Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
  • H10H20/80—Constructional details
  • H10H20/85—Packages
  • H10H20/852—Encapsulations
  • H10H20/854—Encapsulations characterised by their material, e.g. epoxy or silicone resins
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
  • C09K3/00—Materials not provided for elsewhere
  • C09K3/10—Materials in mouldable or extrudable form for sealing or packing joints or covers
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10H—INORGANIC LIGHT-EMITTING SEMICONDUCTOR DEVICES HAVING POTENTIAL BARRIERS
  • H10H20/00—Individual inorganic light-emitting semiconductor devices having potential barriers, e.g. light-emitting diodes [LED]
  • H10H20/01—Manufacture or treatment
  • H10H20/036—Manufacture or treatment of packages
  • H10H20/0362—Manufacture or treatment of packages of encapsulations

Definitions

• the present invention relates to an encapsulant for LEDs.
• LEDs Light emitting diodes
• display devices that are capable of displaying high-quality images by mounting LED chips using minute LEDs called micro-LEDs have been attracting attention (for example, Patent Document 1, etc.).
• LEDs deteriorate when they come into contact with moisture or gas in the atmosphere, reducing light extraction efficiency, so they are usually sealed using a sealant (LED sealant), but micro LEDs are used.
• the LED encapsulant is required to have flexibility so that the cured product can follow the expansion and contraction of the LED chip, the bending of the substrate, and the like.
• An object of the present invention is to provide an LED encapsulant that can be coated with high coating accuracy and whose cured product can follow the expansion and contraction of the LED chip, the bending of the substrate, and the like.
• the present disclosure 1 is an encapsulant for LEDs containing a curable resin and a polymerization initiator, having a viscosity at 25°C of 100 mPa ⁇ s or less, and a cured product having a tensile elongation at break of 50% or more at 25°C. be.
• the present disclosure 2 provides that the curable resin comprises a dithiol compound (A) having two thiol groups in one molecule, a polythiol compound (B) having three or more thiol groups in one molecule, and a polythiol compound (B) having three or more thiol groups in one molecule.
• the LED encapsulant of the present disclosure 1 contains a polyene compound (C) having two or more aliphatic carbon-carbon double bonds.
• the present disclosure 3 contains a curable resin and a polymerization initiator, and the curable resin contains a dithiol compound (A) having two thiol groups in one molecule, and a dithiol compound (A) having three or more thiol groups in one molecule. and a polyene compound (C) having two or more aliphatic carbon-carbon double bonds in one molecule.
• Present Disclosure 4 is the LED encapsulant of Present Disclosure 2 or 3, wherein the polyene compound (C) is a (meth)allyl compound having two or three aliphatic carbon-carbon double bonds in one molecule. It is.
• the present disclosure 5 is the LED encapsulant of the present disclosure 1, 2, 3, or 4 which further contains a leveling agent.
• the present disclosure 6 is the LED encapsulant of the present disclosure 1, 2, 3, 4, or 5 used for coating by an inkjet method.
• the present invention will be explained in detail below.
• the LED encapsulant of the present disclosure 1 is also referred to as the "LED encapsulant of the present invention 1"
• the LED encapsulant of the present disclosure 3 is also referred to as the "LED encapsulant of the present invention 2”. Further, matters common to the LED encapsulant of the first invention and the LED encapsulant of the second invention are not specified or are described as "the LED encapsulant of the present invention.”
• the present inventor has developed an LED encapsulant that uses a combination of specific compounds as a curable resin so that the viscosity at 25°C is below a specific value, and the tensile elongation at break of the cured product is set to a specific value.
• the upper limit of the viscosity of the LED encapsulant of the present invention 1 at 25° C. is 100 mPa ⁇ s. Since the viscosity at 25° C. is 100 mPa ⁇ s or less, the LED encapsulant of the present invention 1 has excellent coating accuracy by an inkjet method or the like.
