MEMS Device Bonding with Squeezed Metal Getter for Moisture Removal
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Solution Overview
Problem
The reliability of MEMS pressure sensors is compromised by moisture within their airtight chambers, and existing methods to remove moisture are inefficient and require additional fabrication procedures.
Innovation Solution
A method involving the formation of a bonding portion with a smaller bonding area and a metal getter on the bonding surface, where the metal getter is squeezed out during substrate bonding to absorb moisture within the airtight chamber, thereby enhancing airtightness without requiring additional fabrication steps.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If additional fabrication procedures are used to remove moisture from the airtight chamber, then moisture removal effectiveness is improved, but device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines the moisture removal function with the existing bonding process by integrating a metal getter layer into the bonding structure. The getter layer is formed as part of the bonding portion, allowing moisture absorption to occur during the normal bonding operation without requiring separate moisture removal steps. This merging of functions resolves the contradiction by achieving effective moisture removal while maintaining simple fabrication procedures.
Solution Approach 2:
The metal getter layer automatically absorbs moisture from the airtight chamber during and after the bonding process without requiring external intervention or additional processing steps. The getter material performs the moisture removal function autonomously through its inherent chemical properties, eliminating the need for complex external moisture removal systems or procedures.
2Reliability
If a metal getter is disposed on the bonding surface, then moisture absorption capability is improved, but bonding strength may be compromised
Solution Approach 1:
The patent applies the metal getter layer locally on the bonding surface rather than uniformly across the entire bonding interface. This localized application ensures that the getter material is present where moisture absorption is needed while maintaining adequate bonding area and strength in other regions. The selective placement resolves the contradiction by preserving bonding strength while enhancing moisture absorption capability.
Solution Approach 2:
The bonding structure becomes a composite of bonding material and metal getter material, where each component performs its specific function. The bonding material provides structural strength and adhesion, while the getter material provides moisture absorption. This composite approach allows both bonding strength and moisture absorption capability to coexist without compromising either property.
3Reliability
If bonding pressure is increased to improve bonding quality, then bonding reliability is improved, but the metal getter may be squeezed out of the bonding position
Solution Approach 1:
The patent performs preliminary action by forming the metal getter layer on the bonding surface before the bonding process begins. This advance preparation ensures that the getter material is already in position to absorb moisture during bonding. By establishing the getter layer beforehand, the system is prepared to handle the bonding pressure without losing the getter material, as the getter is integrated into the bonding structure from the start.
Solution Approach 2:
The metal getter layer is nested within or integrated into the bonding portion structure, where it is embedded or contained within the bonding material matrix. This nesting arrangement prevents the getter material from being squeezed out during bonding, as it is structurally supported and confined by the bonding material while still maintaining contact with the airtight chamber environment for moisture absorption.
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 effectively removes moisture from the airtight chamber, improving the airtightness and reliability of MEMS devices while maintaining the efficiency of existing fabrication processes.
Implementation Method 1
the metal getter is squeezed out of the bonding position to absorb the moisture in the airtight chamber
Data Source
AI summary
A method for manufacturing a MEMS device includes disposing at least one bonding portion having a smaller bonding area in a region where an airtight chamber will be formed, and disposing a metal getter on a bonding surface of the bonding portion. According to this structure, when substrates are bonded to define the airtight chamber, the metal getter is squeezed out of the bonding position due to the larger bonding pressure of the bonding portion with a smaller bonding area. Then, the metal getter is activated to absorb the moisture in the airtight chamber. According to the above process, no additional procedure is needed to remove the moisture in the airtight chamber. A MEMS device manufactured by the above manufacturing method is also disclosed.