A device that applies voltage to a liquid.

Abstract

To improve the durability and reliability of devices that apply voltage to liquids. [Solution] The first substrate (CB1) includes a support (SB1), a plurality of first electrodes (E1), a first wiring (W1) located between the support (SB1) and the first electrodes (E1), a first organic insulating film (PLN1) located between the first wiring (W1) and the first electrodes (E1), a second organic insulating film (PLN2) located between the first organic insulating film (PLN1) and the first electrodes (E1), and a metal layer (ML) located between the first organic insulating film (PLN1) and the second organic insulating film (PLN2) and formed from a metal that is not eroded by the liquid (100).

Description

[Technical Field]

[0001] This disclosure relates to an apparatus for applying voltage to a liquid. [Background technology]

[0002] Various devices utilizing electrowetting have been developed. Patent document 1 discloses an electrowetting display. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Special Publication No. 2016-535866 (published on November 17, 2016) [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] However, not only in electrowetting equipment, but also in devices that apply voltage to liquids, such as devices that measure the potential of liquids, devices that perform electrophoresis, and devices that utilize the electrical reactions of liquids, liquid can penetrate into the internal wiring of the device. Although protective layers are provided to reduce liquid penetration, cracks can develop in the protective layer, and the wiring below the protective layer can be eroded by the liquid. Such erosion reduces the durability and reliability of the device.

[0005] One aspect of this disclosure aims to improve the durability and reliability of a device for applying voltage to a liquid. [Means for solving the problem]

[0006] To solve the above problems, an apparatus for applying voltage to a liquid according to one aspect of the present disclosure is an apparatus for applying voltage to a liquid, comprising: a support; a plurality of first electrodes; a first substrate including a support; a plurality of first electrodes; a first wiring positioned between the support and the plurality of first electrodes; a first organic insulating film positioned between the first wiring and the plurality of first electrodes; a second organic insulating film positioned between the first organic insulating film and the plurality of first electrodes; a metal layer positioned between the first organic insulating film and the second organic insulating film and formed from a metal that is not eroded by the liquid; and a second substrate including a second electrode facing the plurality of first electrodes, wherein a gap is maintained between the first substrate and the second substrate into which the liquid is injected or into which the liquid can be injected. [Effects of the Invention]

[0007] According to one aspect of this disclosure, the durability and reliability of a device for applying voltage to a liquid can be improved. [Brief explanation of the drawing]

[0008] [Figure 1] This is a partial cross-sectional view showing an example of the configuration of an electrowetting apparatus according to one embodiment of the present disclosure. [Figure 2] This is a partial plan view showing an example of the configuration of the first wiring in the electrowetting apparatus shown in Figure 1. [Figure 3] This is a partial plan view showing another example of the configuration of the first wiring in the electrowetting apparatus shown in Figure 1. [Figure 4] This is a partial plan view showing yet another configuration example of the first wiring in the electrowetting apparatus shown in Figure 1, along with a portion of the second wiring. [Figure 5] This is a partial cross-sectional view showing section AA of Figure 4. [Figure 6] This is a partial plan view showing yet another configuration example of the first wiring in the electrowetting apparatus shown in Figure 1, along with a portion of the second wiring. [Figure 7] These are partial cross-sectional views showing section AA in Figures 6 and 8. [Figure 8]This is a partial cross-sectional view showing the BB cross section of FIG. 6 and FIG. 7. [Figure 9] This is a flow diagram showing an example of the method for manufacturing the electrowetting apparatus illustrated in FIG. 1. [Figure 10] This is a partial cross-sectional view showing a configuration example of an electrowetting apparatus according to an embodiment of the present disclosure. [Figure 11] This is a partial plan view showing a configuration example of the first wiring in the electrowetting apparatus illustrated in FIG. 10, together with a part of the second wiring. [Figure 12] This is a partial cross-sectional view showing the AA cross section of FIG. 11. [Figure 13] This is a partial plan view showing another configuration example of the first wiring in the electrowetting apparatus illustrated in FIG. 10, together with a part of the second wiring. [Figure 14] This is a partial cross-sectional view showing the AA cross section of FIG. 13. [Figure 15] This is a partial cross-sectional view showing a configuration example of an electrowetting apparatus according to an embodiment of the present disclosure. [Figure 16] This is a partial plan view showing a configuration example of the first wiring in the electrowetting apparatus illustrated in FIG. 15, together with a part of the second wiring. [Figure 17] This is a partial cross-sectional view showing the AA cross section of FIG. 16. [Figure 18] This is a partial plan view showing another configuration example of the first wiring in the electrowetting apparatus illustrated in FIG. 15, together with a part of the second wiring. [Figure 19] This is a partial cross-sectional view showing the AA cross section of FIG. 18. [Figure 20] This is a partial cross-sectional view showing a configuration example of an electrowetting apparatus according to an embodiment of the present disclosure. [Figure 21] This is a partial plan view showing a configuration example of the first wiring in the electrowetting apparatus illustrated in FIG. 20, together with a part of the second wiring. [Figure 22] This is a partial cross-sectional view showing the AA cross section of FIG. 21. [Figure 23]Figure 20 is a partial plan view showing another example of the configuration of the first wiring in the electrowetting apparatus, along with a portion of the second wiring. [Figure 24] This is a partial cross-sectional view showing section AA in Figure 23. [Figure 25] This is a partial cross-sectional view showing an example of the configuration of an electrowetting apparatus according to one embodiment of the present disclosure. [Modes for carrying out the invention]

[0009] For the sake of simplicity, the following examples illustrate electrowetting apparatuses that utilize electrowetting. However, the scope of this disclosure is not limited to electrowetting apparatuses, but includes apparatuses that apply voltage to liquids, such as apparatuses that measure the potential of liquids, apparatuses that perform electrophoresis, and apparatuses that utilize the electrical reactions of liquids.

[0010] [Embodiment 1] One embodiment of this disclosure is described below.

[0011] (Configuration of the electrowetting device) Figure 1 is a partial cross-sectional view showing an example configuration of an electrowetting apparatus EWA according to one embodiment of the present disclosure. As shown in Figure 1, the electrowetting apparatus EWA according to the present disclosure is an apparatus for applying a voltage to a liquid 100, comprising a first substrate CB1 and a second substrate CB2, wherein a gap GP into which the liquid 100 is injected or into which the liquid 100 can be injected is maintained between the first substrate CB1 and the second substrate CB2. The first substrate CB1 includes a support SB1, a plurality of first electrodes E1, a first wiring W1 located between the support SB1 and the plurality of first electrodes E1, a first organic insulating film PLN1 located between the first wiring W1 and the plurality of first electrodes E1, a second organic insulating film PLN2 located between the first organic insulating film PLN1 and the plurality of first electrodes E1, and a metal layer ML located between the first organic insulating film PLN1 and the second organic insulating film PLN2 and formed from a metal that is not eroded by the liquid 100. The second substrate CB2 includes a second electrode E2 facing the plurality of first electrodes E1.

[0012] The electrowetting apparatus EWA selects one or more first electrodes E1 from a plurality of first electrodes E1 and applies a voltage between the selected first electrodes E1 and second electrodes E2. As a result, a voltage is applied to the portion of the liquid 100 corresponding to the selected first electrodes E1.

[0013] According to the above configuration, the electrowetting apparatus EWA according to this disclosure includes a protective layer PL between the first wiring W1 and a plurality of first electrodes E1, which includes a first organic insulating film PLN1, a second organic insulating film PLN2, and a metal layer ML located between the first organic insulating film PLN1 and the second organic insulating film PLN2 and formed from a metal that is not eroded by the liquid 100. Compared with conventional electrowetting apparatuses in which the protective layer consists of only one organic insulating layer, the protective layer PL according to this disclosure is less susceptible to cracks penetrating in the thickness direction for the following two reasons. One reason is that the total thickness of the protective layer PL according to this disclosure is large due to the plurality of organic insulating films PLN1 and PLN2. The other reason is that even if a crack occurs in any of the plurality of organic insulating films PLN1 and PLN2, the crack is more likely to stop between the plurality of organic insulating films PLN1 and PLN2.

