KR101028473B1 - Lead frame for light emitting diode and method for fabricating the same - Google Patents

Abstract

The present invention relates to a lead frame for a light emitting diode and a method of manufacturing the same, in the manufacture of a high-conductivity-high strength co-implementation material that can be used in a product that requires heat dissipation, alloy design, processing control, high purity and In order to solve the problem that manufacturing was not easy by using the same atomic property control technology, a high-strength buried pattern was formed on a high-strength bulk material or vice versa. By using a technology to compound by the multiplexing, it is possible to easily expand the material selection range, and relates to an invention that can facilitate the production and utilization thereof.

Description

LEAD FRAME FOR LIGHT EMITTING DIODE AND METHOD FOR FABRICATING THE SAME}

The present invention relates to a lead frame for a light emitting diode and a method of manufacturing the same, and by using a combination of a combination of a high-conductivity material and a high-strength material, respectively, it is possible to easily expand the material selection range, the production and utilization It relates to a technology that facilitates.

Efforts to apply light emitting diodes to lighting began in the late 1990s. In 2006, the global market for phosphors for lighting reached about $ 2 billion, and the LED lighting market is expected to grow by more than 20% annually, and the global market for 2012 is expected to grow to over $ 10 billion. The light emitting diode has a long lifespan with high reliability compared to a conventional lighting fixture, has a low maintenance cost, and has a low power consumption, thereby greatly contributing to energy saving.

However, the light emitting diode lighting is relatively severe heat generation, it is a product that requires measures for self-heat dissipation. In particular, in order to improve the heat dissipation characteristics of the light emitting diode, a lead frame connected to the light emitting diode chip should be used as a material capable of simultaneously implementing high-high strength characteristics.

1 is a plan view showing a light emitting diode illumination.

Referring to FIG. 1, a lead module 10 including circuits for lighting design is provided, and a light emitting diode chip 20 is mounted on the lead module 10.

Next, a lead frame 30 connecting the light emitting diode chip 20 and the circuits is formed.

Here, since heat generation is mainly generated in the LED chip 20 which is the core of the LED lighting, the lead frame 30 should have high conductivity for heat dissipation of the LED chip 20. In addition, since the light emitting diode chip 20 should serve to support the lead module 10 to be fixed well, high strength is also required.

In the past, copper (Cu) was mainly used as the lead frame 30 material. Copper is an excellent electrical conductor, which has the advantage of being able to efficiently perform the connection and heat dissipation with the circuit. However, since the strength and softening resistance required as a support are inferior, an alloying element was added to compensate for this. However, when the alloying element is added, since the electrical conductivity is significantly lower than that of pure copper, there is a disadvantage in that it is not suitable for the use of a lead frame material which requires a certain strength, softening resistance, high conductivity, and high workability at the same time.

Therefore, CDA194 (OLIN) (Cu-Fe-P-Zn), CDA195 (OLIN) (Cu-Fe-P) and (Cu-Cr-Ni-P) were developed as high strength materials. Materials such as OLIN151 (Cu-Zr), KFC (Cu-Fe-P), CAC16 (Kebe), and DK3 (Dowa) have been developed as high-conductivity conductive materials. Here, the high strength type has poor electrical conductivity and softening resistance, and the OLIN151 has a problem of being too expensive in the high conductivity type. In addition, CAC16 and DK3 have difficulty in casting and manufacturing methods, CDA194 does not have an elongation satisfying the lead frame, and KFC does not have satisfactory strength.

As such, it is a very difficult task to simultaneously implement high and high strength characteristics. To overcome this problem, we are focusing on material property control technologies such as alloy design, processing control, and high purity.

2 and 3 are planar photographs showing a single phase control process by alloy design according to the prior art.

As shown in FIG. 2, a material having a complex surface structure and poor strength characteristics may be converted into a material having a smooth surface and high conductivity-high strength characteristics as shown in FIG. 3 through alloy design.

However, since such a study requires control of atomic components, the difficulty of the research is high, and the effect is not clear.

The present invention is a heterogeneous material compounding method in which a high-strength conductive material is embedded in a high-strength bulk material, or vice versa, a high-density conductive pattern is embedded in a high-strength bulk material. It is an object of the present invention to provide a method for manufacturing a lead frame for a light emitting diode, which can extend the selection range.

