Sintered Metal Semiconductor Assembly Without Solder Post-Treatment

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Solution Overview

Problem

Existing methods for manufacturing semiconductor devices using laser sintering are complex and require post-treatment processes, particularly due to issues with shrinkage stress and the need for lead-free solder attach materials.

Innovation Solution

A method involving the use of sintered metal powder layers, where a semiconductor device is assembled by alternately providing and laser-sintering metal powder layers to form interconnections, eliminating the need for lead-free solder and post-treatment processes, with the metal pillars and plates made from sintered copper, silver, gold, or stainless steel powder.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If traditional laser sintering methods are used to manufacture semiconductor devices, then metal interconnections can be formed, but the process becomes complex and requires post-treatment processes due to shrinkage stress

Engineering Contradiction:
Improvemanufacturing process simplicityVSAvoidprocess complexity
Core Design Contradiction:
Ease of manufactureVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by controlling laser power, scanning speed, and layer thickness to optimize the sintering process. By adjusting these parameters, the method achieves complete densification without excessive shrinkage stress, eliminating the need for post-treatment processes while maintaining manufacturing simplicity

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent performs preliminary action by pre-heating the substrate and controlling the atmospheric conditions before sintering. This preparation reduces thermal shock and minimizes shrinkage stress during the sintering process, allowing direct formation of dense metal interconnections without subsequent post-treatment

Inventive Principle:
Principle #10Preliminary action

2Reliability

If lead-free solder attach material is used for interconnections, then electronic compliance is achieved, but additional post-treatment processes are required

Engineering Contradiction:
Improveelectronic complianceVSAvoidpost-treatment process requirement
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent extracts the soldering step entirely from the manufacturing process by directly sintering metal powder to form conductive interconnections. This eliminates lead-free solder attach material and all associated post-treatment processes while maintaining electrical connectivity and electronic compliance

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the mechanical soldering process with a thermal sintering process using laser energy. Instead of applying solder material and heating it to melt and bond, the method directly sinters metal powder particles to form solid metal interconnections, eliminating the need for solder and post-solder treatment

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

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 simplifies the manufacturing process by eliminating the need for post-treatment and solder applications, reducing complexity and enabling the formation of robust interconnections suitable for electronics without lead-free solder attach materials.

Implementation Method 1

a scanning laser beam selectively fuses the layer into the desired shape

Methodology Applied
Scientific EffectLaser sintering: Selective Laser Sintering

Implementation Method 2

sintering, with a laser, the layer of the metal powder to form a metal layer

Methodology Applied
Scientific EffectLaser heating: Laser

Data Source

PatentEP4333031A1A semiconductor device and a method of assembling a semiconductor device
Publication Date: 2024.03.06 NEXPERIA BV
  • EP4333031A1 patent drawingFigure 1a~1e
  • EP4333031A1 patent drawingFigure 1f~1j
  • EP4333031A1 patent drawingFigure 2

AI summary

The present disclosure pertains to a semiconductor assembly device comprising a metal layer (5c), a first metal plate (5a), a second metal plate (5b), a metal pillar (3), an encapsulant (6), and a die structure (2) having a first terminal (2a) and a second terminal (2b), wherein the first terminal (2a) of the die structure (2) is in electrically contact with the metal layer (5c), wherein the metal pillar (3) is in electrical contact with the metal layer (5c), and where the second terminal (2b) of the die (2) is in contact with the first metal plate (5a) and the metal pillar (3) is in contact with the second metal plate (5b) and where between the die (2) and the metal pillar (3) and between the first metal plate (5a) and the second metal plate (5b) the encapsulant (6) is provided, and wherein at least one of the metal layer (5c), the first metal plate (5a) or the second metal plate (5b) are made of a sintered metal powder. The disclosure also pertains to a method for manufacturing such semiconductor assembly device.