[0014] According to the above configuration in this disclosure, the presence of a metal layer ML within the protective layer PL makes it easy to electrically connect the first electrode E1 to the first wiring W1, even if the total thickness of the protective layer PL is large. This is because the connection from the first electrode E1 to the first wiring W1 can be realized by dividing it into a connection from the first electrode E1 to the metal layer ML and a connection from the metal layer ML to the first wiring W1.

[0015] In this disclosure, "upper," "upper side," and "upward direction" refer to the side on which the second substrate CB2 is located relative to the first substrate CB1, and this direction is defined as the positive Z-axis direction. "Downward," "lower side," and "downward direction" refer to the side on which the first substrate CB1 is located relative to the second substrate CB2, and this direction is defined as the negative Z-axis direction. "Lateral" and "lateral direction" refer to directions perpendicular to the Z-axis, with one of the directions perpendicular to the Z-axis being defined as the X-axis direction, and the direction perpendicular to both the Z-axis and the X-axis being defined as the Y-axis direction.

[0016] In this disclosure, "cross-sectional view" means a view from a direction perpendicular to the Z-axis, and "plan view" means a view from the Z-axis direction. In this disclosure, "thickness," "height," and "depth" refer to the size in the Z-axis direction.

[0017] The first substrate CB1 may further include a first inorganic insulating film ILD1 located between the first wiring W1 and a plurality of first electrodes. The inorganic film is denser than the organic film and can further reduce the penetration of liquid 100. Therefore, the first inorganic insulating film ILD1 can further reduce the penetration of liquid 100 into the first wiring W1.

[0018] The first inorganic insulating film ILD1 may be located between the first organic insulating film PLN1 and the second organic insulating film PLN2. The first inorganic insulating film ILD1 reduces the penetration of liquid 100 into the first organic insulating film PLN1, reduces swelling of the first organic insulating film PLN1, and reduces the occurrence of cracks in the first organic insulating film PLN1. Therefore, it is difficult for liquid 100 to reach the first wiring W1.

[0019] The first substrate CB1 may further include a second inorganic insulating film ILD2 located between the second organic insulating film PLN2 and a plurality of first electrodes E1. The second inorganic insulating film ILD2 reduces the penetration of liquid 100 into the second organic insulating film PLN2, reduces swelling of the second organic insulating film PLN2, and reduces the occurrence of cracks in the second organic insulating film PLN2. Therefore, the liquid 100 is difficult to reach through the first wiring W1.

[0020] The first substrate CB1 further comprises a first through-conductor TH1 penetrating the first organic insulating film PLN1 and a second through-conductor TH2 penetrating the second organic insulating film. One of the plurality of first electrodes E1 is connected to a metal layer ML through the second through-conductor TH2, and the metal layer ML is connected to a first wiring W1 through the first through-conductor TH1. Therefore, one of the plurality of first electrodes E1 can be electrically connected to the first wiring W1 through the second through-conductor TH2, the metal layer ML, and the first through-conductor TH1. In a plan view, the second through-conductor TH2 is preferably separated from the first through-conductor TH1. Because they are separated, even if the liquid 100 reaches the metal layer ML along the second through-conductor TH2, it is difficult for the liquid 100 to reach the first through-conductor TH1. Therefore, it is difficult for the liquid 100 to reach the first wiring W1.

[0021] The first substrate CB1 may include a plurality of first through conductors TH1 and a plurality of second through conductors TH2 to correspond to a plurality of first electrodes E1. In this case, the metal layer ML includes a plurality of intermediate electrodes ME corresponding to the plurality of first electrodes E1, and the first wiring W1 includes a plurality of connecting electrodes CE corresponding to the plurality of first electrodes E1. Each of the plurality of first electrodes E1 is connected to the corresponding connecting electrode CE via the corresponding second through conductor TH2, the corresponding intermediate electrode ME, and the corresponding first through conductor TH1.

[0022] The first wiring W1 may be a wiring that contains metal that is corroded by the liquid 100. The first wiring W1 may be the wiring in the first substrate CB1 that contains metal that is corroded by the liquid 100 and is closest to the plurality of first electrodes E1 (located furthest up in Figure 1). The first substrate CB1 includes one or more wirings located between the support SB1 and the first wiring W1, for example, a second wiring W2 and a third wiring W3. One or both of the second wiring W2 and the third wiring W3 may be wiring that contains metal that is corroded by the liquid 100. Because the liquid 100 has difficulty reaching the first wiring W1, the liquid 100 also has difficulty reaching the remaining wirings that are further from the first electrodes E1 than the first wiring W1.

[0023] The first substrate CB1 is located between the support SB1 and the first wiring W1 and further comprises a plurality of circuit elements TR corresponding to a plurality of first electrodes E1. The first substrate CB1 may include a circuit layer CL located between the support SB1 and the protective layer PL. The circuit layer CL may include one or more wirings W1, W2, W3 and one or more semiconductor layers SC. The semiconductor layer SC may include an oxide semiconductor such as low-temperature polysilicon (LTPS), amorphous silicon, and indium gallium tin oxide (InGaZnO). The semiconductor layer SC may include either a p-type semiconductor or an n-type semiconductor. The circuit layer CL may include both a p-type semiconductor layer and an n-type semiconductor layer. The circuit element TR may be a transistor having a channel made of the semiconductor layer SC.

[0024] The first substrate CB1 may include a third inorganic insulating film ILD3 located between the first wiring W1 and the second wiring W2.

[0025] The first substrate CB1 may include a liquid-repellent layer WR1 located on the opposite side of the support SB1 from the plurality of first electrodes E1, which repels the liquid 100, and a fourth inorganic insulating film ILD4 located between the plurality of first electrodes E1 and the liquid-repellent layer WR1. The liquid-repellent layer WR1 and the fourth inorganic insulating film ILD4 can cover the plurality of first electrodes E1, reducing contact between the liquid 100 and any one or more of the plurality of first electrodes E1. The liquid-repellent layer WR1 and the fourth inorganic insulating film ILD4 can cover the second organic insulating film PLN2, reducing penetration of the liquid 100 into the second organic insulating film PLN2. The liquid-repellent layer WR1 and the fourth inorganic insulating film ILD4 can reduce penetration of the liquid 100 beyond the second organic insulating film PLN2 towards the support SB1 side (lower side in Figure 1) along the lower surface of the first electrodes E1 and the side surface of the second through-conductor TH2. Therefore, the durability and reliability of the electrowetting apparatus EWA can be further improved.

[0026] The liquid-repellent layer WR1 and the fourth inorganic insulating film ILD4 may be dielectrics. The electrowetting apparatus EWA may be an EWOD (Electrowetting on Dielectric) apparatus in which multiple first electrodes E1 are coated with dielectrics.

[0027] The first substrate CB1 may include a fifth inorganic insulating film ILD5 located between the metal layer ML and the second organic insulating film PLN2, and the first inorganic insulating film ILD1 may be located between the first organic insulating film PLN1 and the metal layer ML. The circuit layer CL of the first substrate CB1 may include a third inorganic insulating film ILD3 located between the first wiring W1 and the second wiring W2, an inorganic insulating film ILD6 located between the first wiring W1 and the first organic insulating film PLN1, an inorganic insulating film ILD7 located between the third wiring W3 and the second wiring W2, an inorganic insulating film ILD8 located between the semiconductor layer SC and the third wiring W3, and an inorganic insulating film ILD9 located between the support SB1 and the third wiring W3.

