Pivot Mount With Switch-Back Spring Arms For Micro Alignment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Miniaturized device manufacturing processes, such as for RF MEMS microswitches and LED display systems, face challenges in aligning miniaturized devices due to difficulties and high costs associated with transferring devices from one wafer to another, particularly in achieving precise alignment in six spatial degrees of freedom.
Innovation Solution
A pivot mount with integrated strain sensing elements and compliant voltage contacts is used, featuring a pivot platform, base, and spring arms with switch-backs, allowing for precise alignment and feedback control through strain sensing, reducing torsional moment, and providing a high signal-to-noise ratio for accurate positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional transfer methods are used to transfer miniaturized devices from one wafer to another, then device transfer can be achieved, but alignment precision and manufacturing cost are compromised
Solution Approach 1:
The transfer head is divided into multiple independent spring arms, each capable of individual deflection and strain measurement. This segmentation allows precise control and measurement of each contact point, enabling high-precision alignment while simplifying the overall control mechanism through modular design.
Solution Approach 2:
Strain sensing elements are integrated into each spring arm to provide real-time feedback on the position and contact force at each transfer head element. This feedback enables closed-loop control for precise alignment in six spatial degrees of freedom, resolving the contradiction between alignment precision and process complexity.
2Measurement precision
If strain sensing elements are integrated into spring arms, then alignment precision is improved, but manufacturing complexity increases
Solution Approach 1:
The strain sensing elements are merged directly into the spring arm structure itself, rather than being separate components. This integration achieves high measurement precision while simplifying manufacturing by reducing the number of assembly steps and components, directly addressing the contradiction between measurement precision and manufacturing ease.
Solution Approach 2:
The spring arms serve multiple functions: they provide mechanical compliance for contact, enable strain measurement through integrated sensing elements, and facilitate precise positioning. This multi-functionality reduces overall system complexity and manufacturing burden while maintaining high measurement precision.
3Manufacturing precision
If switch-backs are added to spring arms to reduce torsional moment, then alignment accuracy is improved, but device complexity increases
Solution Approach 1:
Switch-backs are incorporated into the spring arm geometry to create curved pathways that naturally redirect and reduce torsional moments. This geometric solution improves alignment accuracy by minimizing unwanted rotational forces while maintaining relatively simple spring arm structures, resolving the contradiction between alignment accuracy and structural complexity.
4Reliability
If compliant voltage contacts are used, then electrical connection reliability is improved, but manufacturing complexity increases
Solution Approach 1:
Compliant voltage contacts are implemented using flexible, thin-film structures that can deform to ensure reliable electrical connection. These thin-film contacts achieve high connection reliability while being compatible with standard thin-film deposition processes, thus improving ease of manufacture compared to traditional rigid contact mechanisms.
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 pivot mount enables accurate and repeatable alignment of micro pick-up arrays with a high signal-to-noise ratio, improving the effectiveness of micro device transfer by redistributing pressure uniformly and providing precise feedback for closed-loop motion control, thus enhancing the efficiency and precision of micro device transfer processes.
Implementation Method 1
Each spring arm also includes one or more switch-backs along an axial length of the spring arm such that a pair of first and second lengths of the spring arm immediately adjacent a switch-back are parallel to each other. A first strain sensing element may be located at the first length of the spring arm, and a second strain sensing element may be located at the second length of the spring arm.
Implementation Method 2
a micro pick up array mounted onto the pivot platform of the pivot mount. The micro pick up array may include a plurality of electrostatic transfer heads.
Data Source
AI summary
Systems and methods for aligning a transfer head assembly with a substrate are disclosed. In an embodiment a pivot mount is used for generating a feedback signal in a closed-loop motion control system. In an embodiment, the pivot mount includes a plurality of spring arms, with each spring arm including a switch-back along an axial length of the spring arm such that a pair of first and second lengths of the spring arm are immediately adjacent the switch-back and are parallel to each other. A first strain sensing element is located at the first length, and a second strain sensing element is located at the second length.