JP5500927B2 - Method for manufacturing light emitting device - Google Patents

Description

  The present invention relates to a method for manufacturing a light emitting device using an LED element, and more particularly to a method for manufacturing a light emitting device that achieves high reliability by an airtight sealing structure.

  In recent years, light emitting devices using LED elements have become widespread, and the demand for in-vehicle devices, large-sized televisions, notebook PCs, and the like is rapidly expanding. Along with this, demands for long life, high reliability, energy saving, and the like for light emitting devices using LED elements have become strong, and new technology development for realizing this has been desired.

  Various new technical developments have been made to meet the above requirements. For example, Patent Document 1 discloses a submount substrate made of an inorganic material whose thermal expansion coefficient is close to that of an LED element in order to increase reliability against thermal expansion. A light emitting device is described in which the LED element mounted on is covered with a resin layer mixed with fluorescent particles, and a resin lens is adhered and sealed around the resin layer.

  Hereinafter, the light emitting device described in Patent Document 1 will be described with reference to FIG. In FIG. 8, a light emitting device 100 includes an LED 110, a submount substrate 120 on which the LED 110 is flip-chip mounted, a resin layer 130 containing fluorescent particles formed around the LED 110, and a support on which the submount substrate 120 is further fixed. 140 and a lens 150 that covers the LED 110 and the submount substrate 120 on the upper surface of the support 140. The submount substrate 120 and the support 140 are fixed via a eutectic layer, and the lens 150 is fixed to the support 140 by an ultraviolet curable adhesive layer 170.

The support 140 is provided with a through-hole electrode 141 penetrating therethrough. The submount substrate 120 is bonded to the through-hole electrode 141 with a wire 160 on the upper surface of the support 140 so that the submount substrate 120 is supported by the support 140. Are electrically connected to an output electrode 142 provided on the back surface of the substrate. The lens 150 has a curved surface in order to efficiently extract the light from the LED 110 to the outside.

  In the above configuration, when the light emitting device 100 uses, for example, a blue LED as the LED 110 and a wavelength conversion resin layer mixed with a YAG phosphor as the resin layer 130, the light emitting device 100 can be used as a pseudo white light emitting device.

  Further, in Patent Document 2, for the purpose of a thin package, an organic EL element mounted on a glass substrate is fixed to a flat glass with a glass lid formed by recessing by a sandblasting method or an etching method with an ultraviolet curable adhesive. A sealed organic EL panel is described.

  Further, Patent Document 3 describes a technique of metal-welding a glass lid to a ceramic container in which a small piezoelectric vibrator is mounted as a method for hermetically sealing a piezoelectric vibrator, although it is not a light emitting device. In the cited document 3, the container and the lid that are heated and welded and sealed in a pressure-contact state are held in a state where the container and the lid are maintained with a gap, and the container and the lid are separated from each other vertically. In this state, the metallized layers are melted by heating with a heater, and the two are brought into close contact with each other to perform welding and sealing.

Japanese Patent Laying-Open No. 2007-243076 (see FIG. 1) JP 2001-297878 A (see FIGS. 2 and 3) Japanese Patent No. 2613099 (see FIG. 2)

  As described above, the light emitting device shown in Patent Document 1 is such that the LED element is flip-chip mounted on an inorganic material sub-mount substrate whose thermal expansion coefficient is close to that of the LED element, and a resin layer is provided around the LED element. It is true that it has excellent temperature characteristics such as heat dissipation and thermal strain, and has a long life and high reliability by hermetically sealing with a lens, but it is still not sufficient.

  First, the lens for hermetic sealing is made of resin, and this resin lens is fixed using an ultraviolet curable adhesive, but the sealing structure using a resin lens or adhesive is as follows. Since the airtightness is weak and the airtightness is lost for a long time, it is difficult to maintain the expected long life and high reliability. In addition, since the submount substrate on which the LED element is mounted is bonded to the support that is the second substrate and then sealed by the lens, the structure becomes large, and it cannot meet the expectation of miniaturization and thinning. is there.

