Collective Die-to-Wafer Bonding With Pocketed Carrier Wafers
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Solution Overview
Problem
Existing collective die-to-wafer bonding methods are complex and time-consuming, requiring adhesives and complex debonding processes, which limit their efficiency and scalability for integrating individual chips with different sizes from various production sites and technologies on a single substrate.
Innovation Solution
A method of collective die-to-wafer bonding that uses a carrier wafer with etched pockets to accurately and reliably bond dies to a target substrate without adhesives, leveraging surface-activated metal-metal thermocompression bonding and high-vacuum processing to reduce complexity and increase efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If adhesive-coated carrier wafers and laser debonding are used for collective die bonding, then dies can be placed and transferred, but the process becomes complex and time-consuming
Solution Approach 1:
The invention extracts and eliminates the adhesive layer from the bonding process. Instead of using adhesive-coated carrier wafers that require laser debonding, the patent employs direct metal-to-metal contact between dies and carrier wafer, removing the adhesive removal step and simplifying the overall process while maintaining productivity
Solution Approach 2:
The invention introduces a specialized carrier wafer with recesses as an intermediary structure. This carrier wafer accommodates multiple dies in precise alignment and enables direct thermocompression bonding without adhesives, serving as a mediator that simplifies the bonding process while maintaining high throughput
2Adaptability or versatility
If multiple separately manufactured components are bonded onto a single chip for 3D heterogeneous integration, then functionality and performance increase, but the bonding process becomes more complex
Solution Approach 1:
The invention merges multiple bonding operations into a single collective bonding process. By placing multiple dies on a carrier wafer in recesses and bonding them simultaneously to the target substrate, the process handles diverse components (different sizes, technologies) in one step, increasing versatility while reducing overall process complexity
Solution Approach 2:
The carrier wafer serves multiple functions: it accommodates dies of various sizes through its recess structure, provides alignment references for precise positioning, enables collective handling and transfer, and facilitates direct metal-to-metal bonding. This multi-functional design increases integration capability without proportionally increasing process complexity
3Manufacturing precision
If conventional die placement methods are used without pockets, then the process is simpler, but alignment accuracy decreases
Solution Approach 1:
The carrier wafer features localized recesses at specific positions rather than a uniformly complex structure. Each recess is precisely positioned to accommodate a die with high alignment accuracy, while the rest of the carrier wafer remains simple. This localized structuring achieves high precision without overall structural complexity
Solution Approach 2:
The recesses in the carrier wafer are pre-formed at precise positions before die placement. This preliminary structuring of the carrier wafer with predetermined recess locations enables high alignment accuracy during die placement without requiring complex real-time adjustment mechanisms
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
The method achieves high-yield, cost-effective collective die-to-wafer bonding with improved alignment accuracy and reduced processing time, enabling the integration of dissimilar semiconductor technologies and increasing the functionality and performance of electronic and optoelectronic devices.
Implementation Method 1
bonding the one or more dies placed in the one or more pockets to the target substrate by bringing the one or more dies into contact with the one or more target bonding pads based on surface activated metal-metal thermocompression bonding
Data Source
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AI summary
The present invention relates to a method of performing collective die-to-wafer bonding. The method comprises the steps of: - providing a carrier wafer having a back side and a bonding side opposite the back side and comprising on the bonding side one or more pockets that each are configured for accommodating a die, respectively, - providing a target substrate comprising an integrated circuit, hereinafter IC, and one or more target bonding pads for connecting the one or more dies to the IC, - placing one or more dies in the one or more pockets, respectively, and - bonding the one or more dies placed in the one or more pockets to the tar-get substrate by bringing the one or more dies into contact with the one or more target bonding pads.