KR101549383B1 - Led package and method for fabricating the same - Google Patents

Abstract

A light emitting diode package and a manufacturing method thereof are disclosed. Wherein the light emitting diode package comprises: a base, the first and second lead terminals being spaced apart from each other and including first and second lead terminals, An LED chip located on the first lead terminal and electrically connected to the second lead terminal by a wire; And a resin for supporting the first and second lead terminals and exposing the LED chip, wherein at least one of the first lead terminal and the second lead terminal is formed so as to be adjacent to the side where the first and second lead terminals face each other And at least a part of the protrusion is exposed to the outside.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an LED package,

The present invention relates to an LED (Light Emitting Diode) package and a manufacturing method thereof, and more particularly, to an improvement of an LED package including a translucent encapsulant for encapsulating an LED chip and a housing for encapsulating the encapsulant .

An LED is a semiconductor light emitting device in which electrons and holes meet at a pn junction due to current application and emit light. Generally, a light emitting device having such a structure is fabricated by a package structure including an LED chip. LED package ".

In general, an LED package includes a base provided with an electric terminal on which the LED package is mounted, a light-transmitting encapsulant formed for protecting the LED chip, and the like. A lead frame or a printed circuit board (PCB) is mainly used as a base on which the LED chip is mounted. Depending on the type of base used, the LED package may be divided into a lead frame type and a PCB type. Further, additional components such as a heat sink may be used as a base on which the LED chip is mounted.

 The lead frame type LED package includes a housing defining a cavity in which the encapsulant is formed. Such a housing generally has a function of reflecting light in order to narrow the directing angle, that is, to collect light, and for this reason, it is referred to as a " reflector ". In such an LED package, a liquid transparent resin is injected into the cavity of the housing by a dipping method to form an encapsulating material. Further, the housing is formed by injection molding using an opaque resin material.

In the above-described conventional LED package, the sealing material is formed into an undesired convex shape due to the surface tension acting on the liquid resin. It is known that the shape of the encapsulant hinders various performance of the LED package from an optical point of view. For example, when used for a backlight, the convex portion of the sealing material faces the light guide plate, causing a hot spot phenomenon, that is, an overly bright region in the form of a point as compared with other regions. Note that the convex shape of the encapsulant as described above has a different meaning from the shape of the convex lens designed as intended for the control of the directivity angle of the light. Conversely, when the amount of the liquid resin injected into the cavity is reduced, it is formed into an undesired concave shape, which lowers the luminous efficiency of the LED package.

  In addition, in the conventional LED package, it is difficult to design the divergent angle of light variously. This is because it is difficult to control the divergence angle by designing the shape of the encapsulant, and the light-divergent angle design by the housing And mainly depends on the shape of the reflecting surface (in particular, the reflecting surface angle).

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide an LED package and a method of manufacturing the LED package that can easily design the shape of the sealing material for sealing the LED chip inside the housing to a desired shape.

According to another aspect of the present invention, there is provided an LED package in which a housing is formed of a light-transmissive material capable of adjusting the transparency and the divergence angle, and the width of the divergent angle design is enlarged by adjusting the transparency thereof.

A light emitting diode package according to an aspect of the present invention includes: a base including a first lead terminal and a second lead terminal, the first lead terminal and the second lead terminal being spaced apart from each other; An LED chip located on the first lead terminal and electrically connected to the second lead terminal by a wire; And a resin for supporting the first and second lead terminals and exposing the LED chip, wherein at least one of the first lead terminal and the second lead terminal is formed so that the first and second lead terminals are opposed to each other Wherein at least a part of the protrusion is exposed to the outside.

In each of the first and second lead terminals, the side surface opposite to the opposite side surface may be exposed to the outside.

Furthermore, the protrusions may be connected to the side opposite to the opposite side.

The first lead terminal and the second lead terminal may have a flat plate shape.

The area of the upper surface of each of the first lead terminal and the second lead terminal may be larger than the area of the lower surface thereof.

The shape of the upper surface may be similar to the shape of the lower surface.

The resin may be located on at least a part of the first surface of the first lead terminal and the second lead terminal, and the resin may be located in a space between the first lead terminal and the second lead terminal.

The resin may be located on the side surfaces of the first lead terminal and the second lead terminal.

Each of the first lead terminal and the second lead terminal may include a groove adjacent to the protrusion on a side where the protrusion is located, and the side surface of the groove may be in contact with the resin.

The resin may include a diffusing agent that causes the resin to have light reflectivity.

