JPH11168235A - Light emitting diode - Google Patents

Abstract

[PROBLEMS] To electrically connect an LED chip having a pair of positive and negative electrodes on the same surface side to a wiring pattern of a substrate,
Improves light extraction efficiency. SOLUTION: LE having a pair of positive and negative electrodes on the same surface side
The D chip 13 is electrically connected to the wiring pattern 12 of the substrate 11 via the bump 15 by flip chip bonding. The reflection layer 14 is provided on the lower surface of the LED chip 13. The underside of the LED chip 13 is filled with an underfill resin 16. There is no electrode serving as a shadow on the upper surface side, which is the light emitting surface side of the LED chip 13, so that the light emitting area increases, and the downward light from the light emitting layer is reflected by the reflective layer 14, and the light extraction efficiency as a whole Is improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting diode (LED) formed by electrically connecting a light emitting diode (LED) chip having a pair of positive and negative electrodes on the same surface to a substrate.

[0002]

2. Description of the Related Art As a conventional light emitting diode of this type,
For example, there is a technique described in Japanese Patent Application Laid-Open No. Hei 9-135040. FIG. 8 is a sectional view showing an LED disclosed in Japanese Patent Application Laid-Open No. 9-135040.

Japanese Patent Application Laid-Open No. Hei 9-135040 discloses an LED chip having a pair of positive and negative electrodes on the same surface side. That is, the light emitting diode is formed on the substrate 1 provided with the predetermined wiring pattern 2 via the Ag (silver) paste 4.
The ED chip 3 is bonded. Also, an electrode (not shown) on the upper surface 3a side of the LED chip 3 is electrically connected to the wiring pattern 2 of the substrate 1 by a bonding wire 5 such as an Au (gold) wire. The periphery of the LED chip 3 is sealed with a resin mold 6 such as an epoxy resin to protect the LED chip 3.

In this light emitting diode, light emitted upward from the light emitting layer (active layer) at the pn junction of the LED chip 3
Light is emitted upward from the upper surface 3a as a light emission surface. Also,
Light emitted downward from the light emitting layer of the LED chip 3 is an LED.
The light is diffusely reflected by the paste 4 on the lower surface of the chip 3, and a part of the light is reflected upward and emitted from the upper surface 3a.

[0005]

In the conventional light emitting diode, since the electrode is provided on the upper surface 3a, which is the light emitting surface of the LED chip 3, the electrode becomes a shadow. Therefore, the light emitting area is reduced by the electrode area, the light extraction efficiency is reduced, and there is room for improvement in light emitting efficiency. Also, LE
Since the Ag paste 4 on the lower surface of the D chip 3 changes color over time, the reflection efficiency of downward light decreases, and the light extraction efficiency may further decrease. LED chip 3
Since the bonding wire 5 is used for electrical connection between the electrode and the wiring pattern 2 of the substrate 1, a space for wire bonding is required, and the entire light emitting diode may be increased in size.

Accordingly, the present invention provides a light emitting diode which can electrically connect an LED chip having a pair of positive and negative electrodes on the same surface to a wiring pattern on a substrate, while improving the light extraction efficiency. The purpose is to provide

[0007]

According to a first aspect of the present invention, there is provided a light emitting diode having a substrate having a pair of wiring patterns and a pair of positive and negative electrodes on the same surface side, wherein both electrodes are connected to both wiring patterns of the substrate. LED chips electrically connected via bumps.

According to a second aspect of the present invention, there is provided a light emitting diode having a substrate having a pair of wiring patterns and a pair of positive and negative electrodes on the same surface side, wherein both electrodes are electrically connected to both wiring patterns of the substrate via bumps. And an electrically insulative underfill resin that seals between at least both electrodes of the LED chip.

According to a third aspect of the present invention, there is provided a light emitting diode having a substrate having a pair of wiring patterns and a pair of positive and negative electrodes on the same surface side, wherein both electrodes are electrically connected to both wiring patterns of the substrate via bumps. And an anisotropic conductive paste for sealing at least between both electrodes of the LED chip.

