JP2006086391A - Led package - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an LED package which inhibits a decline in light-emitting efficiency, selecting and using a highly heat conductive material which makes heat dissipation property higher, in order to cope with heat generation from the LED chip of an LED light emitting device. <P>SOLUTION: In the package for the light emitting device including a frame metal base 11, the LED chip 12, and an insulating member 14 which leads out a lead member 13 connected to the LED chip 12; the LED package 10 is constituted by mounting the LED chip 12 at a predetermined position in the frame of the metal base 11, in such a state as the chip is directly put into contact with the highly heat conductive carbon material 16 of a metal impregnated carbon material (MICC). When the metal base 11 comprises a mortar shape side wall member 18 and a bottom plate member 19, the insulating member 14 forms an opening 15 and a conductive pattern is provided for leading outside. The LED chip is mounted on the highly heat conductive carbon material arranged at the opening, and is connected with a lead through a wire bonding 17 and the conductive pattern for leading outside. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a package for a semiconductor light emitting device in which a member having high thermal conductivity and good heat dissipation is used for an LED chip mounting base.

In recent years, light emitting devices using LEDs have been widely used as various light sources. The light emitting element is composed of a semiconductor light emitting diode, which is called an LED chip, and is used by being incorporated in an appropriate package. The LED package is provided with power supply leads. There are an axial type, a radial type, a chip type, and the like according to the lead lead-out state, and a surface mounting chip type that is advantageous in terms of space factor is often used when used for a wiring board or the like. Usually, LED chips are housed in an appropriate container and packaged, and a method for improving light emission efficiency by molding a resin material has also been proposed. For example, regarding the mounting of an LED chip on a container base, Patent Document 1 discloses a proposal for improving luminous efficiency in a package arranged via a light-transmitting insulator. Patent Documents 2 and 3 propose light emitting devices that improve exterior for higher luminance and uniform light emission, and suppress color rendering and chromaticity deviations. Furthermore, Patent Document 4 discloses a structural improvement proposal when a metal package is used.
JP-A-9-307145 Japanese Patent Laid-Open No. 10-190065 JP 2004-71726 A JP 2004-186309 A

  For example, when a base substrate or a package that accommodates an LED chip has a conventional ceramic structure, a green sheet must be prepared and fired separately from the base of the bottom plate and the side wall forming the inclined space. Each green sheet requires processing such as necessary electrode printing and punching, causes dimensional variations in the manufacturing process, defects associated with fine processing, and difficulty in firing and coalescence. In particular, when the base material is alumina ceramics, heat dissipation is poor, and there are defects such as accelerating the heat generation of the LED chip and lowering the light emission efficiency. In order to eliminate such a defect in the ceramic structure, a semiconductor light emitting device having a metal package structure as disclosed in Patent Document 4 has been proposed, but it was not satisfactory in heat dissipation.

  By the way, a problem in the case where the degree of integration is increased and the output is increased for high luminance light emission is a countermeasure for heat dissipation. As a member used for the package, it is desired that the thermal conductivity is particularly excellent, the heat dissipation and the reliability are improved, and the package is small and inexpensive. Furthermore, in view of adverse effects such as lowering of luminous efficiency due to temperature rise due to miniaturization in addition to higher brightness and higher output, the heat dissipation of the LED chip mounting substrate which is a heat source and the package member surrounding it is improved. Requested.

  Accordingly, the present invention has been proposed in view of the above disadvantages, and provides a new and improved LED package in which a light emitting device is configured by using a material having good thermal conductivity for a mounting substrate of an LED chip. Objective.

  According to the present invention, in a light emitting device package comprising a frame metal base, an LED chip disposed in the metal base frame, and an insulating member that leads out a lead member electrically connected to the chip, An LED package is provided in which the chip is mounted at a predetermined position on a metal base in contact with a high thermal conductivity carbon material. Here, the high thermal conductivity carbon material is characterized by using a metal-impregnated carbon material (MICC) and a composite material such as MICC-copper hybrid material or MICC-aluminum hybrid material. The metal-impregnated carbon composite material is not only highly heat-conductive, but also has a low thermal expansion, low elasticity, and is a lightweight material, and is an effective material for heat generation countermeasures for semiconductor materials.

