KR100755619B1 - Method of fabricating led package - Google Patents

Abstract

A method for manufacturing an LED package is provided to form a pattern on a resin package by using a soft stamp having resilient characteristic, thereby forming the pattern simply and uniformly. LED chips(205) mounted on LED package structures(210 to 240) are sealed with a liquid transparent resin. Before the liquid transparent resin is cured, a predetermined recessed pattern is imprinted on a surface of the liquid transparent resin by using a soft stamp(100) made of polymer material and a recessed pattern. The liquid transparent resin is cured to form a resin package. The soft stamp is removed from the LED package structure.

Description

Manufacturing method of LED package {METHOD OF FABRICATING LED PACKAGE}

1A to 1E are cross-sectional views of processes for explaining a method of manufacturing an LED package according to an embodiment of the present invention.

2 is a perspective view of a flexible stamp manufactured according to an embodiment of the present invention.

3a to 3d is a manufacturing process diagram of a flexible stamp according to an embodiment of the present invention.

Figure 4 is a side cross-sectional view showing an example of a conventional LED package.

<Description of the symbols for the main parts of the drawings>

100: Flexible stamp 200: LED package set

207: transparent liquid resin 209: resin packaging

P: Wedge irregularities pattern L: Wedge irregularities pattern line

209: resin packaging

The present invention relates to a method of manufacturing an LED package, and more particularly, to a pattern of the LED package that can be formed in a simple and uniform pattern by performing a pattern formation of the resin packaging part by the imprinting method of the flexible stamp when manufacturing the LED package. It relates to a manufacturing method.

Light Emitting Diode (hereinafter referred to as 'LED') is a semiconductor device that converts electrical energy into optical energy, and is composed of compound semiconductors that emit light of a specific wavelength according to energy band gap, and is used in various fields such as optical communication and display. Is being used by.

The LEDs are available in packages depending on the intended use and required form. In general, the LED package, after mounting the LED chip on the substrate or lead frame on which the electrode pattern is formed, electrically connects the terminal and the electrode pattern (or lead) of the chip, epoxy, silicon, or a combination thereof, and the like on top thereof. It is produced in such a way that the resin packaging portion is formed using.

1 shows an example of a conventional LED package.

Referring to FIG. 1, the LED package 10 includes a lower package substrate 11a having two electrode patterns 12a and 12b formed thereon and an upper package substrate 11b provided with a predetermined groove. The LED chip 13 is mounted on the bottom of the groove by using an adhesive layer, and two electrodes (not shown) of the LED chip 13 may be connected to the upper ends of the electrode patterns 12a and 12b by wires.

The LED chip 13 is surrounded by the resin packaging part 15. The resin packaging part 15 becomes a very important factor affecting the luminous efficiency of the LED package 10. That is, the amount of light emitted from the LED chip 13 may be substantially changed to the outside depending on the optical characteristics (particularly, the refractive index) and the shape of the material of the resin packaging part 15.

 In particular, since the transparent resin such as epoxy resin or silicone resin constituting the resin packaging 15 has a slightly higher refractive index (eg, epoxy resin: 1.5) than the external atmosphere, it is substantially extracted by the light extraction critical angle. The amount of light is limited. Therefore, a lot of light outside the critical angle range inside the resin packaging 15 is totally internally reflected and cannot be extracted to the outside or has a complicated light path. For this reason, there exists a problem that light extraction efficiency becomes low.

In addition, as shown in the example shown in Figure 1, the resin packaging portion 15 formed in the groove portion when the liquid transparent resin is introduced through a dispensing process, etc., because of the wetting (wetting) of the liquid resin, the surface is formed into a curved surface Therefore, the light extraction efficiency is reduced.

On the other hand, in order to enhance the light extraction efficiency, a method of forming an uneven pattern on the surface of the LED package resin has been proposed. Here, it is known that the larger the aspect ratio (ratio of height to resolution) of the uneven pattern and the more uniform the pattern is secured, the higher the emission and light extraction efficiency obtained. However, since a separate process such as etching is required, the manufacturing process is not only complicated, but there is a problem in that it is difficult to form a uniform pattern due to a height deviation that may exist in an LED package as an object.

