JP2006261286A - Package for containing light emitting element and its manufacturing process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a package for containing a light emitting element in which the conical through hole of a ceramic substrate has such a wall surface as emission efficiency of the light emitting element can be enhanced, and to provide its manufacturing process. <P>SOLUTION: The package 10 for containing a light emitting element is produced by bonding a planar first ceramic substrate 11 having a region 13 for mounting a light emitting element 12 on the upper surface, and a second ceramic substrate 15 having a conical through hole 14 for exposing the mounting region 13 of the first ceramic substrate 11 wherein the opening of the through hole is larger on the upper surface side than on the lower surface side, i. e. the side being bonded to the first ceramic substrate 11. Ceramic paste composed of the same ceramic material as that of the second ceramic substrate 15 is applied to the wall surface of the conical through hole 14 and sintered to form a ceramic film 16. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a light-emitting element storage package using a multilayer ceramic substrate for mounting and storing light-emitting elements such as LEDs (Light Emission Diode), and a method for manufacturing the same.

Conventionally, as a light emitting element storage package for storing a light emitting element such as an LED, a package manufactured using plastic or ceramic has been used. Further, recent light emitting devices are required to increase the light output, but to meet this requirement by increasing the current applied to the light emitting device, the temperature of the light emitting device itself is also increased. When the package for housing the light emitting element is made of plastic, there is a problem that the heat resistance is not sufficient. Therefore, recently, in the light emitting element storage package and the manufacturing method thereof, a ceramic package made of alumina (Al ₂ O ₃ ) or the like having high heat resistance is often used. The light emitting element storage package made of ceramic is a reflection that can improve the light emission efficiency by reflecting the light emitted from the issuing element to the wall surface of the cavity part where the issuing element is placed and surrounded. Those that provide layers have been developed.

  A conventional ceramic light-emitting element storage package having a reflective layer for reflecting light on the wall surface of the package and its manufacturing method include a cavity in which a light-emitting element is to be placed on a ceramic green sheet on which conductor wiring is formed. When forming the part, the ceramic green sheet is press-molded so that the cavity part becomes wider in the opening direction, degreased and fired, and then the conductor layer on the cavity part wall surface is plated with noble metal and its manufacturing method is proposed (For example, refer to Patent Document 1). In addition, a conventional ceramic light emitting element storage package having a reflective layer for reflecting light on the wall surface of the package and a method for manufacturing the same include a substantially flat plate shape having a mounting portion for mounting the light emitting element on an upper surface. A ceramic frame having a through hole for accommodating a light emitting element is laminated on the upper surface of the ceramic substrate, and the inner wall of the through hole extends outward at an angle of 55 to 70 degrees with respect to the upper surface of the ceramic substrate. Further, a metal layer having a center line average roughness Ra of 1 to 3 μm and a reflectance of 80% or more for light emitted from the light emitting element is applied to the surface, and a method for manufacturing the same is proposed ( For example, see Patent Document 2).

JP 9-45965 A Japanese Patent Laid-Open No. 2002-232017

However, the conventional light emitting element storage package and the manufacturing method thereof have the following problems.
(1) When forming a cavity part, which is a light emitting element mounting part, by pressing the ceramic green sheet so as to be wide in the opening direction of the cavity part, a part where the ceramic green sheet is refracted Cracks, fractures, etc. occur in the film, making it impossible to exhibit the function as an insulator.
(2) The mortar-shaped through-hole in the cavity portion, which is the light-emitting element mounting portion, can be formed by punching out the ceramic green sheet by increasing the clearance between the punch and die of the punching die. The wall surface of the through hole is not a stable shape, and large irregularities are generated. When the wall surface having such a shape is used as a reflecting plate, the diffusion of light increases, and stable reflected light cannot be obtained. Therefore, it is difficult to improve the light emission efficiency of the light emitting element.
The present invention has been made in view of such circumstances, and provides a light emitting element storage package and a method for manufacturing the same, in which a wall surface of a mortar-shaped through hole of a ceramic substrate can be used as a wall surface capable of improving the light emission efficiency of the light emitting element. The purpose is to provide.

