Stepped Substrate Sealing for Stronger Hermetic Cap Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing piezoelectric devices face issues with bonding strength and airtightness due to limited contact areas between the cap member and substrate, leading to potential misalignment and reduced impact resistance.
Innovation Solution
The introduction of a step portion on the substrate with an inclined or perpendicular wall surface increases the bonding area for the cap member, enhancing bonding strength and airtightness, and the use of a metal or metal film in contact portions with the substrate allows for rigid bonding using a low-melting-point alloy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the cap member is bonded only to the opening section of the cap member, then the bonding process is simple, but the bonding strength between the cap member and substrate is degraded
Solution Approach 1:
The substrate structure transitions from a flat two-dimensional surface to a three-dimensional stepped structure with vertical walls. This dimensional change creates additional bonding surface area (the vertical wall surface of the step portion) without significantly increasing the planar footprint, thereby enhancing bonding strength while maintaining compact device dimensions.
Solution Approach 2:
The bonding interface is segmented into two distinct regions: the opening section and the vertical wall surface of the step portion. This segmentation allows the cap member to bond at multiple locations, distributing the bonding stress and improving overall bonding strength compared to a single bonding region.
2Reliability
If the cap member bonding area is limited to the opening section, then the manufacturing process is simple, but the airtightness of the sealed space is degraded
Solution Approach 1:
The sealing interface extends from a two-dimensional opening perimeter to a three-dimensional vertical wall surface. This additional vertical bonding surface provides a longer sealing path, improving airtightness by creating multiple sealing contact points between the cap member and substrate.
3Strength
If the cap member is bonded to a flat substrate surface, then the bonding area is limited, but the manufacturing process is simple
Solution Approach 1:
The stepped structure with vertical walls is formed on the substrate before the cap member bonding process. This preliminary structural preparation creates an optimized bonding surface that enhances bonding strength without requiring complex bonding procedures, as the enhanced bonding capability is built into the substrate geometry itself.
4Manufacturing precision
If the cap member protrudes from the periphery due to misalignment, then the planar contour dimension standard is not satisfied, but the bonding area increases
Solution Approach 1:
The vertical wall surface of the step portion provides an additional bonding dimension that is less sensitive to lateral misalignment. Even if the cap member is slightly misaligned in the horizontal plane, the vertical bonding surface ensures adequate bonding area and strength, thereby improving alignment tolerance.
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 improves the bonding strength and airtightness of the electronic component, providing enhanced impact resistance and reliability by increasing the bonding area and using a low-melting-point alloy for bonding without damaging the metal or metal layer.
Implementation Method 1
a soldering material comes into contact with around the contact portion between the peripheral surface of the cap member and the metal layer of the substrate, and the soldering material is heated until molten for soldering
Data Source
AI summary
An electronic apparatus includes: a substrate which has a step portion in an edge portion; an electronic component which is bonded to a surface of the substrate inward of the step portion of the substrate; and a cap member which is bonded to the step portion so as to seal the electronic component, wherein a wall surface of the step portion is formed to be inclined from the step portion toward an electronic component bonding region or to be perpendicular to the step portion.