JP2011171476A - Method for manufacturing light emitting diode unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a light emitting diode unit, in a short period of time, while suppressing deterioration and breakage of members such as an LED chip, a phosphor, and a package substrate. <P>SOLUTION: On the package substrate on which LED chips are mounted, a precursor solution containing phosphors and organic metal compounds is supplied and heated. Then, a first vitreous body with phosphors distributed is formed, which seals the light emitting surface of the LED chip (a first vitreous body forming process). After that, a second vitreous body is formed on the first vitreous body by solidifying molten glass drop (a second vitreous body forming process). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a light emitting diode unit, and more specifically, a light emitting diode unit including an LED chip that emits light of a predetermined wavelength and a phosphor that converts the wavelength of light emitted from the LED chip. It relates to the manufacturing method.

  A light emitting diode unit that has an LED chip and emits white light has excellent features such as low power consumption, small size, light weight, low heat generation, mercury-free, and easy adjustment of light quantity. It is expected as a next-generation energy-saving illumination light source that can replace lamps and high-pressure discharge lamps.

  As a method of emitting white light using an LED chip, (1) a method of obtaining white light by combining three or more color LED chips (see Patent Document 1), or (2) blue light, blue-violet light, or near ultraviolet light A method of obtaining white light by combining an LED chip that emits light or the like and a phosphor (see Patent Documents 2 to 4) is known. Of these, the method (1) is difficult to balance the light emission intensity of each color LED chip, so the method of obtaining white light by combining the LED chip and the phosphor as in (2) is the focus. Has been.

  However, gallium nitride-based substrates that are mainly used as LED chip materials that emit blue light and the like have a high refractive index. Therefore, if the surface of the LED chip is in contact with an air layer or the like, light extraction efficiency is achieved by total reflection. There is a problem that will be extremely lowered.

  On the other hand, in the light emitting diode units described in Patent Documents 2 to 4, since the LED chip is sealed with a resin material such as an epoxy resin or a silicone resin, total reflection on the surface of the LED chip is suppressed, It is considered that a decrease in light extraction efficiency can be suppressed. However, such a resin material is prone to deterioration such as coloring due to the light from the LED chip and the influence of heat from the LED chip and the phosphor, and can be durable enough to withstand long-term use. There is a problem that you can not. In particular, when the brightness per unit area is required, such as an LED for a headlight of an automobile, or when an LED chip that emits near-ultraviolet light is used to obtain white light with high color rendering properties, the LED chip Deterioration of the resin material that seals the surface is significant and becomes a problem.

  For such a problem, a method of forming a hemisphere by placing glass sheets above and below an LED chip covered with an insulating layer mixed with a phosphor and press-pressing under a predetermined temperature. (See Patent Document 5).

JP 2003-45206 A JP 2002-185046 A JP 2002-314142 A JP 2005-93681 A JP 200654210 A

  However, in the method described in Patent Document 5, in order to form a glass sheet into a hemispherical shape, an LED chip, a phosphor, a package substrate, and the like are placed under a high temperature and a high pressure for a long time. There is a problem that deterioration and breakage of members are inevitable. Further, in order to form the glass sheet into a hemispherical shape, it is necessary to heat and cool these members as a whole, so that a long time is required for the process, resulting in an increase in cost.

  Such a problem is not only when manufacturing a light emitting diode unit that emits white light, but also with an LED chip that emits light of a predetermined wavelength and a phosphor for converting the wavelength of light emitted from the LED chip. This is a problem that occurs in common when the light emitting diode unit provided is manufactured.

  The present invention has been made in view of the above technical problems, and an object of the present invention is to manufacture in a short time while suppressing deterioration and breakage of members such as LED chips, phosphors, and package substrates. It is to provide a method of manufacturing a light emitting diode unit.

In order to solve the above problems, the present invention has the following features.
1. A light emitting diode unit comprising: an LED chip that emits light of a predetermined wavelength from a light emitting surface; a package substrate on which the LED chip is placed; and a phosphor that converts the wavelength of light emitted from the LED chip. A manufacturing method of
A first glass body in which the phosphor is dispersed is formed by supplying and heating a precursor solution containing an organometallic compound and the phosphor on a package substrate on which the LED chip is placed. And sealing the light emitting surface of the LED chip;
Forming a second glass body on the first glass body by solidifying molten glass droplets. A method for manufacturing a light-emitting diode unit, comprising:

  2. In the step of forming the second glass body, the molten glass droplet having a temperature higher than that of the package substrate is dropped and solidified on the package substrate on which the first glass body is formed. 2. The method for manufacturing a light-emitting diode unit according to 1 above, wherein a second glass body is formed.

