JP2006261290A - 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 frame 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 process for manufacturing a package 10 for containing a light emitting element produced by bonding a ceramic substrate 11 for mounting a light emitting element and a ceramic frame 12 having a conical through hole 13 comprises a step performing screen printing of a conductor print pattern 22 for a conductor wiring pattern 14 onto first ceramic green sheets 20 and 20a for a ceramic substrate 11, a step for boring an insertion hole 24 for the conical through hole 13 in a second ceramic green sheet 23 for the ceramic frame 12, a step for pressing the surface of wall of the insertion hole 24 by means of a press die 26 equipped with an upper die 28 having a rubber body 27 shaped along the surface of wall and a base mount 32 for mounting the second ceramic green sheet 23, and a step for sintering a laminate 25 after it is formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a light emitting element storage package including a ceramic base and a ceramic frame for storing a light emitting element such as a light emitting diode (LED), and more particularly, an LED. The present invention relates to a method for manufacturing a light emitting element storage package capable of improving the light emission efficiency of a light emitting element.

Conventionally, a light-emitting element storage package for storing a light-emitting element such as an LED has been manufactured using plastic, ceramic, or the like. In recent years, light emitting devices have been required to increase the light output. In order to cope with this, if an attempt is made to increase the current flowing through the light emitting device, the light output increases with the increase in the light output. The temperature of the element itself will also rise. In the case where the package for housing such a light emitting element is plastic, the heat resistance from the light emitting element to the high temperature becomes insufficient, causing a problem. Therefore, recently, a package made using a ceramic made of alumina (Al ₂ O ₃ ) or the like having high heat resistance is often used. Further, since the light emitting element storage package is required to improve the light emission efficiency of the light emitted from the light emitting element, the light emission is performed on the wall surface of the portion where the light emitting element is placed and surrounded. There is a need to be able to effectively reflect light emitted from an element. In order to cope with this, the wall surface of the portion of the ceramic light-emitting element storage package on which the light-emitting element is placed and surrounded is formed in a mortar shape with an opening diameter increased outward.

  With reference to FIGS. 4A to 4D, a method for manufacturing a conventional light emitting element storage package 50 (see FIG. 4D) will be described. As shown in FIG. 4A, for example, two first ceramic green sheets 52 and 52a for the ceramic substrate 51 (see FIG. 4D) are provided with via conductors 53 (see FIG. 4). (Refer to (D)) A through-hole for via 54 is formed, and a refractory metal such as tungsten (W) or molybdenum (Mo) is formed in each of the first ceramic green sheets 52 and 52a. A conductor print pattern 56 for the conductor wiring pattern 55 (see FIG. 4D) is formed by screen printing using a conductor paste made of As shown in FIG. 4B, for example, one second ceramic green sheet 58 for the ceramic frame 57 (see FIG. 4D) has a pin and a hole diameter larger than the diameter of the pin. An insertion hole 60 for a mortar-shaped through hole 59 (see FIG. 4D) is formed by punching with a punching die made of a provided die. This punching die is formed by pressing the second ceramic green sheet 58 placed on the die with a pin from above with a clearance between the outer diameter of the pin and the hole diameter of the die. An insertion hole 60 having a small hole diameter on the side contacting the die and a large hole diameter on the side contacting the die can be formed. In addition, on the wall surface of the insertion hole 60, if necessary, a conductor metal film is screen-printed using a conductor paste, and after firing, an Ag plating film or the like is formed on the conductor metal film to form a light-emitting element. It can also be formed in a reflective layer that can more effectively reflect emitted light.

