KR101380386B1 - Light emitting diode package with high reliability - Google Patents

Abstract

A light emitting diode package having high reliability is disclosed. The lead frame includes a chip mounting region, first, second and third leads, and first and second connectors connecting the chip mounting region and the first and second leads, respectively. Meanwhile, a light emitting diode chip is mounted on the chip mounting area and electrically connected to the first and third leads. In addition, a package body surrounds portions of the first, second and third leads, and the first, second and third leads extend out of the package body. The lead frame may include a third connecting portion connecting the first and second connecting portions, and may reduce thermal shock applied to the LED chip by heat introduced through the leads by the third connecting portion. In addition, at least one of the leads may have a through hole for reducing an inflow passage of moisture introduced into the package.

LED package, lead frame, lead

Description

LIGHT EMITTING DIODE PACKAGE WITH HIGH RELIABILITY

The present invention relates to a light emitting diode package, and more particularly, to a light emitting diode package having improved reliability as a light emitting diode package employing a lead frame.

Light emitting diodes are widely used for display lamps, display boards, and displays because they can be realized in color, and they are also used for general illumination because white light can be realized. These light emitting diodes are highly efficient, have a long life span, and are environmentally friendly, and the field of using them is continuously increasing.

On the other hand, inorganic light emitting diodes such as gallium nitride, gallium arsenide, gallium phosphide, etc. are generally manufactured in the form of a chip, and assembled together with a lead frame and a package body to produce various types of light emitting diode packages.

1 is a perspective view illustrating a conventional high flux light emitting diode (LED) lamp, which is a type of light emitting diode package using a lead frame, and FIG. 2 is a plan view illustrating a lead frame used in the LED lamp.

1 and 2, the high flux LED lamp includes a lead frame 10, a light emitting diode chip 20, and a package body 30.

The lead frame 10 includes first and second leads 11a and 11b and third and fourth leads 13a and 13b and a hole cup 15a in the chip mounting region 15. The chip mounting region 15 is connected to the first and second leads 11a and 11b through the first and second connectors 17a and 17b, respectively. Meanwhile, the third and fourth leads are electrically insulated from the chip mounting region, and are connected to each other through the connecting portion 19.

The light emitting diode chip 20 is mounted in the hole cup 15a, and a bonding wire 25 connects the light emitting diode chip 20 and the connecting portion 19 to connect the light emitting diode chip 20 to the third and fourth portions. It is electrically connected to the leads 13a and 13b. In addition, the LED chip 20 is mounted in the hole cup 15a through a conductive adhesive such as silver epoxy and electrically connected to the first and second leads 11a and 11b.

The package body 30 formed of a transparent molding resin encapsulates the leads 11a, 11b, 13a, and 13b and the light emitting diode chip 20. A portion of the package body 30 positioned on the light emitting diode chip 20 may be formed in a lens shape. The package body 30 also surrounds portions of the leads, which extend out of the package body 30. Leads extending out of the package body 30 may be bent as shown in FIG. 1 for surface mounting, but are not limited thereto, and may be used in a pin shape without being bent.

The high flux LED lamp is used in other electronic components such as a printed circuit board. To this end, the first to fourth leads 11a, 11b, 13a, and 13b are attached to other electronic components using a soldering process. The soldering process is performed at a relatively high temperature of about 250 ° C., through which the heat is transferred to the chip mounting region 15. Therefore, the LED chip 20 mounted in the chip mounting region 15 may be damaged by the heat applied during the soldering process. The damage caused by heat is particularly likely to be caused by heat introduced through the first lead 11a and the second lead 11b. Also, as the temperature difference between the first lead and the second lead increases, heat is transferred through the chip mounting region. It flows quickly and is easy to damage the LED chip.

On the other hand, moisture is easily introduced into the package body 30 through the interfaces formed between the package body 30 and the leads. Moisture introduced into the package body deteriorates the LED chip 20 and lowers the reflectance of the hole cup 15a to reduce the light emitting efficiency of the package. This reduces the reliability of the LED package.

