Vacuum coating method and liquid lens module prepared by adopting same

Abstract

The invention provides a vacuum coating method and a liquid lens module prepared by the method, the liquid lens module comprises a first glass plate, a second glass plate, and a metal structural member, a conductive liquid and an oil liquid which are encapsulated between the first glass plate and the second glass plate, and the oil liquid is a fluorine-containing or phenyl-containing organic liquid; the dielectric layer and the hydrophobic layer on the surface of the metal structural member are prepared by the vacuum coating method. The dielectric layer and the hydrophobic layer can be completed only through one-time evaporation, the operation procedures can be reduced, the production efficiency can be improved, the film layer prepared through evaporation is good in uniformity, the hydrophobic layer and the dielectric layer are chemically bonded, the structural strength is higher, and the hydrophobic layer and the dielectric layer are not prone to falling off; the evaporation raw material of the hydrophobic layer adopts olefin organic liquid containing alkyl, siloxane or silyl, and can be used for a liquid lens containing fluorine or phenyl oil liquid, so that the selection range of the organic liquid in the liquid lens is expanded, the hysteresis phenomenon during automatic focusing can be eliminated, and the preparation of the liquid lens with high refractive index and low dispersion can be conveniently realized.

Description

Technical Field

[0001] The present invention relates to the technical field of optical imaging lens preparation, and in particular to a vacuum coating method and a liquid lens module prepared by the method. Background Art

[0002] Autofocus lens is an important component of modern optical imaging technology. At present, the double liquid lens based on the principle of electrowetting is a common type of autofocus lens, which achieves zoom by changing the curvature of the interface between two liquids with different refractive indices. These liquids generally include high-refractive index oil liquids or fluorine-containing organic liquids to reduce dispersion and adjust the liquid density. However, the traditional preparation process uses dipping or spin coating to prepare the Teflon hydrophobic layer in the liquid lens, which has low work efficiency, the coating thickness is prone to unevenness, and the hydrophobic layer of Teflon material limits the selection range of liquid lens materials, especially for organic liquids containing benzene groups or fluorine. Due to the surface tension between them and the Teflon hydrophobic layer, autofocus often exhibits hysteresis, affecting product quality. Summary of the invention

[0003] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a vacuum coating method and a liquid lens module prepared by the method, so as to improve the coating efficiency, ensure the uniformity of the film layer, improve the product quality, and eliminate the hysteresis phenomenon during autofocus.

[0004] To achieve the above object, the present invention adopts the following technical solutions: The present invention provides a vacuum coating method, which is carried out in a vacuum coating device. The vacuum coating device comprises an evaporation chamber, a cracking chamber, a deposition chamber, a cold trap, a vacuum pump connected in sequence, and a coupling agent chamber and a second gas source chamber respectively connected to the deposition chamber.

[0005] The vacuum coating method comprises: Step S1: placing the workpiece to be plated into the deposition chamber, adding parylene powder into the evaporation chamber, adding coupling agent into the coupling agent chamber, and adding organic liquid for a hydrophobic layer into the second gas source chamber; wherein the organic liquid for a hydrophobic layer is an olefin organic liquid containing a hydrocarbon group, a siloxane group or a silane group; Step S2: closing and sealing each chamber, and controlling the pyrolysis chamber and the cold trap to reach a preset temperature respectively; Step S3: Turn on the vacuum pump to evacuate the chamber so that the pressure in the deposition chamber reaches a first preset pressure value; Step S4: opening the coupling agent chamber to heat and increase the temperature to evaporate the coupling agent, and controlling the pressure of the deposition chamber to be a second set pressure value; Step S5: after the coupling agent is evaporated, the evaporation chamber is opened to heat and increase the temperature to evaporate parylene, and the pressure of the deposition chamber is controlled to be a third set pressure value, and the cracked parylene gas enters the deposition chamber, thereby being deposited on the surface of the to-be-plated object to form a dielectric layer; Step S6: when the dielectric layer evaporation is completed and the vacuum degree of the deposition chamber begins to decrease, the second gas source chamber is opened to heat and increase the temperature, and the organic liquid for the hydrophobic layer is evaporated, and the evaporated organic gas enters the deposition chamber, thereby being deposited on the surface of the dielectric layer to form a hydrophobic layer; Step S7: After the hydrophobic layer is evaporated, the coating process ends and the vacuum pump is turned off.

