KR101775657B1 - Manufacturing method for lead frame for light emitting device package - Google Patents

Abstract

A lead frame for a light emitting device package and a manufacturing method thereof are disclosed in the present invention. The manufacturing method of the lead frame is a method of manufacturing a lead frame for a light emitting device package, comprising the steps of: preparing a base substrate for a lead frame; forming a diffusion roughness on the base substrate; And forming a reflective plating layer having a reflective surface.
According to the present invention, there is provided a lead frame for a light emitting element having a light directing angle and a wide radiation width through surface treatment, and a method of manufacturing the same.

Description

Technical Field [0001] The present invention relates to a manufacturing method of a lead frame for a light emitting device package,

The present invention relates to a method of manufacturing a lead frame for a light emitting device package.

The light emitting device package includes a light emitting device in the form of a light source such as an LED (Light Emitting Diode) or an LD (Laser Diode), and a lead frame that supports the light emitting device and provides a current passing path.

The luminance, which is an important characteristic in the light emitting device package, is higher as the reflectance (GAM) of the lead frame and the reflectance of the pre-mold are higher. The directivity angle is determined by the wall angle Is influenced by the shape and characteristics of the lens for the light emitting element which adjusts the light emitting element.

The plating characteristic of the lead frame is focused on improving the performance of the light emitting device package by increasing the reflectance, and the final surface layer of the lead frame is formed as a mirror surface with a very smooth mirror surface.

An object of the present invention is to provide a method of manufacturing a lead frame for a light emitting device having a light directing angle and a wide radiation width through surface treatment.

 In order to achieve the above object and other objects, the present invention provides a method of manufacturing a lead frame,

A manufacturing method of a lead frame for a light emitting device package,

Preparing a base substrate for a lead frame;

Forming a diffusion roughness on the base substrate; And

And forming a reflective plating layer having a spherical structure on the diffused roughness.

For example, in the step of forming the diffusion roughness,

Any one chemical process selected from the etching process or the oxidation process may be applied to the base substrate.

For example, in the step of forming the diffusion roughness,

Any one of the physical processes selected from the mechanical stamping or the surface polishing process can be applied to the base substrate.

At this time, the surface polishing process may include sandblasting.

For example, in the step of forming the diffusion roughness,

A surface roughness plating process can be applied to the base substrate.

At this time, in the surface roughness plating process,

A metal selected from nickel (Ni) or copper (Cu) is used as a plating material,

The plating process can be performed by applying a plating material concentration that is low enough to form a non-uniform plating surface.

Alternatively, in the surface roughness plating process,

A metal selected from nickel (Ni) or copper (Cu) is used as a plating material,

The plating process can be performed by applying a plating current density low enough to form a plating structure of a spherical structure.

As another alternative, in the surface roughness plating process,

A silver strike layer can be formed by applying a plating current density high enough for the plating surface to have a diffused roughness.

For example, in the step of forming the reflective plating layer,

The plating process can be performed by applying a plating current density low enough to form a plating structure of a spherical structure.

At this time, in the step of forming the reflective plating layer,

Plating can be performed with a low current density of 0.3 to 2.0 ASD (A / dm ² ).

For example, in the step of forming the reflective plating layer,

A silver (Ag) plating layer can be formed by applying a polishing agent.

For example, in the method of manufacturing the lead frame,

Forming a metal coating layer including at least one of the metal seed layer and the ground layer in advance of the reflective plating layer.

According to another aspect of the present invention, there is provided a lead frame,

A lead frame for a light emitting device package,

And a reflective plating layer forming a outermost layer of the lead frame and having a plating structure of a spherical structure.

For example, the reflective plated layer may comprise a silver (Ag) plated layer comprising a brightener component.

According to the present invention, it is possible to realize a light emitting device package having a wide view angle that is larger than a directivity angle of 100 to 120 degrees of a general light emitting device package through surface treatment that maximizes light scattering characteristics with respect to the surface of a lead frame have. According to one embodiment of the present invention, a diffusing roughness is formed on the surface of the metal layer of the lead frame, and a reflective plating layer of spherical structure is formed so that the diffusing roughness can be exposed on the outermost plating layer surface.

The light emitting device package having a wider directional angle can be applied to a backlight unit (BLU) for a display and a surface light source for indoor illumination, The number of packages can be significantly reduced.