[0028] The second substrate CB2 may include a support SB2, a liquid-repellent layer WR2 located on the opposite side of the support SB2 from the second electrode E2 and repelling the liquid 100, and an inorganic insulating film ILD10 located between the second electrode E2 and the liquid-repellent layer WR2. The liquid-repellent layer WR2 and the inorganic insulating film ILD10 can cover the second electrode E2, reducing contact between the liquid 100 and the second electrode E2.

[0029] (Wiring configuration) Figure 2 is a partial plan view showing an example configuration of the first wiring W1 in the electrowetting apparatus EWA shown in Figure 1. To aid in understanding Figure 2, the first wiring W1 in Figure 2 is hatched in the same way as in Figure 1. As shown in Figures 1 and 2, the first wiring W1 may include (i) a plurality of connecting electrodes CE that are connected to both a corresponding one of a plurality of first electrodes E1 and a corresponding one of a plurality of circuit elements TR, and (ii) a single supply electrode FE that is not connected to any of the plurality of first electrodes E1 but is connected to each of the plurality of circuit elements TR. The area of ​​the supply electrode FE in plan view is preferably small. For example, the area of ​​the supply electrode FE in plan view is preferably 80% or less, more preferably 50% or less, and even more preferably 30% or less of the area of ​​the first substrate CB1 in plan view. Because the area of ​​the supply electrode FE is small, even if a crack penetrates the protective layer PL in the thickness direction, the probability that the supply electrode FE is present beyond the crack is small. Therefore, the probability of liquid 100 eroding the supply electrode FE through the crack is small.

[0030] Figure 3 is a partial plan view showing another configuration example of the first wiring W1 in the electrowetting apparatus EWA shown in Figure 1. To aid in understanding Figure 3, the first wiring W1 in Figure 3 is hatched in the same way as in Figure 1. As shown in Figures 1 and 3, the first wiring W1 may include (i) a plurality of connecting electrodes CE, each connected to both a corresponding one of a plurality of first electrodes E1 and a corresponding one of a plurality of circuit elements TR, and (ii) a plurality of supply electrodes FE, each not connected to any of the plurality of first electrodes E1 but connected to one or more corresponding circuit elements TR.

[0031] According to the configuration shown in Figure 3, the multiple supply electrodes FE are separated from each other and from the multiple connecting electrodes CE in a plan view. Because the supply electrodes FE are separated from each other and from the connecting electrodes CE, even if the liquid 100 reaches one of the multiple supply electrodes FE, it is difficult for the liquid 100 to reach the other supply electrodes FE and connecting electrodes CE. Therefore, the number of circuit elements TR that are damaged in relation to the corresponding supply electrode FE by a single crack can be limited to a portion of the multiple circuit elements TR. For this reason, a design that allows the electrowetting device EWA to function even if some of the circuit elements TR are damaged, a so-called "highly redundant design," is beneficial. Hereafter, for the sake of simplicity, "circuit elements TR that are damaged in relation to the corresponding supply electrode FE" will be abbreviated as "damaged circuit elements TR."

[0032] Figure 4 is a partial plan view showing yet another configuration example of the first wiring W1 in the electrowetting apparatus EWA shown in Figure 1, along with a portion of the second wiring W2. Figure 5 is a partial cross-sectional view showing section AA of Figure 4. For the sake of simplicity, the second wiring W2 in Figures 4 and 5 shows only the relay electrodes BE connected to two or more supply electrodes FE. As shown in Figures 1 and 4 to 5, the first substrate CB1 further comprises a second wiring W2 located between a plurality of circuit elements TR and a first organic insulating film PLN1, and the first wiring W1 includes (i) a plurality of connecting electrodes CE each connected to one corresponding first electrode E1 and one corresponding circuit element TR, and (ii) a plurality of supply electrodes FE that are not connected to any of the plurality of first electrodes E1 but each connected to one or more corresponding circuit elements TR, then the second wiring W2 may include a plurality of relay electrodes BE each connected to two or more corresponding supply electrodes FE.

[0033] As can be seen from the comparison in Figures 2 to 4, the relay electrode BE can divide the supply electrode FE in both the row and column directions (both the X and Y directions). Therefore, the number of circuit elements TR damaged by a single crack can be further reduced.

[0034] Figure 6 is a partial plan view showing yet another configuration example of the first wiring W1 in the electrowetting apparatus EWA shown in Figure 1, along with a portion of the second wiring W2. Figure 7 is a partial cross-sectional view showing section AA of Figures 6 and 8. Figure 8 is a partial cross-sectional view showing section BB of Figures 6 and 7. For the sake of simplicity in the drawings, the second wiring W2 in Figure 6 shows only the relay electrode BE connected to two or more supply electrodes FE.

[0035] As shown in Figures 1 and 6 to 8, the multiple circuit elements TR may include a first circuit element TR1, a second circuit element TR2 adjacent to the first circuit element TR1 on one side in the row direction (X direction), a third circuit element TR3 adjacent to the first circuit element TR1 on one side in the column direction (Y direction), and a fourth circuit element TR4 adjacent to the first circuit element TR1 on the other side in the column direction (Y direction). The multiple supply electrodes FE may include a first supply electrode FE1 corresponding to the first circuit element TR1, a second supply electrode FE2 corresponding to the second circuit element TR2, a third supply electrode FE3 corresponding to the third circuit element TR3, and a fourth supply electrode FE4 corresponding to the fourth circuit element TR4. In this case, the multiple relay electrodes BE may include a first relay electrode BE1 connected to a first supply electrode FE1 and a second supply electrode FE2, a second relay electrode BE2 connected to a first supply electrode FE1 and a third supply electrode FE3, and a third relay electrode BE3 connected to a first supply electrode FE1 and a fourth supply electrode FE4.

[0036] According to the configuration example shown in Figures 6 to 8, even if the liquid 100 erodes the third supply electrode FE3, power is supplied to the first supply electrode FE and the fourth supply electrode FE4 through the second supply electrode FE2. Therefore, even if a crack occurs that causes the liquid 100 to reach the third supply electrode FE3, the first circuit element TR1 and the fourth circuit element TR4 can still operate. Similarly, even if a crack occurs that causes the liquid 100 to reach the fourth supply electrode FE, the first circuit element TR1 and the third circuit element TR3 can still operate. Thus, the number of circuit elements TR damaged by a single crack can be further reduced. In addition, line defects that damage multiple circuit elements TR arranged in a column direction, such as the first, third, and fourth circuit elements TR1, TR3, and TR4, can be reduced.

[0037] In addition to the metal layer ML, it is beneficial that the first electrode E1, the first through-conductor TH1, and the second through-conductor TH2 are also formed from metals that are not corroded by the liquid 100. The metal layer ML, the first electrode E1, the first through-conductor TH1, and the second through-conductor TH2 may be formed from the same metal or from different metals.

[0038] (Metals that are not corroded by liquids) A metal that is not corroded by liquid 100 is a noble metal or a metal that reacts with liquid 100 to form a passivation layer. A metal that is corroded by liquid 100 is a metal that does not react with liquid 100 to form a passivation layer. In this disclosure, “noble metal” includes gold (Au), silver (Ag), platinum (Pt), palladium (Pd), iridium (Ir), and rhodium (Rh). In this disclosure, “noble metal” further includes alloys composed of two or more metals selected from the group consisting of gold, silver, platinum, palladium, iridium, and rhodium. A component is formed from a noble metal when, in molar ratio, noble metal elements account for 10% or more, preferably 50% or more, and more preferably 80% or more of the composition of that component. In this disclosure, “base metal” and “base metal element” are metals (elements) that are not noble metals (elements).

