JP2007096257A - Glass-coated light-emitting diode element and glass for light-emitting diode element coating - Google Patents

Abstract

Provided is a glass for covering a light-emitting diode with a small expansion coefficient mismatch with the light-emitting diode.
An internal transmittance at a thickness of 1 mm with respect to light having a wavelength of 405 nm is 80% or more, and TeO _{2 is} 40 to 53%, GeO _{2 is} 0 to 10%, and B _{2 is} expressed in terms of mol% based on the following oxide standards. O ₃ 5-30%, Ga ₂ O ₃ 0-10%, Bi ₂ O ₃ 0-10%, ZnO 3-20%, Y ₂ O ₃ 0-3%, La ₂ O ₃ 0-3%, Gd _A glass for covering a light-emitting diode element, consisting essentially of ₂ O ₃ 0 to 7% and Ta ₂ O ₅ 0 to 5%, and containing TeO ₂ + B ₂ O ₃ of 75 mol% or less.
[Selection] Figure 1

Description

  The present invention relates to a light emitting diode element (LED element) in which a light emitting diode (LED) is coated with glass and glass used for the coating.

Conventionally, incandescent bulbs, fluorescent lamps and the like have been widely used as white light sources, but in recent years, so-called white LED elements have been developed as a new type of white light source, and their application to backlights for liquid crystal displays and the like has rapidly progressed. Yes.
In a typical one-chip white LED element currently on the market, an LED having a quantum well structure using InGaN in which GaN is added with In as a light emitting layer is sealed with a resin containing a YAG phosphor.

The white LED element functions as a white light source as follows. That is, when a direct current is passed through the LED, blue light is emitted from the LED, while the YAG phosphor is excited by a part of the blue light, and yellow light (fluorescence) is emitted from the phosphor. This blue light and yellow light are in a complementary color relationship, and they enter and enter the human eye and appear as white light due to the principle of additive color mixing.
However, in such a white LED element in which the LED is sealed with the resin, when it is used for a long period of time, moisture enters the resin and the operation of the LED is hindered. The resin is irradiated with ultraviolet light or blue light emitted from the LED. Discolored and the light transmittance decreased.

As a white LED element that solves such a problem, there has been proposed one in which an LED is provided on a substrate in a flip chip form and the LED is sealed with sol-gel glass (see Patent Document 1).
However, since the sol-gel glass has pores or pores are likely to remain, there is a possibility that LED operation inhibition due to moisture cannot be sufficiently suppressed. In order to solve such a problem of pores, heat treatment is typically performed at 1300 ° C. However, heat treatment at a very high temperature such as 1300 ° C. cannot be applied to the manufacture of LED elements. there were.

As an LED element that solves such a problem, the present inventors have expressed TeO ₂ 20 to 70%, ZnO 5 to 30%, B ₂ O ₃ 0 to 55%, SiO ₂ + GeO ₂ 0 to 10 in terms of mol%. %, Li ₂ O + Na ₂ O + K ₂ O 0-30%, MgO + CaO + SrO + BaO 0-20%, an LED element sealed with TeO ₂ —ZnO-based glass was proposed (see Patent Document 2).

JP 2002-203989 A (pages 2 to 7) Japanese Patent Laying-Open No. 2005-11933 (Table 1)

The TeO ₂ —ZnO glass exemplified in Patent Document 2 is not a sol-gel glass, has a refractive index of 2.02 to 2.08 with respect to light having a wavelength of 400 nm, a glass transition point (Tg) of 335 ° C., and Patent Document Although not described in 2, the estimated value of the softening point (Ts) is 420 ° C. or lower, and the LED can be sealed and the light extraction efficiency from the LED is excellent.
However, the estimated value of the average linear expansion coefficient of this TeO ₂ —ZnO-based glass at 50 to 300 ° C. (hereinafter, this average linear expansion coefficient is referred to as α) is 115 × 10 ^{−7 to} 130 × 10 ⁻⁷ / ° C. Therefore, there is a large difference from α (typically 80 × 10 ⁻⁷ / ° C.) such as sapphire that is usually used as an LED substrate, and this expansion coefficient mismatch may cause problems during or after sealing. was there.
The object of the present invention is to provide a glass-coated LED element and glass for LED element coating that can solve such problems.