1 is a cross-sectional view of a light emitting device to which the present invention is applied.
2 is an enlarged view of a portion II in Fig.
Fig. 3 is a view schematically showing a reflection form by a smooth mirror-surface reflecting surface.
4A to 4C are views for explaining the light emitting state by the mirror-surface reflecting surface.
5 is a diagram schematically showing a reflection pattern by a reflecting surface having surface roughness.
6A to 6C are views for explaining a light emitting state by a reflecting surface having surface roughness.
7 is a schematic view illustrating a form of a surface light source according to a light emitting device package to which the principle of the present invention is applied.
8 is a schematic view showing the shape of a surface light source by a light emitting device package having a specular reflecting surface.
FIGS. 9A to 9E are views illustrating a method of manufacturing a lead frame for a light emitting device package according to an embodiment of the present invention.
10 shows the surface condition of the diffused light.
11A shows the surface state after the surface roughness plating process (Cu-roughing).
Fig. 11B shows a state in which surface roughness is maintained even after silver plating is formed on the surface of Fig. 11A.
Fig. 12 shows a surface state of the nickel plated layer as another form of the surface roughness plating process.
Fig. 13 shows a surface state of the silver plated layer as another form of the surface roughness plating process.
14A to 14C are photographs of enlarged surfaces of the reflective plated layer according to different magnifications.
Fig. 15 shows the surface state of a reflective plating layer (having a diffusing roughness) to which the principle of the present invention is applied.
Fig. 16 shows the surface state of the plating layer (with the mirror surface reflecting surface) to which the principle of the present invention is not applied.
FIGS. 17A through 17C are views showing process steps of forming a light emitting device package from a lead frame according to an embodiment of the present invention.

Hereinafter, a light emitting device package according to a preferred embodiment of the present invention will be described with reference to the accompanying drawings.

FIG. 1 shows a cross-sectional structure of a light emitting device package to which the present invention is applied. Referring to the drawings, the light emitting device package 100 includes a light emitting device 150, a lead frame 110 on which the light emitting device 150 is mounted, and a package 110 formed to receive a part of the lead frame 110 Mold (130). Reflective surfaces 110R and 130R are formed on the upper surface of the lead frame 110 supporting the light emitting device 150 and the cavity side surface of the package mold 130 surrounding the light emitting device 150, The reflecting surfaces 110R and 130R reflect light emitted in a direction other than the effective display direction (L, for example, upward) out of the light emitted from the light emitting element 150 on the outgoing path of the light emitting element 150 And the optical path is switched in the direction L.

The light emitting device 150 may be implemented by a light emitting diode or a laser diode, and the light emitted from the light emitting device 150 may be directly emitted in the effective display direction L, for example, upward, For example, by switching the optical path in the effective display direction L by the cavity reflection surface 130R formed on the lead frame and / or the reflection surface 110R of the lead frame. The light emitting device 150 receives driving power through the lead frame 110 and outputs light. The light emitting device 150 may be electrically connected to the lead frame 110 through a conductive wire 180 such as gold (Au) or silver (Ag).

The lead frame 110 together with the light emitting device 150 is a main component of the package and functions to support the light emitting device 150 and to electrically connect the light emitting device 150 and an external circuit. For example, the lead frame 110 may be electrically connected to the driving circuit substrate S outside the package, and may form a power supply path between the driving circuit substrate S and the light emitting device 150.

The lead frame 110 includes first and second lead regions 110-1 and 110-2 which are spaced apart from each other. The first and second lead regions 110-1 and 110-2 are connected to the light emitting device 150, (Not shown) and a negative terminal (not shown), respectively. The first and second lead regions 110-1 and 110-2 may be formed asymmetrically with respect to each other and the light emitting device 150 may be mounted on the first lead region 110-1.

Each of the first and second lead regions 110-1 and 110-2 may include an inner lead 110a located inside the package and an outer lead 110b located outside the package. The inner lead 110a may be electrically connected to the light emitting device 150 via the conductive wire 180. [ For example, a conductive wire 180 such as gold (Au) or silver (Ag) is suspended between one end of the inner lead 110a and an electrode pad (not shown) of the light emitting device 150 in a suspended state . The external lead 110b is exposed to the outside of the package mold 130 and can form a contact with the driving circuit substrate S outside the package.

The light emitting element 150 and the light emitting element 150 are connected to each other by using the conductive wire 180 having one end connected to the electrode pad (not shown) of the light emitting element 150 and the other end connected to the lead frame 110 The lead frame 110 is electrically connected to the lead frame 110. However, in another embodiment, the lead frame 110 may be electrically connected to the light emitting device 150 using conductive bumps (not shown).

The package mold 130 receives a part of the lead frame 110 and fixes the lead frame 110. The package mold 130 covers the lead frame 110 and a cavity G is formed at a substantially central position of the package mold 130 so that the lead frame 110 is exposed. In the cavity space G, the light emitting device 150 mounted on the lead frame 110 is housed. The cavity G may be formed at a sufficient depth from the upper surface of the package mold 130 to accommodate the light emitting device 150. The package mold 130 reflects light emitted from the light emitting device 150. More specifically, the sidewall defining the cavity G accommodates the light emitted in the lateral direction or in the lateral direction of the light emitting device 150 to switch the optical path upward, that is, in the effective display direction L The reflection surface 130R can be formed. In order to increase the light extraction efficiency of the light emitting device package 100, it is preferable that the cavity reflection surface 130R is formed as a reflection surface with high reflectance and high gloss. For example, the package mold 130 forming the cavity reflection surface 130R can be formed by applying a resin mixed with high reflectance particles such as TiO2 in addition to PPA of engineering plastic type having excellent moldability and workability. The package mold 130 may be formed by injection molding.