  Next, as shown in FIG. 4C, the first ceramic green sheets 52 and 52a and the second ceramic green sheet 58 are overlapped and stacked by applying temperature and pressure to form a stacked body 61. is doing. Next, as shown in FIG. 2 (D), the laminate 61 includes the first ceramic green sheets 52 and 52a, the second ceramic green sheet 58, and the conductor printing pattern at a temperature of about 1650 ° C. in a reducing atmosphere. 56 is simultaneously fired to form a fired body. This fired body is contracted by about 30% from the laminated body 61 by simultaneous firing, from the joined body of the ceramic base body 51 provided with the conductor wiring pattern 55 including the via conductor 53 and the ceramic frame body 57 provided with the mortar-shaped through hole 59. The light emitting element storage package 50 is formed as follows. In the light emitting element storage package 50, a noble metal plating film such as a Ni plating film, an Au plating film, or an Ag plating film is applied to a metal portion exposed to the outside as necessary.

  In a conventional ceramic light emitting element storage package and a manufacturing method thereof, a through hole for storing a light emitting element is formed on the upper surface of a substantially flat ceramic base having a mounting portion for mounting the light emitting element on the upper surface. The inner wall of the through hole spreads outward at an angle of 55 to 70 degrees with respect to the upper surface of the ceramic substrate, and the center line has an average roughness Ra of 1 to 3 μm and emits light. A device in which a metal layer having a reflectance of 80% or more with respect to light emitted from the element is applied, and a manufacturing method thereof have been proposed (for example, see Patent Document 1). In addition, according to the conventional ceramic light emitting element storage package and its manufacturing method, when the cavity portion in which the light emitting element is to be placed is formed on the ceramic green sheet on which the conductor wiring is formed, the ceramic green sheet has the cavity portion. There has been proposed a method in which press molding is performed so as to widen in the opening direction, degreasing, and firing, and then a noble metal plating is applied to the conductor layer on the wall surface of the cavity, and a manufacturing method thereof (see, for example, Patent Document 2).

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

However, the conventional method for manufacturing a light emitting element storage package as described above has the following problems.
(1) The insertion hole for the mortar-shaped through hole in the cavity portion which is the light emitting element mounting portion is formed by punching out the ceramic green sheet for the ceramic frame by increasing the clearance between the punch and the die of the punching die. Although it can be formed, the wall surface of the insertion hole is not a stable shape, and large irregularities are generated. When the wall surface of the insertion hole having such a shape is used as a reflection plate after firing, the diffusion of light increases and stable reflected light cannot be obtained, so it is difficult to improve the light emission efficiency of the light emitting element. ing.
(2) When the concave portion is formed by press-molding the ceramic green sheet so as to be wide in the opening direction of the cavity portion to form the cavity portion which is the light emitting element mounting portion, the portion where the ceramic green sheet is refracted Cracks, fractures, etc. occur in the film, making it impossible to exhibit the function as an insulator.
The present invention has been made in view of such circumstances, and provides a method for manufacturing a package for housing a light emitting element, in which a wall surface of a mortar-shaped through hole of a ceramic frame can be used as a wall surface that can improve the light emission efficiency of the light emitting element. The purpose is to provide.

  A method for manufacturing a light emitting element storage package according to the present invention in accordance with the above object is a ceramic having a flat ceramic base for mounting a light emitting element and a mortar-shaped through hole for surrounding and storing the light emitting element. In a method for manufacturing a light emitting element storage package provided by joining frames, a step of screen printing a conductor printed pattern for a conductor wiring pattern on one or more first ceramic green sheets for a ceramic substrate, and a ceramic frame A step of forming an insertion hole for a mortar-shaped through-hole in which the opening diameter on the upper surface side is larger than the opening diameter on the lower surface side in one or a plurality of second ceramic green sheets for body use, and the second ceramic green sheet An upper mold having a rubber body having a shape along the wall surface, and a base for placing the second ceramic green sheet. A step of pressing the wall with a pressing mold to obtain, after forming the first ceramic green sheet and laminate by laminating a second ceramic green sheet, a step of firing the laminate.

