Conductor and method of manufacturing the same
10886037 ยท 2021-01-05
Assignee
Inventors
- Yui Abe (Miyagi-ken, JP)
- Yoshihiro Taguchi (Miyagi-ken, JP)
- Mitsuo Bito (Miyagi-ken, JP)
- Yoshiyuki Asabe (Miyagi-ken, JP)
- Yasuyuki Kitamura (Miyagi-ken, JP)
- Tomoyuki Yamai (Miyagi-ken, JP)
- Koji Oguma (Miyagi-ken, JP)
- Tomofumi Oba (Miyagi-ken, JP)
Cpc classification
H01L31/1884
ELECTRICITY
H05K2201/0326
ELECTRICITY
H05K2201/0338
ELECTRICITY
Y02E10/50
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
B82Y40/00
PERFORMING OPERATIONS; TRANSPORTING
Y10T428/31678
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y10T428/25
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
Y10T428/31663
GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
H01L31/022466
ELECTRICITY
H10K30/82
ELECTRICITY
H05K2201/0352
ELECTRICITY
B82Y30/00
PERFORMING OPERATIONS; TRANSPORTING
H05K3/388
ELECTRICITY
H01B5/14
ELECTRICITY
H05K1/09
ELECTRICITY
International classification
H01B5/14
ELECTRICITY
H05K1/09
ELECTRICITY
H05K3/38
ELECTRICITY
H01L31/18
ELECTRICITY
Abstract
A conductor includes (i) a substrate, (ii) a transparent conductive film formed on the substrate and including a silver nanowire, (iii) a metal film formed over the transparent conductive film such that at least a portion thereof overlaps the transparent conductive film, and (iv) a buffer film provided between the transparent conductive film and the metal film, the buffer film having adhesion to each of the transparent conductive film and the metal film, and not impeding conductivity between the transparent conductive film and the metal film. Preferably, the buffer film is formed of an organic material having respective functional groups capable of bonding to the transparent conductive film and the metal film.
Claims
1. A conductor for an input display device, the conductor having an input display region and a non-display region, the conductor comprising: a substrate; and a patterned transparent conductive film formed on the substrate, the transparent conductive film having a first portion thereof formed in the input display region and a second portion thereof formed in the non-display region, the transparent conductive film including a silver nanowire, wherein the input display region of the conductor comprises: a plurality of transparent electrodes formed of the first portion of the transparent conductive film, the plurality of transparent electrodes being separated from one another with a space therebetween; and a respective film formed on each of the plurality of transparent electrodes, the respective film being made of a transparent conductive metal oxide, wherein the non-display region of the conductor comprises: the second portion of the transparent conductive film, the second portion including a plurality of wiring patterns separated from one another with a distance therebetween; a metal film formed over the second portion of the transparent conductive film such that a portion thereof overlaps the second portion of the transparent conductive film; and a buffer film provided between the second portion of the transparent conductive film and the metal film, the buffer film being made of the transparent conductive metal oxide and having adhesion to each of the transparent conductive film and the metal film, and not impeding conductivity between the patterned transparent conductive film and the metal film, thereby forming a plurality of wiring portions corresponding to the plurality of wiring patterns of the transparent conductive film, each wiring portion including the metal film, the buffer film, and the second portion of the transparent conductive film, the plurality of wiring portions being separated from one another with a space therebetween, and wherein the metal film is not disposed in the input display region, whereby the input display region serves as an input display area for the input device.
2. The conductor according to claim 1, wherein the metal film is formed of Cu.
3. The conductor according to claim 1, wherein an upper surface of the transparent conductive film is a reverse-sputtered surface, and the buffer film is formed on the reverse-sputtered surface.
