Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K50/00—Organic light-emitting devices
  • H10K50/80—Constructional details
  • H10K50/84—Passivation; Containers; Encapsulations
  • H10K50/844—Encapsulations
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C3/00—Glass compositions
  • C03C3/12—Silica-free oxide glass compositions
  • C03C3/122—Silica-free oxide glass compositions containing oxides of As, Sb, Bi, Mo, W, V, Te as glass formers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B05—SPRAYING OR ATOMISING IN GENERAL; APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D—PROCESSES FOR APPLYING FLUENT MATERIALS TO SURFACES, IN GENERAL
  • B05D5/00—Processes for applying liquids or other fluent materials to surfaces to obtain special surface effects, finishes or structures
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C3/00—Glass compositions
  • C03C3/12—Silica-free oxide glass compositions
  • C03C3/14—Silica-free oxide glass compositions containing boron
• • C—CHEMISTRY; METALLURGY
  • C03—GLASS; MINERAL OR SLAG WOOL
  • C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
  • C03C3/00—Glass compositions
  • C03C3/12—Silica-free oxide glass compositions
  • C03C3/23—Silica-free oxide glass compositions containing halogen and at least one oxide, e.g. oxide of boron
  • C03C3/247—Silica-free oxide glass compositions containing halogen and at least one oxide, e.g. oxide of boron containing fluorine and phosphorus
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05B—ELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
  • H05B33/00—Electroluminescent light sources
  • H05B33/02—Details
  • H05B33/04—Sealing arrangements, e.g. against humidity
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10K—ORGANIC ELECTRIC SOLID-STATE DEVICES
  • H10K59/00—Integrated devices, or assemblies of multiple devices, comprising at least one organic light-emitting element covered by group H10K50/00
  • H10K59/80—Constructional details
  • H10K59/87—Passivation; Containers; Encapsulations
  • H10K59/873—Encapsulations