  In the present invention, since a single or composite material of a high thermal conductivity carbon material is used as a chip mounting base as a base substrate or package component for housing an LED chip, high heat dissipation is ensured and material and processing costs are low. An inexpensive and highly reliable LED package can be provided. In particular, since MICC having a good heat dissipation property or a composite material thereof is used for the LED pellet mounting substrate, the heat generated from the LED pellet is directly absorbed and conducted to the heat dissipator, so that the temperature rise is suppressed and the luminous efficiency is not lowered. In addition, since the material characteristics for the chip mount match the semiconductor parts, the processability on the manufacturing side is improved, and the industrial value is greatly enhanced, such as contributing to mass production and low cost.

  According to a first embodiment of the present invention, there is provided a light emitting device package comprising a frame metal base, an LED chip, and an insulating member for leading a lead member connected to the chip. The LED package is characterized in that the chip is mounted in direct contact with the high thermal conductivity carbon material, the metal base is composed of a mortar-shaped side wall member and a bottom plate member, the insulating member forms an opening and the conductive for external lead-out A LED package having a structure in which a pattern is provided, the LED chip is mounted in contact with a high thermal conductive carbon material disposed in an opening on a bottom plate member, and connected to a lead member through an external lead-out conductive pattern by wire bonding. Here, it is preferable to use a metal-impregnated carbon material or a composite material thereof as the high thermal conductivity carbon material. For example, carbon powder or carbon fiber is hardened and fired, impregnated with a metal such as Cu or Al, or powder fired. Material. The heat conduction is transmitted by lattice vibration of the two-dimensional crystal plane of carbon and exhibits high heat conductivity of 150 to 300 mW / ° C. The high thermal conductivity carbon material has some differences depending on the firing method and the impregnated metal, but preferably the thermal conductivity is 150 mW / ° C. or higher. The coefficient of thermal expansion is 6 to 10 ppm / ° C., which is very close to the coefficient of thermal expansion of a semiconductor such as a cover metal material, Si, or GaAs, and has a low Young's modulus. Therefore, even if a metal, Si, GaAs or the like is bonded on the carbon material, bonding with extremely high reliability can be achieved.

  According to a second embodiment of the present invention, there is provided a light emitting device package comprising a frame metal base, an LED chip, and an insulating member for leading a lead member connected to the chip. An LED package characterized in that the chip is mounted in contact with a high thermal conductivity carbon material, the metal base is composed of a mortar-shaped side wall member, the insulating member is formed with an opening and an external lead-out conductive pattern, The LED chip is an LED package having a structure in which the LED chip is mounted in contact with a high thermal conductivity carbon material disposed on the bottom side of the metal base at an opening, and connected to a lead member through an external lead-out conductive pattern by wire bonding. Here, as the high thermal conductivity carbon material, a metal-impregnated carbon material or a composite material thereof is used as in the first embodiment, and a high thermal conductivity of 150 to 300 mW / ° C., preferably a thermal conductivity. It is desirable that it is 150 mW / ° C. or higher.

  According to a third embodiment of the present invention, there is provided a light emitting device package comprising a frame metal base, an LED chip, and an insulating member for leading a lead member connected to the chip. The LED package is characterized in that the chip is mounted in contact with a high thermal conductivity carbon material, the metal base is composed of a mortar-shaped side wall member and a bottom plate member, the insulating member forms an opening, and the conductive pattern for external derivation has The LED package is an LED package having a structure in which the LED chip is mounted in contact with the high thermal conductivity carbon material of the bottom plate member at the opening, and the LED chip is connected to the lead member through an external lead-out conductive pattern by wire bonding. Here, a metal-impregnated carbon material or a composite material thereof is used as the high thermal conductivity carbon material as in the first embodiment.

