JP2019528201A - Protecting electronic devices - Google Patents

Abstract

The present invention relates to an electronic device which is at least partially covered, preferably completely covered, with a layer comprising a polymer having repeating units derived from vinylidene fluoride. The invention also relates to a protective film for an electronic device comprising at least one gas barrier film with a layer comprising a polymer having a repeating unit derived from vinylidene fluoride. [Selection] Figure 2

Description

  The present invention relates to the protection of electronic devices, in particular optoelectronic devices, against potential attacks of physicochemical origin such as dissolution, corrosion, oxidative degradation, abrasive friction and the like.

  An electronic device is either a single electronic component or a set of electronic components that can perform one or more functions in an electronic circuit.

  Preferably, in the context of the present invention, the electronic device is more specifically capable of emitting, detecting or controlling optoelectronic devices, ie electromagnetic radiation.

  Examples of electronic devices according to the invention, or optoelectronic devices where applicable, include transistors, chips, batteries, photovoltaic elements, light emitting diodes (LEDs), organic light emitting diodes (OLEDs), sensors, actuators, transformers and It is a detector.

  Electronic and optoelectronic devices are used for many purposes such as many electronic devices, equipment or subassemblies, as well as television sets, mobile phones, rigid or flexible screens, thin film photovoltaic element modules, light sources, energy sensors and converters, etc. And used and integrated in applications.

  Electronic and optoelectronic devices are physicochemical attacks caused by liquids and gases such as water vapor and oxygen, impacts, thermomechanical stress, especially those related to temperature changes, friction, contact with foreign objects such as particles, etc. Are susceptible to alterations, deterioration, reduced efficiency, or reduced functionality.

To avoid these problems, especially for atmospheric oxidants such as water and oxygen,
It is known that each layer of a member covers or seals an electronic device with a solid protective layer often accompanied by the form of a multilayer stack having a specific function to protect the device.

  Two main sealing techniques are known.

  The most common first technique consists of providing a gas barrier film that includes one or more gas barrier layers disposed on a polymer substrate. The barrier film is directly attached to the device via the adhesive layer. If there are local defects in the polymer substrate of the barrier film, the effectiveness of the deposited gas barrier structure can be compromised. Therefore, it is known to use a planarization layer to reduce the defect density of the substrate and thereby improve the quality of the subsequently deposited high density gas barrier layer. In this regard, reference can be made to a paper by Fahlteich et al.

US Patent Application Publication No. 2014/0264297 International Publication No. 2007/080338 International Publication No. 2001/032726 US Pat. No. 6,586,547

J. Fahlteich, S. Mogck, T. Wanski, N. Schiller, S. Amberg-Schwab, U. Weber, O. Miesbauer, E. Kuekuepinar, K. Noller and C. Boeffel, "The Role of Defects in Single and Multi-Layer Barriers for Flexible Electronics, "SVC Bulletin Fall 2014, pp. 36-43, 2014.

  In general, this method is performed by laminating a pre-adhered barrier layer onto the device, which becomes the first layer of the sealing structure. Given that the adhesive layer on the barrier film is in the solid state during the process to conform to the surface topology of the device, this process is delicate and there is even a risk of damage to the device due to the applied pressure.

  It is also possible to apply a solid or liquid adhesive layer on the device and then apply a barrier film on this adhesive layer. However, the aforementioned problems remain in this alternative.

  The second technique consists of depositing one or more gas barrier layers directly on the device. For example, liquid deposition including evaporation processes such as spin coating, spray coating, serigraphy, flexography, slot die coating, film stretching (such as non-contact doctor blade method or contact Meyer bar method), inkjet printing, vacuum gas deposition, precursor To deposit gas barrier layers such as chemical deposition, CVD (chemical vapor deposition), PECVD (plasma chemical vapor deposition) or ALD (atomic layer deposition), and combinations thereof, with or without body gas conversion There are various ways.

  US 2014/0264297 describes the use of an acrylate polymer type planarization layer on an organic light emitting diode prior to depositing a multilayer barrier structure.

  There is a need to further improve the protection of electronic devices, particularly optoelectronic devices.

  The present invention relates first to an electronic device which is at least partially, preferably completely covered, with a layer comprising a polymer having repeating units derived from vinylidene fluoride.

  According to one embodiment, the polymer having repeating units of vinylidene fluoride is a copolymer that preferably also includes repeating units derived from hexafluoropropylene.

  According to one embodiment, the copolymer comprises 2 to 50%, preferably 5 to 40% of repeating units derived from hexafluoropropylene in molar ratio.

  According to one embodiment, the layer has a thickness of 1 nm to 50 μm, preferably 100 nm to 20 μm.

