Touch screen panel including multilayer connection wire and method of manufacturing the same

A touch screen panel includes a substrate, a sensing electrode, a connection wire, and a passivation layer. The substrate includes a first area and a second area disposed outside the first area. The sensing electrode is disposed in the first area. The connection wire is electrically connected to the sensing electrode, the connection wire being disposed in the second area. The passivation layer covers portions of the sensing electrode and the connection wire. The sensing electrode includes a first conductive layer disposed on the substrate. The connection wire includes a second conductive layer disposed on the substrate, a metal wiring layer disposed on the second conductive layer, and a capping layer disposed on the second conductive layer.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority from and the benefit of Korean Patent Application No. 10-2015-0053225, filed on Apr. 15, 2015, which is incorporated by reference for all purposes as if fully set forth herein.

BACKGROUND

Field

Exemplary embodiments relate to a touch screen panel and a method of manufacturing the same. More particularly, exemplary embodiments relate to a touch screen panel with improved wiring reliability, and a method of manufacturing the same.

Discussion

A touch screen panel is an input device allowing content displayed via a screen of a display device, or the like, to be selected (or otherwise interacted with) using an input device, such as a finger or hand of a user or an object, e.g., a stylus, etc. In this manner, the user may issue commands via touch or near touch interactions. To this end, such touch screen panels may be utilized to replace other input devices typically connected to a display device, such as a keyboard, a mouse, a trackpad, etc.

Conventional touch screen panels may be categorized based on touch detection schemes, such as, for example, a resistive scheme, a photo-sensing scheme, and a capacitive scheme. The capacitive scheme may be further classified into a self-capacitance scheme and a mutual capacitance scheme. The self-capacitance scheme may facilitate hovering (or near-touch) interactions, as well as multi-touch interactions. A typical self-capacitance type touch screen panel may include a plurality of conductive sensing electrodes spaced apart from one another and formed on a first surface of a substrate. In this manner, each of the plurality of conductive sensing electrodes may correspond to unique position information. Accordingly, when a user's hand or other touch object comes into contact (or near-contact) with the self-capacitance type touch screen panel, a change in capacitance associated with the conductive sensing electrodes may be detected, which may be further utilized to determine a position of interaction. In addition, conventional self-capacitance type touch screen panels may include a plurality of electrode wirings respectively connected to the plurality of conductive sensing electrodes. The plurality of electrode wirings may be arranged between adjacent conductive sensing electrodes.

Typically, the conductive sensing electrodes are formed by applying a hybrid film of a conductive material (e.g., a silver nanowire (AgNW) material) or a conductive transparent oxide (e.g., indium tin oxide (ITO)). To this end, a pad part and a wiring part, such as fan-out part, of the electrode wirings may include copper (Cu) at least because of its selectivity with AgNW and ITO and other processing characteristics. After metal wirings and bridges are formed with a metal, such as copper (Cu), a passivation layer is typically formed on the metal wirings and/or bridges to prevent (or at least reduce) corrosion. For instance, the pad part and the fan-out part may include an inorganic passivation film (e.g., SixNy) for passivation. Further, zinc indium oxide (ZIO) may be applied as a capping layer of the pad part.

It is noted, however, that the inorganic passivation layer and the capping layer are usually deposited at relatively low temperatures when plastic substrates are utilized with the touch screen panels. As such, the inorganic passivation layer and the capping layer may not be suitable in relatively high temperature conditions. Also, corrosion of the Cu in the pad part and the fan-out part may still occur. Moreover, because ZIO and SixNyhave increasing moisture permeability as tissue density is lowered with lower deposition temperatures, the thickness of the capping layer and the passivation layer may be increased to improve their protective features. It is noted, however, that increasing thickness may increase stress, which may cause, at least in part, cracks to form in a lower substrate or hamper bending characteristics of such touch screen panels. Therefore, there is a need for an approach that provides efficient, cost effective techniques to improve the protection and passivation structures in touch screen panels.

