The Resonance Ultrasonic Vibrations (RUV) technology was developed and deployed for off-line and in-line non-destructive crack detection in full-size silicon solar cells. The RUV method relies on deviation of the resonance frequency response curve measured on a cell with peripheral or bulk millimeter-length crack and on identical non-cracked (reference) cells.
The RUV technology allows: (1) rejection of mechanically unstable bare Si wafers before they are introduced into further processing, (2) identification of wafers with mechanical flaws (such as cracks) during production to avoid their in-line breakage and throughput reduction, (3) detection of cracked solar cells before they will be assembled into solar modules to avoid efficiency reduction and product return from the field, and (4) identify solar cells with sub-millimeter size cracks using optional Activation Station plug-in. RUV system also serves as a process control tool to increase yield by eliminating production flaws caused by mechanical defects.
Adjustable to Customer Needs
The sensitivity of RUV systems, which refers to the length of cracks, is adjustable to the needs of the user. The rejecting method is based on a statistical approach. In case studies the accuracy of this method was between 91 - 95%. In production tests, the breakage caused by cracked cells after RUV inspection is reduced below 0.1%. RUV tools are designed to satisfy various customer’s needs and demands. Our application group will perform on-site inspection of your products and provide practical recommendations.
In Line & Offline Configurations
In-line and off-line RUV systems are readily available and can be customized to address specific features. Please Contact Ultrasonic Technologies for more information or to discuss your particular needs.