KR100928635B1 - Side Light Emitting Diode Package - Google Patents

Abstract

In order to minimize the loss of light by making the center of light irradiated from the package coincide with the center of the side of the light guide plate, the semiconductor chip, the die pad to which the semiconductor chip is die-bonded, and the die pad are spaced apart and electrically A lead frame including a lead pad connected to the lead pad and an electrode lead extending from the die pad and the lead pad, the reflector being molded on the lead frame to form an outline and formed around the semiconductor chip, the bottom of the mold It provides a side light emitting diode package including a support for protruding in the mounting surface to increase the center of the reflector from the mounting surface on which the electrode lead is mounted.

Mold, Reflector, Base, Heat Sink, Slope

Description

Side light emitting diode package {SIDE VIEW LED PACKAGE}

The present invention relates to a light emitting diode. More particularly, the present invention relates to a side light emitting diode package capable of improving light reflection efficiency and improving heat dissipation effect.

In general, a light emitting diode (LED) is a device using characteristics of a compound semiconductor, and is a semiconductor that generates infrared light or various colors when a current is applied. The light emitting diode is manufactured in various types of packages by mounting a chip on a lead frame and molding the chip into a desired shape.

Side-emitting light emitting diode packages are used for small display backlight modules used in electronic communication devices such as mobile phones and PDAs. The light emitting diode package having the side light emitting structure has a structure of providing light from the side of the light guide plate, and has an advantage of reducing the thickness of the backlight module as compared with the front light emitting structure.

Since the light emitting diodes do not generate 100% light current, they generate considerable heat during operation. In particular, since a high output light emitting diode generates a great amount of heat, it must be able to dissipate heat generated more quickly and efficiently.

The side light emitting diode package emits light toward the side of the light guide plate. In this process, the loss of light emitted to the light guide plate should be minimized. In addition, as the demand for electronic communication devices such as mobile phones and PDAs has increased in recent years, the thickness of devices has gradually decreased and the thickness of small displays mounted in the devices has been reduced. Therefore, the development of a side light emitting diode package capable of minimizing thickness and having a stable mounting structure and improving total reflection efficiency of light is in need.

Therefore, the center of the light emitted from the package to match the center of the side of the light guide plate to provide a side light emitting diode package that can minimize the loss of light. In addition, it provides a side light emitting diode package that can maximize the luminous efficiency.

In addition, it provides a side light emitting diode package that can be mounted on a substrate more stably.

In addition, it provides a side light emitting diode package that can maximize the heat dissipation effect by allowing the heat generated from the chip to dissipate heat to the outside more quickly.

To this end, the package includes a semiconductor chip, a die pad to which the semiconductor chip is die bonded, a lead pad spaced apart from the die pad, and an electrode lead extending from the die pad and the lead pad, respectively. A lead frame, a mold including a reflector molded to the lead frame to form an outer shape and formed around the semiconductor chip, and protruding to a lower end of the mold to support a center of the reflector from a mounting surface on which an electrode lead is mounted. It may include wealth.

Here, the support may be formed at the lower end of the reflector. The reflector is asymmetrical compared with the thickness of the upper end of the thickness of the bottom portion is increased by the thickness of the base.

As a result, the center height of the reflector is increased by the height of the supporting portion from the substrate so that the center of the reflector coincides with the side center of the light guide plate. Therefore, the light reflected through the reflector from the semiconductor chip is irradiated to the side center of the light guide plate to minimize the light loss.

The base may have a flat bottom surface. Accordingly, when the package is in close contact with the substrate, the flat bottom surface of the support portion is in contact with the substrate, thereby easily securing the flatness of the package.

In addition, the package may further include a heat dissipation pad connected to the die pad of the lead frame to extend outside the mold.

The heat dissipation pad may be integrally formed with the die pad.

Therefore, the heat generated from the chip can be transferred to the heat transfer medium directly passing through the outside of the package through the heat dissipation pad connected to the die pad, thereby maximizing the heat dissipation effect by increasing the heat dissipation area through the heat dissipation pad.

The heat dissipation pad may be grounded to a printed circuit board (PCB) to radiate heat. In addition, the heat radiating pad may be grounded with a separate heat radiating element to radiate heat.

