JP2010272719A - Light emitting diode - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a light emitting diode with improved quality by preventing luminescent colors from varying in chromaticity, and by enhancing adhesion force between a metal base and a wiring board. <P>SOLUTION: In a rear surface of the wiring board 26 in the light emitting diode 20, a lamination pattern 34 for preventing an adhesive agent 36 from flowing into a through-hole 26b is provided on a bonding surface to be bonded to the metal base 24. The lamination pattern 34 has: a damming section 34a which is formed along the edge of the through-hole 26b and sandwiched between the metal base 24 and the wiring board 26; and a bonding reinforcing section 34b which is formed around the damming section 34a and lower than the damming section 34a. The damming section 34a of the lamination pattern 34 dams up the adhesive agent 36 which is sandwiched between the wiring board 26 and the metal base 24 and spreads, to prevent flowing into the through-hole 26b. In the bonding reinforcing section 34b of the lamination pattern 34, the adhesion force is enhanced by increasing the surface area by giving undulation to the bonding surface of the wiring board 26. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a light emitting diode having a substrate structure composed of a metal base and a wiring board, and more particularly, to a structure in which a metal base and a wiring board are bonded with an adhesive.

  Conventionally, as shown in FIG. 6, a substrate structure in this type of light emitting diode has been used in which a resin substrate 4 is attached to the upper surface of a metal plate 2 with an adhesive (see, for example, Patent Document 1). . A through-hole 6 is provided in the resin substrate 4 in this substrate structure. The light emitting element 8 is housed in the through hole 6 and attached to the metal plate 2. The light emitting element 8 is sealed with a light transmitting resin 10 filled in the through hole 6.

  In the conventional light emitting diode, the adhesive is sandwiched between the upper surface of the metal plate 2 formed of a flat surface and the lower surface of the resin substrate 4 formed of the same flat surface. For this reason, as shown in FIGS. 6 and 7, the adhesive 12 spreading between the metal plate 2 and the resin substrate 4 sometimes protrudes into the through hole 6. When the adhesive 12 protrudes into the through hole 6 in this way, the volume in the through hole 6 changes for each light emitting diode. Normally, the through-hole 6 is filled with a light-transmitting resin 10 containing a phosphor. However, since the amount of the light-transmitting resin 10 changes when the volume of the through-hole 6 changes, it is included therein. The amount of phosphor will also change. In particular, there is a problem that when the amount of the phosphor around the light emitting element 8 is changed, the emission color is greatly affected.

Japanese Patent Laid-Open No. 11-298048 (FIG. 1, paragraph number 0020)

  The problem to be solved by the present invention is to solve the above-mentioned problems of the prior art, prevent the chromaticity variation of the luminescent color, and increase the adhesion between the metal base and the wiring board, thereby improving the quality of the light emitting diode. It is to provide.

  The light emitting diode of the present invention is provided at a position corresponding to the light emitting element, a metal base on which the light emitting element is mounted on the surface mounting position, and a surface of the metal base that is bonded with an adhesive. A wiring board having a through-hole, and a light-transmitting resin provided in the through-hole to seal the light-emitting element, and the adhesion on the adhesion surface that adheres to the metal base on the back surface of the wiring board A laminated pattern for preventing the agent from flowing into the through hole is provided.

  The laminated pattern of the light emitting diode is formed along an edge of the through hole and has a damming portion sandwiched between the metal base and the wiring board. Moreover, the said lamination | stacking pattern has an adhesion reinforcement part lower than a blocking part around the said blocking part. Furthermore, the laminated pattern is formed in a mesh shape.

  The laminated pattern is formed of a resist layer or a copper pattern.

  According to the present invention, since the laminated pattern is provided at the periphery of the through hole of the wiring board, it is possible to prevent the adhesive sandwiched between the wiring board and the metal base from flowing into the through hole when the wiring board and the metal base are bonded. it can. Thereby, the volume in the through hole is not changed, and the volume of the light-transmitting resin containing the phosphor is prevented from changing, thereby preventing the chromaticity from being varied.

  In addition, since the laminated pattern is provided with a mesh-like adhesion reinforcing portion, the adhesion area can be increased and the adhesion force to the metal base can be increased.

