Embedded Circuit Package Shielding With Ground-Coupled Conductive Layer
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing leadless package technologies do not provide adequate electromagnetic interference (EMI) shielding for circuit elements, particularly in challenging automotive applications.
Innovation Solution
A conductive layer is applied to cover the side of the packaged circuit system exposed to external EM fields, forming a connection path through an embedding bulk material to couple with the signal ground potential, effectively shielding embedded circuit elements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional leadless package technologies are used, then manufacturing processes are streamlined and package size is reduced, but adequate EMI shielding for circuit elements is not provided
Solution Approach 1:
The patent implements EMI shielding by nesting a conductive shield layer within the packaging structure, specifically forming the shield between the circuit element and the external environment. The shield is integrated into the packaging material layers, creating a nested configuration where the conductive shield is surrounded by dielectric layers, effectively shielding the circuit element without adding external shielding structures.
Solution Approach 2:
The patent introduces a conductive shield layer as an intermediary element between the circuit element and external electromagnetic fields. This shield layer acts as a mediator that intercepts and redirects EM fields, preventing direct interaction between external fields and the circuit element. The shield is connected to ground potential through the packaging structure, creating an effective EMI barrier.
2Object-affected harmful factors
If metal layers are added to each side of assembled MEMS and IC dies for shielding, then EMI protection is achieved, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The patent merges the EMI shielding function with the existing packaging structure by integrating the conductive shield layer into the packaging material layers. Instead of adding separate shielding structures on both sides of the circuit element, the shield is combined with the packaging material itself, reducing the number of discrete components and simplifying the overall device structure.
Solution Approach 2:
The packaging material layers serve multiple functions: they provide mechanical support, environmental protection, and EMI shielding. The dielectric layers surrounding the conductive shield not only insulate the shield but also contribute to the structural integrity of the package, eliminating the need for separate shielding housings or additional protective layers.
3Object-affected harmful factors
If lead frame and grounded lid are used in pre-molded plastic packages for shielding, then EMI protection is provided, but package size and manufacturing complexity increase
Solution Approach 1:
The patent extracts the essential EMI shielding function from the traditional lead frame and grounded lid structure. Instead of using a full lead frame assembly with external grounded lids, the invention implements a simplified shield layer integrated directly into the packaging material, removing unnecessary structural components while retaining the core shielding capability.
Solution Approach 2:
The patent uses thin conductive shield layers integrated within the packaging material instead of rigid lead frames and thick grounded lids. The conductive shield is formed as a thin layer within the dielectric packaging material, providing effective EMI protection while minimizing the package volume and eliminating the need for bulky traditional shielding structures.
4Object-affected harmful factors
If inverted die-pad with metallization on PWB is used in over-molded plastic packages, then shielding is achieved, but manufacturing precision and assembly difficulty increase
Solution Approach 1:
The patent implements EMI shielding as a preliminary action during the packaging material layer formation process, before final assembly. The conductive shield layer is formed and integrated into the packaging structure during manufacturing, eliminating the need for subsequent assembly steps to install separate shielding components. This preliminary integration reduces assembly precision requirements and simplifies the manufacturing process.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The conductive layer maintains the signal ground potential, reducing the impact of external EM fields on circuit elements, particularly MEMS dies, by minimizing capacitive coupling and resonance effects.
Implementation Method 1
a side normally exposed to external EM fields is at least partially covered with a conductive layer, and an embedded integrated circuit die is arranged to form a connection path through an embedding bulk material, and thereby couple the conductive layer and a signal ground potential
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A packaged circuit system structure with circuit elements embedded into a bulk material. At least one of the embedded circuit elements forms a dual coupling that includes an electrical connection to a signal ground potential on one side of the structure and an electrical connection to a conductive layer on the other side of the structure. The conductive layer extends over at least one embedded circuit element that does not form a dual coupling, and thereby provides an effective EMI shielding for it.