High-Frequency Module Antenna Bonding for Thermal Expansion Reliability

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Solution Overview

Problem

The reliability of high-frequency semiconductor devices is compromised due to differences in thermal expansion coefficients between metal terminals and resin, leading to potential wire breakage and reduced reliability at high temperatures.

Innovation Solution

A high-frequency module design where conductive adhesive is bonded to three surfaces of a metal post, including the central surface and two side wall surfaces, ensuring a secure connection between the antenna and the high-frequency circuit on the wiring substrate, reducing the likelihood of peeling or connection cuts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If metal terminals are used to connect the antenna and wiring substrate, then electrical connection is achieved, but the connection may peel due to thermal expansion differences between metal and resin at high temperatures

Engineering Contradiction:
Improveconnection reliabilityVSAvoidbond strength
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent applies composite materials by combining metal post with conductive adhesive to create a hybrid connection structure. The metal post provides electrical conductivity and mechanical support, while the conductive adhesive compensates for thermal expansion differences between metal and resin, preventing peeling at high temperatures through its flexible, adhesive nature.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent changes the material parameters of the connection structure by selecting conductive adhesive with specific thermal expansion properties that match the resin substrate. This parameter matching reduces thermal stress and prevents connection failure under temperature variations.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If conductive adhesive is applied to multiple surfaces of the metal post, then connection reliability improves, but manufacturing complexity increases

Engineering Contradiction:
Improveconnection reliabilityVSAvoidmanufacturing ease
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent extends the adhesive application from a single surface to multiple surfaces (central and side wall surfaces) of the metal post, utilizing three-dimensional space to maximize bonding area. This multi-surface approach distributes mechanical and thermal stresses across different planes, enhancing connection reliability while the adhesive's forgiving nature keeps manufacturing feasible.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

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 enhances the reliability of the high-frequency module by minimizing the risk of connection failure due to thermal expansion differences and allows for efficient component placement, contributing to size reduction.

Implementation Method 1

conductive adhesive is bonded to three surfaces, that is, a central surface and two side wall surfaces of a post made of metal

Methodology Applied
Scientific EffectAdhesion: Adhesive

Data Source

PatentEP3327775B1High-frequency module
Publication Date: 2024.02.07 ALPS ALPINE CO LTD
  • EP3327775B1 patent drawingFigure 1
  • EP3327775B1 patent drawingFigure 2
  • EP3327775B1 patent drawingFigure 3

AI summary

[Object] To provide a high-frequency module having high reliability. [Solution] The high-frequency module includes a wiring substrate 10, a high-frequency circuit 11 including circuit components 15 disposed on the upper surface of the wiring substrate 10, a post 17 disposed on the upper surface of the wiring substrate 10 and made of a metal, a sealing resin 30 covering the circuit components 15, and an antenna substrate 20 disposed on the upper surface of the sealing resin 30 and having an antenna 21 formed by a metal pattern 21a. A groove 31 is provided on the sealing resin 30, at least a part of the post 17 is exposed from the groove 31, a central surface 17a and two opposing side wall surfaces 17b located higher than the central surface 17a are formed at the upper side of the post 17, and a conductive adhesive 13 is bonded to the central surface 17a, the two side wall surfaces 17b, and the antenna 21.