JP2007194526A - Light-emitting module, and manufacturing method thereof - Google Patents

Light-emitting module, and manufacturing method thereof Download PDF

Info

Publication number
JP2007194526A
JP2007194526A JP2006013408A JP2006013408A JP2007194526A JP 2007194526 A JP2007194526 A JP 2007194526A JP 2006013408 A JP2006013408 A JP 2006013408A JP 2006013408 A JP2006013408 A JP 2006013408A JP 2007194526 A JP2007194526 A JP 2007194526A
Authority
JP
Japan
Prior art keywords
light emitting
lead frame
light
resin
emitting module
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP2006013408A
Other languages
Japanese (ja)
Inventor
Keiichi Nakao
Kimiharu Nishiyama
Etsuo Tsujimoto
Tetsuya Tsumura
恵一 中尾
哲也 津村
公治 西山
悦夫 辻本
Original Assignee
Matsushita Electric Ind Co Ltd
松下電器産業株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Matsushita Electric Ind Co Ltd, 松下電器産業株式会社 filed Critical Matsushita Electric Ind Co Ltd
Priority to JP2006013408A priority Critical patent/JP2007194526A/en
Publication of JP2007194526A publication Critical patent/JP2007194526A/en
Pending legal-status Critical Current

Links

Images

Abstract

When a ceramic substrate is used as a heat dissipation substrate for an LED, it is difficult to process the ceramic substrate.
A part of a lead frame 100, which is partly formed into a concave shape, is fixed with a light reflecting material 104, and the lead frame 100 is integrally molded with a metal plate 112 via a heat conducting resin 102, and then a light emitting element. 108 and the reflective ring 114 that can be retrofitted, the light emitted from the light emitting element 108 is reflected by the reflective ring 114, and the heat generated from the light emitting element 108 is transmitted from the lead frame 100 to the heat conducting resin. The light can be transmitted to the metal plate 112 via 102, and the light emission efficiency and heat dissipation efficiency of the light emitting module are improved.
[Selection] Figure 1

Description

  The present invention relates to a light emitting module used for a backlight of a display device having a backlight such as a liquid crystal television and a manufacturing method thereof.

  Conventionally, a cold cathode tube or the like has been used for a backlight of a liquid crystal television or the like, but in recent years, it has been proposed to mount a semiconductor light emitting element such as an LED or a laser on a heat dissipating substrate ( For example, see Patent Document 1).

  FIG. 9 is a cross-sectional view showing an example of a conventional light emitting module. In FIG. 9, the light emitting element 2 is mounted in the recess formed in the ceramic substrate 1. The plurality of ceramic substrates 1 are fixed on the heat sink 3. Further, the plurality of ceramic substrates 1 are electrically connected by a connection substrate 5 having a window portion 4. The light 6 emitted from the LED is emitted to the outside through the window portion 4 formed on the connection substrate 5. In FIG. 9, the wiring in the ceramic substrate 1 having the recesses and the connection substrate 5, the LED wiring, and the like are not shown. Such light emitting modules are used as backlights for liquid crystals and the like. However, since the ceramic element 1 is difficult to process and expensive, there has been a demand for a heat dissipation substrate that is cheaper and has excellent workability.

  On the other hand, the display device side including the liquid crystal TV is desired to expand the color display range. In response to such needs, white LEDs and the like have limitations, and in recent years, red (red), green (green), and blue (blue) single-color light emitting elements, and further purple, orange, red purple, cobalt Attempts have been made to expand the color display range (specifically, the CIE color system, etc.) by adding a special color light emitting element that emits a special color such as blue.

  When such a light emitting module as shown in FIG. 9 is used to meet such needs, while mounting each of these light emitting elements one by one in the concave portion of the ceramic substrate 1, a uniform mixed color (colored and white) is produced as a whole, It is necessary to adjust the color balance (for example, white balance described later). On the other hand, it is known that the luminous efficiency of solid light emitting devices such as LEDs decreases as the temperature rises. Furthermore, the degree of decrease in luminous efficiency with respect to temperature varies depending on the emission color of the LED. For this reason, for example, immediately after the liquid crystal TV is turned on, the LED portion is at room temperature (for example, 25 ° C.), so even if white balance is maintained, the temperature of the LED portion increases (for example, 40 ° C. → 50 ° C.). → 60 ° C.), for example, a phenomenon such as a reduction in red light emission efficiency may occur, and color reproducibility and backlight luminance may also change.

  On the other hand, as shown in FIG. 9, when the ceramic substrate 1 on which the light emitting elements 2 such as LEDs are mounted one by one is arranged on the heat radiating plate 3, it is advantageous from the heat radiating surface. It becomes difficult to produce a white color by mixing light (or to produce a white color having high color rendering properties by mixing RGB + special colors).

Therefore, it is possible to mount a large number of light-emitting elements that can handle higher brightness of the light-emitting elements (necessary to pass a large current) and multi-LEDs (mounting a plurality of LEDs with high density). There is a demand for light-emitting modules that have high processability and excellent heat dissipation.
JP 2004-311791 A

  However, the conventional configuration has a problem that the heat dissipation substrate on which the light emitting element is mounted is a ceramic substrate, which is disadvantageous in terms of workability and cost.

  The present invention solves the above-described conventional problems, and provides a light-emitting module with good processability and a method for manufacturing the same by using a lead frame, an insulator, a reflector, and a metal plate instead of a ceramic substrate. For the purpose.

  In order to solve the above problems, the present invention mounts a light emitting element such as an LED directly on a lead frame having high heat dissipation, and reflects light from the light emitting element by a ring-shaped reflecting material. The generated heat is transmitted from the lead frame to the heat radiating metal plate formed on the back surface through the heat conducting resin.

  The light emitting module obtained by the light emitting module of the present invention and the manufacturing method thereof can efficiently diffuse the heat generated by the light emitting elements such as LEDs and semiconductor lasers, and can effectively cool the light emitting elements such as LEDs.

(Embodiment 1)
Hereinafter, the light emitting module in Embodiment 1 of this invention is demonstrated using FIG. 1, FIG.

