LCP, the most promising material in the 5G era

Article source: Micro-LINK plastic? The 5G era has arrived.
Due to its high-frequency and high-speed characteristics, there will be great changes in the material end
.
Among them, LCP has encountered such a 0→1 development opportunity.
With its low impedance and high tolerance characteristics, it is expected to become the most suitable material
.
As the frequency of 5G increases, the penetration rate of LCP materials and their products will gradually increase, and it is expected that the entire LCP market will rapidly increase to more than tens of billions
.
? 1.
LCP, engineering plastic with excellent performance?? 1.
LCP material: excellent new high-performance special engineering plastic?? Liquid crystal polymer (LCP) refers to a polymer that can exist in a liquid crystal phase under certain conditions, and its characteristics Because the molecules have a higher molecular weight and have an orderly orientation
.
When LCP exists in a liquid crystal phase, it has a low viscosity and a high degree of orientation.
After cooling and solidification, its shape can be maintained stably.
Therefore, LCP materials have excellent mechanical properties
.
In addition, LCP materials also have the characteristics of low moisture absorption, chemical resistance, weather resistance, heat resistance, flame retardancy, low dielectric constant and dielectric loss factor
.
?? LCP can be divided into: (1) lyotropic liquid crystal LLCP, which can form a liquid crystal phase in an organic solution.
Because this type of polymer can only be processed in a solution and cannot be melted, it can be divided into: (1) lyotropic liquid crystal LLCP, which can form a liquid crystal phase in an organic solution.
Can be used as fiber and coating
.
(2) Thermotropic liquid crystal TLCP forms a liquid crystal phase above the melting point or glass transition temperature.
Since this type of polymerization can be processed in the molten state, it can not only form high-strength fibers by solution spinning, but also can be injected, Extrusion and other thermal processing methods form various products
.
The LCP discussed in this article is mainly thermotropic liquid crystal TLCP
.
?? Thermally induced LCP is divided into high heat resistance type (type I), medium heat resistance type (type II) and low heat resistance type (type III) according to the heat distortion temperature.

.
The basic structure of type I TLCP is mainly composed of units derived from p-hydroxybenzoic acid (HBA), biphenol (BP) and different ratios of terephthalic acid (TA)/isophthalic acid (IA), tensile strength and The modulus is the highest in TLCP, and the heat distortion temperature is higher than 300℃
.
It is represented by Solvay's Xydar and Sumitomo's SimikaSuper
.
The main component of Type II TLCP is the unit derived from HBA and 6-hydroxy-2-naphthoic acid (HNA).
The heat distortion temperature is between 240 and 280°C.
It has excellent processing performance and can be processed by extruders and injection molding machines.
Typical The product is Ticona’s Vectra
.
Type III LCP is mainly a copolymer synthesized from HBA and polyethylene terephthalate (PET), with a heat distortion temperature lower than 210°C, such as the non-wholly aromatic series represented by Unichka’s Rodrun
.
?? Figure 1: Several typical LCP structural units? "? LCP materials have excellent heat resistance and molding processability
.
The polymerization method is mainly melt polycondensation, and the fully aromatic LCP is mostly supplemented by solid phase polycondensation to make high Molecular weight products
.
Non-wholly aromatic LCP plastic raw materials are often prepared by one-step or two-step melt polymerization
.
In recent years, the technology of continuous melt polycondensation to produce high molecular weight LCP has been developed
.
Liquid crystal aromatic polyester is due to its macromolecular chain in the liquid crystal state.
It is oriented, it has an unusually regular fibrous structure, special performance, high product strength, no less than metal and ceramics
.
Mechanical properties, dimensional stability, optical properties, electrical properties, chemical resistance, flame retardancy , Good processability, good heat resistance, low thermal expansion coefficient
.
?? Figure 2: Excellent performance of LCP materials? "? 2.
Industrial chain: the middle and upper reaches are technical difficulties, and the downstream is widely used?? In the LCP industry chain, LCP resin The synthesis and film formation are technical difficulties
.
At present, the mainstream synthesis methods of LCP resin include the following 4
.
