JP2009170625A - Light emitting device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve moldability of a wall surrounding a light emitting element. <P>SOLUTION: This light emitting device is provided with: a resin case 3 having a recessed part 31; a first metal lead 4 for mounting an LED chip 2 thereon through an adhesive material; a second metal lead 5 electrically connected to the LED chip 2 through a wire 11; a cutout 42 formed at an end of the first lead 4 on the second lead 5 side; an influx/efflux prevention wall 9 surrounding the LED chip 2, and overlapping at least respective partial parts of a space 20 between the first lead 4 and the second lead 5, the cutout 42 of the first lead 4 in a plan view; and a reflecting layer 6 covering the outside of the influx/efflux prevention wall 9. Moldability is improved by molding the influx/efflux prevention wall 9 integrally with the case 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a light emitting device in which a light emitting element is mounted on a metal lead by an adhesive and the surface of the lead is covered with a reflective layer.

A light-emitting device in which a light-emitting element such as a light-emitting diode (LED) is sealed with a light-transmitting sealing resin such as epoxy or silicon is known (for example, see Patent Document 1). The light emitting device described in Patent Literature 1 includes a reflective frame in which a lead frame is insert-molded with a resin material, a cavity formed in the reflective frame, and a plurality of LED chips independently surrounded by the LED chip. The outer wall of the cup is formed integrally with the reflection frame by the same resin material as the reflection frame, and the inside of the cavity is filled with a translucent resin.
JP 2006-93435 A

  However, in the light emitting device described in Patent Document 1, there is a problem in that when forming the outer wall of the cup, the resin material does not easily flow into the portion directly above the lead frame, and the outer wall cannot be formed into an intended shape.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a light-emitting device capable of improving the moldability of a wall surrounding a light-emitting element.

  In order to achieve the above object, in the present invention, a light emitting element, a resin case having a recess for accommodating the light emitting element, and a bottom surface side of the recess, the light emitting element is mounted via an adhesive. A first lead made of metal, a second lead made of metal that is disposed on the bottom surface side of the recess and spaced apart from the first lead, and is electrically connected to the light emitting element via a wire, A notch formed in an end portion of the first lead on the second lead side, and a bottom surface of the concave portion are formed integrally with the case to surround the light emitting element, and the first lead and the second lead An inflow / outflow prevention wall that at least partially overlaps the gap and the cutout of the first lead in a plan view, and an outer side of the inflow / outflow prevention wall on the bottom surface of the recess, and the inflow / outflow prevention wall covers the light emitting element. Is prevented from flowing out to the side. Emitting device comprising a reflective layer formed by incorporating a filler in the resin, it is provided.

  In the light emitting device, the first lead and the second lead extend in a predetermined direction, and the mounting portion of the light emitting element of the first lead is formed at the center in the width direction so as to protrude toward the second lead, The gap between the first lead and the second lead has a pair of inclined sections symmetric about the width direction center inclined toward the second lead side toward the width direction center, and the notch of the first lead is Preferably, the gap is formed continuously with one of the inclined sections of the gap and extends inclined toward the center in the width direction toward the opposite side of the second lead.

  In the light emitting device, the gap includes a first exposed portion that exposes a bottom portion of the case in the concave portion on the second lead side of the mounting portion, and a bottom portion of the case on the outer side in the width direction of the mounting portion. And a pair of second exposed portions that expose the inside of the recess.

  The light emitting device preferably includes a partition wall that is connected to the inflow / outflow prevention wall and partitions an outer region of the inflow / outflow prevention wall on a bottom surface of the recess.

  In the light emitting device, it is preferable that the partition wall is formed integrally with the inflow / outflow prevention wall and the case.

  In the light emitting device, the wire is preferably formed lower than the inflow / outflow prevention wall, and the inflow / outflow prevention wall has a groove through which the wire is inserted.

  ADVANTAGE OF THE INVENTION According to this invention, the moldability of the wall surrounding a light emitting element can be improved. Further, it is possible to prevent the adhesive of the light emitting element from flowing out to the second lead, and to prevent the reflecting layer covering each lead from flowing out to the light emitting element side.

