Eutectic Conductor Array Assembly for Micron-Scale Semiconductor Bonding
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Solution Overview
Problem
Conventional methods for forming electrical connections for micron-scaled or smaller micro semiconductor structures, such as μLEDs, are inadequate due to the limitations of wire bonding and eutectic bonding machines.
Innovation Solution
An electronic device and manufacturing method that utilizes a conductor array formed by eutectic bonding of conductive pads and electrodes, with a nonconductive connection layer surrounding the conductors, using an In—Au or In—Ni alloy system and a polymer material like epoxy or acrylic, which undergoes viscosity changes at specific temperatures to facilitate bonding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional wire bonding or eutectic bonding machines are used for μLEDs, then electrical connection can be formed, but the process cannot be applied to micron-scaled or smaller micro semiconductor structures due to machine limitations
Solution Approach 1:
The bonding process is segmented into two distinct stages: first forming conductors through eutectic bonding of metal layers, then forming the connection layer in a subsequent step. This segmentation allows each process to be optimized independently, enabling the formation of electrical connections for micron-scaled structures that cannot be achieved with conventional single-step bonding machines.
Solution Approach 2:
The conductor formation is performed as a preliminary action before connection layer formation. By pre-forming the conductors through eutectic bonding of metal layers at specific temperatures, the structure is prepared in advance to receive the connection layer, enabling subsequent bonding of micro semiconductor structures to substrates with precise electrical connectivity.
2Reliability
If eutectic bonding is used to form conductors, then reliable electrical connection is achieved, but manufacturing time and cost increase
Solution Approach 1:
Multiple functions are merged into the connection layer: it provides mechanical support, electrical insulation, and secondary electrical connection. By combining these functions into a single layer formed in one process step, the overall manufacturing time is reduced while maintaining reliable electrical connections through the previously formed conductor structures.
Solution Approach 2:
The process utilizes temperature-dependent parameter changes of the polymer material, which transitions from a viscous state during conductor formation to a solidified state during connection layer formation. This parameter change enables process optimization at different stages, achieving reliable bonding while improving manufacturing efficiency through controlled thermal processing.
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
Enables efficient electrical connection of micro semiconductor structures with reduced manufacturing time and cost, suitable for various electronic devices including display panels and sensing devices.
Implementation Method 1
The polymer material is defined with a viscosity-temperature variation characteristic, wherein the polymer material has a first viscosity at a first temperature, a second viscosity at a second temperature
Implementation Method 2
Each of the conductors is an integrated member formed by eutectic bonding a conductive pad of the target substrate and a conductive electrode of a corresponding one of the micro semiconductor structures
Data Source
AI summary
An electronic device comprises a target substrate, a micro semiconductor structure array, a conductor array, and a connection layer. The micro semiconductor structure array is disposed on the target substrate. The conductor array corresponds to the micro semiconductor structure array, and electrically connects the micro semiconductor structure array to a pattern circuit of the target substrate. The conductors of the conductor array are independent from one another. Each conductor is an integrated member formed by eutectic bonding a conductive pad of the target substrate and a conductive electrode of the corresponding one of the micro semiconductor structures of the micro semiconductor structure array. The connection layer connects the micro semiconductor structures to the target substrate. The connection layer excludes a conductive material. The connection layer contacts and surrounds the conductors, so that the connection layer and the conductors together form a one-layer structure.