Hybrid Tether Structure for Precise Micro-Transfer Printing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing micro-transfer printing methods face challenges in efficiently, accurately, and precisely transferring micro-devices from source wafers to destination substrates due to issues with tether fragility and reliability, leading to improper component transfer.
Innovation Solution
The use of hybrid tethers comprising an organic layer and an inorganic layer, where the organic layer is thicker than the inorganic layer, addresses the challenges by maintaining micro-device position, allowing precise transfer, and minimizing contaminating particles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a fragile tether is used, then the tether can be easily broken by the stamp during transfer, but the chiplet may detach entirely from the wafer prior to transfer printing
Solution Approach 1:
The patent applies composite materials by combining organic and inorganic tether layers. The organic layer provides controlled fracture properties allowing the stamp to break the tether, while the inorganic layer provides sufficient strength to maintain chiplet position on the wafer during processing. This composite structure resolves the contradiction between needing the tether to be breakable yet strong enough to prevent premature detachment.
2Strength
If a robust tether is used, then the chiplet remains securely attached to the wafer, but the stamp cannot detach the chiplet from the wafer reliably
Solution Approach 1:
The composite tether structure with organic and inorganic layers enables differential mechanical properties. The organic layer is designed to fracture under stamp pressure while the inorganic layer maintains overall structural integrity. This allows reliable detachment during transfer while preventing premature failure, resolving the contradiction between strength and transfer reliability.
3Ease of manufacture
If the tether composition is not optimized, then manufacturing is simpler, but improper component transfer occurs due to premature or insufficient breaking
Solution Approach 1:
The patent uses composite tether materials with specific thickness ratios (organic layer thicker than inorganic layer) to achieve controlled fracture behavior. This composition optimization ensures precise component transfer by enabling the tether to break at the correct moment during stamping, resolving the contradiction between manufacturing simplicity and transfer precision.
4Device complexity
If a single-layer tether is used, then the structure is simpler, but it cannot simultaneously maintain position and allow reliable detachment
Solution Approach 1:
The patent employs a two-layer composite tether structure where the organic and inorganic layers provide complementary functions. The organic layer enables controlled fracture for detachment while the inorganic layer maintains structural integrity for position holding. This composite approach resolves the contradiction between structural simplicity and transfer reliability by distributing functions across two specialized layers.
Data Source
AI summary
A micro-device structure comprises a source substrate comprising sacrificial portions laterally spaced apart by anchors. At least a portion of each of the sacrificial portions is exposed through an opening. A micro-device is disposed on (e.g., exclusively in direct contact with) each of the sacrificial portions and laterally attached to one of the anchors by a hybrid tether. The hybrid tether comprises an organic tether layer and an inorganic tether layer.