Capacitance calculation method and substrate thickness calculation method

Abstract

A capacitance calculation method and a substrate thickness calculation method are disclosed. The capacitance calculation method can include a step of measuring a plurality of measurement capacitances using a capacitance measuring device; a step of calculating a plurality of evaporation coefficients for evaporation parameters corresponding to each of the plurality of measurement capacitances, a plurality of exposure coefficients for exposure parameters corresponding to each of the plurality of measurement capacitances, and a plurality of etching coefficients for etching parameters corresponding to each of the plurality of measurement capacitances; a step of calculating a corrected evaporation coefficient for the plurality of evaporation coefficients, a corrected exposure coefficient for the plurality of exposure coefficients, and a corrected etching coefficient for the plurality of etching coefficients; and a step of calculating a capacitance based on a capacitance calculation formula including the evaporation parameters, the corrected evaporation coefficient, the exposure parameters, the corrected exposure coefficient, the etching parameters, and the corrected etching coefficient.

Description

Technical Field

[0001] This invention relates to a capacitance calculation method and a substrate thickness calculation method, and more specifically to a capacitance calculation method that can calculate capacitance during the manufacturing process or a substrate thickness calculation method that can calculate substrate thickness during the manufacturing process. Background Technology

[0002] In a mass production line for a display device, multiple processes are performed to manufacture the display device. To verify that the processes are being performed correctly, measurements can be taken of the display device. For example, these measurements may relate to the physical characteristics of the display device (e.g., capacitance, substrate thickness). These measurements can be performed after the entire manufacturing process of the display device is complete, or after the manufacturing process has reached a specific step.

[0003] In this situation, when the display device malfunctions, it may require a significant amount of time and expense to remanufacture it. Therefore, it is urgently necessary to understand the physical characteristics of the display device during its manufacturing process. Summary of the Invention

[0004] The technical problem addressed by this invention is in this respect, and one object of this invention is to provide a method for calculating capacitance.

[0005] In addition, another object of the present invention is to provide a method for calculating the thickness of a substrate.

[0006] However, the problems to be solved by the present invention are not limited to those mentioned above, and various extensions can be made without departing from the concept and scope of the present invention.

[0007] A capacitance calculation method, according to an embodiment of the present invention, for achieving the above-described objectives, in a display device manufacturing process, for calculating capacitance based on vapor deposition parameters for a vapor deposition process, exposure parameters for an exposure process, and etching parameters for an etching process, includes: measuring a plurality of measurement capacitors using a capacitance measuring device; calculating a plurality of vapor deposition coefficients for each of the plurality of measurement capacitors corresponding to the vapor deposition parameters, a plurality of exposure coefficients for each of the plurality of measurement capacitors corresponding to the exposure parameters, and a plurality of etching coefficients for each of the plurality of measurement capacitors corresponding to the etching parameters; calculating a corrected vapor deposition coefficient for the plurality of vapor deposition coefficients, a corrected exposure coefficient for the plurality of exposure coefficients, and a corrected etching coefficient for the plurality of etching coefficients; and calculating the capacitance based on a capacitance calculation formula including the vapor deposition parameters, the corrected vapor deposition coefficient, the exposure parameters, the corrected exposure coefficient, the etching parameters, and the corrected etching coefficient.

[0008] In one embodiment, the plurality of evaporation coefficients, the plurality of exposure coefficients, and the plurality of etching coefficients may be calculated using multiple regression analysis.

[0009] In one embodiment, the corrected evaporation coefficient, the corrected exposure coefficient, and the corrected etching coefficient may be calculated using Bayes' theorem.

[0010] In one embodiment, after calculating the capacitance, the process may further include: comparing the plurality of measured capacitances with the calculated capacitance, and when the calculated capacitance is within an allowable range, applying the capacitance calculation formula to perform the manufacturing process of the display device.

[0011] In one embodiment, after calculating the capacitance, the plurality of measured capacitances and the calculated capacitance are compared, and if the calculated capacitance is outside the allowable range, the capacitance calculation formula is reset.

[0012] In one embodiment, the display device may include: an active layer; a gate electrode layer disposed on the active layer and at least partially overlapping the active layer; a source electrode layer disposed on the gate electrode layer and at least partially overlapping the gate electrode layer; and a lower electrode layer disposed on the source electrode layer and at least partially overlapping the source electrode layer.

[0013] In one embodiment, the capacitor may be the capacitance between the active layer and the gate electrode layer.

[0014] In one embodiment, the capacitor may be the capacitance between the gate electrode layer and the source electrode layer.

[0015] In one embodiment, the capacitor may be the capacitance between the source electrode layer and the lower electrode layer.

[0016] In one embodiment, the capacitor may be the capacitance between the active layer, the gate electrode layer, and the source electrode layer.

[0017] In one embodiment, the capacitor may be the capacitance between the gate electrode layer, the source electrode layer, and the lower electrode layer.

[0018] In an embodiment, the vapor deposition process may include a chemical vapor deposition process, and the etching process may include a dry etching process.