The present invention is to solve the above problems, an object of the present invention is to produce a simple and uniform pattern of the LED manufacturing process by performing the pattern formation of the resin packaging by the imprinting method of the flexible stamp when manufacturing the LED package It is to provide a method of manufacturing a package.

Another object of the present invention is an LED package that can ensure a light extraction efficiency by forming a pattern with a large aspect ratio evenly over the entire area of the LED package set even in the LED package set may be a height deviation by the adoption of a flexible stamp It is to provide a manufacturing method.

In order to achieve the above object, the manufacturing method of the LED package according to the present invention comprises the steps of encapsulating the LED chip mounted on the LED package structure with a liquid transparent resin; Before the liquid transparent resin is cured, imprinting a desired irregular pattern on the surface of the liquid transparent resin by applying a flexible stamp made of a polymer material having an uneven pattern; Forming a resin package of the LED package structure by curing the liquid transparent resin while the flexible stamp is applied; And removing the flexible stamp from the LED package structure.

The LED package structure has a groove portion on which the LED chip is mounted, and the sealing of the liquid transparent resin may include filling liquid transparent resin into the groove portion.

The flexible stamp has a plurality of wedge-shaped concave-convex pattern lines arranged in one direction on one surface thereof, and the concave-convex pattern line extends in a short direction of the LED package structure.

The forming of the resin packaging may further include performing a degassing process to remove bubbles from the liquid transparent resin in a state where the flexible stamp is applied.

In addition, the method of manufacturing an LED package according to the present invention comprises the steps of: providing a set of a plurality of LED package structures, each of which is mounted on the LED chip is arranged on the same plane; Encapsulating each LED chip mounted on the plurality of LED package structures with a liquid transparent resin; Before the liquid transparent resin is cured, imprinting a desired uneven pattern on the surface of each liquid transparent resin by applying a flexible stamp made of a polymer material having a uneven pattern at a position corresponding to the liquid transparent resin of each LED chip. Doing; Forming a resin package of the plurality of LED package structures by curing the transparent liquid resin while the flexible stamp is applied; And removing the flexible stamp from the plurality of LED package structures.

The set includes a plurality of LED package structures having a lead frame, and has a structure in which lead frames of adjacent LED package structures are integrally connected to each other such that the plurality of LED package structures are arranged on the same plane.

Preferably, the method may further include cutting the leadframe such that the LED package structures are separated from each other.

The method of manufacturing an LED package according to the present invention, in forming a pattern for the purpose of improving the light extraction efficiency in the resin packaging during the manufacture of the LED package to enable a simple and uniform pattern formation compared to the conventional manufacturing process, It may be performed in units of LED packages or in units of LED packages. Here, the LED package is a single LED package structure having a groove portion on which the LED chip is mounted. Also, the LED package set is a set in which a plurality of LED package structures each having an LED chip mounted thereon is arranged on the same plane, and includes a plurality of LED package structures having a lead frame, and the plurality of LED package structures are on the same plane. The leadframes of the LED package structure adjacent to each other to be arranged in the has a structure connected integrally.

In the following description of the manufacturing method of the LED package according to the present invention, LED package set consisting of a plurality of LED package structure to clearly show that the elastic flexible stamp can accommodate the height deviation of the LED package set as the object In the following description, the case is applied.

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

1A to 1D are cross-sectional views illustrating a method of manufacturing an LED package according to an embodiment of the present invention.

First, as shown in FIG. 1A, a plurality of LED package structures 210, 220, 230, 240,..., On which the LED chips 205 are mounted, are arranged on the same plane, respectively. do.

The LED package set 200 includes a plurality of LED package structures 210, 220, 230, 240,... With a leadframe, and adjacent LEDs so that the plurality of LED package structures are arranged on the same plane. The lead frame of the package structure has a structure connected integrally.

