KR102532362B1 - Light emitting device package - Google Patents

Abstract

The embodiment relates to a light emitting device package, comprising: a substrate; a first lead frame and a second lead frame disposed on the substrate; plating layers disposed on upper and lower surfaces of the first lead frame and the second lead frame; a light emitting element electrically connected to the first lead frame and the second lead frame; and a molding portion surrounding the light emitting device, wherein the plating layer includes a first plating layer containing nickel (Ni); and a second plating layer connected to the first plating layer, disposed at an outermost portion of the plating layer, and containing gold (Au).

Description

Light emitting device package {LIGHT EMITTING DEVICE PACKAGE}

The embodiment relates to a light emitting device package.

Light emitting devices such as Light Emitting Diodes (LEDs) or Laser Diodes (LDs) using compound semiconductor materials of groups 3-5 or 2-6 of semiconductors have developed thin film growth technology and device materials to produce red, Various colors such as green, blue, white and ultraviolet can be realized, and white light with high efficiency can be realized by using fluorescent materials or combining colors. , has the advantages of fast response speed, safety, and environmental friendliness.

Therefore, the light emitting diode can replace the light emitting diode backlight that replaces the cold cathode fluorescence lamp (CCFL) constituting the backlight of the transmission module of the optical communication means, the backlight of the LCD (Liquid Crystal Display) display device, and can replace the fluorescent lamp or incandescent light bulb. Applications are expanding to white light emitting diode lighting devices, automobile headlights, and traffic lights.

In the light emitting device, a light emitting structure including a first conductivity type semiconductor layer, an active layer, and a second conductivity type semiconductor layer is formed on a substrate made of sapphire or the like, and a first conductivity type semiconductor layer and a second conductivity type semiconductor layer are respectively formed. A first electrode and a second electrode are disposed.

In the light emitting device package, a first electrode and a second electrode are disposed on a package body, and a light emitting device is disposed on a bottom surface of the package body and electrically connected to the first electrode and the second electrode.

In the light emitting device package, a metal plating layer is disposed on a lead frame, and an adhesive for bonding the light emitting device is applied to the plating layer. The adhesive has a problem in that the durability and reliability of the light emitting device package are greatly reduced as the adhesive strength decreases after a certain time elapses and the light emitting device is lifted from the lead frame.

Embodiments are intended to improve durability and reliability of a light emitting device package.

In order to achieve the above object, the embodiment is a substrate; a first lead frame and a second lead frame disposed on the substrate; plating layers disposed on upper and lower surfaces of the first lead frame and the second lead frame; a light emitting element electrically connected to the first lead frame and the second lead frame; and a molding portion surrounding the light emitting device, wherein the plating layer includes a first plating layer containing nickel (Ni); and a second plating layer connected to the first plating layer, disposed at an outermost portion of the plating layer, and containing gold (Au).

The thickness of the first plating layer may be 1.0 μm to 3.0 μm.

The second plating layer may have a thickness of 0.01 μm to 0.07 μm.

An adhesive member may be disposed between the light emitting element and the plating layer.

The light emitting element may be connected to the first lead frame and the second lead frame, and a first wire and a second wire.

A silicon oxide layer may be disposed between the light emitting element, the plating layer, and the molding part.

The silicon oxide film may be coated on the first wire and the second wire.

A reflector disposed on the plating layer and spaced apart from the light emitting device may be further included.

A silicon oxide layer may be disposed between the plating layer, the reflector, and the molding part.

The silicon oxide film may have a thickness of 0.01 μm to 0.03 μm.

According to the embodiment as described above, the durability and reliability of the light emitting device package can be improved by preventing the light emitting device adhered to the plating layer by the adhesive member from lifting the light emitting device from the plating layer due to a drop in adhesive strength in the process of curing the adhesive member. There are possible effects.

1 is a plan view illustrating a light emitting device package according to an embodiment.
FIG. 2 is a AA′ cross-sectional view of FIG. 1 .
3 is a view showing the structure of a plating layer of a light emitting device package according to an embodiment.
4 is a cross-sectional view showing a light emitting device package according to another embodiment.
5A and 5B are graphs showing the luminous flux change rate over time of the light emitting device package to which the plating layer of the light emitting device package according to the embodiment is applied.
6 is an exploded perspective view illustrating an example of an image display device including a light emitting device package according to an embodiment.
7 is an exploded perspective view illustrating an exemplary embodiment of a lighting device in which a light emitting device package according to the exemplary embodiment is disposed.

