WO2009096685A2

WO2009096685A2 - Led package, and a production method therefor, and a device using the led package

Info

Publication number: WO2009096685A2
Application number: PCT/KR2009/000363
Authority: WO
Inventors: Hyunmin Kim; Seonwook Hwang; Gillsun Lee
Original assignee: Amoleds Co., Ltd.
Priority date: 2008-01-29
Filing date: 2009-01-23
Publication date: 2009-08-06
Also published as: WO2009096685A3

Abstract

The present invention provides an LED package having a wide directivity angle even without the use of a lens, a production method for the same, and a device arranged in such a way as to have a batwing characteristic by using such LEDs. The LED package provided by the present invention comprises: a substrate, of which the lower parts of the side surfaces are formed with recessed solder pads; a pattern electrode which is formed on the upper surface of the substrate and which is electrically connected with the solder pads; a light-emitting element mounted on the upper surface of the pattern electrode; and a fluorescent block which is installed on the upper surface of the substrate and which is for the sideways and upwards emission of the light emitted from the light-emitting element. When the present invention is employed, the directivity angle is greatly widened as compared with a conventional LED package even without the use of a lens since the light from the light-emitting element is emitted upwards and sideways through the fluorescent block. A directivity angle with a batwing characteristic can be obtained if two LED packages, which can emit light sideways and upwards, are provided with their floor surfaces facing each other.

Description

LED package, manufacturing method thereof, and apparatus using the LED package

The present invention relates to an LED package, a method for manufacturing the same, and an apparatus using the LED package, and more particularly, to an LED package capable of emitting light upward and to the side, a method for manufacturing the same, and an apparatus using the LED package.

The current application trend of LED packages is moving from simple indicators of electronic devices to flash lamps of mobile phones to indirect lighting and backlight units of LCD TVs. Furthermore, it is likely to proceed directly to lighting.

Typically, a backlight unit employed in a flat panel display or the like has edge type (called edge type or side view type) and direct type (direct type or top view) depending on the position of a light source (lamp) (for example, an LED package). Method). The edge type backlight unit is provided with a light source on the side of the optical unit. In the direct type backlight unit, light sources are arranged in a row under the optical unit to directly emit light.

In case of installing the direct type backlight unit directly on the flat panel display device, one LED package must be installed for each pixel, and thus, a large number of LED packages must be used. In particular, since the light emitted from the LED has a strong straightness, the emitted light tends to concentrate in the front direction of the LED. Therefore, optical sheets such as a diffusion plate and a diffusion sheet are additionally used in order to uniformly inject light into the liquid crystal display panel as a whole. In light of recent trends toward slimmer display devices and reduced volume and weight, display devices employing direct type backlight units that additionally use optical sheets have limitations in slimming.

On the other hand, the shape of the lens of the LED package may be changed (processed) to further diffuse outgoing light. In this case, since the precise processing of the lens is required, not only manufacturing is difficult, but also manufacturing costs are high.

Accordingly, as shown in FIGS. 1 and 2, the flat panel display includes a pair of side

view LED packages

12a and 12b in a row on an upper surface of a bar type base substrate 10. Use a lot of backlight unit. A typical edge type LED package is an LED package with a reflecting plate, which can be easily understood by those in the same industry.

In the case of the backlight unit of Fig. 2, the left LED package 12a only emits light in the left direction, and the right LED package 12b only emits light in the right direction. That is, light is not emitted to the upper surface of the base substrate 10, but only light is emitted in the left direction and the right direction (that is, the lateral direction) of the base substrate 10.

The backlight unit as shown in FIGS. 1 and 2 uses fewer LED packages than the direct-type backlight unit because light spreads only from side to side to illuminate the screen (not shown).

However, the backlight unit of FIGS. 1 and 2 does not emit light to the upper surface, so when viewed from the front, the shadow unit (also referred to as a dark portion) appears along the long axis of the base substrate 10. This not only degrades the picture quality, but it is also not good visually and reduces the reliability of the product.

In addition, in the backlight unit of FIGS. 1 and 2, a direction angle of about 60 degrees to about 80 degrees is obtained when most of the backlight units are not used. Thus, hemispherical lenses are additionally provided to widen the orientation angle to approximately 120 degrees. In this case, it is necessary to fabricate a lens that is sophisticated enough to obtain a desired orientation angle, and it is very difficult to manufacture the lens precisely. And it is difficult to accurately attach the lens to the LED package. If the lens is not correctly attached in place, the desired orientation angle will not be obtained. Even if the lens is separately installed, it is difficult to obtain a direct angle of more than 120 degrees.

Nowadays, in the technical fields such as flat panel display devices and lighting devices, a wide direction angle of 120 degrees or more is required. However, the conventional technology described above does not satisfy the wide angle of view of 120 degrees or more.

Further, in the technical field, such as a flat panel display device and a lighting device, there is a need for a light source having batwing characteristics. The batwing characteristic means that the center portion has a shape of a light distribution curve that is recessed to the left and right. The batwing characteristic is also called the side emitting characteristic.

To this end, efforts have been made to attach a separate lens to the LED package or to change the shape of the lens, but in this case, the problems described above occur.

The present invention has been proposed to solve the above-mentioned conventional problems, and an object thereof is to provide an LED package and a method of manufacturing the same having a wide orientation angle without using a lens.

Another object of the present invention is to provide a device having a batwing characteristics by using the LED package of the above-described object.

In order to achieve the above object, the LED package according to a preferred embodiment of the present invention, the lower surface of the solder pad is formed recessed substrate; A pattern electrode formed on an upper surface of the substrate and electrically connected to the solder pads; A light emitting device mounted on an upper surface of the pattern electrode; And a phosphor block mounted on an upper surface of the substrate to emit light emitted from the light emitting device upwardly and laterally.

The solder pad is formed by coating the material of the solder pad on the wall surface of the groove formed on the lower side of the substrate.

A conductive pad is formed on the bottom of the substrate, and the conductive pad is electrically connected to the pattern electrode.

The phosphor block covers the upper side and the upper side of the light emitting element, and the upper side of the pattern electrode. Alternatively, the phosphor block covers the upper side and the side side of the light emitting element and the pattern electrode.