In the present invention, the substrate of the LED element having a substrate in which α is 70 × 10 ^{−7 to} 90 × 10 ⁻⁷ / ° C., Ts is 500 ° C. or less, and α is 65 × 10 ^{−7 to} 95 × 10 ^−7. The internal transmittance (hereinafter referred to as T ₄₀₅ ) at a thickness of 1 mm for light having a wavelength of 405 nm at 80 ° C. is 80% or more and the refractive index for the same light (hereinafter referred to as n). Provided is a glass-covered LED element (hereinafter, this glass-covered LED element is referred to as a first LED element) that is coated with glass that is 2.0 or more.
Further, the substrate of the light-emitting diode element having a substrate in which α is 70 × 10 ^{−7 to} 90 × 10 ⁻⁷ / ° C. has a Ts of 500 ° C. or less and α is 65 × 10 ^{−7 to} 95 × 10 ⁻⁷ / A glass-coated light-emitting diode element (hereinafter, this glass-coated LED element is referred to as a second LED element) that is coated with a glass that does not contain PbO and has a T ₄₀₅ of 80% or higher and n of 1.7 or higher. provide.

_Further, there is _{T 405} is 80% or more, _by mol% based on the following _{oxides, TeO 2 40~53%, GeO 2} 0~10%, B 2 O 3 5~30%, Ga 2 O 3 0 _{~10%, Bi 2 O 3 0~10} %, 3~20% ZnO, Y 2 O 3 0~3%, La 2 O 3 0~3%, Gd 2 O 3 0~7%, Ta 2 O 5 Provided is a glass for covering an LED element, essentially consisting of 0 to 5%, and comprising TeO ₂ + B ₂ O ₃ of 75 mol% or less.

According to the present invention, it is possible to cover an LED without impairing the light emitting function of the LED with glass having a large n and a small difference in expansion coefficient from the sapphire substrate.
The LED element covered with such glass has high light extraction efficiency from the glass-coated portion.

FIG. 1 is a conceptual diagram of a cross section of a glass-covered LED element of the present invention, and FIG. 2 is a conceptual diagram for explaining an example of a method for manufacturing the LED element of the present invention, showing the arrangement and cross section of each member. Hereinafter, the present invention will be described with reference to these drawings, but the present invention is not limited thereto.
As illustrated in FIG. 1, the glass-covered LED element of the present invention has an LED element 10 and glass (LED element-covering glass) 1 covering the LED element 10.
The LED element 10 includes a substrate 10S, an LED 10L, a p-electrode 10P, and an n-electrode 10N as constituent members.

The LED 10L typically emits ultraviolet light or blue light having a wavelength of 360 to 480 nm, and examples include a quantum well structure LED (InGaN-based LED) using InGaN in which GaN is added with InGaN as a light emitting layer. The When the LED 10L is an InGaN-based LED, the portions in contact with the p-electrode 10P and the n-electrode 10N are a p-type semiconductor and an n-type semiconductor, respectively.
The LED 10L is formed on one surface of the substrate 10S. In FIG. 1, the surface of the LED 10L facing the surface on which the p-electrode 10P and the n-electrode 10N are formed is in contact with the substrate 10S.

Α of the substrate 10S is 70 × 10 ^{−7 to} 90 × 10 ⁻⁷ / ° C., but typically 75 × 10 ^{−7 to} 85 × 10 ⁻⁷ / ° C. Usually, a sapphire substrate having an α of about 80 × 10 ⁻⁷ / ° C. is used as the substrate 10S.
Both the p electrode 10P and the n electrode 10N are typically made of gold, and are usually electrically connected to the p electrode portion and the n electrode portion (both not shown) of the LED 10L via a buffer layer.

