Interposer Package Structure for Low-Resistance TSV Power Delivery
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Solution Overview
Problem
The high electrical resistance of solders used for connecting through silicon vias (TSVs) in bridge dice hinders power transmission performance.
Innovation Solution
A package structure incorporating an encapsulant and an interposer with a stop layer, conductive through vias, and interconnectors, where the stop layer is positioned to protect the vias and improve electrical connectivity and heat dissipation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If solders are used for electrically connecting to the TSVs, then the TSVs can be connected, but the relatively high electrical resistance of the solders deteriorates the power transmission performance
Solution Approach 1:
The patent extracts and removes the solder material from the electrical connection path between TSVs and interposer. Instead of using solders to make the connection, the TSVs are directly connected to the interposer through mechanical and electrical contact, eliminating the high-resistance solder layer entirely from the power transmission path.
Solution Approach 2:
The patent creates an asymmetric connection structure where the TSV head is exposed and makes direct contact with the interposer surface, rather than using a symmetric solder joint. This asymmetric arrangement allows for direct metal-to-metal contact between the TSV and interposer, reducing electrical resistance compared to the traditional symmetric solder connection.
2Reliability
If the vias are exposed to improve electrical connectivity, then power transmission is enhanced, but the vias become vulnerable to damage during manufacturing processes
Solution Approach 1:
The patent performs preliminary protective actions by forming a protective layer over the exposed TSV heads before subsequent manufacturing steps. This protective layer is applied in advance to prevent damage during later processing, allowing the TSVs to remain exposed for electrical connection while being protected from manufacturing hazards.
Solution Approach 2:
The patent implements beforehand cushioning by creating a protective structure that cushions and protects the exposed TSV heads from potential damage during manufacturing. This protective layer acts as a buffer against mechanical stress, chemical exposure, and other harmful factors that may occur during subsequent fabrication steps.
3Productivity
If the stop layer is positioned to protect the vias, then manufacturing yield is improved, but the structural complexity increases
Solution Approach 1:
The stop layer is designed to perform multiple functions simultaneously: it serves as a protective barrier for the TSVs, provides an etch stop during manufacturing processes, and can also serve as an electrical connection layer or mechanical support structure. This multi-functionality reduces the need for additional separate layers, thereby limiting the increase in structural complexity.
Solution Approach 2:
The patent optimizes the parameters of the stop layer, such as its thickness, material composition, and positioning, to achieve the necessary protection and functionality with minimal added complexity. By carefully controlling these parameters, the stop layer provides effective via protection while maintaining a relatively simple overall structure that does not significantly increase manufacturing complexity.
Data Source
AI summary
A package structure is provided. The package structure includes an encapsulant and an interposer. The encapsulant has a top surface and a bottom surface opposite to the top surface. The interposer is encapsulated by the encapsulant. The interposer includes a main body, an interconnector, and a stop layer. The main body has a first surface and a second surface opposite to the first surface. The interconnector is disposed on the first surface and exposed from the top surface of the encapsulant. The stop layer is on the second surface, wherein a bottom surface of the stop layer is lower than the second surface.