• the preferable upper limit of the viscosity at 25° C. is 50 mPa ⁇ s, and the more preferable upper limit is 30 mPa ⁇ s.
• the lower limit of the viscosity at 25° C. of the LED encapsulant of the present invention 1 is preferably 10.0 mPa ⁇ s, and the more preferable lower limit is 15.0 mPa ⁇ s.
• the preferred upper limit of the viscosity of the LED sealant of the second aspect of the present invention at 25° C. is 100 mPa ⁇ s. Since the viscosity at 25° C. is 100 mPa ⁇ s or less, the LED encapsulant of the second aspect of the present invention has better coating accuracy by an inkjet method or the like.
• a more preferable upper limit of the viscosity at 25° C. is 50 mPa ⁇ s, and an even more preferable upper limit is 30 mPa ⁇ s. From the viewpoint of shape retention after application, etc., the lower limit of the viscosity at 25° C.
• the LED encapsulant of the second invention is preferably 10.0 mPa ⁇ s, and the more preferable lower limit is 15.0 mPa ⁇ s.
• the above viscosity is measured using, for example, VISCOMETER TV-22 (manufactured by Toki Sangyo Co., Ltd.) as an E-type viscometer, No. The measurement can be performed using one rotor at a rotation speed of 100 rpm.
• the lower limit of the tensile elongation at 25° C. of the cured product is 50%. Since the cured product has a tensile elongation at break of 50% or more at 25°C, the cured product of the LED encapsulant of the present invention has excellent flexibility and follows the expansion and contraction of the LED chip and the bending of the substrate. become something that can be done. Although there is no particular preferable upper limit for the tensile elongation at break at 25° C. of the cured product of the LED encapsulant of the present invention 1, the practical upper limit is 500%.
• the preferable lower limit of the tensile elongation at 25° C. of the cured product is 50%. Since the cured product has a tensile elongation at break of 50% or more at 25°C, the cured product of the LED encapsulant of the second invention has excellent flexibility and follows the expansion and contraction of the LED chip and the bending of the substrate. become something that can be done. Although there is no particular preferable upper limit for the tensile elongation at break at 25° C. of the cured product of the LED encapsulant of the present invention 2, the practical upper limit is 500%.
• the tensile elongation at break at 25°C of the cured product was determined using a tensile tester (for example, "Autograph AG-Xplus” manufactured by Shimadzu Corporation) for a cured product with a width of 5 mm, a length of 400 mm, and a thickness of 500 ⁇ m.
• the distance between the grips is 25 mm, and the tensile speed is 5 mm/s.
• the cured product whose tensile elongation at break is measured is, for example, a dithiol compound (A), a polythiol compound (B), a polyene compound (C), and a photo-radical polymerized compound in which the LED encapsulant is a dithiol compound (A), a polythiol compound (B), a polyene compound (C), and
• the LED encapsulant is a dithiol compound (A), a polythiol compound (B), a polyene compound (C)
• an initiator it can be obtained by a method of irradiating the LED encapsulant with ultraviolet rays of 3000 mJ/cm 2 .
• the storage modulus of the cured product at 25° C. has a preferable lower limit of 0.01 MPa and a preferable upper limit of 500 MPa. Since the storage elastic modulus of the cured product at 25° C. is within this range, the LED encapsulant of the present invention has the effect that the cured product follows the expansion and contraction of the LED chip, the bending of the substrate, etc., and the reliability. It becomes better.
• a more preferable lower limit of the storage modulus of the cured product at 25° C. is 0.1 MPa, and a more preferable upper limit is 300 MPa.
• the storage elastic modulus at 25°C of the above cured product was measured using a dynamic viscoelasticity measuring device (for example, "DVA-200" manufactured by IT Instruments Control Co., Ltd.) for a cured product with a width of 5 mm, a length of 400 mm, and a thickness of 500 ⁇ m. ) under the conditions of tensile mode, gripping width of 25 mm, and frequency of 1.0 Hz.
• the LED encapsulant may be a dithiol compound (A), a polythiol compound (B), a polyene compound (C), and a photoradical, which will be described later.
