* Corresponding author: Tel.: #31-224-564949; fax: #31-224-564480. E-mail address: burgers@ecn.nl (A.R. Burgers). Solar Energy Materials & Solar Cells 65 (2001) 347}353 Metallisation patterns for interconnection through holes A.R. Burgers*, J.H. Bultman, A.C. Tip, W.C. Sinke Netherlands Energy Research Foundation ECN, PO Box 1, NL-1755 ZG Petten, Netherlands Abstract ECN has developed a new cell- and module-design for crystalline silicon solar cells called pin-up module (PUM). In this design a limited number of holes (typically 9 or 16) is used to interconnect the front-side metallisation to a foil at the rear side by using pins. In this way the busbars and tabs at the front side are eliminated resulting in several important bene"ts. The e$ciency of the cell becomes independent of the cell area and the e$ciency is higher compared to standard tabbed cells. Another bene"t is the improved visual appearance. In this paper we discuss the design of the metallisation pattern for the cells. A theoretical analysis is presented that shows the gains of the PUM design over conventional cells.  2001 Elsevier Science B.V. All rights reserved. Keywords: Crystalline silicon; Solar cells; Interconnection; Metallisation pattern; PUM 1. Introduction In PV manufacturing, the trends are towards thinner and larger wafers. One limiting factor is that the current has to be transported to the edge of the cell using tabs. As the cells grow larger this gives rise to increasing series resistance losses. Another problem is that for a widening range of applications tabs on crystalline silicon solar cells are considered visually displeasing. The solution we propose is a cell design based on an old patent [1,2] with a limited number of holes through which we interconnect the front-side metallisation to a foil at the rear side by using pins. We call this new design PUM (pin-up module). The 0927-0248/01/$ - see front matter  2001 Elsevier Science B.V. All rights reserved. PII: S 0 9 2 7 - 0 2 4 8 ( 0 0 ) 0 0 1 1 2 - 4