Element Submount Electroplating for Heat Dissipation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current manufacturing techniques for submounts face issues with uneven metal composition and 'edge effect' during eutectic soldering, leading to poor bonding, heat dissipation, and increased costs, making them unsuitable for high-power applications.
Innovation Solution
The use of electroplating and processing techniques to form an element bonding layer that extends beyond the edges of conductive heat-dissipating layers, ensuring a planar surface and even distribution of Au-Sn alloy, while increasing copper layer thickness for improved heat dissipation and bonding reliability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If sputtering technique is used for forming bonding layer, then bonding between metal layers and elements is achieved, but uneven composition of metals results in poor element bonding and contact stability
Solution Approach 1:
The patent changes the deposition method parameter from sputtering to electroplating. This parameter change enables precise control over metal composition and uniform distribution of Au-Sn alloy, eliminating the uneven composition problem that occurs with sputtering and thereby improving element bonding stability
Solution Approach 2:
The patent replaces the physical sputtering process with an electrochemical electroplating process. This substitution allows for better control of metal layer composition and uniformity, resolving the issue of uneven metal distribution that compromises bonding reliability
2Loss of energy
If sputtering process ends at edge of submount, then bonding layer is formed, but raised region near finish point creates voids that reduce heat dissipation
Solution Approach 1:
The patent applies preliminary action by extending the electroplating process beyond the submount edges before final processing. This ensures that the bonding layer is formed uniformly across the entire surface including edge areas, preventing the raised regions and voids that would otherwise form and compromise heat dissipation
Solution Approach 2:
The patent converts the potential harm of extended plating into a benefit by using the extended electroplating process to create an initially oversized bonding layer that is then precisely processed. This approach ensures complete edge coverage and eliminates the raised region problem, transforming what could be material waste into a solution for surface flatness and heat dissipation
3Loss of energy
If thick copper layers are increased for heat dissipation, then heat dissipation is improved, but stress becomes an issue and time cost increases
Solution Approach 1:
The patent changes the deposition parameter from sputtering to electroplating, which enables the formation of thick copper layers without inducing stress. The electroplating process allows precise control of layer thickness and internal stress management, permitting the use of thicker copper layers for improved heat dissipation without compromising product yield
4Manufacturing precision
If planarization technique is used to eliminate uneven surfaces, then edge effect is resolved, but additional step and cost are added to manufacturing process
Solution Approach 1:
The patent applies preliminary action by extending the electroplating process beyond the submount edges during the bonding layer formation step. This preliminary extension ensures uniform coverage and eliminates raised regions at the edges, preventing the need for subsequent planarization steps and reducing manufacturing complexity
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 approach eliminates voids, enhances heat dissipation, and maintains product stability without significant cost increases, making it suitable for high-power applications with improved electrical and thermal conductivities.
Implementation Method 1
forming an element bonding layer through electroplating
Implementation Method 2
electrically conductive copper layers on a substrate usually increase heat dissipation
Implementation Method 3
bonding is achieved by eutectic (e.g., AuSn) soldering
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
The present disclosure provides an element submount and a method for manufacturing the same. The element submount includes a substrate, a first conductive heat-dissipating layer, a second conductive heat-dissipating layer, a first heat-dissipating layer and an element bonding layer. The substrate has opposite first and second surfaces. The first conductive heat-dissipating layer is formed on the first surface. The second conductive heat-dissipating layer is formed on the first surface and separated from the first conductive heat-dissipating layer. The first heat-dissipating layer is formed on the second surface. The element bonding layer is formed on the second conductive heat-dissipating layer. By electroplating and processing techniques, the edge of one or two sides of the element bonding layer exceeds an edge of the second conductive heat-dissipating layer and partially covers a side of the second conductive heat-dissipating layer.