Meyer Burger is a leading global technology company where discovering the unexplored, developing new technologies and improving tried and tested products and processes are the drivers of our customer-focused culture of innovation. Here you will find a selection of technical white papers which provide you in-depth insight into our solutions and technologies.

Automation in PV Manufacturing

The ultimate goal of PV manufacturing is to produce the highest quality of solar cells at the lowest possible cost. Translated into manufacturing requirements, this means that throughput, equipment uptime and yield must be continuously increased in a manufacturing environment while improvements and subsequent generations of products are implemented in parallel.

Automation is a key element in understanding the relevant process behavior, monitoring and controlling the process windows, ensuring stable processes, achieving the necessary product quality at all times, guaranteeing error-free production and promptly detecting any anomalies. Collecting and evaluating all of the applicable data, and controlling equipment performance with a high degree of complexity, rank among the challenges of automation.

The general objective of automation is to move the right material at the right time to the right place and process it correctly – while controlling all of these steps in real time. The ability to do this in a reliable, predictable and flexible manner has a direct impact on factory performance.

In this paper, the main components of automation will be described, and some ROI examples will be discussed for a PV manufacturing line.

Technological developments in module production

In solar module manufacturing, three main processes can be distinguished: cell connection, lamination and testing/sorting. Each of these processes has a major impact on cell efficiency, solar module lifetime and module manufacturer turnover. It is therefore of the utmost importance that all the processes are correct, to get the most out of the cells and guarantee 20–30 years’ lifetime.

This paper describes novel technologies that are used in the module manufacturing process to ensure maximum module efficiency (electrical connection: Soft Touch and SmartWire Connection Technology) and lifetime (cross-linking density: non-disruptive X Link measuring method) as well as module manufacturer turnover (module testing: DragonBack® for high-capacitance solar technologies). All these technologies are ready for the highest efficiency c-Si cells (> 21% cell efficiency).

Meyer Burger‘s heterojunction cell technology

The price of crystalline silicon feedstock has fallen significantly, which means thin-film PV must struggle even harder to increase its market share. Since all the other costs of a PV installation, such as the material for module production and system mounting and the installation expense, are constant or rising, energy harvest per area must be increased through the introduction of affordable, high-efficiency solar cell technology.

Conventional PV solar cells using p-type multicrystalline or monocrystalline silicon wafers have already reached efficiency limits which cannot be exceeded by cheap improvements in production: a technology shift is therefore necessary.

In view of the high-efficiency PV solar cells that have already been commercialized, the most promising technology for mass production with a minimum number of process steps is the p-type a Si:H/n-type c-Si heterojunction cell pioneered by Sanyo’s heterojunction with intrinsic thin layer (HIT) technology. Testing of these cells requires longer pulse durations combined with uniformity and pulse stability. As throughput rates on cell lines continue to grow, a demand for measurement methods to support the higher speeds is created.

Effective quality sorting of crystalline wafers

Improvements in quality and efficiency as well as in cell-line yield rely on the in-line measurement of critical parameters. Physical metrics – such as cracks, chips and thickness – as well as electrical resistivity are common criteria for the sorting of under-performing wafers.

A new method of in-line photoluminescence (PL) imaging enables wafer performance to be assessed in an early production step by measuring crystal defects and impurities, which are key parameters in determining the achievable cell efficiency.