Abstract
A method for manufacturing an electronic device is disclosed, which includes the following steps: providing a first substrate and modifying a surface of the first substrate to obtain a modified surface; applying silane or derivatives thereof on the modified surface to form an adhesion precursor layer; heat-treating the adhesion precursor layer to form an adhesion layer; forming an inorganic layer on the adhesion layer; and forming an active unit on the inorganic layer, wherein the inorganic layer is disposed between the adhesion layer and the active unit.
Claims
1. A method for manufacturing an electronic device, comprising the following steps: providing a first substrate and modifying a surface of the first substrate to obtain a modified surface; applying silane or derivatives thereof on the modified surface to form an adhesion precursor layer; heat-treating the adhesion precursor layer to form an adhesion layer; forming an inorganic layer on the adhesion layer; and forming an active unit on the inorganic layer, wherein the inorganic layer is disposed between the adhesion layer and the active unit.
2. The method of claim 1, wherein a covalent bond is formed between the adhesion layer and the first substrate.
3. The method of claim 1, wherein a covalent bond is formed between the adhesion layer and the inorganic layer.
4. The method of claim 1, wherein the silane or the derivatives thereof is represented by the following formula (I): ##STR00007## wherein each of R.sub.1, R.sub.2 and R.sub.3 independently is H or C.sub.1-6 alkyl; and Y is C.sub.1-20 alkyl, C.sub.2-20 alkenyl, C.sub.1-20 alkyl-epoxy, epoxy, C.sub.1-20 alkyl-acryl, or OC.sub.1-20 alkyl.
5. The method of claim 4, wherein the silane or the derivatives thereof is represented by any one the following formulas (I-1) to (I-3): ##STR00008##
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0024] FIGS. 1A to 1D are perspective views showing a process for manufacturing an electronic device according to one preferred embodiment of the present disclosure;
[0025] FIGS. 2A to 2D are perspective views showing bonds between the first substrate and the adhesion layer during the method for manufacturing an electronic device according to Embodiment 1 of the present disclosure;
[0026] FIG. 3A is an electron spectrum for chemical analysis of silicon (Si) containing in silane used in Embodiment 1 of the present disclosure;
[0027] FIG. 3B is an electron spectrum for chemical analysis of carbon (C) containing in silane used in Embodiment 1 of the present disclosure;
[0028] FIG. 3C is an electron spectrum for chemical analysis of oxygen (O) containing in silane used in Embodiment 1 of the present disclosure;
[0029] FIG. 4A is an electron spectrum for chemical analysis of Si containing in adhesion precursor layer in Embodiment 1 of the present disclosure;
[0030] FIG. 4B is an electron spectrum for chemical analysis of Si containing in adhesion layer in Embodiment 1 of the present disclosure;
[0031] FIG. 5A is an electron spectrum for chemical analysis of O containing in adhesion precursor layer in Embodiment 1 of the present disclosure;
[0032] FIG. 5B is an electron spectrum for chemical analysis of O containing in adhesion layer in Embodiment 1 of the present disclosure;
[0033] FIG. 6A is an electron spectrum for chemical analysis of C containing in adhesion precursor layer in Embodiment 1 of the present disclosure;
[0034] FIG. 6B is an electron spectrum for chemical analysis of C containing in adhesion layer in Embodiment 1 of the present disclosure; and
[0035] FIGS. 7A to 7E are perspective views showing a process for manufacturing an electronic device according to another preferred embodiment of the present disclosure.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0036] The present disclosure has been described in an illustrative manner, and it is to be understood that the terminology used is intended to be in the nature of description rather than of limitation. Many modifications and variations of the present disclosure are possible in light of the above teachings. Therefore, it is to be understood that within the scope of the appended claims, the disclosure may be practiced otherwise than as specifically described.
[0037] FIGS. 1A to 1D are perspective views showing a process for manufacturing an electronic device according to one preferred embodiment of the present disclosure. As shown in FIG. 1A, in the manufacturing process of the electronic device of the present embodiment, a first substrate 12 is firstly provided, which is a polymer substrate. Herein, the polymer substrate suitable for the present embodiment can be a PP, PEN, PET or PI substrate. In addition, a thickness of the first substrate 12 is not particularly limited, and can be adjusted according to the device designs. For example, the thickness of the first substrate 12 can be reduced, to adjust the flexibility of the obtained flexible electronic device. In the present embodiment, the thickness of the first substrate 12 can be ranged from 10 m to 250 m. When the first substrate 12 is a PI substrate, the thickness thereof is preferably between 15 m to 50 m. When the first substrate 12 is a PET substrate, the thickness thereof is preferably about 200 m. However, the present disclosure is not limited thereto.