In addition, the present invention provides a light emitting diode lead frame and a light emitting diode using the same by applying the lead frame manufactured by the above method to the light emitting diode to simultaneously improve the electrical conductivity and heat dissipation characteristics as well as mechanical properties. It is for that purpose.

The method of manufacturing a lead frame for a light emitting diode according to the present invention includes forming a bulk lead frame using a first metal material, forming a plurality of grooves on a surface of the bulk lead frame, and forming a second metal material in the groove. It is characterized in that it comprises a step of embedding.

In addition, the method of manufacturing a lead frame for a light emitting diode according to an embodiment of the present invention comprises the steps of forming a bulk lead frame using a metal material having a tensile strength of 500 ~ 600MPa, a plurality of lines on the bulk lead frame Forming a trench consisting of a type and embedding a metal material having an electrical conductivity of 60% (IACS) or more in the trench.

In addition, a method of manufacturing a lead frame for a light emitting diode according to another embodiment of the present invention comprises the steps of forming a bulk lead frame using a metal material having an electrical conductivity of 60% (IACS) or more, and a plurality of upper parts of the bulk lead frame. Forming a trench consisting of a line type and the step of embedding a metal material having a tensile strength of 500 ~ 600MPa in the trench.

In addition, the light emitting diode lead frame according to the present invention is characterized in that it is manufactured by the above-described method.

In addition, the light emitting diode according to the present invention includes a lead module including a circuit pattern for operating a light emitting diode, a light emitting diode chip mounted on the lead module, and the light emitting diode chip fixed to the lead module, and the light emitting diode In order to release the heat generated in the chip, the light emitting diode lead frame manufactured by the above-described method and a molding layer formed on the light emitting diode chip is characterized in that it comprises a.

The method of manufacturing a lead frame for a light emitting diode according to the present invention is a heterogeneous material compounding method in which a high-strength bulk material is embedded with a high-conductivity conductive pattern or vice versa, thereby expanding the range of material selection. It simplifies the process, improves electrical conductivity and improves heat dissipation characteristics.

In addition, the final product using the high-strength composite structure according to the present invention is easy to manufacture, and further improves the performance, and provides the effect of design diversification and its use range can be extended.

According to the present invention, a high-strength first metal is embedded in a surface of a high-conductivity second metal material which is filled with a second metal material, which is a highly conductive material, in a predetermined pattern form on the surface of the first metal material, which is a high-strength bulk material, or vice versa. By embedding the material, it is easy to manufacture the leadframe, and the high conductivity-high strength property can be more easily obtained.

Here, when the first metal material uses a high strength material, the second metal material formed in a subsequent process should use a high conductivity material. On the contrary, if the first metal material is a highly conductive material, the second metal material should use a high strength material.

In the present invention, a high-strength material suitable as a lead frame for a light emitting diode is preferably one having a tensile strength of 500 to 600 MPa.

High-strength metal material according to an embodiment of the present invention, in the total weight% of the first metal material, carbon (C) 3 to 5% by weight, tin (Sn), phosphorus (P), zinc (Zn), chromium ( It is preferable to use a material consisting of 1 to 20% by weight of at least one material of Cr, manganese (Mn), aluminum (Al), copper (Cu) and titanium (Ti) and the balance of iron (Fe).

Here, the carbon content plays an important role in determining the strength of the metal material. When added in less than 3% by weight it is not possible to obtain the desired tensile strength, if it exceeds 5% by weight may cause a problem that the processing is difficult to increase excessively.

In addition, it is preferable to use a material having high conductivity of 60% (IACS) or more, and it is preferable to use silver (Ag), copper (Cu), gold (Au), aluminum (Al), and beryllium (Be). It is preferable to use a material made of at least one of magnesium (Mg), rhodium (Rh), iridium (Ir), and tungsten (W).

Hereinafter, a light emitting diode lead frame and a method of manufacturing the same according to the present invention will be described in detail.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments described below in detail with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various forms, and only the present embodiments are intended to complete the disclosure of the present invention, and the general knowledge in the art to which the present invention pertains. It is provided to fully convey the scope of the invention to those skilled in the art, and the present invention is defined only by the scope of the claims. Like reference numerals refer to like elements throughout.