Definitions

• the present invention relates to a method for inhibiting oxygen and moisture penetration, and subsequent degradation of a device and the resulting device.
• Examples of this device include a light-emitting device
• OLED organic emitting light diode
• OLED devices The more prominent efforts to extend the lifetime of OLED devices include gettering, encapsulation and extensive device sealing techniques.
• Today one common way for sealing an OLED device is to use different types of epoxies, inorganic materials and/or organic materials that form a seal after they are cured by ultra-violet light, or heated by various means.
• Vitex Systems manufactures and offers for sell a coating under the brand name of BarixTM which is a composite based approach where alternate layers of inorganic materials and organic materials are used to seal the entire surface of the OLED device.
• BarixTM is a composite based approach where alternate layers of inorganic materials and organic materials are used to seal the entire surface of the OLED device.
• the present invention utilizes an LLT (low liquidus- temperature) material, which typically has a low low liquidus temperature (or in specific embodiments a low glass transition temperature) , to form a barrier layer on a device.
• the LLT material includes, but is not limited to, tin fluorophosphate glass, chalcogenide glass, tellurite glass and borate glass.
• the LLT material can be deposited onto the device by, for example, sputtering, co- evaporation, laser ablation, flash evaporation, spraying, pouring, frit-deposition, vapor-deposition, dip-coating, painting or rolling, spin-coating, or any combination thereof.
• Defects in the LLT material from the deposition step can be removed by a consolidation step (for example, heat treatment) , to produce a pore-free, gas and moisture impenetrable protective coating on the device.
• a consolidation step for example, heat treatment
• the consolidation step is only practical with the LLT material where the consolidation temperature is sufficiently low so as to not damage the inner layers in the device.
• the deposition step and/or heat treatment step take place in a vacuum, or in an inert atmosphere, or in ambient conditions depending upon the LLT ' s composition.
• FIGURE 1 is a flowchart illustrating the steps of a method for inhibiting oxygen and moisture degradation of a device in accordance with the present invention
• FIGURE 2 is a cross-sectional side view of the device that is protected by LLT material applied by the method shown in FIGURE 1 in accordance with the present invention.
• FIGURES 3-9 illustrate several different graphs, photos and diagrams that are used to help explain the different experiments and the results of the different experiments which were conducted to demonstrate the capabilities and advantages of the present invention.
• the device 200 includes a heat treated low liquidus temperature (LLT) material 202, one or more inner layers 204 and a support 206.
• the method 100 includes step 102. in which the LLT material 202 is deposited over one or more inner layers 204 located on top of the support 20S (e.g., substrate 206) (see also FIGURE 5) .
• LLT low liquidus temperature
• the LLT material 202 can be deposited using anyone of variety of processes including, for example, sputtering, flash evaporation, spraying, pouring, frit-deposition, vapor-deposition, dip-coating, painting, rolling (for example a film LLT material 202) , spin-coating, a co- evaporation, a laser ablation process, or any combination thereof.
• more than one type of LLT material 202 can be deposited (e.g., sputtered) at the same time over one or more inner layers 204 located on top of the support 206 (e.g., substrate 206).
• the method 100 also includes step
• the device 200 including the deposited LLT material 202 is annealed, consolidated or heat treated.
• the heat treatment step 104 is performed to remove defects
• Some examples of different devices 200 that can be protected by the heat treated LLT material 202 include a light-emitting device (e.g., OLED device), a photovoltaic device, a thin-film sensor, an evanescent waveguide sensor, a food container and a medicine container.
• the deposition step 102 and the heat treatment step 104 can be performed in a vacuum or inert atmosphere. This is done to ensure that the waterless and oxygen-free condition is maintained throughout the sealing process. This is especially important for robust, long-life operation of organic electronics with minimal degradation.
• the device 202 is an OLED device 200 that has multiple inner layers 204 which include a cathode and electro-luminescent materials that are located on the substrate 206.
• the cathode and electro-luminescent materials 204 can be easily damaged if they are heated above for example 100-125 0 C.
• the heat treatment step 104 (so as to minimize or eliminate porosity) would not be possible in this particular application if traditional glass was deposited on the OLED device 200. Because, the temperature (e.g., 600 0 C) needed to remove the defects in a traditional glass (soda-lime) would be so high that the OLED device's inner layers 204 would be damaged.
• the heat treatment step 104 can be performed in this particular application because the temperature (e.g., 120 0 C) needed to remove the defects in the LLT material 202 can be relatively low such that the OLED device's inner layers 204 would not be damaged.
• LLT material 202 makes this all possible because this type of material has a relatively low liquidus temperature ⁇ 1000°C.
• the low liquidus temperature means that the LLT 202 can be heat treated at a relatively low temperature to obtain a pore-free film which will not thermally damage the OLED device's inner layer (s) 204.
• the heat treated LLT material 202 can also be used as a barrier layer on a wide variety of devices 200 in addition to the OLED device 202 such as a thin-film sensor, a photovoltaic device, an evanescent waveguide sensor, a food container, a medicine container or an electronic device that is sensitive to moisture, oxygen or other gases (for example) .
• the LLT material 202 has low liguidus temperature ⁇ _ 1000 0 C (and more preferably ⁇ _ 600 0 C and even more preferably ⁇ 400 0 C) and can include, for example, glass such as tin fluorophosphate glass, chalcogenide glass, tellurite glass, borate glass and phosphate glass (e.g., alkali Zn or SnZn pyrophosphates).
• glass such as tin fluorophosphate glass, chalcogenide glass, tellurite glass, borate glass and phosphate glass (e.g., alkali Zn or SnZn pyrophosphates).
• the low liquidus temperature (LLT) materials can be devoid of heavy metals and other environmentally undesirable materials. • The LLT materials can be durable and exhibit low dissolution rates when immersed in water at 85 0 C ( ⁇ 20 microns per day). See, Tick, P.A., “Water Durable Glasses with Ultra Low Melting Temperatures” , Physics and Chemistry of Glasses, 25(6) pp. 149 - 154 (1984).
• the LLT material can contain dye molecules and can be doped to levels as high as 8mM (4.8 x 10 18 cm “3 ) . See, Tick, P.A., Hall, D. W., "Nonlinear Optical Effects in Organically Doped Low Melting Glasses” , Diffusion and Defect Data, Vol. 53 - 54, pp. 179 - 188, (1987).
• the LLT phosphate glasses have helium permeability coefficients 4 to 5 orders of magnitude less than that of fused silica. See, Peter, K. H., Ho, D.,
• the tin fluorophosphate glass 202 is discussed first and the preferred composition ranges of the various constituents (in parts by weight) are indicated in TABLE 1.
• composition no. 4 composition no. 4
• composition no. 5 composition no. 5
• TABLES 2A and 2B illustrate the compositions of the tested exemplary LLT glasses 202 with their T G (in this example and other examples herein T G is related to the low liquidus temperature) and various constituents as follows:
• FIGURE 3 is a graph that illustrates the results of a weight loss experiment that was conducted for 1000 hours in 85°C water.
• the tested LLT glasses 202 (composition nos . 1, 2 and 4) have a durability that is comparable to Corning Inc . ' s 1737 glass
