Elastomeric Stamp with Relief Features for Precision Semiconductor Transfer
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Solution Overview
Problem
Conventional vacuum grippers struggle with handling ultra-thin, fragile, or small semiconductor chips, and existing dry transfer printing methods face challenges with unstable adhesion control and low yields on non-smooth surfaces.
Innovation Solution
A method using an elastomeric stamp with three-dimensional relief features that applies varying pressures and speeds to control adhesion, allowing for the transfer of semiconductor elements from a donor substrate to a receiving substrate with high precision and accuracy.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a stiff backing layer is used in the elastomeric stamp to achieve high placement accuracy, then manufacturing precision is improved, but the delamination rate becomes unstable and difficult to control during the printing step
Solution Approach 1:
The patent applies the dynamics principle by making the backing layer compliant rather than stiff, allowing it to dynamically adapt to bending forces during the printing process. This compliant backing layer can flex and return to its original shape, maintaining stable delamination rates even when subjected to mechanical stresses during transfer printing operations.
2Ease of operation
If conventional vacuum grippers are used to handle semiconductor chips, then ease of operation is maintained, but they cannot economically handle ultra-thin, fragile, or small chips
Solution Approach 1:
The patent replaces the vacuum-based mechanical gripping system with a dry transfer printing system that uses controlled adhesion forces. This substitution allows for the handling of ultra-thin, fragile, and small semiconductor chips through adhesive interactions rather than mechanical suction, expanding the range of handleable chip types while maintaining operational simplicity.
3Productivity
If dry transfer printing is used to enable massively parallel assembly, then productivity is improved, but adhesion control becomes unstable on non-smooth surfaces
Solution Approach 1:
The patent applies parameter changes by systematically optimizing multiple parameters including elastomeric material composition, stamp geometry, applied pressure, and delamination rate. These parameter adjustments enable stable adhesion control across diverse substrate surfaces, maintaining reliable transfer printing performance while achieving massively parallel assembly capabilities.
4Manufacturing precision
If a stiff backing layer is used in the stamp, then manufacturing precision is improved, but device complexity increases due to difficulty in controlling bending forces
Solution Approach 1:
The compliant backing layer dynamically absorbs and accommodates bending forces through elastic deformation, eliminating the need for complex control mechanisms. This dynamic response simplifies the overall process control while maintaining high placement accuracy, as the material itself adapts to mechanical stresses rather than requiring active compensation systems.
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 enables reliable and high-yield transfer printing of semiconductor elements onto diverse substrates, achieving adhesive strength differences of over three orders of magnitude, facilitating deterministic assembly and versatile substrate compatibility.
Implementation Method 1
dry transfer printing tools rely on surface adhesion forces to control the pickup and release of the semiconductor devices
Implementation Method 2
pressure modulated reversible adhesion
Implementation Method 3
The stamps are brought into contact with the elements on the donor substrate with a first pressure that induces a large contact area between the stamps and the elements. The stamps are then retracted from the donor substrate at a first speed that is sufficient to fracture an interface between the elements and the donor substrate without fracturing an interface between the stamps and the elements. Adhesion between the stamps and the elements is based on van der Waals forces.
Data Source
AI summary
In a method of printing a transferable component, a stamp including an elastomeric post having three-dimensional relief features protruding from a surface thereof is pressed against a component on a donor substrate with a first pressure that is sufficient to mechanically deform the relief features and a region of the post between the relief features to contact the component over a first contact area. The stamp is retracted from the donor substrate such that the component is adhered to the stamp. The stamp including the component adhered thereto is pressed against a receiving substrate with a second pressure that is less than the first pressure to contact the component over a second contact area that is smaller than the first contact area. The stamp is then retracted from the receiving substrate to delaminate the component from the stamp and print the component onto the receiving substrate. Related apparatus and stamps are also discussed.