JP2006019319A - Light emitting diode assembly and method for manufacturing light emitting diode assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light emitting diode assembly using a eutectic solder and a conductive thermosetting adhesive in connection between an electrode of a flip chip type light emitting diode and a wiring formed on a submount, and its manufacture It is about the method.
A light-emitting diode assembly according to the present invention includes a flip-chip light-emitting diode, a submount to which the flip-chip light-emitting diode is attached, a large number of openings, and a wiring connecting the flip-chip light-emitting diodes. And a wiring board on which electrodes and the like are formed. The submount has a pair of wirings formed on the upper surface. The pair of electrodes of the flip chip type light emitting diode and the pair of wirings of the submount are connected via eutectic solder. The electrode formed on the back surface in the vicinity of the opening and the wiring formed on the top surface of the submount are connected via a conductive thermosetting adhesive.
[Selection] Figure 1

Description

  The present invention relates to a flip chip type light emitting diode, a submount, a light emitting diode assembly using a wiring board, and a method for manufacturing the light emitting diode assembly. In particular, the present invention relates to a light emitting diode assembly using a eutectic solder and a conductive adhesive in order to improve the reliability of the connection between the electrode of the flip chip type light emitting diode and the wiring formed on the submount, and The present invention relates to a method for manufacturing a light emitting diode assembly.

  The present invention provides a light-emitting diode assembly and a light-emitting diode assembly in which flip-chip light-emitting diodes are arranged in a matrix and can be formed into a planar, semi-cylindrical, or cylindrical light source by using a flexible wiring board. It relates to a manufacturing method.

  FIG. 4 is a view for explaining a light emitting diode assembly as a conventional example. In FIG. 4, a light emitting diode assembly 40 includes a printed wiring board 41, a submount board 42 provided on the printed wiring board 41, a plastic cylinder 43 surrounding the submount board 42, The flip chip type light emitting diode 45 and a transparent sealing resin 46 covering the flip chip type light emitting diode 45 are configured.

  The plastic cylinder 43 is integrally formed with the lead frame 44 by using, for example, a thermosetting resin mainly composed of an epoxy resin. The transparent sealing resin 46 is a thermosetting resin mainly composed of an epoxy resin, and is selected from those having excellent transparency and heat resistance.

  On the printed wiring board 41, a desired pattern is formed by etching or the like on a printed wiring 411 for connecting to a control circuit (not shown) for blinking the flip chip type light emitting diode 45. The submount substrate 42 has a pair of wirings 422 formed on the upper surface thereof by forming a deposition pattern using etching or a mask. In addition, an insulating film is formed on the submount substrate 42 on, for example, a semiconductor wafer made of silicon, and a pair of wirings 422 are formed thereon.

  The submount substrate 42 is not particularly limited as long as the submount substrate 42 has excellent thermal conductivity and can form wiring. For example, a substrate in which an oxide film insulating layer is formed on the surface of a silicon substrate is used. A wiring is formed on the insulating film by forming a mask and depositing gold. The eutectic solder layer is formed by vapor deposition or plating. Further, the thickness of the wiring manufactured as described above is preferably about 1 μm to 5 μm, for example, and the thickness of the eutectic solder layer is preferably about 0.2 μm to 0.5 μm, for example.

  The plastic cylinder 43 has a lead frame 44 extending therethrough. The plurality of plastic cylinders 43 are integrated by a continuous lead frame 44 (not shown), and the light emitted from the flip chip type light emitting diode 45 is reflected by the inner periphery. Further, the plastic cylinder 43 is integrally manufactured by so-called insert or outsert molding (injection molding) in which the lead frame 44 is embedded in the injection molding.

  The flip chip type light emitting diode 45 has two electrodes at the bottom, and is cut out by dicing from the submount substrate 42 made of a semiconductor wafer, and the electrodes are connected to the wiring 422 of the submount substrate 42, eutectic solder paste, Eutectic solder and flux or gold-tin eutectic solder paste 423 are connected. The eutectic solder applies a flux or the like in advance when the wiring 422 is connected.

  The flip chip type light emitting diode 45 may be red, orange, yellow, green, blue, or the like. The transparent sealing resin 46 has heat resistance, is filled in the plastic cylindrical body 43, and constitutes a flat or convex lens.

