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FPC three main features

FPC three main features

1. Deflection of flexible circuits and reliability of the current FPC are: single-sided, double-sided, multilayer flexible and rigid flexible board four boards. ① Flexible single-sided board is the lowest cost, do not ask for much when the electrical properties of the PCB. When wiring the single-sided, single-sided flexible board should be selected. It has a layer of conductive chemical etching of the graphics, the flexible insulating substrate of the conductive surface layer for rolling copper foil graphics. Insulating substrate may be polyimide, polyethylene terephthalate, p-aramid fiber acetate and polyvinyl chloride. ② flexible double-sided board insulation basement membrane in each of the two sides made of a layer of conductive etched graphics. Metallized holes on both sides of the insulating material to form conductive pathways connecting graphics to meet the deflection of the design and use features. The cover film can protect the single-, double-sided component placement of wires and the location of the instructions. ③ multi-layer flexible board is 3-layer or more layers of single-sided or double-sided flexible circuits laminated together by drilling larvae L, the formation of the metal plating of holes between different layers in the formation of conductive pathways. In this way, without using complex welding process. Multi-layer circuit at a higher reliability, better thermal conductivity of the assembly and provide greater convenience for performance of functions of great differences. Layout in the design, assembly should take into account the size, layers and flexible interaction. ④ traditional rigid flexible board is rigid and flexible substrates laminated together selectively composed. Structure to the formation of metal-based conductive connecting L larvae. If a PCB is, have negative components, rigid flexible board is a good choice. But if all components are in the side, the selection of double-sided flexible board, and laminated on the back of a layer of reinforcing material FR4, will be more economical. ⑤ hybrid structure is a multilayer flexible circuits, conductive metal layers of different composition. The use of an 8-laminate FR-4 as the dielectric layer, the use of polyimide as the outer layer of the medium, from the direction of the main board out of the three different leads, each lead by different metals. Constantan alloy, copper and gold, respectively, lead an independent. Most of the structure of this mixed signal converter used in the conversion and thermal and electrical properties of the relationship between the relatively harsh conditions of low temperature, is the only viable solution. Can be connected through the ease of design and evaluation of the total cost to achieve the best price-performance ratio.

2. Flexible circuit if the economy is relatively simple circuit design, the total volume of small and appropriate space, the traditional way in most of even a lot cheaper. If the line complex, deals with a number of signals or special electrical or mechanical performance requirements, flexible circuit design is a good choice. When the application size and performance beyond the ability of rigid circuit, the flexible assembly is the most economical. On a thin film can be made from within the hole with 5mil and 12mil pad 3mil lines and spacing of the flexible circuit. Therefore, in thin films direct mount chip more reliable. May be because the free ion source Desmear retardant. These may have a protective film, and at a high curing temperature, the higher the glass transition temperature. Flexible-rigid material than the material cost savings due to eliminating the connector. The high cost of raw materials is the flexible circuit of the main reasons for high prices. Larger difference between the prices of raw materials, the lowest-cost polyester flexible circuits used in the cost of raw materials used in rigid circuit 1.5 times the raw materials; high-performance polyimide flexible circuit is as high as 4 times or more. At the same time, the flexible material during the manufacturing process so that it is not easy to automate processing, resulting in decreased production; in the final assembly process prone to shortcomings, including off flexible attachments, fracture lines. When the design is not suitable for applications, such cases more easily. Caused by bending or forming in the high stress, often need to choose to enhance the material or reinforcement material. Despite the high cost of its raw materials, manufacturing problems, but collapsible, flexible and multi-layered puzzle features, will reduce the overall size of components, materials used be reduced, bringing the total costs of the assembly. Flexible circuits industry is in a small but rapidly evolving. Polymer thick-film method is a highly efficient, low-cost production process. The process in the low-cost flexible substrate, the selective conductive polymer screen printing ink. Its representation matrix for the flexible PET. Polymer thick film screen printing method conductors including filler metal filler or toner. Polymer thick film itself was very clean, the use of lead-free SMT adhesive without etching. Addition of Technology and its use of low-cost substrate, polymer thick film circuit is the method of copper circuits polyimide film prices 1 / 10; is the price of rigid circuit boards 1 / 2 ~ 1 / 3. Polymer thick-film method is particularly well suited to the equipment control panel. In mobile phones and other portable products, polymer thick-film method for the printed circuit board components, switches and lighting devices into law polymer thick film circuit. Both cost savings and reduce energy consumption. Generally speaking, the flexible circuit is indeed cost more than rigid circuits, and higher costs. Flexible plate at the time of manufacture, in many cases have to face the fact that many of the parameters exceeds the tolerance range. Manufacture of flexible circuits is the difficulty of the flexible material.

