Solder Alloys and Reflow Microstructure Degradation in Thermal Cycling
Thermal cycling degrades lead-free solder through interfacial intermetallic growth and dynamic recrystallization, which controlled reflow cooling and micro-alloying mitigate.
Rework Cost
Meaning
Financial accounting in electronics manufacturing measures the total expenditure incurred to correct defects in assembled circuit boards before shipment. Calculating the rework cost includes the expense of manual labor, replacement components, specialized tools and the scrap generated during the correction process. This metric acts as a penalty on the efficiency of the factory, reducing the overall yield and delaying delivery schedules.
The financial impact increases as the assembly advances further along the production line before the defect is identified.
Cost Composition
The correction of a defective solder joint or a misaligned component requires skilled technicians to perform manual desoldering and replacement. This action uses expensive materials and exposes the board to the risk of thermal damage from localized heating. The time required for this manual intervention reduces the throughput of the entire production line.
Operational Penalty
Factories monitor this metric to evaluate the effectiveness of their automated optical inspection systems. When the rework cost rises, it indicates that the primary assembly processes are out of control or that the inspection systems are failing to catch defects early. High repair rates also increase the risk of latent defects escaping into the final product.
Commercial Impact
Contract agreements between foreign buyers and Chinese manufacturers often include clauses that limit the allowable percentage of reworked assemblies. If the rate of repair exceeds these contract limits, the buyer may reject the entire shipment or demand price adjustments. Keeping these costs low is essential for maintaining competitive manufacturing margins.