[0019] A substrate thickness calculation method according to an embodiment of the present invention, for achieving the above-described objectives, in a display device manufacturing process, for calculating the thickness of a substrate based on cleaning parameters for a cleaning process, coating parameters for a coating process, and drying parameters for a drying process, includes: measuring a plurality of measured thicknesses using a thickness measuring device; calculating a plurality of cleaning coefficients for each of the plurality of measured thicknesses corresponding to the cleaning parameters, a plurality of coating coefficients for each of the plurality of measured thicknesses corresponding to the coating parameters, and a plurality of drying coefficients for each of the plurality of measured thicknesses corresponding to the drying parameters; calculating a corrected cleaning coefficient for the plurality of cleaning coefficients, a corrected coating coefficient for the plurality of coating coefficients, and a corrected drying coefficient for the plurality of drying coefficients; and calculating the thickness of the substrate based on a substrate thickness calculation formula including the cleaning parameters, the corrected cleaning coefficient, the coating parameters, the corrected coating coefficient, the drying parameters, and the corrected drying coefficient.

[0020] In one embodiment, the plurality of cleaning coefficients, the plurality of coating coefficients, and the plurality of drying coefficients may be calculated by multiple regression analysis.

[0021] In one embodiment, the corrected cleaning coefficient, the corrected coating coefficient, and the corrected drying coefficient may be calculated using Bayes' theorem.

[0022] In one embodiment, after calculating the thickness, the process may further include: comparing the plurality of measured thicknesses with the calculated thickness, and when the calculated thickness is within an allowable range, applying the thickness calculation formula to perform the manufacturing process of the display device.

[0023] In one embodiment, after calculating the thickness, the plurality of measured thicknesses and the calculated thickness are compared, and if the calculated thickness is outside the allowable range, the thickness calculation formula is reset.

[0024] In one embodiment, the substrate may comprise polyimide.

[0025] (Invention Effects)

[0026] According to an embodiment of the present invention, the capacitance calculation method can measure multiple measurement capacitors using a capacitance measuring device, and calculate multiple evaporation coefficients for the evaporation parameters corresponding to each of the multiple measurement capacitors, multiple exposure coefficients for the exposure parameters corresponding to each of the multiple measurement capacitors, and multiple etching coefficients for the etching parameters corresponding to each of the multiple measurement capacitors. It can also calculate corrected evaporation coefficients for the multiple evaporation coefficients, corrected exposure coefficients for the multiple exposure coefficients, and corrected etching coefficients for the multiple etching coefficients, and calculate the capacitance based on a capacitance calculation formula including the evaporation parameters, the corrected evaporation coefficients, the exposure parameters, the corrected exposure coefficients, the etching parameters, and the corrected etching coefficients.

[0027] Therefore, using the aforementioned capacitance calculation formula, the capacitance of another display device can be calculated in its manufacturing process without additional measurement. This allows for determination of whether the capacitance is within acceptable limits based on the parameters during the manufacturing process of that display device.

[0028] However, the effects of the present invention are not limited to those described above, and various extensions can be made without departing from the concept and scope of the present invention. Attached Figure Description

[0029] Figure 1 This is a plan view illustrating a display device according to an embodiment of the present invention.

[0030] Figure 2 It shows that Figure 1 A cross-sectional view of an embodiment of the display device taken along line I-I'.

[0031] Figure 3 This is a flowchart illustrating a capacitance calculation method according to an embodiment of the present invention.

[0032] Figure 4 This is a graph showing the vapor deposition coefficient, exposure coefficient, and etching coefficient for each of the measured capacitors.

[0033] Figure 5 This is a graph showing the vapor deposition coefficient, exposure coefficient, and etching coefficient for each of the measured capacitors.

[0034] Figure 6 This is a flowchart illustrating a method for calculating the thickness of a substrate according to an embodiment of the present invention.

[0035] Figure 7 It is a graph showing the cleaning factor, coating factor, and drying factor for each of the measured thicknesses.

[0036] Figure 8It is a graph showing the cleaning factor, coating factor, and drying factor for each of the measured thicknesses.

[0037] (Explanation of reference numerals in the attached diagram)

[0038] DA: Display area; PX: Pixels

[0039] 110: Substrate 120: Active layer

[0040] 130: Gate insulating layer; 140: Gate electrode layer

[0041] 150: Interlayer insulation layer; 160: Source electrode layer

[0042] 170: Passivation layer; 180: Through-hole insulation layer

[0043] 200: Drive unit 200a: Fan-out wiring

[0044] 200b: Transmission cabling Detailed Implementation

[0045] Hereinafter, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. The same reference numerals are used for the same components in the drawings, and repeated descriptions of the same components are omitted.

[0046] Figure 1 This is a plan view illustrating a display device according to an embodiment of the present invention.

[0047] Reference Figure 1 The display device may include a display area DA and a non-display area NDA surrounding the display area DA.

