As the license is approaching, China's 4G market is staged a wonderful "Three Kingdoms Killing", and all forces are coming to the scene. China Mobile is the most urgent, and with the tacit approval of the regulatory authorities, it will reach commercial scale by the end of the year; China Unicom is the most calm, and its 4G demand is not urgent, so it seems to have the "most confidence" in the issuance of licenses; Depressed, FDD licenses can be encountered but not available, and can only play "Tai Chi push hands" in the face of 4G licenses. China Mobile's largest 4G network has been completed during the year Over the past four years, China Mobile, as the world's largest operator in terms of user size, revenue and profit, has been unhappy. The data shows that China Mobile's 3G network construction investment and terminal subsidies exceeded 210 billion in 4 years. In 2009, when the 3G license was issued, China Mobile ’s investment in TD network exceeded 58.8 billion yuan. However, trapped in the imperfect TD-SCDMA industry chain, China Mobile clearly lacks 3G star terminals compared to the other two operators, and a large number of traditional Global Connect users are "cannibalized" by China Unicom and China Telecom. Although China Mobile's official data currently states that TD users exceed 100 million, 3G network usage is not high, and many provinces are even below 15%. In China Mobile's 2012 financial report, about 3/4 of the data traffic came from the WLAN network, and 2G and 3G data traffic accounted for only 1/4. The 3G network construction cost is huge but the income is limited, causing China Mobile's profit growth to slow down year after year for four consecutive years. China Mobile's net profit in 2012 was 1,293 yuan, a year-on-year increase of 2.7%. However, Pudong Development Bank contributed a total of 18.3 billion yuan in pre-tax profits. If excluded, China Mobile's 2012 net profit fell by 0.5% year-on-year, and the profit for the first time in 10 years has reversed. In the 3G era, China Mobile, which has suffered and suffered, finally chose to "run away" in 4G this year. China Mobile announced at the beginning of the year to promote the TD-LTE 4G "Double Hundred" plan-the TD-LTE network covers 100 cities above the prefecture-level city in China, purchases more than one million TD-LTE terminals, and builds 200,000 4G base stations to cover the population Over 500 million, built the world's largest 4G network. China Mobile said that the capital expenditure on 4G in 2013 will increase 8 times from 5 billion yuan last year to 41.7 billion yuan. However, with the lessons of the 3G era, China Mobile is obviously reluctant to continue to carry the "TD banner" alone in the 4G era. In an e-mail sent by the vice president of China Mobile to the executives of the provincial companies, they proposed "five hopes and five undesirables", which made it clear that they did not want TD-LTE to be operated by an operator. "If we become a 'minority', no matter how hard we try, it will be difficult to succeed." Interestingly, several industry experts subsequently issued an open letter, once again calling on the three major operators should obtain a TD-LTE license, which immediately triggered heated discussions in the industry and the media. Miao Wei, Minister of the Ministry of Industry and Information Technology, accidentally revealed in an interview with the media during the two sessions: "4G licenses are expected to be issued within this year." Xi Guohua, chairman of China Mobile, subsequently responded that "the end of the year will be a more appropriate time point", but information from all parties indicates that TD-LTE The license issuance time may be more advanced. China Unicom clearly stated that 4G only chooses FDD: smooth upgrade Faced with the acceleration of the issuance of 4G licenses, Chang Xiaobing, chairman of China Unicom, finally expressed his attitude. Chang Xiaobing made it clear at the 2012 results conference in Hong Kong recently: "After the management's research, China Unicom will firmly move away from the existing technical route, that is, the FDD 4G network." He also believes that China Unicom has no reason to operate both FDD and TDD 4G networks. China Unicom will smoothly evolve through technology and upgrade existing 3G base stations to 4G. Even if it invests in 4G network construction in the future, it will be controlled at The level within 10 billion yuan. In the 3G era, due to the total construction of new base stations, China Unicom's annual investment in network construction is more than 100 billion yuan, of which more than 70% is used for 3G network investment, second only to China Mobile. Even in 2012, China Unicom still added 92,000 3G base stations. According to relevant personnel of a certain equipment manufacturer, Sohu IT revealed that since 2010, China Unicom has required that the newly added WCDMA base station must support the smooth evolution to FDD-LTE. At present, China Unicom has a total of 331,000 3G base stations, which have all been upgraded to the 3.75G network of HSPA + last year, with a peak downlink rate of 21Mbps. This is also the reason why Chang Xiaobing is most calm when facing the issuance of 4G licenses. According to the technical personnel of the equipment manufacturer, the HSPA + base station provided by China Unicom to FDD LTE in the past two years only needs to add a motherboard and update the RF antenna and software. "One base station can be upgraded by two technicians in one night. ". This is what Chang Xiaobing said: "China Unicom has no reason to operate both FDD and TDD 4G networks. Will China Unicom smoothly evolve through technology and upgrade existing 3G base stations to 4G?" China Telecom stated: Ruqiang will only rent TDD licenses but not build them Compared with China Unicom, the most "tangled" is China Telecom. Because the CDMA EV-DO 3G system it uses does not support a smooth transition to FDD and TDD, if China Telecom chooses to build a network, if China Telecom chooses to build a network, it must build a new one. This is also the reason why China Mobile said that it does not want TDD to be operated by an operator, which is a "dark pull" against China Telecom. However, China Telecom's 3G network is not yet profitable. If it continues to invest heavily in the construction of a 4G network across the country, there will be great pressure. This is also testing the "political wisdom" of the head of China Telecom Wang Xiaochu. Wang Xiaochu said publicly at the 2012 performance announcement recently: "China Telecom hopes to obtain the FDD LTE license. If the government department does not issue the FDD LTE license, China Telecom will consider leasing the network from China Mobile, even with other operators with TD technology. Build a TDD network together because I believe that cooperation is more efficient than building alone. " One stone provokes thousands of waves, and Wang Xiaochu's ingenious response made the industry sigh. An internal employee of China Telecom said on Weibo: "I saw one brother's statement and had fun all morning"; an employee of China Unicom's marketing department lamented "True Wisdom"; an employee of China Mobile Research Institute It is believed that "Telecom was forced to state that TDD license is about to be issued". Two options for 4G in China: or first TDD license Under the clear statement of the heads of the three major operators, China's 4G license is becoming increasingly clear: China Mobile must choose TDD, China Unicom is FDD, and China Telecom has variables: either TDD is forced to choose TDD / FDD dual network dual mode. A certain equipment manufacturer told Sohu IT that FDD-compatible CDMA networks have matured in the international technology. For example, Verizon, the largest operator in the United States, will complete 4G network coverage in the United States by the middle of this year. Ericsson and Aran will provide equipment and Technical Services. However, if you choose TDD / FDD dual mode, in addition to the technical uncertainty, China Telecom must also choose 3 or 2 different frequencies for CDMA / TDD / FDD (FDD uses the current CDMA spectrum). At the same time, as far as the actual situation is concerned, a single TDD base station has a smaller coverage area than an FDD base station, and China Telecom will be "fatigued" in the deployment of base stations. The equipment manufacturer believes that the most likely thing is that China Telecom deploys its own FDD network in key cities, and chooses to lease or co-build with China Mobile ’s TDD network for wide-area coverage in rural areas-but this is also at China Mobile After the TD-LTE network began to cover the rural market. In China, the three major operators in charge are the Ministry of Industry and Information Technology, and the evaluation of the group companies rests with the SASAC. If the SASAC and the Ministry of Industry and Information Technology believe that China Telecom ’s position is conducive to the preservation and appreciation of state-owned assets, it is difficult for China Mobile to refuse China Telecom ’s lease or Co-build application. The industry believes that as the Ministry of Industry and Information Technology and the three major operators have recently expressed their positions for 4G, indicating that the issuance of 4G licenses will be faster than expected at the end of the previous year. It is likely that TDD licenses or FDD licenses will be issued, which is for all parties. It's all a "preferred": China Mobile got a "birth certificate", China Unicom is ready to upgrade the FDD network, and China Telecom can "apply to both sides". If this choice finally becomes a reality, then a phenomenon is very interesting: As China ’s largest CDMA 3G network operator, China Telecom, to lease a 4G network from China Mobile, the world ’s largest 2G network operator, what will happen in the world?
If you need a manufacturer who can manufacture flexible PCB for you, you should make it clear that this PCB manufacturer should have a mature and current process flow for manufacturing flexible circuit board. Considering factors such as manufacturing cost, we suggest that you choose a Chinese PCB manufacturer. Because, at present, PCB Manufacturing industry is basically concentrated in China. It is not only because China's manufacturing industry is very developed, but also because it has a very mature production process and can effectively reduce the cost of manufacturing products for you.
Flexible circuit boards are widely used in automobiles, medical, telecommunications, industry or commerce.