Hereinafter, a preferred embodiment of the present invention that can specifically realize the above object will be described with reference to the accompanying drawings.

In the description of the embodiment according to the present invention, in the case of being described as being formed on "on or under" of each element, on or under (on or under) or under) includes both elements formed by directly contacting each other or by indirectly placing one or more other elements between the two elements. In addition, when expressed as “on or under”, it may include not only the upward direction but also the downward direction based on one element.

In the drawings, the thickness or size of each layer is exaggerated, omitted, or schematically illustrated for convenience and clarity of explanation. Also, the size of each component does not entirely reflect the actual size.

1 is a plan view illustrating a light emitting device package according to an exemplary embodiment, and FIG. 2 is a cross-sectional view taken along line AA' of FIG. 1 .

The light emitting device package 100A according to the present embodiment includes a substrate 110, a first lead frame 121 and a second lead frame 122, a plating layer 130, a light emitting device 150, and a molding part 160. include

In an embodiment, the substrate 110 may be formed of a silicon material, a synthetic resin material, or a metal material, may act as a package body, and may be a thermal conductive substrate to discharge heat generated from the light emitting device 150 to the outside. can be provided with

In addition, a first lead frame 121 and a second lead frame 122 are disposed on the substrate 110, and a first electrode pad and a second electrode pad (not shown) formed on the light emitting device 150 to be described later They are formed to correspond to each other and may be electrically connected.

The first electrode pad (not shown) and the second electrode pad (not shown) are made of at least one of aluminum (Al), titanium (Ti), chromium (Cr), nickel (Ni), copper (Cu), and gold (Au). It may be formed in a single-layer or multi-layer structure, including.

Also, the first lead frame 121 and the second lead frame 122 are electrically separated from each other and supply power to the light emitting device 150 electrically connected to the first lead frame and the second lead frame. Here, the first lead frame and the second lead frame may reflect light emitted from the light emitting device 150 .

The first lead frame and the second lead frame may be made of a conductive material such as copper, and a plating layer 130 may be disposed on upper surfaces of the first lead frame and the second lead frame.

3 is a view showing the structure of a plating layer of a light emitting device package according to an embodiment.

Looking at the plating layer plated on the lead frame of the light emitting device package, the conventional plating layer had a structure in which nickel (Ni), palladium (Pd), and gold (Au) were sequentially stacked in the vertical direction of the plating layer, but as shown in FIG. , The plating layer 130 of the present embodiment is disposed symmetrically up and down around the lead frame, and the first plating layer 131 and the second plating layer connected to the first plating layer 131 are disposed on the outermost side of the plating layer 130 ( 132).

Also, the first plating layer 131 may include nickel (Ni), and the second plating layer 132 may include gold (Au).

The first plating layer 131 may be formed thicker than the second plating layer 132, and the thickness of the first plating layer 131 including nickel (Ni) may be 1.0 μm to 3.0 μm, and gold (Au) may be formed. The thickness of the second plating layer 132 including may be 0.01 μm to 0.07 μm.

If the thickness of the first plating layer containing nickel (Ni) is formed to be smaller than 1.0 μm, the strength of the plating layer may be weakened, so the thickness of the first plating layer may be determined in consideration of strength and corrosion resistance of the plating layer.

After the first plating layer is formed in this way, a second plating layer may be formed by post-treatment plating. In the embodiment, a second plating layer containing gold (Au) is disposed on the first plating layer to prevent sulfur corrosion. can

If the thickness of the second plating layer is less than 0.01 μm, there is a limit to preventing yellow corrosion, and if it is thicker than 0.07 μm, the cost of manufacturing the package increases. It can be formed with a minimum thickness that can reduce manufacturing cost.

4 is a cross-sectional view showing a light emitting device package according to another embodiment.

Referring to FIGS. 2 and 4 , an adhesive member 155 may be disposed and soldered between the light emitting element and the plating layer so that the light emitting element may be connected and fixed on the conductive layer, and the first electrode of the light emitting element 150 may be soldered. It may be disposed between the pad and the first lead frame and between the second electrode pad and the second lead frame, respectively.

Here, the adhesive member 155 is lead-free solder of Au or Sn and Sn/Ag, Sn/Cu, Sn/Zn, Sn/Zn/Bi, Sn/Zn/Bi, Sn/Ag/Cu, Sn/Ag/Bi (Lead-free solder) and high lead and eutectic lead solder.