An object of the present invention is to provide a light emitting diode package having high reliability that is resistant to heat and / or moisture.

Another object of the present invention is to provide a light emitting diode package that can prevent or alleviate damage to a light emitting diode chip by heat applied to mount the package to other electronic components.

In order to solve the above problems, the present invention improves the structure of the lead frame to provide a light emitting diode package having high reliability that is resistant to heat and / or moisture.

A light emitting diode package according to an aspect of the present invention includes a lead frame. The lead frame may include a chip mounting region, first, second and third leads, first and second connecting portions connecting the chip mounting region and the first and second leads, respectively, and the first and second leads. And a third connection part connecting the second leads. A light emitting diode chip is mounted on the chip mounting area and electrically connected to the first and third leads. In addition, a package body surrounds portions of the first, second and third leads. Meanwhile, the first, second and third leads extend outside the package body.

According to one aspect of the invention, the first and second leads are connected by a third connection. Therefore, in the process of soldering or the like, heat traveling to the chip mounting region through the first and second leads, respectively, is balanced by the third connection part, and thus, between the first and second leads near the chip mounting region. The temperature difference may be reduced, and as a result, the thermal shock that may be applied to the LED chip may be alleviated. The third connector may connect the points of the first and second leads spaced apart by the same distance from the chip mounting area.

The lead frame may further include a serif extending from at least one of the first and second connectors. The serif mitigates thermal shock that may be applied to the light emitting diode chip by converting heat traveling to the chip mounting region through the lead to the other direction.

Also, at least one of the first and second connections may have a groove across it. The grooves reduce heat propagation paths to mitigate thermal shocks that may be exerted on the light emitting diode chip.

On the other hand, the lead frame may further include a fourth connector for connecting the end of the fourth li and the third lead and the fourth lead. The fourth connector provides an area in which the bonding wire can be bonded.

In addition, the lead frame may further include a fifth connector connecting the third lead and the fourth lead. The fifth connector helps to balance heat introduced through the third lead and the fourth lead. The fifth connector may connect points of the third and fourth leads spaced apart by the same distance from the fourth connector.

A light emitting diode package according to another aspect of the present invention includes a lead frame. The lead frame includes a chip mounting region, first, second and third leads, and first and second connectors connecting the chip mounting region and the first and second leads, respectively. A light emitting diode chip is mounted on the chip mounting area and electrically connected to the first and third leads. In addition, a package body surrounds portions of the first, second and third leads, and the first, second and third leads extend out of the package body. In addition, at least one of the first, second and third leads has a through hole extending from the inside of the package body to the outside.

The through hole located inside the package body is filled by the package body. Accordingly, the interface area between the lead and the package body in which the through hole is formed is reduced, thereby reducing the path through which moisture can penetrate.

According to embodiments of the present invention, when mounting a package to another electronic component by soldering or the like, it is possible to prevent or alleviate damage to the LED chip due to heat introduced through the leads, and a path through which moisture can penetrate. Can be reduced to improve the moisture resistance of the package.

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. And, in the drawings, the width, length, thickness, etc. of the components may be exaggerated for convenience. Like reference numerals designate like elements throughout the specification.

3 is a perspective view illustrating a high flux light emitting diode lamp according to an exemplary embodiment of the present invention, and FIG. 4 is a plan view illustrating the lead frame of FIG. 3.

3 and 4, the LED lamp includes a lead frame 50, a LED chip 60, and a package body 70.

The lead frame 50 may include first and second leads 51a and 51b, third and fourth leads 53a and 53b, and a chip mounting region 55, and may include a hole cup in the chip mounting region 55. 55a). The chip mounting area 55 is connected to the first and second leads 51a and 51b through the first and second connectors 57a and 57b, respectively.

