KR20080099004A - Light emitting device with submount and method for fabricating the same - Google Patents

Abstract

The uniform fluorescent material layer can be formed on the LED die with leaving the electric wiring part on the sub mount. The loss of fluorescent substance at the can be reduced in forming a fluorescent material layer. A step is for setting up the LED die on the sub mount(10) having the conductive pattern. A step is for forming the electric wiring between the conductive pattern(12) on the sub mount and the LED. A step is for coating the fluorescent substance in the LED die except for the partial region of the conductive pattern. A step is for forming the electric wiring between the electrical terminal and the partial region of the conductive pattern and the out sided of the sub mount which are a region except for a step for coating the fluorescent substance.

Description

LIGHT EMITTING DEVICE WITH SUBMOUNT AND METHOD FOR FABRICATING THE SAME}

1A and 1B are a plan view and a sectional view of a submount in which a conductive pattern is formed according to an embodiment of the present invention.

2 (a) and 2 (b) are a plan view and a sectional view showing a state in which an LED die is mounted on the submount shown in FIG.

3 (a) and 3 (b) are a plan view and a sectional view showing a state in which the submount and the LED die shown in FIG. 2 are electrically wired.

4A and 4B are views for explaining a process of coating a phosphor on a submount on which the LED die shown in FIG. 3 is mounted;

FIG. 5 is a view for explaining a process of cutting a submount mounted with an LED die and coated with a phosphor; FIG.

6 is a cross-sectional view illustrating a light emitting chip formed by the cutting process illustrated in FIG. 5.

FIG. 7 is a cross-sectional view illustrating a light emitting device having a package structure in which the light emitting chip illustrated in FIG. 6 is connected to an electrical terminal outside the submount.

FIG. 8 is an enlarged plan view of the main part of FIG. 7; FIG.

<Code Description of Main Parts of Drawing>

10: submount 12: conductive pattern

15: insulation pattern 20: LED die

30: phosphor layer 100: light emitting chip

120: contact area M: mask jig

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device, and more particularly, to a light emitting device including a submount on which an LED die is mounted and a phosphor coated on the submount, and a method of manufacturing the same.

A light emitting diode (LED) is a device in which electrons and holes meet and emit light at a PN junction by applying current, and are generally manufactured in a package structure in which a chip-shaped LED die is mounted. Often referred to as an 'LED package'. The LED package as described above is generally mounted on a printed circuit board (PCB) and configured to emit light by receiving current from an electrode formed from the printed circuit board (hereinafter, referred to as 'PCB').

Conventionally, a light emitting device using a light emitting chip having a structure in which an LED die is mounted on a submount has been developed. Such a conventional light emitting device is manufactured through a package mounting process of electrically connecting a light emitting chip made of a submount and an LED die mounted thereon to a lead frame and forming a resin or ceramic body supporting the lead frame. In addition, the conventional light emitting device forms a phosphor layer on the light emitting chip by a spray method after the above package mounting process.

However, in the above conventional light emitting device, since the spray process for forming the phosphor layer is performed after package mounting of the light emitting chip, the spray process is performed on a very large area compared to the narrow area where the phosphor layer is actually required, and thereby the phosphor There is a problem that the loss of a lot, and the spray of the phosphor is concentrated in a narrow area, it is difficult to form a uniform phosphor layer.

Accordingly, a technical problem of the present invention is to use a method of coating phosphors on a submount and an LED die except for a portion to be electrically wired with an electrical terminal outside the submount in a state where the LED die is mounted on the submount, A method of reducing the amount of phosphor loss and enabling uniform phosphor coating on the submount region and the LED die, and a light emitting device manufactured by the method.

According to an aspect of the invention, the steps of mounting the LED die on a submount with a conductive pattern, electrically wiring between the LED die and the conductive pattern on the submount, and the above except for a portion of the conductive pattern Coating a phosphor on a submount and the LED die thereon, and electrically wiring between a portion of the conductive pattern excluded from coating the phosphor and an electrical terminal outside the submount A device manufacturing method is provided.

Preferably, in the mounting of the LED die, a plurality of LED dies are mounted on the submount, and in the electrical wiring step, each of the plurality of LED dies is connected with corresponding conductive patterns and bonding wires. The manufacturing method of the light emitting device may further include cutting the submount so that each of the LED dies is included after coating the phosphor, and a plurality of light emitting chips are formed by the cutting. Each of the light emitting chips has a partial region of the conductive pattern electrically connected to the electrical terminal.

