JP2005072397A - Package for containing light emitting element and light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a package for containing a light emitting element which can effectively radiate a light emitted by a light emitting element, and also can enhance a visibility; and to provide a light emitting device. <P>SOLUTION: The package for containing the light emitting element is formed by joining a frame body 2 having a through hole 2a for containing a light emitting element 3 to an upper face of a base 1 having a mounting part 1a for mounting the light emitting element 3 on its upper face so as to surround the mounting part 1a, and the frame body 2 has an inner peripheral face inclined so that an upper opening is smaller than the lower opening of the through hole 2a. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a light emitting element housing package and a light emitting device for housing a light emitting element such as a light emitting diode.

  Conventionally, a ceramic package is used as a light emitting element storage package (hereinafter also referred to as a package) for accommodating a light emitting element such as a light emitting diode. As shown in FIG. 5, the conventional ceramic package has a mounting portion 11a made of a conductor layer for mounting the light emitting element 13 at the center of the upper surface, and is led out from the mounting portion 11a and its periphery to the lower surface. A rectangular parallelepiped ceramic base 11 having a pair of wiring layers 14a and 14b, and a rectangular frame ceramic base joined to the upper surface of the base 11 and having a through-hole 12a for accommodating the light emitting element 13 at the center. Frame body 12. Further, the inner peripheral surface of the through hole 12a of the frame body 12 is formed so as to spread outward with respect to the upper surface of the base 11 in order to radiate light to the outside satisfactorily.

  Then, the light emitting element 13 is fixed to the mounting portion 11a connected to the one wiring layer 14a led out on the upper surface of the base 11 through a conductive bonding material, and the electrode of the light emitting element 13 and the other wiring layer 14b. Are connected to each other through a bonding wire 15, and then a transparent resin is filled in the through hole 12a of the frame body 12 to seal the light emitting element 13, thereby obtaining a light emitting device (for example, Patent Document 1).

  In such a ceramic package, the light emitted from the light emitting element 13 accommodated in the interior is reflected by the inner peripheral surface of the through hole 12a to improve the light emission efficiency of the light emitting device. A metallized metal layer 16a having a plated metal layer 16b made of a metal such as nickel (Ni) or gold (Au) on the inner surface is attached.

  Further, this package is manufactured by a ceramic green sheet (hereinafter also referred to as green sheet) lamination method, and specifically manufactured as follows. A green sheet for the substrate 11 and a green sheet for the frame 12 are prepared, and a through hole for leading out the wiring layers 14a and 14b to the green sheet and a through hole for accommodating the light emitting element 13 are directed upward. Punch out to spread outward from the bottom.

Next, a conductor paste made of a refractory metal powder such as W or Mo for forming the wiring layers 14a and 14b is applied from the upper surface to the lower surface of the green sheet for the substrate 11 by a conventionally well-known screen printing method or the like. The conductor paste for forming the metallized metal layer 16a is applied to the inner peripheral surface of the through-hole of the green sheet for 12 by screen printing or the like. The green sheet for the base body 11 and the green sheet for the frame body 12 are stacked vertically so that the inner peripheral surface of the through hole 12a of the frame body 12 spreads outward with respect to the upper surface of the base body 11, and this is Firing and forming a sintered body. Thereafter, the plated metal layer 16b made of a metal such as Ni or Au is deposited on the exposed surfaces of the wiring layers 14a and 14b and the metallized metal layer 16a by an electroless plating method or an electrolytic plating method.
JP 2002-132017 A

  However, in the above-described conventional package, in order to allow light emitted from the light emitting element 13 to be emitted over a wide range from the opening on the upper surface of the through hole 12a of the frame 12, the penetration of the frame 12 is performed. The inner peripheral surface of the hole 12 a is formed so as to spread outward with respect to the upper surface of the base 11. Thereby, although the light of a light-emitting device can be visually recognized from the outside wide range and a viewing angle can be made wide, the directivity to a front direction will become low. For this reason, the luminance in the front direction is lowered, the contour in the vicinity of the opening of the through hole 12a of the frame 12 is blurred, and the visibility from the front direction is lowered.

  Therefore, the present invention has been completed in view of the above-described conventional problems, and an object of the present invention is to emit light that can efficiently emit light emitted from a light-emitting element and can have high visibility. An object is to provide an element storage package and a light emitting device.

  In the light emitting element storage package according to the present invention, a frame having a through hole for accommodating a light emitting element surrounds the mounting part on the upper surface of a base having a mounting part for mounting the light emitting element on the upper surface. In the bonded light emitting element storage package, the frame body is characterized in that an inner peripheral surface is inclined so that an opening on an upper side is smaller than an opening on a lower side of the through hole.

