JP5144578B2 - Method for manufacturing light emitting device - Google Patents

Description

  The present invention relates to a method for manufacturing a light emitting device in which a light emitting element on a mounting portion is sealed with glass using a mold.

A light-emitting device in which a light-emitting element on a mounting portion is sealed with glass is known (for example, see Patent Document 1). A light emitting device described in Patent Document 1 includes a flip chip type LED element made of a GaN-based semiconductor compound, a substrate having a wiring layer electrically connected to the LED element, and the surface of the substrate by sealing the LED element. A glass sealing portion bonded to the glass sealing portion, and a coating film of Al ₂ O ₃ covering the surface of the glass sealing portion. As the material of the coating film, it is said that SiO ₂ , SiN, MgF ₂ or the like may be used in addition to Al ₂ O ₃ .

  This light-emitting device includes a wiring forming process for forming a circuit pattern on a substrate, an LED element mounting process for flip-mounting an LED element on the circuit pattern of the substrate, and a low-melting glass set in parallel to the plate-shaped low-melting glass substrate 3 Preparatory process, glass sealing process for hot-pressing low melting point glass, forming glass sealing part having optical shape part according to the shape of press mold, and sputtering to cover the surface of glass sealing part And a coat film forming step of forming a coat film by performing the process.

JP 2006-202962 A

  By the way, when manufacturing the light-emitting device described in Patent Document 1, when press molding is performed using a mold that is in close contact with the upper surface of the glass sealing portion, the glass material adheres to the mold when the mold is separated from the glass material. And there exists a possibility that the shape of the upper surface of a glass sealing part may deform | transform with respect to an expected shape.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a light emitting device in which a glass material does not adhere to a mold and the upper surface of the glass material does not deform with respect to an intended shape. It is to provide a manufacturing method.

In order to achieve the above object, the present invention provides a method for manufacturing a light emitting device in which a plurality of light emitting elements on a mounting portion are sealed with a glass material, and the upper surface of the glass material has a softening point of the glass material. A coating film forming step of forming a coating film of a non-glass material having a high melting point, and a molding surface of the mold is brought into contact with the upper surface of the glass material through the coating film, and the lower surface of the glass material is placed on the mounting portion in contact with, seen including a sealing step of sealing the plurality of light emitting elements on the mounting portion is softened by heating the glass material, the sealing step, each of the plurality of light emitting elements A step of disposing an individual glass material with respect to the light emitting element, and the mold pushes the individual glass material to make the upper surface of the individual glass material a curved surface convex upward, and the mold Between the individual glass materials Comprising the step of contacting the mounting portion,
When the sealing step is completed, the entire upper surface of the individual glass material is covered with the coat film, and an exposed portion where the glass material is not bonded is formed between the plurality of light emitting elements on the mounting portion. And the manufacturing method of the light-emitting device which seals the said upper surface by the glass sealing part which made the said upper surface the transmission surface of the emitted light of the said light-emitting element in which the deformation | transformation was prevented with respect to the expected shape. Provided.

  In the method for manufacturing a light emitting device, the coating film may have a melting point higher by 100 ° C. or more than the softening point of the glass material.

  In the method for manufacturing the light emitting device, the molding surface of the mold may have a curved shape.

  The manufacturing method of the light emitting device includes a pre-molding step of previously bending the upper surface of the glass material before the coating film forming step, and the coating on the upper surface of the curved glass material in the coating film forming step. A film may be formed.

  In the method for manufacturing the light emitting device, the coat film may be formed by vapor deposition in the coat film forming step.

  In the method for manufacturing the light emitting device, in the coating film forming step, the coating film may be formed by a sol-gel method.

  According to the present invention, the glass material does not adhere to the mold, and the upper surface of the glass material is not deformed with respect to the desired shape.

FIG. 1 is a schematic longitudinal sectional view of a light emitting device showing an embodiment of the present invention. FIG. 2 is a schematic explanatory view showing a state before the glass material is sealed. FIG. 3 is a schematic explanatory view showing a state at the time of sealing the glass material. FIG. 4 is a plan view of the produced intermediate. FIG. 5 shows a modified example and is a schematic explanatory view showing a state before a glass material is sealed. FIG. 6 shows a modified example and is a schematic explanatory view showing a state before a glass material is sealed. FIG. 7 shows a modified example and is a schematic explanatory view showing a state at the time of sealing processing of a glass material. FIG. 8 is a schematic longitudinal sectional view of a light emitting device showing a modification. FIG. 9 shows a modification and is a schematic explanatory view showing a state at the time of sealing processing of a glass material. FIG. 10 is a plan view of an intermediate body showing a modification. FIG. 11 is a schematic longitudinal sectional view of a light emitting device showing a modification. FIG. 12 is a plan view of an intermediate body showing a modification. FIG. 13 is a schematic longitudinal sectional view of a light emitting device showing a modification. FIG. 14 is a plan view of an intermediate body showing a modification. FIG. 15 is a schematic longitudinal sectional view of a light source device showing an example of use of the light emitting device.