?? (1) Oxidative esterification method: Oxidative esterification method is a direct polymerization method of aromatic carboxylic acid and phenol
.
This method reacts in pyridine or amide solvents under the action of phosphorous compounds or thionyl chloride and other activators and catalysts to obtain high molecular weight LCP.
The reaction conditions of this method are relatively mild, and the molecules can be controlled by the order of monomer addition.
Structural sequence
.
?? (2) Silicone ester method: After the aromatic acid monomer is esterified with trimethylsilyl, it is then combined with the acetylated phenolic monomer to remove the trimethylsilyl acetate through a solution or melt polymerization process.
Molecule, high molecular weight LCP can be obtained
.
?? (3) Phenyl ester method: a method of melt polycondensation of aromatic carboxylic acid phenyl ester and phenolic monomers
.
However, the aromatic carboxylic acid phenyl ester used in this method is relatively expensive, and small molecules of phenol are generated during the reaction process, which is difficult to remove
.
Recently, Sumitomo Chemical has used diphenyl carbonate and phenolic monomers to synthesize LCP with low acetic acid residue through a "one-step" synthesis process, and the resin has good fluidity, which is a potential advantage in the synthesis process
.
?? (4) Acidolysis reaction method: Aromatic dibasic acid and acetylated phenolic monomer are melted and polycondensed, and the by-product acetic acid is removed to obtain LCP
.
This method is currently the main method of LCP industrial production
.
?? 3.
The processing methods of LCP mainly include the following 4 kinds
.
?? (1) Injection molding: Injection molding is the most important molding method for LCP
.
LCP not only has excellent processing fluidity, but also has a fast curing speed, which is suitable for processing by injection molding method
.
Compared with polyphenylene sulfide (PPS) and high temperature resistant nylon (HT-PA), the parts have advantages such as no flash
.
However, because the LCP molecular chain is rigid and rod-shaped, it is easy to be oriented along the flow direction, which leads to shortcomings such as the difference in performance between the parallel to the flow direction and the perpendicular to the flow direction, and the poor weld line strength
.
In recent years, defects such as poor weld line strength and anisotropy have been improved to a certain extent through mold design and other methods.

.
?? (2) Extrusion molding: The extrusion molding method is often used to produce plastic films and pipes
.
Because LCP is prone to anisotropy, the performance of LCP film formed by traditional extrusion process is weak in the transverse direction of melt flow
.
Therefore, currently LCP and other isotropic materials, such as PET, ethylene-vinyl alcohol copolymer (EVOH), etc.
, are formed into multilayer films or pipes through co-extrusion processing
.
?? (3) Solution casting molding: LCP has a low thermal expansion coefficient, excellent dimensional stability, low moisture absorption, excellent high-frequency characteristics and electrical insulation properties, making it widely used in high-frequency circuit substrates
.
Among them, flexible printed boards and embedded circuit boards require flexible layout and high-density wiring, so the molding process requirements are very high
.
Traditional injection molding, extrusion and other methods are difficult to meet its process requirements
.
Sumitomo Chemical produces LCP resin through a special molecular design, and then dissolves it in a special solvent through solvent-cast molding to obtain a film with very good strength and flexibility
.
The solvent used is different from the currently commonly used fluorine-containing phenol solvent, and has strong operability
.
Moreover, the anisotropic defects caused by injection molding and extrusion molding are avoided by the parts after solution casting molding
.
At the same time, more complex substrates can be formed, and more fillers can be mixed
.
At present, LCP film parts processed by this method are being promoted and used in circuit boards
.
?? (4) Blow molding: LCP has excellent gas permeability resistance and solvent resistance.
It can be blow molded into hollow molded products or film products with excellent barrier properties, such as fuel tanks and various Piping
.
However, the low melt tension of LCP leads to serious sag.
Therefore, it is difficult to prepare molded products of the required shape by blow molding.

.
2.
The global LCP resin material production capacity is concentrated in Japan, the United States and China.
The current global LCP resin material production capacity is about 76,000 tons per year, all concentrated in Japan, the United States and China, with capacities of 34,000 tons, 26,000 tons and 16,000 respectively Tons, accounting for 45%, 34% and 21% respectively.
