JP2009130300A - Method of manufacturing light-emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a light-emitting device capable of increasing heat dissipation and dispensing with a flux cleaning step. <P>SOLUTION: A chip mounting step is performed to perform the eutectic junction of an LED chip 10 to a submount member 30 (Fig.1(a)), and then a submount mounting step is performed to perform the eutectic junction of the submount member 30 to a heat transfer plate 21 (Fig.1(b)). Then, a wiring board sticking step is performed to stick a wiring board 22 to one surface side of the heat transfer plate 21 (Fig.1(c)), a wire-bonding step is performed to connect the LED chip 10 to wiring patterns 23, 23 of the wiring board 22 via bonding wires 14, 14, a resin injection step is performed to inject a liquid-like sealing resin 50a that becomes one portion of a sealing section 50 (Fig.1(d)), an optical member sticking step is performed to stick an optical member 60 to the wiring board 22, and a color conversion member sticking step is performed to stick a color conversion member 70 to the wiring board 22 (Fig.1(f)). <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a method of manufacturing a light emitting device using an LED chip (light emitting diode chip).

  Conventionally, an LED chip and a fluorescent material that is excited by light emitted from the LED chip and emits light of a different emission color from the LED chip are combined with a light emitting color different from that of the LED chip. Research and development of light emitting devices that emit mixed color light are being conducted in various places. In addition, as this kind of light emitting device, for example, a device capable of obtaining white light (white light emission spectrum) by combining an LED chip that emits blue light or ultraviolet light and a phosphor is known. .

  Further, as an application example of this type of light emitting device, a lighting fixture using a plurality of light emitting devices capable of obtaining white light is also provided. However, in this type of lighting fixture, it is necessary to mount a plurality of light emitting devices on a circuit board and store them in the fixture main body, so that the thermal resistance from the light emitting portion of the LED chip to the fixture main body increases, Since it is necessary to limit the input power to the LED chip so that the junction temperature does not exceed the maximum junction temperature, the increase in light output is limited.

  On the other hand, in a light emitting device using an LED chip, there has been proposed a light emitting device that can efficiently dissipate heat generated by the LED chip in order to increase the light output (for example, Patent Document 1).

Here, in Patent Document 1, as shown in FIG. 10, a heat transfer plate 21 ′ made of a first heat conductive material and a heat transfer plate 21 that is formed in a plane size smaller than the heat transfer plate 21 ′. The submount member 30 'made of the second heat conductive material joined to one surface side by an adhesive and the submount member 30' joined to the opposite side of the heat transfer plate 21 'by an adhesive. LED chip 10 'and wiring patterns 23' and 23 'electrically connected to LED chip 10' are formed on one surface side of organic insulating base material 22a 'and submount member 30' is on the inside. A wiring board 22 ′ fixed to the one surface side of the heat transfer plate 21 ′, and a LED chip 10 ′ on the wiring board 22 ′. And the bonding wires 14 'and 14' are disposed so as to surround them. A sealing frame 50 ′ and a sealing portion 50 made of a translucent sealing resin containing a phosphor and sealing the LED chip 10 ′ and bonding wires 14 ′ and 14 ′ inside the sealing frame 40 ′. A light-emitting device equipped with 'has been proposed.
Japanese Patent Laying-Open No. 2006-5290 (paragraphs [0020], [0011]-[0016], and FIGS. 5 and 1)

  Incidentally, in the light emitting device having the configuration shown in FIG. 10, the submount member 30 ′ and the heat transfer plate 21 ′ are joined by an adhesive made of an organic material (for example, silicone resin, epoxy resin, etc.). And the thermal resistance from LED chip 10 'to heat-transfer plate 21' will become large, and thermal conductivity will fall.

  Therefore, in manufacturing the light emitting device having the configuration shown in FIG. 10, an adhesive that joins the LED chip 10 ′ and the submount member 30 ′, and an adhesive that joins the submount member 30 ′ and the heat transfer plate 21 ′. In consideration of the heat resistance temperature of the organic insulating base material 22a ′ of the wiring board 22 ′ fixed to the one surface side of the heat transfer plate 21 ′, a silver paste or a solder (SnAgCu) paste may be used. Although it is conceivable, a resin component such as flux remains as a residue on the wiring patterns 23 ′ and 23 ′, which may cause a connection failure such as a bonding failure. Therefore, it is necessary to add a flux cleaning process. .

  The present invention has been made in view of the above-described reasons, and an object of the present invention is to provide a method for manufacturing a light-emitting device that can improve heat dissipation and does not require a flux cleaning step.

  The invention according to claim 1 is a heat transfer plate made of the first heat conductive material, and a second heat conductive material formed in a plane size smaller than the heat transfer plate and joined to one surface side of the heat transfer plate. A submount member comprising: an LED chip bonded to the side opposite to the heat transfer plate side of the submount member; and a wiring pattern electrically connected to the LED chip on one surface side of the organic insulating substrate. A method for manufacturing a light emitting device, comprising: a wiring board formed on the one surface side of the heat transfer plate, in which a window hole in which a submount member is spaced apart and arranged inward is provided in the thickness direction. Before performing the wiring board fixing process for fixing the wiring board to the one surface side of the heat transfer plate, the chip mounting process for eutectic bonding the LED chip to the submount member and the submount member as the heat transfer plate. Equipped with submount for eutectic bonding Characterized in that it comprises a degree.