4. The conductor according to claim 1, wherein the buffer film has a thickness of 2 nm to 100 nm.
5. A method of manufacturing a conductor for an input display device, the conductor having an input display region and a non-display region, the method comprising: providing a substrate having a transparent conductive film including a silver nanowire formed thereon, the transparent conductive film being formed in the input display region and the non-display region; forming a buffer film made of a transparent metal oxide on the transparent conductive film; and forming a metal film on the buffer film formed on the transparent conductive film, the buffer film having adhesion to each of the transparent conductive film and the metal film, and not impeding conductivity between the transparent conductive film and the metal film; patterning the metal film, the buffer film, and the transparent conductive film, thereby: forming in the input display region a plurality of transparent electrodes formed of a first portion of the transparent conductive film formed in the display region, the plurality of transparent electrodes being separated from one another with a space therebetween, each of the plurality of transparent electrodes being provided with a respective film made of the transparent metal oxide formed thereon, the input display region not having the metal film disposed therein, thereby serving as an input display area for the input display device; and forming in the non-display region a plurality of wiring portions each including the metal film, the buffer film, and a second portion of the transparent conductive film formed in the non-display region, the second portion of the transparent conductive film including a plurality of wiring patterns corresponding to the plurality of wiring portions which are separated from one another with a space therebetween.
6. The method of manufacturing a conductor according to claim 5, further comprising: performing reverse sputtering on an upper surface of the transparent conductive film, the buffer film being formed on the upper surface.
7. The method according to claim 5, wherein the buffer film has a thickness of 2 nm to 100 nm.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
(3)
(4)
(5)
(6)
DESCRIPTION OF THE PREFERRED EMBODIMENTS
(7)
(8) A conductor 1 illustrated in
(9) The conductor 1 may have a film shape having flexibility, and may also have a plate shape or a panel shape having high stiffness.
(10) In this specification, transparency and light-transmitting property indicate a state where the visible light transmittance is 50% or higher (preferably 80% or higher).
(11) In
(12) The use of the conductor 1 illustrated in
(13) A configuration in which a display panel is disposed on the surface of the conductor 1 illustrated in
(14) The transparent substrate 2 illustrated in
(15) The transparent conductive film 3 illustrated in
(16) As illustrated in
(17) As illustrated in
(18) The metal film 5 is, for example, a Cu film. Particularly, the buffer film 4 can enhance the adhesion between the metal film 5 and the transparent conductive film 3 including the silver nanowires. In addition, the material of the metal film 5 is not particularly limited, and Al, Ag, Au, Ni, or the like other than Cu may also be selected.
(19) In
(20) It is preferable that the buffer film 4 is made of a transparent metal oxide. As the transparent metal oxide, an inorganic transparent conductive material such as ITO (indium tin oxide), ZnO, or SnO.sub.2 may be used, and among these, it is particularly preferable to select ITO. Accordingly, the adhesion between the transparent conductive film 3 and the metal film 5 can be effectively enhanced.
(21) In addition, it is appropriate that reverse sputtering is performed on an upper surface 3a (see
(22) The upper surface 3a of the transparent conductive film 3 is reformed by the reverse sputtering so that the adhesion between the transparent conductive film 3 and the metal film 5 via the buffer film 4 can be effectively enhanced. It is thought that due to the reverse sputtering, the amount (exposure area) of the silver nanowires 6 which are made of metal and are exposed from the upper surface 3a of the transparent conductive film 3 is increased, or the upper surface 3a of the transparent conductive film 3 is appropriately roughened.
(23) It is preferable that the thickness of the buffer film 4 made of the above-mentioned transparent metal oxide (particularly, ITO) is about 2 nm to 100 nm. In addition, in a case where the buffer film 4 made of the transparent metal oxide (particularly, ITO) is formed without performing the reverse sputtering on the upper surface 3a of the transparent conductive film 3, the thickness of the buffer film 4 is preferably about 20 nm to 100 nm. Accordingly, the adhesion between the transparent conductive film 3 and the metal film 5 can be effectively enhanced.