SUMMARY

Exemplary embodiments provide a touch screen panel with improved wiring reliability.

Exemplary embodiments provide a method of manufacturing a touch screen panel with improved wiring reliability.

According to one or more exemplary embodiments, a touch screen panel includes a substrate, a sensing electrode, a connection wire, and a passivation layer. The substrate includes a first area and a second area disposed outside the first area. The sensing electrode is disposed in the first area. The connection wire is electrically connected to the sensing electrode, the connection wire being disposed in the second area. The passivation layer covers portions of the sensing electrode and the connection wire. The sensing electrode includes a first conductive layer disposed on the substrate. The connection wire includes a second conductive layer disposed on the substrate, a metal wiring layer disposed on the second conductive layer, and a capping layer disposed on the second conductive layer.

According to one or more exemplary embodiments, a method of manufacturing a touch screen panel includes: forming a conductive layer on a substrate, the substrate including a first area and a second area disposed outside the first area; patterning the conductive layer to form a sensing electrode in the first area and a connection wire in the second area; depositing a first metal layer on the connection wire; depositing a second metal layer on the connection wire; patterning, simultaneously, the first metal layer and the second metal layer to form a metal wiring layer and a capping layer; and forming a passivation layer on the substrate. The first area is associated with touch interaction detection.

According to one or more exemplary embodiments, the touch screen panel may increase the reliability of metal wirings in a relatively high temperature and/or relatively high humidity environment, including during manufacturing conditions. To this end, the reliability of the metal wirings may be improved, without affecting a patterning layout, via the application of the capping layer and the passivation layer. Further, due to a difference in etching rates between the metal wiring layer and the capping layer, a T-shaped stacking structure may be formed to not only allow for step coverage, but also lateral passivation.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

FIG. 1is a plan view of a touch screen panel, according to one or more exemplary embodiments.FIGS. 2, 3, and 4are respective cross-sectional views of a sensing electrode, a fan-out part, and a pad part of the touch screen panel ofFIG. 1correspondingly taken along sectional lines II-II′, III-III′, IV-IV′, according to one or more exemplary embodiments.FIGS. 5A, 5B, 5C, and 5Dare respective views of a touch screen panel at various stages of manufacture, according to one or more exemplary embodiments.

Although various exemplary embodiments are described with respect to a touch screen panel associated with an organic light emitting display device, it is contemplated that various exemplary embodiments are also applicable to touch screen panels associated with other display devices, such as, for example, liquid crystal display devices, plasma display devices, field emission display devices, electrophoretic display devices, electrowetting display devices, and the like.

Referring toFIGS. 1-4, 5A, 5B, 5C, and 5D, a touch screen panel may include a substrate100, a sensing electrode unit200, and a connection wiring unit300electrically connected to the sensing electrode unit200. The substrate100may include an active area AA and an adjacent area (e.g., a non-active area) NA disposed outside the active area AA. The connection wiring unit300may include a fan-out part310and a pad part320.

As previously mentioned, the substrate100may be divided into the active area AA and the non-active area NA disposed outside the active area AA. The active area AA may be an area configured to detect touch (or near-touch) interactions and positions. It is noted that the active area AA may overlap a display area (not shown) configured to display an image in association with a display device, such as an organic light emitting display device. As such, the active area AA may overlap pixels of a display panel (not shown) disposed below the touch screen panel, e.g., below substrate100. It is contemplated, however, that the display panel may be disposed above the touch screen panel or may include the touch screen panel. Further, the non-active area NA may be disposed outside the display area in an area that an image is either not displayed or not perceivable to an onlooker. The sensing electrode unit200may be positioned in the active area AA. The connection wiring unit300including a fan-out part310and a pad part320may be positioned in the non-active area NA.