  According to the present invention, before performing the wiring board fixing process for fixing the wiring board to the one surface side of the heat transfer plate, the chip mounting process for eutectic bonding the LED chip to the submount member and the heat transfer to the submount member are performed. Since the submount mounting step for eutectic bonding to the plate is provided, the LED chip is eutectic bonded to the submount member in the chip mounting step, and the submount member is eutectic bonded to the heat transfer plate in the submount mounting step. Therefore, it is not necessary to use flux in the chip mounting process and the submount mounting process, and since the thermal resistance from the LED chip to the heat transfer plate is reduced, the heat dissipation can be improved and the flux cleaning process is unnecessary. Become.

The invention of claim 2 is characterized in that, in the invention of claim 1, the eutectic bonding in each of the chip mounting step and the submount mounting step is AuSu eutectic bonding in an N ₂ gas atmosphere.

  According to the present invention, the thermal resistance from the LED chip to the heat transfer plate can be further reduced as compared to the case where the eutectic bonding in the chip mounting step and the submount mounting step is SnAgCu eutectic bonding. .

  The invention of claim 1 has the effect that heat dissipation can be improved and a flux cleaning step is not required.

(Embodiment 1)
First, after describing the light-emitting device in the present embodiment with reference to FIGS. 2 to 6, a method for manufacturing the light-emitting device will be described with reference to FIG. 1.

  The light emitting device 1 according to the present embodiment includes the LED chip 10 and wiring patterns (conductor patterns) 23 and 23 for supplying power to the LED chip 10 on one surface side, and the LED chip 10 is mounted on the one surface side. The one surface of the mounting board 20 in the form of housing the LED chip 10 between the rectangular board-like mounting board 20 and the mounting board 20, which is an optical member for controlling the light distribution of the light emitted from the LED chip 10. The LED chip 10 and the LED chip 10 are electrically connected to the space surrounded by the dome-shaped optical member 60 made of a translucent material fixed to the side and the optical member 60 and the mounting substrate 20. A sealing portion 50 made of a translucent sealing material that seals a plurality of (two in this embodiment) bonding wires 14, and the sealing portion 50 and the optical member 60 that are emitted from the LED chip 10. It is formed of a phosphor and a translucent material that is excited by the transmitted light and emits light of a color different from the emission color of the LED chip 10, and on the one surface side of the mounting substrate 20 with the mounting substrate 20. And a dome-shaped color conversion member 70 disposed so as to surround the LED chip 10 and the like. Here, the color conversion member 70 is disposed so that an air layer 80 is formed between the light emitting surface 60 b of the optical member 60 on the one surface side of the mounting substrate 20. Further, the mounting substrate 20 has an annular dam portion 27 protruding outside the optical member 60 on the one surface so as to dam the sealing resin overflowing from the space when the optical member 60 is fixed to the mounting substrate 20. Has been.

  Here, when the light-emitting device 1 according to the present embodiment is used as a light source of a lighting fixture, for example, a fixture main body 100 (for example, a metal having high thermal conductivity such as Al or Cu) in the lighting fixture (FIG. 3). 5 and 6) and the mounting substrate 20, a resin sheet containing a filler made of a filler such as silica or alumina and having a low viscosity when heated (for example, an epoxy resin sheet highly filled with fused silica) What is necessary is just to join by the joining member 90 which consists of such an organic green sheet. Here, since the joining member 90 made of the resin sheet has electrical insulation properties, has high thermal conductivity, high fluidity during heating, and high adhesion to the uneven surface, the mounting substrate 20 is made of a metal instrument. Joining to the main body 100 via the joining member 90 (the joining member 90 is heated between the mounting substrate 20 and the instrument main body 100 and then the joining member 90 is heated to thereby heat the mounting substrate 20 and the instrument main body 100. Can be prevented from generating gaps between the bonding member 90 and the mounting substrate 20 and the instrument main body 100, thereby preventing an increase in thermal resistance and variations due to insufficient adhesion. The heat resistance from the LED chip 10 to the instrument body 100 can be reduced and heat dissipation is improved compared to the case where a rubber sheet-like heat dissipation sheet such as Sarcon (registered trademark) is sandwiched. Variations in Rutotomoni thermal resistance is reduced, since the temperature rise of the junction temperature of the LED chip 10 can be suppressed, it can increase the input power, thereby a high light output. In addition, when using the light-emitting device 1 in this embodiment as a light source of a lighting fixture, as shown in FIG. 5, the several light-emitting device 1 is mounted in the fixture main body 100, and the several light-emitting device 1 is connected in series. Or connect in parallel. In addition, the light emitting device 1 is not limited to the metal instrument body 100 but may be bonded to the metal member via the bonding member 90.