By installing a plurality of LED packages of the above-described embodiments on the base substrate, the bottom surface of the plurality of LED packages are opposed to each other, thereby completing the light output module having the batwing characteristics. In addition, a structure in which two LED packages of the above-described embodiments are arranged in one set and arranged in a row may be employed in a backlight unit or a lighting device of a flat panel display.

According to another embodiment of the present invention, an LED package includes: a substrate having inner pads formed therein exposed at both sides; A pattern electrode formed on an upper surface of the substrate and electrically connected to the inner pad; A light emitting device mounted on an upper surface of the pattern electrode; And a phosphor block mounted on an upper surface of the substrate to emit light emitted from the light emitting device upwardly and laterally.

And further comprising a recessed solder pad at the bottom of the side of the substrate, the solder pad being electrically connected with the pattern electrode.

The phosphor block covers the upper side and the side side of the light emitting element and the pattern electrode.

By installing a plurality of LED packages of the other embodiments described above on the base substrate, the bottom surface of the plurality of LED packages are opposed to each other, thereby completing the light output module having the batwing characteristics. In addition, a structure in which two LED packages of the above-described other embodiments are arranged in one set and arranged in a row may be employed in a backlight unit or a lighting device of a flat panel display.

According to an aspect of the present invention, there is provided a method of manufacturing an LED package, comprising: a base substrate preparing step of preparing a base substrate on which a pattern electrode is formed on an upper surface of each unit device region; A splitting groove forming step of forming a splitting groove at a predetermined depth on a bottom surface of the base substrate along a boundary line between unit device regions; A light emitting device mounting step of mounting a light emitting device on an upper surface of the pattern electrode for each unit device region of the base substrate; Combining the base phosphor blocks on the upper surface of the base substrate on which the light emitting device is mounted to form a laminate; A cutting groove forming step of forming a cutting groove at a predetermined depth along a boundary line between the unit element regions on an upper surface of the laminate; And a separating step of separating the laminate into a plurality of unit elements by using the splitting grooves and the cutting grooves, respectively.

In the preparing of the base substrate, the pattern electrodes of each unit device region are separated from each other.

The base substrate preparation step forms an inner pad in a direction crossing the pattern electrode in the base substrate, and electrically connects the inner pad and the pattern electrode to each other. In this case, both ends of the inner pad are exposed to both sides of each unit element separated by the separating step.

In the base substrate preparation step, a solder pad may be additionally formed in the lower portion of the side of the substrate, but the solder pad may be electrically connected to the pattern electrode and the inner pad.

According to the present invention of these embodiments, the following effects are obtained.

1) Since the light of the light emitting device is emitted upward and laterally through the phosphor block, the directivity angle is much wider than that of the conventional LED package without using a lens.

2) Since the reflector is not used, the structure is very simple compared to the conventional LED package.

3) By minimizing the portion of the pattern electrode exposed to the side of the LED package, there is an effect of minimizing the interface separation generated by performing the process for bonding the phosphor block and the substrate. On the other hand, since the pattern electrode is not exposed to the side of the LED package, there is an effect of completely removing the interfacial separation generated by performing the process for bonding the phosphor block and the substrate.

4) It is very efficient because the LED package can be surface mounted directly or edge type as needed.

5) When LED packages capable of emitting light to the side and upward are employed in the backlight unit, shadows (dark areas) are not generated on the base substrate even though fewer LED packages are used than in the prior art. This improves image quality and product reliability.

6) The backlight unit adopting the LED package which can emit light in the side and the upper side has the effect of the surface light source like the conventional CCFL (cold cathode fluorescent lamp) because the LED package can emit the light in the upward and side directions. You can get it.

7) The LED package is manufactured by half sawing method that creates a split groove and a cut groove, thereby easily producing a single reflector-free LED package at high speed. In other words, the time to manufacture the desired finished product is shortened.

8) By manufacturing the LED package in a half sawing method to generate a split groove and a cut groove, the service life of the blade for sawing is lengthened.

9) When the two LED packages capable of emitting light to the side and the top are installed with their bottoms facing each other, a direction angle having a batwing characteristic can be obtained. This is enough to realize a light source having a wide direct angle of the batwing characteristics required by the industry these days.

10) By using the layout structure for the backlight unit to obtain a wide angle of view of the batting characteristics, the shadow of the base board is not generated, which not only improves image quality and product reliability, but also batting characteristics. As a result, the effect is closer to the surface light source.

1 and 2 are views for explaining the configuration of a general backlight unit.

3 to 5 are views for explaining the configuration of the LED package according to the first embodiment of the present invention.

6 is a state diagram of FIG.

7 is a view for explaining a light emitting direction of the LED package according to the first embodiment of the present invention.

8 is a view for explaining the orientation angle of the LED package according to the first embodiment of the present invention.

9 is a view showing a backlight unit using an LED package according to a first embodiment of the present invention.

10 is an exploded perspective view of the LED package according to the second embodiment of the present invention.

FIG. 11 is a perspective view illustrating the remaining parts of the block except for the phosphor block in FIG. 10.

12 is a perspective view of the combination of FIG.

13 is a view for explaining a method of manufacturing an LED package according to a second embodiment of the present invention.

14 is a view showing a light emitting module and a backlight unit in which the light emitting module is installed, which is an example of an application device of the present invention.

15 to 17 are views for explaining the configuration of any one optical module of the light output module of FIG.

18 is a state diagram of FIG.

19 is a light distribution curve diagram of polar coordinates of the light output module of FIG. 14.

20 is a light distribution curve diagram in Cartesian coordinate form for the light output module of FIG.

21 is a view for explaining the difference between the backlight unit which is an example of the application of the present invention and the conventional backlight unit.

Hereinafter, an LED package, a manufacturing method thereof, and an apparatus using the LED package according to an embodiment of the present invention will be described with reference to the accompanying drawings. Hereinafter, it is assumed that the LED package is any SMD type package such as a ceramic package, a plastic package, a lead frame type package, and a plastic + lead frame type package. In the specification of the present invention, the LED package is set to be a light source employed in the backlight unit of the flat panel display device and a light source of the lighting device. The lighting device means a reading light, a street lamp, various indoor lights, and other lights that can use an LED package as a light source in addition to a flat panel display device. Therefore, in the specification of the present invention, the application device may be understood as a concept including a backlight unit, a lighting device, a light emitting module, and the like of a flat panel display device. The light emitting module means that two LED packages described in the following embodiments are formed in one set.

