Transfer Stamp Posts for Particle Capture in Micro-Transfer Printing
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Solution Overview
Problem
Conventional transfer printing methods face challenges in achieving high yields when handling ultra-thin, fragile, or small components, as they often result in misprinted, misplaced, or missing components due to particle contamination from broken tethers, which can interfere with the pick-up and printing processes.
Innovation Solution
The use of oversized stamp posts that overhang and extend beyond the components to capture particles formed during the breaking of tethers, ensuring proper pick-up and printing while allowing for subsequent cleaning to maintain high yields.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If tethers are used to maintain position and alignment of components on a source wafer, then component positioning stability is improved, but particle contamination increases due to tether breaking during pick-up
Solution Approach 1:
The patent extracts and removes particles from the stamp surface after the pick-up operation. A cleaning mechanism is introduced that contacts the stamp posts to remove captured particles, thereby eliminating the harmful byproduct of tether breaking without removing the tether itself
Solution Approach 2:
The patent converts the harmful particle contamination into a beneficial particle capture mechanism. The stamp posts are designed to intentionally capture particles that are generated when tethers break, preventing these particles from contaminating subsequent printing operations. The harmful particles become trapped on the stamp posts where they can be removed in a controlled manner
2Object-generated harmful factors
If stamp posts are made oversized to capture particles, then particle capture capability is improved, but stamp complexity increases
Solution Approach 1:
The patent segments the stamp post structure into distinct functional zones: a pickup zone that contacts the component and a capture zone that extends beyond the component boundaries. This segmentation allows each zone to perform its specific function - the pickup zone maintains component contact while the capture zone intercepts particles without adding overall structural complexity
3Ease of operation
If conventional pick-and-place methods are used for large components, then ease of operation is maintained, but applicability to ultra-thin and small components deteriorates
Solution Approach 1:
The patent creates a universal transfer printing system that can handle multiple component types and sizes. The stamp posts are designed with dimensions and properties that enable them to effectively pick up and transfer both large components and ultra-thin, small components using the same basic mechanism, thereby achieving multi-functionality
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 significantly reduces particle contamination, leading to improved transfer printing yields and minimizing the need for repair operations by effectively capturing and removing particles from the stamp, thus ensuring accurate and efficient transfer of components.
Implementation Method 1
adhesion between an elastomer transfer device and a printable component can be selectively tuned by varying the speed of a print-head
Implementation Method 2
particles formed from breaking or separating tethers can interfere with proper pick up and/or printing of components. Such particles can become airborne after formation and interfere with, for example, subsequent print operations
Data Source
AI summary
A micro-transfer printing system comprises a source substrate having a substrate surface and components disposed in an array on, over, or in the substrate surface Each component has a component extent in a plane parallel to the substrate surface. A stamp comprises a stamp body and stamp posts extending away from the stamp body disposed in an array over the stamp body. Each of the stamp posts has (i) a post location corresponding to a component location of one of the components when the stamp is disposed in alignment with the source substrate, and (ii) a post surface extent on a distal end of the stamp post. The post surface extent is greater than the component extent.