In modern manufacturing, immersion gold and gold plating are common surface treatment methods, widely used to improve product aesthetics, corrosion resistance, conductivity and other properties. However, there are significant differences in the cost structure of these two processes. In-depth understanding of these differences is of great significance for enterprises to reasonably select processes, control production costs, and improve market competitiveness.

Process principles and cost basis

The gold plating process, usually referring to chemical gold plating, is a process that uses chemical oxidation-reduction reactions to deposit a layer of gold on the copper surface of a substrate material, such as a PCB board. The principle is that in a solution containing gold salts, gold ions are reduced through a specific reducing agent and uniformly deposited on the surface of the substrate. This process does not require an external current, is relatively mild, and has relatively simple requirements for the equipment. However, the gold plating process requires precise control of parameters such as the composition, temperature, and pH value of the solution to ensure the quality and thickness uniformity of the gold layer. Due to the relatively slow gold sinking process, a longer processing time is required to achieve the desired gold layer thickness, which to some extent increases the time cost.

The gold plating process is mainly achieved through the principle of electrolysis. In the electrolytic cell, the workpiece to be treated is used as the cathode and gold as the anode, and is placed in the electrolyte containing gold ions. When an electric current passes through, gold ions gain electrons at the cathode, are reduced to gold atoms and deposit on the surface of the workpiece. This process can quickly deposit a relatively thick gold layer on the surface of the workpiece, and the production efficiency is relatively high. However, the electrolysis process requires specialized power supply equipment, which has high demands on the precision and stability of the equipment. As a result, the purchase and maintenance costs of the equipment also increase accordingly.

The cost difference of gold material usage

In terms of the amount of gold used, the gold plating process usually requires more gold. Because gold plating can achieve a relatively thick gold layer deposition, its thickness range is generally between 0.1 and 2.5μm. In contrast, the gold layer obtained by the gold sinking process is thinner. For instance, in the application of PCB boards, the thickness of the gold layer in the gold plating process is generally around 0.05-0.15μm. With the increase of the thickness of the gold layer, the amount of gold material required for the gold plating process increases linearly. Moreover, during the electrolysis process, in order to ensure the continuous supply of deposit ions and the stability of the electroplating effect, the concentration of gold ions in the electrolyte needs to be maintained at a certain level, which means that more gold materials will be consumed during the production process.

In addition, the price fluctuations of gold materials have different degrees of impact on the costs of the two processes. Due to the relatively small amount of gold material used in the gold sinking process, the cost change is relatively small when facing fluctuations in gold prices. As for the gold plating process, which relies heavily on gold materials, any fluctuation in the gold price will have a significant impact on its cost. For instance, when the international gold price rises sharply, the cost of the gold plating process will increase rapidly, exerting considerable cost pressure on enterprises.

Comparison of equipment and labor costs

The equipment required for the gold sinking process is relatively simple, mainly including the reaction tank, solution circulation system, temperature control device, etc. The initial purchase cost of these devices is relatively low, and during daily operation, the maintenance cost is also not high. Due to the relatively stable process, the technical requirements for operators mainly focus on the monitoring and adjustment of solution parameters, and the cost of personnel training is relatively low.

The gold plating process requires specialized electroplating power supplies, rectifiers, electroplating tanks, as well as complex filtration and circulation systems and other equipment. These devices are not only expensive, but also consume a large amount of electricity during operation, resulting in high depreciation and energy consumption costs for the equipment. Meanwhile, the electrolysis process has extremely strict control requirements for process parameters, such as current density, voltage, electroplating time, etc. Any deviation in any parameter may lead to quality problems with the gold layer. This requires operators to possess high professional skills and rich experience, and both the cost of manual training and human resources are relatively high.

Other cost factor considerations

In actual production, there are still some other factors that can affect the costs of the two processes. For instance, in the process of solution preparation and maintenance in the gold plating process, a variety of chemical reagents are required. Although the cost of these reagents is relatively lower than that of gold materials, it still amounts to a considerable expense over a long period of time. Moreover, the wastewater generated during the gold deposition process contains heavy metals and chemical substances, which require specialized treatment to meet environmental protection discharge standards. The cost of wastewater treatment cannot be ignored either.

During the electroplating process of gold plating, problems with the gold layer quality may occur due to improper process control, such as insufficient adhesion of the gold layer and uneven thickness. Once these problems occur, the workpieces often need to be reworked, which not only increases material and time costs but may also lead to a decline in production efficiency. In addition, the gold plating process has high requirements for the production environment. It is necessary to maintain the cleanliness and stable temperature and humidity of the workshop, which will also increase the production cost to a certain extent.

There are multiple differences in cost between the gold sinking process and the gold plating process. When enterprises choose processes, they cannot merely judge based on cost. They also need to comprehensively consider factors such as the performance requirements of the product, production scale, and market positioning. In large-scale production projects where cost control is of great significance, if the product does not have particularly high requirements for the thickness and wear resistance of the gold layer, the cost advantage of the gold sinking process is quite obvious. For some high-end products, such as aerospace electronic equipment, the requirements for product performance and appearance are extremely high. Even if the gold plating process is costly, enterprises may still choose this process to meet the high-quality demands of the products. Only by comprehensively weighing various factors can enterprises make process choices suitable for their own development and maximize cost-effectiveness.