  The light-emitting device of the present invention includes the light-emitting element storage package of the present invention, a light-emitting element mounted on the mounting portion, and a transparent resin that covers the light-emitting element.

  According to the light emitting element storage package of the present invention, since the inner peripheral surface of the frame body is inclined so that the opening on the upper side of the opening on the lower side of the through hole becomes smaller, the opening on the upper side of the through hole. Since the light is more easily emitted in the front direction, the directivity of the light emitted outside can be improved. Moreover, extraneous light leakage can be suppressed by generating diffused reflection of light in the through-hole of the frame and confining the light in the through-hole to some extent, resulting in higher brightness and higher directivity. Therefore, when the light emitting device is viewed from the outside, the outline of the opening on the upper side of the through hole becomes bright and clear, and the visibility can be improved.

  The light-emitting device of the present invention can emit light from the light-emitting element efficiently in the front direction and be clear due to the above configuration. Therefore, it is suitable for a display device or the like.

  The light emitting element storage package of the present invention will be described in detail below. FIG. 1 is a cross-sectional view showing an example of an embodiment of a package according to the present invention. Reference numeral 1 denotes a base body, and 2 denotes a frame, which mainly constitute a package for housing the light emitting element 3.

  In the light emitting element storage package of the present invention, the frame body 2 having the through hole 2a for accommodating the light emitting element 3 is mounted on the upper surface of the base body 1 having the mounting portion 1a for mounting the light emitting element 3 on the upper surface. In the frame 2 joined so as to surround 1a, the inner peripheral surface of the frame 2 is inclined so that the upper opening is smaller than the lower opening of the through hole 2a.

  The substrate 1 in the present invention is made of ceramics or resin, and when made of ceramics, for example, an aluminum oxide sintered body (alumina ceramic), an aluminum nitride sintered body, a mullite sintered body, a glass ceramic sintered body, etc. This is a rectangular parallelepiped box made of ceramics, which is a support for supporting the light emitting element 3, and has a mounting portion 1a formed of a conductor layer for mounting the light emitting element 3 on the upper surface thereof.

  When the substrate 1 is made of, for example, an aluminum oxide sintered body, a suitable organic binder, solvent, etc. are added to and mixed with raw material powders such as aluminum oxide, silicon oxide, magnesium oxide, and calcium oxide to form a slurry. Is formed into a sheet shape by a conventionally known doctor blade method or calendar roll method, etc. to obtain a green sheet (ceramic raw sheet). After that, the green sheet is appropriately punched and laminated at a high temperature. It is manufactured by firing at (about 1600 ° C.).

  In addition, the substrate 1 is formed with a wiring layer 4a led out from the mounting portion 1a on the top surface to the bottom surface and a wiring layer 4b led out from the periphery of the mounting portion 1a to the bottom surface. The mounting portion 1a and the wiring layers 4a and 4b are made of metal powder of metal powder such as W, Mo, manganese (Mn), and the wiring layers 4a and 4b are conductive materials for electrically connecting the light emitting element 3 accommodated in the package to the outside. Road. A light emitting element 3 such as a light emitting diode (LED) or a semiconductor laser (LD) is fixed to the mounting portion 1a by a conductive bonding material such as gold-silicon alloy or silver-epoxy resin, and the wiring layer 4b. The electrodes of the light emitting element 3 are electrically connected via the bonding wires 5.

  The wiring layers 4a and 4b and the mounting portion 1a are conventionally well known in advance on a green sheet serving as the base 1 using a conductive paste obtained by adding an appropriate organic solvent and solvent to a high melting point metal powder such as W. By printing and applying a predetermined pattern by the screen printing method, the substrate 1 is deposited on a predetermined position.

  It should be noted that a metal having excellent corrosion resistance such as Ni, Au, and Ag and excellent wettability of the brazing material is deposited on the exposed surfaces of the wiring layers 4a and 4b and the mounting portion 1a to a thickness of about 1 to 20 μm. The wiring layers 4a and 4b and the mounting portion 1a can be effectively prevented from being oxidized and corroded, and the bonding between the mounting portion 1a and the light emitting element 3 and the connection between the wiring layer 4b and the bonding wire 5 can be strengthened. Can do. Therefore, an Ni plating layer having a thickness of about 1 to 10 μm and an Au plating layer or an Ag plating layer having a thickness of about 0.1 to 3 μm are formed on the exposed surfaces of the wiring layers 4a and 4b and the mounting portion 1a by an electroplating method or the like. It is more preferable to deposit sequentially by electroless plating.

