Ledglass

Ledglass is a building material which contains some functional electronics, light-emitting diodes. The LEDGlass and its technology is described in different articles, It allows for example glass facades to be used as marketing area or windshield glasses to be used as display. This is the reason, why LEDGlass (which may also be described as LED Glass or LED embedded Glass) is a member of the so called electronic functional glasses. Historically, the vacuum sputtering of metals and transparent conductive oxides on polymers has allowed the development of transparent conductive materials and transparent conductive glass. The electrical conductivity of these transparent materials has open a wide window of applications using electronic surface mounted devices (SMD) laminated in glass. LEDs and other electronic SMD may be mounted on transparent conductive films, to produce flexible, and ready to laminate films or directly on transparent conductive glass. While highly flexible film subtrates may be transported by fast and low weight air mail, SMD on metallized glass will result in heavy weight products.
Current Materials
Current SMD embedded materials, have been optimised for being transported as rolled materials and to be used in processes like vacuum bagging or autoclaving lamination using PVB, EVA, TPU or Resin at temperatures below 125 °C.
With a current maximum size of 3500 x 1250 mm the transparent metallisation as well as the connection between the films and the SMD/LED elements have to accept rolled packaging, maximum lamination temperatures of 125 °C, and following sheer stress:
a) 10 N measured at an angle of 45 ° at room temperatures
b) 3 N measured at an angle of 45 ° at 125 °C
After lamination the LEDs are fully embedded in PVB/TPU/EVA or in the resin. If at this stage, the glasses are bended, for example while mounting them, the sheer forces will be higher than 10 N and the electrical connections between the SMD / LED and the films might be destroyed. The same problem may occur if resins do shrink more than 3 % while curing.
Transparent conductive films may also be used for heating. Also for this application, bending and high shrinking sould be avoided.
Static electricity
Static electricity can easily discharge (ESD) through SMD elements like sensors or LEDs. Although high voltage (> 10´000 VDC) but micro ampere pulse ESD will not hurt humans, it will damage certain electronic devices. This damage might not appear instantly, but it can build up over time and cause the device to fail. Any time the charge reaches around 10,000 volts, it is likely to discharge to SMD/LED embedded films. As a matter of fact, ESD is the most damaging form of electrical interference associated with SMD electronics. The following are the most common causes of ESD: moving people, clothes rubbing together, low humidity (example: dry conditions in PVB laminating rooms), improper grounding, motors in electrical devices, unshielded cables, poor grounding connections, unrolling or moving PVB/EVA/TPU and moving rolls or plastic elements of machines. ESD generally does not occur when the humidity is above 50%. One additional low cost option for laminating units is the use of antistatic mats made of rubber or other antistatic materials they stand on while working on the equipment.

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