Spacer Resin Pattern with Truncated Cone Reflective Surface
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing designs for semiconductor light-emitting and light-receiving elements, such as VCSELs and photodetectors, face significant optical coupling loss due to light spreading and misalignment between the optical waveguide and electrical circuit layers, which increases coupling loss and reduces the effective light-receiving area, especially when high response speeds are required.
Innovation Solution
A spacer resin pattern layer with a truncated cone-shaped three-dimensional reflective surface is formed on a semiconductor wafer to precisely align light-emitting or light-receiving elements with both the optical waveguide and electrical circuit layers, using a wafer-level process that includes a through-hole for electrical communication and a metal film deposition, allowing for efficient light coupling and reduced optical loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If light is allowed to spread in space between core end and mirror, then light can reach the light-receiving element, but optical coupling loss increases
Solution Approach 1:
A spacer resin layer is introduced as an intermediary medium between the optical waveguide and the light-receiving element. This spacer layer with controlled refractive index acts as a mediator to guide and confine the light, preventing excessive spreading while maintaining optical coupling efficiency.
Solution Approach 2:
The refractive index of the spacer resin layer is specifically controlled to be between 1.3 and 1.7, which is lower than the core layer but higher than air. This parameter optimization allows the light to be effectively guided through the spacer layer, reducing optical loss while maintaining coupling efficiency.
2Speed
If the effective light-receiving area of the light-receiving element is reduced to increase response speed, then response speed improves, but alignment precision requirements increase
Solution Approach 1:
A curved reflective surface is formed on the lower surface of the spacer resin layer. This curved structure acts as a microlens that focuses and guides the light, providing a larger effective light-receiving area while maintaining precise alignment, thus enabling high response speed without excessive alignment precision requirements.
Solution Approach 2:
The reflective surface is extended into a three-dimensional curved structure rather than a flat surface. This dimensional change creates a focal point effect that concentrates light, effectively increasing the light-receiving area and reducing alignment sensitivity.
3Reliability
If the reflection angle of the mirror is set with high precision to reduce light spreading, then optical coupling efficiency improves, but device complexity and manufacturing difficulty increase
Solution Approach 1:
The separate mirror component is extracted and replaced by forming a reflective surface directly on the lower surface of the spacer resin layer. This integration eliminates the need for separate mirror alignment, reducing device complexity while maintaining optical coupling efficiency through the curved reflective geometry.
4Reliability
If filled via is formed to pass through the optical waveguide for electrical connection, then electrical connection is achieved, but the optical waveguide appears severed and positioning precision becomes critical
Solution Approach 1:
The electrical connection structure is segmented into multiple parts: filled via through the optical waveguide, spacer resin layer with through-hole, and connection to the light-receiving element. This segmentation allows each part to be optimized independently, reducing the overall positioning precision requirements while maintaining reliable electrical connection.
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 spacer resin pattern layer effectively reduces optical coupling loss by modifying the light direction with a tapered structure, increasing precision tolerance for the reflection angle and enhancing alignment between the light-emitting or light-receiving elements and the waveguide, thereby minimizing optical loss.
Implementation Method 1
a truncated cone-shaped three-dimensional reflective surface which guides emitted light from the light-emitting element towards the waveguide pattern layer or which guides received light from the waveguide pattern layer
Data Source
AI summary
Spacer resin pattern layer which precisely aligns a light-emitting element or a light-receiving element relative to both a waveguide pattern layer and electrical circuit pattern layer from the semiconductor wafer level. A substratum of resin having a through-hole provided for electrical communication with an electrical circuit pattern layer is formed on a semiconductor wafer. A truncated cone-shaped three-dimensional reflective surface is formed to guide the emitted light towards or received light from a waveguide pattern layer. A metal film is deposited planarly in a predetermined range from the center when positioned relative to the position of the through-hole. A truncated cone-shaped mold is stamped in the center. By modifying the direction of the light using this tapered structure, the precision tolerance is increased and optical loss is reduced.