Do you really know Multilayer PCB?

WDF-PCB-M-34,6 layer,wonderfulpcb.com

Most materials systems used in PWBs (aka PCBs) are composites of resins, fabric substrates and metal cladding. Each of these components has its own unique electrical and mechanical properties that contribute to the final characteristics of the finished laminates, prepregs and fabricated multilayer boards (MLBs). In most cases variables such as glass style and resin content have offsetting impacts on physical vs. electrical properties.

Data sheets often provide data in standard IPC formats, which may look at properties in rigid laminates (nominal 0.062” made using heavyweight glass at 32–40% resin content) rather than thin lams and prepregs used for multilayer PWBs (which more typically average 55% resin content or more). To further complicate the situation, some product lines are manufactured with consistent resin content for all product thicknesses, thus maintaining the dielectric properties while letting the mechanical properties be dictated by the constructions and resin content.

An understanding of what such variations in properties mean and how they relate to what the users will actually encounter is essential to design, manufacturability, assembly and end-use viability. In this presentation we will look specifically at the effect of glass style and resin content on dielectric constant and CTE and discuss how even at the product design  level it is important for design engineers to take these into consideration.

Conclusions

In most cases, no single value of dielectric constant or in-plane CTE (representative laminate properties that are impacted by resin content variation—obviously there are others as well, but for purposes of keeping this work manageable, we will focus on these two) will hold for all thicknesses of laminate or build-ups for MLBs. In those cases where either or both are critical, it is necessary to control resin content in both laminate and prepreg to ensure that the finished properties fall within the desired and expected ranges.

In some cases, such as with 85N polyimide and 92ML thermally conductive epoxy products, the specific values of Dk and CTE are less critical than other things such as processibility and design flexibility (as for 85N) or thermal conductivity (for 92ML) and so resin contents are allowed to vary so as to meet these needs.

In other cases either CTE (as in 85NT) or dielectric constant (as for Multiclad HF or 25N/FR) are critical needs, and in those cases the resin contents must be held to controlled limits so that the desired properties are consistently held for most or all of the laminate configurations.

Environmental protection PCB technology

Since the eu formally in December 2003 after "lead-free" legislation, the global electronic has great impact, in July 2006, the European Union WEEE directive about scrap electrical and electronics equipment, electrical equipment on restricting certain pollution substances in the ROHS directive and the Japanese association for the advancement of electronics industry (JEIDA) and the national electrical manufacturers association (NEMl) about the lead, the halogen electronic packaging industry has come into effect, the market of electronic products not contain lead, mercury, cadmium, hexavalent chromium, and restrict the use of polymeric brominated diphenyl or brominated flame retardants, PBB, PBDE harmful substances, such as this will impact of the global supply chain operations, including PCB industry and the development of relevant industries.My company to research environmental protection PCB products since 1999, and became one of the earliest recognized global green partner manufacturers Japan panasonic, and environmental protection and is now 99% PCB products are resonant.In this paper, from the raw material control, the choice of lead-free process and control and SMT electronic encapsulation after three aspects, comprehensively expounds how the next generation of PCB products to meet the increasingly stringent environmental requirements.

The selection and control of raw materials
As is known to all, in the PCB industry, mercury, cadmium and hexavalent chromium are almost don't have to, or in addition to containing trace, in the process of wet process will not be deliberate use of PCB manufacturers, so in the choice of raw materials and process, as long as considering the lead Pb and halogen don't overweight can conform to the basic requirements of environmental protection, metal processing is in be lead-free PCB surface (< 0.1% Pb), the traditional PCB and SMT industry, due to the extensive use of lead, tin alloy, such as HAL, solder paste, etc.Lead is a heavy metal elements, is widely distributed in nature, is the three elements of radioactive uranium and thorium, the end product of the decay of actinium, once the body of the lead intake more than its saturation concentration, can appear the symptom such as anemia, calcium deficiency, weakened immunity.Why do you want to lead-free solder?Leaded solder harmful: lead in solders for the soldering is 1% of the total usage weak (30000/5 million tons), and have widely spread the possibility of difficult to fully recovery.Due to environmental pollution, anxiety, such as lead poisoning effect on human body.In the PCB industry, halogen (fluorine, chlorine Cl, Br Br, 1 F) application mainly on the plate and ink.

material choosing
PCB processing eventually formed on the finished product, mainly includes three types of material: plate, surface processing (metal) layer and ink.1.1.1 plate regular plank FR - 4, CEM - 3, because contain a large number of brominated epoxy resin, such as four bromine bisphenol a, polybrominated biphenyls (PCBS), polybrominated diphenyl ether, etc., in the process of combustion, emit high toxic substances, such as dioxin (TCDO), such as benzene, furan, once the intake will not be able to discharge by human body, greatly threatening the human health.So the PCB must be halogen-free copper clad industry base material chlorine (Cl, Br Br is less than 0.09% respectively), phosphorus (P) epoxy resin instead of brominated epoxy resin, with nitrogen (N) phenol to replace the traditional dicyandiamide curing agent.
In addition, the environmental protection plate also has the strong heat resistance, able to lead-free SMT engineering under 260 degrees high temperature for many times, do not change color, stratification, deformation and bending.