  The light-emitting element storage package according to the present invention that meets the above-described object includes a flat plate-like first ceramic substrate having a mounting region for mounting an issuing element on the upper surface, and a mounting region of the first ceramic substrate as an opening. An issuance element storage package comprising a joined body with a second ceramic substrate that has a mortar-shaped through-hole that is exposed and has a larger opening on the upper surface side than the lower surface side that is the joining side with the first ceramic substrate. Then, a ceramic film made of the same ceramic material as that of the second ceramic substrate is applied to the wall surface of the mortar-shaped through-hole and fired.

  The manufacturing method of the light emitting element storage package according to the present invention in accordance with the above object includes a first ceramic green sheet comprising one or a plurality of conductor printing patterns for a conductor wiring pattern of a first ceramic substrate, and a second method. In the manufacturing method of a package for storing an issuing element, in which one or a plurality of second ceramic green sheets each having an insertion hole for a mortar-shaped through-hole of a ceramic substrate are laminated and fired, the first ceramic green Forming a conductor print pattern by screen printing using a conductive paste on the sheet, forming a mortar-shaped insertion hole in the second ceramic green sheet, and the same ceramic material as the second ceramic green sheet on the wall surface of the insertion hole A step of applying a ceramic paste comprising: a screen printing; and a first ceramic green sheet. Laminating the door and a second ceramic green sheet, a step of forming a ceramic film on the wall surface of the bowl-shaped through-holes and then fired.

  The light emitting element storage package according to claim 1 is an issuance element storage package comprising a joined body of a flat plate-like first ceramic substrate and a second ceramic substrate having a mortar-shaped through-hole, Since a ceramic paste made of the same ceramic material as the second ceramic substrate is applied to the wall surface of the through hole and fired, the ceramic film in which the wall surface of the mortar-shaped through hole is flattened with the ceramic paste emits light. It can be set as the reflective surface which can reflect the light emission from an element efficiently, and the light emission efficiency of a light emitting element can be improved. Further, for example, even if a metal film is formed on the upper surface of the ceramic film, a flattened metal film can be formed, and a reflective surface that improves the light emission efficiency of the light emitting element can be obtained.

  The method for manufacturing a light emitting element storage package according to claim 2 includes a step of forming a conductor print pattern by screen printing using a conductor paste on the first ceramic green sheet, and a mortar-like insertion through the second ceramic green sheet. Forming a hole, applying a ceramic paste made of the same ceramic material as the second ceramic green sheet to the wall surface of the insertion hole by screen printing, laminating the first ceramic green sheet and the second ceramic green sheet, Since it has a step of forming a ceramic film on the wall surface of the mortar-shaped through hole, a conductor wiring pattern on which a light emitting element that can be electrically connected to the outside can be formed by a conductor printing pattern, and a ceramic paste can be used. The wall surface of the insertion hole can be a flat ceramic film surface. Method of manufacturing a light-emitting element storing package which can improve the luminous efficiency of the light emitting element can be provided.

Subsequently, the best mode for carrying out the present invention will be described with reference to the accompanying drawings to provide an understanding of the present invention.
Here, FIGS. 1A and 1B are a plan view, a longitudinal sectional view taken along line AA ′, and FIGS. 2A to 2D, respectively, of a light emitting element storage package according to an embodiment of the present invention. These are explanatory drawings of the manufacturing method of the light emitting element storage package, respectively.

As shown in FIGS. 1A and 1B, a light emitting element storage package 10 according to an embodiment of the present invention has an alumina (rectangular, polygonal, circular, etc.) in plan view. For mounting a light emitting element 12 such as an LED on one of both main surfaces of a flat plate-like first ceramic substrate 11 made of one or more of Al ₂ O ₃ ), aluminum nitride (AlN), or the like. A mounting area 13 is provided. In addition, the light emitting element storage package 10 according to the embodiment of the present invention exposes the mounting region 13 of the first ceramic substrate 11 as an opening, and the size of the opening is the first ceramic substrate 11. And a second ceramic substrate 15 made of one or a plurality of sheets such as alumina or aluminum nitride having a mortar-like through hole 14 in a cross-sectional view in which the upper surface side is larger than the lower surface side which is the bonding side. A ceramic paste made of the same ceramic material as the second ceramic substrate 15 is applied to the wall surface of the mortar-shaped through-hole 14 of the second ceramic substrate 15 by screen printing and fired to form a ceramic film 16. have. Since the ceramic film 16 can make the uneven wall surface of the mortar-shaped through-hole 14 of the second ceramic substrate 15 a flat surface, the light emitted from the light emitting element 12 can be effectively reflected. In addition, a plating film may be provided on the surface of the ceramic film 16 in order to reflect light emitted from the light emitting element 12 more effectively.