  In addition, the organic EL panel described in Patent Document 2 is formed by subjecting an organic EL element mounted on a transparent glass substrate for seeing through the display of the organic EL element to recess processing by a sandblasting method or an etching method on a flat glass. The performed glass lid is sealed with an ultraviolet curable adhesive and sealed, so that it has a thin package structure.

  In the case of the organic EL element as in Patent Document 2, since the organic EL element has low heat resistance, the organic EL element is sealed with an ultraviolet curable adhesive having a low bonding temperature. The sealing structure used is weak in airtightness, and in the case of sealing LED elements that require higher airtightness, it is necessary to perform intermetallic bonding such as eutectic bonding for fixing the glass lid and the inorganic material substrate. is there.

  Furthermore, regarding the technique of metal-welding a glass lid to a ceramic container as in Patent Document 3, both the ceramic container and the glass lid are heated by heating from the ceramic container side and the glass lid side. A method of melting the metallized layer was employed. Further, the 32nd to 34th lines in the right column of page 2 of the cited document 3 indicate that “in the embodiment, plate heaters are provided on both the upper and lower sides, but they may be provided only on one side”. Although there is a description, it is clear that the description is merely a mere writing from the viewpoint of heating the upper and lower ceramic containers and the glass lid separately with a space therebetween.

  However, a bonding method for intermetallic bonding such as eutectic bonding has not been established yet for the fixation of dissimilar materials with different thermal expansion coefficients such as this glass lid and inorganic material substrate. Is in the state of being considered. In other words, when a glass lid and an inorganic material substrate such as ceramic are bonded by eutectic bonding using AuSn-Au, after heating and bonding, a difference in contraction occurs due to the difference in thermal expansion coefficient between the two at the cooling stage. As a result, the joined body warps. It has been found that this warpage may cause a crack in the glass lid having a weak tensile force, and a joint portion of the glass lid may be partially broken, which causes a problem in reliability in sealing.

  An object of the present invention is to solve the above-mentioned problems, and in a method of manufacturing a light emitting device in which a glass lid and an inorganic material substrate are fixed by intermetallic bonding such as eutectic bonding, the heat of both during cooling after welding sealing. It is an object of the present invention to provide a method for manufacturing a light-emitting device with improved sealing reliability by reducing warpage of a bonded body caused by a difference in expansion coefficient and preventing cracking or partial chipping of a glass lid.

In order to achieve the above object, the manufacturing method of the present invention includes a light emitting element mounted on a ceramic substrate, and a concave portion formed by sandblasting or wet etching on a flat glass around the light emitting element mounting on the ceramic substrate. covered with a glass lid is transparent lid shape, in the manufacturing method of the light emitting device to be joined by metal deposition, metal deposition and the ceramic substrate and the glass lid, welded to the said ceramic substrate and a glass lid for metal deposition As an underlayer, an Au layer is formed on the ceramic substrate, and an AuSn layer is formed on the glass lid. A heating unit is provided on the ceramic substrate side, a cooling unit is provided on the glass lid side, and the ceramic substrate, the glass lid, cold in the state where the Au over AuSn eutectic bonding is in progress, the opposite side of the bonding surface of the glass lid the cooling means By being, and performing metal deposition by providing a temperature difference and the ceramic substrate and a glass lid.

  For joining the inorganic material substrate and the glass lid, a heating means may be provided only on the inorganic material substrate side, and a cooling means may be provided on the glass lid side.

  The light emitting element is preferably an LED element.

A storage jig made of a material having low thermal conductivity, having an opening recess shape and having a push-up mechanism from the bottom side, a heating lid made of a material having high thermal conductivity covering the opening recess of the storage jig, A step of using a heating device constituted by a heating means for heating the heating lid, and laminating and arranging the ceramic lid and the glass lid on which the light emitting element is mounted in the opening recess of the storage jig with the glass lid facing down A step of covering the opening recess of the storage jig with a heating lid, a step of pressing the ceramic substrate and the glass lid against the heating lid by the push-up mechanism, a step of heating the heating lid with a heating means, in a state in which Au over AuSn eutectic bonding between the ceramic substrate and the glass lid is in progress, the opposite side of the bonding surface of the glass lid was cooled by the cooling means, the temperature of the glass lid Characterized by a step of suppressing.

