JP2008041699A - Led package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inexpensive LED package reducing output loss in a 3-in-1 package or a multi-chip package. <P>SOLUTION: The LED package comprises a plurality of LED chips mounted on a recess having a side face and a bottom face formed of resin and/or conductive metal, wherein the recess is sealed with translucent resin. A barrier partitioning the respective LED chips is integrally molded of the same resin or the same conductive metal as the bottom face. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an LED package. In particular, the present invention relates to an LED package on which a plurality of LED chips are mounted.

  Since LEDs are small and have a long life and excellent luminous efficiency, they are used in applications such as lighting, various displays, and backlights. Also, various structures have been devised according to their use. For example, there are a shell type with high light distribution directivity, a thin and small surface mount type, and a high output type with a heat radiating section. A so-called 3 in 1 package in which three color chips are mounted as a parallel circuit on one LED package is used for a color display as a package capable of producing a full color by current distribution. These are subdivided into many types according to the shape and characteristics. Furthermore, there is a multi-chip package in which a plurality of chips of the same color are mounted to increase the light output. There is also a white package that combines a multi-chip package with a phosphor.

Among these, as a surface mount type, there is a 3 in 1 LED package whose plan view and cross-sectional view are shown in FIGS. A resin molded body 6 made of a thermoplastic resin is integrally molded so that the concave portion 5 is formed on the metal lead portions 1, 2, 3, and 4 divided in four directions. The blue LED chip 7, the green LED chip 8, and the red LED chip 9 are bonded and cured and fixed to the metal lead portions 2, 3 and 4 using a transparent die bonding paste, respectively. The blue LED chip 7, the green LED chip 8 and the red LED chip 9 are two-wire types having two electrodes on the chip surface, and from one electrode to the metal lead parts 2, 3 and 4 on which the chip is mounted, Au wires are connected to the metal leads 1 from the other electrode. A thermosetting translucent resin is filled in the recess 5 so as to cover the LED chips 7, 8, 9 and the gold wire 12. These three-color LED chips are parallel circuits, and by adjusting the current independently, full-color coloring is realized in one package.
As shown in FIG. 2, there is a type in which chips are connected to a series circuit by wires even in the same package.

  In these multi-chip packages, a problem of output loss due to mutual light absorption between chips has been pointed out. In response to this problem, Japanese Patent Application Laid-Open No. 2005-277380 proposes a silicon-based package in which a partition wall surrounding each multichip is formed by partially etching the surface of the silicon substrate. is doing.

  However, in the method disclosed in this patent publication, the process is complicated and long, and the cost is high, including a mirror forming process that suppresses light absorption of silicon. In addition, high costs cannot be denied for application to a general package form as shown in FIG. Furthermore, since the partition wall is formed by etching, it is difficult to make the partition wall a paraboloid excellent in light extraction efficiency.

JP 2005-277380 A

  The present inventor confirmed that when the green chip and the red chip were removed from the conventional 3 in 1 package as shown in FIG. 1, the light emission output of the remaining blue chip increased compared to before removal. Similarly, when the case of leaving the green chip and the case of leaving the red chip was verified, the output increased with the green chip, and it was confirmed that the output with the red chip hardly changed. Table 1 shows the results of comparing the output before and after the removal of the three groups of 10 chips each having an average value and a standard deviation of ± 5% with respect to the outputs of the chips of three colors.

この結果によると、３ ｉｎ １パッケージにする事で青色チップは７１％に出力ダウン、緑色チップは８９％に出力ダウン、赤色チップは９８％に出力ダウンとなっている。トータルの出力は、３ ｉｎ １パッケージで１２．１ｍＷに対し、その他チップを除去した場合の合計が１４．２ｍＷであり、８５％に出力ダウンとなっている。

According to this result, the output of the blue chip is reduced to 71%, the output of the green chip is reduced to 89%, and the output of the red chip is reduced to 98% by using a 3 in 1 package. The total output is 14.2 mW when the other chips are removed compared to 12.1 mW in the 3 in 1 package, and the output is down to 85%.

