Wiring Substrate Seed Layer Adhesion via Inorganic Particle Surface Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing wiring substrates face challenges in achieving high-quality conductor formation and adhesion on glass substrates due to issues with surface roughness and unevenness, which affect the reliability and performance of the substrate.
Innovation Solution
A wiring substrate is developed with a core glass substrate, a resin insulating layer containing inorganic particles, and a conductor layer formed by sputtering, where the inorganic particles within the resin insulating layer have distinct shapes to create a smooth inner wall surface for the via conductors, enhancing adhesion and reducing the thickness of the seed layer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional methods are used to form conductors on glass substrates, then conductor formation is achieved, but surface roughness and unevenness occur affecting adhesion quality
Solution Approach 1:
The patent applies preliminary action by forming the seed layer before the electrolytic plating layer. The seed layer is first deposited on the glass substrate to create a uniform nucleation surface, which then enables the electrolytic plating layer to form with improved adhesion and reduced roughness. This sequential preliminary formation resolves the contradiction by preparing the surface in advance for subsequent conductor deposition.
Solution Approach 2:
The patent uses composite materials by combining the seed layer and electrolytic plating layer into a multi-layer conductor structure. The seed layer provides a foundation with good adhesion to the glass substrate, while the electrolytic plating layer adds conductive properties. This composite approach allows each layer to compensate for the limitations of the other, achieving both good adhesion and smooth surface finish.
2Reliability
If the seed layer is made thicker to improve adhesion, then adhesion is enhanced, but the overall conductor thickness increases
Solution Approach 1:
The patent applies partial action by using a thin seed layer (5-20 nm) that provides sufficient adhesion without excessive thickness. The electrolytic plating layer then adds the necessary conductive thickness. This partial approach to the seed layer thickness resolves the contradiction by using just enough seed layer material to ensure adhesion, rather than making it excessively thick.
Solution Approach 2:
The patent changes the parameter of seed layer thickness to an optimal range (5-20 nm) that balances adhesion requirements with minimal thickness. By carefully controlling this parameter, the patent achieves good adhesion while keeping the overall conductor thickness small, resolving the contradiction between adhesion strength and conductor thickness.
3Manufacturing precision
If inorganic particles are added to the resin insulating layer to improve surface smoothness, then surface finish is improved, but the complexity of the insulating layer increases
Solution Approach 1:
The patent applies local quality by adding inorganic particles specifically to the resin insulating layer that will be in contact with the seed layer, rather than uniformly throughout the entire substrate. This localized addition of particles (with size 0.1-10 μm and concentration 1-50 wt%) provides surface smoothness exactly where needed for adhesion, without unnecessarily complicating the entire insulating layer structure.
Solution Approach 2:
The patent uses composite materials by combining resin and inorganic particles to form the insulating layer. The resin provides electrical insulation and mechanical support, while the inorganic particles provide surface smoothness and adhesion promotion. This composite approach achieves surface smoothness enhancement while maintaining the insulating properties, resolving the contradiction between surface finish and structural simplicity.
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 results in a high-quality wiring substrate with improved adhesion and reduced seed layer thickness, enabling the formation of fine signal wirings and minimizing noise and propagation speed differences, thus enhancing the reliability and performance of the substrate.
Implementation Method 1
The conductor layer and the via conductor are formed such that the seed layer is formed by sputtering
Data Source
AI summary
A wiring substrate includes a core substrate including a glass substrate and a through-hole conductor formed in the glass substrate, a resin insulating layer formed on the core substrate and including resin and inorganic particles, a conductor layer formed on the insulating layer and including a seed layer and an electrolytic plating layer, and a via conductor formed in the insulating layer such that the via conductor is electrically connected to the through-hole conductor formed in the glass substrate and includes the seed layer and electrolytic plating layer extending from the conductor layer. The conductor layer and the via conductor are formed such that the seed layer is formed by sputtering, and the resin insulating layer has an opening in which the via conductor is formed such that the inorganic particles include first particles forming an inner wall surface in the opening and second particles embedded in the insulating layer.