[0038] In some cases, if the first substrate 12 is thin and does not have enough rigidity, the thin first substrate 12 cannot be directly applied on the machine for the rigid substrate. Hence, as shown in FIG. 1A, a carrier 11 can further be provided, and the first substrate 12 is placed on the carrier 11 to enhance the rigidity of the first substrate 12.
[0039] Next, a surface of the first substrate 12 is modified to obtain a hydrophilic surface. Herein, the surface of the first substrate 12 can be modified with UV light or plasma, and then OH groups are exposed on the modified surface.
[0040] Then, as shown in FIG. 1B, the modified surface of the first substrate 12 is coated with silane or derivatives thereof to form an adhesion precursor layer 13. Herein, the adhesion precursor layer 13 can be formed by dip coating, roll coating, printing coating, spin coating, slit coating or other coating manners. The thickness of the adhesion precursor layer 13 can be ranged from 10 nm to 100 nm, and preferably ranged from 30 nm to 40 nm. Herein, the silane or derivatives thereof used for forming the adhesion precursor layer 13 can be represented by the following formula (I):
##STR00003##
wherein each of R.sub.1, R.sub.2 and R.sub.3 independently is H or C.sub.1-6 alkyl; and Y is C.sub.1-20 alkyl, C.sub.2-20 alkenyl, C.sub.1-20 alkyl-epoxy, epoxy, C.sub.1-20 alkyl-acryl, or OC.sub.1-20 alkyl. Herein, OR.sub.1, OR.sub.2 and OR.sub.3 are hydrophilic functional groups (hydrophilic ends), which can combine with the exposed OH groups on the modified surface of the first substrate 12 via a condensation reaction to form covalent bonds. Y is a hydrophobic functional group (hydrophobic end). Herein, the hydrophilic ends of the adhesion precursor layer 13 face toward the first substrate 12, and hydrophobic ends are exposed on the surface of the adhesion precursor layer 13.
[0041] In the present embodiment, specific examples of the silane or derivatives thereof can be any one the following formulas (I-1) to (I-3):
##STR00004##
[0042] Next, as shown in FIG. 1C, a heat treatment is performed to transfer the hydrophobic ends on the surface of the adhesion precursor layer 13 into hydrophilic OH groups, to obtain an adhesion layer 131. Herein, the temperature and the time for the heat treatment can be adjusted according to the property of the silane or derivatives thereof. Preferably, the temperature of the heat treatment can be ranged from 60 C. to 100 C.; and the time thereof can be in a range between 5 min. to 20 min.
[0043] As shown in FIG. 1C, an inorganic layer 14 is formed on the adhesion layer 131, and the OH groups on the surface of the adhesion layer 131 can react with the inorganic layer 14 to form covalent bonds. Before forming the inorganic layer 14, the obtained structure can be placed in an oven to remove water or moisture. The temperature for removing water or moisture can be ranged from 150 C. to 250 C.; and the time thereof can be in a range between 20 min to 120 min. In the present embodiment, the material for the inorganic layer 14 can be a metal oxide or a ceramic material, such as alumina, silicon oxide, silicon nitride and silicon nitroxide. The thickness of the inorganic layer 14 can be ranged from 0.2 m to 1 m, and preferably ranged from 0.2 m to 0.5 m; but the present disclosure is not limited thereto.
[0044] Finally, an active unit 15 is formed on the inorganic layer 14 and the inorganic layer 14 is disposed between the adhesion layer 131 and the active unit 15. After the carrier 11 under the first substrate 12 is removed, the electronic device of the present embodiment is obtained, as shown in FIG. 1D.
[0045] After the above steps, the obtained electronic device of the present embodiment comprises: a first substrate 12 including a polymer substrate; an adhesion layer 131 disposed on the first substrate 12 and comprising a condensation product of silane or derivatives thereof; an inorganic layer 14 disposed on the adhesion layer 131; and an active unit 15 disposed on the inorganic layer 14, wherein the inorganic layer 14 is disposed between the adhesion layer 131 and the active unit 15.
