3DVC Thermal Conductivity Solution
Multidimensional Two-Phase Isothermal Technology, 3D VC Heat Dissipation Technology
With the rapid development of 5G technology, efficient cooling and thermal management have become important challenges in the design of 5G base stations. Against this backdrop, 3D VC technology (three-dimensional two-phase isothermal technology), as an innovative thermal management technology, provides a solution for 5G base stations. This white paper will introduce the definition and working principle of 3D VC, as well as its application advantages in 5G base stations. At the same time, we will also explore the future development prospects of 3D VC to reveal its potential value and broad market prospects in the field of 5G communication.
Part I: Introduction
1.1 Demand Background
With the increasing number of scenarios of co-construction and sharing by operators, the demand for “high power and full bandwidth” has gradually increased. The distributed 5G base stations have been continuously developing towards the integration of multiple frequencies. This has led to a continuous increase in the power consumption of base stations and a continuous growth in power heat density, posing huge challenges to the thermal management of base stations.
1.2 Problem Statement
How to efficiently cool 5G base stations and keep their operating temperature within a controllable range has become an urgent problem to be solved.
1.3 Objectives and Significance
This white paper aims to introduce 3D VC technology and its application in 5G base stations, demonstrating its important significance and potential impact on the field of 5G communication.
Part II: Overview of 3D VC
2.1 Technical Background
Two-phase heat transfer relies on the latent heat of phase change of the working fluid to transfer heat, which has the advantages of high heat transfer efficiency and good isothermality. In recent years, it has been widely used for heat dissipation of electronic devices. From the development trend of two-phase isothermal technology, it can be seen that from the linear isothermal of one-dimensional heat pipes, to the planar isothermal of two-dimensional VC, it will eventually develop into three-dimensional integrated isothermal, that is, the 3D VC technology path.
2.2 Definition and Principle
3D VC connects the cavity of the substrate with the inner cavity of the PCI fins through a welding process to form an integrated cavity. The cavity is filled with a working fluid and sealed. The working fluid evaporates on the inner cavity side of the substrate close to the chip and condenses on the inner cavity side of the fins far from the heat source. Through the design of gravity-driven and the loop, a two-phase cycle is formed, and an ideal isothermal effect can be achieved.
2.3 Technical Characteristics
3D VC can significantly expand the isothermal range and enhance the heat dissipation capacity, featuring technical characteristics such as “high heat conduction performance and good isothermal effect, and compact structure”. Through the integrated design of the substrate and heat dissipation fins, 3D VC further reduces the heat transfer temperature difference, increases the isothermality of the substrate and heat dissipation fins, and improves the convective heat transfer efficiency. It can significantly reduce the temperature of the chip in the high heat flux density area, which is the key to solving the heat problem in high heat flux density scenarios of 5G base stations and provides the possibility for the miniaturization and lightweight design of base station products.
Part III: Application of 3D VC in 5G Base Stations
3.1 Analysis of Heat Dissipation Problems
There are local high heat flux density chips in 5G base stations, making local heat dissipation difficult. Through current technologies such as thermal conductive materials, shell materials, and two-dimensional isothermal technologies (substrate HP/fin PCI), the thermal resistance of the heat sink can be reduced, but the improvement of heat dissipation in high heat flux areas is very limited.
3.2 Application Advantages of 3D VC
Without introducing external moving parts to enhance heat dissipation, 3D VC transfers the heat of the chip to the far end of the fins more efficiently through the thermal diffusion of the three-dimensional structure. It has heat dissipation advantages such as “efficient heat dissipation, uniform temperature distribution, and reduction of hotspots”, which can meet the bottleneck requirements of heat dissipation for high-power devices and isothermal in high heat flux density areas.
3.3 Analysis of Practical Cases
FREYR and ZTE jointly developed and sampled a 3D VC prototype, achieving the first application example in 5G base stations.
Through the actual measurement and verification of the thermal design team of ZTE, compared with the PCI whole machine solution, the Tmax of the 3D VC whole machine solution is reduced by more than 10°C. The isothermality of the substrate area is maintained within 3°C, and the isothermality of the heat dissipation fins is maintained within 3°C. This shows that 3D VC can rely on its efficient three-dimensional isothermal ability to solve the heat problem in the high heat flux density chip area, providing the possibility for the further miniaturization and lightweight design of base station products.
Through the actual measurement and verification of the thermal design team of ZTE, compared with the PCI whole machine solution, the Tmax of the 3D VC whole machine solution is reduced by more than 10°C. The isothermality of the substrate area is maintained within 3°C, and the isothermality of the heat dissipation fins is maintained within 3°C. This shows that 3D VC can rely on its efficient three-dimensional isothermal ability to solve the heat problem in the high heat flux density chip area, providing the possibility for the further miniaturization and lightweight design of base station products.
Part IV: Future Development Prospects
4.1 Technical Improvement and Innovation
Although 3D VC has significant advantages compared with traditional heat dissipation solutions, there is still room for further heat dissipation potential. Looking forward to the future development trend of 3D VC technology, it includes aspects such as material improvement, structural innovation, manufacturing process optimization, and two-phase enhancement.
※ Material improvement: Lightweight and highly conductive shell materials, and refrigerants with excellent thermal properties;
※ Structural innovation: Innovation of support structures, innovation of fin-shaped architectures, and innovation of the whole machine assembly structure;
※ Process optimization: Pipeline forming process, heat dissipation fin opening process, module welding process, capillary process, and whole machine assembly process;
※ Two-phase enhancement: Pipeline design, local boiling enhancement structure, two-phase cycle architecture design, and anti-gravity liquid replenishment design.
※ Material improvement: Lightweight and highly conductive shell materials, and refrigerants with excellent thermal properties;
※ Structural innovation: Innovation of support structures, innovation of fin-shaped architectures, and innovation of the whole machine assembly structure;
※ Process optimization: Pipeline forming process, heat dissipation fin opening process, module welding process, capillary process, and whole machine assembly process;
※ Two-phase enhancement: Pipeline design, local boiling enhancement structure, two-phase cycle architecture design, and anti-gravity liquid replenishment design.
4.2 Market Prospects and Commercial Applications
- 3D VC breaks through the thermal conductivity limit of materials through phase change isothermal technology, greatly improving the isothermal effect. With flexible layout and diverse forms, it is the key technical direction for future 5G base stations to meet the design requirements of high density and lightweight.
- The aluminum 3D VC industry is currently in its infancy and has certain applications in IT and photovoltaic inverters. With the continuous increase in the high power consumption and lightweight extreme requirements of 5G base stations, the research and application of large-scale aluminum 3D VC in the communication field are heating up rapidly.
- Base station products have the requirement of maintenance-free operation, putting forward extremely high requirements for the reliability of 3D VC, which brings great challenges to the process implementation and process control of 3D VC. Some manufacturers are cautious in R&D before mass production, but more manufacturers have actively laid out and promoted the development of relevant supply chains and technologies, which is a high-tech with a promising future.
Part V: Conclusion
As an innovative thermal management technology, 3D VC has great application advantages in 5G base stations. It can match the development of “high power and full bandwidth” of 5G base stations and meet the “lightweight and high integration” needs of customers, which is of great importance and potential value for the development of 5G communication.
The development and application of 3D VC are limited by process implementation and the supply chain ecosystem, and require the joint efforts of all parties in the relevant industrial chain to promote the further R&D and commercial application of 3D VC technology.
The development and application of 3D VC are limited by process implementation and the supply chain ecosystem, and require the joint efforts of all parties in the relevant industrial chain to promote the further R&D and commercial application of 3D VC technology.