For more information, pls contact: wonderful11@wonderfulpcb.com

Aluminum board process-B

5.4 board inspection
5.4.1 line surface must be in accordance with the requirements of the MI to check all the content.
5.4.2 must check on aluminum surface, aluminum surface dry film cannot have film falls and broken.
5.5 etching
5.5.1 for copper base is commonly 4 oz, will there is a certain difficulty in etching.First plate must be approved by the captain in person to do board, made in the spot check, line width, line spacing should be strengthened once every 10 PNL plate spot check line width, and make records.
5.5.2 recommended parameters: speed: 7 ~ 11 dm/min pressure: 2.5 kg/cm2 proportion: 25 be temperature: 55 ℃ (the above parameters are for reference only, the test plate results shall prevail)
5.5.3 back membrane should be paid attention to the time of the control between 4 ~ 6 min, because aluminium will reaction with NaOH, but also must ensure that the membrane clean, backing down membrane liquid membrane was not allowed to turn up the heat.No protective film of the plate, aluminum, from liquid membrane in the back up after the board will not stay to wash water on a board in time of liquid membrane, prevent the alkali corrosion of aluminum surface.  
5.6 corrosion inspection
5.6.1 normal board.
5.6.2 it is forbidden to use the blade repair line, in order to avoid injury and dielectric layer.
5.7 the solder mask
5.7.1 production process:
Brush copper surface grinding plate (only) to screen printing green oil (the first), and preliminary drying screen printing green oil (second) and the preliminary drying - exposure and development - plate mill, the acid pickling process. Under the soft brush - after curing -
5.7.2 reference parameters:
5.7.2.1 yarn used 36 t + 100 t
First 75 ℃ 5.7.2.2 x 20-30 min;The second 75 ℃ x 20-30 min
5.7.2.3 exposure: 60/65 (single) 9 ~ 11
5.7.2.4 enhancement: speed: 1.6 ~ 1.8 m/min pressure: 3.0 kg/m2 (total pressure)
5.7.2.5 curing: after 90 ℃ * 60 min + 60 min + 110 ℃ 150 ℃ above x 60 min parameters for the use of the DSR - 2200 tl ink, used only for reference.
5.7.3 note printing for control of air bubbles, if need, can add 1-2% of the diluent.
5.7.4 clappers before clappers member should check panel, there is a problem of instruct the captain and then to the clapper.   
5.8 HASL
5.8.1 spray before tin for aluminum plate with protective film tear protective film after spray tin.    
5.8.2 edge with both hands, it is strictly prohibited by hand directly touch the plate (especially aluminum surface).
5.8.3 operation, fight chafed.
5.8.4 tin cookie sheet before 130 ℃, 1 hour, and baking sheet to spray tin interval time less than 10 minutes.In order to avoid temperature difference cause a layered with ink.    
5.8.5 rework plate spray is only allowed to return once, if more than one board, to distinguish for special treatment.    
5.9 aluminum surface passivation treatment
5.9.1 level passivation process: (1) scrubbing brush (500 #) to (2) water - > (3) passivation, (4) washing the x 3-5. Dry - 6 drying
Note: (1) grinding plate: only aluminum surface grinding, FR4 parameter grinding plate.First board to check line no scratches, as well as the tin cried, uniform grinding crack.
(3)passivation: potion ingredients open cylinder quantity cylinder volume liquid temperature control concentration spraying in tank pressurization rate
Na2CO3 (CP) 50 g / 6500 g l, 130 l, 40 ~ 50 ℃ 2.0 ~ 3.0 1.0 ~ 1.5 m/min effective soaking time 10 ~ 15 s 100 m2 CP (K2CrO4) 15 g/l,  1950 g NaOH (CP) 390 g, 3 g/l
6 drying: 80 ~ 90 ℃.
Tyle = "the oledata.mso - spacerun: 'yes', the font size: 10.5000 pt; the font-family:" tahoma "; "> 5.7.2.5 curing: after 90 ℃ * 60 min + 60 min + 110 ℃ 150 ℃ above x 60 min parameters for the use of the DSR - 2200 tl ink, used only for reference.
5.7.3 note printing for control of air bubbles, if need, can add 1-2% of the diluent.   
5.7.4 clappers before clappers member should check panel, there is a problem of instruct the captain and then to the clapper.  

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Flex PCB - What is Flex PCB

FPC and the birth and development of the PCB, Rigid-Flex PCB gave birth to this new product. Therefore, Flex PCB is flexible circuit board and rigid circuit boards, after lamination processes, according to the relevant process requirements together, forming characteristics have FPC PCB board characteristics.

1.Flex PCB - Production Process：

Because Flex PCB is a combination of FPC and the PCB, Flex PCB production should also have the FPC PCB production equipment and production equipment. First, the combination of soft board electronics engineer to draw a line and shape according to demand, then, can be issued to the Flex PCB production plant, through CAM engineers relevant documents for processing, planning, and then arrange FPC production line production need FPC, PCB production line to produce PCB, after these two soft board and hard board out, according to the planning requirements for electronic engineers, the FPC and PCB through seamless lamination lamination machine, and then through a series of detailed links, ultimately process the Flex PCB. A very important aspect should Flex PCB difficult, more details before shipping, are generally required to conduct the inspection, its value is relatively high, so as not to let the supply and demand sides related loss of interest.

2. Flex PCB - Advantages and Disadvantages：

Advantages: FPC Flex PCB along with features and characteristics of the PCB, so it can be used in some special requirements of the product among the region has some flexibility, but also have a certain rigidity region of the internal space-saving products reduce the volume of the finished product, improve product performance is very helpful.

Cons: Flex PCB production process many, difficult to produce low yields, cast materials, manpower more, so its price is more expensive, relatively long production cycle.

3. Flex PCB - Related Applications

Flex PCB's characteristics determine its application in all areas covered by FPC PCB applications, such as:

1.Mobile telephone

2.Keypad and side buttons, etc.

3.Computer and the LCD screen

Such as motherboards and display

a.CD Walkman

b.Drives

c.NOTEBOOK.

4. New Uses

Components of a hard disk drive (HDD, hard disk drive) suspension circuit and xe packaging board, etc.

PCB material appearance defects common measures and industry analysis of commonly used terms

The reason PND (Pits and Dents) pits and depressions occur: fish  any fines particles adsorbed by the edges due to static electricity, the upper plate  residual water Material of the active air drop of dust and debris attached to the copper plate. Solution: identify the problem immediately to re-grind plate and, after washing on the line of the most fundamental solution to reduce staff contact and exposure to air time, to complete the clean room stacked combination of cutting and automatic installation of devices to eliminate static electricity.

  SLP (Slippage) slip occurs:   piece of content R / C high and  flow R / F is greater than the pressure is too easy to produce timely, and every pot temperature is too large and cause uneven flow  substrate per pot Chan will lead to poor positioning piece slip responses: Chan piece R / C, R / F high vertical machine (or water Liquidation machine) can also alter the conditions on Chan laminated CYCLE such as reduced heating rate as amended, postponed the pressure, reduce stress, if a larger temperature difference between each pot can reduce tension lowering capacity to overcome the poor pay more attention to improving the positioning operation.