According to one or more exemplary embodiments, the substrate100may be formed from any suitable material, such as, for example, one or more materials with relatively high heat resistance and relatively high chemical resistance. It is also contemplated that the substrate100may be a flexible substrate, e.g., configured to undergo flexing interactions (e.g., bending, twisting, folding, rolling, etc.) without failure, such as without plastic deformation. For example, the substrate100may be a thin film substrate formed of one or more materials selected from the group consisting of polyethyleneterephthalate (PET), polycarbonate (PC), acryl, polymethylmethacryate (PMMA), triacetylcellulose (TAC), polyethersolfone (PES), and polyimide (PI). In addition, non-tempered glass or tempered glass may also be utilized as a material of the substrate100.

The sensing electrode unit200includes a plurality of conductive patterns (or sensing electrodes) for sensing a touch interaction (e.g., touch or near-touch input). The conductive patterns may be evenly distributed in the active area AA. It is contemplated, however, that any other suitable configuration of the conductive patterns may be utilized in association with exemplary embodiments described herein.

According to one or more exemplary embodiments, the touch screen panel may be a self-capacitance type touch screen panel including a structure in which the sensing electrode units200and connection wiring units300electrically connected to the sensing electrode units200are connected in one-to-one correspondence. The connection wiring unit300extends to the fan-out part310and the pad part320of the non-active area NA by way of the active area AA.

As seen inFIG. 1, the sensing electrode units200are formed as quadrangular patterns in a lattice structure, but exemplary embodiments are not limited thereto. For instance, the sensing electrode units200may be configured in any suitable manner, such as having a polygonal shape, e.g., a diamond shape, a triangular shape, a hexagonal shape, etc., a circular shape, an oval shape, or any other shape. Moreover, although the sensing electrode units200and the connection wiring units300are shown connected in one-to-one correspondence, the sensing electrode units200may each have a structure including first sensing electrode units arranged in a first direction, second sensing electrode units arranged in a second direction intersecting the first direction, first bridge patterns connecting adjacent ones of the first sensing electrode units, and second bridge patterns connected adjacent ones of the second sensing electrode units.

The connection wiring units300may be formed of the same material and on (or in) the same layer as that of the sensing electrode units200. It is also contemplated that the connection wiring units300and the sensing electrode units200may be formed of different materials and on (or in) different layers. A line width of the connection wiring units300may be relatively narrow to increase line density, as well as improve other performance metrics of the touch screen panel. For instance, the line width of the connection wiring units300may be in a range from a few micrometers to tens of micrometers. It is contemplated, however, that any other suitable line width may be utilized in association with exemplary embodiments described herein.

As illustrated inFIGS. 2, 5A, and 5B, a conductive layer11is formed on the substrate100, and a conductive transparent oxide layer12is formed on the conductive layer11and patterned via wet etching and/or dry etching to form the sensing electrode unit200. To this end, a passivation layer20may be formed on the sensing electrode unit200. It is noted that a metal nanowire may be used in the conductive layer11, which may be formed of silver nanowire (AgNW). It is contemplated, however, that any other suitable material may be utilized. The conductive layer11may be formed with any suitable shape and thickness. Further, indium tin oxide (ITO) may be used to form the conductive transparent oxide layer12. It is contemplated, however, that any other suitable conductive transparent oxide may be utilized, such as, for example, aluminum zinc oxide (AZO), gallium zinc oxide (GZO), indium zinc oxide (IZO), etc. It is also contemplated that one or more conductive polymers (ICP) may be utilized, such as, for example, polyaniline (PANI), poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS), etc. As with the conductive layer11, the conductive transparent oxide layer12may be formed with any suitable shape and thickness. The passivation layer20may be an organic passivation layer20formed of any suitable organic material.

