Stretchable Tape Transfer for Multi-Element Hybrid Bonding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional methods for fabricating microLED displays and integrated visible/shortwave infrared (SWIR) sensors are slow and expensive due to the individual placement of singulated elements, which involves transferring elements from a first substrate to a second substrate with different spacing requirements.
Innovation Solution
The use of direct bonding techniques, such as hybrid bonding, to connect elements without an adhesive, allowing for simultaneous transfer and alignment of multiple elements by stretching a stretchable tape to adjust spacing, followed by direct hybrid bonding to a carrier.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If pick and place technique is used to individually transfer elements, then manufacturing precision can be maintained, but productivity is reduced and manufacturing cost increases
Solution Approach 1:
Multiple individual pick and place operations are merged into a single reflow soldering process. The patent combines multiple elements onto a temporary carrier at different spacings, then uses one collective reflow event to permanently attach all elements simultaneously, replacing many sequential operations with one parallel process.
Solution Approach 2:
Elements are preliminarily attached to a temporary carrier using solder paste and undergo preliminary positioning before the final reflow soldering step. This preliminary action allows elements to be pre-positioned and held in place, enabling subsequent precision alignment and collective permanent attachment without requiring individual precision placement operations.
2Manufacturing precision
If pick and place technique is used to individually transfer elements, then element placement can be controlled, but loss of time increases due to sequential processing
Solution Approach 1:
Multiple sequential pick and place operations are merged into a single reflow soldering process. The patent combines multiple elements onto a temporary carrier at different spacings, then uses one collective reflow event to permanently attach all elements simultaneously, replacing many sequential operations with one parallel process.
Solution Approach 2:
The process maintains continuous useful action by using a temporary carrier to hold elements in a ready state, then performing a continuous reflow soldering operation that permanently attaches all elements in one uninterrupted process, eliminating idle time between individual placement operations.
3Adaptability or versatility
If elements are transferred from first substrate to second substrate with different spacing, then adaptability to different pitch requirements is achieved, but device complexity increases due to multiple substrates and transfer steps
Solution Approach 1:
A temporary carrier serves as an intermediary between the first substrate and second substrate. Elements are first attached to the temporary carrier at one spacing, then the entire assembly is reflowed to permanently attach elements to the final substrate at a different spacing. The temporary carrier mediates the spacing transformation without requiring complex individual transfer operations.
Solution Approach 2:
The process changes the spatial parameter (spacing/pitch) of elements by utilizing the flexibility of the temporary carrier. Elements are positioned at different spacings on the temporary carrier compared to the final substrate, and the reflow process accommodates this parameter change, enabling pitch adaptation without complex repositioning operations.
4Reliability
If conventional processes are used for element transfer, then reliability of individual element placement is maintained, but productivity and cost effectiveness deteriorate
Solution Approach 1:
Multiple individual pick and place operations are merged into a single reflow soldering process. The patent combines multiple elements onto a temporary carrier at different spacings, then uses one collective reflow event to permanently attach all elements simultaneously, replacing many sequential operations with one parallel process.
Solution Approach 2:
The mechanical pick and place system is replaced with a thermal reflow soldering process. Instead of using mechanical grippers to individually pick and place elements, the patent uses solder paste adhesion followed by controlled thermal reflow to permanently attach multiple elements simultaneously, substituting mechanical precision operations with a thermal field-based process.
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 method reduces fabrication time and cost by enabling simultaneous transfer and alignment of multiple elements, achieving smaller pitches and avoiding the issues associated with soldering, thus enhancing the efficiency of the manufacturing process.
Implementation Method 1
stretching the stretchable tape to increase separation between the singulated elements
Implementation Method 2
direct bonding techniques, such as hybrid bonding, to connect elements without an adhesive
Data Source
AI summary
A method of transferring a plurality of individual elements including providing a plurality of singulated elements on a stretchable tape, stretching the stretchable tape to increase separation between the singulated elements and forming a reconstituted wafer with at least one of the plurality of elements.