The frame 2 of the present invention is made of ceramics, resin, metal or the like. For example, when the frame 2 is made of an aluminum oxide sintered body, a through-hole 2a having a circular or quadrangular cross-sectional shape for accommodating the light emitting element 3 in the center of the frame 2 is formed on the green sheet. For example, it is manufactured by stacking a plurality of sheets and firing them at a high temperature (1600 ° C.).

  A metal layer 6 serving as a reflection layer for favorably reflecting light emitted from the light emitting element 3 is preferably attached to the inner peripheral surface of the through hole 2a of the frame body 2. For example, when the metal layer 6 is composed of a metallized metal layer 6a and a plated metal layer 6b on the surface thereof, a refractory metal such as W, Mo, Mn or the like is formed on the inner peripheral surface of the through hole 2a of the green sheet serving as the frame 2. A conductive paste obtained by adding and mixing a suitable organic solvent and a solvent is printed and applied in a predetermined pattern by a well-known screen printing method, so that substantially the entire inner peripheral surface of the through-hole 2a or a predetermined position is obtained. The metallized metal layer 6a is deposited.

When the frame 2 is made of an aluminum oxide sintered body, the metallized metal layer 6a preferably contains 1 to 5 parts by weight of Mo with respect to 100 parts by weight of W. When the amount is less than 1 part by weight, the frame body 2 is made of an aluminum oxide sintered body (coefficient of thermal expansion: about 7.8 × 10 ⁻⁶ / ° C.) and W (coefficient of thermal expansion: about 4.6 × 10 ^−6). / ° C.) and Mo (thermal expansion coefficient: about 5.7 × 10 ⁻⁶ / ° C.), the thermal stress due to the difference in thermal expansion coefficient from the metal layer 6a tends to increase. If it exceeds 5 parts by weight, the adhesion strength of the metallized metal layer 6a to the frame 2 tends to be weakened. That is, the metallized metal layer 6a has an alumina sintered body as compared with W having a thermal expansion coefficient of about 4.6 × 10 ⁻⁶ / ° C. and a thermal expansion coefficient of about 5.7 × 10 ⁻⁶ / ° C. By adding a small amount of Mo having a thermal expansion coefficient close to that, the thermal expansion coefficient approximates that of an alumina sintered body. As a result, the reliability of deposition of the metallized metal layer 6a on the frame 2 is greatly improved.

  Further, a plated metal layer 6b made of Ni, Au, Ag or the like is deposited on the metallized metal layer 6a, whereby the light emitted from the light emitting element 3 accommodated in the through hole 2a is emitted by the plated metal layer 6b. Can be better reflected and emitted to the outside. The plated metal layer 6b preferably has a reflectance of 80% or more with respect to light emitted from the light emitting element 3 accommodated in the through hole 2a. If it is less than 80%, it becomes difficult to satisfactorily reflect the light emitted from the light emitting element 3 accommodated in the through hole 2a.

  Further, the base body 1 and the frame body 2 may be made of different materials, for example, the base body 1 and the frame body 2 may be different ceramics, or the base body 1 may be ceramics and the frame body 2 may be resin.

  The metal layer 6 is formed by depositing a highly reflective metal such as Au, Ag, or Al on the inner peripheral surface of the through hole 2a by a vapor deposition method or the like, or a highly reflective metal plate such as Au, Ag, or Al. Alternatively, a metal foil may be applied to the inner peripheral surface of the through hole 2a. Further, when the frame 2 is made of a metal having a high reflectivity, the metal layer 6 may not be particularly deposited.

  In the present invention, the inner peripheral surface of the frame 2 is inclined so that the upper opening is smaller than the lower opening of the through hole 2a. Thereby, the light radiated to the outside of the package is more likely to be radiated in the front direction of the package from the opening on the upper side of the through hole 2a, so that the directivity of the light can be improved. Further, by causing irregular reflection of light in the through-hole 2a and confining the light in the through-hole 2a to some extent, it is possible to suppress extra light leakage, and the light in the front direction has high brightness and high directivity. can do. Therefore, since the light in the front direction has high luminance and high directivity, when the light emitting device is viewed from the outside, the outline of the through hole 2a becomes bright and clear, and the visibility is high. be able to.

  Further, the angle θ formed by the inner peripheral surface of the through hole 2a and the upper surface of the base 1 is preferably 95 to 135 degrees. If θ is less than 95 degrees, the light emitted from the light emitting element 3 is likely to be radiated in a wider range than the opening above the through hole 2a, and the directivity in the front direction is reduced. If θ exceeds 135 degrees, it becomes difficult to radiate light to the outside, and the package becomes large.

