KR100694847B1 - Light emitting diode and manufacturing method thereof - Google Patents

Abstract

An LED is provided to facilitate coupling of a heat sink slug by using a hole structure for easily bonding the heat sink slug to a frame substrate having a circuit pattern. A frame substrate includes a coupling hole, a protrusion protruding inward from the upper part of the inner circumferential surface of the coupling hole, and an electrode terminal formed as a circuit pattern in the periphery of the coupling hole. A heat sink slug is placed on the lower surface of the protrusion to be bonded to the protrusion. An LED chip(130) is mounted on the heat sink slug exposed through the coupling hole. A conductive coupling unit electrically connects the LED chip with the electrode terminal. A lens(150) is coupled to the frame substrate to cover the LED chip. The electrode terminal penetrates the frame substrate to be formed on the upper and the lower surface of the frame substrate, and the conductive coupling unit is a conductive wire(140). The longitudinal section of the lens includes an upper surface of a wave type.

Description

LIGHT EMITTING DIODE AND MANUFACTURING METHOD THEREOF

1 is a perspective view of a light emitting diode according to the prior art.

FIG. 2 is a perspective view taken along line AA ′ of FIG. 1 for schematically illustrating a structure and fabrication procedure of a light emitting diode according to the prior art; FIG.

Figure 3 is a perspective view showing another light emitting diode according to the prior art.

4 is a perspective view of a light emitting diode according to a preferred embodiment of the present invention.

5 is a cutaway perspective view of the light emitting diode of FIG. 3;

FIG. 6 is a longitudinal cross-sectional view for describing light emission characteristics of the light emitting diode of FIG. 3. FIG.

7 is a longitudinal cross-sectional view of a light emitting diode having a planar lens surface in accordance with a preferred embodiment of the present invention.

8 is an enlarged longitudinal sectional view of a wave type lens used in a comparative experiment.

9 is a flowchart illustrating a method of manufacturing a light emitting diode according to a preferred embodiment of the present invention.

<Description of the symbols for the main parts of the drawings>

200: light emitting diode 210: frame substrate

213: coupling hole 215: step

217: electrode terminal 220: heat sink slug

230: light emitting diode chip 240: gold (Au) wire

250: Lens 260: PCB

The present invention relates to a light emitting diode and a method of manufacturing the same.

Referring to FIGS. 1 and 2, a conventional light emitting diode is molded in a lead frame 17 with a plastic resin to form a housing 10, and a hole formed in the center of the housing 10. A heat sink 20 for discharging heat generated from the light emitting diode chip 30 to the outside is inserted. After the LED chip 30 is mounted on the top surface of the heat sink 20, the LED chip 30 and the lead frame 17 are bonded to the wire 40, and then the plastic lens 50 is bonded to silicon. Alternatively, the light emitting diode 1 is completed by fixing to the housing 10 with epoxy.

Such a light emitting diode has to be inserted into the housing 10 individually by the heat sink 20 at the time of manufacture, there is a problem that is not suitable for mass production, the lead frame (17) when surface-mounting the light emitting diode (SMT) ) And the bottom of the heat sink 20 are likely to generate a step, so that the bottom of the heat sink 20 is not completely adhered to the PCB (not shown).

Referring to FIG. 3, another conventional light emitting diode is formed by injecting a polyamide-based plastic (PA, PPA, etc.) resin around the lead frame 117 to form a housing 110. After mounting the LED chip 130 in the recessed portion of the 110 and bonding the lead frame 117 and the wire 140, the lens 150 is applied by applying silicon or epoxy to the upper surface of the housing 110 To form the light emitting diode 100 is completed.

Such a light emitting diode 100 has an optical characteristic for each light emitting diode due to a deviation in the application of silicon or epoxy for forming the lens 150 in the manufacturing process, that is, in dispensing a certain amount. There is a problem that the difference occurs.

The present invention is easy to combine the heat sink slug at the time of manufacturing, and the light emitting diode suitable for increasing the productivity in mass production by soldering (Soldering) in a general reflow method during surface mount (SMT) on the PCB and It is to provide a manufacturing method.

In addition, the present invention provides a light emitting diode having a lens having excellent light efficiency and uniform optical characteristics, and a method of manufacturing the same.

According to an aspect of the invention, the frame substrate including a coupling hole, a stepped protruding inward from the upper end of the inner peripheral surface of the coupling hole, and the electrode terminal formed in the circuit pattern around the coupling hole; A heat sink slug seated and bonded to the bottom surface of the stepped portion; A light emitting diode chip mounted on the heat sink slug exposed through the coupling hole; Conductive coupling means for electrically connecting the light emitting diode chip and the electrode terminal; A light emitting diode is coupled to an upper surface of the frame substrate and includes a lens covering the light emitting diode chip.

