Semiconductor Package Redistribution Structure With Cu-Ni Skin Layer
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Solution Overview
Problem
Existing semiconductor package manufacturing processes face challenges in achieving reliable redistribution structures due to undesired chemical reactions between copper and photo-imageable dielectric (PID) materials during curing, leading to irregular via hole profiles and deteriorated interface characteristics.
Innovation Solution
A semiconductor package design featuring a metal layer with a copper-nickel skin layer, where copper atoms diffuse into a nickel finishing layer during curing, forming a homogeneous Cu1-xNix alloy with low reactivity to PID materials, thereby preventing reaction by-products and enhancing interfacial properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copper is used as the metal layer material, then electrical conductivity is improved, but chemical reactivity with PID materials during curing causes harmful side effects
Solution Approach 1:
The patent applies composite materials by creating a Cu-Nix alloy structure where a copper base layer provides high electrical conductivity while a nickel skin layer (10-100 nm thick) provides chemical inertness. This composite structure resolves the contradiction by combining the beneficial properties of both materials: copper's conductivity and nickel's resistance to chemical reactions with PID materials during curing.
Solution Approach 2:
The patent applies local quality by creating a gradient structure where the nickel concentration varies through the thickness of the skin layer. The nickel content is controlled to be 1-50 at% in the skin layer, with higher nickel concentration at the surface providing chemical protection while maintaining underlying copper's conductivity. This localized compositional variation optimizes both electrical and chemical properties.
2Manufacturing precision
If additional cleaning and etching steps are added to remove reaction by-products, then manufacturing precision is improved, but process complexity increases
Solution Approach 1:
The patent converts the harmful chemical reactivity of copper into a beneficial process feature. By using Cu-Nix alloy where nickel suppresses unwanted reactions, the curing process itself becomes a beneficial step that forms a protective nickel skin layer without generating harmful by-products. This eliminates the need for subsequent cleaning and etching steps, simplifying the manufacturing process while maintaining high precision.
3Object-generated harmful factors
If copper atoms diffuse into nickel finishing layer during curing, then chemical reactivity is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The patent applies parameter changes by precisely controlling the nickel layer thickness (10-100 nm) and nickel concentration (1-50 at%) to achieve optimal balance between chemical protection and manufacturing feasibility. By optimizing these parameters, the diffusion of copper into nickel during curing is controlled to form a homogeneous alloy structure without requiring excessive manufacturing precision, as the controlled diffusion itself creates the desired protective skin layer.
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 improves the reliability of electrical connections and simplifies the manufacturing process by eliminating the need for additional cleaning and etching steps, resulting in a more reliable and efficient redistribution structure.
Implementation Method 1
copper atoms diffuse into a nickel finishing layer during curing, forming a homogeneous Cu1-xNix alloy
Data Source
AI summary
Provided is a semiconductor package. The semiconductor package including a redistribution structure including a plurality of redistribution conductive patterns, a plurality of conductive vias connected to at least one of the plurality of redistribution conductive patterns, a plurality of lower pads connected to the plurality of conductive vias, and a plurality of redistribution insulation layers and the plurality of redistribution conductive patterns alternating each other, a semiconductor chip arranged on the redistribution structure, and an external connection terminal attached to the plurality of lower surface pads of the redistribution structure, wherein each of the plurality of redistribution conductive patterns includes a metal layer including copper and a skin layer arranged on an upper surface of the metal layer and including copper and nickel, may be provided.