Die Bonding Adhesive Particle Distribution Against Wet-Spreading

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Solution Overview

Problem

Photosemiconductor devices face contamination issues due to wet-spreading of die bonding adhesive materials, which interfere with wire bonding and die bonding, and existing solutions like forming grooves on lead electrodes do not fully address the problem.

Innovation Solution

A semiconductor device with a base body and a semiconductor element bonded using an adhesive member containing surface-treated particles or particles with a dispersing agent, where at least a part of the adhesive member's marginal portion has uneven particle distribution, suppressing wet-spreading through capillary forces and convection currents.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If die bonding adhesive material is applied to bond semiconductor element on base body, then bonding strength is improved, but wet-spreading occurs contaminating the upper surface of substrate

Engineering Contradiction:
Improvebonding strengthVSAvoidcontamination from wet-spreading
Core Design Contradiction:
StrengthVSObject-affected harmful factors

Solution Approach 1:

The adhesive member incorporates particles with non-uniform distribution where the concentration of particles varies in different regions. Specifically, the particle concentration is higher near the marginal portion and lower toward the center, creating local variations in viscosity and surface tension that suppress wet-spreading at the edges while maintaining bonding strength in the bonding region

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The adhesive member is formulated as a composite material containing a resin base and dispersed particles (such as metal particles, oxide particles, or phosphor particles). This composite structure modifies the rheological properties of the adhesive to control wet-spreading behavior while maintaining effective bonding characteristics

Inventive Principle:
Principle #40Composite materials

2Object-affected harmful factors

If groove is formed on surface of lead electrode to prevent wet-spreading, then contamination is reduced, but device complexity and manufacturing difficulty increase

Engineering Contradiction:
Improvecontamination from wet-spreadingVSAvoidstructural complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

Instead of modifying the geometric structure of the base body or lead electrode, the invention changes the material parameters of the adhesive member itself by incorporating particles with specific concentration distributions. This approach controls wet-spreading through material composition rather than structural design, avoiding increased device complexity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The solution extracts the wet-spreading control function from the base body structure and transfers it to the adhesive member composition. By formulating the adhesive with appropriate particle distributions, the adhesive itself becomes the active element that prevents wet-spreading, eliminating the need for additional structural features like grooves

Inventive Principle:
Principle #2Taking out (Extraction)

3Ease of manufacture

If particles are uniformly distributed in adhesive member, then manufacturing simplicity is maintained, but wet-spreading cannot be suppressed

Engineering Contradiction:
Improvemanufacturing simplicityVSAvoidwet-spreading
Core Design Contradiction:
Ease of manufactureVSObject-affected harmful factors

Solution Approach 1:

The adhesive member incorporates particles with non-uniform distribution where the concentration of particles varies in different regions. Specifically, the particle concentration is higher near the marginal portion and lower toward the center, creating local variations in viscosity and surface tension that suppress wet-spreading at the edges while maintaining bonding strength in the bonding region

Inventive Principle:
Principle #3Local quality

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

Effectively prevents contamination and ensures strong connections between the base body and semiconductor element, reducing electrical open defects and heat radiation issues while allowing for high-density mounting.

Implementation Method 1

at least a part of the marginal portion of the adhesive member is a region where the particles are unevenly distributed

Methodology Applied
Scientific EffectCapillary force: Capillary Action

Implementation Method 2

suppressing wet-spreading through capillary forces and convection currents

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP3696866B1Semiconductor device
Publication Date: 2023.11.01 NICHIA CORP
  • EP3696866B1 patent drawingFigure 1A~1B
  • EP3696866B1 patent drawingFigure 2A~2B
  • EP3696866B1 patent drawingFigure 3A~3B

AI summary

The present invention provides a semiconductor device in which wet-spreading of an adhesive member for bonding the semiconductor element on a base body is suppressed. The semiconductor device (100) of the present invention is a semiconductor device including a base body (10), and a semiconductor element (20) bonded on the base body via an adhesive member (30), wherein the adhesive member (30) contains surface-treated particles (40), or particles (40) that coexist with a dispersing agent, and at least a part of the marginal portion (301) of the adhesive member is a region where the particles (40) are unevenly distributed.