  The LED chip 10 is a GaN-based blue LED chip that emits blue light, and uses an n-type SiC substrate having a lattice constant and a crystal structure close to GaN as compared to a sapphire substrate and having conductivity as a crystal growth substrate. In addition, a light-emitting portion formed of a GaN-based compound semiconductor material and having a double-heterostructure, for example, on the main surface side of the SiC substrate is grown by an epitaxial growth method (for example, MOVPE method). The growth substrate is not limited to the SC substrate, and may be a GaN substrate, for example. Here, the LED chip 10 has an anode electrode (not shown) formed on one surface side (upper surface side in FIG. 2A) and a cathode electrode on the other surface side (lower surface side in FIG. 2A). Is formed. The cathode electrode and the anode electrode are composed of a laminated film of a Ni film and an Au film, but the material of the cathode electrode and the anode electrode is not particularly limited, and a material capable of obtaining good ohmic characteristics For example, Al or the like may be employed. Further, the structure of the LED chip 10 is not particularly limited. For example, a light emitting unit is formed by supporting a light emitting unit after epitaxially growing the light emitting unit or the like on the main surface side of the crystal growth substrate. Alternatively, a substrate obtained by removing the crystal growth substrate or the like may be used.

  The mounting board 20 is a rectangular plate-shaped heat transfer plate 21 made of a first heat conductive material (for example, Cu) and a planar size smaller than the heat transfer plate 21 and larger than the LED chip 10. A submount member 30 made of a second heat conductive material (for example, AlN) joined to one surface side (the upper surface side in FIG. 2A) of the hot plate 21, and an organic insulating base material 22a. The above-described wiring patterns 23 and 23 that are electrically connected to the LED chip 10 are formed on one surface side, and a window hole 24 in which the submount member 30 is spaced apart on the inner side is provided in the thickness direction. And a wiring board 22 composed of a rectangular flexible wiring board fixed to the one surface side of the heat transfer plate 21, and the LED chip on the opposite side of the submount member 30 from the heat transfer plate 21 side. 10 is contact It is. Therefore, the heat generated in the LED chip 10 is transferred to the submount member 30 and the heat transfer plate 21 without passing through the wiring board 22. Here, the wiring board 22 is fixed to the one surface side of the heat transfer plate 21 via, for example, a polyolefin-based fixing sheet 29 (see FIG. 3). An alignment mark 21c (see FIG. 3) for increasing the positioning accuracy of the submount member 30 is formed on the one surface of the heat transfer plate 21.

  In the present embodiment, Cu is employed as the first thermal conductive material of the heat transfer plate 21. However, the present invention is not limited to Cu, and for example, Al may be employed. In the present embodiment, the LED chip 10 is mounted on the heat transfer plate 21 so that the light emitting portion of the LED chip 10 is farther from the heat transfer plate 21 than the crystal growth substrate. The heat transfer plate 21 may be mounted so as to be closer to the heat transfer plate 21 than the crystal growth substrate. In consideration of light extraction efficiency, it is desirable to arrange the light emitting part on the side away from the heat transfer plate 21, but in this embodiment, the crystal growth substrate and the light emitting part have the same refractive index. Therefore, even if the light emitting part is arranged on the side close to the heat transfer plate 21, the light extraction loss does not become too large.

  The wiring board 22 is provided with a pair of wiring patterns 23 and 23 for supplying power to the LED chip 10 on one surface side of an organic insulating base material 22a made of a polyimide film. In addition, a protective layer 26 made of a white resist (resin) covering a portion of the organic insulating base material 22a where the wiring patterns 23, 23 are not formed is laminated. Therefore, the light emitted from the side surface of the LED chip 10 and incident on the surface of the protective layer 26 is reflected by the surface of the protective layer 26, thereby preventing the light emitted from the LED chip 10 from being absorbed by the wiring substrate 22. Thus, the light output can be improved by improving the light extraction efficiency to the outside. In addition, each wiring pattern 23 and 23 is formed in the outer periphery shape a little smaller than half of the outer periphery shape of the organic type insulating base material 22a. Further, as a material of the organic insulating base material 22a, FR4, FR5, paper phenol, or the like may be employed.

  The protective layer 26 is patterned so that two portions of the wiring patterns 23 and 23 are exposed in the vicinity of the window hole 24 of the wiring substrate 22 and one portion of the wiring patterns 23 and 23 is exposed in the peripheral portion of the wiring substrate 22. In each wiring pattern 23, 23, two rectangular portions exposed in the vicinity of the window hole 24 of the wiring substrate 22 constitute a terminal portion 23 a to which the bonding wire 14 is connected. The circular part exposed in the part constitutes the external connection electrode part 23b. In addition, the wiring patterns 23 and 23 of the wiring board 22 are comprised by the laminated film of Cu film | membrane, Ni film | membrane, and Au film | membrane. In addition, “+” is used for the external connection electrode portion 23b (the right external connection electrode portion 23b in FIG. 6) to which the anode electrode of the LED chip 10 is electrically connected, of the two external connection electrode portions 23b. Is displayed, and “−” is formed on the external connection electrode portion 23b (the left external connection electrode portion 23b in FIG. 6) to which the cathode electrode of the LED chip 10 is electrically connected. Therefore, the polarities of the external connection electrode portions 23b and 23b in the light emitting device 1 can be visually recognized, and erroneous connection can be prevented.

