Pulvérisation de billes calibrées.
To ensure the uniform spacing of the two glass plates of an LCD display, spacers are used. Previously, spherical spacers have been sprayed onto one of the two glass plates, prior to the assembly of the LCD display. Today in most cases, so called litho-spacer are used - the spacers are defined by a lithographic processes and formed by deposition and etching technologies. The new process is particularly suitable for mass production of high-resolution displays. However, there are still some LCD applications, where high resolution is not required and the costs of the new litho-spacer are simply too high. Therefore, the conventional spacer spray process is still justified, even though nowadays it is hard to find a manufacturer for the corresponding spacer spray systems. Our former partner for spacer spray machines SE (Shibuya Electric) has stopped production as well as company of Nishin, formerly the largest manufacturer of dry spacer spray machines. Crystec can still assist you to find appropriate equipment.
Special spacers, consisting of glass or plastic are sprayed on the lower glass plate of a display, in order to ensure the equal distance of the two glass plates over the hole LCD area. Spacer cluster formation needs to be avoided, because spacer clusters could be disturbingly visible in the display.
|Spacer Spray Machine|
|Spacer in LCD|
There are three different methods to spray spacers on the glass plate: Solvent can be used in order to assist the spraying process, spacer spraying can be performed completely dry and you can use a semi-dry process. All three methods have certain advantages and disadvantages.
The heart of the machine is the spray chamber with the spacer spray head.
|Spacer Sprayer Shindo|
Spacer Spray Equipment is available as a stand alone tool as well as integrated, in-line equipment. For mass production spacer sprayers are combined with cleaning equipment and other process tools in a production line.
A quality check unit for the spacer spray process can be also included in an automatic machine. In this case a spacer counter is implemented. On the following picture you can see this type of wafer counter.
The distribution of the spacers on the glass plate needs to be very homogeneous in order to get high quality displays and spacer clusters are not allowed.