[0048] In one embodiment, a plurality of pixels PX can be configured in the display area DA. The pixels PX can be arranged in a matrix across the entire surface of the display area DA. However, this is exemplary, and the pixels PX can be arranged in various forms in the display area DA. The display device can display an image in the display area DA through the pixels PX. The display device may include an organic light-emitting display device. However, this is exemplary, and the display device may include a liquid crystal display device, an electrophoretic display device, a plasma display device, etc.

[0049] In one embodiment, a driving unit 200 for driving the pixel PX may be configured in the non-display area NDA. The driving unit 200 transmits signals (e.g., data signals, power supply voltage, etc.) to the display area DA via fan-out wiring 200a. The driving unit 200 receives the signals via transmission wiring 200b. The driving unit 200 transmits the signals to the display area DA via the fan-out wiring 200a. Figure 1 The diagram shows the driving unit 200 disposed in the non-display area NDA, but it is not limited thereto. For example, the driving unit 200 may also be disposed on the circuit film 300. The circuit film 300 can receive the signal from the outside by being disposed on the non-display area NDA.

[0050] The fan-out wiring 200a may be configured on the non-display area NDA. The fan-out wiring 200a may be configured between the display area DA and the driving unit 200. The fan-out wiring 200a enables electrical connection between the driving unit 200 configured in the non-display area NDA and the pixel PX configured in the display area DA. The fan-out wiring 200a may include data signal wiring, power supply voltage wiring, etc.

[0051] Figure 2 It shows that Figure 1 A cross-sectional view of an embodiment of the display device taken along line I-I'.

[0052] Reference Figure 1 as well as Figure 2 The display device may include a substrate 110, an active layer 120, a gate insulating layer 130, a gate electrode layer 140, an interlayer insulating layer 150, a source electrode layer 160, a passivation layer 170, a via insulating layer 180, a pixel defining film (PDL), and an organic light-emitting diode (OLED). The OLED may include a lower electrode layer 190, an intermediate layer 192, and an upper electrode layer 194. In one embodiment, the active layer 120, the gate electrode layer 140, the source electrode layer 160, the lower electrode layer 190, and the upper electrode layer 194 may be defined as conductive layers.

[0053] The substrate 110 may include a glass substrate, a quartz substrate, a plastic substrate, etc. In one embodiment, the substrate 110 may include a plastic substrate, thereby allowing the display device to have flexible characteristics. In this case, the substrate 110 may have a structure in which at least one organic film layer and at least one barrier layer are alternately stacked. For example, the organic film layer may be formed using an organic substance such as polyimide, and the barrier layer may be formed using an inorganic substance.

[0054] A buffer layer (not shown) may be disposed on the substrate 110. The buffer layer can prevent metal atoms or impurities from diffusing from the substrate 110 to the active layer 120. In addition, during the crystallization process for forming the active layer 120, the buffer layer can be used to uniformly form the active layer 120 by adjusting the heating rate.

[0055] The active layer 120 may be disposed on the buffer layer. In one embodiment, the active layer 120 may include a silicon semiconductor. For example, the silicon semiconductor may include amorphous silicon, polycrystalline silicon, etc. In one embodiment, the active layer 120 may include an oxide semiconductor. For example, the oxide semiconductor may include one or a combination of oxides of zinc, indium, gallium, tin, titanium, and phosphorus. Specifically, the oxide semiconductor may include one or more of zinc oxide, zinc-tin oxide, zinc-indium oxide, indium oxide, titanium oxide, indium gallium-zinc oxide, and indium-zinc-tin oxide.

[0056] The gate insulating layer 130 may be disposed on the active layer 120. The gate insulating layer 130 may function to insulate the active layer 120 and the gate electrode layer 140. The gate insulating layer 130 may contain an insulating material. For example, the gate insulating layer 130 may contain silicon oxide, silicon nitride, titanium oxide, tantalum oxide, etc.

[0057] The gate electrode layer 140 may be disposed on the gate insulating layer 130. A gate signal for applying an on / off signal to a transistor may be applied to the gate electrode layer 140. The gate electrode layer 140 may contain metals, alloys, conductive metal oxides, transparent conductive materials, etc. For example, the gate electrode layer 140 may contain silver, silver-containing alloys, molybdenum, molybdenum-containing alloys, aluminum, aluminum-containing alloys, aluminum nitrides, tungsten, tungsten nitrides, copper, nickel, chromium, chromium nitrides, titanium, tantalum, platinum, scandium, indium tin oxide, indium zinc oxide, etc.

[0058] The interlayer insulating layer 150 may be disposed on the gate electrode layer 140. The interlayer insulating layer 150 may function to insulate the gate electrode layer 140 and the source electrode layer 160. The interlayer insulating layer 150 may contain an insulating material. For example, the interlayer insulating layer 150 may contain silicon oxide, silicon nitride, titanium oxide, tantalum oxide, etc.

[0059] The source electrode layer 160 can be disposed on the interlayer insulating layer 150. The source electrode layer 160 can contain metals, alloys, conductive metal oxides, transparent conductive materials, etc.

