KR20050017979A - Light emitting diode package and method for manufacturing light emitting diode package - Google Patents

Abstract

PURPOSE: An LED(light emitting diode) package is provided to improve optical efficiency by mounting an LED on a silicon sub mount having a reflection plate and by installing the silicon sub mount having the LED in a leadframe. CONSTITUTION: A sub mount(200) includes reflection holes in which an LED(203) and a reflection part are disposed. A leadframe(301) is connected to the sub mount. The LED is electrically connected to the leadframe by a connection unit. The leadframe is supported by a substrate. A wall(305) is disposed along the circumference of the edge of the substrate. A mold part is encapsulated in the wall.

Description

LIGHT EMITTING DIODE PACKAGE AND METHOD FOR MANUFACTURING LIGHT EMITTING DIODE PACKAGE}

The present invention relates to a light emitting diode package and a method for manufacturing the same, and more particularly, to a light emitting diode package and a method for manufacturing the same, which can improve the brightness and reliability of a manufactured package in a high output diode used in a large area.

Generally, a light emitting diode (LED) is also called a light emitting diode, which is a device used to send and receive signals by converting an electric signal into an infrared, visible or light form using the characteristics of a compound semiconductor.

Usually, the use range of LED is used in home appliances, remote controllers, electronic signs, indicators, and various automation devices, and the types are largely divided into Infrared Emitting Diode (IRD) and Visible Light Emitting Diode (VLED).

The structure of the LED is generally as follows.

In general, unlike a red LED, a blue LED forms an N-type GaN layer on a sapphire substrate, forms an N-metal on one side of the N-type GaN layer surface, and then continues to form an active layer in addition to the N-metal formed region. To form.

Then, a P-type GaN layer is formed on the active layer, and P-metal is formed on the P-type GaN layer to manufacture a blue LED.

The active layer is a layer that generates light by combining holes transmitted through the P metal and electrons transmitted through the N metal.

The LED manufactured as described above is used according to the intensity of light output, and is used for home appliances, electronic signs, and the like. The following shows a structure in which LEDs are packaged on a backlight lead frame.

FIG. 1 is a view illustrating a structure of a blue LED package according to the prior art, and as shown, a lead frame 101 for backlight is formed around a polymer poly 100, and a blue LED ( 103 is mounted.

A wall (WALL) 107 having a constant height is formed around the edge of the polymer poly 100. After the LED 103 is adhered on the lead frame 101, the lead frame 101 is bonded to a P electrode and an N electrode formed on the LED 103 by wire bonding. Electrical contacts with the wirings on

As described above, the molding operation is performed by the epoxy resin 106 after the bonding process of the wire 105 is completed, and the epoxy resin 106 is filled in an inner space formed along the edge of the lead frame 101. Enclose it.

2 is a view showing a white LED package structure according to the prior art.

As shown in FIG. 2, a blue LED 103 is manufactured as a package to generate white light.

The blue LED 113 is adhered and mounted on the backlight lead frame 111 formed along the polymer poly 110. The P electrode and the N electrode of the mounted LED 113 are taken out and electrically contacted to the conductive pattern on the lead frame 111 by a wire 115 bonding operation.

When the wire 115 is bonded to the LED 113, a mold 116 in which phosphors are mixed with an epoxy resin is molded on the LED 113.

Therefore, blue light generated by the blue LED 113 is converted into white light by the phosphor included in the mold 116 and then emits white light to the outside.

However, the LED package generating the blue and white light described above has a structure in which it is difficult to form a reflector on the lead frame in order to improve light efficiency.

In particular, a phosphor molded into an LED package generating white light has a problem in that a high-power LED for high heat generation deforms a fluorescent component and deteriorates the quality of white light.

That is, the structure in which the LED is directly mounted on the lead frame as described above has a problem in that heat dissipation is difficult and deterioration occurs.

In addition, since each LED is packaged and wire bonded, there is a problem in mass production.

An object of the present invention is to provide a light emitting diode package and a method of manufacturing the same, which can improve light efficiency at large area and high output by mounting a light emitting diode on a silicon sub-mount and molding by double mold. have.