The electrode terminal is formed through the frame substrate on the upper and lower surfaces of the frame substrate, the conductive coupling means is preferably a conductive wire.

The longitudinal cross section of the lens preferably includes an upper surface of a wave shape.

According to another aspect of the invention, (a) forming a frame substrate including a coupling hole, a stepped protruding inward from the upper end of the inner peripheral surface of the coupling hole, and an electrode terminal formed in a circuit pattern on the outer peripheral portion of the coupling hole Wow; (b) coupling a heat sink slug to the coupling hole; (c) mounting a light emitting diode chip on an exposed top surface of the heat sink slug; (d) electrically connecting the light emitting diode chip to the electrode terminal; (e) installing a mold coated with a releasing agent on the frame substrate and applying pressure to the mold with the mold press; (f) injecting and curing an epoxy resin into the mold to mold the lens; (g) A method of manufacturing a light emitting diode comprising removing the mold and dicing the molded frame substrate to a predetermined size is provided.

Step (b) is preferably carried out by bonding using any one or more of an adhesive (Glue), an epoxy resin, and a thermal compound.

The mold preferably includes an upper surface having a longitudinal cross section.

The step (f) is performed by injection molding by mixing the main ingredient of the liquid epoxy and the curing agent in a predetermined mixing ratio, or by performing epoxy molding in the form of an epoxy molded compound (EMC) by transfer molding. It is desirable to be.

It is preferable that a diffusion agent or a phosphor is mixed in the epoxy resin corresponding to the color of the light emitting diode.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of a light emitting diode and a method of manufacturing the same according to the present invention, in the description with reference to the accompanying drawings the same or corresponding configuration regardless of reference numerals Elements are given the same reference numerals and redundant description thereof will be omitted.

4 is a perspective view illustrating a light emitting diode according to a preferred embodiment of the present invention, FIG. 5 is a cutaway perspective view of FIG. 3, and FIG. 6 is a longitudinal cross-sectional view of the light emitting diode of FIG. 3 for explaining light emission characteristics.

4 to 7, the light emitting diode 200 according to the present embodiment is roughly classified into a frame substrate 210, a heat sink slug 220, and a light emitting diode chip 230.

The frame substrate 210 has a coupling hole 213 formed at the center thereof so that the heat sink slug 220 can be seated and bonded, and a step 215 protrudes inward from the upper end of the inner circumferential surface of the coupling hole 213 to be heated. The sink slug 220 is prevented from being separated upward in the coupling hole 213 and the bottom surface of the step 215 serves to provide an adhesive surface to which the heat sink slug 220 can be bonded.

The heat sink slug 220 discharges heat generated from the light emitting diode chip 230 to the outside, and in this embodiment, nickel (Ni) and silver (Ag) are plated on a copper (Cu) core. do.

The electrode terminal 217 is formed in a circuit pattern on the outer circumferential portion of the coupling hole 213. The electrode terminal is a general PCB circuit pattern formation method that forms land patterns in various ways, such as forming circuit patterns on copper foil laminated plates on the upper and lower surfaces, and connects upper and lower circuits to via holes. Is formed.

The light emitting diode chip 230 is mounted on an upper surface of the heat sink slug 220 exposed through the coupling hole 213. In the present embodiment, the light emitting diode chip 230 is die-attached in such a manner as to be coupled between an upper surface of the heat sink slug 220 and a lower surface of the light emitting diode chip 230 via a paste (not shown) having excellent thermal conductivity. Die Attach).

The LED chip 230 mounted on the heat sink slug 220 is electrically connected to the electrode terminal 217 formed on the upper surface of the frame substrate 210 by conductive coupling means. In the present embodiment, although gold (Au) wire 240 is used as the conductive bonding means, various means such as conductive paste and tab bonding may be used.

The lens 250 is formed on the upper surface of the frame substrate 210 while the light emitting diode chip 230 and the electrode terminal 217 are wire bonded.

In FIG. 6, the longitudinal cross section of the lens 250 has an upper surface having a wave shape. As shown in FIG. 7, when the upper surface of the lens 250 ′ is a plane, light rays incident at an angle greater than or equal to the critical angle θ to the boundary surface of the lens among light rays emitted from the light emitting diode are totally reflected inside the lens 250 ′. Since there is a problem that the luminance (light quantity, brightness) of the light emitting diode 200 'is reduced, the longitudinal cross section of the lens 250 is formed in a wave shape.