  1A and 1B are a top view and a cross-sectional view illustrating a light-emitting module according to Embodiment 1, in which FIG. 1A is a top view, and FIG. 1B and FIG. It is sectional drawing in arbitrary parts. In FIG. 1, 100 is a lead frame, 102 is a heat conducting resin, 104 is a light reflecting material, 106 is a dotted line, 108 is a light emitting element, and the light emitting element 108 is a light emitting element such as an LED or a laser. 110 is an arrow, 112 is a metal plate, and 114 is a reflection ring.

  In the first embodiment, a part of the lead plate 100 that has been processed into a concave shape in advance via the heat conducting resin 102 and further fixed by the light reflecting material 104 is insulated and fixed on the metal plate 112. It will be. The light emitting element 108 is mounted on a portion surrounded by the light reflecting material 104 formed in the concave shape of the lead frame 100. Then, light emitted from the light-emitting element 108 (corresponding to the arrow 110 in FIGS. 1B and 1C) is reflected forward by the reflection ring 114 to increase the light emission efficiency.

  First, description will be made with reference to FIG. In FIG. 1A, lead frames 100 are insulated from each other through a heat conductive resin 102 in a state of being divided into a plurality of parts. A dotted line 106 indicates the bending position of the lead frame 100. As the lead frame 100 is bent at the position of the dotted line 106 in FIG. 1A, as shown in FIG. 1B and FIG. It shows forming a recess. The light emitting element 108 is formed so as to straddle the plurality of lead frames 100 (note that the light emitting element 108 does not necessarily have to be mounted straddling). In addition, although it is a wire wire for mounting the light emitting element 108 (in the case of wire bonding connection), members such as conductive resin and solder (in the case of flip chip mounting) are not shown in FIG. .

  Note that portions of the plurality of lead frames 100 on which the light emitting elements 108 are mounted are fixed by a light reflecting material 104 instead of the heat conducting resin 102. Further, a ring-shaped reflection ring 114 is fixed around the portion of the lead frame 100 where the light emitting element 108 is mounted, and light emitted from the light emitting element 108 is reflected forward by the side surface of the reflection ring 114. The Rukoto.

  Next, description will be made with reference to FIG. FIG. 1B corresponds to a cross-sectional view at an arbitrary position in FIG. In FIG. 1 (B), a part of the lead frame 100 is recessed, and the bottom of the recessed part is formed of the lead frame 100 and a light reflecting material 104 that fills the gap. Then, the light emitted from the light emitting element 108 formed thereon is reflected by the reflecting ring 114 as shown by an arrow 110, and the luminous efficiency is increased.

  1C corresponds to a cross-sectional view at an arbitrary position in FIG. 1A as in FIG. 1B. As shown in FIG. 1C, the light emitted from the light emitting element 108 is reflected forward by the light reflecting material 104 and the reflecting ring 114 as indicated by an arrow 110. As shown in FIG. 1C, the light reflectance in the vicinity of the light emitting element 108 can be increased by forming the light reflecting material 104 between the lead frames 100. For this reason, even when a plurality of light emitting elements 108 each having a different emission color are mounted within the area surrounded by the reflection ring 114, the color mixture (or white formation by color mixture) can be facilitated.

  Next, a more detailed description will be given with reference to FIG. FIG. 2 is a top view showing the shape of the lead frame, and corresponds to a top view in which the light emitting element and the reflection ring are removed from FIG. As can be seen from FIG. 2, the lead frame 100 is also formed under the reflective ring 114 and the light emitting element 108. Further, it can be seen that the leading end portion of the lead frame 100 (or the vicinity of the portion where the light emitting element 108 is mounted) is fixed by the light reflecting material 104. As shown in FIG. 2, the light reflectance in the vicinity of the light emitting element 108 can be increased by forming the light reflecting material 104 between the lead frames 100. Therefore, even when a plurality of light emitting elements each having a different emission color are mounted within the area surrounded by the reflection ring 114, the color mixture (or white formation by color mixture) can be facilitated.

  Next, FIG. 3 illustrates how heat generated in the light emitting element 108 is diffused. FIG. 3 is a diagram showing how heat is diffused, in which the light emitting element 108 is omitted from FIG. In FIG. 3A, an arrow 110a is an arrow indicating a direction in which heat is transmitted from the light-emitting element 108 (not illustrated in FIG. 3A). 3A that heat generated in the light-emitting element 108 (not shown in FIG. 3A) is diffused along the lead frame 100 in the direction of the arrow 110a.

  FIG. 3B is a cross-sectional view illustrating a state of heat diffusion in the cross section of FIG. In FIG. 3, it can be seen that the heat generated in the light emitting element 108 diffuses along the shape of the lead frame 100 in the direction of the arrow 110 b in the lead frame 100 that is partially processed into a concave shape.

  FIG. 3C is a cross-sectional view illustrating a state of heat diffusion in the cross section of FIG. As shown in FIG. 3C, it can be seen that the heat transmitted to the lead frame 100 diffuses to the metal plate 112 through the heat conductive resin 102 as indicated by an arrow 110c.

As the heat conducting resin 102, it is desirable to use a resin in which a highly heat dissipating inorganic filler is dispersed in a curable resin. The inorganic filler has a substantially spherical shape, and its diameter is suitably from 0.1 to 100 microns (if it is less than 0.1 microns, it becomes difficult to disperse in the resin, and if it exceeds 100 microns, the heat conductive resin The thickness of 102 increases and affects the thermal diffusivity). Therefore, the amount of the inorganic filler in the heat conducting resin 102 is filled at a high concentration of 70 to 95% by weight in order to increase the thermal conductivity. In particular, in the present embodiment, the inorganic filler is a mixture of two types of Al 2 O 3 having an average particle size of 3 microns and an average particle size of 12 microns. By using the Al 2 O 3 of the large and small two types of particle size, it is possible to fill the Al 2 O 3 of small particle size in the gap Al 2 O 3 of large particle size, Al 2 O 3 90 wt% near Can be filled to a high concentration. As a result, the thermal conductivity of the heat conducting resin 102 is about 5 W / (m · K). The inorganic filler may include at least one selected from the group consisting of MgO, BN, SiO 2 , SiC, Si 3 N 4 , and AlN instead of Al 2 O 3 .