  As described above, in the manufacturing method of the present invention, in the light emitting device using the light emitting element in which the glass lid and the inorganic material substrate are fixed by intermetallic bonding such as eutectic bonding, heating for performing intermetallic bonding is performed with thermal conductivity. A light-emitting device that is performed only from a high inorganic material substrate side and reduces the warpage of the joined body due to the difference in thermal expansion coefficient at the cooling stage by reducing the thermal expansion of the glass lid, thereby improving the sealing reliability. Can be provided.

It is sectional drawing of the light-emitting device in 1st Embodiment of this invention. It is process drawing which shows the manufacturing process of the light-emitting device shown in FIG. It is process drawing which shows the process process of the glass cover used for the light-emitting device shown in FIG. It is process drawing which shows the process process of the glass cover used for the light-emitting device shown in FIG. It is process drawing which shows the manufacturing process of the light-emitting device shown in FIG. 1, and has shown the cross section of each element. It is sectional drawing of the sealing device which seals the light-emitting device shown in FIG. It is a characteristic table | surface which shows the characteristic and combination of the inorganic material board | substrate and glass cover in this invention. It is sectional drawing of the sealing device in 2nd Embodiment of this invention. It is sectional drawing of the light-emitting device in a prior art.

  Hereinafter, a method for manufacturing a light-emitting device according to an embodiment of the present invention will be described with reference to the drawings. 1 to 6 show a method for manufacturing a light-emitting device according to a first embodiment of the present invention. FIG. 1 is a cross-sectional view of the light-emitting device, and FIG. 2 is a process chart showing manufacturing steps of the light-emitting device shown in FIG. 3a and 3b are process diagrams showing the processing steps of the glass lid used in the light emitting device shown in FIG. 1, FIG. 4 is a process diagram showing the processing steps of the light emitting device shown in FIG. 1, and FIG. Sectional drawing of the sealing device which seals a light-emitting device, FIG. 6 is a characteristic table | surface which shows the characteristic and combination of the inorganic material board | substrate and glass cover in this invention.

  FIG. 1 is a cross-sectional view of a light emitting device 10, in which a wiring pattern 2 a is formed on the upper surface side of the inorganic material substrate 2, and an output electrode 2 b is formed on the back surface, and the wiring pattern 2 a on the upper surface side and the output electrode 2 b on the back surface are formed. Are connected by a through hole 2c. The LED 1 is flip-chip mounted (hereinafter abbreviated as FC mounting) on the wiring pattern 2 a of the inorganic material substrate 2, and the wavelength conversion layer 3 made of a resin layer mixed with fluorescent particles is coated around the LED 1. Yes. Further, the light emitting device 10 is completed by welding and sealing the glass lid 5 with the adhesive layer 4 formed around the mounting area of the LED element 1 on the upper surface side of the inorganic material substrate 2.

  Note that the adhesive layer 4 for joining the inorganic material substrate 2 and the glass lid 5 in the present embodiment includes a welding base layer 4 a (Au) formed on the inorganic material substrate 2 and a welding base layer 4 b ( AuSn) is formed by performing Au—Sn eutectic bonding under a pressure condition of 300 ° C., and the inorganic material substrate 2 and the glass lid 5 are welded and sealed by this eutectic bonding.

  Next, a manufacturing process of the light emitting device 10 will be described with reference to FIG. First, in the substrate process, an inorganic material substrate such as AIN (aluminum nitride), Al2O3 (aluminum oxide), Si (silicon) or the like is used as the inorganic material substrate 2, and the LED element 1 is FC mounted on the inorganic material substrate 2. An Au layer is formed as a welding underlayer 4a for bonding the AuSn electrode and the glass lid 5 for the purpose. Moreover, as an LED element process, Au bump 1a for FC mounting to LED element 1 is formed. In the FC mounting process, the wiring pattern 2a of the inorganic material substrate 2 and the Au bump 1a of the LED element 1 are positioned, and FC mounting is performed by Au—Sn eutectic bonding under a pressure condition of 300 ° C. In the wavelength conversion layer covering step, the phosphor cap formed by the phosphor resin-mixed silicon resin formed in the phosphor molding step is placed on the LED element 1 or the phosphor resin-mixed silicon resin is applied by a dispenser or squeegee. The wavelength conversion layer 3 is formed by directly covering the element 1.