In order to achieve the above object, a light emitting diode package according to the present invention,

A sub-mount including a light emitting diode and a reflecting hole in which a reflecting portion is disposed;

A lead frame connected to the sub mount;

Connecting means for electrically connecting the light emitting diode and the lead frame;

A substrate supporting the lead frame;

A wall disposed along an edge of the substrate; And

And a mold part encapsulated in the wall.

Here, the mold part comprises a double layer of the first mold part and the second mold part, the first mold part is disposed on the reflection hole of the sub-mount, and the second mold part is disposed inside the wall. It is done.

The mold part includes a phosphor for absorbing the light wavelength generated by the light emitting diode to emit light of another wavelength, and the first or second mold layer includes a phosphor for absorbing the wavelength of the light emitting diode to emit another wavelength. Is a molding structure including at least one, wherein the first and second mold layers are molded by selecting any one of a silicone resin or an epoxy resin, and the first and second molds are each different from each other of a silicone resin or an epoxy resin. It is molded by selecting one, the substrate is characterized in that the polymer poly.

In addition, the interface structure of the mold layer has a shape of any one of concave or concave-convex, the structure of the reflecting portion is formed of any one of a multilayer structure consisting of Ag / Cr / Au or Ni / Ag / Cr / Au, The light emitting diode disposed on the reflective hole of the silicon submount is electrically connected to the lead frame by wire bonding, and the light emitting diode disposed on the reflective hole of the silicon submount is reflected by flip chip bonding. And the reflector and the lead frame are electrically connected by wire bonding, and the reflector and the lead frame are electrically connected through a via hole formed in the silicon sub-mount.

In addition, the LED package manufacturing method according to the present invention,

Etching the reflection hole of the sub-mount to bond the light emitting diode;

Forming a reflecting plate in the etched reflecting hole;

Applying a reflective coating on the reflector to increase light reflectance;

Bonding the light emitting diode to the reflector;

Mounting the sub-mount to which the light emitting diode is bonded to a lead frame formed on a substrate;

Electrically connecting the light emitting diode and the lead frame;

Forming a wall around the substrate edge; And

Forming a first mold layer and a second mold layer in the wall; Characterized in that it comprises a.

Here, the first mold layer is formed by injecting a molding liquid into the reflective hole of the sub-mount, and when forming the first mold layer, the molding liquid is discharged in units of wafers, and the first mold layer is a silicone resin And a phosphor mixed with the molding liquid, the second mold layer is formed with a molding liquid of epoxy resin, and the coating film coated on the reflection plate of the sub-mount is characterized in that the Ag metal.

According to the present invention, there is an advantage of improving the light efficiency by mounting the LED on the silicon sub-mount in which the reflector is formed.

In addition, the heat generated from the LED is not only easily discharged by the silicon sub-mount, but also has an effect of increasing the quality of the package due to the excellent processing characteristics of silicon.

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

3 is a view showing a state in which the LED is mounted on the silicon sub-mount in accordance with the present invention.

As illustrated in FIG. 3, the silicon wafer is etched to form a silicon submount 200 having holes for mounting the LEDs 203. On the reflective hole formed in the silicon sub-mount 200, a multilayer structure reflector 201 composed of Ag / Cr / Au or Ni / Ag / Cr / Au thin films was formed.

The reflective hole is applied to a bulk micro machining technique to perform anisotropic etching for 50 to 100 minutes at an etching rate of 3 to 4 μm per minute in a solution in which a silicon wafer is mixed with an etchant KOH, an isopropyl alcohol, and distilled water. To emit light.

The LED 203 is mounted on the reflector plate 201, and is formed to be die-bonded in the silicon sub-mount 200 before mounting on the lead frame.

In addition, the LED 203 is die-bonded inside the silicon sub-mount 200, wire-bonded, and a molding liquid is injected to form a mold 202. The brightness of the mold 202 is changed according to the interface shape of the mold 202. In addition, since the degree of light intensity, light efficiency is affected, it is injected to have various forms.

The structure of the mold 202 is formed in a concave or concave-convex shape to improve the light efficiency, such as the brightness of light when the light emitted from the LED 203 is emitted to the outside.

