You’ve perfected your next-generation cell technology. Whether it’s the high efficiency of Heterojunction (HJT) or the groundbreaking potential of Perovskite, the most difficult R&D is behind you.
But now you face the final, most critical manufacturing step: lamination. This is where billion-dollar ideas can be destroyed in minutes by the brute force of a standard thermal process.
The conventional lamination cycle, running at 150°C or higher, is simply not an option. For HJT cells, these temperatures cause irreversible hydrogen effusion, destroying the delicate amorphous silicon passivation layers that make the technology so powerful. For perovskites, it’s even worse—the cells are not only temperature-sensitive but also mechanically fragile and fatally allergic to moisture.
How do you build a robust, reliable module when the very process designed to protect the cells is the thing that can kill them?
This isn’t a material problem; it’s a process engineering challenge. It requires a fundamental rethinking of the interplay of encapsulant chemistry, time-temperature profiles, and pressure control. At PVTestLab, we don’t just talk about theory—we engineer and validate these processes daily on our full-scale industrial R&D line. Here’s how we solve the low-temperature lamination puzzle.
Encapsulant Chemistry—Your First Line of Defense
Lamination is a chemical reaction. The challenge lies in finding an encapsulant that achieves a strong, durable bond and a hermetic seal at temperatures low enough to preserve cell integrity. Simply lowering the heat with standard EVA is a recipe for delamination and moisture ingress.
Our applied research validates next-generation encapsulants under real industrial conditions. We conduct structured experiments comparing materials like Thermoplastic Polyolefins (TPO) and advanced Polyolefin Elastomers (POE), which are designed specifically for lower curing temperatures.
In our lamination trials, we’ve observed clear performance differences:
Adhesion: Specialized POE formulations consistently achieve superior adhesion to both glass and backsheets at cure temperatures below 140°C, a critical factor for preventing delamination in HJT modules.
Moisture Barrier: For highly sensitive perovskite cells, TPOs demonstrate the lowest moisture vapor transmission rates (MVTR), creating a true hermetic seal essential for long-term stability.
Practical Guideline: The choice of encapsulant is the foundation of a successful low-temperature process. Your materials must be validated not in a lab oven, but in a full-scale laminator that mimics the thermal dynamics and pressures of production. Before scaling, a comparative material and lamination trial is the single best way to de-risk your module design.
Mastering the Time-Temperature-Pressure Profile
With the right material selected, the next challenge is designing the perfect thermal recipe. It’s a delicate balance: you need enough thermal energy to trigger the encapsulant’s cross-linking reaction but not enough to damage the cell. This „sweet spot“ is an incredibly narrow window.
At PVTestLab, we engineer multi-stage time-temperature profiles that move beyond a simple „heat and hold“ approach. Through disciplined parameter studies, we map the exact effects of temperature ramps, hold times, and cooling rates on module quality.
Our process data consistently shows that a carefully controlled cycle, often operating below 125°C, achieves full curing while preserving cell efficiency. A successful profile limits the power conversion efficiency (PCE) drop to less than 1% absolute—a result we validate with our AAA Class flasher post-lamination. An aggressive profile might save a few minutes, but it can cause thermal stress that permanently degrades cell performance.
Practical Guideline: A multi-stage profile is non-negotiable for HJT and perovskite. Our research indicates that a profile with an initial low-temperature hold to completely evacuate air, followed by a precise ramp to the target cure temperature, delivers the most reliable results, ensuring both cell integrity and complete encapsulant cross-linking.
Pressure & Vacuum Control—The Mechanical Dimension
Temperature gets most of the attention, but uncontrolled mechanical stress is an equally silent killer of fragile cells. Perovskite cells, in particular, can crack under non-uniform pressure, creating defects that are invisible to the naked eye but catastrophic for long-term reliability.
The key is to apply pressure evenly and precisely. Our industrial laminators are equipped with PIN lift systems that support the entire module surface during the process, preventing the sagging and point-loads that cause microcracks. We use Electroluminescence (EL) testing before and after every trial to validate that our pressure profiles are not inducing new cell damage.
This level of control is about more than just preventing cracks; it’s about ensuring a void-free laminate.
„Perfect vacuum and precise pressure control are what separate a lab prototype from an industrial-grade product. Air bubbles or voids around cells are pathways for moisture and lead to rapid degradation. In a low-temperature process, you don’t have the luxury of high heat to force out imperfections—you have to get the mechanics right from the start.“
— Patrick Thoma, PV Process Specialist
Practical Guideline: Your lamination process must be evaluated for its mechanical impact, not just its thermal profile. Always perform high-resolution EL testing after lamination to ensure your pressure and vacuum settings haven’t created hidden defects that will cause field failures down the line.
From Theory to a Scalable Process
Low-temperature lamination isn’t about finding a single magic number. It’s about an integrated process where encapsulant chemistry, the thermal profile, and mechanical forces are perfectly synchronized. Each element must be tested and validated together, under conditions that mirror your future production line.
Breaking the challenge down into these three core engineering dimensions is how you move from a theoretical solution to a reliable, data-backed process ready for industrial scaling. The path from the lab to the factory is paved with applied research and hands-on prototyping.
Frequently Asked Questions
-
Can’t I just use my standard laminator at a lower temperature?
While possible in theory, standard laminators often lack the precise temperature uniformity and multi-stage profile control needed for these sensitive applications. More importantly, a standard process is designed for standard encapsulants. Using a traditional EVA at a lower temperature will likely result in under-curing, leading to delamination and poor durability. -
What is the real-world impact on module lifetime and bankability?
When engineered correctly, modules laminated at low temperatures with advanced encapsulants can meet and even exceed IEC 61215 and 61730 reliability standards. The key is proving it. Our quality and reliability testing services use climatic simulation and thermal cycling to validate that the chosen process delivers a module that will survive 25+ years in the field. -
How does a longer, low-temperature cycle affect production throughput?
Low-temperature cycles can sometimes be longer than conventional ones. However, this is often offset by a dramatic increase in yield. The cost of a few extra minutes in the laminator is insignificant compared to the cost of scrapping a batch of high-efficiency HJT or perovskite cells due to thermal damage. Our process optimization work focuses on finding the ideal balance between cycle time and yield. -
How can I test my specific cells and encapsulant materials?
The only way to be certain is to test your exact bill of materials on an industrial-scale line. PVTestLab was created for this very purpose. You can rent our entire R&D production line, including our experienced process engineers, to conduct your own lamination trials and gather the data you need to move forward with confidence.
Validate Your Process Before You Scale
The theory is clear, but validation is essential. The next step is to see how your materials and cell designs perform under real industrial conditions. Stop speculating and start measuring.
Contact our engineering team to discuss your project and schedule a prototyping day at PVTestLab.