Wafer-Level Passivation Structure with Elastic Spacers for Warpage Tolerance
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Wafer-level packaging processes for micro-devices are susceptible to wafer warpage and are not suitable for structures requiring low-temperature processes, which hinders the effective protection of driving portions in micro-electromechanical systems (MEMS) and micro-fluidic devices.
Innovation Solution
A passivation structure comprising a substrate with elastic spacers and an anti-adhesion layer, where the spacers are formed from materials like polydimethylsiloxane (PDMS) and the anti-adhesion layer from metallic, oxide, or nitride films, allowing for bonding without contacting the driving portions and tolerating wafer warpage, using a method that includes forming dangling bonds and aligning the spacers in a lattice pattern.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a wafer-level packaging process is used to protect driving portions, then large-scale production and cost-effectiveness are enabled, but wafer warpage occurs and low-temperature processes cannot be applied
Solution Approach 1:
The patent employs an elastic spacer made of a flexible material that can deform to accommodate wafer warpage during the wafer-level packaging process. The elastic spacer acts as a flexible element that absorbs dimensional changes and stress, allowing the packaging structure to maintain integrity despite substrate warping, thus enabling both large-scale production and warpage tolerance.
Solution Approach 2:
The patent changes the physical parameters of the packaging structure by introducing an elastic spacer with specific mechanical properties (elasticity, compliance) that allow it to adapt to warpage conditions. This parameter change enables the structure to tolerate dimensional variations while maintaining the protective function, resolving the contradiction between productivity and reliability.
2Ease of manufacture
If a wafer-level packaging process is used, then cost-effectiveness is improved, but the process cannot be applied to structures requiring low-temperature processing
Solution Approach 1:
The elastic spacer functions as a flexible component that can be processed at low temperatures, making the packaging process compatible with temperature-sensitive devices. The material properties of the elastic spacer allow it to be formed and bonded without requiring high-temperature processing, thus enabling cost-effective wafer-level packaging for low-temperature applications.
Solution Approach 2:
The patent modifies the processing parameters by selecting materials and bonding methods that operate at low temperatures. The elastic spacer's material characteristics enable bonding and structuring at reduced temperatures, expanding the versatility of the wafer-level packaging process to include temperature-sensitive micro-devices while maintaining cost-effectiveness.
3Object-affected harmful factors
If a cap structure with cavity is used to protect driving portions, then protection is provided, but the structure complexity increases
Solution Approach 1:
The elastic spacer creates a simplified protective structure that defines a cavity space without requiring a complex cap assembly. The flexible spacer itself forms the protective barrier and structural support, eliminating the need for additional cap components while maintaining protection for the driving portion, thus reducing overall structure complexity.
Solution Approach 2:
The patent extracts the essential protective function from a complex cap structure and implements it through a simpler elastic spacer-based design. By removing unnecessary components and retaining only the critical protective and spacing functions, the structure complexity is reduced while maintaining effective protection of the driving portion.
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 effectively protects the driving portions of micro-devices by maintaining the desired spacer height and preventing contamination, while being adaptable to low-temperature processes and large-scale production, ensuring the spacers' elastic properties accommodate substrate warpage and provide a strong bond.
Implementation Method 1
a spacer on the substrate, the spacer having an elastic property
Implementation Method 2
an anti-adhesion layer on a portion of the substrate and surrounded by the spacer
Implementation Method 3
forming a dangling bond on a surface of an elastic material film, forming an anti-adhesion layer on a portion of a first substrate, covering the anti-adhesion layer and the first substrate with the elastic material film having the dangling bond to bond the anti-adhesion layer and the first substrate to the elastic material film
Implementation Method 4
The forming of a dangling bond may include treating the surface of the elastic material film with an oxygen plasma
Data Source
AI summary
A wafer-level passivation structure of a micro-device, a micro-device including the same, and methods of manufacturing the wafer-level passivation structure and the micro-device may be provided. In particular, the passivation structure may include a spacer that is disposed on a substrate, covers a portion of the first surface, and has an elastic property, and an anti-adhesion layer that is disposed on a surface of the substrate between the spacer. The spacer may form a lattice pattern. The spacer may be formed of a silicon. The anti-adhesion layer may be a metallic film, an oxide film, or a nitride film.