KR20150049644A - Lead frame, light emitting diode package including the lead frame, and method of manufacturing the lead frame - Google Patents

Abstract

The present invention discloses a lead frame, a light emitting diode (LED) package including the same, and a method for manufacturing the same. According to an embodiment of the present invention, the lead frame comprises: a base device; a first metal layer which is disposed on the upper side of the base device and is made of a nickel-palladium alloy; and a second metal layer which is disposed on the upper side of the first metal layer and is made of silver. In the nickel-palladium alloy, wt% of nickel is larger than wt% of palladium.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a lead frame, an LED package including the lead frame, and a manufacturing method of the lead frame,

The present invention relates to a lead frame, an LED package including the lead frame, and a method of manufacturing the lead frame.

The lead frame not only electrically connects the semiconductor chip to an external device but also supports a semiconductor chip. The semiconductor chip is bonded to the upper surface of the lead frame, the semiconductor chip is bonded to the upper surface of the lead frame using a bonding wire, and the upper surface of the lead frame is sealed with a mold resin, ). The semiconductor package thus manufactured is mounted on an external device. At this time, a solder ball is disposed on the lower surface of the lead frame to connect to an external device, for example, a printed circuit board.

The lead frame can be used as a lighting element by using LED (Light Emitting Diode). An LED package is manufactured by bonding an LED chip to an upper surface of a lead frame and then sealing an upper surface of the lead frame with a mold resin. In order to improve the performance of the LED package as an illumination device, the light emitted from the LED chip must be transmitted to the outside without being absorbed by the lead frame.

Therefore, in order to increase the reflectivity of the light transmitted to the outside, the roughness of the plating layer formed on the upper surface of the lead frame in contact with the LED chip is important.

A semiconductor package manufacturing method using a general lead frame as described above is specifically disclosed in Korean Patent Laid-Open Publication No. 2000-0038929 (entitled " Semiconductor Package Manufacturing Method ").

Korean Patent Publication No. 2000-0038929

Embodiments of the present invention are intended to provide a lead frame in which the roughness of the surface is uniformly formed, an LED package including the lead frame, and a method of manufacturing the lead frame.

An aspect of the present invention is a method of manufacturing a semiconductor device comprising a base material, a first metal layer disposed on the base material and formed of a nickel-palladium alloy, and a second metal layer disposed on the first metal layer and formed of silver , Wherein the nickel-palladium alloy provides a leadframe wherein the weight percent of nickel is greater than the weight percent of palladium.

Also, the thickness of the first metal layer may be 0.8 to 5.1 micrometers [um].

Also, The palladium contained in the nickel-palladium alloy in the first metal layer may be 2 to 32 wt%.

In addition, the second metal layer may be formed to have a thickness of 5 to 50 micrometers [um].

The nickel-palladium alloy layer may be at least one selected from the group consisting of Ag, Au, Ni, Cu, Co, Mo, Ru, (In). ≪ / RTI >

The first metal layer may further include a third metal layer disposed between the first metal layer and the second metal layer and formed of palladium.

According to another aspect of the present invention, there is provided a semiconductor device comprising a base material having a die pad and a lead portion, a first metal layer disposed on the base material and formed of a nickel-palladium alloy, a second metal layer disposed on the first metal layer, Wherein the nickel-palladium alloy comprises: a leadframe wherein the weight percentage of nickel is greater than the weight percentage of palladium; an LED chip bonded to the die pad; (LED) package including a plurality of bonding wires connecting the LED chips.

Also, the thickness of the first metal layer may be 0.8 to 5.1 micrometers [um].

The palladium contained in the nickel-palladium alloy in the first metal layer may be 2 to 32 wt%.

In addition, the second metal layer may be formed to have a thickness of 5 to 50 micrometers [um].

The first metal layer may further include a third metal layer disposed between the first metal layer and the second metal layer and formed of palladium.

