Fan-Out Interconnect Structure With Sacrificial Layer De-Bonding

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Solution Overview

Problem

In the packaging of semiconductor chips, existing technologies face challenges in protecting delicate adhesive layers from chemical damage during the formation of fan-out interconnect structures, which can lead to difficulties in de-bonding and damage to the package.

Innovation Solution

The use of a sacrificial layer, such as an organic or metal layer, is introduced to prevent chemical penetration and protect the adhesive layer, allowing for the formation of through-vias and redistribution lines while ensuring the adhesive layer remains intact for proper de-bonding.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If chemical etching is used to form through-vias in the adhesive layer, then through-vias can be formed for electrical interconnection, but the adhesive layer suffers chemical damage and loses its bonding capability

Engineering Contradiction:

Improvethrough-via formationVSAvoidadhesive layer integrity

Core Design Contradiction:

Manufacturing precisionVSReliability

Solution Approach 1:

The adhesive layer is segmented into multiple layers: a first adhesive layer that is chemically resistant and a second adhesive layer that provides bonding capability. This segmentation allows the first layer to protect against chemical etching while the second layer maintains bonding function, resolving the contradiction between via formation and adhesive integrity.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A chemically resistant adhesive layer is introduced as an intermediary between the substrate and the bonding adhesive layer. This intermediary layer protects the bonding adhesive from chemical etching damage during through-via formation, enabling via creation without compromising the adhesive's bonding capability.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If the adhesive layer is protected from chemical damage, then de-bonding can be performed successfully, but the process complexity increases due to additional protective layers

Engineering Contradiction:

Improvede-bonding successVSAvoidadhesive layer structure

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

Different regions of the adhesive structure have different chemical resistance properties. The first adhesive layer in the via region is chemically resistant to protect during etching, while other regions use bonding-oriented adhesive material. This local differentiation enables both protection and bonding without requiring complete structural redesign.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS20240321621A1Fan-out interconnect structure and methods forming the same

Publication Date: 2024.09.26 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A method includes forming an adhesive layer over a carrier, forming a sacrificial layer over the adhesive layer, forming through-vias over the sacrificial layer, and placing a device die over the sacrificial layer. The Method further includes molding and planarizing the device die and the through-vias, de-bonding the carrier by removing the adhesive layer, and removing the sacrificial layer.