  In the 3 in 1 package, the main cause of the increase in loss in the order of the red chip, the green chip, and the blue chip is light absorption between the chips. A general LED does not absorb light having a wavelength longer than the emission wavelength but has a property of absorbing light having a wavelength shorter than the emission wavelength. Therefore, the light emitted from the blue LED chip is absorbed by the green LED chip and the red LED chip. On the other hand, light emitted from the green LED chip is not absorbed by the blue LED chip, but is absorbed by the red LED chip. Further, light emitted from the red LED chip is not absorbed by the blue LED chip or the green LED chip. Due to such a principle, the output loss of the red LED chip, the green LED chip, and the blue LED chip occurs in the 3 in 1 package.

この表から判るとおり、３個チップを搭載しても光出力は３倍になっていない。この原因は、３ ｉｎ １パッケージの場合と同様、あるチップから放出した光が別のチップに再吸収された為である。 Table 2 shows a comparison between the case where three chips of the same color are arranged in series and the case where two chips are removed to leave one chip. The arrangement of the chip and the arrangement of the wires are as shown in FIG.

As can be seen from this table, even if three chips are mounted, the light output is not tripled. This is because light emitted from one chip is reabsorbed by another chip, as in the case of the 3 in 1 package.

  As described above, it is a problem to be solved by the present invention to provide a low-cost package and method for reducing these total output losses in a 3 in 1 package and a multi-chip package.

  In order to reduce this output loss, the light emitted from the chip may be prevented from directly hitting other LED chips. That is, the present invention provides the following inventions.

  (1) In an LED package in which a plurality of LED chips are mounted in a recess having a side surface and a bottom surface formed of a resin and / or a conductive metal, and the recess is sealed with a translucent resin, the LED chip The LED package characterized in that the barrier separating each is integrally formed of the same resin or the same conductive metal as the bottom surface.

  (2) The LED package as described in (1) above, wherein the plurality of LED chips include LED chips having different emission wavelengths.

  (3) The LED package as described in the above item (2), wherein the LED chips are blue, green and red.

  (4) The LED package according to any one of (1) to (3), wherein a side surface of the concave portion is integrally formed of the same metal material or the same resin material as the bottom surface.

  (5) In any one of the above items 1 to 4, wherein the resin material contains at least one additive selected from the group consisting of titanium dioxide, zirconium dioxide, potassium titanate, aluminum nitride, and boron nitride. The described LED package.

  (6) The LED package according to any one of (1) to (5), wherein a height of the barrier is not less than a height of the LED chip.

  (7) The LED package according to any one of the above items 1 to 6, wherein the side surface of the barrier and / or the side surface of the recess is a paraboloid.

(8) A display comprising the LED package according to any one of 1 to 7 above.
(9) A backlight comprising the LED package according to any one of 1 to 7 above.

The LED package of the present invention suppresses light absorption to another LED chip by providing a barrier between the metal lead portions on which the respective chips are mounted on the bottom surface of the concave portion where the light emitting element (LED chip) is mounted. Thus, an LED package with high output or high efficiency is realized.
Furthermore, by integrally molding the barrier with the same material as the bottom surface of the recess, the process is simplified and a compact and low-cost LED package is obtained.

  4 and 5 are a schematic plan view and a schematic cross-sectional view of the surface-mount type LED package of the present invention produced in Example 1 described later. 8 and 9 are a schematic plan view and a schematic cross-sectional view of a bullet-type LED package of the present invention produced in Example 3 described later. The LED package of the present invention is an LED package having a recess 5, a plurality of semiconductor light emitting elements (LED chips) 20 mounted on the bottom of the recess, and the recess sealed with a translucent resin. The height of the barrier 10 separating the semiconductor light emitting elements formed on the bottom surface is preferably set to be equal to or higher than the height of the chip. This barrier is preferably made of the same resin or metal as the bottom surface constituting the recess, and is integrally molded with the bottom surface. The side surface that forms the recess together with the bottom surface is also preferably integrally formed with the bottom surface and the barrier, but the side surface may be formed of a material that is separate from the bottom surface and the barrier.

