KR100867568B1

KR100867568B1 - Heat radiation type led package

Info

Publication number: KR100867568B1
Application number: KR20070048827A
Authority: KR
Inventors: 강석진; 김도형; 최혁중
Original assignee: 서울반도체 주식회사
Priority date: 2007-05-18
Filing date: 2007-05-18
Publication date: 2008-11-10

Abstract

A heat radiation type LED package is provided to have improved heat radiation performance by forming a cup at which LED chips are laid by a lead frame and making the cup be exposed to the outside. A first lead frame(12) and a second lead frame(14) are formed at an outer part of a cup at which gap is formed in multistep. A supporting member(20) is formed by molding synthetic resin to cover some portions of the first and second lead frames and not to cover a cup bottom plane formed by recessions(122,142). Therefore, the bottom planes of the recessions, that is to say, the bottom planes of the cup are exposed to the outside. The bottom planes of the cup are placed at the plane which is the same plane of bottom of the supporting member. The first and second lead frames include wings(124,144) which are extend from the recession to the side portion of the supporting member.

Description

Heat dissipation LED package {HEAT RADIATION TYPE LED PACKAGE}

1 is a perspective view from above of a heat dissipating LED package according to an embodiment of the present invention;

2 is a perspective view from below of a heat dissipation LED package according to an embodiment of the present invention;

Figure 3 is a cross-sectional view showing a heat dissipation LED package according to an embodiment of the present invention.

Figure 4 is a perspective view of the first and second lead frame of the heat dissipation LED package shown in Figures 1-3.

12: first lead frame 14: second lead frame

122, 142: depression 123, 143: cup bottom surface

124, 144: wing 20: support member

30: sealing member 32: first sealing member

34: second sealing member 102: fixing hole

2: LED chip 5: base end

6: upper side

The present invention relates to an LED package, and more particularly, to a heat-dissipating LED package having a lead frame having improved heat dissipation performance and having sealing structures in a multi-stage cup having a reliable structure and / or a predetermined lens shape. It is about.

A light emitting diode (LED) is a device in which electrons and holes meet and emit light at a PN junction by applying an electric current, and are generally manufactured in a package structure in which an LED chip is mounted. LED package. The LED package as described above is generally mounted on a printed circuit board (PCB) and configured to emit light by receiving a current from an electrode formed on the printed circuit board.

In the LED package, heat generated from the LED chip directly affects the light emitting performance and lifetime of the LED package. The reason is that heat generated in the LED chip causes dislocations and mismatches in the crystal structure of the LED chip when the LED chip stays in the LED chip for a long time.

Accordingly, in the related art, techniques for promoting the release of heat generated from the LED chip have been proposed. Among them, instead of mounting the LED chip on the lead frame, an LED package in which a heat dissipating slug made of a metal material having excellent thermal conductivity is inserted into the package body and the LED chip is mounted on the heat dissipating slug.

However, the conventional LED package has a relatively large volume compared to the heat dissipation area where the heat dissipation slug is exposed to the outside, so that its use is limited unless it is an expensive thermal conductive material, and many processes for installing the heat dissipation slug are also required. There is a problem that is followed by difficulty. In addition, the above heat dissipation slugs can be a cause of deterioration of the compactness of the LED package.

In addition, the conventional LED package is a material of the package body for supporting the lead frame and the heat-dissipating slug, usually a synthetic resin such as PPA, which has a problem that the synthetic resin is discolored by the light energy of the LED chip.

Accordingly, the present applicant has developed an LED package having improved heat dissipation performance by forming a cup on which an LED chip is placed by lead frames and exposing the cup to the outside. It is possible to sequentially form different sealing members made of resin in the cup of the developed LED package, and the applicant has found that it is difficult to design and form each of the sealing members in a desired shape and / or a reliable structure.

Therefore, the technical problem to be achieved by the present invention is to form a cup on which the LED chip is placed by the lead frames and the cup is exposed to the outside has improved heat dissipation performance, the sealing member in the cup is reliable structure and / or predetermined It is to provide a heat dissipation LED package that can have a lens shape.