[0060] The passivation layer 170 may be disposed on the source electrode layer 160. The passivation layer 170 can eliminate the steps caused by the source electrode layer 160 to prevent defects in the organic light-emitting diode (OLED). The passivation layer 170 may contain insulating materials such as silicon nitride and silicon oxide.

[0061] The via insulating layer 180 may be disposed on the passivation layer 170. The via insulating layer may contain an organic insulating material. For example, the via insulating layer 180 may contain a photoresist, a polyacrylic resin, a polyimide resin, an acrylic resin, etc.

[0062] The lower electrode layer 190 can be disposed on the through-hole insulating layer 180. The lower electrode layer 190 can contain metal, alloy, conductive metal oxide, transparent conductive material, etc. In one embodiment, the lower electrode layer 190 can be used as an anode electrode. In one embodiment, the lower electrode layer 190 can be used as a cathode electrode.

[0063] A pixel delimiting film (PDL) dividing the light-emitting area of ​​each pixel (PX) can be disposed on the through-hole insulating layer 180. The pixel delimiting film (PDL) can be an organic insulating film formed of organic materials. As said organic materials, it can include organic insulating substances such as polypropylene compounds, polyimide compounds, fluorinated carbon compounds such as polytetrafluoroethylene, and benzocyclobutene compounds. The pixel delimiting film (PDL) may include an opening exposing the upper surface of the lower electrode layer 190. In one embodiment, the lower electrode layer 190 can be used as an anode electrode. In one embodiment, the lower electrode layer 190 can be used as a cathode electrode.

[0064] The intermediate layer 192 can be disposed on the lower electrode layer 190. The intermediate layer 192 can be a single layer, but it can also be a multilayer comprising various functional layers. For example, the intermediate layer 192 can have a structure in which a hole injection layer, a hole transport layer, an emission layer, an electron transport layer, and an electron injection layer are stacked, either as a single layer or in combination.

[0065] The upper electrode layer 194 may be disposed on the intermediate layer 192. The upper electrode layer 194 may cover the pixel defining film (PDL) on the intermediate layer 192. In one embodiment, the upper electrode layer 194 may serve as a cathode electrode. In another embodiment, the upper electrode layer 194 may serve as an anode electrode.

[0066] A capacitor can be formed using two conductive layers and an insulating layer disposed between the two conductive layers. The electrical energy stored in the display device can vary depending on the capacitance of the capacitor. The capacitor can perform the function of suppressing sharp voltage rises or falls in the display device. That is, the performance of the display device can vary depending on the capacitance. In one embodiment, the capacitor can be a storage capacitor for storing electrical energy. In another embodiment, the capacitor can also be a parasitic capacitor generated when an electrical signal is applied to the conductive layer.

[0067] Conventionally, after certain steps in the manufacturing process of the display device (e.g., the step of forming the source electrode layer 160, the step of forming the upper electrode layer 194, etc.), the capacitance of the display device can be measured using a capacitance measuring device. However, a drawback in this case is that when the target capacitance cannot be ensured for the display device, the manufacturing yield of the display device decreases due to remanufacturing.

[0068] However, the capacitance calculation method according to the present invention, which will be described below, can calculate the capacitance using a capacitance calculation formula that includes parameters for multiple display device manufacturing processes. Therefore, the capacitance can be determined in advance using the capacitance calculation formula during the manufacturing process of the display device.

[0069] Figure 3 This is a flowchart illustrating a capacitance calculation method according to an embodiment of the present invention. Figure 4 This is a graph showing the vapor deposition coefficient, exposure coefficient, and etching coefficient for each of the measured capacitors.

[0070] Reference Figures 2 to 4 Multiple capacitance measurements can be performed using a capacitance measurement device (S100). The measurement can be performed on a specific area of ​​the display device. For example, the capacitance measurement can be performed on a square area with a length of 200 μm in both the horizontal and vertical directions on a planar diagram. The capacitance measurement can be performed after attaching a first measuring probe to the upper conductive layer and a second measuring probe to the lower conductive layer. In one embodiment, the capacitance measurement can be performed on the active layer 120 and the gate electrode layer 140. For example, the first to m-th capacitance measurements can be performed on the active layer 120 and the gate electrode layer 140 (where m is a natural number greater than 2). Thus, for... Figure 2The measurement of the capacitance of each conductive layer can be performed repeatedly. In one embodiment, the measurement of the capacitance can also be performed on the gate electrode layer 140 and the source electrode layer 160. In one embodiment, the measurement of the capacitance can be performed on the source electrode layer 160 and the lower electrode layer 190. In one embodiment, the measurement of the capacitance can be performed on the active layer 120, the gate electrode layer 140, and the source electrode layer 160. In one embodiment, the measurement of the capacitance can be performed on the gate electrode layer 140, the source electrode layer 160, and the lower electrode layer 190.

[0071] Subsequently, multiple evaporation coefficients, multiple exposure coefficients, and multiple etching coefficients corresponding to each of the plurality of measuring capacitors can be calculated (S110). In one embodiment, the display device can be manufactured using evaporation processes, exposure processes, etching processes, etc. Therefore, the relationship between the parameters and the measuring capacitors can be determined using evaporation parameters for the evaporation process, exposure parameters for the exposure process, etching parameters for the etching process, etc., and the measuring capacitors. In one embodiment, to determine the relationship, the multiple evaporation coefficients, the multiple exposure coefficients, and the multiple etching coefficients can be calculated using multiple regression analysis.