And, if the thickness (BLT: Bonding Layer Thickness) of the adhesive member 155 is too thin, the buffer layer ( Buffer Layer), and if the thickness of the adhesive member 155 is provided thickly, the adhesive strength becomes unstable.

Therefore, the thickness of the adhesive member can be formed to adhere between the first lead frame 121 and the second lead frame 122 and the light emitting device 150 and at the same time serve as a buffer layer. there is.

Meanwhile, a reflector 115 may be disposed on the plating layer, and the reflector 115 is spaced apart from the edge of the light emitting element 150 disposed on the plating layer and is disposed on the first lead frame 121 and the second lead frame 122. can be placed. Here, the reflector 115 may increase luminance by reflecting light emitted from the light emitting device 150 to the front surface of the light emitting device package (upward direction in FIGS. 2 and 4 ).

Further, the molding unit 160 may surround the light emitting element 150 to protect the light emitting element 150 and may be disposed around the light emitting element 150, and act as a lens by changing a path of light emitted from the light emitting element 150. can The molding part 160 may contain a phosphor and be excited by the light of the first wavelength region emitted from the light emitting device 150 to emit light of the second wavelength region.

In addition, as shown, the molding unit 160 is formed in a dome type in which a part of the region corresponding to the light emitting element 150 is recessed, or disposed in a different shape to adjust the light emission angle of the light emitting element package. It could be.

Although not shown, a phosphor layer may be positioned on the light emitting element 150, and the phosphor layer may be arranged with a constant thickness by using a conformal coating method, and the function of the phosphor layer may be described above. It may be the same as the case where a phosphor is disposed in one molding part 160 .

The light emitting device 150 may be provided as a flip chip, and may be vertically flip-chip bonded and disposed on an upper surface of a substrate.

In addition, the light emitting device 150 mounted on the light emitting device package may be arranged as a vertical light emitting device or a horizontal light emitting device. In this embodiment, the first electrode pad and the second electrode pad (not shown) of the light emitting device 150 are connected to the first lead frame and the second lead frame by first wires 151 and second wires 152, respectively. can be electrically connected.

The first wire and the second wire may be made of a conductive material and may be made of gold (Au) having a diameter of about 0.8 to 1.6 millimeters. If the thickness of the wire is too thin, it may be cut by an external force, and if the thickness is too thick, material costs increase and light emitted from the light emitting device may become an obstacle to progress.

On the other hand, when the adhesive member disposed between the plating layer and the light emitting element is cured, the second plating layer of the plating layer inhibits the curing of the adhesive member, thereby greatly reducing the adhesive strength of the adhesive member. To prevent this, as indicated by thick solid lines in FIGS. 2 and 4 , a silicon oxide film 140 may be disposed between the light emitting element and the plating layer and the molding part, and the silicon oxide film 140 may be made of SiO ₂ or the like. And, the thickness of the silicon oxide film may be 0.01 μm to 0.03 μm.

Also, the silicon oxide film 140 may be coated on the first wire 151 and the second wire 152 to prevent corrosion of the wire.

In addition, the silicon oxide layer 140 may be disposed between the plating layer 130 and the reflector 115 and the molding part 160 .

In this way, since the silicon oxide film is disposed on the plating layer, the light emitting element disposed on the plating layer, and the reflector, the light emitting element adhered to the plating layer by the adhesive member is prevented from lifting the light emitting element from the plating layer due to a decrease in adhesive strength during the process of curing the adhesive member. In addition, it is possible to prevent lifting between the reflector and the molding part due to heat generated from the light emitting device, thereby improving durability and reliability of the light emitting device package.

5A and 5B are graphs showing the luminous flux change rate over time of the light emitting device package to which the plating layer of the light emitting device package according to the embodiment is applied.

During use of the light emitting device package, the luminous flux change rate with time must be maintained within a certain range to ensure reliability of the light emitting device package. The luminous flux change rate of a light emitting device package to which a conventional plating layer is applied is larger than a certain range for a specific time period.

5A and 5B, when the thickness of the second plating layer containing gold (Au) is 0.05 μm, the luminous flux change rate of the light emitting device package over time for 1,000 hours is measured to be 97.23% to 120.26%, and the standard The deviation (STDEV) peaks at 5.14% after 336 hours. On the other hand, in the conventional structure in which plating layers are stacked in the order of copper (Cu), nickel (Ni), palladium (Pd), and gold (Au), the luminous flux change rate of the light emitting device package is measured as 100.00% to 125.47%, and the standard deviation ( STDEV) is 8.88% when 336 hours have elapsed, and it can be seen that the luminous flux change rate over time of the light emitting device package to which the plating layer of the light emitting device package according to the present embodiment is applied is small and thus reliability can be increased.