  The thermosetting insulating resin contains at least one kind of resin among epoxy resin, phenol resin and cyanate resin. These resins are excellent in heat resistance and electrical insulation. If the thickness of the heat conducting resin 102 is reduced, the heat generated in the light emitting element 108 attached to the lead frame 100 can be easily transferred to the metal plate 112, but conversely, the insulation breakdown voltage becomes a problem, and if it is too thick, the thermal resistance increases. In view of the withstand voltage and thermal resistance, the optimum thickness may be set to 50 microns or more and 1000 microns or less.

  As described above, in the first embodiment, a filler having good thermal conductivity is added as the heat conductive resin 102, and a filler having excellent light reflectivity is added to the light reflecting material 104. (Or the formation of white light by mixing different monochromatic lights).

  The color of the heat conductive resin 102 is desirably white (or colorless near white). This is because when the color is black, red, blue, or the like, it is difficult to reflect the light emitted from the light emitting element, which affects the light emission efficiency.

  The light reflecting material 104 may have a ring shape (or donut shape) to cover the entire recess formed by the lead frame 100. Moreover, the shape of the side surface of the light reflecting material 104 can be formed so as to become narrower toward the bottom, so that the light reflection efficiency is improved. In addition, it goes without saying that the light reflection direction can be optimized by making the side surfaces of the projections 110 radial, quadratic curves, cubic curves or the like.

(Embodiment 2)
Hereinafter, an example of the manufacturing method of the light emitting module in Embodiment 2 of this invention is demonstrated using FIGS. 4-5 is sectional drawing which shows an example of the manufacturing method of the light emitting module in Embodiment 2, 116 is transparent resin, 118 is a lens.

  FIG. 4A is a cross section of the lead frame 100, and a part of the lead frame 100 is stamped with a fine pattern on a mounting portion of a light emitting element with a mold or the like. FIG. 4B is a cross-sectional view showing a state in which a part of the lead frame 100 is fixed by the light reflecting material 104 and a part of the lead frame 100 is further bent. By fixing a part of the lead frame 100 with the light reflecting material 104, the deformation of the lead frame 100 can be prevented. In addition, as the light reflecting material 104, a resin material mainly including a white resin used for manufacturing an LED chip or the like (a white pigment is added as necessary) can be used. Moreover, since the member can be injection-molded, its productivity can be improved. At this time, a part of the lead frame 100 can be bent. This bending may be performed before or after the light reflecting material 104 is molded.

  Next, as shown in FIG. 4C, the lead frame 100 on which the light reflecting material 104 is formed and the metal plate 112 are integrally molded using the heat conductive resin 102. In this integral molding, a press device using a mold can be used. For example, the heat conductive resin 102 can be cured in a mold (not shown) by heating in a range of 80 ° C. to 200 ° C. (for example, 180 ° C.). In this way, the lead frame 100 on which the light reflecting material 104 is molded and the metal plate 112 are fixed by the heat conductive resin 102 by the heat conductive resin 102.

  Next, as shown in FIG. 4D, the light-emitting element 108 is mounted. Here, the light-emitting element 108 can be mounted by any method such as solder mounting, wire bonder mounting, or flip chip mounting.

  As shown in FIG. 4E, the reflecting ring 114 is mounted as indicated by an arrow 110. Here, by forming the protrusion 122 or the like on the reflection ring 114, the reflection ring 114 can be temporarily fixed to the heat conducting resin 102 or the lead frame 100. By mounting the reflective ring 114 after mounting the light emitting element 108 in this way, the mountability of the light emitting element 108 (mounting density is increased or mounting time is shortened) can be improved. As described above, since the reflective ring 114 can be set after the light emitting element 108 is mounted, the presence of the reflective ring 114 does not get in the way when the light emitting element 108 is mounted with high density. The reflective ring 114 can be fixed using an adhesive or the like, or may be temporarily fixed (to fill the resin in the next step).

  Next, as shown in FIG. 5A, a transparent resin 116a is poured into a portion surrounded by the reflection ring 114 and cured. As shown in FIG. 5A, the transparent resin 116a may be appropriately filled in the portion surrounded by the reflective ring 114. If necessary, the entire portion surrounded by the reflective ring 114 can be covered with the transparent resin 116a. In this case, as shown in FIG. 5B, it is desirable that the transparent resin 116c overflowing from the reflection ring 114 be received in the gap between the reflection ring 114 and the lead frame 100. In this way, the process can be stabilized.

  FIG. 5C is a cross-sectional view showing a state where the lens 118 is set on the transparent resin 116b. By receiving the overflowing transparent resin 116c in the gap with the lead frame 100 outside the reflection ring 114, the influence on the mountability of the lens 118 can be prevented. Further, the reflective ring 114 can be fixed in the recess formed by the lead frame 100 by the transparent resin 116c.

  Next, a more detailed description will be given with reference to FIG. FIG. 6 is a perspective view of the reflecting ring. In FIG. 6, the light emitting element 108 and the lead frame 100 mounted in the light reflecting ring are not shown. 120 is a groove, and 122 is a protrusion.

  As shown in FIG. 6A, by forming a groove 120 in a part of the reflective ring 114, when the transparent resin 116 is introduced using a dispenser or the like as indicated by an arrow 110a, an excess transparent resin is used. 116b can be stored outside (the portion described in FIGS. 5B and 5C) as indicated by an arrow 110b.

  Further, as shown in FIG. 6B, the protrusion 122 is formed on a part of the reflection ring 114, so that the alignment can be ensured when the lens 118 is set as indicated by the arrow 110c. If necessary, a concave portion (not shown) corresponding to the protrusion 122 can be formed in the lens 118.

  Note that the transparent resin 116 covering the light-emitting element 108 is preferably made of PMMA (polymethyl methacrylate) or a silicon-based transparent resin. When an epoxy resin is used here, it is necessary to add a UV inhibitor for preventing yellowing of the epoxy. This is because the LED is white, and further, the epoxy resin may be yellowed by blue light. Also, it is desirable to use a soft material such as silicon (having at least a lower hardness than epoxy). By using a soft (flexible) resin material, the light-emitting element 108 generates heat, and stress concentration at the connection portion between the light-emitting element 108 and the lead frame 100 when the thermal expansion occurs can be prevented. Similarly, stress concentration on the gold wire when the light emitting element 108 and the lead frame 100 are bonded and connected can be reduced (the gold wire is difficult to cut).