(24) In addition, it is preferable that reverse sputtering is performed on an upper surface 4a (see
(25) Accordingly, the adhesion between the transparent conductive film 3 including the silver nanowires and the metal film 5 can be more effectively enhanced. In addition, conductivity between the transparent conductive film 3 and the metal film 5 via the buffer film 4 can be maintained at a good level.
(26) Otherwise, the buffer film 4 may be made of an organic material having a functional group which is bonded to each of the transparent conductive film 3 and the metal film 5. The film thickness of the buffer film 4 is very small due to a process which will be described later, and the transparent conductive film 3 and the metal film 5 are in a state of being electrically connected to each other via the buffer film 4. Otherwise, the buffer film 4 is intermittently formed on the upper surface 3a of the transparent conductive film 3, and the transparent conductive film 3 and the metal film 5 are in a state of being electrically connected to each other via the buffer film 4.
(27) It is preferable that the above-mentioned organic material is a triazine compound having an alkoxy group and a thiol group, or an alkoxy group and an azide group. Specifically, it is appropriate that the triazine compound has a structure shown in Chem. 7 or Chem. 8 as follows.
(28) ##STR00002##
(29) Accordingly, the adhesion between the transparent conductive film and the metal film can be effectively enhanced.
(30) In addition, it is preferable that a heat treatment is performed on the organic material in order to more effectively enhance the adhesion. It is appropriate that the heat treatment is performed at about 100 C. for several to tens of minutes. The heat treatment may be performed during the process of forming the buffer film 4 using the triazine compound shown in Chemical Formula 7 or Chemical Formula 8 shown above, or may be performed after the process of forming the buffer film 4 (any of before, during, and after the formation of the metal film 5).
(31)
(32) In the process illustrated in
(33) As illustrated in
(34) A conductive substrate in which the transparent conductive film 3 including the silver nanowires is formed on the transparent substrate 2 in advance may be prepared, or the transparent conductive film 3 may be formed on the transparent substrate 2 by applying a coating liquid including the silver nanowires onto the transparent substrate 2 and performing a predetermined heat treatment thereon.
(35) It is preferable that the buffer film 4 illustrated in
(36) Otherwise, the buffer film 4 may also be formed of an organic material having a functional group which is bonded to each of the transparent conductive film 3 and the metal film 5 formed in the process of
(37) The formation of the buffer film 4 using the organic material is performed through an immersion process of a liquid containing the organic material, a cleaning process, a drying process, and the like.
(38) In
(39) In the process illustrated in
(40) It is preferable that the metal film 5 is formed of a Cu film.
(41) Subsequently, a resist layer 8 is applied to an upper surface 5a of the metal film 5. A prebaking treatment or an exposing and developing treatment is performed on the resist layer 8 such that the resist layer 8 having a pattern illustrated in
(42) Subsequently, in the process illustrated in
(43) Next, in the process of
(44) Subsequently, in
(45) Furthermore, by removing the resist layer 9, the conductor 1 illustrated in
(46) In the manufacturing method described above, the metal film 5 is formed on the transparent conductive film 3 via the buffer film 4. Accordingly, the adhesion between the transparent conductive film 3 including the silver nanowires and the metal film 5 can be effectively enhanced.
(47) In
(48) Here, a configuration in which a portion of the metal film 5 overlaps the transparent conductive film 3 and the buffer film 4 is interposed therebetween in the overlapping portion may also be employed.
EXAMPLES
(49) In an experiment, conductors of Comparative Examples 1 to 4 and Examples 1 to 8 were formed.
(50) In all of the conductors, a common conductive substrate in which a transparent conductive film including silver nanowires is formed on a transparent substrate was used, and a Cu film having a film thickness of 150 nm was further formed as a metal film.