  3. In the step of forming the second glass body, the molten glass droplet is pressurized with the package substrate and the upper mold before the dropped molten glass droplet is solidified, and the second glass body is shaped into a predetermined shape. 3. The method for producing a light-emitting diode unit according to 2 above, wherein the light-emitting diode unit is molded.

  4). In the step of forming the second glass body, the molten glass droplet having a temperature higher than that of the lower mold is dropped on the lower mold, and the package substrate on which the first glass body is formed is turned upside down. The first glass body is shaped into a predetermined shape by pressurizing the molten glass drop with the package substrate and the lower mold before the dropped molten glass drop is solidified. The manufacturing method of the light emitting diode unit of description.

  5. 5. The method for manufacturing a light-emitting diode unit according to any one of 1 to 4, wherein the organometallic compound is a metal alkoxide.

  6). 6. The method of manufacturing a light emitting diode unit according to 5, wherein the metal alkoxide is tetraethoxysilane or polysiloxane.

  According to the present invention, after the precursor solution containing the phosphor and the organometallic compound is supplied and heated, the light emitting surface of the LED chip is sealed with the first glass body in which the phosphor is dispersed. Since the second glass body is formed on the first glass body by solidifying the molten glass droplet, the light emitting surface of the LED chip can be sealed in a very short time. Therefore, members such as LED chips, phosphors, and package substrates are not placed under high temperature and high pressure for a long time, and deterioration and breakage of these members during manufacturing can be suppressed. Therefore, a light emitting diode unit can be manufactured in a short time while suppressing deterioration and breakage of members such as an LED chip, a phosphor, and a package substrate.

It is sectional drawing of the package board | substrate which mounts an LED chip. It is sectional drawing which shows the package substrate in which the 1st glass body was formed. It is a schematic diagram which shows the 2nd glass body formation process in 1st Embodiment. It is sectional drawing of the light emitting diode unit manufactured by 1st Embodiment. It is a schematic diagram which shows the 2nd glass body formation process in 2nd Embodiment. It is sectional drawing of the light emitting diode unit manufactured by 2nd Embodiment. It is a schematic diagram which shows the 2nd glass body formation process in 3rd Embodiment.

  Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS. 1 to 7, but the present invention is not limited to the embodiments.

<First Embodiment>
The manufacturing method of the light emitting diode unit of 1st Embodiment is demonstrated with reference to FIGS. In the method of manufacturing the light emitting diode unit according to the present embodiment, the phosphor is dispersed by supplying and heating a precursor solution containing the phosphor and the organometallic compound on the package substrate on which the LED chip is placed. Forming the first glass body and sealing the light emitting surface of the LED chip (first glass body forming process), and solidifying the molten glass droplets, the second on the first glass body A step of forming a glass body (second glass body forming step). In the second glass body forming step, a second glass body is formed by dropping and solidifying a molten glass droplet having a temperature higher than that of the package substrate on the package substrate on which the first glass body is formed.

(First glass body forming step)
FIG. 1A is a cross-sectional view showing an example of a package substrate 20 on which the LED chip 10 is placed. The LED chip 10 has a light emitting surface 12 that emits light of a predetermined wavelength, and is called a flip chip type having an electrode portion 11 for receiving power on the back surface facing the light emitting surface 12. There are no particular restrictions on the type of semiconductor that constitutes the LED chip 10. For example, a known LED chip such as one using a gallium nitride semiconductor (GaN, InGaN, AlInGaN, etc.) may be appropriately selected and used. The emitted light may be blue light, blue-green light, near ultraviolet light, ultraviolet light, or the like. The chip size is not limited, and may be 0.35 mm square (small chip) or 1 mm square (large chip). If the chip size is large, the amount of heat generation also increases. However, since the LED chip 10 is sealed with a glass body having excellent heat resistance in the manufacturing method of this embodiment, even if a large 1 mm square chip is used, it is durable. It is possible to manufacture a light emitting diode unit excellent in the above.

  The package substrate 20 has a lead portion 21 for supplying power to the LED chip 10 via the electrode portion 11. The material of the package substrate 20 is preferably a highly insulating ceramic material such as aluminum nitride or aluminum oxide. These ceramic materials can also be preferably used from the viewpoint of high adhesion to the first glass body. Further, a heat resistant resin or a metal material may be used. In the case of a conductive material, an insulating film is preferably provided on the surface.