• FIGURE 4 is a graph that indicates that the weight loss measurements of the tested LLT glasses 202 (composition nos. 1 and 4-5) .
• FIGURE 5 is a cross-sectional side view of an oven 502 which contains a device 200 that includes LLT glass films 202 (composition no. 1), two inner layers 204 (Al and Ca) and a substrate 206 (Corning Inc. 1 S 1737 glass substrate).
• the Al and Ca layers 204 were deposited on the thick substrate 206 and then encapsulated with LLT glass films 202 (composition no. 1) .
• the "calcium patch” test was performed as follows. A 100 nm Ca film 204 was evaporated onto a Corning Inc . ' s 1737 glass substrate 206. Then, a 200 nm Al layer 204 was evaporated on the Ca film 204. The Al layer 204 was used to simulate the conditions of a cathode typically used to produce polymer light emitting diodes (PLEDs) . Using a “dual-boat" customized Cressington evaporator, the 1737 glass substrate 206 was maintained at 130 0 C and approximately 10 "s Torr during the Ca and Al evaporation steps.
• PLEDs polymer light emitting diodes
• the LLT glass 202 (composition no. 1) was then sputtered onto the Al and Ca layers 204 under relatively gentle RF power deposition conditions (30 W forward/1 W reflected RF power) and low argon pressure ( ⁇ 19 seem) (see step 102 in FIGURE 1) .
• the sputtering was performed for 24 hours to obtain a glass thickness in the range of 2.5 ⁇ m (chamber pressure ⁇ 10 "3 Torr) . It should be noted that the LLT material thickness can be made as thick as one needs depending on one's chosen deposition duration.
• FIGURE 6 shows the pictures of the tested devices 200 which were taken at regular intervals to follow the rate of calcium oxidation which is an indication of the permeation properties of the LTG glass films 202.
• the images in the bottom row were taken, at the indicated time intervals, of a sample device 200 prepared without any heating of the LLT glass sputtered glass layer 202.
• the images in the middle row were taken of a similar device 200 that was heated (at 121°C) during the first hour of the 24 hour glass deposition time interval. And, the tested device 200 shown in the top row was prepared similarly except that it was heated (at 121°C) after the 24 hour glass deposition time interval. Clearly, the tested device 200 shown in the top row that had the entire LTG glass thickness subjected to heat-treatment fended off oxygen and water attack best .
• FIGURE 7 is a graph that illustrates the percentage of calcium area oxidized due to time spent in the 85°C and 85% relative humidity oven 502 for the three tested devices 200 (see FIGURE 6) and one non-covered device.
• data 702 represents the percentage of the calcium patch surface area that was oxidized on a calcium patch that had the 100 nm calcium and 200 nm aluminum layers but was not coated with LLT glass 202.
• data 704 represents the calcium patch surface area that was oxidized in one of the tested devices 200 which had a 2.5 ⁇ m sputtered LLT glass layer 202 (composition no. 1) that was not heat treated.
• Data 706 represents the calcium patch surface area that was oxidized in another tested device 200 which had a 2.5 ⁇ m sputtered LLT glass layer 202 (composition no. 1) that was heat treated at 121°C for the first hour during the 24 hour deposition period.
• data 708 represents the calcium patch surface area that was oxidized in another test device 200 which had a 2.5 ⁇ ra sputtered LLT glass layer 202 (composition no. 1) that was heat treated at 121°C for one hour after the 24 hour deposition period. As can be seen, the device 200 that was heat treated after the deposition period performed the best.
• the water permeation rate in the tested devices 200 were estimated by first calculating the total amount of calcium metal in the 100 nm layer 204. Then, by consulting FIGURE 7 and other additional data, we estimated the time it took for half the calcium in the W x 1" x 100 nm patch to become oxidized, the so-called half life. This yields the average number of grams oxidized with water vapor per day, per unit meter 2 in an 85/85 environment. To convert to ambient conditions, a scale factor was introduced between the ambient time (ambient half life) and time spent in the 85/85 environment (85/85 half life) .
• FIGURES 9A and 9B The data associated with the tested device 200 that had LLT glass 204 (composition no. 1) which was heat treated after the deposition step is shown in FIGURES 9A and 9B. Also, shown is data associated with Vitex system's BarixTM seals. As can be seen, the tested device 200 performed better than the device that used a BarixTM seal . It should be noted that the photograph/graph in FIGURE 9B also shows the relative levels of oxygen permeability of typical polymers and coatings and the sensitivity limits of current test equipment .
• LLT materials which have low liquidus temperatures to form a barrier layer with permeation properties comparable to the material itself.
• the LLT materials include, but are not limited to, tin fluorophosphate glass, chalcogenide glass, tellurite glass, phosphate glass and borate glass. These LLT materials are especially suitable for inhibiting oxygen or/and moisture degradation common to electronic devices, food or medicine. In addition, these LLT materials may be used to reduce, for example, photochemical, hydrolytic, and oxidative damage due to chemically active permeants .
• the LLT materials may be deposited using one or more of the following methods such as sputtering, evaporation, spraying, pouring, frit-deposition, vapor-deposition, dip- coating, painting or rolling, spin-coat-ing (for example) .
• Defects in the LLT materials from the deposition step are removed by a consolidation step (heat treatment) in order to produce a pore-free, gas and moisture impenetrable protective coating on the device.
• the barrier layer is quite durable, exhibiting low weight loss (0.28%) in standardized 1000 hour, 85°C water-immersion tests, and enduring over 600 hours in calcium patch tests, in 85°C and 85% relative humidity chambers.
• the consolidation step is truly practical with the LLT materials where the consolidation temperature is sufficiently low to inhibit thermal damage to nearby layers.
• the sputter-deposited thin film material is composed of 66% Sn 4+ and 34% Sn 2+ .
• the tin oxidation state is driven to 100% tetravalent tin (i.e., Sn 4+ ). It is believed these differences in the Sn changes the stoichiometric composition and as a result the Tg of the deposited and heat treated composition no. 1 film.
• barrier layers containing a subset of durable low liquidus temperature materials provide substantial protection from oxygen and water attack (and transport) beyond traditional physically-deposited oxide barrier layers.
• the preferred barrier layers described herein can have a water and oxygen permeance below 10 "6 g/m 2 /day and 10 "5 cc/m 2 /atm/day, respectively.
• physically-deposited low liguidus temperature thin- film barrier layers can be annealed at temperatures suitable for retaining the integrity of adjoining organic layer material physicochemical properties. This last feature makes durable low liquidus temperature materials unique compared with other physically deposited oxide barrier layers.
• low liquidus temperature materials can be annealed at a low temperature so as to remove mesoscopic defects from the physically deposited layers and also retain the physicochemical properties of the adjoining organic under-layers . This is in contrast to the VitexTM method in which the defects are not removed. Moreover, it has been shown that these low liquidus temperature barrier layers can be used to form an integral part of various devices (e.g., waveguide, grating sensors, photonic crystals etc.) while inhibiting the transport of materials detrimental to high-performance operation.
• various devices e.g., waveguide, grating sensors, photonic crystals etc.
• low liquidus temperature materials can be made which contain small-composite materials or other electro-optic dopants. These dopants can optimize the refractive indices or add additional electro-optic features to a device 200. This can be particularly, useful when the device 200 is a waveguide sensor.