According to one embodiment, the layer, 20 nm or less, more specifically 10nm or less, even more preferably less roughness _{R a} 7 nm.

  According to one embodiment, the layer is covered with one or more additional protective layers, preferably with at least one gas barrier layer, or an adhesive layer and at least one gas barrier film.

  According to one embodiment, a polymer layer comprising repeating units derived from vinylidene fluoride is the only protective layer of the device.

  According to one embodiment, an electronic device selected from transistors, chips, batteries, photovoltaic elements, light emitting diodes, organic light emitting diodes, sensors, actuators, transformers and photodetectors, preferably optoelectronic devices Even more preferred are organic light emitting diodes or organic photovoltaic elements.

  The invention also relates to a protective film for an electronic device comprising at least one gas barrier film with a layer comprising a polymer having a repeating unit derived from vinylidene fluoride.

  According to one embodiment, at least one gas barrier film includes an inorganic layer.

  According to one embodiment, the layer comprising a polymer having repeating units derived from vinylidene fluoride is a copolymer, preferably comprising repeating units derived from hexafluoropropylene, and / or in a molar ratio. 2 to 50%, preferably 5 to 40% of repeating units derived from hexafluoropropylene.

According to one embodiment, the layer comprising a polymer having repeating units derived from vinylidene fluoride has a thickness of 1 nm to 50 μm, preferably 100 nm to 20 μm, and / or 20 nm or less, more specifically Is characterized by _a roughness Ra of 10 nm or less, even more preferably 7 nm or less.

  The present invention is also a method for manufacturing an electronic device as described above, comprising the steps of preparing a solution or dispersion containing a polymer containing a repeating unit of vinylidene fluoride, and depositing the solution or the dispersion on the surface The present invention relates to an electronic device manufacturing method including a process and an evaporation process.

  According to one embodiment, the solution or the dispersion is directly deposited on the surface of the electronic device.

  According to one embodiment, the manufacturing method includes depositing one or more additional protective layers, preferably one or more gas barrier layers.

  According to one embodiment, the manufacturing method includes the steps of depositing an adhesive on the fluorinated polymer layer and then laminating the gas barrier film, or laminating the gas barrier film precoated with the adhesive layer. It is characterized by.

  The present invention also relates to a method for manufacturing an electronic device comprising providing a protective film as described above and applying the protective film to the surface of the electronic device according to the present invention.

  The invention also relates to an apparatus comprising one or more electronic devices according to the invention.

  According to one embodiment, the device is selected from a television set, a mobile phone, a rigid screen, a flexible screen, a photovoltaic element module, a light source, a sensor and an energy converter.

  According to one embodiment, the electronic device is disposed on the surface of the apparatus, and the layer comprising a polymer having repeating units derived from vinylidene fluoride is disposed between the surface of the electronic device and the surface, The electronic device has an opposite surface comprising said polymer comprising a repeating unit derived from vinylidene fluoride and / or one or more additional protective layers, preferably one or more gas barrier layers or adhesive layers and It is covered with a gas barrier film.

  The present invention makes it possible to overcome the drawbacks of the prior art. More specifically, it provides an improved technique for protecting electronic devices, particularly optoelectronic devices.

  The present invention provides a polymer having a repeating unit of vinylidene fluoride (VDF) (hereinafter referred to as “fluorinated polymer”) as a passivation layer or a planarizing layer for forming a protective layer of the device. Based on the use of).

  This layer can be formed by placing the fluorinated polymer in a solution or dispersion and applying the solution or dispersion to the surface of the device. In this way, the surface roughness after evaporation of the solvent can be significantly reduced. Advantageously and surprisingly, when the fluorinated polymer is deposited on the device, it adheres well to any additional layers of the device and protective structure.

  Furthermore, preferably it never changes the initial performance of the device, and in an advantageous embodiment, this performance is further improved, especially when the device is an optoelectronic device. While not wishing to be bound by any theory, we believe that this improvement may be due to optical effects.

  The thickness of the fluorinated polymer layer can be easily controlled by the thickness of the deposited liquid layer and the concentration of the solution or dispersion. It is possible even at very low values, which are difficult to obtain, especially with the methods using prior art adhesive layers.

The fluorinated polymer layer also makes it possible to protect the device during successive deposition (sealing) of the layers of the barrier structure.
-When laminating a barrier film, the fluorinated polymer layer plays a protective role with respect to the adhesive application and / or laminating process.
-Or when depositing one or more thin layers directly by forming a barrier structure on the device, the fluorinated polymer layer planarizes the structure and thus reduces the number of defects in the barrier structure that are subsequently deposited. By reducing it, it is possible to improve the properties of the barrier structure.