[0039] Liquid 100 is a liquid selected from the group consisting of ionic liquids, polar liquids such as water and alcohol, and electrolyte solutions. Ionic liquids are molten salts, preferably room-temperature molten salts, that have a melting point of 100°C or less. For this reason, liquid 100 is prone to eroding base metals. Some base metals, such as titanium (Ti), niobium (Nb), tungsten (W), chromium (Cr), and nickel (Ni), form a passivation layer with liquid 100, while others, such as aluminum (Al), molybdenum (Mo), and copper (Cu), do not form a passivation layer with liquid 100. When the metal layer ML is formed from a base metal that becomes passivated, when liquid 100 comes into contact with the metal layer ML, a passivation layer is formed on the surface of the metal layer ML, protecting the interior of the metal layer ML. Therefore, even if liquid 100 penetrates to the metal layer ML, the metal layer ML can still contribute to electrical conduction between the first electrode E1 and the first wiring W1. The increase in electrical resistance of the metal layer ML due to the formation of a passivation layer is either negligible in practical terms, or the metal layer ML can be designed with this increase in electrical resistance in mind.

[0040] It is beneficial that the metal not eroded by liquid 100 is a base metal that reacts with liquid 100 to form a passivation layer. Precious metals cannot be wet-etched or dry-etched, making it difficult to process them into desired shapes. On the other hand, base metals can be etched, making it easy to pattern the metal layer ML. The metal not eroded by liquid 100 may be, for example, one metal selected from the group consisting of titanium, niobium, tungsten, chromium, and nickel, or an alloy consisting of two or more metals selected from the group.

[0041] (Manufacturing method) Figure 9 is a flowchart showing an example of a manufacturing method for the electrowetting apparatus EWA shown in Figure 1. As shown in Figure 9, a support SB1 of the first substrate CB1 is prepared (step S110), and a circuit layer CL is formed on the support SB1 (step S120).

[0042] A first organic insulating film PLN1 is formed on the circuit layer CL (step S130), and a contact hole CH1 is formed in the first organic insulating film PLN1 that penetrates the first organic insulating film PLN1 (step S140). The first organic insulating film PLN1 may be formed by coating and solidifying a liquid containing an organic resin such as an allyl resin and a polyimide resin on the circuit layer CL. Preferably, the first organic insulating film PLN1 is formed from a photosensitive resin, so-called photoresist, so that the contact hole CH1 can be formed using photolithography technology.

[0043] Then, a first inorganic insulating film ILD1 is formed on the first organic insulating film PLN1 (step S150). The first inorganic insulating film ILD1 is silicon oxide (SiO x ), silicon nitride (SiO x ) or silicon oxide nitride (SiO x N y The material may be a single layer containing ) or a multilayer in which silicon oxide and silicon nitride are alternately stacked. A metal layer ML is formed on the first inorganic insulating film ILD1, and the first through-conductor TH1 is formed in each of the multiple contact holes CH1 of the first organic insulating film PLN1 (step S160).

[0044] Then, a fifth inorganic insulating film ILD5 is formed on the metal layer ML (step S170). The fifth inorganic insulating film ILD5 is silicon oxide (SiO x ), silicon nitride (SiO x ) or silicon oxide nitride (SiO x N y) may be a single layer, or may be a multilayer in which silicon oxide and silicon nitride are alternately laminated. A second organic insulating film PLN2 is formed on the fifth inorganic insulating film ILD5 (step S180), and a contact hole CH2 penetrating the second organic insulating film PLN2 is formed in the second organic insulating film PLN2 (step S190). The second organic insulating film PLN2 may be formed by applying and solidifying a liquid containing an organic resin such as an allyl-based resin and a polyimide-based resin on the fifth inorganic insulating film ILD5. The second organic insulating film PLN2 is preferably formed from a photoresist so that the contact hole CH2 can be formed using a photolithography technique.

[0045] Then, a second inorganic insulating film ILD2 is formed on the second organic insulating film PLN2 (step S210). The second inorganic insulating film ILD2 is made of silicon oxide (SiO x ), silicon nitride (SiO x ), or silicon oxynitride (SiO x N y ) may be a single layer, or may be a multilayer in which silicon oxide and silicon nitride are alternately laminated. A plurality of first electrodes E1 are formed on the second inorganic insulating film ILD2, and second through conductors TH2 are formed in each of the plurality of contact holes CH2 of the second organic insulating film PLN2 (step S220).

[0046] Then, a fourth inorganic insulating film ILD4 is formed on the plurality of first electrodes E1 (step S230). The fourth inorganic insulating film ILD4 is made of silicon oxide (SiO x ), silicon nitride (SiO x ), or silicon oxynitride (SiO x N y ) may be a single layer, or may be a multilayer in which silicon oxide and silicon nitride are alternately laminated. The fourth inorganic insulating film ILD4 may be formed by depositing any one or more of silicon nitride, silicon oxide, and silicon nitride oxide to a total thickness of 100 nm or more and 400 nm or less.

[0047] A liquid-repellent layer WR1 is formed on the fourth inorganic insulating film ILD4 (step S240). The liquid-repellent layer WR1 may be formed by applying and drying a water-repellent surface treatment agent, such as a fluorine-based coating agent, to the fourth inorganic insulating film ILD4. The application method may be any method, such as dip coating, slit coating, or printing. The thickness of the liquid-repellent layer WR1 may be 30 nm or more and 100 nm or less. As a result, the first substrate CB1 is formed (step S100).

[0048] Furthermore, a support SB2 for the second substrate CB2 is prepared (step S310), a second electrode E2 is formed on the support SB2 (step S320), an inorganic insulating film ILD10 is formed on the second electrode E2 (step S330), and a liquid-repellent layer WR2 is formed on the inorganic insulating film ILD8 (step S340). As a result, the second substrate CB2 is formed (step S300).

[0049] The first substrate CB1 has mounting terminals, and the fourth inorganic insulating film ILD4 and the liquid-repellent layer WR1 of the first substrate CB1 are patterned so that the mounting terminals are exposed. This patterning may be done using photolithography and dry etching, or by using the lift-off method. The second substrate CB2 also has mounting terminals, and the inorganic insulating film ILD10 and the liquid-repellent layer WR2 of the second substrate CB2 are also patterned so that the mounting terminals are exposed.

[0050] After both the first substrate CB1 and the second substrate CB2 are completed, the second substrate CB2 is fixed to the first substrate CB1 so that a gap GP is maintained between the first substrate CB1 and the second substrate CB2 (step S400). The first electrode E1 and the second electrode E2 are located between the supports SB1 and SB2 of the first substrate CB1 and the second substrate CB2, and the gap GP is located between the first electrode E1 and the second electrode E2. A spacer may be placed between the first substrate CB1 and the second substrate CB2 to maintain the gap GP.

[0051] (Examples) Referring to Figures 1 and 9, the manufacturing of the first substrate CB1 in one embodiment of this embodiment 1 will be described below.

[0052] A glass substrate was prepared as the support SB1 for the first substrate CB1 (step S110). A base coat film was formed on the glass substrate by depositing a 100 nm thick silicon oxide film and a 100 nm thick silicon nitride film in that order using a chemical vapor deposition (CVD) apparatus. The base coat film corresponds to the inorganic insulating film ILD9 in Figure 1. A 40 nm thick LTPS film was deposited on the base coat film, and the LTPS underwent dehydrogenation annealing and laser annealing treatments. The LTPS was then patterned to form a semiconductor layer SC. A 100 nm thick silicon oxide film was deposited on the semiconductor layer SC using a CVD apparatus to form a gate insulating film. The gate insulating film corresponds to the inorganic insulating film ILD8 in Figure 1. A 300 nm thick molybdenum tungsten (MoW) alloy film was deposited on the gate insulating film using a sputtering apparatus, and the MoW alloy film was patterned to form a gate electrode. The gate electrode corresponds to wiring W3 in Figure 1.