(51) TABLE-US-00001 TABLE 1 Cross-cut test results Pre-treatment conditions Edge Center Comparative Absent C C Example 1 Comparative UV-ozone C C Example 2 Comparative Excimer UV C C Example 3 Comparative Only reverse sputtering C C Example 4 Example 1 ITO buffer film (20 nm) B B Example 2 ITO buffer film (100 nm) B B Example 3 Reverse sputtering & ITO buffer film (2 A A nm) Example 4 Reverse sputtering & ITO buffer film (20 A A nm) Example 5 Reverse sputtering & ITO buffer film (100 A A nm) Example 6 Reverse sputtering & ITO buffer film (20 A A mm) => leaving in atmosphere reverse sputtering Example 7 TES treatment A A Example 8 P-TES treatment A A
(52) As shown in Table 1, in Comparative Example 1, before forming the metal film (Cu film), a pre-treatment was not performed on the transparent conductive film.
(53) In addition, as shown in Table 1, in Comparative Example 2, the surface of the transparent conductive film was subjected to a surface treatment by UV-ozone, and thereafter the metal film (Cu film) was formed. In addition, in Comparative Example 3, an excimer UV treatment was performed on the surface of the transparent conductive film, and thereafter metal film (Cu film) was formed.
(54) In addition, in Examples 1 and 2, reverse sputtering was not performed on the upper surface of the transparent conductive film.
(55) As shown in Table 1, in Example 1, a buffer film made of ITO was formed on the upper surface of the transparent conductive film including the silver nanowires to a film thickness of 20 nm, and thereafter the metal film (Cu film) was formed on the buffer film. In addition, in Example 2, a buffer film made of ITO was formed on the upper surface of the transparent conductive film including the silver nanowires to a film thickness of 100 nm, and thereafter the metal film (Cu film) was formed on the buffer film.
(56) In addition, as shown in Table 1, in Example 3, after reverse sputtering was performed on the upper surface of the transparent conductive film including the silver nanowires, a buffer film made of ITO was formed on the upper surface to a film thickness of 2 nm, and the metal film (Cu film) was subsequently formed on the buffer film. In addition, in Example 4, after reverse sputtering was performed on the upper surface of the transparent conductive film including the silver nanowires, a buffer film made of ITO was formed on the upper surface to a film thickness of 20 nm, and the metal film (Cu film) was subsequently formed on the buffer film. In addition, in Example 5, after reverse sputtering was performed on the upper surface of the transparent conductive film including the silver nanowires, a buffer film made of ITO was formed on the upper surface to a film thickness of 100 nm, and the metal film (Cu film) was subsequently formed on the buffer film. In addition, in Example 6, after reverse sputtering was performed on the upper surface of the transparent conductive film including the silver nanowires, a buffer film made of ITO was formed on the upper surface to a film thickness of 20 nm. Subsequently, the resultant was removed from the sputtering device once and was left in the atmosphere for about one day. Thereafter, the resultant was put into the sputtering device again, the sputtering device was evacuated, reverse sputtering was performed on the upper surface of the buffer film, and then the metal film (Cu film) was formed on the buffer film.
(57) As for the reverse sputtering conditions described above, in any of the above cases, the pressure was set to about 200 mTorr and the power was set to about 5 mW/cm.sup.2 in an inert atmosphere (in Ar).
(58) In addition, in Example 7, a buffer film made of the triazine compound (hereinafter, referred to as TES) expressed by Chemical Formula 7 shown above was formed on the upper surface of the transparent conductive film including the silver nanowires, and the metal film (Cu film) was subsequently formed on the buffer film. In Example 7, the buffer film was formed through the processes of immersion in a (3%) aqueous solution of KOH, rinsing with H.sub.2O, immersion in a TES/ethanol liquid, rinsing with H.sub.2O, and a hot plate (80 C.) (TES treatment). Furthermore, after forming the metal film, a heat treatment was performed thereon at 100 C. for 10 minutes.