[0046] Hereinafter, the following Embodiment 1 is used to describe the reaction and bonding between the adhesion layer 131 and the first substrate 12 as well as between the adhesion layer 131 and the inorganic layer 14 in details.
Embodiment 1
[0047] In the present embodiment, the first substrate is a PI substrate, and the silane derivative is the compound represented by the following formula (I-1):
##STR00005##
[0048] FIGS. 2A to 2D are perspective views showing bonds between the first substrate and the adhesion layer during the method for manufacturing the electronic device of the present embodiment.
[0049] As shown in FIG. 1A, a first substrate 12 is firstly provided, which is a PI substrate. Then, a surface of the first substrate 12 is modified, and OH groups are exposed on the modified surface, as shown in FIG. 2A. Herein, the reaction for the modification of the PI substrate with UV light is represented by the following Scheme I.
##STR00006##
[0050] In FIG. 2A, in order to simply illustrate the bonding between the first substrate 12 and the sequential adhesion layer, only the carboxyl groups (COOH) generated after the modification are shown on the first substrate 12.
[0051] Next, as shown in FIGS. 1B, 2A and 2B, the compound of the formula (I-1) is coated on the modified surface of the first substrate 12 to form an adhesion precursor layer 13. The oxygen atoms of the hydrophilic functional groups, Si(OH).sub.3 (hydrophilic ends) have high electron density and good reactivity. Hence, after forming the adhesion precursor layer 13, the hydrophilic ends can combine with the exposed OH groups on the modified surface of the first substrate 12 via a condensation reaction, to form COSi covalent bonds, as shown in FIG. 2B. The hydrophobic functional groups, epoxy (hydrophobic ends) are exposed on the surface of the adhesion precursor layer 13. Herein, only one layer of the silane derivative is shown in the figure. However, a person skilled in the art can understand that the obtained adhesion precursor layer 13 comprises multi-layers of the silane derivative.
[0052] After performing the heat treatment under 70 C. for 10 min, the epoxy groups on the surface of the adhesion precursor layer 13 undergo ring opening reactions and transfer into hydrophilic OH groups, and an adhesion layer 131 is obtained, as shown in FIGS. 1C and 2C. In the present embodiment, the adhesion layer 131 has a thickness of about 40 nm.
[0053] Finally, as shown in FIGS. 1C and 2D, silicon oxide is deposited on the adhesion layer 131 to form an inorganic layer 14. The OH groups on the adhesion layer 131 can further combine with the silicon oxide via a condensation reaction, to form COSi covalent bonds.
[0054] The silicon oxide layer as the inorganic layer 14 is exemplified in the present embodiment. However, in other embodiment of the present disclosure, the material of the inorganic layer 14 can be alumina, silicon oxide, silicon nitride or silicon nitroxide, and the generated covalent bonds between the inorganic layer 14 and the adhesion layer 131 can be -M1-M2-C, in which M1 is Si or Al, and M2 is O or N.
[0055] As shown in FIGS. 2A to 2D, when the adhesion layer 131 of the present embodiment is formed between the first substrate 12 and the inorganic layer 14, the problem of the poor adhesion at the heterogeneous interface between the surfaces of the inorganic layer 14 and the first substrate 12 can be improved due to the formed covalent bonds between the adhesion layer 131 and the first substrate 12/the inorganic layer 14. The results of the scanning electron microscope (SEM) also confirmed that pinholes are found between the first substrate 12 and the inorganic layer 14 if the adhesion layer 131 is not disposed therebetween. When the adhesion layer 131 is disposed between the first substrate 12 and the inorganic layer 14, no pinholes are found at the interfaces and thus the peeling problem can be prevented.
[0056] In addition, the electron spectroscopy for chemical analysis (ESCA) was further performed to confirm whether the covalent bonds are respectively formed between the adhesion layer 131 and the first substrate 12/the inorganic layer 14.
[0057] FIGS. 3A to 3C respectively are electron spectra for chemical analysis of silicon (Si), carbon (C) and oxygen (O) containing in silane compound of formula (I-1) used in the present embodiment before the coating process. The value from the electron spectra are respectively listed in the following Tables 1 to 3. R in RCO.sub.2SiC refers to the group of PI other than COOH. Herein, the electron spectra were measured by applying the compound of formula (I-1) on a glass substrate.