  Dry (Dried Laminate) board dry Analysis: Poor glass cloth coupling agent compatibility with resin resulting in poor wetting. Or  piece over so that timely pressure hardening resin flow is bad if found to have low flow  board that will produce dry, this condition at the time of solder measured 詴 prone stratification. Solution: glass cloth surface finish problems, please materials manufacturers improved  low traffic reduces varnish water  of time or improve  piece   flow of time and, if not serious Dry Lamination may amend conditions such as increased temperature rate, the pressure on early, increasing pressure. 

PCB Prototype Assembly Creates Unique Boards

PCBs are important part of all electronic equipment that is used these days. The layout and design of a PCB is crucial for the entire product. This key element or components can define product’s success as well as failure, because this is what the product performance is dependent on. In the meantime, if pcb assembly make any mistakes such as wrong assembly, absent assembly etc, will occur big problem in product’s function!

Most (although not all) of firms only provide manufacturing services, so it's entirely on you to provide specifications for a quality device and to hope they are able to deliver it. If the specs were flawed, or if counterfeit parts sabotage it, there will be little you can do about it. Wonderful PCB Technology Co., Ltd is PCB manufacturer and has PCB assembly line in house, which provide you whole services of PCB! Wonderful PCB provide high quality PCB assembly prototype, which can often save you a lot further down the road.

The Benefits of PCB Prototype Assembly

Think of it as an insurance policy: If you spend a bit more money up-front, you'll save yourself a lot of hassle later on. After all, these days, you can't risk your company's reputation on dodgy electronics. Once a firm becomes known for poor products, it can be extremely hard to undo the damage without a full (and costly) rebranding effort.

With PCB prototype assembly services, you get the breathing room you need to thoroughly test your design before committing to a production run.

As an experienced electronics manufacturing Service Company, Wonderful PCB can often begin by improving your design right from the start. Many initial designs are overly-complex, or fail to take advantage of the latest manufacturing technologies on offer. Allowing the manufacturer to look over your design and suggest changes can very often result in simplified designs that reduce component use, making them both cheaper and more reliable.

PCB Prototype Assembly Builds Better Boards

Simply put, prototyping services help you create a better product. You'll be able to put items on shelves which are less expensive, more reliable, safer, and more compliant with health and environmental regulations.

Given that your reputation really is all you have on the Internet, why gamble with untested products? Put a little more money into prototyping, and you'll reap the benefits throughout your products' entire life cycle.

Aluminum PCB board Application

Led aluminum pcb thermal conductivity
Led aluminum board and thermal conductivity aluminum board in the middle of the insulating layer (generally is PP, now has a thermal conductive adhesive, etc.), it is one of the three major measure of aluminum plate quality, heat resistance and pressure value is another two performance).Aluminum plate thermal conductivity can be tested after plate bonding instrument tests data, the high value of thermal conductivity is generally ceramic, copper, etc., but due to the cost into consideration, is currently on the market mainstream electronic aluminum plate, aluminum plate thermal conductivity of the corresponding is parameters of people's concern, the higher the coefficient of thermal conductivity is one of the symbols of the better performance.

Led aluminum plate classification
Led fluorescent lamp aluminum plate is aluminum plate classification, street light aluminum plate, tube light aluminum plate, wall lamp aluminum plate, shoot the aluminum plate, energy-saving light aluminum plate, electrodeless lamp aluminum plate, aluminum board, ceiling aluminum plate, wash wall lamp aluminum plate, the ball bubble lamp aluminum plate, tunnel light aluminum plate, floodlight, aluminum plate, aluminum plate, wall lamp high-power aluminum plate, small power aluminum plate, guardrail tube aluminum plate, neon lights aluminum plate, corn lamp aluminum plate, the candle light aluminum plate, absorb dome light aluminum plate, kitchen lamp aluminum plate, corridor lights aluminum plate, buried lights aluminum plate, dared light aluminum plate, industrial and mining lamp aluminum plate, aluminum plate bridge lights, floor tile lamp aluminum plate, stair light aluminum plate.

LED aluminum plate insulating layer
LED aluminum plate insulation layer is one of the most core technology of aluminum plate, the main adhesive, insulation and thermal conductivity of the function.Aluminum base board insulation is a power module.
Structure of the largest thermal barrier.Insulation heat conduction performance, the better, the more conducive to the spread of the heat produced during the operation, will be conducive to reduce the operating temperature of the device, so as to improve the module of power load, reducing the volume and prolong life, improve the power output, etc.
LED aluminum plate
1, audio equipment: input, output amplifier, balanced amplifier, audio amplifier, preamplifier, power amplifier, etc.   
2, power equipment, switching regulator ` DC/AC converter ` SW regulator, etc.   
3, communication electronic equipment: high frequency increase ` filtering electrical ` transmitting circuit.   
4, office automation equipment, motor drives, etc.    
5, automobile, electronic regulator ` igniter ` power controller, etc.   
6, a computer: CPU board ` diskette drive ` power supply device, etc.   
7, power module, inverter ` solid relay ` rectifier bridge, etc

About PCB Service

1. Installation and welding of parts
the last step is the installation and welding the parts. Both THT and SMT parts use of machinery and equipment to install is placed on the PCB.
THT parts are usually called the Wave Soldering (Wave Soldering) way of welding. This allows all parts to a welding on the PCB.First to pin cut close to the board, and slightly bent so that parts can be fixed. Then the PCB will be moved to the co solvent on the waves of make contact to help at the bottom of the solvent, it can be on the base metal of the oxide to get rid of. After the heated PCB, the move to the melting of solder, at the bottom and contact after welding is completed.
Automatic welding of SMT parts way is called to flow back to welding (Over Reflow Soldering).Contains co solvent and solder paste in welding, the parts installed on the PCB after the first treatment time, was a PCB again after heating treatment. For PCB cooling after welding is completed, the next is to prepare the final test of PCB.

2. Proofing
PCB's Chinese name is called printed circuit board, also known as printed circuit boards; printed circuit board is an important electronic component is electronic components support body? The provider of the electrical connection in the electronic components. Because it is made of so called electronic printing "printed circuit board.
PCB proofing is refers to the pilot production of printed circuit board before mass production is mainly used for electronic engineers in the design of circuit? And complete the PCB Layout to the factory after small batch trial-produce process is the PCB proofing. And PCB proofing production quantity generally no specific boundary is an engineer in product design has been finished to confirm and complete the test before we call it PCB proofing.

