Composite Middle Frame Plating for Lightweight Phones and Antennas

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Solution Overview

Problem

Existing technologies face a challenge in simultaneously reducing the weight of electronic devices while maintaining the functionality of antennas, as materials like carbon fiber reinforced resin composites cause dielectric and loss tangent issues that affect antenna performance.

Innovation Solution

A middle frame assembly is designed using a carbon fiber reinforced resin composite material with a metal plating layer, where the metal plating layer's thickness and resistivity are optimized to match those of metal materials, ensuring minimal impact on antenna performance, and a protective layer is added to prevent the metal plating from detaching.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Weight of moving object

If plastics with high strength and high toughness (such as glass fiber reinforced polyurethane) are used instead of metal alloys in the middle frame, then the weight of the mobile phone is reduced, but the dielectric constant and loss tangent of the middle frame become larger, which has an impact on antenna function

Engineering Contradiction:
Improveweight of mobile phoneVSAvoidantenna function
Core Design Contradiction:
Weight of moving objectVSReliability

Solution Approach 1:

The patent uses a composite material structure consisting of a plastic base body (such as glass fiber reinforced polyurethane) combined with a metal plating layer. This composite structure allows the middle frame to benefit from the low weight and high strength of plastics while the metal plating layer provides good antenna performance by maintaining appropriate dielectric constant and loss tangent characteristics.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The patent optimizes the thickness and material composition of the metal plating layer to control the overall dielectric constant and loss tangent of the middle frame. By adjusting these parameters, the frame achieves both lightweight properties and acceptable antenna performance.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If a metal plating layer is added to the plastic middle frame to improve antenna performance, then the dielectric constant and loss tangent are optimized, but the metal plating may detach from the plastic base body

Engineering Contradiction:
Improveantenna functionVSAvoidbonding between metal plating and plastic base body
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent introduces an adhesive layer as an intermediary between the metal plating layer and the plastic base body. This adhesive layer serves as a bonding medium that ensures strong adhesion between the two materials, preventing detachment of the metal plating while maintaining the integrity of the composite structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a three-layer composite structure consisting of the plastic base body, adhesive layer, and metal plating layer. This multi-layer composite design addresses the bonding issue by using materials specifically selected for their compatibility and bonding characteristics, ensuring long-term stability of the assembly.

Inventive Principle:
Principle #40Composite materials

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 solution achieves a lightweight electronic device without compromising antenna functionality, maintaining performance and structural integrity.

Implementation Method 1

a first metal plating layer compounded on a surface of the base body

Methodology Applied
Scientific EffectMetal plating: Electroplating

Data Source

PatentEP4283961B1Middle frame assembly and electronic device
Publication Date: 2025.07.02 HONOR DEVICE CO LTD
  • EP4283961B1 patent drawingFigure 1~2
  • EP4283961B1 patent drawingFigure 3~4
  • EP4283961B1 patent drawingFigure 5

AI summary

Embodiments of this application provide a middle frame assembly, including a middle plate and a frame disposed around an outer edge of the middle plate, where the middle plate includes a first carbon fiber reinforced resin composite material base body and a first metal plating layer compounded on a surface of the base body. The embodiments of this application further provide a preparation method for a middle frame assembly and an electronic device in the middle frame assembly. The embodiments of this application use a carbon fiber reinforced resin composite material, for example, a carbon fiber reinforced epoxy resin composite material, a carbon fiber reinforced phenolic resin composite material, or a carbon fiber reinforced polytetrafluoroethylene resin composite material, as a middle plate base body of the middle frame assembly, which significantly reduces a weight of the middle frame assembly and has advantages of good rigidity and high strength. In addition, the metal plating layer compounded on the surface of the carbon fiber reinforced resin composite material base body resolves problems of a wave absorption effect and a PIM of the carbon fiber reinforced resin composite material, so that an antenna function of the electronic device is not affected.