  A bank 22 for storing the precursor solution is preferably formed around the portion of the package substrate 20 on which the LED chip 10 is placed. Thereby, the required amount of the precursor solution can be easily supplied regardless of the viscosity of the precursor solution. The bank 22 is preferably formed higher than the light emitting surface 12 so that the light emitting surface 12 of the LED chip 10 can be reliably sealed. Further, when a part of the light emitted from the LED chip 10 or the light converted in wavelength by the phosphor reaches the bank 22, the light is reflected by the bank 22 and efficiently emitted forward. The bank 22 is preferably a predetermined inclined surface. Thereby, the luminous efficiency of the light emitting diode unit can be improved.

  The LED chip 10 is mounted on the package substrate 20 in a state where the electrode portion 11 and the lead portion 21 are electrically connected. For connection between the electrode portion 11 of the LED chip 10 and the lead portion 21 of the package substrate 20, a normal flip chip bonding method may be used. For example, bumps (protrusions) made of a conductive material are provided on the lead portion 21, the package substrate 20 is fixed on a high-temperature heater, and the load is adjusted while adjusting the position of the LED chip 10 and the package substrate 20 by image processing. The method of connecting by adding. When connecting, it is also preferable to apply ultrasonic waves in addition to the heat and load of the heater. The LED chip 10 is not limited to the flip chip type, and may be a type in which the electrode part 11 of the LED chip 10 and the lead part 21 of the package substrate 20 are connected by wire bonding.

  It is also preferable to arrange a plurality of LED chips 10 on one package substrate 20. FIG. 1B is a schematic diagram when three LED chips 10 are arranged on one package substrate 20. The configuration in which a plurality of LED chips 10 are arranged on one package substrate 20 in this way is particularly suitable for applications that require a high luminous flux.

  In the present embodiment, a precursor solution containing a phosphor and an organometallic compound is supplied and heated on the package substrate 20 on which the LED chip 10 is mounted, whereby the phosphor is dispersed. A glass body is formed to seal the light emitting surface 12 of the LED chip 10. Since the precursor solution has high fluidity, a necessary region can be reliably sealed by the first glass body 30 without placing the LED chip 10 or the like under a high temperature and high pressure for a long time. A highly efficient light emitting diode unit can be manufactured. FIG. 2 is a cross-sectional view showing a state where the light emitting surface 12 of the LED chip 10 is sealed with the first glass body 30 in which the phosphor is dispersed. 2A shows an example in which one LED chip 10 is mounted on one package substrate 20, and FIG. 2B shows a case in which three LED chips 10 are arranged on one package substrate 20. FIG. Each example is shown.

  The precursor solution supplied on the package substrate 20 contains a metal organic compound (organometallic compound) which is a component of the first glass body 30, and after passing through a sol and gel state by a reaction such as hydrolysis. This is a solution (sol-gel solution) for forming a glass body by heating, and contains a phosphor that converts the wavelength of light emitted from the LED chip 10.

  There are no particular restrictions on the type of metal constituting the organometallic compound, and it is sufficient that a translucent glass body can be formed. From the viewpoint of stability of the formed glass body and ease of manufacture, Si is included. It is preferable that Moreover, multiple types of metals may be included. Examples of preferable organometallic compounds include metal alkoxides, metal acetylacetonates, metal carboxylates, and the like. Among these, metal alkoxides are preferable because they are easily gelled by hydrolysis and polymerization reaction, and tetraethoxysilane and polysiloxane are particularly preferable. A plurality of types of organometallic compounds may be used in combination. As a precursor solution, it is preferable to contain water, a solvent, a catalyst, etc. for hydrolysis other than the said organometallic compound suitably. Examples of the solvent include alcohols such as methanol, ethanol, propanol, and butanol. Examples of the catalyst include hydrochloric acid, sulfuric acid, nitric acid, acetic acid, hydrofluoric acid, ammonia and the like.

  When tetraethoxysilane is used as the organometallic compound, the mixing ratio is preferably 110 to 180 parts by mass of ethyl alcohol and 15 to 120 parts by mass of pure water with respect to 100 parts by mass of tetraethoxysilane. More preferably, 138 parts by mass of ethyl alcohol and 52 parts by mass of pure water with respect to parts by mass. In this case, the heating temperature for heating the gel is preferably 150 ° C. to 250 ° C., and more preferably 150 ° C. to 200 ° C. from the viewpoint of further suppressing deterioration of the LED chip 10 and the like. When polysiloxane is used as the organometallic compound, a commercially available polysiloxane dispersion (COAT-AT manufactured by CIK Nanotech) may be used. The heating temperature after coating is preferably 150 ° C. to 250 ° C., and more preferably 150 ° C. to 200 ° C. from the viewpoint of further suppressing deterioration of the LED chip 10 and the like.

