Thin Film Capacitor Via Hole Segmentation for Diffusion Barrier

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Solution Overview

Problem

Conventional thin film capacitors face performance degradation due to unreacted products in the insulating layer, which can lead to water or hydrogen diffusion into the dielectric layer, causing capacitance deterioration.

Innovation Solution

A thin film capacitor design with a cover layer and insulating layer configuration, featuring via holes with specific opening diameters that create a longer connection path between the dielectric and insulating layers, preventing unreacted product-derived water or hydrogen from reaching the dielectric layer, and using inorganic insulating materials for enhanced adhesion and protection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an insulating layer is laminated on the capacitance portion to provide protection, then protective function is improved, but unreacted products in the insulating layer can generate water or hydrogen that diffuses to the dielectric layer causing performance deterioration

Engineering Contradiction:

Improveprotective functionVSAvoidwater or hydrogen diffusion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The opening is divided into two distinct portions: a first opening portion passing through the insulating layer and a second opening portion passing through the cover layer. This segmentation creates a discontinuous path that prevents direct diffusion of water or hydrogen from the insulating layer to the dielectric layer, while still allowing the opening to serve its electrical connection function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The opening structure transitions from a simple vertical hole to a stepped configuration with different diameters at different heights. The first opening portion has a larger inner diameter than the second opening portion, creating a dimensional variation that lengthens the diffusion path and blocks harmful substances from reaching the dielectric layer.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Reliability

If a via hole is formed to expose an electrode layer for connection, then electrical connection is improved, but the opening path may allow water or hydrogen to reach the dielectric layer

Engineering Contradiction:

Improveelectrical connectionVSAvoidwater or hydrogen diffusion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The opening is segmented into two portions with different functions: the first opening portion provides electrical connection by exposing the electrode layer, while the second opening portion with smaller diameter creates a barrier that prevents water or hydrogen diffusion to the dielectric layer.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Different portions of the opening have different inner diameters tailored to different functions. The first opening portion has a larger diameter to ensure proper electrical connection and electrode exposure, while the second opening portion has a smaller diameter to block diffusion paths, creating local quality variations that satisfy both requirements simultaneously.

Inventive Principle:

Principle #3Local quality

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 configuration effectively prevents performance deterioration of the capacitance portion by creating a barrier that inhibits the diffusion of water or hydrogen from unreacted products in the insulating layer, thereby maintaining the capacitor's performance and preventing damage.

Implementation Method 1

When water, hydrogen or the like is generated from these unreacted products, there is a possibility that the water, hydrogen or the like may diffuse from the insulating layer to the dielectric layer

Methodology Applied

Scientific EffectDiffusion: Diffusion

Implementation Method 2

it is possible to secure a long connection path between the dielectric layer forming the capacitance portion covered with the cover layer and the insulating layer laminated above the cover layer. Therefore, even when water, hydrogen, or the like is generated from unreacted products contained in the insulating layer, these components can be prevented from reaching the dielectric layer

Methodology Applied

Scientific EffectPhysical containment: Physical Containment

Data Source

PatentUS11114248B2Thin film capacitor and manufacturing method thereof

Publication Date: 2021.09.07 TDK CORP

AI summary

A thin film capacitor includes a capacitance portion in which a plurality of electrode layers and dielectric layers are alternately laminated, a cover layer, an insulating layer, a via hole in which one electrode layer different from an uppermost electrode layer among the plurality of electrode layers is exposed at a bottom surface thereof, and an opening which is provided inside the via hole and in which the one electrode layer is exposed at a bottom surface thereof, and in which the cover layer and the insulating layer are exposed at a side surface. The opening includes a first opening portion which passes through the insulating layer and a second opening portion which is provided below the first opening portion and passes through the cover layer, and when an inner diameter of the first opening portion is D1 and an inner diameter of the second opening portion is D2, D1>D2.