PTC Overcurrent Protection Device with Integrated Electroplated Nickel Layer
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Solution Overview
Problem
Existing over-current protection devices using PTC materials face challenges in mass production due to the need for manual attachment of nickel plates during spot-welding, which is costly and inefficient.
Innovation Solution
A protective circuit board design featuring a PTC device with insulation and electrode layers, allowing for direct spot-welding of the over-current protection device to a PCM or external electrode plate, eliminating the need for manual attachment and enabling flexible manufacturing processes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a nickel plate is attached to the PTC device to protect it during spot-welding, then the PTC device is protected from damage, but manual attachment is required which reduces productivity and increases cost
Solution Approach 1:
The patent combines the nickel plate protection function directly into the PTC device structure by forming a nickel layer on the copper electrode layer through electroplating. This integration eliminates the need for separate manual attachment of nickel plates, enabling automated spot-welding while protecting the PTC device from damage.
Solution Approach 2:
The copper electrode layer serves multiple functions: it provides electrical connection and acts as a base layer for electroplating the nickel protective layer. This multi-functional design allows the same structure to serve both electrical and protective purposes, eliminating the need for separate components.
2Reliability
If a nickel plate is manually attached to the PTC device, then spot-welding can be performed safely, but the manufacturing process becomes complex and costly
Solution Approach 1:
The protective nickel layer is merged with the copper electrode layer through electroplating, creating an integrated structure. This eliminates the need for separate manual assembly steps and reduces manufacturing process complexity while maintaining the protective function during spot-welding.
Solution Approach 2:
The manual mechanical attachment process is replaced with an automated electroplating process. The nickel layer is deposited onto the copper electrode layer through electrochemical means, eliminating the need for manual handling and attachment operations.
3Productivity
If the PTC device is directly spot-welded without protection, then mass production is facilitated, but the nickel foils are damaged
Solution Approach 1:
The nickel protective layer is formed on the copper electrode layer before the spot-welding process. This preliminary protective coating prevents damage to the nickel foils during subsequent spot-welding operations, enabling direct automated welding without manual protection.
4Reliability
If manual attachment of nickel plates is used, then PTC device protection is ensured, but manufacturing time and cost increase
Solution Approach 1:
The manual mechanical attachment process is replaced with automated electroplating followed by direct spot-welding. This substitution eliminates time-consuming manual operations while ensuring the PTC device is protected through the electroplated nickel layer.
Solution Approach 2:
The protective nickel layer and copper electrode layer are merged into a single integrated structure through electroplating. This integration allows the PTC device to be directly spot-welded without additional manual protection steps, significantly reducing manufacturing time.
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 design simplifies the manufacturing process, reduces costs, and ensures stable PTC device performance by avoiding high temperatures during spot-welding, with improved resistance recovery characteristics compared to traditional methods.
Implementation Method 1
the resistance of conductive materials having a positive temperature coefficient (PTC) characteristic is very sensitive to temperature variation
Implementation Method 2
the conductive channel electrically connects the PTC device and the electrode layer
Data Source
AI summary
The over-current protection device of the present invention can be used for over-current protection to PCM. The over-current protection device comprises a PTC device, at least one insulation layer; at least one electrode layer and at least one conductive channel. The insulation layer is placed on a surface of the PTC device, and the electrode layer is formed on the insulation layer afterwards. As a result, the insulation layer is between the electrode layer and the PTC device. The electrode layer serves as a surface of the over-current protection device. The conductive channel electrically connects the PTC device and the electrode layer. In an embodiment, the conductive channel is a blind hole penetrating through the electrode layer and the insulation layer and ending at the surface of the PTC device, and the surface of the blind hole is coated with a conductive layer to electrically connect the PTC device and the electrode layer.