  The phosphor contained in the precursor solution converts the wavelength of light emitted from the LED chip 10 and may be appropriately selected and used according to the application and type of the light emitting diode unit 50 to be manufactured. When a chip that emits blue light is used as the LED chip 10, for example, a blue LED chip + yellow is used by using a yellow phosphor that converts the wavelength of blue light into yellow light (excited by blue light and emits yellow light). White light can be obtained by adopting a phosphor structure. By using two or more kinds of phosphors, for example, a configuration of blue LED chip + yellow phosphor + red phosphor or a configuration of blue LED chip + green phosphor + red phosphor can be used. When a chip that emits near-ultraviolet light is used as the LED chip 10, a configuration of near-ultraviolet LED chip + blue phosphor + yellow phosphor or a near-UV LED chip + blue phosphor + green phosphor + red phosphor With this configuration, white light can be obtained.

  Suitable phosphors include YAG phosphors, silicate phosphors, nitride phosphors, oxynitride phosphors, sulfide phosphors, thiogallate phosphors, aluminate phosphors, and the like.

  When a plurality of types of phosphors are used, the first glass body may be formed by including all the phosphors in a single precursor solution, or two or more types of precursors having different types of phosphors to be contained You may form the 1st glass body of the structure which laminated | stacked the several glass body using the body solution. In general, when a plurality of types of phosphors are used at the same time, loss due to so-called multistage excitation, in which light emitted from the first phosphor excites another second phosphor, tends to be a problem. From the viewpoint of effectively reducing the loss due to such multi-stage excitation, it is preferable to have a configuration in which a plurality of glass bodies having different types of phosphors are stacked. Furthermore, by arranging the phosphor having the longer emission wavelength on the side where the light from the LED chip 10 serving as the light source reaches first, and arranging the phosphor having the shorter emission wavelength on the side reaching later, Loss due to multistage excitation can be reduced more effectively.

What is necessary is just to adjust content of fluorescent substance according to the kind etc. of organometallic compound. For example, when polysiloxane is used as the organometallic compound, the mass ratio of the solid content (SiO ₂ ) of the polysiloxane contained in the precursor solution to the phosphor is fluorescent with respect to 100 parts by mass of the solid content of the polysiloxane. 1 to 100 parts by mass of the body is preferable. When tetraethoxysilane is used as the organometallic compound, the mass ratio of tetraethoxysilane and phosphor contained in the precursor solution is 0.03-4. 5 parts by mass is preferred.

  The precursor solution preferably contains nanoparticles. By containing the nanoparticles, the viscosity of the precursor solution is increased, so that the precipitation rate of the phosphor is decreased, and it becomes easy to uniformly disperse the phosphor in the precursor solution. For example, nanoparticles of various oxides such as silica and magnesium fluoride nanoparticles are suitable. When using an organic compound of Si as the organometallic compound, it is preferable to contain silica nanoparticles from the viewpoint of stability with the glass body to be formed. The nanoparticles preferably have a 50% particle diameter (median diameter) of 1 nm to 500 nm. The shape of the nanoparticles is not particularly limited, but spherical fine particles are preferably used. The particle size distribution is not particularly limited, but from the viewpoint of uniformly dispersing the phosphor, those having a relatively narrow distribution are preferably used rather than those having a wide distribution. The shape and particle size distribution of the nanoparticles can be confirmed using SEM and TEM. The content of the nanoparticles is preferably 0.1% by mass to 25% by mass with respect to the entire composition including the phosphor. Further, in order to disperse the nano-particle phosphor more uniformly, it is also preferable to disperse the precursor solution mixed with the phosphor by applying ultrasonic waves.

(Second glass body forming step)
Next, the molten glass droplet is solidified to form a second glass body on the first glass body. This process completes the light emitting diode unit. In the present embodiment, a second glass body is formed by dropping and solidifying molten glass droplets having a temperature higher than that of the package substrate on the package substrate on which the first glass body is formed. Drawing 3 (a)-(c) is a mimetic diagram showing the 2nd glass body formation process in this embodiment in order. FIG. 4 is a cross-sectional view of the light emitting diode unit 50 manufactured in this embodiment. FIG. 4A shows a configuration when one LED chip 10 is provided, and FIG. 4B shows a configuration when three LED chips 10 are provided.

