Multi-Layer Overmold Pedal Assembly for PCB Sealing
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Solution Overview
Problem
Conventional connector assemblies lack effective protection for circuit boards and electrical components, as the housing cavities do not independently safeguard these components against environmental and packaging-related hazards.
Innovation Solution
The implementation of a connector assembly with multiple layers of different overmold materials, where a low-pressure epoxy overmold encases the circuit board and terminal pins, a polybutylene terephthalate (PBT) overmold forms a connector interface, and a high-pressure mold defines a housing to encapsulate the previous layers, providing enhanced protection and sealing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a single housing cavity is used to protect the circuit board and electrical components, then the structure is simple, but the protection effectiveness against environmental hazards is insufficient
Solution Approach 1:
The housing is divided into multiple cavities (first housing cavity, second housing cavity, third housing cavity), each providing protection for different components. The circuit board is positioned in the first cavity, terminal pins extend through the second cavity, and electrical components are housed in the third cavity. This segmentation allows each cavity to be optimized for specific protection requirements while maintaining overall structural integrity.
Solution Approach 2:
The patent employs a multi-material construction where the housing is formed from a first material, the overmold is formed from a second material different from the first material, and the sealant is formed from a third material different from both the first and second materials. This composite material approach enables each layer to contribute specific properties (structural strength, flexibility, sealing capability) to achieve superior protection effectiveness.
2Reliability
If multi-layer overmold materials are used to enhance protection, then the sealing and protection effectiveness is improved, but the manufacturing process becomes more complex
Solution Approach 1:
The circuit board is positioned within the housing cavity before the overmold is formed. The terminal pins are inserted through the housing before the overmold encapsulation process. This preliminary positioning allows the overmold to be formed in a single continuous operation that automatically seals around pre-positioned components, reducing the need for subsequent assembly steps while maintaining effective sealing.
Solution Approach 2:
The patent implements a nested structure where the first housing cavity contains the circuit board, the second housing cavity encapsulates the terminal pins while surrounding the first cavity, and the third housing cavity provides an outer layer containing both previous cavities. The overmold material is injected to form these nested layers in sequence, with each layer automatically conforming to and sealing the components within, simplifying the manufacturing process despite the multi-layer complexity.
Data Source
AI summary
Embodiments herein are directed to an assembly that includes a circuit board, a plurality of terminal pins, a first material layer, a second material layer, and a third material layer. The plurality of terminal pins extend from the circuit board. The first material layer encases a portion of the circuit board. The second material layer encapsulates a portion of the plurality of terminal pins and encases the first material layer. The second material layer defines a connector interface. A material of the second material layer is different from a material of the first material layer. The third material layer encases the first material layer and at least a portion of the second material layer. The third material layer defines a housing that is formed from a material different then the material of the first material layer and different from the material of the second material.