U.S. patent application number 10/956022 was filed with the patent office on 2005-05-12 for electro-optical apparatus, manufacturing method thereof, and electronic instrument.
This patent application is currently assigned to Seiko Epson Corporation. Invention is credited to Hayashi, Kenji.
Application Number | 20050098113 10/956022 |
Document ID | / |
Family ID | 19152595 |
Filed Date | 2005-05-12 |
United States Patent
Application |
20050098113 |
Kind Code |
A1 |
Hayashi, Kenji |
May 12, 2005 |
Electro-optical apparatus, manufacturing method thereof, and
electronic instrument
Abstract
The invention achieves a reduction in a thickness while
suppressing a thermal effect. An apparatus includes a
light-emitting element and a sealing layer to hermetically seal the
light-emitting element. The sealing layer includes a heat radiation
layer having thermal conductivity.
Inventors: |
Hayashi, Kenji; (Suwa-shi,
JP) |
Correspondence
Address: |
OLIFF & BERRIDGE, PLC
P.O. BOX 19928
ALEXANDRIA
VA
22320
US
|
Assignee: |
Seiko Epson Corporation
Tokyo
JP
|
Family ID: |
19152595 |
Appl. No.: |
10/956022 |
Filed: |
October 4, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10956022 |
Oct 4, 2004 |
|
|
|
10285542 |
Nov 1, 2002 |
|
|
|
Current U.S.
Class: |
118/718 |
Current CPC
Class: |
H01L 51/529 20130101;
H01L 33/44 20130101; H01L 33/641 20130101; H01L 51/5253
20130101 |
Class at
Publication: |
118/718 |
International
Class: |
C23C 016/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 2, 2001 |
JP |
2001-338045 |
Claims
1. A light-emitting apparatus, comprising: a substrate; a light
emitting element formed on the substrate; and a sealing layer to
seal the light-emitting element, the sealing layer including a
planarizing layer formed above the light-emitting element and at
least a first layer and a second layer formed above the planarizing
layer, the first layer being made of an insulating film, the second
layer being formed of a material including at least one element
selected from a group comprising boron, carbon, nitrogen, aluminum,
silicon, phosphorus, oxygen, cerium, ytterbium, samarium, erbium,
yttrium, lanthanum, gadolinium, dysprosium, neodymium, gold, silver
and copper.
2. The light-emitting apparatus according to claim 1, the first
layer being formed on both of the top and side of the planarizing
layer and extending to the substrate.
3. The light-emitting apparatus according to claim 1, the second
layer being formed above the planarizing layer and extending to the
first layer.
4. The light-emitting apparatus according to claim 1, the sealing
layer further including an insulating layer between the first layer
and the second layer.
5. The light-emitting apparatus according to claim 1, further
comprising a gas permeable protection film formed on the upper side
of the sealing layer.
Description
[0001] This is a Continuation of application Ser. No. 10/285,542
filed Nov. 1, 2002. The entire disclosure of the prior application
is hereby incorporated by reference herein in its entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of Invention
[0003] The present invention relates to an electro-optical
apparatus, a manufacturing method thereof, and an electronic
instrument having the electro-optical apparatus. More specifically,
the invention relates to an electro-optical apparatus having a
light-emitting element, such as an organic EL apparatus, a
manufacturing method thereof, and an electronic instrument having
the electro-optical apparatus.
[0004] 2. Description of Related Art
[0005] A related art electro-optical apparatus, such as a liquid
crystal apparatus and an organic EL (electroluminescence)
apparatus, may have a plurality of circuit elements, electrodes,
liquid crystal elements, or EL elements deposited on a substrate.
For example, the organic EL apparatus has a light-emitting element
containing a light-emitting substance, and being sandwiched by
electrode layers formed of an anode and a cathode, so that it
utilizes a light-emitting phenomena of positive holes injected from
the anode side and electrons injected from the cathode side, which
are rejoined together in a light-emittable light-emitting layer so
as to be inactivated from an excited state.
SUMMARY OF THE INVENTION
[0006] Such a related art electro-optical apparatus mentioned
above, however, has the following problems.
