Copper Edge Seal Ring Interposer for Moisture Barrier Reliability

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing fan-out wafer level packages (FOWLP) require an interposer with sufficient mechanical strength to withstand bonding processes, but existing interposers may not adequately block moisture, hydrogen, and contaminants, which can compromise the integrity of the semiconductor devices.

Innovation Solution

The use of a copper-based edge seal ring structure in the organic interposer that blocks lateral ingress of moisture, hydrogen, and contaminants, formed through a series of deposition and etching processes to create a robust seal around the package-side bump structures and redistribution interconnect structures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If existing interposer structures are used, then the mechanical strength may be sufficient, but moisture, hydrogen, and contaminants can still ingress into the package

Engineering Contradiction:

Improveprotection against moisture, hydrogen, and contaminantsVSAvoidinterposer structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The interposer is divided into distinct functional regions: a first interposer region with a first dielectric material and a second interposer region with a second dielectric material having different properties. This segmentation allows each region to be optimized for specific functions, with the first region providing mechanical support and the second region providing enhanced environmental protection, thereby resolving the contradiction between reliability and structural simplicity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different dielectric materials are applied to different regions of the interposer based on local requirements. The first dielectric material is used where mechanical strength is prioritized, while the second dielectric material with different properties (such as lower moisture absorption or better barrier properties) is used in regions more susceptible to contaminant ingress. This local differentiation optimizes protection without requiring complete structural redesign.

Inventive Principle:

Principle #3Local quality

2Reliability

If the interposer uses aluminum-based metallic ring structures, then manufacturing may be easier, but aluminum reacts with moisture and hydrogen compromising reliability

Engineering Contradiction:

Improveresistance to moisture and hydrogenVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The material composition parameter of the metallic ring structures is changed from aluminum-based to copper-based materials. This parameter change eliminates the chemical reactivity issue with moisture and hydrogen that plagues aluminum, while copper offers comparable or superior electrical and mechanical properties. The manufacturing processes for copper-based structures are well-established in the semiconductor industry, minimizing the impact on ease of manufacture.

Inventive Principle:

Principle #35Parameter changes

3Reliability

If a copper-based edge seal ring structure is implemented, then protection against contaminants is improved, but manufacturing precision requirements increase

Engineering Contradiction:

Improvecontaminant blocking capabilityVSAvoidcopper ring structure precision

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The copper-based metallic ring structures are formed as integral parts of the interposer structure during the manufacturing process, before final assembly. This preliminary formation allows for precise control of the copper ring dimensions and positioning through established electroplating or electroless plating processes. The copper rings are deposited on prepared substrates with pre-defined patterns, ensuring high precision without requiring additional post-processing steps.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The interposer employs a composite structure combining copper-based metallic ring structures with dielectric materials. The copper rings provide the barrier function against contaminant ingress, while the surrounding dielectric materials provide mechanical support and isolation. This composite approach allows the copper rings to be optimized for their barrier function without bearing the full mechanical load, thereby reducing the precision requirements for the copper ring fabrication compared to a standalone copper structure.

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS12622276B2Interposer including a copper edge seal ring structure and methods of forming the same

Publication Date: 2026.05.05 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

An organic interposer includes interconnect-level dielectric material layers embedding redistribution interconnect structures, package-side bump structures located on a first side of the interconnect-level dielectric material layers, at least one dielectric capping layer located on a second side of the interconnect-level dielectric material layers, a bonding-level dielectric layer located on the at least one dielectric capping layer, metallic pad structures including pad via portions embedded in the at least one dielectric capping layer and pad plate portions embedded in the bonding-level dielectric layer, and an edge seal ring structure vertically extending from a first horizontal plane including bonding surfaces of the package-side bump structures to a second horizontal plane including distal planar surfaces of the metallic pad structures. The edge seal ring structure may include a vertical stack of metallic ring structures that are free of aluminum and laterally surround the package-side bump structures and the redistribution interconnect structures.