[0072] For example, the capacitance can be calculated as [(dielectric constant * area) / thickness]. Here, the area refers to the overlapping area of ​​the conductive layer and the insulating layer, and the thickness refers to the thickness of the insulating layer. According to the capacitance calculation method of the present invention, the capacitance can be obtained by substituting the etching parameters and the exposure parameters for the area and the evaporation parameters for the thickness.

[0073] In one embodiment, the plurality of vapor deposition coefficients can be calculated for each of the plurality of measuring capacitors corresponding to the vapor deposition parameters. The vapor deposition process may include chemical vapor deposition, physical vapor deposition, spin-coating glass, etc. For example, the vapor deposition parameters may involve any one of vapor deposition temperature, vapor deposition pressure, vapor deposition rate, vapor deposition time, and vapor deposition solution concentration. However, this is illustrative, and the vapor deposition parameters may also include parameters that affect the vapor deposition process.

[0074] In one embodiment, the plurality of exposure coefficients can be calculated for the exposure parameters corresponding to each of the plurality of measuring capacitors. For example, the exposure parameters may involve any one of exposure amount, exposure time, exposure speed, exposure temperature, exhaust pressure, and exhaust time. However, this is illustrative, and the exposure parameters may also include parameters that affect the exposure process.

[0075] In one embodiment, multiple etching coefficients can be calculated for each of the etching parameters corresponding to the plurality of measured capacitors. The etching process may include dry etching, wet etching, laser etching, etc. For example, the etching parameters may involve any one of etching temperature, etching pressure, etching rate, etching time, and the material being etched. However, this is exemplary, and the etching parameters may also include parameters that affect the etching process.

[0076] For example, the first to m-th measurement capacitances for the active layer 120 and the gate electrode layer 140 can be measured. The vapor deposition parameters affecting the first to m-th measurement capacitances may involve the vapor deposition temperature. The exposure parameters affecting the first to m-th measurement capacitances may involve the exposure rate. The etching parameters affecting the first to m-th measurement capacitances may involve the etching time. The vapor deposition coefficient, exposure coefficient, and etching coefficient for the first measurement capacitance can be calculated using the multivariate regression analysis. Furthermore, the vapor deposition coefficient, exposure coefficient, and etching coefficient for the m-th measurement capacitance can be calculated using the multivariate regression analysis.

[0077] Subsequently, the corrected evaporation coefficient, corrected exposure coefficient, and corrected etching coefficient can be calculated (S120). The corrected evaporation coefficient, corrected exposure coefficient, and corrected etching coefficient can be calculated using Bayes' theorem. In one embodiment, the corrected evaporation coefficient, corrected exposure coefficient, and corrected etching coefficient can be calculated using an arithmetic mean. However, this is exemplary, and the corrected evaporation coefficient, corrected exposure coefficient, and corrected etching coefficient can be calculated using various methods. In one embodiment, the corrected evaporation coefficient can be calculated for the plurality of evaporation coefficients. For example, the corrected evaporation coefficient can be calculated using Bayes' theorem for the evaporation coefficients for the first measuring capacitor to the m-th measuring capacitor. The corrected exposure coefficient can be calculated for the plurality of exposure coefficients. For example, the corrected exposure coefficient can be calculated using Bayes' theorem for the exposure coefficients for the first measuring capacitor to the m-th measuring capacitor. The corrected etching coefficient can be calculated for the plurality of etching coefficients. For example, the etch coefficient can be corrected by Bayes' theorem for the etch coefficient from the first measuring capacitor to the etch coefficient for the m-th measuring capacitor.

[0078] Subsequently, the capacitance can be calculated based on the capacitance calculation formula (S130). The capacitance calculation formula may include the evaporation parameters, the corrected evaporation coefficient, the exposure parameters, the corrected exposure coefficient, the etching parameters, and the corrected etching coefficient. For example, the capacitance can be calculated by adding the products of the evaporation parameters and the corrected evaporation coefficient, the exposure parameters and the corrected exposure coefficient, and the etching parameters and the corrected etching coefficient.

[0079] The estimated capacitance based on variations in process conditions, such as those for the vapor deposition, exposure, and etching processes, can be predicted using the capacitance calculation formula. For example, when the manufacturing process of the display device is performed by changing the vapor deposition rate and the etching pressure, the estimated capacitance can be predicted by substituting the changed vapor deposition parameters and the changed etching parameters into the capacitance calculation formula. Therefore, when the display device exhibits an unexpected capacitance, it is possible to determine which parameter is causing the issue based on the estimated capacitance.

[0080] After comparing the calculated capacitance with the measured capacitance (S140), it can be determined whether the capacitance calculation formula is applicable (S150). In one embodiment, when the calculated capacitance is within an acceptable range, the capacitance calculation formula can be applied to continue the manufacturing process of the display device. Furthermore, the capacitance calculation formula can also be used when manufacturing another display device.