  A conductor wiring pattern 18 including via conductors 17 for electrically connecting upper and lower layers formed in the light emitting element storage package 10 is a mounting region on one main surface side of the first ceramic substrate 11. 13, in order to make it electrically conductive by using a die bond pad 19 for mounting the light emitting element 12 and a wire bond system (this system is shown in FIG. 1) connected to the light emitting element 12 by a bonding wire 20. The bonding pad 21 is formed. Alternatively, the conductor wiring pattern 18 is in an electrically conductive state by using a flip chip method in which a connection bump provided on the light emitting element 12 is directly connected to the mounting region 13 on one main surface side of the first ceramic substrate 11. It is formed as a bonding pad 21 or the like. In addition, the conductor wiring pattern 18 is connected to the outside on the other main surface side of the first ceramic substrate 11 or on the upper surface side of the second ceramic substrate 15 so as to be in an electrically conductive state. It is formed as a terminal pad 22 or the like.

2A to 2D, a method for manufacturing the light emitting element storage package 10 according to the embodiment of the present invention will be described. A ceramic green sheet made of ceramic such as Al ₂ O ₃ or AlN is used in the method for manufacturing the light emitting element storage package 10. When this ceramic green sheet is made of, for example, Al ₂ O ₃ ceramic, a powder obtained by adding an appropriate amount of a sintering aid such as magnesia, silica, calcia to Al ₂ O ₃ powder and a plasticizer such as dioctyl phthalate Then, a binder such as an acrylic resin, and a solvent such as toluene, xylene, and alcohols are added and sufficiently kneaded, and then defoamed to create a slurry having a viscosity of 2000 to 40000 cps. It is formed into a roll sheet having a thickness of 0.25 mm, and is cut into an appropriate size to produce a ceramic green sheet.

  As shown in FIG. 2A, one or a plurality of ceramic green sheets are prepared for the first ceramic substrate 11. Here, for example, the first ceramic green sheet 23 composed of two sheets, 23a is prepared. The two first ceramic green sheets 23 and 23a are provided with via holes 24 for forming the via conductors 17 as necessary using a punching die or a punching machine. Forming. The first ceramic green sheet 23 on the upper side of the two sheets is screen-printed using a conductive paste made of a refractory metal such as tungsten (W) or molybdenum (Mo), and the die bond pad 19. The conductor printed pattern 25 for the conductor wiring pattern 18 (see FIG. 2D) such as the bonding pad 21 and the via conductor 17 is formed. The first ceramic green sheet 23a on the lower side of the two sheets is screened using a conductive paste made of a refractory metal that can be fired simultaneously with a ceramic such as tungsten (W) or molybdenum (Mo). Conductor wiring patterns 18 such as connecting wiring patterns for connecting the via conductors 17 formed on the first ceramic green sheets 23 and 23a by printing, via conductors 17 and external connection terminal pads 22 (FIG. 2 ( The conductive printed pattern 25a for reference D) is formed.

  As shown in FIG. 2B, one or more ceramic green sheets are prepared for the second ceramic substrate 15. Here, for example, the second ceramic green sheet 26 made of one sheet is prepared. I'm preparing. The second ceramic green sheet 26 is punched with a punching die comprising a pin and a die having a hole diameter larger than the diameter of the pin to form an insertion hole 27 for the mortar-shaped through hole 14. A punching die composed of a pin and a die having a hole diameter larger than the diameter of the pin has a second ceramic green sheet 26 placed on the die by a clearance between the outer diameter of the pin and the hole diameter of the die. The second ceramic green sheet 26 is formed with a mortar-shaped insertion hole 27 having a small hole diameter on the side in contact with the pin and a large hole diameter on the side in contact with the die. it can. A ceramic printing pattern 28 for the ceramic film 16 is formed on the wall surface of the mortar-shaped insertion hole 27 by applying screen printing using a ceramic paste made of the same ceramic material as the second ceramic green sheet 26. ing. In this screen printing, ceramic paste is easily printed on the wall surface of the mortar-shaped insertion hole 27 by screen-printing ceramic paste so that the portion of the mortar-shaped insertion hole 27 can be sucked from the bottom of the printing stand of the screen printer. Can be formed. Moreover, since the ceramic paste used here is relatively low in viscosity and rich in fluidity, the uneven state of the wall surface of the mortar-shaped insertion hole 27 can be made a flat surface. In addition, on the upper surface of the ceramic printing pattern 28 provided on the wall surface of the mortar-shaped insertion hole 27, a conductive metal film may be provided by screen printing using a conductive paste as necessary. On this conductive metal film, an Ag plating film or the like can be formed, and a reflective layer that can more effectively reflect the light emitted from the light emitting element 12 can be formed.

