When it comes to producing PCB assemblies, perhaps the best material to use is aluminum. As a manufacturing material, aluminum provides a variety of benefits including universality, eco-friendliness, good thermal characteristics, and low cost, to mention a few. Unfortunately, the biggest problem is that aluminum is not completely compatible with solder paste. This creates problems of mounting components on to the board. What exactly is the connection between aluminum and solder? Let’s find out.
The Problem
In 2006, RoHS created restrictions on the kind of materials that were used in soldering. This resulted in many problems for PCB manufacturers. Traditional materials used in solder like lead and flame retardant haloids were eliminated. While this was useful in reducing health and environmental issues, it also led to problems when aluminum was combined with the solder. Some of the problems were copper dissolution, weak solder joints, and greater vulnerability to damage.
The Solution
To counteract this problem, an ingenious solution was suggested – do away with the solder paste altogether. Today, a new process called SAFE (Solderless Assembly for Electronics) meets this requirement. The unique aspect of this process is related to the steps and placement methods. Before the assembly process begins, the components are first tested to ensure that they do not have any defects, and are fit for use. Once this process is complete, the components are burned into the carrier plate of the aluminum housing.
Benefits of SAFE
The solderless method provides a variety of benefits, not just for aluminum housings, but for other PCB assembly processes as well:
- It can be performed using traditional pick and place assembly equipment.
- With the lack of solder, the problem of moisture sensitivity is eliminated.
- The number of steps in the assembly process is reduced considerably.
- In turn, the above benefit also leads to immense reductions in time, effort, and expenditure.
- As the main housing material, aluminum allows for balanced thermal management.
The use of the SAFE method has led to safer assembly processes, and overall cost-effective PCB manufacturing procedures.
