RENA Systems For Single-Side Etching & Edge Isolation

Etching steps for removing doped glass layers and isolating wafer edges are essential in solar cell manufacturing, particularly for PERC, TOPCon, and back-contact concepts. These processes are typically carried out with inline wet-chemical systems designed for selective, single-side treatments.

For the latest TaiyangNews Market Survey on Solar Cell Production Equipment 2025, RENA has provided data for 5 products, with the InEtchSide 4+ being the latest. This is an inline wet chemical processing system for single-side etching, designed for the removal of silicon oxide and doped glasses such as PSG and BSG, and compatible with solar cell technologies including PERC, IBC, and TOPCon. The system is based on RENA’s NIAK4 platform, featuring 12 lanes for 182 mm (M10)  and 10 lanes for 210 mm (G12) wafers. It offers a gross throughput of 16,000 wafers per hour for M10 and 13,500 wafers per hour for G12. The tool handles wafer sizes of up to G13, a thickness of 100 μm, and supports a mechanical yield of 99.5%, with 97% uptime. According to Michael Vees, Sales Director Solar, RENA Technologies GmbH, this compact 20 m² tool supports production capacities exceeding 1 GW all by itself.

The InEtchSide 3+ is an older variant for single-side HF etching. It accommodates up to 6 lanes of M10 wafers or 5 lanes of G12 wafers, with throughputs of 7,200 and 5,500 wafers per hour, respectively. While these 2 systems are part of RENA’s cluster solutions, the company also offers full inline solutions for doped glass etching, edge isolation, and wraparound removal (see Etching Of Doped Glass & Polysilicon, and Edge Isolation).

The InOxSide Blue series covers the edge isolation step, and for the survey, RENA has provided data for InOxSide 3+ Blue 2. This tool performs single-side etching, BSG etching, and cleaning. It uses HF for glass etching and KOH-based alkaline chemistry for other etching and polishing steps. It processes M10 wafers in 6 lanes or G12 wafers in 5 lanes, with throughputs of 5,000 and 3,700 wafers per hour, respectively. InOxSide3+ Fusion belongs to the same category and shares the same throughput but supports both alkaline and acidic chemistries for single-side etching. The InOxSide 3+ Acidic variant achieves glass and side etching using exclusively acidic chemistry – HF, nitric acid, and sulfuric acid – while KOH is used for rinsing. This tool processes up to 5,000 M10 wafers per hour.

The text is an edited excerpt from TaiyangNews’ latest Market Survey on Solar Cell Production Equipment 2025, which can be downloaded for free here.