Multilayer PCB Capacitor Section Using Nickel-Copper Electrodes
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Solution Overview
Problem
Multilayer printed wiring boards experience a decrease in electrical potential due to switching noise, and existing capacitor designs face issues with insufficient decoupling effect and insulation resistance degradation due to metal migration and high-heat processing.
Innovation Solution
A multilayer printed wiring board with a capacitor section featuring a dielectric layer sandwiched between a first electrode with a high ionization tendency for negative charges and a second electrode with a lower ionization tendency for positive charges, made from metals like nickel and copper, respectively, to minimize metal migration and maintain insulation resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a capacitor section is added to suppress switching noise, then the electrical potential stability is improved, but the device complexity increases
Solution Approach 1:
The capacitor section is integrated into the multilayer printed wiring board structure by combining it with existing insulation layers and conductive patterns. The capacitor electrodes are formed using the same lamination and patterning processes as the wiring board layers, merging two functions (capacitance and wiring) into a single integrated structure, thereby suppressing switching noise without significantly increasing device complexity
Solution Approach 2:
The capacitor section serves multiple functions: it provides decoupling capacitance to suppress switching noise, maintains power source line electrical potential stability, and is constructed using the same materials and processes as the wiring board itself. This multi-functionality approach allows the capacitor to address electrical stability issues while utilizing existing manufacturing capabilities
2Ease of manufacture
If conventional capacitor electrodes are used with high-heat processing, then manufacturing ease is improved, but metal migration occurs causing insulation resistance degradation
Solution Approach 1:
The patent changes the material parameters of the capacitor electrodes by selecting metals with appropriate ionization tendencies. The first electrode uses a metal with higher ionization tendency (e.g., nickel) and the second electrode uses a metal with lower ionization tendency (e.g., copper). This parameter change in material selection prevents metal migration during high-heat processing while maintaining ease of manufacture through standard plating processes
Solution Approach 2:
The capacitor electrodes are constructed using composite material selection where different metals are used for the first and second electrodes based on their ionization characteristics. This composite approach (nickel-copper combination) creates a material system that resists metal migration under thermal stress while remaining compatible with conventional manufacturing processes
3Ease of manufacture
If metal electrodes are used for capacitor sections, then ease of manufacture is improved, but metal migration reduces lifespan
Solution Approach 1:
The patent changes the material parameters by selecting metals with specific ionization tendencies for the capacitor electrodes. The first electrode uses a metal with higher ionization tendency (nickel) and the second electrode uses a metal with lower ionization tendency (copper). This parameter optimization prevents metal migration during operation and manufacturing, thereby extending the lifespan of the capacitor section while maintaining ease of manufacture through standard metal plating processes
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 design effectively suppresses power source line potential falloff and reduces metal migration, maintaining high insulation resistance and capacitance, thus enhancing the lifespan and performance of the multilayer printed wiring board.
Implementation Method 1
a capacitor section coupled to the resin insulating layer. The capacitor section includes a first electrode including a first metal and configured to be charged by a negative charge, and a second electrode including a second metal and opposing the first electrode, the second electrode configured to be charged by a positive charge
Implementation Method 2
an ionization tendency of the first metal is larger than and ionization tendency of the second metal
Data Source
AI summary
A multilayer printed wiring board includes a core substrate, a resin insulation layer laminated on the core substrate and a capacitor section coupled to the resin insulating layer. The capacitor section includes a first electrode including a first metal and configured to be charged by a negative charge, and a second electrode including a second metal and opposing the first electrode, the second electrode configured to be charged by a positive charge. A dielectric layer is interposed between the first electrode and second electrode, and an ionization tendency of the first metal is larger than and ionization tendency of the second metal.