Metal Pillar Bump with Polymer Passivation Protection

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing wafer level chip scale packaging (WLCSP) technologies face manufacturing challenges due to limitations in the formation of post-passivation interconnects and conductive bump structures, which affect the reliability and electrical performance of semiconductor devices.

Innovation Solution

A semiconductor device structure is formed using a seed layer to create metal pillar bumps and interconnects, followed by a polymer-containing passivation layer with protrusion portions that provide sidewall protection and mechanical support, simplifying the fabrication process and enhancing structural strength and reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional WLCSP packaging technology is used, then manufacturing simplicity and low cost are achieved, but reliability and electrical performance are insufficient due to limitations in post-passivation interconnect and bump structure formation

Engineering Contradiction:

Improvedevice reliabilityVSAvoidfabrication process complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The fabrication process is divided into distinct stages: forming metal pillar bumps first, then forming the passivation layer, and finally forming the conductive bumps. This segmentation allows each structure to be optimized independently, improving overall reliability while maintaining process simplicity through standardized sequential steps

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The metal pillar bumps are formed in advance before the passivation layer is applied. This preliminary action provides a stable structural foundation that enhances subsequent bump formation and improves overall device reliability without adding complex process steps

Inventive Principle:

Principle #10Preliminary action

2Strength

If conventional bump formation methods are used, then manufacturing simplicity is maintained, but structural strength and resistance to delamination are insufficient

Engineering Contradiction:

Improvestructural strengthVSAvoidfabrication simplicity

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The structure combines metal pillar bumps with a polymer-containing passivation layer to create a composite structure. The metal provides structural strength and electrical conductivity, while the polymer matrix provides mechanical support and adhesion, preventing delamination without complicating the manufacturing process

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The passivation layer is formulated with polymer materials specifically at the bump regions to provide enhanced local mechanical support and adhesion. This localized quality enhancement strengthens the bump structure where it is most needed while maintaining overall fabrication simplicity

Inventive Principle:

Principle #3Local quality

3Reliability

If additional protective structures are added to bumps, then reliability and structural integrity are improved, but manufacturing complexity and processing costs increase

Engineering Contradiction:

Improvedevice reliabilityVSAvoidprocessing complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The protective function is merged into the passivation layer itself by incorporating polymer materials during the standard passivation process. This eliminates the need for separate protective coating steps, maintaining ease of manufacture while providing enhanced reliability through the composite structure

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The passivation layer serves multiple functions simultaneously: electrical insulation, mechanical protection, and adhesion prevention. By making the passivation layer multi-functional, additional protective features are achieved without adding separate manufacturing steps or increasing processing complexity

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 solution improves the reliability and electrical performance of semiconductor devices by reducing delamination risks and processing costs, while maintaining effective electrical contact and structural integrity.

Implementation Method 1

forming a polymer-containing passivation layer over the metal layer, wherein the polymer-containing passivation layer provides a mechanical support to the metal pillar bump

Methodology Applied

Scientific EffectMechanical support:

Data Source

PatentUS11171100B2Semiconductor device structure with protected bump and method of forming the same

Publication Date: 2021.11.09 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Structures and formation methods of a semiconductor device structure are provided. The method includes forming a seed layer to cover a first passivation layer over a semiconductor substrate. The method also includes forming a metal layer to partially cover the seed layer by using the seed layer as an electrode layer in a first plating process and forming a metal pillar bump over the metal layer by using the seed layer as an electrode layer in a second plating process. In addition, the method includes forming a second passivation layer over the metal layer, wherein the second passivation layer includes a protrusion portion extending from a top surface of the second passivation layer and surrounding the sidewall of the metal pillar bump.