  1 to 4 show a first embodiment of the present invention, and FIG. 1 is an external perspective view of a light emitting device.

  As shown in FIG. 1, the light emitting device 1 is a top view type, and is disposed on the bottom side of the LED chip 2, a resin case 3 having a recess 31 in which the LED chip 2 is accommodated, and the recess 31. A metal first lead 4 on which the LED chip 2 is mounted, and a metal second lead 5 disposed on the bottom surface side of the recess 31 so as to be separated from the first lead 4 are provided. The recess 31 of the case 3 is covered with the reflective layer 6 except for the vicinity of the LED chip 2. The case 3 is preferably made of a material that hardly deteriorates due to heat, light, or the like. For example, a resin such as polyphthalamide, epoxy, or silicone is used. In addition, the case 3 can be appropriately changed in the grade of transparency and reflectance. However, in order to increase the luminous intensity of the light emitting device 1, it is preferable to use a white type having a high reflectance. Examples of the metal used for the first lead 4 and the second lead 5 include aluminum (Al), silver (Ag), and copper (Cu).

  The case 3 has a substantially rectangular parallelepiped shape as a whole, and the leads 4 and 5 extend outward from the case 3. The opening 32 of the recess 31 is circular in plan view, and the side wall of the recess 31 forms a reflector portion 33 so as to expand toward the opening 32. The recess 31 is filled with a sealing resin 7 that seals the LED chip 2. The sealing resin 7 is preferably made of a material that is less susceptible to heat, light such as light, and light. For example, a resin such as epoxy, silicone, and epoxy / silicone hybrid can be used. In this embodiment, the sealing resin 7 is silicone, and the upper portion of the sealing resin 7 is covered with a translucent cover member 8.

FIG. 2 is an explanatory plan view of the light emitting device. In FIG. 2, illustration of the reflective layer 6, the sealing resin 7, and the cover member 8 is abbreviate | omitted for description.
As shown in FIG. 2, the LED chip 2 is disposed at the center of the bottom surface of the recess 31. The LED chip 2 is mounted on the first lead 4, and the side is surrounded by an inflow / outflow prevention wall 9. The inflow / outflow prevention wall 9 is formed in a circular shape centering on the LED chip 2 in plan view. The LED chip 2 is a face-up type in which a pair of electrodes is formed on the upper surface, and each electrode is electrically connected to the first lead 4 and the second lead 5 by wires 10 and 11. In the present embodiment, the LED chip 2 that is made of a GaN-based semiconductor and emits blue light is used.

FIG. 3 is an explanatory view of the arrangement of the first lead and the second lead.
As shown in FIG. 3, the first lead 4 and the second lead 5 each extend in the same direction (vertical direction in FIG. 3) and are separated from each other at the longitudinal ends. The gap 20 between the first lead 4 and the second lead 5 has a substantially constant dimension over the width direction of each lead 4, 5 and is formed symmetrically with respect to the width direction. The gap 20 has a pair of end sections 21 extending in the width direction on each width direction end side, and a pair of symmetrical in the width direction center inclined toward the second lead 5 side toward the width direction center on the width direction center side. The inclined section 22 is continuously formed. The center in the width direction here is the center in the width direction of the leads 4 and 5. Note that a notch 51 is formed in a connection portion of each inclined section 22 in the second lead 5, and the dimension of the gap 20 is increased only in the portion where the notch 51 is formed. Each inclined section 22 is formed in a straight line and overlaps a part of the inflow / outflow prevention wall 9 in plan view.

  Also, a mounting portion 41 for mounting the LED chip 2 is formed on the center side in the width direction of the end portion in the longitudinal direction of the first lead 4. A part of the mounting portion 41 protrudes toward the second lead 5, and this protruding portion corresponds to each inclined section 22 of the gap 20. The gap 20 between the first lead 4 and the second lead 5 includes a first exposed portion 23 that exposes the bottom of the case 3 in the recess 31 on the second lead 5 side of the mounting portion 41, and an outer side in the width direction of the mounting portion 41. And a pair of second exposed portions 24 for exposing the bottom portion of the case 3 in the recess 31.