With reference toFIGS. 3, 5A, 5B, and 5C, in the fan-out part310forming a portion of the connection wiring unit300, a conductive layer11is formed on the substrate, a conductive transparent oxide layer12is formed on the conductive layer11, a metal for a metal wiring layer13and a metal for a capping layer14are sequentially formed on the conductive transparent oxide layer12and collectively patterned via wet etching and/or dry etching. The conductive layer11and the conductive transparent oxide layer12may be the same as conductive layer11and conductive transparent oxide layer12described in association with the sensing electrode units200. At least one of copper, aluminum, and silver, or alloys thereof may be used in the metal wiring layer13formed on the conductive transparent oxide layer12. Further, one or more of titanium (Ti), molybdenum (Mo), nickel (Ni), chromium (Cr), and tungsten (W), or alloys thereof may be used in the capping layer14formed on the metal wiring layer13. It is contemplated, however, that any suitable metal (or conductive polymer) may be utilized to form the metal wiring layer13and the capping layer14. A thickness of the capping layer14may be greater than or equal to 100 Å.

According to one or more exemplary embodiments, the metal wiring layer13and the capping layer14are formed of different materials. In this manner, a T-shaped stacking structure may be generated due to a difference in etching rates of the metal wiring layer13and the capping layer14, which allows for step coverage via the application of the passivation layer20, such as an organic passivation layer, which is formed after the patterning of the metal wiring layer13and the capping layer14. To this end, the stack structure in combination with the passivation layer20also enables lateral passivation and preventing (or otherwise reducing) lateral corrosion of the metal wiring layer13and the capping layer14.

Turning toFIGS. 4, 5A, 5B, 5C, and 5C, in the pad part320forming a portion of the connection wiring unit300, a conductive layer11is formed on the substrate100, a conductive transparent oxide layer12is formed on the conductive layer11, and a metal for a metal wiring layer13and a metal for a capping layer14are sequentially formed on the conductive transparent oxide layer12. The metal wiring layer13and the capping layer14are collectively patterned through wet etching and/or dry etching to form a metal wiring layer13and a capping layer14. It is noted that the conductive layer11and the conductive transparent oxide layer12may be the same as the conductive layer11and the conductive transparent oxide layer12described in association with the sensing electrode unit200. To this end, the metal wiring layer13and the capping layer14may be the same as the metal wiring layer13and the capping layer14described in association with the fan-out part310.

As illustrated inFIG. 5C, a passivation layer20is formed to cover all the layers on the substrate on which the sensing electrode unit200, the fan-out part310, and the pad part320have been formed. Like the fan-out part310, the T-shaped stacking structure formed in the pad part320may be generated due to a difference in etching rates of the metal wiring layer13and the capping layer14, which allows for step coverage via the application of the passivation layer20, such as an organic passivation layer, which is formed after the patterning of the metal wiring layer13and the capping layer14. To this end, the stack structure in combination with the passivation layer20also enables lateral passivation and preventing (or otherwise reducing) lateral corrosion of the metal wiring layer13and the capping layer14.

As seen inFIG. 5D, the capping layer14on the pad part320may be exposed via patterning of the passivation layer20. For instance, the passivation layer may be photo-patterned, however, it is contemplated that any other suitable patterning technique may be utilized in association with exemplary embodiments descried herein.

FIGS. 6, 7, and 8are respective cross-sectional views of a sensing electrode unit, a fan-out part, and a pad part of a touch screen panel, according to one or more exemplary embodiments. The sensing electrode unit201, the fan-out part311, and the pad part321may be similar to the sensing electrode unit200, the fan-out part310, and the pad part320, and, therefore, to avoid obscuring exemplary embodiments described herein, redundant descriptions will also be avoided.

As seen inFIG. 6, the sensing electrode unit201may include a conductive layer11formed on the substrate100. The conductive layer11may be patterned via wet and/or dry etching to form the sensing electrode unit201. A passivation layer20is formed on the substrate100with the sensing electrode unit201formed between the passivation layer and the substrate100. Silver nanowire (AgNW) may be used to form the conductive layer11. In this manner, the sensing electrode unit201omits the transparent oxide layer12, and, as such, may be a single layer structure versus a multilayer structure as inFIGS. 2, 5A, 5B, 5C, and 5D.