[0006] Preferably, the boiling point of the organic liquid for the hydrophobic layer is 200° C. to 400° C. and the molecular weight is 300 to 600.

[0007] Preferably, the organic liquid for the hydrophobic layer is methacryloxypropyl tris(trimethylsiloxy)silane, butenyl tris(trimethylsiloxy)silane or vinyloctyltetramethylsilane.

[0008] Preferably, the first set pressure value is 1Pa-5Pa; the second set pressure value is 1Pa-10Pa; and the third set pressure value is 1Pa-5Pa.

[0009] Preferably, the temperature for evaporating parylene in step S5 is 110°C to 160°C; and the temperature for evaporating the organic liquid for the hydrophobic layer in step S6 is 100°C to 300°C.

[0010] According to another aspect of the present invention, a liquid lens module is provided, which includes a first glass plate, a second glass plate, and a metal structure encapsulated between the first glass plate and the second glass plate, a conductive liquid and an oil liquid, wherein the oil liquid is an organic liquid containing fluorine or phenyl; the surface of the metal structure is coated with a dielectric layer and a hydrophobic layer from the inside to the outside, and the dielectric layer and the hydrophobic layer are prepared by the vacuum coating method as described above.

[0011] Preferably, the metal structure is arranged on the second glass plate, and an inverted frustum-shaped accommodating cavity is formed between the metal structure and the second glass plate, and the oil liquid is in the accommodating cavity; the conductive liquid is arranged between the first glass plate and the oil liquid; the metal structure is used to connect a control circuit, and the control circuit is used to adjust the interface curvature between the conductive liquid and the oil liquid based on the electrowetting principle, thereby achieving zooming.

[0012] Preferably, the volume of the oil liquid is smaller than the volume of the accommodating chamber, and the contact interface between the conductive liquid and the oil liquid is located in the accommodating chamber.

[0013] Preferably, the conductive liquid is water, ethanol, ethylene glycol or glycerol.

[0014] Preferably, 0.1%wt to 0.5%wt of a salt substance is added to the conductive liquid, and the salt substance is one or more of sodium chloride, potassium chloride, sodium sulfate or potassium sulfate.

[0015] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention adopts a vacuum coating method to prepare a dielectric layer and a hydrophobic layer, and only one evaporation process is required to complete the process. Compared with the process of dipping or spin coating a Teflon hydrophobic layer, the operating procedures can be reduced, the production efficiency can be improved, the production cycle can be shortened, and the film layer prepared by evaporation has good uniformity. The hydrophobic layer and the dielectric layer are chemically bonded, the structural strength is higher, and it is less likely to fall off. The hydrophobic layer evaporation raw material adopts an olefin organic liquid containing a hydrocarbon group, a siloxane group or a silane group, which is suitable for a liquid lens using a fluorine-containing or phenyl oil-containing liquid, thereby expanding the selection range of organic liquids in the liquid lens, being able to eliminate the hysteresis phenomenon during autofocusing, and facilitating the preparation of a high refractive index, low dispersion liquid lens. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 The figure is a flow chart of a vacuum coating method according to an embodiment of the present invention.

[0017] Figure 2 It is a schematic structural diagram of a vacuum coating device according to an embodiment of the present invention.

[0018] Figure 3 FIG. 4 is a schematic structural diagram of a liquid lens module according to an embodiment of the present invention.