The diffusing agent may be at least one selected from the group consisting of TiO _{2 ,} SiO _{2 ,} ZnO, and Y ₂ O ₃ .

The resin may have a white color.

The light emitting diode package may further include an encapsulant that encapsulates the LED chip and includes a phosphor.

The encapsulant may have a convex upper surface.

According to an embodiment of the present invention, the width of adjustment of the light directing angle of the LED package is widened, and it becomes easier to design the LED package with a desired light directing angle. In addition, various problems caused by the shape of the encapsulant, which is not intended during manufacturing, such as a hot spot phenomenon in which the portion of the light guide plate and the LED package contacting the encapsulant are excessively bright when used for a backlight, It is possible to solve problems such as deterioration of efficiency. Also, according to the embodiment of the present invention, the encapsulant and the housing are formed by transfer molding, which is economical compared to the conventional one because the encapsulant and the housing can be formed by replacing only the mold with the molding equipment left intact. Also, according to the embodiment of the present invention, unlike the existing technology in which the sealing members are separately formed by using the dipping method, a single mold having a plurality of spaces for forming the sealing material is used, By filling the liquefied resin at once and rapidly curing it, it is possible to produce a large number of LED packages in a short period of time, thereby greatly improving the productivity of the LED package.

1 is a perspective view illustrating an LED package according to an embodiment of the present invention;
2 is a cross-sectional view of another LED package according to an embodiment of the present invention.
3A to 3C are photographs showing an LED package whose transparency is adjusted according to the diffuser content of the light transmitting housing.
4 (a) and 4 (b) are cross-sectional views illustrating an LED package according to other embodiments of the present invention.
5 is a view for explaining a manufacturing process of an LED package according to an embodiment of the present invention.
6 is a view for explaining a transfer molding process of the housing and the sealing material in the LED package manufacturing process shown in FIG.
7 is a view for explaining a manufacturing process of an LED package according to another embodiment of the present invention.
FIG. 8 is a view for explaining a transfer molding process of an encapsulating material according to another embodiment of the present invention, showing a transfer molding process in a manner suitable for forming an encapsulation material of an LED package having a thin-walled housing.
9 is a view for explaining a transfer molding process of an encapsulating material according to another embodiment of the present invention.
10 illustrates an LED package according to another embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided by way of example so that those skilled in the art can fully understand the spirit of the present invention. Therefore, the present invention is not limited to the embodiments described below, but may be embodied in other forms. In the drawings, the width, length, thickness, and the like of the components may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

FIG. 1 is a perspective view illustrating an LED package according to an embodiment of the present invention, and FIG. 2 is a cross-sectional view illustrating an LED package according to an embodiment of the present invention.

1 and 2, the LED package 1 according to the present embodiment is a base on which the LED chip 2 is mounted. The lead frame 1 includes first and second lead terminals 12 and 14 10). The lead frame 10 is formed by cutting from one large metal sheet patterned to provide the first and second lead terminals 12 and 14 and a plurality of lead frames 10 are obtained from the sheet metal . The cutting of the lead frame 10 is performed after the formation of the housing 20 and the sealing material 30, which will be described below.

The LED chip 2 is attached to the upper surface of the first lead terminal 12 of the lead frame 10 and the LED chip 2 on the first lead terminal 12 is bonded to the upper surface of the first lead terminal 12 by the bonding wire And is electrically connected to the second lead terminal 14.

In addition, the LED package 1 of the present embodiment includes the housing 20 and the sealing material 30. The encapsulant 30 encapsulates the LED chip 2 so as to protect the LED chip 2 and the like while being made of a light transmitting material. The housing 20 can function as a reflector and is formed to have a shape that surrounds the side surface of the sealing material 30 and exposes an upper portion of the sealing material 30. In this embodiment, the housing 20 serves to support the lead frame 10, that is, the first and second lead terminals 12 and 14.

As will be described in detail below, the sealing material 30 and the housing 20 are formed by transfer molding. In this embodiment, the housing 20 is formed by transfer molding using an epoxy molding compound (EMC) so as to support the lead frame 10 before the encapsulation material 30 is formed. At this time, the bottom surface of the housing 20 is substantially flush with the bottom surface of the lead frame 10, so that the first and second lead terminals 12 And 14 are exposed to the outside in the vicinity of the bottom surface of the housing 20 without a bending process.

The housing 20 is made of a transparent dielectric material such as TiO ₂ or SiO 2, ZNO, Y ₂ O (shown in FIG. 2) having a white color, milky white color and / ₃ by a transfer molding method using a mixed material. Accordingly, the housing 20 includes the diffusion agent 21. The transparency of the housing 20 and the directivity angle of the LED package 1 can be adjusted according to the amount of the diffusing agent 21 mixed into the transparent EMC.