  1 to 4 show an embodiment of the present invention, and FIG. 1 is a schematic longitudinal sectional view of a light emitting device.

  As shown in FIG. 1, the light emitting device 1 includes an LED element 2 made of a flip-chip GaN-based semiconductor material, a wiring board 3 on which the LED element 2 is mounted, and a tungsten (W)- A circuit pattern 4 composed of nickel (Ni) -gold (Au), a glass sealing portion 6 that seals the LED element 2 and is bonded to the wiring substrate 3, and is formed on the upper surface of the glass sealing portion 6. Coating film 7. In addition, a hollow portion 5 in which glass does not surround is formed between the LED element 2 and the wiring board 3. In the present embodiment, the wiring board 3 and the circuit pattern 4 constitute a mounting portion for mounting the LED element 2 and supplying power to the LED element 2.

The LED element 2 as a light emitting element is obtained by epitaxially growing a group III nitride semiconductor on the surface of a growth substrate made of sapphire (Al ₂ O ₃ ), whereby a buffer layer, an n-type layer, an MQW layer, p The mold layer is formed in this order. The LED element 2 is epitaxially grown at 700 ° C. or higher, and has a heat resistant temperature of 600 ° C. or higher, which is stable with respect to a processing temperature in a sealing process using a low-melting-point heat-sealing glass described later. The LED element 2 includes a p-side electrode provided on the surface of the p-type layer and a p-side pad electrode formed on the p-side electrode, and a part thereof is etched from the p-type layer to the n-type layer. The n-side electrode is formed on the exposed n-type layer. Au bumps 28 are formed on the p-side pad electrode and the n-side electrode, respectively.

  The p-side electrode is made of, for example, rhodium (Rh), and functions as a light reflection layer that reflects light emitted from the MQW layer as the light emitting layer in the direction of the growth substrate. The material of the p-side electrode can be changed as appropriate. In the present embodiment, two p-side pad electrodes are formed on the p-side electrode, and an Au bump 28 is formed on each p-side pad electrode. The number of p-side pad electrodes may be three, for example, and the number of p-side pad electrodes formed on the p-side electrode can be changed as appropriate.

  The n-side electrode has a contact layer and a pad layer formed in the same area. The n-side electrode is formed of an Al layer, a thin Ni layer that covers the Al layer, and an Au layer that covers the surface of the Ni layer. Note that the material of the n-side electrode can be changed as appropriate. In the present embodiment, the n-side electrode is formed at the corner of the LED element 2 in plan view, and the p-side electrode is formed almost entirely except for the formation region of the n-side electrode.

The LED element 2 has a thickness of 100 μm and a 346 μm square, and has a thermal expansion coefficient of 7 × 10 ⁻⁶ / ° C. Here, although the thermal expansion coefficient of the GaN layer of the LED element 2 is 5 × 10 ⁻⁶ / ° C., the thermal expansion coefficient of the growth substrate made of sapphire occupying most is 7 × 10 ⁻⁶ / ° C., The thermal expansion coefficient of the LED element 2 body is equal to the thermal expansion coefficient of the growth substrate. In addition, in each figure, in order to clarify the structure of each part of the LED element 2, each part is shown by the size different from an actual size.

The wiring board 3 is made of a polycrystalline sintered material of alumina (Al ₂ O ₃ ), is formed to have a thickness of 0.25 mm and a 1.0 mm square, and has a thermal expansion coefficient α of 7 × 10 ⁻⁶ / ° C. is there. As shown in FIG. 1, the circuit pattern 4 of the wiring board 3 includes a surface pattern 41 formed on the substrate surface and electrically connected to the LED element 2, and a back surface formed on the substrate back surface and connectable to an external terminal. And a pattern 42. The surface pattern 41 includes a W layer 4a patterned according to the electrode shape of the LED element 2, a thin film Ni layer 4b covering the surface of the W layer 4a, and a thin film Au layer covering the surface of the Ni layer 4b. 4c. The back surface pattern 42 includes a W layer 4a patterned according to an external connection terminal 44 described later, a thin film Ni layer 4b covering the surface of the W layer 4a, and a thin film Au layer covering the surface of the Ni layer 4b. 4c. The front surface pattern 41 and the back surface pattern 42 are electrically connected by a via pattern 43 made of W provided in a via hole 3a penetrating the wiring board 3 in the thickness direction. One external connection terminal 44 is provided on each of the anode side and the cathode side. Each external connection terminal 44 is diagonally arranged on the wiring board 3 in plan view.

