Raytron at SNEC PV+ 2026: Evaluating Cu-Al Composite PV Ribbon for Non-Silicon Module Cost Reduction

Why PV Ribbon Matters in Non-Silicon Cost Reduction

PV ribbon is only one part of the bill of materials, but it directly affects series resistance, shading, solder contact, thermo-mechanical stress, stringer stability and long-term reliability. A change evaluated only by price per kilogram can shift purchasing savings into manufacturing losses, power loss or quality risk.

Raytron's development approach is to minimize unnecessary changes to existing module manufacturing processes where practical. Geometry, conductor structure and solderable surface are first matched to the customer's process, followed by comparable samples and validation on the actual stringer and module qualification system.

Focus Product: Cu-Al Composite PV Ribbon

The composite ribbon uses a clad conductor substrate with a solderable surface system selected for the target module process. The copper layer provides continuous copper surface functionality and a base for joining, while the aluminum or aluminum-alloy core reduces copper consumption and mass per unit length. Resistance, density, strength, elongation, yield behavior, surface quality and soldering performance are determined by the complete structure.

The SNEC discussion focused on multi-slice, multi-busbar and BC modules. Each cell platform has different requirements for ribbon diameter or width and thickness, shading, low-temperature soldering, softness, yield strength, joint layout and current path. One fixed ribbon specification should not be assumed to fit every module architecture.

What Must Be Validated from Material to Module

• Geometry: thickness, width or diameter, tolerance, roundness, flatness, camber and winding quality;
• Electrical performance: resistance per unit length, conductivity, series loss, module power impact and hot-spot risk;
• Soldering: solder-layer thickness and uniformity, wetting, stringing temperature, flux, speed, peel force and joint consistency;
• Mechanical compatibility: tensile properties, elongation, yield behavior, repeated bending, post-solder stress, cell bow and breakage risk;
• Equipment compatibility: payoff, tension, straightening, soldering head, vision system, cycle time and unplanned stops;
• Reliability: thermal cycling, damp heat, mechanical load, potential-induced degradation, corrosion and long-term power stability;
• Economics: material savings, process investment, yield change and qualification cost per meter, cell, module and gigawatt.

A Practical Joint-Validation Path

Step 1 — establish the baseline: document the current ribbon, cell, module layout, stringer and existing peel-force, power, breakage and reliability data.

Step 2 — define candidate specifications: design one to three composite ribbon options around target resistance, shading, softness and equipment limits. Avoid changing too many variables in the first sample round.

Step 3 — validate in layers: incoming inspection and solderability first, small-batch stringing and lamination second, then full-module electrical and reliability testing. Each stage should have pass criteria and stop conditions.

Step 4 — calculate the real business case: proceed to pilot production only when material savings, line yield, power, reliability and supply risk meet the overall target.

Parameters That Accelerate Evaluation

• Cell technology: TOPCon, HJT, BC or another platform; cell size, slicing strategy and busbar layout;
• Current ribbon type, dimensions, tolerances, temper, solder alloy and coating thickness;
• Target resistance per unit length, module power or copper-reduction/cost target per GW;
• Stringer model, line speed, soldering temperature, flux, tension and peel-force standard;
• Module layout, series-parallel configuration, operating current and reliability requirements;
• Sample quantity, validation timing and expected annual volume or production capacity.

What "Minimal Production-Line Change" Should Mean

Raytron aims to design materials and specifications that reduce the amount of equipment and process modification required for customer adoption. This is not an unconditional guarantee for every stringer, module platform or ribbon specification.

Tension, soldering temperature, head configuration, speed, vision parameters or quality criteria may still require adjustment. Marketing and commercial documents therefore use wording such as "developed for compatibility evaluation with existing lines" or "designed to minimize adoption changes" rather than absolute claims.