Ceramic-Plastic Middle Frame Structure for Lighter Electronic Housings

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Ceramic materials used in mobile phone components increase the weight of the device while reducing strength when thickness is reduced to meet weight requirements.

Innovation Solution

A middle frame design incorporating a metal middle plate, a plastic frame, and a gapless ceramic frame, where the ceramic frame is surrounded by the plastic frame, enhancing strength and allowing for reduced thickness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a unibody structure is used to integrate the middle frame and battery cover, then manufacturing precision and structural strength are improved, but device complexity increases due to the need for precise molding and assembly tolerances

Engineering Contradiction:
Improvestructural strengthVSAvoiddevice complexity
Core Design Contradiction:
StrengthVSDevice complexity

Solution Approach 1:

The middle frame is divided into a first portion and a second portion that are separately molded and then joined together through ultrasonic welding. This segmentation allows each portion to be manufactured independently with standard tolerances, reducing molding complexity while maintaining overall structural integrity through the welding joint.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If the battery cover is integrated into the middle frame, then the number of parts is reduced and assembly is simplified, but repairability and modularity worsen

Engineering Contradiction:
Improveassembly simplicityVSAvoidrepairability
Core Design Contradiction:
Ease of operationVSEase of repair

Solution Approach 1:

The battery cover is designed as a separate removable component that attaches to the middle frame through positioning protrusions and recesses. This allows the battery cover to be easily removed and replaced for repair or upgrade purposes, while still providing simplified assembly during initial device assembly.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The middle frame incorporates a clamping structure with movable clamping portions that can dynamically adjust to secure the battery cover during normal operation, yet allow for easy removal when needed for repair or battery replacement.

Inventive Principle:
Principle #15Dynamics

3Strength

If ultrasonic welding is used to join the first and second portions of the middle frame, then joint strength is improved, but manufacturing precision requirements increase

Engineering Contradiction:
Improvejoint strengthVSAvoidmolding precision
Core Design Contradiction:
StrengthVSManufacturing precision

Solution Approach 1:

The middle frame portions are designed with specific joining structures including positioning protrusions and recesses that guide alignment during assembly. These features compensate for normal molding tolerances and ensure proper positioning before ultrasonic welding, allowing standard molding precision while achieving strong joints.

Inventive Principle:
Principle #1Segmentation

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 design reduces the weight of the electronic device while maintaining strength and enabling complex internal structure designs, with the ceramic frame providing a high-quality feel and hardness.

Implementation Method 1

a welding portion, configured to weld the first portion and the second portion to form the middle frame

Methodology Applied
Scientific EffectUltrasonic welding: Ultrasonic Vibration

Data Source

PatentEP3979608B1Middle frame, battery cover, and electronic device
Publication Date: 2026.04.22 HUAWEI TECH CO LTD
  • EP3979608B1 patent drawingFigure 1
  • EP3979608B1 patent drawingFigure 2
  • EP3979608B1 patent drawingFigure 3

AI summary

Embodiments of this application provide a middle frame, a battery cover, and an electronic device. The electronic device may include a mobile or fixed terminal with an edge frame or a housing, such as a mobile phone, a tablet computer, a notebook computer, an ultra-mobile personal computer (UMPC), a handheld computer, a walkie-talkie, a netbook, a POS machine, a personal digital assistant (PDA), an event data recorder, a wearable device, a virtual reality device, a wireless USB flash drive, a Bluetooth speaker/headset, or a vehicle-mounted device. Two types of materials: ceramics and plastic, are used to form a middle frame and a battery cover, thereby reducing a weight of the electronic device. This resolves a problem that is of a relatively large weight of an existing electronic device and that is caused when a pure ceramic middle frame and a pure ceramic battery cover are used in the electronic device.