(First embodiment)

3 to 5 are views for explaining the configuration of the LED package according to the first embodiment of the present invention. 6 is a state diagram of FIG.

The LED package of the embodiment of the present invention includes the substrate 20, the phosphor block 30, and the LED chip 40.

The board | substrate 20 can be any if it can mount the LED chip 40 (light emitting element) at high density. For example, the material of the substrate 20 may include alumina, quartz, calcium zirconate, forsterite, SiC, graphite, fusedsilica, and mullite. Cordierite, zirconia, beryllia, and aluminum nitride, low temperature co-fired ceramic (LTCC), plastics, metals, varistors, and the like. Preferably, it is best to manufacture using a ZnO series varistor material. This is because varistors of ZnO series have high thermal conductivity. The production of ZnO-based varistor material not only functions as a varistor, but also allows the LED package to be rapidly cooled due to the high thermal conductivity of the varistor itself. In the first embodiment of the present invention, the material of the substrate 20 is assumed to be ceramic. The ceramic can be used as a multi-layer ceramic package (MLP) through the firing process by forming a metal conductor wiring pattern thereon.

Pattern electrodes

22 and 24 are formed on the upper surface of the substrate 20. The pattern electrode consists of a cathode electrode 22 and an anode electrode 24 spaced apart from each other. For example, the

pattern electrodes

22 and 24 take the form of a lead frame plated with on (Ag). The anode electrode 24 is formed on the substrate 20 so as to be spaced apart from the cathode electrode 22 for electrical insulation.

Although the planar shape of the board | substrate 20 was made rectangular in the figure, it may be square. If the planar shape of the substrate 20 is square, the planar shape of the phosphor block 30 will also be square. As a result of the experiment, it was found that the direction of the orientation is generally larger than the case of the rectangular shape of the plane shape. It is preferable that the plane size (width * length) of the substrate 20 and the plane size (width * length) of the phosphor block 30 are the same. This is to make it easier to place the LED package of the present invention when the edge is disposed. Here, to make the plane size of the substrate 20 and the plane size of the phosphor block 30 identical may be understood to include not only numerically the same but also some errors.

A portion of the edges of the

pattern electrodes

22 and 24 exposed to the adjacent side surface on the upper surface of the substrate 20 was minimized. This is to minimize the interface separation between the substrate block 20 and the phosphor block 30 that may be generated by performing a process (eg, oven curing) for bonding the phosphor block 30 to the substrate 20 later. For that. That is, the more portions of the edges of the

pattern electrodes

22 and 24 that are exposed from the upper surface of the substrate 20 to the adjacent side surfaces, the more likely that the interface separation occurs by the process for bonding the phosphor block 30 and the substrate 20. many. Thus, the interface separation can be minimized by removing the edge portions of each of the cathode electrode 22 and the anode electrode 24.

Conductive pads

26 and 28 are formed on the bottom surface of the substrate 20. The

conductive pads

26 and 28 are made of a conductive material. The

conductive pads

26 and 28 are spaced apart from each other. The conductive pad 26 is connected to the cathode electrode 22 through a through hole 25 penetrating through the substrate 20. The conductive pad 28 is connected to the anode electrode 24 through the through hole 25 penetrating the substrate 20. The through hole 25 is formed by a punching operation.

Solder pads 23 are connected to the

conductive pads

26 and 28 at the sides of the substrate 20, respectively. The solder pads 23 are coated with Ag, AgPd, Au, or the like. In the case of AgPd, the ratio of Pd is selected in consideration of physical properties with the material of the substrate 20. The reason for using Ag, AgPd, Au is because it reacts well with solder. What is necessary is just to determine the coating material of the solder pad 23 in consideration of each condition. As a method of coating Ag, AgPd, Au, etc., a conductive powder such as Ag, AgPd, Au, etc. is made into a fine powder, mixed with an organic binder, and pasted to form a paste. That is, the method of coating on the wall surface of the solder pad 23 to be formed) may be used. Of course, a printing or plating process may be further performed to prevent peeling that may occur in the reflow process after surface mounting of the LED package.

If there is a method that can form the solder pads 23 in addition to the coating method described above, it is possible to employ. Instead of the thin coating method, the material of the solder pad 23 may be completely filled in each groove or a piece of metal of the same size as the groove may be bonded to each groove. However, in that case, there is a high possibility that the solder pads 23 fall off during sawing for a single piece. Therefore, it is preferable to employ a thin coating method.

Of course, it is also possible to coat the material of the solder pad 23 at the position without making a groove in the lower portion of one side of the substrate 20. In this case, when the completed LED package is laid down (that is, the area where the solder pad 23 is formed closely adheres to the surface of the lower PCB substrate (not shown)), the LED package may be slightly damaged due to the thickness of the solder pad 23. It is inclined form. The tilted LED package makes it difficult to obtain the desired alignment curve. Therefore, it is more preferable to form a groove in the lower portion of one side of the substrate 20 to form the solder pad 23 in the groove.

When the LED package of the first embodiment is mounted in a top view (ie, mounted in a state as shown in FIG. 6), the

conductive pads

26 and 28 on the bottom of the substrate 20 are disposed on the lower PCB substrate (not shown). Soldered). Of course, in this case, when soldering of the

conductive pads

26 and 28 is difficult, the solder pads 23 may be soldered together. The solder pads 23 provide for ease of soldering. The solder pad 23 on the side of the substrate 20 is soldered to the lower PCB substrate (not shown) even when the LED package of the first embodiment is mounted in an edge type (that is, the LED package of FIG. 6 is laid down 90 degrees). You can. That is, the LED package of the first embodiment can be surface mounted in both a direct type and an edge type.

