Future demand for silicon wafers in the photovoltaic industry chain:
Wafer slicing can not only effectively reduce the consumption of silicon materials, but also bring more possibilities to the battery and component end due to the flexibility of wafer reflected in wafer slicing. The silicon wafer is separated by the restriction of chip equipment, diamond wire, process, etc., and then the requirements of battery and component technology change. For example, the symmetrical structure, low temperature or stress-free manufacturing process of heterojunction batteries (HIT) can be fully adapted to thinner silicon wafers, and its efficiency is not affected by the thickness, even if reduced to about 100 m, relying on ultra-low surface composite, short-circuit current Isc loss can be compensated by open circuit voltage Voc.
The slicing equipment and cutting process should be required to meet higher requirements for slicing. It is necessary to achieve higher cutting stability under the condition of high wire speed. The cutting fluid system needs better lead-in to play the role of cooling, lubrication and chip removal. Diamond wire requires better grain uniformity and better cutting ability. Other insert machine, cleaning machine, sorting machine also need to be optimized. At the end of the cutting process, the ultra-thin sheet is more likely to show bending, and the edge warping of the feed and draw knife, so it is necessary to have a better matching degree with the equipment and diamond wire at the end of the cutting process.
Wafer becomes larger
The promotion of large-size silicon wafers is mainly reflected in the compatibility of the cutting equipment to large-size silicon rods. The existing diamond wire slicers on the market are not applicable to G12 large-size silicon wafers. In addition, there is a certain opposition between large size and slicing. In slicing, large size silicon wafers put forward higher requirements on slicing machines, diamond wires and cutting technology, which can reduce debris, TTV, line marks, and possible bending and warping of large size wafers
In 2020, with the continuous decline in the cost of silicon materials, the cost of pulling crystals, and the excess capacity of single crystal silicon wafers, the promotion of the standard of single crystal silicon wafers in the industry will also be accelerated. It can be seen in the table that the area of the M2, G1, and M6 square single crystal silicon wafers has increased by 0.56%, 0.85%, and 0.50% respectively compared to the quasi-square single crystal silicon wafers. The biggest advantage of the square single crystal is that it can increase the efficiency of the module, and can also solve the problem of the quasi-square chip forming an irregular shape at the pitch of the half-chip module, making the module more beautiful.