Nowadays, for generating electricity solar modules are used more often than a few years ago. In this work, the electrical connections between solar cells (made from crystalline silicium) are investigated. Normally, these connections are soldered or sticked, but very thin solar cells have problems with that. Because of intensive temperature changings and different coefficients of thermal expansion of the involved materials, very often breaks in the cells can appear. Therefore, in this work a new method is observed: The permanent electrical connection is achieved just by pressure. In detail, the following themes are examined: - Pressure measurements The production of solar modules has many steps with different complexity and costs. Here, the contact strips are looked at in detail, which connect the solar cells in the solar module. Nowadays, these contact strips are soldered by the producers to build up the electrical connection. In this work, it is proved, that the expensive soldering could be replaced just by pressing contacts. Maybe the usually (in the production) used contact pressure is enough for this purpose. In this method, the solar cells overlap and therefore mechanical stresses could destroy them. A test set-up is constructed to investigate the various aspects of pressure on overlapped solar cells. The deformed solar cells were also modelled theoretically to obtain the actual pressure on the contact strips between the cells. - Profiles of height A functioning minimodule is build with the overlapped solar cells. It was laminated (without backsheet) at a pressure of 800mbar. The backside of the module was then scanned with a height-profiler to find out the deformation of the solar cells. - Measurements of contact resistance If there is a change to a solder-free connection method, the contact resistance must not be much higher. Otherwise, too much of the produced power is dissipated in this area because there are many solder joints in a common solar module. - Potential Induced Degradation - PID Since a few years, many operators of photovoltaic power plants noticed a decreasing power after some months or years of operation time. This effect preferable acts at modules which are in the negative range of the electrical potential spectrum. In this work, PID is investigated theoretically and independent of the experimental researches.