According to a fourth aspect of the present invention, in the light emitting diode according to any one of the first to third aspects, the wiring pattern of the substrate includes an electrode portion which is opposed to the substrate at a distance in a longitudinal direction of the substrate. The LED chip has a substantially rectangular plate shape, and the pair of positive and negative electrodes is arranged in a diagonal direction of the LED chip, and the pair of positive and negative electrodes is disposed to face and electrically connect to both electrode portions of the wiring pattern. Things.

According to a fifth aspect of the present invention, in the light emitting diode according to any one of the first to third aspects, the wiring pattern of the substrate is opposed to the wiring pattern at an interval in a direction inclined with the length direction of the substrate. The LED chip has a substantially rectangular plate shape, and the pair of positive and negative electrodes are arranged diagonally in the LED chip. Is to be connected to.

According to a sixth aspect of the present invention, in the light emitting diode according to any one of the first to third aspects, the wiring pattern of the substrate includes an electrode portion which is opposed to the wiring pattern at an interval in the longitudinal direction of the substrate. The LED chip has a substantially rectangular plate shape, and the pair of positive and negative electrodes is arranged in the length direction thereof, and the pair of positive and negative electrodes are disposed to face and electrically connect to the electrode portion of the wiring pattern. Things.

According to a seventh aspect of the present invention, in the light emitting diode according to any one of the first to sixth aspects, the substrate is an MID substrate.

[0014]

Embodiments of the present invention will be described below.

FIG. 1 is a sectional view showing the entire structure of the light emitting diode according to the first embodiment of the present invention. FIG.
FIG. 2 is a cross-sectional view illustrating a main part of the light emitting diode according to the first embodiment of the present invention.

As shown in FIG. 1, the light emitting diode according to the first embodiment includes a substrate 11 having a predetermined wiring pattern 12 forming a pair of positive and negative electrodes, and an LED chip 13. On the lower surface of the LED chip 13, a reflective layer 14 made of a metal layer such as an Au pad is formed on the entire surface by metal deposition or the like. The LED chip 13 has a pair of positive and negative electrodes (not shown) on the same surface side (the lower surface side in the figure), and both electrodes are electrically connected to both wiring patterns 12 of the substrate 11 via bumps 15 by flip chip bonding. To connect to.

As shown in FIG. 2, the light emitting diode of the first embodiment further includes an insulating underfill resin 16 for sealing at least between a pair of positive and negative electrodes of the LED chip 13. Specifically, the underfill resin 1
Reference numeral 6 is made of an insulating resin such as an epoxy resin, covers the entire periphery of the LED chip 13, and seals a gap between the lower surface of the LED chip 13 and the surface of the substrate 11. That is, the underfill resin 16 is filled between the two electrodes of the LED chip 13 to maintain their electrical insulation. In the light-emitting diode of the first embodiment, the entire periphery of the LED chip 13 is sealed and protected by a resin mold 6 such as an epoxy resin, similarly to the conventional example.

Here, flip chip bonding is
The bump 15 is used in an assembly wiring process of a semiconductor manufacturing technology such as an LSI, and various bumps such as an Au bump and a solder bump can be used as the bump 15. The substrate 11 is made of glass epoxy resin, BT
A normal insulating substrate made of resin or the like can be used. The printed wiring 12 is formed by using an electrode wiring technique of a normal semiconductor manufacturing technique such as an etching method. For example, the printed wiring 12 is formed by stacking a metal plating layer such as Au on a base metal layer such as Cu + Ni.

LED having a pair of positive and negative electrodes on the same side
For example, the techniques described in JP-A-4-10671 and JP-A-5-21846 can be used. Among them, Japanese Patent Application Laid-Open No. 4-10671 discloses that an n-GaN (n-type gallium nitride) layer and an i-GaN (i-type gallium nitride) layer are sequentially grown and laminated on a sapphire substrate which is an insulator. Discloses a blue light emitting LED formed by the above method. In this LED, one of a pair of positive and negative electrodes is i-
It is provided on the surface of the GaN layer, and the other of the pair of positive and negative electrodes is an i-G
It is provided through the aN layer. These electrodes are joined to a lead frame for electrical connection.