The reflector 201 may improve light efficiency by reflecting light generated from the LED 203 to the outside, but when the LED 203 is mounted by flip chip bonding, an external lead frame and the silicon sub-mount The P and N electrodes of the LED 203 are electrically connected to the terminals of the lower lead frame by the via hole region penetrating 200 (shown in FIGS. 8A and 8B).

In this case, since the LED 203 is flip chip bonded on the reflecting plate 201, the lead frame is electrically connected to the reflecting plate 201 formed of a conductive metal by wire bonding.

However, when die bonding the LED 203, the silicon sub-mount 200 is die bonded to the lead frame and wire bonded to electrically connect the P and N electrodes of the LED 203 to each other.

4A-4C illustrate blue LED packages molded and manufactured according to the present invention.

As shown in FIG. 4A, in order to generate blue light, the LED 203 is mounted using the silicon sub-mount 200 described with reference to FIG. 3, and then, again, a lead frame formed around the polymer poly 300 ( The silicon submount 200 having the LED 203 mounted thereon is mounted by a die bonding method.

When the silicon submount 200 is die-bonded to the lead frame 301, the P and N electrodes of the LED 203 and the lead frame 301 and the wire 303 are bonded to each other. The wire 303 is bonded by drawing the lead wire from the LED 203 mounted in the reflection hole to the lead frame 301.

As such, when the wire 303 is bonded, the silicon sub-mount is injected by injecting a silicon-based material or an epoxy resin 307 into a wall (WALL) 305 having a constant height around the edge of the polymer poly 300. The package is sealed while molding 200.

FIG. 4B is a LED package having a double mold structure, and as shown, die-bonds the LED 203 on the silicon sub-mount 200, and then wire-bonds the lead frame and the LED 203, and a silicone-based resin. Injecting the molding liquid on the reflection hole of the silicon sub-mount 200 to form a first mold 207, and discharges the molding liquid in wafer units when forming the first mold.

As described above with reference to FIG. 3, in order to improve light efficiency of the LED 203 mounted on the silicon sub-mount 200, the mold shape is formed in a concave or concave-convex shape.

When the first mold 207 is formed in the reflective hole of the silicon sub-mount 200, a molding liquid is injected into the wall 305 on the polymer poly 300 to form a second mold 227 to form a double mold. Complete the structure.

In the molding liquid, various resins such as silicone resin, epoxy resin, polyimide resin, etc. are used in consideration of LED characteristics and thermal characteristics, and high resistance silicone resin having excellent thermal characteristics is mainly used.

However, in FIG. 4C, as a method of forming the double mold structure by another method, as shown in FIG. 4A, the LED 203 is mounted by die bonding on the silicon sub-mount 200 and then read again. The silicon submount 200 is die-bonded to the frame 301, and the P and N electrodes of the LED 203 disposed on the reflection hole of the silicon submount 200 and the lead frame 301 are subsequently removed. The wire 303 is electrically bonded.

Then, when the silicon submount 200 is die-bonded to the lead frame 301 and the LED 203 is bonded to the lead frame 301 and the wire 303, the silicon submount 200 may be bonded using a silicone resin. Injecting the molding liquid to the region 200) to form the first mold 237, and when the first mold 237 is formed, the epoxy resin-based molding liquid continues to the wall 305 region of the polymer poly 300. Is injected to form a second mold 247.

Since the LED package having the structure as described above is primarily die-bonded on the silicon sub-mount, it is possible to form a reflector on the silicon sub-mount to improve the light efficiency.

Conventionally, although it is difficult to manufacture the reflector 201 reflecting the light generated from the LED 203 on the lead frame 301, the reflector may be formed in the present invention because of the high processability of the silicon sub-mount.

In addition, the silicon sub-mount having the LED mounted thereon is easy to dissipate heat, thereby preventing deterioration of light quality and package failure caused by heat.

5A-5E illustrate white LED packages molded and manufactured according to the present invention.

 In FIGS. 5A to 5E, unlike FIG. 4A to FIG. 4D, an LED is mounted using the silicon submount described with reference to FIG. 3 to generate white light.