• a polymerization initiator When a polymerization initiator is contained, it can be obtained by a method such as irradiating the LED sealant with ultraviolet rays of 3000 mJ/cm 2 .
• the LED encapsulant of the present invention contains a curable resin.
• the curable resin is a dithiol compound (A) having two thiol groups in one molecule, and a polythiol compound (B) having three or more thiol groups in one molecule. , and a polyene compound (C) having two or more aliphatic carbon-carbon double bonds in one molecule.
• the curable resin may be a dithiol compound (A) having two thiol groups in one molecule, a polythiol compound (A) having three or more thiol groups in one molecule ( B) and a polyene compound (C) having two or more aliphatic carbon-carbon double bonds in one molecule.
• the resulting LED encapsulant has low viscosity and excellent applicability, and the cured product has excellent flexibility.
• the resulting cured product of the LED encapsulant also has excellent heat resistance.
• the thiol group possessed by the dithiol compound (A) is preferably a secondary thiol group. Since the thiol group of the dithiol compound (A) is a secondary thiol group, the resulting LED encapsulant has excellent storage stability.
• dithiol compound (A) examples include 1,4-bis(3-mercaptobutyryloxy)butane, butanediol bisthiopropionate, ethylene bis(3-mercaptopropionate), 1,2-bis (2-mercaptoethoxy)ethane, ethylene bis(thioglycolate), and the like. These dithiol compounds (A) may be used alone or in combination of two or more.
• the preferable lower limit of the content of the dithiol compound (A) in 100 parts by weight of the curable resin is 20 parts by weight, and the preferable upper limit is 70 parts by weight.
• the resulting LED encapsulant has excellent flexibility.
• a more preferable lower limit of the content of the dithiol compound (A) is 30 parts by mass, and a more preferable upper limit is 60 parts by mass.
• the thiol group contained in the polythiol compound (B) is preferably a secondary thiol group. Since the thiol group possessed by the polythiol compound (B) is a secondary thiol group, the resulting LED encapsulant has excellent storage stability.
• the polythiol compound (B) preferably has 3 to 6 thiol groups in one molecule, and more preferably 3 to 4 thiol groups. .
• polythiol compound (B) examples include 1,3,5-tris(2-(3-sulfanylbutanoyloxy)ethyl)-1,3,5-triazinane-2,4,6-trione, pentaerythritol Examples include tetrakis (3-mercaptobutyrate), pentaerythritol tetrakis (3-mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate), and the like. These polythiol compounds (B) may be used alone or in combination of two or more.
• the preferable lower limit of the content of the polythiol compound (B) in 100 parts by weight of the curable resin is 2.0 parts by weight, and the preferable upper limit is 70 parts by weight.
• the resulting LED encapsulant has excellent flexibility and low viscosity.
• a more preferable lower limit of the content of the polythiol compound (B) is 3.0 parts by mass, and a more preferable upper limit is 30 parts by mass.
• polyene compound (C) examples include diallyl isophthalate, diallyl maleate, diallyl diphenate, triallyl isocyanurate, pentaerythritol tetraallyl ether, 1,3,4,6-tetraallyltetrahydroimidazo[4,5 -d]imidazole-2,5(1H,3H)-dione and the like.
• the polyene compound (C) is preferably a (meth)allyl compound having two or three aliphatic carbon-carbon double bonds in one molecule.
• These polyene compounds (C) may be used alone or in combination of two or more.
• the above-mentioned "(meth)allyl” means allyl or methallyl.
• the preferable lower limit of the content of the polyene compound (C) in 100 parts by weight of the curable resin is 20 parts by weight, and the preferable upper limit is 60 parts by weight.
• the resulting LED encapsulant has excellent flexibility and low viscosity.
• a more preferable lower limit of the content of the polyene compound (C) is 30 parts by mass, and a more preferable upper limit is 50 parts by mass.