The glass sealing portion 6 is made of ZnO—B ₂ O ₃ —SiO ₂ —Nb ₂ O ₅ —Na ₂ O—Li ₂ O-based heat fusion glass. The composition of the glass is not limited to this. For example, the heat-sealing glass may not contain Li ₂ O, or may contain ZrO ₂ , TiO ₂ or the like as an optional component. Good. This heat-fusible glass has a glass transition temperature (Tg) of 490 ° C., a yield point (At) of 520 ° C., a softening point of 545 ° C., and a glass temperature higher than the temperature at which the epitaxial growth layer of the LED element 2 is formed. The transition temperature (Tg) is sufficiently low. In this embodiment, the glass transition temperature (Tg) is lower by 200 ° C. or more than the formation temperature of the epitaxial growth layer. Moreover, the coefficient of thermal expansion (α) at 100 ° C. to 300 ° C. of the heat-fusible glass is 6 × 10 ⁻⁶ / ° C. When the thermal expansion coefficient (α) exceeds the glass transition temperature (Tg), a larger numerical value is obtained. As a result, the heat-sealing glass is bonded to the wiring board 3 at about 550 ° C. and can be hot-pressed. Moreover, the refractive index of the heat sealing | fusion glass of the glass sealing part 6 is 1.7.

The composition of the heat-sealing glass is arbitrary as long as the glass transition temperature (Tg) is lower than the heat-resistant temperature of the LED element 2 and the thermal expansion coefficient (α) is equivalent to that of the wiring board 3. Examples of the glass having a relatively low glass transition temperature and a relatively low coefficient of thermal expansion include, for example, a ZnO—SiO ₂ —R ₂ O system (where R is at least one selected from Group I elements such as Li, Na, and K). ) Glass, phosphate glass and lead glass. Of these glasses, ZnO—SiO ₂ —R ₂ O glass is preferable because it has better moisture resistance than phosphoric acid glass and does not cause environmental problems like lead glass. is there.

  Here, the heat-fusible glass is glass that is molded in a softened state by heating, and is different from glass that is molded by a sol-gel method. Since the sol-gel glass has a large volume change at the time of molding, cracks are likely to occur, and it is difficult to form a thick film of glass. However, the heat-fused glass can avoid this problem. Further, since the sol-gel glass generates pores, airtightness may be impaired. However, the heat-sealed glass does not cause this problem, and the LED element 2 can be accurately sealed.

Further, the heat-sealing glass is generally processed with a viscosity that is orders of magnitude higher than the level of high viscosity in the resin. Furthermore, in the case of glass, the viscosity does not decrease to a general resin sealing level even if the yield point exceeds several tens of degrees Celsius. Moreover, since it will require the temperature which exceeds the crystal growth temperature of a LED element when it is going to make it the viscosity of the level at the time of general resin molding, it is preferable to process at 10 ⁴ poise or more.

  As shown in FIG. 1, the glass sealing part 6 covers the light emitting element 2 and the wiring board 3 entirely, and has a maximum thickness of 0.5 mm. The glass sealing portion 6 has an upper surface 6a that forms a curved surface that protrudes upward, and a flat surface 6b that extends parallel to the wiring board 3 from the lower end of the upper surface 6a. In the present embodiment, the entire surface of the wiring board 3 is covered with the glass sealing portion 6.

The coat film 7 is made of a transparent non-glass material and is formed on the entire upper surface of the glass sealing portion 6. The coat film 7 is made of a material having a melting point higher than the softening point of the glass material of the glass sealing portion 6. In the present embodiment, the melting point of the coating film 7 is higher by 100 ° C. or more than the softening point of the glass material. In the present embodiment, the coat film 7 is made of alumina (Al ₂ O ₃ ), has a melting point of 2050 ° C., and a film thickness of 0.1 μm. The material of the coating film 7 is arbitrary. For example, SiO ₂ (melting point: 1600 ° C.), TiO ₂ (melting point: 1870 ° C.), ZrO (melting point: 2700 ° C.), MgO (melting point: 2800 ° C.), Y ₂ It may be another transparent oxide such as O ₃ (melting point: 2410 ° C.), or may be a transparent fluoride such as MgF ₂ (melting point: 1248 ° C.).

The light emitting device 1 configured as described above is manufactured through the following steps.
First, a glass component oxide powder is heated to 1200 ° C. and stirred in a molten state. And after solidifying the glass material 60, it slices so that it may correspond to the maximum thickness of the glass sealing part 6, and processes it into plate shape (plate shape process process). Thereafter, an alumina coating film 7 is formed on the upper surface of the glass material 60 (coating film forming step). In the present embodiment, the coating film 7 is formed by vapor deposition, specifically, by sputtering. The coating film 7 may be deposited by a method other than sputtering. Furthermore, the coat film 7 can be formed by a method other than vapor deposition. For example, alkoxide may be applied to the upper surface of the glass material 60, and the coat film 7 may be formed by a sol-gel method.