  Moreover, since the laminated pattern is provided on the back surface of the wiring board, the mechanical strength of the wiring board can be increased. Thereby, the curvature of a wiring board can be reduced. In particular, if the warping of the wiring board is large, there may be a gap between the wiring board and the circuit board to which the wiring board is attached, resulting in a portion where the solder does not sufficiently ride, which may cause mounting defects. Thus, it is possible to prevent the occurrence of mounting defects. Furthermore, the wiring board made of resin may be deteriorated by light or heat from the light emitting element and the mechanical strength may gradually decrease. However, the reinforcement by the laminated pattern can prevent the strength from being deteriorated due to deterioration over time. .

It is a longitudinal cross-sectional view of the light emitting diode which concerns on one Example of this invention. It is an external appearance perspective view of the light emitting diode shown in FIG. It is the disassembled perspective view seen from the back surface side of the light emitting diode shown in FIG. It is a longitudinal cross-sectional view which shows the example of a partial change of the light emitting diode shown in FIG. It is the disassembled perspective view seen from the back surface side of the light emitting diode shown in FIG. It is sectional drawing of the conventional light emitting diode. It is a top view of the light emitting diode shown in FIG.

  The light-emitting diode of the present invention includes a metal base on which a light-emitting element is mounted at a mounting position on a surface, a wiring board that is bonded to the surface with an adhesive and has a through-hole at a position corresponding to the mounting position, and a through-hole. And a light-transmitting resin that seals the light-emitting element. On the back surface of the wiring substrate in this light emitting diode, a laminated pattern for preventing the adhesive from flowing into the through hole is provided on the adhesive surface that adheres to the metal base. The laminated pattern includes a damming portion formed along the edge of the through hole and sandwiched between the metal base and the wiring board, and an adhesive reinforcement portion formed around the damming portion and lower than the damming portion. ing. The damming portion of the laminated pattern dampens the adhesive that is sandwiched between the wiring substrate and the metal base and prevents the adhesive from flowing into the through hole. Moreover, the adhesion reinforcement part of a lamination | stacking pattern raises the adhesive force by making the adhesion surface of a wiring board undulate, and increasing a surface area.

  1 is a longitudinal sectional view of a light emitting diode according to an embodiment of the present invention, FIG. 2 is an external perspective view thereof, and FIG. 3 is an exploded perspective view thereof. The light emitting diode 20 seals the light emitting elements 22, a metal base 24 on which the light emitting elements 22 are mounted, a wiring board 26 bonded to the metal base 24 with an adhesive 36, and the light emitting elements 22. A light transmissive resin 28 and a lens 30 covering the outside of the light transmissive resin 28 are provided.

  In the present embodiment, eight light emitting elements 22 (only two are shown in FIG. 1) are provided, and a die bonding paste 32 such as silicone is used for die bonding at a mounting position 24a at the center of the surface of the metal base 24. Has been. The metal base 24 is made of a metal such as aluminum and is formed in a rectangular plate shape.

  The wiring board 26 is made of an insulating resin such as BT resin, and has a plurality of conductive patterns 26 a that go from the front surface to the back surface through the side surface to the back surface, and the light emitting element 22 is wire bonded. A through hole 26 b is provided in the center of the wiring substrate 26 at a portion corresponding to the mounting position 24 a of the metal base 24. The through hole 26b is formed so that the light emitting element 22 is accommodated in the metal base 24 and the wiring board 26 when the through hole 26b is bonded.

  On the other hand, on the back surface of the wiring board 26, a laminated pattern 34 is provided around the through hole 26b. The laminated pattern 34 is composed of a resist layer, a copper pattern, and the like, and is formed by printing, etching, or the like. The laminated pattern 34 has a damming portion 34a formed along the edge of the through hole 26b, and an adhesion reinforcing portion 34b provided around the damming portion 34a. The damming portion 34 a is formed in a ring shape and is sandwiched between the wiring board 26 and the metal base 24. Moreover, the adhesion reinforcement part 34b is formed in the mesh shape by the combination of the ring-shaped part surrounding the dampening part 34a, and the linear part which connects it to radial direction. The adhesion reinforcing portion 34b is formed so that its height is lower than that of the damming portion 34a, and is set so that a gap is formed between the tip and the metal base 24 in which the adhesive 36 can go around. ing.

