Soluble copper anode material for wet processes
Electrolytic copper pellets are a common form of copper raw material in PCB, EMS and semiconductor wet-process plants. Made by electrolysis, they have high purity, a stable crystal structure and controllable impurities. The common size is a 3 mm × 4 mm cylinder: pellets are placed in titanium anode baskets in the plating bath as a soluble anode, dissolving continuously to replenish copper ions during plating — a consumable in circuit board and microelectronic packaging copper plating.
A JIAHON affiliated company supplies customers throughout Taiwan. Grades of 99.93% and higher purity (99.99%+) are available; COA, MSDS and certificate of origin on request for quality and engineering review.
Specifications
| Item | Details |
|---|---|
| Product | Electrolytic copper pellets |
| Size on this page | CuP10Kg/CA, purity > 99.93%, 3 mm diameter × 4 mm long (cylindrical) |
| Purity | ≥ 99.93%; 99.99% / 99.999% (5N) optional |
| Common sizes | 2 × 3 mm, 3 × 4 mm, 5 × 5 mm (cylindrical); spherical on request |
| Appearance | Reddish metallic luster, smooth surface, no heavy brown oxidation |
| Density | Approx. 8.96 g/cm³ |
| Melting point | 1083°C |
| Typical impurities (reference) | Fe ≤ 50 ppm, S ≤ 25 ppm, Pb ≤ 20 ppm, Sb / Bi / As / Sn each ≤ 10 ppm |
| Packing | 10 kg paper drum (CuP10Kg/CA on this page), 25 kg drum, 100 kg / 500 kg bulk boxes |
| Standard | Per supplier’s certificate of analysis (COA) |
Values refer to the size on this page and common industry ranges; actual purity grade, size and impurity limits depend on downstream process requirements and the supplier’s specification, confirmed case by case.
Applications
Copper pellets in anode baskets dissolve gradually during electrolysis, so the line does not have to stop to change anode plates — suited to high-frequency, high-throughput plating systems.
- PCB copper plating: through-hole plating and surface copper build-up. Pellets in titanium baskets dissolve under DC power to replenish copper ions; typical bath copper is 18–25 g/L at pH about 0.5–1.0 (sulfate system). For soluble anodes in PCB acid copper sulfate plating, phosphorized copper (about 0.04–0.06% P) is used — please confirm with your chemical supplier’s specification before choosing.
- Semiconductor / microelectronic bump plating: Cu pillar / Cu bump plating needs 99.99% or higher purity to avoid corrosion or signal problems; bath maintenance is demanding, and pellets should come with COA and batch traceability. Some advanced processes specify OFHC copper.
- Electroless copper replenishment: in electroless copper for double-sided and multilayer PCBs (bath with Cu²⁺, complexing agent and formaldehyde reducer), copper ions are consumed over time and replenished with pellets or copper sulfate solution; 99.93% purity is sufficient, with addition rate adjusted to bath analysis.
- Copper electroforming, surface finishing and alloy master batches: electroformed molds, decorative copper plating and adding copper in alloy melting (Cu-Sn / Cu-Zn / Cu-Ni). Electroforming needs high purity to avoid brittle deposits; choose purity and pellet shape by application.