When the light emitting diode is used as a light source of a backlight in an LCD display, since the lens 250 is in a wave shape, light emitted from a chip is emitted from the lens 250. Light above the critical angle θ is not reflected into the lens 250 on the interface of the surface, but diverges out of the lens 250 to increase the light efficiency, and the directivity is wide so that the light is spread evenly to a wide range. Can generate high light.

8 is an enlarged longitudinal sectional view of a wave type lens used in a comparative experiment. Referring to Figure 8 will be described a comparative experiment according to the image shape of the lens.

The image shape of the lens used in the comparative experiments is classified into a wave type and a flat type. The configuration of the light emitting diode having the wave type lens is shown in FIG. 6, and the configuration of the light emitting diode having the flat type lens is shown in FIG. 7. Since the experiment was performed only by changing the shape of the lens, the overall configuration of the light emitting diode used in the experiment is the same as described above, and a detailed description thereof will be omitted.

The size of the lens used in the experiment was 7.0 (mm) x 6.3 (mm), and the height (h) was 1.5 (mm). As a factor for specifying the wave shape of the upper surface of the lens, the horizontal distance (d) of the valley and the floor is 0.4 (mm), the radius of curvature of the curved surface (R) is 0.26 (mm), and the valley and the floor The angles α and α 'formed by the tangents at the contacts were set to 90 °, respectively.

In addition, the size of used in the experiment was 1 × 1 × 0.08 [W × D × H, mm], and the applied power was 3.5 (V) and 350 (mA).

Under the above conditions, the measurement distance with the light source (light emitting diode) was 10 (cm) and the dark room environment was created, and then the light intensity and the wavelength were measured with a detector. Instrument's C140-B instrument was used as the detector. JIG TOOL connected with optical fiber was connected to C140-B measuring equipment and the light emitting diode mounted on the socket was inserted into JIG TOOL (JIG of cylindrical dark room atmosphere) connected with detector sensor and optical fiber.

As shown in Table 1, the experimental results of the comparative experiments show that the light intensity of the light emitting diode with the wave type lens is increased by about 10.4% compared to the light emitting diode with the flat type lens. I could see.

No. Wave type (Figure 6) Flat type (Fig. 7) Rate of Change (Luminous Intensity) magnitude wavelength magnitude wavelength One 6.45 529.3 4.00 534.0 2 6.30 529.9 3.98 534.2 3 5.96 528.8 5.83 531.7 4 5.80 531.8 6.34 530.8 5 6.82 529.2 6.20 531.5 6 6.38 529.2 6.16 531.5 7 6.51 531.1 6.15 527.1 8 6.66 529.8 6.11 531.7 9 6.62 530.7 6.09 531.5 10 6.72 531.8 6.17 527.5 11 6.14 530.2 6.12 531.3 12 6.64 529.0 6.28 531.1 13 6.03 529.0 6.26 527.2 14 6.69 529.1 6.24 530.6 15 6.41 530.4 5.99 527.4 16 7.27 529.7 6.10 531.5 17 7.32 531.2 5.98 527.1 18 6.41 530.1 6.11 532.1 19 7.10 530.5 6.10 532.1 20 6.44 529.8 6.16 531.6 Max. 7.32 531.8 6.34 534.2 15.3% Avg. 6.53 530.0 5.92 530.7 10.4% Min. 5.80 528.8 3.98 527.1 45.8%

<Table 1: Comparative Experiment Data According to Image Shape of Lens>

9 is a flowchart illustrating a method of manufacturing a light emitting diode according to a preferred embodiment of the present invention.

Referring to FIG. 9, in the frame substrate forming step 410, a coupling hole penetrated up and down in the center, a stepped protrusion inward from the upper end of the inner circumferential surface of the coupling hole, and an electrode terminal formed in a circuit pattern on the outer circumference of the coupling hole Manufacturing a frame substrate having a.

The electrode terminal is formed as a circuit pattern, and land patterns are formed on the upper and lower surfaces of the copper-clad laminate by etching to form circuit patterns, and the upper and lower circuits are connected by via holes. It is formed by the general PCB circuit pattern formation method.

In the heat sink slug coupling step 420, the heat sink is seated and coupled to the coupling hole by bonding the lower surface of the step and the upper surface of the heat sink slug through an adhesive means.

As the bonding means, individual substances or mixtures such as glue, epoxy resin, and thermal compound can be used.