One embodiment of an electronic device according to the invention is schematically shown in a top view (top) and a cross-sectional view (bottom). Aging in (A) bare electronic devices, (B) electronic devices having a fluorinated polymer layer according to the invention, or (C) electronic devices sealed with a conventional gas barrier film, as described in the Examples The result of a test is shown. The aging period is displayed on the x-axis (in hours) and the normalized performance of the device is displayed on the y-axis. Figure 3 shows the results of a test measuring the normalized conversion efficiency (on the y-axis) of a photovoltaic device at various processing stages (on the x-axis). The symbol (X) indicates that with the fluorinated polymer layer provided by the present invention, and the symbol (O) indicates that without the fluorinated polymer layer provided by the present invention. For solutions containing fluorinated polymers at concentrations of 5% and 10%, (1) before and after the deposition of the fluorinated polymer layer provided by the present invention and (2) the conversion efficiency of the photovoltaic device (y The result of the test measuring (on-axis) is shown. It is a confocal microscope observation result which shows the effect of planarization of the fluorinated polymer layer by this invention with respect to an electronic device. Image A corresponds to a bare device and image B corresponds to a device covered with a fluorinated polymer layer. For solutions containing fluorinated polymers at 5% and 10% concentrations, (1) before and (2) after the deposition of the photovoltaic device and barrier layer provided by the present invention The result of the test which measures conversion efficiency (on the y-axis) is shown.

  In the following description, the present invention will be described in more detail and without limitation.

  The present invention is based on the use of a fluorinated polymer, which includes repeat units derived from VDF and optionally other repeat units (ie, obtained by polymerization of VDF monomers and optionally other monomers). Polymer).

  Specifically, a homopolymer (PVDF) can be used. Preferably, however, a copolymer is used, which term here has a polymer obtained by polymerization of VDF and at least one other comonomer, i.e. having repeating units derived from VDF and at least one other comonomer. Polymers are shown generically. Strictly speaking, it is preferably a copolymer having repeating units derived from VDF and only one other comonomer.

Preferably, the comonomer (or comonomers) is a halogenated alkene, more preferably a fluorinated alkene. Halogenated propene or ethylene, especially fluoroethylene (or vinyl fluoride), chlorofluoroethylene (1-chloro-1-fluoroethylene and 1-chloro-2-fluoroethylene), trifluoroethylene, chlorodifluoroethylene (especially 1-chloro Chloro-2,2-difluoroethylene), 1-bromo-2,2-difluoroethylene, bromotrifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, trifluoropropene (especially 3,3,3-trifluoropropene) Tetrafluoropropene (especially 2,3,3,3-tetrafluoropropene), chlorotrifluoropropene (especially 2-chloro-3,3,3-trifluoropropene), pentafluoropropene (especially 1,1,3) , 3,3-Pentafluoropro Mention may be made of hexafluoropropenes, also referred to as pens or 1,2,3,3,3-pentafluoropropenes) and hexafluoropropylene. It may also be a perfluoroalkyl vinyl ether of the general formula R _f —O—CF—CF ₂ . _Rf is an alkyl group, preferably C1-C4. Preferred examples are PPVE (perfluoropropyl vinyl ether) and PMVE (perfluoromethyl vinyl ether).

  Conveniently, the fluorinated polymer is a thermoplastic polymer (as opposed to a fluoroelastomer). Fluorinated polymers containing a high percentage of patterns derived from VDF comonomers tend to be thermoplastic.

  As used herein, “thermoplastic” refers to a non-elastomeric polymer. Elastomeric polymers can be stretched to twice their initial length at ambient temperature, as shown in ASTM in Special Technical Publication no. 184., and within 10% error after stress relief Is defined as a polymer that rapidly recovers its initial length.

  The fluorine-containing polymer used in the present invention can be obtained by a known polymerization method such as polymerization in a solution, emulsion or suspension. According to one embodiment, it is prepared by a polymerization process in an emulsion in the absence of a fluorinated surfactant.

  The fluorinated polymer used in the present invention, when it is a copolymer, may be homogeneous or heterogeneous and is preferably homogeneous. A homogeneous polymer has a uniform chain structure and the statistical distribution of comonomers does not change between polymer chains. In a heterogeneous polymer, the polymer chain has a distribution of average comonomer content of types with multiple peaks or spreads: thus it includes a polymer chain rich in comonomer and a polymer chain depleted in said comonomer . An example of non-uniform PVDF is described in International Publication No. 2007/080338 pamphlet (Patent Document 2).

  Homogeneous copolymers can be prepared using a one-step process in which comonomers are gradually injected while maintaining a constant mass ratio between them.