How to choose
| Application | Purity | Size | Notes |
|---|---|---|---|
| PCB through-hole plating | Per chemical supplier (phosphorized copper is common for acid copper anodes) | 3 × 4 mm (this page) | Mainstream size |
| FPC plating | 99.93% / 99.99% | 2–3 × 3–4 mm | Per bath requirements |
| Semiconductor Cu bump | ≥ 99.99% (4N+) | 3 × 4 mm / 5 × 5 mm | COA with batch number required |
| Electroless copper replenishment | 99.93% | 3 × 4 mm | Add according to bath analysis |
| Electroforming / alloy melting | Depends on application | Depends on application | Alloy master batches can use lower purity |
Pellets vs anode plates vs rod vs powder
| Form | Main use | Advantage | Limitation |
|---|---|---|---|
| Electrolytic pellets (3–5 mm) | Replenishing titanium baskets in PCB / semiconductor plating | Add as you go, stable copper supply | Needs titanium baskets |
| Copper anode plates | Anodes for high-throughput plating lines | Large capacity, stable | Changing requires stopping the line |
| Copper rod (8 × 600 mm) | EDM electrodes, melting additions | Regular shape, easy to machine | Not recommended for plating replenishment |
| Copper powder (< 100 µm) | Powder metallurgy, conductive pastes, impregnation | Large surface area, easy to mix | Not recommended for plating |
In practice, many PCB plants use both: anode plates for main capacity and pellets for top-up to keep the bath stable. Semiconductor Cu bump lines often use only high-purity pellets, as the pellet form allows precise replenishment. Anode plates, rods and powder are available on request.
Purity grades
| Purity | Name | Typical impurities | Typical use |
|---|---|---|---|
| 99.93% | General industrial | Traces of O, Fe, S | PCB plating, electroless copper replenishment |
| 99.99% | 4N | Metal ions < 100 ppm | Semiconductor packaging Cu bump / Cu pillar |
| 99.999% | 5N | Metal ions < 10 ppm | Front-end semiconductor Cu interconnects |
A common mistake is buying the highest purity “to be safe”. Purity should follow the downstream process and chemical supplier’s specification — 4N for packaging, 5N and above for front-end; for PCB acid copper anodes, suppliers often specify phosphorized copper (about 0.04–0.06% P). The option on this page is purity > 99.93%; 99.99% and above on request.
Consumption and purchase planning
By Faraday’s law, 1 ampere-hour (Ah) deposits 1.186 g of copper (theoretical).
| Current | Operating time | Ah per day | Theoretical consumption | Actual (with losses) |
|---|---|---|---|---|
| 500 A | 8 h / day | 4000 Ah | 4.7 kg / day | 5.0–5.5 kg / day |
| 1000 A | 8 h / day | 8000 Ah | 9.5 kg / day | 10–11 kg / day |
| 2000 A | 16 h / day | 32000 Ah | 38 kg / day | 40–45 kg / day |
Plan purchases as daily consumption × working days × a safety factor of 1.1–1.15. Example: a 1000 A line uses about 10 kg / day × 26 days × 1.15 ≈ 300 kg / month. Set up a replenishment SOP — a fixed amount at fixed times each day, or automatic replenishment based on real-time copper concentration monitoring.
Selection, storage and purchasing
- Selection: downstream process (PCB / semiconductor / electroless) → purity grade (99.93% / 99.99%+) → pellet shape and size (3 × 4 mm mainstream) → consumption (Ah × 1.186 g) → purchase and COA.
- Storage: keep sealed in the supplied packing in a cool, dry place (below 60% RH) and use within 3–6 months of opening. Heavily oxidized batches can be pickled in dilute sulfuric acid (5–10%) before use. Semiconductor-grade copper should be vacuum-packed and used immediately after opening.
- Purchase documents: COA (Cu % and Fe / S / Pb / Sb / Bi / As / Sn in ppm), MSDS, certificate of origin, batch traceability (required for semiconductor use) and outgoing inspection report. Specify impurity limits and terms for nonconforming material in the purchase contract.
- Replenishment SOP: fixed-interval replenishment suits stable production; real-time replenishment (bath monitoring + automatic feeding) suits 24-hour high-speed lines. Keep monthly bath chemistry records to track copper concentration and replenishment efficiency.
- Titanium baskets and waste: use acid-resistant titanium baskets with 5–10 mm mesh (pellets go in, fines don’t fall out) and clean out sludge regularly. Copper-bearing waste must be treated by electrolytic recovery or chemical precipitation according to local environmental regulations.
When you request a quote, please tell us: purity, size, monthly quantity and application.
Email us for a quote: [email protected]