UV Light-Emitting Package With Intermediary Lens Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In existing light-emitting devices, stress is generated due to differences in linear expansion coefficients between the base member and the cover member functioning as a lens, leading to potential damage or detachment of the lens.
Innovation Solution
A light-emitting device design that includes a base member with a recess, a light-transmissive member, and a lens bonded to the light-transmissive member using inorganic adhesive members, where the absolute difference in linear expansion coefficients between the base member and light-transmissive member is smaller than that between the base member and the lens, thereby stabilizing the bonding of components.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the cover member (lens) is disposed directly on the base member, then the device structure is simplified, but stress is generated due to linear expansion coefficient difference causing lens damage or detachment
Solution Approach 1:
The patent introduces a light-transmissive member as an intermediary component between the base member and the lens. This intermediate layer acts as a buffer that reduces the direct stress transmission caused by linear expansion coefficient differences, thereby preventing lens damage or detachment while maintaining structural integration.
Solution Approach 2:
The patent employs a composite structure consisting of the base member, light-transmissive member, and lens as separate bonded components. This composite approach allows each component to be optimized for its specific function while the bonding interface manages the thermal expansion mismatch, improving overall reliability.
2Ease of manufacture
If members are bonded directly together, then manufacturing process is simplified, but bonding stability is reduced due to thermal expansion stress
Solution Approach 1:
The light-transmissive member serves as an intermediary bonding interface that distributes thermal stress across a larger area and reduces peak stresses at the bonding joints, enabling stable bonding without complicating the manufacturing process.
3Productivity
If lens is bonded to base member directly, then assembly steps are reduced, but stress concentration occurs leading to lens damage
Solution Approach 1:
The light-transmissive member acts as a stress-distributing intermediary that prevents stress concentration on the lens while adding only one additional bonding step to the assembly process, maintaining acceptable productivity while significantly improving lens integrity.
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 ensures stable bonding of members, reduces stress on the lens, and enhances the efficiency of ultraviolet light emission by minimizing optical loss and maintaining a hermetically sealed state, thus preventing damage or detachment of the lens.
Implementation Method 1
a lens bonded to the light-transmissive member with the first inorganic adhesive member
Implementation Method 2
a light-transmissive member disposed on the upper surface of the base member
Implementation Method 3
a phosphor layer disposed on the light-transmissive member
Data Source
AI summary
A light-emitting device includes a base member having an upper surface and a recess on an upper surface side; a light-emitting element disposed in the recess and configured to emit ultraviolet light; a light-transmissive member disposed on the upper surface; a first inorganic adhesive member disposed on the light-transmissive member; and a lens bonded to the light-transmissive member with the first inorganic adhesive member. An absolute value of a difference in linear expansion coefficient between the base member and the light-transmissive member is smaller than an absolute value of a difference in linear expansion coefficient between the base member and the lens.