  In order to integrally mold the barrier 10 with the resin or metal forming the bottom surface of the recess 5, in the manufacturing process of the recess, in the resin injection molding as shown in FIGS. 4 and 5, the resin mold is used as shown in FIGS. 8 and 9. In such press molding, it is only necessary to provide a barrier for each mold, which is desirable in terms of process shortening and manufacturing cost. The semiconductor light emitting element may be installed on a conductive material such as a metal lead part at the bottom of the recess, or may be installed and mounted on an insulating material such as resin or ceramic.

  The thickness of the barrier formed on the bottom surface is desirably set to a thickness sufficient to shield light between chips. In the case of a resin containing a white filler, although it depends on the concentration of the filler, it is designed to be, for example, about 50 μm or more in order not to transmit light. When the barrier is formed by the metal reflecting surface as shown in FIGS. 8 and 9, it may be thinner.

  In the present invention, the shape of the barrier is an inclined surface constituted by a flat surface, or a curved surface typified by a conical surface, a paraboloid, or the like so that light from the side of the chip is changed in the light emission direction of the package. Something is desirable. In particular, a parabolic surface is preferable. Further, it is desirable that the surface of the barrier is a regular reflection surface made of metal coating or the like, or a diffuse reflection surface made of white filler or the like, in order to suppress light loss.

The present invention is not limited to a 3 in 1 package, a multi-chip package in which a plurality of LED chips of the same color are mounted, a chip-on-board (COB) in which a large number of LED chips are directly mounted on a substrate, a chip-on film (COF), etc. Also effective.
The present invention is not limited to a single-color multichip LED package, but is also effective for a multichip LED package combined with a phosphor, a chip-on-board, and the like.
The element mounted in the barrier in the present invention is not limited to a semiconductor light emitting element, but is also effective for an element that absorbs and scatters light from a light emitting element such as a Zener diode or a chip resistor.

  Hereinafter, an embodiment of the present invention will be described by taking an LED package made of resin integrally molded as an example. In the LED package of the present invention, as shown in FIGS. 4 and 5 in a plan view and a cross-sectional view, the resin molded body 6 forming the recess 5 and the barrier 10 is integrated with the metal leads 1 to 4. The LED chip is mounted on the lead portion on the bottom surface of the recess. The bottom surface of the LED chip is fixed by a die bonding paste, and the electrode on the top surface of the light emitting element 20 is connected to the metal lead 1 by a gold wire 12. These light emitting elements and gold wires are covered with a translucent resin that seals the recess 5. This LED package can emit light by energizing a metal lead. Hereinafter, each component of the present invention will be described sequentially.

  The resin molded body having a barrier constituting the LED package is formed by injection molding a thermoplastic resin on the metal leads (1 to 4). Formation of the resin molded body having a barrier can realize various shapes by designing a mold used for injection molding.

  The overall size of the resin molded body is, for example, a concave portion that is molded to have a length of 1.5 to 20 mm, a width of 1.5 to 20 mm, and a height of about 0.3 to 10 mm, and serves as a mounting portion of the light emitting element. The size is about 1 to 19 mm in length, 1 to 19 mm in width, and about 0.2 to 9 mm in height. However, these sizes are not limited to these values. As for the shape, it is possible to freely select a shape such as a rectangular parallelepiped, a cylindrical shape, and a conical shape for both the whole and the concave portion. The bottom surface of the recess can also be circular, elliptical or polygonal.

  The cross-sectional angle of the side surface of the recess can be freely designed to control the directivity angle of the light distribution, and the cross-sectional shape thereof may be constituted by a straight line as in the conventional example of FIG. You may be comprised from the curve. From the viewpoint of light extraction efficiency, it is preferable that the bottom surface of the recess and the surface of the side surface are smooth without any step, but it may be better to roughen the surface of the bottom surface of the recess and the side surface for convenience of color mixing.