TABLE-US-00001 TABLE 1 Si spectrum Chemical state Binding energy Area % SiOH 99.2 eV 8317.0 100
TABLE-US-00002 TABLE 2 C spectrum Chemical state Binding energy Area % SiC 283.4 eV 5611.87 60.7 COH (epoxy) 281.9 eV 3633.27 39.3
TABLE-US-00003 TABLE 3 O spectrum Chemical state Binding energy Area % COH 529.5 eV 15398.7 23.1 SiOHSiO.sub.2 529.3 eV 51475.9 76.9
[0058] As shown in FIG. 3A and Table 1, the peaks found in Si spectrum are symmetric and the binding energy is relative low. This result indicates that the Si end in the compound of formula (I-1) is present in a completely hydrolyzed form (Si(OH).sub.3) and does not condense into SiO.sub.2.
[0059] As shown in FIGS. 3B and 3C and Tables 2 and 3, from the areas of the fitting peaks, the carbon chain on the Si end has three carbon atoms, and the carbon chain on the epoxy has two carbon atoms. In addition, three OH groups bind to the Si end, and one oxygen is belonged to the epoxy group. These results are consistent with the chemical formula of the compound of formula (I-1).
[0060] FIGS. 4A and 4B are respectively electron spectra for chemical analysis of Si containing in the adhesion precursor layer after the coating process and in the adhesion layer formed after the heat treatment process. The value from the electron spectra are respectively listed in the following Tables 4 to 5. In addition, the values from the electron spectra shown in FIGS. 3A, 4A and 4B are further summarized in the following Table 6. In FIGS. 4A and 4B, R in RCO.sub.2SiC refers to the group of PI other than COOH. COSiR refers to the group that an epoxy group (providing COH) in one silane compound combines with the hydroxyl group (providing HOSiR) in another silane compound via a condensation reaction.
TABLE-US-00004 TABLE 4 Si spectrum of the adhesion precursor layer Chemical state Binding energy Area % RCO.sub.2SiC 99.9 eV 335.3 17.3 SiO.sub.2 99.4 eV 338.4 17.5 SiOH 99.2 eV 1259.0 65.2
TABLE-US-00005 TABLE 5 Si spectrum of the adhesion layer Chemical state Binding energy Area % RCO.sub.2SiC 99.9 eV 1541.8 68.0 SiO.sub.2 99.4 eV 668.7 29.5 SiOH 99.2 eV 57.7 2.5
TABLE-US-00006 TABLE 6 Binding % Chemical state energy FIG. 3A FIG. 4A FIG. 4B RCO.sub.2SiC or 99.9 eV 17.3 68.0 RCOSiC SiO.sub.2 99.4 eV 17.5 29.5 SiOH 99.2 eV 100 65.2 2.5
[0061] As shown in FIGS. 3A and 4A and Table 4, the signal of SiOH found in the adhesion precursor layer after the coating process is reduced, comparing to the signal of SiOH found in the silane compound of formula (I-1) before the coating process. This result indicates that the Si ends of the silane compound of formula (I-1) can face to the PI substrate and combine with the OH group on the PI substrate to form a covalent bound via a condensation reaction.
[0062] As shown in FIGS. 3A, 4A and 4B and Table 6, the signals of RCO.sub.2SiC, COSR and SiO.sub.2 found in the adhesion precursor layer after the coating process and the adhesion layer after the heat treatment process are reduced, comparing to those found in the silane compound of formula (I-1) before the coating process. These results indicate that the condensation reaction of the silane compound is complete after the heat treatment process.
[0063] FIGS. 5A and 5B are respectively electron spectra for chemical analysis of O containing in the adhesion precursor layer after the coating process and in the adhesion layer formed after the heat treatment process. The value from the electron spectra are respectively listed in the following Tables 7 to 8. In addition, the values from the electron spectra shown in FIGS. 3C, 5A and 5B are further summarized in the following Table 9.
TABLE-US-00007 TABLE 7 O spectrum of the adhesion precursor layer Chemical state Binding energy Area % COH 529.5 eV 5539.8 37.5 SiOH, SiO.sub.2 529.3 eV 9236.7 62.5
TABLE-US-00008 TABLE 8 O spectrum of the adhesion layer Chemical state Binding energy Area % COH 529.5 eV 33831.5 89.6 SiOH, SiO.sub.2 529.3 eV 3924.7 10.4
TABLE-US-00009 TABLE 9 Binding % Chemical state energy FIG. 3C FIG. 5A FIG. 5B COH 529.5 eV 23.1 37.5 89.6 SiOH, SiO.sub.2 529.3 eV 76.9 62.5 10.4
[0064] As shown in FIGS. 3C, 5A and 5B and Table 9, the O signal represented by the peak of SiOH, SiO.sub.2 is left-shifted, and the ratio of the peak of COH is increased. This result indicates that the epoxy group in the silane compound undergoes a ring opening reaction.
