Semiconductor Package With Hydrostatic Stress Filling

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Solution Overview

Problem

Existing semiconductor device packages face challenges in managing anisotropic stress, which can lead to parameter drift and reduced stability of electrical components due to environmental influences and encapsulation processes.

Innovation Solution

A multi-shell semiconductor device package structure is introduced, where a stronger outer package part surrounds a second package part filled with a material like silicone gel, creating a hydrostatic stress state by ensuring equal stress distribution along orthogonal main stress directions, thereby suppressing shear stresses and enhancing stability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single package part encapsulates the device, then the structure is simple and manufacturing is easier, but anisotropic stress acts on the device causing parameter drift and reduced stability

Engineering Contradiction:
Improvepackage structureVSAvoidelectrical parameter stability
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The package is divided into multiple package parts (first package part, second package part, third package part) with different materials and mechanical properties. This segmentation allows each part to contribute differently to stress management, with softer parts absorbing anisotropic stresses and harder parts providing structural support, thereby preventing parameter drift while maintaining manufacturing feasibility.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention employs composite material construction where different package parts are made from materials with varying mechanical properties (different Young's moduli). This composite structure enables the package to manage stresses more effectively, creating a hydrostatic stress state that protects the device from anisotropic stress-induced parameter drift.

Inventive Principle:
Principle #40Composite materials

2Reliability

If environmental influences and additional potting compounds are applied, then shock resistance and temperature stress reduction are improved, but shear stresses increase causing parameter drift

Engineering Contradiction:
Improveshock resistance and temperature stabilityVSAvoidshear stress on device
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

Different regions of the package structure are assigned different material properties tailored to local requirements. The softer package parts are positioned to absorb environmental stresses, while the harder package parts provide structural support. This local differentiation allows the package to resist shock and temperature stresses without transmitting harmful shear stresses to the device.

Inventive Principle:
Principle #3Local quality

3Reliability

If the encapsulation process applies compressive stress, then the device is protected and enclosed, but anisotropic compressive stress causes parameter drift

Engineering Contradiction:
Improvedevice protectionVSAvoidanisotropic compressive stress
Core Design Contradiction:
ReliabilityVSStress or pressure

Solution Approach 1:

The multi-part package structure is designed beforehand to cushion and distribute encapsulation stresses. The softer package parts act as stress-absorbing elements that prevent anisotropic compressive stress from reaching the device during the encapsulation process, while still providing adequate protection.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

4Adaptability or versatility

If feed-through connections are introduced, then electrical functionality is enabled, but shear stresses occur during fixing and soldering

Engineering Contradiction:
Improveelectrical connectivityVSAvoidshear stress during assembly
Core Design Contradiction:
Adaptability or versatilityVSStress or pressure

Solution Approach 1:

The multi-part package structure acts as an intermediary that decouples the stress transmission path during feed-through connection assembly. The softer package parts absorb shear stresses generated during fixing and soldering operations, preventing these stresses from being transmitted to the device while still allowing electrical functionality to be achieved.

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3451374B1Semiconductor device package
Publication Date: 2023.03.15 TDK MICRONAS GMBH
  • EP3451374B1 patent drawingFigure 1~2

AI summary

A semiconductor device package, comprising a device disposed in a package, wherein the device has at least two electrical connections which pass through the package, and wherein the package comprises a first package part and a second package part, and the first package part surrounds the second package part and the first package part comprises a different material than the second package part, and the second package part comprises a filling material, and the filling material surrounds the device and the three main stresses of the stress tensor, which stresses act on the device along the main stress directions formed orthogonally to one another, are of the same magnitude due to the filling material, so that there is a hydrostatic stress state for the device.