3D-Micromac AG, the industry leader in laser micromachining, is going to introduce the brand-new microDICE OTF system at SNEC 2015. The system uses Thermal-Laser-Separation for cutting of cells into half cells. By using half cell technology the average module power yield can be increased significantly.
Cell separation has become industrial relevant due to the introduction of half-cell modules concepts, which allow a substantial power gain. The standard industrial process of p-type cells is based on a laser scribing and subsequently mechanical cleaving. The disadvantages of this process are the reduction of the cell efficiency, the reduced mechanical strength and the expensive handling due to the combination of a laser process with a subsequent cleaving.
3D-Micromac has overcome these weaknesses with the brand-new microDICE OTF using Thermal-Laser-Separation for splitting PV cells into half cells. The separated cells show a significantly higher mechanical strength, better edge quality as well as a lower power reduction compared to laser scribing and cleaving approaches.
The highly-productive system microDICE OTF achieves a throughput of 3,600 cells per hour of incoming full cells. The optical set-up relies on the industry-proven on-the-fly technology successfully used at 3D-Micromac’s laser structuring tools for processing of PERC cells. It guarantees highest productivity and an outstanding price-performance ratio. The laser processing is realized during the continuous transport of the cells under the laser source, whereby the relative motion of the cells is automatically compensated for. Stops for the positioning of the individual cells are completely eliminated. The continual movement of the conveyor belt results in an almost 100-percent capacity utilization of the laser source. The microDICE OTF is a fully automatic 24/7 production solution and can be offered as stand-alone or inline system.
Background information on Thermal-Laser-Separation
Thermal-Laser-Separation (TLS) is used in the semiconductor industry's back-end to separate semiconductor wafer in components. The process is based on thermal induced mechanical stress, generated by a well-adjusted combination of a laser heating and cooling.
The method is suitable for most brittle materials in the semiconductor industry, including Si, SiC, Ge and GaAs wafers. Compared to traditional separation technologies, TLS impresses with clean, micro-crack-free edges and greater resulting bending strength. The complete cleaving is a one pass process with a speed of up to 300 mm/s. The relatively low temperature (no material is ablated or melted) in combination with the high cleaving speed are the reason that the electrical properties are not influenced by the separation step. Furthermore, the high throughput and wear-free processing offer great potential for reducing production costs and cost of ownership.