  Note that the light-emitting element mounted on the light-emitting module is preferably a light-emitting element having at least one different emission color. Color rendering properties can be improved by using a plurality of light emitting elements 108 having different light emission colors, and the color mixing properties of each other can be improved by mounting a plurality of these in a region surrounded by one light reflector. It is done. In addition, one or more emission colors of the plurality of light emitting elements 108 may be white. As described above, in the configuration of the second embodiment, by utilizing the excellent heat dissipation, even the light emitting element 108 whose light emission efficiency is easily affected by the temperature (or the degree of influence is different) is affected by the temperature. Hateful. Needless to say, even when the temperature of the light emitting module itself rises, the light emitting elements 108 can be individually controlled via the lead frame 100.

(Embodiment 3)
Hereinafter, an example of another method for manufacturing the light emitting module according to Embodiment 3 of the present invention will be described with reference to FIG. FIG. 7 is a cross-sectional view showing an example of a method for manufacturing a light emitting module in the third embodiment. The difference between the second embodiment and the third embodiment is that the side and bottom surfaces of the lead frame 100 are covered with the light reflecting material 104 (corresponding to the third embodiment), and only the side surface of the lead frame 100 is covered with the light reflecting material 104. Covering (corresponding to the second embodiment). As shown in the third embodiment, not only the side surface but also the lower surface of the lead frame 100 is covered with the light reflecting material 104, so that the deformation of the lead frame 100 can be prevented and a short circuit between the lead frame 100 and the metal plate 112 can be prevented. . This is because the lead frame 100 and the metal plate 112 are insulated by the multilayer of the light reflecting material 104 and the heat conductive resin 102.

  FIG. 7A is a cross-sectional view of the lead frame 100. Thus, by making the lead frame 100 planar, fine processing (or fine punching) by a press or the like is facilitated.

  Next, as shown in FIG. 7B, the back and front of the lead frame 100 are fixed by the light reflecting material 104. In this step, a technique such as injection molding can be used. In this way, deformation of the lead frame 100 can be prevented. At the same time, the wall can be formed. In addition, the light reflecting material 104 can be embedded in the back surface of the lead frame 100 (on the heat conducting resin 102 side). In this way, a part of the light reflecting material 104 can be formed in a gap between the lead frames 100 and a position between the lead frame 100 and the heat conducting resin 102 so as to avoid a position directly below the light emitting element 108. The reason why the light reflecting material 104 is not formed under the lead frame 100 directly under the light emitting element 108 is that the heat conduction from the lead frame 100 to the heat conducting resin 102 is not affected.

  Next, the heat conductive resin 102 is used to integrate with the metal plate 112. In this integral molding, a heat press or the like (not shown including a mold or the like) can be used.

  As shown in FIG. 7C, the lead frame 100 fixed with the light reflecting material 104 and the heat conducting resin 102a are integrated by first preliminarily molding the heat conducting resin 102a and the lead frame 100 (or pregel or pregel molding). Later, as shown by the arrow 110, the metal plate 112 may be pressed and heat-cured. Further, as shown in FIG. 8C described later, the heat conducting resin 102 may be set between the lead frame 100 and the metal plate 112 and pressed to cure the heat conducting resin 102. Thus, a structure as shown in FIG. 7D is formed, the light emitting element 108 is mounted, and then the reflection ring 114 is mounted. By mounting the reflective ring 114 after mounting the light emitting element 108 in this way, the mountability of the light emitting element 108 is not affected. Further, by forming a protrusion 122 or the like on a part of the reflecting ring 114, the reflecting ring 114 is temporarily fixed to the surface of the lead frame 100 or the heat conducting resin 102 (after temporarily fixing, and then covered with a transparent resin 116). Is also good).

  Alternatively, like the heat conducting resin 102b, a part may be exposed from the lead frame 100, and the reflective ring 114 may be positioned by this, or the reflective ring 114 may be temporarily fixed.

(Embodiment 4)
Hereinafter, an example of the manufacturing method of the light emitting module in Embodiment 4 of this invention is demonstrated using FIG.

  FIG. 8 is a cross-sectional view illustrating an example in which the thickness of the heat conducting resin is controlled using the shape of the light reflecting resin.

  FIG. 8A is a cross-sectional view showing an example of the shape of the light reflecting material 104 formed on the lead frame 100. The lower portion of the light reflecting material 104 is exposed downward from the lead frame 100, and the metal plate 112 is removed. The spacer portion 124 is to be fitted (and to control the thickness of the heat conductive resin 102 filled between the metal plate 112 and the lead frame 100).

  FIG. 8B is a cross-sectional view showing a state in which the light reflecting material 104 and the lead frame 100 are integrated. In FIG. 8B, a spacer portion 124 is formed under the lead frame 100 to fit the metal plate 112 (further controlling the thickness of the heat conducting resin 102 filled between the metal plate 112 and the lead frame 100). Has been.

  FIG. 8C is a cross-sectional view showing a state in which the lead frame 100 and the metal plate 112 are integrated using the heat conductive resin 102. In the direction indicated by the arrow 110, the heat conducting resin 102 is set between the lead frame 100 partially fixed by the light reflecting material 104 using a mold (not shown) and the metal plate 112. Is cured and integrally molded.

  FIG. 8D is a cross-sectional view after being integrally molded, and the gap between the metal plate 112 and the lead frame 100 is made constant by the spacer portion 124 formed by the light reflecting material 104, and the heat conductive resin 102 is filled therebetween. Is done. By filling the heat conductive resin 102 between the metal plate 112 and the spacer portion 124 in this way, even when the shape of the metal plate 112 is a quadrangle, the heat conductive resin 102 can be circulated to every corner of the square. Therefore, the efficiency of heat conduction from the lead frame 100 to the metal plate 112 through the heat conducting resin 102 can be increased. Then, the reflecting portion 114 is set in the direction of the arrow 110.

  Here, by covering not only the side surface of the lead frame 100 but also the back surface thereof with a part of the light reflecting material 104, the fixing of the lead frame 100 can be ensured and the short circuit between the lead frame 100 and the metal plate 112 can be prevented. The heat conducting resin 102 can be made thin.