  Next, a method for manufacturing the light emitting diode assembly 40 will be described. The submount substrate 42 forms an insulating film on a substrate made of a semiconductor wafer made of silicon, for example. A wiring 422 is formed in a desired shape on the insulating film. On the wiring 422 formed on the submount substrate 42, eutectic solder paste, eutectic solder and flux, or gold-tin eutectic solder paste 423 is placed in a predetermined amount, for example, by a robot or the like. Placed.

  On the eutectic solder paste, eutectic solder and flux, or gold-tin eutectic solder paste 423, electrodes of a plurality of flip chip type light emitting diodes 45 are disposed, and then passed through a reflow furnace (not shown). Thus, the flip chip type light emitting diode 45 and the wiring 422 provided on the submount substrate 42 are connected.

  For example, by setting the gold-tin eutectic solder paste 423 in the reflow furnace at a predetermined ratio, when the flux diverges by heating, the solder or the like does not spread and become thin and adjacent to each other. Do not short circuit with wiring.

  Thereafter, the submount substrate 42 is diced so that the plurality of flip chip type light emitting diodes 45 are arranged one by one, thereby forming a submount. Each of the diced flip chip type light emitting diodes 45 is selected by inspecting a non-defective product or a defective product by an inspection device (not shown).

  On the other hand, the plurality of plastic cylinders 43 surrounding the flip-chip type light emitting diode 45 are integrally formed by insert or outsert molding with a lead frame 44 penetrating through the inside thereof during molding. The submount substrate 42 provided with the plurality of flip chip type light emitting diodes 45 cuts the lead frame 44 portion into a single plastic cylinder 43.

  One end of the lead frame 44 protruding inside the one plastic cylinder 43 is formed on the submount substrate 42 through a conductive adhesive mainly composed of epoxy resin and silver particles, for example. Connected to the wiring 422. The upper surface of the plastic cylinder 43 is sealed with a transparent sealing resin 46. The shape of the transparent sealing resin 46 can be a flat plate or a convex lens according to the purpose of use.

Thereafter, on the printed wiring 411 formed on the printed wiring board 41, the other end of the lead frame 44 protruding outside the at least one plastic cylinder 43 is bent, and the leading end thereof is connected. The printed wiring board 41 is, for example, covered with a transparent resin as necessary after the submount substrates 42 are arranged in a line, a matrix, or a desired shape according to the purpose of use. The details of the light-emitting diode assembly and the manufacturing method thereof are described in Japanese Patent Application No. 2004-107043.
Japanese Patent Application No. 2004-107043

  A flip chip light-emitting diode that extracts light from the light-emitting layer from the surface opposite to the electrode does not block light by the electrode, and thus has high brightness and good light emission efficiency. However, the single flip-chip type light emitting diode has a problem that the amount of light is insufficient when used as a surface light source.

  Since the flip-chip type light emitting diode is made of a silicon substrate, it needs to be assembled after it is once connected to the submount substrate. Therefore, there is a problem that it takes a lot of time to make a surface light source. Further, since the flip-chip type light emitting diode is provided on a printed wiring board that supplies power, it is difficult to bend it into a three-dimensional light source.

  In order to solve the above-described problems, the present invention can reduce the surface light source by reflowing the wiring formed on the submount and the electrodes of the matrix wiring substrate with eutectic solder. An object of the present invention is to provide a light emitting diode assembly and a method for manufacturing the light emitting diode assembly, which can prevent a short circuit between wirings.

  The present invention connects a submount wiring provided with a flip-chip type light emitting diode to a matrix-like flexible multilayer wiring board and supplies power from the flexible wiring board so that it is semicylindrical or cylindrical. An object of the present invention is to provide a light emitting diode assembly that can be used as a three-dimensional light source and a method for manufacturing the light emitting diode assembly.

  According to the present invention, since the heat of the flip chip type light emitting diode is transmitted to the outside through the sub mount and the heat sink by providing the heat sink at the lower part of the submount, the heat generated by the flip chip type light emitting diode is stored inside. It is an object of the present invention to provide a light-emitting diode assembly and a method for manufacturing the light-emitting diode assembly that do not deteriorate in efficiency even with aging.

(First invention)
A light emitting diode assembly according to a first aspect of the present invention is a flip chip type light emitting diode in which a pair of electrodes are formed on a lower surface, a submount in which a pair or a plurality of pairs of wirings are formed on an upper surface, and the flip chip type light emitting diode. The eutectic solder connecting the pair of electrodes and the pair of wirings of the submount, and a large number of openings for inserting the flip chip type light emitting diodes on the submount are formed, and electrodes are formed on the back surface in the vicinity of the openings And a conductive adhesive that connects the wiring formed on the back surface in the vicinity of the opening and the wiring formed on the upper surface of the submount.

