KR20080017527A - Led package and method of manufacturing the same - Google Patents

Abstract

A light emitting element and a manufacturing method of the same are provided are provided to improve color coordinate uniformity of white light by equalizing path differences with respect to all kinds of light radiated therefrom. A light emitting element package includes a package body, an electrode(200), a light emitting element(400), a light-transmitting barrier rib(300), and a phosphor. The package body includes an installation part of the light emitting element. The electrode is formed on the package body. The light emitting element is installed on the installation part. The light-transmitting barrier rib is positioned at a peripheral part of the light emitting element. The phosphor is deposited on the light-transmitting barrier rib. The light-transmitting barrier rib is formed of a light-transmitting photoresist, a photosensitive polymer or a glass.

Description

Light emitting device package and its manufacturing method {LED package and method of manufacturing the same}

1 is a cross-sectional view showing an example of a general light emitting device.

2 is a cross-sectional view showing an example of a conventional light emitting device package for white light emission.

3 to 5 are cross-sectional views showing a first embodiment of the present invention.

3 is a cross-sectional view showing a step of forming a partition wall.

4 is a cross-sectional view showing a step of mounting a light emitting device.

5 is a cross-sectional view showing a step of filling the filler.

6 to 8 are cross-sectional views showing a second embodiment of the present invention.

9 is a sectional view showing a third embodiment of the present invention.

10 and 11 are sectional views showing the fourth embodiment of the present invention.

<Brief description of the main parts of the drawing>

100: substrate 101: package body

110: through hole 120: mounting portion

200 electrode 210 front electrode

220: rear electrode 300: partition wall

310: filler 400: light emitting device

The present invention relates to a light emitting device package and a method for manufacturing the same, and more particularly, to a light emitting device package capable of emitting uniform white light and a method of manufacturing the same.

Light Emitting Diodes (LEDs) are well-known semiconductor light emitting devices that convert current into light.In 1962, red LEDs using GaAsP compound semiconductors were commercialized, along with GaP: N series green LEDs. It has been used as a light source for display images of electronic devices, including.

The wavelength of light emitted by such LEDs depends on the semiconductor material used to make the LEDs. This is because the wavelength of the emitted light depends on the band-gap of the semiconductor material, which represents the energy difference between the valence band electrons and the conduction band electrons.

Gallium nitride compound semiconductors (Gallium Nitride (GaN)) have attracted much attention in the field of high power electronics development due to their high thermal stability and wide bandgap (0.8-6.2 eV). One reason for this is that GaN can be combined with other elements (indium (In), aluminum (Al), etc.) to produce semiconductor layers that emit green, blue and white light.

This adjustable emission wavelength allows the material to be tailored to specific device characteristics. For example, GaN can be used to create white LEDs that can replace incandescent and blue LEDs that are beneficial for optical recording.

In addition, in the case of the conventional green LED, it was initially implemented as GaP, which was inefficient as an indirect transition type material, and thus practical pure green light emission could not be obtained. However, as InGaN thin film growth succeeded, high brightness green LED could be realized. It became.

Because of these and other benefits, the GaN series LED market is growing rapidly. Therefore, since commercial introduction in 1994, GaN-based optoelectronic device technology has rapidly developed.

Since the efficiency of GaN light emitting diodes outperformed the efficiency of incandescent lamps and is now comparable to that of fluorescent lamps, the GaN LED market is expected to continue to grow rapidly.

The development of this technology replaces not only display devices but also LED backlights, fluorescent lamps, and incandescent lamps, which replace the Cold Cathode Fluorescence Lamp (CCFL), which forms the backlight of optical communication means, transmission modules, and liquid crystal display (LCD) displays. Applications are expanding to white light emitting diode lighting devices and signals.

On the other hand, in addition to LEDs driven by DC power, LED chips for high voltage AC, which operate on general AC power, have also been developed. For this purpose, in order to apply light emitting devices, the operating voltage must be high at the same power and the driving current must be low. The brightness should be high.

A manufacturing step of the structure of a general LED device is performed on the substrate 1 such as sapphire, buffer layer 2, n-type semiconductor layer 3, active layer 4, p-type semiconductor layer 5, as shown in FIG. Are deposited successively, and the mesa (MESA) patterned to expose the n-type semiconductor layer (3), the current diffusion layer (6) is formed on the p-type semiconductor layer (5) with a transparent electrode that is easy to transmit light do.

Thereafter, the p-type electrode 7 and the n-type electrode 8 are formed on the p-type semiconductor layer 5 and the n-type semiconductor layer 3 for electrical connection with an external circuit, thereby forming an LED structure. Produce 10.