In the glass lid manufacturing process, after a Ti, Pt, and Au base treatment is performed on the flat glass, a welding base layer forming step for forming the AuSn welding base layer 4b, and a processing mask is formed on the welding base layer 4b. A processing mask forming step, a glass lid processing step for forming a recess in the flat glass by sandblasting using the processing mask, and a mask removal step for removing the processing mask.
In the glass lid bonding step, the Au—Sn co-bonding is performed under a pressure condition of 300 ° C. by the welding underlayer 4a (Au) formed on the inorganic material substrate 2 and the welding underlayer 4b (AuSn) formed on the glass lid 5. The inorganic material substrate 2 and the glass lid 5 are welded together by crystal bonding. In addition, the glass lid bonding step was performed in vacuum or in an inert gas, whereby the sealed case was made in a vacuum or an inert gas atmosphere, and the LED element 1 and the organic resin silicon resin were formed. Deterioration of the wavelength conversion layer 3 can be prevented.

  The electrical characteristics and chromaticity of the completed light emitting device 10 are measured in the characteristic measurement process after the glass lid bonding process is completed, and ranking is performed according to the result.

  In the glass lid bonding step in the method for manufacturing the light emitting device, problems when melt sealing is performed by providing heating means on both the inorganic material substrate 2 and the glass lid 5 as in the prior art will be described. First, assuming that the expansion coefficients of both materials are relatively similar, the thermal conductivity of both is inorganic when AIN (aluminum nitride) is used for the inorganic material substrate 2 and borosilicate glass is used for the glass lid 5. While the material substrate 2 is 170 (W / m · k), the glass lid 5 is 0.816 (W / m · k), and the inorganic material substrate 2 is 200 times higher.

Next, the difference in heating method will be described.
As a bonding method in the AuSn eutectic of the LED using the inorganic material substrate and the glass lid this time, first, bonding by heating from the glass lid side on which the AuSn layer is formed was tried. However, while repeating the bonding, it was found that heating from the glass lid side could not be performed satisfactorily, followed by heating on both sides, and finally heating from the inorganic material substrate side, leading to good bonding. The mechanism is examined below. First, considering the heating of those with good and poor thermal conductivity, if only a part of the one with good thermal conductivity is heated, the heated heat will immediately diffuse to the unheated part and only part of it will be heated. Despite being heated, the overall temperature difference does not appear so much and it is heated. On the other hand, if only a part of the material with poor thermal conductivity is heated, the heated heat will not diffuse easily to the unheated part, resulting in a large temperature difference between the heated part and the other parts. .

  Therefore, in the heating from the glass lid side, only the surface layer opposite to the glass bonding surface is heated, and the heat does not reach the bonding surface within the bonding time, and the AuSn layer cannot be completely melted. It is thought that it was not possible. In addition, the temperature difference between the heated surface layer and the joint surface opposite to it increases, and the glass lid warps due to the difference in expansion, resulting in a state where the joint surface is not in surface contact. It seems to multiply. Subsequently, although both sides are heated, it can be said that heating the glass lid side is unsuitable for joining because the problem of warpage is considered to occur in the same way. In fact, when both sides are heated and joined, the warpage becomes large. By applying a load in a warped state, most of the items coming out of the apparatus after the joining were broken. When considering the bonding of the glass lid and the inorganic material substrate as described above, the heating from the glass lid side is not suitable for the bonding. I was able to get it. That is, by suppressing the heat conduction due to heating to the vicinity of the bonding surface of the glass lid, the warpage on the glass lid side can be minimized, and as a result, the warpage after bonding can be reduced and a good bonded state can be obtained.