  On the other hand, a wiring board 3 having via holes 3a is prepared, and W paste is screen-printed on the surface of the wiring board 3 according to the circuit pattern. Next, the wiring board 3 on which the W paste is printed is heat-treated at a temperature of 1000 ° C. to burn W on the wiring board 3, and further, Ni plating and Au plating are performed on the W to form a circuit pattern 4 (pattern) Forming step).

  In the present embodiment, the circuit pattern 4 is formed on the wiring board 3 after firing the ceramic. This is because if the circuit pattern 4 is formed on a ceramic before firing (for example, a green sheet) and then fired, the accuracy of the circuit pattern 4 is poor due to thermal expansion and contraction due to heating and cooling during firing and after firing. Because it becomes.

  In forming the circuit pattern 4 on the fired ceramic, instead of printing the W paste and heat-treating it, depositing a metal such as Cr, Ti, or the like, and pasting the Cu foil into a predetermined shape Etching may be performed, and Ni plating and Au plating may be applied thereto.

  Next, the plurality of LED elements 2 are mounted on the wiring board 3 at equal intervals in the vertical and horizontal directions (element mounting process). Specifically, the plurality of LED elements 2 are electrically bonded to the surface pattern 41 of the circuit pattern 4 of the wiring board 3 by the Au bumps 28. In the present embodiment, a total of three bump bondings are performed: two points on the p side and one point on the n side.

FIG. 2 is a schematic explanatory view showing a state before the glass material is sealed.
A glass material 60 on which a coating film 7 is formed is disposed above the wiring board 3 on which each LED element 2 is mounted, and the wiring board 3 and the glass material 60 are placed by a lower heater 91 and an upper mold 92. Insert from above and below. The heater 91 has a flat upper surface 91a, and the mold 92 has a curved surface 92a. In the present embodiment, a heating device is built in the mold 92, and the temperature of the heater 91 and the mold 92 is adjusted independently.

FIG. 3 is a schematic explanatory view showing a state at the time of sealing the glass material.
Next, as shown in FIG. 3, the molding surface 92 a of the mold 92 is brought into contact with the upper surface of the glass material 60 through the coat film 7, and the lower surface of the glass material 60 is brought into contact with the mounting portion 3. Is softened by heating to seal the LED element 2 on the mounting portion 3 (sealing step). The glass material 60 is heated to a temperature higher than the softening point of the glass material 60 and lower than the melting point of the coating film 7. At this time, since the melting point of the coating film 7 is lower than the sealing temperature of the glass material 60, the coating film 7 does not melt and adhere to the mold 92. That is, the melting point of the coating film 7 needs to be higher than the sealing temperature of the glass material 60. Although depending on the conditions, the glass material 60 can be sealed even if the temperature is lower than the softening point as long as the temperature is higher than the glass transition temperature, for example, the temperature near the yield point.

Further, although glass sealing is preferably performed at a low temperature as much as possible in order to reduce damage to the LED element 2, if the influence of this damage can be ignored, the glass can be pressed to about 10 ⁴ poise that can be pressed. The material 60 may be heated. The sealing temperature of the glass material 60 at this time is a temperature 100 ° C. higher than the softening point. In this case, the melting point of the coating film 7 must be higher than the softening point of the glass material 60 by 100 ° C. or more.

  In addition, when glass sealing is performed at a temperature equal to or higher than the crystal growth temperature of the light emitting layer of the LED element 2, the LED element 2 is broken, and the light emitting device 1 cannot be manufactured under these conditions. Thereby, the glass sealing process is performed at a temperature lower than the crystal growth temperature of the light emitting layer of the LED element 2. Therefore, if the melting point of the coating film 7 is higher than the crystal growth temperature of the light emitting layer of the LED element 2, it can surely cope with the glass sealing process.

  In this embodiment, the wiring board 3 and the glass material 60 are heated and sandwiched by the heater 91 and the mold 92, and hot pressing is performed in a nitrogen atmosphere. The glass material 60 may be heated before the placement on the wiring board 3 or may be heated after the placement. The upper surface of the glass material 60 is deformed along with the coating film 7 along the molding surface 92 a of the mold 92.

  Here, the hot pressing process may be performed in an inert atmosphere with respect to each member, and may be performed in, for example, a vacuum in addition to the nitrogen atmosphere. Through the above steps, the intermediate body 10 as shown in FIG. 3 in a state where the plurality of light emitting devices 1 are connected in the lateral direction is manufactured. Thereafter, the mold 92 is separated from the glass sealing portion 6 and the intermediate body 10 is taken out (separation step).