The heat dissipation pad may be installed between the two electrode leads. In addition, the two electrode leads may be bent toward the front side of the mold and the heat radiation pad may be bent toward the rear side. Accordingly, two electrode leads and the heat dissipation pad form three support points to prevent the package from being twisted.

In addition, the present package may have a structure in which both inner surfaces of the reflector form an inclined surface at an angle of 20 ° to 45 ° outward with respect to the front direction.

Thus, even if the thickness of the package is reduced, the front light emitting effect can be maximized through the inclined surfaces on both sides of the reflector.

According to this package, it is possible to irradiate light to the center of the incident surface of the light guide plate to minimize the loss of light, it is possible to increase the light reflection efficiency to increase the luminous efficiency. As a result, the manufacturing cost can be extremely reduced by realizing sufficient optical brightness with relatively low power consumption.

In addition, it is possible to maximize the heat dissipation effect by shortening the heat dissipation path of the semiconductor chip and increasing the heat dissipation area.

In addition, it improves the adhesion and flatness with the bottom surface when the package is mounted, it is possible to mount more stable through the three support points.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. As those skilled in the art would realize, the described embodiments may be modified in various different ways, all without departing from the spirit or scope of the present invention.

It is noted that the figures are schematic and not drawn to scale. The relative dimensions and ratios of the parts in the figures have been exaggerated or reduced in size for clarity and convenience in the figures and any dimensions are merely exemplary and not limiting. And the same structure, element or part that appears in more than one figure the same reference numerals are used in different embodiments to indicate corresponding or similar features.

1 is a perspective view of a side light emitting diode package according to the present embodiment.

Here, the X-axis direction of FIG. 1 is a light emitting surface from which light is emitted from the semiconductor chip and is a surface that is substantially coupled to the light guide plate side of the display, and a direction opposite to the Z-axis is a surface that is coupled onto the substrate. In the following description, for convenience of description, the Z-axis direction will be described as the upper surface, the opposite direction to the lower surface, the Y-axis direction to the side, and the X-axis direction to the front.

According to the above drawings, the side light emitting diode package 100 according to the present embodiment includes a lead frame 10, a semiconductor chip 20, a mold 30 forming an external shape, and a support protruding from a lower surface of the mold 30. It includes a portion 40 and the heat dissipation pad 50 extending to the outside of the mold 30.

The lead frame 10 is connected to the die pad 11 to which the semiconductor chip 20 is die-bonded, spaced apart from the die pad 11, and connected to the semiconductor chip 20 by a wire 14 to be electrically energized. The lead pad 12, the one side die pad 11 and the lead pad 12 are formed integrally with each other and extend outside the mold 30 to include an electrode lead 13 for applying a current.

The semiconductor chip 20 is a device that emits light and is die-bonded to the die pad 11 through a die adhesive and electrically connected to the lead pad 12 through a gold wire 14. . The mold 30 is molded to the lead frame 10 to form a body. The reflector 31 is formed around the semiconductor chip 20 to reflect light emitted from the semiconductor chip 20 to improve light emission efficiency. To maximize. That is, the mold 30 is a rectangular structure formed by injection or transfer molding of resin on the lead frame 10. In addition, a reflector 31 protrudes from the top, bottom, left, and right sides of the mold in which the semiconductor chip 20 is located so that a center thereof is grooved to form a groove. Filler 32 is filled in reflector 31. The filler 32 is filled in the reflector to protect the lead frame 10 and the semiconductor chip 20 from moisture and the like, and the material thereof is not particularly limited.

Here, the base portion 40 having a predetermined thickness protrudes from the bottom surface of the mold 30 to increase the center height of the reflector from the substrate on which the package is mounted. The support portion 40 has a flat bottomed structure, and when the package is mounted on the substrate, the flatness of the package can be more easily secured.

As shown in FIG. 2, the supporting part 40 according to the present exemplary embodiment is positioned at the center of the lower surface of the mold, that is, between the electrode leads 13. Substantially, the support 40 is formed on the lower surface of the reflector 31 formed on the front surface of the mold. The thickness of the support 40 is to correspond to the thickness of the electrode lead (13). The electrode lead 13 and the support portion 40 that are bent to be in close contact with the bottom surface of the mold 30 may be placed on the same plane at the same height.