In order to achieve the above technical problem, the heat-dissipating LED package according to an embodiment of the present invention, at least one LED chip; Lead frames forming a cup including a base end on which the LED chip is placed and at least one upper end thereon; And a support member supporting the lead frames such that the bottom surface of the cup is exposed to the outside.

According to a preferred embodiment of the present invention, the leadframes are composed of first and second leadframes having recesses adjacent to each other, and the cups are formed by the recesses. A plurality of sealing members are sequentially formed at the base end of the cup and the at least one upper end. The cup is composed of a base end on which the first encapsulation member is formed and one upper end on which the second encapsulation member is formed, or a base end on which the first encapsulation member is formed, and second and third encapsulation members are sequentially formed thereon. It consists of first and second upper ends. The at least one upper end includes an inclined surface. The first and second leadframes have wings extending from the recesses to the outside of the support member. The support member is formed by molding a resin so as to cover part of the first and second lead frames to avoid the cup bottom surface. Fixing holes may be formed in the first and second lead frames to fill resin forming the supporting member. In addition, it is preferable that rough surfaces are formed on the first and second lead frames to avoid the LED chip.

The cup bottom surfaces of the depressions can be electrical contacts, most preferably the cup bottom surfaces of the depressions are electrical contacts and the wings are heat dissipating. At this time, the cup bottom surface of the depression that serves as the electrical contact portion is also exposed to the outside, of course, the addition of heat radiation. Alternatively, the cup bottom surface of the depressions may be a heat dissipation portion and the vanes may be electrical contact portions.

In addition, the bottom surface of the cup and the bottom surface of the support member of the recesses are preferably located on the same plane.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The following embodiments are provided as examples to ensure that the spirit of the present invention can be fully conveyed to those skilled in the art. Accordingly, the present invention is not limited to the embodiments described below and may be embodied in other forms. And, in the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. Like numbers refer to like elements throughout.

1 is a perspective view from above of a heat dissipation LED package according to an embodiment of the present invention, Figure 2 is a perspective perspective view from below of the heat dissipation LED package shown in Figure 1, Figure 3 is Figures 1 and 2 4 is a cross-sectional view illustrating a heat dissipation type LED package, and FIG. 4 is a perspective view illustrating first and second lead frames of the heat dissipation type LED package of FIGS. 1 to 3.

As shown in the figure, the heat dissipating LED package 1 of the present embodiment includes at least one LED chip 2, lead frames 12 and 14 for applying a current to the LED chip 2, and the lead. A member 20 (hereinafter referred to as a 'support member') for supporting the frames 12 and 14, and light-transmitting sealing members 30 formed to protect the LED chip 2 are included.

The lead frames 12 and 14 include one cup including a base end 5 on which the LED chip 2 is located and an upper end 6 positioned on the base end 5. Here, the one cup has a base end 5 on which the first encapsulation member 32 covering the LED chip 2 is formed, and one upper end on which the second encapsulation member 34 is formed. 6) or the first and second upper ends of the base end 5 and the second encapsulation member 34 and the third encapsulation member (not shown) are formed in this order. The depth of the stage 5 and the upper side 6 may be thin or deep depending on the light pattern. As such, the one cup may be formed in multiple stages. Accordingly, the multi-molding structure can be reliably implemented by forming the sealing members by the cups formed in multiple stages.

The first and second lead frames 12 and 14 each have a substantially plate shape while being made of a metal material. The first and second lead frames 12 and 14 are spaced apart from each other while being supported by the support member 20. The recessed parts 122 and 142 mount the LED chip 2 therein.

As shown, the first leadframe 12 and the second leadframe 14 have a cup outer portion, in particular, the edges of the first and second leadframes 12, 14 having a multi-stage gap therebetween. It is formed to be relatively large in the vicinity, which contributes to improving the support strength and durability of the support member 20 for supporting the first and second lead frames 12 and 14.