The package mold 130 constitutes an outer appearance of the light emitting device package 100 and a part of the lead frame 110 electrically connected to the light emitting device 150 is electrically connected to the outside of the package mold 130 through the conductive wire 180 Respectively.

FIG. 1 shows a package mold 130 for switching the path of light emitted from the light emitting device 150. However, the package mold 130 is not essential in the present invention. As described later, by forming the reflective surface 110R on the upper surface of the lead frame 110, the traveling direction of light emitted in a direction other than the effective display direction L can be switched. By omitting the package mold 130, the structure of the entire light emitting device package 100 can be simplified.

The sealing resin 190 is injected into the cavity space G in which the light emitting device 150 is housed so that the light emitting device 150 is physically and electrically protected from the external environment. More specifically, in the cavity space G, a sealing resin 190 may be applied to insulate the light emitting device 150 and the bonding portion from the external environment and prevent foreign matter from entering. The bonding portion may refer to a connecting portion between the light emitting device 150 and the conductive wire 180 and a connecting portion between the conductive wire 180 and the lead frame 110. As shown in the figure, the sealing resin 190 may fill the cavity G by filling the light emitting device 150 and the conductive wire 180.

The light emitting element 150 is embedded by the sealing resin 190 and the light emitted from the light emitting element 150 is output through the sealing resin 190. The sealing resin 190 may be formed of a light transparent resin material, or may be formed of a light transparent resin material mixed with a fluorescent material. For example, the sealing resin 190 may be formed of silicone resin, epoxy resin, or the like, but is not limited thereto. The sealing resin 190 may have a high light transmittance and may be formed by a combination action with, for example, a lens The diffraction grating may be formed of a material having a refractive index suitable for diffusing the outgoing light of the incident light.

The sealing resin 190 may contribute to the purpose of diffusing the outgoing light from the light emitting element 150 with a wide radiation width and may be formed in a lens shape which is, for example, hemispherical or hemispherical . For example, the outgoing light can be diffused with a wide radiation width due to the refracting action of the sealing resin 190. Although not shown in the drawings, a separate lens (not shown) may be attached on the sealing resin 190. For example, a silicone lens (not shown) having a hemispherical shape or a shape close thereto may be applied. The outgoing light from the light emitting element 150 can be diffused over a wide radiation width through the refracting power of a lens (not shown).

2 is an enlarged view of a portion II in Fig. For example, the lead frame 110 includes a base substrate 112, a metal coating layer 115 formed on the base substrate 112 for enhancing interlayer coupling between different materials, And the reflective plating layer 117 formed thereon may be sequentially formed.

A reflective surface 110R for receiving the light emitted from the light emitting device 150 is formed on the top surface of the lead frame 110. A predetermined surface roughness or diffusion roughness for light diffusion is formed on the reflective surface 110R. May be formed. The reflective surface having the surface roughness (or diffusion roughness, the same applies hereinafter) promotes irregular reflection or scattering of light emitted from the light emitting element 150, so that light can be diffused over a wide radiation width.

The reflective surface 110R of the lead frame 110 may be embodied as a reflective plating layer 117 forming the outermost edge of the lead frame 110. [ The reflective plating layer 117 can be selected as a material having a high reflective characteristic in a visible light band. Examples of such a high reflective material include aluminum (Al), silver (Ag), gold (Au) Further, these high-reflectivity materials may be formed of an alloy material including other functional components. The reflective surface 110R of the lead frame 110 may be formed of a high-gloss metallic material and thus may have a higher reflectance than the package mold 130 (cavity reflective surface 130R) formed of a resin-based material .

Light emitted from the light emitting element 150 in the effective display direction L, for example, upward, can be directly applied to the display surface. The light emitted in a direction other than the effective display direction L may be formed by using the cavity wall surface formed in the package mold 130 as the reflecting surface 130R or the lead frame 110 formed on the bottom surface of the light emitting element 150 as the reflecting surface 130R, (110R) to switch the optical path to the effective display direction (L). For example, light emitted from the light emitting element 150 in the lateral direction or the bottom surface direction is guided by the cavity reflection surface 130R of the package mold 130 or by the reflection surface 110R of the lead frame 110 The light whose direction of light traveling is changed by the reflecting surface 110R of the lead frame 110 is reflected again by the cavity reflecting surface 130R so that the effective display direction L ≪ / RTI > The light emitted in a direction other than the effective display direction L is reflected by the cavity reflection surface 130R of the cavity space G accommodating the light emitting element 150 and the lead frame 110 The light extraction efficiency of the light emitting device package 100 can be increased by switching the light path by using the reflective surface 110R of the light emitting device package 100. [

The reflective surface 110R of the lead frame 110 reflects the light emitted from the light emitting device 150 in the effective display direction L, for example, upward. That is, the light emitted from the light emitting element 150 is switched in the effective display direction L by the reflective surface 110R having a predetermined surface roughness or diffusion roughness. At this time, the light incident on the reflection surface 110R according to the surface roughness (or diffusing roughness) formed on the surface of the reflection surface 110R is reflected at various orientation angles according to the incident position.