According to another aspect of the present invention, there is provided a method of manufacturing a semiconductor device, comprising: performing electrolytic degreasing or pickling on a base material having a die pad and a lead portion; Forming a nickel-palladium alloy layer on top of the base material by electroplating; Wherein the step of forming a nickel-palladium alloy layer comprises forming a silver metal layer disposed on top of the nickel-palladium alloy layer, wherein the nickel-palladium alloy layer forming step comprises forming a nickel- .

In addition, the thickness of the nickel-palladium alloy layer may be 0.8 to 5.1 micrometers [um].

In addition, palladium in the nickel-palladium alloy layer may be formed to 2 to 32 wt%.

In addition, the silver metal layer may be formed to have a thickness of 5 to 50 micrometers [um].

Also, And forming a palladium metal layer disposed between the nickel-palladium alloy layer and the silver metal layer.

The silver metal layer forming step may be formed by any one of a chemical vapor deposition (CVD) method, a sputtering method, and a plasma reaction method.

The step of forming the palladium metal layer may be performed by any one of a chemical vapor deposition (CVD) method, a sputtering method, and a plasma reaction method.

Embodiments of the present invention can improve the reflectivity of the lead frame by uniformly forming the roughness of the surface of the lead frame and increase the efficiency of the LED package using the lead frame. In addition, the heat-scattering prevention layer may be formed on the lead frame to improve the durability of the lead frame and the LED package using the lead frame. Of course, the scope of the present invention is not limited by these effects.

1 is a schematic cross-sectional view of an LED package manufactured using a lead frame according to an embodiment of the present invention.
2 is a plan view of the lead frame shown in Fig.
3 is a cross-sectional view of a portion of the lead frame shown in Fig.
4 is a cross-sectional view of a portion of another embodiment of the lead frame shown in Fig.
5 is a photograph showing a surface texture of a lead frame according to an embodiment of the present invention.
6 is a graph showing the change in the reflectance according to the weight percentage of palladium in the nickel-palladium alloy.
FIG. 7 is a graph showing the change in reflectivity depending on the thickness of the nickel-palladium alloy. FIG.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will become more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which: FIG. The present invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. Is provided to fully convey the scope of the invention to those skilled in the art, and the invention is only defined by the scope of the claims. It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. In the present specification, the singular form includes plural forms unless otherwise specified in the specification. It is noted that the terms "comprises" and / or "comprising" used in the specification are intended to be inclusive in a manner similar to the components, steps, operations, and / Or additions. The terms first, second, etc. may be used to describe various elements, but the elements should not be limited by terms. Terms are used only for the purpose of distinguishing one component from another.

In this specification, the terms "upper surface" and "lower surface" or "upper surface" and "lower surface" are relative concepts, and the surface or portion located relatively upward with respect to the direction of gravity is referred to as the upper surface or the upper surface. Further, a surface or a portion located relatively downward with respect to the direction of gravity is referred to as a lower surface or a lower surface. In each figure, the direction of gravity is indicated by "D1".

1 is a schematic cross-sectional view of an LED package manufactured using a lead frame according to an embodiment of the present invention. 2 is a plan view of the lead frame shown in Fig.

1 and 2, a light emitting diode (LED) package 1000 according to an embodiment of the present invention includes a lead frame 101, an LED chip (not shown) bonded to the lead frame 101 200, a bonding wire 300 connecting the LED chip 200 and the lead frame 101 and the upper surface of the lead frame 101, the LED chip 200 and the bonding wire 300 And includes a mold resin 400 that encapsulates the resin.

First, a lead frame 101 which is an embodiment of the present invention included in an LED package 1000 will be described.

The lead frame 101 has a die pad 11 and a lead portion 12. An LED chip 200 is attached to an upper surface of the lead frame 101 corresponding to the die pad 11. The lead section 12 is formed of a plurality of leads and the upper surface of the lead frame 101 corresponding to the leads is connected to the LED chip 200 by bonding wires 300. Although not shown, the lower surface of the lead frame 101 corresponding to the leads may be connected to an external device (not shown) through a solder ball (not shown).

The electric signal output from the LED chip 200 is transmitted to the external device through the lead unit 12 and the electric signal input from the external device to the lead unit 12 is transmitted to the LED chip 200).