  Here, the manufacturing method of the light emitting element storage package is as follows. The upper die of the pressing mold is porous with silicon oil impregnated and made of silicon rubber having a hardness of 20 ° to 50 °, and the upper surface of the insertion hole is opened. It has a metal plate that is provided by fitting a rubber body into a through-hole having an opening diameter that is substantially the same as the aperture, and has a hardness substantially equivalent to the hardness of the rubber body so as to cover the rubber body and the back surface of the metal plate. The rubber plate has a rubber plate, transmits the pressing force to the rubber body and the metal plate through the rubber plate, and presses the upper surface of the second ceramic green sheet placed on the press-type base with the metal plate. The body is pressed on the base and spreads in the lateral direction, and the wall surface of the insertion hole of the second ceramic green sheet is pressed.

  The method of manufacturing a light emitting element storage package according to claim 1 or claim 2 dependent thereon, screen-printing a conductor printed pattern for a conductor wiring pattern on one or a plurality of first ceramic green sheets for a ceramic substrate. And a step of forming an insertion hole for a mortar-shaped through-hole in which the opening diameter on the upper surface side is larger than the opening diameter on the lower surface side in one or a plurality of second ceramic green sheets for the ceramic frame, The wall surface of the insertion hole of the second ceramic green sheet is pressed against the wall surface by a pressing mold having an upper mold having a rubber body having a shape along the wall surface and a base for placing the second ceramic green sheet. And a step of laminating the first ceramic green sheet and the second ceramic green sheet to form a laminate, and then firing the laminate. The printed wiring pattern can form a conductor wiring pattern that can be electrically connected to the outside on the first ceramic green sheet for the ceramic substrate, and the insertion hole of the second ceramic green sheet for the ceramic frame body by the pressing die Manufacture of a package for housing a light-emitting element in which the wall surface can be flattened and the light-emitting element can be mounted on the fired package to improve the light emission efficiency from the light-emitting element on the wall surface of the ceramic mortar-shaped through hole A method can be provided.

  In particular, the manufacturing method of the light emitting element storage package according to claim 2 is characterized in that the upper die of the pressing mold is porous with silicon oil impregnated and made of silicon rubber having a hardness of 20 ° to 50 °, and the insertion hole It has a metal plate that is provided by fitting a rubber body into a through-hole having an opening diameter that is substantially the same as the opening diameter on the upper surface side, and substantially the same hardness as the rubber body so as to cover the rubber body and the back surface of the metal plate. The upper surface of the second ceramic green sheet placed on the base of the pressing mold is transmitted with the metal plate by transmitting the pressing force to the rubber body and the metal plate through the rubber plate. While pressing, the rubber body is pressed on the base and spreads in the lateral direction, pressing the wall surface of the insertion hole of the second ceramic green sheet, so the metal plate pressed by the rubber plate pushes the second ceramic green sheet Firmly fixed The rubber body pressed by the rubber plate is made of silicon rubber with a hardness of 20 ° to 50 ° impregnated with silicon oil. The rubber body and the base are inflated laterally and the pressure is inserted as hydrostatic pressure. It is possible to provide a method for manufacturing a light emitting element storage package that can be transmitted to the entire hole wall surface and that can flatten the insertion hole wall surface of the second ceramic green sheet.

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 explanatory diagrams of a light emitting element storage package manufactured by the method for manufacturing a light emitting element storage package according to an embodiment of the present invention. FIGS. (D) is explanatory drawing of the manufacturing method of the package for the said light emitting element accommodation, respectively, FIG. 3 (A)-(C) is explanatory drawing of the pressing method of the through-hole wall surface in the manufacturing method of the said light emitting element accommodation package, respectively. .