  Next, the manufacturing process of the glass lid 5 will be described with reference to FIGS. 3A and 3B with reference to the process chart of the glass lid manufacturing shown in FIG. The figure shows the cross section of the element in each process of glass lid manufacture, FIG. 3a shows the glass lid processing process, and FIG. 3b shows each process after the glass lid completion process. First, Step A in FIG. 3A corresponds to the welding underlayer forming step in FIG. 2, and the AuSn welding underlayer 4 b is formed by patterning on the flat glass 50. Step B corresponds to the processing mask formation step of FIG. 2, and a mask 15 having an opening 15 a corresponding to the concave portion 5 a of the glass lid 5 is formed by patterning on the upper surface of the welding base layer 4 b. Next, the process C corresponds to the glass lid processing process of FIG. 2, and the concave portion 5 a is formed by sandblasting using the mask 15 and injecting the sand particles 25 at a high pressure. In addition, as for the internal shape of the recessed part 5a formed by the injection | emission of the sand particle 25, a roundness is formed in a corner and the satin pattern by an unevenness | corrugation is formed in the whole inner surface. The process D corresponds to the mask removing process of FIG. 2, and the mask 15 is removed from the glass lid after the recess processing is finished, as shown by the dotted line, to expose the welding underlayer 4b.

  As the mask at this time, a resin resist or a metal mask is used, and the shape of the recess 5a can be arbitrarily formed by adjusting the sand particle size, the spraying speed, and the spraying time. The recess processing in the step B is not limited to the sand blast processing method shown in the embodiment, and other methods can be performed by a sputter etching method, an ion etching method, a wet etching method using a hydrofluoric acid aqueous solution, or the like.

  Next, process X in FIG. 3b is a glass lid completion process after the mask removal process in FIG. 2, and process Y and process Z are separation and individualization processes used as necessary. In the process X, an AuSn layer as a welding base layer 4b is formed around the recess 5a of the glass lid 5. Next, in the process Y, it cut | disconnects using the cutting | disconnection means 39, such as a diamond blade and a laser scriber, and it isolate | separates into each glass cover 5 as shown to the process Z. In addition, in the next glass lid joining process, it may supply with the glass cover of the aggregate | assembly of the process X as needed, and may supply with the single glass cover of the process Z.

  Next, a method for manufacturing the light emitting device 10 will be described. FIG. 4 shows a manufacturing process of the light emitting device 10 and shows a cross section of each element. That is, the substrate process A corresponds to the substrate manufacturing process of FIG. 2, and the wiring pattern 2 a, the through hole 2 c, the output electrode 2 b on the inorganic material substrate 2, and Au as a welding base layer 4 a for bonding to the glass lid 5. A layer is formed. The element mounting process B corresponds to the FC mounting process and the wavelength conversion layer coating process of FIG. 2, the LED 1 is FC mounted on the wiring pattern 2 a of the inorganic material substrate 2 by the Au bump 1 a, and the wavelength conversion layer 3 is surrounded around the LED 1. As described above, the light emitting portion 10a is configured by covering and covering a phosphor cap created by silicon resin molding.

  The glass lid bonding step C corresponds to the glass lid bonding step of FIG. 2, and the inorganic material substrate 2 and the glass lid 5 shown in FIG. 3 b are overlapped, and the heater substrate 38 is provided only on the lower side of the inorganic material substrate 2. It is provided and metal welding is performed by heating. That is, the Au—Sn eutectic bonding is performed by the AuSn welding base layer 4 b formed on the bonding surface of the glass lid 5 created in FIG. 3 b and the Au welding base layer 4 a formed on the inorganic material substrate 2. By doing so, the adhesive layer 4 is formed as shown in step D, and the light emitting device 10 is hermetically sealed.

