Fan-Out Package Alignment Marks for Compact High-Density Routing

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Solution Overview

Problem

Integrated fan-out packages face challenges related to compactness and precise alignment of components, leading to alignment failure and reduced integration density.

Innovation Solution

A manufacturing process for integrated fan-out packages that includes the formation of a redistribution structure with conductive vias and alignment marks, utilizing a grid pattern for enhanced overlay accuracy and reduced signal noise, ensuring precise placement of components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If integrated fan-out packages use compact design to reduce package area, then package compactness is improved, but alignment precision deteriorates leading to alignment failure

Engineering Contradiction:

Improvepackage areaVSAvoidalignment precision

Core Design Contradiction:

Area of stationary objectVSManufacturing precision

Solution Approach 1:

The package structure is segmented into distinct functional layers including substrate, encapsulant, and redistribution structure with separate alignment mark layers. This segmentation allows independent optimization of each layer's alignment marks without interfering with overall package compactness.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Alignment marks serve as intermediary reference structures between different package layers. These marks provide a common reference framework that enables precise alignment across compact dimensions by mediating the positioning relationship between substrate, encapsulant, and redistribution structure.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Quantity of substance

If integrated fan-out packages increase integration density by reducing component size, then integration density is improved, but alignment reliability deteriorates

Engineering Contradiction:

Improveintegration densityVSAvoidalignment reliability

Core Design Contradiction:

Quantity of substanceVSReliability

Solution Approach 1:

The alignment system transitions from two-dimensional planar alignment to three-dimensional multi-layer alignment using vertical stacking of alignment marks across different layers. This dimensional extension provides additional alignment reference points that maintain reliability even as component sizes shrink and integration density increases.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The alignment mark design incorporates specific geometric parameters and material properties that optimize alignment performance. By carefully controlling the size, shape, and material composition of alignment marks, the system maintains high alignment reliability despite reduced component dimensions and increased integration density.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentUS20250323209A1Integrated fan-out package and manufacturing method thereof

Publication Date: 2025.10.16 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

An integrated fan-out (InFO) package includes a die, an encapsulant laterally encapsulating the die, and a redistribution structure. The redistribution structure is disposed on the encapsulant. The redistribution structure includes a plurality of routing patterns and a plurality of alignment marks. The routing patterns are electrically connected to the die. The alignment marks surround the routing patterns. The alignment marks are electrically insulated from the die and the routing patterns. At least one of the alignment marks is in physical contact with the encapsulant, and the alignment marks located at different level heights are arranged in a non-overlapping manner vertically.