Optical Semiconductor Element Bonding Layer Design
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Solution Overview
Problem
Conventional optical semiconductor elements face issues with reduced heat dissipation efficiency due to voids and uneven spreading of die attach materials in the bonding layer between the semiconductor chip and the submount, leading to decreased performance and shorter service life.
Innovation Solution
The optical semiconductor element employs a bonding layer that extends to all exposed surfaces of the submount electrode, ensuring uniform coverage and minimizing unbonded portions, thereby enhancing heat dissipation and maintaining high flatness for improved performance and longevity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a conventional die attach material bonding method is used, then the bonding process is simple, but voids and uneven spreading occur in the bonding layer, reducing heat dissipation efficiency
Solution Approach 1:
The patent changes the physical-chemical parameters of the bonding interface by introducing a metal oxide layer and controlling its thickness (5-50 nm) and composition. This parameter change enables the die attach material to bond uniformly to both the semiconductor chip and submount, eliminating voids and uneven spreading while maintaining process simplicity. The metal oxide layer acts as an intermediate layer that facilitates reliable thermal and electrical contact.
2Ease of manufacture
If the bonding layer has voids and uneven spreading, then the manufacturing process is easier, but the service life of the optical semiconductor element is reduced
Solution Approach 1:
The patent applies beforehand cushioning by pre-forming a metal oxide layer on the submount surface before bonding the die attach material. This intermediate oxide layer serves as a cushioning interface that ensures uniform bonding and prevents the formation of voids and uneven spreading. By preparing this protective intermediate layer in advance, the patent eliminates reliability issues that would otherwise reduce service life, while maintaining the simplicity of the overall manufacturing process.
3Device complexity
If the bonding layer is formed with conventional methods, then the process is straightforward, but unbonded portions reduce heat dissipation efficiency
Solution Approach 1:
The patent introduces a metal oxide layer as an intermediary between the submount and the die attach material. This intermediary layer mediates the bonding process, ensuring that the die attach material bonds uniformly to both surfaces. The intermediary oxide layer eliminates unbonded portions and ensures complete thermal contact, thereby maintaining heat dissipation efficiency without increasing device complexity. The intermediate layer acts as a bridge that facilitates reliable thermal and 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
This configuration significantly improves heat dissipation efficiency and extends the service life of the optical semiconductor element by preventing voids and ensuring uniform current density, while maintaining designed light distribution characteristics and emission output.
Implementation Method 1
the efficiency of heat dissipation may be lowered due to voids generated in the bonding layer formed of the die attach material
Data Source
Figure 1
Figure 2A~2B
Figure 3A~3B
AI summary
Provided is an optical semiconductor element (11) in which an unbonded portion between an optical semiconductor chip (20) and a submount (12) is made small, the heat dissipation efficiency becomes high, and the service life can be made long. The optical semiconductor element (11) can include: a plate-shaped submount (12) having a mounting surface; a submount electrode (13) provided on the mounting surface of the submount (12) and having a rectangular shape as a whole; and a semiconductor chip (20) including an element substrate (18), a semiconductor structure layer (19) formed on the element substrate (18), and a chip electrode (17) bonded to the submount electrode (13) via a bonding layer (15). Herein, the chip electrode (17) has a shape with chipped corners corresponding to four corners of the submount electrode (13), the submount electrode (13) has an exposed surface that is a portion exposed from the chip electrode (17) at the four corners and bonded to the chip electrode (17) to coincide with each other, and the bonding layer (15) extends to all the four corners of the exposed surface (13S).