As shown in FIG. 5A, in order to generate white light, the LED 403 is mounted on the silicon sub-mount 400 in which the reflection hole and the reflection plate are formed, and then the lead frame is formed around the polymer poly 500. The silicon submount 400 is mounted to the 501 by a die bonding method.

When the silicon submount 400 is die-bonded to the polymer poly 500, the P and N electrodes of the LED 403 and the lead frame 501 and the wire 503 are bonded to each other. 400. The lead wire is drawn out to the lead frame 501 from the LED 403 mounted in the reflection hole, and the wire 503 is bonded.

As such, when the wire 503 is bonded, a silicon-based material and a phosphor resin are mixed (506) and injected into a wall (WALL: 505) having a constant height around the edge of the polymer poly 500, and then molded. The silicon submount 400 is encapsulated while forming a layer.

In the LED package having the structure as described above, the light generated from the LED 403 generates light to the outside while generating white light in the molding layer 506 in which the silicon-based material and the phosphor are mixed.

In this case, the wavelength of the light generated by the LED 403 is converted to have a wavelength of white light in the phosphor, and then generates white light to the outside of the package.

As shown in FIG. 5B, as shown in FIG. 3, the LED 403 is die-bonded on the silicon sub-mount 400, and then mounted on the lead frame 501 by die bonding, and then the silicon is mounted. The P and N electrodes of the LED 403 die-bonded on the reflection hole of the sub-mount 400 and the lead frame 501 are electrically connected to each other by wire bonding.

After wire-bonding the LED 403 and the lead frame 501, a first mold 517 is formed by injecting a molding liquid mixed with a silicone-based resin and a phosphor into a reflection hole on the silicon sub-mount 400. .

At this time, the interface shape of the first mold 517 is formed in a concave or concave-convex shape to improve the light efficiency generated by the LED 403.

As described above, when the first mold 517 is formed on the reflective hole of the silicon sub-mount 400, the molding liquid made of epoxy resin is continuously injected into the wall 505 on the polymer poly 500. A mold 507 is formed to encapsulate the silicon submount 400 in a package form.

However, in FIG. 5C, the LED package is manufactured in a manner opposite to the double mold structure in FIG. 5B.

As shown in FIG. 5B, after die-bonding the LED 403 on the silicon submount 400, the silicon submount 400 is mounted on the lead frame 501, and then the wire 503 is bonded. Proceed with the process.

When the LED 403 of the silicon submount 400 is wire bonded, a molding liquid made of a silicone-based resin is injected into the reflective hole of the silicon submount 400, unlike in FIG. 5B, to form a first mold 527. Form.

At this time, as described with reference to FIG. 5B, by adjusting the interface shape of the mold to form concave or concave-convex shape, LED light efficiency is improved.

After the first mold 527 is formed, a resin in which an epoxy resin and a phosphor are mixed is injected into the wall 505 of the polymer poly 500 to form a second mold 537 to form an LED package. Complete

As shown in FIG. 5D, a method of forming a double mold structure by another method, as shown in FIG. 5B, after die-bonding the LEDs 403 onto the silicon sub-mount 400 and then a lead frame Die bonding to 501.

Then, the wire 503 is taken out from the LED 403 mounted on the silicon submount 400 to perform wire bonding with the lead frame 501.

Then, a molding liquid in which a silicone resin and a phosphor are mixed into the wall 505 of the polymer poly 500 is injected into the silicon submount 400 to form a first mold 547, and then the first mold 547 is formed. The second mold 557 is formed by injecting a molding liquid of epoxy resin onto the first mold 547.

FIG. 5E illustrates an LED package having a structure opposite to that of FIG. 5D. The silicon sub-mount 400 in which the LED 403 is die-bonded is die-bonded to the lead frame 501 and then wire 503 is bonded.

Thereafter, a first mold 567 is formed by injecting a molding liquid of a silicone resin into the silicon submount 400 region, and then a second mold 577 is formed by mixing an epoxy resin and a phosphor.

In the present invention, by using a double mold structure, it is possible to prevent the deterioration of the light quality by the deformation of the phosphor with respect to the LED used for high power, and to mount the LED on the silicon sub-mount to the wafer-type silicon substrate by etching the reflection hole And a metal film is deposited, and then etched to form a reflective plate, thereby producing a silicon sub-mount in which the LED is mounted in large quantities.

