MEMS Accelerometer Selective Laser Etching Nonlinearities
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Solution Overview
Problem
Force-balance accelerometers face performance issues due to nonlinearities, particularly the 1/D effect and degraded precision in high gravitational startup situations, affecting navigation systems' accuracy.
Innovation Solution
The in-plane MEMS accelerometer device employs selective laser etching to increase the density of isolated conductive coil traces and pick-off comb tines within the proof mass, reducing nonlinearities and improving precision by forming these features on a quartz substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If selective laser etching is used to increase the density of coil traces and pick-off comb tines, then measurement precision is improved by reducing nonlinearities, but device complexity increases due to the advanced manufacturing process
Solution Approach 1:
The patent replaces traditional mechanical etching methods with selective laser etching to form conductive coil traces and pick-off comb tines. This substitution enables higher density structures with reduced nonlinearities, directly improving measurement precision while accepting increased manufacturing process complexity as a necessary trade-off for enhanced navigation accuracy
Solution Approach 2:
The patent changes the manufacturing parameters by using selective laser etching instead of conventional methods, which allows for increased density of coil traces and pick-off comb tines. This parameter change reduces the 1/D effect and nonlinearities, thereby improving measurement precision for navigation applications
2Measurement precision
If the density of coil traces and pick-off comb tines is increased to reduce nonlinearities, then measurement precision improves, but manufacturing precision requirements become more stringent
Solution Approach 1:
The patent replaces mechanical etching with selective laser etching, which provides superior control over trace and tine formation. This substitution enables the manufacturing of higher density structures with tighter precision requirements, as the laser process can achieve finer feature sizes and more consistent geometries compared to mechanical methods
Solution Approach 2:
The patent introduces a new dimension of control by using laser etching, which adds temporal and spatial precision control beyond traditional mechanical methods. The selective laser etching process can precisely control the depth, width, and position of each trace and tine, enabling high-density structures that meet stringent manufacturing precision requirements
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 enhances the precision of navigation functions by increasing the density of coil and comb structures, thereby reducing nonlinearities and improving the accuracy of the MEMS accelerometer device.
Implementation Method 1
forming one or more isolated conductive coil traces and/or pick-off comb tines of the one or more pick-off combs by selective laser etching
Data Source
AI summary
An example Micro Electro-Mechanical Systems (MEMS) accelerometer device includes a proof mass comprising at least one of one or more isolated conductive coil traces or one or more pick-off combs within the proof mass, the one or more pick-off combs comprising a plurality of pick-off comb tines; a pole-piece layer coupled to the proof mass; and a return-path layer coupled to the proof mass, wherein the at least one of the one or more isolated conductive coil traces or the one or more pick-off combs are formed by selective laser etching.