[0053] Next, the semiconductor layer SC was subjected to low-concentration doping and high-concentration doping treatments through the gate insulating film and gate electrode. After doping, a first interlayer insulating film was formed by depositing a 700 nm thick silicon oxide film and a 200 nm thick silicon nitride film on the gate electrode using a CVD apparatus. The first interlayer insulating film corresponds to the inorganic insulating film ILD7 in Figure 1. A connection contact hole was formed in the first interlayer insulating film, and a 30 nm titanium film, a 300 nm thick aluminum film, and a 20 nm thick titanium film were deposited on the first interlayer insulating film in this order using a sputtering apparatus. The source electrode was formed by patterning the titanium / aluminum / titanium laminate. The source electrode corresponds to wiring W2 in Figure 1.

[0054] Next, a second interlayer insulating film was formed by depositing a 300 nm thick silicon nitride film on the source electrode using a CVD apparatus. The second interlayer insulating film corresponds to the third inorganic insulating film ILD3 in Figure 1. A connection contact hole was formed in the second interlayer insulating film, and a 100 nm thick titanium film, a 600 nm thick aluminum film, and a 20 nm thick titanium film were deposited on the second interlayer insulating film in that order using a sputtering apparatus. The electrode was then formed by patterning the Ti / Al / Ti laminate. This electrode corresponds to wiring W1 in Figure 1.

[0055] Next, a third interlayer insulating film was formed by depositing a 400 nm thick silicon oxide film and a 150 nm thick silicon nitride film on the electrode using a CVD apparatus. The third interlayer insulating film corresponds to the inorganic insulating film ILD6 in Figure 1. A first planarization layer was formed by coating and solidifying a liquid containing photoresist on the third interlayer insulating film. The first planarization layer corresponds to the first organic insulating film PLN1 in Figure 1. The first planarization layer was patterned using 2 μm photolithography to form contact holes CH penetrating the first planarization layer. This corresponds to steps S110 to S140 in Figure 9.

[0056] Next, a 100 nm thick silicon oxide film was deposited on the first organic insulating film PLN1 using a CVD apparatus to form the first inorganic insulating film ILD1 (step S150). Then, by simultaneously etching the third interlayer insulating film and the first inorganic insulating film ILD1, a connecting contact hole was formed that passes through the contact hole CH1 and penetrates the third interlayer insulating film and the first inorganic insulating film ILD1. Then, a 100 nm thick titanium film was deposited on the first inorganic insulating film ILD1 using a sputtering apparatus, and the titanium film was patterned to form the metal layer ML and the first through-conductor TH1 (step S160).

[0057] Next, a 100 nm thick silicon nitride film was deposited on the metal layer ML using a CVD apparatus to form a fifth inorganic insulating film ILD5 (step S170). Then, a second planarization layer was formed on the fifth inorganic insulating film ILD5 by coating and solidifying a liquid containing a photoresist (step S180). The second planarization layer corresponds to the second organic insulating film PLN2 in Figure 1. The second planarization layer was patterned using 2 μm photolithography to form contact holes CH2 penetrating the second planarization layer (step S190).

[0058] Next, a 200 nm thick silicon nitride film was deposited on the second organic insulating film PLN2 using a CVD apparatus to form a second inorganic insulating film ILD2 (step S210). Then, by simultaneously etching the fifth inorganic insulating film ILD5 and the second inorganic insulating film ILD2, a connecting contact hole was formed that passes through the contact hole CH2 and penetrates both the fifth inorganic insulating film ILD5 and the second inorganic insulating film ILD2. Then, a 300 nm thick titanium film was deposited on the second inorganic insulating film ILD2 using a sputtering apparatus, and multiple first electrodes E1 and second through-conductors TH2 were formed by patterning the titanium film (step S220).

[0059] A fourth inorganic insulating film ILD4 was formed on multiple first electrodes E1 (step S230). Then, the fourth inorganic insulating film ILD4 was patterned using photolithography and dry etching to remove the fourth inorganic insulating film ILD4 on the mounting terminals. A liquid-repellent layer WR1 was formed on the fourth inorganic insulating film ILD4 by applying and drying a surface treatment agent that forms a fluorine-based water-repellent film. Then, the liquid-repellent layer WR1 was patterned using photolithography and dry etching to remove the liquid-repellent layer WR1 on the mounting terminals.

[0060] [Embodiment 2] Other embodiments of this disclosure are described below. For the sake of clarity, components having the same function as those described in the above embodiments are denoted by the same reference numerals, and their descriptions are not repeated.

[0061] Figure 10 is a partial cross-sectional view showing an example configuration of an electrowetting apparatus EWA according to one embodiment of the present disclosure. Figure 11 is a partial plan view showing an example configuration of the first wiring W1 in the electrowetting apparatus EWA shown in Figure 10, together with a part of the second wiring W2. Figure 12 is a partial cross-sectional view showing cross section AA of Figure 11. For the sake of simplicity in the drawings, the second wiring W2 in Figures 11 and 12 only shows the relay electrode BE connected to two or more supply electrodes FE.

[0062] As shown in Figures 10 to 12, when the first wiring W1 includes (i) a plurality of connecting electrodes CE that are connected to both a corresponding one of a plurality of first electrodes E1 and a corresponding one of a plurality of circuit elements TR, and (ii) a plurality of supply electrodes FE that are not connected to any of the plurality of first electrodes E1 but are connected to one or more corresponding ones of the plurality of circuit elements TR, and the second wiring W2 includes a plurality of intermediate electrodes BE that are connected to two or more corresponding ones of the plurality of supply electrodes FE, it is beneficial for the second wiring W2 to be made of a metal that is not corroded by the liquid 100. With this, even if the liquid 100 reaches and corrodes one of the plurality of supply electrodes FE, the intermediate electrodes BE will not be corroded by the liquid 100, and it will be difficult for the liquid 100 to reach the other supply electrodes FE via the intermediate electrodes BE. Therefore, the number of circuit elements TR that are damaged by a single crack can be further reduced.

[0063] The first substrate CB1 does not need to include a third inorganic insulating film ILD3 located between the first wiring W1 and the second wiring W2. The first wiring W1 is located between the second wiring W2 and the first organic insulating film PLN1, and the first wiring W1 may be in direct contact with the second wiring W2.

[0064] The circuit layer CL of the first substrate CB1 may include one or more wirings containing metal that are located between the support SB1 and the first wiring W1 and are eroded by the liquid 100, such as the third wiring W3 and the fourth wiring W4. The circuit layer CL may include multiple inorganic insulating films, such as the inorganic insulating film ILD6 located between the first wiring W1 and the first organic insulating film PLN1, the inorganic insulating film ILD7 located between the third wiring W3 and the second wiring W2, the inorganic insulating film ILD8 located between the fourth wiring W4 and the third wiring W3, the inorganic insulating film ILD11 located between the semiconductor layer SC and the fourth wiring W4, and the inorganic insulating film ILD9 located between the support SB1 and the third wiring W3.

[0065] Figure 13 is a partial plan view showing another configuration example of the first wiring W1 in the electrowetting apparatus EWA shown in Figure 10, along with a portion of the second wiring W2. Figure 14 is a partial cross-sectional view showing section AA of Figure 13. For the sake of simplicity, the second wiring W2 in Figures 13 and 14 only shows the intermediate electrode BE connected to two or more supply electrodes FE. As shown in Figures 13 and 14, the intermediate electrode BE may be connected to three or more supply electrodes FE. Compared to the configuration examples in Figures 11 and 12, the electrical resistance of the wiring with the supply electrodes FE and intermediate electrode BE combined is smaller according to the configuration examples in Figures 13 and 14.