  Further, by forming a part of the light reflecting material 104 as the spacer portion 124 that holds the gap between the lead frame 100 and the metal plate 112, the molding accuracy of the heat conductive resin 102 between the lead frame 100 and the metal plate 112 is improved. In addition, it is possible to ensure that the heat conducting resin 102 wraps around in details and gaps.

Next, the insulating material will be described in more detail. The heat conducting resin 102 is composed of a filler and a resin. The filler is preferably an inorganic filler. The inorganic filler desirably contains at least one selected from the group consisting of Al 2 O 3 , MgO, BN, SiO 2 , SiC, Si 3 N 4 , and AlN. When an inorganic filler is used, heat dissipation can be improved, but when using MgO in particular, the linear thermal expansion coefficient can be increased. Further, when SiO 2 is used, the dielectric constant can be reduced, and when BN is used, the linear thermal expansion coefficient can be reduced. In this way, the heat conductive resin 102 having a thermal conductivity of 1 W / (m · K) or more and 20 W / (m · K) or less can be formed. In addition, when heat conductivity is less than 1 W / (m * K), it influences the heat dissipation of a light emitting module. Moreover, when it is going to make thermal conductivity higher than 20 W / (m * K), it is necessary to increase the amount of fillers and may affect the workability at the time of a press.

  The resin is preferably a thermosetting resin, and specifically includes at least one selected from the group consisting of an epoxy resin, a phenol resin, and an isocyanate resin.

The inorganic filler has a substantially spherical shape and a diameter of 0.1 to 100 μm. The smaller the particle size, the better the filling rate into the resin. Therefore, the filling amount (or content) of the inorganic filler in the heat conducting resin 102 is filled at a high concentration of 70 to 95% by weight in order to increase the heat conductivity. In particular, in the present embodiment, the inorganic filler is a mixture of two types of Al 2 O 3 having an average particle size of 3 microns and an average particle size of 12 microns. By using the Al 2 O 3 of the large and small two types of particle size, it is possible to fill the Al 2 O 3 of small particle size in the gap Al 2 O 3 of large particle size, Al 2 O 3 90 wt% near Can be filled to a high concentration. As a result, the thermal conductivity of the heat conducting resin 102 is about 5 W / (m · K). In addition, when the filling rate of a filler is less than 70 weight%, thermal conductivity may fall. Further, if the filling rate (or content rate) of the filler exceeds 95% by weight, the moldability of the unheated heat conducting resin 102 may be affected, and the adhesiveness between the heat conducting resin 102 and the lead frame 100 (for example, embedded) Case or when pasted on the surface).

  The thermosetting insulating resin contains at least one kind of resin among epoxy resin, phenol resin and cyanate resin. These resins are excellent in heat resistance and electrical insulation.

  If the thickness of the insulator made of the heat conducting resin 102 is reduced, the heat generated in the light emitting element 108 attached to the lead frame 100 can be easily transferred to the metal plate 112, but conversely, the withstand voltage becomes a problem. Since the thermal resistance increases, the optimum thickness may be set in consideration of the withstand voltage and the thermal resistance.

  Next, the material of the lead frame 100 will be described. The lead frame is preferably made mainly of copper. This is because copper has both excellent thermal conductivity and electrical conductivity. In order to improve the workability and thermal conductivity as a lead frame, the copper material used as the lead frame 100 is selected from a group of at least Sn, Zr, Ni, Si, Zn, P, Fe, etc. other than copper. It is desirable to use an alloy comprising at least one material. For example, an alloy (hereinafter referred to as Cu + Sn) in which Cu is a main component and Sn is added thereto can be used. In the case of a Cu + Sn alloy, for example, by adding Sn to 0.1 wt% or more and less than 0.15 wt%, the softening temperature can be increased to 400 ° C. For comparison, the lead frame 100 was made using Sn-free copper (Cu> 99.96 wt%). Although the conductivity was low, distortion was generated especially in the formed heat-radiating substrate at the formation part of the convex part 110. There was a case. Therefore, when a detailed examination was made, the softening point of the material was as low as about 200 ° C., so that the reliability (repetition of heat generation / cooling, etc.) at the time of subsequent component mounting (soldering) or after mounting of the light-emitting element 108 was improved. It was expected that it could be deformed. On the other hand, when a material of Cu + Sn> 99.96 wt% was used, it was not particularly affected by the heat generated by various mounted components or a plurality of LEDs. There was no effect on solderability and die bondability. Therefore, when the softening point of this material was measured, it was found to be 400 ° C. Thus, it is desirable to add some elements mainly composed of copper. In the case of Zr as an element added to copper, a range of 0.015 wt% or more and 0.15 wt% is desirable. When the amount added is less than 0.015 wt%, the effect of increasing the softening temperature may be small. On the other hand, if the amount added is more than 0.15 wt%, the electrical characteristics may be affected. Also, the softening temperature can be increased by adding Ni, Si, Zn, P or the like. In this case, Ni is preferably 0.1 wt% or more and less than 5 wt%, Si is 0.01 wt% or more and 2 wt% or less, Zn is 0.1 wt% or more and less than 5 wt%, and P is preferably 0.005 wt% or more and less than 0.1 wt%. . And these elements can make the softening point of a copper raw material high by adding single or multiple in this range. In addition, when there are few addition amounts than the ratio described here, the softening point raise effect may be low. Moreover, when there are more than the ratio described here, there exists a possibility of affecting the electrical conductivity. Similarly, in the case of Fe, 0.1 wt% or more and 5 wt% or less is desirable, and in the case of Cr, 0.05 wt% or more and 1 wt% or less are desirable. These elements are the same as those described above.