The lead frame 50 may include a third connection part 51c connecting the first and second leads 51a and 51b. The third connector 51c may connect the points of the first and second leads 51a and 51b separated by the same distance from the chip mounting area 55, but is not limited thereto. Meanwhile, the third and fourth leads may be electrically insulated from the chip mounting region, and may be connected to each other through the fourth connector 59. In addition, the lead frame 50 may include a fifth connector 53c connecting the third and fourth leads 53a and 53b. The fifth connector 53c may connect the points of the third and fourth leads 53a and 53b separated by the same distance from the fourth connector 59, but is not limited thereto.

The third connector 51c equilibrates the heat introduced through the first and second leads 51a and 51b in both leads during a package mounting process such as soldering. For example, when a relatively large amount of heat is introduced through the first lead 51a, heat is transferred from the first lead 51a to the second lead 51b through the third connecting portion 51c, and thus the first lead and the first lead 51a. Thermal equilibrium can be achieved between the second leads. Accordingly, the temperature difference between the first lead and the second lead can be reduced with the chip mounting region 55 interposed therebetween. The fifth connector 53c is in thermal equilibrium between the third lead 53a and the fourth lead 53b similarly to the third connector.

The lead frame 50 may include a serif 57s extending from at least one of the first and second connecting portions 57a and 57b. These serifs 57s switch paths of heat flowing from the first or second leads to the chip mounting region 55 to prevent thermal shock from being applied to the chip mounting region 55 by a sudden heat flow. The shape of the serif 57s is not particularly limited, but the end portion thereof is located away from the connection portions 57a and 57b.

Meanwhile, at least one of the first and second connecting portions 57a and 57b may have a groove 57g crossing it. The groove 57g slows the transfer rate of heat flowing from the first or second leads 51a and 51b through the first or second connection portions 57a and 57b, thereby exerting heat shock on the chip mounting region 55. Relax The groove 57g may completely cross the connecting portions 57a and 57b, but is not limited thereto and may be defined between both edges of the connecting portions 57a and 57b.

Meanwhile, the first, second, third and fourth leads 51a, 51b, 53a, and 53b may have through holes 51h and 53h. These through holes 51h and 53h reduce the cross-sectional area of the heat passages flowing through the leads during the soldering process to mitigate thermal shock to the chip mounting region 55. In addition, the through holes 51h and 53h may reduce the inflow of moisture into the package. This will be described later.

The lead frame 50 may be formed by pressing a metal plate, for example, copper plate, or may be formed by a casting technique. 4, each lead of the lead frame 50 may be bent as necessary.

The LED chip 60 is mounted in the hole cup 55a in the chip mounting area 55. The LED chip 60 may be attached to the bottom surface of the hole cup 55a through a conductive adhesive (not shown) such as silver (Ag) epoxy. Accordingly, the LED chip 60 is electrically connected to the first and second leads 51a and 51b. In addition, the light emitting diode chip 60 may be electrically connected to the first lead or the second lead through a bonding wire. In this case, the light emitting diode chip 60 may be connected to the hole cup 55a through a non-conductive adhesive. It may be attached to the bottom surface. The light emitting diode chip 60 is made of a compound semiconductor of gallium nitride series, gallium arsenide series or gallium series.

Meanwhile, a bonding wire 65 connects the LED chip 60 and the fourth connector 59 to electrically connect the LED chip 60 to the third and fourth leads 53a and 53b. . The fourth connection portion 59 provides a relatively wide area to which the bonding wire 65 can be connected to help the wire connection. Alternatively, the bonding wire 65 may be directly connected to the third or fourth leads 53a and 53b.

The light emitting diode chip 60 may be formed of a group III-V compound semiconductor such as gallium nitride, gallium arsenide, or gallium, or a group II-VI compound semiconductor such as ZnO.

