Solder paste and flux composition analysis
Separate the metal powder from the flux vehicle
Solder paste typically contains metal powder dispersed in a flux vehicle that supports printing and soldering. The powder commonly contains a tin-based alloy, while the vehicle can contain resinous ingredients, activators, solvents and rheology modifiers. A paste question should therefore distinguish the metal composition from the organic vehicle rather than asking for one undifferentiated ingredient list. For an assembly-material study, we relate supported chemical observations to the particular material question you declare.
What metal composition can and cannot describe
ICP-MS can contribute metal-composition information in a formulation study, with methods selected for the particular sample. An alloy-composition comparison is distinct from the metal fraction of the whole paste, because the paste also contains an organic vehicle. Neither composition alone describes powder size, particle shape, surface oxidation or printing behavior. For example, a manufacturer who wants to compare paste printing should distinguish a changed alloy hypothesis from a changed vehicle or powder-condition hypothesis.
Flux ingredients and residues are different analytical objects
Fluxes commonly use ingredients that help remove surface oxides and support wetting during soldering. Resinous components and activators can change during heating, while volatile ingredients can leave. A post-soldering residue therefore describes retained material after processing rather than the untouched liquid flux. Identifying an organic acid or resin family in a residue does not establish its original amount in the liquid product.
Prepare the question around a defined coupon
A newly prepared residue coupon can help distinguish retained flux chemistry from contributions of the underlying board or metal surface. State the substrate, the applied material and the drying or heating history, including any visible remaining liquid. For a comparison, similar substrate and preparation histories make a chemical difference easier to interpret. For the general limits of replacing a liquid with a dry sample, see alternative sample forms.
SDS review comes before any receipt decision
Solder paste and flux are not on our list of pre-reviewed product types, so they are reviewed case by case after declaration with an SDS. A semi-solid solder paste still requires review; its consistency does not override ingredient or import restrictions. Alcohol-based liquid flux is a non-water-based liquid and is not received from overseas as supplied. A freshly prepared dried or cured post-soldering residue coupon may be proposed, but it is reviewed case by case after declaration and must not be treated as automatically acceptable. We do not receive used assemblies, recovered production waste or scrap from overseas.
How to start
We review overseas industrial samples before acceptance. Use our industrial analysis page and sample-shipping guide to prepare your declaration. Our reports are research-grade analytical reports from a laboratory that is not accredited. They cannot be used for product registration or legal proceedings.
FAQ
Does a metal-composition result describe the entire solder paste?
A metal-composition result describes the metal question, while whole-paste composition also includes the flux vehicle and requires a clear sample basis.
Can residue analysis recover the original alcohol blend?
A dried residue does not preserve alcohol that evaporated, so its composition cannot establish the original volatile blend by itself.
Is a paste accepted because it is semi-solid?
Semi-solid solder paste is reviewed case by case after declaration and SDS review, with the ingredient restrictions still applying.
Can a residue result establish electronics reliability?
A residue result identifies supported chemistry in that specimen; reliability also depends on electrical conditions, moisture, residue distribution and the assembly process.
Send a sample declaration and state the material and question you want us to review.