[0065] FIGS. 6A and 6B are respectively electron spectra for chemical analysis of C containing in the adhesion precursor layer after the coating process and in the adhesion layer formed after the heat treatment process. The value from the electron spectra are respectively listed in the following Tables 10 to 11. In addition, the values from the electron spectra shown in FIGS. 3B, 6A and 6B are further summarized in the following Table 12.
TABLE-US-00010 TABLE 10 C spectrum of the adhesion precursor layer Chemical state Binding energy Area % RCO.sub.2SiC 285.5 eV 2493.2 8.3 SiC 283.4 eV 9922.8 32.9 COH (Epoxy) 281.9 eV 17730.6 58.8
TABLE-US-00011 TABLE 11 C spectrum of the adhesion layer Chemical state Binding energy Area % RCO.sub.2SiC 285.5 eV 3231.1 10.7 SiC 283.4 eV 11302.9 37.3 COH (Epoxy) 281.9 eV 15781.4 52.0
TABLE-US-00012 TABLE 12 Binding % Chemical state energy FIG. 3B FIG. 6A FIG. 6B RCO.sub.2SiC 285.5 eV 8.3 10.7 SiC 283.4 eV 60.7 32.9 37.3 COH (Epoxy) 281.9 eV 39.3 58.8 52.0
[0066] As shown in FIGS. 3B, 6A and 6B and Table 12, the ratio of the peak of RCO.sub.2SiC is increased after the heat treatment process. This result indicates that the heat can facilitate the condensation reaction more complete.
[0067] The aforementioned results confirm that the adhesion layer used in the present disclosure can simultaneously form covalent bonds with the polymer substrate and the inorganic substrate. Therefore, the poor adhesion at the heterogeneous interfaces between the polymer substrate and the inorganic layer can be enhanced; therefore, the performance and the yield rate of the electronic devices can be improved.
[0068] FIGS. 7A to 7E are perspective views showing a process for manufacturing an electronic device according to another preferred embodiment of the present disclosure. The process for manufacturing the electronic device of the present embodiment is similar to that shown in FIGS. 1A to 1D. The steps shown in FIGS. 7A to 7C are similar to the steps shown in FIGS. 1A to 1C, except that the active unit is not directly formed on the inorganic layer 14 in the present embodiment. After forming the inorganic layer 14 in the present embodiment, another adhesion layer 131 is formed on the inorganic layer 14. Next, anther polymer substrate 12 is formed on the adhesion layer 131. Then, further another adhesion layer 131 and another inorganic layer 14 are sequentially formed on the adhesion layer 131. The processes for forming the adhesion layers 131, 131 and the inorganic layer 14 are similar to those illustrated before, and are not repeated again.
[0069] Finally, an active unit 15 is formed on the inorganic layer 14; and the carrier 11 under the first substrate 12 is removed to obtain the electronic device of the present embodiment, as shown in FIG. 7E.
[0070] Compared to the electronic device shown in FIG. 1D, the electronic device shown in FIG. 7E has a multi-layer structure with plural first substrates 12, 12. Hence, the rigidity of the device shown in FIG. 7E can further be improved, and the problem that the device may be cured after removing the carrier 11 can be solved.
[0071] The electronic device and the method for manufacturing the same of the present disclosure can be applied to any electronic device equipped with a polymer substrate, such as flexible display devices, flexible touch devices, solar cells, lightings, flexible printing circuit boards, electronic papers and radio frequency identification systems.
[0072] In addition, when the electronic device provided by the present disclosures is a flexible display device, it can combine with a flexible touch panel to form a touch display device. Furthermore, the display devices or the touch display devices provided by the aforementioned embodiments can be applied to any electronic device for displaying images and touch sensing, for example, monitors, mobile phones, notebooks, cameras, video cameras, music players, navigation systems, and televisions.
[0073] Although the present disclosure has been explained in relation to its preferred embodiment, it is to be understood that many other possible modifications and variations can be made without departing from the spirit and scope of the disclosure as hereinafter claimed.
