Conductive Layer Reinforcing Section for Semiconductor Stress Management

Solution Overview

Problem

Semiconductor devices face issues with stress-induced cracks in conductive layers under electrode pads or bumps due to bonding and residual stress, which impair the characteristics of semiconductor elements and interconnects.

Innovation Solution

The semiconductor device incorporates a reinforcing section at the connection area between conductive layers, positioned strategically relative to the edge of the electrode pad or bump, to mitigate stress and prevent cracks, using a configuration that includes a first conductive layer with a specific width, a second conductive layer with a smaller width, an interlayer dielectric, and a passivation layer with openings for bumps, allowing for enhanced mechanical strength and reliable connections.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conductive layer is formed under an electrode pad or bump, then electrical connection is achieved, but stress-induced cracks occur due to bonding and residual stress

Engineering Contradiction:

Improvereliability of conductive layerVSAvoidmechanical strength of conductive layer

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The patent applies local quality by creating a reinforcing section with different material composition or structure at the specific location under the electrode pad or bump. This reinforcing section has enhanced mechanical properties compared to the surrounding conductive layer, providing localized stress resistance where it is most needed while maintaining electrical connectivity throughout the conductive layer.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent employs composite materials by combining the base conductive material with additional reinforcing materials or structures. The conductive layer includes a reinforcing section that may consist of different materials or multi-layer structures, creating a composite that simultaneously provides electrical conductivity and enhanced mechanical strength to resist stress-induced cracks.

Inventive Principle:

Principle #40Composite materials

2Reliability

If the connection section is positioned under the electrode pad, then electrical connection is established, but stress concentration occurs leading to cracks

Engineering Contradiction:

Improveconnection reliabilityVSAvoidstress concentration

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent applies local quality by creating a reinforcing section with different material composition or structure at the specific location under the electrode pad or bump. This reinforcing section has enhanced mechanical properties compared to the surrounding conductive layer, providing localized stress resistance where it is most needed while maintaining electrical connectivity throughout the conductive layer.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements beforehand cushioning by pre-positioning the reinforcing section at the connection location before stress application occurs during bonding. This reinforcing structure acts as a preventive measure, cushioning against the anticipated stress concentration and preventing crack formation before it can occur during the bonding process or device operation.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Strength

If a reinforcing section is added to the conductive layer, then crack resistance is improved, but device complexity increases

Engineering Contradiction:

Improvecrack resistance of conductive layerVSAvoidstructural complexity of conductive layer

Core Design Contradiction:

StrengthVSDevice complexity

Solution Approach 1:

The patent applies local quality by creating a reinforcing section with different material composition or structure at the specific location under the electrode pad or bump. This reinforcing section has enhanced mechanical properties compared to the surrounding conductive layer, providing localized stress resistance where it is most needed while maintaining electrical connectivity throughout the conductive layer.

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The patent implements partial action by applying the reinforcing section only at the critical connection location under the electrode pad or bump, rather than throughout the entire conductive layer. This localized reinforcement provides sufficient crack resistance at the stress-prone area while minimizing the overall structural complexity and material usage compared to a fully reinforced conductive layer.

Inventive Principle:

Principle #16Partial or excessive action

Data Source

PatentUS8878365B2Semiconductor device having a conductive layer reliably formed under an electrode pad

Publication Date: 2014.11.04 SEIKO EPSON CORP

AI summary

A semiconductor device, including: a semiconductor layer; a first conductive layer formed above the semiconductor layer and having a first width; a second conductive layer connected to the first conductive layer and having a second width which is smaller than the first width; an interlayer dielectric formed above the first conductive layer and the second conductive layer; and an electrode pad formed above the interlayer dielectric. A connection section at which the first conductive layer and the second conductive layer are connected is disposed in a specific region positioned inward from a line extending vertically downward from an edge of the electrode pad; and a reinforcing section is provided at the connection section.