  Further, the first lead 4 is formed with a groove-shaped notch 42 extending from the end portion on the second lead 5 side toward the center side in the width direction toward the opposite side to the second lead 5. In the present embodiment, the notch 42 extends from one connecting portion of the end section 21 and the inclined section 22 in the gap 20, is formed in parallel with the other inclined section 22, and is partially flat with the part of the inflow / outflow prevention wall 9. It overlaps visually. The mounting portion 41 of the first lead 4 has a quadrangular shape in which each inclined section 22 and the notch 42 form three sides and the remaining one side is the base end. Further, the notch 42 has an exposed portion 42 a that exposes the bottom portion of the case 3 into the recess 31 on the side opposite to the second lead 5 side of the mounting portion 41.

  The first lead 4 is formed with a prevention wall hole 43 that is formed independently of the gap 20 and the notch 42 and overlaps a part of the inflow / outflow prevention wall 9 in plan view. In the present embodiment, the prevention wall hole 43 has a circular shape in plan view, and is formed in the proximal end portion of the mounting portion 41.

  The first lead 4 and the second lead 5 are formed with a plurality of outer edge holes 44, 45, 52, 53 that overlap the outer edge of the bottom surface of the recess 31 in plan view. In the present embodiment, the first lead 4 has a quadrangular first outer edge hole 44 formed at the center in the width direction, and a circular second outer edge hole 45 formed at one side in the width direction. Further, the second lead 5 is formed with a square-shaped first outer edge hole 52 at the center in the width direction and a circular second outer edge hole 53 at the other side in the width direction. The first outer edge holes 44 and 52 mainly have a function of preventing the leads 4 and 5 from being detached from the case 3. The second outer edge holes 45 and 53 mainly have a function of preventing peeling from the bottom surface of the resin material filled in the recess 31.

4 is a cross-sectional view taken along line AA in FIG.
As shown in FIG. 4, the LED chip 2 is mounted on the mounting portion 41 via a die bond paste 12 as an adhesive. In the present embodiment, the die bond paste 12 is made of, for example, an epoxy resin. A reflective layer 6 that covers the outside of the inflow / outflow prevention wall 9 is formed on the surface of the recess 31. The reflective layer 6 is made of a resin containing an inorganic filler. In the present embodiment, titanium oxide is used as the inorganic filler, and silicone is used as the resin.

  The inflow / outflow prevention wall 9 is formed integrally with the case 3, has a substantially cylindrical shape, and is formed higher than the LED chip 2 over the entire circumference. The wires 10 and 11 connect the electrodes of the LED chip 2 and the leads 4 and 5 across the inflow / outflow prevention wall 9. In the present embodiment, the inner surface of the inflow / outflow prevention wall 9 is perpendicular to the bottom surface of the recess 31, and the outer surface is formed so as to incline radially inwardly upward. The outer surface of the inflow / outflow prevention wall 9 is inclined at a predetermined angle so that the distance to the wires 10 and 11 is substantially constant.

  The light emitting device 1 configured as described above is manufactured by the following steps. First, the first lead 4 and the second lead 5 are formed into the shape shown in FIG. 3 by press working or the like. Then, the case 3 and the inflow / outflow prevention wall 9 are integrally formed by insert molding while the first lead 4 and the second lead 5 are inserted. Next, the LED chip 2 is mounted on the mounting portion 41 using the die bond paste 12. At this time, since the LED chip 2 is surrounded by the inflow / outflow prevention wall 9, the die bond paste 12 does not flow out of the outflow / inflow prevention wall 9. Thereafter, the wires 10 and 11 are formed, and the reflective layer 6 is applied to the inner surface of the recess 31 of the case 3. At this time, since the LED chip 2 is surrounded by the inflow / outflow prevention wall 9, the resin of the reflective layer 6 does not flow into the inflow / outflow prevention wall 9. Next, the sealing resin 7 is filled into the recess 31 of the case 3 by potting or the like, and the sealing resin 7 is cured to complete the light emitting device 1. The sealing resin 7 may be an ultraviolet curable type, a thermosetting type, or the like, but a thermosetting type is preferable in consideration of manufacturing equipment.