Ts of glass 1 is 500 ° C. or less. If it exceeds 500 ° C., the temperature for heat treatment to cover the LED element 10 with the glass 1 becomes too high, and the light emitting function of the LED element 10 may be impaired. Preferably it is 490 degrees C or less.
It is preferable that Tg of the glass 1 is 450 degrees C or less for the same reason.

Α of the glass 1 is 65 × 10 ^{−7 to} 95 × 10 ⁻⁷ / ° C. If α is outside this range, the expansion coefficient mismatch with the substrate 10S becomes too large. When the substrate 10S is a sapphire substrate or the like having an α of 75 × 10 ^{−7 to} 85 × 10 ⁻⁷ / ° C., the α of the glass 1 is 70 × 10 ^{−7 to} 90 × 10 ⁻⁷ / ° C. Is preferred.

The glass 1 covers at least the substrate 10S.
Since n of the glass 1 is 1.7 or more in the second LED element, and 2.0 or more in the first LED element, n is as follows when the substrate 10S is a sapphire substrate (n is about 2.5). Even when it is large, the return of light to the substrate 10S due to reflection is suppressed, and the light extraction efficiency from the substrate 10S can be increased.
In the second LED element, n of the glass 1 is preferably 1.9 or more, more preferably 2.0 or more.

Since T ₄₀₅ of the glass 1 is 80% or more, a decrease in the amount of light due to light absorption can be suppressed, and the light extraction efficiency can be increased. Preferably it is 85% or more, more preferably 90% or more, and particularly preferably 93% or more.

  The glass 1 does not contain PbO in the second LED element, but preferably does not contain PbO in the first LED element.

Examples of the glass 1 include TeO ₂ —B ₂ O ₃ —ZnO-based glass containing 40 to 53 mol% of TeO ₂ .
In TeO ₂ —B ₂ O ₃ —ZnO-based glass, when TeO ₂ is less than 40 mol%, n decreases or Ts increases. Preferably it is 43 mol% or more. If it exceeds 53 mol%, α increases. Typically, it is 51 mol% or less.
The exemplified TeO ₂ —B ₂ O ₃ —ZnO-based glass is the glass for covering an LED element of the present invention (hereinafter simply referred to as the glass of the present invention) in the first LED element, and Ts is 500 ° C. Hereinafter, α is 65 × 10 ^{−7 to} 95 × 10 ⁻⁷ / ° C., n is 2.0 or more, and the second LED element is the glass of the present invention, does not contain PbO, and Ts is 500 ° C. or less. , Α is preferably 65 × 10 ^{−7 to} 95 × 10 ⁻⁷ / ° C., and n is 1.7 or more.

Next, an example of a method for producing the glass-coated LED element of the present invention as shown in FIG. 1 will be described with reference to FIG.
First, a glass 1 having a shape as shown in FIG. 2, that is, a glass 1 having a shape in which a part of a sphere is cut and its cut surface is flat is manufactured as follows. That is, a heat-resistant plate is prepared and a release material powder is sprayed thereon to form a release material layer. A small piece of glass 1 is placed on the release material layer and heated to a temperature equal to or higher than Ts of glass 1 to soften and flow glass 1 so that it becomes almost spherical due to surface tension. The substantially spherical glass 1 obtained in this way has a flat portion in contact with the release material layer, and its shape is such that a part of the sphere is cut and its cut surface is flat. The heat-resistant plate is exemplified by a silicon wafer, and the release material powder is exemplified by boron nitride powder.

Next, although the release material layer 30 is formed on the heat-resistant plate 20, the LED element 10 is placed on the release material layer 30 so that the substrate 10S faces upward. In addition, as what formed the mold release material layer 30 in the heat-resistant board 20, what was used for producing the glass 1 of the said shape is used.
The glass 1 having the shape produced as described above is placed on the LED element 10 and heated to a temperature equal to or higher than Ts of the glass 1 to soften and flow the glass 1 to cover at least the substrate 10S portion of the LED element 10. To do. In FIG. 2, the side surface of the LED element 10 is also covered.

