LIGHT EMITTING DEVICE AND METHOD OF MANUFACTURING LIGHT EMITTING DEVICE
A light emitting device, according to the present embodiment, has a first insulator, which is transparent to light, a first conductor layer, which is provided on a surface of the first insulator, a second insulator, which is transparent to light and arranged to oppose the first conductor layer, a light emitting element, which is arranged between the first insulator and the second insulator, and connected to the first conductor layer, and a third insulator, which is transparent to light and arranged between the first insulator and the second insulator, and the tensile storage elastic modulus of the third insulator is 1.0×10 9 Pa or greater, up to 1.0×10 10 Pa, at 0° C., and 1.0×10 6 Pa or greater, up to 6.0×10 8 Pa, at 130° C.
1 . A light emitting device, comprising:
a first insulator, which is transparent to light;
a first conductor layer, which is provided on a surface of the first insulator;
a second insulator, which is transparent to light and arranged to oppose the first conductor layer;
a light emitting element, which is arranged between the first insulator and the second insulator, and connected to the first conductor layer; and
a third insulator, which is transparent to light and arranged between the first insulator and the second insulator,
wherein a tensile storage elastic modulus of the third insulator is 1.0×10 9 Pa or greater, up to 1.0×10 10 Pa, at 0° C., and 1.0×10 6 Pa or greater, up to 6.0×10 8 Pa, at 130° C.
2 . A light emitting device comprising:
a first insulator, which is transparent to light;
a first conductor layer, which is provided on a surface of the first insulator;
a second insulator, which is transparent to light and arranged to oppose the first conductor layer;
a light emitting element, which is arranged between the first insulator and the second insulator and connected to the first conductor layer; and
a third insulator, which is transparent to light and arranged between the first insulator and the second insulator,
wherein, after a thermal cycle test, in which one minute of exposure in an environment with a temperature of 25° C., five minutes of exposure in an environment with a temperature of −40° C., one minute of exposure in the environment with the temperature of 25° C., and exposure in an environment with a temperature of 110° C. are carried out every five minutes, is performed 100 times, in a state in which the light emitting element is unlit, the light emitting element can be lit.
3 . The light emitting device according to claim 2 , wherein, after a thermal cycle test, in which one minute of exposure in an environment with a temperature of 25° C., five minutes of exposure in an environment with a temperature of −40° C., one minute of exposure in the environment with the temperature of 25° C., and exposure in an environment with a temperature of 110° C. are carried out every five minutes, is performed 1000 times, in a state in which the light emitting element is unlit, the light emitting element can be lit.
4 . The light emitting device according to claim 1 , wherein a plurality of light emitting elements are arranged between the first insulator and the second insulator.
5 . The light emitting device according to claim 4 , wherein the plurality of light emitting elements comprise a first light emitting element and a second light emitting element, which are both based on different standards.
6 . The light emitting device according to claim 5 , wherein:
a plurality of light emitting element groups comprising the first light emitting element and the second light emitting element are formed; and
the light emitting elements to constitute the light emitting element groups are arranged so as to be recognized as a single bright spot.
7 . The light emitting device according to claim 1 , further comprising a second conductor layer, which is provided on a surface of the second insulator, wherein the light emitting element is connected to the first conductor layer and the second conductor layer.
8 . The light emitting device according to claim 1 , wherein the tensile storage elastic modulus of the third insulator is 2.0×10 6 Pa or greater, up to 2.0×10 8 Pa, at 130° C.
9 . The light emitting device according to claim 1 , wherein a temperature at which mechanical loss tangent of the third insulator becomes maximum is 20° C. or higher, up to 130° C.
10 . The light emitting device according to claim 9 , wherein the temperature at which mechanical loss tangent of the third insulator becomes maximum is 20° C. or more and lower than 117° C.
11 . The light emitting device according to claim 1 , wherein, when a humidity is changed from 40% to 85% in an environment in which a temperature is 85° C., an expansion coefficient of the third insulator is less than 10%.
12 . The light emitting device according to claim 1 , wherein a water-absorption coefficient of the third insulator is 0.1% or higher in an environment in which a temperature is 85° C. and a humidity is 85%.
13 . The light emitting device according to claim 1 , wherein, in an environment in which a temperature is 85° C. and a humidity is 85%, the light emitting element keeps lighting for 1000 hours or longer in a state in which the light emitting element is bent along a circle having a radius of 50 mm.
14 . The light emitting device according to claim 1 , wherein an electrode of the light emitting element is connected to the conductor layer via a bump provided on the electrode.
15 . A method of manufacturing a light emitting device, comprising the steps of:
forming a conductor layer on one side of a first insulator, which is transparent to light;
arranging an insulating sheet on one side of the first insulator and the conductor layer;
positioning an electrode of a light emitting element on a pad of the conductor layer, and mounting the light emitting element on the sheet;
arranging a second insulator, which is transparent to light, on one side of the light emitting element; and
heating and pressing a composite of the first insulator, the second insulator, the sheet and the light emitting element, under vacuum,
wherein a tensile storage elastic modulus of the sheet is 1.0×10 9 Pa or greater, up to 1.0×10 10 Pa, at 0° C., and 1.0×10 6 Pa or greater, up to 6.0×10 8 Pa, at 130° C.