On the other hand, the LED package of the first embodiment can be surface mounted in a direct type and an edge type without forming the

conductive pads

26 and 28. For example, in FIG. 3, the grooves for forming the solder pads 23 may be dug deeper to directly connect the

pattern electrodes

22 and 24 and the solder pads 23 through the through holes 25. In this way, the surface mounting in the direct type by the solder pad 23 is possible, and the surface mounting in the edge type is also possible.

The LED chip 40 is mounted on the pattern electrode (for example, the cathode electrode 22). The LED chip 40 is electrically connected to the anode electrode 24 through the wire 42. Although not shown in the drawings, the LED chip 40 and the cathode electrode 22 are insulated by an insulating material. If necessary, the anode electrode may be used as the cathode electrode and the cathode electrode may be replaced with the anode electrode. In this case, the driving power application method may be reversed.

The phosphor block 30 is stacked on the upper surface of the substrate 20 on which the LED chip 40 is mounted. The phosphor block 30 may be composed of silicon (or epoxy) without using phosphor or silicon (or epoxy) and diffuser if the LED chip 40 can emit white light. When no phosphor is used, the silicon block may be referred to instead of the phosphor block. The phosphor block 30 is a mixture of yellow phosphor and silicon (or epoxy) if the LED chip 40 emits blue light, for example. It is natural that the type and compounding degree of the phosphor can be sufficiently controlled.

The LED package of the first embodiment described above does not have a separate reflector. As a result, light emission to the left and right side surfaces (a direction; side) and light emission to the upper surface (b direction; upward) are possible as shown in FIG. 7. Although the a direction of FIG. 7 is illustrated as meaning only light output toward the left and right sides, it is preferable to include light output toward the short side of the phosphor block 30. In FIG. 7, the long axis of the LED package 50 is referred to as the X axis, and the short axis is set to the Y axis, and the luminance of the X axis and the Y axis is compared with Table 1 below.

Table 1

	I _F [mA]	IV [cd]
Y axis (side emission)	20	0.256
X axis (upper emission)	20	0.578

That is, if the luminous intensity ("0.578") by the upper emission (emission in the b direction) is 100%, the luminous intensity ("0.256") by the side emission (the emission in the a direction) is 44% of the luminous intensity by the upper emission. It is enough. In other words, the luminous intensity of the side light emission relative to the top light emission is about 50%.

On the other hand, looking at the orientation angle based on the X-axis and the orientation angle based on the Y-axis, as shown in the light distribution curve of FIG. The X-axis orientation angle is approximately 160 degrees to 170 degrees as in FIG. 8A, and the Y-axis orientation angle is approximately 140 to 145 degrees as in FIG. 8B.

It can be seen that the LED package of the first embodiment has a much larger orientation angle than that of the conventional LED package.

Referring to FIG. 8A, the LED package of the first embodiment may also be viewed as having a batwing characteristic. Of course, this is somewhat inferior to FIG. 19 which will be described later.

According to the LED package of the first embodiment described above, since the light of the light emitting device is emitted upward and laterally through the phosphor block, the directivity angle is much wider than that of the conventional LED package. In addition, since the reflective plate is not used, the structure is very simple compared to the conventional LED package.

By minimizing the portion of the pattern electrode exposed to the side of the LED package, there is an effect of minimizing the interface separation generated by performing a process for bonding the phosphor block and the substrate (eg, oven curing).

Both direct mounting and edge mounting are possible.

9 is a view illustrating a backlight unit employing an LED package according to a first embodiment of the present invention.

The LED package of the above-described first embodiment (that is, the LED package capable of emitting light in the side and upward) can be employed in the backlight unit. That is, the plurality of LED packages 50 are spaced apart from each other at predetermined intervals on the bar type base substrate 10 and are arranged in one line.

When the LED package 50 (that is, the LED package capable of emitting light to the side and upward) is installed on the base substrate 10 as shown in FIG. 9, a smaller number of LED packages can be used than in the related art (FIG. 2). do. In addition, light emission toward the side and the upper side is performed together so that shadows (also called dark portions) do not occur along the long axis of the base substrate 10. This not only improves image quality as compared to the conventional art, but also improves the visual quality and reliability of the product.

Thus, the backlight unit employing the LED package of the first embodiment is an example of the application device in the present invention. In the backlight unit employing the LED package of the first embodiment, LED packages capable of emitting light to the side and the top are arranged one by one, thereby generating shadows (dark portions) on the base substrate even though fewer LED packages are used than in the related art. It won't let you. This improves image quality and product reliability.

In the backlight unit employing the LED package of the first embodiment, the LED package emits light in all directions, thereby obtaining the effect of the surface light source.

The LED package of the first embodiment described above can serve as a light source sufficiently for an illumination device or the like, in addition to being employed in the backlight unit of the flat panel display device. Accordingly, it is very effectively used for lighting devices requiring a wide directing angle of 120 degrees or more.

In the first embodiment described above,

protrusions

22a and 24a are formed on both sides of the cathode electrode 22 and the anode electrode 24, respectively (see FIG. 3). The

protrusions

22a and 24a are exposed to both sides of the upper surface of the substrate 20, respectively. The

protrusions

22a and 24a are used for connecting the plating lines with other LED packages which are positioned next to the corresponding LED packages in the manufacturing process. The

pattern electrodes

22 and 24 are plated (for example, silver plated) by an electroplating process utilizing the

protrusions

22a and 24a.

In the first embodiment, in order to minimize the interfacial separation generated when the phosphor block 30 and the substrate 20 are combined, the pattern electrode is disposed on the side of the substrate 20 except for the

protrusions

22a and 24a for the plating process. (22, 24) was not exposed.

However, there is a case where the heterojunction between the silicon of the phosphor block 30 and the

protrusions

22a and 24a is not properly performed because the

protrusions

22a and 24a still remain. In that case, after the mold, the interface separation between the substrate 20 and the phosphor block 30 (more specifically, the interface separation between the

protrusions

22a and 24a and the phosphor block 30) occurs. When the interfacial separation occurs, moisture is penetrated by the floating in the corresponding area, which adversely affects the operation reliability of the LED package.