3 is a cross-sectional view of a portion of the lead frame shown in Fig.

Referring to FIG. 3, the lead frame 101 includes a base material 10, a first metal layer 1, and a second metal layer 2.

The base material 10 is a base material on which a plurality of metal layers are formed. The base material 10 is provided as a rigid material that supports a plurality of metal layers in a flat manner. For example, the base material 10 may be formed of copper (Cu), a hard copper alloy (Cu alloy), or a heat-treated copper (Cu).

However, the present invention is not limited to this, and the base material 10 may be provided as a flexible material which can be bent according to a user's request. For example, the base material 10 may be formed of a soft copper alloy (Cu alloy) or aluminum (Al).

The upper and lower surfaces of the base material 10 can be formed smoothly. However, the present invention is not limited thereto, and the top and bottom surfaces of the lead frame may have different characteristics. For example, the upper surface of the base material 10 may be rough, and the lower surface of the base material 10 may be smoothly formed. At this time, in order to roughly form the upper surface of the base material 10, mechanical or chemical surface treatment, plasma treatment, or electrolytic polishing treatment may be performed.

Further, the roughness of the upper surface and the lower surface of the base material 10 may be formed in the opposite manner. At this time, the lower surface of the roughly formed base material 10 may be formed in the same manner as the upper surface of the roughly formed base material 10 described above.

The first metal layer 1 is disposed on the base material 10 and may be formed of an alloy of nickel (Ni) and palladium (Pd). The Ni-Pd alloy may be formed such that the weight percent of nickel (Ni) is greater than the weight percent of palladium (Pd). In addition, the nickel-palladium alloy layer (Ni-Pd alloy) may contain at least one selected from the group consisting of silver (Ag), gold (Au), nickel (Ni), copper (Cu), cobalt (Co), molybdenum Mo), ruthenium (Ru), tin (Sn), and indium (In). (Au), nickel (Ni), copper (Cu), cobalt (Co), molybdenum (Mo), ruthenium (Ru), tin (Sn), and indium (Pd) contained in the nickel- In does not exceed about 40% of the total weight of the total nickel-palladium alloy layer. It can be formed within the above range in consideration of the refractory property, corrosion resistance, thermal conductivity, and economical efficiency of the lead frame 101.

The second metal layer 2 may be formed of an alloy disposed on the first metal layer 1 and containing silver (Ag) and silver (Ag). The second metal layer 2 may be formed of a metal such as gold (Au), nickel (Ni), copper (Cu), cobalt (Co), molybdenum (Mo), ruthenium (Ru), tin (Ag) alloy layer may be further formed. At least one of gold (Au), nickel (Ni), copper (Cu), cobalt (Co), molybdenum (Mo), ruthenium (Ru), tin (Sn), and indium (In) It is preferred that one weight does not exceed about 40% of the total weight of the total silver (Ag) alloy layer. It can be formed within the above range in consideration of the refractory property, corrosion resistance, thermal conductivity, and economical efficiency of the lead frame 101.

The thickness of the second metal layer 2 may be 5 to 50 micrometers [um]. This is because the second metal layer 2 is formed using an expensive metal. In order to reduce the material cost, the second metal layer 2 is improved in economy, and the surface roughness of the second metal layer 2 is uniformly maintained.

An LED chip 200 may be disposed on the other surface of the second metal layer 2. At this time, the light emitted from the LED chip 200 is reflected by the lead frame 101 and emitted to the outside.

4 is a cross-sectional view of a portion of another embodiment of the lead frame shown in Fig.

Referring to FIG. 4, the lead frame 102 includes a base material 10 ', a first metal layer 1', a second metal layer 2 ', and a third metal layer 3'. The base material 10 ', the first metal layer 1', and the second metal layer 2 'are the same as or similar to those of the lead frame 101 described above, and thus the detailed description thereof will be omitted.

The third metal layer 3 'may be disposed between the first metal layer 1' and the second metal layer 2 '. In detail, one surface of the third metal layer 3 'is formed in contact with one surface of the first metal layer 1' and the other surface of the third metal layer 3 'is formed in contact with the surface of the second metal layer 2' And may be formed in contact with the surface.