The surface roughness may be a regular pattern having a constant period, or may be an amorphous pattern formed randomly. The reflective surface 110R having surface roughness converts incident light directed downward from the light emitting element 150 into an effective display direction L, for example, upward, and at the same time spreads the incident light widely. That is, incident light having the same incident angle passes through the reflection surface 110R and is emitted at various orientations. The reflective surface 110R having a surface roughness can diffuse light so as to have a wide emission width and diffuse light over a wide display surface, thereby obtaining a uniform luminance.

The light emitting device package 100 may be applied to a display device, and may be applied to a lighting device for a flat display device. For example, when a point light source such as a backlight of a display device is configured by using a point light source such as the light emitting device package 100, a plurality of light emitting device packages 100 may be arranged in parallel So as to have a uniform light distribution over the whole display surface and prevent a low luminance area, a dark spot or a dead area from being formed in a part of the display surface.

For example, the light emitting device package 100 may be mounted on the driving circuit substrate S in a plurality of arrangements, and the light emitting device packages 100 are supplied with driving power through the driving circuit substrate S Light can be output.

At this time, it is possible to provide uniform brightness over a wide area of the display surface by diffusing the light with a wide radiation width through the reflection surface 110R having the surface roughness (diffusive illumination). The use of the light emitting device package 100 of a light beam diffused over a relatively wide range can provide a planar light source with a uniform luminance distribution even with a relatively small number of the light emitting device packages 100, . In this regard, by applying the reflective surface 110R having a surface roughness, it is possible to provide a planar light source having a uniform luminance while using a small number of the light emitting device packages 100. [

As shown in FIG. 3, the light incident on the relatively smooth specular reflection surface R1 has a dominant light intensity Lm at the main directivity angle, and a relatively weak light intensity Lm at the other directivity angles other than the main directivity angle. It shows strength. That is, it corresponds to a specular reflection or a similar reflection form. The light intensity of the reflected light is concentrated on the main directivity angle and shows a distinctive directionality and a so-called Gaussian distribution in which the light intensity is rapidly attenuated in the other directional angles.

Figs. 4A to 4C show a light emitting device package having a relatively smooth specular reflection surface R1 on a lead frame. Fig. FIGS. 4A to 4C are diagrams illustrating a light emitting state, a light intensity distribution according to a radial direction angle, and an actual light emitting state on a display surface, respectively. Referring to the drawings, in the case of a package having a smooth specular reflection surface R1, light is concentrated relatively upward, and a light intensity distribution with a relatively much attenuated shape is observed at other orientations. As can be seen from FIG. 4C, the central region of the display surface exhibits intensively high brightness, while the other peripheral regions have a low low-brightness region.

As shown in FIG. 5, the light incident on the relatively rough surface, that is, the reflection surface R2 having a predetermined surface roughness (diffusing roughness) shows the light intensity Lm dominant in the main directivity angle, The light intensity is widely distributed at other directional angles, and the directionality tends to be relaxed even if the light intensity is high at the main directional angle. This corresponds to the form of diffuse reflection. That is, the distribution of the directivity angle has a broad spectrum centering on the main directivity angle, spreading over a wide directivity angle range and widening the radiation width.

6A to 6C are views showing a light emitting state of a light emitting device package having a reflection surface (R2 ') on which a diffused illumination is formed on a lead frame. 6A to 6C are diagrams each schematically showing a light emitting state, a diagram showing a distribution of light intensity according to an emission angle in a radial direction, and a diagram showing an actual light emitting state on a display surface, respectively. Referring to the drawings, in the case of a package having a diffusive reflection surface (R 2 '), a relatively wide light is diffused at a wide radiation width, and a relatively uniform light intensity distribution is seen over other directional angles other than upward. 6C, it can be seen that the luminance is uniformly distributed not only in the central region of the display region but also in the peripheral region thereof, and has a relatively wide high luminance region.

It can be confirmed that the light intensity is relatively uniform over various directional angles when compared with the specular reflection surface R1 shown in Fig. This is because, in the case of the reflection surfaces (R2, R2 ') having surface roughness (diffusive illumination), the light beams are emitted at different directing angles depending on the incident position of light, and the light intensity is relatively uniform, Is spread. That is, the light intensity of a Lambertian distribution having a relatively high light intensity at the main directivity angle but a light intensity at another directivity angle is also uniformized to some extent.