Through Via

Through Via Mounting: This mounting technique involves different components which have lead wires that are led to the board through holes, hence the name. In this method, leads rely on holes in a multilayer Aluminum pcb. The leads are then finally soldered to offer permanent mounting. The technology finds usage in DIP aka Dual Inline Packaging and Pin Grid Array Package.
Surface Mounting: This is a relatively new mounting method worked out seeing a tremendous increase in the number of pins in Integrated Circuits. As demand for smaller weight and size of packaged weight increased, there was felt a need for a new, improved technology that came to be known as surface mount technology (SMT). In this leads are soldered on PCB surface directly rather than using hole mounting. The technology is used in Flatpack Packages and Chip Carrier Packages.
There are some points that make SMT different from Through Hole, which have been briefly summarized below:
1.    SMT has helped significantly in solving the space problems that were commonly noticed with the Through Hole mounting.
2.    The pin count has increased greatly in SMT when compared to its older counterparts.
3.    In SMT, the components are leadless and are directly mounted to the board surface. In Through Hole the components have lead wires that are taken to the wiring boards via
holes.
4.    The Pads on the surface in SMT are not used for connection of layers on the printed wiring boards.
5.    The components in the Though Hole Technology are larger which leads to lower component density per unit area. The packing density that can be achieved with SMT is very high as this allows mounting component on both sides, when needed.
6.    SMT has made possible applications that seemed impossible with through hole.
7.    SMT is suitable for high volume production that gives access to lowered cost of unit assemblies which is not possible with through hole technology.
8.    With SMT acquiring higher circuit speed is easier due to the reduced size. SMT fulfils one of the prime marketing requirements while assisting in making high performance circuits in a very small size.
9.    SMT has a disadvantage as the capital investment involved in its machinery and production is higher.
10.    Designing, production, skill and technology required in implementing SMT is very advanced when compared to through hole technology.

When comparing both, SMT surpasses Through Hole in advantages, which clearly define and justify the majority (90%) use of this technology in board assemblies. Through Hole however is anticipated to remain in use in testing and prototype applications that may need manual adjustments and replacements. Its complete disappearance from the scene seems to be ruled out. Contact wonderful02@wonderfulpcb.com if you have any inquiry about PCB.

How to chat with customers When they visit our factory

Dialogue 1

A: If you are staying here for a few days, we’d be delighted to see you at our factory.
B: It’s very kind of you to say so. My associate and I will be interested in visiting your factory.
A: Let us know when you are free. We’ll arrange the tour for you.
B: Thank you. I’ll give you a call this afternoon to set the time. There’s nothing like seeing things with one’s own eyes.
A: That’s for sure. You’ll know our products better after the visit.

Dialogue 2

A: I’ll show you around and explain the operation as we go along.
B: That’ll be most helpful.
A: That is our office block. We have all the administrative departments there. Down there is the research and development section.
B: How much do you spend on development every year?
A: About 3-4% of the gross sales.
B: What’s that building opposite us?
A: That’s the warehouse. We keep a stock of the faster moving items so that urgent orders can be met quickly from stock.
B: If I placed an order now, how long would it be before I got delivery?
A: It would largely depend on the size of the order and the items you want.

Dialogue 3

A: Put on the helmet, please.
B: Do we need to put on the jackets too?
A: You’d better, to protect your clothes. Now please watch your step.
B: Thank you. Is the production line fully automated?
A: Well, not fully automated.
B: I see. How do you control the quality?
A: All products have to go through five checks in the whole manufacturing process.
B: What’s the monthly output?
A: One thousand units per month now. But we’ll be making 1,200 units beginning with October.
B: What’s your usual percentage of rejects?
A: About 2% in normal operations.
B: That’s wonderful. Is that where the finished products come off?
A: Yes. Shall we take a break now?

Dialogue 4

A: It was very kind of you to give me a tour of the place. It gave me a good idea of your product PCB Application.
B: It’s a pleasure to show our factory to our customers. What’s your general impression, may I ask?
A: Very impressive, indeed, especially the speed of your NW Model.
B: That’s our latest development. A product with high performance. We put it on the market just two months ago.
A: The machine gives you an edge over your competitors, I guess.
B: Certainly. No one can match us as far as speed is concerned.
A: Could you give me some brochures for that machine? And the price if possible.
B: Right. Here is our sales catalog and literature.
A: Thank you. I think we may be able to work together in the future.

Shirley Xia
Oversea sales
Wonderful PCB

 A Floor 6, Nanyuan Fengye Mansion, Nanshan Avenue, Nanshan District, Shenzhen City 518054, China.
T +86-755-86229518-821 / Cell phone and whatsApp:008613480796172
F  +86 755 2607 3529|
e  wonderful25@wonderfulpcb.com |
w  www.wonderfulpcb.com  | Skype:wonderful-pcb02
Welcome to our trading shows:
Booth: 9G27, HK Globalsources Oct.11-14th,2014 AsiaWorld-Expo, Hongkong
Booth：A3.274-1，2014.11.11-2014.11.14，the Electronica in Munich, Germany

Designing Your Circuit

Before you can consider any physical designs or schematic connections you must have a clear idea of what you want your design to do. This means taking some time to sit down and define what you want to accomplish, consider the challenges, and pick the right components for the job.
Determining Your Goals
The first step in designing the perfect Multilayer pcb is to have a well-defined set of goals that you would like your design to accomplish. To steal a little bit from the business world, you should always set SMART goals for your project, this means:
Specific
Measurable
Attainable
Realistic
Time Bound
As a personal example, I have started working on another side project for my own use. The bathroom in my apartment is too dark in the evening for me to get around in, but when I turn the light on it is way too bright and wakes me up.
To fix this little issue I thought I would just go buy a small lamp. Unfortunately, I am a little bit too picky and couldn’t find a lamp that I liked. That is when I had the idea to design one of my own. Of course, I’m not talking about just any lamp. I wanted a multi-color, adjustable brightness, wirelessly controlled lamp.
Sounds cool right? Of course it does! So before the idea was able to leave my head I jotted it down in my notebook and began planning.
At this point, my goals were pretty broad, let’s take a look at what I had:

Multi-color lamp
Adjustable brightness
Wireless control
Unfortunately none of these goals are very specific at all. What do I mean by multi-color? Is that two colors, three, or any variable color? What is adjustable brightness? I mean technically on and off would be two different brightness settings right? Wireless control? What, do I want to use Wi-Fi, Bluetooth, infrared, RF, Zigbee, sound? Any of these options would be possible.