The third metal layer 3 'may be formed of palladium (Pd). And may be formed of a Pd alloy depending on the purpose, structure, and arrangement of the lead frame 102. The palladium alloy layer may contain at least one selected from the group consisting of silver (Ag), gold (Au), copper (Cu), cobalt (Co), molybdenum (Mo), ruthenium (Ru), tin In) may be further formed. The weight of at least one of silver (Ag), gold (Au), copper (Cu), cobalt (Co), molybdenum (Mo), ruthenium (Ru), tin (Sn) and indium Preferably does not exceed about 40% of the total weight of the total palladium alloy layer. It is possible to form the lead frame 102 within the above range in consideration of the fire resistance, the corrosion resistance, the thermal conductivity, and the economical efficiency of the lead frame 102.

The third metal layer 3 'prevents heat transmitted from the upper layer of the third metal layer 3' from penetrating into the lower layer of the third metal layer 3 '. Heat is introduced from the surface of the second metal layer 2 'in detail and the heat is transmitted through the second metal layer 2' formed of silver (Ag) or silver alloy To the first metal layer 1 'formed at the bottom. The heat causes the residual stress of the lead frame 102 to affect the durability of the lead frame 102.

5 is a photograph showing the surface texture of the lead frame 102 according to an embodiment of the present invention. In Fig. 5, [um] represents a micrometer.

Referring to FIG. 5, the roughness of the surface texture depending on whether or not a nickel-palladium alloy layer is formed can be compared.

FIG. 5A is a graph showing the results of the deposition of a palladium (Pd) metal layer formed of palladium (Pd) on the nickel (Ni) metal layer formed of nickel and a silver (Ag) metal layer formed of silver on the palladium And is a lead frame 101a to be stacked. The lead frame 101a has a thickness of 40 micrometers [um].

FIG. 5B is a cross-sectional view illustrating a state in which a palladium (Pd) metal layer formed of palladium (Pd) is laminated on a nickel (Ni) metal layer formed of nickel (Ni) ) Metal layer is laminated on the lead frame 101b. The thickness of the lead frame 101b is 20 micrometers [um].

FIG. 5c is a cross-sectional view illustrating a process of depositing a palladium (Pd) metal layer formed of palladium (Pd) on a nickel-palladium alloy layer formed of an alloy of nickel (Ni) and palladium (Pd) And a lead frame 101c including a silver (Ag) metal layer formed of silver (Ag) on the metal layer. The thickness of the lead frame 101c is 20 micrometers [um]. The structure of the lead frame 101c is similar to that of the lead frame 102 shown in Fig. Therefore, the following results can be applied to the lead frame 102 of another embodiment of the present invention, and further the present invention can be applied to the lead frame 101 of the embodiment of the present invention.

A silver (Ag) metal layer formed of silver (Ag) in the outermost layer of the lead frame is affected by the illuminance of the metal layer formed under the silver (Ag) metal layer. Therefore, the illuminance of the metal layer formed under the silver (Ag) metal layer determines the illuminance of the silver (Ag) metal layer.

5A and 5B, the roughness of the surface of the silver (Ag) metal layer is smaller than that of FIG. 5A. When the metal layer is formed thick, the structure of the metal layer becomes dense and the crystal of the metal layer becomes hard. Therefore, the roughness of the metal layer may be reduced as the metal layer is thickened, and the roughness of the metal layer may be uniformly formed. The Ni metal layer of the lead frame 101a is thicker than the Ni metal layer of the lead frame 101b. Therefore, the nickel (Ni) metal layer of the lead frame 101a is thickened, and the structure of the nickel (Ni) metal layer becomes dense and the crystal becomes hard, so the surface roughness of the silver (Ag) metal layer decreases.

