Sintering Bonding Sheet for Semiconductor Yield

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Solution Overview

Problem

Conventional sintering bonding techniques for semiconductor devices are inefficient, particularly in the transfer step where a sheet for sintering bonding is not effectively cut into small pieces for each semiconductor chip, leading to low yield and reliability issues, especially for high-temperature power semiconductor devices using SiC or GaN.

Innovation Solution

A sheet for sintering bonding comprising an electrically conductive metal containing sinterable particles and a binder component, with specific shear strength and minimum load values measured by SAICAS and nanoindentation methods, ensuring proper adhesion and cuttability, allowing for efficient transfer and high-yield production of semiconductor devices.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If a sheet for sintering bonding is pressed against semiconductor chips to transfer material, then collective supply to multiple chips is achieved, but incomplete cutting leaves portions attached to surroundings causing low yield

Engineering Contradiction:
Improvecollective supply efficiencyVSAvoidtransfer completeness
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The sheet for sintering bonding is segmented into multiple regions, each corresponding to a semiconductor chip. The sheet is divided into a first region that contacts the chips and a second region that serves as a base material. This segmentation enables complete separation and transfer of material to each chip while maintaining collective supply efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention extracts the essential functional portion of the sheet (the first region containing sintering material) from the base material (second region). This extraction ensures that only the necessary material is transferred to the chips, while the base material remains as a separate support structure that can be easily removed.

Inventive Principle:
Principle #2Taking out (Extraction)

2Manufacturing precision

If sintering bonding material is applied to every semiconductor chip individually, then precise material placement is achieved, but production efficiency decreases

Engineering Contradiction:
Improvematerial placement precisionVSAvoidproduction efficiency
Core Design Contradiction:
Manufacturing precisionVSProductivity

Solution Approach 1:

The invention merges the material application process for multiple chips into a single collective operation. The sheet for sintering bonding simultaneously contacts multiple semiconductor chips, allowing material to be supplied to all chips in one step rather than individually, thereby maintaining precision while dramatically improving productivity.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If conventional sintering bonding materials are used, then basic bonding function is achieved, but high-temperature reliability for power semiconductor devices is insufficient

Engineering Contradiction:
Improvebonding functionalityVSAvoidhigh-temperature reliability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The sheet for sintering bonding employs composite material composition that combines multiple components with complementary properties. This composite structure provides both the necessary bonding functionality and enhanced high-temperature reliability required for power semiconductor devices, overcoming the limitations of conventional single-material approaches.

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 sheet for sintering bonding achieves a balance between adhesiveness and cuttability, enabling efficient transfer of the sintering material to semiconductor chips and forming a reliable sintered layer, thereby improving the yield and reliability of semiconductor device production, especially for high-temperature applications.

Implementation Method 1

a heating step is carried out under predetermined temperature and pressurization conditions such that volatilization of the solvent and the like in the material for sintering bonding occurs between the supporting substrate and the semiconductor chip thereon, and sintering between sinterable particles proceeds

Methodology Applied
Scientific EffectSintering: Sintering

Implementation Method 2

volatilization of the solvent and the like in the material for sintering bonding occurs between the supporting substrate and the semiconductor chip thereon

Methodology Applied
Scientific EffectVolatilization: Evaporation

Data Source

PatentEP3709351A1Sheet for sintering bonding with base material
Publication Date: 2020.09.16 NITTO DENKO CORP
  • EP3709351A1 patent drawingFigure 1~2
  • EP3709351A1 patent drawingFigure 3(a)~3(c)
  • EP3709351A1 patent drawingFigure 4~5

AI summary

A sheet for sintering bonding (10) comprises an electrically conductive metal containing sinterable particles and a binder component. In the sheet for sintering bonding (10), the shear strength at 23°C (F) (in MPa), measured in accordance with a SAICAS method and the minimum load (f) (in µN), which is reached during an unloading process in load-displacement measurement in accordance with a nanoindentation method, satisfy 0.1 ≤ F/f ≤ 1. The shear strength at 23°C (F) measured in accordance with a SAICAS method may be 2 to 40 MPa. The minimum load (f) which is reached during an unloading process in load-displacement measurement in accordance with a nanoindentation method may be 30 to 100 µN. A sheet body (X) has a laminated structure comprising a base material (B) and the sheet for sintering bonding (10). The sheet for sintering bonding (10) may be collectively transferred from the base material (B) to a plurality of chips (C) on a tape for processing (T1) by lamination and subsequent separation of the base material (B), wherein a small piece of the sheet for sintering bonding (10) is cut during the separation step so as to form a layer of material for sintering bonding (11) on each chip (C).