Among them, American and Japanese companies began mass production of LCP materials in the 1980s.
China entered the LCP field late and relied on imports from the United States and Japan for a long time.
Companies such as Kingfa Technology, Plite, Water Co.
, Ltd.
, and Jujia New Materials have successively put into production, and the production capacity of LCP materials has grown rapidly
.
With the advent of the 5G era, the demand for LCP materials is expected to usher in rapid growth in the future
.
?? 1.
Market structure: Dominated by the United States and Japan, and the rise of domestic materials is imminent? Domestic film-specific resin and film development started late, and the production of LCP film resin and film is almost monopolized by Japan and the United States
.
Many Japanese and American manufacturers in the LCP industry chain have vertical integration capabilities
.
Japan's Sumitomo Group (Sumitomo Chemical/Sumitomo Electric) is currently the only manufacturer with integrated production capacity from LCP resin to modules
.
In 2016, Murata Manufacturing Co.
, Ltd.
merged upstream through the acquisition of Japan Primatec, a LCP film manufacturer, and possessed the integrated production capacity of LCP film to flexible board (the film withdrew from the LCP antenna module business in 2017)
.
Japan's Fujikura Electronics has the ability to produce satoshi LCP soft boards to modules, and has advantages in high-frequency microwave soft boards and high-speed interface transmission lines
.
?? There are many suppliers of LCP resin materials, but the commercially available LCP multilayer boards are very limited
.
LCP resin materials leader Polyplastics, Sumitomo Chemical, Celanese, etc.
, have begun to develop and commercialize LCP in 1985
.
Domestic manufacturers Water Co.
, Ltd.
, Plite, Kingfa Technology and Jujia New Materials have successfully entered the LCP resin market
.
?? Table 1: Major global manufacturers of liquid crystal polymers? "? 2.
The downstream application fields of LCP materials continue to expand?? LCP has a wide range of downstream applications.
LCP
combines the characteristics of polymer materials and liquid crystal materials, and has outstanding integration Performance, it has been widely used in aerospace, electronics, automotive industry and other fields
.
At the same time, with the development of new LCP products, emerging applications are still expanding
.
?? Figure 3: Wide range of LCP downstream applications? "? 2019 The annual global demand for LCP is about 74,000 tons, which is mainly used in the early stage of electronics.
With the rapid growth of demand in 5G and other fields in the future, the demand for consumer electronics and electronic appliances is expected to grow rapidly
.
?? "? 3.
With the advent of the 5G era, LCP demand will usher in an explosion? The 5G era is approaching gradually.
Due to the high frequency and high speed of 5G, the requirements for materials have further increased, especially in the signal transmission process to reduce loss is very important
.
LCP is currently the material with the lowest dielectric loss in the field of engineering plastics and has the strongest overall advantage.
We believe that the use of LCP materials will be greatly increased in the future on the base station and mobile phones
.
?? Figure 6: Introduction to LCP materials? "? 1.
Mobile phones At the end, the LCP module is expected to become a terminal solution for the antenna end of the mobile phone? In the mobile phone end of the 5G field, LCP, with its good transmission loss, bendability, dimensional stability and low water absorption, is the most technically compatible with antenna requirements Material
.
??? At present, the PI substrate FPC antenna module is still the mainstream design of mobile phones
.
However, with the advent of the 5G era, it is expected that the replacement of MPI and LCP substrate FPC will accelerate
.
Taking company A as an example, the LCP soft board antenna solution was introduced in iPhone 8 for the first time.
In 2018, the three models of XR/XS/XS max will continue to use the LCP antenna solution, using 3/3/2 LCP antennas respectively.

.
We think this is a company A's advance layout for the 5G era
.
?? At present, the performance of MPI has been greatly improved by adjusting the formula, and the performance is equivalent to that of LCP in the Sub-6GHz spectrum (but there is still a gap in the millimeter wave spectrum), and the cost is 20-30% lower than that of LCP antennas
.
In addition, from the perspective of the supply chain, the current LCP film is basically monopolized by Japanese companies, and MPI has far more suppliers than LCP.