The plurality of LED package structures 210, 220, 230, 240,..., For example, the LED package structures 210 may have lower substrates 201a having electrode patterns 203a and 203b and groove portions C. It consists of the upper substrate 201b, and the LED chip 205 is mounted in the groove portion C of the upper substrate 201b. The electrode patterns 203a and 203b may be understood as an electrode structure connected to the back electrode through the conductive via hole. Here, the electrode structure performs a function of a lead frame connecting the plurality of LED package structures 210, 220, 230, 240, ... to each other.

Since the LED package set 200 has a structure in which lead frames of LED package structures adjacent to each other are integrally connected, height deviations may exist, for example, as shown in FIG. 1A and the LED package structure 210. It is understood that the height deviation h1 exists because the body height of the LED package structure is different between the LED package structures 220, and the height deviation h2 exists between the LED package structure 230 and the LED package structure 240. Can be.

Next, as shown in Figure 1b, the liquid phase in each groove portion (C) so that each LED chip 205 mounted in the plurality of LED package structure (210, 220, 230, 240, ...) is sealed The transparent resin 207 is introduced.

The liquid transparent resin 207 may be a transparent resin such as a silicone resin, an epoxy resin, or a mixed resin thereof, and a known process such as a dispensing process may be used.

In the present step, it is preferable that the amount of the liquid transparent resin 207 is slightly higher than the height of the groove C to form a desired uneven pattern regardless of the size of the flexible stamp. More preferably, the liquid transparent resin 207 does not flow to an undesired region, but is introduced in an amount such that the liquid transparent resin 207 is kept convex by surface tension.

Next, as shown in FIG. 1C, before the liquid transparent resin 207 is cured, a flexible stamp having an uneven pattern at a position corresponding to the liquid transparent resin 207 of each LED chip 205. 100) is applied to perform imprinting of desired irregularities on the surface of each of the liquid transparent resins 207. In this case, the flexible stamp 100 is compressed along the height deviation h1 and h2 of the LED package set 200 due to the flexible elastic property of the flexible stamp 100.

The resin packaging part 209 of the plurality of LED package structures is formed by curing the liquid transparent resin 207 in the state where the flexible stamp 100 is applied.

In particular, the flexible stamp 100 is made of a silicon polymer material or an elastic polymer material including the same so as to accommodate a height deviation existing between each LED package structure.

This imprinting (stamping) process requires a constant pressure and temperature (120 ~ 150 ℃), depending on the type of resin or uneven pattern of the flexible stamp 100, the radius of the curing for a certain time to facilitate the subsequent stamp separation process It can be carried out in a burn state.

Next, as shown in FIG. 1D, the flexible stamp 100 is removed from the LED package set 200, and it can be seen that a uniform uneven pattern P is formed on each LED package structure.

Preferably, the flexible stamp 100 is removed so that the uneven pattern P transferred to the upper surface of the resin packaging part 209 is not damaged.

In addition, a defoaming process may be performed to remove bubbles from the liquid transparent resin 207 that is cured while the flexible stamp 100 is attached.

Finally, as shown in FIG. 1E, the cutting process of the lead frame is performed to separate the LED package structures 210, 220, 230, 240,... From the LED package set 200.

As described above, the flexible stamp 100 may be compressed along the height deviations h3 and h4 due to the soft elasticity of the LEDs even though the height deviations h3 and h4 exist between the LED package structures. Allow a uniform pattern to be formed on the package structure.

As a result, a uniform pattern can be formed for all LED package products across the entire area of the LED package set, thereby providing an LED package with further improved light extraction efficiency.

The flexible stamp according to the present invention may be produced in various patterns according to the uneven pattern of the surface of the resin packaging, Figure 2 is a perspective view of the flexible stamp produced according to an embodiment of the present invention.

Referring to FIG. 2, the flexible stamp 100 has a plurality of wedge-shaped concave-convex pattern lines L arranged along one direction on one surface thereof, and the wedge-shaped concave-convex pattern line L has a long axis L1 of a rectangular groove portion. According to the short axis (L2) is not formed in one direction only.