  The submount member 30 includes a stress relaxation function for relaxing stress acting on the LED chip 10 due to a difference in linear expansion coefficient between the LED chip 10 and the heat transfer plate 21, and heat generated by the LED chip 10. 21 has a heat conduction function of transferring heat to a wider range than the chip size of the LED chip 10. Therefore, in the light emitting device 1 of the present embodiment, since the LED chip 10 is mounted on the heat transfer plate 21 via the submount member 30, the heat generated in the LED chip 10 is transferred to the submount member 30 and the heat transfer plate 21. The heat acting on the LED chip 10 due to the difference in linear expansion coefficient between the LED chip 10 and the heat transfer plate 21 can be relieved.

  In the present embodiment, AlN having a relatively high thermal conductivity and insulation is used as the material of the submount member 30, and the LED chip 10 has the cathode electrode on the LED chip 10 side of the submount member 30. A conductive pattern 31 (see FIG. 3) provided on the surface and connected to the cathode electrode and electrically connected to one wiring pattern 23 via a bonding wire 14 made of a fine metal wire (for example, a gold fine wire, an aluminum fine wire, etc.) The anode electrode is electrically connected to the other wiring pattern 23 via the bonding wire 14. Here, the LED chip 10 and the submount member 30 are eutectic bonded by AuSn, and the submount member 30 and the heat transfer plate 21 are also eutectic bonded by AuSn, but in any eutectic bonding, A metal layer made of Au is formed in advance on the bonding surface.

  The material of the submount member 30 is not limited to AlN, and any material may be used as long as the linear expansion coefficient is relatively close to the material of the crystal growth substrate of the LED chip 10 and the heat conductivity is relatively high. For example, composite SiC, Si Cu, CuW, etc. may be employed. The submount member 30 has the above-described heat conduction function, and the area of the surface of the heat transfer plate 21 on the LED chip 10 side is sufficiently larger than the area of the surface of the LED chip 10 on the heat transfer plate 21 side. Larger is desirable.

  In the light emitting device 1 according to this embodiment, the thickness dimension of the submount member 30 is set so that the surface of the submount member 30 is farther from the heat transfer plate 21 than the surface of the protective layer 26 of the wiring board 22. In addition, light emitted from the LED chip 10 to the side can be prevented from being absorbed by the wiring board 22 through the inner peripheral surface of the window hole 24 of the wiring board 22. In addition, if a reflective film that reflects the light emitted from the LED chip 10 is formed around the bonding portion with the LED chip 10 on the surface of the submount member 30 on the side to which the LED chip 10 is bonded, the LED chip 10 is formed. It is possible to prevent the light radiated from the side surface from being absorbed by the submount member 30 and to further increase the light extraction efficiency to the outside. Here, the reflective film may be formed of, for example, a laminated film of a Ni film and an Ag film.

  As a translucent sealing material which is a material of the above-mentioned sealing part 50, although silicone resin is used, not only silicone resin but acrylic resin, glass, etc. may be used, for example.

  The optical member 60 is a molded product of a translucent material (for example, silicone resin, acrylic resin, glass, etc.) and is formed in a dome shape. Here, in this embodiment, since the optical member 60 is formed of a silicone resin molded product, the difference in refractive index and the linear expansion coefficient between the optical member 60 and the sealing portion 50 can be reduced.

  By the way, the optical member 60 has a light emitting surface 60b formed in a convex curved surface shape that does not totally reflect the light incident from the light incident surface 60a at the boundary between the light emitting surface 60b and the air layer 80 described above. 10 and the optical axis coincide with each other. Therefore, the light emitted from the LED chip 10 and incident on the light incident surface 60a of the optical member 60 can easily reach the color conversion member 70 without being totally reflected at the boundary between the light emitting surface 60b and the air layer 80, The total luminous flux can be increased. The light emitted from the side surface of the LED chip 10 propagates through the sealing portion 50, the optical member 60, and the air layer 80 to reach the color conversion member 70 to excite the phosphor of the color conversion member 70 or to the phosphor. Passes through the color conversion member 70 without colliding. Further, the optical member 60 is formed so that the thickness is uniform along the normal direction regardless of the position.

  The color conversion member 70 is a mixture of a translucent material such as a silicone resin and a particulate yellow phosphor that emits broad yellow light when excited by the blue light emitted from the LED chip 10. It is comprised by the molded article (that is, the color conversion member 70 contains fluorescent substance). Therefore, in the light emitting device 1 of the present embodiment, the blue light emitted from the LED chip 10 and the light emitted from the yellow phosphor are emitted through the outer surface 70b of the color conversion member 70, and white light is obtained. Can do. The translucent material used as the material of the color conversion member 70 is not limited to a silicone resin, but an organic / inorganic hybrid in which, for example, an acrylic resin, glass, an organic component and an inorganic component are mixed and combined at the nm level or the molecular level. Materials etc. may be adopted. Further, the phosphor mixed with the translucent material used as the material of the color conversion member 70 is not limited to the yellow phosphor. For example, white light can be obtained by mixing a red phosphor and a green phosphor.

  Here, the color conversion member 70 has an inner surface 70 a formed along the light emitting surface 60 b of the optical member 60. Therefore, the distance between the light emitting surface 60b and the inner surface 70a of the color conversion member 70 in the normal direction is a substantially constant value regardless of the position of the light emitting surface 60b of the optical member 60. In addition, the color conversion member 70 is shape | molded so that the thickness along a normal line direction may become uniform irrespective of a position. In addition, the color conversion member 70 may be fixed to the mounting substrate 20 with an end edge (periphery of the opening) on the mounting substrate 20 side using, for example, an adhesive (for example, silicone resin, epoxy resin).