  In addition, in order to more freely control the light distribution characteristics and the reflection characteristics of the side surfaces of the recesses in which the light emitting elements are mounted, it is possible to plate the side surfaces with silver or the like. In addition, the bottom surface and the side surface of the concave portion may be molded at a time at the time of integral molding, but the side surface portion may be composed of different materials without being integrally molded. It is also possible to arrange a resin reflector with silver plating on the side surface. In this case, it can be combined by attaching a reflector after mounting the light emitting element.

  As the thermoplastic resin used for molding, it is particularly desirable to select a resin having excellent heat resistance, weather resistance and mechanical strength. As the type of resin, polyamide, polyphthalamide, polyphenylene sulfide, liquid crystal polymer, polyether sulfone, polyether imide, polybutylene terephthalate, and the like can be used. Furthermore, by adding any of titanium dioxide, zirconium dioxide, potassium titanate, aluminum nitride, and boron nitride as a light reflecting agent in these resins, light from the light emitting element is formed on the bottom and side surfaces of the recess. Thus, the light extraction efficiency of the entire package can be increased.

  The metal leads (1 to 4) are metal plates having a thickness of about 0.1 to 0.5 mm, based on an iron / copper alloy as a metal having excellent workability and thermal conductivity, and a plating layer thereon As a part of a lead frame in which nickel, titanium, gold, silver or the like is laminated by several μm. The reason for plating is to improve corrosion resistance and light reflectivity. In particular, selecting a highly reflective metal such as silver as the outermost plating layer increases the amount of light emitted outside the package. preferable. In many cases, gold is selected as the outermost surface of the metal lead in terms of adhesion of wire bonding. However, when the wavelength of the light emitting element is 600 nm or less, the metal surface having the higher reflectivity than gold is selected as the outermost surface of the metal lead. Is preferable from the viewpoint of light extraction.

  The resin molded body in which the bottom surface and the side surface are integrally molded with respect to the recess for mounting the light emitting element has been described above, but it is also possible to use a structure in which the bottom surface and the side surface are separated, and a metal base substrate can be used as the bottom surface. The metal base substrate is a heat-dissipating aluminum or copper substrate with a heat-resistant resin laminated as an insulating thin film in a thickness of 1 to 100 μm, and a copper plate is laminated on it, and gold or silver plating is applied via Ni or the like. Yes. After forming a wiring pattern by etching by photolithography, it can be produced by forming an insulating thin film to protect a portion other than a semiconductor element such as an LED chip and an area necessary for wire bonding.

  Moreover, the resin layer used as the insulating thin film can increase the light extraction efficiency by adding any of titanium dioxide, zirconium dioxide, potassium titanate, aluminum nitride and boron nitride as a light reflecting agent for improving the reflectance. it can.

  Further, it is desirable to improve the light distribution characteristic and the reflection characteristic from the side surface by disposing a reflector as the side surface forming the recess. The reflector is made of metal or resin, and can freely take a size of 2 to 30 mm in length and width and 2 to 10 mm in height, but is not limited to this size. A shape such as an inverted cone shape and an inverted pyramid shape can be freely selected. In order to improve the light reflectance, the side surface may be silver-plated.

  The compound semiconductor light emitting device (LED chip) used in the present invention is selected from a material made of a compound semiconductor single crystal such as GaP, GaAs, GaAlAs, GaAsP, AlInGaP, and InGaN as a light emitting layer, thereby allowing ultraviolet light to infrared light. It is possible to select a light emission wavelength over a wide range. A compound semiconductor epitaxial wafer can be produced by laminating a light emitting layer on an appropriate substrate by an epitaxial growth method such as LPE, VPE, or MOCVD. The epitaxial wafer is subjected to constant thickness processing by a wrapper or a grinding machine, and then an electrode is formed by lithography. After forming the electrode, it can be divided by a dicer or a breaker to obtain an element. When a semiconductor substrate is used for epitaxial growth, the electrodes can be formed on the lower surface of the substrate and the upper surface of the epitaxial growth layer, so that contacts may be made on the upper and lower surfaces of the light emitting element. Therefore, when the LED package is mounted, the lower surface of the light emitting element can be connected with a conductive die bonding paste, so that the wire bonding may be performed at least once on the upper surface electrode. On the other hand, in the case of a light-emitting device using InGaN as a light-emitting layer, particularly when a light-emitting layer is grown on an insulating sapphire substrate, the electrodes are provided on the same surface by etching the epitaxial growth layer and contact is made from the same surface. There is a need. In this case, it is necessary to perform wire bonding at least twice.