The package body 70 encapsulates the leads 51a, 51b, 53a, and 53b, the light emitting diode chip 60, and the bonding wire 65. The package body 70 may be formed of a transparent molding resin such as epoxy or silicon. A portion of the package body 70 on the upper portion of the light emitting diode chip 60 may be formed in a lens shape, and thus light emitted from the light emitting diode chip 70 may be emitted within a predetermined direction angle. Meanwhile, before forming the package body 70, a molding resin (not shown) covering the light emitting diode chip 60 may be formed in the hole cup 55a. The molding resin formed in the package body 70 or the hole cup 55a may contain a phosphor, and emits light of various colors by the combination of the phosphor and the light emitted from the LED chip 60. Can provide.

The package body 70 surrounds portions of the leads, and the leads extend out of the package body 70. Leads extending outside the package body 70 may be bent as shown in FIG. 3 for surface mounting, but are not limited thereto, and may be used in a pin shape without being bent.

As shown in FIG. 3, the third connection part 51c or the fifth connection part 53c may be located inside the package body 70, but is not limited thereto. The third connection part 51c or the fifth connection part 53c may be located outside the package body 70. You may.

Meanwhile, the through holes 51h and 53h formed in the leads extend from the inside of the package body 70 to the outside. Therefore, the interface area between the leads 51a, 51b, 53a, and 53b formed on the surface of the package body 70 and the package body 70 may be reduced. This reduction in the interface area reduces the passage of moisture entering through the interface, thereby improving the moisture resistance of the package.

In addition, the through holes 51h and 53h may extend to the bent portions indicated by dotted lines, as shown in FIG. 4, and the through holes facilitate bending of the leads.

According to the present exemplary embodiment, a light emitting diode mounted on the chip mounting region 55 by balancing the heat introduced through the leads in the high temperature process such as soldering by the third connector 51c and the fifth connector 53c. Heat shock applied to the chip 60 is alleviated. In addition, by forming the serifs 57s or the grooves 57g, the flow of heat to the chip mounting region 55 may be delayed to prevent sudden thermal shocks from being applied to the LED chip 60 in a high temperature process such as soldering. Can be. In addition, by reducing the area of the interface formed between the package body 70 and the leads, it is possible to improve the moisture resistance of the package.

5 is a perspective view illustrating a light emitting diode package according to another embodiment of the present invention, and FIG. 6 is a plan view illustrating a lead frame used in the light emitting diode package of FIG. 5.

5 and 6, the LED package includes a lead frame 110, a LED chip 120, and a package body 130.

As described with reference to FIG. 4, the lead frame 110 includes a chip mounting region 115, first to fourth leads 111a, 111b, 113a, and 113b, first and second connectors 117a, 117b), and may include a third connecting portion 111c, a fourth connecting portion 119, and a fifth connecting portion 113c. In addition, at least one of the first and second connections 117a, 117b may have a serif 117s extending therefrom and may also have a groove 117g across it. In addition, through holes 111h and 113h may be formed in the first to fourth leads.

However, in the present exemplary embodiment, the chip mounting area 115 may be a flat surface. That is, the hole cup 55a as shown in FIG. 3 may be omitted.

Meanwhile, the LED chip 120 is mounted on the chip mounting region 115 and is electrically connected to the fourth connector 119 through the bonding wire 125. As described above, the LED chip 120 may be attached to the chip mounting region 115 through a conductive adhesive (not shown) to be electrically connected to the first and second leads 111a and 111b. The present invention is not limited thereto, and may be attached to the chip mounting region 115 through a non-conductive adhesive and electrically connected to the first or second lead through a bonding wire.

Meanwhile, the package body 130 surrounds and supports portions of the leads 111a, 111b, 113a, and 113b. The package body 130 may be formed of a plastic such as polyphthalamide (PPA), and may be opaque. The package body 130 may have an opening exposing the chip mounting region 115, and the opening may be filled with a transparent molding resin. The transparent molding resin may contain a phosphor, and light of various colors may be realized by the combination of the phosphor and the light emitting diode chip 120.

