approach 2:
The nested arrangement of three PCBs with the cavity structure maximizes space utilization within the limited thickness, allowing components to be positioned on multiple surfaces and within the cavity volume
Data Source
AI summary
A printed circuit board (PCB) assembly includes a main PCB, a body PCB and a cover PCB. The main PCB has a first electronic component mounted thereon. The body PCB is mounted on the main PCB and includes a cavity therethrough. The first electronic component is positioned within the cavity when the body PCB is mounted on the main PCB. The cover PCB is aligned and mounted on the body PCB to cover the cavity. The cover PCB has a second electronic component mounted on a surface thereof. When the cover PCB is mounted on the body PCB, the second electronic component is positioned within the cavity and faces the main PCB. A method of fabricating the PCB assembly and a mobile terminal including the PCB assembly are also provided.