  As shown in FIGS. 1A and 1B, a light emitting element storage package 10 manufactured by the method for manufacturing a light emitting element storage package according to an embodiment of the present invention is a flat plate made of one or a plurality of sheets. It is manufactured as a joined body in which a ceramic base body 11 and one or a plurality of ceramic frame bodies 12 are joined to the upper surface thereof. When viewed in plan, the ceramic substrate 11 having a rectangular shape, a polygonal shape, a circular shape, or the like is configured such that a light emitting element such as an LED can be placed on one of the two main surfaces. Further, the ceramic frame 12 has a shape in which the upper surface of the ceramic base 11 is exposed with the light emitting element mounting portion as an opening, and the size of the opening is larger on the upper surface than the lower surface that is the bonding side with the ceramic base 11. A mortar-shaped through-hole 13 is provided in one or more cross-sections for surrounding and storing the light emitting element. Since the wall surface of the mortar-shaped through-hole 13 of the ceramic frame 12 is pressed by a pressing mold to make the uneven wall surface a flat surface, light emitted from the light emitting element can be effectively reflected. In addition, a metal film and / or a plating film may be provided on the surface of the mortar-shaped through hole 13 in order to reflect light emitted from the light emitting element more effectively.

  In this light emitting element storage package 10, the conductor wiring pattern 14 is mounted on the light emitting element mounting portion of the ceramic substrate 11. (This method is shown in FIG. 1) and is formed to be used as a bonding pad 16 or the like for making it electrically conductive. Alternatively, the conductor wiring pattern 14 is used as a bonding pad 16 or the like for electrically connecting to the light emitting element mounting portion of the ceramic substrate 11 by using a flip chip method in which a connection bump provided on the light emitting element is directly connected. Is formed. The conductor wiring pattern 14 is one of the conductor wiring patterns 14 on the back surface side of the ceramic substrate 11 or on the upper surface side of the ceramic substrate 11 that is exposed to the outside by cutting out the outer peripheral portion of the ceramic frame 12. It is formed as an external connection terminal pad 19 or the like for connecting to the bonding pad 16 through the connecting conductor pattern 17 and the via conductor 18 and making it electrically conductive with the outside.

With reference to FIGS. 2A to 2D, a method of manufacturing the light emitting element storage package 10 according to an embodiment of the present invention will be described. Here, FIGS. 2A to 2C show the state of the ceramic green sheet before firing of the ceramic of the light emitting element housing package 10, and FIG. 2D shows the light emitting element of the finished state after firing of the ceramic. A storage package 10 is shown. A light emitting element housing manufactured as a joined body of a ceramic frame body 12 having a flat ceramic substrate 11 for mounting a light emitting element and a mortar-like through hole 13 for enclosing and housing the light emitting element on the upper surface thereof. A ceramic green sheet made of ceramic such as Al ₂ O ₃ or AlN is used for the manufacturing method of the package 10. For example, when the ceramic is made of Al ₂ O ₃ , this ceramic green sheet is obtained by adding a suitable amount of a sintering aid such as magnesia, silica, or calcia to Al ₂ O ₃ powder, and adding plastic such as dioctyl phthalate. Agent, a binder such as acrylic resin, and a solvent such as toluene, xylene, alcohols, etc. are added and kneaded sufficiently, and then defoamed to create a slurry having a viscosity of 2000 to 40000 cps. For example, it is formed into a roll-like sheet having a thickness of 0.25 mm, and is cut into an appropriate size.

  As shown in FIG. 2A, one or a plurality of ceramic green sheets are prepared for the ceramic substrate 11. Here, for example, two first ceramic green sheets 20, 20a are prepared. is doing. The two first ceramic green sheets 20 and 20a are provided with via holes 21 for forming via conductors 18 as necessary using a punching die or a punching machine. Forming. The first ceramic green sheet 20 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 15. The conductor printed pattern 22 for the conductor wiring pattern 14 such as the bonding pad 16 and the via conductor 18 is formed. The first ceramic green sheet 20a 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 for conductor wiring pattern 14 such as connecting wiring pattern 17, via conductor 18, and external connection terminal pad 19 for connecting between via conductors 18 formed by printing on first ceramic green sheets 20 and 20 a. A print pattern 22 is formed.