  In the glass lid bonding step, the heater substrate 38 is provided only on the lower side of the inorganic material substrate 2 and the heating state of each part when heated is examined. The inorganic material substrate 2 in contact with the heater substrate 38 and having high thermal conductivity. It is heated rapidly and uniformly to 300 ° C, which is the eutectic heating temperature. By this heating, the welding base layer 4a (Au) formed on the inorganic material substrate 2 and the welding base layer 4b (AuSn) formed on the glass lid 5 are heated to 280 ° C. which is the eutectic temperature, and further the glass lid 5 is welded. The vicinity of the formation surface of the base layer 4b is heated to a eutectic temperature of 280 ° C., whereby the inorganic material substrate 2 and the glass lid 5 are metal-welded by Au—Sn eutectic bonding. However, since the thermal conductivity of the glass lid is low in the portion of the glass lid 5 away from the surface on which the welded underlayer 4b is formed, heat from the inorganic material substrate 2 side is difficult to be transmitted and the temperature rise is reduced.

  Thus, by providing a temperature difference between the inorganic material substrate 2 and the glass lid 5 in the glass lid bonding step and heating, the thermal expansion on the glass lid side is reduced, so that the difference in thermal shrinkage is reduced. It is presumed that the occurrence of cracks and cracks can be suppressed. In addition, the mechanism that suppresses cracking and cracking is because warpage is reduced by reducing the thermal expansion on the glass side, the bonding surface is in surface contact, and it is possible to bond on the entire bonding margin on the glass side. It is given as. In fact, compared with the conventional double-sided heating method, the single-sided heating method of the present invention can solve the problems caused by the occurrence of cracks and cracks in the glass lid. Further, it has been found that the occurrence of cracks and cracks is more likely to occur when the recesses are formed on the flat plate than when the glass lid 5 is a flat plate. This is considered to be caused by a large shrinkage deformation due to the difference in thickness of the glass lid. Therefore, the effect of the present invention is further great when a glass lid subjected to such recess processing is used.

  The formation of the welding base layer in the glass lid bonding step will be described. As the welding base layer formed for metal welding the inorganic material substrate 2 and the glass lid 5, the Au layer of the welding base layer 4 a and the AuSn layer of the welding base layer 4 b are attached to the inorganic material substrate 2 and the glass lid 5. On the other hand, eutectic bonding is performed regardless of which one is formed. However, in the present invention, considering obtaining better bonding conditions, the following is obtained. In other words, since it is necessary to melt the welding base layer 4b on the glass lid 5 side by heating from the inorganic material substrate 2 side, the inorganic base substrate is made by making the welding base layer 4b on the glass lid side a good meltable AuSn layer. It can be confirmed that heat conduction from the second side to the glass lid side has been performed reliably.

  As described above, the glass lid bonding step C is further improved in reliability by hermetic sealing by performing the glass lid bonding step C in a vacuum or in an inert gas atmosphere.

  Next, the configuration of the sealing device for sealing the light emitting device 10 will be described with reference to FIG. FIG. 5 is a cross-sectional view of a sealing device that seals the light emitting device 10 shown in FIG. 1, and the sealing device 60 accommodates the inorganic material substrate 2 and the glass lid 5 that constitute the light emitting device 10. And a jig body 61 having a pin through hole 61b, a heating lid 62 detachably covering the storage recess 61a, a heating means 63 for heating the heating lid 62, and the pin through hole 61b of the jig body 61. A plurality of load pins 64 that are inserted in a possible manner and an elevating means 65 for elevating and lowering the load pins 64 are configured. In the present embodiment, a halogen lamp is used as the heating means 63, SUS303 is used as the material of the jig body 61 and the load pin 64, and a SiC plate having good heat conductivity is used as the heating lid 62. .

  Next, the sealing process of the light emitting device 10 by the sealing device 60 will be described. First, the glass recess 5 of the light emitting device 10 is placed on the lower side, the inorganic material substrate 2 is placed on the upper side, and the welding base layers 4a and 4b are put together in the housing recess 61a of the sealing device 60. Next, the heating lid 62 is placed on the housing recess 61 a of the jig body 61. In this state, the lifting / lowering means 65 is operated to raise the weighting pin 64, whereby the glass lid 5 and the inorganic material substrate 2 are raised toward the heating lid 62, and then a predetermined load is applied by abutting. Stop. In this state, the preparation for the sealing process is completed.

