THE IMPORTANCE OF PASTE RHEOLOGY IN （糊流变学的重要性）.pdf

THE IMPORTANCE OF PASTE RHEOLOGY IN IMPROVING FINE LINE, THICK FILM SCREEN PRINTING OF FRONT SIDE METALLIZATION Jaap Hoornstra, Arthur W. Weeber, Hugo H.C. de Moor, Wim C. Sinke Netherlands Energy Research Foundation - ECN, PO Box 1, NL-1755 ZG Petten P(+31)-224-564697, F(+31)-224-563214, hoornstra@ecn.nl ABSTRACT: An important requirement in the processing of front side metallization for solar cells is to print fine lines with a high aspect ratio in mass production. Rheology is a key feature to describe the paste printing behaviour, but it is difficult to both characterize the aspects of easy printing and non-slumping using basic rotation viscometry. In this work a new approach is applied, using oscillation rheometry, to simulate the paste behaviour during printing in a single experiment. Time tests are performed on seven commercially available silver pastes, and are interpreted in terms of easy printing, slumping, etc. The results of screen printing tests on the seven pastes confirm the interpretation of the measured complex shear modulus and loss angle. Keywords: Metallization - 1: Experimental methods - 2: Manufacturing and processing - 3 1. INTRODUCTION is to find a rheometrical procedure to simulate the behaviour of the paste during printing. Several Metallization is an efficiency limiting step in solar cell commercially available silver pastes were subjected to processing. For multi-crystalline solar cells an optimal screen printing and rheometrical tests and the printing front side metallization consists of multi