According to the light emitting device package according to the present embodiment, as palladium (Pd) is removed from the plating layer, costs for manufacturing the plating layer can be reduced, and reliability and durability of the light emitting device package can be improved.

A plurality of light emitting device packages according to the embodiment are arrayed on a substrate, and optical members such as a light guide plate, a prism sheet, a diffusion sheet, and the like may be disposed on a light path of the light emitting device package. The light emitting device package, substrate, and optical member may function as a light unit. Another embodiment may be implemented as a display device including a semiconductor light emitting device or a light emitting device package described in the above embodiments, an indicating device, and a lighting system. For example, the lighting system may include a lamp and a street light. .

Hereinafter, a backlight unit and a lighting device will be described as an embodiment of a lighting system in which the above-described light emitting device or light emitting device package is disposed.

6 is an exploded perspective view showing an example of an image display device including a light emitting device package according to an embodiment.

As shown in FIG. 6, the image display device 900 according to this embodiment is disposed in front of a light source module, a reflector 920 on the bottom cover 910, and the reflector 920, and in the light source module A light guide plate 940 for guiding emitted light to the front of the image display device, a first prism sheet 950 and a second prism sheet 960 disposed in front of the light guide plate 940, the second prism sheet ( It includes a panel 970 disposed in front of the panel 960 and a color filter 980 disposed in the first half of the panel 970.

The light source module includes the light emitting device package 935 on the circuit board 930 . Here, a PCB or the like may be used as the circuit board 930, and the light emitting device package 935 is as described above.

The image display device may use a direct type backlight unit as well as the edge type backlight unit shown in FIG. 6 .

In the light emitting device package used in the above-described image display device, a silicon oxide film is formed on the surfaces of the first lead frame and the second lead frame to prevent penetration of moisture or air from the outside, thereby improving durability and reliability.

7 is an exploded perspective view illustrating an exemplary embodiment of a lighting device in which a light emitting device package according to the exemplary embodiment is disposed.

The lighting device according to the present embodiment may include a cover 1100 , a light source module 1200 , a radiator 1400 , a power supply unit 1600 , an inner case 1700 , and a socket 1800 . In addition, the lighting device according to the embodiment may further include any one or more of the member 1300 and the holder 1500, and the light source module 1200 may include the light emitting device package according to the above-described embodiments. .

The cover 1100 may have a bulb or hemisphere shape, be hollow, and may be provided in a shape in which one part is open. The cover 1100 may be optically coupled to the light source module 1200 . For example, the cover 1100 can diffuse, scatter, or excite the light provided from the light source module 1200 . The cover 1100 may be a kind of optical member. The cover 1100 may be combined with the heat dissipation body 1400 . The cover 1100 may have a coupling portion coupled to the heat dissipation body 1400 .

The inner surface of the cover 1100 may be coated with milky white paint. The milky white paint may include a diffusion material that diffuses light. The surface roughness of the inner surface of the cover 1100 may be greater than that of the outer surface of the cover 1100 . This is to sufficiently scatter and diffuse the light from the light source module 1200 and emit it to the outside.

The material of the cover 1100 may be glass, plastic, polypropylene (PP), polyethylene (PE), or polycarbonate (PC). Here, polycarbonate is excellent in light resistance, heat resistance, and strength. The cover 1100 may be transparent or opaque so that the light source module 1200 can be seen from the outside. The cover 1100 may be formed through blow molding.

The light source module 1200 may be disposed on one surface of the heat dissipation body 1400 . Thus, heat from the light source module 1200 is conducted to the heat dissipation body 1400 . The light source module 1200 may include a light emitting device package 1210 , a connection plate 1230 , and a connector 1250 . The light emitting device package 1210 is as shown in the above-described embodiments, and a silicon oxide film is formed on the surfaces of the first lead frame and the second lead frame to prevent penetration of moisture or air from the outside, thereby improving durability and reliability. can be improved

The member 1300 is disposed on the upper surface of the heat sink 1400 and has guide grooves 1310 into which a plurality of light emitting device packages 1210 and a connector 1250 are inserted. The guide groove 1310 corresponds to the board of the light emitting device package 1210 and the connector 1250 .