• the LED encapsulant of the present invention contains a polymerization initiator.
• the polymerization initiator include a photoradical polymerization initiator and a thermal radical polymerization initiator, and the photoradical polymerization initiator is preferably used.
• photoradical polymerization initiator examples include benzophenone compounds, acetophenone compounds, acylphosphine oxide compounds, titanocene compounds, oxime ester compounds, benzoin ether compounds, and thioxanthone compounds.
• photoradical polymerization initiator examples include 1-hydroxycyclohexylphenyl ketone, 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-1-butanone, 2-(dimethylamino )-2-((4-methylphenyl)methyl)-1-(4-(4-morpholinyl)phenyl)-1-butanone, 2,2-dimethoxy-1,2-diphenylethan-1-one, bis( 2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2-methyl-1-(4-methylthiophenyl)-2-morpholinopropan-1-one, 1-(4-(2-hydroxyethoxy)-phenyl) -2-hydroxy-2-methyl-1-propan-1-one, 1-(4-(phenylthio)phenyl)-1,2-octanedione 2-(O-benzoyloxime), 2,4,6-trimethyl Examples include benzoyldiphenylphosphin
• thermal radical polymerization initiator examples include those composed of azo compounds, organic peroxides, and the like.
• examples of the azo compound include those having a structure in which a plurality of units such as polyalkylene oxide and polydimethylsiloxane are bonded via an azo group.
• the polymeric azo compound having a structure in which a plurality of units such as polyalkylene oxide are bonded via an azo group is preferably one having a polyethylene oxide structure.
• the azo compound mentioned above is, for example, a polycondensate of 4,4'-azobis(4-cyanopentanoic acid) and polyalkylene glycol, or a polycondensate of 4,4'-azobis(4-cyanopentanoic acid) and a terminal
• examples include polycondensates of polydimethylsiloxane having amino groups.
• examples of the organic peroxide include ketone peroxide, peroxyketal, hydroperoxide, dialkyl peroxide, peroxy ester, diacyl peroxide, peroxydicarbonate, and the like.
• the content of the polymerization initiator has a preferable lower limit of 0.1 parts by weight and a preferable upper limit of 5.0 parts by weight based on 100 parts by weight of the curable resin. When the content of the polymerization initiator is within this range, the resulting LED encapsulant has better storage stability and curability.
• a more preferable lower limit of the content of the polymerization initiator is 0.5 parts by mass, and a more preferable upper limit is 2.0 parts by mass.
• the LED encapsulant of the present invention further contains a leveling agent from the viewpoint of the flatness of the coating film.
• leveling agent examples include silicone leveling agents, fluorine leveling agents, acrylic leveling agents, and the like.
• the content of the leveling agent has a preferable lower limit of 0.01 parts by weight and a preferable upper limit of 10 parts by weight based on 100 parts by weight of the curable resin. When the content of the leveling agent is within this range, the resulting LED encapsulant has better applicability and coating film flatness.
• a more preferable lower limit of the content of the leveling agent is 0.1 parts by mass, and a more preferable upper limit is 1.0 parts by mass.
• the LED encapsulant of the present invention may further contain additives such as fillers, plasticizers, surfactants, flame retardants, antistatic agents, antifoaming agents, ultraviolet absorbers, etc., within a range that does not impede the object of the present invention. May contain.
• the method for producing the LED encapsulant of the present invention includes, for example, a dithiol compound (A), a polythiol compound (B), a polyene compound (C), a polymerization initiator, and a leveling agent added as necessary. Examples include a method of uniformly mixing the above with a stirrer.
• the LED encapsulant of the present invention is preferably one that can be cured by at least one of light irradiation and heating, and more preferably one that can be cured by light irradiation.
• Examples of the method for curing the LED sealant of the present invention by light irradiation include a method of irradiating light with a wavelength of 300 to 400 nm and an integrated light amount of 300 to 3000 mJ/cm 2 .
