Multilayer Ceramics Substrate Interfacial Reaction Phase
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Solution Overview
Problem
Existing multilayer ceramics substrates rely heavily on glass as an adhesive for bonding strength, which is insufficient for long-term reliability, particularly after pressure cooker tests, as the bonding strength deteriorates over time.
Innovation Solution
A reaction phase is formed at the interface between the ceramics substrate layers and the surface conductor by reacting a ceramics component with a glass component, enhancing bonding strength without relying solely on glass adhesion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If glass is used as an adhesive to form an undercoat layer between the ceramics substrate layer and surface conductor, then the initial bonding strength is improved, but the bonding strength deteriorates over time after reliability testing
Solution Approach 1:
The invention changes the chemical composition parameters of the conductor paste by adding specific glass components (B2O3: 1-10 wt%, SiO2: 1-10 wt%, Al2O3: 1-10 wt%) to react with the ceramics substrate. This chemical reaction creates a reaction phase at the interface that fundamentally changes the bonding mechanism from simple adhesion to chemical bonding, resolving the deterioration issue after PCT testing
Solution Approach 2:
The invention creates a composite structure at the interface consisting of the ceramics substrate, the conductor paste with glass components, and the reaction phase formed by their chemical reaction. This composite material system combines the advantages of both materials and the reaction phase, providing superior bonding strength and reliability compared to using glass adhesive alone
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 reaction phase significantly improves and maintains bonding strength both initially and after testing, such as a pressure cooker test, providing a highly reliable multilayer ceramics substrate.
Implementation Method 1
a reaction phase formed by a reaction between a ceramics component contained in a ceramics substrate layer and a glass component contained in a surface conductor is deposited at an interface between the surface conductor and the ceramics substrate layer
Data Source
AI summary
A highly reliable ceramics substrate which can sufficiently secure a bonding strength of a surface conductor in an initial state and after a lapse of time (e.g., after a PCT) is provided. The multilayer ceramics substrate has a surface conductor on at least one surface of a multilayer body constituted by a plurality of laminated ceramics substrate layers. A reaction phase formed by a reaction between a ceramics component in the ceramics substrate layers and a glass component in the surface conductor is deposited at an interface between the surface conductor and ceramics substrate layers. For example, an alumina filler in the ceramics substrate layers and Zn in the surface conductor react with each other, thereby forming ZnAl2O4 as the reaction phase.