[0007] Since the organic EL apparatus having the above-mentioned
structure has a current-drive type light-emitting element, a
current has to be fed between the anode and the cathode when light
is emitted. As a result, the element generates heat when emitting
light, and when oxygen and moisture exist around the element, the
oxidation of an element material due to the oxygen and moisture is
promoted so as to degrade the element. An alkaline metal and
alkaline earth metal used especially in the cathode are liable to
be oxidized. A typical example of the element degradation due to
the oxygen and water is a production of a dark spot and the
development thereof. The dark spot means a defective luminous spot.
When the degradation of the light-emitting element is accelerated
in connection with the driving of the organic EL apparatus,
instability with time, such as reducing luminance brightness and
luminous instability, and reduced duration of life, have
occurred.
[0008] Exemplary structures to suppress the above-mentioned
degradation include: the light-emitting element being sandwiched by
a pair of glass plates using an adhesive so as to seal the element
off the atmosphere, and a cooling device being provided to supply
cooling fluid on either surface of the substrate, as disclosed in
Japanese Unexamined Patent Application Publication No. 2001-196165.
In using the glass plate, however, the problem arises that the
thickness of the apparatus is increased since at least two glass
plates are used. Also, in providing the cooling device, the
increase in size of the apparatus cannot be avoided because of the
necessity of forming a flow path for the fluid.
[0009] The present invention addresses the problems mentioned
above, and provides an electro-optical apparatus capable of
reducing or suppressing a thermal effect and also having a reduced
thickness. The invention also provides a manufacturing method
thereof, and an electronic instrument including the electro-optical
apparatus.
[0010] In order to address or achieve the above, the present
invention adopts the following exemplary arrangements.
[0011] An electro-optical apparatus according to the present
invention includes a light-emitting element and a sealing layer to
hermetically seal the light-emitting element. The sealing layer
includes a heat radiation layer having thermal conductivity.
[0012] Therefore, in the electro-optical apparatus according to the
present invention, by hermetically sealing the light-emitting
element with the film-shaped sealing layer, the degradation thereof
due to oxygen or moisture can be reduced or suppressed without
increasing the thickness. Even when heat is generated by the
emitting light of the light-emitting element, for example, because
the heat can be radiated via the heat radiation layer, a material
of the element can be reduced or suppressed against oxidation,
enabling the degradation of the light-emitting element to be
furthermore reduced or prevented.
[0013] The heat radiation layer may be made of a metallic layer,
such as film-shaped gold, silver, or copper. In this case, since
the thermal conductivity in the gold, silver, and copper is large,
the heat produced by light emitting of the light-emitting element
can be effectively radiated according to the present invention. By
reducing the thickness of the heat radiation layer to 10 nm or
less, for example, an excellent light-transmissivity can be
obtained especially in the gold and silver. Therefore, when the
light produced by the light-emitting element is projected via the
sealing layer so as to derive the light from a common electrode,
the light can be transmitted with small loss.
[0014] The heat radiation layer may also adopt an insulating film
to protect the transmission of an alkaline metal. The insulating
film may be formed of a material including at least one element
selected from B (boron), C (carbon), and N (nitrogen) and at least
one element selected from Al (aluminum), Si (silicon), and P
(phosphorus), and a material including Si, Al, N, O, and M (where M
is at least one kind of rare earth elements, and it is preferably
at least one element selected from Ce (cerium), Yb (ytterbium), Sm
(samarium), Er (erbium), Y (yttrium), La (lanthanum), Gd
(gadolinium), Dy (dysprosium), and Nd (neodymium)). In this case,
by arranging the insulating film in the vicinity of the
light-emitting element, the blocking effect against moisture and an
alkaline metal can be obtained, while the function of an insulating
film also having a heat radiation effect can be obtained, enabling
the degradation of the light-emitting element to be suppressed.
[0015] Also, the present invention may be provided such that one of
the gas barrier layer made of an inorganic compound, and the heat
radiation layer made of an organic compound, is formed on the upper
side of the insulating layer.