Next, the glass of the present invention will be described.
T ₄₀₅ of the glass of the present invention is preferably 85% or more, more preferably 90% or more, and particularly preferably 93% or more.
The Ts of the glass of the present invention is preferably 500 ° C. or lower, more preferably 490 ° C. or lower.
Α of the glass of the present invention is preferably 65 × 10 ^{−7 to} 95 × 10 ⁻⁷ / ° C., typically 75 × 10 ^{−7 to} 85 × 10 ⁻⁷ / ° C.
N of the glass of the present invention is preferably 1.7 or more, more preferably 1.9 or more, and particularly preferably 2.0 or more.
The glass of the present invention preferably has Ts of 500 ° C. or lower, α of 65 × 10 ^{−7 to} 95 × 10 ⁻⁷ / ° C., and n of 1.7 or more.

It is preferable that the glass of this invention can be manufactured by melting at a temperature of 980 ° C. or lower. Otherwise, it would be difficult to melt the glass using a gold crucible (melting point: 1063 ° C.), and it would have to be melted using a platinum or platinum alloy crucible. There exists a possibility that _T405 may fall by dissolving.

Hereinafter, the composition of the glass of the present invention will be described with mol% simply expressed as%.
TeO ₂ is a glass network former and is essential. If it is less than 40%, n becomes small or Ts becomes high. Preferably it is 43% or more. If it exceeds 53%, α becomes large. Preferably it is 51% or less.
GeO ₂ is not essential, but may be incorporated up to 10% in order to form a glass skeleton, increase T ₄₀₅ , stabilize the glass, or suppress devitrification. If it exceeds 10%, Ts becomes high. Preferably it is 7% or less. When GeO ₂ is contained, its content is preferably 1% or more, more preferably 3% or more.
The total content of TeO ₂ and GeO ₂ is preferably 42 to 58%. If it is less than 42%, the glass may become unstable. More preferably, it is 45% or more. If it exceeds 58%, α tends to be large or Ts may be high. More preferably, it is 55% or less.

B ₂ O ₃ is a component that forms a glass skeleton and is essential. If it is less than 5%, the glass becomes unstable. Preferably it is 10% or more. If it exceeds 30%, n becomes small, or chemical durability such as water resistance is lowered. Preferably it is 20% or less.
The total content of TeO ₂ and B ₂ O ₃ is 75% or less. If it exceeds 75%, α becomes large. Preferably it is 70% or less.

Ga ₂ O ₃ is not essential, but may be contained up to 10% in order to increase n. If it exceeds 10%, the glass becomes unstable. Preferably it is 8% or less. When Ga ₂ O ₃ is contained, its content is preferably 1% or more, more preferably 3% or more.
Bi ₂ O ₃ is not essential, but may be contained up to 10% in order to increase n. If it exceeds 10%, T ₄₀₅ becomes low. Preferably it is 5% or less. When Bi ₂ O ₃ is contained, its content is preferably at least 0.1%, more preferably at least 0.5%.
The total content of B ₂ O ₃ , Ga ₂ O ₃ and Bi ₂ O ₃ is preferably 15 to 35%. If it is less than 15%, vitrification may be difficult. More preferably, it is 20% or more. If it exceeds 35%, the glass may become unstable. More preferably, it is 30% or less.

ZnO is a component that stabilizes the glass and is essential. If it is less than 3%, the glass becomes unstable. Preferably it is 10% or more. If it exceeds 20%, it must be dissolved at a temperature exceeding 980 ° C. Preferably it is 19% or less.
Y ₂ O ₃ is not essential, but may be contained up to 3% in order to suppress devitrification. If it exceeds 3%, n becomes small. Preferably it is 1% or less. When Y ₂ O ₃ is contained, its content is preferably at least 0.1%, more preferably at least 0.5%.
La ₂ O ₃ is not essential, but may be contained up to 3% in order to suppress devitrification. If it exceeds 3%, n becomes small. Preferably it is 1% or less. When La ₂ O ₃ is contained, its content is preferably at least 0.1%, more preferably at least 0.5%.