Light is diffused over a wide area of the display surface as the light is diffused over the reflection surface (R2, R2 ') of the surface roughness (diffusive illumination), and uniform lightness can be provided, It is possible to provide a planar light source having a luminance distribution. In this regard, it is possible to obtain a surface light source with a uniform luminance distribution even in a relatively small number of light emitting device packages by using a light emitting device package having a relatively large spot size, so that the manufacturing cost of the surface light source is reduced There is an advantage that it can be.

However, applying a mirror surface R1 having a relatively smooth mirror surface is limited to a relatively narrow range of the directivity angle, and is unevenly distributed in the spectrum with a narrow directivity angle. Therefore, in order to provide a planar light source having an even luminance distribution, a relatively large number of light emitting device packages must be applied, which leads directly to an increase in manufacturing cost.

In the reflective surfaces (R2, R2 ') having surface roughness (diffusive roughness), the light traveling path is switched according to the surface roughness, and the light traveling path is changed so as to have various orienting angles depending on the incident angle depending on the incident position. At this time, as shown in the figure, the reflecting surfaces R2 and R2 having surface roughness have different surface states depending on the incident position, so that the incident angle can be differentiated. Accordingly, the spectrum of the directing angle is diffused widely . The diffusion of the light intensity over such a wide range means that it is suitable for a planar light source having a uniform light distribution and means that the number of light emitting device packages necessary for providing a planar light source can be reduced .

7 and 8 are views showing a form of a surface light source configured by applying the light emitting device packages LED1 and LED2. FIG. 7 is a light source to which a light emitting device package (LED1) to which the principle of the present invention is applied is applied, and FIG. 8 is a light source to which a light emitting device package (LED2) to which the principle of the present invention is not applied is applied.

When a planar light source for display is constituted by a point light source such as the light emitting device packages LED1 and LED2, a plurality of light emitting device packages LED1 and LED2 are arranged in parallel, It is essential to remove the low luminance area or the dark spot or the dead area where the outgoing light of the LEDs LED1 and LED2 reaches and the outgoing light does not reach on the display surface D.

Referring to the drawings, a plurality of light emitting device packages LED1 and LED2 may be mounted on a driving circuit substrate S in a matrix array, and light emitting device packages LED1 and LED2 may be mounted on a driving circuit substrate S The driving power can be supplied and light can be emitted.

As can be seen from Fig. 7, a region directly above each light emitting device package LED1 obtains sufficient luminance from the light emitted directly from each light emitting device package LED1. The area between the adjacent light emitting device packages LED1 can pass through the reflection surface having surface roughness so that light diffused at a wide radiation width can be mixed and a sufficient luminance can be obtained. And the reference numeral P schematically shows the luminance profile on the display surface D. [ For example, the light emitted from the light emitting device package LED1 in a direction other than the effective display direction is reflected by the cavity wall surface formed in the package mold 130 (see FIG. 1) as the reflecting surface 130R, The lead frame 110 formed on the bottom surface is used as the reflecting surface 110R to switch the optical path in the effective display direction. For example, light emitted from the light emitting element 150 in the lateral direction or the bottom surface direction is guided by the cavity reflection surface 130R of the package mold 130 or by the reflection surface 110R of the lead frame 110 The light is diffused at a wide radiation width by the surface roughness (diffusion roughness) formed on the reflective surface 110R of the lead frame 110R, so that a relatively small number of the light emitting device packages LED1 A constant display area can be illuminated with a uniform luminance.

As shown in Fig. 8, when a light emitting device package LED2 having a relatively narrow emission width is applied, a larger number of light emitting device packages LED2 are required to illuminate the same display area with uniform luminance . This is because the emission width of each individual light emitting device package LED2 is narrow, so that a large number of the light emitting device packages LED2 must be densely arranged. Also, as can be seen from FIG. 8, a relatively dark low luminance region may be formed or a dead area may be formed due to the illumination not reaching the region between the neighboring light emitting device packages LED2.

7 in which the principle of the present invention is applied, the outgoing light from each light emitting device package LED1 spreads and spreads over a wide radiation width, so that a relatively small number of the light emitting device packages LED1 are applied, A uniform luminance distribution can be obtained.

Hereinafter, with reference to Figs. 9A to 9E, a description will be given of a method of manufacturing a lead frame to be used for mounting a light emitting device. First, as shown in FIG. 9A, a base substrate 210 for a lead frame is prepared. As the base substrate 210, a common lead frame material can be applied. For example, An alloy thin plate, an alloy thin plate mainly composed of iron-nickel, or the like can be applied.

Next, as shown in Fig. 9B, a patterning process for forming a lead frame pattern on the base substrate 210 proceeds. In the patterning process, a lead frame pattern having the first lead region 210-1 and the second lead region 210-2 having different polarities can be formed by removing a portion of the base substrate 210, Chemical etching, mechanical stamping, punching, and the like can all be applied. For example, the first and second lead regions 210-1 and 210-2 may be formed asymmetrically with respect to each other, and one of the lead regions 210-1 and 210-2 may be formed to be larger And the light emitting element can be mounted on the lead region 210-1 formed to be larger.