  Next, as shown in FIG. 2C, the first ceramic green sheets 23 and 23 a and the second ceramic green sheet 26 are overlapped and stacked by applying temperature and pressure to form a stacked body 29. is doing. Next, as shown in FIG. 2D, the laminate 29 is composed of the first ceramic green sheets 23 and 23a, the second ceramic green sheet 26, and the conductor printed pattern 25 at a temperature of about 1650 ° C. in a reducing atmosphere. 25a and the ceramic printed pattern 28 are simultaneously fired to form a fired body. This fired body shrinks about 30% from the laminate 29 by simultaneous firing, and the first ceramic substrate 11 provided with the conductor wiring pattern 18 and the second ceramic provided with the ceramic film 16 on the wall surface of the mortar-shaped through-hole 14. The light emitting element storage package 10 is formed of a bonded body of the substrate 15. The light emitting element storage package 10 is provided with a noble metal plating film such as a Ni plating film, an Au plating film, or an Ag plating film on a metal portion exposed to the outside as necessary.

  The light emitting element storage package of the present invention can be used for illumination, a display, or the like that can be equipped with a light emitting element such as an LED to improve the light emission efficiency.

(A), (B) is a top view of the light emitting element storage package which concerns on one embodiment of this invention, respectively, and an A-A 'line longitudinal cross-sectional view. (A)-(D) is explanatory drawing of the manufacturing method of the package for the said light emitting element accommodation, respectively.

Explanation of symbols

  10: Light-emitting element storage package, 11: First ceramic substrate, 12: Light-emitting element, 13: Mounting area, 14: Mortar-shaped through hole, 15: Second ceramic substrate, 16: Ceramic film, 17: Via conductor , 18: conductor wiring pattern, 19: die bond pad, 20: bonding wire, 21: bonding pad, 22: external connection terminal pad, 23, 23a: first ceramic green sheet, 24: through-hole for via, 25, 25a : Conductor print pattern, 26: Second ceramic green sheet, 27: Insertion hole, 28: Ceramic print pattern, 29: Laminate

Claims (2)

A flat plate-like first ceramic substrate having a mounting region for mounting the issuing element on the upper surface, and the mounting region of the first ceramic substrate is exposed as an opening, and the size of the opening is the first An issuance element storage package comprising a joined body with a second ceramic substrate having a mortar-shaped through hole whose upper surface side is larger than the lower surface side which is the bonding side with the ceramic substrate
A package for receiving element storage, comprising a ceramic film on which a ceramic paste made of the same ceramic material as that of the second ceramic substrate is applied and fired on a wall surface of the mortar-shaped through hole. One or a plurality of first ceramic green sheets each having a conductor printed pattern for a conductor wiring pattern of a first ceramic substrate, and one or a plurality of sheets having an insertion hole for a mortar-shaped through hole of a second ceramic substrate In the manufacturing method of the package for storage of the issuing element formed by laminating and firing the second ceramic green sheet comprising:
Forming the conductor print pattern by screen printing using a conductor paste on the first ceramic green sheet;
Forming the mortar-shaped insertion hole in the second ceramic green sheet, and applying a ceramic paste made of the same ceramic material as the second ceramic green sheet to the wall surface of the insertion hole by screen printing;
A manufacturing method for an issuance element storage package, comprising: laminating the first ceramic green sheet and the second ceramic green sheet and firing to form a ceramic film on a wall surface of the mortar-shaped through-hole. Method.

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