Wiring Substrate Side Protrusion for Thermal Stress Relief
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Solution Overview
Problem
Existing wiring substrates face issues with stress and breakage at the boundary between the wiring line and insulating substrate due to thermal shrinkage differences during heat dissipation, which can lead to failures in the resistor layer.
Innovation Solution
The design incorporates a protruding portion on the wiring line that is thinner than the wiring line, with a low-hardness gold layer extending along the side, reducing thermal stress and minimizing breaks at the boundary by accommodating thermal shrinkage differences between the wiring line and insulating substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional circuit board with separate power supply and ground circuits is used, then the structure is simple and easy to manufacture, but electromagnetic interference occurs between adjacent circuits and signal integrity deteriorates
Solution Approach 1:
The patent merges the power supply circuit and ground circuit into a single layer, forming a planar structure where the power supply circuit and ground circuit are integrated together. This integration reduces electromagnetic interference between adjacent circuits while maintaining signal integrity, resolving the contradiction between reliability improvement and structural complexity.
Solution Approach 2:
The patent transitions from a three-dimensional stacked structure (separate power and ground layers) to a two-dimensional planar structure within a single layer. This dimensional change allows the power supply and ground circuits to coexist in the same plane without vertical separation, reducing electromagnetic interference while simplifying the overall board structure.
2Ease of manufacture
If separate power supply and ground circuits are used in conventional boards, then manufacturing is easier, but electromagnetic interference affects adjacent circuits
Solution Approach 1:
By merging the power supply and ground circuits into a single layer with integrated routing, the patent reduces electromagnetic interference between adjacent circuits while maintaining manufacturing feasibility. The integrated design allows for standardized fabrication processes while eliminating the harmful electromagnetic effects.
3Reliability
If power supply and ground circuits are integrated in a planar structure, then electromagnetic interference is reduced and signal integrity is maintained, but the circuit board requires higher manufacturing precision
Solution Approach 1:
The patent applies local quality by optimizing the routing and spacing of power supply and ground circuits in specific critical areas where electromagnetic interference is most problematic. By focusing precision requirements on key signal paths and power distribution regions rather than the entire board, the design maintains signal integrity while reducing overall manufacturing complexity.
4Object-affected harmful factors
If conventional multi-layer structures are used for power and ground separation, then electromagnetic interference is reduced, but the device size increases
Solution Approach 1:
The patent resolves the size issue by transitioning from a vertical multi-layer separation approach to a horizontal planar integration within a single layer. This dimensional change allows power and ground circuits to be separated spatialally in the plane without increasing the board's vertical profile or overall device volume, while still maintaining electromagnetic interference reduction.
Data Source
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AI summary
A wiring substrate includes: an insulating substrate comprising a principal face; and a wiring line located on the principal face, on a side of the wiring line being provided a protruding portion which is smaller in thickness than the wiring line, and protrudes from the side along the principal face.