Next, the base substrate 210 is subjected to a surface treatment to remove the oxide film formed on the surface, and a plating pretreatment step for activating the surface of the base substrate 210 is performed. In this pre-plating process, for example, a series of processes consisting of electro degreasing, acid dip, chemical polishing, acid dip, neutralization, Unit processes.

Next, as shown in Fig. 9C, a diffusive roughness processing process for roughing the surface of the base substrate 210 for light diffusion is performed. For example, the diffusion roughing process is a process of forming a surface roughness at a level not exceeding a target level so that the shape, such as the pattern, structure, etc., of the lead frame 210 is not collapsed. Here, the diffusion roughness means a surface roughness formed at a level sufficient to promote light diffusion at a level that does not change the pattern or structure of the lead frame. For example, the surface roughness of the diffusive roughness treatment may mean an etch depth d of approximately 1.0 to 5.0 μm.

More specifically, in the diffusive roughness treatment, a chemical treatment such as a chemical etching (micro etching, soft etching, flash etching) or a oxidation (black oxidation, brown oxidation) for forming a shallow corrosion depth, And a physical treatment process such as a polishing process such as a sand blast.

For example, in the chemical etching, a diffusion etching treatment solution is applied to the base substrate 210, and a soft etching solution or a stripping agent based on hydrous sulfuric acid or perspiration can be used in combination. More specifically, in the diffusive roughness treatment, a copper remover and an oxidizing agent type roughing agent may be applied to the base substrate 210 for about 10 to 60 seconds. Fig. 10 shows the surface state after such diffuse illumination processing.

In the diffusive roughness processing, an abrasive process such as mechanical stamping, sandblasting, or the like may be applied. In this case, the diffusive illumination process may precede the patterning of the raw base substrate 210, and the patterning process may be followed for the diffusely-illuminated base substrate 210.

In addition, in the diffusive roughness treatment, various surface roughness plating processes may be applied in addition to the surface treatment process as described above. For example, a surface roughness plating process using nickel or copper may be applied (Ni-roughing, Cu- roughing). For example, nickel or copper is plated on a base substrate 210 of a raw material, and plating is performed by applying a high current in a plating solution containing nickel (Ni), copper (Cu), or the like as a plating material at a low concentration A nickel plating layer or a copper plating layer having a surface roughness (or a diffusion roughness) is formed on the base substrate 210. For example, since a low-concentration plating material is used, not only a plating layer that is uniformly dispersed and densely formed on the base substrate 210 is formed, but a plating material is concentrated on the base substrate 210 A plated layer of a rough surface can be formed. At this time, in the case of forming the nickel or copper plating layer with a thin layer thickness (5 탆 or less) in such a surface roughness plating process, it is preferable to form a nickel or copper plating layer after the plating pretreatment. 11A shows the surface state after the surface roughness process (Cu-roughing). Fig. 11B shows a state in which surface roughness is maintained even after silver plating is formed on the surface of Fig. 11A.

As another mode of the surface roughness plating process, there is a method of forming a nickel (Ni) plating layer or a copper (Cu) plating layer at a low current (1.0 to 2.0 ASD or less) to form a nickel plating structure (copper plating structure) into a spherical structure . Fig. 12 shows a surface state in which the diffusion roughness is formed by using this type of surface roughness process (nickel plated layer).

As another form of the surface roughness plating process, there is a method of forming a silver strike plating layer at a high current (3 to 5 ASD) to form a diffusion roughness (surface roughness) in the surface texture. Fig. 13 shows the surface state in which the diffusing roughness (surface roughness) is formed using this type of surface roughness plating process. The silver strike plating layer may be regarded as a plating pretreatment step preceding the reflective plating layer to be described later, or may be regarded as one unit process of forming the reflective plating layer as one configuration of the reflective plating layer. Since the Ag strike plating layer itself contributes to the enhancement of the interlayer bonding force, formation of a seed layer for enhancing the interlayer bonding strength can be omitted.

Next, as shown in FIG. 9D, a metal coating layer 215 may be formed on the base substrate 210. The metal coating layer 215 may include a metal seed layer 211 and a ground layer 213, for example. The metal seed layer 211 is for enhancing the bonding force between the base substrate 210 and the copper alloy and improving the plating quality. The metal seed layer 211 may be formed of a specific metal material having a good adhesion to the base substrate 210 and an excellent interlayer bonding force, and a corresponding candidate material group may be considered depending on the substrate material. For example, , And a copper strike (Cu strike) layer.

An underlayer 213 may be formed on the metal seed layer 211. The underlayer 213 is a base layer preceding the reflective plating layer and improves the bonding characteristics of the conductive wire 180 that mediates electrical connection with the light emitting device 150, As a diffusion preventing film.