In the light emitting device, when voltage is applied between the p-type electrode 7 and the n-type electrode 8 in an external circuit, holes and electrons are injected into the p-type electrode 7 and the n-type electrode 8. As holes and electrons recombine in the active layer 4, extra energy is converted into light and emitted to the outside through the transparent electrode and the substrate.

The LED 10 manufactured by the above method is bonded to a sub-mount made of silicon or ceramic and used in a package form or mounted in another package.

There are two methods of making a white light source using the LED 10. First, a white light source is made using the blue, green, and red LEDs 10, or a phosphor is formed on the blue and violet light emitting devices. There is a method of making a white light source using.

2 illustrates a surface mounted light emitting device package 20 to which a molding technology of a lead frame structure is applied.

The light emitting device package 20 is die-bonded to the lead frame 21 made of a conductive metal to the LED 10 and the zener diode 30 to complement the withstand voltage characteristics by using a bonding resin.

The n-type electrode of the LED 10 and the p-type electrode of the Zener diode 30 and the p-type electrode of the LED 10 and the n-type electrode of the Zener diode 30 are connected in parallel, and two In order to electrically connect the electrode with the electrode 22 located in the lead frame 21, the wire 23 is used to electrically connect the electrode.

In the next process, the filler 24 mixed with the molding composite resin powder and the phosphor is trapped on the lead frame 21 to which the LED 10 is bonded to convert the wavelength of light emitted from the light emitting device 10. Various kinds of light emitting sources including a white light source are manufactured.

With respect to the light emitted from such a structure, the light paths indicated by a, b, and c will be described by way of example.

In the a, b, and c paths corresponding to the light paths from which the light emitted from the LED 10 may collide with the phosphor, the a path has a higher probability of colliding with the phosphor than the b path and the c path. It emits white light that it contains.

On the other hand, since the b-path has a smaller probability of colliding with the phosphor than the a- and c-paths, the b-path emits white light including blue, thereby causing a problem in that color coordinates are non-uniform for each position of the white light emitting device.

As such, there is a problem in that a path difference occurs when reaching the surface and uniform light cannot be obtained, and color reproducibility is deteriorated due to non-uniformity of the phosphor contained in the epoxy.

SUMMARY OF THE INVENTION The present invention has been made in an effort to provide a light emitting device package and a method of manufacturing the same, which can implement a white light emitting device capable of improving color coordinate uniformity by position of the light emitting device by using uniform phosphor formation.

In order to achieve the above technical problem, the present invention, a light emitting device package, comprising: a package body having a mounting portion of the light emitting device; An electrode formed on the package body; A light emitting element mounted on the mounting portion; A translucent partition wall positioned at a periphery of the light emitting device; It is preferably configured to include a phosphor filled in the partition wall.

The partition wall may be formed of any one of a light transmissive photoresist, a photosensitive polymer, and glass.

In addition, the partition wall may be formed such that the distance between the partition wall and the light emitting device is constant, and in particular, the height difference between the upper side and the partition wall of the light emitting device is formed to be equal to the distance between the side portion and the partition wall of the light emitting device. It is preferable.

The package body may be formed of any one of a submount, a ceramic substrate, and a semiconductor substrate.

The electrode may include a front electrode positioned on the front surface of the package body and connected to the light emitting device; Located on the rear of the package body and may be configured to include a back electrode connected to the front electrode.

In this case, the front electrode and the rear electrode may be connected through a through hole penetrating the package body, and the through hole is preferably formed in an isolation region of the package.

On the other hand, the phosphor may be mixed with the filler and filled in the partition wall.

A lead connected to the partition wall and the phosphor by a wire; It may further include a lens attached to the upper side of the light emitting device.

The light emitting device may be a horizontal light emitting device that is wire bonded or flip chip bonded, and a vertical light emitting device may also be used.

In another aspect, the present invention provides a method of manufacturing a light emitting device package, comprising: forming a partition wall defining a region around the light emitting device on a mounting portion on which a light emitting device is to be mounted on a substrate; Mounting a light emitting element on the mounting portion; It is preferably configured to include a step of filling the phosphor inside the partition wall.

Prior to forming the barrier rib, the method may further include forming an electrode on the substrate.

The barrier rib may be formed by coating a photosensitive polymer on the substrate and then using a photolithography process. The barrier rib may be formed by attaching a barrier rib of a light transmissive material to the substrate.

On the other hand, the phosphor may be filled by mixing with epoxy or silicone gel.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First Embodiment

3 to 5 illustrate manufacturing steps of the light emitting device package according to the first embodiment of the present invention.

First, as shown in FIG. 3, a through hole 110 is formed in a substrate 100 of a 2D sub-mount of a light emitting device, a ceramic substrate to be used as a package, or a silicon substrate by a laser or an etching method.