Japanese Patent Laid-Open Publication No. Hei 5-21846 discloses, for example, a buffer layer made of AlN (aluminum nitride), a high carrier concentration n + layer made of GaN, a low carrier concentration n layer made of GaN,
Discloses a blue light-emitting LED in which an i-layer consisting of In this LED, one of the pair of positive and negative electrodes is provided at the center of the surface of the i-layer, and the other of the pair of positive and negative electrodes is connected to the high carrier concentration n + layer from the side. These electrodes are joined to a lead frame for electrical connection. As the LED chip 13, various LED chips having a pair of positive and negative electrodes on the same surface side can be used in addition to those described in JP-A-4-10671 or JP-A-5-21846.

Next, the manufacturing method and operation of the light emitting diode according to the first embodiment configured as described above will be described.

First, the light emitting diode of Embodiment 1
LE in which a conductive paste (conductive adhesive) is applied to the wiring pattern 12 of the substrate 11 and bumps 15 are previously attached to the electrodes
The D chip 13 is positioned and placed on the wiring pattern 12. Next, the bump 15 is cured while the LED chip 13 is pressed against the substrate 11, and the pair of positive and negative electrodes is electrically connected to the corresponding wiring pattern 12. The LED chip is pressurized and cured by, for example, maintaining the temperature of the resin part at about 170 to 200 degrees Celsius for about 30 seconds under a pressing state of about 10 kgf / mm ² or more. After that, the underfill resin 16 is applied to the gap between the substrate 11 and the LED chip 13, penetratingly filled, and cured.

As a result, the underfill resin 16 becomes L
Electrical insulation between the pair of positive and negative electrodes of the ED chip 13 is ensured, and a short circuit between them is prevented. Note that the underfill resin 16 may be applied to the substrate 12 first, the LED chip 13 with the bump 15 previously attached thereto may be positioned and mounted thereon, and may be press-hardened under the same conditions as described above. After the pressure bonding of the LED chip 13, the periphery of the LED chip 13 is sealed with a resin mold 6 such as an epoxy resin, and
By protecting the ED chip 13, a light emitting diode as a final product is formed.

The light emitting diode thus formed has an L
Since the pair of positive and negative electrodes of the ED chip 13 are located on the lower surface side opposite to the light emitting surface, there is no shadow on the upper surface 13a, which is the light emitting surface, and the entire upper surface 13a of the LED chip 13 Is the light emitting area. LED chip 1
3, the reflection layer 14 is formed on the entire lower surface, so that the reflection efficiency of downward light can be increased. As a result, the light extraction efficiency from the LED chip 13 is increased, and the luminous efficiency or luminance can be improved. Also, the LED chip 13
The electrical connection between the two electrodes and the two wiring patterns 12 on the substrate 11 is performed by flip-chip bonding, so that a space for wire bonding as in the related art is unnecessary, and the entire light emitting diode can be reduced in size. Furthermore, since both electrodes of the LED chip 13 can be directly connected to both the wiring patterns 12 of the substrate 11, the heat dissipation during driving the LED chip 13 is improved, and the reliability and durability of the light emitting diode are improved.

FIG. 3 is a sectional view showing a main part of a light emitting diode according to a second embodiment of the present invention.

The light emitting diode of the second embodiment differs from the light emitting diode of the first embodiment in that an anisotropic conductive resin 21 is used instead of the underfill resin 16, and the other configuration is the same. , Only the main parts are illustrated and described. That is, the light emitting diode of the second embodiment uses the anisotropic conductive paste 21 for the LED chip 1.
3 at least between the pair of positive and negative electrodes. This anisotropic conductive paste 21 itself is formed by adding 5 to 10 Ag particles such as an Ag filler with an insulating coat to an epoxy-based resin.
%. The entire periphery of the LED chip 13 is covered with the anisotropic conductive paste 21, and
The space between the LED chip 13 and the surface of the substrate 11 is sealed.
Thereby, the LED chip 1 is connected via the wiring pattern 12.
When a voltage is applied between the two electrodes 3, the anisotropic conductive paste 21 maintains electrical insulation in a horizontal direction or a horizontal direction (horizontal direction in FIG. 3) and a vertical direction or a vertical direction (in FIG. 3). (Up and down direction) to ensure electrical continuity. Note that the light emitting diode of Embodiment 2 is also similar to the conventional example.
The entire periphery of the LED chip 13 is sealed and protected by a resin mold 6 such as an epoxy resin.