  Hexafluoropropene (HFP) is a preferred comonomer. Therefore, the fluorinated polymer of the present invention is preferably a P (VDF-HFP) copolymer.

  The P (VDF-HFP) copolymer is particularly as described in International Publication No. 2001/032726 (Patent Document 3) and US Pat. No. 6,586,547 (Patent Document 4). Explicitly referenced.

  The molar ratio of repeating units derived from VDF in the fluorinated polymer is preferably equal to 50-98%, in particular 60-95%.

  Therefore, in the case of P (VDF-HFP) copolymer, the molar ratio of repeating units derived from HFP is preferably 2 to 50%, in particular 5 to 40%.

Preferably, the viscosity of the fluorinated polymer is equal to 0.1-100 kPo (kilopoise) as measured at 230 ° C. and a shear rate of 100 s ⁻¹ .

  Fluorinated polymers may be used as coatings for electronic devices.

  The electronic device may in particular comprise a substrate and an electronic element supported thereon, which may comprise a layer of conductive material, semiconductor material or the like. The electronic elements are preferably on one side of the substrate, but in some embodiments they may be on both sides of the substrate.

  The fluorinated polymer coating may cover all or part of the electronic device and all or part of the substrate. Preferably, the fluorinated polymer covers at least a portion of the substrate and at least a portion of the electronic device to perform its planarization function. The fluorinated polymer may cover all or part of one of the two surfaces of the substrate (preferably the surface containing the electronic elements), or may cover all or part of both surfaces of the substrate.

  The substrate may in particular be a sheet of metal, silicon, glass, quartz or polymer, preferably a sheet of polyethylene terephthalate (PET) or polyethylene naphthalate (PEN).

  The thickness of the substrate may preferably be 3 μm to 4 mm, more specifically 12 μm to 200 μm.

  The maximum thickness of the electronic elements on the substrate may in particular be 10 nm to 1 mm, preferably 20 nm to 500 μm.

  A preferably transparent, eg glass cover, can be placed over the device and all coating layers described below (these coating layers are also preferably transparent).

  The present invention particularly presents the utility of the fluorinated polymer for forming a planarization layer on an electronic device. This is at least transport and subsequent sealing or final without adding an additional barrier layer (thin inorganic layer, or organic / inorganic multilayer, or glass / adhesive cover, or gas barrier film / adhesive) It has the advantage of protecting the device from external damage for a sufficient time to allow the final object to be laminated (via adhesive) which provides a good sealing function. The planarization layer further allows the device to be mechanically protected during the optional barrier film lamination process.

  In a first embodiment, the fluorinated polymer layer is intended to passivate or planarize the surface of the device to be protected (ie make it more inert or more planar). (Especially optoelectronic devices) placed directly or entirely. Next, one or more additional protective layers are disposed on the planarization layer. Additional layers can be placed immediately after or after the planarization layer deposition and drying (solidification).

  In a first alternative of the first embodiment, at least one gas barrier layer is disposed directly on the fluorinated polymer planarization layer.

  In a second alternative of the first embodiment, an adhesive layer and then a gas barrier film not previously exposed to the adhesive is placed on the planarization layer. The gas barrier film is adhered onto the planarization layer by an adhesive layer deposited directly on the planarization layer.

  In a third alternative of the first embodiment, a gas barrier film that has been previously exposed to an adhesive (ie, including an adhesive layer) is placed over the planarization layer. The adhesive layer of the barrier film is applied directly on the planarizing layer of the fluorinated polymer.

  “At least one gas barrier layer” also refers to a multilayer structure of a plurality of gas barrier layers deposited sequentially, optionally with one or more intercalation layers.

  “Barrier film” refers to a multi-layer structure formed prior to assembly into a device comprising a polymer substrate or substrate and one or more gas barrier layers, and optionally one or more intercalation layers. The preformed barrier film may be assembled on a device coated with a planarization layer and an adhesive layer, in particular according to the second alternative of the first embodiment.

  In some cases, an additional fluorinated polymer layer is placed over the gas barrier film or barrier layer structure deposited directly (without adhesive) on the electronic device. In this latter case, this allows the protection of the film or structure of the last gas barrier layer.

The sealing assembly of an electronic device comprising a barrier layer structure formed by gas barrier film or continuous deposition on the device may be of the HB (High Barrier) or UHB (Ultra High Barrier) type in particular. The HB film or HB structure has a vapor permeation flow rate of 10 ⁻³ to 10 ⁻⁵ g · m ⁻² · j ⁻¹ , and the UHB film or UHB structure has 10 ⁻⁵ g · m ⁻² · j. ^It has a vapor permeation flow rate of less than ^-1 .