• Examples of the light source for irradiating the LED encapsulant of the present invention include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, an excimer laser, a chemical lamp, a black light lamp, a microwave-excited mercury lamp, Examples include metal halide lamps, sodium lamps, halogen lamps, xenon lamps, LED lamps, fluorescent lamps, sunlight, and electron beam irradiation devices. These light sources may be used alone or in combination of two or more.
• Examples of the means for irradiating light to the LED encapsulant of the present invention include simultaneous irradiation with various light sources, sequential irradiation with time differences, and combination irradiation of simultaneous irradiation and sequential irradiation. Means may also be used.
• the LED encapsulant of the present invention can be applied with high application accuracy, it is particularly preferably used for application by an inkjet method.
• an LED encapsulant that can be applied with high application accuracy and whose cured product can follow the expansion and contraction of the LED chip, the bending of the substrate, and the like.
• Examples 1 to 14, Comparative Examples 1 and 2 The LED encapsulants of Examples 1 to 14 and Comparative Examples 1 and 2 were prepared by stirring and mixing each material using a stirring mixer according to the compounding ratios listed in Tables 1 and 2.
• Awatori Rentaro ARE-310 (manufactured by Shinky Co., Ltd.) was used.
• an E-type viscometer (manufactured by Toki Sangyo Co., Ltd., "VISCOMETER TV-22") and No. The viscosity was measured using a No. 1 rotor at 25° C. and a rotation speed of 100 rpm. The results are shown in Tables 1 and 2.
• each LED encapsulant obtained in Examples and Comparative Examples was coated on a slide glass to a thickness of 500 ⁇ m, and then ultraviolet rays (wavelength 365 nm) of 100 mW/cm 2 were applied using a metal halide lamp. was irradiated for 30 seconds to cure the LED encapsulant.
• the obtained cured product was cut into a piece having a width of 5 mm, a length of 400 mm, and a thickness of 500 ⁇ m to obtain a test piece.
• the tensile elongation at break of the obtained test piece was measured using a tensile testing machine (Shimadzu Corporation, "Autograph AG-XPlus”) at 25°C, distance between grips 25 mm, and tensile speed 5 mm/s. did.
• the results are shown in Tables 1 and 2.
• the LED encapsulant obtained in Comparative Example 1 the cured product became too soft and it was not possible to prepare a test piece.
• each LED encapsulant obtained in Examples and Comparative Examples was coated on a slide glass to a thickness of 500 ⁇ m, and then ultraviolet rays (wavelength 365 nm) of 100 mW/cm 2 were applied using a metal halide lamp. was irradiated for 30 seconds to cure the LED encapsulant.
• the obtained cured product was cut into a piece having a width of 5 mm, a length of 400 mm, and a thickness of 500 ⁇ m to obtain a test piece.
• the obtained test piece was measured using a dynamic viscoelasticity measuring device (for example, "DVA-200” manufactured by IT Instruments Control Co., Ltd.) at 25°C, tensile mode, grip width 25 mm, and frequency 1.0 Hz.
• the storage modulus was measured. When the storage elastic modulus is 0.1 MPa or more and less than 10 MPa, it is " ⁇ ", when it is 10 MPa or more and less than 300 MPa, it is “ ⁇ ”, and when it is less than 0.1 MPa or 300 MPa or more, it is "x”. was evaluated. In addition, regarding the LED encapsulant obtained in Comparative Example 1, the cured product became too soft and it was not possible to prepare a test piece.
• an LED encapsulant that can be applied with high application accuracy and whose cured product can follow the expansion and contraction of the LED chip, the bending of the substrate, and the like.

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• 2023
  • 2023-06-16 CN CN202380035676.1A patent/CN119096373A/zh active Pending
  • 2023-06-16 KR KR1020247035387A patent/KR20250023340A/ko active Pending
  • 2023-06-16 JP JP2023547708A patent/JPWO2023248952A1/ja active Pending
  • 2023-06-16 WO PCT/JP2023/022448 patent/WO2023248952A1/ja not_active Ceased
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