PCB RF Module Cavity Layout for RF/DC Integration
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing RF circuit modules require multiple cavities to accommodate RF and DC connections, increasing cost and complexity, while maintaining thermal performance and allowing for die-level rework in high-value assemblies.
Innovation Solution
A design with a conductive layer patterned on the surface for microwave transmission lines, incorporating a ground plane board and shielding layer, and a component supporting board with BGA connections, reducing the number of cavities needed to two (one for the RF component and one for RF and DC connections) and utilizing the z-dimension to minimize the x-y footprint, thereby reducing costs and maintaining thermal performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple cavities are used to accommodate RF and DC connections, then thermal performance is maintained and die-level rework is enabled, but manufacturing cost and device complexity increase
Solution Approach 1:
The patent combines RF and DC connection functions into a single cavity structure. The circuit board is configured with a first cavity that accommodates both RF connectors and DC power connections, eliminating the need for separate cavities for each function. This merging reduces the total number of cavities while maintaining all necessary connection pathways and thermal performance characteristics.
Solution Approach 2:
The single cavity structure serves multiple functions simultaneously: it provides mechanical support for both RF and DC connections, enables thermal management for the RF component, and allows die-level rework capability. The cavity is designed with multi-functional characteristics that accommodate different types of connectors and connection methods within the same structural space.
2Object-affected harmful factors
If multiple cavities are used to accommodate RF and DC connections, then proper shielding and transmission line configuration are achieved, but manufacturing cost increases
Solution Approach 1:
The patent merges shielding functions into the single cavity structure, where the cavity walls and circuit board layers provide electromagnetic shielding for both RF and DC connections simultaneously. This eliminates the need for separate shielding structures that would be required if multiple cavities were used, thereby reducing manufacturing cost while maintaining shielding effectiveness.
Solution Approach 2:
The circuit board employs composite material construction with multiple layers including ground planes, signal layers, and dielectric materials that provide both mechanical support and electromagnetic shielding. The combination of conductive ground planes and insulating dielectric layers creates effective shielding within the single cavity structure without requiring additional separate shielding components.
3Ease of manufacture
If the x-y footprint is minimized by utilizing the z-dimension, then manufacturing cost is reduced, but thermal performance may be compromised
Solution Approach 1:
The patent utilizes the z-dimension (vertical dimension) to minimize the x-y footprint by stacking RF and DC connections vertically within the single cavity. The circuit board is configured with layers arranged in the z-direction, allowing compact packaging while maintaining adequate thermal pathways. The RF component is positioned to optimize thermal conduction to the ground plane and heat sink structures in the vertical direction.
Solution Approach 2:
The patent introduces thermal interface materials and conductive pathways as intermediaries between the RF component and the ground plane/heat sink structures. These intermediary elements ensure efficient thermal transfer from the RF component through the circuit board layers to the external heat dissipation structures, maintaining thermal performance despite the compact z-dimensional stacking arrangement.
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
This configuration reduces the overall cost by minimizing the x-y footprint, allows for die-level rework, and maintains thermal performance without dielectric loading issues, while providing effective shielding and easy connection through BGA, making all components low-cost and efficient.
Implementation Method 1
a conductive layer patterned on the surface to provide portions of microwave transmission lines for coupling RF energy to, and from, the RF component
Implementation Method 2
incorporating a ground plane board and shielding layer
Implementation Method 3
mounted to a heat spreader and bonded to the cold plate with a suitable conductive epoxy
Data Source
Figure 1
Figure 2
Figure 2A
AI summary
An RF circuit module having RF and DC contacts on a surface of a circuit board. An RF component having RF and DC contacts is disposed in a cavity of the circuit board. Electrical connectors bridge the cavity to connect the RF contacts on the circuit board to the RF contacts on the RF component and the DC contacts on the circuit board to the DC contacts on the RF component. A plug member is disposed in the cavity which has a dielectric member with an outer portion disposed over the RF and DC contacts on the circuit board and an inner portion elevated above the RF and DC contacts. The plug member has one portion of electrical conductors disposed on an upper surface of the inner portion and another portion disposed under the outer portion on, and electrically connected to, the DC contacts on the circuit board.