(Second invention)
In the light-emitting diode assembly of the second invention, the openings of the first invention are formed in a matrix shape, and the green flip-chip type light-emitting diode, the blue flip-chip type light-emitting diode, and the red flip-chip type light-emitting diode are each arbitrary. The voltage and / or current applied to each of the flip chip type light emitting diodes is controlled by a control circuit.

(Third invention)
The light emitting diode assembly of the third invention includes three flip chip type light emitting diodes of green, blue, and red each having a pair of electrodes formed on the lower surface, and a submount having three pairs of wirings formed on the upper surface. , Eutectic solder for connecting three pairs of electrodes of the three flip-chip type light emitting diodes and three pairs of wirings of the submount, and a large number of three flip chip type light emitting diodes on the submount. A wiring board having an opening formed therein and an electrode formed in the vicinity of the opening; an electrode formed in the vicinity of the opening; and a conductive adhesive connecting the wiring formed on the upper surface of the submount. It is characterized by being.

(Fourth invention)
In the light emitting diode assembly of the fourth invention, the openings of the third invention are formed in a matrix shape, and the color tone is controlled by controlling the voltage and / or current by the control circuit.

(Fifth invention)
In the light-emitting diode assembly of the fifth invention, the wiring boards of the first to fourth inventions are flexible multilayer wiring boards.

(Sixth invention)
According to a sixth aspect of the present invention, there is provided a light emitting diode assembly manufacturing method comprising: mounting a eutectic solder on a predetermined position of each wiring of a submount substrate on which a plurality of pairs or a plurality of pairs of wirings are formed on an upper surface; After placing each electrode of the flip chip type light emitting diode having a pair of electrodes formed on the lower surface of the eutectic solder, it is heated in a reflow furnace and flipped with the wiring of the submount via the eutectic solder. A chip-type light emitting diode electrode is connected, the submount substrate is diced to form a submount on which one flip chip type light emitting diode is mounted, and a large number of openings are formed. A submount light emitting die in which the one flip chip type light emitting diode is placed in each opening of a wiring board on which electrodes corresponding to the submount wiring are formed. Together put over de, and the rear surface to the formed electrode of the opening vicinity, characterized in that to connect the wiring and formed on the upper surface of the submount with conductive adhesive.

(Seventh invention)
According to a seventh aspect of the present invention, there is provided a method of manufacturing a light emitting diode assembly, comprising placing eutectic solder at a predetermined position of each wiring of a submount substrate on which a large number of three pairs of wirings are formed on the upper surface. After each electrode of three flip chip type light emitting diodes of green, blue, and red having a pair of electrodes formed on the lower surface is placed on the crystal solder, it is heated in a reflow furnace and passed through the eutectic solder. One submount on which three flip chip type light emitting diodes of green, blue and red are mounted by connecting the wiring of the submount and the electrode of the flip chip type light emitting diode and dicing the submount substrate. A large number of openings are formed, and each of the green, blue, and red 3 is formed in each opening of the wiring board in which an electrode corresponding to the wiring of the submount is formed on the back surface in the vicinity of the opening. The flip-chip type light emitting diode of the submount was inserted, and the electrode formed on the back surface near the opening and the wiring formed on the top surface of the submount were connected by a conductive adhesive It is characterized by that.

(Eighth invention)
In the method for manufacturing a light-emitting diode assembly according to the eighth invention, the wiring board according to the sixth invention or the seventh invention comprises a flexible multilayer board, and the openings according to the sixth invention or the seventh invention are formed in a matrix. It is characterized by.

  According to the present invention, since the electrode of the flip-chip type light emitting diode and the wiring of the submount are connected using the eutectic solder, it is possible to prevent the solder from spreading and short-circuiting with the adjacent wiring.

  According to the present invention, the wiring of the submount and the electrode of the flip chip type light emitting diode are eutectic solder, and the electrode of the wiring board and the wiring of the submount are electrically conductive adhesive having a melting point lower than that of the eutectic solder. By doing so, when the conductive adhesive is heat-cured, the connecting portion by the eutectic solder does not melt and leave.

  According to the present invention, flip-chip type light emitting diodes composed of three colors are arranged at arbitrary positions, and by controlling the voltage and / or current by the arrangement and control circuit, images, characters, patterns, signs, It can be used for many purposes as a signal, lighting, etc.