The metal seed layer 211 and the ground layer 215 may be interposed between different metal layers stacked on each other to increase the interlayer coupling force. The metal constituting the base substrate 210 may be formed on the surface of the lead frame To protect the reflective plating layer and to prevent the formation of harmful components.

The metal coat layer 215 is not limited to the metal seed layer 211 and the ground layer 213. The metal coat layer 215 may have various forms in which a single metal layer or an intermetallic metal layer of the same kind is stacked in two or more layers as necessary . Any one of the metal seed layer 211 and the ground layer 213 may be omitted, for example, the metal seed layer 211 may be omitted depending on plating conditions and plating characteristics.

Next, as shown in FIG. 9E, a reflective plating layer 217 is formed on the base substrate 210. However, although not shown in the drawing, a silver strike layer may be formed in advance of the reflective plating layer 217 for the purpose of enhancing the interlayer coupling force.

The reflection plating layer 217 contributes to the purpose of increasing light extraction efficiency of the light emitting device 150 by reflecting light emitted from the light emitting device 150 with high reflectance (gloss). The reflective plating layer 217 may be selected as a material having high reflective properties in a visible light band. Examples of such a high reflective material include aluminum (Al), silver (Ag), gold (Au) Further, these high-reflectivity materials may be formed of an alloy material including other functional components.

For example, the reflective plating layer 217 may be formed of a silver (Ag) plating layer or a silver (Ag) plating layer such as silver (Al) . The reflective plating layer 217 may be formed of a silver (Ag) plating layer, and the silver (Ag) plating layer may be formed by mixing a sufficient amount of a brightener together with a silver (Ag) component. For example, in the formation of the reflective plating layer 217, a plating layer is grown on the surface of a plating material (for example, a base substrate) obtained in a high-gloss (Ag) plating bath, Plating is performed at a low current density so that the plating layer can grow. For example, in the formation of the reflective plating layer, plating may be performed at a low current density of 0.3 to 2.0 ASD (A / dm ² ) with a lower limit of 0.3 ASD and a lower limit of 2.0 ASD. More specifically, a current density of 1 ASD (A / dm < ² >) may be applied in forming the reflective plating layer 217. [ The reflective plating layer 217 formed by applying such a low low current density has a spherical structure, not a needle-shaped structure. In the formation of the silver (Ag) plating layer, high-speed plating is performed at a high current density, for example, a high current density of 5 to 10 ASD, so that the plating structure of the silver (Ag) plating layer has a needle-like structure.

The reflective plating layer 217 is plated at a low current density by applying a low current density to form a spherical structure as shown in FIG. 9E, and the diffusing roughness formed on the base substrate 210 can be exposed to the outside. That is, by performing low-speed plating, the plating layer is formed slowly along the diffusion roughness formed on the base substrate 210, so that the surface of the reflective plating layer 217 has a diffusion roughness.

When high-speed plating applying a high current density is applied to the surface subjected to the diffused roughness, the diffused roughness is buried by the plating layer and the smooth plating surface is formed, so that the effect of the diffused roughing treatment is canceled. Since the reflective plating layer 217 has a spherical plating structure and is formed by low-speed plating, the diffusion roughness for light diffusion can be maintained.

9E, a reflective plating layer 217 may be formed along the surface of the base substrate 210 having a diffused roughness, that is, a surface roughness, and the reflective plating layer 217 may be formed as a recess- Can be formed along the irregularities, and the plating structure of the spherical structure following the concave-convexity is displayed.

The reflective coating layer 217 forms the outermost surface of the lead frame and forms a reflecting surface on the light-emitting path from the light emitting element. Therefore, the reflection plating layer 217 needs to be formed to have a sufficient thickness t by adding a certain amount of a brightening agent.

Figs. 14A to 14C show photographs in which the surfaces of the reflective plated layers are magnified at different magnifications. 14A to 14C are enlarged photographs at magnifications of 5000, 1000, and 100 magnifications, respectively.

Referring to the drawing, the reflective plating layer 217 has a diffusing roughness and has a highly-glossy surface of spherical structure. The reflection plating layer 217 has a reflectance (gloss) in the range of 0.6 to 1.2 GAM as a result of measurement using a measuring instrument of the VAS 300 series. The reflective coating layer 217 has a milky white surface as compared with the reflective surface obtained by high-speed plating with a high current density.

Fig. 15 shows a surface state of a reflective plating layer (with a diffusing roughness) to which the principle of the present invention is applied, and Fig. 16 shows a surface state of a plating layer (with a mirror reflection surface) to which the principle of the present invention is not applied. In the case of the reflective plated layer in Fig. 15, it has a milky white surface with a diffused roughness along the surface, but in the case of the mirror-surface reflective surface in Fig. 16, it has a surface that appears black in appearance.

Meanwhile, reel-to-reel plating or batch plating can be applied to low-speed plating using a low current density. However, in the above-mentioned reel-to-reel plating process, it is necessary to increase the length of the process line in order to perform low-speed plating on the base material which is fed at a constant feed rate from the base material wound in roll form, Can be suitably applied.