Gd ₂ O ₃ is not essential, but may be contained up to 7% in order to suppress devitrification. If it exceeds 7%, Ts becomes high. Preferably it is 5% or less. When Gd ₂ O ₃ is contained, its content is preferably 1% or more, more preferably 3% or more.
Ta ₂ O ₅ is not essential, but may be contained up to 5% in order to increase n. If it exceeds 5%, Ts becomes high. Preferably it is 4% or less. When Ta ₂ O ₅ is contained, its content is preferably 1% or more, more preferably 2% or more.
The total content of Y ₂ O ₃ , La ₂ O ₃ , Gd ₂ O ₃ and Ta ₂ O ₅ is preferably 1 to 15%. If it is less than 1%, devitrification tends to occur. More preferably, it is 3% or more. If it exceeds 15%, vitrification tends to be difficult. More preferably, it is 10% or less.

TeO ₂ + GeO ₂ is _{42~58%, B 2 O 3 +} Ga 2 O 3 + Bi 2 O 3 15 to 35% and _{Y 2 O 3 + La 2 O} 3 + Gd 2 O 3 + Ta 2 O 5 is 1% to 15% It is preferable that
The glass of the present invention consists essentially of the above components, but may contain other components as long as the object of the present invention is not impaired. When such components are contained, the total content of these components is preferably 10% or less, more preferably 5% or less.

Examples of the other components include TiO ₂ . TiO ₂ may be contained when it is desired to adjust n or prevent solarization. If the content exceeds 2%, T ₄₀₅ decreases or α increases. Typically, it is 1.3% or less.
Moreover, although it may contain an alkali metal oxide for lowering Ts or the like, its content is preferably less than 1% because it may cause an electrical problem. Does not contain oxides.
In addition, it is preferable that the glass of this invention does not contain PbO.

For Examples 1-13, were blended raw materials so as to have the composition shown in column mol% from TeO ₂ of Table up Na ₂ O prepared formulation material 450 g, gold crucible of this capacity 300cc And dissolved at 950 ° C. for 2.5 hours. At this time, the molten glass was homogenized by stirring with a gold stirrer for 1 hour. The homogenized molten glass was poured into a carbon mold and formed into a plate shape.
In Example 11, the glass adhering to the inner wall of the gold crucible after the molten glass was poured out was cooled in the air as it was, and then small pieces of glass adhering to the inner wall were collected.
About Example 14, although it shape | molded in the same manner as Examples 1-13, since devitrification was remarkable, it melt | dissolved as follows. That is, 100 g of the prepared raw material was prepared, put in a gold crucible with a capacity of 100 cc, and melted at 995 ° C. for 1 hour. At this time, stirring with a gold stirrer was not performed because the melting temperature was close to the melting point of gold and the shape could not be maintained. The molten glass with insufficient homogenization obtained in this way was poured out and formed into a plate shape, followed by slow cooling.
Examples 1 to 12 are examples, and examples 13 and 14 are comparative examples.

About the obtained glass, Ts (unit: ° C.), Tg (unit: ° C.), α (unit: 10 ⁻⁷ / ° C.), n, and T ₄₀₅ (unit:%) were measured. These measurement methods are described below. The Ts measurement method is simple and the accuracy is ± 15 ° C.
Ts: A sample processed into a cylindrical shape having a diameter of 5 mm and a length of 20 mm was subjected to a pressure of 4.9 kPa (10 g load) using a thermomechanical analyzer DILATOMETER 5000 (trade name) manufactured by Mac Science Co., Ltd. ), The temperature rising rate was set to 5 ° C./min, and the temperature at which the sample softened and the sample elongation detection part could not be pushed (oblique point) was determined. In Example 7, the value estimated from the composition, not the measured value, is shown together with the estimation accuracy. Example 14 was not measured or estimated.
Tg: 150 mg of a sample processed into a powder form was filled in a platinum pan and measured with a thermal analyzer TG / DTA6300 (trade name) manufactured by Seiko Instruments Inc.
α: A sample processed into a cylindrical shape having a diameter of 5 mm and a length of 20 mm was measured at a heating rate of 5 ° C./min using the thermomechanical analyzer. The expansion coefficient at 50 to 300 ° C. was determined in increments of 25 ° C., and the average value was taken as α. For Example 7, not the measured value but the value estimated from the composition is shown together with the estimation accuracy.
n: Glass was processed into a triangular prism having a side of 30 mm and a thickness of 10 mm, and measured with a precision spectrometer GMR-1 (trade name) manufactured by Kalnew Optical.

