Chip Protection Device with Enclosed Micro-Gap
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Solution Overview
Problem
Conventional chip-type protection devices face limitations in achieving narrow gap widths between discharge electrodes due to the use of high-temperature processes and materials that are inert to electrodes, leading to high manufacturing costs and reduced safety against electrostatic discharge (ESD).
Innovation Solution
A chip-type protection device with an enclosed micro-gap between electrodes, fabricated using photolithography and electroplating, where the gap is optionally under vacuum or filled with air or an inert gas, and a surrounding wall forms a chamber to protect the electrodes from contamination and oxidation, allowing for lower initial discharge voltage and improved safety.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a laser or diamond blade is used to form the gap between electrodes, then the gap can be formed, but the gap width cannot be reduced beyond 10-30 μm
Solution Approach 1:
The patent replaces mechanical gap formation methods (laser cutting, diamond blade cutting) with a photolithography-based approach. The gap is formed by depositing a sacrificial material layer and then selectively removing it through chemical etching, allowing precise control of gap width at the micrometer scale without the limitations of mechanical cutting tools.
Solution Approach 2:
The patent changes the approach from direct mechanical gap formation to a multi-step process involving material deposition and selective removal. By controlling the thickness of the sacrificial material layer and the etching parameters, the gap width can be precisely controlled at 10-30 μm, overcoming the limitations of laser or diamond blade cutting.
2Reliability
If the outer protective layer is formed by sintering at high temperature, then the protective layer is formed, but the manufacturing cost increases and the process becomes complicated
Solution Approach 1:
The patent changes the forming method of the outer protective layer from high-temperature sintering to low-temperature curing. The protective layer material is applied as a slurry or paste and then cured at relatively low temperatures (e.g., 80-150°C), eliminating the need for expensive high-temperature sintering equipment and reducing manufacturing costs while maintaining protective layer quality.
Solution Approach 2:
The patent replaces the thermal sintering process with a chemical curing process. The protective layer material undergoes polymerization or cross-linking at low temperatures through chemical reactions, achieving the desired mechanical properties without the high temperatures required for sintering, thereby simplifying the manufacturing process and reducing costs.
3Quantity of substance
If volatile material is evaporated to fill the chamber, then the chamber is filled with gas, but the material must be inert to electrodes which limits material selection
Solution Approach 1:
The patent performs the gas filling operation before forming the outer protective layer. The chamber is filled with the desired gas (air, inert gas, or vacuum) while the structure is still open, allowing flexible material selection without concerns about chemical reactions during subsequent processing. The outer protective layer is then formed to seal and protect the filled gas.
4Ease of manufacture
If the gap width is wide (10-30 μm), then the device is easier to manufacture, but the discharge voltage becomes too high risking circuit safety
Solution Approach 1:
The patent uses photolithography and chemical etching to achieve precise gap width control at 10-30 μm, enabling lower discharge voltages for circuit safety while maintaining ease of manufacture through standard semiconductor fabrication processes. This replaces the limitation of mechanical cutting methods that could not achieve such precise narrow gaps.
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 enables the production of protection devices with improved precision, lower manufacturing costs, and enhanced safety against ESD, with the ability to discharge at lower voltages, thus providing higher circuit safety and prolonged product life.
Implementation Method 1
The sacrificial material layer is then removed by chemical etching, thereby forming a micro-gap between the paired discharge electrodes
Implementation Method 2
a surrounding wall hermetically enclosing, together with the substrate, the micro-gaps to constitute a chamber having a predetermined gaseous environment
Implementation Method 3
fabricated using photolithography and electroplating
Implementation Method 4
fabricated using photolithography and electroplating
Data Source
AI summary
The present invention relates to a chip-type protection device having an enclosed micro-gap between electrodes. The invention includes a substrate on which a pair of discharge electrodes extend towards each other by a micro-gap. A wall is disposed in a manner spaced apart from the micro-gaps by a predetermined distance, on which a cover portion is mounted in a straddling manner across the micro-gaps. The wall and the cover portion are integrated under a predetermined gaseous environment to form a hermectic chamber on which an outer protective layer is coated. End electrodes are subsequently formed on the substrate in a manner connected to conductive portions of the discharge electrodes. The invention provides a protection device against over-voltage.