Direct-Bonded Interface Structure for Hermetic Chip Sealing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing adhesives used in semiconductor device fabrication and packaging are often permeable to gases, which can damage sensitive integrated devices, and may also create long-term reliability issues.
Innovation Solution
The use of interface structures comprising conductive and non-conductive features that are directly bonded without an intervening adhesive, creating a sealed environment around integrated devices by defining an effectively annular or closed profile.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If adhesives are used to attach cap to substrate, then the integrated device is sealed from outside environs, but the adhesives are permeable to gases allowing gas penetration into the cavity
Solution Approach 1:
The patent removes the adhesive layer from the sealing interface, extracting the harmful permeable element from the system. The cap is directly bonded to the substrate without any intervening adhesive material, eliminating the gas permeation pathway that existed through the adhesive layer.
Solution Approach 2:
The bonding interface uses a composite structure combining metal cap, ceramic substrate, and metallization layers. This composite material approach creates a hermetic seal with gas impermeability, replacing the single-material adhesive solution with a multi-material direct bond structure.
2Reliability
If solder is used as adhesive, then sealing is achieved, but long term reliability issues arise
Solution Approach 1:
The patent changes the bonding parameters by using direct metal-to-ceramic bonding with metallization layers instead of soldering. This involves controlling bonding temperature, pressure, and surface preparation parameters to create a reliable bond without the long-term reliability issues of solder.
Solution Approach 2:
The patent replaces solder (which has known long-term reliability issues) with a direct bonding approach using metallization layers. This new bonding method creates a more durable, long-lasting seal that eliminates the need for replacement due to solder degradation over time.
3Object-affected harmful factors
If direct bonding without adhesive is used, then gas sealing is improved, but bonding process complexity increases
Solution Approach 1:
The patent applies preliminary actions by depositing metallization layers on the cap and substrate surfaces before bonding. This surface preparation is performed in advance during fabrication, so that when bonding occurs, the surfaces are already optimized for direct bonding, simplifying the actual bonding process.
Solution Approach 2:
The metallization layers act as intermediary elements between the metal cap and ceramic substrate. These intermediate layers facilitate the direct bond by providing compatible bonding surfaces, reducing the complexity of bonding dissimilar materials directly together.
Data Source
AI summary
A bonded structure can include a first element having a first conductive interface feature and a second element having a second conductive interface feature. An integrated device can be coupled to or formed with the first element or the second element. The first conductive interface feature can be directly bonded to the second conductive interface feature to define an interface structure. The interface structure can be disposed about the integrated device in an at least partially annular profile to connect the first and second elements.