As such, the substrate 100 on which the through holes 110 are formed becomes a package body.

An electrode 200 connected to the mounting unit 120 to which the light emitting device is bonded is formed on the front surface of the substrate 100.

As shown in FIG. 3, the electrode 200 is connected to the front and rear surfaces of the substrate 100 using metal lines. That is, the front electrode 210 connected to the light emitting device and the rear electrode 220 formed on the back of the substrate 100 may be connected to each other by the through hole 110.

The back electrode 220 may be electrically connected to an external circuit for supplying current to the light emitting device.

In this case, the through hole 110 is preferably formed in the separation region of the package.

Subsequently, the partition 300 having excellent light transmittance at regular intervals is formed on the front surface of the substrate 100 on which the light emitting device 400 is mounted.

The partition 300 may be formed using a photosensitive polymer. That is, the photosensitive polymer may be coated on the entire surface of the substrate 100, and the photosensitive polymer in the portion where the partition wall 300 is formed may be left by using a photolithography process, and the photosensitive polymer in the other region may be removed.

In addition, a barrier material 300 may be formed by forming a material having excellent light transmittance such as glass in the form of a barrier and bonding the substrate 100 to the substrate 100.

As described above, after the submount or the package is manufactured, the light emitting device 400 is bonded as shown in FIG. 4.

Subsequently, as shown in FIG. 5, the space between the barrier rib and the light emitting device is filled with a filler 310 such as epoxy or silicon gel containing phosphor.

The barrier rib 300 may be formed such that the height difference between the upper surface of the light emitting device 400 and the barrier rib 300 is equal to the distance between the side portion of the light emitting device 400 and the barrier rib 300.

Accordingly, the light emitted from the side of the light emitting device 400 of the A and B paths of FIG. 5 and the light emitted to the upper part of the light emitting device 400 of the C path may have the same path difference, thereby forming a uniform light distribution. Will be.

The light emitting device 400 may use both a horizontal light emitting device and a vertical light emitting device.

Subsequently, a lens (not shown) may be further configured on the substrate 100 on which the light emitting device 400 is packaged, and then separated into individual packages and used.

Second Embodiment

6 to 8 illustrate manufacturing steps of the light emitting device package according to the second embodiment of the present invention.

As shown in FIG. 6, first, a through hole 110 is formed on a silicon substrate 100 to be used as a sub-mount or package of a light emitting device using a solution capable of anisotropic etching such as KOH or TMAH.

As such, when the through-hole 110 is formed by etching, the through-hole 110 as shown in FIG. 6 is formed, and the etching for forming the through-hole 110 is performed by etching the front and rear surfaces of the substrate, respectively. Can be connected to each other.

Subsequently, an electrode 200 connected to the mounting unit 120 to which the light emitting device is bonded is formed on the front surface of the substrate 100.

The electrode 200, as in the first embodiment, so that the front electrode 210 and the rear electrode 220 formed on the back of the substrate 100 to be connected to the light emitting device are connected to each other by the through hole 110. can do.

In addition, the process of forming the partition 300, mounting the light emitting device 400 on the mounting unit 120, and filling the filler 310 is the same as in the first embodiment.

Third Embodiment

9 shows a light emitting device package according to a third embodiment of the present invention.

In the light emitting device package, the light emitting device 400 is bonded to the aluminum slug 130 having a mirror surface by using an adhesive 140, and a material having excellent light transmitting property is used around the light emitting device 400. The partition 300 is formed.

Between the barrier rib 300 and the light emitting device 400, a filler 310 such as epoxy or silicon gel containing phosphor is filled.

Meanwhile, the lead 150 fixed by the package body 101 is electrically connected to the electrode of the light emitting device 400 by the conductive wire 160.

As described above, the lens 170 may be formed or directly attached to the upper side of the package body 101 to which the light emitting device 400 is bonded.

The partition wall 300 is preferably formed such that the height difference between the upper surface of the light emitting device 400 and the partition wall 300 is equal to the distance between the side portion of the light emitting device 400 and the partition wall 300. Same as the above embodiment.

Fourth Embodiment

10 and 11 illustrate manufacturing steps of the light emitting device package according to the fourth embodiment of the present invention.

That is, as shown in FIG. 10, the through-hole 110 is formed in the ceramic substrate or silicon substrate 100 to be used as a sub-mount or package of the light emitting device by a laser or etching method, and the mounting unit 120 on which the light emitting device is to be mounted. ).

As shown in the drawing, the mounting part 120 is formed in a groove shape etched and recessed inward to reflect the light emitted from the side of the light emitting device upward.

As such, the substrate 100 on which the through holes 110 are formed becomes a package body.