  The dropping of the molten glass droplet 44 is performed by heating a pipe-shaped dropping nozzle 51 connected to a melting tank (not shown) containing molten glass to a predetermined temperature by a heater 52. When the dripping nozzle 51 is heated to a predetermined temperature, the molten glass 43 is supplied to the tip of the dripping nozzle 51 by its own weight and accumulates in a droplet shape by the surface tension (FIG. 3A). When the molten glass 43 collected at the tip of the dropping nozzle 51 reaches a certain weight, it is separated from the dropping nozzle 51 by gravity and becomes a molten glass drop 44 and falls downward (FIG. 3B).

  The weight of the molten glass droplet 44 dropped from the dropping nozzle 51 can be adjusted by the outer diameter of the tip of the dropping nozzle 51 and the like, and depending on the type of glass, the molten glass droplet 44 of about 0.1 to 2 g is dropped. Can be made. In addition to the method of separating from the dropping nozzle 51 only by gravity, a method of pressurizing and extruding the molten glass 43 or a method of separating by applying an external force such as airflow or vibration may be used. Further, the molten glass droplet 44 dropped from the dropping nozzle 51 is once collided with a member provided with a through-hole, and a part of the collided molten glass droplet 44 is passed through the through-pore, thereby miniaturizing. The molten glass droplet 44 may be dropped. By using such a method, it is possible to obtain a molten glass droplet 44 having a size of 0.01 g, for example, so that a smaller light emitting diode unit than the case where the molten glass droplet 44 dropped from the dropping nozzle 51 is used as it is. Manufacture is possible.

  The molten glass droplet 44 dropped from the dropping nozzle 51 falls on the package substrate 20, is rapidly cooled and solidified by heat conduction to the package substrate 20, and the second glass is formed on the first glass body 30. A body 40 is formed (FIG. 3C). Depending on the size of the molten glass droplet 44, etc., the solidification is usually completed several seconds to several tens of seconds after the molten glass droplet 44 is dropped.

  It is also preferable to heat the package substrate 20 including the first glass body 30 to a predetermined temperature lower than the temperature of the molten glass droplet 44 before dropping the molten glass droplet 44. Thereby, the familiarity of the molten glass with respect to the first glass body 30 and the package substrate 20 is improved, and the molten glass easily spreads over the entire necessary range in a short time. In addition, there is a merit that adhesion to the first glass body 30 and the package substrate 20 is improved. On the other hand, when the temperature of the package substrate 20 is too high, the LED chip 10 and the like are liable to deteriorate. From such a viewpoint, the temperature of the package substrate 20 when the molten glass droplet 44 is dropped is preferably in the range of 50 ° C. to 200 ° C., and more preferably in the range of 80 ° C. to 150 ° C.

  As described above, according to the method of the present embodiment, it is not necessary to heat the LED chip 10 and the package substrate 20 with the heater for a long time, and only a very short temperature increase due to heat conduction from the molten glass droplet 44 is required. Deterioration due to heat can be sufficiently suppressed. In addition, since the second glass body 40 is formed on the first glass body 30 in which the phosphor is dispersed, the volume of the first glass body 30 can be kept small, and the precursor solution is heated. When forming the 1st glass body 30, the crack of a glass body and generation | occurrence | production of a crack can be suppressed.

  There is no restriction | limiting in particular in the kind of glass which can be used, A well-known glass can be selected and used according to a use. Examples thereof include optical glasses such as borosilicate glass, silicate glass, phosphate glass, and lanthanum glass. From the viewpoint of suppressing the reflection of light at the boundary surface between the first glass body 30 and the second glass body 40 and further improving the light extraction efficiency, the first glass body 30 and the second glass body 40. Is preferably selected and used so that the difference in refractive index is small.

  As shown in FIGS. 4 (a) and 4 (b), the surface of the second glass body 40 has a gentle convex shape. However, by changing the temperature and size of the molten glass droplet 44 to be dropped, the surface convexity can be changed. Can be adjusted. For example, when the temperature of the molten glass droplet 44 to be dropped is increased, the viscosity is lowered, and the surface of the second glass body 40 has a flatter shape (the curvature is reduced). Conversely, when the temperature of the molten glass droplet 44 is lowered, the viscosity increases, and the surface of the second glass body 40 has a tighter convex shape (the curvature increases). Thus, the 2nd glass body 40 can be made into the suitable shape according to the condensing characteristic requested | required by changing the conditions which dripped the molten glass droplet 44. FIG.

