low volume pcb assembly is very important for a new product

For one new electronic production, engineer need to evaluate and make some test before they decide to make into volume production. Low volume pcb assembly is widely defined as sample production.

What is the main work one should do in low volume pcb assembly stage? Of cousre, the gerber file and bom list of the project should be finished by the designer. One should consider the cost of the project and choose the right material, size of the unit board and the components’ part no. As you know the pcb cost contain pcb price, components price and the assembling cost. Each aspect should be controlled before you make the low volume pcb asssembly job.


To be specific, pcb price is based on the material, unit size and special process you choose for the board. Usually we would choose normal material with cheaper process,such like KB FR4 material with HASL surface treatment. For the component part, can used some cheaper and inglorious brands for the simple devices, such as capacitors,resistors and connectors. The assembling part is based on the components you choose. This part would be effect too much. So if you control these three parts well for the low volume pcb assembly job. You would make it in best cost.


The test job of the low volume pcb assembly would be very important. We may call it functional testing. So it is better to make functional testing before you make into volume production so that you can cut down your risk. We always like to make some functional testing before volume production. I think that is very important.


More interested about our pcb product, please see in the website:www.wonderfulpcb.com



My e-mail address: wonderful12@wonderfulpcb.com

Typical Types of PCB

As we know there are many standards to specify PCB, such as material, function, construction and so on. Now here we classify PCB according to construction. There are typically three categories: Single Board, Double Sided Board and Multiple Sided Board.

Single Board

All PCBs have two sides, top and bottom. But single sided PCB means only one side has the conductive circuit that used to assemble components. The other side has no circuit. It was born at early 1950s, generally applied at radios, washer, automatic sales machine and all kinds of home or commercial machines. The biggest merit of single board is cheap but the design of circuit is demanding. Another thing is that it’s very easy to distinguish single sided PCB.

Double Sided Board

Now we may have clear idea what is double sided PCB. That means both side of PCB have conductive circuit, which have lots of plated vias and PADs on them. Double sided PCB is widely used in electronic products. They will be used to CD player, mouse, fan, TV and so on. Compared to single board, double sided board are relatively complicated, so will be used at more advanced fields. Also, it’s easy to distinguish double sided PCB. Usually we could see circuit on both sides.

Multiple PCB

We could see also has circuit on both sides of multiple PCB. But the difference between double sided PCB is that see by side face of PCB, we will find multiple PCB material has some black horizontal lines. Multiple PCB is much more complicated and expensive than above two. Generally, there are three methods to manufacture multiple sided boards: PTH, Clearance Hole and Build Up. PTH is the mainstream of multiple sides board manufacture. High reliability and assembly density are some merits of it. So it can be normally used at demanding high reliability and technology field, such as military, aerospace, medical machines, communications and so on.

Conclusion

Wonderful PCB (HK) Limited is a professional manufacturer for PCB for more than 20 years. If anything else doesn’t understand, welcome to inquiry to wonderful22@wonderfulpcb.com

Laser Technology in PCB

In PCB production, actually, sometimes we will use the laser technology. U.K. researchers are exploring whether laser technology can provide a low-cost, chemical-free method of making printed circuit boards.

The project is developing a dry printing method that uses no chemicals. DMU’s Rapid Prototyping and Manufacturing Group, led by Professor David Wimpenny, will develop a deposition system based on a combination of laser printing and fiber laser consolidation of the deposited material. The project will initially look at laying conductive tracks on the circuit boards but could also be used to deposit layers of dielectric or protective materials, solder for connection of devices and also to print legends on boards. De Montfort University Leicester (DMU) academics are taking part in the Laser Printed Electronics (LPE) two-year research project aimed at providing an environmentally friendly production method for PCBs.

In commercial production, two kinds of laser technology can be used for laser drilling. One is CO2 laser, wavelength is in the wave band of far infrared ray. It is widely used in industrial micro hole (diameter is above 100um) drilling on printed circuit board. Due to very short punching time needed for one hole, so this kind of technology has high productivity. The other is ultraviolet laser , widely used in drilling holes with diameter less than 100 μm(especially productive when drilling diameter under 80μm) . The application of miniature circuit diagram enables diameter even to be less than 50μm. Therefore, in order to satisfy the increasing demand on micro via productivity, many manufacturers have started to introduce double-headed laser drilling system. The following is three main types in the present market:
· double-headed ultraviolet laser drilling system;
· double-headed CO2 laser drilling system;
· mixed laser drilling system(ultraviolet and CO2).

Each has its own advantages and disadvantages. Laser drilling system can simply be divided into two types: the double drill bits with single wavelength system and double drill bits with double wavelength system. No matter which type, there are two main parts affecting the drilling ability:
· laser energy/pulse energy;
· beam-positioning system.



Also, during FPC production, we will use laser technology to make the FPC shape. Wonderful PCB has many years experience in the laser technology production. If any need or questions, welcome your inquiry: China PCB Board Manufacturer

Printed circuit board assembly

Components on a PCB are connected electronically to the designed circuits by two different methods. The first method is called "Through Hole Technology" and the second and newest method is called "Surface Mount Technology" Through Hole Technology requires a component that has thin wires, or leads, which are pushed through small holes in the substrate and soldered to connection pads in the circuits on the other side of the board. The contact with the holes and pull of gravity between the leads and the sides of the holes enables the components to stay in place until they are soldered. Surface Mount Technology has stubby J-shaped or L-shaped legs on each component keeping contact with the printed circuits directly.

A solder paste consisting of glue, flux, and solder are then applied at this point of contact to allow the components to be held in place until the actual solder is melted or "reflowed," in an special oven to make the final connection complete. Although surface mount technology requires greater attention and care in the placement of the components, its benefits are that it eliminates the time-consuming drilling process as well as the space-consuming connection pads characteristic with Through Hole Technology. In today’s manufacturing, both technologies are frequently used.

Wonderful PCB limited is a professional PCB manufacture, but we also experience in PCB assembly,for THT manufacture, we using semi-automatic and automatic insertion equipment and ensuring proper tape and reel component purchasing, we deliver timely and low-cost solutions. PCB assembly depot offers both automated and hand assembling of through hole components. Our assembly lines support both simple and complex board assemblies. For assemblies like nuts/bolts, riveting and studs, that require manual/mechanical assembly, we have a team of highly trained, qualified and experienced assemblers. We have advanced equipment for SMD from screen printers to smt placement machines to reflow ovens.

Printed circuit board with India Market

India is known to be the fifth largest economy of the world with the second largest Gross Domestic Product among many emerging economies. cheap Labour and more and more skilled people in printed circuit board(PCB) industry , attract customers all over the world buy PCB or set up factory in india . But still many india company buy PCB from china, because we have very advanced equipment and production capacity, also with highly skilled engineers .

In wonderful PCB Limited, 15% is Indian customers, some cooperate with us more than 10 years, because we have very high quality and good price, they don’t need to worry about any things for cooperating with us, we have Professional Engineers to solve technical problem, perfect quality inspection system and Good sales team for communication and service.

Our PCB capabilities include 1 to 28 layer PCB’s, Material - FR4 , CEM1, CEM3, aluminum FPC, RFPC, and Special material, Thickness 0.8mm to 6.5 mm, Copper Finish 1oz-6oz, Surface Finish - HASL Leaded free and HASL with lead ,Immersion Gold/silver/Tin, flash gold, gold finger ,OSP.

Materials of Flexible printed circuit board (PCB).

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 napthalate (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 also typically is 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.

 

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.