The tensile strength of the copper alloy used for the lead frame 100 is desirably 600 N / mm 2 or less. In the case of a material having a tensile strength exceeding 600 N / mm 2 , the workability of the lead frame 100 may be affected. Further, such a material having a high tensile strength tends to increase its electric resistance, so that it may not be suitable for high current applications such as LEDs used in the first embodiment. On the other hand, by setting the tensile strength to 600 N / mm 2 or less (and if the lead frame 100 requires fine and complicated processing, desirably 400 N / mm 2 or less), the springback (pressure even if bent to the required angle) If it is removed, the occurrence of rebound by reaction force) can be suppressed, and the formation accuracy of the recess 114 can be improved. As described above, as the lead frame material, the electrical conductivity can be lowered by using Cu as a main component, the workability can be improved by further softening, and the heat dissipation effect by the lead frame 100 can also be enhanced. The tensile strength of the copper alloy used for the lead frame 100 is desirably 10 N / mm 2 or more. This is because the copper alloy used for the lead frame 100 needs to have a strength higher than the tensile strength (about 30 to 70 N / mm 2 ) of general lead-free solder. When the tensile strength of the copper alloy used for the lead frame 100 is less than 10 N / mm 2 , when the light emitting element 108, the driving semiconductor component, the chip component, etc. are soldered and mounted on the lead frame 100, the lead frame is not the solder portion. There is a possibility of cohesive failure at 100 parts.

  It should be noted that the solder layer so as to improve the solderability in advance on the surface of the lead frame 100 exposed from the heat conductive resin 102 (the light emitting element 108 or a mounting surface of a control IC or chip component (not shown)). By forming the tin layer, it is possible to improve the component mounting property to the lead frame 100 and to prevent the wiring from being rusted because the heat capacity is large and the soldering is difficult compared with the glass epoxy substrate or the like. It is desirable that no solder layer be formed on the surface of the lead frame 100 that is in contact with the heat conductive resin 102 (or the embedded surface). When a solder layer or a tin layer is formed on the surface in contact with the heat conducting resin 102 in this way, this layer becomes soft during soldering, which may affect the adhesion (or bond strength) between the lead frame 100 and the heat conducting resin 102. . 1 and 2, the solder layer and the tin layer are not shown.

The metal metal plate 112 is made of aluminum, copper, or an alloy containing them as a main component, which has good thermal conductivity. In particular, in the present embodiment, the thickness of the metal plate 112 is 1 mm, but the thickness can be designed according to the specifications of a backlight or the like (in addition, when the thickness of the metal plate 112 is 0.1 mm or less, heat dissipation and (If the thickness of the metal plate 112 exceeds 50 mm, it is disadvantageous in terms of weight.) The metal plate 112 is not only a plate-like material, but also has a fin portion (or uneven portion) to increase the surface area on the surface opposite to the surface on which the insulators are laminated in order to further improve heat dissipation. You may do it. The linear expansion coefficient is 8 × 10 −6 / ° C. to 20 × 10 −6 / ° C. By bringing the coefficient of linear expansion close to the linear expansion coefficient of the metal plate 112 and the light emitting element 108, warpage and distortion of the entire substrate can be reduced. In addition, when these components are surface-mounted, matching the thermal expansion coefficients with each other is also important in terms of reliability. Further, the metal plate 112 can be screwed to another heat radiating plate (not shown).

  As the lead frame 100, a metal plate mainly made of copper, at least a part of which is punched in advance, can be used. The thickness of the lead frame 100 is desirably 0.1 mm or greater and 1.0 mm or less (more desirably 0.3 mm or greater and 0.5 mm or less). This is because a large current (for example, 30 A to 150 A, which may further increase depending on the number of LEDs to be driven) is required to control the LEDs. Moreover, when the thickness of the lead frame 100 is less than 0.10 mm, pressing may be difficult. If the thickness of the lead frame 100 exceeds 1 mm, pattern miniaturization may be affected at the time of punching with a press. Here, it is not desirable to use a copper foil (for example, a thickness of 10 to 50 microns) instead of the lead frame 100. In the case of the present invention, the heat generated in the LED is widely diffused through the lead frame 100. Therefore, the greater the thickness of the lead frame 100, the more effective the thermal diffusion through the lead frame 100. On the other hand, when a copper foil is used instead of the lead frame 100, the thickness of the copper foil is thinner than that of the lead frame, which may make it difficult for heat diffusion.

  Furthermore, by devising the temperature profile when the heat conducting resin 102 and the lead frame 100 are heated and pressed, the heat conducting resin can be softened (decrease in viscosity) and the influence on the lead frame 100 can be suppressed. Thus, by separating the molding process of the lead frame 100 and the molding process of the pre-molded lead frame 100 and the heat conductive resin 102 separately, a light emitting module using a lead frame having a large thickness and excellent heat dissipation is obtained. It can be formed at low cost.

  In this way, the heat conductive resin 102 which is an insulating layer made of the metal plate 112 and a resin composition containing an inorganic filler and a thermosetting resin on the metal plate 112 and the heat conductive resin 102 are fixed, and partly The lead frame is formed of a lead frame 100 mainly composed of copper, in which a concave portion is formed and a part of the concave portion is fixed by a light reflecting material 104, and a reflective ring 114, and is surrounded by the reflective ring 114. A light emitting module in which a part of light emitted from the light emitting element mounted on 100 can be reflected by the reflecting ring 114 is provided.

  Further, a heat conductive resin 102 which is an insulating layer made of a metal plate 112, a resin composition containing an inorganic filler and a thermosetting resin on the metal plate 112, and fixed through the heat conductive resin 102, and partially On the lead frame 100 surrounded by the reflection ring 114, a lead frame 100 mainly composed of copper in which a recess is formed, and a part of the recess is fixed by a light reflecting material 104. The mounted light-emitting element 108 and a transparent resin 116 covering the light-emitting element 108, and a part of the transparent resin 116 has a structure that accumulates in the gap between the reflective ring 114 and the lead frame 100. A light emitting module is provided.

  Then, the heat conducting resin 102 is cured in a state in which the heat conducting resin 102 which is an insulating resin is sandwiched between the lead frame 100 which is formed with a recess at least in part and fixed by the light reflecting material 104 and the metal plate 112, After the metal plate 112 and the lead frame 100 fixed by the light reflecting material 104 are integrated, a light emitting module is manufactured by mounting the light emitting element 108 and the reflecting ring 114.

  Further, the heat conducting resin 102 is cured in a state in which the heat conducting resin 102 which is an insulating resin is sandwiched between the lead frame 100 which is formed with a recess at least in part and fixed with a light reflecting material, and the metal plate 112, After the metal plate 112 and the lead frame 100 fixed by the light reflecting material 104 are integrated, the light emitting element 108 and the reflective ring 114 are mounted in the concave portion, and then covered with a transparent resin 116 to manufacture a light emitting module. To do.