On the other hand, in order to manufacture the LED package of the first embodiment described above, the LED chip is mounted after first placing a lead frame plate (that is, a plate formed with an electrode shape to be used as a pattern electrode and being silver plated) on a substrate of the original plate. After wire-bonding the LED chip, the phosphor block plate of the original plate is placed by molding or the like. Thereafter, the sawing machine is sawed to complete the single package LED. Such a manufacturing process can be sufficiently inferred by those skilled in the same industry using well-known techniques based on the structure described above. In addition, this manufacturing process will take a full sawing method for simultaneously cutting the phosphor block 30 and the ceramic substrate 20. This pull sawing method requires a lot of work time because the phosphor block 30 and the ceramic substrate 20 must be cut at the same time. Of course, if the sawing speed is increased, working time can be reduced, but this will not only make the cutting surface uneven but also have a high possibility of burrs on the cutting surface. In addition, since the ceramic is harder than the phosphor, the service life of the blade for sawing is not long. As a result, the requirements of the blades increase, thereby increasing the operating cost.

Therefore, the second embodiment to be described below is characterized by completely eliminating the interface separation between the substrate and the phosphor block, shortening the finished product manufacturing time and extending the service life of the blade.

(Second embodiment)

10 is an exploded perspective view of the LED package according to the second embodiment of the present invention. FIG. 11 is a perspective view illustrating the remaining parts of the block except for the phosphor block in FIG. 10. 12 is a perspective view of the combination of FIG. The same reference numerals are given to the same components as those of the above-described first embodiment among the components in FIGS. 10 to 12, and detailed description thereof will be omitted.

The LED package of the second embodiment includes the substrate 60, the phosphor block 30, and the LED chip 40.

The description of the substrate 60 is the same as that of the substrate 20 of the first embodiment described above.

In the second embodiment, the substrate 60 is formed by stacking a plurality of

ceramic sheets

61, 62, 63, 64. In the lowermost ceramic sheet 64, two through holes 65 are spaced apart from each other and are formed in the vertical direction. The through hole 65 is formed by a punching operation.

Positive (+) and negative (-) conductive pads 68 (68a, 68b) are formed on the bottom of the lowermost ceramic sheet 64 so as to be spaced apart from each other. The conductive pad 68 is made of a conductive material.

The

conductive pads

68a and 68b are in close contact with the corresponding through holes 65. The ceramic sheet 63 is stacked on the upper surface of the ceramic sheet 64, and two through holes 65 are spaced apart from each other in the ceramic sheet 63 to be formed in the vertical direction.

On the upper surface of the ceramic sheet 63,

inner pads

67a, 67b and 67, which are thin metal foils, are provided in a direction crossing the

pattern electrodes

66a, 66b and 66. One of the two through holes 65 of the ceramic sheet 63 is in contact with the inner pad 67a. The other through hole 65 of the ceramic sheet 63 is in contact with the inner pad 67b. In addition, the through holes 65 of the

ceramic sheets

63 and 64 are in contact with the through holes facing up and down.

The ceramic sheet 62 is laminated on the upper surface of the ceramic sheet 63 in which the

inner pads

67a and 67b are in close contact. In the ceramic sheet 62, two through holes 65 are spaced apart from each other and are formed in a vertical direction.

The ceramic sheet 61 is laminated on the upper surface of the ceramic sheet 62. In the ceramic sheet 61, two through holes 65 are spaced apart from each other and are formed in a vertical direction. In addition, the through holes 65 of the

ceramic sheets

61 and 62 are in contact with the through holes facing up and down.

The through hole 65 shown in FIG. 10 is filled with a conductive material.

The pattern electrode 66 is formed on the upper surface of the ceramic sheet 61. The pattern electrode 66 includes a cathode electrode 66a and an anode electrode 66b spaced apart from each other. The cathode electrode 66a is in contact with one of the two through holes 65 of the ceramic sheet 61, and the anode electrode 66b is in contact with the other through hole 65 of the ceramic sheet 61. The anode electrode 66b is formed spaced apart from the cathode electrode 66a for electrical insulation.

The cathode electrode 66a is connected to the inner pad 67a and the conductive pad 68a through the through hole 65. The anode electrode 66b is connected to the inner pad 67b and the conductive pad 68b through the through hole 65. Both ends of the

inner pads

67a and 67b are exposed to both sides of the substrate 60. The pattern electrode 66 is plated (for example, silver plated) by an electroplating process utilizing the

inner pads

67a and 67b. The

pattern electrodes

66a and 66b are not exposed to the side of the LED package as shown in FIG. 12, and both ends of the

inner pads

67a and 67b are exposed to both sides of the substrate 60. The

pattern electrodes

66a and 66b are not exposed so that the phosphor block 30 and the substrate (when performing a process for bonding the phosphor block 30 and the substrate 60 later (eg, oven curing, etc.) are performed. This is to prevent the interfacial separation between 60). That is, in the first embodiment, there are

protrusions

22a and 24a (see FIG. 3), so that the interface separation occurs at the portion of the protrusion. In the second embodiment, since the protrusion is removed, the substrate 60 and the phosphor block 30 are removed. Interfacial separation does not occur in the bonding process of the liver.

The

inner pads

67a and 67b are mainly used for plating line connection with other adjacent LED packages during the LED package manufacturing process.

When the LED package 90 of FIG. 12 is laid down without standing, the lower PCB substrate (not shown) is directed to the lower PCB substrate (not shown) with the

inner pads

67a and 67b facing the lower PCB substrate (not shown). May be soldered). In this way, it is possible to mount the LED package 90 to the direct type and the edge type. For example, as shown in FIG. 12, when the LED package 90 is erected and surface mounted, it becomes a direct type, and when it is placed on its surface, it becomes an edge type. Of course, when the surface is mounted to the edge type, the exposed portions of the

inner pads

67a and 67b may be too small to solder. Even if soldered, the edge-mounted LED package 90 may be kept slightly inclined. Therefore, although not shown in FIGS. 10 to 12, it is more preferable to form the solder pad 23 of the first embodiment on the substrate 60.

The phosphor block 30 is stacked on the upper surface of the substrate 60 on which the LED chip 40 is mounted.