(59) In addition, in Example 8, a buffer film made of the triazine compound (hereinafter, referred to as P-TES) expressed by Chemical Formula 8 shown above was formed on the upper surface of the transparent conductive film including the silver nanowires, and the metal film (Cu film) was subsequently formed on the buffer film. In Example 8, the buffer film was formed through the processes of immersion in P-TES/IPA (0.1%), drying with a dryer, UV irradiation, and rinsing with ethanol (P-TES treatment). Furthermore, after forming the metal film, a heat treatment was performed thereon at 100 C. for 10 minutes.
(60) In addition, a cross-cut test (JIS K 5600-5-6) was performed on each of the samples of Comparative Examples 1 to 4 and Examples 1 to 8. The cross-cut test was performed on the center and the edge of each of the samples.
(61) Here, A shown in Table 1 is the result of a case where no separation had occurred, B is the result of a case where separation was very partially seen, and C is the result of a case where separation was seen over the entire area.
(62) As shown in Table 1, it was seen that Examples had better results in the cross-cut test than those of Comparative Examples, and had good adhesion between the transparent conductive film including the silver nanowires and the metal film (Cu film).
(63) In addition, as shown in Table 1, it was seen that Examples 3 to 6 had obtained better adhesion than Examples 1 and 2. Therefore, it was seen that, by forming the buffer film made of ITO after performing reverse sputtering on the surface of the transparent conductive film, the adhesion between the transparent conductive film and the metal film could be more effectively enhanced. Furthermore, it was seen that, as in Example 6, even when the buffer film was left in the atmosphere once after being formed, the adhesion could be effectively enhanced by performing reverse sputtering on the upper surface of the buffer film.
(64) In both of Example 7 in which the TES treatment was performed and Example 8 in which the P-TES treatment was performed, the heat treatment was performed, and thus it was seen that good adhesion could be obtained.
(65) Next, in Comparative Example 1 in which the pre-treatment was not performed, Example 9 in which the TES treatment was performed, and Example 10 in which the P-TES treatment was performed, elements of the surface of the transparent conductive film and the composition ratios thereof were obtained by XPS (X-ray photoelectron spectroscopy). The results are shown in Table 2.
(66) TABLE-US-00002 TABLE 2 Detection element & composition ratio (at %) C N O Ag Si Others Comparative 49.89 1.36 15.64 0.16 32.95 Example 1 Example 9 64.51 5.97 25.06 0.11 1.63 2.72 Example 10 61.36 14.52 20.69 0.19 2.58 0.39
(67) As shown in Table 2, in Example 9 and Example 10, Si included in the treatment liquid was detected.
(68) In addition, in Example 9 and Example 10, a small amount of Ag that was detected in Comparative Example 1 in which the pre-treatment was not performed was detected.
(69) From this, it was seen that by performing the TES treatment of Example 9 or performing the P-TES treatment of Example 10, the buffer film made of the organic material (triazine compound) was formed on the upper surface of the transparent conductive film. In addition, it is thought that the buffer film is very thin or is intermittently formed.
(70) In addition, in Comparative Example 1, Example 9, and Example 10, haze values, Tt values (transmittances), and sheet resistances were measured. The results are shown in Table 3 as follows.
(71) TABLE-US-00003 TABLE 3 Tt Sheet resistance Haze [%] [/] Comparative 0.99 91.34 65.125 Example 1 Example 9 1.29 91.1 62.625 Example 10 1.08 92.26 64.25
(72) In addition, regarding the sheet resistance, a silver paste was applied to a region at 5 mm from both ends of a sheet in a size of 25 mm50 mm, the resultant was baked at 120 C. for 30 minutes, and the bulk resistance thereof was obtained.
(73) As shown in Table 3, each of the haze values, the Tt values, and the sheet resistances in the samples were substantially the same. As described above, it was seen that, in Examples, the adhesion between the transparent conductive film and the metal film could be enhanced while maintaining various properties such as the light-transmitting property and conductivity.
(74) It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and alterations may occur depending on design requirements and other factors insofar as they are within the scope of the appended claims or the equivalents thereof.