Thinning Electronic Chips Using Separation Structure as Stop
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Solution Overview
Problem
The challenge lies in accurately thinning electronic chips or wafers while maintaining high precision and preventing quality deterioration during handling, as conventional methods exhibit limited accuracy and risk of damage due to the need for temporary carriers.
Innovation Solution
A method involving the formation of a separation structure within the electronic chip or wafer, which serves as a thinning stop, allowing for encapsulation before thinning, thereby using the encapsulating structure as a stable mechanical base and eliminating the need for temporary carriers, enabling precise and uniform thinning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If electronic chips are thinned before encapsulation, then the chip thickness can be reduced, but the handling and processing becomes difficult and prone to damage
Solution Approach 1:
The chip is encapsulated before thinning is performed. This preliminary encapsulation provides mechanical support and protection during the subsequent thinning process, eliminating the need to handle fragile thinned chips. The encapsulating structure serves as a temporary carrier that is later removed after thinning is complete.
Solution Approach 2:
The encapsulating structure acts as an intermediary carrier during the thinning process. It provides the mechanical strength needed for handling while allowing the chip to be thinned to the desired thickness. After thinning, the encapsulating structure is removed, leaving the thinned chip without having been handled in a fragile state.
2Ease of operation
If electronic chips are thinned after encapsulation, then handling is simplified, but achieving high precision and uniformity in thinning becomes difficult
Solution Approach 1:
The mechanical thinning process is replaced with a chemical etching process. The etching slurry selectively removes material from the chip背面 (back surface) through chemical reaction, providing uniform and precise thinning across the entire chip surface. This chemical approach eliminates mechanical contact that could cause non-uniformity or damage.
Solution Approach 2:
The thinning process transitions from mechanical removal to chemical etching by changing the physical-chemical parameters of the material removal mechanism. The etching slurry's chemical composition and etching rate are controlled to achieve precise and uniform thinning, with the process automatically stopping when the separation structure is reached.
3Device complexity
If conventional thinning methods are used, then the process is simple, but accuracy and uniformity of thinning are limited
Solution Approach 1:
The chip structure is segmented into two parts by introducing a separation structure at a specific depth. This separation structure serves as a built-in stop layer that defines the precise termination point for thinning. The etching process selectively removes material down to this separation structure, ensuring accurate and uniform thickness control without requiring complex external stopping 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
This approach ensures high precision and uniformity in thinning, reduces the risk of damage, and allows for the production of extremely thin electronic chips suitable for power applications by using the encapsulating structure as both a package and a thinning mask.
Implementation Method 1
the chip structure comprises a material being selectively etchable relative to a material of the separation structure and a material of the encapsulating structure
Data Source
AI summary
A method of forming a thinned encapsulated chip structure, wherein the method comprises providing a separation structure arranged within an electronic chip, encapsulating part of the electronic chip by an encapsulating structure, and thinning selectively the electronic chip partially encapsulated by the encapsulating structure so that the encapsulating structure remains with a larger thickness than the thinned electronic chip, wherein the separation structure functions as a thinning stop.