5A and 5C, the surface roughness of the silver (Ag) metal layer is smaller than that of FIG. 5B. The thickness of the lead frame 101c in FIG. 5C is 20 micrometers [um] and the thickness of the lead frame 101a in FIG. 5A is 40 micrometers [um]. That is, when the nickel (Ni) metal layer of FIG. 5A is replaced with the Ni-Pd alloy of FIG. 5C, the thickness of the Ni-Pd alloy layer is reduced, You can reduce usage. Also, the surface roughness of the silver (Ag) metal layer can be lowered.

6 is a graph showing a change in reflectance according to the weight percentage of palladium (Pd) in a nickel-palladium alloy (Ni-Pd alloy). Table 1 shows experimental data on the change of the reflectance according to the weight percentage of palladium (Pd) in the Ni-Pd alloy.

Referring to FIG. 6 and the following Table 1, it is possible to grasp the limited range of the thickness of the Ni-Pd alloy layer through the change of the reflectivity depending on the thickness of the Ni-Pd alloy layer.

[Table 1]

The experimental conditions are as follows. To control the palladium (Pd) content in the Ni-Pd alloy, the concentration of palladium (Pd) in the alloys and the density of the current used for plating were varied. The acidity of the alloy was maintained at PH4, and the temperature of the alloy was also fixed at 40 degrees. The thickness of the silver (Ag) metal layer formed on the surface of the nickel-palladium alloy (Ni-Pd alloy) was fixed at 20 micrometers.

The units shown in Table 1 are as follows. The concentration of palladium (Pd) is the concentration of palladium in the nickel / palladium alloy plating solution. The current density is the average current density (ASD), expressed in A / dm². The unit of plating time is seconds (S). The unit of thickness of the Ni-Pd alloy layer is in micrometers [um]. The fraction of palladium (Pd) represents the mass fraction of palladium (Pd) in the alloy based on mass.

The X-axis of the graph in FIG. 6 shows comparative examples and experimental examples. A lead frame including a nickel (Ni) metal layer formed on a silver metal layer is set as a comparative example. (Comparative Example) A nickel-palladium alloy layer (Ni-Pd alloy) (Experimental Examples 1 to 6) Experimental examples are set according to the weight percentage of palladium (Pd) in the nickel-palladium alloy layer (Ni-Pd alloy).

In Fig. 6, the Y-axis of the graph represents the value of GAM. The GAM values are measured on a GAM instrument (VSR-400) that measures reflectivity. GAM equipment (VSR-400) is used to measure the plating gloss of I.C lead frame or LED lead frame. The numerical value of GAM has a range from 0 to a maximum of 4.0, and a higher value of the GAM indicates a substance having a higher reflectivity.

The results of Experimental Examples 1 to 6 are as follows. In the case where the Ni-Pd alloy layer is disposed under the silver (Ag) metal layer, the effect of increasing the numerical value of GAM by about 0.2 as compared with the case where the nickel (Ni) metal layer is formed under the silver . Also, the value of GAM according to the weight percentage change of palladium (Pd) in the nickel-palladium alloy layer (Ni-Pd alloy) is almost constant. However, since palladium (Pd) is an expensive metal, it is preferable that the weight percentage of palladium is formed within 32% in consideration of economical factors. The weight percentage of palladium in the nickel-palladium alloy layer can be set between 2% and 32%.

 FIG. 7 is a graph showing a change in reflectivity according to the thickness of the nickel-palladium alloy layer. FIG. Table 2 shows experimental data on the change of the reflectivity according to the thickness of the nickel-palladium alloy layer (Ni-Pd alloy).

7 and Table 2, it is possible to grasp the limited range of the thickness of the Ni-Pd alloy layer by changing the reflectivity according to the thickness of the Ni-Pd alloy layer.

[Table 2]

The experimental conditions are as follows. The plating time was varied to control the thickness of the nickel-palladium alloy layer. The acidity of the alloy was maintained at PH4, and the temperature of the alloy was also fixed at 40 degrees. The thickness of the silver (Ag) metal layer formed on the surface of the nickel-palladium alloy (Ni-Pd alloy) was fixed at 70 micrometers [um]. The units shown in Table 2 are the same as those in Table 1 above.