  Note that the reflective ring 114 may be set after the light emitting element 108 is mounted, or the light emitting element 108 may be set after the reflective ring 114 is set. This may be judged in the process design.

As the light reflecting material 104, white ceramic powder such as TiO 2 or MgO, or light reflecting powder having high light reflection such as glass powder or micro glass beads is dispersed in a thermoplastic resin having high heat resistance. Can be used. Various members are commercially available for surface mounting LEDs, and such members can be used. In addition, as a method of molding such a commercially available light reflecting material 104 with the lead frame 100, a material having high mass productivity such as injection molding can be selected. Note that the light reflectance in the visible light region of the light reflecting material 104 is desirably 90% or more and 99.9% or less. When the light reflectance is less than 90%, the reflection efficiency at the reflection ring 114 is affected. Further, if the light reflectance is made higher than 99.9%, the light reflecting material 104 may become very expensive. The light reflecting material 104 is preferably white. By making it white, color mixing of monochromatic light such as Red, Green, Blue, etc. is facilitated.

  In addition, the light emitting element 108 is mounted on the lead frame within the area surrounded by the light reflecting material 104, and further covered with the transparent resin 116b or the like, so that the light emitting element 108 can be protected and the plurality of light emitting elements 108 can be high. Density bear mounting is possible. In addition, by mounting a plurality of light emitting elements 108 at a high density, it becomes easy to uniformize white color due to color mixing.

  Further, in this case, one or more of the plurality of light emitting elements 108 has white colored light so that an effect of facilitating color mixing can be obtained.

  Needless to say, a white ceramic element (alumina sintered body or the like), a metal material, a resin material, or a light reflecting material 104 formed into a ring shape by injection molding or the like can be used as the reflecting ring 114. In addition, the reflective ring 114 is formed (retrofitted) after the light emitting element 108 so that the mounting of the issuing element 108 is not hindered.

  The light reflecting material 104 can be injection molded using, for example, a polycarbonate resin in which a white pigment is dispersed. In particular, in the case of polycarbonate resin, it is desirable that the resin is sufficiently dried before injection molding. This is because the polycarbonate resin is a hydrophilic resin and absorbs moisture in the air. Therefore, if injection molding is performed without drying, a hydrolysis reaction of the resin may occur during molding, and the molecular weight of the resin may decrease, affecting the quality of the molded body. Therefore, the drying is desirably performed at 100 ° C. or higher (desirably performed at 110 ° C. to 130 ° C. for 4 to 6 hours). The molding temperature is preferably in the range of 250 ° C to 300 ° C, and the mold temperature is preferably in the range of 50 ° C to 120 ° C. If the temperature is lower than this range, the moldability may be affected. When the molding temperature is higher than this range, the moldability and the physical properties of the resin of the molded body may be affected.

In addition, PPS and liquid crystal polymer can be selected as the resin for the light reflecting material 104. In the case of such a resin (for example, a liquid crystal polymer), the injection temperature is around 340 ° C. (desirably 270 ° C. or more and 380 ° C. or less. If the temperature range is lower than this temperature range, the injection moldability may be affected. May affect the resin). Similarly, the mold is heated to around 100 ° C. (preferably 50 ° C. or more and 130 ° C. or less, which may affect the moldability if it is lower than this temperature range. The same applies if it is higher than this temperature range). It is desirable to do. Examples of the white pigment to be added here may be used TiO 2, Al 2 O 3, MgO or the like. The particle diameter of these pigments is preferably 10 microns or less and 0.01 microns or more (preferably 5 microns or less and 0.1 microns or more). If it is larger than 10 microns, the moldability may be affected. On the other hand, when the particle size is less than 0.01 micron, the specific surface area of the powder becomes too large, which may affect the fluidity during injection molding.

  As described above, since the light emitting module according to the present invention can be used to stably light a large number of light emitting elements, in addition to backlights such as liquid crystal TVs, projectors, projectors, etc. It can also be applied to color rendering applications.

Top view and cross-sectional view illustrating a light-emitting module according to Embodiment 1 Top view showing the shape of the lead frame Diagram showing how heat diffuses Sectional drawing which shows an example of the manufacturing method of the light emitting module in Embodiment 2. Sectional drawing which shows an example of the manufacturing method of the light emitting module in Embodiment 2. Reflective ring perspective view Sectional drawing which shows an example of the manufacturing method of the light emitting module in Embodiment 3. Sectional drawing which shows an example which performs thickness control of heat conductive resin using the shape of light reflection resin Sectional drawing which shows an example of the conventional light emitting module

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Lead frame 102 Thermal conductive resin 104 Light reflecting material 106 Dotted line 108 Light emitting element 110 Arrow 112 Metal plate 114 Reflective ring 116 Transparent resin 118 Lens 120 Groove part 122 Projection part 124 Spacer part

Claims (18)

