Front Electrode Laser Surface Modification for Resin Adhesion

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Solution Overview

Problem

The formation of a polyimide film on a front electrode in semiconductor apparatuses complicates production, increases costs, and reduces ease of assembly due to stress-induced chip warpage and reduced solder joinability.

Innovation Solution

Modifying the outermost surface of a front electrode using laser irradiation to form a laser-modified portion, which is then covered with a resin sealing material, thereby enhancing adhesion and preventing peeling without the need for a polyimide film.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a polyimide film is formed on the front electrode to prevent peeling, then reliability is improved, but device complexity and manufacturing cost increase

Engineering Contradiction:

Improvepeeling preventionVSAvoidproduction steps

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts and eliminates the polyimide film layer from the structure, replacing it with a simplified design where the front electrode directly contacts the sealing resin. This removes the complex film formation steps while maintaining peeling prevention through proper material selection and interface design.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The front electrode is designed to serve multiple functions: it provides electrical connection, structural support, and direct bonding interface with the sealing resin. By making the electrode multifunctional, the patent eliminates the need for separate polyimide film that would otherwise provide structural and bonding functions.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Reliability

If a polyimide film is formed on the front electrode to prevent peeling, then reliability is improved, but manufacturing cost increases

Engineering Contradiction:

Improvepeeling preventionVSAvoidproduction cost

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent removes the polyimide film formation process entirely, eliminating associated material costs, equipment requirements, and process steps. The simplified structure reduces manufacturing complexity and cost while maintaining reliability through direct electrode-resin bonding.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The patent uses cost-effective materials and processes, replacing expensive polyimide film formation with simpler, more economical direct bonding techniques that achieve the same protective function at lower cost.

Inventive Principle:

Principle #27Cheap short-living objects (Disposable)

3Reliability

If a polyimide film is formed on the front electrode to prevent peeling, then reliability is improved, but ease of assembly deteriorates due to chip warpage

Engineering Contradiction:

Improvepeeling preventionVSAvoidassembly ease

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

By removing the polyimide film, the patent eliminates the source of stress-induced warpage. The direct bonding structure reduces thermal and mechanical stress, resulting in flatter chips that are easier to handle and assemble without complex warpage compensation techniques.

Inventive Principle:

Principle #2Taking out (Extraction)

4Reliability

If a polyimide film is formed on the front electrode to prevent peeling, then reliability is improved, but ease of assembly deteriorates due to reduced solder joinability

Engineering Contradiction:

Improvepeeling preventionVSAvoidsolder joinability

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The patent eliminates the polyimide film that interfered with soldering, allowing direct solder contact with the front electrode. This improves wetting and joinability while maintaining peeling prevention through alternative bonding mechanisms at the electrode-resin interface.

Inventive Principle:

Principle #2Taking out (Extraction)

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 production costs and enhances ease of assembly by improving adhesion and preventing cracks in the semiconductor apparatus, while also reducing chip warpage and improving solder wettability.

Implementation Method 1

modifies an outermost surface of a front electrode by laser irradiation

Methodology Applied

Scientific EffectLaser irradiation: Laser

Implementation Method 2

a first laser-modified portion whose outermost surface is oxidized and roughened

Methodology Applied

Scientific EffectOxidation: Oxidation

Data Source

PatentUS20250191916A1Semiconductor apparatus and method for producing the same

Publication Date: 2025.06.12 MITSUBISHI ELECTRIC CORP

AI summary

The present disclosure relates to a semiconductor apparatus and a method for producing the same and has as its object to provide a semiconductor apparatus and a method for producing the same capable of achieving reduction in semiconductor apparatus costs and enhancement in ease of assembly by modifying an outermost surface of a front electrode by laser irradiation. The semiconductor apparatus of the present disclosure includes a front electrode solder-joined portion of the present disclosure, solder, a resin sealing material, and a semiconductor device which is mounted underneath the front electrode solder-joined portion. The front electrode solder-joined portion has a first laser-modified portion whose outermost surface is oxidized and roughened and a first solder-joined region which is joined to the solder, and the laser-modified portion is covered with the resin sealing material.