Sensor Housing Creep Barrier for Potting Contamination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In small sensors, the combination of capillary action, complex geometry, and hydrophilic wetting behavior causes potting compounds like epoxy resins or silicones to run out during the potting process, leading to contamination of products and systems.
Innovation Solution
A housing with a circumferential edge featuring an outward descending slope and continuous curvature at the open upper side of the receiving chamber, which acts as a creep barrier to prevent the potting compound from running out, allowing for temporary overfilling and reducing the risk of cracking and corrosion, while enabling efficient filling of an enclosed interior chamber.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the receiving chamber has a simple geometry for easy manufacturing, then the potting compound may run out during the potting process due to capillary action and hydrophilic wetting behavior, but if the geometry is complex with creep barriers, then the manufacturing becomes more difficult
Solution Approach 1:
The circumferential edge is designed with a continuous curvature instead of sharp edges or complex geometric features. This curved geometry prevents capillary action that would cause the potting compound to run out, while maintaining a simple overall housing structure that is easy to manufacture. The curvature radius is specifically chosen to be large enough to prevent compound adhesion and running out.
Solution Approach 2:
The invention changes the geometric parameter of the circumferential edge from sharp or complex shapes to a specific curvature radius. This parameter modification fundamentally alters the interaction between the potting compound and the housing edge, preventing capillary rise and compound running out without requiring complex multi-feature geometries.
2Strength
If the circumferential edge has a sharp geometry to define the receiving chamber boundary, then the potting compound may crack due to stress concentration, but if the edge is rounded, then the receiving chamber geometry becomes less precise
Solution Approach 1:
The circumferential edge is designed with a continuous curvature that eliminates sharp corners and stress concentration points. This curved geometry prevents cracking of the potting compound during curing and thermal cycling, while the curvature radius is controlled to maintain sufficient geometric precision for the receiving chamber.
3Reliability
If the receiving chamber is completely filled with potting compound to ensure full protection, then the potting compound may run out during filling, but if overfilling is prevented, then the enclosed interior chamber may not be fully filled
Solution Approach 1:
The continuous curvature of the circumferential edge creates a self-containing geometry that prevents the potting compound from running out during the filling process. This allows the chamber to be completely filled with potting compound to ensure full protection of electronic components, while the curved edge contains the compound throughout the filling process.
Solution Approach 2:
The invention allows for complete filling of the receiving chamber with potting compound, going beyond what would be possible with traditional sharp-edged chambers. The continuous curvature enables the potting compound to be filled to the very edge without running out, ensuring complete protection of components.
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 prevents contamination, ensures a stable and robust potting process with quicker cycle times, and reduces the risk of cracking and corrosion by forming a stable convex potting compound surface, suitable for various sensor designs including small rotational speed sensors.
Implementation Method 1
the combination of the capillary action associated with small dimensions, a complex geometry and/or concave edges and a hydrophilic wetting behavior can cause the potting compound to run out during the potting process
Implementation Method 2
the circumferential edge prevents the potting compound from running out and the product and system from becoming contaminated
Implementation Method 3
the combination of the capillary action associated with small dimensions, a complex geometry and/or concave edges and a hydrophilic wetting behavior can cause the potting compound to run out during the potting process
Data Source
AI summary
A housing with an open receiving chamber which has a circumferential edge in the form of a creepage barrier at an open upper face is disclosed. The receiving chamber is filled with a casting compound, and the hardened casting compound forms a concave surface relative to the circumferential edge at the open upper face. A sensor is also disclosed that includes such a housing. In addition, a method for casting an open receiving chamber of such a housing is disclosed. The open receiving chamber has an opening at one end leading to an enclosed interior adjoining the open receiving chamber. The enclosed interior is filled with the casting compound, and the open upper face of the receiving chamber has a varying height where the upper face transitions into the enclosed interior. The circumferential edge has an outwardly descending inclination and a continuous curvature formed by tangential transitions in order to overcome the height difference, and the circumferential edge allows the receiving chamber to be temporarily overfilled, thereby forming a stable convex casting compound surface, during the casting process.