Next, a description will be given of a method and an operation of manufacturing the light emitting diode according to the second embodiment configured as described above.

The light emitting diode of Embodiment 2
Anisotropic conductive paste 21 is applied to wiring pattern 12 of substrate 11
Is applied, the LED chip 13 having the bump 15 attached to the electrode in advance is positioned on the wiring pattern 12 and placed with the anisotropic conductive paste 21 interposed therebetween. Thereafter, as in the first embodiment, the LED chip 13 is pressed and the bump 15 is cured, and the pair of positive and negative electrodes is electrically connected to the corresponding wiring pattern 12. Thereby, the anisotropic conductive paste 21 secures the electrical insulation in the horizontal direction, that is, between the two electrodes of the LED chip 13, and the short circuit between them is prevented. At the same time, the anisotropic conductive paste 21 is in the vertical direction,
Electrical conduction between the positive and negative electrodes of the LED chip 13 and the wiring pattern 12 of the substrate 11 is ensured.

Therefore, L for the wiring pattern 12
Even if the positioning of the ED chip 13 is somewhat inaccurate,
A short circuit does not occur between the positive and negative electrodes, and conductivity between the positive and negative electrodes and the wiring pattern 12 is ensured. Also, LE
Even when the height of the bump 15 attached to each electrode of the D chip 13 varies, the Ag particles of the anisotropic conductive paste 21 absorb the variation, so that the reliability in the electrical connection with the wiring pattern 12 increases. . As a result, the positioning accuracy may vary to some extent, and the positioning operation can be simplified. In particular, it is suitable for flip-chip bonding of the LED chip 13 in which the pitch between electrodes is narrower than that of a normal LSI and high reliability is required for securing insulation between the electrodes, and the operation reliability of the light emitting diode is further improved. Thus, product quality can be further improved.

FIG. 4 is a plan view of a light emitting diode according to the third embodiment of the present invention.

The third embodiment is characterized in that the structure for ensuring electrical insulation between the electrodes of the LED chip is improved, and the overall configuration is the same as in the first and second embodiments. That is, as shown in FIG. 4, the light emitting diode of the third embodiment has a predetermined wiring pattern 32 forming a pair of positive and negative electrodes.
And a LED chip 33. Although not shown, the lower surface of the LED chip 33 is provided with the first embodiment.
A reflective layer similar to the reflective layer 14 is formed on the entire surface.
The LED chip 33 has a pair of positive and negative electrodes on the same surface side (the lower surface side in the figure), and both electrodes are electrically connected to both wiring patterns 32 of the substrate 31 via bumps 35 by flip chip bonding. It has become.

Basically, the substrate 31, the wiring pattern 3
2. The LED chip 33 and the bump 35 are
Except for the specific pattern shape 2 and the electrode position of the LED chip 33, the configuration can be the same as that of the substrate 11, the wiring pattern 12, the LED chip 13 and the bump 15 of the first and second embodiments. On the other hand, when these specific configurations are described in detail, the substrate 31 has a substantially rectangular plate shape. The two wiring patterns 32 have a symmetrical shape and the substrate 3
Electrodes 32 opposed to each other at intervals in the longitudinal direction
a. The electrode portion 32a extends along a center line extending in the length direction of the substrate 31. Furthermore,
The LED chip 33 has a square plate shape, and the pair of positive and negative electrodes is arranged on a diagonal line (in a diagonal direction).
The distance between the tips of the electrode portions 32a (the pitch between the electrode portions) is the same as the distance between the electrodes of the LED chip 33 (the pitch between the electrodes). Thereby, the LED chip 3
3 is arranged at the center of the substrate 31 so that the diagonal direction coincides with the center line extending in the length direction of the substrate 31 so that L
The two electrodes of the ED chip 33 are arranged to face the front ends of the two electrode portions 32 a of the wiring pattern 32. The pair of positive and negative electrodes of the LED chip 33 are electrically connected to the corresponding electrode portions 32a via the bumps 35. That is, in the third embodiment, the LED chip 33
Since the electrodes are arranged in the diagonal direction, the pitch between the electrodes can be widened. In accordance with this, the pitch between the electrode portions 32a of the wiring pattern 32 can be set wider.