As illustrated inFIG. 7, in the fan-out part311forming a portion of the connection wiring unit, a conductive layer11is formed on the substrate100, a metal wiring layer13is formed on the conductive layer11, and a capping layer14is formed on the metal wiring layer13. The metal wiring layer13and the capping layer14may be simultaneously patterned, and, thereafter, a passivation layer20may be formed on the substrate with the fan-out part311formed therebetween. In this manner, the fan-out part311may omit the conductive transparent oxide layer12, as in the sensing electrode unit201. As such, the conductive layer11, the metal wiring layer13, the capping layer14, and the passivation layer20are otherwise the same as those described in association withFIGS. 1-4, 5A, 5B, 5C, and 5D.

As previously described, the metal wiring layer13and the capping layer14may be sequentially deposited on the conductive layer11and collectively patterned using wet etching and/or dry etching. This may form a T-shaped stacking structure due to a difference in etching rates of the metal wiring layer13and the capping layer14. This may allow for step coverage via the application of the passivation layer20, such as an organic passivation layer, which is formed after the patterning of the metal wiring layer13and the capping layer14. To this end, the stack structure in combination with the passivation layer20also enables lateral passivation and preventing (or otherwise reducing) lateral corrosion of the metal wiring layer13and the capping layer14.

Turning toFIG. 8, in the pad part321forming a portion the connection wiring unit, a conductive layer11is formed on the substrate100, a metal wiring layer13is formed on the conductive layer11, a capping layer14is formed on the metal wiring layer13, a passivation layer20is formed on the substrate100with the pad part321formed therebetween. The passivation layer is patterned (e.g., photo-patterned) to expose portions of the capping layer14. In this manner, the pad part321omits the conductive transparent oxide layer12described in association withFIGS. 4, 5A, 5B, 5C, and 5D. The conductive layer11, the metal wiring layer13, the capping layer14, and the passivation layer20are otherwise the same as described in association withFIGS. 4, 5A, 5B, 5C, and 5D.

As previously described, the metal wiring layer13and the capping layer14may be sequentially deposited on the conductive layer11and collectively patterned using wet etching and/or dry etching. This may form a T-shaped stacking structure due to a difference in etching rates of the metal wiring layer13and the capping layer14. This may allow for step coverage via the application of the passivation layer20, such as an organic passivation layer, which is formed after the patterning of the metal wiring layer13and the capping layer14. To this end, the stack structure in combination with the passivation layer20also enables lateral passivation and preventing (or otherwise reducing) lateral corrosion of the metal wiring layer13and the capping layer14.

FIGS. 9, 10, and 11are respective cross-sectional views of a sensing electrode unit, a fan-out part, and a pad part of a touch screen panel, according to one or more exemplary embodiments. The sensing electrode unit202, the fan-out part312, and the pad part322may be similar to the sensing electrode unit200, the fan-out part310, and the pad part320, and, therefore, to avoid obscuring exemplary embodiments described herein, redundant descriptions will also be avoided.

As seen inFIG. 9, the sensing electrode unit202may include a conductive layer11formed on the substrate100and a conductive transparent oxide layer12formed on the conductive layer11. The conductive layer11and the conductive transparent oxide layer12may be patterned via wet and/or dry etching to form the sensing electrode unit202. A passivation layer20may be formed on the substrate100with the sensing electrode unit202formed therebetween. As such, the conductive layer11, the conductive transparent oxide layer12, and the passivation layer20are the same as those described in association withFIGS. 2, 5A, 5B, 5C, and5D. That is, the sensing electrode unit202is the same as the sensing electrode unit200.

With reference toFIG. 10, in the fan-out part310forming a portion of the connection wiring unit, a conductive layer11is formed on the substrate100, a metal wiring layer13is formed on the conductive layer11, a capping layer14is formed on the metal wiring layer13, and a conductive transparent oxide layer12is formed on the capping layer14. A passivation layer20is then formed on the substrate100with the fan-out part312formed therebetween. The conductive layer11, the metal wiring layer13, the capping layer14, and the passivation layer20are the same as described in association withFIGS. 3, 5A, 5B, 5C, and 5D.