  By the way, the above-mentioned lighting fixture using the light-emitting device 1 in the present embodiment as a light source has a wiring pattern 202 that defines the connection relationship of each light-emitting device 1 as shown in FIGS. A circuit board 200 formed on one surface side is provided. In the present embodiment, the plurality of light emitting devices 1 are connected in series. However, the connection relationship between the plurality of light emitting devices 1 is not particularly limited. For example, the light emitting devices 1 may be connected in parallel or connected in series. And parallel connection may be combined.

  The circuit board 200 is disposed in the shallow bottomed cylindrical instrument body 100 so as to be separated from the bottom wall 100a of the instrument body 100, and the circuit board 200 is disposed at a position corresponding to each light-emitting device 1 respectively. An aperture window 204 through which a part passes is formed. In addition, as a material of the insulating base material 201 of the circuit board 200, for example, a glass epoxy resin such as FR4 may be adopted, but not limited to a glass epoxy resin, for example, a polyimide resin, a phenol resin, or the like may be used. . Moreover, the shape of the instrument main body 100 is not specifically limited, For example, flat form may be sufficient.

  The circuit board 200 described above is provided with a wire insertion hole 206 through which a lead wire for power supply inserted through the insertion hole 100c formed in the bottom wall 100a of the instrument body 100 is inserted. A pair of electric wires inserted through 206 is electrically connected. Further, the circuit board 200 has a light reflecting layer 203 made of a white resist layer formed on the surface side opposite to the bottom wall 100 a side of the instrument body 100, and most of the wiring pattern 202 is the light reflecting layer 203. Covered by.

  In the circuit board 200, the opening size of each opening window 204 is set to be slightly larger than the planar size of the mounting substrate 20 in the light emitting device 1. In addition, in order to prevent an overvoltage from being applied to the LED chip 10 of the light emitting device 1, a surface mount type Zener diode 231 (see FIG. 6) for preventing overvoltage and a surface mount type ceramic are provided on the circuit board 200. A capacitor 232 (see FIG. 6) is mounted in the vicinity of each opening window 204.

  On the other hand, in the light emitting device 1, each external connection electrode portion 23 b of the mounting board 20 is electrically connected to the wiring pattern 202 of the circuit board 200 via the terminal board 210. Here, the terminal plate 210 forms a terminal piece 211 that is joined to the wiring pattern 202 by using solder or the like so as to overlap the wiring pattern 202 by bending one end of an elongated metal plate into an L shape. The other end portion is bent in a J shape to form a terminal piece 212 to be joined to the external connection electrode portion 23b using solder or the like so that the thickness direction thereof matches. It is possible to relieve the stress generated at the joint between the connection terminal 210, the external connection electrode portion 23b, and the wiring pattern 202 due to the difference in linear expansion coefficient with the circuit board 200. Connection reliability with the substrate 200 can be improved.

  Further, in the light emitting device 1 according to the present embodiment, as described above, when the optical member 60 is fixed to the mounting substrate 20 outside the optical member 60 on the one surface of the mounting substrate 20, the space (the optical member 60 and An annular (in the present embodiment, annular) dam portion 27 is provided to dam up the sealing resin overflowing from the space surrounded by the mounting substrate 20. Here, the dam portion 27 is formed of a white resist. In addition, the dam portion 27 extends inward from the inner peripheral surface of the dam portion 27 to center the center of the dam portion 27 and the central axis of the optical member 60 (four in this embodiment). The claw portions 27b are spaced apart in the circumferential direction and provided at equal intervals, and also serve as a positioning portion for the color conversion member 70. Here, the number of the claw portions 27b for centering is not limited to four, but it is desirable to provide at least three, and the sealing resin that can be stored between the dam portion 27 and the optical member 60 In order to increase the permissible amount, it is desirable that the width dimension of the centering claw portion 27b is small.

  Further, the color conversion member 70 has a notch 71 that engages with the weir 27 on the edge of the mounting substrate 20 side over the entire circumference. Therefore, in the light emitting device 1 according to the present embodiment, the positioning accuracy of the color conversion member 70 with respect to the mounting substrate 20 can be increased, and the interval between the color conversion member 70 and the optical member 60 can be shortened. The notch 71 is open on the edge side and the inner surface 70a side of the color conversion member 70.

  Further, in the wiring patterns 23 and 23 on the mounting board 20 described above, the portions exposed outside the color conversion member 70 constitute the above-described external connection electrode portions 23b and 23b.

  Hereinafter, the manufacturing method of the light-emitting device 1 of this embodiment is demonstrated, referring FIG.