The LED package according to the second embodiment does not have a separate reflector. Accordingly, when viewed in the upright state as shown in FIG. 7, light exit to the left and right side surfaces (side direction; a direction) and light exit to the upper surface (upward direction; b direction) are possible. When the long axis of the LED package of the second embodiment is set to the X axis and the short axis is set to the Y axis, and the luminance of the X axis and the Y axis is compared, the result shown in Table 1 is obtained.

A method of manufacturing the LED package according to the second embodiment will be described with reference to the drawings of FIG. 13 as follows.

First, the base substrate 600 is prepared. The base substrate 600 is manufactured to a size that can be separated into a plurality of substrates (60). When the base phosphor block 300 is stacked on the base substrate 600 and then cut, the base phosphor block 300 is separated into a plurality of LED packages. The separated single package LED is called a unit element, and the area occupied by each unit element is called a unit element region. The preparation of the base substrate 600 includes a plurality of unit device regions, wherein a pattern electrode is formed on the upper surface of each unit device region, and a pad is formed across the pattern electrode. It is to be understood that the base substrates are electrically connected to each other.

The process of manufacturing the base substrate 600 is as follows. The predetermined raw material powder is prepared. That is, low-temperature co-fired ceramic (LTCC) raw material powders and multilayer chip capacitor (MLCC) raw material powders prepared by adding various additives to commercially available glass frit are prepared. PVB-based binder (binder) to the prepared raw material powder is measured by about 6wt% relative to the raw material powder and dissolved in toluene / alcohol (toluene / alcohol) solvent (solvent) is added. The mill is then milled and mixed with a ball mill for about 24 hours to produce a slurry. This slurry is produced by a method such as a doctor blade and a plurality of molded sheets (sheets such as the molded sheet 602 of Fig. 13A) of a desired size. In each molded sheet, two through holes 65 spaced apart from each other by unit device regions are formed in the vertical direction. The through hole 65 is formed by a punching operation. The conductive material is filled in the through hole 65.

When a plurality of molded sheets are manufactured, the second molded sheet 602 is laminated on the upper surface of the first molded sheet 601 of the lowermost layer as shown in FIG. Of course, one molded sheet having a thickness of the combined thickness of the first molded sheet 601 and the second molded sheet 602 may be used.

Next, as illustrated in FIG. 13B,

inner pads

671, 672, 673, and 674, which are thin metal foils, are formed on the upper surface of the second molding sheet 602 in the vertical direction. That is, the inner pad 671 covers the through holes 65 vertically arranged on the leftmost side of the upper surface of the second molding sheet 602. The inner pad 672 covers the through holes 65 arranged in a row from the left side to the second length side on the top surface of the second molding sheet 602. The inner pad 673 covers the through holes 65 arranged in a row from the top of the second molding sheet 602 to the third from the left. The inner pad 674 covers the through holes 65 arranged in a row from the top of the second molding sheet 602 to the fourth from the left (ie, the rightmost).

Next, as shown in FIG. 13C, the third molding sheet 603 and the fourth molding sheet 604 are sequentially stacked. Thereafter, the laminated plurality of molded sheets is pressed.

Subsequently, as illustrated in FIG. 13D,

pattern electrodes

661, 662, 663, and 664 are formed on the upper surface of the fourth molding sheet 604. The

pattern electrodes

661, 662, 663, 664 can be formed by printing the conductive paste using a silk screen.

Pattern electrodes

661 and 662 are formed in one unit element region, and

pattern electrodes

663 and 664 are formed in one unit element region. Here, the

pattern electrodes

661, 662, 663, 664 are the pattern electrodes 66 of the completed LED package. Although the

conductive pads

68a and 68b have not been described separately, the

conductive pads

68a and 68b may be formed on the bottom surface of the first molding sheet 601 before the following light emitting element mounting operation is performed. Of course, you may form the

conductive pads

68a and 68b for each LED package after each LED package is manufactured as needed. The formation timings of the

conductive pads

68a and 68b may vary depending on the situation. Although reference numerals for the base substrates are not described in FIG. 13D, the first to

fourth molding sheets

601, 602, 603, and 604 may be collectively understood as the base substrate 600.

Thereafter, the

pattern electrodes

661, 662, 663, and 664 are plated (eg, silver plated) by an electroplating process using the

inner pads

671, 672, 673, and 674.

Subsequently, a splitting groove 70 is formed in the bottom surface of the base substrate as shown in FIG. 13E. The cleavage groove 70 is formed at a predetermined value along a boundary line between the unit device regions in an upward direction from the bottom of the base substrate 600. For example, the splitting groove 70 is formed in an inverted V shape. The inverted V-shaped split groove 70 may be sufficiently formed by using a device that can groove the base substrate 600 made of a ceramic material. It is preferable to form the splitting groove 70 only in the base substrate 600. This is because the rigidity of the base phosphor block 300 and the base substrate 600 are different from each other. It is not so desirable to form the splitting grooves 70 in all of the heterogeneous blocks with one type of groove forming tool.

The plating process for the

pattern electrodes

661, 662, 663, and 664 described above may be performed after the cleavage groove 70 forming process.

Thereafter, the base substrate 600 of FIG. 13E is sintered.

Subsequently, as shown in FIG. 13F, after the light emitting device 40 is mounted in each unit device region, wire bonding is performed.

Then, as shown in FIG. 13G, the base phosphor block 300 is laminated on the upper surface of the fourth molding sheet 604 on which the light emitting device 40 is mounted, for example, by molding or the like, to form the laminate 700. do. The base phosphor block 300 is manufactured to a size that can be separated into a plurality of phosphor blocks 30. The base phosphor block 300 may be manufactured in a desired size by mixing silicon (or epoxy) and phosphor. The base phosphor block 300 may be made of silicon (or epoxy), except for phosphor, if necessary, or may be made of a mixture of silicon (or epoxy) and a diffuser. For example, the base phosphor block 300 and the base substrate 600 are coupled to each other by, for example, oven curing. In other words, a dam (not shown) or a mold frame (not shown) having a predetermined height is provided along the edge of the surface of the base substrate 600 to secure a dispensing area, and then a mixture of phosphor and silicon is dispensed. Dispensing in the fencing area. By dispensing, the upper surface of the base substrate 600 is a mold station in which a phosphor layer made of a mixture of phosphor and silicon (part of which becomes a base phosphor block) is formed. Thereafter, for example, an air bubble removing process for the dispensed mixture is performed while oven curing is performed for about 30 minutes at a temperature of approximately 70 ° C. After removing the dam or mold mold after the bubble removing process, the final curing (for example, curing at about 70 ° C. for about 1 hour and curing at about 150 ° C. for 1 hour) is shown in FIG. A laminate 700 such as) is completed.

