Capacitive Touch Sensor (Film Type) Production Process

When using photosensitive Ag

Pattern Design / Data Editing

The design data for the ITO pattern and the metal circuit pattern (bezel area) is created using a CAM system. That pattern data is edited and treated for use according to the process and application.

● Setup Station CU-9000

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ITO Film Processing

A transparent electrode film such as ITO is sputtered onto the film at the base of the touch sensor. After then annealing, crystallinity and optical transmittance is increased while sheet resistance is lowered.

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ITO Pattern Formation

An ITO design pattern for sensing the touched coordinates is formed and photoresist is laminated onto the surface of the ITO film.

Direct Exposure

Direct Pattern Exposure

tflow_01.jpgThe ITO design pattern is exposed directly onto the surface of the ITO film laminated with photoresist according to the CAM data, without using a photomask. The exposure data is corrected in real-time in accord with expansion, contraction and distortion of the film.

● Direct Imaging System Ledia

With Photomask

Photomask Creation

tflow_02.jpg The pattern is plotted onto the film or glass to create an exposure photomask.

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Photomask Inspection

tflow_03.jpg Photomask expansion and contraction, and the width of the lines in its circuit pattern, are measured and inspected for defects.

● Automatic Optical Photomask Inspection System​​​​​​​ MI-9700
● Automatic Optical Inspection System​​​​​​​ PI-9400

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Pattern Exposure

tflow_04.jpg The ITO design pattern is exposed through a photomask onto the surface of the ITO film laminated with photoresist.

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Developing, Etching & Stripping After the photoresist is developed, the ITO film is etched with a solution and the unnecessary photoresist is stripped off. tflow_05.jpg
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Metal Circuit Pattern Formation (Bezel Area)

Metal with a lower resistance (photosensitive silver paste) is used to create the metal circuit pattern as the lead wires from the viewer area to the PCB. Using the screen or other printing method, photosensitive silver paste is applied to the metal circuit pattern (bezel area) and then dried.

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Direct Exposure​​​​​​​

Direct Pattern Exposure

tflow_07.jpgThe metal circuit pattern is exposed directly on the surface of the ITO film applied with photosensitive silver paste according to the CAM data, without using a photomask. The exposure data is corrected in real-time in accord with expansion, contraction and distortion of the film.

● Direct Imaging System Ledia

 

With Photomask​​​​​​​

Photomask Creation

The pattern is plotted onto the film or glass to create an exposure photomask.

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Photomask Inspection

Photomask expansion and contraction, and the width of the lines in its circuit pattern, are measured and inspected for defects.
● Automatic Optical Photomask Inspection System​​​​​​​ MI-9700
● Automatic Optical Inspection System​​​​​​​ PI-9400

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Pattern Exposure

The metal circuit pattern is exposed through a photomask onto the surface of the ITO film applied with photosensitive silver paste.

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Developing & Curing

The metal circuit pattern is developed and the ITO film is heated to give it adhesive properties.

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Circuit Pattern Inspection

The metal circuit pattern is inspected for defects and appearance. 
● Automatic Optical Photomask Inspection System:​​​​​​​ MI-9700
● Automatic Optical Inspection System:​​​​​​​ PI series

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Protective Layer Formation / ITO Film Bonding (for GFF)

A protective layer is formed by applying a protective agent or sputtering SiO2. In the case of a GFF structure, the ITO films that form the X-axis and Y-axis electrodes are stacked together.

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Connection to PCB

Connection is made to the printed circuit board and the sensor is complete.