Preferably, the conductive pattern includes first and second conductive patterns having different polarities separated by an insulating pattern, and coating the phosphor may include masking a portion of the region crossing the insulating pattern with a mask jig. In the hidden state, it is made by coating a phosphor on the submount on which the LED die is mounted. By the above-described phosphor coating, the portion covered by the mask jig becomes the first conductive pattern and the second conductive pattern adjacent to each other without the phosphor coated. In addition, an LED die is mounted on the first conductive pattern, and the LED die is connected to the second conductive pattern by electrical wiring. Furthermore, when the mask jig passes between neighboring LED dies, the first and second conductive patterns electrically connected to one LED die of one of the neighboring LED dies and the first electrically connected to the remaining LED dies. The first and second conductive patterns may be formed in common with each other.

Preferably, the step of coating the phosphor is by spray or electrophoresis.

Preferably, the submount on which the conductive pattern is formed is formed by metal plating leaving an insulating pattern on an insulating substrate. More preferably, the conductive pattern includes first and second conductive patterns having different polarities. The LED die is a vertical light emitting diode attached to the first conductive pattern and connected to the second conductive pattern by a bonding wire.

According to another aspect of the present invention, a submount having a conductive pattern formed thereon, an LED die mounted on the submount and electrically connected to the conductive pattern on the submount, and a phosphor coated on the submount and the LED die. And a contact region formed by exposing a portion of the conductive pattern on the submount to be excluded from the coating process, and an electrical terminal provided outside the submount and connected to the contact region by electrical wiring. A light emitting device is provided.

Preferably, the electrical terminal consists of a leadframe of the LED package supported by the package body.

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

1 to 8 are views for explaining a method of manufacturing a light emitting device according to the present invention.

1A and 1B, a plan view and a cross-sectional view of the submount 10 in which the conductive pattern 12 is formed are shown. The submount 10 is formed of a substrate made of a non-conductive material such as Si or AlN. The conductive pattern 12 is made of a metal plating layer of a predetermined shape formed by a process such as plating using a mask. The portion where the metal plating layer is not formed by the mask becomes the insulating pattern 15.

Referring to FIG. 1A, the conductive pattern 12 is limited to the first conductive pattern 12a and the second conductive pattern 12b by the dotted line and the insulating pattern 15. have. The displayed dotted line is a portion where cutting is performed during the cutting of the submount 10, which will be described in detail below. The second conductive patterns 12b are separated and insulated from each other with the insulating pattern 15 interposed therebetween. The conductive pattern 12 is formed of a metal material having good conductivity such as Au, Ag, Al, or the like.

2A and 2B are a plan view and a cross-sectional view showing a state in which a plurality of LED dies 20 are mounted on a submount 10 on which a conductive pattern 12 is formed. The LED dies 20 are each mounted in a plurality of regions divided by a plurality of dotted lines crossing each other. As described above, the dotted lines represent the cutting lines of the submount 10. In addition, it can be seen from FIG. 2A that the regions on the submount 10 on which the plurality of LED dies 20 are mounted are regions on the first conductive pattern 12a described above. At this time, since each of the LED die 20 is a vertical light emitting diode and attached to the first conductive pattern 12 by a conductive adhesive, the LED die 20 is the first conductive pattern 12a at the bottom surface ) And the state that can be energized.

3A and 3B are a plan view and a cross-sectional view showing a state in which electrical wiring is formed between the LED die 20 and the second conductive pattern 12b mounted on the submount 10. The electrical wiring is formed by connecting the electrode on the upper end of the LED die 20 and the second conductive pattern 12b to each other by using a bonding wire W1. By the above electrical wiring, the LED die 20 is in a state capable of energizing both the first conductive pattern 12a and the second conductive pattern 12b.

Since the submount 10 has not been cut yet, the first conductive pattern 12a and the second conductive pattern 12b are not electrically insulated, but the cutting process to be described below along the dotted lines of FIG. 3. The first conductive pattern 12a and the second conductive pattern 12b are insulated from each other with the insulating pattern 15 interposed therebetween. FIG. 3A shows that two bonding wires W1 are used for each LED die 20 for the electrical wiring, but one bonding wire for each LED die 20 is shown. It is also possible to make electrical wiring using only W1).