In addition, the uneven pattern line (L) is preferably extended in the uniaxial direction (L2) of the plurality of LED package structure as shown in Figure 1c. This contributes to the improvement of the light extraction efficiency of the LED package because the number of uneven pattern lines for the same area increases.

As the size of each uneven pattern, the degree of improvement in light extraction efficiency may vary. For example, in the structure where the cross section illustrated in FIG. 2 is a triangle, it is possible to design by appropriately selecting the length (d) of the base of the cross section or the height (h) of the triangle.

In addition, the flexible stamp 100 preferably has a flat plate structure. The flexible stamp 100 of the flat structure may solve the disadvantageous optical effect by forming a curved surface generated by the wettability of the liquid resin 207 flat. At this time, the amount of the liquid transparent resin 207 is preferably formed somewhat higher than the height of the groove (C).

On the other hand, Figures 3a to 3d is a manufacturing process diagram of a flexible stamp according to an embodiment of the present invention, preparing a master 300 engraved with an embossed pattern, pouring a polymer precursor on the prepared master 300, cured to an elastic solid In other words, the flexible stamp 100 is manufactured.

It is intended that the invention not be limited by the foregoing embodiments and the accompanying drawings, but rather by the claims appended hereto. Accordingly, various forms of substitution, modification, and alteration may be made by those skilled in the art without departing from the technical spirit of the present invention described in the claims, which are also within the scope of the present invention. something to do.

As described above, according to the present invention, since the pattern formation of the resin packaging part is performed by an imprinting method using a flexible stamp having elastic properties, the manufacturing process is simple and uniform. to provide.

In addition, when applied to an LED package set consisting of a plurality of LED packages, the elastic flexible stamp can accommodate the height deviation of the LED package set as an object, so that a pattern with a large aspect ratio is spread over the entire area of the LED package set. It can form uniformly. Therefore, it is possible to provide an LED package with improved light emission and light extraction efficiency.

In addition, the flexible flexible stamp in the present invention is less likely to be contaminated or damaged during imprinting and can be manufactured using a low-cost polymer material, thereby providing a side effect of lowering the manufacturing cost of the LED package.

Claims (8)

Encapsulating the LED chip mounted on the LED package structure with a liquid transparent resin; Before the liquid transparent resin is cured, imprinting a desired irregular pattern on the surface of the liquid transparent resin by applying a flexible stamp made of a polymer material having an uneven pattern; Forming a resin package of the LED package structure by curing the liquid transparent resin while the flexible stamp is applied; And Removing the flexible stamp from the LED package structure. The method of claim 1, The LED package structure has a groove portion on which the LED chip is mounted, The encapsulating the liquid transparent resin is a method of manufacturing an LED package, characterized in that the step of filling the liquid transparent resin in the groove portion. The method of claim 1, The flexible stamp is a manufacturing method of the LED package, characterized in that it comprises a plurality of wedge-shaped irregular pattern lines arranged in one direction on one surface. The method of claim 3, The uneven pattern line is a manufacturing method of the LED package, characterized in that extending in the short direction of the LED package structure. The method of claim 1, The forming of the resin package may further include performing a degassing process to remove bubbles from the liquid transparent resin in a state where the flexible stamp is applied. Providing a set in which a plurality of LED package structures each having an LED chip mounted thereon are arranged on the same plane; Encapsulating each LED chip mounted on the plurality of LED package structures with a liquid transparent resin; Before the liquid transparent resin is cured, imprinting a desired uneven pattern on the surface of each liquid transparent resin by applying a flexible stamp made of a polymer material having a uneven pattern at a position corresponding to the liquid transparent resin of each LED chip. Doing; Forming a resin package of the plurality of LED package structures by curing the transparent liquid resin while the flexible stamp is applied; And Removing the flexible stamp from the plurality of LED package structures. The method of claim 6, The set includes a plurality of LED package structure having a lead frame, LEDs, characterized in that the lead frame of the adjacent LED package structure is integrally connected so that the plurality of LED package structure is arranged on the same plane Method of making the package. The method of claim 7, wherein And cutting the leadframe so that the LED package structures are separated from each other.

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