In certain non standard cases, the circuit manufacturer may be called upon to create a specialty laminate by using a specified alternative metal foil, such as a special copper alloy or other metal foil in the construction. This is accomplished by laminating the foil to a base film with or without an adhesive depending on the nature and properties of the base film.
Tips of flexible PCB design
The shortest distance between two points is a straight line, so a circuit trace is a circuit trace on a flexcircuit will look like a circuit trace on a Rigid Circuit Board , right? Actually there can be considerable differences between designing a rigid PCB and a flexible PCB. Because of the flexibility feature, there are unique issues affecting robustness. For example, since flex can bend, one needs to be sure that bending does not crack or break solders joints near a bend location. For this reason, design features like radiused corners and filleted pads are common on flexible circuits. Another issue is the substrate used for flex is not as dimensionally stable vs. the hardboard cousin. Allowances for dimensional changes may be required for flexible PCB design. Most PCB design software is tailored to rigid printed circuit materials and features. Tradeoffs occur when this same software is used to design flexible PCB's.
At JHYPCB, we specialize in the fabrication and assembly of flexible PCB products for use in the manufacturing of medical devices and various types of telecommunication and industrial equipment. Our Custom PCB manufacturing capabilities allow us to develop and produce a top-performing flex PCB that meets your unique requirements. We can also work with you to produce a custom flex PCB Prototype that will significantly improve your prospects of a successful project outcome. For detailed capabilities, please refer to the following form.
Flexible PCB Flex PCB,Flexible Printed Circuit,Flexi Circuits,Flexible Circuits JingHongYi PCB (HK) Co., Limited , https://www.pcbjhy.com
Flexible PCB , allowing the board to conform to a desired shape, or to flex during its use.
WHAT IS FLEXIBLE PCB?
Flexible PCB, also known as Flexible electronics, flexible circuit board, Flex PCB , flex circuits, is a technology for assembling electronic circuits by mounting electronic devices on flexible plastic substrates, such as polyimide, PEEK or transparent conductive polyester film. Additionally, flex circuits can be screen printed silver circuits on polyester. Flexible electronic assemblies may be manufactured using identical components used for rigid Printed Circuit Boards, allowing the board to conform to a desired shape, or to flex during its use. An alternative approach to flexible electronics suggests various etching techniques to thin down the traditional silicon substrate to few tens of micrometers to gain reasonable flexibility, referred to as flexible silicon (~ 5 mm bending radius).
What are Advantages of Flexible PCB?
Flexible PCB is essentially different from Rigid PCB . Although rigid PCB is currently the most produced PCB in the world, the use of flexible PCB has many advantages, including:
Thsse benefits make flex PCBs ideally fit for a wide range of applications in industries such as Military, Transportation, Medical, Consumer Electronics, Automotive, Aerospace, Communications and Industrial.
Flex PCB disadvantages also exist:
Flexible PCB Applications
Types of Flexible PCB
There are a few basic constructions of flexible circuits but there is significant variation between the different types in terms of their construction. Following is a review of the most common types of flexible circuit constructions
Single-sided flexible circuits have a single conductor layer made of either a metal or conductive (metal filled) polymer on a flexible dielectric film. Component termination features are accessible only from one side. Holes may be formed in the base film to allow component leads to pass through for interconnection, normally by soldering. Single sided flex circuits can be fabricated with or without such protective coatings as cover layers or cover coats, however the use of a protective coating over circuits is the most common practice. The development of surface mounted devices on sputtered conductive films has enabled the production of transparent LED Films, which is used in LED Glass but also in flexible automotive lighting composites.
Double access flex, also known as back bared flex, are flexible circuits having a single conductor layer but which is processed so as to allow access to selected features of the conductor pattern from both sides. While this type of circuit has certain benefits, the specialized processing requirements for accessing the features limits its use.
Sculptured flex circuits are a novel subset of normal flexible circuit structures. The manufacturing process involves a special flex circuit multi-step etching method which yields a flexible circuit having finished copper conductors wherein the thickness of the conductor differs at various places along their length. (i.e., the conductors are thin in flexible areas and thick at interconnection points.).