  This vapor permeation flow rate can be measured as follows. A given target gas (vapor) partial pressure is maintained on the upstream surface of the sample. The target gas concentration depends on standards defined in the standard (for example, 85% humidity and 38 ° C. temperature for water measurement according to standards ASTM D3985-95 and F1249-90). The downstream surface of the sample is maintained at a zero permeation partial pressure by a neutral gas stream (nitrogen) that transports gas diffused into the sample to the sensor or by vacuum. The measurement is performed under a constant flow (steady state following the transition state).

  Inorganic layers can be used in particular as gas barrier layers that are arranged or already present in the barrier film to be built on devices planarized by the planarization layer of the present invention.

The inorganic layer can be composed in particular of oxides, nitrides or metal oxynitrides. Such layers may be deposited, for example, using chemical vapor deposition or thin layer deposition techniques under vacuum such as CVD (PECVD, ALD) or physical vapor deposition (vapor deposition, sputtering). The thickness of the inorganic layer is in the order of several hundred nanometers, in particular in the case of deposition by PECVD or PVD (for example deposition of SiO ₂ by PECVD or PVD), and thus for example from 50 nm to 1 μm, more preferably from 100 nm to 700 nm, or It may be 200 to 500 nm. The thickness of the inorganic layer is the case of deposition by ALD (for example, deposition of Al ₂ O ₃ , ZnO, or ZnO: Al, SiO ₂ , TiO ₂ , Ta ₂ O ₅ , HfO ₂ , or SnO ₂ ). Can have a thinner thickness on the order of several tens of nanometers, thus for example 10 to 100 nm, more preferably 15 to 50 nm, in particular 20 to 40 nm. While deposition by ALD may achieve a thickness of several molecular layers, it is preferable to stack a sufficient number of layers to reach the thickness given here as an example.

An example of a product obtained according to the first embodiment of the present invention includes a structure in which the following are superimposed.
1. 1. electronic device A planarization layer of a fluorinated polymer;
3. A first dense inorganic layer (eg of the metal oxide or nitride type);
4). Intercalation polymer layer (preferably having a thickness of a few microns, for example 1-25 μm, in particular 2-5 μm);
5. Additional dense inorganic layer (eg of the metal oxide or nitride type);
6). If necessary, 3. Or 4. The layer is repeated again, for example once or twice.
7. In some cases, it may be a protective outer layer of the last dense inorganic layer, in particular a fluorinated polymer layer as described above.

Another example of a product obtained in accordance with the first embodiment of the present invention includes a structure that superimposes:
1. 1. electronic device Planarizing layer of fluorinated polymer;
3. Adhesive layer;
4. one or more successive pairs of a) a dense inorganic layer (eg of the metal oxide or nitride type), b) an intercalated polymer layer (preferably a few microns, for example 1-25 μm, in particular 2 And finally c) after the assembly of the barrier film with the flattened and glued device, placed in the outermost position of the laminate and A gas barrier film comprising a polymer substrate that also functions as an outer protective layer.

  Each dense inorganic layer may be as described above. The polymer substrate of the barrier film can be made from, for example, polyethylene terephthalate (PET) or polyethylene naphthalate (PEN). The polymer substrate of the flexible device may also be made from polyethylene terephthalate (PET) or polyethylene naphthalate (PEN).

  Each intercalation polymer layer can be made from an organic polymer, such as a material having acrylic chemistry, or an organic / inorganic hybrid material, such as a material marketed under the name Ormocer®, for example. it can.

Instead of overlaying a dense inorganic layer and an intercalation polymer layer, a hybrid multilayer structure with a continuous change in composition between the SiO _x N _y inorganic form and the SiO _x C _y hybrid form (this structure is obtained by PECVD deposition) Can be used).

  Alternatively, the multilayer structure may include a flexible glass layer.

  In a first alternative of the first embodiment, the dense layer is formed directly on the fluorinated polymer layer of the present invention, for example by ALD, PECVD or PVD, or by liquid evaporation and application of potential energy by radiation or heat. The dense barrier layer can be deposited by liquid deposition techniques that can be converted into a barrier layer (eg, spin coating, slot die coating, spray coating, film stretching, etc.). In this case, the barrier layer generally does not include a polymer substrate, but in some cases an intercalation polymer layer can be used as the first layer above the fluorinated polymer layer.

  When a gas barrier film is used, it can be applied over the fluorinated polymer layer, particularly by laminating by roll-to-roll or vacuum methods.

  The adhesive used may in particular be a pressure sensitive adhesive or a photocrosslinkable or heat crosslinkable adhesive.

  Preferably, the adhesive for assembling the flattened device that has not been pre-adhered with the barrier film is a film of hot-melt material such as a copolymer of ethylene and vinyl acetate (EVA) or silicone A liquid adhesive such as can be used. Thermal post-crosslinking may be used.

