Active PCB Vibration Cancellation for Shock-Induced Damage
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Solution Overview
Problem
Conventional methods for reducing shock-induced vibrations in printed circuit boards (PCBs) and other platforms in mobile environments either increase the size and mass of the subsystems or require significant design effort due to the need for custom vibration-isolation structures, and they do not effectively address vibration-induced damage and measurement errors.
Innovation Solution
An active vibration-sensing and cancelling system that uses sensors and actuators to generate counter vibrations with opposite phase and magnitude to cancel out shock-induced vibrations, allowing for reduced size and mass of the PCB assembly and eliminating the need for large vibration-isolation structures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a vibration-isolation structure is used to reduce shock-induced vibrations, then damage to PCB and components is reduced, but the size and mass of the subsystem increase
Solution Approach 1:
The patent replaces the passive mechanical vibration-isolation structure with an active control system that uses sensors to detect vibrations and actuators to generate counter-vibrations. This substitution eliminates the need for heavy mechanical isolation structures while providing effective vibration cancellation through dynamic counteracting forces.
Solution Approach 2:
The patent changes the stiffness parameter of the PCB by embedding actuators within the PCB layers. These actuators can dynamically adjust the local stiffness characteristics of the PCB to counteract vibrations, replacing the need for a separate vibration-isolation structure with large sway space.
2Reliability
If a vibration-isolation structure with large sway space is used, then vibration damping is improved, but the device complexity increases
Solution Approach 1:
The patent merges the vibration cancellation functionality directly into the PCB structure by embedding actuators within the PCB layers. This integration eliminates the need for separate vibration-isolation structures and reduces overall device complexity while maintaining effective vibration damping capability.
Solution Approach 2:
The PCB serves multiple functions: it provides structural support, electrical connections, and active vibration cancellation through embedded actuators. This multi-functionality eliminates the need for dedicated vibration-isolation structures, reducing device complexity while maintaining damping performance.
3Strength
If the PCB is made stiffer to reduce vibration, then vibration resistance is improved, but the mass and size of the PCB increase
Solution Approach 1:
The patent transitions from a static stiff PCB design to a dynamic system where actuators embedded in the PCB actively adjust local stiffness characteristics in response to detected vibrations. This allows the PCB to maintain appropriate rigidity during normal operation while providing active vibration cancellation when needed, without requiring increased overall mass or size.
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 reduces vibration-induced damage and errors, allows for smaller and lighter subsystems, and reduces design complexity by using a universal vibration-cancel circuit that can be applied across various PCB configurations.
Implementation Method 1
The actuator is configured to generate, in counter-response to the sensed vibration, a counter-vibration that has an opposite phase and magnitude to the vibration of the platform
Data Source
AI summary
An embodiment includes generating a sense signal that represents a first vibration of a platform, and reducing a level of the first vibration by generating, in response to the sense signal, a second vibration in the platform. For example, a sensor generates a sense signal representing a first vibration induced (e.g., a shock-induced vibration) in the platform. And a vibration-cancel circuit reduces or eliminates a level of the first vibration in response to the sense signal. For example, the vibration-cancel circuit reduces a magnitude of a first vibration induced in a platform, or eliminates the first vibration altogether, by generating, in the platform, a second vibration having a magnitude approximately equal to the magnitude of the first vibration and having a phase approximately opposite to the phase of the first vibration. That is, the second vibration cancels the first vibration to reduce the net vibration that the platform experiences.