[0066] (Examples) Referring to Figure 10, the manufacturing of the first substrate CB1 in one embodiment of this second example will be described below.

[0067] Similar to the embodiment of Embodiment 1 described above, a support SB1 was prepared, and the base coat film to the second interlayer insulating film was formed and patterned as appropriate. In the embodiment of Embodiment 2, the base coat film, LTPS and gate insulating film correspond to the inorganic insulating film ILD9, semiconductor layer SC and inorganic insulating film ILD11 in Figure 10. In the embodiment of Embodiment 2, the gate electrode, first interlayer insulating film, source electrode and second interlayer insulating film correspond to the fourth wiring W4, inorganic insulating film ILD8, third wiring W3 and inorganic insulating film ILD7 in Figure 10.

[0068] Next, a 100 nm thick titanium film was deposited on the second interlayer insulating film using a sputtering apparatus, and the second wiring W2 was formed by patterning the titanium film. Then, a 100 nm thick titanium film, a 600 nm thick aluminum film, and a 20 nm thick titanium film were deposited in this order on the second interlayer insulating film and the second wiring W2 using a sputtering apparatus, and the first wiring W1 was formed by patterning the Ti / Al / Ti laminate.

[0069] Next, similar to the embodiment of Embodiment 1 described above, the third interlayer insulating film was formed up to the liquid-repellent layer WR1, and patterning was performed as appropriate. In the embodiment of Embodiment 2, the third interlayer insulating film, the first planarization layer, and the second planarization layer correspond to the inorganic insulating film ILD6, the first organic insulating film PLN1, and the second organic insulating film PLN2 in Figure 10.

[0070] [Embodiment 3] Figure 15 is a partial cross-sectional view showing an example configuration of an electrowetting apparatus EWA according to one embodiment of the present disclosure. Figure 16 is a partial plan view showing an example configuration of the first wiring W1 in the electrowetting apparatus EWA shown in Figure 15, together with a part of the second wiring W2. Figure 17 is a partial cross-sectional view showing cross section AA of Figure 16. For the sake of simplicity in the drawings, the second wiring W2 in Figures 16 and 17 shows only the relay electrode BE connected to two or more supply electrodes FE. As shown in Figures 15 to 17, the second wiring W2 may be located between the first wiring W1 and the first organic insulating film PLN1, and the second wiring W2 may be in direct contact with the first wiring W1.

[0071] Figure 18 is a partial plan view showing another configuration example of the first wiring W1 in the electrowetting apparatus EWA shown in Figure 15, along with a portion of the second wiring W2. Figure 19 is a partial cross-sectional view showing section AA of Figure 18. For the sake of simplicity, the second wiring W2 in Figures 18 and 19 only shows the intermediate electrode BE connected to two or more supply electrodes FE. As shown in Figures 18 and 19, the intermediate electrode BE may be connected to three or more supply electrodes FE. Compared to the configuration examples in Figures 16 and 17, the electrical resistance of the wiring with the supply electrodes FE and intermediate electrode BE combined is smaller according to the configuration examples in Figures 18 and 19.

[0072] (Examples) Referring to Figure 15, the manufacturing of the first substrate CB1 in one embodiment of this third embodiment will be described below. Similar to the embodiments of embodiments 1 and 2 described above, a support SB1 was prepared, and the base coat film to the second interlayer insulating film was formed and patterned as appropriate. In the embodiment of this third embodiment, the base coat film, LTPS and gate insulating film correspond to the inorganic insulating film ILD9, semiconductor layer SC and inorganic insulating film ILD11 in Figure 15. In the embodiment of this third embodiment, the gate electrode, first interlayer insulating film, source electrode and second interlayer insulating film correspond to the fourth wiring W4, inorganic insulating film ILD8, third wiring W3 and inorganic insulating film ILD7 in Figure 15.

[0073] Next, a 100 nm thick titanium film, a 600 nm thick aluminum film, and a 20 nm thick titanium film were deposited in that order on the second interlayer insulating film using a sputtering apparatus, and the first wiring W1 was formed by patterning the Ti / Al / Ti laminate. Then, a 100 nm thick titanium film was deposited on the second interlayer insulating film and the first wiring W1 using a sputtering apparatus, and the second wiring W2 was formed by patterning the titanium film.

[0074] Next, similar to the embodiments of Embodiments 1 and 2 described above, the third interlayer insulating film was formed up to the liquid-repellent layer WR1, and patterning was performed as appropriate. In the embodiment of Embodiment 3, the third interlayer insulating film, the first planarization layer, and the second planarization layer correspond to the inorganic insulating film ILD6, the first organic insulating film PLN1, and the second organic insulating film PLN2 in Figure 15.

[0075] [Embodiment 4] Figure 20 is a partial cross-sectional view showing an example configuration of an electrowetting apparatus EWA according to one embodiment of the present disclosure. Figure 21 is a partial plan view showing an example configuration of the first wiring W1 in the electrowetting apparatus EWA shown in Figure 20, together with a part of the second wiring W2. Figure 22 is a partial cross-sectional view showing cross section AA of Figure 21. For the sake of simplicity in the drawings, the second wiring W2 in Figures 21 and 22 shows only the relay electrode BE connected to two or more supply electrodes FE. As shown in Figures 20 to 22, the second wiring W2 is located between the first wiring W1 and the first organic insulating film PLN1, and the first substrate CB1 may include a third inorganic insulating film ILD3 located between the first wiring W1 and the second wiring W2.

[0076] Figure 23 is a partial plan view showing another configuration example of the first wiring W1 in the electrowetting apparatus EWA shown in Figure 20, along with a portion of the second wiring W2. Figure 24 is a partial cross-sectional view showing section AA of Figure 23. For the sake of simplicity, the second wiring W2 in Figures 23 and 24 only shows the intermediate electrode BE connected to two or more supply electrodes FE. As shown in Figures 23 and 24, the intermediate electrode BE may be connected to three or more supply electrodes FE. Compared to the configuration examples in Figures 21 and 22, the electrical resistance of the wiring with the supply electrodes FE and intermediate electrode BE combined is smaller according to the configuration examples in Figures 23 and 24.

[0077] (Examples) Referring to Figure 20, the manufacturing of the first substrate CB1 in one embodiment of this embodiment 4 will be described below. Similar to the embodiments of embodiments 1 to 3 described above, a support SB1 was prepared, and the base coat film to the second interlayer insulating film was formed and patterned as appropriate. In the embodiment of this embodiment 4, the base coat film, LTPS, and gate insulating film correspond to the inorganic insulating film ILD9, semiconductor layer SC, and inorganic insulating film ILD11 in Figure 20. In the embodiment of this embodiment 3, the gate electrode, first interlayer insulating film, source electrode, and second interlayer insulating film correspond to the fourth wiring W4, inorganic insulating film ILD8, third wiring W3, and inorganic insulating film ILD7 in Figure 20.

[0078] Next, a 100 nm thick titanium film, a 600 nm thick aluminum film, and a 20 nm thick titanium film were deposited in that order on the second interlayer insulating film using a sputtering apparatus, and the first wiring W1 was formed by patterning the Ti / Al / Ti laminate. Then, a 100 nm thick silicon nitride film was deposited on the first wiring W1 using a CVD apparatus to form the fourth interlayer insulating film. The fourth interlayer insulating film corresponds to the third inorganic insulating film ILD3 in Figure 20. Then, connection contact holes were formed in the fourth interlayer insulating film, and a 100 nm thick titanium film was deposited on the fourth interlayer insulating film using a sputtering apparatus, and the second wiring W2 was formed by patterning the titanium film.