From the perspective of supply chain stability and bargaining power, company A has reduced the number of LCP antennas in the short term; but consider With the release of long-term domestic production capacity and the gradual breakthrough in technology, we believe that with the gradual localization of LCP film materials, the cost of LCP substrate soft boards will drop significantly and the market will accelerate expansion
.
???? According to the 5G development roadmap released by Yole, the future communication frequency will be increased in two stages
.
The goal of the first phase is to increase the communication frequency to 6GHz by 2020, and the goal of the second phase is to further increase to 30-60GHz after 2020
.
In terms of market applications, the signal frequency of terminal antennas such as smart phones has been increasing, high-frequency applications are increasing, and the demand for high-speed and large-capacity is also increasing
.
In order to adapt to the current high-frequency and high-speed trend from wireless networks to terminal applications, soft boards are used as antennas and transmission lines in terminal equipment.
We believe that the MPI antenna may only be a transition, and the main market in the future will be LCP antennas
.
? "? 2.
On the base station side, LCP oscillators are expected to become the mainstream route?? 5G base stations have stricter requirements for oscillators: (1) High integration, active antenna unit (AAU) integrating RRU and AAU, supporting more antennas Frequency bands need to improve production efficiency, SMT has become AAU's manufacturing process, and the antenna element material has a temperature resistance of more than 260°C
.
(2) Massive MIMO and beamforming antenna technology require more antennas and materials Lightweight, plastic antenna oscillator becomes a trend
.
(3) The electromagnetic wave attenuation of the millimeter wave band is large, and the antenna oscillator material is required to have low dielectric loss
.
? At present, the types of antenna oscillators on the market can be roughly divided into three types: metal die-casting, PCB patch and plastic oscillators.
Among them, plastic oscillators have two process schemes: LDS (Laser Direct Forming Technology) and selective electroplating
.
The antenna vibrator in the 4G era is mainly made of metal, and the manufacturing process is mainly based on casting and sheet metal technology.
The weight and volume are large, and the signal transmission accuracy cannot meet the requirements of the 5G era.
However, the PCB patch is light in weight.
, The cost is controllable, but the surface loss is high, and the requirements for construction and installation are also high
.
?? And through modified plastic materials, the shape of the antenna vibrator is manufactured by injection molding, and then the plastic surface of the vibrator is metalized by special technology.
Compared with the sheet metal and die-casting process, the 3D plastic vibrator is in addition to It has advantages in weight, and can also meet the accuracy requirements that cannot be achieved by sheet metal and die-casting processes.
It can better adapt to high-frequency scenarios above 3.
5GHz and will become the mainstream solution for antenna oscillators in the 5G era
.
?? "? The current mainstream vibrator uses PPS (polyphenylene sulfide) as the main modified plastic solution.
Compared with PPS material, LCP material has the advantages of low dielectric loss, good weather resistance, and low overall cost.
It is expected to accelerate its entry into the supply chain system
.
?? "Four, the market space exceeds 10 billion, and the value of the film is better than the resin.
We calculate according to the mobile phone terminal and the base station terminal to calculate the demand space of the LCP market in the future
.
?? We have made the following assumptions:?? 1) Mobile phone, in 2019, 2020, 2021, 2022 and 2025, the penetration rate of Apple's system is 50%, 75%, 100%, 100% and 100% respectively; Android system penetration The rates are 0%, 7%, 14%, 21%, and 40%; 2) At the base station, the market share of LCP oscillators in 2019, 2020, 2021, 2022, and 2025 are 0, 20%, and 30%, respectively.
, 40% and 80%
.
?? "? We believe that the LCP market will exceed 10 billion in the future, of which the market space of LCP film will exceed 10 billion
.
At present, the main manufacturers of LCP film are still foreign companies, but some domestic resin companies and film-drawing companies are already doing it.
Samples and achieved good results.
It is currently in the stage of industrialization preparation.
We expect that some companies will form substantial sales in the second half of 2020
.
?? The demand for LCP resin will grow rapidly, and the total demand for the industry is expected to be in the next 5 years.
Doubled, among which the demand for high-end grades suitable for drawing films will grow rapidly
.