Millimeter Wave Module Impedance Matching via Segmented Via Capacitors

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing millimeter wave modules experience transmission loss due to inductance in conductor patterns extending between layers, leading to impedance mismatching in the millimeter wave frequency band.

Innovation Solution

A millimeter wave module configuration that includes an insulating substrate with conductive members and a dielectric member, forming a capacitor structure to match impedance, using a columnar shape for conductive members and a dielectric member with a higher dielectric constant than the substrate, and chamfered corners to reduce electric field concentration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a conductor pattern extends in the thickness direction to connect conductor patterns on multiple layers, then electrical connection between layers is achieved, but inductance increases causing impedance mismatching and transmission loss

Engineering Contradiction:

Improveelectrical connection between layersVSAvoidtransmission loss

Core Design Contradiction:

ReliabilityVSLoss of energy

Solution Approach 1:

The conductor pattern extending in the thickness direction is divided into multiple segments by inserting via holes between them. Each segment is formed on a different layer and connected through via holes filled with conductive material. This segmentation reduces the overall inductance of the connection path while maintaining electrical connectivity between layers, thereby reducing transmission loss in the millimeter wave frequency band.

Inventive Principle:

Principle #1Segmentation

2Reliability

If a conductor pattern extends in the thickness direction to connect conductor patterns on multiple layers, then electrical connection between layers is achieved, but impedance matching becomes difficult in the millimeter wave frequency band

Engineering Contradiction:

Improveelectrical connection between layersVSAvoidimpedance matching

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

Dielectric members with different dielectric constants are strategically placed in specific regions around the conductor pattern segments and via holes. By locally adjusting the dielectric properties in different areas of the connection path, the characteristic impedance can be controlled and matched across layers. This local quality adjustment enables precise impedance matching in the millimeter wave frequency band while maintaining reliable electrical connection.

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

The configuration effectively reduces transmission loss and achieves impedance matching between layers, ensuring low-loss millimeter wave signal transmission with high precision manufacturing.

Implementation Method 1

a dielectric member for generating capacitance. The dielectric member for generating capacitance is disposed between the first conductive member and the second conductive member, is in contact with the first conductive member and the second conductive member

Methodology Applied

Scientific EffectCapacitance: Capacitance

Implementation Method 2

The dielectric member for generating capacitance is disposed between the first conductive member and the second conductive member, is in contact with the first conductive member and the second conductive member, and has a dielectric constant different from a dielectric constant of the insulating substrate

Methodology Applied

Scientific EffectDielectric: Dielectric

Data Source

PatentUS11557821B2Millimeter wave module including first and second conductor patterns connected by first and second conductive members extending through an insulating substrate and methods of manufacture

Publication Date: 2023.01.17 MURATA MFG CO LTD

AI summary

Signal conductor patterns (21, 31) are respectively formed on a first main surface (101) and a second main surface (102) of an insulating substrate (100). Ground conductor patterns (222, 322) are formed on the first main surface (101) and the second main surface (102). A first conductive member (41) is formed in the insulating substrate (100) and electrically connects the signal conductor patterns (21, 31) in the thickness direction. A second conductive member (42) is formed in the insulating substrate (100) and connected to the ground conductor patterns (222, 322). A dielectric member (43) is disposed between the first conductive member (41) and the second conductive member (42), is in contact with the first conductive member (41) and the second conductive member (42), and has a dielectric constant different from the dielectric constant of the insulating substrate (100).