The light emitting diode of the third embodiment is
As in the first or second embodiment, the underfill resin 16 or the anisotropic conductive paste
The entire periphery of the ED chip 33 and the LED chip 3
The gap between the lower surface of the substrate 3 and the surface of the substrate 31 is sealed. Further, similarly to the conventional example, the entire periphery of the LED chip 33 is sealed and protected by a resin mold 6 such as an epoxy resin.

The light emitting diode of the third embodiment configured as described above is manufactured in the same manner as in the first or second embodiment, and has the same functions and effects. In addition, since the light emitting diode of the third embodiment has a pair of positive and negative electrodes arranged in a diagonal direction of the LED chip 33, the LED chip 33
And the pitch between the electrode portions 32a of the wiring pattern 32 become larger. As a result, as compared with the case where the electrodes are arranged in the length direction of the LED chip 33 as in Embodiment 1 or 2, the short circuit between the electrodes is more effectively prevented, and the operation reliability of the light emitting diode is improved. It is possible to further improve the product quality.

FIG. 5 is a plan view of a light emitting diode according to a fourth embodiment of the present invention.

In the fourth embodiment, as in the third embodiment, L
It is characterized in that the structure for ensuring electrical insulation between the electrodes of the ED chip is improved, and the overall configuration is the same as in the first and second embodiments. That is, as shown in FIG. 5, the light emitting diode according to the fourth embodiment includes a substrate 41 having a predetermined wiring pattern 42 forming a pair of positive and negative electrodes, and an LED chip 43. Although not shown, a reflection layer similar to the reflection layer 14 of the first embodiment is formed on the entire lower surface of the LED chip 43. The LED chip 43 has a pair of positive and negative electrodes on the same surface side (the lower surface side in the drawing), and both electrodes are electrically connected to both wiring patterns 42 of the substrate 41 via bumps 45 by flip chip bonding. It has become.

The basic configuration of the fourth embodiment is similar to that of the third embodiment.
However, the specific pattern shape of the wiring pattern 42 is different from that of the wiring pattern 32 of the third embodiment. That is, basically, the substrate 41, the wiring pattern 42, the LED chip 43, and the bump 45 are formed by the specific pattern shape of the wiring pattern 42 and the LED chip 43.
Except for the positions of the electrodes described above, the configuration can be the same as that of the substrate 11, the wiring pattern 12, the LED chip 13, and the bumps 15 of the first and second embodiments. On the other hand, when these specific configurations are described in detail, the substrate 41 has a substantially rectangular plate shape,
In addition, the two wiring patterns 42 are symmetrical in shape and have electrode portions 42a opposed to each other at intervals in the direction inclined with respect to the length direction of the substrate 41.

That is, the electrode portion 42a is extended so as to be inclined in a direction away from the center line extending in the length direction of the substrate 41 at a predetermined angle. Further, the LED chip 43 has a square plate shape, and the pair of positive and negative electrodes is arranged on a diagonal line thereof. The distance between the tips of the electrode portions 42a is the same as the distance between the electrodes of the LED chip 43. As a result, the LED chip 43 is connected to the center line of the substrate 4.
The two electrodes of the LED chip 43 are arranged so as to be opposed to the front ends of the two electrode portions 42 a of the wiring pattern 42 by being aligned with the center line extending in the length direction of the first and the center of the substrate 41. The pair of positive and negative electrodes of the LED chip 43 are electrically connected to the corresponding electrode portions 42a via bumps 45.