  According to the present invention, a submount on which three flip chip type light emitting diodes of green, blue, and red are placed is disposed in each of the openings formed in a matrix, and the three flip chip type light emitting diodes are controlled by a control circuit. By controlling the color tone, the color tone is controlled and can be used for many applications as an image, a character, a pattern, a sign, a signal, a lighting, or the like.

  According to the present invention, heat generated from the flip-chip type light emitting diode can be released to the outside through the submount and the wiring board or the heat radiating plate, and connection failure and deterioration due to secular change can be prevented.

  According to the present invention, since the flip-chip type light emitting diode is attached to the flexible wiring board through the submount, a surface light source, a semi-cylindrical light source, and a cylindrical light source can be easily manufactured. It can be applied to signal devices, display devices, and decorations.

  According to the present invention, since the light emitting diode assembly can be made thin, it can be used for a display lamp in a narrow place, a backlight in a liquid crystal display device, and the like.

(First invention)
The light emitting diode assembly of the first invention includes a flip chip type light emitting diode, a submount to which the flip chip type light emitting diode is attached, a large number of openings, wiring electrodes for connecting the flip chip type light emitting diodes, and the like. The wiring board is formed.

  The flip chip type light emitting diode is of a type in which a pair of electrodes are formed on the lower surface and emits light from the upper surface. The submount has a pair or a plurality of pairs of wires formed on the upper surface. The pair of electrodes of the flip chip type light emitting diode and the pair of wirings of the submount are connected via eutectic solder.

  The wiring board has a large number of openings for receiving the flip-chip light emitting diodes on the submount, and electrodes are formed on the back surface in the vicinity of the openings. The electrode formed on the back surface near the opening and the wiring formed on the top surface of the submount are connected via a conductive adhesive.

  Since the conductive adhesive has a melting temperature lower than that of the eutectic solder, when connecting the wiring of the submount and the electrode of the wiring substrate, the connection between the electrode of the flip-chip type light emitting diode and the wiring of the submount is performed. Does not come off. The wiring board may be a surface light source in which the flip-chip light emitting diodes are arranged in a desired shape.

  The conductive adhesive is preferably, for example, a thermosetting conductive adhesive. As another conductive adhesive, there is a one-pack type acrylic resin-based adhesive or a one-pack type epoxy resin-based adhesive.

(Second invention)
A light emitting diode assembly according to a second aspect of the present invention is the green flip chip type light emitting diode, the blue flip chip type light emitting diode, and the red color light emitting diode, each of which has openings formed in a matrix in the wiring board. The flip chip type light emitting diode is disposed at an arbitrary position. Further, the flip-chip type light emitting diode composed of the three colors can be used for many purposes as an image, a character, a sign, a pattern, a signal, etc. by controlling the arrangement and the voltage and / or current by the control circuit. it can.

(Third invention)
A light emitting diode assembly of a third invention includes three flip chip type light emitting diodes of green, blue and red, a submount to which the three flip chip type light emitting diodes of green, blue and red are attached, An opening and a wiring board on which wiring electrodes for connecting the flip chip light emitting diodes are formed.

  The three flip chip type light emitting diodes of green, blue and red are of a type in which three pairs of electrodes are formed on the lower surface and light is emitted from the upper surface. In one submount, three pairs of wirings for attaching the three-color flip chip type light emitting diodes are formed on the upper surface. Three pairs of electrodes of the flip chip type light emitting diode and three pairs of wirings of the submount are connected via eutectic solder.

  The wiring board has a large number of openings for inserting the flip chip type light emitting diodes on the submount, and electrodes are formed on the back surface in the vicinity of the openings. The three pairs of electrodes formed on the back surface in the vicinity of the opening and the three pairs of wirings formed on the top surface of the submount are respectively connected via a conductive adhesive. The conductive adhesive is preferably a thermosetting adhesive similar to that of the first invention, or a one-pack or two-pack epoxy resin adhesive.

  Since the conductive adhesive has a melting temperature lower than that of the eutectic solder, when connecting the three pairs of wirings of the submount and the electrodes of the wiring board, the three pairs of electrodes of the three flip chip type light emitting diodes are used. And the three pairs of wires on the submount do not come off. The wiring board may be a surface light source having an opening arranged in a desired shape.

(Fourth invention)
In the light emitting diode assembly of the fourth invention, the openings of the wiring board are formed in a matrix, and three flip chip type light emitting diodes of green, blue and red provided in one submount are arranged in the openings. Further, the color tone of the three flip-chip light emitting diodes is controlled by controlling the voltage and / or current by a control circuit.