  1. A metal plate,
    An insulating layer comprising an inorganic filler on the metal plate and a resin composition containing a thermosetting resin;
    A lead frame mainly composed of copper fixed through the insulating layer, partially formed with a recess, and a portion of the recess fixed with a light reflecting material;
    A reflection ring,
    A light emitting module in which a part of light emitted from a light emitting element mounted on a lead frame surrounded by the reflective ring is reflected by the reflective ring.
  2. A metal plate,
    An insulating layer comprising an inorganic filler on the metal plate and a resin composition containing a thermosetting resin;
    A lead frame mainly composed of copper fixed through the insulating layer, partially formed with a recess, and a portion of the recess fixed with a light reflecting material;
    With reflection ring,
    A light emitting element mounted on the lead frame surrounded by the reflective ring, and a resin covering the light emitting element,
    A light emitting module having a structure in which a part of the resin accumulates in a gap between the reflection ring and the lead frame.
  3. The light emitting module according to claim 1, wherein the reflective ring has a light reflectance in a visible light region of 90% or more and 99.9% or less.
  4. 3. The light emitting module according to claim 1, wherein the light reflecting material has a light reflectance of 90% or more and 99.9% or less in a visible light region in which light reflecting powder is dispersed in a resin. .
  5. The light emitting module according to claim 1, wherein the light emitting element is mounted on the lead frame within an area surrounded by the light reflecting material and is further protected with a resin.
  6. The light emitting module according to claim 1, wherein a plurality of light emitting elements each having a different emission color are mounted in an area surrounded by a ring-shaped reflecting material.
  7. The light emitting module according to claim 1, wherein at least one of the plurality of light emitting elements has a white emission color.
  8. 2. The light emitting module according to claim 1, wherein the lead frame has a thickness of 0.10 mm to 1.0 mm, and at least a part of the lead frame is processed into a concave shape before being integrated with the insulating layer.
  9. The light emitting module according to claim 1, wherein the thermal conductivity of the insulating layer is 1 W / (m · K) or more and 20 W / (m · K) or less.
  10. 3. The light emitting module according to claim 1, wherein the inorganic filler includes at least one selected from the group consisting of Al 2 O 3 , MgO, BN, SiO 2 , SiC, Si 3 N 4 , and AlN.
  11. The light emitting module according to claim 1, wherein the thermosetting resin includes at least one selected from the group consisting of an epoxy resin, a phenol resin, and an isocyanate resin.
  12. The light emitting module according to claim 1, wherein the insulating layer is white.
  13. The light emitting module according to claim 1, wherein the reflective material is white.
  14. Sn is 0.1 wt% to 0.15 wt%, Zr is 0.015 wt% to 0.15 wt%, Ni is 0.1 wt% to 5 wt%, Si is 0.01 wt% to 2 wt%, Zn is Lead frame mainly composed of copper containing at least one selected from the group of 0.1 wt% to 5 wt%, P is 0.005 wt% to 0.1 wt%, and Fe is 0.1 wt% to 5 wt%. The light emitting module according to claim 1, wherein the light emitting module is used.
  15. 3. The light emitting module according to claim 1, wherein a part of the light reflecting material is formed at a gap between the lead frames and at a position between the lead frame and the insulating layer so as to avoid a position immediately below the light emitting element.
  16. The light emitting module according to claim 1, wherein a part of the light reflecting material forms a spacer that holds a gap between the lead frame and the metal plate.
  17. A lead frame having a recess formed at least in part and fixed with a light reflecting material;
    In a state where the insulating resin is sandwiched between the metal plates, the insulating resin is cured,
    After integrating the metal plate and the lead frame fixed with a light reflecting material,
    A method for manufacturing a light emitting module on which a light emitting element and a reflective ring are mounted.
  18. A lead frame having a recess formed at least in part and fixed with a light reflecting material;
    In a state where the insulating resin is sandwiched between the metal plates, the insulating resin is cured,
    After integrating the metal plate and the lead frame fixed with a light reflecting material,
    A method for manufacturing a light-emitting module, in which a light-emitting element and a reflective ring are mounted in the recess and then covered with a transparent resin.
JP2006013408A 2006-01-23 2006-01-23 Light-emitting module, and manufacturing method thereof Pending JP2007194526A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2006013408A JP2007194526A (en) 2006-01-23 2006-01-23 Light-emitting module, and manufacturing method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2006013408A JP2007194526A (en) 2006-01-23 2006-01-23 Light-emitting module, and manufacturing method thereof

Publications (1)

Publication Number Publication Date
JP2007194526A true JP2007194526A (en) 2007-08-02

Family

ID=38449958

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2006013408A Pending JP2007194526A (en) 2006-01-23 2006-01-23 Light-emitting module, and manufacturing method thereof

Country Status (1)

Country Link
JP (1) JP2007194526A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007288198A (en) * 2006-04-17 2007-11-01 Samsung Electro-Mechanics Co Ltd Light emitting diode package and its manufacturing method
JP2011154911A (en) * 2010-01-27 2011-08-11 Ichikoh Ind Ltd Light source unit for semiconductor light source of vehicular lighting fixture, and vehicular lighting fixture
JP2013153068A (en) * 2012-01-25 2013-08-08 Shinko Electric Ind Co Ltd Wiring board, light emitting device, and manufacturing method of wiring board

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007288198A (en) * 2006-04-17 2007-11-01 Samsung Electro-Mechanics Co Ltd Light emitting diode package and its manufacturing method
US8168453B2 (en) 2006-04-17 2012-05-01 Samsung Led Co., Ltd. Light emitting diode package and fabrication method thereof
US8735931B2 (en) 2006-04-17 2014-05-27 Samsung Electronics Co., Ltd. Light emitting diode package and fabrication method thereof
JP2011154911A (en) * 2010-01-27 2011-08-11 Ichikoh Ind Ltd Light source unit for semiconductor light source of vehicular lighting fixture, and vehicular lighting fixture
JP2013153068A (en) * 2012-01-25 2013-08-08 Shinko Electric Ind Co Ltd Wiring board, light emitting device, and manufacturing method of wiring board

Similar Documents

Publication Publication Date Title
US10263161B2 (en) Resin molding, surface mounted light emitting apparatus and methods for manufacturing the same
US9076948B2 (en) Light emitting apparatus and production method thereof
JP2016154255A (en) Light-emitting device
US9159884B2 (en) Light emitting device having cavity side surfaces with recesses
US10115876B2 (en) Light emitting device mount, leadframe, and light emitting apparatus
US8932886B2 (en) Power light emitting die package with reflecting lens and the method of making the same
US10090446B2 (en) Light emitting device and method for manufacturing the same
JP5759413B2 (en) light emitting diode package
US8076691B2 (en) Package for light emitting device and method for packaging the same
EP2413389B1 (en) Light emitting device package
US9406852B2 (en) Light emitting device
JP5695488B2 (en) Luminous body package
EP2824721B1 (en) Light emitting device
US9362461B2 (en) Light emitting device and lighting system having the same
US20150129908A1 (en) Led module
JP5418592B2 (en) Light emitting device
TWI550897B (en) Power surface mount light emitting die package
EP2346100B1 (en) Light emitting apparatus and lighting system
JP5204866B2 (en) Light emitting device package and lighting system including the same
US9647190B2 (en) Package for light emitting apparatus and light emitting apparatus including the same
US7187010B2 (en) Semiconductor light emitting device
EP2819190B1 (en) Semiconductor light emitting module and method for manufacturing the same
US9502610B2 (en) Method for manufacturing light emitting device
US9310062B2 (en) Light-emitting device and method of manufacturing the same
KR101905535B1 (en) Light emitting device and light apparatus having thereof