Purity 99.99% · CAS 7440-50-8 · Cu
Copper Powder 99.99% (4N) — additive manufacturing grade
Additive manufacturing, conductive inks
Overview
Inert-gas atomised, spherical, low-oxygen copper powder screened to AM-ready cuts (15–45 µm and 45–106 µm). High flowability and packing density for laser powder bed fusion and binder jetting.
Typical trace impurities
| Impurity | Typical max |
|---|---|
| O (oxygen) | ≤ 800 ppm |
| Fe | ≤ 20 ppm |
| Ag | ≤ 15 ppm |
| S | ≤ 15 ppm |
Indicative values. The certificate of analysis for your lot is the binding document.
Where this grade is used
- ▪Laser powder bed fusion and binder jetting service bureaus
- ▪Heat exchanger and induction coil printing
- ▪Conductive ink and paste manufacturers
- ▪Thermal management composite producers
Common forms
Spherical (gas atomised), AM-graded cuts
Specification at a glance
| Material | Copper Powder (Cu) |
|---|---|
| Purity | 99.99% (4N), metals basis |
| CAS | 7440-50-8 |
| Production route | Water or gas atomisation from refined cathode copper |
| Available forms | Spherical (gas atomised), AM-graded cuts |
| Analysis method | ICP-MS trace analysis with LECO combustion for O/C/S |
| Documentation | Certificate of analysis per lot, RoHS and REACH statements, country of origin |
| Typical packaging | 50 g argon-sealed jar · 500 g · 5 kg · Bulk drums |
What 99.99% (4N) actually means
4N is shorthand for 99.99% purity on a metals basis: at most 0.01% of the material, by weight, is something other than Cu. The metals-basis convention excludes dissolved gases and, for powders, surface oxygen — which is why oxygen is quoted separately in the trace table below.
Two lots at the same nominal purity are not interchangeable if the residual elements differ. For this grade the limiting element is typically O (oxygen) at ≤ 800 ppm. What matters is which impurities your process is sensitive to — judge a lot on its full trace analysis, not on the headline number.
Choosing 4N versus the neighbouring grades
Coming from 99.9% (3N): the step up buys you tighter trace control for additive manufacturing, conductive inks. If your process tolerates the residuals of 3N, the lower grade remains the more economical and more widely available choice.
Going up to 99.999% (5N) is worth it when sputtering targets, electroplating chemistry describes your application; expect a materially higher cost per kilo and scarcer availability for a difference few processes can detect otherwise.
When in doubt, qualify both adjacent grades on a sample and run your own incoming inspection before committing a process to either.
Quality control and traceability
Copper Powder at 99.99% is normally released against a lot-specific certificate of analysis stating the assay, the trace elements measured and the method used (ICP-MS trace analysis with LECO combustion for O/C/S). Well-run lots stay traceable from the refinery batch through to the container that reaches the laboratory.
- ▪A retained sample per lot, so a later question can be re-tested against the original material
- ▪Independent third-party verification, used when the assay is contractually critical
- ▪Incoming inspection on the receiving side — the certificate states the method, not the result you will measure
Handling, storage and shipping
- ▪Fine copper powder oxidises at the surface; keep containers sealed and open them under inert gas or dry air for grades from 5N upward.
- ▪Sub-45 µm cuts are classified as a combustible dust — ground equipment, avoid dust clouds and follow ATEX or NFPA 484 practice on site.
- ▪Store between 5 °C and 30 °C at low humidity, away from ammonia, acids and sulphur compounds.
Frequently asked questions
Common questions from buyers specifying copper powder at 99.99%.
- Is 99.99% copper powder the right grade for my application?
- It is the usual choice for additive manufacturing, conductive inks. Below it, 99.9% (3N) covers less demanding work at lower cost. Above it, 99.999% (5N) is reserved for sputtering targets, electroplating chemistry.
- What does the 4N designation mean?
- The N notation counts the nines in the assay: 4N equals 99.99% Cu on a metals basis, with the balance made up of the trace elements listed in the analysis table.
- Which impurities are measured and reported?
- ICP-MS trace analysis with LECO combustion for O/C/S is used, and a certificate of analysis reports each element in the table above, starting with O (oxygen) at ≤ 800 ppm. The scope of a scan can be widened to further elements when a process is sensitive to one in particular.
- How is this grade normally packed?
- 50 g argon-sealed jar, 500 g, 5 kg, Bulk drums. Sub-45 µm cuts are classified as a combustible dust — ground equipment, avoid dust clouds and follow ATEX or NFPA 484 practice on site.
- Which forms is 99.99% copper powder available in?
- Commonly: spherical (gas atomised), am-graded cuts. The form is often a bigger practical constraint than the assay itself, because the last processing step has to preserve the purity already achieved.