  Since the color tone is controlled, the light emitting diode assembly of the fourth invention can display characters, images and the like beautifully, and can be used for many purposes such as display, decoration, display device, signal and the like.

(Fifth invention)
In the light-emitting diode assembly of the fifth invention, the wiring board of the first to fourth inventions is a flexible multilayer wiring board. The light-emitting diode assembly made of the flexible multilayer wiring board can be shaped in accordance with the intended use. In particular, the light emitting diode assembly can be used for a cylindrical display, a display device, a signal, and the like.

(Sixth invention)
In the method of assembling the light-emitting diode assembly according to the sixth aspect of the invention, first, eutectic solder is placed at a predetermined position of each wiring of the submount substrate on which a plurality of pairs or a plurality of wirings are formed on the upper surface. Next, each electrode of a flip chip type light emitting diode having a pair of electrodes formed on the lower surface is disposed on the eutectic solder of each pair of wirings.

  Thereafter, the wiring of the submount and the electrode of the flip chip type light emitting diode are connected to each other through eutectic solder when heated in a reflow furnace. The submount substrate is diced to form a submount on which one flip chip type light emitting diode is mounted. A large number of openings are formed in the wiring substrate, and electrodes corresponding to the wiring of the submount are formed on the back surface in the vicinity of the openings.

A light emitting diode of a submount on which the one flip chip type light emitting diode is mounted is inserted into each opening of the wiring board, and an electrode formed on the back surface near the opening and an upper surface of the submount. The formed wiring is connected via a conductive adhesive.
(Seventh invention)
In the method of assembling the light-emitting diode assembly according to the seventh aspect of the invention, first, eutectic solder is placed at predetermined positions of each wiring of the submount substrate on which a large number of three pairs of wirings are formed on the upper surface. Next, on the eutectic solder of the three pairs of wirings, each electrode of three flip chip type light emitting diodes of green, blue, and red having a pair of electrodes formed on the lower surface is arranged.

  Thereafter, the wiring of the submount and the electrode of the flip chip type light emitting diode are connected to each other through eutectic solder when heated in a reflow furnace. The submount substrate is diced to form one submount on which three flip chip type light emitting diodes of green, blue, and red are mounted. A large number of openings are formed in the wiring substrate, and electrodes corresponding to the wiring of the submount are formed on the back surface in the vicinity of the openings.

  A light emitting diode of a submount on which the three flip chip type light emitting diodes of green, blue, and red are placed is inserted into each opening of the wiring board, and an electrode formed on the back surface in the vicinity of the opening; The wiring formed on the upper surface of the submount is connected via a conductive adhesive.

(Eighth invention)
In the manufacturing method of the light-emitting diode assembly according to the eighth invention, the wiring board according to the sixth or seventh invention is a flexible multilayer wiring board. The flexible multilayer wiring board can collect electrodes in the vertical and horizontal directions of the matrix, and by controlling each of them, many expressions can be made in the case of characters or images.

  FIG. 1 is a schematic sectional view for explaining a light emitting diode assembly according to an embodiment of the present invention. FIG. 2 is a plan view for explaining a matrix wiring board constituting a light emitting diode assembly according to an embodiment of the present invention. 1 and 2, the light-emitting diode assembly 11 includes a submount 13 provided on the heat sink 12, a flip-chip light-emitting diode 14, and a wiring for electrically connecting the wiring 131 of the submount 13. And at least a substrate 15. A pair of electrodes is provided on the lower surface of the flip chip type light emitting diode 14. The heat dissipation plate 12 can be omitted when the number of the light emitting diode assemblies 11 is small.

  The light emitting diode assembly 11 can cover the whole by selecting a member having excellent transparency and heat resistance, if necessary. Moreover, the member excellent in transparency and heat resistance consists of a thermosetting resin which has an epoxy resin as a main component.

  The wiring board 15 has a printed wiring 1 (electrode) 152 for connecting the flip-chip light emitting diode 14 to a control circuit (not shown) for blinking, for example, formed in a desired pattern by etching or the like. Yes.

  The submount 13 is disposed at least between the wiring board 15 and the heat sink 12. The heat radiating plate 12 is made of, for example, copper, aluminum, or an alloy thereof, and is formed relatively thin so as to have flexibility.

  The submount 13 has a pair of wirings 131 formed on its upper surface by forming an evaporation pattern using etching or a mask. In the submount 13, for example, an insulating film is formed on a semiconductor wafer made of silicon, and a pair of wirings 131 is formed thereon.

