Flowmeter Corrosion Resistance via Inorganic-Organic Composite Film
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional flowmeters face challenges with corrosion resistance due to high moisture permeability and low adhesion strength of polyimide resin, which can lead to corrosion of aluminum wires and pads on silicon substrates, making it difficult to create complex electronic circuits.
Innovation Solution
A flowmeter design featuring a silicon substrate with a diaphragm and aluminum pad, where an organic protective film with high adhesion properties is used, and an adhesion film is applied between the exposed portion and the aluminum pad, along with a mold resin to prevent moisture penetration and enhance corrosion resistance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If polyimide resin is used as organic protective film, then it provides protective function, but moisture permeability increases and adhesion strength decreases
Solution Approach 1:
The patent uses a composite structure combining inorganic oxide film (silicon oxide or silicon nitride) with organic polyimide resin. The inorganic oxide film serves as a moisture barrier layer with low permeability, while the polyimide resin provides protective and adhesive functions. This composite structure resolves the contradiction by leveraging the low moisture permeability of inorganic materials while maintaining the benefits of organic materials.
Solution Approach 2:
The inorganic oxide film acts as an intermediary layer between the aluminum wiring and the external environment. It specifically blocks moisture penetration to the aluminum components while allowing the polyimide resin to fulfill its protective and adhesive roles. This intermediary inorganic layer prevents the harmful effect of moisture reaching the aluminum without interfering with the functional benefits of the organic layer.
2Reliability
If polyimide resin is used as protective film, then it provides protection, but adhesion strength to epoxy resin decreases causing peeling
Solution Approach 1:
The composite structure of inorganic oxide film and polyimide resin creates multiple adhesion interfaces. The inorganic oxide film provides strong adhesion to the epoxy resin mold, while the polyimide resin adheres to the silicon substrate. This layered composite approach distributes adhesion requirements across different material interfaces, achieving overall high adhesion strength.
Solution Approach 2:
The patent changes the surface properties and chemical composition parameters of the protective film by using inorganic oxide material instead of pure organic material. This parameter change results in superior adhesion characteristics to the epoxy resin mold, preventing peeling while maintaining corrosion resistance.
3Ease of manufacture
If aluminum wire is configured on silicon substrate, then electronic circuits can be formed, but corrosion occurs due to moisture penetration
Solution Approach 1:
The inorganic oxide film serves as a protective intermediary layer between the aluminum wiring and the external environment. It specifically blocks moisture penetration to the aluminum components while allowing the polyimide resin to fulfill its protective and adhesive roles. This intermediary inorganic layer prevents the harmful effect of moisture reaching the aluminum without interfering with the functional benefits of the organic layer.
Solution Approach 2:
The composite structure combining inorganic oxide film with organic polyimide resin provides both corrosion protection and adhesion. The inorganic layer protects aluminum from moisture while the organic layer provides flexibility and bonding, enabling complex aluminum wire configurations without corrosion.
Data Source
AI summary
A flowmeter that improves a corrosion resistance is provided.The flowmeter includes a silicon substrate having a diaphragm where a heater is formed, an aluminum pad formed on a silicon substrate, an organic protective film laminated on the silicon substrate, and a mold resin that covers the silicon substrate. The diaphragm has an exposed portion exposed from the organic protective film, an adhesion surface high in adhesion property to the mold resin is laminated on the silicon substrate, and an adhesion film of the mold resin to the adhesion film is provided between the exposed portion and the aluminum pad.