[0019] In the figure, 10-liquid lens module, 1-first glass plate, 2-second glass plate, 3-conductive liquid, 4-oil liquid, 5-metal structural part, 6-dielectric layer, 7-hydrophobic layer, 20-vacuum coating equipment, 21-evaporation chamber, 22-cracking chamber, 23-deposition chamber, 24-cold trap, 25-vacuum pump, 26-coupling agent chamber, 27-second gas source chamber. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the embodiment of the present application will be clearly and completely described below in conjunction with the drawings of the embodiment of the present application. Obviously, the described embodiment is a part of the embodiment of the present application, rather than all the embodiments. Based on the described embodiment of the present application, all other embodiments obtained by ordinary technicians in this field without creative work belong to the scope of protection of this application. It can be understood that, in the absence of conflict, some technical means of the various embodiments described herein can be replaced or combined with each other.

[0021] In the description of this application, if there are terms such as "first", "second", etc., they are only used to distinguish the objects described and do not have any order or technical meaning. Therefore, an object defined as "first", "second", etc. may explicitly or implicitly include one or more of the objects. In addition, "one" or "a" and similar words do not indicate a quantity limitation, but rather indicate the presence of at least one, and "multiple" means no less than two.

[0022] In the description of the specification of the present application, reference to "one embodiment" or "some embodiments" etc. means that one or more embodiments of the present application include a specific feature, structure or characteristic described in conjunction with the embodiment. Therefore, the phrases "in one embodiment", "in some embodiments", "in some other embodiments", "in some other embodiments", etc. appearing in different places in the specification do not necessarily refer to the same embodiment, but mean "one or more but not all embodiments", unless otherwise specifically emphasized in other ways.

[0023] See also Figure 1 , Figure 1 The present invention provides a vacuum coating method, wherein: Figure 2 The process is carried out in the vacuum coating device 20 shown, wherein the vacuum coating device 20 includes an evaporation chamber 21, a cracking chamber 22, a deposition chamber 23, a cold trap 24, a vacuum pump 25, and a coupling agent chamber 26 and a second gas source chamber 27 respectively connected to the deposition chamber 23 in sequence.

[0024] The vacuum coating method comprises: Step S1: Place the object to be plated into the deposition chamber 23, add parylene powder into the evaporation chamber 21, add coupling agent into the coupling agent chamber 26, and add organic liquid for hydrophobic layer into the second gas source chamber 27. The organic liquid for hydrophobic layer is an olefin organic liquid containing hydrocarbon group, siloxane group or silane group.

[0025] In applications, parylene powder can be selected from commercially available parylene raw material products according to needs, which are used for preparing dielectric layers after evaporation, thereby enhancing the waterproof and corrosion resistance of the parts to be plated, and playing the role of isolating electrodes and preventing short circuits. The organic liquid for the hydrophobic layer uses a high-boiling-point olefin organic liquid containing hydrocarbon groups, siloxane groups or silane groups, which can be applied to liquid lenses using fluorine-containing or phenyl oil-containing liquids, expanding the selection range of organic liquids in liquid lenses, and can weaken the surface tension effect and eliminate the hysteresis phenomenon during autofocus. The coupling agent can use existing products such as silane coupling agents. The coupling agent is used to form a chemical bond between the dielectric layer and the hydrophobic layer to enhance the strength, adhesion, hydrophobicity and anti-aging properties of the coating.

[0026] Step S2: Close and seal each chamber, and control the pyrolysis chamber 22 and the cold trap 24 to reach a preset temperature, respectively. The preset temperatures of the pyrolysis chamber 22 and the cold trap 24 can be reasonably set according to actual needs.

[0027] Step S3: Turn on the vacuum pump 25 to evacuate the chamber 23 to a first preset pressure value, wherein the first preset pressure value can be reasonably set according to actual needs.

[0028] Step S4: Open the coupling agent chamber 26 to heat and increase the temperature to evaporate the coupling agent, and control the pressure of the deposition chamber 23 to a second set pressure value. The temperature and the second set pressure value during the evaporation of the coupling agent can be reasonably set according to actual needs.