The X-axis of the graph of Fig. 7 shows comparative examples and experimental examples. A lead frame including a silver (Ag) metal layer formed on a base material is set as a comparative example. (Comparative Example) A lead frame including a nickel-palladium alloy layer (Ni-Pd alloy) The lead frame is set as an experimental example. (Experimental Examples 1 to 4) An experimental example is set according to the thickness of the nickel-palladium alloy layer (Ni-Pd alloy). The Y axis represents the value of GAM.

Experimental Examples 1 to 4 were judged in comparison with Comparative Examples. When a Ni-Pd alloy layer is disposed under the silver (Ag) metal layer, it has a GAM synergistic effect as compared with a lead frame (comparative example) in which a silver (Ag) metal layer is formed on the base material. However, as the alloy thickness of the Ni-Pd alloy increases, the GAM falls due to the growth of the plating crystal, so that it is necessary to set the upper limit of the thickness of the Ni-Pd alloy layer. Further, when the alloy thickness of the nickel-palladium alloy layer (Ni-Pd alloy) is reduced, the heat resistance of the nickel-palladium alloy layer (Ni-Pd alloy) is weakened. When the heat resistance of the Ni-Pd alloy is weakened, the thermal diffusion to the lower part of the Ni-Pd alloy easily occurs and the durability of the lead frame is weakened. Therefore, the nickel- It is necessary to set the lower limit of the thickness of the Ni-Pd alloy. The thickness of the nickel-palladium alloy layer (Ni-Pd alloy) can be set from 0.8 (um) to 5.1 (um).

Another embodiment of the present invention is an LED package 1000 using the lead frames 101 and 102 described above. For convenience of explanation, the lead frame 101 of FIG. 3 will be mainly described.

Referring again to FIG. 1, an LED chip 200 is mounted on a portion of the upper surface of the lead frame 101 corresponding to the die pad (11 in FIG. 2). A gold (Au) or copper (Cu) bonding wire 300 is bonded to a portion of the upper surface of the lead frame 101 corresponding to the lead portion (12 in FIG. 2). The bonding wire 300 must firmly bond with the lead frame 101 so that there is no problem of disconnection in signal transmission thereafter.

The LED chip 200 is mounted on the upper surface of the lead frame 101 and the lead wire 101 is bonded to the bonding wire 300 and then the lead wire 101 is bonded to the lead frame 101 by a mold resin 400 such as an epoxy molding compound, Encapsulation of the upper surface of the frame 101 is performed.

An LED chip 200 is mounted on a silver (Ag) metal layer (2 in Fig. 3) formed at an outermost portion of the lead frame 101. [ When the LED package 1000 is used as an illumination device, an electric signal output from the LED chip 200 may be transmitted to an external device (not shown) through a lead portion. Also, an electric signal input from the external device to the lead unit can be transmitted to the LED chip 200.

The light emitted from the LED chip 200 may be emitted to the outside to serve as a lighting device. At this time, the light hits the surface of the silver (Ag) metal layer (2 in FIG. 3) formed at the outermost portion of the lead frame 101 contacting the LED chip 200.

Some of the light is emitted to the outside by reflection, and a part of the light is absorbed by the silver (Ag) metal layer 2. And some of them may disappear due to the interference of light. At this time, the amount of light reflected to the outside is determined according to the surface roughness of the silver (Ag) metal layer 2.

In detail, when the surface roughness of the silver (Ag) metal layer 2 is large and the roughness is uneven, the reflected light may interfere with each other, and some of the light may be extinguished. Also, since the reflected light is diffuse, it can not use the light that emits effectively.

When the surface roughness of the silver (Ag) metal layer 2 is small and the roughness is uniform, interference of reflected light is small and the amount of light to be extinguished can be reduced. Also, since the specular reflection occurs, it is possible to utilize light that emits effectively.

The surface roughness of the silver (Ag) metal layer 2 is greatly affected by the metal layer formed under the silver (Ag) metal layer 2. Therefore, by making the roughness of the metal layer formed under the silver (Ag) metal layer 2 uniform, light generated in the LED package 1000 can be effectively used.

