Weldable Transition Unit for Flexible Interconnect Circuits
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for connecting external components to flexible interconnect circuits, such as soldering nickel tabs to copper traces, are inefficient and unreliable, especially when trying to weld directly to thin copper traces, which results in mechanically weak welds and requires additional manufacturing steps.
Innovation Solution
The use of weldable transition units with transition pads made from conductive materials like aluminum, which can be directly welded to the flexible interconnect circuits, eliminating the need for intermediate components and simplifying the connection process by forming a single welding step that connects external components to the conductive traces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If nickel tabs are soldered to copper traces, then connections can be formed, but the manufacturing process becomes complex and requires multiple steps
Solution Approach 1:
The patent extracts the intermediate nickel tab component from the connection process. Instead of soldering nickel tabs to copper traces, the invention directly welds aluminum conductive traces to aluminum busbars, eliminating the need for nickel tabs and reducing manufacturing steps to a single welding operation.
Solution Approach 2:
The patent introduces an aluminum layer as an intermediate conductive layer between the copper trace and aluminum busbar. This aluminum layer is deposited on the copper trace and serves as a welding surface, enabling direct aluminum-to-aluminum welding while maintaining electrical connection through the copper trace.
2Device complexity
If direct welding is attempted on thin copper traces, then manufacturing steps are reduced, but the weld strength becomes mechanically weak
Solution Approach 1:
The patent changes the material parameter of the welding surface from copper to aluminum by depositing an aluminum layer on the copper trace. This parameter change enables stronger welds because aluminum-to-aluminum welding produces mechanically stronger joints compared to welding directly on thin copper traces.
Solution Approach 2:
The patent creates a composite structure consisting of copper trace with an aluminum coating layer. This composite material combines the electrical conductivity of copper with the weldability and strength of aluminum, allowing the thin trace to form strong welds without sacrificing its fundamental properties.
3Reliability
If aluminum conductive traces are used, then welding reliability is improved, but material compatibility challenges arise
Solution Approach 1:
The patent applies local quality by using different materials in different locations: copper for the trace (providing flexibility and electrical conductivity), aluminum coating on the welding surface (providing weldability), and aluminum for the busbar (providing structural strength). This localized material selection optimizes each region for its specific function while ensuring overall compatibility.
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 enhances the reliability and strength of connections between external components and flexible interconnect circuits, reduces manufacturing complexity and costs, and allows for the integration of various electronic devices onto flexible interconnect circuits with improved mechanical and electrical integrity.
Implementation Method 1
a weldable transition unit welded to the conductive trace, forming a weld
Data Source
AI summary
Described herein are methods for forming welded and soldered connections to flexible interconnect circuits and assemblies comprising such connections. An assembly can include a weldable transition unit having a transition pad and a solderable pad. The transition pad may comprise aluminum and can be welded to the aluminum conductive trace of a flexible interconnect circuit. The solderable pad can be soldered to the electrical contact of a device (e.g., a resistor, capacitor). In some examples, the weldable transition unit may comprise a stiffener mechanically connected to the transition pad to provide mechanical support of the transition pad and devices soldered to the transition pad. In some examples, the device soldered to the weldable transition unit may include one or more individual electronic components. In some examples, the device soldered to the weldable transition unit may be a printed circuit board (PCB) having solderable traces.