[0081] For example, when the difference between the calculated capacitance and the measured capacitance is below a certain range (e.g., below 1% of the measured capacitance), it can be determined that the calculated capacitance is within the allowable range.

[0082] In one embodiment, when the calculated capacitance is outside the allowable range, the capacitance calculation formula can be reset. For example, the correction coefficient can be recalculated by recalculating the plurality of coefficients, thereby resetting the capacitance calculation formula.

[0083] For example, when the calculated capacitance exceeds a certain range (e.g., the difference between the calculated capacitance and the measured capacitance divided by the measured capacitance exceeds 5% of the measured capacitance), it can be determined that the calculated capacitance is outside the allowable range.

[0084] Thus, the capacitance calculation method according to embodiments of the present invention can also calculate the capacitance during the manufacturing process, preventing a decrease in the quality of the display device. Furthermore, the capacitance can be calculated using parameters related to the manufacturing process via the capacitance calculation formula without utilizing the capacitance measuring device. This improves the manufacturing yield of the display device.

[0085] Figure 5 This is a graph showing the vapor deposition coefficient, exposure coefficient, and etching coefficient for each of the measured capacitors.

[0086] Reference Figure 5 The vapor deposition parameters affecting the first to m-th measuring capacitors can be n. For example, the first vapor deposition parameter could be the vapor deposition temperature, the second vapor deposition parameter could be the vapor deposition pressure, the third vapor deposition parameter could be the vapor deposition time, and the nth vapor deposition parameter could be the vapor deposition rate. The exposure parameters affecting the first to m-th measuring capacitors can be p. For example, the first exposure parameter could be the exposure temperature, the second exposure parameter could be the exposure time, the third exposure parameter could be the exposure rate, and the pth exposure parameter could be the exhaust pressure. The etching parameters affecting the first to m-th measuring capacitors can be q. For example, the first etching parameter could be the etching pressure, the second etching parameter could be the etching time, the third etching parameter could be the etching rate, and the qth etching parameter could be the etching temperature (where n, p, and q are natural numbers greater than or equal to 2).

[0087] The first to nth evaporation coefficients corresponding to the first measuring capacitor, up to the first to nth evaporation coefficients corresponding to the mth measuring capacitor, can be calculated using the multivariate regression analysis. Similarly, the first to pth exposure coefficients corresponding to the first measuring capacitor, up to the first to pth exposure coefficients corresponding to the mth measuring capacitor, can be calculated using the multivariate regression analysis. Furthermore, the first to qth etching coefficients corresponding to the first measuring capacitor, up to the first to qth etching coefficients corresponding to the mth measuring capacitor, can be calculated using the multivariate regression analysis.

[0088] For example, a first corrected evaporation coefficient can be calculated using the Bayesian theorem for the first evaporation coefficient for the first measuring capacitor up to the first evaporation coefficient for the m-th measuring capacitor. Additionally, an n-th corrected evaporation coefficient can be calculated using the Bayesian theorem for the n-th evaporation coefficient for the first measuring capacitor up to the n-th evaporation coefficient for the m-th measuring capacitor. This can also be applied to the corrected exposure coefficient and the corrected etching coefficient.

[0089] Figure 6 This is a flowchart illustrating a method for calculating the thickness of a substrate according to an embodiment of the present invention. Figure 7 It is a graph showing the cleaning factor, coating factor, and drying factor for each of the measured thicknesses.

[0090] Reference Figure 6 as well as Figure 7Multiple thickness measurements can be performed using a substrate thickness measuring device (S200). The measurement can be performed on a specific area of ​​the display device. For example, the measurement can be performed multiple times on the same area of ​​the substrate. Alternatively, the measurement can be performed on each of the multiple areas after the substrate has been divided into multiple areas.

[0091] Subsequently, multiple cleaning coefficients, multiple coating coefficients, and multiple drying coefficients corresponding to each of the multiple measured thicknesses can be calculated (S210). In one embodiment, the substrate can be manufactured through a cleaning process, a coating process, a drying process, etc. Therefore, the relationship between the parameters and the measured thickness can be determined using cleaning parameters for the cleaning process, coating parameters for the coating process, drying parameters for the drying process, etc., and the measured thickness. In one embodiment, to determine the relationship, the multiple cleaning coefficients, the multiple coating coefficients, and the multiple drying coefficients can be calculated using multiple regression analysis.

[0092] In one embodiment, a plurality of cleaning coefficients can be calculated for each of the plurality of cleaning parameters corresponding to each of the plurality of measured thicknesses. For example, the cleaning parameters may involve any one of cleaning pressure, cleaning speed, number of cleaning cycles, and cleaning time. However, this is illustrative, and the cleaning parameters may also include parameters that affect the cleaning process.

[0093] In one embodiment, a plurality of coating coefficients can be calculated for each of the coating parameters corresponding to each of the plurality of measured thicknesses. For example, the coating parameters may involve any one of coating time, coating speed, coating temperature, and coating pressure. However, this is illustrative, and the coating parameters may also include parameters that affect the coating process.

