Method of bonding a semiconductor die to a wafer

Solution Overview

Problem

The challenge in bonding semiconductor dies to master wafers using direct bonding methods is the inability to pressurize thin dies without causing cracks, leading to incomplete bonding or peeling due to heat expansion of through electrodes.

Innovation Solution

A bonding method involving thickness processing, hydrophilizing, temporary bonding, main bonding with pressurization and heating, protective agent application, and etching to ensure complete bonding without damage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If direct bonding is performed without bonding medium, then bonding quality between through electrodes is improved, but thin dies cannot be pressurized without causing cracks

Engineering Contradiction:

Improvebonding qualityVSAvoiddie integrity

Core Design Contradiction:

ReliabilityVSStrength

Solution Approach 1:

The die thickness is increased in advance before bonding, providing sufficient thickness to withstand pressurization during bonding while ensuring complete bonding of through electrodes. After bonding, the excess thickness is removed through etching to restore the original specifications.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A protective layer is applied to the die surface before bonding to cushion and distribute the pressurization force during bonding, preventing stress concentration that could cause cracks in thin dies while still allowing effective bonding pressure to be applied.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If thin dies are pressurized during bonding, then complete bonding of through electrodes is achieved, but cracks occur inside the die

Engineering Contradiction:

Improvebonding completenessVSAvoiddie damage

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The die thickness is increased in advance before bonding, providing sufficient thickness to withstand pressurization during bonding while ensuring complete bonding of through electrodes. After bonding, the excess thickness is removed through etching to restore the original specifications.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A protective layer is applied to the die surface before bonding to cushion and distribute the pressurization force during bonding, preventing stress concentration that could cause cracks in thin dies while still allowing effective bonding pressure to be applied.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

3Stress or pressure

If bonding head pressurizes thin dies, then bonding pressure is sufficient for complete bonding, but the bonding head cannot effectively pressurize without causing damage

Engineering Contradiction:

Improvebonding pressureVSAvoiddie structural integrity

Core Design Contradiction:

Stress or pressureVSStrength

Solution Approach 1:

The die thickness is increased in advance before bonding, providing sufficient thickness to withstand pressurization during bonding while ensuring complete bonding of through electrodes. After bonding, the excess thickness is removed through etching to restore the original specifications.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

A protective layer is applied to the die surface before bonding to cushion and distribute the pressurization force during bonding, preventing stress concentration that could cause cracks in thin dies while still allowing effective bonding pressure to be applied.

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

Ensures efficient bonding of semiconductor dies to master wafers with improved bonding quality and reduced damage, preventing cracks and peeling, thereby enhancing production yield.

Implementation Method 1

a hydrophilizing treating step S1 for hydrophilizing a bonding surface between the die D and the master wafer MW

Methodology Applied

Scientific EffectHydrophilizing: Hydrophile

Implementation Method 2

the bonding surface is surface-treated using a plasma

Methodology Applied

Scientific EffectPlasma treatment: Plasma

Implementation Method 3

a temporary bonding step S2 for temporarily bonding the bonding surface which has been hydrophilized at a room temperature to each other

Methodology Applied

Scientific EffectAdhesion: Adhesive

Implementation Method 4

In the complete bonding step S3, a high temperature is transferred to the die D. The first through electrode WE and the second through electrode DE may be expanded by a heat

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 5

a bonding head temporarily bonds the die D to the bonding surface of the master wafer MW. During a temporary bonding, a first through electrode WE of the master wafer MW and a second through electrode DE of the die D may be aligned with each other

Methodology Applied

Scientific EffectMechanical pressurization: Compression

Data Source

PatentUS12506113B2Method of bonding a semiconductor die to a wafer

Publication Date: 2025.12.23 SYSTEM ENGINEERING MEGA SOLUTION CO LTD

AI summary

The inventive concept provides a bonding method. The bonding method includes bonding a second bonding object to a first bonding object, which is a bonding step; providing a protective agent to a region of the first bonding object which is not bonded to the second bonding object, which is a protective agent providing step; and etching a backside of the second bonding object, which is an etching step.