[0029] Step S5: After the coupling agent is evaporated, the evaporation chamber is opened for heating and temperature rise to evaporate parylene, and the pressure of the deposition chamber 23 is controlled to be a third set pressure value, and the evaporated and cracked parylene gas enters the deposition chamber 23, thereby depositing a dielectric layer on the surface of the to-be-plated piece. Among them, the temperature and the third set pressure value during the evaporation of parylene can be reasonably set according to actual needs. By using the vacuum evaporation method of parylene, the dielectric layer formed has a uniform thickness, a good coating effect, and a high coating efficiency.

[0030] Step S6: When the dielectric layer is evaporated and the vacuum degree of the deposition chamber 23 begins to decrease, the second gas source chamber 27 is opened for heating and temperature rise, and the organic liquid for the hydrophobic layer is evaporated. The evaporated organic gas enters the deposition chamber 23, thereby depositing on the surface of the dielectric layer to form a hydrophobic layer. Among them, the temperature when evaporating the organic liquid for the hydrophobic layer can be reasonably set according to actual needs. By using the vacuum evaporation method of the hydrophobic layer organic liquid, the hydrophobic layer formed has a uniform thickness, good coating effect, and high coating efficiency.

[0031] Step S7: After the hydrophobic layer is evaporated, the coating process ends and the vacuum pump is turned off.

[0032] The present invention adopts a vacuum coating method to prepare a dielectric layer and a hydrophobic layer, and only one evaporation process is required to complete the process, which can reduce the operation process, improve production efficiency, shorten the production cycle, and the film layer prepared by evaporation has good uniformity. The hydrophobic layer and the dielectric layer are chemically bonded, have higher structural strength, and are less likely to fall off. The evaporation raw material of the hydrophobic layer adopts an olefin organic liquid containing a hydrocarbon group, a siloxane group or a silane group, which is suitable for a liquid lens using a fluorine-containing or phenyl oil-containing liquid, thereby expanding the selection range of organic liquids in the liquid lens, being able to eliminate the hysteresis phenomenon during automatic focusing, and improving product quality.

[0033] In some preferred embodiments of the present invention, the boiling point of the organic liquid used in the hydrophobic layer is 200° C. to 400° C., and the molecular weight is 300 to 600.

[0034] Furthermore, the organic liquid for the hydrophobic layer can be organic liquids such as methacryloyloxypropyl tris(trimethylsiloxy)silane, butenyl tris(trimethylsiloxy)silane or vinyloctyltetramethylsilane, which can be applied to liquid lenses containing fluorine or phenyl oil liquids to reduce the surface tension and eliminate the hysteresis phenomenon during autofocus.

[0035] In some embodiments, the first set pressure value is 1Pa-5Pa; the second set pressure value is 1Pa-10Pa; and the third set pressure value is 1Pa-5Pa.

[0036] In other embodiments, the preset temperature of the cracking chamber 22 in step S2 is 500° C. to 700° C., the preset temperature of the cold trap 24 is -100° C. to -80° C., the temperature of the coupling agent during evaporation in step S4 is 50° C. to 150° C., the temperature of the parylene during evaporation in step S5 is 110° C. to 160° C., and the temperature of the organic liquid for the hydrophobic layer during evaporation in step S6 is 100° C. to 300° C. However, the present invention is not limited thereto, and in other embodiments, the set temperature and pressure values ​​can be reasonably set according to actual needs.

[0037] According to another aspect of the present invention, a liquid lens module is also provided. Figure 3 , Figure 3 The present invention is a schematic diagram of the structure of a liquid lens module according to an embodiment of the present invention. The liquid lens module 10 comprises a first glass plate 1, a second glass plate 2, a metal structure 5 encapsulated between the first glass plate 1 and the second glass plate 2, a conductive liquid 3 and an oil liquid 4, and the oil liquid 4 can be a fluorine-containing or phenyl-containing organic liquid. The surface of the metal structure 5 is coated with a dielectric layer 6 and a hydrophobic layer 7 from the inside to the outside, and the dielectric layer 6 and the hydrophobic layer 7 are prepared by the vacuum coating method as described above. The dielectric layer 6 and the hydrophobic layer 7 only need to be completed by a single evaporation process, which can reduce the operation process, improve production efficiency, shorten the production cycle, and the film layer prepared by evaporation has good uniformity, the hydrophobic layer and the dielectric layer are chemically bonded, the structural strength is higher, and it is not easy to fall off; the hydrophobic layer evaporation raw material adopts an olefin organic liquid containing a hydrocarbon group, a siloxane group or a silane group, which is suitable for a liquid lens using a fluorine-containing or phenyl-containing oil liquid, and can eliminate the hysteresis phenomenon during automatic focusing, and is convenient for realizing the preparation of a high refractive index and low dispersion liquid lens.

