DATA MODUL Press Release

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DATA MODUL Press Release

PCAP touch screens have conquered the medical industry

29 November 2023


Thanks to developments in gloved operation or operating through liquids as well as the optimization of touch screens through optical bonding, increasing numbers of PCAP touch monitors are being used at PoC and in other medical areas. However, it is rare to see manufacturers offering TFT displays bonded with a touch screen unit. For this reason, DATA MODUL established and improved in-house expertise in optical bonding since 2011.

Bonding means the connection of device components using an optical, transparent adhesive – the refractive index of which must match that of the media to be bonded. A distinction is made here between the bonding of cover glass and PCAP Touch, cover glass, and TFT. Bonding minimizes distracting reflections, does not dampen the capacitive touch field, and achieves user stability against interference factors. In addition it is not possible that dust enter in between the PCAP sensor and the glass. Due to the increasing demand for medical PCAP solutions with customer-specific glass surfaces, DATA MODUL is constantly expanding the range and optimizing quality standards. All over Europe, only DATA MODUL currently offers the in-house availability of all common bonding technologies. They anticipate that the demand for individual and standardized optimization projects will continue and increase. Fundamentally, the current bonding technologies such as AirGap, LOCA, OCA, gel, and the new hybrid bonding provide the best possible optimization solutions for all display and touch variants available on the market:

LOCA (liquid optical clear adhesive)

This liquid glue method is flexible and can be used at all display sizes. It is suited to hard-to-hard bonding and cured via UV light. The LOCA adhesive is used for bonding cover glass to glass-based touch sensors (SITO) and industrial TFT displays with metal frames (bezels) to a cover glass (with or without touch).

OCA (optical clear adhesive)

Dry bonding or OCA roll lamination applies a touch sensor film to the cover glass (hard-to-soft). The top OCA of the touch sensor is used here, so that no additional bonding glue is required. Major advantage of OCA bonding is that projects can be completed quickly and cost-effectively.


This method was used for resistive touch sensors and is the forerunner of bonding technology. In contrast to full-surface bonding with liquid glue (LOCA), in AirGap bonding, a double-sided adhesive tape is applied around the TFT frame, which bonds the TFT and the touch or glass to one another. An air gap is maintained between the two components in the process.


This method is used in processing frameless displays. Gel pads are tailored to the size of the display surface and bond the glass or touch sensors to the TFT. This would not be possible in liquid bonding procedures (LOCA). Diagonals from 1.3” to 14” and mobile applications with round memory-in-pixel (MIP) displays can also be realized.


DATA MODUL is one of a few companies to provide this new process that has been further developed from LOCA and OCA processes. This process bonds and glues touch, glass and display (hard-to-hard) fully automatically. This method is particularly suitable for high-volume projects with special requirements, like the manufacturing of medical devices for example.

Gap filling

After the assembly of a PCAP touch monitor / HMI / embedded display in a housing there is always a gap between the screen and the housing frame which cannot be avoided when the product is being manufactured. Particularly in the development of medical products, there are high hygiene requirements. One example is that gaps on devices must be avoided. Through gap filling, gaps are filled with a special glue and can so be sealed securely. This stops impurities or liquids from entering or getting stuck in there. At DATA MODUL, a pick & place machine carries out the gap filling under cleanroom conditions. The special adhesive is suitable for temperatures from -40 to 100°C and covers all requirements for medical devices.


DATA MODUL AG with its 23 offices worldwide is one of the leading specialist suppliers of display, touch, embedded, monitor and panel PC solutions for professional applications. Based on its extensive display portfolio, DATA MODUL has established itself over the course of 45 years as an industry display technology partner and European market leader in the field of display distribution. DATA MODUL focuses on the development of its own products, customer-specific solutions and is constantly extending its value-added services for a wide range of sectors.