Thus, by forming the support portion 40 having a predetermined thickness on the lower surface of the mold 30, the present package can substantially increase the center height of the reflector with respect to the substrate while forming the same thickness of the upper and lower surfaces of the reflector 31. . Therefore, the center of the reflector and the side center of the light guide plate coincide with each other, and this operation will be described later.

On the other hand, the heat radiation pad 50 is integrally formed on the die pad 11 and exposed to the outside of the mold 30.

As shown in FIG. 3, the heat dissipation pad 50 is exposed toward the center of the mold 30 and is bent toward the rear surface of the mold 30. Therefore, the supporting part 40 is located on the front surface of the mold, and the heat dissipation pad is located on the rear surface of the mold.

As described above, since the heat radiating pad 50 connected to the die pad 11 is exposed to the outside of the mold 30, heat generated from the semiconductor chip 20 may be radiated more quickly through the heat radiating pads 50. It becomes possible. Such a structure can provide more heat dissipation area than the conventional structure in which heat dissipation is provided only by electrode leads, and thus heat transfer can be performed quickly.

The thickness of the heat dissipation pad 50 corresponds to the thickness of the base 40. Accordingly, as shown in FIG. 4, the heat radiation pad 50 and the support portion 40 that are bent at the bottom surface of the mold may have the same height and be placed on the same plane.

In this case, the heat radiating pad 50 is bent toward the rear surface of the mold 30 to serve as three supports for stably supporting the package together with the two electrode leads 13 bent toward the front surface of the mold.

Accordingly, the package can be mounted on the substrate more flatly and without distortion by the base 40 having a flat bottom surface, the heat dissipation pad 50 and the electrode lead 13 serving as a three-point support. .

Meanwhile, the package 100 has a structure in which inclined surfaces 33 are formed on both side surfaces of the reflector 31 so as to maximize the reflection efficiency of light emitted from the semiconductor chip 20. The inclined surface has a structure inclined outward at an angle of 20 ° to 45 ° based on a direction perpendicular to the front surface of the reflector (X-axis direction).

When the angle of the inclined surface 33 is smaller than 20 °, the moldability is excellent at the time of injection of the package, but there is a disadvantage in that light scattering occurs and the light emission angle is reduced. When the angle of the inclined surface 33 is greater than 45 °, the formability of the package becomes difficult, and the luminous intensity is lowered due to the light spreading to the left and right sides than the light reflection.

Accordingly, even if the thickness of the package is reduced by the inclined surface structure at an appropriate angle as described above, the light loss reflected to the front surface can be minimized. When the thickness of the package 100 is reduced, the angle between the upper and lower surfaces of the reflector becomes very small. However, by forming the inclined surface 33 having the angle on both sides of the reflector 31 as described above it is possible to maximize the front light emitting effect.

Hereinafter, the manufacturing process of the LED package will be described.

The plurality of pads 11 and the lead parts 12 constituting the lead frame 10 are alternately arranged to form a group, and the mold 30 and light integration for supporting the lead frame 10 are integrated. Reflector 31, which is a reflective structure for forming, is formed through injection molding or transfer molding. At this time, the reflector is formed to form an inclined surface of the angle of 20 ° ~ 45 ° on both inner surfaces, the support portion 40 of a predetermined thickness is formed on the lower surface of the reflector. The electrode lead 13 and the heat dissipation pad 50 protrude to the rear surface of the mold 30 through the above process.

Then, dotting a heat radiation adhesive to each pad portion 11 of the lead frame 10 and attaching the light emitting semiconductor chip 20 to the heat radiation adhesive by a die bonding process, the semiconductor with a gold wire 14 Through the process of connecting the chip 20 and the lead frame 10.

After the electrode bonding process by the gold wire 14, the mold 30 is seated in the mold and the filler 32 is filled between the reflectors 31.

When the above process is completed, each of the arrayed package 100 is trimmed and individualized, and the electrode lead 13 and the heat dissipation pad 40 are bent through a forming process to the side and the rear of the mold 30. Close contact

The forming process may be performed immediately after the mold 30 is formed and is not particularly limited in the manufacturing order.

