PTC Device Laminated Substrate 0201 Form Factor
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Solution Overview
Problem
Existing PTC devices face challenges in achieving the required thin thickness for surface-mount applications, particularly in the 0201 form factor, due to limitations in resistive material substrate thickness and potential misalignment of internal and external circuits, leading to structural weakness and reduced manufacturing yield.
Innovation Solution
A PTC device design featuring a laminated substrate with a first and second PTC material layer, metal layers, and an insulating layer with through holes filled with PTC material, eliminating internal circuits and using prepreg supports for enhanced structural strength, allowing for simpler manufacturing and smaller sizes like 0402 or 0201 without material inflation and misalignment issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If the device is downsized to form factor 0201 to reduce space occupation, then the area of the device is reduced, but the thickness becomes too thin to be achieved structurally
Solution Approach 1:
The patent transitions from a traditional planar structure to a three-dimensional stacked configuration with multiple PTC material layers (first PTC material layer, second PTC material layer) separated by an insulating layer. This vertical stacking allows the device to achieve the required electrical functionality while maintaining a compact footprint and controlled thickness that meets the 0201 form factor requirements.
Solution Approach 2:
The patent employs a composite structure consisting of multiple PTC material layers combined with an insulating layer containing through holes. This composite design enables the device to achieve both the necessary electrical characteristics and mechanical strength at reduced thickness, resolving the contradiction between miniaturization and structural integrity.
2Adaptability or versatility
If internal circuits and external electrode layers are added to the PTC device, then the functionality is improved, but misalignment between internal circuit and external circuit occurs reducing manufacturing yield
Solution Approach 1:
The patent removes the complex internal circuit design from the device structure. Instead of incorporating trace patterns and internal routing, the invention uses a simplified configuration where the first and second conductive layers serve as external electrodes, eliminating the misalignment issues between internal and external circuits while maintaining over-current protection functionality.
Solution Approach 2:
Rather than embedding internal circuits within the substrate and connecting to external electrodes, the patent inverts the approach by making the conductive layers themselves the external electrodes. This reversal eliminates the alignment problem between internal and external circuitry while preserving the essential PTC protection function.
3Length of stationary object
If the PTC device is made without prepreg layers to reduce thickness, then the device thickness is reduced, but the device may flaw due to insufficient strength during manufacturing
Solution Approach 1:
The patent creates a composite structure where the insulating layer with through holes filled with PTC material provides both mechanical support and electrical functionality. This composite design delivers the necessary structural strength during manufacturing while maintaining the reduced thickness required for 0201 form factor compliance.
Solution Approach 2:
The insulating layer incorporates through holes filled with PTC material, creating a porous-like structure that provides mechanical interlocking and enhanced strength. This approach allows the device to achieve both thinness and sufficient structural integrity during manufacturing and packaging processes.
4Length of stationary object
If electrode layers are etched or cut to form grooves for isolating electrodes, then the thickness is controlled, but the groove may be misaligned due to inflation and retraction of the PTC material
Solution Approach 1:
The patent performs the isolation function preliminarily by using the insulating layer with pre-formed through holes to separate the first and second PTC material layers. This preliminary isolation structure prevents misalignment issues that would occur with post-formed grooves, as the through holes are established before the PTC material layers are assembled and cured.
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 enables the production of PTC devices with equal width and height, preventing rollover issues, increasing manufacturing yield, and providing structural strength, while maintaining over-current protection and temperature sensing capabilities.
Implementation Method 1
The resistive material has PTC characteristic that the resistance thereof remains extremely low at room temperature and instantaneously increases to thousand times when the temperature reaches a critical temperature
Implementation Method 2
The laminated substrate comprises a first conductive layer, a second conductive layer and an insulating layer laminated between the first and second conductive layers
Data Source
AI summary
A PTC device comprises a laminated substrate, a first PTC material layer, a second PTC material layer, a first metal layer and a second metal layer. The laminated substrate comprises a first conductive layer, a second conductive layer and an insulating layer laminated between the first and second conductive layers. The first PTC material layer is disposed on the first conductive layer, and the second PTC material layer is disposed on the second conductive layer. The first metal layer is disposed on the first PTC material layer, and the second metal layer is disposed on the second PTC material layer. The insulating layer has a through hole filled with PTC material to form a PTC connecting member of which one end connects to the first PTC material layer and another end connects to the second PTC material layer.