Selecting A Wave Soldering Machine

You’ve decided on wave soldering machine to manufacture your components. How to choose the correct system? There are many to choose, but only one or two that will be right for you. 

Let’s go over what wave soldering machines are out there and how to determine which is right for you and your operation. 

Wave Soldering Machines

The basic way that wave soldering machines work is that a wave of liquid solder is created by sending out into the chamber inside the soldering machine via a nozzle. The wave travels across the chamber in a particular wave pattern, determined by the design of the machine. 

The PCB travels through the machine via conveyor belt, passing through the wave of solder and thereby soldering the components. 

Types of Wave Soldering

There are two types of wave: 

Laminar flow wave soldering machines produce a steady stream of parallel lines of solder. To the casual observer, it would look like solid streams or a waterfall smoothly flowing from one side to the other. 

Turbulent wave soldering produces a much rougher wave, almost like a geyser erupting. These soldering waves erupt upward at select points. All wave soldering machines fall into one of these two categories. However, other aspects of a wave soldering system must also be considered. 

The flux system will either be a foam flux or spray flux system. Foam flux applies a bath of flux to the board by aerating a pot of flux until it produces a foam that drips onto the board. A spray flux system applies a liquid flux via a pressurized spray nozzle. 

Preheating will be by convection heating – just like an oven in your home – or by infrared. Preheating components is critical to temperature management of your soldering components.

Conveyor systems will be automated in-line systems, manually-operated conveyor systems, or a palletized system. In-line systems feed boards from where components are attached, but not soldered, straight into the wave soldering machine. Conveyor systems speak for themselves, and palletized systems work by placing a board (or several boards) in a small pallet that is then loaded into the machine for batch soldering. 

Every specification has its pluses and minuses, so ultimately the best wave soldering system will be the right system for you.  

Which Is The Best Wave Soldering System For Me? 

The best wave soldering system for you is the one with the best-suited capabilities to your product.

Wave Soldering by Application

Laminar wave soldering is best-suited for simple applications. If your product only has surface-mount components, laminar flow is for you. However, turbulent wave nozzles are best suited to boards with through-hole components. If your components need a significant amount of through-hole soldering you may want to consider looking at a selective soldering system instead. Turbulent waves also have the benefit of wicking away any excess solder, preventing bridges from forming.

Choosing the Right Flux System

As to flux, spray flux systems are the most exact, and since they must be used in a high-pressure chamber, tend to correlate with little to no evaporation or degradation of flux. Foam flux systems can result in evaporation if not contained, and flux can degrade a little more easily. However, spray systems are much more expensive, require much more expertise to operate and must be serviced daily without exception.

Preheating for Wave Soldering

Infrared heating produces good heat, but isn’t the most precise. Convection produces even, very precise heating. The good news is preheating doesn’t affect cost in the same way other components will; many systems come with both. However, convection heating is better suited for use with no-clean flux, making for a drier surface and doesn’t require post-soldering cleaning.

Wave Solder Conveyor Systems

As to conveyor systems, automated in-line systems are the most expensive and are only well suited to high-volume production of homogenous products. In other words, if you make a lot of the same board every day, this is the better system. No operators are required as boards are sent on their way to the machine via the in-line system the second components are attached.

Manual conveyor systems move boards through the machine. They must be hand-loaded and removed by an operator. These are lower-cost, but are best-suited to low- to mid-volume production of relatively homogenous product. You can change board specs, but cannot stray too far. Additionally, the conveyor inside the machine must fit the board well; too-thin or oddly-shaped boards can result in errors if not sized correctly for the interior conveyor system. 

Pallet systems use a pallet that a board is loaded into, then sent through the soldering machine. The pallet holds the board and can also act as masking and direct solder flow. The pallet is usually customizable, allowing for multiple sizes and shapes of board to be soldered in the same system. However, they are very time consuming, as operators must put all boards in pallets prior to soldering. They are also the lowest-cost options. Thus, if you produce low numbers of product, but a diverse product lineup, this would be the better system. 

What to Consider Before Buying A Wave Soldering System

Know yourself and your business, and you will be able to accomplish a lot. That includes finding a wave soldering system for your operation. 

You need to know the type of soldering that is required. Will your product require through-hole components or just surface-mount? If the latter, a laminar wave is better but the former will require turbulent wave soldering if not laser or other type of selective soldering. 

You must know the volume and diversity of your product. Do you produce large numbers of the same board? Or do you produce small to medium numbers of several boards? This will tell you what kind of conveyor system to use. You must know the sizes of boards you’ll be making; that will tell you the size of the wave soldering system you’ll need. 

You also need to know your support capacities. Will you have adequate staff for servicing and operation? Or do you run as lean and mean as possible? The latter operation is better-suited to the simplest system they can get that will meet their requirements. 

Make sure you speak to a wave soldering system manufacturer prior to purchase. They will be able to talk to you, consult on what kind of system will be best for you, and be able to take you forward in the decision-making and purchasing process.