FIG. 6 is a view illustrating an LED mounted on a silicon sub-mount in a flip chip method according to the present invention. As shown in FIG. 6, reflecting holes are formed on the silicon sub-mount 600, and a reflecting plate 601 is formed. A reflective metal film is deposited for this purpose.

As described above, in the case where the LED 603 that is not the wire 605 bonding operation is mounted by the flip chip method, an intermediate region where the P electrode and the N electrode of the LED 603 are in contact with each other during the formation of the reflector 601. In the open form.

Therefore, when the LED 603 is mounted in a flip chip state, the P electrode and the N electrode are electrically connected to the reflecting plate 601 to bond the wire 605 directly to the reflecting plate 601 when mounted on the lead frame. To be electrically connected to the lead frame.

As described above, when the LED 603 is mounted on the silicon sub-mount 600 by a flip chip method, unlike die bonding, the LED 603 does not need to be wire-bonded first, but directly on the reflection hole of the silicon sub-mount 600. You can proceed to molding.

In this case, the molded interface shape may be formed in a concave or concave-convex shape to improve the light efficiency of the LED 603.

FIG. 7 is a view for explaining a process in which LEDs are mounted on a silicon sub-mount and mass-produced according to the present invention, and a plurality of reflective holes are formed on the silicon wafer 700 and the reflective plate metal 701 is deposited. By etching this, a large number of silicon submounts can be manufactured.

As shown in the figure, a plurality of reflecting holes were formed, a reflecting plate 701 was formed, and then the LED 703 was mounted with a flip chip. According to the mounted flip chip, the wafer 700 may be cut to manufacture a plurality of silicon sub-mounts in which LEDs are mounted on a single silicon wafer.

The molding operation on the reflection hole of the silicon sub-mount may also be performed on the entire wafer by using a dispenser.

8A and 8B illustrate a state in which an LED is connected to a lead frame by a via hole in a flip chip bonded structure in a silicon sub-mount according to the present invention.

As shown in FIG. 8A, an etching process is performed to form reflective holes on the silicon sub-mount 801, and a reflective plate 805 is formed on the reflective holes.

The LED 807 is mounted on the reflector 805 by flip chip bonding, and the reflector 805 and the P and N electrodes of the LED are electrically contacted by solder balls 809.

A via hole (VIA HOLE) 803 is formed in the silicon submount region of the region corresponding to the reflector plate 805 on the silicon submount 801, and a metal conductor is filled therein.

When the LED 807 is mounted on the silicon sub-mount 801 by flip chip bonding, as shown in FIG. 8B, the LED 807 is directly die-bonded to the lead frame 815 disposed on the polymer poly 830.

The via hole 803 formed on the silicon submount 801 and the lead frame 815 are electrically contacted by a solder ball 810.

That is, the LEDs 807 are flip-chip bonded by solder balls on the reflection holes of the silicon sub-mounts 801, and the via holes 803 formed in the silicon sub-mounts 801 are the lead frame 815 and the solder balls ( 810 is electrically contacted.

Therefore, the LED package fabrication by flip chip bonding and via hole eliminates the wire bonding process, and the molding order is manufactured in the same manner as the formation method of the double mold structure shown in FIGS. 5A to 5D.

In the present invention, by using a silicon sub-mount, it is possible to produce a larger area than the conventional LED lead frame for backlight, and to increase the usable current size, which is suitable when high power is required.

As described in detail above, the present invention mounts the LED on the silicon sub-mount in which the reflecting plate is formed, and mounts the LED on the lead frame, thereby improving the light efficiency.

In addition, due to the high thermal conductivity of the silicon sub-mount and the double mold structure, the heat generated from the LED can be easily transferred to the lower frame, and UV deterioration, yellowing, and chip protection during light emission are enhanced. Can be.

The present invention is not limited to the above-described embodiments, and various changes can be made by those skilled in the art without departing from the gist of the present invention as claimed in the following claims.

1 is a view showing a blue LED package structure according to the prior art.