The Ni-Pd alloy layer formed under the silver (Ag) metal layer 2 may be formed such that the weight percentage of nickel (Ni) is greater than the weight percentage of palladium (Pd). In addition, palladium (Pd) may be formed in an amount of 2 to 32% by weight in the nickel-palladium alloy (Ni-Pd alloy) 1 to make the roughness of the silver (Ag) metal layer 2 uniform. Further, the thickness of the Ni-Pd alloy layer 1 may be 0.8 to 5.1 micrometers [um] (um) to make the roughness of the Ag metal layer 2 uniform. At this time, the silver (Ag) metal layer 2 is formed at a thickness of 5 to 50 micrometers to effectively maintain the uniform roughness of the Ni-Pd alloy layer 1 formed thereunder.

And also generates heat together with light generated from the LED chip (200). The heat is emitted to the outside to maintain the durability of the lighting device using the LED chip (200). A palladium (Pd) metal layer (3 'in FIG. 4) may be formed on top of the nickel-palladium alloy layer (Ni-Pd alloy; The palladium (Pd) metal layer 3 'prevents the diffusion of heat, which is a total of the silver metal layer (2' in FIG. 4) formed on the palladium (Pd) metal layer 3 '. That is, the palladium (Pd) metal layer 3 'can serve as a thermal diffusion barrier. Further, the roughness of the surface of the palladium (Pd) metal layer 3 'is uniformly formed, and the light emission from the upper silver (Ag) metal layer 2' can be effectively formed.

A method of manufacturing the lead frames 101 and 102 according to another embodiment of the present invention is as follows.

The base material having the die pad and the lead portion is subjected to electrolytic degreasing or acid cleaning. Electrolytic degreasing removes contaminants on the surface of the base material and activates the surface of the base material. In addition, acid cleaning removes contaminants from the surface of the base material using acid.

Thereafter, a step of forming a nickel-palladium alloy layer (Ni-Pd alloy) disposed on the base material by electroplating is performed. An alloy plating solution of nickel and palladium is installed in an apparatus for performing electroplating. Electroplating is performed by controlling the appropriate current density according to the mass% of palladium (Pd) or the thickness of the nickel-palladium alloy layer (Ni-Pd alloy) in the Ni-Pd alloy layer.

In the step of forming the Ni-Pd alloy, the Ni-Pd alloy may be formed so that the weight percentage of nickel (Ni) is larger than the weight percentage of palladium (Pd) . The thickness of the Ni-Pd alloy layer may be 0.8 to 5.1 micrometers [um]. In addition, the palladium (Pd) in the nickel-palladium alloy layer (Ni-Pd alloy) may be formed to 2 to 32 wt%.

Thereafter, a step of forming a silver (Ag) metal layer disposed on top of the nickel-palladium alloy layer (Ni-Pd alloy) is performed. The silver (Ag) metal layer can be formed using any one of a plasma reaction method, a CVD (chemical vapor deposition) method, and a sputtering method. Particularly, when a silver (Ag) metal layer is formed by performing a plasma reaction in a vacuum state, the palladium (Pd) metal layer can be formed into a more dense structure. At this time, the thickness of the silver (Ag) metal layer may be 5 to 50 micrometers [um].

After the step of forming the nickel-palladium alloy layer (Ni-Pd alloy) by the electroplating method, the step of forming the palladium (Pd) metal layer may be performed and then the step of forming the silver (Ag) metal layer may be performed. The step of forming the palladium (Pd) metal layer may be performed by any one of a plasma reaction method, a CVD (chemical vapor deposition) method, and a sputtering method as in the above-described method of forming the silver (Ag) .

A Ni-Pd alloy layer 1 is formed under the silver metal layer 2 formed at the outermost portion of the lead frame 101 to form a silver (Ag) metal layer 2 ) Surface roughness can be uniformly formed. The reflectivity of light generated from the LED chip 200 is increased in the LED package 1000 in which the LED chip 200 is mounted on the lead frame 101, Can be improved.

