Elastic Wave Filter Module with Support Substrate Integration

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Existing radio-frequency modules with elastic wave filters have a thick filter substrate that increases the module's height, making handling difficult and prone to cracking, and require additional passive elements on the module substrate, which complicates design and increases size.

Innovation Solution

A filter component with a passive element that includes a thinner filter substrate reinforced by a support substrate, allowing passive elements to be integrated within or on the support substrate, reducing the number of wiring electrodes on the module substrate and minimizing the overall module height.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the filter substrate is made thick to prevent cracking and improve handling, then the structural strength is improved, but the module height increases

Engineering Contradiction:

Improvestructural strengthVSAvoidmodule height

Core Design Contradiction:

StrengthVSLength of stationary object

Solution Approach 1:

The filter component is divided into two separate substrates: a filter substrate for the elastic wave filter and a support substrate for passive elements. This segmentation allows each substrate to be optimized independently - the filter substrate can be thin for low height while the support substrate provides structural strength and houses passive elements, resolving the contradiction between strength and height.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Passive elements are moved from the module substrate plane to the support substrate, which is stacked in another dimension (vertical layering). This dimensional change allows passive elements to be integrated within the filter component structure rather than occupying space on the module substrate, reducing overall module height while maintaining functionality.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If passive elements are placed on the module substrate, then the filter functionality is achieved, but the device complexity increases

Engineering Contradiction:

Improvefilter functionalityVSAvoiddevice complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The support substrate merges multiple functions into a single component: it provides structural support for the filter substrate, integrates passive elements (inductors, capacitors, resistors), and serves as a mounting platform. This consolidation reduces device complexity by eliminating the need for separate passive elements on the module substrate while maintaining all filter functionalities.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The support substrate is designed as a multi-functional element that simultaneously provides mechanical support, electrical functionality through integrated passive elements, and structural stability. This universality reduces the overall number of components needed in the module, simplifying the device while achieving comprehensive filter functionality.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Length of stationary object

If passive elements are integrated on the support substrate, then the module height is reduced, but the manufacturing precision requirements increase

Engineering Contradiction:

Improvemodule heightVSAvoidmanufacturing precision

Core Design Contradiction:

Length of stationary objectVSManufacturing precision

Solution Approach 1:

Passive elements are pre-integrated onto the support substrate during its fabrication process before the filter substrate is mounted. This preliminary action allows passive elements to be positioned and connected with controlled precision during a dedicated manufacturing stage, rather than requiring high-precision assembly of multiple separate components later, thus managing manufacturing precision requirements effectively.

Inventive Principle:

Principle #10Preliminary action

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 enables a smaller and thinner filter component with improved handling and reduced module height, while maintaining the functionality of the elastic wave filter, and enhances flexibility in designing radio-frequency modules.

Implementation Method 1

A support substrate is disposed on the other main surface of the filter substrate

Methodology Applied

Scientific EffectMechanical support:

Implementation Method 2

an elastic wave filter including an elastic wave resonator disposed in a predetermined region of one main surface of the filter substrate

Methodology Applied

Scientific EffectElastic wave:

Implementation Method 3

The filter substrate 2 is a piezoelectric substrate made of a piezoelectric substance such as lithium niobate, lithium tantalate, or quartz

Methodology Applied

Scientific EffectPiezoelectric effect: Piezoelectric Effect

Data Source

PatentUS10236859B2Filter component with passive element and radio-frequency module

Publication Date: 2019.03.19 MURATA MFG CO LTD

AI summary

A filter component with a passive element includes a filter substrate, an elastic wave filter including an elastic wave resonator in a predetermined region of one main surface of the filter substrate, and a support substrate on another main surface of the filter substrate, wherein a passive element is provided in or on a support substrate, the passive element includes a wiring electrode and is electrically connected to the elastic wave filter.