Intrinsically Safe Circuit Board Arrangement with Frame Encapsulation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing portable electronic devices, such as two-way radios, face challenges in maintaining size efficiency while ensuring intrinsic safety in hazardous environments with volatile components, as conventional encapsulation methods consume space and require additional protection circuits.
Innovation Solution
A circuit board arrangement with a frame structure between two circuit boards, where an encapsulant material is injected to fill the space and cure, providing thermal insulation and preventing gas contact, thus eliminating the need for additional protection circuits and allowing for a compact design.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional encapsulation techniques are used (spraying or dipping encapsulant material onto circuit boards), then circuit components are protected from fault conditions and gas contact, but the device consumes considerable space and requires additional protection on connections between circuit boards
Solution Approach 1:
The patent merges the encapsulation of multiple circuit boards into a single unified encapsulant material layer that covers all circuit boards and their interconnections simultaneously. This eliminates the need for separate encapsulation of each board and connector, reducing total space consumption while maintaining protection reliability.
Solution Approach 2:
The encapsulant material serves multiple functions simultaneously: it protects circuit components from fault conditions, prevents gas contact with all circuit boards, and protects all connections between circuit boards. This multi-functionality eliminates the need for separate protection mechanisms for each concern.
2Reliability
If redundant limiting circuits are used to prevent excessive energy storage, then intrinsic safety is improved, but the circuitry becomes more complex and signal degradation occurs
Solution Approach 1:
The patent extracts the safety function from the circuitry itself and places it in the physical encapsulation structure. Instead of adding limiting circuits to the electrical system, the encapsulant material physically isolates all energy-storing components, preventing fault conditions without adding electrical complexity.
Solution Approach 2:
The encapsulant material acts as an intermediary barrier between volatile atmospheric components and circuit components. This physical mediation prevents ignition risks without requiring complex electrical control circuits, simplifying the overall system while maintaining intrinsic safety.
3Temperature
If oversized components are used for heat dissipation, then thermal safety is improved, but the device size increases
Solution Approach 1:
The patent uses a thin film encapsulant material that provides thermal management through its encapsulation function rather than relying on oversized heat dissipation components. The encapsulant layer creates a controlled thermal environment for circuit components without requiring additional space for thermal management hardware.
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 solution effectively encapsulates circuit components, preventing ignition risks and allowing for a compact, intrinsically safe design suitable for hazardous environments without the need for additional protection circuits, adhering to safety standards like ATEX.
Implementation Method 1
providing thermal insulation and preventing gas contact
Implementation Method 2
an encapsulant material is used to fill the volume bounded by the frame structure between the first and second circuit boards. The encapsulant material can be injected through the one of the circuit boards to fill the space bounded by the frame structure between the circuit boards. Upon curing, the encapsulant material becomes solid, and adheres to the circuit components and the circuit board and frame structure.
Data Source
AI summary
A method and circuit board arrangement for an intrinsically safe portable device includes two or more circuit boards having a frame structure that forms a contiguous boundary around a space between the circuit boards. In the space there are circuit components mounted on both circuit boards, and a connector that connect the two circuit boards. An encapsulant material fills the space bounded by the frame structure between the circuit boards to exclude airborne material from coming into contact with the encapsulated circuit components.