[0079] Next, similar to the embodiments described in Embodiments 1 to 3 above, the third interlayer insulating film was formed up to the liquid-repellent layer WR1, and patterning was performed as appropriate. In the embodiment of Embodiment 3, the third interlayer insulating film, the first planarization layer, and the second planarization layer correspond to the inorganic insulating film ILD6, the first organic insulating film PLN1, and the second organic insulating film PLN2 in Figure 15.

[0080] [Embodiment 5] Figure 25 is a partial cross-sectional view showing an example configuration of an electrowetting apparatus EWA according to one embodiment of the present disclosure. As shown in Figure 25, the electrowetting apparatus EWA may be configured such that at least one of the plurality of first electrodes E1 is in direct contact with the liquid 100. In other words, in the first substrate CB1 of the electrowetting apparatus EWA according to the present disclosure, one or more of the plurality of first electrodes E1 may be exposed inside the gap GP.

[0081] The configuration according to this embodiment 5 can be combined with the configurations according to embodiments 2 to 4 described above. A configuration in which the second inorganic insulating film ILD2 and the liquid-repellent layer WR1 are removed from the first substrate CB1 according to embodiments 2 to 4 described above is also included in the scope of this disclosure.

[0082] 〔summary〕 Apparatus according to Embodiment 1 of the present disclosure is an apparatus for applying voltage to a liquid, comprising: a support; a plurality of first electrodes; a first substrate including a support; a plurality of first electrodes; a first wiring positioned between the support and the plurality of first electrodes; a first organic insulating film positioned between the first wiring and the plurality of first electrodes; a second organic insulating film positioned between the first organic insulating film and the plurality of first electrodes; a metal layer positioned between the first organic insulating film and the second organic insulating film and formed from a metal that is not eroded by the liquid; and a second substrate including a second electrode facing the plurality of first electrodes, wherein a gap is maintained between the first substrate and the second substrate in which the liquid is injected or can be injected.

[0083] According to the above configuration, the electrowetting apparatus according to this disclosure includes a protective layer between the first wiring and a plurality of first electrodes, comprising a first organic insulating film, a second organic insulating film, and a metal layer located between the first and second organic insulating films and formed from a metal that is not eroded by the liquid 100. Therefore, cracks are less likely to penetrate the protective layer according to this disclosure in the thickness direction. In addition, even if the total thickness of the protective layer is large, it is easy to electrically connect the first electrodes to the first wiring.

[0084] The apparatus according to aspect 2 of the present disclosure may have a configuration in which, in aspect 1, the first substrate further includes a first inorganic insulating film located between the first wiring and the plurality of first electrodes.

[0085] With the above configuration, the penetration of liquid into the first wiring can be further reduced.

[0086] In the apparatus according to embodiment 3 of the present disclosure, the first inorganic insulating film may be configured such that, in embodiment 1 or 2, the first inorganic insulating film is located between the first organic insulating film and the second organic insulating film.

[0087] With the above configuration, the penetration of liquid into the first wiring can be further reduced.

[0088] The apparatus according to embodiment 4 of the present disclosure may have a configuration in which, in embodiment 3, the first substrate further includes a second inorganic insulating film located between the second organic insulating film and the plurality of first electrodes.

[0089] With the above configuration, the intrusion of liquid into the first wiring can be further reduced.

[0090] The apparatus according to aspect 5 of the present disclosure may be configured such that, in any one embodiment of aspects 1 to 4 above, the first substrate further comprises a first through-conductor penetrating the first organic insulating film and a second through-conductor penetrating the second organic insulating film, one of the plurality of first electrodes is connected to the metal layer through the second through-conductor, the metal layer is connected to the first wiring through the first through-conductor, and the second through-conductor is separated from the first through-conductor in a plan view.

[0091] With the above configuration, the penetration of liquid into the first wiring can be further reduced.

[0092] The apparatus according to aspect 6 of the present disclosure may be configured such that, in any one of aspects 1 to 5 above, the first wiring is the wiring closest to the plurality of first electrodes among the wiring containing metal that is eroded by the liquid.

[0093] With the above configuration, the liquid has difficulty reaching the first wiring, and therefore the liquid has difficulty reaching all of the wiring containing metal that would be corroded by the liquid.

[0094] The apparatus according to Embodiment 7 of the present disclosure may be configured such that, in any one embodiment of Embodiments 1 to 6, the first substrate is located between the support and the first wiring and further comprises a plurality of circuit elements corresponding to the plurality of first electrodes, the first wiring includes a plurality of connecting electrodes each connected to one corresponding of the plurality of first electrodes and one corresponding of the plurality of circuit elements, and a supply electrode that is not connected to the plurality of first electrodes but is connected to the plurality of circuit elements, and the area of ​​the supply electrode in plan view is 80% or less of the area of ​​the first substrate in plan view.

[0095] According to the above configuration, the area of ​​the supply electrode FE in a plan view is small. Therefore, even if a crack penetrates the protective layer in the thickness direction, the probability that the supply electrode is located beyond the crack is small.

[0096] The apparatus according to aspect 8 of the present disclosure may be configured such that, in any one embodiment of aspects 1 to 6, the first substrate is located between the support and the first wiring and further comprises a plurality of circuit elements corresponding to the plurality of first electrodes, the first wiring includes a plurality of connecting electrodes each connected to both a corresponding one of the plurality of first electrodes and a corresponding one of the plurality of circuit elements, and a plurality of supply electrodes that are not connected to the plurality of first electrodes but each connected to one or more corresponding circuit elements, the plurality of supply electrodes are separated from each other and from the plurality of connecting electrodes in a plan view.

[0097] In the above configuration, the supply electrodes are separated from each other and also from the connecting electrodes. Therefore, even if liquid reaches one of the supply electrodes, it is difficult for the liquid to reach the other supply electrodes and connecting electrodes. Consequently, the number of circuit elements damaged by a single crack can be reduced.

[0098] The apparatus according to aspect 9 of the present disclosure may, in aspect 8, further comprises a second wiring positioned between the plurality of circuit elements and the first organic insulating film, wherein the second wiring includes a plurality of relay electrodes each connected to two or more corresponding supply electrodes.

[0099] According to the above configuration, the supply electrodes can be divided in both the row and column directions by the relay electrodes. Therefore, the number of circuit elements damaged by a single crack can be further reduced.

[0100] In the apparatus according to aspect 10 of the present disclosure, the second wiring may be made of the metal that is not corroded by the liquid, as in aspect 9 above.

[0101] With the above configuration, even if the liquid reaches and corrodes one of the multiple supply electrodes, the intermediate electrode will not be corroded by the liquid, making it difficult for the liquid to reach other supply electrodes via the intermediate electrode. Therefore, the number of circuit elements damaged by a single crack can be further reduced.

[0102] The apparatus according to aspect 11 of the present disclosure may be configured such that, in aspect 9 or 10, the plurality of circuit elements include a first circuit element, a second circuit element adjacent to the first circuit element on one side in the row direction, a third circuit element adjacent to the first circuit element on one side in the column direction, and a fourth circuit element adjacent to the first circuit element on the other side in the column direction; the plurality of supply electrodes include a first supply electrode corresponding to the first circuit element, a second supply electrode corresponding to the second circuit element, a third supply electrode corresponding to the third circuit element, and a fourth supply electrode corresponding to the fourth circuit element; and the plurality of relay electrodes include a first relay electrode connected to the first supply electrode and the second supply electrode, a second relay electrode connected to the first supply electrode and the third supply electrode, and a third relay electrode connected to the first supply electrode and the fourth supply electrode.