  The submount 13 is not particularly limited as long as it has excellent thermal conductivity and can form a wiring. For example, a submount 13 in which an insulating layer of an oxide film is formed on the surface of a silicon substrate is used. A wiring 131 is formed on the insulating film by forming a mask and depositing gold.

  The eutectic solder layer 16 is formed on the wiring 131 formed on the submount 13 by vapor deposition or plating. Furthermore, the thickness of the wiring 131 manufactured as described above is preferably about 1 μm to 5 μm, for example, and the thickness of the eutectic solder layer 16 is preferably about 0.2 μm to 0.5 μm, for example.

  On the eutectic solder layer 16, an electrode 18 of the flip chip type light emitting diode 14 is placed, and then passed through a reflow furnace (not shown). The electrode 18 of the flip chip type light emitting diode 14 and the wiring 131 of the submount 13 are connected via the eutectic solder 16.

  As shown in FIG. 2, the matrix wiring substrate 15 has openings 151 formed in a matrix shape, and electrodes 152 and 152 ′ are formed in series on the back surface through the openings 151. . The flip chip type light emitting diode 14 is inserted into the opening 151 as shown in FIG. At that time, the electrodes 152 and 152 ′ are connected to the wiring 131 of the submount 13 through the conductive adhesive 17.

  Examples of the conductive adhesive 17 include a room-temperature curing type, or an acrylic resin + conductive spar + solvent, or a one-component acrylic resin system or a two-component acrylic resin system that is reactively cured at room temperature. The conductive spatula is cured by applying heat so that the hardener does not react with the silver powder.

  The flip-chip type light emitting diode 14 has two electrodes (not shown) at the bottom, and is cut out by dicing from a submount substrate made of a semiconductor wafer to form a submount 13. The submount substrate may be continuous without being diced, but is not flexible and can only be used as a surface light source.

  The electrodes of the flip chip type light emitting diode 14 are connected to the wiring 131 of the submount 13 by eutectic solder paste, eutectic solder and flux, or gold-tin eutectic solder paste. The eutectic solder applies a flux or the like in advance when the wiring 131 is connected.

  The flip chip type light emitting diode 14 may be red, orange, yellow, green, blue or the like. The flip chip type light emitting diode 14 can be changed in pattern, color tone, and the like by arranging green, blue, and red at arbitrary positions and controlling a power supply voltage (not shown).

  Next, a method for manufacturing the light emitting diode assembly 11 will be described. As the submount substrate, for example, an insulating film is formed on a substrate made of a semiconductor wafer made of silicon. A wiring 131 is formed in a desired shape on the insulating film. On the wiring 131 formed on the submount substrate, eutectic solder paste, eutectic solder and flux, or gold-tin eutectic solder paste is placed at a predetermined position by a predetermined amount, for example, a robot. Is done.

  On the eutectic solder paste, eutectic solder and flux, or gold-tin eutectic solder paste, electrodes 18 of a plurality of flip chip type light emitting diodes 14 are disposed, and then passed through a reflow furnace (not shown). Thus, the electrode 18 of the flip chip type light emitting diode 14 and the wiring 131 provided on the submount substrate are connected through the eutectic solder 16.

  For example, the gold-tin eutectic solder paste in the reflow furnace is in the proportion described later, so that when the flux is diffused by heating, the solder does not spread and become thin and adjacent to each other. There is no short circuit with wiring.

  Thereafter, the submount substrate is diced so that the plurality of flip chip type light emitting diodes 14 are arranged one by one, thereby forming the submount 13. Each of the diced flip chip type light emitting diodes 14 is selected by inspecting a non-defective product or a defective product by an inspection device (not shown).

  The matrix wiring board 15 shown in FIG. 2 can be a flexible wiring board. Similarly to the above, electrodes 152 and 152 'are formed on the flexible wiring board. After the conductive adhesive 17 is placed on the wiring 131 of the submount 13, by applying predetermined heat with the electrodes 152, 152 'of the matrix-like flexible wiring board 15 facing down, Connected mechanically and electrically.

  The conductive adhesive 17 is mainly composed of, for example, an epoxy resin and silver particles. Then, the submount 13 is attached to the heat sink 12 as needed.

  The gold-tin eutectic solder paste used in this example was 80% by weight of gold, 20% by weight of tin and flux (manufactured by Arakawa Chemical), and the adhesion area was 0.23 × 0.23 μm. Test samples 1 to 10 had an adhesive strength of about 800 to 900 g.