[0094] In one embodiment, multiple drying coefficients can be calculated for each of the plurality of measured thicknesses corresponding to the drying parameters. For example, the drying parameters may involve any of drying temperature, drying rate, drying time, and humidity. However, this is illustrative, and the drying parameters may also include parameters that affect the drying process.

[0095] For example, the thicknesses from the first to the mth measurement can be measured. The cleaning parameters affecting the first to the mth measurement thicknesses may involve the cleaning pressure. The coating parameters affecting the first to the mth measurement thicknesses may involve the coating time. The drying parameters affecting the first to the mth measurement thicknesses may involve the drying temperature. The cleaning coefficient, coating coefficient, and drying coefficient for the first measurement thickness can be calculated using the multiple regression analysis. Furthermore, the cleaning coefficient, coating coefficient, and drying coefficient for the mth measurement thickness can also be calculated using the multiple regression analysis.

[0096] Subsequently, a corrected cleaning coefficient, a corrected coating coefficient, and a corrected drying coefficient can be calculated (S220). The corrected cleaning coefficient, the corrected coating coefficient, and the corrected drying coefficient can be calculated using the Bayesian theorem. In one embodiment, the corrected cleaning coefficient, the corrected coating coefficient, and the corrected drying coefficient can be calculated using the arithmetic mean. However, this is illustrative, and the corrected cleaning coefficient, the corrected coating coefficient, and the corrected drying coefficient can be calculated using various methods. In one embodiment, a corrected cleaning coefficient can be calculated for the plurality of cleaning coefficients. For example, the corrected cleaning coefficient can be calculated using the Bayesian theorem for cleaning coefficients from the first measured thickness to the m-th measured thickness. A corrected coating coefficient can be calculated for the plurality of coating coefficients. For example, the corrected coating coefficient can be calculated using the Bayesian theorem for coating coefficients from the first measured thickness to the m-th measured thickness. A corrected drying coefficient can be calculated for the plurality of drying coefficients. For example, the corrected drying coefficient can be calculated using the Bayesian theorem for drying coefficients from the first measured thickness to the m-th measured thickness.

[0097] Subsequently, the thickness of the substrate can be calculated based on a thickness calculation formula (S230). The thickness calculation formula may include the cleaning parameters, the corrected cleaning coefficient, the coating parameters, the corrected coating coefficient, the drying parameters, and the corrected drying coefficient. For example, the thickness of the substrate can be calculated by adding the products of the cleaning parameters and the corrected cleaning coefficient, the coating parameters and the corrected coating coefficient, and the drying parameters and the corrected drying coefficient.

[0098] The thickness can be predicted based on variations in process conditions, such as those for the cleaning process, coating process, and drying process, using the thickness calculation formula. For example, when the substrate manufacturing process is performed by changing the cleaning pressure and the coating temperature, the predicted thickness can be predicted by substituting the changed cleaning parameters and the changed coating parameters into the thickness calculation formula. Therefore, when the substrate has a thickness that is not predicted, it is possible to determine which parameter is causing the issue based on the predicted thickness.

[0099] After comparing the calculated thickness with the measured thickness (S240), it can be determined whether the thickness calculation formula is applicable (S250). In one embodiment, when the calculated thickness is within an allowable range, the thickness calculation formula can be applied to continue the manufacturing process of the display device. The thickness calculation formula can also be used when manufacturing another display device.

[0100] For example, when the difference between the calculated thickness and the measured thickness is below a certain range (e.g., below 0.5% of the measured thickness), it can be determined that the calculated thickness is within the allowable range.

[0101] In one embodiment, when the calculated thickness is outside the allowable range, the thickness calculation formula can be reset. For example, the correction coefficients can be recalculated to reset the thickness calculation formula.

[0102] For example, when the calculated thickness exceeds a certain range (e.g., the difference between the calculated thickness and the measured thickness divided by the measured thickness exceeds 2% of the measured thickness), it can be determined that the calculated thickness is outside the allowable range.

[0103] Figure 8 It is a graph showing the cleaning factor, coating factor, and drying factor for each of the measured thicknesses.

[0104] Reference Figure 8There can be n cleaning parameters affecting the first to m measured thicknesses. For example, the first cleaning parameter could be the cleaning temperature, the second cleaning parameter the cleaning pressure, the third cleaning parameter the cleaning time, and the nth cleaning parameter the cleaning speed. There can be p coating parameters affecting the first to m measured thicknesses. For example, the first coating parameter could be the coating temperature, the second coating parameter the coating time, the third coating parameter the coating speed, and the pth coating parameter the coating pressure. There can be q drying parameters affecting the first to m measured thicknesses. For example, the first drying parameter could be the drying pressure, the second drying parameter the drying time, the third drying parameter the drying speed, and the qth etching parameter the drying temperature.

