Laser-Patterned Shielding Layers for Multi-Stacked Packages

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Solution Overview

Problem

Existing semiconductor package shielding methods complicate the formation of multi-layered packages, making it difficult to accommodate higher component density in smaller electronic devices due to electromagnetic interference (EMI) shielding requirements.

Innovation Solution

The use of laser-based redistribution and multi-stacked packages with patterned EMI shielding layers, where a conductive shielding layer is formed over the encapsulant and selectively patterned using a laser to create contact pads and conductive traces, allowing for the integration of multiple layers while maintaining EMI shielding effectiveness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If conductive shielding layers are formed over semiconductor packages to protect from EMI, then electromagnetic interference protection is improved, but the complexity of forming multi-layered packages increases

Engineering Contradiction:

ImproveEMI protectionVSAvoidmulti-layered package formation complexity

Core Design Contradiction:

Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The shielding layer is segmented into specific functional areas rather than forming a continuous layer. The laser selectively removes shielding material in regions where signal transmission is needed, creating isolated contact pads and conductive traces while maintaining shielding in other areas. This segmentation allows multi-layered packaging while preserving EMI protection where required.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the shielding layer have different properties - some areas maintain continuous shielding coverage while other areas are selectively removed to create conductive pathways. The laser patterning process creates local variations in the shielding layer, providing EMI protection in certain zones while enabling electrical connectivity in specific locations.

Inventive Principle:

Principle #3Local quality

2Object-affected harmful factors

If continuous shielding layers are used to protect semiconductor components from EMI, then electromagnetic interference protection is improved, but the ability to create conductive pathways for multi-layer integration is reduced

Engineering Contradiction:

ImproveEMI protectionVSAvoidconductive pathway formation

Core Design Contradiction:

Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

Conductive pathways are created by removing shielding material from specific regions of the continuous shielding layer. The laser selectively extracts shielding material to form contact pads and conductive traces, allowing electrical connectivity between layers while maintaining the shielding structure in remaining areas. This extraction approach enables both EMI protection and multi-layer integration.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The traditional mechanical or photolithographic patterning process is replaced with laser-based selective removal. The laser provides precise, contactless patterning of the shielding layer, enabling complex conductive pathway formation without the limitations of mechanical tools or chemical etching processes.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Object-affected harmful factors

If shielding layers are formed over entire package surfaces, then electromagnetic interference protection is improved, but the component density in limited area is reduced

Engineering Contradiction:

ImproveEMI protectionVSAvoidcomponent density

Core Design Contradiction:

Object-affected harmful factorsVSQuantity of substance

Solution Approach 1:

The shielding coverage is segmented to provide protection only where necessary rather than covering the entire package surface. By selectively removing shielding material in specific regions, the design allows higher component density in areas where shielding is not required, while maintaining EMI protection in sensitive regions.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The shielding layer exhibits local quality variations, providing full coverage in areas requiring EMI protection while being selectively removed in areas where component placement is needed. This localized approach to shielding enables optimal balance between EMI protection and component density.

Inventive Principle:

Principle #3Local quality

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 enables the creation of high-density semiconductor packages with improved performance and flexibility, reducing the likelihood of interference and enhancing the integration of components within a limited area, thus addressing the challenge of forming multi-layered packages with effective EMI shielding.

Implementation Method 1

selectively patterned using a laser to create contact pads and conductive traces

Methodology Applied

Scientific EffectLaser ablation: Laser Ablation

Data Source

PatentUS11862572B2Laser-based redistribution and multi-stacked packages

Publication Date: 2024.01.02 STATS CHIPPAC MANAGEMENT PTE LTD

AI summary

A semiconductor device has a first package layer. A first shielding layer is formed over the first package layer. The first shielding layer is patterned to form a redistribution layer. An electrical component is disposed over the redistribution layer. An encapsulant is deposited over the electrical component. A second shielding layer is formed over the encapsulant. The second shielding layer is patterned. The patterning of the first shielding layer and second shielding layer can be done with a laser. The second shielding layer can be patterned to form an antenna.