3. The cost of flexible circuits in spite of the cost of the above-mentioned factors, but the price of flexible assembly is declining, more rigid and traditional circuit similar. The main reason is the introduction of the updated materials, improved production technology and structural change. The structure now makes the product a higher thermal stability, very few materials do not match. Some updated materials from copper layer can be thinner and more sophisticated system of lines, so that components are smaller, more suitable for small load space. The past, the use of copper foil roll adhesion process will be coated with adhesive in the media today, you can not use the adhesive directly on the media to generate copper foil. These technologies can be a few micron thick copper layer, to be 3m. 1 and even more narrow width precision lines. After removing some of the adhesive with a flame-retardant properties of flexible circuits. This will speed up the certification process uL can further reduce costs. Flexible circuit board solder masks and other surface coatings to enable flexible assembly to further reduce costs. In the next few years, smaller, more complex and higher cost-assembled flexible circuit will require more innovative approaches to assembly, and the need to increase the hybrid flexible circuits. The flexible circuit industry challenge is to use its technological advantages, with the computer, remote communications, consumer demand, as well as synchronous dynamic markets. In addition, the flexible circuit in the lead up to play an important role. FPC is referred to as the Flexible Printed Circuit, also known as the soft circuit board, flexible printed circuit boards, flexible circuit boards, referred to as soft board or FPC, with a high density wiring, light weight, thin thickness characteristics. Mainly used in mobile phones, laptop, PDA, digital video cameras, LCM, and many other products. FPC flexible printed circuit is a polyimide or polyester film to a substrate made of a high degree of reliability, excellent flexible printed circuit. Features: 1. Be free to bending, folding, winding, three-dimensional space can be mobile and flexible. 2. Thermal performance can be used to reduce the size of FPC. 3. The realization of lightweight, small and thin to achieve component integration of devices and wires to connect. FPC applications MP3, MP4 players, portable CD players, home VCD, DVD, digital cameras, cell phones and mobile phone batteries, medical, automotive, aerospace and military field of epoxy CCL FPC become an important species with flexible features to epoxy resin for the substrate FCCL (FPC), has a special function as a result of the use of increasingly broad-based epoxy resin copper clad laminate is becoming an important species. However, late start to be in China to catch up. Epoxy Flexible Printed Circuit Board has been since the realization of industrial production has gone through the course of development for more than 30 years. 70s from the 20th century, the beginning of industrialization into a real large-scale production until the late 80’s, as a new class of polyimide film materials available and the application of flexible printed circuit board so that FPC had no adhesive formulations The FPC (generally referred to as “second-type FPC”). Into the 90’s developed the world’s circuits and high-density coverage of the corresponding photosensitive film, made in the design of FPC has made significant changes. Due to open up new application fields, the form of its products have taken place in the concept of non-small changes, which it expanded to include TAB, COB with a wider range of substrates. In the 90’s by the rise of the latter half of the high-density FPC has begun to enter the large-scale industrial production. Its circuit to the more micro-graphic extent of the rapid development of high-density FPC is also a rapidly growing market demand.