FIG. 4 is a plan view of the produced intermediate.
As shown in FIG. 4, the intermediate body 10 has a quadrangular shape in a plan view, and a curved upper surface 6 a is formed on the glass sealing portion 6 of each light emitting device 1, and each glass sealing portion 6 is a flat surface. 6c is continuously formed. Thereafter, the wiring substrate 3 integrated with the glass sealing portion 6 is set in a dicing device, and the light emitting device 1 is diced so as to divide the glass sealing portion 6 and the wiring substrate 3 into each LED element 2. Complete (division process).

  In the light emitting device 1 configured as described above, when a voltage is applied to the LED element 2 through the circuit pattern 4, blue light is emitted from the LED element 2. Blue light emitted from the LED element 2 is radiated to the outside through the upper surface 6 a of the glass sealing portion 6. At this time, since the upper surface 6a of the glass sealing portion 6 has a curved surface that protrudes upward, the glass sealing portion 6 for light emitted obliquely upward from the LED element 2 and the outside (air) Since the incident angle to the interface can be made within the critical angle, the light extraction efficiency is improved as compared with the case of a flat surface.

  Further, since the coating film 7 is interposed between the mold 92 and the glass material 60 during the sealing process of the LED element 2, when the mold 92 is separated from the glass material 60, the glass is attached to the mold 92. The material 60 does not adhere and the surface shape of the upper surface 6a is not deformed relative to the desired shape. In particular, in this embodiment, since the molding surface 92a of the mold 92 is curved and the glass material 60 tends to adhere to the concave portion of the molding surface 92a, the mold release property is dramatically improved by providing the coating film 7. Can be made. Therefore, the upper surface 6a of the glass sealing part 6 is made into an intended shape, and desired optical characteristics can be obtained.

  Furthermore, since the circuit pattern 4 is formed on the wiring board 3 after firing the ceramic, the position accuracy of the circuit pattern 4 can be increased, and the position accuracy of the LED element 2 electrically connected to the circuit pattern 4 is increased. Can also be high. As a result, the shift of the relative positional relationship between the mold 92 and each circuit pattern 4 of the wiring board 3 is minimized, and the center of the LED element 2 of the manufactured light emitting device 1 and the upper surface 6a of the glass sealing portion 6 is made. Deviation from the shaft can be suppressed. Note that the circuit pattern 4 may be formed before firing the ceramic of the wiring board 3 when the relative positional relationship between the LED element 2 and the upper surface 6a of the glass sealing portion 6 is not required. .

Moreover, since ZnO—B ₂ O ₃ —SiO ₂ —Nb ₂ O ₅ —Na ₂ O—Li ₂ O-based heat fusion glass was used as the glass sealing portion 6, the stability of the glass sealing portion 6 and The weather resistance can be improved. Therefore, even when the light-emitting device 1 is used for a long period of time in a harsh environment or the like, the deterioration of the glass sealing portion 6 is suppressed, and the decrease in light extraction efficiency with time is effectively suppressed. Can do. Furthermore, since the glass sealing part 6 has a high refractive index and a high transmittance characteristic, it is possible to realize both high reliability and high luminous efficiency.

  Further, since glass having a yield point (At) lower than the epitaxial growth temperature of the semiconductor layer of the LED element 2 is used as the glass sealing portion 6, the LED element 2 is not damaged by thermal damage during hot pressing, and the semiconductor. Processing sufficiently lower than the crystal growth temperature of the layer is possible.

  Furthermore, since the thermal expansion coefficients of the wiring board 3 and the glass sealing part 6 are equal, after bonding at high temperature, adhesion failure such as peeling and cracking is unlikely to occur even at room temperature or low temperature. Furthermore, glass generally has a characteristic that the coefficient of thermal expansion increases at a temperature equal to or higher than the Tg point. When glass sealing is performed at a temperature equal to or higher than the Tg point, the glass is not only lower than the Tg point but also higher than the Tg point. Considering the coefficient of thermal expansion at temperature is desirable for stable glass sealing. That is, the glass material which comprises the glass sealing part 6 is made into the equivalent thermal expansion coefficient which considered the thermal expansion coefficient including the thermal expansion coefficient in the temperature more than above-mentioned Tg point, and the thermal expansion coefficient of the wiring board 3. Thus, the internal stress that causes warping of the wiring board 3 can be reduced, and the shearing breakage of the glass can be prevented even though the adhesion between the wiring board 3 and the glass sealing portion 6 is obtained. Can do. Therefore, the size of the wiring substrate 3 and the glass sealing portion 6 can be increased to increase the quantity that can be collectively produced. Further, according to the inventor's confirmation, peeling and cracking did not occur even in the liquid phase thermal shock test 1000 cycles at −40 ° C. ← → 100 ° C. Furthermore, as a basic confirmation of joining a glass piece of 5 mm × 5 mm size to a ceramic substrate, an experiment was conducted with a combination of various thermal expansion coefficients for both glass and ceramic substrate. It was confirmed that bonding was possible without causing cracks when the ratio of thermal expansion coefficients of the members was 0.85 or more. Although it depends on the rigidity and size of the member, the fact that the coefficient of thermal expansion is the same indicates this range.

