Stacked Semiconductor Package RF Shielding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing semiconductor packages with side-by-side compartmental shielding solutions require additional space, increasing the footprint and necessitating a method to reduce this footprint while maintaining effective RF shielding.
Innovation Solution
A semiconductor device design featuring a first and second substrate with metal traces, where electronic components are attached and encapsulated with a mold compound, and a conductive coating is applied to exposed metal layers on the substrates to form an RF shield, reducing the overall footprint.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If side by side compartmental shielding solution is used, then RF shielding effectiveness is improved, but package footprint area increases
Solution Approach 1:
The patent transitions from a planar side-by-side shielding layout to a three-dimensional stacked configuration. Multiple substrates are vertically stacked with RF shields positioned between them, utilizing the vertical dimension (Z-axis) to achieve compartmental shielding. This dimensional change allows shielding functionality to be maintained while significantly reducing the horizontal footprint area.
Solution Approach 2:
The patent implements nested shielding structures where RF shields are positioned within and between stacked substrates. The shields are integrated into the vertical stack, with each substrate containing or being surrounded by shielding elements. This nesting approach allows multiple shielding compartments to be compactly arranged in three-dimensional space, reducing the overall package footprint while maintaining effective RF isolation.
2Reliability
If embedded shields are used, then compartmental shielding is achieved, but manufacturing complexity increases
Solution Approach 1:
The patent combines multiple functions into integrated structures. The RF shields are formed using the same metal trace layers and interconnect structures that are already part of the substrate design. By merging the shielding function with existing signal and power distribution networks, the patent avoids adding separate embedded shield components, thereby reducing manufacturing complexity while achieving effective compartmental shielding.
3Reliability
If metal cans with compartmental features are used, then RF shielding is improved, but package volume increases
Solution Approach 1:
The patent replaces traditional horizontal metal can shielding with a vertical stacking architecture. Instead of expanding the package footprint horizontally to accommodate compartmental shields, the solution stacks substrates vertically with integrated shields between them. This dimensional reorganization maintains comprehensive RF shielding coverage while minimizing the horizontal volume footprint.
Solution Approach 2:
The patent uses thin metal trace layers and conductive films formed on substrate surfaces as RF shields, replacing bulky metal can structures. These thin-film shielding layers are deposited or patterned directly onto the substrate surfaces, providing effective RF shielding with minimal thickness and volume occupation, thereby reducing overall package volume.
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 solution effectively minimizes the footprint of semiconductor packages by creating a compartmental RF shield that reduces electromagnetic interference, preventing external RF radiation from interfering with internal components while maintaining efficient electrical connections.
Implementation Method 1
A conductive coating is applied to the mold compound and to the at least one metal layer exposed on at least one side surface of the first substrate and second substrate
Data Source
AI summary
A semiconductor device has a first substrate having a plurality of metal traces. At least one electronic component is electrically attached to a first surface of the first substrate. A second substrate has a plurality of metal traces and attached to the first substrate. At least one electronic component is electrically attached to a first surface of the second substrate. An RF shield is formed on the first substrate to minimizing Electro-Magnetic Interference (EMI) radiation and Radio Frequency (RF) radiation to the at least one electronic component on the first substrate to form an RF shield. A mold compound is used for encapsulating the semiconductor device.