  According to a fourth embodiment of the present invention, there is provided a light emitting device package comprising a frame metal base, an LED chip, and an insulating member for leading a lead member connected to the chip. An LED package comprising a chip mounted in contact with a high thermal conductivity carbon material, wherein the metal base is an integrally formed body of a mortar-shaped side wall member and a bottom plate member having a through hole, and the insulating member is the lead member The LED chip is mounted in contact with the high thermal conductivity carbon material placed on the bottom plate member, and connected to the tip surface of the lead member by wire bonding. This is an LED package having the structure described above. Here, a metal-impregnated carbon material or a composite material thereof is used as the high thermal conductivity carbon material as in the first embodiment. In addition, this carbon material is lightweight, excellent in workability, and has a low elastic modulus, which is one of the features of the carbon material. Applicable. For example, even if materials having different thermal expansion coefficients are laminated with a carbon material, the carbon material absorbs internal stress. Also, if the LED substrate is brazed directly on the Cu plate, the thermal expansion coefficient differs by about twice, so stress is applied to the LED substrate, and the LED substrate is cracked normally. Even if the LED substrate is brazed onto the composite substrate, the carbon material absorbs internal stress due to the difference in thermal expansion, and the LED substrate does not break. Therefore, in such a package structure, the heat generated by the LED chip is immediately absorbed and dissipated by the high thermal conductive carbon material, and thus the light emission efficiency is not lowered.

  Hereinafter, an axial lead type LED package according to a first embodiment of the present invention will be described with reference to FIG. The LED package 10 is a light emitting device package including a frame metal base 11, an LED chip 12, and an insulating member 14 for leading a lead member 13 connected to the LED chip 12. The LED chip 12 is mounted at a predetermined position with a brazing material or an adhesive so as to be in direct contact with the high thermal conductivity carbon material 16. The metal base 11 includes a mortar-shaped side wall member 18 and a bottom plate member 19, the insulating member 14 forms an opening 15 and is provided with a conductive pattern for leading out, and the LED chip 12 is disposed in the opening 15 on the bottom plate member. The LED package is mounted in direct contact with the high thermal conductivity carbon material 16 and connected to the lead member 13 by wire bonding 17 via an external lead-out conductive pattern. Here, a metal-impregnated carbon material (MICC) was used as the high thermal conductivity carbon material 16. Specifically, carbon powder or carbon fiber is hardened and fired, and impregnated with a metal such as Cu or Al. The heat conduction is transmitted by lattice vibration of the two-dimensional crystal plane of carbon and exhibits high heat conductivity of 150 to 300 mW / ° C.

  In the second embodiment, as shown in FIG. 2, the LED package 20 includes a frame body metal base 21, an LED chip 22, and a ceramic insulating member 24 for leading a lead member 23 connected to the chip. In the light emitting device package, the LED chip 22 is mounted at a predetermined position in the frame of the metal base 21 in direct contact with the high thermal conductivity carbon material 26. The metal base 21 is composed of a mortar-shaped side wall member 28, the insulating member 24 is formed with an opening 25 and an external lead-out conductive pattern is provided, and the LED chip 22 is a high thermal conductivity that also serves as a bottom plate member of the metal base 21 at the opening 25. The structure is mounted in contact with the carbon material 26 and is connected to the lead member 23 via the external lead-out conductive pattern by wire bonding 27. Here, the high thermal conductivity carbon material 26 was a metal-impregnated carbon material having a high thermal conductivity of 150 to 300 mW / ° C. as in the first embodiment.

  In the third embodiment, as shown in FIG. 3, the LED package 30 includes a frame metal base 31, an LED chip 32, and a ceramic insulating member 34 for leading a lead member 33 connected to the chip. In the light emitting device package, the LED chip 32 is mounted in a predetermined position within the frame of the metal base 31 in direct contact with the high thermal conductivity carbon material 36. The metal base 31 includes a mortar-shaped side wall member 38 and a bottom plate member 39, and is an insulating member. 34 has an opening 35 and is provided with a conductive pattern for leading out, and the LED chip 32 is mounted in contact with the high thermal conductivity carbon material 36 bonded to the bottom plate member 39 of the metal base 31 at the opening 35, and wire bonding. 37 is connected to the lead member 33 via an external lead-out conductive pattern. Here, the high thermal conductivity carbon material 36 was a metal-impregnated carbon material having a high thermal conductivity of 150 to 300 mW / ° C. as in the first embodiment.

