Dual-Resin Sealing for Stable Electronic Detection Units
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electronic devices using thermosetting resins for sealing suffer from stress relaxation phenomena, leading to fluctuations in detection unit characteristics, while thermoplastic resins require additional protective measures against curing shrinkage stress, complicating the manufacturing process.
Innovation Solution
An electronic device design incorporating a dual-sealing resin system, where a thermosetting resin portion seals the detection unit and a thermoplastic resin portion with a hardness of 60 or less seals the electronic components, utilizing a viscosity range of 500 mPa·s to 10000 mPa·s to stabilize stress and reduce manufacturing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If thermosetting resin is used to seal the detection unit, then the detection unit is well protected, but stress relaxation occurs causing detection characteristics to fluctuate
Solution Approach 1:
The sealing resin is divided into two distinct portions: a thermosetting resin portion that seals the detection unit and a thermoplastic resin portion that seals the electronic component. This segmentation allows each portion to perform its specific function independently, with the thermosetting resin providing protection without stress relaxation and the thermoplastic resin absorbing stress without affecting detection characteristics.
Solution Approach 2:
Different regions of the sealing resin are assigned different material properties. The thermosetting resin portion has properties optimized for protecting the detection unit (high strength, low stress relaxation), while the thermoplastic resin portion has properties optimized for stress absorption (lower hardness, higher flexibility). This local differentiation resolves the contradiction by ensuring that the property causing stress relaxation in one region does not affect the detection unit in another region.
2Ease of operation
If thermoplastic resin is used to seal electronic components, then stress is relaxed, but additional protective processes are required against curing shrinkage stress
Solution Approach 1:
The sealing resin is segmented into two portions with distinct functions. The thermoplastic resin portion provides stress relaxation for the electronic component, while the thermosetting resin portion is positioned to protect against curing shrinkage stress. This segmentation eliminates the need for additional protective measures while maintaining stress relaxation benefits.
Solution Approach 2:
The thermosetting resin portion acts as an intermediary protective layer between the external environment and the electronic component, shielding the component from curing shrinkage stress while the thermoplastic resin portion provides stress relaxation. This intermediary structure simplifies the manufacturing process by eliminating the need for separate protective coatings.
3Manufacturing precision
If dual-sealing resin system is used, then detection stability is improved, but device structure becomes more complex
Solution Approach 1:
The thermosetting resin portion and thermoplastic resin portion are merged into a single integrated sealing resin structure that simultaneously performs both sealing functions. This merging approach maintains detection stability while avoiding the complexity of separate sealing systems, as the two resin portions work together in a unified structure.
Solution Approach 2:
The sealing resin is formulated as a composite material system combining thermosetting and thermoplastic resin portions. This composite structure integrates the advantages of both resin types (protection without stress relaxation from thermosetting resin, and stress relaxation from thermoplastic resin) into a single unified sealing system, achieving detection stability without significant structural complexity.
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 dual-sealing resin system stabilizes the detection unit's stress over time, relaxes stress in electronic components, and shortens the production time by using a thermoplastic resin with low viscosity, ensuring stable detection performance and improved manufacturing efficiency.
Implementation Method 1
The thermosetting resin generates a shrinkage stress during curing
Implementation Method 2
there is generated a stress relaxation phenomenon that internal stress applied on the sealed member decreases with time
Data Source
Figure 1
Figure 2
Figure 3~5
AI summary
A post-sealing stress remaining in an electronic device is relaxed to detect the approach or presence of a detection target with stable accuracy. An electronic device includes a detection unit (210) configured to detect the approach or presence of the detection target, an electronic component that is electrically connected to the detection unit (210), a case member configured to accommodate the detection unit and the electronic component therein, and a sealing resin (120) that is formed in the case member. The sealing resin (120) includes a thermosetting resin portion (121) that is formed in the case member so as to seal the detection unit, and a thermoplastic resin portion (122) that is formed so as to seal a portion other than the thermosetting resin portion (121) in the case member. The thermoplastic resin portion (122) has a hardness (Shore D) of 60 or less.