Semiconductor Redistribution Layer Adhesion via Titanium Mediator
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Solution Overview
Problem
The adhesion between the insulating layer and the conductive member in semiconductor devices with a redistribution layer is poor, leading to potential peeling issues when the redistribution layer warps, which is a challenge in manufacturing thinner semiconductor devices.
Innovation Solution
Incorporating titanium layers between the insulating layer and the conductive members, along with a nickel layer and gold layers, to enhance adhesion and prevent peeling, while using copper for the conductive members to maintain low resistivity and high conductivity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If copper conductive members are used in the redistribution layer, then electrical conductivity is improved, but adhesion to the organic insulating layer deteriorates
Solution Approach 1:
The patent introduces a titanium adhesion layer as an intermediary between the copper conductive member and the organic insulating layer. This titanium layer serves as a mediator that bonds to both materials, resolving the adhesion problem while maintaining copper's superior electrical conductivity. The titanium layer is formed by sputtering or electroplating, creating a stable interface that prevents peeling during redistribution layer warping.
2Length of moving object
If the redistribution layer is made thinner to meet device requirements, then device thickness is reduced, but adhesion between insulating layer and conductive member becomes more critical and peeling risk increases
Solution Approach 1:
The titanium adhesion layer acts as a mediator that ensures reliable bonding between the copper conductive member and organic insulating layer, even when the overall redistribution layer thickness is reduced. This intermediary layer prevents peeling failures that would otherwise occur more readily in thinner structures due to increased stress concentration.
Solution Approach 2:
The patent creates a composite structure consisting of multiple materials (copper, titanium, organic insulating layer) with complementary properties. The copper provides conductivity, the titanium provides adhesion, and the organic layer provides insulation and flexibility. This composite approach allows thinning of the overall structure while maintaining connection reliability through the synergistic combination of materials.
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 use of titanium and nickel layers improves the adhesion between the organic insulating layer and copper conductive members, preventing peeling and allowing for the creation of thinner semiconductor devices with reliable connections.
Implementation Method 1
the adhesion between the insulating layer and the conductive member is poor; and the conductive member may peel from the insulating layer
Implementation Method 2
a conductive member that is made of copper (Cu) is buried inside an insulating layer made of an organic material
Data Source
AI summary
A semiconductor device includes a redistribution layer, a bump bonded to a first surface of the redistribution layer, and a chip bonded to a second surface of the redistribution layer. The redistribution layer includes an insulating layer, a conductive member connecting the bump to the chip and being provided inside the insulating layer, a bonding electrode connected between the conductive member and the bump, and a conductive layer provided between the insulating layer and the conductive member and between the bonding electrode and the conductive member. A resistivity of the conductive member is lower than a resistivity of the conductive layer.