  The light transmissive resin 28 is made of a resin such as silicone and contains a phosphor such as YAG. The light transmissive resin 28 is formed so as to seal the light emitting element 22, fill the through hole 26 b, and rise above the wiring board 26. The lens 30 is made of a resin such as silicone, and is formed so that the central part is hemispherically raised. The lens 30 in this embodiment is bonded to the wiring board 26 by bonding the outer peripheral end 30a thereof onto the resist 38 provided on the surface of the wiring board 26 with an adhesive 40. In addition, the light-transmitting resin 28 in this embodiment is filled in the inside through a hole (not shown) provided in the lens 30 adhered on the wiring board 26 in this way, thereby sealing the light emitting element 22. It stops and fills the inside of the through hole 26b.

  In the light emitting diode 20 having the above-described configuration, when the metal base 24 and the wiring board 26 are bonded, as shown in FIG. 3, the adhesive 36 is prevented from getting on the damming portion 34a of the laminated pattern 34, and adhesion reinforcement is performed. The adhesive 36 is applied to the back surface of the wiring board 26 by printing or the like so that the adhesive 36A is placed in the radial direction of the portion 34b or the adhesive 36B is placed in an arc shape along the adhesion reinforcing portion 34b. The adhesive 36 </ b> A or 36 </ b> B shown in FIG. 3 spreads along the surface when the metal base 24 is overlaid on the back surface of the wiring board 26, and spreads between the wiring board 26 and the metal base 24. At this time, the damming portion 34a of the laminated pattern 34 is sandwiched between the wiring board 26 and the metal base 24 as shown in FIG. Can be prevented. In particular, when the metal base 24 and the wiring board 26 are bonded, they are pressurized and bonded, and when the light emitting diode 20 is manufactured and mounted, the adhesive 36 is softened and easily flows. Even in such a case, it is possible to reliably prevent the adhesive 36 from protruding into the through hole 26b by the damming portion 34a. In the case of this embodiment, the adhesive 36 is guided toward the outside of the wiring board 26 and the metal base 24, and even if it protrudes from between the wiring board 26 and the metal base 24, It does not affect light emission or the like only by protruding outside.

  On the other hand, as shown in FIG. 1, a gap is formed between the adhesive reinforcing portion 34b and the metal base 24 so that the adhesive 36 wraps around, so that the adhesive 36 gets over the adhesive reinforcing portion 34b and spreads widely. . Thereby, the adhesive reinforcement part 34b will be in the state which bites into the adhesive agent 36, and it can increase an adhesion area and can strengthen adhesive force.

  As shown in FIG. 3, the adhesive 36 may be applied to positions corresponding to the four corners of the metal base 24 to increase the adhesive force.

  Further, as shown in FIGS. 4 and 5, a damming portion 34 c is added at a position corresponding to the outer shape of the metal base 24, and the damming portion 34 c prevents the adhesive 36 from protruding outside the metal base 24. Is possible.

2 Metal plate 4 Resin substrate 6 Through hole 8 Light emitting element 10 Light transmitting resin 12 Adhesive 20 Light emitting diode 22 Light emitting element 24 Metal base 24a Mounting position 26 Wiring board 26a Conductive pattern 26b Through hole 28 Light transmitting resin 30 Lens 30a Outer circumference End 32 Die bond paste 34 Laminate pattern 34a, 34c Damping part 34b Adhesive reinforcement part 36, 36A, 36B, 36C Adhesive 38 Resist 40 Adhesive

Claims (6)

A light emitting element;
A metal base on which the light emitting element is mounted at the mounting position on the surface;
A wiring board having a through-hole bonded to the surface of the metal base with an adhesive and provided at a position corresponding to the mounting position;
A light-transmitting resin provided in the through hole and sealing the light emitting element;
A light emitting diode comprising:
A light-emitting diode, wherein a laminated pattern for preventing the adhesive from flowing into the through hole is provided on an adhesive surface that adheres to the metal base on a back surface of the wiring board. 2. The light emitting diode according to claim 1, wherein the multilayer pattern includes a damming portion that is formed along an edge of the through hole and is sandwiched between the metal base and the wiring board. The light emitting diode according to claim 2, wherein the laminated pattern has an adhesive reinforcement portion lower than the damming portion around the damming portion. 4. The light emitting diode according to claim 3, wherein the laminated pattern is formed in a mesh shape. The light emitting diode according to claim 4, wherein the laminated pattern is formed of a resist layer. The light emitting diode according to claim 4, wherein the laminated pattern is formed of a copper pattern.

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