[0016] Thereby, according to the present invention, by hermetically
sealing the light-emitting element with the gas barrier layer, the
degradation due to oxygen and moisture can be suppressed without
increasing the thickness. Forming a planarized insulating layer
also planarizes the gas barrier layer or the heat radiation layer
which is formed on the upper side of the insulating layer,
preventing the reduction in barrier that is otherwise degraded by
strain due to unevenness.
[0017] The present invention may be provided such that the organic
compound constituting the insulating layer is a polymer. For
example, the polymer is made by curing or polymerizing monomers or
precursors that were previously applied. Using monomers or
precursors with low viscosity forms an excellently planarized
polymer layer.
[0018] According to the present invention, a gas-permeable
protection film may be formed on the upper side of the sealing
layer.
[0019] Thereby, according to the present invention, the scratching
resistance of the sealing layer, and by extension the scratching
resistance of the electro-optical apparatus, is enhanced, reducing
or preventing damage to the sealing layer and the light-emitting
layer due to an external impact. Since the protection film is
gas-permeable, the heat produced in the sealing layer is liable to
be radiated to the outside of the apparatus. The protection film
may be formed on the entire surface of the substrate or may be
patterned. In view of contaminant sticking, water absorption,
moisture absorption, and impact resistance, the protection film may
preferably be a material with low surface-active energy, such as a
fluorine polymer, silicone resin, polyolefine resin, and
polycarbonate resin.
[0020] An electronic instrument according to the present invention
includes the electro-optical apparatus described above.
[0021] Thereby, according to the present invention, an electronic
instrument with a long life span and thin thickness can be
obtained, in which the degradation of the light-emitting element is
reduced or suppressed.
[0022] On the other hand, a manufacturing method of an
electro-optical apparatus according to the present invention, the
electro-optical apparatus having a light-emitting element, includes
forming a sealing layer to hermetically seal the light-emitting
element. Forming the sealing layer includes forming a heat
radiation layer having thermal conductivity.
[0023] Thereby, according to the manufacturing method of the
present invention, by hermetically sealing the light-emitting
element with the film-shaped sealing layer, the degradation due to
oxygen and moisture can be reduced or suppressed without increasing
the thickness. Also, even when heat is produced by light emitting
of the light-emitting element, for example, because the heat can be
radiated via the heat radiating layer, the oxidation of a material
of the element can be reduced or suppressed, further reducing or
preventing the degradation of the light-emitting element.
[0024] According to the present invention, forming the sealing
layer may include covering an insulating layer made of an organic
compound on the light-emitting element and forming one of a gas
barrier layer made of an inorganic compound and the heat radiation
layer on the insulating layer.
[0025] Thereby, according to the present invention, by hermetically
sealing the light-emitting element with the gas barrier layer, the
degradation due to oxygen and moisture can be reduced or suppressed
without increasing the thickness. Covering the light-emitting
element with the insulating layer enables the surface of the
insulating layer to be planarized. Therefore, the gas barrier layer
formed on the upper side of the insulating layer is also
planarized, reducing or preventing the reduction in barrier that is
otherwise degraded by strain due to unevenness.
[0026] The present invention may be provided such that the organic
compound constituting the insulating layer is a polymer. For
example, the polymer is made by curing or polymerizing monomers or
precursors that were previously applied. Using monomers or
precursors with low viscosity forms an excellently planarized
polymer layer.
[0027] The present invention may also be provided such that the
heat radiation layer is formed of a metallic layer such as
film-shaped gold, silver, or copper.
[0028] Thereby, since the thermal conductivity in the gold, silver,
and copper is large, the heat produced by light emitting of the
light-emitting element can be effectively radiated according to the
present invention. By reducing the thickness of the heat radiation
layer to 10 nm or less, for example, excellent light-transmissivity
can be obtained, especially in the gold and silver. Therefore, when
the light produced by the light-emitting element is projected via
the sealing layer so as to derive the light from a common
electrode, the light can be transmitted with only a small loss.
[0029] The present invention may also include forming a
gas-permeable protection film on the upper side of the sealing
layer.