3A to 3C are photographs of actual products of the LED package in which the transparency of the housing is changed according to the amount of diffusion agent. LED package shown in Figure 3a, TiO ₂ An LED package comprising a housing formed by a transparent EMC that does not include a diffusing agent at all, the housing being substantially transparent and having a large amount of light emission through the housing, resulting in a relatively wide steering angle. LED package shown in Figure 3b, TiO ₂ An LED package including a housing formed by an EMC mixed with a diffusing agent of 0.3%, wherein the housing is translucent and has a large amount of reflecting light toward the sealing material from the inner side of the housing, Angle is relatively narrow. The LED package shown in FIG. 3C is an LED package including a housing formed by EMC mixed with 3% of TiO ₂ diffusers. The LED package has the lowest transparency and emits light at a narrow light directing angle of approximately 120 degrees suitable for the backlight unit .

1 and 2, the housing 20 has a shape that entirely covers the side surface of the sealing material 30 and permits the upper portion of the sealing material 30 to be exposed. In this embodiment, since the housing 20 supporting the lead frame 10 is formed before the encapsulant 30, the housing 20 includes a cavity defining the position of the encapsulant 30 to be formed next . In the present embodiment, the encapsulant 30 is formed by molding using a light-transmitting resin such as epoxy or silicone, and is formed by molding using a mold, in particular transfer molding, to obtain a desired shape.

The encapsulant 30 has a flat top surface 31 on which light is mainly emitted. Such a planar shape can be achieved by transfer molding, and in the case of the prior art in which a liquid material is injected into the cavity of the housing to form the sealing material, the intended planar shape as described above can not be obtained by the surface tension. The encapsulant 30 may include a phosphor that is excited by light of a specific wavelength and emits light of a different wavelength.

By performing the transfer molding of the sealing material 30, it is possible to form the sealing material 30 in which the upper surface 31 is flat. Further, by transfer molding the encapsulation material 30, it is possible to form, for example, a semi-spherical convex or concave lens shape or various lens-shaped encapsulation encapsulation materials 30 having a Fresnel pattern . At this time, the Fresnel pattern may be a pattern in which roughness exists, and the lens of such a pattern contributes to widening the directivity angle. 4 (a) shows a structure of an LED package 1 according to another embodiment of the present invention in which a lenticular encapsulant 30 having a hemispherical top surface is formed by a transfer molding method.

On the other hand, the base on which the LED chip 2 is mounted may be a base other than the lead frame 10 of the previous embodiment. For example, the LED according to another embodiment of the present invention shown in Fig. 4 (b) The package 1 uses a PCB (Printed Circuit Board) 100 as a base on which the LED chip 2 is mounted. 4 (b), the PCB 100 is provided with an area where the LED chip 2 is mounted at the center thereof, and the first and second LED chips 2 and 3, which are electrically connected to the LED chip 2 by the bonding wire, The second electrode patterns 102 and 103 are formed by plating. As in the previous embodiment, both the encapsulant 30 and the housing 20 are formed by transfer molding.

Although only the transfer molding of the housing 20 and the transfer molding of the next encapsulant 30 have been described above, the encapsulating material 30 may be transferred before the transfer molding and the housing 20 later may be transfer molded Can be considered. Regardless of the order, transfer molding of the housing and the sealing material separately is particularly easy when both the housing and the sealing material are made of a thermosetting resin such as epoxy or silicone, As shown in FIG.

When transfer molding is used, it is possible to make an integrated housing 20 having a structure in which a plurality of partial housings are stacked by transfer molding at least two times at the time of forming the housing. Also, by using the transfer molding, it is possible to make an integrated encapsulant 30 having a structure in which a plurality of partial encapsulating materials are laminated by transfer molding at least twice. The transfer molding performed twice or more as above is defined as a multiple transfer molding.

Various embodiments of the method for manufacturing the LED package described above will now be described.

5 is a plan view illustrating a method of fabricating an LED package according to an embodiment of the present invention.

First, as shown in Fig. 5A, a lead frame 10 composed of first and second lead terminals 12 and 14 is prepared. At this time, the LED chip is mounted on the lead frame 10 and the bonding wire is connected. However, for convenience of illustration, the LED chip and the bonding wire are omitted in the drawing. Further, in a manufacturing process of an actual LED package, the lead frame 10 is a part of a patterned metal thin plate including a large number of lead frames in an uncut state, but for ease of illustration and explanation, one lead frame 10 ) Are shown in a cut state.