  Next, the sealing device 60 is evacuated. The heating lid 62 is heated by operating a halogen lamp as the heating means 63. The heating lid 62 made of a black SiC plate having good heat conduction absorbs the radiant heat of the halogen lamp well, and the temperature rises uniformly and quickly. Then, since the inorganic material substrate 2 abutted against the heating lid 62 has a high thermal conductivity, it is heated uniformly as the temperature of the heating lid 62 rises. When the inorganic material substrate 2 reaches a melting temperature of 300 ° C., the AuSn layer of the welding base layer 4b on the glass lid 5 side pressed against the inorganic material substrate 2 is melted, and eutectic bonding is performed. However, since the glass lid 5 has a low thermal conductivity, the vicinity of the portion where the welded underlayer 4b is formed is heated to the eutectic temperature of 280 ° C. However, the temperature rise of the glass lid as a whole is suppressed, so that the thermal expansion is small. Become. As a result, the difference in thermal shrinkage during cooling after the sealing step is reduced, and the occurrence of cracks and cracks in the glass lid can be suppressed.

  Next, the combination of the inorganic material substrate 2 and the glass lid 5 will be described. FIG. 6 is a characteristic table showing the characteristics and combinations of the inorganic material substrate 2 and the glass lid 5. Table 1 shows three types of the inorganic material substrate 2, and Table 3 shows three types of the glass lid 5. And the arrow provided between Table 2 has shown the combination. That is, Table 1 shows thermal conductivity and linear expansion coefficient for three kinds of substrate materials of the inorganic material substrate 2: AIN (aluminum nitride), Si (silicon), and Al2O3 (aluminum oxide). As the glass material of the glass lid 5, linear expansion coefficients are shown for three types of borosilicate glass (1), borosilicate glass (2), and borosilicate crown glass.

  Focusing on the linear expansion coefficient in Tables 1 and 2, the substrate material of the inorganic substrate 2 is AIN of 44 [× 10 −7 / ° C.], Si of 30 [× 10 −7 / ° C.], and Al 2 O 3 of 74 [× 10-7 / ° C], whereas borosilicate glass (1), which is a glass material of the glass lid 5, is 47 [× 10-7 / ° C], and borosilicate glass (2) is 33 [× 10-7 / ° C]. [° C.] and borosilicate crown glass is 74 [× 10 −7 / ° C.]. Looking at the relationship between each of these three types of materials, as indicated by the arrows, the AIN, which is the substrate material of the inorganic material substrate 2, is a glass material for the glass lid with respect to a linear expansion coefficient of 44 [× 10−7 / ° C.]. A certain borosilicate glass (1) shows an approximate value of 47 [× 10 −7 / ° C.], and the linear expansion coefficient of the substrate material Si is 30 [× 10 −7 / ° C.], The glass material borosilicate glass (2) approximates to 33 [× 10 −7 / ° C.], and similarly the linear expansion coefficient of the substrate material Al 2 O 3 is 74 [× 10 −7 / ° C.], but the glass material. The linear expansion coefficient of borosilicate crown glass is approximately 74 [× 10 −7 / ° C.].

  As described with reference to FIG. 2, when Au—Sn eutectic bonding is performed between the inorganic material substrate 2 and the glass lid 5, the temperature is high at 300 ° C. Therefore, the linear expansion coefficient between the inorganic material substrate 2 and the glass lid 5 is high. If they are different, troubles such as cracking and chipping occur due to the difference in the linear expansion coefficient. Therefore, it is necessary to select a material that approximates the linear expansion coefficient between the inorganic material substrate 2 and the glass lid 5 as much as possible. In this sense, it can be seen that combinations of materials indicated by arrows as shown in Tables 1 and 2 are desirable. Further, among the glass materials shown in Table 2, as a material available on the market, there is “VIDREX” (product name of Beatrex Co., Ltd.) as borosilicate glass (1), and “Pyrex” as borosilicate glass (2). (Registered trademark) "(trade name of Corning) has this characteristic.

