Introduction and Significance of PCB (Printed Circuit Board) & PCBA

Posted on 2019-12-16

In our daily life the use of electronics is becoming more dominant in consumer goods. The need to reduce the size and cost of producing the electronics is insisting manufacturers to find better solutions.

So what is the solution?

Most of the electronics goods these days rely on printed circuit board or PCB. As electronics technology has shifted from relays and vacuum tubes to semiconductors and integrated circuits, the concerns of electronics industries have reduced considerably.

Before printed circuit boards, electrical circuits were built by attaching wires to components. Electrical connections were built by soldering metal components together with wire. The circuits were larger with many electronic components and contained many wires.

Due to greater in number,the wires tangling and or space/size problems were there. These issues created clumsy designs. Such kinds of connections also cause problems in maintenance. While the reliability of these circuits suffer too. The manufacturing and production speedis slow because of manual soldering of multiple components to their wired connections.

So, before the invention or advent of PCB,electronic circuits were manufactured through tedious anddifficultmethods. This often resulted in failures at wire connections and short circuits.

 

 

But how will you understand what a PCB circuit is?

 

Printed Circuit Board (PCBs)

An electrical circuit with semiconductor conductors and components that are contained in a form of mechanical structure is known as a printed circuit board. Conductive paths are impressed or printed onto board, which connectsdifferent components on it, such as transistors, integrated circuits, and resistors. A PCB is a slightly thin board mostly made of fiberglass, type of epoxy, or other enclosed material.A combination of a number of non-conductive sheets constitutes PCB.

 

printed circuit board

 

These are put for bakingin an industrial oven to melt the solder for joining the connections.A PCB works on the copper film/assemblythat is placed inside for the flow of current. A PCB holds various electronic components having connectionswithout using visible wires, which facilitates its use.

Most PCBs are simple and use composition of only a single layer for simple electronics. More sophisticated hardware such as computer graphics cards or motherboards require multiple layers.

Electronic products and Computing Devices that use PCBs are like Motherboards, Network Cards, Graphic Cards and the internal circuitry of hard/CD-ROM drives.

The use of PCBs in electronics is widespread. Although PCBs are in essentially integral part of all computersand related peripherals, most often many other electronic devices are also using PCBs. For instance TVs, Radios, Digital cameras and cell phones

As electronics is serving almost all the spheres of life. Therefore in addition to their use in consumer goods and computers, different types of PCBs are part of a variety of other fields as well. These include:

  • Medical Devices
  • Industrial Machinery
  • Automatic Lighting controllers
  • Automotive and aerospace industries
  • Artificial intelligence

 

PCB board Assembly using PCBs

 

PCBA or commonly known as (Printed Circuit Board Assembly) is basically a board that is built afterwardsprinting solder paste on the PCB, and later mounting different components like ICs (Integrated Circuits),resistors,capacitors and other components like transformers. Every PCBA is requirements specific.

PCBs production uses industrial ovens but a PCBA usually undergoes ‘reflow furnace heating’ to establish a mechanical connection between the PCB and the components.

 

 

printed circuit board

 

 

Difference between PCBA and PCB

The explanation of a PCBA should refer to as a combination of mentioned components and electronic accessories along with the PCB. But the assembly of a circuit board is different from process of manufacturing a PCB. Multiple processes like creating PCB prototypes and PCB designing are part of manufacturing PCB. When a PCB is ready, soldering of active and passive electronic components comes into action for using it in electronic gadgets and equipment.

So it is process of assembly or soldering of different electronic components to a printed circuit board. Even speaking in more simple words, PCBA is actually the PCB with assembled components. This assembly of components depends on the type of electronics,purpose of circuit and type of PCB.

The process of PCBA typically involves following seven steps:

  • Paste Stenciling
  • Placement
  • Reflow
  • Manual Assembly
  • Inspection and Testing
  • Washing
  • Packaging

 

These phases go side by side and/or collectively, too. Different methods are in use but soldering, placing and assembly are always must.

Solder Paste: By using a couple of printed circuit board files, the manufacturers develop solder screen with holes on some positions for pads of depositing solder. This solder screen helps in marking the areas for the requirement of pasting solder on the board. These areas are the component pads, to place the components on PCB.

Small grains and flux mixing, in a form of paste, develops the solder. The depositing of this solder paste into places is just like some printing process.

Using the solder screen, a runner moves across it for squeezing a small mount of paste through the holes of solder screen as described earlier, by placing it directly onto PCB board and registering the correct positions. For ensuring that the end connections or joints have the right amount of solder, there is a controlling system.

Pick and Place: There is a machine loaded with the components reel. It picks the electronic components from the reels or some dispensers and places these onto the correct positions on the board with the added solder paste.

If the board is not jolted, the tension of the solder paste is sufficient to keep the components in place.

For securing the components to the PCB board, the machines add glue in form of small dots, in certain assembly processes. This happens when it is wave soldered board. In such processes the glue used can undergo degradation and helps in soldering process. But the presence of glue sometimes makes any sort of repair far more difficult.

The printed circuit board design information provides the information required for position and component, to programme the picks and place machine. This simplifies the machine programming.

Soldering: The board with electronic components added to it, now passes through the soldering machine. In case of wave soldering process, the machine provides the solder instead of adding the solder paste to the board before. Processes of such sort are not widely in use for surface mount components.Reflow soldering techniques are rather more popular in manufacturers these days.