Since the LED die 20 is a vertical light emitting diode, the bonding wire W1 is used only for the electrical wiring between the LED die 20 and the second conductive pattern 12b. However, in the case of using a light emitting diode in which the P-type electrode and the N-type electrode are exposed in the upward direction as the LED die, using the bonding wires connected to the P-type and the N-type electrode exposed in the upper direction, the LED die and Electrical wiring may also be performed between the first and second conductive patterns 12a and 12b.

4A and 4B are views for explaining a process of coating a phosphor on a submount 10 having a plurality of LED dies 20 mounted thereon. As shown in Fig. 4A, immediately before coating of the phosphor, the mask jig M is raised to span the areas on the submount 10 defined by the dotted lines. At this time, the mask jig M spans the first conductive pattern 12a and the second conductive pattern 12b in each region. Then, using a spray method or an electrophoresis method, the phosphor is coated on the submount 10 in which the plurality of LEDs 20 are mounted. Here, the mask jig M is placed to cross the insulating pattern 15 that separates the first conductive pattern 12a and the second conductive pattern 12b.

By the phosphor coating process, a phosphor layer 30 as shown in FIG. 4B is formed on the plurality of LEDs 20. In this case, the phosphor is coated on the submount 10, but the region including a part of the first and second conductive patterns 12a and 12b covered by the mask jig M is excluded from the formation of the phosphor layer. do. In addition, as shown in FIG. 5, a region where the formation of the phosphor layer is excluded is exposed with a conductive pattern, and regions where the conductive pattern is exposed are contacts of each of the first and second conductive patterns 12a and 12b. Region 120 (see FIGS. 5-8).

5 shows a process of cutting the submount 10 so that each of the LED dies 20 is included along a dotted line, i. In FIG. 5, the area marked with a dot hatch represents the area coated with the phosphor. Referring to FIG. 5, a unit light emitting chip 100 is formed by cutting a submount in which one individual LED die 20 is mounted from one large submount 10 in which a plurality of LED dies 20 are mounted. . In the present specification, the term "light emitting chip" is defined as a chip having a structure in which the LED die 20 is mounted on the cut submount.

As shown in FIG. 5, the light emitting chip 100 includes one LED die 20 mounted on a first conductive pattern 12a of a submount, and the LED die 20 includes a second conductive pattern. It is connected by 12b and the bonding wire W1. The light emitting chip 100 is coated with a phosphor denoted by a dot hatch except for the portion covered by the mask jig M (see FIG. 4) in the phosphor coating process described above. The region where the phosphor is not coated by the mask jig M becomes the contact regions 120a and 120b allowing partial exposure of each of the first and second conductive patterns.

According to a preferred embodiment of the present invention, the portion covered by the mask jig (M), the contact region (120a, 120b) of each of the first conductive pattern and the second conductive pattern adjacent to each other without the phosphor is coated The LED die 20 is mounted on the first conductive pattern 12a, and the LED die 20 is connected to an electrical wiring (particularly, a bonding wire) in the contact region 120b of the second conductive pattern 12b. Is connected by. Furthermore, when the mask jig M passes between neighboring LED dies 20 and 20, the mask jig M is electrically connected to one LED die 20 of one of the neighboring LED dies 20 and 20. The contact regions 120a and 120b of the first and second conductive patterns 12a and 12b to be contacted and the contact regions 120a of the first and second conductive patterns 12a and 12b to be electrically connected to the remaining LED dies 20. , 120b) may be formed in common with each other, which will be clearly understood from the accompanying drawings.

6 illustrates a cross-sectional structure of the light emitting chip 100 formed by the cutting process described above. Referring to FIG. 6, the light emitting chip 100 may include a submount 10 having conductive patterns 12, that is, first and second conductive patterns 12a and 12b, and a first conductive pattern 12a. An LED die 20 mounted on and connected to the second conductive pattern 12b by a bonding wire W1 and a phosphor layer 30 uniformly formed on a portion of the LED die 20 and the submount 10. It includes. In addition, a portion of the conductive pattern 12 of the submount excluded from the phosphor coating process remains as the contact region 120. The contact region 120 is composed of first and second contact regions 120a and 120b which are part of each of the first and second conductive patterns 12a and 12b, which are illustrated in FIGS. 5 and 8.