4A to 4E are cross-sectional views illustrating a method of manufacturing a lead frame for a light emitting diode according to an embodiment of the present invention.

Referring to FIG. 4A, a bulk lead frame 100 is formed using a first metal material. In this case, the bulk lead frame 100 is formed using a cutting or punching process after forming a thin plate using a first metal material.

Next, a photosensitive film 110 for forming a groove is formed on the surface of the first metal material.

Referring to FIG. 4B, after the lithography process is performed to form the photoresist pattern 115, the bulk leadframe 100 is immersed in the etching solution 120. In this case, the entire bulk lead frame 100 is contained in the etching solution 120, but in order to clearly indicate the groove forming process, the etching solution 120 is not illustrated on the photoresist pattern 115. Thus, the present invention is not limited by the etching process shown.

Referring to FIG. 4C, the surface of the bulk lead frame 100 is etched by the etching process to form the groove 130.

Referring to FIG. 4D, the groove 130 is expanded while the photosensitive film pattern 115 is removed. In this case, the groove 130 is not necessarily formed using a lithography process, but may be formed directly using the laser without the etching process.

In addition, the groove 130 may be formed on one surface or both surfaces of the bulk lead frame 100. One embodiment of the groove 130 according to the present invention is a grid pattern formed by crossing the line pattern. In addition, it may be formed in a honeycomb type, the present invention is not limited by the shape of the groove 130.

Referring to FIG. 4E, a second metal material is filled in the groove 130 to form a lead frame for a light emitting diode.

5 is a cross-sectional view showing a lead frame for a light emitting diode according to the present invention.

Referring to FIG. 5, a circuit pattern 210 for driving a light emitting diode is formed on the lead module 200. Here, the circuit pattern 210 represents a copper pad portion.

Next, the light emitting diode chip 220 is mounted on the circuit pattern 210, and the light emitting diode chip 220 is connected by the lead frame 230 according to the present invention. In this case, a complementary material pattern 240 is formed on the surface of the leadframe 230 to compensate for the characteristics of the leadframe 230.

Here, when the leadframe is used as a high-strength material, a high-conductivity pattern made of a highly conductive material is formed on the surface of the leadframe, and when the leadframe is used as the high-conductivity material, a high-strength pattern made of high strength material is formed on the surface of the leadframe. The former case may be used in the light emitting diode device in which the strength is important, and the latter case may be used in the light emitting diode device in which the conductivity is more important.

In addition, it is possible to freely select or expand the range of material selection for lead frame formation because only one material having only one characteristic is concentrated and used.

Next, a solder resist 215 for protecting the circuit pattern 210 and the lead module 200 is formed on the front surface of the lead module 200, and a molding layer including phosphors on the light emitting diode chip 220. 225 is formed.

6 is a cross-sectional view showing a groove formed in the upper portion of the electrolytic copper foil.

FIG. 6 is a cross-sectional view illustrating the formation of a groove on an electrolytic copper foil after forming an electrolytic copper foil on a substrate formed of a polymer by using a lithography process.

Here, since the electrolytic copper foil is a highly conductive material, it is possible to form a lead frame having high strength and high conductivity at the same time by embedding a high strength material in the groove.

7 is a plan view showing a lead frame for a light emitting diode according to the present invention.

FIG. 7 is a view taken from the top of a buried metal material Ag having high conductivity in a groove of a bulk lead frame including a lattice groove as shown in FIG. 6. In this case, in order to improve the strength of the bulk lead frame, a rolled copper foil was used instead of the electrolytic copper foil. That is, by forming a high conductivity pattern on a high-strength material, two characteristics of high-strength and high-conductivity can be harmoniously coexist.

8 is a cross-sectional view showing a light emitting diode manufactured using a lead frame according to the present invention.

Referring to FIG. 8, the light emitting diode chip 310 is formed on the anode lead frame 350 formed integrally with the lead module. At this time, the portion where the light emitting diode chip 310 is mounted is preferably formed to be concave in a semi-circular shape for smooth light emission.

