Surface-Mount Circuits on Molded Plastic Substrates
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Solution Overview
Problem
Conventional printed circuit board assemblies (PCBAs) are inflexible and require significant space, making it challenging to integrate electronics into miniature devices and products with unique shapes, leading to undesirable space requirements and increased costs.
Innovation Solution
A method for forming electronic circuits on molded plastic substrates using laser etching and selective plating to create conductive traces and pads, followed by surface mounting components with conductive bonding material, allowing for flexible and compact integration of electronics into multi-dimensional devices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If conventional PCB techniques are used, then manufacturing precision and reliability are maintained, but device complexity and cost increase
Solution Approach 1:
The patent extracts the circuit board function from the traditional rigid PCB substrate and relocates it to a molded plastic housing. The housing itself becomes the structural platform that carries conductive traces and mounting features, eliminating the need for a separate PCB while maintaining electrical connectivity and mechanical support functions.
Solution Approach 2:
The molded plastic housing performs multiple functions simultaneously: it provides mechanical protection for internal components, serves as the structural framework of the device, acts as the circuit board through integrated conductive traces, and provides mounting surfaces for components. This multi-functionality reduces overall device complexity while maintaining manufacturing precision through established molding techniques.
2Productivity
If surface mount technology is applied to molded plastic substrates, then productivity and cost reduction are achieved, but manufacturing precision and reliability deteriorate
Solution Approach 1:
The patent incorporates conductive traces and mounting features directly into the molded plastic substrate during the molding process itself. This preliminary action creates a pre-prepared substrate with integrated electrical pathways and component mounting locations, enabling subsequent surface mount technology application without requiring separate PCB fabrication steps. The molding process inherently provides the precision needed for SMT component placement.
Solution Approach 2:
The patent changes the material parameter from traditional rigid PCB materials to molded plastic materials, and changes the trace formation method from copper etching to conductive compound integration during molding. These parameter changes enable direct integration of electrical pathways into the housing structure, facilitating SMT application while maintaining manufacturing precision through control of molding parameters such as temperature, pressure, and material composition.
3Device complexity
If molded plastic substrates are used, then device complexity and cost are reduced, but reliability deteriorates due to bacterial growth and material degradation
Solution Approach 1:
The patent incorporates mold release agents and bonding agents during the molding process that create chemically inert environments within the molded substrate. These agents prevent bacterial growth by creating non-nutritive surfaces and prevent material degradation by stabilizing the plastic matrix. The inert environment is embedded within the substrate structure itself, providing long-term reliability without adding device complexity.
4Ease of manufacture
If conductive traces are formed on molded plastic substrates, then manufacturing cost and complexity are reduced, but manufacturing precision deteriorates due to trace definition accuracy
Solution Approach 1:
The patent replaces the mechanical/chemical process of copper etching and trace deposition with a molding process that integrates conductive traces directly into the plastic substrate. Instead of using complex PCB fabrication machinery for trace formation, the invention uses standard injection molding equipment with modified tooling to embed conductive compounds in precise patterns during the molding cycle. This substitution maintains manufacturing precision through molding cavity design while dramatically simplifying the manufacturing process and reducing costs.
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 approach enables the miniaturization and integration of electronics, reduces space requirements, and offers design flexibility, enabling the creation of complex shapes and hybrid configurations while maintaining reliable electrical performance.
Implementation Method 1
a molded plastic substrate (304, 404) comprising one or more electrically conductive traces comprising plating on a laseretched, activated portion of the molded plastic substrate (304, 404) defining each electrically conductive trace
Data Source
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AI summary
The present invention discloses an electric circuit and a method for forming the electronic circuit. The electronic circuit comprises a molded plastic substrate (304, 404) comprising one or more electrically conductive traces comprising plating on a laseretched, activated portion of the molded plastic substrate (304, 404) defining each electrically conductive trace; at least one electrically conductive pad (302A-302C, 402) at one or more predetermined positions along the one or more electrically conductive traces; and an electrical component surface mounted to the at least one electrically conductive pad (302A-302C, 402) with an electrically conductive bonding material (408).