Flexible Chip Package Structure with Photosensitive Encapsulation

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Solution Overview

Problem

Existing semiconductor chip packaging methods are not fully satisfactory as device scaling-down continues, particularly in terms of flexibility and reliability, as they struggle to maintain mechanical and structural support while ensuring adequate protection and connectivity.

Innovation Solution

A chip package structure is formed using a flexible protection layer, a photosensitive layer, and a redistribution layer, with a carrier substrate providing temporary support, and an anisotropic conductive paste connecting the chip to a printed circuit board, allowing for flexibility and improved connectivity.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If traditional chip packaging methods are used, then mechanical support and structural stability are maintained, but flexibility and adaptability are limited

Engineering Contradiction:

ImproveflexibilityVSAvoidmechanical support

Core Design Contradiction:

Adaptability or versatilityVSStrength

Solution Approach 1:

The packaging structure is divided into multiple functional layers including a flexible substrate layer, chip mounting layer, and protective encapsulation layer. This segmentation allows each layer to perform its specific function optimally while contributing to overall flexibility without compromising structural support.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent employs flexible substrate materials and thin film encapsulation layers to create a bendable packaging structure. These flexible components replace traditional rigid packaging materials, enabling the chip package to adapt to curved surfaces and flexible circuit boards while maintaining mechanical integrity through careful material selection and layer design.

Inventive Principle:

Principle #30Flexible shells and thin films

2Device complexity

If chip size is reduced for scaling, then device complexity and integration are improved, but manufacturing precision and reliability become more difficult to maintain

Engineering Contradiction:

ImproveintegrationVSAvoidpackaging precision

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent implements preliminary alignment features and pre-formed conductive structures on the flexible substrate before chip mounting. This preliminary preparation ensures precise positioning of miniaturized chips and their electrical connections, overcoming the manufacturing precision challenges associated with reduced chip sizes and high integration densities.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The flexible substrate acts as an intermediary platform that provides a stable mounting surface and integrated electrical interconnect structure for small chips. This intermediary layer facilitates precise positioning and reliable electrical connections even when chips are miniaturized, bridging the gap between small chip dimensions and manufacturing precision requirements.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If protection layer thickness is increased for better protection, then reliability is improved, but flexibility and thinness are reduced

Engineering Contradiction:

ImproveprotectionVSAvoidthickness

Core Design Contradiction:

ReliabilityVSLength of moving object

Solution Approach 1:

The patent uses composite encapsulation materials that combine high mechanical strength and protective properties with flexible characteristics. These composite protection layers provide adequate mechanical protection and environmental sealing for the chip while remaining thin and flexible, eliminating the need to increase thickness to achieve reliable protection.

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 solution enables the creation of a flexible chip package structure that maintains mechanical integrity, provides effective protection, and enhances connectivity, addressing the limitations of existing methods by allowing for thinner, more reliable, and cost-effective packaging.

Implementation Method 1

an anisotropic conductive paste connecting the chip to a printed circuit board

Methodology Applied

Scientific EffectElectrical conduction: Conduction (electrical)

Implementation Method 2

a second photosensitive layer formed around sidewalls and a top surface of the second chip

Methodology Applied

Scientific EffectPhotopolymerization: Photopolymerisation

Data Source

PatentUS10879153B2Chip package structure

Publication Date: 2020.12.29 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Chip package structures are provided. The chip package structure includes a protection layer and a first chip disposed over the protection layer. The chip package structure further includes a first photosensitive layer formed around sidewalls of the first chip and covering a top surface of the first chip and a second chip disposed over the first photosensitive layer. In addition, the first chip and the second chip are separated by the first photosensitive layer.