PBN Container Aperture Geometry for Conductive Film Durability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing PBN containers used for electron beam evaporation suffer from durability issues due to peeling of the conductive film, breakage, and difficulty in uniformly melting and depositing evaporation materials, leading to short lifespan and reduced productivity.
Innovation Solution
A PBN container design with a specific angle between the cut face and adjacent wall surfaces (20° to 80°) and a curvature radius of 0.2 mm to 3.0 mm at the aperture tip, combined with a conductive film, to minimize residual stress and peeling, and optimize surface roughness and density for improved durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conductive film is laminated on the surface of a PBN container body to enable uniform melting and prevent charge-up, then the container can produce uniform high-purity metal films, but the container becomes prone to breakage and has short lifespan
Solution Approach 1:
The invention changes the geometric parameters of the container by specifying that the angle θ between the cut face and adjacent wall surface must be 20° to 80°, and the curvature radius R of the aperture tip must be 0.2 mm to 3.0 mm. These parameter changes optimize the stress distribution in the PBN material, preventing crack propagation and improving container durability while maintaining the conductive film's effectiveness.
Solution Approach 2:
The invention uses a composite structure combining PBN (pyrolytic boron nitride) as the base material with a conductive film coating. This composite approach leverages the chemical inertness and high melting point of PBN while adding the electrical conductivity needed for uniform electron beam heating, achieving both film quality and container longevity through proper material combination and geometric design.
2Manufacturing precision
If the aperture tip has a sharp edge for precise positioning, then the container can be accurately positioned in the evaporation system, but stress concentration occurs leading to crack initiation and container failure
Solution Approach 1:
The invention applies curvature to the aperture tip by specifying a curvature radius R of 0.2 mm to 3.0 mm. This rounded geometry eliminates stress concentration at sharp edges, preventing crack initiation while still providing sufficient positioning accuracy for the evaporation system through the controlled curved surface.
3Ease of manufacture
If the container wall is made thin to reduce material usage and cost, then the container is more economical, but the container becomes prone to breakage and has reduced durability
Solution Approach 1:
The invention optimizes the wall thickness parameter within specific ranges to achieve the best balance between material efficiency and durability. By combining optimized thickness with the specified angle θ (20° to 80°) and curvature radius R (0.2 mm to 3.0 mm), the container achieves maximum strength-to-weight ratio, preventing breakage while minimizing material usage.
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 results in a PBN container with enhanced durability, allowing stable, long-term production of high-purity metal films and reducing the frequency of container exchanges, thereby lowering operational costs.
Implementation Method 1
Because the conductive film is heated by the electron beam in the case of using this PBN hearth liner, an evaporation material can be wholly melted
Implementation Method 2
the electron beam is irradiated into evaporation material, thereby heating and evaporating the material, and the evaporated material is deposited onto the substrate, and thus, a thin film is formed on the substrate
Data Source
AI summary
A PBN container including a container body made of a laminate of pyrolytic boron nitride, and a conductive film coating a surface of the container body, in which an angle θ between a cut face of the container body and an inner wall surface or an outer wall surface of the container body adjacent to the cut face is 20° or more and 80° or less across an entire circumference of an aperture of the container body, and a tip portion of the aperture of the container body has a shape having a curvature radius R of 0.2 mm or more and 3.0 mm or less across the entire circumference of the aperture of the container body. The PBN container is excellent in durability where the conductive film is laminated on a surface of the container body formed by depositing PBN, and the method for producing such a PBN container.