<Second Embodiment>
The manufacturing method of the light emitting diode unit of 2nd Embodiment is demonstrated with reference to FIG. 5, FIG. In the method of manufacturing the light emitting diode unit according to the present embodiment, the phosphor is dispersed by supplying and heating a precursor solution containing the phosphor and the organometallic compound on the package substrate on which the LED chip is placed. Forming the first glass body and sealing the light emitting surface of the LED chip (first glass body forming process), and solidifying the molten glass droplets, the second on the first glass body A step of forming a glass body (second glass body forming step). In the second glass body forming step of the present embodiment, after dropping a molten glass droplet having a temperature higher than that of the package substrate on the package substrate on which the first glass body is formed, before the molten glass droplet is solidified. Then, the molten glass droplet is pressed by the package substrate and the upper mold to form the second glass body into a predetermined shape. About a 1st glass body formation process, it is the same as that of the case of the above-mentioned 1st Embodiment. Hereinafter, a description will be given centering on differences from the first embodiment.

  FIGS. 5A to 5D are schematic views sequentially illustrating a second glass body forming step in the second embodiment. First, similarly to the case of the first embodiment, a molten glass droplet 44 having a temperature higher than that of the package substrate 20 is dropped on the package substrate 20 on which the first glass body 30 is formed by the first glass body forming step. (FIGS. 5A and 5B). The dropping of the molten glass droplet 44 is performed by heating the dropping nozzle 51 to a predetermined temperature by the heater 52. The details of the dropping method of the molten glass droplet 44 are the same as in the case of the first embodiment.

  After dropping the molten glass droplet 44, the package substrate 20 is moved to a position facing the upper mold 61, and before the molten glass droplet 44 is cooled and solidified, the molten glass droplet 44 is formed between the package substrate 20 and the upper mold 61. And the second glass body 40 is formed into a predetermined shape (FIG. 5C). The molding surface 63 of the upper mold 61 is previously processed into a predetermined shape corresponding to the shape of the second glass body 40 of the light emitting diode unit 50 to be manufactured. The molten glass droplet 44 is rapidly cooled by heat conduction to the package substrate 20 and the upper mold 61 and solidifies in a short time to become the second glass body 40. After releasing the pressure, the upper die 61 is moved upward, and the obtained light emitting diode unit 50 is recovered (FIG. 5D). The light emitting diode unit 50 is completed by this process. As described above, in this embodiment, since the dropped molten glass droplet 44 is pressed and deformed, the pressing load is much higher than when the glass sheet is heated and pressed together with the members such as the package substrate 20. It can be kept small, and can be sufficiently deformed in a very short pressurization time. Therefore, the light emitting diode unit 50 can be manufactured in a short time while sufficiently suppressing deterioration due to temperature and damage due to pressure of each member.

  The load applied to form the molten glass droplet 44 and the pressurizing time may be appropriately set according to the size of the molten glass droplet 44, etc. Usually, a load in the range of several tens to several hundreds N is from several seconds to In many cases, it is sufficient to apply pressure for several tens of seconds. Further, the applied load may be changed with time. The means for applying the load is not particularly limited, and known driving means such as an air cylinder, a hydraulic cylinder, a servo motor, etc. may be appropriately selected and used.

  The upper mold 61 is preferably heated to a predetermined temperature in advance. The predetermined temperature is a temperature that is lower than the temperature of the molten glass droplet 44 to be dripped and is cooled and solidified by pressure molding, and may be appropriately selected according to the type of glass to be used. Good. Generally, when the temperature of the upper mold 61 is too low, wrinkles are likely to occur on the surface of the glass molded body. On the other hand, if the temperature is set higher than necessary, the life of the upper die 61 is likely to be shortened due to fusion with the glass or oxidation of the surface. From these viewpoints, the temperature of the upper mold 61 is preferably set in the range of Tg-100 ° C to Tg + 100 ° C, where Tg is the glass transition temperature of the glass used, and the range of Tg-100 ° C to Tg + 50 ° C. It is more preferable to set to. As a heating means for heating the upper mold 61, a known heating means can be appropriately selected and used. For example, an infrared heating device, a high-frequency induction heating device, a cartridge heater that is used by being embedded in the upper die 61, a sheet heater that is used while being in contact with the outside of the upper die 61, and the like are suitable.

