Integrated Optical Module Metal Bonding for Heat-Stable Alignment
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Solution Overview
Problem
Existing optical devices face challenges in miniaturization due to their large component size and free space optical systems, and they suffer from reliability issues such as decreased alignment accuracy and heat dissipation problems caused by ultraviolet-curable adhesives.
Innovation Solution
An integrated optical device is designed with a mounting base, an optical semiconductor device, a substrate, and an optical waveguide, where the optical semiconductor device is connected to the mounting base through a metal layer, and the mounting base is connected to the substrate through another metal layer, ensuring efficient heat dissipation and improved bonding strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a free space optical system using mirrors and lenses is used to integrate multiple optical elements, then the device can achieve multifunctionality, but the device size becomes large and miniaturization is limited
Solution Approach 1:
The patent merges multiple discrete optical elements (mirrors, lenses, optical semiconductor devices) into a single integrated optical device structure. The optical semiconductor device is mounted on a mounting base that is integrated with the substrate containing the optical waveguide, eliminating the need for separate mirrors and lenses to redirect light paths. This consolidation achieves multifunctionality while significantly reducing device volume.
Solution Approach 2:
The patent replaces the mechanical free space optical system (using mirrors and lenses for light redirection) with an integrated waveguide-based optical system. Light is guided through the substrate via total internal reflection in the optical waveguide, eliminating the need for mechanical optical components and reducing device size while maintaining optical functionality.
2Ease of manufacture
If ultraviolet-curable adhesive is used to bond the semiconductor chip and PLC chip, then the bonding process is simple, but the alignment accuracy decreases due to expansion and contraction during temperature changes
Solution Approach 1:
The patent extracts and eliminates the ultraviolet-curable adhesive from the bonding process. Instead of using adhesive to bond the mounting base to the substrate, the invention uses direct thermal bonding or eutectic bonding through metal layers, which do not exhibit expansion and contraction issues during temperature changes, thereby maintaining alignment accuracy while still providing simple bonding process.
Solution Approach 2:
The patent changes the bonding method from chemical adhesive bonding to thermal/metallurgical bonding. By using metal layers that are thermally bonded or eutectically bonded, the system achieves temperature-stable bonding without the expansion and contraction problems of polymer-based ultraviolet-curable adhesives, maintaining alignment precision across temperature variations.
3Strength
If ultraviolet-curable adhesive is used to bond components, then the bonding strength is sufficient for assembly, but heat dissipation performance deteriorates
Solution Approach 1:
The patent removes the ultraviolet-curable adhesive from the bonding structure and replaces it with metal layer bonding. The metal layers provide both sufficient bonding strength and excellent thermal conductivity, simultaneously achieving strong assembly and efficient heat dissipation from the optical semiconductor device to the substrate and packaging.
Solution Approach 2:
The patent uses composite metal layer structures (multiple metal layers with different properties) to achieve both strong bonding and efficient heat dissipation. The metal layers provide mechanical strength for bonding while their high thermal conductivity enables effective heat transfer, creating a composite material solution that addresses both requirements.
4Device complexity
If the optical semiconductor device is directly mounted on the substrate, then the device structure is simplified, but the bonding strength is insufficient and the device may slip off during wire-bonding
Solution Approach 1:
The patent segments the bonding structure into multiple functional layers: the optical semiconductor device is mounted on a mounting base, which is then bonded to the substrate through metal layers. This segmentation allows the mounting base to provide mechanical support and positioning while the metal layers provide strong bonding, preventing slippage during wire-bonding without significantly increasing overall structural complexity.
Solution Approach 2:
The patent employs composite material structures with multiple metal layers providing both mechanical strength and thermal management. The layered metal structure creates strong bonding between the mounting base and substrate, preventing device slippage during wire-bonding while maintaining a relatively simple integrated overall structure.
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 solution effectively suppresses temperature-dependent laser emission and enhances the bonding strength of components to the package, leading to improved reliability and efficient heat dissipation in the integrated optical device.
Implementation Method 1
the optical semiconductor device is connected to the mounting base through a metal layer
Implementation Method 2
an optical waveguide which is provided on a surface of the substrate, wherein an incident surface of the optical waveguide is disposed to face an emission surface of the optical semiconductor device
Data Source
AI summary
An integrated optical device includes: a mounting base; an optical semiconductor device which is provided on a surface of the mounting base; a substrate; and an optical waveguide which is provided on a surface of the substrate, wherein an incident surface of the optical waveguide is disposed to face an emission surface of the optical semiconductor device, wherein light emitted from the optical semiconductor device is able to be incident to the optical waveguide, wherein the optical semiconductor device is connected to the mounting base through a metal layer, wherein the mounting base is connected to the substrate through the other metal layer, and wherein a mounting base bottom surface on the side opposite to a surface of the mounting base and a substrate bottom surface on the side opposite to a surface of the substrate are provided on the substantially same plane.