The third connector 111c and the fifth connector 113c may be located outside the package body 130, but are not limited thereto and may be embedded in the package body 130.

The leads extend outside the package body 130, and end portions thereof may be bent to allow surface mounting. End ends of the leads may be bent outward from the package body 130, but are not limited thereto and may be bent toward the bottom surface of the package body 130. Meanwhile, the end ends of the leads may not be bent but may maintain a pin shape.

The present invention is not limited to the high flux LED lamps or light emitting diode packages described above, but may also be applied to other light emitting diode packages that employ a leadframe having a chip mounting area and leads. In addition, in the embodiments of the present invention, a lead frame having four leads has been described as an example, but is not limited thereto. The lead frame may also be applied to a lead frame having three leads or five or more leads.

1 is a perspective view illustrating a conventional high flux light emitting diode lamp.

FIG. 2 is a plan view illustrating a lead frame used in the light emitting diode lamp of FIG. 1.

3 is a perspective view illustrating a high flux light emitting diode lamp according to an embodiment of the present invention.

4 is a plan view illustrating a lead frame used in the light emitting diode lamp of FIG. 3.

5 is a perspective view illustrating a light emitting diode package according to another embodiment of the present invention.

6 is a plan view illustrating a lead frame used in the LED package of FIG. 5.

Claims (12)

A chip mounting region, first, second and third leads, first and second connectors connecting the chip mounting region and the first and second leads, respectively, and the first and second leads A lead frame including a third connecting portion to connect to the lead frame; A light emitting diode chip mounted on the chip mounting region and electrically connected to the first and third leads; And A package body surrounding portions of the first, second and third leads, The first, second and third leads extend outside the package body, At least one of the first and second connections has a groove across it. The method according to claim 1, And the third connector connects the points of the first and second leads separated by the same distance from the chip mounting area. The method according to claim 1, The lead frame further comprises a serif extending from at least one of the first and second connections. The method according to claim 1, At least one of the first, second and third leads has a through hole, the through hole extending from the inside of the package body to the outside. The method of claim 4, The through-holes located in the package body are filled by the package body. The method according to claim 1, The lead frame comprises a fourth lead; And Further comprising a fourth connecting portion connecting the ends of the third lead and the fourth lead, The light emitting diode package is electrically connected to the third lead by a bonding wire connecting the light emitting diode chip and the fourth connector. The method of claim 6, The light emitting diode package further comprises a fifth connector connecting the third lead and the fourth lead. The method of claim 7, And the fifth connector connects the points of the third and fourth leads spaced apart by the same distance from the fourth connector. A lead frame including a chip mounting region, first, second and third leads, and first and second connectors connecting the chip mounting region and the first and second leads, respectively; A light emitting diode chip mounted on the chip mounting region and electrically connected to the first and third leads; And A package body surrounding portions of the first, second and third leads, The first, second and third leads extend outside the package body, At least one of the first, second and third leads has a through hole extending from the inside of the package body to the outside, At least one of the first and second connections has a groove across it. The method of claim 9, The lead frame further comprises a serif extending from at least one of the first and second connections. A chip mounting region, first, second, third and fourth leads, first and second connectors connecting the chip mounting region and the first and second leads, respectively, and the first and second leads. A lead frame including a third connection part connecting the two leads and a fourth connection part connecting the ends of the third lead and the fourth lead; A light emitting diode chip mounted on the chip mounting region and electrically connected to the first and third leads; A package body surrounding portions of the first, second and third leads; And A fifth connector connecting the third lead and the fourth lead; The first, second and third leads extend outside the package body, The LED package is electrically connected to the third lead by a bonding wire connecting the light emitting diode chip and the fourth connector. The method of claim 11, And the fifth connector connects the points of the third and fourth leads spaced apart by the same distance from the fourth connector.

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