[0105] The first to nth cleaning coefficients corresponding to the first measured thickness can be calculated using the multiple regression analysis. The first to nth cleaning coefficients corresponding to the mth measured thickness can be calculated using the multiple regression analysis. The first to pth coating coefficients corresponding to the first measured thickness can be calculated using the multiple regression analysis. The first to pth coating coefficients corresponding to the mth measured thickness can be calculated using the multiple regression analysis. The first to qth drying coefficients corresponding to the first measured thickness can be calculated using the multiple regression analysis. The first to qth drying coefficients corresponding to the mth measured thickness can be calculated using the multiple regression analysis.

[0106] For example, a first corrected cleaning coefficient can be calculated using the Bayesian theorem for the first cleaning coefficient for the first measured thickness up to the first cleaning coefficient for the m-th measured thickness. Additionally, an n-th corrected cleaning coefficient can be calculated using the Bayesian theorem for the n-th cleaning coefficient for the first measured thickness up to the n-th cleaning coefficient for the m-th measured thickness. This can also be applied to the corrected coating coefficient and the corrected drying coefficient.

[0107] Thus, the substrate thickness calculation method according to embodiments of the present invention can also calculate the substrate thickness during the manufacturing process, preventing a reduction in the quality of the display device. Furthermore, the presence of defects in the display device can be determined during the manufacturing process based on these parameters without the need for additional measurements, thereby improving the manufacturing yield of the display device.

[0108] As described above, although the invention has been described with reference to exemplary embodiments, those skilled in the art will understand that various modifications and alterations can be made to the invention without departing from the concept and scope of the invention as set forth in the claims.

[0109] (Industry availability)

[0110] This invention can be applied to capacitance calculation methods and substrate thickness calculation methods. For example, it can be applied when calculating the capacitance and substrate thickness of high-resolution smartphones, mobile phones, smart tablets, smartwatches, tablet PCs, vehicle navigation systems, televisions, computer monitors, laptops, etc.

Claims

1. A capacitance calculation method, wherein, in the manufacturing process of a display device, capacitance is calculated based on vapor deposition parameters for a vapor deposition process, exposure parameters for an exposure process, and etching parameters for an etching process, wherein, The capacitance calculation method includes: The steps for measuring multiple capacitances using a capacitance measuring device; The steps include calculating multiple evaporation coefficients for each of the multiple measurement capacitors, multiple exposure coefficients for each of the multiple measurement capacitors, and multiple etching coefficients for each of the multiple measurement capacitors. The steps of calculating the corrected evaporation coefficient for the plurality of evaporation coefficients, the corrected exposure coefficient for the plurality of exposure coefficients, and the corrected etch coefficient for the plurality of etch coefficients; and The step of calculating the capacitance by adding together the products of the evaporation parameters and the corrected evaporation coefficient, the exposure parameters and the corrected exposure coefficient, and the etching parameters and the corrected etching coefficient. The evaporation coefficient is used to determine the relationship between the evaporation parameters and the measurement capacitance; the exposure coefficient is used to determine the relationship between the exposure parameters and the measurement capacitance; and the etching coefficient is used to determine the relationship between the etching parameters and the measurement capacitance. The plurality of evaporation coefficients, the plurality of exposure coefficients, and the plurality of etching coefficients were calculated through multiple regression analysis. The corrected evaporation coefficient, the corrected exposure coefficient, and the corrected etching coefficient are calculated using Bayes' theorem.

2. The capacitance calculation method according to claim 1, characterized in that, After the step of calculating the capacitance By comparing the plurality of measured capacitances with the calculated capacitance, and when the calculated capacitance is within an allowable range, the capacitance calculation formula is applied to perform the manufacturing process of the display device.

3. The capacitance calculation method according to claim 1, characterized in that, After the step of calculating the capacitance The multiple measured capacitances and the calculated capacitance are compared, and when the calculated capacitance is outside the allowable range, the capacitance calculation formula is reset.

4. The capacitance calculation method according to claim 1, characterized in that, The display device includes: Active layer; A gate electrode layer is disposed on the active layer and at least partially overlaps the active layer; A source electrode layer, disposed on the gate electrode layer, and at least partially overlapping the gate electrode layer; and The lower electrode layer is disposed on the source electrode layer and at least partially overlaps the source electrode layer.

5. The capacitance calculation method according to claim 4, characterized in that, The capacitor is the capacitance between the active layer and the gate electrode layer.

6. The capacitance calculation method according to claim 4, characterized in that, The capacitance is the capacitance between the gate electrode layer and the source electrode layer.

7. The capacitance calculation method according to claim 4, characterized in that, The capacitance is the capacitance between the source electrode layer and the lower electrode layer.

8. The capacitance calculation method according to claim 4, characterized in that, The capacitor is the capacitance between the active layer, the gate electrode layer, and the source electrode layer.

9. The capacitance calculation method according to claim 4, characterized in that, The capacitance is the capacitance between the gate electrode layer, the source electrode layer, and the lower electrode layer.

10. The capacitance calculation method according to claim 4, characterized in that, The vapor deposition process includes chemical vapor deposition, and the etching process includes dry etching.

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