Key takeaways:
Laser processing is becoming increasingly important for BC manufacturing, supporting large-area ablation, precise patterning, and adaptation to different cell structures
Integrated texturing and polishing processes have reduced the number of wet-chemical steps, lowering processing costs and improving surface quality
Insulation adhesives serve both electrical and mechanical functions, helping prevent leakage, improve reliability, and support more flexible module designs
Back contact (BC) technology has established itself as the leading high-efficiency cell architecture. Further developments in this technology depend on continuous improvements in manufacturing processes, such as laser processing, wet chemical treatment, and other materials that play an important role in simplifying production, reducing costs, and delivering high performance.
As part of its presentation at TaiyangNews STC.I 2026, DR Laser gave an overview of laser applications in cell processing and highlighted 3 focus areas for BC-related developments. First is large-spot ablation, which requires a uniform energy distribution and stable control to enable consistent processing over larger areas. Second, fine-tuning of patterning is achieved through time-serial scanning and AI-assisted visualization. The goal here is to improve the alignment accuracy and ensure effective isolation of p- and n-type regions. The final one is flexible laser ablation optimization, enabling adaptation across different film types and BC structures, supported by multiple laser-source configurations and proven processing recipes.
LONGi’s white paper also mentions wet-process optimization and insulation-adhesion technology as key breakthroughs that have helped BC’s progress. As for the wet-chemistry part, BC production traditionally relied on 8 to 10 separate wet-chemical steps, which not only increased costs but also extended the production cycle and introduced surface defects. Recent advances, particularly the adoption of integrated texturing and polishing enabled by mixed-acid chemistries, have significantly simplified this sequence. The number of wet steps has been reduced to just a few, cutting process time by more than half and substantially lowering wet processing costs. At the same time, fewer process steps translate into better surface quality, reduced recombination, and improved overall device performance. In parallel, innovations in surface texturing, such as submicron pyramid structures, have further lowered reflectance and enhanced both efficiency and visual uniformity.
Equally important is the development of insulation adhesive technology, which addresses a fundamental challenge of BC architecture. With both p+ and n+ contacts located on the rear side and separated by very narrow distances, the risk of electrical leakage is inherently high. This is further complicated by the integration of multiple layers with different thermal properties, leading to mechanical stress at interfaces. Insulation adhesives play a dual role here: they act as a reliable electrical barrier while also providing mechanical buffering to accommodate these stresses. Advances in this material system have been instrumental in preventing short circuits, improving module reliability, and enabling more flexible circuit designs. At the module level, this also supports more efficient soldering processes and contributes to cost reduction in encapsulation.
The text is an edited excerpt from TaiyangNews’ report on Cell & Module Technology Trends 2026, which can be downloaded for free here.