If the palladium (Pd) metal layer 3 'is formed on the nickel-palladium alloy layer 1' of the lead frame 102, the palladium (Pd) metal layer 3 ' Can play a role. The heat generated in the LED chip 200 passing through the silver (Ag) metal layer 2 'and transferred to the metal layer under the lead frame 102 may be blocked by the palladium (Pd) metal layer 3'. Therefore, the durability of the lead frame 102 and the LED package 1000 using the lead frame 102 can be improved, thereby reducing the operation cost of the equipment.

Although the present invention has been described in connection with the above-mentioned preferred embodiments, it is possible to make various modifications and variations without departing from the spirit and scope of the invention. Accordingly, it is intended that the appended claims cover all such modifications and variations as fall within the true spirit of the invention.

1, 1 ': a first metal layer, a nickel-palladium alloy layer (Ni-Pd alloy)
2, 2 ': a second metal layer, a silver (Ag) metal layer
3 ': a third metal layer, a palladium (Pd) metal layer
10: Base material
11: die pad
12:
101, 102: lead frame
200: LED chip
300: bonding wire
400: Mold resin
1000: LED package

Claims (18)

Base material;
A first metal layer disposed on the base material and formed of a nickel-palladium alloy; And
And a second metal layer disposed on the first metal layer and formed of silver,
Wherein the nickel-palladium alloy has a weight percent of nickel greater than a weight percentage of palladium. The method according to claim 1,
Wherein the first metal layer has a thickness of 0.8 to 5.1 micrometers [um]. The method according to claim 1,
Wherein the palladium contained in the nickel-palladium alloy in the first metal layer is formed to 2 to 32 wt%. The method according to claim 1,
Wherein the second metal layer is formed with 5 to 50 micrometers [um]. The method according to claim 1,
The nickel-palladium alloy layer may be at least one selected from the group consisting of Ag, Au, Ni, Cu, Co, Mo, Ru, ). ≪ / RTI > The method according to claim 1,
And a third metal layer disposed between the first metal layer and the second metal layer, the third metal layer being formed of palladium. A base material having a die pad and a lead portion, a first metal layer disposed on the base material and formed of a nickel-palladium alloy, and a second metal layer disposed on the first metal layer and formed of silver, - the palladium alloy has a leadframe wherein the weight percentage of nickel is greater than the weight percentage of palladium;
An LED chip bonded to the die pad; And
And a plurality of bonding wires connecting the LED chip and the lead portion. 8. The method of claim 7,
Wherein the first metal layer has a thickness of 0.8 to 5.1 micrometers [um]. 8. The method of claim 7,
Wherein the palladium contained in the nickel-palladium alloy in the first metal layer is 2 to 32 wt%. 8. The method of claim 7,
Wherein the second metal layer is formed with 5 to 50 micrometers [um]. The method of claim 7, wherein
And a third metal layer disposed between the first metal layer and the second metal layer and formed of palladium. Performing electrolytic degreasing or pickling on a base material having a die pad and a lead portion;
Forming a nickel-palladium alloy layer on top of the base material by electroplating;
Forming a silver layer disposed on top of the nickel-palladium alloy layer,
Wherein the nickel-palladium alloy layer forming step is such that the weight percentage of nickel is greater than the weight percentage of palladium. 13. The method of claim 12,
Wherein the nickel-palladium alloy layer has a thickness of 0.8 to 5.1 micrometers [um]. 13. The method of claim 12,
Wherein the palladium in the nickel-palladium alloy layer is formed to 2 to 32 wt%. 13. The method of claim 12,
Wherein the silver layer is formed at 5 to 50 micrometers [um]. The method of claim 12, wherein
And forming a palladium layer disposed between the nickel-palladium alloy layer and the silver layer. 13. The method of claim 12,
Wherein the silver layer forming step is formed by any one of a chemical vapor deposition (CVD) method, a sputtering method, and a plasma reaction method. 17. The method of claim 16,
Wherein the step of forming the palladium layer is formed by any one of a chemical vapor deposition (CVD) method, a sputtering method, and a plasma reaction method.

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