The support member 20 is formed by molding a synthetic resin so as to cover a part of the first and second lead frames 12 and 14, avoiding the cup bottom surface formed by the recesses 122 and 142. Accordingly, the bottom surfaces of the depressions 122 and 142, that is, the cup bottom surfaces 123 and 143, are exposed to the outside, which is illustrated in FIGS. 2 and 3. The cup bar bottom surfaces 123 and 143 may be positioned on substantially the same plane as the bottom surface of the support member 20. In this case, the cup bottom surfaces 123 and 143 may be, for example, external. It may be an electrical contact portion connected to two electrode patterns formed on a printed circuit board (not shown). In addition, since the cup bottom surfaces 123 and 143 are exposed to the outside in a thin thickness and a large area, the cup bottom surfaces 123 and 143 may greatly contribute to dissipating heat of the LED chip 2 to the outside.

In addition, the first and second lead frames 12 and 14 include wings 124 and 144 extending from the recesses 122 and 142 to the outside of the side surface of the support member 20. The wings 124 and 144 form a heat dissipation portion that emits heat from the LED chip 2 to the outside air, and in particular, each of the wings 124 and 144 is exposed to the outside air in the shape of a wide plate. The heat generated in the LED chip 2 can be effectively released into the outside air by convection. In this case, the wing parts 124 and 144 may be used as electrical contact parts, and in this case, the cup bottom surfaces 123 and 143 may perform only a heat dissipation function.

According to the exemplary embodiment of the present invention, the recess 122 of the first lead frame 12 is attached to the LED chip 2 and is electrically connected to the first lead frame 12. In addition, the recess 142 of the LED chip 2 and the second lead frame 14 are electrically connected to each other by conductive wires. In addition, the inner surface of the depressions 122 and 142, that is, the inner surface of the upper end 6 of the cup, is an inclined surface that reflects some of the light emitted from the LED chip 2 upward.

Furthermore, the first and second leadframes 12, 14 include a rough surface R, as is well illustrated in the enlarged view of FIG. 3. The rough surface R is, for example, a surface formed by a surface treatment process such as sand blasting, and scatters light in the recesses 122 and 142 to contribute to widening the directing angle of the light and increasing the efficiency of the light. In the outer portion of the depressions 122 and 142 covered by the support member 20, the adhesion of the first and second lead frames 12 and 14 to the resin constituting the support member 20. You can increase it. In addition, the rough surface (R) is to increase the adhesive strength with the resin forming the sealing member by a sand blasting treatment inside the cup except the area in which the LED chip 2 and the wire is bonded in one cup formed in multiple stages. Can be. At this time, the rough surface (R) may be formed by other processes or processes other than the above-described sand blasting process, and the shape of the mounting surface (R) is not limited by the illustrated drawings and may be formed in various patterns. Can be.

In addition, as shown in FIG. 4, a plurality of fixing holes 102 are formed in the upper and lower through-out sides of the recesses 122 and 142 of the first and second lead frames 12 and 14. . The plurality of fixing holes 102 define a space in which the liquid resin is filled and cured when molding the support member 20 with a liquid resin.

Accordingly, a portion of the support member 20 may penetrate up and down through the fixing hole 102, whereby the first and second lead frames 12 and 14 may support the support member 20. It can be supported more firmly by.

1 and 3, encapsulation members 30 made of a light-transmissive resin are formed in a base end 5 and an upper end 6 positioned thereon in a cup formed by the recesses 122 and 142. It is formed in this order. Accordingly, the lens phenomenon can be formed more effectively.

According to the exemplary embodiment of the present invention, the encapsulation members 30 may include a first encapsulation member 32 mainly composed of a silicone resin formed at the base end 5 of the cup, and an upper end 6 of the cup. And a second encapsulation member 34 mainly composed of an epoxy resin or a hard silicone resin. At this time, it is preferable that any one of the first sealing member 32 and the second sealing member 34 includes a phosphor. In addition, the silicone resin forming the first encapsulation member 32 may ensure the reliability of the LED package under high temperature, high humidity conditions and thermal shock conditions. The second encapsulation member 34 preferably has a convex lens shape, but this does not limit the present invention.

In addition, between the first encapsulation member 32 and the second encapsulation member 34, a resin having an intermediate property between the epoxy resin and the silicone resin may be used to prevent interfacial peeling caused by the difference in physical properties between the epoxy resin and the silicone resin. It is desirable to spray or apply thinly.