  Next, a method for manufacturing the light emitting device 10 according to the second embodiment of the present invention will be described with reference to FIG. FIG. 7 is a cross-sectional view of a sealing device 70 for sealing the light emitting device 10 according to the second embodiment of the present invention. The basic configuration is the same as that of the sealing device 60 shown in FIG. A number is attached and the overlapping description is omitted.

The difference between the sealing device 70 and the sealing device 60 is that a cooling device 71 is provided in the elevating means 65. The sealing operation is the same as that of the sealing device 60 shown in FIG. 5 except that the load pin 64 is raised by the lifting means 65 and the inorganic material substrate 2 and the glass lid 5 are abutted against the heating lid 62. Then, the cooling device 71 is operated to cool the opposite side of the joint surface of the glass lid 5 via the load pin 64. As a result, in the state where the eutectic bonding between the inorganic material substrate 2 and the glass lid 5 is performed by heating the heating lid 62, the opposite side of the glass lid 5 is cooled, thereby suppressing the temperature rise of the glass lid 5.
As a result, the difference in thermal shrinkage during cooling of the entire glass lid is reduced, and the effect of suppressing the occurrence of cracks and cracks in the glass lid is increased.

  As mentioned above, although it described about the combination of blue LED and YAG fluorescent substance in embodiment, it is not limited to this, It is applicable also to the combination of near ultraviolet LED and each color fluorescent substance, etc., and the inorganic in this invention The sealing technique for the combination of the material substrate and the glass lid is also effective for sealing elements other than LEDs.

1 LED
DESCRIPTION OF SYMBOLS 1a Au bump 2 Inorganic material board | substrate 2a Wiring pattern 2b Output electrode 2c Through hole 3 Wavelength conversion layer 4 Adhesive layer 4a, 4b Welding base layer 5 Glass lid 5a Recess 10 Light emitting device 10a Light emitting part 15 Mask 15a Opening part 25 Sand particle 38 Heater Substrate 50 Flat glass 60, 70 Sealing device 61 Jig body 61a Storage recess 61b Pin through hole 62 Heating lid 63 Heating means 64 Load pin 65 Lifting means 71 Cooling device

Claims (2)

A light emitting element is mounted on a ceramic substrate, and a glass lid, which is a transparent lid with a U-shaped cross section in which a concave portion is formed by sandblasting or wet etching on a flat glass around the light emitting element mounting on the ceramic substrate, and is metal-welded In the method of manufacturing a light emitting device to be joined by the metal bonding, the metal welding between the ceramic substrate and the glass lid is performed by using an Au layer on the ceramic substrate as a welding base layer for metal welding the ceramic substrate and the glass lid. An AuSn layer is formed on the glass lid, a heating means is provided on the ceramic substrate side, a cooling means is provided on the glass lid side, and Au—AuSn eutectic bonding between the ceramic substrate and the glass lid is in progress . The surface of the glass lid opposite to the bonding surface is cooled by the cooling means, and the ceramic substrate and Method for manufacturing a light emitting device which is characterized in that the metal deposition by providing a temperature difference and lath lid. A storage jig made of a material having low thermal conductivity, having an opening recess shape and having a push-up mechanism from the bottom side, a heating lid made of a material having high thermal conductivity covering the opening recess of the storage jig, A step of using a heating device constituted by a heating means for heating the heating lid, and laminating and arranging the ceramic lid and the glass lid on which the light emitting element is mounted in the opening recess of the storage jig with the glass lid facing down A step of covering the opening recess of the storage jig with a heating lid, a step of pressing the ceramic substrate and the glass lid against the heating lid by the push-up mechanism, a step of heating the heating lid with a heating means, in a state in which Au over AuSn eutectic bonding between the ceramic substrate and the glass lid is in progress, the opposite side of the bonding surface of the glass lid was cooled by the cooling means, the temperature of the glass lid Method of manufacturing a light emitting device characterized by a step of suppressing.

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