Next, as shown in Fig. 5 (b), the lead frame 10 is formed with a housing 20 by transfer molding. The housing 20 exposes the first and second lead terminals 12 and 14 upward through its own cavity. The housing 20 formed on the lead frame 10 supports the lead frame 10. At this time, it is preferable that the molding material used for transfer molding of the housing 20 is a solid EMC obtained by adding a diffusing agent to a transparent transparent EMC material in the form of a tablet. However, a light transmitting resin such as silicon can be used without using epoxy as a main component.

Next, as shown in Fig. 5 (c), the encapsulating material 30 of epoxy or silicon material for encapsulating the LED chip (not shown in Fig. 5) is transferred by transfer molding to the inside of the cavity . The transfer molding of the sealing material 30 uses a solid-state EMC (in particular, a tablet-shaped EMC). Other molding using a mold may be considered, and injection molding using, for example, liquid epoxy or liquid silicone may be used for forming the sealing material. In addition, the shape of the encapsulant 30 molded using the mold is preliminarily determined by a mold designed in advance, and it is preferable that the encapsulant 30 has a flat or lenticular shape. At this time, since the sealing material 30 is formed in the cavity of the housing 20, the housing 20 has a shape that entirely covers the side surface of the sealing material 30.

6 (a) is a view for explaining a transfer molding process of the housing 20, and FIG. 6 (b) is a view for explaining a transfer molding process of the sealing material 30. FIG.

6A, a resin is injected into a mold M1 for forming a housing containing an injection port I under a high-temperature and high-pressure condition, the resin is filled into the mold M1, Thereby forming the housing 20. At this time, the gate 20 (see FIG. 6 (b)) used for transfer molding of the encapsulant 30 to be performed next may be formed in advance in the housing 20. In addition, instead of the gate G, a groove previously formed in the upper end of the cavity of the housing 20 can be used as a resin injection gate.

6B, the resin is injected into the cavity of the housing 20 and the mold M2 through the injection port I of the sealing material mold M2 and the gate G formed in advance in the housing 20, As shown in FIG. At this time, the upper surface of the sealing material is determined by the mold M2, for example, to have a flat shape or a lens shape.

Although the process shown in Figs. 5 and 6 is performed with respect to the lead frame 10, it may be done for other types of bases such as PCB instead of the lead frame 10, The process shown in Figs. 5 and 6 may be followed.

FIG. 7 is a plan view illustrating a method of fabricating an LED package according to another embodiment of the present invention. Referring to FIG.

First, a lead frame 10 composed of first and second lead terminals 12 and 14 as shown in Fig. 7 (a) is prepared. At this time, the LED chip is mounted on the lead frame 10 and the bonding wire is connected. However, for convenience of illustration, the LED chip and the bonding wire are omitted in the drawing. Further, in a manufacturing process of an actual LED package, the lead frame 10 is a part of a patterned metal thin plate including a large number of lead frames in an uncut state, but for ease of illustration and explanation, one lead frame 10 ) Are shown in a cut state.

Next, as shown in Fig. 7 (b), an encapsulating material 30 for encapsulating the LED chip (not shown in Fig. 7) is formed in advance before the housing 20 is formed. The encapsulant 30 is formed to support the lead frame 10 constituted by the first and second lead terminals 12 and 14. The sealing material 30 is formed in a predetermined shape by a mold for transfer molding. The transfer molding of the encapsulant 30 uses a solid-state EMC (in particular, a tablet-shaped EMC), and the solid-state EMC may include a phosphor. Alternatively, injection molding in which a liquid epoxy or liquid silicon is injected into a mold may be used for molding the encapsulant 30. In this case, the liquid epoxy or the liquid silicone may contain a phosphor.

Next, as shown in FIG. 7C, the housing 20 is formed so as to surround the side surface of the sealing material 30, and transfer molding may also be used at this time. The molding material used for transfer molding of the housing 20 may be a solid EMC or a liquid epoxy or silicone which is made into a tabular form in which a diffusing agent is added to a powdery transparent EMC material.

8 is a view for explaining a process of transfer molding by directly injecting resin into a cavity of an inverted housing 20 according to another embodiment of the present invention. The mold M3 blocks the cavity of the housing 20 and the injection port I is directly connected to the cavity of the housing 20 in the mold M3. Such a transfer molding process can be suitably used for forming an encapsulant of a side view type LED package, for example, in which the housing 20 is easily broken because the thickness of the housing 20 is thin.