  Furthermore, since the thermal expansion coefficients of the LED element 2 and the glass sealing portion 6 are equal, the thermal expansion coefficient of the members including the wiring board 3 is equal, and even in the temperature difference between high temperature processing and normal temperature in glass sealing. The internal stress is extremely small, and stable workability without causing cracks can be obtained. Further, since the internal stress can be reduced, the impact resistance is improved and the glass-sealed LED having excellent reliability can be obtained.

  Since the front surface pattern 41 of the wiring board 3 is drawn out to the back surface pattern 42 by the via pattern 43, it is possible to manufacture without requiring any special measures such as glass entering an unnecessary portion or covering the electric terminal. The process can be simplified. Moreover, since the plate-shaped pre-sealing glass 11 can be collectively sealed with respect to the plurality of LED elements 2, the plurality of light emitting devices 1 can be easily mass-produced by dicer cutting. Since heat-bonded glass is processed in a high-viscosity state, it is not necessary to take sufficient measures against the flow of the sealing material like resin, and the external terminals are pulled out to the back surface without using via holes. If so, it can be used for mass production.

  In the above embodiment, the coating film 7 is formed on the plate-shaped glass material 60 and the upper surface of the glass material 60 is deformed together with the coating film 7. However, for example, as shown in FIG. Prior to the forming step, a pre-molding step in which the upper surface of the glass material 60 is curved in advance may be included, and the upper surface of the glass material 60 may be molded into a desired shape in advance. In this case, the coating film 7 is formed on the upper surface of the glass material 60 after the upper surface is molded. Thereby, the deformation amount of the upper surface of the glass material 60 at the time of sealing can be reduced, and the stress applied to the coat film 7 can be reduced. The molding in the pre-molding step may be performed by pouring the molten glass material 60 into a mold, or may be performed by pressing the plate-shaped glass material 60 with a mold.

  Further, for example, as shown in FIG. 6, before the sealing step, a housing portion forming step of forming the housing portion 61 of the LED element 2 is included on the lower surface of the glass material 60, and the lower surface of the glass material 60 is the LED element 2. You may make it contact with the heater 91, without contacting. The housing portion forming step may be before or after the coating film forming step, or may be performed simultaneously with the pre-molding step of curving the upper surface of the glass material 60 or after the pre-molding step. In this case, since the heat can be directly transferred from the heater 91 to the glass material 60 without using the LED element 2, the glass material 60 can be quickly heated. In this case, by previously deforming the upper surface of the glass material 60, the lower surface side of the glass material 60 may be preferentially heated to seal the LED element 2, and the mold 92 is not provided with a heating device. In both cases, the sealing process is not greatly affected. As shown in FIG. 6, when the upper surface of the glass material 60 has already been formed into the desired shape, it is not necessary to heat the upper surface side of the glass material 60, and the glass material 60 is not provided with a heating device in the mold 92. By lowering the temperature on the upper surface side of 60, the releasability of the glass material 60 with respect to the mold 92 can be further improved.

  Moreover, in the said embodiment, although what showed the several LED element 2 collectively sealed by the one glass material 60 formed in plate shape, as shown, for example in FIG. 7, each LED element 2 is shown. You may make it arrange | position the separate glass material 60 for every. In this case, the mold 92 comes into contact with the wiring board 3 between the LED elements 2. And as shown in FIG. 8, the exposed part 31 to which the glass sealing part 6 is not joined is formed in the upper surface outer periphery of the wiring board 3. As shown in FIG.

  Moreover, in the said embodiment, you may make the glass sealing part 6 contain the fluorescent substance 8 as shown, for example in FIG.7 and FIG.8. When excited by light emitted from the LED element 2, the phosphor 8 emits visible light having a longer wavelength than the light. If the LED element 2 emits blue light and the phosphor 8 emits yellow light, the light-emitting device 1 that emits white light can be obtained. Further, for example, the light emitting device 1 may be configured such that the LED element 2 emits ultraviolet light and emits white light using three kinds of phosphors 8 of blue, green, and red.

  Further, as shown in FIG. 9, the portion directly above the LED element 2 of the glass material 60 is pushed in by the mold 92 to form a recess 62 in the portion directly above the LED element 2, and the portion directly above the LED element 2 on the upper surface of the glass material 60. You may form the curved surface which dents. As a result, as shown in FIG. 10, the intermediate body in which the plurality of LED elements 2 are mounted on the wiring board 3 side by side in the vertical direction and the horizontal direction, and the concave portion 62 extending in the vertical direction is formed immediately above each LED element 2. 10 is produced.