Double-sided flex circuits are flex circuits having two conductor layers. These flex circuits can be fabricated with or without plated through holes, though the plated through hole variation is much more common. When constructed without plated through holes and connection features are accessed from one side only, the circuit is defined as a "Type V (5)" according to military specifications. It is not a common practice but it is an option. Because of the plated through hole, terminations for electronic components are provided for on both sides of the circuit, thus allowing components to be placed on either side. Depending on design requirements, double-sided flex circuits can be fabricated with protective coverlayers on one, both or neither side of the completed circuit but are most commonly produced with the protective layer on both sides. One major advantage of this type of substrate is that it allows crossover connections to be made very easy. Many single sided circuits are built on a double sided substrate just because they have one of two crossover connections. An example of this use is the circuit connecting a mousepad to the motherboard of a laptop. All connections on that circuit are located on only one side of the substrate, except a very small crossover connection which uses the second side of the substrate.
Flex circuits having three or more layers of conductors are known as multilayer flex circuits. Commonly the layers are interconnected by means of plated through holes, though this is not a requirement of the definition for it is possible to provide openings to access lower circuit level features. The layers of the multilayer flex circuit may or may not be continuously laminated together throughout the construction with the obvious exception of the areas occupied by plated through-holes. The practice of discontinuous lamination is common in cases where maximum flexibility is required. This is accomplished by leaving unbonded the areas where flexing or bending is to occur.
Rigid flex PCB circuits are a hybrid construction flex circuit consisting of rigid and flexible substrates which are laminated together into a single structure. Rigid-flex circuits should not be confused with rigidized flex constructions, which are simply flex circuits to which a stiffener is attached to support the weight of the electronic components locally. A rigidized or stiffened flex circuit can have one or more conductor layers. Thus while the two terms may sound similar, they represent products that are quite different.
The layers of a rigid flex are also normally electrically interconnected by means of plated through holes. Over the years, rigid-flex circuits have enjoyed tremendous popularity among military product designer, however the technology has found increased use in commercial products. While often considered a specialty product for low volume applications because of the challenges, an impressive effort to use the technology was made by Compaq computer in the production of boards for a laptop computer in the 1990s. While the computer's main rigid-flex PCBA did not flex during use, subsequent designs by Compaq utilized rigid-flex circuits for the hinged display cable, passing 10s of 1000s of flexures during testing. By 2013, the use of rigid-flex circuits in consumer laptop computers is now common.
Rigid flex PCB board are normally multilayer structures; however, two metal layer constructions are sometimes used.
Polymer thick film (PTF) flex circuits are true printed circuits in that the conductors are actually printed onto a polymer base film. They are typically single conductor layer structures, however two or more metal layers can be printed sequentially with insulating layers printed between printed conductor layers, or on both sides. While lower in conductor conductivity and thus not suitable for all applications, PTF circuits have successfully served in a wide range of low-power applications at slightly higher voltages. Keyboards are a common application, however, there are a wide range of potential applications for this cost-effective approach to flex circuit manufacture.
Flexible PCB materials
Each element of the flex circuit construction must be able to consistently meet the demands placed upon it for the life of the product. In addition, the material must work reliably in concert with the other elements of the flexible circuit construction to assure ease of manufacture and reliability. Following are brief descriptions of the basic elements of flex circuit construction and their functions.
The base material is the flexible polymer film which provides the foundation for the laminate. Under normal circumstances, the flex circuit base material provides most primary physical and electrical properties of the flexible circuit. In the case of adhesiveless circuit constructions, the base material provides all of the characteristic properties. While a wide range of thickness is possible, most flexible films are provided in a narrow range of relatively thin dimension from 12 µm to 125 µm (1/2 mil to 5 mils) but thinner and thicker material are possible. Thinner materials are of course more flexible and for most material, stiffness increase is proportional to the cube of thickness. Thus for example, means that if the thickness is doubled, the material becomes eight times stiffer and will only deflect 1/8 as much under the same load. There are a number of different materials used as base films including: polyester (PET), polyimide (PI), polyethylene naphthalate (PEN), polyetherimide (PEI), along with various fluropolymers (FEP) and copolymers. Polyimide films are most prevalent owing to their blend of advantageous electrical, mechanical, chemical and thermal properties.
Adhesives are used as the bonding medium for creating a laminate. When it comes to temperature resistance, the adhesive is typically the performance limiting element of a laminate especially when polyimide is the base material. Because of the earlier difficulties associated with polyimide adhesives, many polyimide flex circuits presently employ adhesive systems of different polymer families. However some newer thermoplastic polyimide adhesives are making important in-roads. As with the base films, adhesives come in different thickness. Thickness selection is typically a function of the application. For example, different adhesive thickness is commonly used in the creation of cover layers in order to meet the fill demands of different copper foil thickness which may be encountered.