  As described above, according to the light emitting device 1 of the present embodiment, the LED chip 2 is surrounded by the inflow / outflow prevention wall 9, so that the die bond paste 12 is formed between the wires 10 and 11 and the leads 4 and 5. It does not flow out to the connecting portion, and it is possible to prevent the bonding failure between the wires 10 and 11 and the leads 4 and 5 due to the bleed-out of the die bond paste 12. In addition, the resin of the reflective layer 6 does not flow into the mounting location of the LED chip 2, the reflective layer 6 contacts the LED chip 2, and the light emitted from the LED chip 2 is not blocked by the reflective layer 6. .

  Further, according to the light emitting device 1 of the present embodiment, the inflow / outflow prevention wall 9 is seen in a plan view with the gap 20 between the first lead 4 and the second lead 5, the notch 42 of the first lead 4 and the hole 43 for the prevention wall. Therefore, the resin can be accurately poured into the inflow / outflow prevention wall 9 when the case 3 is molded, and the moldability of the inflow / outflow prevention wall 9 is improved. Further, since the inflow / outflow prevention wall 9 is formed integrally with the case 3, the inflow / outflow prevention wall 9 can be simultaneously formed in the forming process of the case 3, and the inflow / outflow prevention wall 9 is provided. Will not increase. Further, since the inflow / outflow prevention wall 9 is integral with the case 3, the strength of the inflow / outflow prevention wall 9 can be increased, which is extremely advantageous in practical use.

  In addition, since the inflow / outflow prevention wall 9 is formed in a circular shape, atmospheric gas such as air hardly remains inside the inflow / outflow prevention wall 9 when the sealing resin 7 is filled. Thus, no bubbles are generated in the sealing resin 7. Furthermore, when stress is applied to the inflow / outflow prevention wall 9, the stress can be dispersed.

  In the embodiment, the light emitted from the LED chip 2 is emitted to the outside without being wavelength-converted. For example, as shown in FIG. In this case, a part of the light emitted from the LED chip 2 may be wavelength-converted. When the LED chip 2 that emits blue light is used, yellow light such as YAG (Yttrium Aluminum Garnet) or silicate is used as the phosphor 13 so that white light can be emitted by a combination of blue light and yellow light. It can be released to the outside. The phosphor 13 may be dispersed in the sealing resin 7 and allowed to settle. In the light emitting device 1 of FIG. 5, the phosphor 13 is filled only inside the inflow / outflow prevention wall 9, and the color unevenness of the light emitted to the outside is suppressed.

  Moreover, in the said embodiment, although the notch 42 formed what was formed in groove shape, the shape of the notch 42 is not limited to groove shape, For example, it may form in shapes, such as circular shape and a rectangular shape. it can. Further, the number of notches formed in the first lead 4 is also arbitrary. For example, in addition to the notch 42 extending from the connecting portion of one of the end section 21 and the inclined section 22 (left side in FIG. 2), the other lead You may further form the notch extended from the connection part of a connection part (right side in FIG. 2).

  6 and 7 show a second embodiment of the present invention. FIG. 6 is a plan view of the light emitting device, and FIG. 7 is a cross-sectional view taken along the line BB of FIG. The second embodiment is different from the first embodiment in that the height of the wire is lower than the inflow / outflow prevention wall, and a groove through which the wire is inserted is formed in the inflow / outflow prevention wall.

  As shown in FIG. 6, the inflow / outflow prevention wall 9 of the light emitting device 101 has two grooves 91 through which the wires 110 and 111 are inserted. Each groove 91 is formed to extend in the radial direction. As shown in FIG. 7, the wires 110 and 111 are formed lower than the inflow / outflow prevention wall 9. Note that, except for the inflow / outflow prevention wall 9 and the wires 110 and 111, they are the same as in the first embodiment, and therefore will not be described in detail here.

