Laminated Metal Shielding for Scratch-Resistant Semiconductor Packages
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Solution Overview
Problem
Existing semiconductor packages face challenges in effectively preventing electromagnetic interference (EMI) while maintaining the integrity of the metal film shield, as the protection film can be scraped during characteristic inspections, leading to potential exposure of the metal layers and reduced adhesion between layers.
Innovation Solution
A semiconductor package design featuring a laminated metal film with multiple layers, including a first metal layer, a copper-based second layer with lower resistance, an alloy third layer with improved adhesion, and a stainless steel or titanium fourth layer, which are deposited at specific temperatures to enhance adhesion and resistance, ensuring effective electromagnetic shielding and protection against scratching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single-layer metal film is used for electromagnetic shielding, then the structure is simple and manufacturing is easy, but the adhesion between layers is insufficient and the shielding effectiveness is reduced when scratched
Solution Approach 1:
The patent employs a laminated metal film structure consisting of multiple layers with different materials (e.g., Cu, Ni, Au, Ag, Al) to achieve both ease of manufacture and high reliability. Each layer serves a specific function: some layers provide excellent adhesion to the resin, others provide low resistance for EMI shielding, and outer layers provide scratch resistance. This composite structure resolves the contradiction by combining the advantages of different materials in a multi-layer configuration that is manufactured through sequential deposition processes.
Solution Approach 2:
The metal film is segmented into multiple functional layers rather than using a single uniform layer. The segmentation allows each layer to be optimized for its specific purpose: adhesion promotion, electrical conductivity, or mechanical protection. This segmentation resolves the technical contradiction by distributing functions across multiple layers, thereby achieving both manufacturing feasibility and superior performance.
2Ease of operation
If the protection film is made thin to avoid scratching, then the inspection process is easier, but the metal layers become exposed and EMI shielding is compromised
Solution Approach 1:
The protective metal film is designed as a composite structure with multiple layers having different thicknesses and material properties. The outer layers are specifically designed to be scratch-resistant while the total thickness is controlled to be as thin as possible. This allows the protection film to be thin enough for easy inspection while still providing adequate mechanical protection and EMI shielding through the optimized multi-layer composition.
Solution Approach 2:
Different regions and layers of the protection film have different local qualities optimized for specific functions. The outer layers have higher hardness and scratch resistance, while inner layers provide electrical conductivity and adhesion. This local differentiation allows the film to be thin overall while maintaining protection capabilities, resolving the contradiction between inspection ease and shielding effectiveness.
3Object-affected harmful factors
If a thick metal film is used to ensure EMI shielding, then the shielding effectiveness is high, but the adhesion between layers deteriorates and manufacturing complexity increases
Solution Approach 1:
The thick metal film required for EMI shielding is segmented into multiple thinner layers, each with optimized thickness and material composition. This segmentation maintains the total shielding effectiveness while improving inter-layer adhesion and reducing manufacturing complexity. Each layer can be deposited under optimized conditions, and the segmented structure allows for better stress distribution and adhesion promotion at each interface.
Solution Approach 2:
The patent uses composite material layers with different properties to achieve effective EMI shielding without requiring excessive thickness. By combining materials with different electrical conductivities, adhesion properties, and mechanical strengths, the multi-layer structure achieves high shielding effectiveness while maintaining good inter-layer adhesion and manageable manufacturing complexity.
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
The laminated metal film structure improves adhesion between layers, enhances the electromagnetic shielding effect, and prevents exposure of the metal layers, even when scratched, while maintaining low resistance values for effective shielding.
Implementation Method 1
a metal film covering a surface and side surfaces of the resin layer 70, the metal film being a laminated film including a plurality of metal layers 91 to 94
Data Source
AI summary
A semiconductor package according to one embodiment comprises a substrate. A semiconductor chip is provided on the substrate. A resin layer is configured to cover the semiconductor chip on the substrate. A metal film is configured to cover a surface and side surfaces of the resin layer. The metal film is a laminated film including first to fourth metal layers. The first metal layer is configured to cover the resin layer. The second metal layer includes a first metal material that is different from a material of the first metal layer. The third metal layer includes an alloy of the first metal material forming the second metal layer and a second metal material different from the first metal material. The fourth metal layer is configured to cover the second or third metal layer.