The Right Way to Solder on Printed Circuit Boards

mwcms on October 28, 2022

Soldering is the most vital part of the PCB assembly process. It’s where the electrical components get attached to circuit boards. Without electrical components, no PCB would function effectively. There are various methods to sell electrical components to PCB and ensure electrical currents pass through the conductive pathways efficiently.

The main issue is that many people don’t know the right way to solder electrical components on circuit boards. Since a bunch of them are being used in factories, it can be quite tricky to pick the right one. We will discuss some of the top soldering techniques so you can choose the one that’s right for your business.

The Right Way of Soldering on Printed Circuit Boards

In the electronics world, soldering is a fundamental skill that nearly every professional must have at some point. Soldering and electronics go together like a fork and spoon.

Although people learn how to design, build, and release electronics without picking up a soldering iron, it’s still a vital part of the industry. Let’s check out a few soldering methods and techniques commonly used these days.

1.      Reflow Soldering

It’s the most common soldering method factories use today, especially for manufacturing surface mount technology or SMT printed circuit boards. This soldering method involves using a heated soldering paste to attach electrical components to the circuit board. The paste looks like molten metal, enabling professionals to connect pins and pads seamlessly. However, it results in permanent attachment.

2.      Wave Soldering

Wave soldering was once extremely popular for wave soldering. However, it’s still commonly used for surface-mount technology circuit boards. Printed circuit boards that go through the through-hole process (i.e., drilling holes in the board to fit electrical components) usually also go through the wave soldering process.

Generally, factories utilize wave soldering to produce massive PCB assemblies. The PCBs go over molten solder in a pan that looks nothing less than a wave pool. Once through, electrical components get attached to the circuit board.

Before coming in contact with the molten solder, the components are already glued to the board. Due to an additional step that reduces efficiency and somewhat increases the time and money consumption, reflow soldering replaced wave soldering.

3.      Braze Soldering

Soft and hard soldering is nothing compared to brazing. Brazing results in fortified joints between the printed circuit boards and electrical components, including transistors, inductors, and capacitors. It uses high temperatures to attach electrical components to circuit boards.

Although it’s similar to hard soldering (discussed later), brazing involves melting the underside of the metal components to get attached to the board. It causes the least thermal deformation and is one of the best soldering techniques for mass PCB production.

4.      Soft Soldering

Soft soldering is the perfect option for compact and fragile circuit board components. Soft soldering doesn’t damage the electrical components through high heat or molten solder. In this process, the temperature of the molten solder is below 400 degrees Celsius or 752 degrees Fahrenheit.

If the temperature goes over, it becomes “braze soldering”. The low-temperature technique is for smaller components prone to breaking at high temperatures or heat conditions. Although it’s suitable for small components and fragile boards, it doesn’t produce the strongest joints.

5.      Silver Soldering (or Hard Soldering)

This soldering technique also yields strong joints between components and circuit boards. However, combining metal components such as gold, silver, or brass-plated components is best. It’s used to connect and attach the same metals in other industries.

Conclusion

What type of printed circuit board you’re producing will determine the right soldering technique. Other factors influencing the soldering technique include existing capabilities, materials, and requirements.

Check which soldering technique offers the most lasting results and try to match it with your PCB requirements. Partnering with a solid PCB manufacturing company could ease the process and increase soldering efficiency.

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.