RDL Package Structure with Encapsulant Recess for Adhesion

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Solution Overview

Problem

The semiconductor industry faces challenges in achieving high integration density and compact packaging of electronic components due to limitations in reducing feature size and packaging efficiency, particularly in the formation of reliable and compact 3D packaging structures that enhance adhesion and prevent water permeation.

Innovation Solution

The method involves forming a package structure with a redistribution layer (RDL) and encapsulant that includes a recess and extending part, where the encapsulant extends into the RDL structure, increasing contact area and enhancing adhesion, and using a combination of polymer and conductive materials to create a robust and compact package with improved reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Productivity

If traditional packaging methods are used, then manufacturing simplicity is maintained, but integration density and compactness are limited

Engineering Contradiction:

Improveintegration densityVSAvoidpackage structure complexity

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The encapsulant includes a recess that receives and nests the adhesive layer and die assembly, creating a compact nested structure where multiple components occupy overlapping spatial volumes. This nesting approach enables higher integration density without proportionally increasing the package footprint.

Inventive Principle:

Principle #7Nested doll (Nesting)

Solution Approach 2:

The patent transitions from traditional 2D planar packaging to 3D vertical packaging by stacking the die, adhesive layer, and encapsulant with recess in multiple layers. This dimensional change allows increased integration density by utilizing vertical space rather than only horizontal expansion.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Productivity

If feature size is continuously reduced, then integration density improves, but manufacturing precision requirements increase

Engineering Contradiction:

Improveintegration densityVSAvoidfeature size control

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The package structure is segmented into distinct functional layers (die, adhesive layer, encapsulant with recess) that can be manufactured and assembled separately. This segmentation allows each component to be optimized independently, reducing the cumulative precision requirements compared to monolithic small-featured structures.

Inventive Principle:

Principle #1Segmentation

3Reliability

If adhesion is enhanced through increased contact area, then reliability improves, but manufacturing complexity increases

Engineering Contradiction:

Improveadhesion strengthVSAvoidencapsulant structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The encapsulant features a localized recess structure that concentrates adhesion enhancement in the specific region where the die and adhesive layer are positioned, rather than requiring complex structures throughout the entire encapsulant. This local quality approach improves reliability at the critical interface while minimizing overall manufacturing complexity.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS11158576B2Package structure having redistribution layer structures

Publication Date: 2021.10.26 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

A package structure includes a redistribution layer (RDL) structure, a die, and an encapsulant. The die is attached to the RDL structure through an adhesive layer. The encapsulant is disposed on the RDL structure and laterally encapsulates the die and the adhesive layer. The encapsulant includes a protruding part extending into the RDL structure and having a bottom surface in contact with the RDL structure.