Following will be continued in next chapter.

Shirley Xia
Oversea sales
Wonderful PCB

 A Floor 6, Nanyuan Fengye Mansion, Nanshan Avenue, Nanshan District, Shenzhen City 518054, China.
T +86-755-86229518-821 / Cell phone and whatsApp:008613480796172
F  +86 755 2607 3529|
e  wonderful25@wonderfulpcb.com |
w  www.wonderfulpcb.com  | Skype:wonderful-pcb02
Welcome to our trading shows:
Booth: 9G27, HK Globalsources Oct.11-14th,2014 AsiaWorld-Expo, Hongkong
Booth：A3.274-1，2014.11.11-2014.11.14，the Electronica in Munich, Germany

About TG

TG is the glass transition temperature, i.e. the melting point. Circuit board must resist fire, just to say, at a certain temperature it does not burn, only to become soften. At this point the temperature is called the glass transition temperature (TG point), this value is related to the durability of the quick turn PCB size.
What is a high TG PCB circuit boards and what is the advantages of high TG PCB?
High TG printed circuit board means when the temperature of the substrate increased to a certain degree then the board will become "rubbery" from the "glassy" , this temperature is called the glass transition temperature (TG). That is, TG is the highest temperature of the substrate to maintain rigidity (℃). When PCB substrate material at a high temperature, it will be continuously softened, deformed, melting or the similar phenomenon, and also sharply decreased in mechanical, electrical characteristics, this will influence the life of the product.
The general sheet TG is above 130 ℃, high TG is above 170 ℃, medium TG is above 150 ℃; usually PCB whose TG≥170 ℃, called high TG PCB; If TG of substrate is higher, the heat resistance of the printed circuit board, moisture resistance, chemical resistance, stability and other characteristics will be improved.

From  Shirley Xia
PCB manufacturer 
Wonderful PCB company
www.wonderfulpcb.com
Email: wonderful25@wonderfulpcb.com

PCB Classification

According to the circuit layer classification: divided into single panel, double panel and laminated. Common sandwich plate is commonly 4 layer board or 6 layer boards; complex sandwich plate can reach dozens of layers.

1. Single – Sided PCB
http://www.wonderfulpcb.com/Single-Sided-PCB.html

Single panel (Single - Sided Boards) in the most basic on the PCB of parts on one side, the conductor is focused on the other side (have SMT components with lead to one side, the plug-in device to the other side).Because the wires in only one side, so this kind of PCB is called Single panel (Single sided).Because single panel in the design of lines, there are many restrictions (because only one side, wiring must around the path alone cannot cross between), so only use this kind of early circuit board.


2. Double - Sided PCB
http://www.wonderfulpcb.com/Double-Sided-PCB.html
Double panel (Double - Sided Boards) to both sides of the circuit board wiring, but it took two wires, must have the appropriate circuit connection between two sides. This circuit is called the "bridge" between the guide hole (via).Guide hole is on the PCB, or coated with metal small hole, it can be connected to both sides of the wire. Because the area of the double panel a times larger than a single panel, double panel solved because wiring of the difficulty in the single panel (can be conduction through the hole to the other side), it is more suitable for use in more complex than a single panel circuit.

3. Multi - Layer PCB
http://www.wonderfulpcb.com/Multilayer-PCB.html
Sandwich plate (Multi - Layer Boards) in order to increase the area of the wiring, a multilayer wiring board using the more single or double. With a double lining, two one-way for outer layer or two double lining, two blocks of single outer layer of the printed circuit board, through the positioning system and alternate insulation adhesive materials and conductive graphics interconnection according to design requirement of printed circuit board becomes four, six layer printed circuit board, also known as multilayer printed circuit board. Layer number of the board does not mean that there are several independent wiring layer, under special circumstances will join empty layer to control board thickness, layer number usually is even, and contains the outer two layers. Most of the motherboard is 4 to 8 layer structure, but technical theory can be nearly 100 layers of PCB. Large supercomputers are used quite layers of the motherboard, but because this kind of computer can replace with many ordinary computer cluster, super sandwich plate has not been used gradually. Because each layer of PCB are closely combined, the actual number is generally not too easy to see, but if you look closely at the motherboard, can still see it.

Designing Your Circuit

Before you can consider any physical designs or schematic connections you must have a clear idea of what you want your design to do. This means taking some time to sit down and define what you want to accomplish, consider the challenges, and pick the right components for the job.
Determining Your Goals
The first step in designing the perfect circuit boards is to have a well-defined set of goals that you would like your design to accomplish. To steal a little bit from the business world, you should always set SMART goals for your project, this means:
Specific
Measurable
Attainable
Realistic
Time Bound
As a personal example, I have started working on another side project for my own use. The bathroom in my apartment is too dark in the evening for me to get around in, but when I turn the light on it is way too bright and wakes me up.
To fix this little issue I thought I would just go buy a small lamp. Unfortunately, I am a little bit too picky and couldn’t find a lamp that I liked. That is when I had the idea to design one of my own. Of course, I’m not talking about just any lamp. I wanted a multi-color, adjustable brightness, wirelessly controlled lamp.
Sounds cool right? Of course it does! So before the idea was able to leave my head I jotted it down in my notebook and began planning.
At this point, my goals were pretty broad, let’s take a look at what I had:

Multi-color lamp
Adjustable brightness
Wireless control
Unfortunately none of these goals are very specific at all. What do I mean by multi-color? Is that two colors, three, or any variable color? What is adjustable brightness? I mean technically on and off would be two different brightness settings right? Wireless control? What, do I want to use Wi-Fi, Bluetooth, infrared, RF, Zigbee, sound? Any of these options would be possible.

Following will be continued in next chapter.

