Adhesive tapes for the production of solar modules

CMC Klebetechnik GmbH

Not only the VDMA in Germany with its specialist department "Photovoltaics means of production" but also many other research communities (e.g. Fraunhofer ISE) and associations of undertakings (e.g. BSW-Solar, BSI) are convinced that the return of solar module production is possible. The demand for solar modules in Europe is estimated to be around 100 GWh per year (source: VDMA, Dr. Jutta Trube). Currently, the majority of solar modules required for this are purchased from Asia.

The supply bottlenecks in the coronavirus crisis have shown that Europe has the chance to cover this multi-billion-euro market again with modules produced in this part of the world. Because even without subsidies, the production costs for the solar fields have since fallen so much that a return on investment will be possible within a few years. In addition, other regenerative technologies (e.g. energy storage through hydrogen) will require large volumes of additional electric power. With electricity generation prices under 4 cents/kWh, solar power is also now the cheapest source of electrical power (apart from e.g. hydro power in Norway or geothermal energy in Iceland). Within a few years, it is anticipated that the module price will have fallen again by another 25%, with technology that has been optimised further and will include bifacial modules. Guaranteed terms of more than 25 years facilitate a positive yield over a long period of time.

It is thus not surprising that a rapid expansion of European production capacity is being driven forward with initiatives such as the "Solar Manufacturing Accelerator".

Connection boxes

For the affixation of connection boxes for solar modules, CMC Klebetechnik offers a high-strengthdouble-sided adhesive tape. The acrylate adhesive which is extremely resistant to weather and is available in different material strengths offers long-term adhesion to glass and plastics. It can be pre-installed (e.g. on the base of the housing). When it is processed, the protective paper is peeled off and very good anchoring is achieved by simply pressing it against the surface. No further processing steps are required.

Adhesive tapes for the production of solar modules
Adhesive tapes for the production of solar modules

Frame adhesion

The adhesion of glass modules to the aluminium carrier frames is done with double-sided adhesive tapes. Pure acrylate adhesive tapes from CMC Klebetechnik which are extremely resistant to weather affix and seal at the same time. Capillaries are thus unable to form and moisture cannot penetrate into the modules from the side.

Temporary repairs after hailstorm

Despite improved glass technology, the front glass of solar modules can be damaged during a violent weather event. Breakages or selective shattering of the glass are possible. At these points, moisture and atmospheric oxygen can penetrate into the inner structure of the solar module. The consequences are corrosion on the strip conductors and a degradation of the silicon wafer. Adhesive tapes from ETFE (CMC 77701) can be a temporary solution until the affected modules are replaced during a more major repair. The film is highly transparent for the entire light spectrum up into the UV range, it seals reliably and offers above all long-term weather resistance, thus preventing further destruction of the module. The self-cleaning surface (Teflon®-like) prevents the accumulation of dirt.

Adhesive tapes that are resistant to high temperatures

On places on which soldering or, for instance, resistance welding is done, adhesive tapes from Kapton® film can be used as protection. The polyimide film is thermally stable for a short time above 450°C and thus protects the underlying layers from the effect of heat. Kapton® films are used worldwide in the production of electronics thanks to their dimensional stability during the soldering process.

However, Kapton® adhesive tapes can also be used as a frame adhesive tape in the autoclave process. They stabilise and seal the layer structure of the solar modules during the production process and protect the sensitive edges. The high heat stability of the Kapton film means that the pre-assembled modules are easily vented and bonded in the autoclave process.

Head of Application Management

Gerald Friederici

If you have any questions, please contact:

Gerald Friederici

Tel.: +49 6233 872 356

E-Mail: friederici (at) cmc.de