Outgoing Quality Inspection of flexible pcb

This time let’s see the outgoing quality inspection of flexible pcb, so you can see how can we control the quality of flexible pcb. See below our test items:

1. The material of your required. Include the based material,coverlayer,stiffener,silkscreen, etc
2. Testing: Peel strength, Chemical resistance test, Bending test, Thermal stree test;
3. Finished treatment;
4. Outline dimension;
5. 100% open/short testing of flexible pcb;
6. Appearance inspect.

After these inspect items, then we will pack the flexible pcb goods, and send out.

The production tolerances of flexible pcb

Would you like to know the flexible pcb production capabilities and tolerances of CMD circuits? Please see below CMD can make for you.

1. tolerance of overall thickness   +/-0.03mm
2. positional and dimensional tolerance of edges and holes   about +/-0.10mm
3. minimum trace width and spacing (1/2 oz. copper)     0.05mm/0.05mm
4. minimum distance of traces and holes to an edge of the flex pcb 0.15mm, better is 0.20mm

These are the most common tolerances of the flexible pcb, if your board have more strict required, please send us to check if we can make.

CMD Circuits specilize in making flexible pcb, flexible circuits, rigid pcb, aluminum pcb.

FPC ENIG surface plated

Now the popular of the FPC surface plating is ENIG, but what’s the ENIG? It’s Nickel Immersion Gold.

The flexible circuits copper surface is plated of Ni/Au. The deposition thickness of the inner Ni layer is generally3~6um, the deposition thickness of the outer Au thin, usually 0.03 ~ 0.1um. Ni as the barrier layer between Cu and soldering tin. Welding, outside Au in the solder which melts rapidly with soldering tin and then turn into Ni/Sn intermetallic compounds with inner Ni. The gold-plated to prevent Ni oxidation during storage or passive, it should be enough gold plating density, the thickness can not be too thin.

CMD Circuits almost all flexible circuits are with the ENIG plated for customers, all of our staff are with the many years experience in line, and our customers are very satisfy with our quality when they compare with others’.

Relative Posts:
1. The structure of FPC;
2. the whole thickness of FPCs;
3. Flexible Circuits Production Process.

The thickness of Coverlayer

There are normal three kinds of coverlayer of flexible circuits(flexible pcb), please see below thickness:

1)12.5UM:     PI:12.5UM    AD:15UM           Thickness:27.5UM

                         PI:12.5UM    AD:25UM           Thickness :37.5UM
             
2)  25UM:     PI:25UM     AD:25UM            Thickness:55UM

If you need any other information of flexible circuits and flexible pcb, please contact us anytime.

PCB Dry film photoresist structure and main components

This time let’s talk about the PCB Dry film photoresist structure and main components.

1. PCB Dry film photoresist structure:

Dry film photoresist consist of the polyester film, photoresist film and polyethylene protective film three parts.

Polyester film is the based of Photosensitive layer, the thickness is usual 25um.
 
Polyethylene film is a protective film covered with a photosensitive layer on the top to prevent dirt dry dust and dirt.
General thickness of polyethylene film is also 25um.

Photoresist was the subject of dry filmmany,mostly is the negative light material.

2.The main components of photoresist film  :

1) binder (film-forming resin)

2) Light monomer

3) Photoinitiator

4) Plasticizer

5) tackifier

6) thermal polymerization inhibitor

7) pigment

(8)  Solvent
The solvent must be used to dissolve the above components, usually acetone and alcohol.

If you want to know more about produce procedure the rigid pcb,aluminum pcb, please contact with us anytime.

How to distinguish films?

In general, the master film is also known as the black film, mainly used to copy the work film (yellow film), but not necessarily only a yellow film for work, are also black films do work. It mainly to do high-precision HDI board or to a one-time savings in the production of small quantities of circuit boards and flexibe pcb. Yellow films mainly used in ordinary printed circuit boards and mass production.