In the embodiment of the present invention, the encapsulation members 30 are formed by dividing the first encapsulation member 32 and the second encapsulation member 34, but the base end 5 on the cup and the first and second portions thereon. When the upper end (not shown) is formed, it is divided into a first sealing member 32, a second sealing member 34 and a third sealing member (not shown).

In addition, the LED package 1 according to the present embodiment includes a means for preventing the liquid resin from flowing out when the liquid resin is filled in the cup to form the encapsulation member 30. The means consists of a dam portion 22 formed at an upper end of the support member 20 to form a step with the upper ends of the recesses 122 and 142. Here, in order to improve the light efficiency, it is preferable that the stage of the dam part 22 be manufactured to a minimum thickness such that the reliability is not affected. More preferably, when the multi-molding can be performed in the cup itself formed in multiple stages, the stage of the dam part 22 can be removed.

The resin constituting the support member 20 does not exist on the inner surface of the cup defined by the first and second lead frames 12 and 14, but at the expense of the effect obtained by the absence of the resin. If it is desired to improve the specific performance of the LED package, it may also be considered to have a portion of the support member made of resin present on the inner surface of the cup.

According to an embodiment of the present invention, by forming the sealing members in one cup forming a base end and at least one upper end positioned on the base end, it is possible to reliably implement the multi-molding structure, thereby making the shape of the sealing members constant Can be formed, and the effect of increasing the light efficiency can be obtained.

In addition, the heat dissipation LED package according to the present invention can improve the heat dissipation characteristics of the LED package by greatly increasing the area where the LED chip is exposed to the outside of the first and second lead frame, thereby preventing the degradation of the LED package performance It can improve the life of LED package.

In addition, the heat dissipation type LED package according to the present invention has an advantage of having sufficient heat dissipation performance even without structurally and economically inefficient installation of heat dissipation slugs.

And, in the heat-dissipating LED package of the present invention, unlike a cup in which an LED chip is mounted on a conventional package body, a cup is formed in the first and second lead frames, and a cup in which the LED chip is mounted on a package body is formed. There is an effect that solves the problems, such as a decrease in light efficiency or discoloration of the package body caused when.

Claims

At least one LED chip;

Lead frames forming a cup including a base end on which the LED chip is placed and at least one upper end thereon; And

And a support member supporting the lead frames such that the bottom surface of the cup is exposed to the outside.

The method according to claim 1,

The lead frames are made of a first lead and a second lead frame each having a recess adjacent to each other, the heat dissipation LED package, characterized in that the cup is formed by the recesses.

The method according to claim 1,

The heat dissipation LED package further comprises a plurality of sealing members are formed in the base end of the cup and the at least one upper end in order.

The method according to claim 1,

The cup is a heat-dissipating LED package, characterized in that consisting of a base end formed with a first sealing member and one upper end formed with a second sealing member thereon.

The method according to claim 1,

The cup is a heat-dissipating LED package, characterized in that consisting of the base end is formed with the first sealing member and the first and second upper end is formed on the second and third sealing member in turn.

The method according to claim 1,

The at least one upper end is a heat dissipation LED package, characterized in that it comprises an inclined surface.

The method according to claim 2,

The first and the second lead frame has a heat dissipation LED package, characterized in that the wing portions extending from the respective recessed portion to the outside of the support member.

The method according to claim 1,

The support member is a heat-dissipating LED package, characterized in that formed by molding a resin to cover a portion of the first and second lead frame to avoid the bottom surface of the cup.

The method according to claim 8,

The first and second lead frame is a heat dissipation LED package, characterized in that the fixing hole is filled with the resin forming the support member.

The method according to claim 2,

The heat dissipation LED package further comprises a rough surface formed on the first and second lead frames to avoid the LED chip.

The method according to claim 2,

The heat dissipation LED package, characterized in that the cup bottom surface of the depressions are electrical contacts.

The method according to claim 7,

The heat sink type LED package, characterized in that the cup bottom surface of the recessed portion is an electrical contact portion and the wings are heat radiating portion.

The method according to claim 7,

The heat sink type LED package, characterized in that the cup bottom surface of the recessed portion is a heat dissipation portion and the wings are electrical contact portion.

The method according to claim 2,

The bottom surface of the cup and the bottom surface of the support member of the recessed portion is characterized in that located on the same plane.