  In the overall first embodiment described above, the fluorinated polymer layer can improve the gas barrier properties of the additional layer deposited on top. This represents an advantage over other types of planarization or passivation layers known as state of the art.

  Because of its stabilizing effect, the fluorinated polymer layer may be relatively corrosive (and therefore not directly compatible with the device), but using an adhesive with useful properties (eg, a barrier). Also good.

  In a second embodiment, the fluorinated polymer layer is the only protective layer of the device (except for possible covers). Specifically, it is surprisingly observed that the fluorinated polymer layer of the present invention alone provides a certain level of protection against chemical degradation and reduced device performance.

  For example, the fluorinated polymer layer of the present invention can be used as a temporary or temporary protective layer, particularly with respect to dust and contaminants. This layer is then removed by a simple cleaning step, for example with a solvent (eg the solvent used during the deposition of the layer). Such removal of the fluorinated polymer layer is easier to perform than when an adhesive layer is used, as in the prior art.

  In a third embodiment, the fluorinated polymer layer is associated with at least one gas barrier film (as described above in connection with the first embodiment). The electronic device can then be coated with the multilayer assembly. In this case, the fluorinated polymer layer can function as the adhesive described with respect to the first embodiment. The multi-layer assembly may or may not be pre-coated with a fluorinated polymer layer according to the present invention, and can be applied by laminating to the surface of the device.

  In all of the above embodiments, the fluorinated polymer layer is disposed on an electronic device on one side of the substrate described above (preferably the surface on which the electronic elements are disposed), or more preferably on both sides of the substrate. May be. The same applies to the different additional protective multilayer structures described above.

  In the fourth embodiment, the electronic device is arranged on the surface of an article that may be curved, for example. In this case, a fluorinated polymer layer according to the present invention can be provided between the surface of the article and the electronic device. On the other side of the electronic device, it is possible to provide protection according to any one of the three embodiments described above. For example, it is possible to apply a fluorinated polymer layer on the surface of the article, then the electronic device, and then a protective layer on the other side of the electronic device. Alternatively, it is possible to apply a fluorinated polymer layer on one side of the device, deposit the device thus coated on the surface of the article, and then apply a protective layer to the other side of the device. These methods can avoid completely sealing both sides of the device prior to the step of laminating it on the surface of the article, which is fragile, especially if the surface is curved.

  Examples of the target article may include helmets, ornaments, furniture elements, building elements, sports items such as shoes, balls, and frisbees, transportation vehicle components, and the like.

  In all of the above embodiments, the fluorinated polymer layer can be prepared by liquid deposition.

  For this purpose, the solution of the fluorinated polymer is dissolved in a solvent (with uniform dissolution of the fluorinated polymer at the molecular level) or a dispersion in which the fluorinated polymer is dispersed in a carrier fluid (the fluorinated polymer is in the form of particles Formed in). This solution or dispersion is also called ink. The ink is applied to the surface of the subject (especially directly on the surface of the electronic device). The solvent or carrier fluid is then evaporated to solidify the fluorinated polymer layer by bonding of fluorinated polymer molecules or particles to form a continuous film.

  In particular, water or a miscible water / organic solvent mixture can be used as the carrier fluid for producing the dispersion.

  As the solvent for producing the solution, a solvent selected from those capable of dissolving the fluorinated polymer (preferably homogeneously forming a transparent solution) is used. In particular, for example, ketones containing acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, ethers containing dibutyl ether, for example, esters containing methyl acetate, ethyl acetate, propyl acetate, butyl acetate, etc. .

  The present invention, when applied, makes it possible to avoid the use of highly toxic solvents such as dimethylformamide (DMF) or N-methylpyrrolidone.

  The mass concentration of the fluorinated polymer in the solution or dispersion is preferably from 0.01 to 50%, more preferably from 0.5 to 25%, still more preferably from 3 to 15%.

  Also, the ink is used in the synthesis of a fluorinated polymer, or one or more additions added to improve the properties of the ink, such as, for example, the wettability of the surface of an electronic device, or the adhesion to the surface, for example An agent may be included.

  Preferred additives are in particular cosolvents that change the surface tension of the ink. In particular, in the case of a solution, it may contain a linear alkane group or cyclic alkane group such as heptane, cyclohexane, decane or dodecane, or an aromatic compound such as toluene or ethylbenzene.

  The ink application may be performed by an application method by discrete or continuous means. It is particularly possible to use spin coating, spray coating, serigraphy, flexography, slot die coating, film stretching, ink jet printing. Preferred coating methods are spin coating, slot die printing, or doctor blade type film stretching (without contact with the device).

