MEMS Shutter Passivation Film Removal via Anisotropic Etching
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The manufacturing throughput of MEMS display devices is significantly reduced due to the difficulty in applying photolithography processes and the need for specialized devices to remove the passivation film from terminals, which is also time-consuming and inefficient.
Innovation Solution
A display device design featuring a MEMS shutter with a specific spring and anchor configuration, where the insulation film is only present on surfaces perpendicular to the substrate, allowing for electrostatic driving and efficient removal of the passivation film using anisotropic etching, thereby eliminating the need for specialized devices and maintaining high throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photolithography process is applied to remove passivation film from terminal, then manufacturing precision is improved, but device complexity increases and manufacturing throughput decreases due to difficulty in applying the process after MEMS shutter formation
Solution Approach 1:
The passivation film removal process is segmented into two distinct stages: (1) first removal before MEMS shutter formation to enable photolithography application, and (2) second removal after bonding to expose terminals for signal supply. This segmentation allows each stage to use appropriate methods without interfering with the other, resolving the contradiction between precision and complexity.
Solution Approach 2:
The passivation film is preliminarily removed from the terminal region before forming the MEMS shutter and before bonding substrates. This preliminary action enables subsequent photolithography processes to be applied effectively, and ensures terminals are exposed in advance, avoiding the need for complex post-bonding removal operations.
2Manufacturing precision
If dry etching process is used to remove passivation film after bonding substrates, then manufacturing precision is improved, but productivity decreases significantly and specialized devices are required
Solution Approach 1:
The passivation film removal is performed as a preliminary action before substrate bonding, when the structure is still accessible and standard photolithography equipment can be used. This avoids the need for specialized post-bonding etching devices and maintains high manufacturing throughput while achieving precise terminal exposure.
Solution Approach 2:
The difficult post-bonding passivation film removal step is extracted and relocated to the pre-bonding stage. By taking out this problematic operation from the post-bonding sequence, the patent eliminates the need for specialized devices and maintains productivity while still achieving the necessary terminal exposure.
3Ease of operation
If laser irradiation method is used to remove passivation film, then ease of operation is improved, but productivity decreases significantly
Solution Approach 1:
The passivation film removal is performed preliminarily before MEMS shutter formation and before substrate bonding, when large-area batch processing is still possible. This preliminary timing allows standard photolithography methods to be used effectively, maintaining productivity while achieving the operational simplicity of targeted removal.
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 solution enables efficient removal of the passivation film without reducing manufacturing throughput, allowing for cost-effective production of MEMS display devices without requiring specialized equipment.
Implementation Method 1
allowing for electrostatic driving and efficient removal of the passivation film using anisotropic etching
Implementation Method 2
the first spring and the second spring may be electrostatically driven by a potential difference between the first anchor and the second anchor
Data Source
AI summary
The MEMS shutter includes a shutter having an aperture part, a first spring connected to the shutter, a first anchor connected to the first spring, a second spring and a second anchor connected to the second spring, an insulation film on a surface of the shutter, the first spring, the second spring, the first anchor and the second anchor, the surfaces being in a perpendicular direction to a surface of a substrate, and the insulation film is not present on a surface of the plurality of terminals, and a surface of the shutter, the first spring, the second spring, the first anchor and the second anchor, the surfaces being in a parallel direction to a surface of the substrate and on the opposite side of the side facing the substrate.