Semiconductor Bump Structure with Composite Shell for Bridge Prevention

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Current semiconductor packages face challenges in achieving high integration and performance due to limitations in existing integration technologies, requiring multiple chips to be stacked while maintaining structural integrity and preventing process defects and bridge failures.

Innovation Solution

A semiconductor package design featuring a bump structure with a core portion and a shell portion, where the shell portion surrounds the core portion and has a higher melting point, allowing for efficient stacking and connection of semiconductor chips while preventing bridge failures and reducing process defects.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If multiple semiconductor chips are stacked to increase integration, then the degree of integration is improved, but the risk of bridge failures and process defects increases

Engineering Contradiction:

Improvedegree of integrationVSAvoidstructural integrity

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The bump structure is segmented into a core portion and a shell portion with different material compositions and melting points. The core portion provides electrical connection while the shell portion acts as a protective barrier, preventing material migration and bridge failures between adjacent bumps during the stacking process

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The bump structure uses composite materials with different melting points - the core portion contains a lower melting point material for reliable electrical connection, while the shell portion contains a higher melting point material that prevents bridge failures by maintaining structural integrity at elevated temperatures during processing

Inventive Principle:

Principle #40Composite materials

2Productivity

If finer pitches are used to increase integration density, then the degree of integration is improved, but the risk of bridge failures increases

Engineering Contradiction:

Improveintegration densityVSAvoidbridge failures

Core Design Contradiction:

ProductivityVSObject-affected harmful factors

Solution Approach 1:

The shell portion acts as an intermediary protective layer between adjacent core portions. This intermediate structure prevents direct contact and potential bridging between neighboring bumps, enabling finer pitches while maintaining reliability by isolating each bump structure

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The composite bump structure with the higher melting point shell material provides thermal and physical isolation between adjacent bumps at finer pitches, preventing material flow and bridge failures even when bumps are closely spaced

Inventive Principle:

Principle #40Composite materials

3Reliability

If higher temperatures are applied during processing to ensure connection, then the joining reliability is improved, but the risk of process defects increases

Engineering Contradiction:

Improvejoining reliabilityVSAvoidprocess defects

Core Design Contradiction:

ReliabilityVSObject-generated harmful factors

Solution Approach 1:

The bump structure has local quality variations with different melting points in different regions - the core portion melts at a lower temperature to ensure reliable electrical connection and material flow, while the shell portion maintains higher melting point to prevent process defects such as bridge failures during temperature cycling

Inventive Principle:

Principle #3Local quality

Solution Approach 2:

The higher melting point shell portion provides beforehand protection against bridge failures and material migration during high-temperature processing steps. This protective shell is in place before processing occurs, cushioning against potential harmful effects of thermal exposure

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

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 design enhances the performance of semiconductor packages by maintaining structural integrity under high temperatures, preventing bridge failures, and reducing process constraints, enabling finer pitches and lower manufacturing defects.

Implementation Method 1

the shell portion has a higher melting point than the core portion

Methodology Applied

Scientific EffectMelting point difference: Melting

Implementation Method 2

forming a core portion by joining the first sidewall of the first core portion and the first sidewall of the second core portion

Methodology Applied

Scientific EffectThermal bonding: Soldering

Data Source

PatentUS11705416B2Semiconductor package including stacked semiconductor chips and method for fabricating the same

Publication Date: 2023.07.18 SK HYNIX INC

AI summary

A semiconductor package may include: a first semiconductor chip; a second semiconductor chip disposed over the first semiconductor chip; and a bump structure interposed between the first semiconductor chip and the second semiconductor chip to connect the first semiconductor chip and the second semiconductor chip, wherein the bump structure includes a core portion and a shell portion, the shell portion surrounding all side ails of the core portion, and wherein the shell portion has a higher melting point than the core portion.