First, a structure shown in FIG. 1A is obtained by performing a chip mounting process in which the LED chip 10 is eutectic bonded to the submount member 30. Here, the eutectic bonding in the chip mounting step is AuSu eutectic bonding in an N ₂ gas atmosphere, and an AuSn layer is previously metallized on the metal layer on the bonding surface of the submount member 30 by sputtering or the like. In addition, the submount member 30 is heated by a heating source (such as a heater) from the side opposite to the surface on which the conductor pattern 31 is provided, and the AuSn layer is melted at a temperature of 320 ° C. or higher, so The mount member 30 is brought close to each other and eutectic bonding is performed. The heating source and heating method in the chip mounting process are not particularly limited. Further, in the chip mounting step, the pre-formed AuSn solder is supplied onto the metal layer on the bonding surface of the submount member 30, and then the submount member 30 is moved from the side opposite to the surface on which the conductor pattern 31 is provided. The LED chip 10 and the submount member 30 may be brought close to each other and eutectic bonded in a state where the AuSn solder is melted at a temperature of 320 ° C. or higher by heating with a heat source.

After the above-described chip mounting process, a submount mounting process in which the submount member 30 is eutectic bonded to the heat transfer plate 21 is performed to obtain the structure shown in FIG. Here, the eutectic bonding in the submount mounting process is AuSu eutectic bonding in an N ₂ gas atmosphere, and a pre-formed AuSn solder is supplied onto the metal layer on the bonding surface of the heat transfer plate 21, and thereafter The submount member 30 and the heat transfer plate 21 are brought close to each other and the eutectic bonding is performed in a state where the AuSn solder is melted at a temperature of 320 ° C. or higher by heating the heat transfer plate 21 from the other surface side with a heating source (such as a heater) I try to let them. The heating source and heating method in the submount mounting process are not particularly limited. In the submount mounting step, an AuSn layer is metallized in advance on the metal layer on the bonding surface of the heat transfer plate 21 by sputtering or the like, and the heat transfer plate 21 is heated from the other surface side by a heating source. The submount member 30 and the heat transfer plate 21 may be brought close to each other and eutectic bonded in a state where the AuSn layer is melted at a temperature of 320 ° C. or higher.

  After the above chip mounting step and submount mounting step are completed, a wiring substrate fixing step for fixing the wiring substrate 22 to the one surface side of the heat transfer plate 21 is performed to obtain the structure shown in FIG. . Here, in the wiring board fixing step, the wiring board 22 and the heat transfer plate 21 are fixed using the polyolefin-based fixing sheet 29 (see FIG. 3), but the material of the fixing sheet 29 is particularly limited. It is not a thing.

  After the above-described wiring board fixing process, a wire bonding process for electrically connecting the LED chip 10 and the wiring patterns 23 and 23 of the wiring board 22 via the bonding wires 14 and 14 is performed. A liquid sealing resin (a part of the sealing portion 50 described above) is formed in the gap between the submount member 30 and the wiring substrate 22 from the resin injection hole 28 (see FIG. 3) formed continuously in the window hole 24. For example, a resin injecting step of injecting a liquid sealing resin (for example, silicone resin) 50a that becomes a part of the above-described sealing portion 50 into the inside of the dome-shaped optical member 60 while injecting a silicone resin) 50a. Then, as shown in FIG. 1D, the optical member 60 is made to face the mounting substrate 20. Here, in the resin injection step, an appropriate amount (quantitative amount) of the sealing resin 50a larger than the volume of the inner space of the optical member 60 is injected into the inside of the dome-shaped optical member 60.

  Thereafter, the optical member 60 and the mounting substrate 20 are brought close to each other, and the optical member 60 is positioned and then the liquid sealing resin 50a is cured as shown in FIG. An optical member fixing step for fixing the member 60 to the wiring board 22 is performed. Here, the sealing resin 50a accumulated in the space surrounded by the optical member 60, the weir 27, and the protective layer 26 on the one surface side of the mounting substrate 20 is cured to be the resin shown in FIG. Part (surplus part) 50b.

  Thereafter, a color conversion member fixing step for fixing the color conversion member 70 to the wiring substrate 22 with an adhesive (for example, silicone resin) is performed, thereby obtaining the light emitting device 1 having the structure shown in FIG.

  According to the method for manufacturing the light emitting device 1 of the present embodiment described above, the LED chip 10 is attached to the submount member 30 before performing the wiring board fixing step of fixing the wiring board 22 to the one surface side of the heat transfer plate 21. A chip mounting step for eutectic bonding and a submount mounting step for eutectic bonding of the submount member 30 to the heat transfer plate 21, so that the LED chip 10 is eutectic bonded to the submount member 30 in the chip mounting step. In addition, since the submount member 30 is eutectic bonded to the heat transfer plate 21 in the submount mounting process, it is not necessary to use flux in the chip mounting process and the submount mounting process. Therefore, the heat dissipation can be improved and the flux cleaning process is not necessary. In the above-described manufacturing method, an example in which the submount mounting process is performed after the chip mounting process and then the wiring board fixing process is described, but the order of the chip mounting process and the submount mounting process may be reversed. After performing the submount mounting process for eutectic bonding the submount member 30 to the heat transfer plate 21, the chip mounting process for eutectic bonding the LED chip 10 to the submount member 30 is performed, and then the wiring board fixing process is performed. You may make it perform.

Further, in the above manufacturing method, the eutectic bonding in each of the chip mounting process and the submount mounting process is AuSu eutectic bonding in an N ₂ gas atmosphere, and therefore, the eutectic bonding in the chip mounting process and the submount mounting process. Compared with the case of SnAgCu eutectic bonding, the thermal resistance from the LED chip 10 to the heat transfer plate 21 can be further reduced.