  The thickness of the fluorinated polymer layer thus formed is preferably in the range of 1 nm to 50 μm, preferably 10 nm to 30 μm, and even more preferably 100 nm to 20 μm.

The surface roughness of the fluorinated polymer layer (measured with a surface shape measuring device (profilometer)) is preferably (R _a , root mean square) preferably equal to or less than 20 nm, more specifically 10 nm. Is less than or equal to, and even more preferably less than or equal to 7 nm. This surface roughness can be determined by topographic surface measurement using an alpha step IQ type surface profile measuring device.

<Example>
The following examples illustrate, but do not limit, the invention.

  Example 1-Effect of fluorinated polymer layer on aging (compared to barrier film)

Three organic photovoltaic devices supported on a PET substrate were tested: one (A) without protection, the other (B) coated with a fluorinated polymer layer according to the invention, and finally One is (C) covered by laminating a gas barrier film having a gas barrier performance with a vapor permeation flow rate of 10 ⁻³ g · m ⁻² · j ⁻¹ .

  The fluorinated polymer according to the invention is a P (VDF-HFP) copolymer having a molar ratio of 76% VDF and 24% HFP. The copolymer was deposited by spin coating with an acetone solution (concentration 2% by mass) to obtain a layer having a thickness of 1 to 2 μm.

These devices are shown schematically in FIG. They are formed by sequential deposition of the following layers on a substrate 1 made from transparent conductive PET precoated with a thin layer of ITO (Indium Tin Oxide) and deposition to form Cr / Au contacts 6 did. :
-Electron conductive layer 2ETL made of zinc oxide and having a thickness of 50 nm.
Active organic semiconductor layer 3 (polymer P3HT) with a thickness of -250 nm.
A hole conducting layer 4 (HTL, type pedot: pss) having a thickness of −60 nm.
A deposited silver electrode layer 5 with a thickness of 100 nm.
A metallization layer 6 for Cr / Au contacts.

  The performance (conversion efficiency) of these three devices was measured over time by an accelerated deterioration test in a chamber maintained at 65 ° C. and 85% relative humidity. The electrical performance was accurately measured by current / voltage measurements according to incident radiance AM1.5 (IEC 60904).

  The results are shown in FIG.

  At the end of the first 48 hours of aging, the behavior of the device coated with the fluorinated polymer layer according to the present invention is a 20% reduction in the performance of the unprotected device, and the conventional method (high gas barrier film lamination) ) Was the same as the behavior of the device encapsulated in (5) or about 5% lower than that.

With long-term aging over 300 hours, devices with fluorinated polymer layers according to the present invention did not degrade faster than unprotected devices. After 1000 hours of aging, the unprotected device was reduced by 80%, while the device with the fluorinated polymer layer according to the invention has a conversion efficiency reduced by 60%. This behavior is even more surprising considering that the gas barrier properties (water vapor) of a fluorinated polymer layer according to the invention having a thickness of the order of 2 microns is about 200 g · m ⁻² · j ⁻¹ . Therefore, the observed effect cannot be related to gas barrier properties.

  Example 2-Effect of fluorinated polymer layer on efficiency (in the presence of barrier film)

The conversion efficiency of a photovoltaic device similar to that of Example 1 was measured (according to the method of Example 1) at various processing steps.
In the case of -A (according to the present invention): (1) After manufacturing the device, (2) After depositing the fluorinated polymer layer, (3) After adding the connector tape, (4) A barrier film similar to Example 1 After deposition.
In the case of -B (comparative example): (1) After manufacturing the device, (3) After adding the connector tape, (4) After depositing the barrier film as in Example 1.

  The results are shown in FIG. 3 (A: symbol x; B: symbol ◯). It can be seen that the efficiency (normalized by the post-manufacturing value of (1) above) decreases during the barrier film laminating process. However, this degradation associated with barrier film laminates is much lower when a fluorinated polymer layer is present. The presence of the fluorinated polymer layer makes it possible even to obtain an overall improved efficiency after laminating the barrier film compared to the efficiency immediately after the production of the photovoltaic device.

  Example 3-Effect of fluorinated polymer layer on efficiency and planarization (with no other protective layer)

  The conversion efficiency in the photovoltaic element similar to that of Example 1 (except that the substrate is made of glass) is (1) before coating with the fluorinated polymer according to the present invention, and (2) coating with the fluorinated polymer. It was measured later (according to the method of Example 1). The application was tested at two different concentrations, ie 5% and 10% polymer solutions.

  The results are shown in FIG. It can be seen that the fluorinated polymer layer according to the present invention improves the conversion efficiency of the device.

