Hybrid Bonded Multilayer Body With Resin Insulation for Void Control

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Solution Overview

Problem

Hybrid bonding in semiconductor manufacturing faces issues with low bonding strength of SiO2 insulating layers and void generation due to foreign matters, leading to electrical continuity failures and reduced reliability of laminates.

Innovation Solution

A method involving direct bonding of substrates with exposed metal electrodes and resin layers containing specific resins like polyimides and polybenzoxazoles, which have functional groups for improved adhesion and insulation, along with optional inorganic insulating layers, to enhance bonding strength and reduce voids.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If SiO2 insulating layer is used in hybrid bonding, then insulation is provided, but bonding strength is low

Engineering Contradiction:
Improvebonding strengthVSAvoidelectrical continuity
Core Design Contradiction:
StrengthVSReliability

Solution Approach 1:

The patent uses a composite resin layer combining inorganic filler particles (such as silica, alumina, or boehmite) with organic resin materials (epoxy, polyimide, or polybenzoxazole). This composite structure provides both mechanical bonding strength from the resin matrix and insulation properties from the inorganic fillers, resolving the contradiction between bonding strength and electrical insulation.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent modifies the physical and chemical parameters of the insulating layer by controlling filler particle size (0.1-10 μm), filler concentration (30-70 wt%), and resin composition. These parameter changes optimize both bonding strength and insulation properties, eliminating the trade-off between these two characteristics.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If chip dicing is performed to create chips for C2W bonding, then chip production is enabled, but foreign matters are generated that cause voids in bonding interface

Engineering Contradiction:
Improvechip productionVSAvoidbonding interface quality
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The resin layer is designed with controlled porosity and viscoelastic properties that allow it to absorb and accommodate foreign particles generated during dicing. The resin matrix can deform to envelop small contaminants, preventing them from creating voids at the bonding interface while maintaining overall bonding quality.

Inventive Principle:
Principle #31Porous materials

Solution Approach 2:

The patent optimizes resin viscosity, curing characteristics, and thermal expansion coefficients to match the dicing process conditions. By adjusting these parameters, the resin remains workable during assembly but forms a robust bond that tolerates minor contaminants, enabling high-productivity dicing without compromising bonding interface quality.

Inventive Principle:
Principle #35Parameter changes

3Productivity

If electrode density is increased for high integration, then mounting density is improved, but bonding reliability decreases due to voids and foreign matters

Engineering Contradiction:
Improvemounting densityVSAvoidbonding interface reliability
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The patent creates local quality variations in the resin layer by controlling filler distribution, resin crosslinking density, and layer thickness in different regions. This allows the bonding interface to have enhanced properties at critical high-density electrode areas while maintaining overall structural integrity, enabling high mounting density without sacrificing reliability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The composite resin structure with strategically distributed inorganic fillers provides localized reinforcement and void-prevention capabilities in high-density bonding regions. The combination of resin and filler creates a material that can accommodate the stress and contamination challenges of high-electrode-density bonding while maintaining electrical insulation and mechanical strength.

Inventive Principle:
Principle #40Composite 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 method results in laminates with high bonding strength and minimal voids, ensuring high reliability and electrical integrity.

Implementation Method 1

step (III) of laminating the first substrate and the second substrate together by direct bonding

Methodology Applied
Scientific EffectDirect bonding: Welding

Data Source

PatentEP4651186A1Method for producing multilayer body, and resin composition
Publication Date: 2025.11.19 TORAY INDUSTRIES INC
  • EP4651186A1 patent drawingFigure 1~2
  • EP4651186A1 patent drawingFigure 3a~3e
  • EP4651186A1 patent drawingFigure 4a~4f

AI summary

The present invention addresses the problem of conventional insulating layers that are formed of SiO2, the problem being low bonding strength. The present invention also addresses the problem of conduction failure of an electrode or reliability decrease of an obtained multilayer body in cases where a semiconductor element is bonded by means of C2W. The present invention provides a method for producing a multilayer body, the method comprising: a step (I) of preparing a first substrate which is provided, on the same surface of a substrate main body, with an exposed metal electrode (A-1) and an exposed resin layer (B-1); a step (II) of preparing a second substrate which is provided, on the same surface of a substrate main body, with an exposed metal electrode (A-2) and an exposed resin layer (B-2), or alternatively with an exposed metal electrode (A-2) and an exposed inorganic insulating layer (C); and a step (III) of bonding the first substrate and the second substrate to each other by means of direct bonding, while having at least a part of the metal electrode (A-1) and the metal electrode (A-2) face each other and having at least a part of the resin layer (B-1) and the resin layer (B-2) face each other, or alternatively having at least a part of the metal electrode (A-1) and the metal electrode (A-2) face each other and having at least a part of the resin layer (B-1) and the inorganic insulating layer (C) face each other. With respect to this method for producing a multilayer body, the resin layer (B-1) and the resin layer (B-2) each contain a specific resin.