Next, the light emitting diode chip 310, the anode lead frame 350, and the cathode lead frame 355 are connected to each other by wire bonding 340, and light emission is formed on the anode lead frame 350 formed in a semicircular concave shape. The phosphor layer 320 is filled, and a molding layer is formed around the anode and cathode lead frames 350 and 355 and the entire light emitting diode chip 310 in a shell shape. At this time, the molding layer is formed using a transparent epoxy resin or a transparent silicone resin.

In the shell type light emitting diode 300 of this type, the anode and cathode lead frames 350 and 355 do not use a conventional alloy material in order to have high strength and high conductivity, and have high strength characteristics and high conductivity characteristics. Each of the two materials is combined to form a composite.

In the following, specific characteristics and comparative examples of the above-described lead frame of the present invention will be described and their characteristics will be described.

Example 1

First, the high-strength material includes 3% by weight of carbon (C), 0.02% by weight of tin (Sn), 0.05% by weight of phosphorus (P), and 0.3% by weight of zinc (Zn), and the balance of iron (Fe) and other impurities. A bulk leadframe having a size of 50 mm * 50 mm and a thickness of 0.1 mm is formed using the metal material.

Next, grooves having a line width of 100 μm and a depth of 200 μm are formed in a lattice shape on the surface of the bulk lead frame, and a lead frame is formed by embedding copper (Cu) as a highly conductive material in the grooves.

Example 2

Except for forming the carbon (C) content of the high-strength material in Example 1 to 5% by weight all performed the same to form a lead frame.

Example 3

In Example 1, a bulk lead frame is formed using copper, and a lead frame is formed by embedding a metal material including carbon on the surface thereof.

Comparative Example 1

Except for forming the carbon (C) content of the high-strength material in Example 1 to 2% by weight all performed the same to form a lead frame.

Comparative Example 2

Instead of using the composite material as described above, a lead frame having a size of 50 mm * 50 mm and a thickness of 0.1 mm is formed using a CDA195 (OLIN) Cu-Fe-P alloy material.

A summary of the results of examining the characteristics of the lead frame according to each of the above embodiments and comparative examples is shown as Table 1 below.

TABLE 1

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 The tensile strength
(MPa) 495 620 480 450 400 Electrical conductivity
(% IACS) 75.8 73.2 80.7 58.3 52.6

As described above, it can be seen that in the case of Examples 1 to 3 according to the present invention, excellent tensile strength and electrical conductivity required as lead frames can be obtained. In a general material, the thermal conductivity is also increased according to the electrical conductivity, so that the heterojunction lead frame according to the present invention may exhibit excellent heat dissipation characteristics.

In addition, in Example 3, the conductivity characteristics are better than the strength characteristics, and thus, a heterojunction material may be variously used according to the use and characteristics of the light emitting diode device.

In addition, as can be seen in Examples 1 and 2, the strength can be easily adjusted according to the carbon content. In the case of Comparative Example 1 it can be seen that the strength of the carbon is less than the range specified in the present invention. In this case, the electrical conductivity may also be easily increased by using different materials embedded in the grooves as silver instead of copper, or by extending the surfaces on which the grooves are formed on both sides of the bulk lead frame.

This application example can also be applied to Example 3, by replacing the material used as the bulk lead frame from copper to silver, the electrical conductivity can be improved, and in order to further strengthen the strength, the groove forming surface may be expanded. .

On the other hand, in the case of the lead frame by the alloy ratio as in Comparative Example 1 can not change the high-high strength properties other than the predetermined characteristics, the characteristics also appear to be inferior to the present invention.

Therefore, the heterojunction leadframe using the composite material according to the present invention can expand the range of material selection, and can simplify the manufacturing process and improve the electrical conductivity and heat dissipation characteristics.

Although the embodiments of the present invention have been described above with reference to the accompanying drawings, the present invention is not limited to the above embodiments, but may be modified in various forms, and having ordinary skill in the art to which the present invention pertains. It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without changing the technical spirit or essential features of the present invention. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive.

1 is a plan view of a light emitting diode illumination;

2 and 3 are planar photographs showing a single phase control process by alloy design according to the prior art.