  According to the light emitting device 101 configured as described above, since the wires 110 and 111 are disposed in the groove 91, the force applied to the wires 110 and 111 when the sealing resin 7 expands and contracts can be reduced. Thus, the reliability of the wires 110 and 111 can be dramatically improved.

  8 to 10 show a third embodiment of the present invention, and FIG. 8 is a plan view of the light emitting device. The third embodiment is different from the second embodiment mainly in that a partition wall 92 that connects the inflow / outflow prevention wall 9 and the reflector portion 33 of the case 3 is provided.

  As shown in FIG. 8, the light emitting device 201 includes a partition wall 92 formed continuously with the inflow / outflow prevention wall 9 and the reflector portion 33. The partition wall 92 extends radially outward from the inflow / outflow prevention wall 9 and partitions the bottom surface of the recess 31. In the present embodiment, a total of three partition walls 92 are provided at equal intervals in the circumferential direction. One of the three partition walls 92 overlaps the end section 21 of the gap 20 in plan view.

FIG. 9 is an explanatory diagram of the arrangement of the first lead and the second lead.
As shown in FIG. 9, the first lead 4 is formed with a groove-shaped notch 46 extending in parallel with one inclined section 22 from the end of the notch 42 parallel to the other inclined section 22. The notch 46 overlaps a part of the inflow / outflow prevention wall 9 in plan view. Further, the first lead 4 is formed with a groove-shaped notch 47 that is continuous with the notch 46 and overlaps with one of the partition walls 92 in plan view. A circular outer edge hole 48 is continuously formed at the end of the notch 47.

  The second lead 5 is formed with a groove-shaped notch 54 that is continuous with the other inclined section 22 and overlaps one of the partition walls 92 in plan view. A circular outer edge hole 53 is continuously formed at the end of the notch 54.

10 is a cross-sectional view taken along the line CC of FIG.
As shown in FIG. 10, the partition wall 92 is formed at the same height as the inflow / outflow prevention wall 9. The partition wall 92 is formed integrally with the case 3 and the inflow / outflow prevention wall 9. The three partition walls 92 overlap the end section 21 of the gap 20, the cutout 47 of the first lead 4, and the cutout 53 of the second lead 5 in plan view.

  According to the light emitting device 201 configured as described above, since the partition wall 92 is formed, the volume of the sealing resin 7 filled in the recess 31 of the case 3 is reduced, and the expansion / The load on the LED chip 2 and the wires 110 and 111 at the time of contraction can be reduced. Further, since the bottom surface of the recess 31 is partitioned by the partition walls 92, the amount of movement of the sealing resin 7 near the bottom surface of the recess 31 when the sealing resin 7 expands and contracts can be reduced. In addition, the load on the LED chip 2 and the wires 110 and 111 can be reduced.

  In the third embodiment, three partition walls 92 are provided. However, the number of partition walls 92 is arbitrary.

  In the first to third embodiments, the light emitting devices 1, 101, and 201 are top view types. However, it is needless to say that the side view type, chip on board type, or the like may be used. is there.

  Moreover, in each said embodiment, although what emitted blue light was shown as LED chip 2, you may use what emits green light or red light, for example. Alternatively, a light emitting device that emits white light by mounting three LED chips of blue, green, and red on separate lead portions may be used. Further, although the light emitting device using the GaN-based semiconductor material as the LED chip 2 has been described, a light-emitting element made of another semiconductor material such as ZnSe-based or SiC-based may be used.

  In addition, although the first lead 4 and the LED chip 2 are electrically connected by the wires 10 and 110, the lower surface of the LED chip 2 may be used as an electrode and the wires 10 and 110 may be omitted. In this case, the die bond paste 12 becomes a conductive adhesive.

  In each of the embodiments, the light emitting device 1 is shown in which the case 3 is made of resin. However, the case 3 may be made of ceramic if the case 3 and the inflow / outflow prevention wall 9 are integrally formed. .