Landscapes

• Chemical & Material Sciences (AREA)
• Materials Engineering (AREA)
• Engineering & Computer Science (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Geochemistry & Mineralogy (AREA)
• Life Sciences & Earth Sciences (AREA)
• Organic Chemistry (AREA)
• Physics & Mathematics (AREA)
• Optics & Photonics (AREA)
• Electroluminescent Light Sources (AREA)
• Physical Vapour Deposition (AREA)
• Glass Compositions (AREA)
• Laminated Bodies (AREA)
• Surface Treatment Of Glass (AREA)

Priority Applications (3)

Applications Claiming Priority (2)

Publications (1)

Family

ID=37460166

Family Applications (1)

Country Status (7)

Cited By (11)

Families Citing this family (44)

Citations (7)

Family Cites Families (204)

• 2005
  • 2005-08-18 US US11/207,691 patent/US20070040501A1/en not_active Abandoned
• 2006
  • 2006-08-09 EP EP06800857.2A patent/EP1929559B1/en not_active Ceased
  • 2006-08-09 JP JP2008526984A patent/JP5113054B2/ja not_active Expired - Fee Related
  • 2006-08-09 KR KR1020087006506A patent/KR101353226B1/ko not_active Expired - Fee Related
  • 2006-08-09 WO PCT/US2006/030670 patent/WO2007021627A1/en not_active Ceased
  • 2006-08-09 CN CN200680030038.7A patent/CN101243562A/zh active Pending
  • 2006-08-17 TW TW095130327A patent/TWI360904B/zh not_active IP Right Cessation
• 2014
  • 2014-03-24 US US14/223,380 patent/US9050622B2/en not_active Expired - Fee Related

Patent Citations (7)

Also Published As

Similar Documents

Legal Events