Embedded Substrate Chip Packaging With Stop-Ring Grinding Control
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Solution Overview
Problem
In existing chip packaging technologies, the use of columnar metal pillars for grinding leads to excessive grinding depth, making it difficult to control grinding process parameters, resulting in damage to chip pads and electrical failures due to shearing forces, and the one-time plastic package structure is prone to warping and cracking during grinding.
Innovation Solution
A chip packaging method that involves forming a stop ring between the conductive pillar and the bump using micro-etching, allowing for controlled grinding with the stop ring as a grinding stop layer, and using a protective layer to prevent damage to the chip and encapsulant, enabling precise exposure of conductive pillars and avoiding excessive grinding.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If columnar metal pillars are used for grinding, then the grinding process can be performed, but excessive grinding depth occurs and chip pads are damaged
Solution Approach 1:
A stop ring is formed on the columnar metal pillar before the grinding process begins. This stop ring serves as a predetermined physical limit that prevents the grinding tool from removing excessive material. By preparing this protective feature in advance, the patent ensures that the chip pad will not be damaged during grinding, thus resolving the contradiction between achieving sufficient grinding depth and preventing over-grinding damage.
Solution Approach 2:
The stop ring acts as an intermediary element between the grinding tool and the chip pad. It provides a physical barrier that mediates the interaction between these two components, allowing the grinding process to proceed while preventing direct contact between the grinding tool and the chip pad surface. This intermediary structure enables precise control of grinding depth without compromising chip pad integrity.
2Ease of manufacture
If conventional grinding is performed without a stop layer, then grinding can be completed, but it is impossible to control grinding process parameters resulting in damage
Solution Approach 1:
The stop ring on the columnar metal pillar provides self-regulating control during the grinding process. As the grinding tool removes material from the protective layer, it naturally encounters the stop ring, which automatically signals when the predetermined grinding depth has been reached. This self-service mechanism eliminates the need for complex external control systems, maintaining ease of manufacture while achieving precise grinding parameter control.
3Device complexity
If the protective layer is ground without a stop ring, then the process is simpler, but excessive grinding causes chip safety issues
Solution Approach 1:
Rather than making the entire columnar metal pillar complex, the patent applies a localized feature - the stop ring - only at the critical location where depth control is needed. This stop ring is formed on a localized portion of the pillar surface, providing the necessary protective function without significantly increasing overall structural complexity. The local quality approach maintains simplicity while ensuring chip safety.
4Measurement precision
If excessive grinding is performed to ensure exposure, then all material is removed, but chip pads are damaged and electrical failures occur
Solution Approach 1:
The stop ring provides beforehand cushioning by creating a protective barrier that cushions against the harmful effect of excessive grinding. Before the grinding process begins, the stop ring is positioned to ensure that even if grinding continues longer than intended, the chip pad will be protected from damage. This prior cushioning approach ensures accurate exposure of conductive pillars while preventing chip pad damage and electrical failures.
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 prevents excessive grinding, enhances chip safety, and improves device reliability by allowing precise control of grinding parameters and reducing the risk of electrical failures and structural damage.
Implementation Method 1
performing grinding on the protective layer with the stop ring as a grinding stop layer, so as to expose the stop ring and the second conductive pillar
Data Source
AI summary
A chip packaging method, a chip packaging module, and an embedded substrate chip packaging structure are provided. Firstly, a carrier is used to form a first encapsulant on the carrier, a first conductive pillar is formed in the first encapsulant, and a bump is formed at the top of the first conductive pillar, then the bump is etched through a micro-etching process, so that a stop ring can be formed between the bump and the first conductive pillar after the bump is partially etched, and then a first chip is mounted in the mounting groove, and the first chip has a flip-chip structure.