Shirley Xia
Oversea sales
Wonderful PCB

 A Floor 6, Nanyuan Fengye Mansion, Nanshan Avenue, Nanshan District, Shenzhen City 518054, China.
T +86-755-86229518-821 / Cell phone and whatsApp:008613480796172
F  +86 755 2607 3529|
e  wonderful25@wonderfulpcb.com |
w  www.wonderfulpcb.com  | Skype:wonderful-pcb02
Welcome to our trading shows:
Booth: 9G27, HK Globalsources Oct.11-14th,2014 AsiaWorld-Expo, Hongkong
Booth：A3.274-1，2014.11.11-2014.11.14，the Electronica in Munich, Germany

Multilayer PCB design method (I)

11.2.1 General principles of components layout
7). The serial number of components should be close to the components of the border to decorate, uniform size, direction and tidy, not with components, holes and overlap welding plate. Components or connector pins 1 said direction; Is the sign of the cathode should be clearly marked on the PCB, not allowed to be covered; power conversion components (such as DC/DC converter, linear transformation power supply and switching power supply) side should have enough heat dissipation space and installation space, with sufficient welding outer space, etc.

11.2.2 General principles of the components wiring
Design personnel in the process of Multilayer pcb wiring needs to follow the general principles are as follows.
1)Components printed line spacing of setting principles. Amount of space between different network constraints are produced by electric insulation, process and component size and other factors. Such as a pin spacing is 8 mil chip components, then the chip of the [Clearance Constraint] cannot be set to 10 mil, designers need to separate this chip set a 6 mil design rules. At the same time, the distance between set to take into account the manufacturer's production capacity.
In addition, the influence of components is an important factor in electrical insulation, if two components or network of potential difference is bigger, be considered for electrical insulation problems. In general environment, clearance safe voltage of 200 V/mm, or 5.08 V/mil. So when the same piece of circuit board when there are both high voltage circuit and low voltage circuit, you need to pay special attention to enough safe distance.

WonderfuI Printed Circuit Board

From the number of layers and the development direction of PCB board to points, the PCB industry into a single panel, double panel, conventional multilayer flexible board, HDI (high density interconnect) board, package substrate and other six major product segments . From the product life cycle "lead-in period - growing - maturity - a recession" and four-cycle dimension view, where a single panel, double panel electronics products because they do not fit the current trends in the application of thin short, is in recession, its value gradually reduce the proportion of developed countries and regions such as Japan, Korea and Taiwan has been very little in the local production of such products, many manufacturers have made it clear that no longer meet single and double panel. Conventional multilayer and HDI products, process capability maturity are more sophisticated, higher value-added products, is currently the most major PCB factory full Zhugong direction, Chinese manufacturers are only a handful of ultrasound and electronic production techniques; scratch plates, especially high-density flexible and rigid PCB board, due to the current technology is not yet mature, a lot of manufacturers failed to achieve mass production of products are growing, but because it has more than a rigid plate adapted to digital products features flexible plate growth is high, is the future direction of the various manufacturers.
     
IC package substrate used, whether it is R & D or manufacturing in the electronics industry in developed countries such as Japan, South Korea, more mature, but in the country is still in the exploratory stage technology, only Ibiden (Beijing) Co., Ltd., Advanced Semiconductor (Shanghai) Co., Ltd., Zhuhai Doumen Chao Yi Electronics Co., Ltd., one of the few manufacturers in small batches. This is because of China's IC industry is still underdeveloped, but with the multinational electronics giant will continue to move to China IC R & D institutions, and improve China's own R & D and production levels of IC package substrate will have a huge market, is a big vision plant development. China's hard board (single-sided, double-sided, multilayer, HDI board) share reached 70%, of which 5 percent share of the plywood accounted for the largest proportion, followed by soft board with 15.6% of the proportion of second place. Due to the pressure of oversupply, most manufacturers to enter the price war, output growth is lower than expected.      
        
PCB domestic product from the future development trend, output growth is slightly lower than the sales growth was mainly the product gradually to the multilayer structure, the development of high precision. Our multilayer and HDI board is in the business of growing, expanding, increasingly mature technology. MLB is still the mainstream market development; and HDI board by the downstream electronic information products upgrading demand-pull, is in a period of rapid development.

Sophie Deng
_______________________________________
Wonderful PCB Limited
NO.32A,Building NO.1, XianDaiC hengHuaTing,ChuangYeRoad|NanShan District,ShenZhen City 518054|  China  T +86-755-86229518-806 | F  +86 755 2607 3529|  e  wonderful08@wonderfulpcb.com |
w  www.wonderfulpcb.com  | Skype:wonderful-07   |                                                   
Welcome to our trading shows:
1.Booth: L32,Expo Electronic 2013,Apr.10-12th in CROCUS EXPO,Moscow,Russia
2.Booth: 11J36, HK Global sources  Apr.12-15th, 2013 Asia World-Expo, Hong Kong
3.Booth: 9J35, HK Global sources Oct.12-15th,2013 Asia World-Expo, Hong Kong
4.Booth: 70206, CES  2014  Jan,8th-11th in Las Vegas, USA

Drilling in Printed Circuit Board

    A circuit board drilling is just like a common drill, except that it is optimized for drilling holes in the printed circuit board as opposed to drilling holes in other materials such as wood. Holes are normally drilled in circuit boards which made from tungsten because of its mechanical properties. Another difference of circuit board drilling from wood drilling is that, the size of this type of drill can vary greatly because it typically is very small. Sometimes, this drill is made by people, but it more often is combined with a drill press for automated drilling by the machines.

   There are two main drilling holes in the pcb board. One is NPTH hole, another is PTH hole. All the holes in the single sided printed circuit board are NPTH hole. That’s because no need for electronic conduction between layers in single sided PCB. It has just one copper foil layer. PTH hole will appear in double sided or multilayer PCB.
These holes exist for the electronic conduction among layers. So it may have Copper in these holes.
   While as explained, circuit board drilling holes must be very small. We usually use unit mil to indicate it. What’s more tungsten is a very hard metal. So circuit board drilling holes are made by drill bits. The PCB drill bits are made of micro grain carbide. They are used primarily in CNC machines for drilling printed circuit boards for electronics, but their toughness and accuracy lend them to uses in other industries. When a hole has to be drilled through a circuit board, the bit must go through copper traces, which are sturdy and hard. That’s a subtle work. A piece of printed circuit board may have several thousand of drilling holes including NPTH and PTH holes, so many PCB boards are finished drilling by machines!
   One thing we should pay attention to is the smear when drilling holes in a PCB. For multilayer boards, those with three layers or more, drilling typically produces a smear of the high temperature decomposition products of bonding agent in the laminate system. We should remove the smear before plating through these holes. So we need to have a chemical de-smear process, or plasma-etch. The de-smear process remove smear to ensure that a good connection or electronic conduction among layers when the holes are plated through. If smear remains in the PTH holes, it may cause short cut in the printed circuit board. Some bad PCB products are rejected just because the smear of the holes!