  By dividing the intermediate body 10 by dicing, the light emitting device 1 as shown in FIG. 11 is manufactured. In FIG. 11, the side surface 6 c of the glass sealing portion 6 is formed flush with the wiring board 3. In the light emitting device 1, the light emitted from the LED element 2 is reflected by the upper surface 6 a having a curved surface, and light is extracted from the side surface 6 c of the glass sealing portion 6. In the light emitting device 1 of FIG. 11, by making the refractive index of the coating film 7 smaller than that of the glass sealing portion 6, the condition of total reflection on the upper surface 6 a is established, and the light extraction efficiency is improved. In the light emitting device 1, even if dirt is attached to the upper surface of the coating film 7, the light is totally reflected at the interface between the coating film 7 and the glass sealing portion 6, so that the light extraction efficiency does not decrease.

  Moreover, as shown in FIG. 12, you may make it form the recessed part 62 only in the part directly above the LED element 2. As shown in FIG. In FIG. 12, a flat surface 6 d having a circular shape in plan view is formed immediately above the LED element 2. The light emitting device 1 manufactured in this way uniformly emits the light emitted from the LED element 2 over the circumferential direction. Further, on the flat surface 6 d immediately above the LED element 2, light is transmitted in a direction substantially perpendicular to the wiring board 3 without being totally reflected.

  Moreover, as shown in FIG. 13, the light-emitting device 1 may have a plurality of LED elements 2. The light emitting device 1 of FIG. 13 forms a linear light source in which nine LED elements 2 are arranged in a line. In the light-emitting device 1 of FIG. 13, the upper surface 6a of the glass sealing part 6 is formed in the same cross section over the elongate direction, and is curving upwards about the width direction. As shown in FIG. 14, the light emitting device 1 can be manufactured by continuously forming a plurality of long light emitting devices 1 in the width direction in the intermediate body 10 and dicing in the width direction. . In the intermediate body 10 shown in FIG. 14, the concave portions 62 of the glass material 60 are formed at the divided portions of the light emitting devices 1.

  In addition, as shown in FIG. 15, the light emitting device 1 in which the upper surface 6 a of the glass sealing portion 6 on which the plurality of LED elements 2 are mounted is curved is mounted and used inside a housing 101 having an opening 102. The light source device 100 can be used. A reflection surface 103 that reflects light emitted from the light emitting device 1 is formed on the inner surface of the housing 101. In this case, it is desirable that the light emitting device 1 does not contain the phosphor 8 and the phosphor layer 104 containing the phosphor 8 is provided in the opening 102. Thereby, in the light emitting device 1, light can be efficiently extracted from the upper surface 6 a of the glass sealing portion 6, and the extracted light can be uniformly converted by the phosphor layer 104.

  Moreover, in the said embodiment, although what used sapphire and the board | substrate of GaN-type semiconductor material was illustrated, you may use a board | substrate for GaN, SiC, etc. other than sapphire. Further, the light emitting device 1 using the GaN-based semiconductor material as the LED element 2 has been described. However, the LED element is not limited to the GaN-based LED element 2, and other semiconductors such as ZnSe-based and SiC-based, for example. A light emitting element made of a material may be used. The emission wavelength of the LED element 2 is also arbitrary, and the LED element 2 may emit green light, yellow light, orange light, red light, or the like. Furthermore, the radiation rate from the upper surface of the LED element 2 is increased by performing chemical treatment on the upper surface of the LED element 2, and the amount of radiation emitted to the optical surface of the glass sealing portion 6 formed above the LED element 2 is increased. May be more.

Furthermore, the glass sealing portion 6 of the _{embodiment, B 2 O 3 -SiO 2 -Li} 2 O-Na 2 O-ZnO-Nb 2 O 5 system some of ZnO composition of heat melting glass Bi ₂ O ₃ may be used to further increase the refractive index of the heat-sealing glass. The refractive index of the heat-sealing glass is preferably 1.8. And when using the heat sealing | fusing glass whose refractive index is 1.8, using the light emitting element whose refractive index (nd) of a board | substrate is 1.8 or more improves the extraction efficiency of the light from a light emitting element. It is preferable because the luminous efficiency can be improved. Examples of the light emitting element having a refractive index of 1.8 or more include a light emitting element in which a GaN-based semiconductor is formed on a Ga ₂ O ₃ substrate, a GaN substrate, a SiC substrate, or the like.

Further, in the above embodiment shows what the wiring board 3 as a mounting portion made of alumina (Al 2 _{O 3),} may be formed from a ceramic other than alumina. Furthermore, it goes without saying that the mounting portion may be a metal lead frame. Here, as a ceramic substrate made of a high thermal conductivity material that is more excellent in thermal conductivity than alumina, for example, BeO (thermal expansion coefficient α: 7.6 × 10 ⁻⁶ / ° C., thermal conductivity: 250 W / (m · k) ) May be used. Even in the substrate made of BeO, good sealing properties can be obtained by the pre-sealing glass.