  The material of the upper mold 61 can be appropriately selected from known materials as a mold for producing a glass molded body by pressure molding. For example, various heat-resistant alloys (such as stainless steel), super hard materials mainly composed of tungsten carbide, various ceramics (such as silicon carbide, silicon nitride, and aluminum nitride), composite materials containing carbon, and the like can be given. It is also preferable to provide a coating layer on the molding surface 63 in order to improve the durability of the upper mold 61 and prevent fusion with the glass. There are no particular restrictions on the material of the coating layer. For example, various metals (chromium, aluminum, titanium, etc.), nitrides (chromium nitride, aluminum nitride, titanium nitride, boron nitride, etc.), oxides (chromium oxide, aluminum oxide, Titanium oxide or the like) can be used.

  FIG. 6 is a cross-sectional view of the light emitting diode unit 50 manufactured by the method of the present embodiment. 6 (a) and 6 (b) show the configuration when one LED chip 10 is provided, and FIG. 6 (c) shows the configuration when three LED chips 10 are provided.

  According to the method of the present embodiment, the second glass body 40 is molded by pressurizing the molten glass droplet 44 with the molding surface 63 of the upper mold 61 formed in a predetermined shape and the package substrate 20. A desired shape according to the application can be easily formed. For example, the surface of the second glass body 40 can be formed into a convex shape having a large curvature like the light emitting diode unit 50 of FIG. 6A by applying pressure with the upper mold 61 whose molding surface 63 is a concave surface. And the surface of the 2nd glass body 40 can also be made into a plane like the light emitting diode unit 50 of FIG.6 (b) by pressurizing with the upper mold | type 61 which the molding surface 63 becomes a plane. Further, in the case of a configuration including a plurality of LED chips 10, a shape in which a plurality of convex portions corresponding to each LED chip 10 are arranged as in the light emitting diode unit 50 of FIG. . As described above, even when the conventional glass sheet is heated and pressed together with the members such as the package substrate 20 for a long time, even if the shape cannot be formed unless high temperature and high pressure are applied, it takes a very short time. It can be formed by applying a small pressure.

<Third Embodiment>
A manufacturing method of the light emitting diode unit of the third embodiment will be described with reference to FIG. In the method of manufacturing the light emitting diode unit according to the present embodiment, the phosphor is dispersed by supplying and heating a precursor solution containing the phosphor and the organometallic compound on the package substrate on which the LED chip is placed. Forming the first glass body and sealing the light emitting surface of the LED chip (first glass body forming process), and solidifying the molten glass droplets, the second on the first glass body A step of forming a glass body (second glass body forming step). In the second glass body forming step of this embodiment, molten glass droplets having a temperature higher than that of the lower mold are dropped on the lower mold, and the package substrate on which the first glass body is formed is turned upside down to be melted. Before the glass droplet is solidified, the molten glass droplet is pressed with the package substrate and the lower mold to form the second glass body into a predetermined shape. About a 1st glass body formation process, it is the same as that of the case of the above-mentioned 1st Embodiment. Hereinafter, a description will be given focusing on differences from the first and second embodiments.

  FIGS. 7A to 7D are schematic views sequentially illustrating a second glass body forming step in the third embodiment. First, a molten glass droplet 44 having a temperature higher than that of the lower die 62 is dropped on the molding surface 64 of the lower die 62 (FIGS. 7A and 7B). The molding surface 64 is previously processed into a predetermined shape corresponding to the shape of the second glass body 40 of the light emitting diode unit 50 to be manufactured. The dropping of the molten glass droplet 44 is performed by heating the dropping nozzle 51 to a predetermined temperature by the heater 52. The details of the dropping method of the molten glass droplet 44 are the same as in the case of the first embodiment.

  Next, the package substrate 20 on which the first glass body 30 is formed by the first glass body forming step similar to that of the first embodiment is turned upside down, and the dropped molten glass droplet 44 is cooled and solidified. At the previous predetermined timing, the molten glass droplet 44 is pressurized by the package substrate 20 and the lower mold 62 (FIG. 7C). The molten glass droplet 44 is rapidly cooled by heat conduction to the package substrate 20 and the lower mold 62 and solidifies in a short time to become the second glass body 40. After the second glass body 40 is cooled to a predetermined temperature, the package substrate 20 is moved upward, and the obtained light emitting diode unit 50 is recovered (FIG. 7D). The light emitting diode unit 50 is completed by this process. The configuration of the light emitting diode unit 50 manufactured by the method of this embodiment is the same as that of the second embodiment shown in FIG.