  Moreover, in each said embodiment, although the inflow / outflow prevention wall 9 was formed in the planar view circular shape, polygonal shape etc. may be sufficient, for example. In addition, although the outer surface of the inflow / outflow prevention wall 9 is inclined, it may be perpendicular to the bottom surface of the recess 31. In this case, it is possible to prevent the reflective layer 6 from climbing up the outer surface.

  Moreover, in each said embodiment, although the light-emitting device using an LED chip as a light emitting element was demonstrated, a light emitting element is not limited to an LED element. Further, a protective element such as a Zener diode may be provided in addition to the light emitting element, and other specific details such as a detailed structure can be appropriately changed.

FIG. 1 is an external perspective view of a light-emitting device showing a first embodiment of the present invention. FIG. 2 is an explanatory plan view of the light emitting device. FIG. 3 is an explanatory view of the arrangement of the first lead and the second lead. 4 is a cross-sectional view taken along line AA in FIG. FIG. 5 is a longitudinal sectional view of a light emitting device showing a modification. FIG. 6 is a plan view of a light-emitting device showing a second embodiment of the present invention. 7 is a cross-sectional view taken along line BB in FIG. FIG. 8 is a plan view of a light-emitting device showing a third embodiment of the present invention. FIG. 9 is an explanatory diagram of the arrangement of the first lead and the second lead. 10 is a cross-sectional view taken along the line CC of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Light-emitting device 2 LED chip 3 Case 4 1st lead 5 2nd lead 6 Reflective layer 7 Sealing resin 8 Cover member 9 Outflow / inflow prevention wall 10 Wire 11 Wire 12 Die bond paste 13 Phosphor 20 Gap 21 End section 22 Inclined section 31 recess 32 opening 33 reflector portion 41 mounting portion 42 notch 43 prevention wall hole 44 outer edge hole 45 outer edge hole 46 notch 47 notch 48 outer edge hole 51 notch 52 outer edge hole 53 outer edge hole 54 Notch 91 Groove 92 Partition wall 101 Light emitting device 110 Wire 111 Wire 201 Light emitting device

Claims (6)

A light emitting element;
A resin case having a recess for accommodating the light emitting element;
A metal first lead disposed on the bottom surface side of the recess, on which the light emitting element is mounted via an adhesive;
A metal second lead disposed on the bottom surface side of the recess and spaced apart from the first lead and electrically connected to the light emitting element via a wire;
A notch formed in an end of the first lead on the second lead side;
Formed integrally with the case on the bottom surface of the recess, surrounds the light emitting element, and at least a part of the gap between the first lead and the second lead and the notch of the first lead overlap each other in plan view. An inflow / outflow prevention wall,
A light emitting device comprising: a reflection layer that covers an outer side of the inflow / outflow prevention wall at the bottom surface of the concave portion, is prevented from flowing out toward the light emitting element by the inflow / outflow prevention wall, and contains a filler in a resin. . The first lead and the second lead extend in a predetermined direction,
The light emitting element mounting portion of the first lead is formed at the center in the width direction so as to protrude toward the second lead,
The gap between the first lead and the second lead has a pair of inclined sections that are symmetric about the center in the width direction inclined toward the second lead side toward the center in the width direction,
2. The light emitting device according to claim 1, wherein the notch of the first lead is formed continuously with one of the inclined sections of the gap and extends while being inclined toward the center in the width direction toward the opposite side of the second lead. apparatus. The gap is
A first exposed portion that exposes a bottom portion of the case in the concave portion on the second lead side of the mounting portion;
The light-emitting device according to claim 2, further comprising: a pair of second exposed portions that expose the bottom portion of the case in the concave portion on the outer side in the width direction of the mounting portion.   The light-emitting device according to claim 3, further comprising a partition wall that is connected to the inflow / outflow prevention wall and partitions an outer region of the inflow / outflow prevention wall on a bottom surface of the recess.   The light-emitting device according to claim 4, wherein the partition wall is formed integrally with the inflow / outflow prevention wall and the case. The wire is formed lower than the inflow / outflow prevention wall,
6. The light emitting device according to claim 5, wherein the inflow / outflow prevention wall has a groove through which the wire is inserted.

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