  In the fourth embodiment, as shown in FIG. 4, the LED package 40 includes a frame metal base 41, an LED chip 42, and a glass insulating member 44 that leads out a lead member 43 connected to the chip. In the light emitting device package, the frame metal base 41 is an LED package in which the LED chip 42 is mounted in a predetermined position in the frame of the metal base in contact with the high thermal conductivity carbon material 46. The metal base 41 is a mortar. An insulating member 44 made of glass has a lead member 43 penetrating through the opening 45, and the leading end surface of the lead member penetrates the bottom plate member 49. The LED chip 42 is mounted in contact with the high thermal conductivity carbon material 46 disposed on the bottom plate member, and protrudes from the hole. The structure LED package that is connected to the distal end surface of the lead member. Here, the high thermal conductivity carbon material 46 was a metal-impregnated carbon material having a high thermal conductivity of 150 to 300 mW / ° C. as in the first embodiment. The lead member 43 is embedded in a state of penetrating the glass insulator member 44, and a terminal electrode is exposed on the back surface side to form a surface mount chip type structure.

  The high thermal conductivity carbon material (MICC) used in the above-described embodiments has high thermal conductivity, low elastic modulus (low elasticity), low thermal expansion, and high strength, light weight and excellent workability. As a low-cost material, it has high mechanical strength and can exhibit stable performance without any processing problems. In other words, the conventional ceramic package was manufactured by laminating a ceramic plate called a cofirer in which a plurality of green sheets were stacked and baked, so the package cost was high. However, it is extremely advantageous, and the application to the field of LED light emitting devices that are becoming smaller is promoted.

  The present invention is applied to a package member of an LED light-emitting device that requires heat dissipation, and provides a product that improves luminous efficiency by suppressing a temperature rise due to heat generation of the LED chip.

It is sectional drawing which shows the principal part of the LED package of Example 1 which concerns on this invention. Similarly, it is sectional drawing which shows the principal part of the LED package of Example 2. FIG. Similarly, it is sectional drawing which shows the principal part of the LED package of Example 3. FIG. Similarly, it is sectional drawing which shows the principal part of the LED package of Example 4. FIG.

Explanation of symbols

10, 20, 30, 40; LED package,
11, 21, 31, 41; metal base,
12, 22, 32, 42; LED chip,
13, 23, 33, 43; lead member,
14, 24, 34, 44; insulating member (ceramic, glass),
15, 25, 35, 45; opening,
16, 26, 36, 46; high thermal conductivity carbon material (metal-impregnated carbon material or composite material),
17, 27, 37, 47; wire bonding 18, 28, 38, 48; mortar-shaped side wall members 19, 39, 49;

Claims (6)

Light emitting device package comprising: a frame-shaped metal base; an LED chip disposed within the metal base frame; a lead member electrically connected to the chip; and an insulating member holding the lead member Wherein the LED chip is mounted in contact with a high thermal conductivity carbon material at a predetermined position of the metal base. The LED package according to claim 1, wherein the high thermal conductivity carbon material is a metal-impregnated carbon material or a composite material thereof. The metal base is composed of a mortar-shaped side wall member and a bottom plate member, the insulating member forms an opening and is provided with a conductive pattern for leading out, and the LED chip is disposed in the opening on the bottom plate member. 3. The LED package according to claim 1, wherein the LED package is mounted in direct contact with a conductive carbon material and connected to the lead member through the conductive pattern by wire bonding. The metal base is formed of a mortar-shaped side wall member, the insulating member forms an opening and an external lead-out conductive pattern, and the LED chip is disposed on the bottom side of the metal base at the opening. The LED package according to claim 1, wherein the LED package is mounted in direct contact with a carbon material and connected to the lead member through the conductive pattern by wire bonding. The metal base includes a mortar-shaped side wall member and a bottom plate member, the insulating member forms an opening and is provided with a conductive pattern for external derivation, and the LED chip is disposed on the bottom plate member at the opening. 3. The LED package according to claim 1, wherein the LED package is mounted in direct contact with a conductive carbon material and connected to the lead member through the conductive pattern by wire bonding. The metal base includes a mortar-shaped side wall member and a bottom plate member having a through hole, and the insulating member penetrates the lead member, and a leading end surface of the lead member protrudes from the through hole of the bottom plate member, and the LED 3. The LED package according to claim 1, wherein the chip is mounted in contact with the high thermal conductivity carbon material disposed on the bottom plate member, and is connected to a front end surface of the lead member by wire bonding.

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