[0038] In a preferred embodiment of the present invention, a metal structure 6 is provided on the second glass plate 2, and an inverted cone-shaped accommodation cavity is formed between the metal structure 6 and the second glass plate 2, and the oil liquid 4 is in the accommodation cavity. The conductive liquid 3 is provided between the first glass plate 1 and the oil liquid 4. The metal structure 5 is used to connect a control circuit (not shown in the figure), and the control circuit is used to adjust the interface curvature between the conductive liquid 3 and the oil liquid 4 based on the electrowetting principle, so as to achieve zooming. The electrowetting principle belongs to the prior art and will not be described in detail here.

[0039] Furthermore, the volume of the oil liquid 4 is smaller than the volume of the containing cavity, and the contact interface between the conductive liquid 3 and the oil liquid 4 is located in the containing cavity, so as to ensure that the interface curvature between the conductive liquid 3 and the oil liquid 4 can be adjusted based on the electrowetting principle to achieve zooming, thereby ensuring the reliability of the liquid lens module 10.

[0040] The conductive liquid 3 and the oil liquid 4 are two incompatible liquids with different refractive indices. In some embodiments, the oil liquid 4 can be an organic liquid such as fluorinated naphthalene, perfluoroalkylbenzene, perfluorophenylsiloxane, etc., and the conductive liquid 3 can be water, ethanol, ethylene glycol or propylene glycol, etc. Phenyl-containing organic liquids usually have a higher refractive index and can be used in the preparation of high-refractive index liquid lenses; fluorinated organic liquids have a larger Abbe number and lower dispersion, and can be used in the preparation of low-dispersion liquid lenses. The hydrophobic layer 7 prepared by the above-mentioned vacuum coating method can eliminate the hysteresis phenomenon during autofocus and improve product quality.

[0041] In some preferred embodiments of the present invention, 0.1%wt to 0.5%wt of salt substances may be added to the conductive liquid 3, and the salt substances are one or more of sodium chloride, potassium chloride, sodium sulfate or potassium sulfate, which can enhance the conductivity and improve the performance of the liquid lens module.

[0042] In summary, the present invention adopts a vacuum coating method to prepare the dielectric layer and the hydrophobic layer, and only one evaporation process is required to complete the process, which can reduce the operating procedures, improve production efficiency, shorten the production cycle, and the film layer prepared by evaporation has good uniformity. The hydrophobic layer and the dielectric layer are chemically bonded, have higher structural strength, and are less likely to fall off; the evaporation raw material of the hydrophobic layer adopts an olefin organic liquid containing a hydrocarbon group, a siloxane group or a silane group, which is suitable for a liquid lens using a fluorine-containing or phenyl oil-containing liquid, expands the selection range of organic liquids in the liquid lens, can eliminate the hysteresis phenomenon during autofocus, and is convenient for the preparation of a high refractive index, low dispersion liquid lens.

[0043] The present invention has been described by the above-mentioned relevant embodiments, however, the above-mentioned embodiments are only examples for implementing the present invention. It must be pointed out that the disclosed embodiments do not limit the scope of the present invention. On the contrary, changes and modifications made without departing from the spirit and scope of the present invention are all within the scope of patent protection of the present invention.