  Further, according to the above-described manufacturing method, it is difficult to generate a void in the sealing portion 50 during the manufacturing process, and it is possible to provide the light emitting device 1 with high reliability and high light output. Here, before the optical member 60 is brought close to the mounting substrate 20 (that is, in the stage of FIG. 1D), the sealing resin 50a injected into the gap between the submount member 30 and the wiring substrate 22 is cured. When the optical member 60 and the mounting substrate 20 are brought close to each other, voids can be easily removed, and voids can be prevented from being generated in the sealing portion 50, and disconnection of the bonding wires 14 and 14 and reduction in light output can be prevented. Further, in the light emitting device 1 described above, since the optical member 60 and the inner peripheral surface of the dam portion 27 are separated from each other, the sealing resin 50a overflows to the outside of the dam portion 27 and on the external connection electrode portions 23b and 23b. It is possible to prevent the external connection electrode portions 23b and 23b from causing poor soldering and the like.

  As shown in FIG. 7, the same material as the weir 27 (in this embodiment, between the annular weir 27 and each external connection electrode 23 b, 23 b on the one surface of the mounting substrate 20, If the arc-shaped resin stoppers 25, 25 formed of white resist are provided, it is possible to more reliably prevent the sealing resin 50a from adhering to the surfaces of the external connection electrode portions 23b, 23b during manufacturing. it can.

  The LED chip 10 has the anode electrode formed on the one surface side and the cathode electrode formed on the other surface side. The anode electrode and the cathode electrode are formed on the one surface side. In this case, both the anode electrode and the cathode electrode can be directly connected to the wiring patterns 23 and 23 via the bonding wires 14 and 14. Further, the number of LED chips 10 mounted on the submount member 30 is not limited to one, and may be plural.

(Embodiment 2)
The basic configuration of the light-emitting device 1 in the present embodiment is substantially the same as that in the first embodiment. As shown in FIG. 8, a plurality of pieces (only two are shown in FIG. LED chips 10 are mounted and connected in series, and an annular frame 40 made of a translucent material (for example, silicone resin, glass, etc.) surrounding the plurality of LED chips 10 is a submount. A frame body sealing portion 150 that is fixed on the member 30 and seals each LED chip 10 and each bonding wire 14 is provided inside the frame body 40, and the sealing portion 50 is the frame body 40 and the frame body sealing portion. The point which is formed so that 150 may be covered is different. In addition, the same code | symbol is attached | subjected to the component similar to Embodiment 1, and description is abbreviate | omitted.

  Hereinafter, a method for manufacturing the light emitting device 1 of the present embodiment will be described with reference to FIG. 9, but description of the same steps as those of the first embodiment will be omitted as appropriate.

  First, a structure shown in FIG. 9A is obtained by performing a chip mounting process in which a plurality of LED chips 10 are eutectic bonded to the submount member 30.

  Thereafter, a first wire bonding step of electrically connecting the plurality of LED chips 10 on the submount member 30 by the bonding wires 14 is performed to obtain the structure shown in FIG.

  Then, the structure shown in FIG. 9C is obtained by performing a submount mounting process in which the submount member 30 is eutectic bonded to the heat transfer plate 21.

  Next, a frame body fixing step of fixing the frame body 40 on the submount member 30 with an adhesive (for example, silicone resin) is performed. Subsequently, each LED chip 10 and each bonding wire 14 is placed inside the frame body 40. A frame body sealing step for forming a frame body sealing portion 150 is performed by filling and curing a light-transmitting sealing resin (for example, silicone resin) that seals the wiring board, and then the wiring substrate 22 is transmitted. By performing the wiring board fixing process for fixing to the one surface side of the hot plate 21, the structure shown in FIG. 9D is obtained.

  After the above-described wiring board fixing process, a second wire bonding process for electrically connecting the series circuit of the plurality of LED chips 10 and the wiring patterns 23 and 23 of the wiring board 22 via the bonding wires 14 and 14 is performed. By doing so, the structure shown in FIG.

  Subsequently, a part of the above-described sealing portion 50 is inserted into the gap between the submount member 30 and the wiring board 22 from the resin injection hole 28 (see FIG. 3) formed continuously in the window hole 24 of the wiring board 22. A liquid sealing resin (for example, a silicone resin) is injected, and a liquid sealing resin (for example, a silicone resin) to be a part of the sealing portion 50 is injected inside the dome-shaped optical member 60. After performing the resin injection step, the optical member 60 is made to face the mounting substrate 20, and then the optical member 60 and the mounting substrate 20 are brought close to each other, and after positioning the optical member 60, the liquid sealing resin is cured. Then, the sealing portion 50 is formed and the optical member fixing step for fixing the optical member 60 to the wiring board 22 is performed, thereby obtaining the structure shown in FIG.

  Thereafter, a color conversion member fixing step for fixing the color conversion member 70 to the wiring board 22 with an adhesive (for example, silicone resin) is performed, whereby the light emitting device 1 having the structure shown in FIG. 9G is obtained.