  As shown in FIG. 2B, one or a plurality of ceramic green sheets for the ceramic frame 12 are prepared. Here, for example, a second ceramic green sheet 23 composed of one sheet is prepared. is doing. The second ceramic green sheet 23 is formed by punching with a punching die made of a pin and a die having a hole diameter larger than the diameter of the pin, and forming an insertion hole 24 for the mortar-shaped through hole 13. is doing. A punching die composed of a pin and a die provided with a hole diameter larger than the diameter of the pin has a second ceramic green sheet 23 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 23 is formed with a mortar-shaped insertion hole 24 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.

  Next, the wall surface of the mortar-shaped insertion hole 24 of the second ceramic green sheet 23 is pressed by a pressing die 26 (see FIGS. 3A to 3C), which will be described later. The pressing die 26 includes a rubber body 27 having a shape along the wall surface of the insertion hole 24, a metal plate 30 having a through hole 29 for surrounding and supporting the side surface of the rubber body 27, and the rubber body 27 and the metal plate 30. The upper die 28 having a rubber plate 31 provided on the back surface thereof and a base 32 on which the second ceramic green sheet 23 is placed. In some cases, a conductive metal film may be provided on the wall surface of the mortar-shaped insertion hole 24 by screen printing using a conductive paste as necessary. With this conductive metal film, a plating film by electrolytic plating can be formed on the wall surface of the insertion hole 24, and a reflective layer that can more effectively reflect the light emitted from the light emitting element can be formed.

  Next, as shown in FIG. 2C, the first ceramic green sheets 20 and 20 a and the second ceramic green sheet 23 are overlapped and stacked by applying temperature and pressure to form a stacked body 25. is doing. Next, as shown in FIG. 2D, the laminate 25 is composed of the first ceramic green sheets 20 and 20a, the second ceramic green sheet 23, and the conductor printing pattern at a temperature of about 1650 ° C. in a reducing atmosphere. 22 is simultaneously fired to form a fired body. This fired body shrinks about 30% from the laminate 25 by simultaneous firing, and the wall surface of the ceramic substrate 11 on which the conductor wiring pattern 14 is provided and the wall surface of the mortar-shaped through-hole 13 are pressed to become a flat surface. The light emitting element housing package 10 is formed of a joined body of ceramic frame bodies 12 to be provided. 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.

  Next, referring to FIGS. 3A to 3C, the wall surface of the insertion hole 24 formed in the second ceramic green sheet 23 in the method for manufacturing the light emitting element storage package 10 according to the embodiment of the present invention. Details of the pressing method will be described in detail. As shown in FIG. 3 (A), the upper die 28 of the pressing die 26 has a rubber body 27 made of silicon rubber that is impregnated with silicon oil and has a hardness of 20 ° to 50 °. ing. Further, the upper die 28 of the pressing die 26 is provided with a metal plate 30 provided with a through hole 29 having an opening diameter substantially equal to the opening diameter on the upper surface side of the insertion hole 24 and abutting the upper surface of the second ceramic green sheet 23. Has as a surface. The rubber plate 27 is fitted in the through hole 29 of the metal plate 30 so that the side surface of the rubber plate 27 is surrounded. Further, the upper die 28 of the pressing die 26 has a rubber plate 31 having a hardness substantially equal to the hardness 20 ° to 50 ° of the rubber body 27 so as to cover the rubber body 27 and the back surface of the metal plate 30. Yes. On the other hand, the pressing die 26 includes a base 32 made of a metal surface having a flat upper surface so as to face the upper die 28 in a parallel state. Then, on the base 32 between the upper mold 28 and the base 32, the second ceramic green sheet 23 in which the insertion hole 24 is formed is placed.