Alternatively, the reflective plating layer 217 may be formed over the entire area of the base substrate 210. Alternatively, the reflective plating layer 217 may be formed only on the area of the base substrate 210 within a range where emitted light of the light emitting device can reach, , It is also possible to form the reflection plating layer 217 only in a range corresponding to the inner area of the lead frame.

Through these preceding processes, a finished lead frame is formed. Thereafter, a post-treatment process may be performed. The post-treatment process can prevent the discoloration of the reflective plating layer 217 and allow the process for drying the finished lead frame to proceed. For example, the post-treatment process may be performed by a series of unit processes including an electro-cleaning process, an anti-tarnish process, and a dry process.

Hereinafter, a method of manufacturing a light emitting device package using the lead frame will be described with reference to FIGS. 17A to 17C. FIG.

First, as shown in FIG. 17A, a package mold 330 is formed to accommodate a part of the lead frame 310. For example, the package mold 330 may be formed by injection molding. The package mold 330 receives a part of the lead frame 310 and a cavity space G for exposing the mounting area of the lead frame 310 is formed at the center of the package mold 330. For example, the package mold 330 may be formed by applying a resin mixed with high reflectance particles such as TiO 2 in addition to PPA of an engineering plastic type having excellent moldability and workability.

17B, the light emitting device 350 is mounted on the mounting area of the lead frame 310 through the cavity space G formed in the package mold 330. Next, as shown in FIG. For example, the light emitting device 350 may be implemented as a light emitting diode.

Next, the electrode pad (not shown) of the light emitting device 350 and the lead frame 310 are electrically connected. For example, one end of the conductive wire 380 may be connected to the electrode pad of the light emitting device 350, while the other end of the conductive wire 380 may be connected to the lead frame 310 to electrically connect the two. have. The conductive wire 380 may be formed of fine wires such as gold (Au) and silver (Ag).

Next, as shown in Fig. 19C, a sealing resin 390 is applied in the cavity space G. Then, as shown in Fig. For example, the sealing resin 390 may be applied so that the light emitting device 350 and the conductive wire 380 are embedded in the cavity space G of the package mold 330 . For example, the sealing resin 390 may be formed of a light transparent resin material, or may be formed of a light transparent resin material mixed with a fluorescent material. For example, the sealing resin 390 may be formed of a silicone resin, an epoxy resin, or the like. The sealing resin 390 may be formed in a hemispherical lens shape, and a separate lens (not shown) may be further formed on the sealing resin 390 if necessary.

Throughout this specification, when it is assumed that another layer is formed on any one of the layers, the term "above " refers collectively to the upper part and does not mean that the upper layer exists directly on the lower layer, But also includes a case where another layer is interposed.

For example, when the diffusion roughness is formed on the base substrate 210, the diffusion roughness does not mean that the diffusion roughness is directly formed on the surface of the base substrate 210. For example, when a nickel plating layer, a copper plating layer, or a silver strike layer formed by a surface roughness plating process is present on the base substrate 210, that is, when the diffusion roughness is lower than the nickel plating layer, the copper plating layer, Is meant to encompass the case of being formed on a strike layer or the like.

For example, the fact that the reflection plating layer 217 is formed on the diffusion roughness does not mean only when the reflection plating layer 217 is directly formed on the surface of the base substrate 210 on which the diffusion roughness is formed. For example, the case where a strike layer exists on the base substrate 210 is also meant to encompass.

While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100: light emitting device package 110, 310: lead frame
110-1 and 210-1: first lead regions 110-2 and 210-2: second lead regions
110a: inner lead 110b: outer lead
110R: Reflective surface of lead frame 112, 210: Base substrate
115, 215 metal coating layer 117, 217 reflective coating layer
130, 330: package mold 130R: cavity reflection surface
150, 350: light emitting element 180, 380: conductive wire
190,390: Sealing resin
G: Cavity space R1, R2, R2 ': Reflection surface
LED1, LED2: light emitting device package S:
L: Display direction t: Thickness of reflective plating layer

Claims (14)

A manufacturing method of a lead frame for a light emitting device package,
Preparing a base substrate for a lead frame;
Forming a diffusion roughness on the base substrate and forming a diffusion roughness in an inner region of the base substrate including a mounting position of the light emitting device, the method comprising the steps of: ; And
Forming a reflective plating layer having a spherical structure on the diffusing surface, the plating is performed at a low current density of 0.3 to 2.0 ASD (A / dm ² ) to form a reflective plating layer having a surface gloss in the range of 0.6 to 1.2 GAM And forming the lead frame. delete delete delete delete delete delete delete delete delete The method according to claim 1,
In the step of forming the reflective plating layer,
And a silver (Ag) plating layer is formed by applying a polishing agent. The method according to claim 1,
Forming a metal coating layer including at least one of a metal seed layer and a ground layer in advance of the reflective plating layer. delete delete

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