  According to the manufacturing method of the light emitting device 1 of the present embodiment described above, the wiring board fixing step of fixing the wiring board 22 to the one surface side of the heat transfer plate 21 as in the manufacturing method described in the first embodiment. Before performing the step, the chip mounting step of eutectic bonding the LED chip 10 to the submount member 30 and the submount mounting step of eutectic bonding the submount member 30 to the heat transfer plate 21 are provided. 10 is eutectic bonded to the submount member 30, and the submount member 30 is eutectic bonded to the heat transfer plate 21 in the submount mounting process. Therefore, it is necessary to use a flux in the chip mounting process and the submount mounting process. In addition, since the thermal resistance from the LED chip 10 to the heat transfer plate 21 is reduced, heat dissipation can be improved and Box cleaning process becomes unnecessary. In the above-described manufacturing method, an example in which the submount mounting process is performed after the chip mounting process and then the wiring board fixing process is described, but the order of the chip mounting process and the submount mounting process may be reversed. The chip mounting process is performed after the submount mounting process. After the chip mounting process, the first wire bonding process, the frame fixing process, the frame sealing process, the wiring board fixing process, and the second wire bonding are performed. The step, the optical member fixing step, and the color conversion member fixing step may be sequentially performed.

  Further, in the method for manufacturing the light emitting device 1 according to the first embodiment, the organic substance evaporated from the fixing sheet 29 when performing the wiring board fixing process for fixing the wiring board 22 to the one surface side of the heat transfer plate 21 is used. Although it is conceivable that the electrode is contaminated and bonding failure occurs in the wire bonding process, according to the manufacturing method of the light emitting device 1 of the present embodiment, the first wire bonding process is performed before the wiring board fixing process. Since the electrode of the LED chip 10 is connected to the bonding wire 14, it is possible to prevent the electrode of the LED chip 10 from being contaminated and to prevent the occurrence of bonding failure. In the second wire bonding process, a wire having a larger diameter than that in the first wire bonding process can be used, and a stronger ultrasonic vibration can be applied compared to the LED chip 10. Even if the wiring patterns 23 and 23 of the wiring board 22 and the conductor pattern of the submount member 30 are contaminated by the organic matter, it is possible to prevent a bonding failure from occurring.

  In the above-described embodiment, a blue LED chip whose emission color is blue is used as the LED chip 10 and a SiC substrate is used as the crystal growth substrate. However, a GaN substrate or sapphire is used instead of the SiC substrate. A substrate may be used, and when a SiC substrate or a GaN substrate is used, the crystal growth substrate has a higher thermal conductivity than the case where a sapphire substrate, which is an insulator, is used as the crystal growth substrate. The thermal resistance of the circuit board can be reduced. Moreover, the light radiated | emitted from LED chip 10 is not restricted to blue light, For example, red light, green light, purple light, ultraviolet light etc. may be sufficient. Moreover, although the above-mentioned embodiment demonstrated the manufacturing method of the light-emitting device 1 provided with the color conversion member 70, the color conversion member 70 does not necessarily need to be provided and a fluorescent substance layer is laminated | stacked as the LED chip 10. FIG. A structure having a different structure may be used.

FIG. 6 is a cross-sectional view of main processes for describing the method for manufacturing the light emitting device in the first embodiment. It is a schematic sectional drawing of the light-emitting device in the same as the above. It is a principal part schematic disassembled perspective view of the lighting fixture using the light-emitting device same as the above. It is a principal part schematic plan view of the light-emitting device same as the above. It is a principal part schematic disassembled perspective view of the lighting fixture using the light-emitting device same as the above. It is a principal part schematic perspective view of the lighting fixture using the light-emitting device in the same as the above. It is a principal part schematic disassembled perspective view of the lighting fixture using the light-emitting device of the other structural example same as the above. 6 is a schematic cross-sectional view of a light emitting device according to Embodiment 2. FIG. It is main process sectional drawing for demonstrating the manufacturing method of the light-emitting device same as the above. It is a schematic sectional drawing which shows the light-emitting device in a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light-emitting device 10 LED chip 14 Bonding wire 21 Heat-transfer plate 22 Wiring board 22a Organic insulation base material 23 Wiring pattern 24 Window hole 30 Submount member 50 Sealing part 50a Sealing resin 60 Optical member 70 Color conversion member

Claims (2)

  A heat transfer plate made of a first heat conductive material, a submount member made of a second heat conductive material formed in a plane size smaller than the heat transfer plate and joined to one surface side of the heat transfer plate, An LED chip bonded to the side opposite to the heat transfer plate side in the submount member, and a wiring pattern electrically connected to the LED chip formed on one surface side of the organic insulating base material and the submount member Is a manufacturing method of a light-emitting device, comprising: a wiring board fixed to the one surface side of the heat transfer plate, wherein a window hole that is spaced apart inwardly extends in the thickness direction. Before performing the wiring board fixing process for fixing to the one surface side of the heat transfer plate, the chip mounting process for eutectic bonding the LED chip to the submount member and the submount mounting for eutectic bonding the submount member to the heat transfer plate To have a process Method of manufacturing a light emitting device according to symptoms. _{2. The} method for manufacturing a light emitting device according to claim 1, wherein the eutectic bonding in each of the chip mounting step and the submount mounting step is AuSu eutectic bonding in an N ₂ gas atmosphere.

Images