  By observation with a confocal microscope at the step between the active layer 3 and the hole conducting layer 4 (see FIG. 1), (A) before deposition of the fluorinated polymer layer and (B) fluorinated polymer layer ( The surface flattening effect was confirmed after deposition of a 10% concentration solution. An image is shown in FIG.

  Example 4-Effect of fluorinated polymer layer on efficiency (as opposed to no other protective layer)

  This example was performed in the same manner as Example 3 except that the deposition of the inorganic gas barrier layer by liquid deposition and UV treatment at 185 nm was performed immediately after deposition of the fluorinated polymer layer.

The results are shown in FIG. It can be seen that the fluorinated polymer layer according to the invention covered with a barrier layer improves the conversion efficiency of the device.

Claims (20)

  An electronic device covered at least partially, preferably completely directly, with a layer comprising a polymer having repeating units derived from vinylidene fluoride.   The electronic device according to claim 1, wherein the polymer containing a repeating unit of vinylidene fluoride is a copolymer which preferably also contains a repeating unit derived from hexafluoropropylene.   The electronic device according to claim 2, wherein the copolymer contains 2 to 50%, preferably 5 to 40%, of repeating units derived from hexafluoropropylene in a molar ratio.   The electronic device according to claim 1, wherein the layer has a thickness of 1 nm to 50 μm, preferably 100 nm to 20 μm. It said layer, 20 nm or less, more specifically 10nm or less, even more preferably less roughness R _a 7 nm, electronic device according to any one of claims 1 to 4.   Any of the preceding claims, wherein the layer is covered with one or more additional protective layers, preferably with at least one gas barrier layer, or with an adhesive layer and at least one gas barrier film. An electronic device according to claim 1.   The electronic device according to any one of claims 1 to 6, wherein the polymer layer containing a repeating unit derived from vinylidene fluoride is the only protective layer of the device.   Electronic devices selected from transistors, chips, batteries, photovoltaic elements, light emitting diodes, organic light emitting diodes, sensors, actuators, transformers and photodetectors, preferably optoelectronic devices, even more preferably organic light emitting The electronic device according to claim 1, wherein the electronic device is a diode or an organic photovoltaic element.   A protective film for an electronic device comprising at least one gas barrier film with a layer comprising a polymer having a repeating unit derived from vinylidene fluoride.   The protective film for electronic devices according to claim 9, wherein the at least one gas barrier film includes an inorganic layer. The layer comprising a polymer having a repeating unit derived from vinylidene fluoride,
A copolymer, preferably comprising repeating units derived from hexafluoropropylene,
And / or
Containing repeating units derived from hexafluoropropylene in a molar ratio of 2-50%, preferably 5-40%,
The protective film for electronic devices of Claim 9 or 10 characterized by the above-mentioned. The layer comprising a polymer having a repeating unit derived from vinylidene fluoride,
Having a thickness of 1 nm to 50 μm, preferably 100 nm to 20 μm,
And / or
The protective film for an electronic device according to any one of claims 9 to 11, which has _a roughness Ra of 20 nm or less, more specifically 10 nm or less, and even more preferably 7 nm or less. A method of manufacturing an electronic device according to any one of claims 1 to 8,
Providing a solution or dispersion containing a polymer comprising repeating units of vinylidene fluoride;
Depositing the solution or the dispersion on a surface;
An evaporation step,
Electronic device manufacturing method.   The method of manufacturing an electronic device according to claim 13, wherein the solution or the dispersion liquid is directly deposited on a surface of the electronic device.   15. A method of manufacturing an electronic device according to claim 13 or 14, comprising depositing one or more additional protective layers, preferably one or more gas barrier layers. Depositing an adhesive on the fluorinated polymer layer and then laminating a gas barrier film;
Or
The method for producing an electronic device according to claim 13, comprising a step of laminating a gas barrier film precoated with an adhesive layer.   It provides the protective film for electronic devices as described in any one of Claims 9-12, and applies the said protective film to the surface of the electronic device as described in any one of Claims 1-8. A method for manufacturing an electronic device, comprising:   9. An apparatus comprising one or more electronic devices according to any one of claims 1-8.   19. The device according to claim 18, selected from a television set, a mobile phone, a rigid screen, a flexible screen, a photovoltaic element module, a light source, a sensor and an energy converter. 20. An apparatus according to claim 18 or 19, comprising
The electronic device is disposed on a surface of the apparatus;
The layer comprising a polymer having repeating units derived from vinylidene fluoride is disposed between the surface of the electronic device and the surface;
The electronic device has an opposite surface,
By said layer comprising a polymer having repeating units derived from vinylidene fluoride,
And / or
A device characterized in that it is covered by one or more additional protective layers, preferably one or more gas barrier layers or adhesive layers and a gas barrier film.

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