Positive film for the use of graphical electroplating, developing is the circuits, leaving the role of anti-corrosion plating, mainly tin and pb plating. Negatives film used for direct etching, leaving the role of circuits. When distinguish the films, the smooth side is black film, in contrast, is yellow film. And generally use scratching pen to scratch the film can be seen smooth side.

Please Note: There are both glossy and matte side of yellow film, and the second is easy to find easy-to-oil surface indentation when using. On film circuits (copper), the transmitting is negative film, opaque positive film.

CMD Circuits is specializing in manufacturing the printed circuit boards, flexible pcb and aluminum pcb, please contact us if any inquiries.

Aluminum pcb applications

Aluminum PCB is one of metal-based pcb,including copper foil,thermal insulating layer and metal substrate three parts,and now the aluminum pcb is widely used in the many applications.

1. Audio devices: input,output amplifiers,balanced amplifiers,audio amplifiers,preamplifiers,power amplifiers and so on.
2. Power Supply: Switching Regulator,DC / AC converter,SW regulator and so on.
3. Telecommunications electronic equipments: high-frequency electric amplifiers,transmitter circuit board.
4. Office automation equipments: motor drive,and so on.
5. Automotive: Electronic Ignition,power controller.
6. Computer: CPU board,power controller,floppy disk drive devices.
7. Power modules: converter,power rectifier bridges.
8, lamp lighting: As an advocate to promote energy-saving lamps and colorful energy-saving LED lights are very popular by the market,while the aluminum pcb used in LED lights have begun a large-scale applications.
CMD Circuits have provided the high quality and competitve cost aluminum pcb,aluminum base pcb and other metal base pcb. Please contact us if you have any inquires.

PCB drilling quality problems analysis and solutions

In the PCB drilling process may have the following quality problems:
1, partial hole, porous & leak holes;
2, broken drill bits;
3, blocking the hole (hole with debris);
4, no drill through;
5, burr hole, rough, smudge;
6, the surface burrs.

Here is a quick solution of pcb  drilling quality problems. The method is from 1 to last to  find out the problems.

1. Check the settings of drilling parameters are correct, mainly speed and lower speed. Confirmed whether it is setting or procedural issue.

2. If drilling parameters are right, put printed circuit boards on two machines(Note: to be the same machine model),and using the same or different settings of drilling to confirm the problem is the machine problems or procedural issues. As the probability is too less of the two machine have the same problems, then you can know the problem is the The equipment or procedural problems.

3. If the problems still have, replace of the raw materials and test materials.

4. If the problem still have, replace of the drill bit to test, generally the brand-name manufacturers drilling bits with less problems.

CMD Circuits have the strict quality control systems to ensure the quality of our producting, including rigid pcb, flexible pcb, aluminum pcb and all items. Please contact with us if you need any further information.

The outline of printed circuit board processing techniques

The people who engaged in printed circuit board processing will be understanding, PCB outline processing is also one of the difficulties of PCB making, most of the PCB is a rectangle shape, but a considerable number of PCB have a special shape.

PCB outline processing methods:

1. Milling outline: the use of CNC milling machines process outline, it should be provied the milling outline data and corresponding positioning holes data, these datas provided by the programmer. As there is not a great distance between the printed circuit boards, generally about 3mm, so generally use 3mm or 2.4mm diameter cutter.

2. Punching outline: the use of punch punching outline, need of the mold and let positioning pin correspond to the positioning hole of the PCB, usually selected 3.0mm hole for positioning the holes.

3. Open “V” groove: the use of “V” groove cutting machine along the PCB design “V” slot cut the boards into several connected parts;

4. Drill outline: the use of drill to drill holes at the edge of the contour.

Normally open “V” groove and drill only for processing aids.

With the development of printed circuit board design, outline processing technology is also developing. Our company also follow up with the development of requirements of PCB technology and production to keep our products with high quality.

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