Cost and Quality Analysis of Gold Sinking Process in PCB Manufacturing
First, cost analysis
The material cost is high.
The core material of the gold plating process is gold, and its price is directly linked to the international gold price, resulting in a significantly higher material cost than other surface treatment processes (such as tin immersion and OSP).
The complexity of the process increases costs: Gold plating requires the formation of a nickel-gold alloy layer on the copper surface through chemical deposition, involving multiple chemical reactions (such as nickel plating and gold displacement). It is necessary to precisely control the composition, concentration, temperature and time of the plating solution, further pushing up the manufacturing cost.
The process parameters are strictly controlled
The gold plating process has extremely high requirements for parameter control. To avoid the "black plate effect" (poor welding caused by oxidation of the nickel layer), additional equipment and manpower need to be invested for quality monitoring, which indirectly increases costs.
Comprehensive cost comparison
The cost of the gold plating process is generally higher than that of tin immersion, OSP and other processes, but lower than that of gold plating (because the gold plating layer is thicker and uses more gold).
Typical cost data:
Gold sinking process: approximately 30 to 100 yuan per square meter (depending on the thickness of the gold layer, the number of PCB layers and the complexity of the design).
Tin dipping process: approximately 10 to 20 yuan per square meter.
OSP process: approximately 5 to 15 yuan per square meter.
Gold plating process: 1.5 to 2 times more expensive than gold sinking.
Second, quality analysis
Excellent performance
Oxidation resistance and corrosion resistance: The dense gold layer can effectively prevent copper oxidation and extend the storage life of PCBS (no oxidation for more than half a year), making it suitable for long-term inventory.
Soldering performance: High surface flatness, suitable for high-density and fine-pitch SMT mounting (such as BGA, QFN packaging), and soldering reliability is superior to HASL and other processes.
Conductivity and signal integrity: The gold and nickel layers offer excellent conductivity, making them suitable for high-frequency circuits and reducing signal loss.
Applicable scenarios
High-end electronic products, such as communication equipment, medical devices, aerospace, etc., have extremely high requirements for PCB performance, reliability and environmental adaptability. The additional cost of the gold plating process is worth investing in.
Complex PCB design: Friendly to HDI and blind buried vias, it will not cause problems due to uneven electroplating.
Limitations
The gold layer is relatively thin: Excessive welding operations may cause the gold layer to wear out, exposing the nickel layer and affecting the weldability.
Black disk risk: If the nickel layer is not properly treated, it may turn black and cause false soldering. Strict process control is required.
Third, the trade-off between cost and quality
High cost corresponds to high performance
The high cost of the gold sinking process mainly stems from the use of precious metals and complex techniques. However, the oxidation resistance, corrosion resistance, welding reliability and electrical conductivity it offers are unmatched by other processes.
The application scenario determines the choice
Recommended gold plating process: If the product has strict requirements for performance, reliability and environmental adaptability (such as high-end communication equipment and medical equipment), the gold plating process is the best choice.
Alternative solutions: If cost control is more sensitive and performance requirements are relatively low (such as for general consumer electronics), tin dipping or OSP processes can be considered.