In the step of mounting and bonding the light emitting diode chip 430, the light emitting diode chip is mounted and bonded using a paste having excellent thermal conductivity on the exposed upper surface of the heat sink slug through the coupling hole.

In the electrical connection step 440 between the LED chip and the electrode terminal, the electrode terminal formed on the top surface of the LED chip and the frame substrate mounted on the heat sink slug is bonded with gold (Au) wire. In addition to wire bonding, various means such as conductive paste and tab bonding may be used.

In the lens forming step 450 using a mold, a mold having a release agent applied therein is installed on the frame substrate to facilitate ejection, and an epoxy resin is injected into the mold while applying pressure to the mold with a mold press. After curing under a predetermined curing condition, the lens is molded by demolding.

In the epoxy resin injected into the mold, a diffusion agent or a phosphor may be mixed corresponding to the color of the light emitting diode.

In addition, as a method of molding a lens, the liquid epoxy and the curing agent applied in the present embodiment are mixed at a predetermined mixing ratio, so that not only injection molding but also epoxy in the form of EMC (Epoxy Molded Compound) is transferred. Various methods such as transfer molding may be considered.

Finally, in the dicing step 460 of the frame substrate, by dicing the frame substrate in which the lens is molded to a predetermined size to complete the light emitting diode according to the present invention, a method of manufacturing a light emitting diode suitable for mass production is provided. .

Although the preferred embodiments of the present invention have been described above, those skilled in the art can variously modify and modify the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. It will be appreciated that it can be changed.

According to the present invention having the above configuration, by adopting a hole structure that is easy to bond the heat sink slug to the frame substrate on which the circuit pattern is formed, not only facilitates the coupling of the heat sink slug during manufacturing, but also the light emitting diode on the PCB It is possible to provide a light emitting diode suitable for increasing productivity in mass production by soldering in a general reflow method during surface mounting (SMT) and a method of manufacturing the same.

In addition, by molding an epoxy resin in a mold to form a lens in a constant shape and size, it is possible to form a lens of a variety of shapes having a relatively uniform optical characteristics for each light emitting diode. In particular, the surface adopts a wave-shaped lens, so that light above the critical angle is not reflected on the interface of the lens surface and is emitted outside the light emitting diode, so that the light efficiency is excellent, the directivity is high, and the light can emit high uniformity. And a method for producing the same.

Claims (8)

A frame substrate including a coupling hole, a step projecting inwardly from an upper end of an inner circumferential surface of the coupling hole, and an electrode terminal formed in a circuit pattern around the coupling hole; A heat sink slug seated and bonded to the bottom surface of the stepped portion; A light emitting diode chip mounted on the heat sink slug exposed through the coupling hole; Conductive coupling means for electrically connecting the light emitting diode chip and the electrode terminal; A lens coupled to the frame substrate to cover the light emitting diode chip; The electrode terminal penetrates the frame substrate and is formed on the upper and lower surfaces of the frame substrate, wherein the conductive coupling means is a light emitting diode, characterized in that the conductive wire. delete The method of claim 1, The longitudinal cross section of the lens includes a top surface of the wave (Wave) shape. (a) forming a frame substrate including a coupling hole, a stepped protrusion protruding inward from an upper end of an inner circumferential surface of the coupling hole, and an electrode terminal formed in a circuit pattern around the coupling hole; (b) coupling a heat sink slug to the coupling hole; (c) mounting a light emitting diode chip on an exposed top surface of the heat sink slug; (d) electrically connecting the light emitting diode chip to the electrode terminal; (e) installing a mold coated with a releasing agent on the frame substrate and applying pressure to the mold with the mold press; (f) injecting and curing an epoxy resin into the mold to mold the lens; (g) removing the mold and dicing the molded frame substrate to a predetermined size. The method of claim 4, wherein The step (b) is a light emitting diode manufacturing method performed by bonding using any one or more of the adhesive (Glue), epoxy resin, and the thermal compound (Thermal Compound). The method of claim 4, wherein The mold includes a light emitting diode manufacturing method comprising a top surface having a wave-shaped longitudinal section. The method of claim 4, wherein The step (f) is performed by injection molding by mixing the main ingredient of the liquid epoxy and the curing agent in a predetermined mixing ratio, or by performing epoxy molding in the form of an epoxy molded compound (EMC) by transfer molding. Method for manufacturing a light emitting diode. The method of claim 4, wherein The epoxy-based resin is a light emitting diode manufacturing method comprising a diffusion agent or a phosphor corresponding to the color of the light emitting diode.

Images