  The size of the light-emitting element can be freely designed according to the required opto-electrical characteristics, and is a square having a side of 200 to 1000 μm and a height of 50 to 300 μm, but is not limited thereto. .

  Note that a plurality of the same light emitting elements may be mounted on the LED package of the present invention, or a plurality of light emitting elements having different emission wavelengths may be mounted.

  The compound semiconductor light emitting element is fixed on the metal lead portion or the resin molding constituting the bottom surface of the recess by a die bonding paste. When the structure of the light emitting element is an upper and lower electrode type, it is necessary to make contact with the bottom surface. Therefore, a conductive thermosetting epoxy resin containing silver particles is used as a filler. After the die bonding paste is applied, the light emitting element is die bonded and bonded by being thermally cured at 100 to 150 ° C. in an oven. On the other hand, in the case where the structure of the light emitting element is an electrode formed on the same surface, it is not necessary to make contact on the bottom surface, and therefore an insulating die bonding paste that does not contain silver particles can be used. In particular, in the case of an LED package equipped with a light emitting element having a large light emission wavelength with a large energy, the resin of the die bonding paste deteriorates with the passage of energized light emission time, and the light extraction efficiency tends to be lowered. Therefore, it is desirable to select a die bonding paste made of light-resistant epoxy resin or silicone resin.

  As the sealing resin, it is desirable to select a material having a high light transmittance and a high refractive index at the emission wavelength of the LED package in order to improve the light extraction efficiency. Accordingly, an epoxy resin or a silicone resin is selected as a resin that satisfies the properties of high heat resistance, weather resistance, and mechanical strength. Examples of the main epoxy resin include bisphenol A glycidyl ether and bisphenol F glycidyl ether, and it is desirable to add an alicyclic epoxy in order to enhance the effects of suppressing thermal deformation, weather resistance, and discoloration prevention particularly at high temperatures. . However, the epoxy resin is vulnerable to light having a short wavelength of 500 nm or less and high heat, and the deterioration progresses with the lapse of driving time, the light transmittance is remarkably lowered, and the light emission efficiency may be reduced. On the other hand, a silicone resin is more suitable than an epoxy resin in terms of light resistance and heat resistance, and is therefore suitable as a sealing resin for a short wavelength light emitting element. Furthermore, since the plasticity after curing of the silicone resin is larger than that of the epoxy resin, the volume change of the sealing resin due to the heat treatment is preferable from the point that it is difficult to cause the outer shape deformation of the resin molded body constituting the LED package. However, it is not preferable when the degree of adhesion to the resin molding is low or when the expansion coefficient fluctuates greatly around the LED operating temperature. Therefore, it is necessary to select an appropriate sealing resin according to the operating conditions of the LED package.

  The LED package of the present invention is particularly effective for applications such as displays and backlights, taking advantage of the features of low output loss and high emission intensity. Further, it can be widely used for various illuminations and indicators.

  Hereinafter, the present invention will be specifically described based on Examples and Comparative Examples, but the present invention is not limited to these Examples.

(Example 1)
FIG. 4 is a schematic plan view of the LED package manufactured in this example, and FIG. 5 is a schematic cross-sectional view taken along the line AA ′ of FIG. In the figure, 1-4 are metal lead portions, 5 is a recess, 6 is a resin molding, 10 is a barrier, 12 is a gold wire, and 20 is an LED chip. A compound semiconductor light emitting device (LED chip) is a so-called face-up type light emitting device in which an epitaxial layer including an InGaN light emitting layer is grown on a sapphire substrate and then both n-side and p-side electrodes are formed from the upper surface of the light emitting device. It is an element. A method for manufacturing a light-emitting element is described below.

