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Publication Date: 2013-Apr-25

Publishing Venue

The Prior Art Database


An apparatus for printing screen printing material (M) on a substrate (21) is provided. The apparatus includes at least one printing tool (22). The at least one confining element (30) is positioned on at least one side of the printing tool (22). The at least one confining element (30) typically includes at least one confining plate (130).

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Embodiments of the present disclosure relate to an apparatus for printing on a

5 substrate, such can be used, for example, for screen printing in the production of solar cells.


Solar cells are photovoltaic (PV) devices that convert sunlight directly into

10 electrical power. The PV market is growing rapidly and constantly and this, combined with the need to substantially reduce the costs of electricity produced from solar energy, has stimulated research into innovative solutions for manufacturing high-quality solar cells at low cost. Therefore, one major component in making commercially viable solar cells for obtaining electric

15 energy lies in reducing the manufacturing costs required to form the solar cells. This can be done by improving the yield and increasing the substrate throughput.

  Solar cells commonly include silicon semiconductor substrates, which may be single or multicrystalline silicon substrates.

Solar cells typically have one or more p-n junctions. Each p-n junction

20 comprises two different regions within a semiconductor material where one side is denoted as the p-type region and the other as the n-type region. When the p-n junction of a solar cell is exposed to sunlight, the sunlight is directly converted to electricity through the PV effect. Solar cells generate a specific amount of electric power and are tiled into solar modules sized to deliver the desired amount of

25 system power. Solar modules are joined into panels with specific frames and

  Generally, a standard silicon solar cell is fabricated on a wafer which includes a p-type base region, an n-type emitter region, and a p-n junction region disposed therebetween. An n-type region, or n-type semiconductor, is formed by doping

30 the semiconductor with certain types of elements (e.g. phosphorous (P), arsenic (As) or antimony (Sb)), in order to increase the number of negative charge carriers, i.e. electrons. Similarly, a p-type region, or p-type semiconductor, is formed by the addition of trivalent atoms to the crystal lattice, resulting in a

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missing electron from one of the four covalent bonds normal for the silicon lattice. Thus the dopant atom can accept an electron from a neighboring atoms covalent bond to complete the fourth bond. The dopant atom accepts an electron, causing the loss of half of one bond from the neighboring atom and resulting in

5 the formation of a "hole".
When light falls on the solar cell, energy from the incident photons generates electron-hole pairs on both sides of the p-n junction region. Electrons diffuse across the p-n junction to a lower energy level, and holes diffuse in the opposite direction, creating a negative charge on the emitter and a corresponding positive

10 charge builds up in the base. When an electrical circuit is made between the emitter and the base and the p-n junction is exposed to c...