[0030] Thereby, according to the present invention, the scratching
resistance of the sealing layer, and by extension the scratching
resistance of the electro-optical apparatus, is enhanced, reducing
or preventing damage to the sealing layer and the light-emitting
layer due to an external impact. Since the protection film is
gas-permeable, the heat produced in the sealing layer is liable to
be radiated to the outside of the apparatus. The protection film
may be formed on the entire surface of the substrate or may be
patterned. In view of contaminant sticking, water absorption,
moisture absorption, and abrasion resistance, the protection film
may preferably be a material with low surface-active energy, such
as a fluorine polymer, silicone resin, polyolefine resin, and
polycarbonate resin.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] FIG. 1 is a sectional view of a light-emitting element on a
substrate sealed with a sealing layer, in accordance with an
embodiment of the present invention;
[0032] FIGS. 2(a)-2(c) are perspective views that show examples of
an electronic instrument having an organic EL apparatus, and
include a mobile phone, a watch-type electronic instrument, and a
portable information processing apparatus, respectively.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0033] Exemplary embodiments of an electro-optical apparatus, a
manufacturing method thereof, and an electronic instrument
according to the present invention are described below with
reference to FIGS. 1 and 2.
[0034] The electro-optical apparatus according to the present
invention is exemplified by an organic EL apparatus in this
description.
[0035] An organic EL apparatus (electro-optical apparatus) 1 shown
in FIG. 1 includes a transparent substrate 2, a light-emitting
element 3, and a sealing layer 4 to hermetically seal the
light-emitting element 3, which are formed on the transparent
substrate 2. The transparent substrate 2 can be made of plastics,
such as polyolefins, polyesters, polyacrylate, polycarbonate,
polyethersulfone, and polyetherketone, and transparent materials,
such as glass, for example. According to the exemplary embodiment,
glass is used.
[0036] The light-emitting element 3 substantially includes an anode
5 formed on the transparent substrate 2, a hole-transporting layer
6, an insulating layer 7 formed so as to expose a surface of the
anode 5 joining to the hole-transporting layer 6, an organic
light-emitting layer 8, an electron-transporting layer 9, and a
cathode 10.
[0037] The anode 5 can be formed of elemental substances, such as
aluminum (Al), gold (Au), silver (Ag), magnesium (Mg), nickel (Ni),
zinc-vanadium (Zn--V), indium (In), and tin (Sn); a compound or
mixture of these elemental substances; and a conductive adhesive
containing a metallic filler, for example. According to the
embodiment, ITO (indium tin oxide) is used. The anode 5 is
preferably formed by sputtering, ion plating, or vacuum deposition.
It may also be formed by printing with a spin coater, gravure
coater, or knife coater; screen printing; or flexography. It is
preferable that the light transmittance of the anode 5 be set to be
80% or more.
[0038] The hole-transporting layer 6 may be formed by co-depositing
a carbazole polymer and a TPD (triphenyl compound) so as to have a
film thickness in the range of 10 nm to 1000 nm (100 nm to 700 nm,
more preferably), for example. As an alternative process, the
hole-transporting layer 6 may be formed on the anode 5 by drying
and heating treatments after positive-hole injecting and ejecting
an ink composition containing a transporting material onto the
anode 5 by an inkjet method, for example. A mixture of a
polythiophenic derivative, such as polyethylenedioxythiophene and
polystyrenesulfonic acid, may be used as the ink composition by
dissolving it into a polar solvent, such as isopropyl alcohol.
[0039] The insulating film 7 may be patterned using a
photolithographic and an etching technology after depositing
SiO.sub.2 on the entire surface of the substrate by a CVD
method.
[0040] The organic light-emitting layer 8, as with the
hole-transporting layer 6, may be formed on the hole-transporting
layer 6 by drying and heating treatments after ejecting an ink
composition containing a light-emitting layer material onto the
hole-transporting layer 6 by an inkjet method. Light-emitting
materials for use in the organic light-emitting layer 8 may include
a fluorenyl polymer derivative, a (poly)paraphenylenevinylene
derivative, a polyphenylene derivative, a polyfluorene derivative,
polyvinylcarbazole, a polythiophene derivative, perylene coloring
matter, coumarin coloring matter, Rhodamine coloring matter, other
low-molecular-weight organic EL materials soluble in a benzene
derivative, and a polymer organic EL material. In addition,
suitable materials for the inkjet method include: a
paraphenylenevinylene derivative, a polyphenylene derivative, a
polyfluorene derivative, polyvinylcarbazole, and a polythiophene
derivative, for example. Suitable materials for mask vacuum
deposition include perylene coloring matter, coumarin coloring
matter, and Rhodamine coloring matter, for example.