In the light emitting device, a gallium nitride compound semiconductor layer was laminated on a substrate made of sapphire via a buffer layer made of AlN. The gallium nitride compound semiconductor layer includes a Ge-doped n-type GaN contact layer having a thickness of 10 μm, a Si-doped n-type In _0.1 Ga _0.9 N cladding layer having a thickness of 20 nm, a Si-doped GaN barrier layer having a thickness of 16 nm, and a thickness of 2. A 5 nm In _0.06 Ga _0.94 N well layer is stacked five times, and finally a light emitting layer having a multiple quantum well structure provided with a barrier layer, a 10 nm thick Mg-doped p-type Al _0.07 Ga _0.93 N cladding layer and a thickness of 180 nm Mg-doped p-type Al _0.02 Ga _0.98 N contact layer. From a transparent electrode layer made of ITO having a thickness of 200 nm and a bonding pad of Au / Ti / Al / Ti / Au5 layer structure (thickness is 50/20/10/100/200 nm, respectively) on the p-type AlGaN contact layer A positive electrode was formed. A negative electrode having a two-layer structure of Ti / Au was formed on the n-type GaN contact layer. The light extraction surface was the ITO electrode side. The substrate was ground to make the element thickness 80 μm. An element having an element size of 350 μm square was manufactured. This element has two electrodes on the light emitting surface, and is a type in which electricity is supplied using two wires. When 20 mA was applied, light was emitted in blue with a dominant wavelength of 470 nm.

  In addition, by forming an epi structure with an increased In composition in the InGaN well layer, a green light emitting device having a dominant wavelength of 525 nm was fabricated.

  On the other hand, a light emitting device was fabricated by replacing an AlInGaP-based light emitting device structure epitaxially grown on a GaAs substrate from a GaAs substrate to a GaP substrate. This element has two electrodes on the light emitting surface, and is a type in which electricity is supplied using two wires. When 20 mA was applied, it emitted red light with a dominant wavelength of 625 nm.

  The resin molding 6 was molded so that polyphthalamide resin containing titanium dioxide was integrally molded with the metal lead portions 1, 2, 3, and 4. The LED package molded as shown in FIGS. 4 and 5 is a rectangular parallelepiped having a length of 3.2 mm, a width of 2.8 mm, and a height of 1.8 mm, and the bottom surface of the recess 5 in which the light emitting element is mounted is approximately 1.8 mm in diameter and has an opening. Was formed into a circle having a diameter of 2.4 mm and a height of 0.85 mm. In addition, the side surface of the concave portion has a conical shape. The metal lead portion is exposed on the bottom surface. A barrier 10 is further formed on the bottom surface to separate the chips individually, and the slope of the barrier is a flat slope. The height of the barrier is 0.15 mm, and the inclination angle from the bottom surface of the barrier is substantially the same as the inclination angle of the recess. Moreover, the width | variety in the bottom face of a barrier is 0.16 mm.

  The blue, red, and green light emitting elements are sequentially bonded to the light emitting element bonding side metal leads 2, 3, and 4 with a transparent epoxy resin, and then cured at 150 ° C. for 90 minutes, and then the upper electrode and each metal Between the leads, wire bonding was performed with a gold wire having a diameter of 25 μm. Thereafter, silicone resin was poured into the recesses, and after sealing the light emitting element and the wire, the resin was cured at 150 ° C. for 180 minutes to complete the LED package.

  The output when each load is individually applied to the blue chip (load 5 mA), the green chip (load 20 mA), and the red chip (load 10 mA) of the 3 in 1 LED package manufactured in this example is 4. It was 0 mW, 6.0 mW, 4.1 mW, and it was 14.1 mW in total.

(Comparative Example 1)
FIG. 1 is a schematic plan view of an LED package manufactured in this comparative example, and FIG. 3 is a schematic cross-sectional view taken along line AA ′ of FIG. The numbers in the figure are the same as those in FIGS. An LED package was produced in the same manner as in Example 1 except that the conventional type without a barrier at the bottom of the recess was used.

