Chemical Assessment
Gravimetric analysis defines this method of testing for total nonvolatile matter in flux, which helps determine the percentage of solids remaining after evaporation. ipc-tm-650 2.3.4 provides a repeatable procedure for ensuring that soldering fluxes conform to specified purity and composition requirements. Engineers utilize this standard to detect excessive residue that might bridge fine-pitch leads or interfere with conformal coating adhesion.
Process Requirement
The procedure begins by placing a measured quantity of flux into a tared aluminum dish. Heating occurs in a controlled laboratory oven set to a precise temperature until the mass stabilizes. Technicians record the weight of the remaining material after cooling in a desiccator to prevent moisture absorption.
Calculation involves dividing the weight of the residue by the original sample weight to produce the final nonvolatile content value. Consistent application of these steps guards against batch variations that might degrade electrical reliability or long-term performance of finished circuit assemblies.
Performance Limitation
Precise measurement of nonvolatile content helps distinguish between high-activity fluxes and low-solids options. Accuracy relies entirely on the stability of the drying conditions and the precision of the analytical balance. Laboratory environments must strictly maintain the temperature profile to avoid boiling off volatile solvents while simultaneously scorching the active solid components.
Proper adherence to this protocol reduces the risk of ionic contamination or electrical leakage paths on the board surface.