[0041] Also, the electron-transporting layer 9 may be formed by
evaporating and depositing a metallic complex compound made from a
metal and organic ligand, which are preferably Alq3
(tris(8-quinolinolate)alumi- num complex), Znq2
(bis(8-quinolinolate)zinc complex), Bebq2
(bis(8-quinolinolate)berilium complex), Zn-BTZ
(2-(o-hydroxyphenyl)benzot- hiazolezinc), and a perylene derivative
so as to have a film thickness in the range of 10 nm to 1000 nm
(100 nm to 700 nm, more preferably).
[0042] The cathode 10 may be formed by a metal having a low work
function capable of efficiently injecting electrons into the
electron-transporting layer 9, which preferably includes elemental
substances, such as Ca, Au, Mg, Sn, In, Ag, Li, and Al; or alloys
of these elemental substances, for example. According to the
embodiment, the cathode 10 employs a double layer system of a
cathode using mainly Ca and a reflection layer using mainly Al.
[0043] Although not shown, the organic EL apparatus according to
the embodiment is of an active matrix type, in practice, in which a
plurality of data lines and a plurality of scanning lines are
arranged in a lattice, and to each of pixels that are defined by
the data lines and the scanning lines and arrayed in a matrix
arrangement, the light-emitting element 3 is connected via a
driving TFT such as a switching transistor and a driving
transistor. When a driving signal is supplied via the data line or
scanning line, a current passes through between electrodes, so that
the light-emitting element 3 emits light toward the outside of the
transparent substrate 2 so as to turn on the pixel. In addition, it
is obvious that not only the active matrix type but also a passive
driving type display may be incorporated into the present
invention.
[0044] The sealing layer 4 is formed by sequentially depositing an
insulating layer 11 covering the light-emitting element 3, a gas
barrier layer 12, an insulating layer 13, and a heat radiation
layer 14 on the light-emitting element 3.
[0045] The insulating layers 11 and 13 are fabricated by an organic
polymer. Specifically, as the insulating layers 11 and 13,
polyacrylate, polymethacrylate, PET, polyethylene, or
polypropylene; or the combination of these polymers, may be used,
for example.
[0046] The gas barrier layer 12 is made of an inorganic compound
having gas-barrier properties, such as an inorganic oxide, an
inorganic nitride, and an inorganic carbide. Specifically, as the
gas barrier layer 12, indium oxide (In.sub.2O.sub.3), tin oxide
(SnO.sub.2), or the above-mentioned ITO; or the combination of
these compounds, may be used, for example. Silicon oxide
(SiO.sub.2), aluminum oxide (Al.sub.2O.sub.3), titanium oxide
(TiO.sub.3), aluminum nitride (AlN), silicon nitride (SiN), silicon
carbide (SiC), silicon oxynitride (SiON), and diamond-like carbon
(DLC); and the combination of these compounds, can also be
used.
[0047] The heat radiation layer 14 is made of a metallic film with
a high coefficient of thermal conductivity, such as gold (Au),
silver (Ag), and copper (Cu). The relationship between the thermal
conductivity .lambda. and the electrical conductivity .sigma. at
the same temperature of the metal satisfies that
.lambda./.sigma.=constant according to the Wiedemann-Franz law.
Therefore, for a metal having a high thermal conductivity, a metal
having a high electrical conductivity may be selected, so that the
above-mentioned gold, silver, and copper may be selected. These
metals include metals that are liable to be oxidized and that are
very expensive, so an alloy of two or more of them or an alloy of
them to which metallic elements, such as zinc, tin, and aluminum,
can be added to the extent that does not change the thermal
conductivity very much.