The output when each load is applied individually to the blue chip (load 5 mA), green chip (load 20 mA), and red chip (load 10 mA) of the obtained 3 in 1 LED package is 2.9 mW and 5.3 mW, respectively. It was 4.1 mW, and it was 12.3 mW in total.
It was shown that the present invention having a barrier had a higher total output and reduced output loss due to absorption between chips.

(Example 2)
FIG. 6 is a schematic plan view of an LED package manufactured in this example, and FIG. 7 is a schematic cross-sectional view taken along line AA ′ of FIG. The numbers in the figure are the same as those in FIGS. An LED package was produced in the same manner as in Example 1 except that the resin molded body 6 was produced as follows.

  The molded LED package is a rectangular parallelepiped having a length of 3.2 mm, a width of 2.8 mm, and a height of 1.8 mm. The bottom surface of the recess 5 on which the light emitting element is mounted is a circle having a diameter of about 1.8 mm and an opening having a diameter of 2.4 mm. And was molded to a height of 0.85 mm. In addition, the side surface of the concave portion has a parabolic shape in which the cross-sectional shape is composed of a parabola. Individual recesses 15 for individually storing chips are formed on the bottom surface, and the metal lead portions are exposed on the bottom surface. The side surface of each individual recess serves as a barrier 10. The diameter of the individual recess opening is 0.7 mm, the diameter of the bottom of the individual recess is 0.6 mm, the depth of the individual recess, that is, the height of the barrier is 0.15 mm, and the shape of the side surface of the individual recess, that is, the shape of the slope of the barrier In addition, the cross-sectional shape is a parabolic shape composed of parabolas.

  The output when each load is applied individually to the blue chip (load 5 mA), green chip (load 20 mA), and red chip (load 10 mA) of the obtained 3 in 1 LED package is 4.2 mW and 6.3 mW, respectively. It was 4.3 mW, and it was 14.8 mW in total.

(Example 3)
FIG. 8 is a schematic plan view of a bullet-type LED package manufactured in this example, and FIG. 9 is a schematic cross-sectional view taken along line AA ′ of FIG. The numbers in the figure are the same as those in FIGS. A resin-made bullet lens for the purpose of protecting the chip and the wire portion, improving the light extraction efficiency, and controlling the light distribution angle seals the mount lead 30 and the outer leads 64-66. The material of the lead is a copper alloy, and the surface is coated with silver. The same light emitting element as in Example 1 was used. The bullet frame LED lead frame forms a cup portion by punching and crushing unnecessary portions using a press machine. The cup portion of the mount lead 30 shown in FIGS. 8 and 9 was manufactured by forming a mold of a portion to be crushed into a peach crack shape.

  Further, the bullet-type LED package molded as shown in FIGS. 8 and 9 has a bullet lens portion having a diameter of 5 mm and a height of 9.0 mm. The bottom surface of the concave portion of the mount lead on which the light emitting element is mounted was formed into a circular shape having a diameter of 0.75 mm and an opening portion having a diameter of 1.4 mm, and a height of 0.35 mm. Moreover, the side surface of the recessed part is comprised from the conical surface. Further, individual recesses 61 to 63 for individually storing chips are formed on the bottom surface, and the metal lead portions are exposed on the bottom surface. As in FIGS. 6 and 7, the side surface of each individual recess serves as a barrier 10. The individual recess has a fan shape obtained by dividing the circle into three equal parts, and the diameter of the circle including the three individual recesses is 0.7 mm at the opening and 0.6 mm at the bottom. The depth of the individual recess, that is, the height of the barrier is 0.15 mm. The side surfaces of the individual recesses, that is, the shape of the slopes of the barriers, are also composed of conical surfaces as with the side surfaces of the recesses.

  The same blue, red, and green light emitting elements as in Example 1 were die-bonded to the bottom surfaces of the individual recesses 61, 62, and 63 using a transparent epoxy resin, and then cured at 150 ° C. for 90 minutes, and then each chip. The negative electrode pad and the mount lead to which the chip was bonded were wire-bonded with a gold wire 12 having a diameter of 25 μm. Further, wire bonding was performed from the positive electrode pad of each chip to the outer leads 64, 65, 66 for each chip with a gold wire having a diameter of 25 μm. Thereafter, a two-component mixed type epoxy resin was poured into a casting case for forming a bullet lens, the above-mentioned lead frame after wire bonding was inserted into the casting case, and then the epoxy resin was heated and cured in an oven. The lead frame to which the bullet lens was fixed was removed from the casting case, and the tie bar was cut to complete a 3 in 1 bullet-type LED package with four individual terminals.