  Such a frame 2 can be formed by a punching method using a punching die or the like. At this time, the inner peripheral surface of the through hole formed in the green sheet for the frame body 2 is formed so as to spread at an angle θ of 5 to 45 degrees from one main surface to the other main surface of the green sheet. Thus, by forming the inner peripheral surface of the through hole 2a so as to spread at an angle θ of 5 to 45 degrees from one main surface of the green sheet to the other main surface, Are laminated so that the inner peripheral surface of the through-hole 2a of the frame body 2 becomes narrower inward as it goes upward at an angle θ of 95 to 135 degrees with respect to the upper surface of the base body 1. .

  Moreover, it is preferable that arithmetic mean roughness Ra of the surface of the inner peripheral surface of the through-hole 2a or the surface of the metal layer 6 when the metal layer 6 is deposited is 3 μm or more. When the thickness is 3 μm or more, light emitted from the light emitting element 3 accommodated in the through hole 2a is easily scattered.

  In addition, a resin containing a fluorescent agent or the like may be applied to a portion where the upper surface of the base body 1 is exposed or a portion where the reflective layer is not formed on the inner peripheral surface of the through hole 2a of the frame body 2. Can be satisfactorily reflected in the through hole 2a.

  Further, a dark color such as black or brown is used as the frame body 2 or, as shown in the cross-sectional view of FIG. Thus, when viewed from the front, the distinction between brightness and darkness between the opening on the upper side of the through hole 2a and the upper surface of the frame 2 is clarified, and the visibility of the light emitting device when viewed from the front is improved. Can do.

  Further, the inner peripheral surface of the through hole 2a of the frame body 2 may be a concave curved surface, and in this case, the effect of suppressing extra light leakage by confining the light in the through hole 2a to some extent is more effective. Will increase.

  Furthermore, the upper end portion of the inner peripheral surface of the through hole 2a may be formed so as to be perpendicular to the upper surface of the base 1, or the upper end portion may be inclined so as to spread slightly outward. In this case, the opening on the upper side of the through hole 2a when viewed from the front becomes brighter and visibility can be improved.

  The light emitting device of the present invention includes the package of the present invention, the light emitting element 3 mounted on the mounting portion 1a, and a transparent resin such as a silicone resin or an epoxy resin that covers the light emitting element 3. Thereby, the light of the light emitting element 3 can be efficiently emitted in the front direction and can be made clear. The transparent resin covering the light emitting element 3 may cover the light emitting element 3 and the periphery thereof, or may fill the through hole 2a and cover the light emitting element 3.

  Further, as shown in a cross-sectional view in FIG. 3, the light-emitting element storage package and the light-emitting device of the present invention are arranged in a dot matrix shape, so that it can be used as a suitable display device.

  It should be noted that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention. For example, as shown in the cross-sectional view of the package in FIG. 4, the light emitting element 3 is directly mounted on the upper surface of the base 1 without forming the mounting portion 1a as a conductor layer, and the electrodes of the light emitting element 3 are electrically connected to the periphery thereof. The metallized wiring conductors 4a and 4b connected to may be formed. In this case, the light emitting element 3 is mounted on the mounting portion 1a, and the electrodes of the light emitting element 3 and the metallized wiring conductors 4a and 4b are electrically connected via the bonding wires 5a and 5b. Further, a plurality of light emitting elements 3 may be mounted, or a plurality of wiring layers may be formed.

It is sectional drawing which shows an example of embodiment about the light emitting element accommodation package of this invention. It is sectional drawing which shows the other example of embodiment about the light emitting element storage package of this invention. It is sectional drawing which shows the other example of embodiment about the light emitting element storage package of this invention. It is sectional drawing which shows the other example of embodiment about the light emitting element storage package of this invention. It is sectional drawing of the conventional package for light emitting element accommodation.

Explanation of symbols

1: Base 1a: Mounting portion 2: Frame 2a: Through hole 3: Light emitting element 4a, 4b: Wiring layer 6a: Metallized metal layer 6b: Plating metal layer

Claims (2)

In a light emitting element storage package, a frame having a through hole for accommodating a light emitting element is joined to an upper surface of a base having a mounting part for mounting the light emitting element on the upper surface so as to surround the mounting part. The frame body has an inner peripheral surface inclined so that an opening on an upper side of an opening on a lower side of the through hole is smaller. A light emitting device comprising: the light emitting element storage package according to claim 1; a light emitting element mounted on the mounting portion; and a transparent resin covering the light emitting element.

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