Through the above process, the supporting part 40 is formed to protrude on the rear surface of the mold 30, and the heat dissipation pad 50 is exposed, thereby manufacturing the side light emitting diode package 100.

On the other hand, Figure 5 is a schematic diagram showing a state of use of the side light emitting diode package of the above structure.

As shown in FIG. 5, the package is mounted on the substrate 80 of the backlight unit to irradiate light toward the side of the light guide plate 70. Reflecting sheets 71 and 72 are attached to upper and lower surfaces of the light guide plate 70. The light guide plate is raised above a predetermined height with respect to the substrate by the thickness of the reflective sheet 72 on the lower surface of the reflective sheet.

When the package 100 is mounted on the substrate 80, the support 40 formed on the bottom surface of the mold is in contact with the substrate 80. The center of the reflector 31 formed on the front of the mold is moved upward by the thickness of the support portion 40. Accordingly, the center of the reflector 31 of the mold coincides with the center of the side of the light guide plate 70 lifted by the reflective sheet 72 on the bottom surface. The light emitted from the reflector 31 is irradiated to the center of the side surface, which is the incident surface of the light guide plate 70 to minimize the light loss.

In addition, the support part 40 is made of a flat surface in the process of mounting the package 100 on the substrate 80, the support portion 40 is placed on the substrate 80, the horizontal of the package 100 The natural fit allows the package to be installed flat with the light guide plate without misalignment.

The heat dissipation pad 50 exposed to the bottom surface of the mold 30 is grounded on a substrate to transfer heat to the substrate.

Therefore, the heat generated in the semiconductor chip 20 is transferred directly to the substrate 80 through the heat dissipation pad 50 connected to the die pad 11 to be heat treated through a faster path and through a wider heat dissipation surface. It becomes possible.

While the exemplary embodiments of the invention have been illustrated and described as described above, various modifications and other embodiments may be made by those skilled in the art. Such modifications and other embodiments are all considered and included in the appended claims, without departing from the true spirit and scope of the invention.

1 is a perspective view of a side light emitting diode package according to an embodiment of the present invention.

2 is a front view of a side light emitting diode package according to an embodiment of the present invention.

3 is a rear view of a side light emitting diode package according to an embodiment of the present invention.

4 is a side cross-sectional view of a side light emitting diode package according to an embodiment of the present invention.

5 is a schematic diagram illustrating a state of use of a side light emitting diode package according to an exemplary embodiment of the present invention.

Explanation of symbols on the main parts of the drawings

10: lead frame 11: die pad

12: lead pad 13: electrode lead

14: wire 20: semiconductor chip

30 mold 31 reflector

32: filler 33: inclined surface

40: base 50: heat dissipation pad

Claims (8)

A semiconductor chip that emits light, A lead frame including a die pad to which the semiconductor chip is die-bonded, a lead pad spaced from the die pad and electrically connected to the semiconductor chip, and an electrode lead extending from the die pad and the lead pad, respectively; A mold including a reflector molded in the lead frame to form an outline and formed around the semiconductor chip; Protruding portion formed at the lower end of the mold to raise the center of the reflector from the mounting surface on which the electrode lead is mounted, a support for matching the center between the upper and lower ends of the reflector and the side center of the light guide plate Side light emitting diode package comprising a. The method of claim 1, The support part is a side light emitting diode package formed on the bottom of the reflector. The method of claim 1, The base portion is a side surface light emitting diode package having a flat surface. The method of claim 1, And a heat dissipation pad connected to the die pad of the lead frame and extending outside the mold. The method of claim 4, wherein The heat dissipation pad is a side light emitting diode package formed integrally with the die pad. The method of claim 4, wherein The heat radiation pad is a side light emitting diode package corresponding to the thickness of the base. The method of claim 4, wherein The heat dissipation pad is installed between the two electrode leads, the two electrode leads are bent toward the front side of the mold, the heat dissipation pad is bent toward the rear side to support the three point light emitting diode package. The method according to claim 1 or 4, The reflector is a side light emitting diode package of which both inner surfaces are inclined at an angle of 20 ° to 45 ° outward with respect to the front direction.

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