Inertial Sensor Package Sealing With Vent Hole Moisture Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inertial measurement devices are susceptible to moisture ingress through sealing resins, leading to stress variations that affect sensor accuracy and reliability.
Innovation Solution
A configuration involving a substrate, cap, and sealing material to create a hermetically sealed internal space with a communication hole for air release, sealed by soldering, using a joining material to join the cap to the substrate, ensuring the internal space is filled with inert gas.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a sealing resin is used to seal the inertial sensor, then the sensor is protected from moisture, but the sealing resin stress varies causing sensor deformation and measurement error
Solution Approach 1:
A communication hole is introduced as an intermediary structure between the sealed internal space and the external environment. This hole allows the sealing resin to maintain its sealing function while providing a pathway for stress relief, preventing the resin stress variations that cause sensor deformation. The communication hole acts as a mediator that preserves both moisture protection and measurement accuracy.
Solution Approach 2:
The invention changes the physical state or parameters of the sealing system by introducing a communication hole that alters the stress distribution characteristics of the sealing resin. This parameter change allows the resin to maintain sealing effectiveness while reducing the harmful stress variations that affect sensor precision.
2Reliability
If the internal space is completely sealed, then moisture protection is improved, but air trapped during manufacturing causes sensor deformation
Solution Approach 1:
The communication hole is designed and positioned in advance during the manufacturing process to serve as a preliminary action. It allows air to be released during assembly before final sealing, preventing air trapping that would cause sensor deformation. This preliminary structural feature ensures both moisture protection and manufacturing precision.
Solution Approach 2:
The communication hole extracts or removes the harmful element (trapped air) from the internal space during manufacturing. By providing an escape pathway for air bubbles, the invention prevents air entrapment that would otherwise cause sensor deformation, while maintaining the sealed structure for moisture protection.
3Manufacturing precision
If a communication hole is added for air release, then air trapping is prevented, but the structure becomes more complex
Solution Approach 1:
The communication hole is designed to serve multiple functions: it allows air release during manufacturing, provides stress relief for the sealing resin, and can be integrated into existing substrate or cap structures. This multi-functionality reduces the need for additional separate components, thereby limiting the increase in device complexity while achieving air release capability.
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 provides a moisture-resistant inertial measurement device with high detection accuracy and reliability by preventing moisture ingress, maintaining stable sensor output over time.
Implementation Method 1
sealing the communication hole by soldering
Implementation Method 2
performing reflow on the substrate
Data Source
AI summary
An inertial measurement device includes: a substrate having a joining area; a cap; a sensor device accommodated in a resin package and disposed in a mounting area on the substrate in an internal space between the substrate and the cap; and a sealing material and a joining material configured to join the cap to the substrate in the joining area of the substrate. The joining material surrounds the mounting area and has a communication hole for communication between the internal space and the outside, and the sealing material closes the communication hole.