[0103] According to the above configuration, the number of circuit elements damaged by a single crack can be further reduced. In addition, line defects that damage multiple circuit elements arranged in a column can be reduced.

[0104] The apparatus according to aspect 12 of the present disclosure may be configured such that, in any one of aspects 9 to 11 above, the first wiring is located between the second wiring and the first organic insulating film, and the first wiring is in direct contact with the second wiring.

[0105] The apparatus according to aspect 13 of the present disclosure may be configured such that, in any one of aspects 9 to 11 above, the second wiring is located between the first wiring and the first organic insulating film, and the second wiring is in direct contact with the first wiring.

[0106] The apparatus according to embodiment 14 of the present disclosure may have a configuration in which, in any one embodiment of embodiments 9 to 11, the second wiring is located between the first wiring and the first organic insulating film, and the first substrate further includes a third inorganic insulating film located between the first wiring and the second wiring.

[0107] The apparatus according to aspect 15 of this disclosure may be configured such that, in any one of aspects 1 to 14 above, the metal that is not eroded by the liquid is a noble metal or a metal that reacts with the liquid to form a passivation layer.

[0108] The apparatus according to aspect 16 of the present disclosure may be configured such that, in any one aspect of aspects 1 to 15, the metal that is not eroded by the liquid is one metal selected from the group consisting of titanium, niobium, tungsten, chromium, and nickel, or an alloy consisting of two or more metals selected from the group.

[0109] The apparatus according to aspect 17 of the present disclosure may, in any one of aspects 1 to 16 above, have a configuration in which the first substrate includes a liquid-repellent layer located on the opposite side of the support from the plurality of first electrodes and repelling the liquid, and a fourth inorganic insulating film located between the plurality of first electrodes and the liquid-repellent layer.

[0110] According to the above configuration, the liquid-repellent layer and the fourth inorganic insulating film reduce contact between the liquid and the first electrode and the first wiring.

[0111] The apparatus according to aspect 18 of this disclosure may have a configuration in which, in any one of the above aspects 1 to 16, one or more of the plurality of first electrodes are exposed inside the gap.

[0112] According to the above configuration, one or more first electrodes can come into direct contact with the liquid 100.

[0113] This disclosure is not limited to the embodiments described above, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of this disclosure. Furthermore, new technical features can be formed by combining the technical means disclosed in each embodiment. [Explanation of symbols]

[0114] 100 liquid CB1 1st board CB2 Second board E1 1st electrode E2 2nd electrode GP gap ILD1 First Inorganic Insulating Film ILD2 Second Inorganic Insulating Film M1 First Wiring M2 2nd wiring ML metal layer PLN1 First Organic Insulating Film PLN2 Second Organic Insulating Film SB1, SB2 Support WR1, WR1 liquid repellent layer EWA Electrowetting Equipment

Claims

1. A device for applying voltage to a liquid, A first substrate comprising a support, a plurality of first electrodes, a first wiring positioned between the support and the plurality of first electrodes, a first organic insulating film positioned between the first wiring and the plurality of first electrodes, a second organic insulating film positioned between the first organic insulating film and the plurality of first electrodes, and a metal layer positioned between the first organic insulating film and the second organic insulating film and formed from a metal that is not eroded by the liquid, The device comprises a second substrate including a second electrode facing the plurality of first electrodes, An apparatus in which the liquid is injected or an injection gap is maintained between the first substrate and the second substrate.

2. The apparatus according to claim 1, wherein the first substrate further includes a first inorganic insulating film located between the first wiring and the plurality of first electrodes.

3. The apparatus according to claim 2, wherein the first inorganic insulating film is located between the first organic insulating film and the second organic insulating film.

4. The apparatus according to claim 3, wherein the first substrate further includes a second inorganic insulating film located between the second organic insulating film and the plurality of first electrodes.

5. The first substrate further comprises a first through-conductor penetrating the first organic insulating film and a second through-conductor penetrating the second organic insulating film. One of the plurality of first electrodes is connected to the metal layer through the second through conductor. The metal layer is connected to the first wiring through the first through-conductor, The apparatus according to claim 1, wherein the second through conductor is separated from the first through conductor in a plan view.

6. The apparatus according to claim 1, wherein the first wiring is the wiring closest to the plurality of first electrodes among the wiring containing metal that is corroded by the liquid.

7. The first substrate is located between the support and the first wiring and further comprises a plurality of circuit elements corresponding to the plurality of first electrodes, The first wiring is, Multiple connecting electrodes, each connected to a corresponding one of the plurality of first electrodes and a corresponding one of the plurality of circuit elements, It includes one supply electrode that is not connected to the plurality of first electrodes but is connected to the plurality of circuit elements, The apparatus according to claim 1, wherein the area of ​​the supply electrode in a plan view is 80% or less of the area of ​​the first substrate in a plan view.

8. The first substrate is located between the support and the first wiring and further comprises a plurality of circuit elements corresponding to the plurality of first electrodes, The first wiring is, Multiple connecting electrodes, each connected to a corresponding one of the plurality of first electrodes and a corresponding one of the plurality of circuit elements, It includes a plurality of supply electrodes that are not connected to the plurality of first electrodes, but are each connected to one or more corresponding circuit elements, The apparatus according to claim 1, wherein the plurality of supply electrodes are separated from each other and from the plurality of connecting electrodes in a plan view.

9. The first substrate further comprises a second wiring positioned between the plurality of circuit elements and the first organic insulating film, The apparatus according to claim 8, wherein the second wiring includes a plurality of relay electrodes, each connected to two or more corresponding supply electrodes.

10. The apparatus according to claim 9, wherein the second wiring is made of the metal that is not corroded by the liquid.

11. The aforementioned plurality of circuit elements are First circuit element and The first circuit element is adjacent to a second circuit element on one side in the row direction, A third circuit element adjacent to the first circuit element on one side in the column direction, The first circuit element includes a fourth circuit element adjacent to it on the other side in the column direction, The plurality of supply electrodes are A first supply electrode corresponding to the first circuit element, A second supply electrode corresponding to the second circuit element, A third supply electrode corresponding to the third circuit element, The system includes a fourth supply electrode corresponding to the fourth circuit element, The aforementioned multiple relay electrodes are A first relay electrode connected to the first supply electrode and the second supply electrode, A second relay electrode connected to the first supply electrode and the third supply electrode, The apparatus according to claim 9, further comprising a third relay electrode connected to the first supply electrode and the fourth supply electrode.

12. The first wiring is located between the second wiring and the first organic insulating film. The apparatus according to claim 9, wherein the first wiring is in direct contact with the second wiring.

13. The second wiring is located between the first wiring and the first organic insulating film. The apparatus according to claim 9, wherein the second wiring is in direct contact with the first wiring.

14. The second wiring is located between the first wiring and the first organic insulating film. The apparatus according to claim 9, wherein the first substrate further comprises a third inorganic insulating film located between the first wiring and the second wiring.

15. The apparatus according to claim 1, wherein the metal that is not eroded by the liquid is a noble metal or a metal that reacts with the liquid to form a passivation layer.

16. The apparatus according to claim 1, wherein the metal that is not corroded by the liquid is one metal selected from the group consisting of titanium, niobium, tungsten, chromium, and nickel, or an alloy consisting of two or more metals selected from the group.

17. The first substrate is A liquid-repellent layer is located on the opposite side of the support from the plurality of first electrodes, and repels the liquid. The apparatus according to claim 1, further comprising a fourth inorganic insulating film located between the plurality of first electrodes and the liquid-repellent layer.

18. The apparatus according to claim 1, wherein one or more of the plurality of first electrodes are exposed inside the gap.

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