A metal foil is most commonly used as the conductive element of a flexible laminate. The metal foil is the material from which the circuit paths are normally etched. A wide variety of metal foils of varying thickness are available from which to choose and create a flex circuit, however copper foils, serve the vast majority of all flexible circuit applications. Copper's excellent balance of cost and physical and electrical performance attributes make it an excellent choice. There are actually many different types of copper foil. The IPC identifies eight different types of copper foil for printed circuits divided into two much broader categories, electrodeposited and wrought, each having four sub-types.) As a result, there are a number of different types of copper foil available for flex circuit applications to serve the varied purposes of different end products. With most copper foil, a thin surface treatment is commonly applied to one side of the foil to improve its adhesion to the base film. Copper foils are of two basic types: wrought (rolled) and electrodeposited and their properties are quite different. Rolled and annealed foils are the most common choice, however thinner films which are electroplated are becoming increasingly popular.
tools
Both PCBs and flexible PCBs use similar tooling such as CAD files, photo tools and electrical test fixtures. Perhaps the biggest difference is around the cutline definition. Flexible circuits provide unlimited configuration opportunities that often results in very odd shapes and sizes. Circuit boards often are rectangular or may have some notches or curved outlines routered. Because of this nuance, steel rule dies and hard tool dies are probably used more often for flexible PCBs than for boards, at least for ultra high volume applications. Laser definition of the circuit outline is also a common flexcircuit process. Other differences in tooling involve fixturing that may be required to handle flexible substrates.
JHYPCB: A Leading Flexible PCB Manufacturer from China
Items
Manufacturing Capability
PCB Layers
1 - 8layers
Laminate
DuPont PI, Shengyi PI
Maximum PCB Size(Length x Width)
Single Sided PCB
480*4000mm
Double Sided PCB
480*1800mm
Multilayers
236*600mm
Minimum Board Thickness
Single Sided PCB
0.05mm+/-0.02mm
Double Sided PCB
0.08mm+/-0.02mm
Multilayers
As per Gerber
Finished Board Thickness
1-6L
0.05mm-0.6mm
8L
1.6mm
Min Tracing/Spacing
Copper Thickness 1/3 oz:
0.076mm/0.076mm (1-6L)
0.05mm/0.05mm (8L)
Copper Thickness 1/2 oz:
0.076mm/0.076mm (1-6L)
0.06mm/0.06mm (8L)
Copper Thickness 1oz:
0.1mm/0.1mm (1-6L)
0.065mm/0.065mm (8L)
Min. Annular Ring
4mil
Minimum Hole Size
1-6L
0.2mm(8mil) (CNC)
8L
0.15mm(CNC)
Solder Mask Color
Green, White, Blue, Black, Red, Yellow
Solder-stop coating---Coverlay
PI and PET film
Silkscreen Color
White, Black, Yellow
Surface Finish
OSP
e HASL
ENIG(Electroless NickLead-Free Gold)
Ni thickness:2-6um
Au thickness:0.025-0.05um
Flash Gold
Ni thickness:2-8um
Au thickness:0.025-0.15um
Immersion Tin
Tin thickness:0.5-1um
PlatingTin
Tin thickness:1-10um
Laser cuPunching
Special technologies
Peelable solder mask
Gold fingers
Stiffener (only for PI/FR4 substrate)
Impedance Control+/-10%
Rigid Flex PCB
YOU MAY ASK:
Single-sided flexible circuits have a single conductor layer made of either a metal or conductive (metal filled) polymer on a flexible dielectric film. ... Holes may be formed in the base film to allow component leads to pass through for interconnection, normally by soldering.
Rigid flex printed circuit boards are boards using a combination of flexible and rigid board technologies in an application. Most rigid flex boards consist of multiple layers of flexible circuit substrates attached to one or more rigid boards externally and/or internally, depending upon the design of the application.
Paul Eisler
Some historical information about flexible circuitry. Paul Eisler is generally credited as being the inventor of the Printed Circuit Board. Paul Eisler was an Austrian inventor, born in Vienna in 1907. In 1936 Paul Eisler invented the process of using conductive epoxy to create circuit patterns.
A thin film circuit board as a set forth in claim 4, wherein the insulator layer comprises a polyimide obtained from biphenyltetracarboxylic dianhydride and phenylenediamine.
The flex banner are basically used to shout your messages or product endorsement from the rooftops or the roadsides. ... The flex banner is printed using solvent in and therefore these banners are really cost effective medium of promoting.
Helpful Resources
July 18, 2020