Claims

1. A vacuum coating method, Features: The vacuum coating method is carried out in a vacuum coating device, which includes an evaporation chamber, a cracking chamber, a deposition chamber, a cold trap, a vacuum pump, and a coupling agent chamber and a second gas source chamber respectively connected to the deposition chamber. The vacuum coating method comprises: Step S1: placing the workpiece to be plated into the deposition chamber, adding parylene powder into the evaporation chamber, adding coupling agent into the coupling agent chamber, and adding organic liquid for a hydrophobic layer into the second gas source chamber; wherein the organic liquid for a hydrophobic layer is an olefin organic liquid containing a hydrocarbon group, a siloxane group or a silane group; Step S2: closing and sealing each chamber, and controlling the pyrolysis chamber and the cold trap to reach a preset temperature respectively; Step S3: Turn on the vacuum pump to evacuate the chamber so that the pressure in the deposition chamber reaches a first preset pressure value; Step S4: opening the coupling agent chamber to heat and increase the temperature to evaporate the coupling agent, and controlling the pressure of the deposition chamber to be a second set pressure value; Step S5: after the coupling agent is evaporated, the evaporation chamber is opened to heat and increase the temperature to evaporate parylene, and the pressure of the deposition chamber is controlled to be a third set pressure value, and the cracked parylene gas enters the deposition chamber, thereby being deposited on the surface of the to-be-plated object to form a dielectric layer; Step S6: when the dielectric layer evaporation is completed and the vacuum degree of the deposition chamber begins to decrease, the second gas source chamber is opened to heat and increase the temperature, and the organic liquid for the hydrophobic layer is evaporated, and the evaporated organic gas enters the deposition chamber, thereby being deposited on the surface of the dielectric layer to form a hydrophobic layer; Step S7: After the hydrophobic layer is evaporated, the coating process ends and the vacuum pump is turned off.

2. The vacuum coating method according to claim 1, Features: The boiling point of the organic liquid used for the hydrophobic layer is 200° C. to 400° C., and the molecular weight is 300 to 600.

3. The vacuum coating method according to claim 1, Features: The organic liquid for the hydrophobic layer is methacryloxypropyl tris(trimethylsiloxy)silane, butenyl tris(trimethylsiloxy)silane or vinyloctyltetramethylsilane.

4. The vacuum coating method according to claim 1, Features: The first set pressure value is 1Pa-5Pa; the second set pressure value is 1Pa-10Pa; and the third set pressure value is 1Pa-5Pa.

5. The vacuum coating method according to claim 1, Features: The temperature for evaporating parylene in step S5 is 110°C to 160°C; the temperature for evaporating the organic liquid for the hydrophobic layer in step S6 is 100°C to 300°C.

6. A liquid lens module, Features: The invention comprises a first glass plate, a second glass plate, a metal structure encapsulated between the first glass plate and the second glass plate, a conductive liquid and an oil liquid, wherein the oil liquid is an organic liquid containing fluorine or phenyl; a dielectric layer and a hydrophobic layer are coated on the surface of the metal structure from the inside to the outside, and the dielectric layer and the hydrophobic layer are prepared by the vacuum coating method according to any one of claims 1 to 5.

7. The liquid lens module according to claim 6, Features: The metal structure is arranged on the second glass plate, and an inverted cone-shaped accommodating cavity is formed between the metal structure and the second glass plate, and the oil liquid is in the accommodating cavity; the conductive liquid is arranged between the first glass plate and the oil liquid; the metal structure is used to connect the control circuit, and the control circuit is used to adjust the interface curvature between the conductive liquid and the oil liquid based on the electrowetting principle, so as to achieve zooming.

8. The liquid lens module according to claim 7, Features: The volume of the oil liquid is smaller than the volume of the accommodating cavity, and the contact interface between the conductive liquid and the oil liquid is located in the accommodating cavity.

9. The liquid lens module according to claim 6, Features: The conductive liquid is water, ethanol, ethylene glycol or glycerol.

10. The liquid lens module according to claim 6, Features: 0.1%wt-0.5%wt of salt substances are added to the conductive liquid, and the salt substances are one or more of sodium chloride, potassium chloride, sodium sulfate or potassium sulfate.

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