T ₄₀₅ : Two plate-like glass samples having both sides mirror-polished and having a size of 2 cm × 2 cm and thicknesses of 1 mm and 5 mm were prepared using a spectrophotometer U-3500 (trade name) manufactured by Hitachi, Ltd. The transmittance for light having a wavelength of 405 nm is measured. T ₄₀₅ (unit:%) is calculated according to the following equation, where T 1 and T 5 are the transmittances of the plate samples having a thickness of 1 mm and 5 mm obtained by the measurement, respectively.
T ₄₀₅ = 100 × exp [(2/3) × log _e (T5 / T1)].

In Examples 9, 11, 13, and 14, the water resistance RW and acid resistance RA were evaluated as follows according to the evaluation method established by the Japan Optical Glass Industry Association. The grade is shown in the appropriate column of the table.
RW: Glass particles having a diameter of 420 to 600 μm were prepared, and the mass reduction ratio when immersed in 80 ml of pure water at 100 ° C. for 1 hour was measured. When the mass reduction ratio is less than 0.05, it is grade 1, when it is 0.05 or more and less than 0.10, grade 2; Grades 60 and below 1.10 were grade 5, and grades 1 and 10 were grade 6. RW is preferably grade 1.
RA: Glass grains having a diameter of 420 to 600 μm were prepared, and the mass reduction ratio when immersed in 80 ml of a 0.01 N nitric acid aqueous solution at 100 ° C. for 1 hour was measured. If the mass reduction ratio is less than 0.20, it is grade 1, it is grade 2 if it is 0.20 or more and less than 0.35, grade 3 if it is 0.35 or more and less than 0.65, grade 4 if it is 0.65 or more and less than 1.20. Grades 20 and below 2.20 were grade 5, and grades 2.20 and above were grade 6. RA is preferably grade 1.

Example 1
Using the glass piece of Example 11, a glass-covered LED element was produced by the method described above with reference to FIG.
A 6-inch silicon wafer manufactured by Osaka Titanium Co. was used as the heat-resistant plate, and boron nitride powder boron spray manufactured by Kaken Kogyo Co., Ltd. was sprayed thereon as a release material powder. The boron nitride powder layer was so thick that the silicon wafer surface could not be seen.

  A glass piece weighing about 30 mg is placed on a boron nitride powder layer on a silicon wafer and heated from 25 ° C. to 610 ° C. at a rate of 5 ° C. per minute using a muffle furnace FP41 made by Yamato Kagaku. Hold for 15 minutes. Thereafter, the glass A was cooled at a rate of 5 ° C. per minute to obtain a glass A having a shape shown as symbol 1 in FIG. This glass had a height of 1.9 mm, a maximum width in the horizontal direction of 2.0 mm, and a flat surface portion (circular shape) of the bottom surface having a diameter of 0.8 mm.

Next, on the boron nitride powder layer on the silicon wafer, many blue light emitting LED bare chips GB-3070 manufactured by Showa Denko KK were dispersed from a height of about 3 cm.
The LED bare chip has InGaN formed as a semiconductor layer on a sapphire substrate, and has a size of 300 μm × 300 μm and a thickness of 80 μm. On the surface opposite to the sapphire substrate, a p-electrode and an n-electrode whose surfaces are gold are formed, and each electrode has a circular shape with a diameter of 110 μm.