Worldwide Semiconductor Sales Expected to Reach $358 Billion in 2015

Worldwide semiconductor revenue is forecast to reach $358 billion in 2015, a 5.4 percent increase from 2014, but down from the previous quarter's forecast of 5.8 percent growth, according to Gartner, Inc. The market is being driven by strong growth in application-specific standard products (ASSPs) in smartphones, along with DRAM and NAND flash in ultramobiles and solid-state drives (SSDs).

"Semiconductor revenue growth in 2015 is expected to slow from the 7.9 percent growth experienced in 2014 as DRAM returns to more traditional price reductions and the industry burns off excess holiday inventory," said Jon Erensen, research director of Gartner. "DRAM pricing was unusually firm in 2014 due to short supply, which propelled DRAM to be the fastest-growing device type in 2014 with 31.7 percent revenue growth. DRAM supply and demand will be in line in 2015, driving bit pricing down a more traditional 16.8 percent and reducing annual DRAM revenue growth to 7.7 percent."

From an application point of view, smartphones, SSDs and ultramobiles will see the largest dollar increases. In 2015, compute applications will continue to be the largest market for semiconductors, followed by wireless and consumer applications. Combined, these three device categories represent more than two-thirds of total semiconductor revenue and have the most influence on the overall strength of the semiconductor market.

However, in 2015, the industrial electronics segment is expected to outperform overall semiconductor market growth and other electronic application categories with revenue growth of 9.1 percent. The growth will be driven mainly by LED lighting applications for industrial and residential purposes and smart city projects. In addition, the Internet of Things (IoT) will continue to drive very strong unit growth in 2015 and beyond.

Following industrial applications, wireless applications — driven mainly by mobile phones — will be the next biggest growth market for semiconductors in 2015. However, the 2015 revenue growth forecast for wireless applications, and specifically mobile phones, remains the same as the previous quarter's forecast.

"While mobile phone semiconductor sales will remain robust, driven by the accelerating shift to smartphones and 4G Long Term Evolution, there is concern that weak sell-through for other electronic equipment categories will result in higher inventory levels and drag down semiconductor sales in the first quarter of 2015," said Mr. Erensen.

Copper Traces

The copper traces on your PCB are easily the most important part of the design so it is important to understand what they’re doing and what limitations you should consider.
As I mentioned earlier, copper traces are created by removing copper from the solid sheet that sits on top of the base material.
This means that the traces on your board are in fact just thin layers of copper. I don’t know about you, but when I discovered that it came as a bit of a surprise (relax I didn’t just find this out). For the longest time I assumed that PCBs were manufactured by pouring copper into a mold, letting it cool, and then somehow melting an insulator around the copper.
The thin sheet nature of these traces mean that there are some constraints to consider when routing your traces, most importantly, size considerations. All of these nuances will be discussed in detail in part 2.

Following will be continued in next chapter.

Shirley Xia
Oversea sales
Wonderful PCB

 A Floor 6, Nanyuan Fengye Mansion, Nanshan Avenue, Nanshan District, Shenzhen City 518054, China.
T +86-755-86229518-821 / Cell phone and whatsApp:008613480796172
F  +86 755 2607 3529|
e  wonderful25@wonderfulpcb.com |
w  www.wonderfulpcb.com  | Skype:wonderful-pcb02
Welcome to our trading shows:
Booth: 9G27, HK Globalsources Oct.11-14th,2014 AsiaWorld-Expo, Hongkong
Booth：A3.274-1，2014.11.11-2014.11.14，the Electronica in Munich, Germany

PCB Applications

Classic applications for Printed Circuits are General Electronics PCB assembly, Dedicated Service Electronics Class, high Reliability Electronics.

Consumer Electronics – Digital Wrist Watch, CD Player, Am/FM/Radio/Alarm Clock, television, Calculator, Digital Coffee Pot, Microwave Oven, Home Alarm Systems, Cellular Telephone, Home Computer, Home Theater/Stereo Surround Sound System, Cable Television Converter Box, Hand Held Video Games, Remote control electronic toy, LOJACK auto recovery system etc. Telecommunications – Point to Point Microwave Transceivers, Police/ Fire/ Rescue Radios, Digital Network Equipment, SATCOM transceivers, Commercial and Private Aircraft Radios and Instrumentation, Cell Telephone Relay Stations, CB Radio/2 Way Talkie Talkies, etc. Industrial Electronics and Instrumentation – Weather Radar and Weather related Telemetry, Oscilloscopes, Network Analyzers, Ohm Meters, Temperature meters, Strain Gauges, Environmental Chambers and Ovens, Spectrum Analyzers, Solar Photo voltaic Power Co generation equipment, DC to AC Power Inverts, Switcher Power Supplies, CCD Telescopes. Military Electronics – IFF transponders, IR detectors, Night Vision Goggles, Military grade Computers with encryption, Fire Control circuits, Satellite Navigation instrumentation, Encrypted Frequency Hopping VHF Radios, Direction Finding Equipment, Missile Guidance Systems, FLIR Pod Test equipment, etc. Aerospace Electronics – Satellite systems, Space Shuttle controls and system, Aircraft communications and controls, etc…
Automotive Electronics – Automotive Ignition Controls, Emission monitoring and controls, Fuel Air Mixture, Fuel Injection, Climate controls, Dash Instrumentation, Radio/TV entertainment accessories, etc. Medical Electronics – Heart Monitors, Automated Medicine dispensing equipment, Breathing machine, Dialysis machine, Laser assisted tooth whitening machine, Laser optical corrective surgery machine LASIX, X-ray or CAT Scan equipment, MRI Imaging equipment, etc…

According to IPC-2221 1.6 Printed board assemblies are classified by intended end item use. The Performance Classes are listed as follows: Class 1 - General Electronics Products - Includes consumer products, some computer or computer peripherals, and general military hardware suitable for applications where cosmetic defects are not as important, and the major requirement of the board is its functionality. Class 2 - Dedicated Service Electronics – Includes Communication Equipment, sophisticated business machines, instruments and military equipment where high performance and extended life are required, and for which uninterrupted service is desired but not critical. Certain Cosmetic imperfections are allowed.
Class 3 – High Reliability Electronics – Includes Military and Commercial equipment where continued performance or performance on demand is critical. Equipment failure or down time is not tolerated and must function when required in the case of life support systems, or critical weapons systems. As for applications where high levels of assurance are required and service is essential.