The surface of the member 1300 may be applied or coated with a light reflecting material. For example, the surface of the member 1300 may be coated or coated with a white paint. The member 1300 reflects the light reflected on the inner surface of the cover 1100 and returned to the light source module 1200 toward the cover 1100 again. Accordingly, light efficiency of the lighting device according to the embodiment may be improved.

The member 1300 may be made of an insulating material, for example. The connection plate 1230 of the light source module 1200 may include an electrically conductive material. Thus, electrical contact may be made between the radiator 1400 and the connection plate 1230 . The member 1300 is made of an insulating material to block an electrical short between the connection plate 1230 and the radiator 1400 . The radiator 1400 receives heat from the light source module 1200 and heat from the power supply unit 1600 and dissipates heat.

The holder 1500 blocks the receiving groove 1719 of the insulating part 1710 of the inner case 1700 . Thus, the power supply unit 1600 accommodated in the insulation unit 1710 of the inner case 1700 is sealed. The holder 1500 has a guide protrusion 1510 . The guide protrusion 1510 has a hole through which the protrusion 1610 of the power supply unit 1600 passes.

The power supply unit 1600 processes or converts an electrical signal received from the outside and provides it to the light source module 1200 . The power supply unit 1600 is accommodated in the receiving groove 1719 of the inner case 1700, and is sealed inside the inner case 1700 by the holder 1500. The power supply unit 1600 may include a protrusion 1610, a guide unit 1630, a base 1650, and an extension unit 1670.

The guide part 1630 has a shape protruding outward from one side of the base 1650 . The guide part 1630 may be inserted into the holder 1500 . A plurality of components may be disposed on one surface of the base 1650 . A number of parts include, for example, a DC converter for converting AC power provided from an external power source into DC power, a driving chip for controlling driving of the light source module 1200, and ESD for protecting the light source module 1200. (ElectroStatic discharge) protection device, etc. may be included, but is not limited thereto.

The extension part 1670 has a shape protruding outward from the other side of the base 1650 . The extension part 1670 is inserted into the connection part 1750 of the inner case 1700 and receives an electrical signal from the outside. For example, the width of the extension part 1670 may be equal to or smaller than the width of the connection part 1750 of the inner case 1700 . Each end of the "+ wire" and the "- wire" may be electrically connected to the extension 1670, and the other ends of the "+ wire" and the "- wire" may be electrically connected to the socket 1800. .

The inner case 1700 may include a molding part together with the power supply part 1600 therein. The molding part is a part where the molding liquid is hardened, and allows the power supply part 1600 to be fixed inside the inner case 1700 .

Although the above has been described with reference to the embodiments, this is only an example and does not limit the present invention, and those skilled in the art to which the present invention belongs will not deviate from the essential characteristics of the present embodiment. It will be appreciated that various variations and applications are possible. For example, each component specifically shown in the embodiment can be modified and implemented. And differences related to these modifications and applications should be construed as being included in the scope of the present invention as defined in the appended claims.

100A, 100B: light emitting device package 110: substrate
115: reflector 121: first lead frame
122: second lead frame 130: plating layer
140: silicon oxide film 150: light emitting device
151: first wire 152: second wire
155: adhesive member 160: molding part

Claims (10)

Board;
a first lead frame and a second lead frame disposed on the substrate;
plating layers disposed on upper and lower surfaces of the first lead frame and the second lead frame;
an adhesive member disposed on the plating layer;
a light emitting element electrically connected to the first lead frame and the second lead frame and disposed on the adhesive member;
a molding part surrounding the light emitting element; and
A silicon oxide film disposed between the light emitting element, the plating layer, and the molding part;
The plating layer is
A first plating layer containing nickel (Ni); and
a second plating layer connected to the first plating layer, disposed at an outermost portion of the plating layer, and containing gold (Au);
The light emitting element is electrically connected to the first lead frame and the second lead frame with a first wire and a second wire, respectively,
The silicon oxide film is coated on the first wire and the second wire,
The thickness of the second plating layer is 0.01 μm to 0.07 μm,
The length of the second plating layer is the same as the length of the first plating layer light emitting device package. delete The method of claim 1, wherein the light emitting device package
A light emitting device package further comprising a reflector disposed on the plating layer and spaced apart from the light emitting device. The light emitting device package of claim 3 , wherein the silicon oxide layer is disposed between the plating layer, the reflector, and the molding part. The light emitting device package of claim 1 , wherein the silicon oxide layer has a thickness of 0.01 μm to 0.03 μm.

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