The light emitting chip 100 is connected to electrical terminals to constitute a light emitting device that emits light by electric power applied through the electrical terminals. In this embodiment, the electrical terminals are the first and second leadframes 222, 224 supported by the package body, as shown in FIGS. 7 and 8.

FIG. 7 is a cross-sectional view illustrating a light emitting device having a package structure including the light emitting chip 100, and FIG. 8 is an enlarged front view of a main part of the light emitting device shown in FIG. 7.

Referring to FIG. 7, the light emitting chip 100 includes first and second lead frames 222 and 224 in which the contact region 120, which is a part of the conductive pattern 12, is mounted on the heat dissipation slug 210, and the electrical terminals are electrical terminals. Are each connected to. The first and second lead frames 222 and 224 are supported by a package body 200 formed of resin or ceramic, and an opening for exposing the light emitting chip 100 is formed in the package body 200. The light-transmitting sealing member 240 is formed in the opening to protect the light emitting chip 100.

Referring to FIG. 8, the contact region 120 is composed of first and second contact regions 120a and 120b which are each part of the first and second conductive patterns 12a and 12b, respectively. The two contact regions 120a and 120b are connected to the first and second lead frames 222 and 224 by bonding wires W2 and W2, respectively.

The present invention mounts the LED die 20 on the submount 10 on which the conductive pattern 12 is formed, and electrically wires the LED die 20 and the conductive pattern 12, and then the submount ( The main feature is to form a phosphor while leaving a part of 10) as the contact region 120, and thus, the other matters except for the above features may be modified in various ways. In addition, the electrical terminal connected to the contact area 120 does not necessarily have to have a lead frame structure as shown in FIGS. 7 and 8.

 According to the present invention, in the manufacture of a light emitting device using a submount on which an LED die is mounted, a uniform phosphor layer can be formed on the LED die while leaving portions to be electrically wired on the submount, and the phosphor layer forming process It has the effect of greatly reducing the phosphor loss in.

Claims (10)

Mounting an LED die on the submount on which the conductive pattern is formed; Electrical wiring between the LED die and a conductive pattern on the submount; Coating a phosphor on the submount and the LED die thereon except for a portion of the conductive pattern; Electrically wiring between a portion of the conductive pattern excluded from coating the phosphor and an electrical terminal outside the submount; Light emitting device manufacturing method comprising. The method of claim 1, wherein in the mounting of the LED die, a plurality of LED dies are mounted on the submount, and in the electrical wiring, each of the plurality of LED dies is connected with corresponding conductive patterns and bonding wires. Light emitting device manufacturing method characterized in that. 3. The method of claim 2, further comprising: cutting the submount to include each of the LED dies after coating the phosphor, wherein a plurality of light emitting chips are formed by the cutting; And a partial region of the conductive pattern electrically connected to the electrical terminal is disposed on each chip. The method of claim 1, wherein the conductive pattern includes first and second conductive patterns having different polarities separated by an insulating pattern, and the coating of the phosphor may include partial regions of the first and second conductive patterns. A method of manufacturing a light emitting device, characterized in that the phosphor is coated on the submount on which the LED die is mounted in a state covered by a mask jig. The method of claim 4, wherein the mask jig is placed to pass between LED dies adjacent to each other on a submount. The method of claim 4, wherein the coating of the phosphor is performed by spray or electrophoresis. The method of claim 1, wherein the submount on which the conductive pattern is formed is formed by metal plating leaving an insulating pattern on an insulating substrate. The method of claim 1, wherein the conductive pattern includes first and second conductive patterns having different polarities separated by an insulating pattern, and the LED die is attached to the first conductive pattern and is bonded to the second conductive pattern. Light emitting device manufacturing method characterized in that the vertical light emitting diode connected to. A submount on which a conductive pattern is formed; An LED die mounted on the submount and electrically connected to a conductive pattern on the submount; A phosphor layer formed by coating a phosphor on the submount and the LED die; A contact region formed by exposing the conductive pattern on the submount by being excluded from the coating process; An electrical terminal provided outside the submount and connected to the contact area by electrical wiring; Light emitting device comprising. 10. The light emitting device of claim 9, wherein the electrical terminal is a lead frame of an LED package supported by a package body.

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