Subsequently, as shown in (h) of FIG. 13, the cutting groove 80 is formed by sawing a predetermined depth along the boundary line between the unit element regions on the upper surface of the stack 700, that is, the upper surface of the base phosphor block 300. Here, the cutting groove 80 is formed to a depth close to the splitting groove 70. In the exemplary embodiment of the present invention, the height (depth) of the splitting groove 70 and the depth of the cutting groove 80 are not exemplified because the size of the LED package of the single piece to be completed may be various. The depth enough to be close to the above-described splitting groove 70 is laminated by the splitting groove 70 and the cutting groove 80 by applying mechanical or artificial force to the stack 700 in a subsequent separation process. It means a depth that the sieve 700 can be easily separated into each unit element. In the embodiment of the present invention, the sawing speed is not so much as full sawing, but as half sawing (half sawing), so that the sawing speed can be made higher speed (for example, 20 ~ 30mm / s or more) to produce a finished product You can shorten the time to. Then, since the sawing is as thin as half sawing, the service life of the blade (not shown) for sawing is longer than in the past. That is, because the base phosphor block 300 which is less rigid than the ceramic base substrate 600 can be sawed at a higher speed, the time required to manufacture the finished product as well as the conventional full sawing can be shortened. The service life of the blade will be extended. In other words, in the second embodiment, sawing for the base phosphor block 300 and the base substrate 600 is performed separately. In this case, since the optimum sawing speed may be provided to the base phosphor block 300 and the base substrate 600, the sawing operation may not be performed excessively, and the above-described time reduction and life extension of the blade may be obtained.

Finally, as shown in (i) of FIG. 13, the unit 700 is formed by the split grooves 70 and the cutting grooves 80 by mechanically or artificially applying a force to the stack 700. To separate. Each separate unit element 90 is a reflector-free LED package that is desired to be obtained in the second embodiment.

According to this second embodiment, the interface separation phenomenon between the substrate and the phosphor block can be completely eliminated by removing the protrusions in the first embodiment, which are exposed from both sides of the upper surface of the substrate.

By sawing as much as half sawing, rather than full sawing, the sawing speed can be made faster (e.g., 20 to 30 mm / s or more), resulting in a shorter time to manufacture the finished product. . It is not the conventional full sawing method, but the sawing of the thickness as much as half sawing, so that the service life of the blade for sawing is longer than in the past.

In addition, since the LED package of the second embodiment can sufficiently serve as a light source for a flat panel display device and a lighting device, the LED package is effectively used for a flat panel display device and a lighting device requiring a wide directivity angle of 120 degrees or more.

The light output module 54 is characterized in that it has a wider direct angle than the direct angle of the conventional LED package, as well as a direct angle having a batwing characteristic (or side emitting characteristic). To implement this, the light output module 54 sets two

light modules

50 and 52 into one set. The

optical modules

50 and 52 are mentioned later. The optical module here may be understood as the LED package of the first or second embodiment described above.

The light output module 54 is installed in the backlight unit, for example. On the base substrate 10 of the backlight unit, the bottom surface of the first optical module 50 and the bottom surface of the second optical module 52 are installed to face each other.

15 to 17 are views for explaining the configuration of any one optical module of the light output module of FIG. 18 is a state diagram of FIG. Since the first optical module 50 and the second optical module 52 constituting the light output module are configured in the same manner, the configuration of the first optical module 50 will be described below. The 2nd optical module 52 can fully grasp | ascertain with the structural description of the 1st optical module 50 mentioned later. Since the first optical module 50 is almost the same as the LED packages of the first and second embodiments described above, the same reference numerals are given for each component and detailed description thereof will be omitted.

The first optical module 50 includes a substrate 20, a phosphor block 30, and an LED chip 40.

In the state of FIG. 18, when the first optical module 50 is mounted with the solder pad 23 portion sideways to the side of the PCB substrate (not shown), the solder pad 23 of the substrate 20 is lowered. It is soldered to a PCB substrate (not shown).

When the first optical module 50 in FIGS. 15 to 18 is compared with the LED package of the first embodiment, the

protrusions

22a and 24a of the

pattern electrodes

22 and 24 are slightly removed. Those skilled in the art can easily infer the configuration and manufacturing process of the first optical module 50 based on the description of the first and second embodiments described above. And it is possible to fully remove the

protrusions

22a and 24a by a well-known technique for those skilled in the same industry.

Therefore, the first optical module 50 in FIGS. 15 to 18 may be regarded as substantially the same as the LED package of the first or second embodiment.

On the other hand, the first optical module 50 in the standing state as shown in Figure 7 can be emitted to the left and right side (a direction; lateral direction) and the light output to the upper surface (b direction; upward direction). When the long axis of the first optical module 50 is set as the X axis and the short axis is set as the Y axis, and the luminance of the X axis and the Y axis is compared, the result shown in Table 1 is obtained.

In this way, the light output module 54 may lay the first optical module 50 and the second optical module 52 having about 50% of the luminous intensity of the upper side emission compared to the upper side emission. In this way, it is as shown in FIG. That is, when arranged as shown in FIG. 14, the light output module 54 may emit light in the upward direction and the lateral direction.

When the first optical module 50 and the second optical module 52 are laid side by side, the upper surface of the first optical module 50 and the second optical module 52 is a side surface, so that the light exit module 54 The luminance of the lateral light emission becomes larger. This results in batwing characteristics.

