Two Variables behind the Market Prosperity of Touch Sensor

In addition to out-cell projected capacitive sensor, embedded on-cell touch panel will gain benefits from Samsung’s introduction strategy in series of Galaxy flagship cellphone; in-cell touch panel be promoted by the attractive Apple iPhone. Overall, despite the increasingly expanded touch sensor market, there is experiencing two significant changes since 2012: one is the evolution of sensor structure; second is the new-generation ITO alterative material. 

 

Currently, transparent electrode material used in projected capacitive sensor mainly focus on ITO (indium tin oxide); and sensor substrate include glass and film. On the basis of a pair of XY transparent electrode designs in projected capacitive, there needs more than one layer of substrate. However, to make thinner, low-cost sensor to suit terminal products, sensor structure has always been in evolution, which also affects the supply chain of upstream material. Furthermore, panel manufacturers are attempting to enter touch industry via in-cell and on-cell integrated embedded sensor panel.

 

The largest application end products of touch sensor are mobile computing devices, especially smartphone and Tablet PC, and notebook is set to be the next important devices. Although these devices tend to use touch interface, the ecological characteristics of various industries cause the change in upstream touch panel suppliers. For instance, regional, multi-brand, differentiated factor of smartphone leads to growth space for different sensor structures; but notebook shows much converged ecosystem; along with high Windows 8 threshold specification and sensor cost, currently, monolithic structure (OGS) represent 90% shares and vendors with production capacity is few.

 

From smartphone, tablets to notebook, touch sensor growingly increases square, and challenges line material. For instance, for over 10-inch notebook, even 20-inch all-in-one PC, ITO material based sensor should lower its sheet resistance as much as possible, or power consumption, flexibility will be problems. But corresponding ITO film sensor supply is relatively tight, resulting in market traction of new-generation ITO alternative material since 2013.

 

The major problem for ITO’s application in touch sensing circuit is its process and brittle properties. A lot of new-generation materials are available to supply chain to replace ITO and as new generation of transparent electrode material, which not only can be adopted in display, but also in solar energy, printed circuit boards. At present, metal mesh and sliver nanowires are the two major sensor line materials by touch screen manufacturers. New-generation ITO alternative material surpasses ITO in optical transmittance and conductivity specifications; its coating process and institutional characteristics are also key concerns. Most replaced material has already discarded sputtering process but use wet coating to support softness, surface induction line and substrate.

 

In addition to specification (the basic requirement), the maturity of process and supply chain is the key. On supply chain side, raw material, coating and pattern etching processes all get the recognition and import of touch module manufacturers; only terminal application sees obvious value, relative high cost is acceptable. And cost usually drops with mass production capacity, maturity. The majority of these new materials can achieve a lower resistance value, therefore generate significant value to 10-inch above application. If starting from large size and moving to mall and medium size step by step, the first beneficial are ITO material, ITO film and sputtering equipment suppliers. If material manufacturers directly integrate coating and pattern etches process, what will leave to touch module vendors is only the fitting business which is in its infancy, but still implies change to future supply chain.