  Next, as shown in FIGS. 3B and 3C, the upper die 28 of the pressing die 26 to which the pressing force is transmitted to the rubber body 27 and the metal plate 30 via the rubber plate 31 is The front end of the rubber body 27 is exposed from the opening of the insertion hole 24 of the second ceramic green sheet 23 while pressing the upper surface of the second ceramic green sheet 23 placed on the base 32 with the metal plate 30. While pressing on the base 32, it is spread laterally to press the wall surface of the insertion hole 24 of the second ceramic green sheet 23. The wall surface of the insertion hole 24 is formed into a flat surface by this pressing, and light from the light emitting element can be efficiently reflected. Here, when the hardness of the rubber body 27 is less than 20 °, the rubber body 27 becomes so soft that the force pressing the wall surface of the insertion hole 24 becomes weak, and the wall surface of the insertion hole 24 cannot be flattened. Further, if the hardness of the rubber body 27 exceeds 50 °, the rubber body 27 becomes too hard and the lateral bulge is reduced, and the wall surface of the insertion hole 24 cannot be flattened. On the other hand, when the hardness of the rubber plate 31 is not substantially equal to the hardness of the rubber body 27, the pressing force of the rubber body 27 and the swelling in the lateral direction cannot be exhibited normally, and the wall surface of the insertion hole 24 is flat. It becomes impossible to make it.

  The light emitting element storage package of the present invention can be used for illumination, a display, or the like by mounting a light emitting element such as an LED.

(A), (B) is explanatory drawing of the light emitting element storage package produced with the manufacturing method of the light emitting element storage package which concerns on one embodiment of this invention, respectively. (A)-(D) is explanatory drawing of the manufacturing method of the package for the said light emitting element accommodation, respectively. (A)-(C) is explanatory drawing of the pressing method of the wall surface of an insertion hole in the manufacturing method of the package for the said light emitting element accommodation, respectively. It is explanatory drawing of the manufacturing method of the conventional light emitting element storage package.

Explanation of symbols

  10: Light-emitting element storage package, 11: Ceramic substrate, 12: Ceramic frame, 13: Mortar-shaped through hole, 14: Conductor wiring pattern, 15: Die bond pad, 16: Bonding pad, 17: Connecting conductor pattern, 18: Via conductor, 19: external connection terminal pad, 20, 20a: first ceramic green sheet, 21: through hole for via, 22: conductor printed pattern, 23: second ceramic green sheet, 24: insertion hole, 25: Laminated body, 26: pressing mold, 27: rubber body, 28: upper mold, 29: through hole, 30: metal plate, 31: rubber plate, 32: base

Claims (2)

In a method for manufacturing a light emitting element storage package provided by joining a flat ceramic base for mounting a light emitting element and a ceramic frame having a mortar-shaped through hole for surrounding and storing the light emitting element,
Screen printing a conductor print pattern for a conductor wiring pattern on one or more first ceramic green sheets for the ceramic substrate;
Drilling an insertion hole for the mortar-shaped through-hole in which the opening diameter on the upper surface side is larger than the opening diameter on the lower surface side in one or more second ceramic green sheets for the ceramic frame;
A pressing die comprising an upper mold having a rubber body having a shape along the wall surface of the insertion hole of the second ceramic green sheet, and a base for placing the second ceramic green sheet. Pressing the wall surface with,
A method of manufacturing a light emitting element storage package, comprising: laminating the first ceramic green sheet and the second ceramic green sheet to form a laminate, and then firing the laminate.   2. The method for manufacturing a light emitting element storage package according to claim 1, wherein the upper die of the pressing die is made of porous silicon rubber impregnated with silicon oil and having a hardness of 20 ° to 50 °, and the insertion The rubber plate has a metal plate provided by fitting the rubber body into a through hole having an opening diameter substantially equal to the opening diameter on the upper surface side of the hole, and covers the rubber body and the back surface of the metal plate so as to cover the rubber A rubber plate having a hardness substantially equal to the hardness of the body, the pressing force transmitted to the rubber body and the metal plate via the rubber plate, and placed on the base of the pressing mold While pressing the upper surface of the second ceramic green sheet with the metal plate, the rubber body is pressed onto the base and spreads in the lateral direction to press the wall surface of the insertion hole of the second ceramic green sheet. Features Manufacturing method of light emitting element storage package.

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