Everything You Need to Know About Circuit Board Assembly!

mwcms on September 13, 2021

Most of the electrical appliances that run our lives on a daily basis include about 300 feet of tiny wires inside. This wire is the main component that adds connectivity inside an electrical product. It allows all the other small components in an electrical appliance to work seamlessly together.

The more complex an electrical appliance is, the larger the number of components and the wire inside it. However, you may be wondering where this wire is located. Well, this is where the printed circuit board assembly comes into play.

What is a PCB?

The printed circuit board or PCB is the small circuit board inside most electrical appliances. They are either green or blue and at first glance, they look like ordinary pieces of scrap plastic. But in reality, they are actually a multi-layered board that consists of an abundance of copper wires.

This scrap of flat metal is the surface on which manufacturers will precisely and carefully place all the essential components using expensive heavy machinery. Along with that, small copper wires will connect between the components and provide the necessary connectivity that occurs between all the components. This connectivity allows the components to work together and as a result, this paves the way for an electrical appliance to function.

What is inside?

The printed circuit board consists of ten conductive layers. The top and bottom layers of the Circuit board assembly make for surfaces on which manufacturers will mount components and they also act as multiple antennae. Moreover, each of these components on the circuit board requires plenty of power and ground and the PCB has entire layers that are only responsible for providing power and ground.

They are also aptly named power planes and ground planes due to their specialized role. Other ground planes that make the circuit board assembly serve the purpose of electromagnetic shielding and heat dissipation. The remaining four middle layers carry all the communication traces, which means that they carry all the signal wires.

Each of the conductive layers is copper, and between these conductive layers, there is insulating fiberglass, along with an epoxy resin that protects against the flow of electricity between the layers. A common PCB has a total of ten conductive layers, however, in a more technical and complex application, the layers can range up to 50 or more layers.

On the other hand, you may also find a PCB board that is simpler, with only two layers. Not to mention, on the top and bottom layers of a PCB, you will find a coat of solder mask, which offers a surface on which manufacturers will place components using high-tech machines. On top of the soldering mask is the silkscreen, which is nothing but the ink that indicates the placements for components by marking the circuit board.

The Assembly Process

After all the components of the PCB are manufactured, they need to be assembled before the PCB can go into the production line. This assembly process will involve the application of solder masks, automated component placement, along with the electrical testing of the bare board.

Final Thoughts

Printed circuit boards are more widely used inside computing devices, and since each model of smart phones and laptops along with other devices are different, the shapes and designs of circuit board assembly also differ vastly. Overall, it is fair to say that they are integral components of the modern technical era, and without them, none of the highest technical appliances can function.

 

 

Everything You Need to Know about Solder Mask Material

mwcms on July 16, 2021

Solder Mask material is a fine layer of polymer. In terms of application, engineers will often use this material for copper traces in a circuit board, PCB. It is an essential material in circuit building projects, protecting the PCB from oxidization. This is, however, not the only use case and benefit of solder masks when it comes to the construction of circuit boards.

PREVENTS THE BRIDGES FROM DEVELOPING

Printed Circuit Boards or PCB usually has components of copper placed extremely close to each other. The solder masking helps an engineer avoid solder bridges from manifesting due to the pads spaced closely.

Solder bridge refers to an electrical connection between two copper components on a PCB board. Therefore, the correct application of a Solder Mask can be instrumental in avoiding this issue. Their use case for PCBs is increasingly widespread and fine-tuned into the mass production of circuit boards.

Hence, you will not only find the solder mask material as a hand assembly use case but also integral to the mass production companies of PCB. Companies involved in mass production often use wave or reflow techniques to solder their circuits.

APPLICATION PROCESS

The application process of solder involves firstly, applying the solder material on the board, and then following it up with making openings into the material for the copper components. Engineers that craft circuit boards will make these openings, often by using photolithography techniques.

Traditionally, solder mask material has a green physical appearance, but you can find it in many other colors as well. You can also use solder-masking techniques to construct your very own solder mask at home.

Hence, the quantity, quality, or type of the solder mask material ultimately depends on the particular PCB. Every PCB is different, not only in terms of size but also in terms of applications. PCBs for certain electronic instruments may have more components than some others.
Therefore, the physical dimensions of a particular PCB, the number of openings, and the volume and sizes of components are considerations that factor in before every soldering process.

TYPES

Typically, you can find four types of solder mask materials, each having its unique physical properties and distinct applications.

TOP-BOTTOM SIDE MASKS

The use of this type of solder mask is common amongst electronic engineers. They use this type of solder to recognize the openings in the solder layer. The layering of this solder mask often follows a film or an epoxy technique.

EPOXY LIQUID SOLDER MASKS

This is one of the cheaper solder masking options since it is a polymer that you can easily silkscreen on the PCB. Silk-screening refers to a printing method in which you have to apply woven mesh to hold the ink patterns.

LIQUID SOLDER MASK/PHOTO IMAGEABLE SOLDER MASK

This solder material is often the more superior out of the four. In terms of property, it is a mixture of two different liquid components. For this reason, it has a much higher shelf life than other solder mask liquids. Furthermore, it is also versatile in its application, meaning, that you can use multiple techniques to apply this solder mask material type.

DRY FILM PHOTO IMAGEABLE SOLDER MATERIAL

This type of solder mask material is excellent for high-density wiring boards. Since the film is dry, it is less likely to escape through the holes. Moreover, when using dry film, you should use the vacuum lamination application technique.

CONCLUSION

Solder mask materials are emphatic for the PCB industry. Without their application, all circuit boards are vulnerable to damages due to short circuits. Moreover, they also have an essential role in the functionality of the particular circuit board, and they allow aspiring circuit board creators to practice their PCB crafting skills.