  On the other hand, the bonding strength between the conventional submount and the electrode of the flip-chip type light emitting diode is about 80 g per piece as a result of performing the same test as described above for five bumps (diameter 80 μm). Yes, compared with the present example, the strength was about 1/10 or less.

  1 and 2 show a light-emitting diode assembly 11 in which a large number of flip-chip light-emitting diodes 14 are assembled in a matrix, and can be used as a surface light source. Since the surface light source is assembled from a large number of flip-chip light emitting diodes 14, the surface light source can generate a large amount of light and can be used for illumination, signal devices, displays, display devices, and decorations.

  Since the surface light source is composed of the flexible wiring board 15 and the thin heat sink 12 having flexibility, it can be formed into a semi-cylindrical shape or a cylindrical shape. Since the semi-cylindrical or cylindrical light source is irradiated with light at 180 degrees or 360 degrees, it is excellent for illumination, display, display, and decoration.

  FIG. 3 (a) is a diagram for explaining an example in which three-color flip-chip type light emitting diodes are incorporated in one submount according to the second embodiment of the present invention, and (b) is the three-color flip chip. It is a figure for demonstrating the example of multilayer wiring while arrange | positioning a type | mold light emitting diode in matrix form. The multilayer wiring in this embodiment is distinguished by a one-dot chain line, a two-dot chain line, etc. in FIG. 3B, but is actually electrically connected by a through hole.

  In FIG. 3A, a red light emitting diode 341, a green light emitting diode 342, and a blue light emitting diode 33 are mounted on the submount 34. Each light emitting diode includes a pair of electrodes 351 to 353 and a common electrode 354.

  3B, the wiring board 36 has submounts 34 on which the three light emitting diodes 341, 342, and 343 shown in FIG. , 352, 353 and the common electrode 354 are connected to the electrodes provided in the lower part of the wiring board 36. The electrodes 351, 352, and 353 are connected to each other in columns in the matrix to form a multilayer wiring electrode 362, and are collected at the lower part of the wiring board 36.

  Further, the common electrode 354 is collected as a common electrode 363 on the left side with the rows in the matrix being common. By selecting one of the multilayer wiring electrodes 362 and the common electrode 363 provided in the lower part, one flip-chip type light emitting diode (three colors) in the matrix can be selected. The multilayer wiring electrode 362 can change the color tone of one flip chip type light emitting diode (three colors) in the matrix by applying different voltages to the three flip chip type light emitting diodes of green, blue and red. it can.

  As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example. The present invention can be modified in various ways without departing from the scope of the claims. The flip chip type light emitting diode of the present invention, submount, wiring board, matrix wiring board, heat sink, electrode, wiring, eutectic solder paste, eutectic solder and flux, gold-tin eutectic solder paste, etc. A well-known or well-known thing can be used.

  In the flip-chip type light emitting diode of the present invention, one or at least a plurality of colors of red, orange, yellow, green, and blue can be arranged in a desired shape on the wiring board. One submount including three light emitting diodes of green, blue, and red can change the color tone by controlling the voltage.

  The present invention can be used for bulletin boards, advertising devices, etc. in addition to lighting, signals, indicator lamps, and displays by arranging the flip-chip light emitting diodes in a matrix or other shapes. Further, the flip chip type light emitting diode can be displayed in various characters, images, patterns or the like by signals from the control circuit by appropriately arranging the respective colors in advance.

  The light-emitting diode assembly of the present invention can be used in accordance with various applications by arbitrarily forming the shapes of the flexible wiring board and the matrix-like flexible wiring board. The conductive adhesive may be solder having a lower melting point than eutectic solder.

  When the light-emitting diode assembly of the present invention is used as a display device, the portion other than the light-emitting portion is covered with black stripes, etc., but details thereof are omitted, and the conventional liquid crystal display panel technology is used. Can do. In addition, as for the multilayer wiring board, a through hole or the like is similarly omitted, but a known or well-known one can be used.