  The output when each load is individually applied to the blue chip (load 5 mA), green chip (load 20 mA), and red chip (load 10 mA) of the obtained 3 in 1 LED package is 4.5 mW and 6.5 mW, respectively. It was 4.4 mW, and it was 15.4 mW in total.

(Comparative Example 2)
FIG. 10 is a schematic plan view of an LED package manufactured in this comparative example, and FIG. 11 is a schematic cross-sectional view taken along line AA ′ of FIG. The numbers in the figure are the same as those in FIGS. An LED package was produced in the same manner as in Example 1 except that the conventional type was not provided with no individual concave portions, that is, no barrier on the bottom surface of the concave portions.

The output when each load is applied individually to the blue chip (load 5 mA), green chip (load 20 mA), and red chip (load 10 mA) of the obtained 3 in 1 LED package is 3.3 mW and 5.6 mW, respectively. It was 4.3 mW, and it was 13.2 mW in total.
Compared with the results of Example 3, it was shown that the present invention having a barrier had a higher total output and reduced output loss due to absorption between chips.

  Since the LED package of the present invention can suppress mutual absorption between chips at the time of multichip mounting, it can be widely used for improving the efficiency of various displays, backlights, indicators, lighting, etc. Very large.

FIG. 10 is a schematic plan view of a conventional multichip package produced in Comparative Example 1 in parallel arrangement. It is a schematic plan view of a conventional multi-chip package arranged in series. It is a cross-sectional schematic diagram in A-A 'of FIG. 1 is a schematic plan view of a surface mount type multichip package of the present invention produced in Example 1. FIG. It is a cross-sectional schematic diagram in A-A 'of FIG. 6 is a schematic plan view of a surface mount type multichip package of the present invention produced in Example 2. FIG. It is a cross-sectional schematic diagram in A-A 'of FIG. 6 is a schematic plan view of a shell-type multichip package of the present invention produced in Example 3. FIG. It is a cross-sectional schematic diagram in A-A 'of FIG. 10 is a schematic plan view of a conventional shell-type multichip package manufactured in Comparative Example 2. FIG. It is a cross-sectional schematic diagram in A-A 'of FIG.

Explanation of symbols

1-4 Metal leads 5 Recess 6 Resin molding 7 Blue LED chip 8 Green LED chip 9 Red LED chip 10 Barrier 12 Gold wire 15 Individual recess 20 LED chip 30 Mount lead 61-63 Individual recess 64-66 Outer lead

Claims (9)

  In an LED package in which a plurality of LED chips are mounted in a recess having a side surface and a bottom surface formed of resin and / or conductive metal, and the recess is sealed with a translucent resin, the LED chips are separated from each other. An LED package, wherein the barrier is integrally formed of the same resin or the same conductive metal as the bottom surface.   The LED package according to claim 1, wherein the plurality of LED chips include LED chips having different emission wavelengths.   The LED package according to claim 2, wherein the LED chips are blue, green and red.   The LED package according to any one of claims 1 to 3, wherein a side surface of the recess is integrally formed of the same metal material or the same resin material as the bottom surface.   The LED according to any one of claims 1 to 4, wherein the resin material contains at least one additive selected from the group consisting of titanium dioxide, zirconium dioxide, potassium titanate, aluminum nitride, and boron nitride. package.   The LED package according to any one of claims 1 to 5, wherein a height of the barrier is not less than a height of the LED chip.   The LED package according to claim 1, wherein a side surface of the barrier and / or a side surface of the recess is a paraboloid.   The display which uses the LED package as described in any one of Claims 1-7.   The backlight which consists of an LED package as described in any one of Claims 1-7.

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