PCB Wiring Irregularities for Vibration Stress Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional physical quantity measurement devices for internal combustion engines face issues with wiring breakage due to stress caused by vibrations, particularly when the device is cantilevered and exposed to the intake air flow, leading to potential corrosion and durability concerns.
Innovation Solution
A physical quantity measurement device with a printed circuit board that features irregularities along one direction of its surface, oriented in the same direction as the housing's protrusion into the intake air passage, which reduces stress concentration and enhances durability by aligning the formation direction of these irregularities with the stress direction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the physical quantity measurement device is installed in a cantilevered state protruding from the main passage wall, then it can measure intake air physical quantities, but the device vibrates under engine rotation influence causing housing warp and stress on the circuit board
Solution Approach 1:
The patent applies local quality by creating irregularities only in specific regions of the circuit board surface where stress concentration occurs. These irregularities are formed in the wiring areas that are most susceptible to vibration-induced stress, rather than modifying the entire board uniformly. This localized modification reduces stress concentration at critical points while maintaining the overall circuit board structure and functionality.
Solution Approach 2:
The patent implements preliminary action by pre-forming irregularities on the circuit board surface before the board is subjected to vibration stress during engine operation. These irregularities are created in advance as a preventive measure to reduce stress concentration and prevent wiring breakage before it occurs, rather than attempting to repair or reinforce after stress damage begins.
2Reliability
If irregularities are formed on the circuit board surface, then stress concentration is reduced and wiring breakage is suppressed, but the circuit board manufacturing process becomes more complex
Solution Approach 1:
The patent applies parameter changes by modifying the surface topology of the circuit board through controlled irregularities. These irregularities change the geometric parameters of the wiring areas, creating a surface profile that reduces stress concentration. The irregularities are formed with specific characteristics (direction, depth, distribution) that optimize stress distribution while maintaining manufacturing feasibility.
Data Source
AI summary
A device which measures a physical quantity of a gas flowing through a main passage is described. The device includes a flange for fixing to the main passage; a housing that protrudes toward an inside of the main passage from the flange; and a printed circuit board fixed to the housing on which a measuring element that measures the physical quantity is mounted. Wiring of the printed circuit board has a plurality of irregularities formed along one direction of a surface, and the wiring is arranged such that a formation direction of the irregularities is oriented along a protruding direction of the housing toward an inside of the main passage. The irregularities may be polishing marks formed using a cylindrical polishing wheel or rolling marks of the wiring of the printed circuit board.