The Challenge

A leading PCB manufacturer for automotive and aerospace electronics was struggling with their conductive paste formulation. The ultra-fine copper powder they were sourcing oxidized rapidly during storage, causing inconsistent viscosity and conductivity degradation within 3 months. This resulted in:

• Variable line resistance on high-density interconnect (HDI) traces
• Frequent paste re-mixing and shelf-life waste
• Quality rejects on fine-pitch BGA interconnects

The Solution

LSBT developed a proprietary surface-passivated sub-micron copper powder using our CU-SF spherical copper powder base with a protective organic coating. The key innovations:

• Sub-micron particle size — D50 of 0.8 µm for fine-line printing down to 20 µm line width
• Surface passivation — organic monolayer prevents oxidation while allowing full sintering activation
• 12-month shelf stability — stored at room temperature without nitrogen blanketing
• Excellent dispersion — in both epoxy and solvent-based paste vehicles

The Results

The new copper powder paste enabled consistent printing of 20 µm trace lines with 18% lower electrical resistance compared to the previous formulation. Shelf stability was extended from 3 months to 12 months, reducing material waste by over 60%.

Quality Assurance

Every batch undergoes particle size analysis (laser diffraction), oxygen content testing, and conductivity verification. We maintain lot traceability and provide full COA documentation for each shipment.