9 is a view showing a molding method of an encapsulant according to another embodiment of the present invention. Referring to FIG. 9, a cavity 201 in which the LED chip is accommodated is formed in the housing 20, and the cavity 201 is closed by a plate-shaped mold M4 located on the upper side. A groove 202 is formed in a corner of the cavity 201 (more preferably in the vicinity of the vertex of the cavity). The groove 202 is formed in the mold 201 with the cavity 201 closed by the mold M4. M4, and the injection passage of the resin is formed in the cavity 201. [

When the resin is injected through the injection hole G and the groove 202 and the injected resin is cured, the encapsulant 30 is formed in the cavity 201. For example, in the case of using the mold M4 in which the surface of the cavity 201 is flat, the sealing material 30 having the flat upper surface is used as the upper portion of the sealing material 30. [ . If one surface of the mold M4 for blocking the cavity 30 is formed into a spherical shape, a concavo-convex shape (roughness), or any other shape, a spherical lens corresponding to the spherical lens, a concave-convex type Plznel lens, The lens structure may be formed by a structure of a lens. The roughness or roughness of the lens may be regular or irregular.

Although not shown, an upper mold and a lower mold, which house and support the housing or the LED package including the mold and the mold M4 used for the molding together, form a set with the mold M4, Can be used.

10 is a plan view showing an LED package according to another embodiment of the present invention. Referring to FIG. 10, a plurality of recesses 102 are formed on a base 10, which may be a lead frame, a PCB or other substrate, to receive the LED chip 102. Furthermore, another plurality of recesses 103 are formed on the base 10 to accommodate the bonding pads (or wire balls) of the bonding wires. The concave portions 102 and 103 prevent the LED package from becoming slimmer (or compact) by adding the thickness of the LED chip 102 or the bonding pad (or the wire ball). Particularly, the recess 102 in which the LED chip 102 is accommodated may be filled with a resin (preferably a silicone resin) for preventing deterioration and / or containing a phosphor. The concave portions 102 and 103 can contribute to increase the bonding force between the sealing material 30 and the base 10. [ It is conceivable to form a plurality of recesses on the base 10 in contact with the sealing material to increase the bonding force regardless of the positions of the LED chips and the bonding pads.

The present invention is not limited to the above embodiments and can be applied to all kinds of LED packages having an encapsulant and a housing. For example, a top view LED package, a side view type LED A package type, a PCB type or a chip LED package, a lamp type LED package, or a high flux LED package.

Claims (14)

A base including a first lead terminal and a second lead terminal, the first lead terminal and the second lead terminal being spaced apart from each other and including side surfaces facing each other;
An LED chip located on the first lead terminal and electrically connected to the second lead terminal by a wire; And
And a resin for partially sealing and supporting the first and second lead terminals and exposing the LED chip,
Wherein the first lead terminal and the second lead terminal each include a side surface facing each other and another side surface adjacent to the side surface facing each other,
At least one of the first lead terminal and the second lead terminal includes a protrusion protruding from another side adjacent to the mutually facing side,
And at least a part of the protrusion is exposed to the outside of the resin. The method according to claim 1,
Wherein a side face of each of the first and second lead terminals opposite to the opposite side face is exposed to the outside. The method of claim 2,
And the protrusion is connected to the side opposite to the opposite side. The method according to claim 1,
Wherein the first lead terminal and the second lead terminal are flat plate-shaped. The method according to claim 1,
Wherein an area of an upper surface of each of the first lead terminal and a second lead terminal is larger than an area of a lower surface thereof. The method of claim 5,
Wherein the shape of the upper surface is similar to the shape of the lower surface. The method of claim 5,
Wherein the resin is located on at least a part of the first surface of the first lead terminal and the second lead terminal, and the resin is located in a space between the first lead terminal and the second lead terminal. The method according to claim 1,
And the resin is located on a side of the first lead terminal and the second lead terminal. The method according to claim 1,
Wherein each of the first lead terminal and the second lead terminal includes a groove located adjacent to the projection on a side where the projection is located,
And a side surface of the groove is in contact with the resin. The method according to claim 1,
Wherein the resin comprises a diffusing agent that causes the resin to have light reflectivity. The method of claim 10,
Wherein the light diffusing agent is at least one selected from the group consisting of TiO _{2 ,} SiO _{2 ,} ZnO, and Y ₂ O ₃ . The method according to claim 1,
Wherein the resin has a white color. The method according to claim 1,
Further comprising an encapsulant that encapsulates the LED chip and includes a phosphor. 14. The method of claim 13,
Wherein the encapsulation material has a convex upper surface.

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