Inspection: Inspection phase is important after passing the boards through the soldering process. For surface mount boards that is employing a great number of components, manual inspection is not an option. Instead a far more suitable solution is automatic optical inspection. Machines are available for inspecting boards and detecting the wrong components.They can also find misplaced components and poor joints.

Test: There are several methods for testing the electronic products. It is necessary stage before the products leave the factory. For testing and measurements, some analysis techniques are run on small scale prototypes and assemblies. They help to look more closely, to inspect at solder joint issues, potential shorts and functionality.

Feedback: The optical inspection after the soldering stage helps in achieving and ensuring satisfaction of running manufacturing process. For investigating any failures, monitoring the outputs is necessary. The detection and quick rectification of process defects is important instead of building boards with similar kind of problem. Feedback is significant at every failure investigating stage.

Once the printed circuit board assembly process ends, then comes the phases of final washing and packaging.

New horizons: In Comparison to previous generations, less power consuming and denser electronics are making it possible to test exciting and new medical technologies. High-powered industrial machineries are commonly using PCBs too. Then automotive industries are making use of flexible PCBAs and PCBs that are capable of withstanding high-vibration environments.

PCBAs in Automotive Industries

The world’s leading automobiles associations and manufacturers set up the international automotive working group or IATF in 1996. Its task was to coordinate to establish International standards for vehicle quality system.

PCBAs inducted in automobiles industry certainly set to ensure high degree of reliability. For this purpose strict compliance of IATF16949 standards remain industry’s essential.This is to provide high standard PCB based automobile to customers.

Challenges.  Suppliers of PCB technologies are facing the challenges of providing more reliable and highperformance PCBAs to consumers. Eventually it is to gain market confidence and built greater use of applications in this field. However PCBs offers a lot to automobilesmanufacturers. They can enjoy the potential of bringing a set of advanced and high-frequency technologies to their users.

Talking of automobile users, PCBs are bringing a change in the way people drive. For its passengers, PCBs and automotive pcba are offering an enhanced experience of driving and greater safety. Estimations tell that as the owners of vehicles are demanding accessories even more, the need of PCBs will grow. Passenger viewing a television is an example for this. With the help of such technology’s introduction automobile drivers are enjoying better safety norms, low power consumption. Ease of operation and availability of ready-made solutionsreducesthe assembly cost and enhance comforts.

So, there is a great number of factors that are influencing the use of PCBs in automobiles. This involvesfrom dealer support systems, sub-assemblies and trucks, to passenger vehicles. Automotive PCB includes drive, control, safety, communication, display, entertainment and fields other than these. GPS navigation system, ECU systems that control the engines, several securing and safety features and anti-lock brake systems all require the use of PCBs.

Other areas of PCB usage. The following represents a few of automobile applications and factors that are insisting the use of PCBs

  • Requirements of Stringent Pollution
  • Climate Control and Assemblies for Blowers
  • Times wiper
  • Electronic mirror controls
  • Interior LED lighting systems
  • Electronic lamp driving
  • Blinkers
  • Car Radios
  • Stereo and audio components
  • Fan speed control
  • Navigation system
  • Advanced Assistance Systems for Drivers
  • Park Assist and Intelligent Sensors
  • Transmission sensors
  • On board radar
  • Engine timing systems
  • ECL/ECU modules
  • Engine management systems
  • DC/AC power converters
  • Meter Clusters and Steering Electronics
  • Electronic power steering
  • Digital displays
  • Electric control section
  • Antilock brake system
  • Automobile multimedia part
  • Electronic key
  • Power relays
  • Body controllers
  • Communication Controls Amplifiers and Tuners
  • Remote Controls and Toll Tags
  • Electric Vehicle Control Units and Inverters
  • Low Electro-Magnetic Interference
  • End-To-End Services
  • Electronics components rapid fall in prices
  • Short development cycle time

 

Advance PCBs.  Such kind of advanced Printed Circuit Boards are becoming essential component of the latest cars. So automobile industries and the vehicle designing companies are implementing a full perimeter electronic system within the back, sides and front of the cars. The cars manufacturers are using these sensors to not only detect objects but also to provide information about object moving around.

But Printed Circuit Boards for the use in automotive industry require long life services at a highly competitive rate with high reliability. The precise designing of PCBs that automobiles are using, can endure harsh conditions that automotive electronics encounters.They can also be very lightweight, depending on design and specifications, which is a necessity for transportation industries. To be present in applications like of these, circuits are also able to conform in tight spaces too. Spaces as behind the instrument gauge or inside instrument panels and a dashboard in cars.

 

printed circuit board

 

The requirement of PCB is to maintain environment conditions and high reliability in the service life. These have to regulate body control systems and safety, control instruments, electronic switches and all kind of control sensors. The power control system consists of Automobile powertrain system. The ordinary organic resin printed circuit boards can not meet the requirements. So because of hot parts and the engine, the production companies are using even more ceramic substrate instead of organic resin.

The installed automotive printed circuit board assemblies automatically outputs signals to the actuators to control the vehicle operations by using a predetermined program. It does this by stopping input signals of various sensors in accordance to that operations.

 

 

These PCBs and PCBAs hold Key Specifications/Features like Immersion Gold and Lead free HASL to perform coating for preventing humidity.In short PCBs and printed circuit board assemblies are used widely in automobile industry.

In the nutshell wherever electronics is providing technological advances it is significantly due to induction of PCBs and PCBAs.