The light distribution module in polar coordinates based on a data sheet obtained by measuring the light output module 54 implemented as shown in FIG. 14 by using a goniometer (eg, OL770 goniometer) is shown in FIG. 19. In addition, a light distribution curve in the form of a rectangular coordinate based on a data sheet obtained by measuring the light output module 54 implemented as shown in FIG. 14 using a goniometer (eg, OL770 goniometer) is shown in FIG. 20. 19 and 20, it can be seen that the light output module 54 has a wide direct angle of about 170 degrees. 19 and 20, the center portion is pitted and shows a direction angle characteristic spreading left and right, which is referred to as a batwing characteristic or a side emitting characteristic. Usually, the view angle is defined as 1 or 100% of the center point or the point with the highest brightness, and reaches a range of 50% relative to the center or the point with the highest brightness. it means.

As such, it can be seen that the light output module 54 has a wider direct angle as well as a direct angle having a batwing characteristic compared to the direct angle of the conventional LED package.

21 is a view for explaining the difference between the backlight unit which is an example of the application of the present invention and the conventional backlight unit. (a) is a backlight unit according to the embodiment of the present invention in which the light output module 54 is installed, and (b) is a conventional backlight unit.

As shown in (a) of FIG. 21, when the light emitting modules (including the first optical module and the second optical module) are arranged side by side in a row to operate on the base substrate, light output in the upper direction and the left and right sides is performed. It can be seen.

FIG. 21 (b) shows that when two LED packages (ie, only one light exit in one direction of the package structure) are disposed side by side as in the light exit module of the present invention, the light exit only in the left and right sides. Is done.

That is, the backlight unit according to the embodiment of the present invention, in which the light output module 54 is installed, emits light in the upward direction and the left and right sides, and the conventional backlight unit emits light only in the left and right sides. .

Conventional backlight units do not emit light in the upward direction so that shading (also called dark portions) occurs along the long axis of the base substrate (ie, between two LED packages).

However, in the backlight unit according to the exemplary embodiment of the present invention, the light emitted upward from the first optical module and the second optical module are mixed with each other so that shading does not occur. This not only improves image quality as compared to the conventional art, but also improves the visual quality and reliability of the product. In addition, it can be seen that the arrangement structure as shown in FIG. 21A is closer to the surface light source as compared with the arrangement as shown in FIG. 9.

Of course, in the present invention, although the light emitting module is adopted in the backlight unit, it can be sufficiently employed in the lighting device that requires a light source requiring a directing angle having the batwing characteristics.

On the other hand, the present invention is not limited only to the above-described embodiment, but can be modified and modified within the scope not departing from the gist of the present invention, and the technical spirit to which such modifications and variations are applied also belong to the following claims Must see

Claims

A substrate on which a solder pad is recessed in a lower portion of a side surface;

A pattern electrode formed on an upper surface of the substrate and electrically connected to the solder pads;

A light emitting device mounted on an upper surface of the pattern electrode; And

And a phosphor block mounted on an upper surface of the substrate and configured to emit light emitted from the light emitting device upwardly and laterally.
The method according to claim 1,

The solder pad is an LED package, characterized in that formed by coating the material of the solder pad on the wall surface of the groove formed on the lower side of the substrate.
The method according to claim 1,

A conductive pad is formed on the bottom of the substrate,

The conductive package is an LED package, characterized in that electrically connected with the pattern electrode.
The method according to claim 1,

The phosphor block covers the upper and the side of the light emitting device, and the LED package, characterized in that to cover the upper side of the pattern electrode.
The method according to claim 1,

The phosphor block covers the upper and the side of the light emitting element and the pattern electrode.
A plurality of LED packages of claim 1 are installed on the base substrate,

The plurality of LED package is characterized in that the bottom surface is installed facing each other.
The method according to claim 6,

And said plurality of LED packages are arranged in a row in a set of two.
A substrate having internal pads formed therein exposed to both sides thereof;

A pattern electrode formed on an upper surface of the substrate and electrically connected to the inner pad;

A light emitting device mounted on an upper surface of the pattern electrode; And

And a phosphor block mounted on an upper surface of the substrate and configured to emit light emitted from the light emitting device upwardly and laterally.
The method according to claim 8,

A conductive pad is formed on the bottom of the substrate,

The conductive package is an LED package, characterized in that electrically connected with the pattern electrode.
The method according to claim 8,

Further comprising a solder pad recessed in the lower portion of the side of the substrate,

And the solder pad is electrically connected to the pattern electrode.
The method according to claim 10,

The solder pad is an LED package, characterized in that formed by coating the material of the solder pad on the wall surface of the groove formed on the lower side of the substrate.
The method according to claim 8,

The phosphor block covers the upper and the side of the light emitting element and the pattern electrode.
A plurality of LED packages of claim 10 are installed on the base substrate,

The plurality of LED package is characterized in that the bottom surface is installed facing each other.
The method according to claim 13,

And said plurality of LED packages are arranged in a row in a set of two.
A base substrate preparation step of preparing a base substrate having a pattern electrode formed on an upper surface of each unit device region;

A splitting groove forming step of forming a splitting groove at a predetermined depth on a bottom surface of the base substrate along a boundary line between unit device regions;

A light emitting device mounting step of mounting a light emitting device on an upper surface of the pattern electrode for each unit device region of the base substrate;

A bonding step of forming a laminate by stacking base phosphor blocks on an upper surface of the base substrate on which the light emitting device is mounted;

A cutting groove forming step of forming a cutting groove at a predetermined depth along a boundary line between unit device regions on an upper surface of the laminate; And

And a separation step of separating the stack into a plurality of unit elements by using the split grooves and the cut grooves, respectively.
The method according to claim 15,

The preparing of the base substrate is a method of manufacturing an LED package, characterized in that the pattern electrodes of each unit device region are separated from each other.
The method according to claim 15,

The preparing of the base substrate may include forming an inner pad in a direction crossing the pattern electrode in the base substrate, and electrically connecting the inner pad and the pattern electrode to each other.
The method according to claim 17,

A method of manufacturing an LED package, characterized in that both ends of the inner pad are exposed to both sides of each unit element separated by the separating step.
The method according to claim 17,

The method of preparing the base substrate may further include forming concave solder pads on the lower side of the substrate, and electrically connecting the solder pads to the pattern electrodes and the inner pads.