4A to 4E are cross-sectional views illustrating a method of manufacturing a lead frame for a light emitting diode according to an embodiment of the present invention.

5 is a cross-sectional view showing a lead frame for a light emitting diode according to the present invention.

6 is a cross-sectional view showing a groove formed in an upper portion of an electrolytic copper foil.

Figure 7 is a planar photograph showing a lead frame for a light emitting diode according to the present invention.

8 is a cross-sectional view showing a light emitting diode manufactured using a lead frame according to the present invention.

Claims (20)

Forming a bulk leadframe using the first metal material; Forming a plurality of grooves on a surface of the bulk leadframe; And And embedding a second metal material in the groove. The first metal material is formed using any one material selected from materials having high strength properties and materials having high conductivity properties, and the second metal material is selected from materials having high strength properties and materials having high conductivity properties. By using any one material, by using a material having properties that are contrary to the properties of the first metal material, the high-strength and high-strength characteristics of the bulk lead frame is complementary to each other, The material having high strength properties is 3 to 5% by weight of carbon (C), tin (Sn), phosphorus (P), zinc (Zn), chromium (Cr), manganese (Mn), aluminum (Al), copper (Cu ) And 1 to 20% by weight of at least one material of titanium (Ti) and the balance of iron (Fe), and the material having high conductivity is silver (Ag), copper (Cu), gold ( Lead frame for light emitting diodes using a material consisting of at least one of Au), aluminum (Al), beryllium (Be), magnesium (Mg), rhodium (Rh), iridium (Ir) and tungsten (W) Manufacturing method. The method of claim 1, The bulk lead frame is a light emitting diode lead frame manufacturing method characterized in that formed by using a cutting or punching process after forming a thin plate using the first metal material. The method of claim 1, The groove is a lithography process or a method of manufacturing a lead frame for a light emitting diode, characterized in that using a laser. The method of claim 1, The groove is a lead frame manufacturing method for a light emitting diode, characterized in that formed on one side or both sides of the bulk lead frame. The method of claim 1, The groove is a light emitting diode lead frame manufacturing method characterized in that formed in a lattice pattern formed by crossing the line pattern. The method of claim 1, The groove is a honeycomb lead frame manufacturing method, characterized in that formed in the honeycomb. delete delete The method of claim 1, The material having the high strength characteristics is a light emitting diode lead frame manufacturing method characterized in that it has a tensile strength of 500 ~ 600MPa. delete The method of claim 1, The material having high conductivity has a conductivity of 60% (IACS) or more. delete 3-5% by weight of carbon (C), tin (Sn), phosphorus (P), zinc (Zn), chromium (Cr), manganese (Mn), aluminum (Al), copper (Cu) and titanium (Ti) Forming a bulk leadframe using a metal material composed of at least one material by weight of 1 to 20% by weight and the balance of iron (Fe) and having a tensile strength of 500 to 600 MPa; Forming a trench formed in a plurality of line types on the bulk lead frame; And At least any one of silver (Ag), copper (Cu), gold (Au), aluminum (Al), beryllium (Be), magnesium (Mg), rhodium (Rh), iridium (Ir), and tungsten (W) in the trench. A method for manufacturing a lead frame for a light emitting diode, comprising the step of embedding a metal material having one or more electrical conductivity of 60% (IACS) or more. Made of at least one of silver (Ag), copper (Cu), gold (Au), aluminum (Al), beryllium (Be), magnesium (Mg), rhodium (Rh), iridium (Ir) and tungsten (W) Forming a bulk lead frame using a metal material having an electrical conductivity of 60% (IACS) or more; Forming a trench formed in a plurality of line types on the bulk lead frame; And 3 to 5% by weight of carbon (C), tin (Sn), phosphorus (P), zinc (Zn), chromium (Cr), manganese (Mn), aluminum (Al), copper (Cu) and titanium ( 1 to 20% by weight of at least one material of Ti) and the remainder of the iron (Fe), comprising a step of embedding a metal material having a tensile strength of 500 ~ 600MPa Way. delete delete A lead frame for a light emitting diode, which is manufactured by the method of any one of claims 1 to 6, 9 and 11. delete delete delete

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