Furthermore, for example, a W—Cu substrate may be used as another highly heat conductive substrate. As a W-Cu substrate, a W90-Cu10 substrate (thermal expansion coefficient α: 6.5 × 10 ⁻⁶ / ° C., thermal conductivity: 180 W / (m · k)), a W85-Cu15 substrate (thermal expansion coefficient α: By using 7.2 × 10 ⁻⁶ / ° C. and thermal conductivity: 190 W / (m · k)), it is possible to impart high thermal conductivity while ensuring good bonding strength with the glass sealing portion. Therefore, it is possible to cope with an increase in the amount of light and output of the LED with a margin.

  Moreover, in the said embodiment, although the light-emitting device using an LED element as a light emitting element was demonstrated, a light emitting element is not limited to an LED element. Moreover, in the said embodiment, although the intermediate body 10 was produced, this was divided | segmented and the some light-emitting device 1 was obtained simultaneously, it was made to perform a sealing process for every light emitting element 1 one. Of course, other detailed structures and the like can be changed as appropriate.

DESCRIPTION OF SYMBOLS 1 Light-emitting device 2 LED element 3 Wiring board 3a Via hole 4 Circuit pattern 4a W layer 4b Ni layer 4c Au layer 4d Ag layer 5 Hollow part 6 Glass sealing part 6a Upper surface 6b Flat surface 6c Side surface 6d Flat surface 7 Coat film 8 Phosphor DESCRIPTION OF SYMBOLS 10 Intermediate body 28 Au bump 41 Surface pattern 42 Back surface pattern 43 Via pattern 44 External connection terminal 60 Glass material 61 Housing part 62 Recessed part 91 Heater 91a Upper surface 92 Mold 92a Molding surface 100 Light source device 101 Case 102 Opening 103 Reflecting surface 104 Fluorescence Body layer

Claims (7)

A method of manufacturing a light emitting device in which a plurality of light emitting elements on a mounting portion is sealed with a glass material,
A coating film forming step of forming a coating film of a non-glass material having a melting point higher than the softening point of the glass material on the upper surface of the glass material;
The molding surface of the mold is brought into contact with the upper surface of the glass material through the coat film, the lower surface of the glass material is brought into contact with the mounting portion, and the glass material is softened by heating to be on the mounting portion. a sealing step of sealing the plurality of light emitting elements, only including,
The sealing step includes a step of disposing an individual glass material for each of the light emitting elements of the plurality of light emitting elements, and the mold pushes the individual glass material and moves the upper surface of the individual glass material upward. And a step of contacting the mounting portion through the gap between the individual glass materials, and a curved surface that is convex.
When the sealing step is completed, the entire upper surface of the individual glass material is covered with the coat film, and an exposed portion where the glass material is not bonded is formed between the plurality of light emitting elements on the mounting portion. And the manufacturing method of the light-emitting device which seals the said upper surface by the glass sealing part which made the said upper surface the transmission surface of the emitted light of the said light-emitting element in which the deformation | transformation was prevented with respect to the expected shape .   The manufacturing method of the light-emitting device according to claim 1, wherein the coating film has a melting point higher by 100 ° C. or more than a softening point of the glass material.   The light emitting device manufacturing method according to claim 2, wherein the molding surface of the mold has a curved shape. Before the coating film forming step, including a pre-molding step of previously bending the upper surface of the glass material,
The manufacturing method of the light-emitting device according to claim 3, wherein in the coating film forming step, the coating film is formed on an upper surface of the curved glass material.   The method for manufacturing a light emitting device according to claim 4, wherein in the coating film forming step, the coating film is formed by vapor deposition.   The method for manufacturing a light emitting device according to claim 4, wherein in the coating film forming step, the coating film is formed by a sol-gel method. A method of manufacturing a light emitting device in which a light emitting element on a mounting portion is sealed with a glass material,
A coating film forming step of forming a coating film of a non-glass material having a melting point higher than the softening point of the glass material on the upper surface of the glass material;
The molding surface of the mold is brought into contact with the upper surface of the glass material through the coat film, the lower surface of the glass material is brought into contact with the mounting portion, and the glass material is softened by heating to be on the mounting portion. Sealing step for sealing the light emitting element,
In the sealing step, the portion directly above the light emitting element of the glass material is pushed in by the mold to form a recess in the portion directly above the light emitting element, so that the portion directly above the light emitting element on the upper surface of the glass material is Forming a concave curved surface;
When the sealing process is finished, the light emitting device is sealed by a glass sealing portion in which the upper surface is a reflection surface of the light emitted from the light emitting element, the deformation of the light emitting element being prevented from being expected. Manufacturing method.

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