Protective RDL Package Structure for Fine-Pitch Signal Reliability

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The semiconductor industry faces challenges in achieving high-density and high-frequency packaging due to limitations in the formation of redistribution layer (RDL) structures, which affect the integration density and reliability of electronic components.

Innovation Solution

A method for forming dual and single damascene conductive patterns using a via-first process, involving the creation of trench and via openings in dielectric layers, followed by the deposition of conductive materials and planarization, to fabricate redistribution layers with improved planarity and reduced transmission loss, suitable for high-density applications.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional RDL formation processes are used, then manufacturing cost is reduced, but transmission loss increases and electrical reliability deteriorates

Engineering Contradiction:

Improveelectrical reliabilityVSAvoidtransmission loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The RDL structure is segmented into multiple conductive patterns formed through separate via-first and trench-first processes, allowing optimization of each segment's electrical properties. The conductive patterns are divided into different regions (first, second, third conductive patterns) with distinct formation methods to minimize transmission loss in each area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different regions of the RDL structure are assigned different local qualities through selective process application. High-frequency signal paths use conductive patterns formed by the via-first process with optimized properties, while other areas use traditional methods, creating local quality variations that reduce overall transmission loss.

Inventive Principle:

Principle #3Local quality

2Quantity of substance

If feature size is reduced to increase integration density, then more components can be integrated, but manufacturing precision requirements increase

Engineering Contradiction:

Improveintegration densityVSAvoidfeature size precision

Core Design Contradiction:

Quantity of substanceVSManufacturing precision

Solution Approach 1:

Via openings are formed preliminarily before trench openings in the via-first process, establishing precise reference points that guide subsequent trench formation. This preliminary action ensures that even as feature sizes reduce, the manufacturing precision is maintained through a hierarchical approach to pattern formation.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The process transitions from planar pattern formation to three-dimensional structure formation by creating via openings that extend vertically through dielectric layers, then forming trenches between these vias. This dimensional approach allows integration density to increase while maintaining precision through vertical rather than horizontal scaling.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Quantity of substance

If RDL structures are formed for high-density applications, then integration density increases, but process complexity increases

Engineering Contradiction:

Improveintegration densityVSAvoidprocess complexity

Core Design Contradiction:

Quantity of substanceVSDevice complexity

Solution Approach 1:

The conventional approach is inverted by forming via openings first and then trenches between them, rather than forming trenches first and adding vias later. This inversion simplifies the process logic and reduces complexity while achieving the same high-density RDL structure.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The via-first process serves multiple functions: it establishes conductive connections, defines pattern boundaries, and provides structural references for subsequent processing steps. This multi-functionality reduces the number of separate process steps needed, thereby reducing overall process complexity despite the increased integration density.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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 enables the fabrication of packages with lower costs and reduced transmission loss, achieving high-resolution and fine-pitch RDL structures with enhanced electrical reliability and breakdown voltage, suitable for high-density and high-frequency applications.

Implementation Method 1

deposition of conductive materials

Methodology Applied

Scientific EffectPhysical Vapour Deposition: Physical Vapour Deposition

Implementation Method 2

deposition of conductive materials

Methodology Applied

Scientific EffectChemical Vapour Deposition: Chemical Vapour Deposition

Implementation Method 3

planarization

Methodology Applied

Scientific EffectMechanical polishing:

Implementation Method 4

planarization

Methodology Applied

Scientific EffectChemical-mechanical polishing:

Data Source

PatentUS12057406B2Package having redistribution layer structure with protective layer

Publication Date: 2024.08.06 TAIWAN SEMICONDUCTOR MANUFACTURING CO LTD

AI summary

Provided is a package including: a die having an upper surface and including at least one conductive pad disposed adjacent to the upper surface; a first pillar structure over the die; and a second pillar structure aside the first pillar structure, wherein the second pillar structure is electrically connected to the conductive pad of the die, and defining a recess portion recessed from a side surface of the second pillar structure, wherein the second pillar structure and the conductive pad have different conductivities.