[0048] A manufacturing process of the sealing layer 4 structured as
above (sealing-layer forming process) is described below. First,
organic monomer is applied by spray coating, etc., so as to cover
the light-emitting element 3, and then cured and polymerized to
form the insulating layer 11. Then, by vacuum deposition,
low-temperature sputtering, and CVD, the gas barrier layer 12 made
of an inorganic compound is formed on the insulating layer 11
(partly on the substrate 2). Since the insulating layer 11 is
formed as an active precursor by curing the organic monomer
applied, the top surface thereof (surface on which the gas barrier
layer 12 is formed) is planarized. Therefore, the gas barrier layer
12 is also planarized following the insulating layer 11. Then, the
insulating layer 13 is formed by the same process as the insulating
layer 11.
[0049] Consecutively, the heat radiation layer 14 made of a
metallic film is formed (film-formed) on the insulating layer 13
(partly on the gas barrier layer 12). The heat radiation layer 14,
as with the gas barrier layer 12, is formed by vacuum deposition,
low-temperature sputtering, or CVD. Since the insulating layer 13
is the organic polymer formed on the planarized gas barrier layer
12, the top surface thereof is planarized, so that the heat
radiation layer 14 formed on the insulating layer 13 is also
planarized. Although not shown, the heat radiation layer 14 is
connected to a heatsink so as to efficiently radiate the
transmitted heat. In manufacturing the gas barrier layer 12 and the
heat radiation layer 14, the cost is reduced by using the same
common mask.
[0050] In the organic EL apparatus 1 arranged as described above,
the light-emitting element 3 is sealed by the sealing layer 4
having the gas barrier layer 12, so that degradation due to oxygen
or moisture is reduced or suppressed. Also, the heat generated in
the light-emitting element 3 is transmitted to the heat radiation
layer 14 and radiated via the insulating layer 11, the gas barrier
layer 12, and the insulating layer 13 (partly via the insulating
layer 11 and the gas barrier layer 12).
[0051] In such a manner, according to the embodiment, the factors
of degradation of the light-emitting element 3 or an electrode,
such as oxygen and moisture, are sealed with the film-shaped
sealing layer 4, and the heat produced in the light-emitting
element 3 is radiated therewith, so that the degradation of the
light-emitting element 3 or the electrode due to oxygen, moisture,
and heat can be reduced or suppressed without increasing the
thickness, so that an organic EL apparatus 1 with a thin thickness
and long life span can be provided.
[0052] According to the embodiment, since on the insulating layers
11 and 13 made of an organic polymer, the gas barrier layer 12 and
the heat radiating layer 14 are respectively formed, the gas
barrier layer 12 and the heat radiating layer 14 are planarized,
preventing the reduction in barrier in advance, which is otherwise
degraded by strain due to unevenness.
[0053] Next, examples of electronic instruments having the organic
EL apparatus 1 according to the embodiment will be described.
[0054] FIG. 2(a) is a perspective view showing an example of a
mobile phone. In FIG. 2(a), numeral 1000 denotes a mobile phone
body, and numeral 1001 denotes a display using the organic EL
apparatus 1.
[0055] FIG. 2(b) is a perspective view showing an example of a
watch-type electronic instrument. In FIG. 2(b), numeral 1100
denotes a watch body, and numeral 1101 denotes a display using the
organic EL apparatus 1.
[0056] FIG. 2(c) is a perspective view showing an example of a
portable information processing apparatus, such as a word processor
and personal computer. In FIG. 2(c), numeral 1200 denotes the
information processing apparatus, numeral 1202 denotes an input
unit such as a keyboard, numeral 1204 denotes an
information-processing apparatus body, and numeral 1206 denotes a
display using the organic EL apparatus 1.
[0057] The electronic instruments shown in FIGS. 2(a) to 2(c)
include the organic EL apparatuses 1 according to the embodiment,
enabling an electronic instrument having an organic EL display with
a thin thickness and long life span to be provided.
[0058] In addition, the technical scope of the present invention is
not limited to the embodiments described above, and various
modifications may be made within the spirit of the present
invention.