Cleaner production technology of production process in PCB production

PCB is a printed circuit board (Printed Circuit Board) abbreviation, is a substrate for the electronic parts assembly. Its main function is to enable the various electronic components forming a predetermined circuit connection, starting relay transmission function, is the key of electronic interconnection of electronic products.

The rapid development of PCB industry, to bring economic development and at the same time also has brought serious influence to environment protection. Printed circuit board production and processing process, material type, energy consumption, water consumption, pollutant generation, as well as some poisonous and harmful or toxic substance use, all for the PCB industry as a " heavy polluting industries " hat. With the strengthening of enterprise and government awareness of environmental protection, pollution status of enterprises has improved, but the PCB industry is more and more big, lead to the entire Aluminum pcb industry pollution is still very big.
Cleaner production is to continually taken to improve the design, use of clean energy and raw materials, adopt advanced technology and equipment, improve the management, utilization and other measures, from the source to reduce pollution, improve resource utilization efficiency, reduce or avoid the generation and emission of pollutants during the process of production, services and products to use, in order to reduce or eliminate the hazards on human health and the environment. Cleaner production is a new kind of creative thought, the thought will be the overall preventive environmental strategy applied to production processes, products and services, to improve ecological efficiency and reduce human and environmental risks. For the production process, saving raw materials and energy requirements, eliminating toxic raw materials, reduce the quantity and toxicity of all waste. The product requires reducing adverse impacts from raw material extraction to final disposal of the entire life cycle. Also, requirements of environmental factors go into the design and services.
In recent years, a lot of research on China's PCB clean production for domestic surgery, in this paper, clean production technology of PCB throughout the production process uses were summarized, from product design, material selection, production process and equipment, energy and resources comprehensive utilization and management mechanism and other aspects of narrative, with a view to the enterprise, researchers and decision makers to grasp the situation, continue to promote clean production technology in China PCB industry.

FPC Assembly

Nowadays, technology is already very mature to rigid Printed circuit board, however, many problem may be faced by operator during SMT to FPC.
1 False soldering, short soldering,Tin beads.
2.The Reason is due to the hardness of  raw material of FPC(Flexible printed circuit) caused, FPC is out of shape when meet the hot air and high temperature in reflew machine. Lead the wave shape to FPC, and the slop to FPC pads, then cause the flow of molten tin (liquid tin under high temperature), which cause False soldering, short soldering,Tin beads.(The main reason is the hardness of FPC). So if make the hardness of FPC into the same situation as rigid printed circuit board, and all soldering problem to FPC can be solved. The condition is you should know the SMT process to PCB. And then improve the hardness of Flexible Printed circuit into with the same hardness as rigid PCB, and then FPC SMT can be realized. And some problem, like no fix hole, no mark point, or the FPC is over long, which are the fault of designer, and it is also hard to be solved even to rigid PCB SMT. And NG rate can be only reduced based on personal experience or device independence.

According to above comment, the main solution is to improve the hardness of FPC the same as hardness of Rigid-flex pcb.

B. How to realize stable soldering to FPC
How to get the stable FPC (flexible circuit board) to the rigid PCB welding effects depends on the degree of hardness.
Methods: using jigs(carrier, handling plate) to make FPC perform as rigid board during SMT.

Below is the instruction of Magnetic reflow soldering tray
The material
1. Choose imported alloy material: good flatness, stable performance under high temperature
2. High temperature resistant magnet (300 degrees) to ensure permanent magnet during reflow soldering process.
3.The special steel, with magnetic treatment and good elasticity, and no deformation under high temperature.
4.Performance
(1) Because the flatness to FPC surface cause from the steel pressure l, it can reduce the flow of solder tin during reflow, which can ensure the good quality of soldering and reduce the NG soldering at meanwhile.
(2) Ensure the life of tray when choosing tray material.
(3) Easy and convenient operation with high stability.
(4) Heat insulation, prevent the FPC from deformation
There’s no special requirement to the composition of solder paste of FPC, the size of the tin ball particles and the amount of metal content, etc will be subject to if there is narrow space of IC pins on FPC, BUT FPC has high performance requirements to the solder paste printing, solder paste should has good thixotropy, solder paste should be able to easily be printed , demoulding and can be firmly adhere to the surface of FPC, there will be no mold release lead the hole in stencil filled with tin or such as collapse after printing.

Because FPC fixed on the pallet before SMT,  and the FPC with high temperature heat-resistant pressure-sensitive adhesive tapes for purpose of location, which make its planar inconsistencies, thus FPC printing surface is unlikely to be as smooth as rigid PCB and the same consistent on thickness and hardness, so operator should not use a metal scraper, and should use the polyurethane scraper which with hardness of 80-90 degree.

Solder paste printing machine is best to be with the best optical positioning system, otherwise will have great influence to printing quality, FPC although fixed on the load board, however, there always be small space between FPC and the load board, this is the biggest difference as rigid PCB board, thus the equipment parameters’s setting will also has great influence to the printing effect.

Printing stations is also the key location to prevent FPC from being smudgy, need to wear glove then can go ahead for operation, at meanwhile,  workstation should be kept clean, stencil should be frequently wiped to be clean, to prevent the solder paste to pollute the gold fingers and gold plated key button.

Control of FPC SMT

According to the properties of the products, components quantity and efficiency of mounting, it is OK to adopt high-speed placement machine for SMT. Because every piece of FPC has positioning with fiducial MARK, therefore, there’s no big difference on surface mounting technology between FPC SMD mounting and rigid PCB SMD mounting. It is important to note that although the FPC are fixed on the load board, but its surface can’t be the same flatness like rigid PCB board surface, local space must  exist between FPC and load board, so, the height of suction nozzle’s dropping, compression of blowing should be exactly setted.  On other side, most bare FPC performance as panel; format, and the rate of good finished product relatively low, so it if normal that there’re part of pieces with not good quality, which request recognition function on BAD MARK to SMT machine, otherwise, when mounting FPC panel with the status of not all pieces are good, will show low efficiency.