As shown in FIG. 10, an electrode 200 connected to the front and rear surfaces of the substrate 100 is formed on the substrate 100 by using a metal line.

That is, the electrode 200 may allow the front electrode 210 connected to the light emitting device and the rear electrode 220 formed on the back of the substrate 100 to be connected to each other by the through hole 110.

In this case, the through hole 110 is preferably formed in the separation region of the package.

Subsequently, the partition 300 having excellent light transmittance at regular intervals is formed on the front surface of the substrate 100 on which the light emitting device 400 is mounted.

The partition 300 may be formed using a photosensitive polymer. That is, the photosensitive polymer may be coated on the entire surface of the substrate 100, and the photosensitive polymer in the portion where the partition wall 300 is formed may be left by using a photolithography process, and the photosensitive polymer in the other region may be removed. A barrier material 300 may be formed by forming a material having excellent light transmittance such as glass in the form of a barrier rib and joining the substrate 100.

In this manner, after the submount or the package is manufactured, the light emitting device 400 is bonded. In this case, as illustrated, the light emitting device 400 may be mounted by flip chip bonding.

That is, the horizontal light emitting device may be bonded to the electrode 200 in an inverted structure, and in this case, a zener diode (not shown) may be provided on the electrode.

Thereafter, as shown in FIG. 11, the space between the barrier rib and the light emitting device is filled with a filler 310 such as epoxy or silicon gel containing phosphor.

The barrier rib 300 may be formed such that the height difference between the upper surface of the light emitting device 400 and the barrier rib 300 is equal to the distance between the side portion of the light emitting device 400 and the barrier rib 300.

The light emitted from the light emitting device 400 has almost the same path through the phosphor, which is the same as the above embodiment.

At this time, the light emitted from the side of the light emitting device 400 changes the wavelength of the light through the phosphor, the partition 300 is excellent in light transmission, so the emitted light passes through the partition 300 and the mounting portion 120 Reflected at the side wall and directed upwards.

In this case, a separate reflective film (not shown) may be formed on the sidewall 121 of the mounting part 120.

The above embodiment is an example for explaining the technical idea of the present invention in detail, and the present invention is not limited to the above embodiment, various modifications are possible, and various embodiments of the technical idea are all protected by the present invention. It belongs to the scope.

The present invention as described above has the following effects.

First, the uniformity of the color coordinates of the white light can be greatly improved by equalizing the path difference with respect to all the light emitted from the light emitting device.

Second, a white light source suitable for mass production and excellent in reproducibility can be obtained by forming a package and a partition wall using a semiconductor process.

Claims (16)

In the light emitting device package, A package body having a mounting portion of the light emitting element; An electrode formed on the package body; A light emitting element mounted on the mounting portion; A translucent partition wall positioned at a periphery of the light emitting device; Light emitting device package comprising a phosphor filled in the partition wall. The light emitting device package of claim 1, wherein the barrier rib is formed of any one of a light transmissive photoresist, a photosensitive polymer, and glass. The light emitting device package of claim 1, wherein the partition wall is formed such that a distance between the partition wall and the light emitting device is constant. The light emitting device package of claim 1, wherein the height difference between the upper surface of the light emitting device and the partition wall is equal to a distance between the side of the light emitting device and the partition wall. The light emitting device package according to claim 1, wherein the package body is any one of a submount, a ceramic substrate, and a semiconductor substrate. The method of claim 1, wherein the electrode, A front electrode positioned on the front surface of the package body and connected to the light emitting device; The light emitting device package, characterized in that comprising a rear electrode located on the rear of the package body and connected to the front electrode. The light emitting device package of claim 6, wherein the front electrode and the rear electrode are connected through a through hole passing through the package body. The light emitting device package according to claim 7, wherein the through hole is formed in an isolation region of the package. The light emitting device package of claim 1, wherein the phosphor is mixed with a filler to fill the partition wall. The method of claim 1, A lead connected by the electrode and a wire; The light emitting device package further comprises a lens attached to the upper side of the light emitting device. The light emitting device package of claim 1, wherein the light emitting device is flip chip bonded. In the manufacturing method of the light emitting device package, Forming a partition on a substrate on which a light emitting device is to be mounted, the partition defining a region around the light emitting device; Mounting a light emitting element on the mounting portion; Method of manufacturing a light emitting device package comprising the step of filling the phosphor inside the partition wall. The method of claim 12, further comprising forming an electrode on the substrate before the forming of the partition wall. The method of claim 12, wherein the barrier rib is formed by coating a photosensitive polymer on the substrate using a photolithography process. The method of claim 12, wherein the partition wall is formed by attaching a partition wall of a light transmissive material to the substrate. The method of claim 12, wherein the phosphor is mixed with an epoxy or a silicone gel to fill the phosphor.

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