Sinter Sheet with Chip Convex Portions for Stress-Free Press-Sintering

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Solution Overview

Problem

The existing manufacturing method for semiconductor devices requires forming grooves in the connected member, which complicates the process and makes mass production difficult, and there is a risk of damaging the semiconductor chip during the pressing process.

Innovation Solution

A semiconductor device structure that uses a sinter sheet with concave portions corresponding to the convex portions of the semiconductor chip, where the sinter sheet is press-sintered to form a middle-layer sintered member with a specific sinter density distribution, avoiding stress concentration on the chip and allowing for easier manufacturing without grooves in the connected member.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If grooves are formed in the connected member to prevent stress concentration, then the semiconductor chip is protected from damage, but the manufacturing process becomes complicated and mass production becomes difficult

Engineering Contradiction:

Improvechip protectionVSAvoidmanufacturing process

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

Instead of forming grooves in the connected member to protect the chip, the invention inverts the approach by forming convex portions directly on the semiconductor chip. This eliminates the need for grooves in the connected member, simplifying the manufacturing process while still protecting the chip from stress concentration during pressing operations.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The invention extracts the protective feature (grooves) from the connected member and transfers it to the semiconductor chip as convex portions. This extraction simplifies the connected member's structure and manufacturing process while maintaining the chip protection function through the relocated convex portions that distribute pressing stress.

Inventive Principle:

Principle #2Taking out (Extraction)

2Temperature

If a press-sintered body is used between the semiconductor chip and connected member, then heat conductivity is improved, but the manufacturing complexity increases due to the need for groove formation

Engineering Contradiction:

Improveheat conductivityVSAvoidstructure complexity

Core Design Contradiction:

TemperatureVSDevice complexity

Solution Approach 1:

The invention inverts the traditional structure by placing convex portions on the chip rather than grooves in the connected member. This maintains the heat-conductive press-sintered body function while reducing structural complexity, as the press-sintered body now fills the spaces between convex portions rather than requiring precise groove formation in the connected member.

Inventive Principle:

Principle #13The other way round (Inversion)

3Strength

If the connected member is pressed to connect to the semiconductor chip, then the connection is formed, but stress concentrates on the convex portions of the chip causing potential damage

Engineering Contradiction:

Improveconnection strengthVSAvoidstress concentration

Core Design Contradiction:

StrengthVSObject-affected harmful factors

Solution Approach 1:

The invention applies local quality by creating convex portions with specific geometric characteristics on the chip surface. These convex portions have optimized dimensions and distributions that locally manage stress during pressing, preventing stress concentration while maintaining strong connections. The press-sintered body material properties are also optimized locally to distribute stress evenly.

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

This approach reduces the risk of chip damage during manufacturing, simplifies the production process, and maintains high heat conductivity comparable to or exceeding that of solder, while allowing for mass production of semiconductor devices.

Implementation Method 1

the sinter sheet formed between the semiconductor chip and the connected member is heated and pressed to form the sintered member and to connect the semiconductor chip to the connected member

Methodology Applied

Scientific EffectSintering: Sintering

Implementation Method 2

it is possible to increase heat conductivity, when compared with a case in which solder is provided between the semiconductor chip and the connected member

Methodology Applied

Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentUS11557563B2Sinter sheet, semiconductor device and manufacturing method thereof

Publication Date: 2023.01.17 DENSO CORP

AI summary

A sintered member is provided between a semiconductor chip and a terminal. The sintered member is made of a sinter sheet by heating and pressing the same. The semiconductor chip is connected to the terminal via the sintered member. Convex portions are formed at a front-side surface of the semiconductor chip. Concave portions, each of which has such a shape corresponding to that of each convex portion of the semiconductor chip, are formed at a surface of the sintered member facing to the semiconductor chip.