Figure 2 shows a white LED package structure according to the prior art.

3 is a view showing a state in which the LED is mounted on the silicon sub-mount in accordance with the present invention.

4A-4C illustrate blue LED packages manufactured molded according to the present invention.

5A-5E illustrate white LED packages molded and manufactured according to the present invention.

6 is a view showing a state in which the LED is mounted in a flip chip method on the silicon sub-mount in accordance with the present invention.

7 is a view for explaining the process of mass-producing the LED is mounted on the silicon sub-mount in accordance with the present invention.

8A and 8B illustrate a state in which an LED is connected to a lead frame by a via hole in a flip chip bonded structure in a silicon sub-mount according to the present invention.

* Description of the symbols for the main parts of the drawings *

200: silicon submount 201: reflector

203: light emitting diode (LED) 237: first mold

247: second mold 300: polymer poly

301: lead frame 303: wire

305: wall

Claims (20)

A sub-mount including a light emitting diode and a reflecting hole in which a reflecting portion is disposed; A lead frame connected to the sub mount; Connecting means for electrically connecting the light emitting diode and the lead frame; A substrate supporting the lead frame; A wall disposed along an edge of the substrate; And And a mold part encapsulated in the wall. The method of claim 1, The mold unit is a light emitting diode package, characterized in that consisting of a double layer of the first mold portion and the second mold portion. The method of claim 2, The first mold unit is a light emitting diode package, characterized in that disposed on the reflection hole of the sub-mount. The method of claim 2 or 3, The second mold portion is a light emitting diode package, characterized in that disposed in the wall. The method of claim 1, The mold unit includes a phosphor for absorbing the light wavelength generated by the light emitting diode to emit light of another wavelength. The method of claim 2 or 3, The first or the second mold layer is a light emitting diode package, characterized in that the molding structure containing at least any one of the phosphor for absorbing the wavelength of the light emitting diode to give a different wavelength. The method of claim 2 or 6, The first and second mold layers are molded by selecting any one of a silicone resin or an epoxy resin. The method according to claim 2 or 6, The first and the second mold is a light emitting diode package, characterized in that molded by selecting any one of the silicone resin or epoxy resin different from each other. The method according to claim 1 or 5, The substrate is a light emitting diode package, characterized in that the polymer poly. The method according to claim 2 or 6, The interface structure of the mold layer is a light emitting diode package, characterized in that having any one of concave or concave-convex shape. The method according to claim 1 or 5, The reflector has a structure of any one of a multi-layer structure consisting of Ag / Cr / Au or Ni / Ag / Cr / Au. The method according to claim 1 or 5, The light emitting diode package disposed on the reflective hole of the silicon submount is electrically connected to the lead frame by wire bonding. The method according to claim 1 or 5, The light emitting diode package disposed on the reflective hole of the silicon sub-mount is connected to the reflecting unit by flip chip bonding. The method of claim 13, And the reflector and the lead frame are electrically connected by wire bonding. The method of claim 13, And the reflector and the lead frame are electrically connected to each other through a via hole formed in the silicon submount. Etching the reflection hole of the sub-mount to bond the light emitting diode; Forming a reflecting plate in the etched reflecting hole; Applying a reflective coating on the reflector to increase light reflectance; Bonding the light emitting diode to the reflector; Mounting the sub-mount to which the light emitting diode is bonded to a lead frame formed on a substrate; Electrically connecting the light emitting diode and the lead frame; Forming a wall around the substrate edge; And Forming a first mold layer and a second mold layer in the wall; Method for manufacturing a light emitting diode package comprising a. The method of claim 16, The first mold layer is formed by injecting a molding liquid into the reflection hole of the sub-mount LED package manufacturing method. The method of claim 16, When the first mold layer is formed, the molding solution is characterized in that the molding liquid is ejected in units of wafers. The method of claim 16 or 17, The first mold layer is formed of a molding liquid in which a silicone resin and a phosphor are mixed, and the second mold layer is formed of a molding liquid of an epoxy resin. The method of claim 16 or 19, The coating film coated on the reflector of the sub-mount is a light emitting diode package manufacturing method characterized in that the Ag metal.