Among the scattered bare chips, the one having the electrode forming surface in contact with the boron nitride powder layer and the sapphire substrate being the top surface is selected, and the glass A is placed so that the center of the bottom surface is on the sapphire substrate. The same heat treatment as in the production was performed. As a result, a glass-covered LED element having a shape in which the sapphire substrate was covered with glass and the bare chip was recessed in the glass as shown in FIG. 1 was obtained. The dimensions of the coated glass, such as the height and the maximum width in the horizontal direction, were almost the same as those of the glass A, and the glass was not adhered to the electrode forming surface.
When a voltage of 3.5 V was applied between the p electrode and the n electrode of this glass-coated LED element by a manual prober using a DC power supply MC35-1A manufactured by Kikusui Electronics Co., Ltd., light was emitted.

(Example 2)
A glass-coated LED element was produced by a method different from that in Example 1.
First, an LED made by Toyoda Gosei (product name: E1C60-0B011-03) was flip-chip mounted on an alumina substrate (thickness: 1 mm, size: 50 mm × 100 mm) on which a gold wiring pattern was formed.
On the other hand, the glass plate of Example 11 having a thickness of 1.5 mm and a size of 3 mm × 3 mm was prepared, and both surfaces thereof were mirror-polished.

  This mirror-polished glass plate is placed on an LED on an alumina substrate on which the LED is flip-chip mounted, heated to 610 ° C. at a rate of 1 ° C. per minute, and held at that temperature for 15 minutes. Was softened and flowed to coat the LED. Cooling was performed at a rate of 1 ° C. per minute up to about 400 ° C., and at a temperature lower than that, natural cooling was performed while being left in the furnace.

The thickness of the coated glass of the obtained glass-coated LED element was about 1.7 mm, and the maximum width in the horizontal direction was 2.2 mm.
The coated glass and the LED were in close contact as far as visual observation was made. Moreover, there were few bubbles in the coated glass, and when observed with an optical microscope, only a few having a diameter of about 10 μm were confirmed.
With respect to this glass-coated LED element, the light emission intensity at a constant current measurement of 20 mA was measured using an LED tester LX4681A (trade name) manufactured by Technolog.

(Comparative Example 1)
For comparison, an alumina substrate on which the LED was flip-chip mounted was prepared separately, and the emission intensity was measured for the LED in the same manner as in Example 2 without coating the glass. The ratio of emission intensity was 0.69: 1.00. That is, the emission intensity of the glass-coated LED element of the present invention was 1.45 times that of the uncoated LED element.

(Comparative Example 2)
For comparison, a resin-coated LED element was produced as follows.
First, an alumina substrate on which the LED was flip-chip mounted was prepared separately.
Next, about 25 ml of gel-like silicone resin precursor LPS3400 (trade name) for LED manufactured by Shin-Etsu Chemical Co., Ltd. is dropped on the LED on the alumina substrate, and then kept at 100 ° C. for 1 hour and further at 150 ° C. The silicone resin precursor was polymerized by holding for a period of time, and the LED was coated with a silicone resin (n = 1.410).

  The resin-coated LED element thus obtained was measured for emission intensity in the same manner as in Example 2. As a result, the ratio of emission intensity between Comparative Example 2 and Example 2 was 0.83: 1.00. That is, the emission intensity of the glass-coated LED element of the present invention was 1.21 times that of the resin-coated LED element.

  It can be used as a blue LED element. Moreover, if phosphor powder that emits yellow fluorescence using blue light as excitation light is put in glass, it can be used as a white LED element.

The conceptual diagram of the cross section of the glass-coated LED element of this invention. The cross-sectional conceptual diagram explaining the manufacturing method of the glass covering LED element of this invention.

