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Solder Machines: The Different Types of Solder Machines for Your Project

Even if you’re new to the electronics world, there’s a high chance you’ve heard about soldering. It’s pretty essential for making connections and adding components to your board. However, you’ll need solder machines to accomplish any of this. Although the tool is popular, you might not know what type is best for your project.

This article will look at the soldering machine types and how they work. We’ll also explain what solder machines are to refresh your memory.

Solder Machines

Robotic soldering machine

Robotic soldering machine

Soldering machines are tools that use heat to melt lead-based metals. These metals are what we call solder. Also, you can heat this tool to very high temperatures, up to 600 degrees Fahrenheit.

These machines can include soldering guns, iron, or pencils. Though they all look different, one these soldering machines have in common is a heated, pointed tip. This tip provides precise and accurate solder melting.

Soldering gun

Soldering gun

More importantly, these soldering tools help establish electrical continuity between two wires. They’re also hot enough to keep the solder melted until removed. Most solder machines require you to hook them up to power stations—these stations supply power to the tool and temperature control.

Wave Soldering Machine

Soldering machine

Soldering machine

Most PCB manufacturers use wave soldering for large scaled PCB assembly. They also use it to solder boards using leaded or SMD components quickly. But using this method requires some special machinery.

That’s where the wave soldering machine comes in. This machinery has a heated tank of solder that’s always ready for use. Plus, the tank stays at an adequate temperature to keep the solder melted and prepared for the soldering process.

But how does this machine work? Well, there’s a wave of solder set up inside the tank for manufacturers to add to circuit boards. Only the board’s underside will contact the solder wave when they pass it through the wave soldering machine.

However, this process requires a lot of care, especially when adjusting the solder wave’s height. It must be the perfect amount to avoid solder overflowing from the top side. If such happens, it’ll get into areas that don’t need soldering.

Additionally, you’ll need some metal fingers to secure the PCB on the conveyor. They’re usually made from titanium and can withstand the heat of the soldering machine.


Soldering machine

Soldering machine

First, you’ll need to add a solder resist layer before wave soldering. It includes a varnish-like layer that won’t allow the solder to stick to the surface. However, you’ll only leave areas where you want solder exposed.

Also, ensure your pad has enough spacing between solder pads before soldering. If it’s too close, you’ll risk having solder bridges. Then, you can use foam or spray flux to ensure the solderable areas are clean and free from oxidation.

Next, you’ll move the board through the wave soldering machine. It’ll then subject your board to extreme temperatures. However, remember to preheat the board before starting the process to prevent thermal shocks.

Reflow Soldering Machine

Reflow solder machine

Reflow solder machine

A reflow soldering machine is an oven. These reflow ovens are large machines widely used in PCB assembly & production. Also, these machines offer soldering capabilities for small and large assembly areas.

You can get smaller reflow soldering machines, especially for minor rework and prototype areas. However, these won’t have the soldering power of the more significant variants.

The principle behind reflow soldering requires applying solder paste to the board areas you want to solder. Then, you’ll place the components on the board and pass the assembly through a heating tunnel.

In this tunnel, you can control the amount of heat so that it melts and secures the components without damaging the board.

The reflow soldering machine is one of the most reliable ways to connect SMD components.


Automated soldering machine

Automated soldering machine

The first step is applying solder paste and adding components to your PCB. Remember to only add solder to areas you need it. A soldering paste and mask machine can help you with that.

After applying the paste, you can use a pick and place machine to accurately place your components on the board. The paste’s surface tension is enough to secure them firmly. Then, pass the board through your reflow soldering machine.

Slowly heat the board to the required temperature. If you do it too fast, the heat won’t circulate to all areas. But if you do it too slowly, the board won’t hit the necessary temperature. The acceptable temperature increase rate is 2 to 3 degrees per second.

After reaching the required temperature, the process enters the thermal soak stage. Here, you’ll maintain the temperature to ensure all areas have the right temperature. Next, the reflow process starts when the board reaches the maximum temperature. This is where the solder melts and creates solder joints.

Finally, the board cools off within 30 to 100-degree Celcius temperature ranges.

Final Words

When we say soldering, the first thing that comes to mind is the standard soldering iron or pencil, but PCB manufacturers can’t sell every PCB individually. So instead, they use more advanced techniques and machinery for mass production.

You can get two solder machines: wave and reflow soldering. Wave soldering machines use melted solder stored in a tank, while reflow uses an oven-like engine to melt solder paste placed on the PCB.

Do you have any questions? Feel free to reach us, and we’ll be happy to help.

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Hommer Zhao
Hi, I am Hommer, the founder of WellPCB. So far, we have more than 4,000 customers worldwide. If you have any questions, you can feel free to contact me. I really appreciate any help you can provide.