[0059] For example, according to the embodiment, the insulating
layer 13 is arranged between the gas barrier layer 12 and the heat
radiation layer 14. However, the insulating layer 13 is not
necessarily needed, so that the heat radiation layer 14 may also be
directly arranged on the gas barrier layer 12. The positional
arrangement between the gas barrier layer 12 and the heat radiation
layer 14 shown in the embodiment is an example. Contrarily, the
heat radiation layer 14 may be formed on the insulating layer 11
while the gas barrier layer 12 may be formed on the insulating
layer 13. However, the arrangement that the heat radiation layer 14
is exposed to the outside increases the surface area of the
exposing atmosphere, if the heat radiation effect is considered,
the arrangement shown in the embodiment is preferable.
[0060] Also, according to the embodiment described above, the heat
radiation layer 14 is formed of a metallic film. However, the
invention is not limited to this arrangement, and an insulating
film protecting the transmission of an alkaline metal may be
adopted. The insulating film may be formed of a material including
at least one element selected from B (boron), C (carbon), and N
(nitrogen) and at least one element selected from Al (aluminum), Si
(silicon), and P (phosphorus), and a material including Si, Al, N,
O, and M (where M is at least one kind of rare earth elements, and
it is preferably at least one element selected from Ce (cerium), Yb
(ytterbium), Sm (samarium), Er (erbium), Y (yttrium), La
(lanthanum), Gd (gadolinium), Dy (dysprosium), and Nd (neodymium)),
for example. In this case, by arranging the insulating film in the
vicinity of the light-emitting element, the blocking effect against
moisture and an alkaline metal can be obtained while the function
of an insulating film also having a heat radiation effect can be
obtained, enabling the degradation of the light-emitting element to
be reduced or suppressed.
[0061] The insulating layer 11 is formed by applying an organic
monomer so as to cover the light-emitting element 3, and curing it
to be polymerized. It may be formed by polymerization after an
organic monomer is applied. In addition, the specific materials
shown in the embodiment are only examples, so that appropriate
alternation may be possible.
[0062] Furthermore, according to the embodiment, a type of
apparatus that emits light by the light-emitting element 3 which
projects light to the outside of the apparatus via the transparent
substrate 2 is exemplified. Alternatively, a type of apparatus that
emits light by the light-emitting element 3 which projects light
from the common electrode opposite to the transparent substrate 2
via the sealing layer 4 may be applicable. In this case, when the
metallic film constituting the heat radiation layer 14 is gold or
silver having high thermal conductivity, the heat is effectively
radiated while high light-transmissivity (transparency) can be
obtained using a gold film with a thickness of 10 nm or less,
enabling an organic EL apparatus with small loss of transmitted
light to be obtained.
[0063] As described in the embodiment, in an arrangement that the
heat radiation layer 14 is exposed on the surface of the sealing
layer 4, although it is advantageous in heat radiation, in order to
enhance abrasion resistance (scratching resistance), a protection
film made of a film or coated layer may be formed on the heat
radiation layer 14 (i.e., sealing layer 4). In this case, in view
of contaminant sticking, water absorption, moisture absorption, and
abrasion resistance, the protection film may preferably be a
material with low surface-active energy, such as a fluorine
polymer, silicone resin, polyolefine resin, and polycarbonate
resin. The protection film may also be formed on the entire surface
of the substrate or may be patterned, and furthermore it may
preferably have high gas-permeability (1000
cm.sup.3/m.sup.2.multidot.24 hr, or more). Thereby, the heat
transmitted to the heat radiation layer 14 can be radiated to the
atmosphere via the protection film, enhancing a radiation
effect.
[0064] In addition, according to the embodiment, only one layer of
the gas barrier layer 12 is arranged. The invention is not limited
to this arrangement and forming two layers or more enables the gas
barrier to be more enhanced. In this case, it is preferable that a
plurality of units, each unit being constituted by a gas barrier
layer and an organic polymer layer (insulating layer), be laid up.
Also, not only glass, but also plastics, may be used as the
substrate.
[0065] As described above, according to the present invention, an
electro-optical apparatus with a thin thickness and long life span
without reduction in gas barrier, and an electronic instrument
having a display with the same capability, can be readily obtained.
The present invention also enables an electro-optical apparatus
with high heat radiation and abrasive resistance to be obtained, in
which light is derived from the common electrode with only a small
loss of the transmitted light.
* * * * *