Explanation of symbols

1: Glass (glass for LED element coating)
10: LED element 10S: Substrate 10L: LED
10P: p electrode 10N: n electrode 20: heat resistant plate 30: release material layer

Claims (12)

The substrate of the light emitting diode element having an average linear expansion coefficient has a substrate which is ^{70 × 10 -7 ~90 × 10 -7} / ℃ at 50 to 300 ° C. is a softening point of 500 ° C. or less, the average linear expansion coefficient of 65 A glass coating coated with glass having an internal transmittance of 80% or more at a thickness of 1 mm for light having a wavelength of 405 nm and a refractive index of 2.0 or more for the light of × 10 ^{−7 to} 95 × 10 ⁻⁷ / ° C. Light emitting diode element.   The glass-coated light-emitting diode device according to claim 1, wherein the glass does not contain PbO. The substrate of the light emitting diode element having an average linear expansion coefficient has a substrate which is ^{70 × 10 -7 ~90 × 10 -7} / ℃ at 50 to 300 ° C. is a softening point of 500 ° C. or less, the average linear expansion coefficient of 65 × 10 ^{−7 to} 95 × 10 ⁻⁷ / ° C., coated with glass not containing PbO with an internal transmittance of 80% or more at a thickness of 1 mm for light of wavelength 405 nm and a refractive index of 1.7 or more for the light. A glass-coated light-emitting diode device.   The glass-coated light-emitting diode device according to claim 1, wherein the substrate is a sapphire substrate. The glass-coated light-emitting diode element according to claim 1, wherein the glass is TeO ₂ —B ₂ O ₃ —ZnO-based glass and contains 40 to 53 mol% of TeO ₂ . The glass in mole% based on the following _{oxides, TeO 2 + GeO 2 42~58%} , B 2 O 3 + Ga 2 O 3 + Bi 2 O 3 15~35%, 3~20% ZnO, Y 2 O 3 + La The glass-coated light-emitting diode device according to claim 5, comprising essentially 1 to 15% of ₂ O ₃ + Gd ₂ O ₃ + Ta ₂ O ₅ , wherein TeO ₂ + B ₂ O ₃ is 75 mol% or less. The glass _in mole% based on the following _{oxides, TeO 2 40~53%, GeO 2} 0~10%, B 2 O 3 5~30%, Ga 2 O 3 0~10%, Bi 2 O 3 0 _{~10%, 3~20% ZnO, Y} 2 O 3 0~3%, La 2 O 3 0~3%, Gd 2 O 3 0~7%, Ta 2 O 5 0~5%, essentially from The glass-coated light-emitting diode device according to claim 1, 2, 3, 4 or 6. The internal transmittance at a thickness of 1 mm with respect to light having a wavelength of 405 nm is 80% or more, and TeO ₂ 40 to 53%, GeO ₂ 0 to 10%, B ₂ O ₃ 5 30%, Ga ₂ O ₃ 0-10%, Bi ₂ O ₃ 0-10%, ZnO 3-20%, Y ₂ O ₃ 0-3%, La ₂ O ₃ 0-3%, Gd ₂ O ₃ 0 A glass for covering a light-emitting diode element, essentially consisting of ˜7%, Ta ₂ O ₅ 0-5%, and TeO ₂ + B ₂ O ₃ being 75 mol% or less. TeO ₂ + GeO ₂ is 42 to 58 mol%, B ₂ O ₃ + Ga ₂ O ₃ + Bi ₂ O ₃ is 15 to 35 mol%, Y ₂ O ₃ + La ₂ O ₃ + Gd ₂ O ₃ + Ta ₂ O ₅ is 1 to 15 The glass for covering a light-emitting diode element according to claim 8, which is mol%.   The glass for light emitting diode element coating | cover of Claim 8 or 9 which does not contain PbO. The softening point is 500 ° C. or lower, the average linear expansion coefficient at 50 to 300 ° C. is 65 × 10 ^{−7 to} 95 × 10 ⁻⁷ / ° C., and the refractive index for light having a wavelength of 405 nm is 1.7 or more. Or the glass for covering a light emitting diode element according to 10; The glass for covering a light-emitting diode element according to claim 11, wherein the refractive index is 2.0 or more.

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