1 is a schematic cross-sectional view for explaining a light emitting diode assembly in an embodiment of the present invention. (Example 1) In the Example of this invention, it is a top view for demonstrating the matrix-like wiring board which comprises a light emitting diode assembly. (A) is a diagram for explaining an example in which a flip-chip type light emitting diode of three colors is incorporated in one submount in the second embodiment of the present invention, and (b) is a flip chip type light emission of the three colors. It is a figure for demonstrating the example of multilayer wiring while arrange | positioning a diode in matrix form. (Example 2) It is a figure for demonstrating the light emitting diode assembly as a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Light emitting diode assembly 12 ... Heat sink 13 ... Submount 131 ... Wiring 14 ... Flip chip type light emitting diode 15 ... Wiring board (flexible wiring board)
151 ... Opening 152, 152 '... Electrode 16 ... Eutectic solder 17 ... Conductive adhesive 18 ... Flip chip type light emitting diode electrode 34 ... Submount 341 ... Red Light-emitting diode 342 Green light-emitting diode 343 Blue light-emitting diode 351 to 353 Electrode 354 Common electrode 36 Wiring substrate 361 Opening 362 Multi-layer wiring electrode 363・ Common electrode

Claims (8)

A flip chip light emitting diode having a pair of electrodes formed on the lower surface;
A submount in which one or more pairs of wires are formed on the upper surface;
Eutectic solder connecting a pair of electrodes of the flip-chip type light emitting diode and a pair of wirings of the submount;
A wiring board in which a large number of openings for inserting flip chip type light emitting diodes on the submount are formed, and electrodes are formed on the back surface in the vicinity of the openings,
A conductive adhesive that connects the electrode formed on the back surface near the opening and the wiring formed on the top surface of the submount;
A light emitting diode assembly comprising at least:   The openings are formed in a matrix, and a green flip chip type light emitting diode, a blue flip chip type light emitting diode, and a red flip chip type light emitting diode are arranged at arbitrary positions. The light emitting diode assembly of claim 1, wherein a voltage and / or current applied to the light emitting diode is controlled. Three flip chip type light emitting diodes of green, blue and red, each having a pair of electrodes formed on the lower surface;
A submount in which three pairs of wires are formed on the upper surface;
Eutectic solder for connecting three pairs of electrodes of the three flip-chip type light emitting diodes and three pairs of wirings of the submount,
A wiring board having a plurality of openings for receiving three flip-chip light emitting diodes on the submount, and electrodes formed in the vicinity of the openings;
A conductive adhesive connecting the electrode formed in the vicinity of the opening and the wiring formed on the upper surface of the submount;
A light emitting diode assembly comprising at least:   4. The light emitting diode assembly according to claim 3, wherein the openings are formed in a matrix and the color tone is controlled by controlling the voltage and / or current by a control circuit.   The light emitting diode assembly according to claim 1, wherein the wiring board is a flexible multilayer wiring board. Eutectic solder is placed at a predetermined position of each wiring of the submount substrate in which a large number of pairs or wirings are formed on the upper surface,
After disposing each electrode of the flip chip type light emitting diode having a pair of electrodes formed on the lower surface thereof on the eutectic solder of each pair of wirings,
Heating in a reflow furnace, connecting the wiring of the submount and the electrode of the flip chip type light emitting diode through eutectic solder,
The submount substrate is diced to form a submount on which one flip chip type light emitting diode is mounted,
A plurality of openings are formed, and on the back surface in the vicinity of the openings, an electrode corresponding to the wiring of the submount is formed. In each opening of the wiring board, the one flip chip type light emitting diode is mounted. A method for manufacturing a light-emitting diode assembly, comprising: inserting a light-emitting diode; and connecting an electrode formed on a back surface near the opening and a wiring formed on an upper surface of a submount with a conductive adhesive. Eutectic solder is placed at a predetermined position of each wiring on the submount substrate on which a large number of three pairs of wirings are formed on the upper surface,
After arranging each electrode of three flip chip type light emitting diodes of green, blue and red, each having a pair of electrodes formed on the lower surface thereof on the eutectic solder of the three pairs of wirings,
Heating in a reflow furnace, connecting the wiring of the submount and the electrode of the flip chip type light emitting diode through eutectic solder,
The submount substrate is diced into one submount on which three flip chip type light emitting diodes of green, blue, and red are mounted,
The three flip chip type light emitting diodes of green, blue and red are mounted on each opening of the wiring board in which a large number of openings are formed, and electrodes corresponding to the wirings of the submount are formed on the back surface in the vicinity of the openings. A light-emitting diode assembly comprising: a light-emitting diode placed on a submount; and an electrode formed on the back surface near the opening and a wiring formed on the top surface of the sub-mount connected with a conductive adhesive. Solid manufacturing method.   8. The method of manufacturing a light-emitting diode assembly according to claim 6, wherein the wiring board is made of a flexible multilayer board, and the openings are formed in a matrix.

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