  The timing for pressurizing the molten glass droplets 44 with the package substrate 20 and the lower mold 62 is preferably slower from the viewpoint of suppressing deterioration of the LED chip 10 and the like due to heat, but if it is too late, the second glass body 42 is moved. The pressure required for forming into a predetermined shape is increased. From such a viewpoint, it is preferable to pressurize the molten glass droplet 44 several seconds to several tens of seconds after the molten glass droplet 44 is dropped onto the lower mold 62. What is necessary is just to set suitably the load and pressurization time to apply. The lower mold 62 is preferably heated to a predetermined temperature in advance. Thereby, the shape of the surface of the second glass body 40 formed by the transfer of the lower mold 62 is stabilized. The predetermined temperature is a temperature lower than the temperature of the molten glass droplet 44 to be dropped, and may be appropriately selected according to the type of glass to be used. The material of the lower mold 62 is preferably a material that has high heat resistance and does not easily react with molten glass, and the same material as that of the upper mold 61 is preferably used.

  It is also preferable to heat the package substrate 20 on which the first glass body 30 is formed to a predetermined temperature lower than the temperature of the molten glass droplet 44. Thereby, the familiarity of the molten glass with respect to the first glass body 30 and the package substrate 20 is improved, and the molten glass easily spreads over the entire necessary range in a short time. Further, there is an advantage that the adhesion between the second glass body 42 and the first glass body 30 or the package substrate 20 after the molten glass droplet 44 is solidified is improved. On the other hand, when the temperature of the package substrate 20 is too high, the LED chip 10 and the like are liable to deteriorate. From such a viewpoint, the temperature of the package substrate 20 is preferably in the range of 50 ° C to 200 ° C, and more preferably in the range of 80 ° C to 150 ° C.

  As described above, in the present embodiment, the molten glass droplet 44 is dropped on the molding surface 64 of the lower mold 62 formed in a predetermined shape, so that the second glass body 40 is desired without applying high pressure. It can be formed in the shape of Further, since the molten glass droplet 44 and the package substrate 20 come into contact with each other at a predetermined timing after the dropped molten glass droplet 44 is cooled to some extent, the LED chip 10 or the like due to the influence of heat from the molten glass droplet 44 is used. Degradation can be minimized. Accordingly, the light emitting diode unit 50 can be manufactured in a short time while sufficiently suppressing deterioration due to temperature and damage due to pressure of each member.

DESCRIPTION OF SYMBOLS 10 LED chip 11 Electrode part 12 Light emission surface 20 Package board 21 Lead part 22 Bank 30 1st glass body 40 2nd glass body 43 Molten glass 44 Molten glass droplet 50 Light emitting diode unit 51 Dripping nozzle 52 Heater 61 Upper mold | type 62 Bottom Mold 63, 64 Molding surface

Claims (6)

A light emitting diode unit comprising: an LED chip that emits light of a predetermined wavelength from a light emitting surface; a package substrate on which the LED chip is placed; and a phosphor that converts the wavelength of light emitted from the LED chip. A manufacturing method of
A first glass body in which the phosphor is dispersed is formed by supplying and heating a precursor solution containing an organometallic compound and the phosphor on a package substrate on which the LED chip is placed. And sealing the light emitting surface of the LED chip;
Forming a second glass body on the first glass body by solidifying molten glass droplets. A method for manufacturing a light-emitting diode unit, comprising:   In the step of forming the second glass body, the molten glass droplet having a temperature higher than that of the package substrate is dropped and solidified on the package substrate on which the first glass body is formed. The method for manufacturing the light emitting diode unit according to claim 1, wherein a second glass body is formed.   In the step of forming the second glass body, the molten glass droplet is pressurized with the package substrate and the upper mold before the dropped molten glass droplet is solidified, and the second glass body is shaped into a predetermined shape. The method of manufacturing a light emitting diode unit according to claim 2, wherein the light emitting diode unit is formed into a shape.   In the step of forming the second glass body, the molten glass droplet having a temperature higher than that of the lower mold is dropped on the lower mold, and the package substrate on which the first glass body is formed is turned upside down. The molten glass droplet is pressed by the package substrate and the lower mold before the dropped molten glass droplet is solidified, and the second glass body is formed into a predetermined shape. 2. A method for producing a light emitting diode unit according to 1.   The method for manufacturing a light-emitting diode unit according to claim 1, wherein the organometallic compound is a metal alkoxide.   6. The method of manufacturing a light emitting diode unit according to claim 5, wherein the metal alkoxide is tetraethoxysilane or polysiloxane.

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