Accordingly, the metal wiring layer13and the capping layer14may be sequentially deposited on the conductive layer11and collectively patterned using wet etching and/or dry etching. This may form a T-shaped stacking structure due to a difference in etching rates of the metal wiring layer13and the capping layer14. This may allow for step coverage via the application of the passivation layer20, such as an organic passivation layer, which is formed after the patterning of the metal wiring layer13and the capping layer14. To this end, the stack structure in combination with the passivation layer20also enables lateral passivation and preventing (or otherwise reducing) lateral corrosion of the metal wiring layer13and the capping layer14.

Differently than as described in association withFIGS. 3, 5A, 5B, 5C, and 5D, a conductive transparent oxide layer122is deposited on the substrate100with the capping layer14formed thereon, such that the conductive transparent oxide layer122is formed on an upper portion of the capping layer14and on end portions of the conductive layer11. According to one or more exemplary embodiments, the thickness of the conductive transparent oxide layer122on the capping layer14may be the same as or different than the thickness of the conductive transparent oxide layer122on the end portions of the conductive layer11. Moreover, although not illustrated, the conductive transparent oxide layer122may provide lateral sidewall coverage on exposed portions of the metal wiring layer13.

Referring toFIG. 11, in the pad part322forming a portion of the connection wiring unit, a conductive layer11is formed on the substrate100, a metal wiring layer13is formed on the conductive layer11, a capping layer14is formed on the metal wiring layer13, a conductive transparent oxide layer122is formed on the capping layer14. Thereafter, a passivation layer20is formed on the substrate100with the pad part322formed therebetween. It is noted that the conductive layer11, the metal wiring layer13, and the capping layer14are the same as described in association withFIGS. 3, 5A, 5B, 5C, and 5D.

Accordingly, the metal wiring layer13and the capping layer14may be sequentially deposited on the conductive layer11and collectively patterned using wet etching and/or dry etching. This may form a T-shaped stacking structure due to a difference in etching rates of the metal wiring layer13and the capping layer14. This may allow for step coverage via the application of the passivation layer20, such as an organic passivation layer, which is formed after the patterning of the metal wiring layer13and the capping layer14. To this end, the stack structure in combination with the passivation layer20also enables lateral passivation and preventing (or otherwise reducing) lateral corrosion of the metal wiring layer13and the capping layer14.

Differently than as described in association withFIGS. 3, 5A, 5B, 5C, and 5D, a conductive transparent oxide layer122is deposited on the substrate100with the capping layer14formed thereon, such that the conductive transparent oxide layer122is formed on an upper portion of the capping layer14and on end portions of the conductive layer11. According to one or more exemplary embodiments, the thickness of the conductive transparent oxide layer122on the capping layer14may be the same as or different than the thickness of the conductive transparent oxide layer122on the end portions of the conductive layer11. Moreover, although not illustrated, the conductive transparent oxide layer122may provide lateral sidewall coverage on exposed portions of the metal wiring layer13.

The passivation layer20may be patterned (e.g., photo-patterned) to expose portions of the conductive transparent oxide layer122that are disposed on the capping layer14.

According to one or more exemplary embodiments, a portion of the connection wiring unit may be deposited with the same material, and, thereby, formed together with the sensing electrode unit. To this end, the portion of the connection wiring unit may be simultaneously patterned with the sensing electrode unit. For example, as described in association withFIGS. 1-4, 5A, 5B, 5C, and 5D, the conductive layer11and the conductive transparent oxide layer12may be simultaneously formed and simultaneously patterned to form the sensing electrode unit200and the connection wiring unit300. As described in association withFIGS. 9-11, the conductive layer11may be simultaneously formed and patterned to form the sensing electrode unit and the connection wiring unit. To this end, the conductive transparent oxide layer122of the sensing electrode unit and the conductive transparent oxide layer122on the capping layer14of the connection wiring unit may be simultaneously formed and patterned. It is contemplated, however, that the conductive transparent oxide layers122ofFIGS. 10 and 11may be formed in any suitable fashion.