That is, in the fourth embodiment, as in the third embodiment, since the electrodes are arranged in the diagonal direction of the LED chip 43, the pitch between the electrodes can be widened. In accordance with this, the pitch between the electrode portions 42a of the wiring pattern 42 can be set wider. Furthermore, wiring pattern 4
2 was changed, and the electrode portion 42a was extended in the direction away from each other so as to incline with the length direction of the substrate 41. Therefore, the LED chip 43 was placed on the substrate 41 in the normal state (the center line was aligned). Can be arranged.

The light emitting diode of the fourth embodiment is
As in the first or second embodiment, the underfill resin 16 or the anisotropic conductive paste
The entire periphery of the ED chip 43 and the LED chip 4
The gap between the lower surface of the substrate 3 and the surface of the substrate 41 is sealed. As in the conventional example, the entire periphery of the LED chip 43 is sealed and protected by a resin mold 6 such as an epoxy resin.

The light emitting diode of the fourth embodiment configured as described above is manufactured in the same manner as in the first or second embodiment, and has the same functions and effects. In addition, the light emitting diode of the fourth embodiment has the same effect as that of the third embodiment because a pair of positive and negative electrodes is arranged in the diagonal direction of the LED chip 43. Further, the LED chip 43 is attached to the substrate 4
Since the LED chip 43 can be arranged in a normal state, the operation of positioning or arranging the LED chip 43 can be performed by an ordinary method.
That is, the same effect as in the third embodiment can be exerted only by substantially changing the pattern shape of the wiring pattern 42.

FIG. 6 is a plan view of a light emitting diode according to the fifth embodiment of the present invention.

The fifth embodiment is similar to the third and fourth embodiments in that the structure for ensuring electrical insulation between the electrodes of the LED chip is improved, and the overall configuration is the same as in the first and second embodiments. Is the same as That is, as shown in FIG. 6, the light emitting diode of the fifth embodiment includes a substrate 51 having a predetermined wiring pattern 52 forming a pair of positive and negative electrodes, and a light emitting diode (LE).
A D chip 53 is provided. Although not shown, a reflection layer similar to the reflection layer 14 of the first embodiment is formed on the entire lower surface of the LED chip 53. The LED chip 53 has a pair of positive and negative electrodes on the same surface side (the lower surface side in the figure), and both electrodes are electrically connected to both wiring patterns 52 of the substrate 51 via bumps 55 by flip chip bonding. It has become.

The basic configuration of the fifth embodiment is similar to that of the third embodiment.
However, the shape of the LED chip 53 is different from that of the LED chip 33 of the third embodiment. That is, basically, the substrate 51, the wiring pattern 52, the LE
The D chip 53 and the bump 55 have the same configuration except for the specific pattern shape of the wiring pattern 52 and the shape of the LED chip 53.
Substrate 11, wiring pattern 12, L of first and second embodiments
The same configuration as the ED chip 13 and the bump 15 can be used. On the other hand, when these specific configurations are described in detail, the substrate 51 has a substantially rectangular plate shape, and both the wiring patterns 52 have a symmetrical shape, and are arranged facing each other at intervals in the length direction of the substrate 51. Each has an electrode part 52a to be formed. The electrode portion 52a extends along a center line extending in the length direction of the substrate 51. Further, the LED chip 53 has a rectangular plate shape, and the pair of positive and negative electrodes is arranged in a length direction. The interval between the tips of the electrode portions 52a is the same as the interval between the electrodes of the LED chip 53. Accordingly, the LED chip 53 is arranged at the center of the substrate 51 such that the center line extending in the length direction coincides with the center line extending in the length direction of the substrate 51, so that the LE
The two electrodes of the D chip 53 are arranged to face the front ends of the two electrode portions 52a of the wiring pattern 52. And such L
An electrode section 52 corresponding to a pair of positive and negative electrodes of the ED chip 53;
a to be electrically connected via a bump 55. That is, in the fifth embodiment, the LED chip 5
Since the electrodes are arranged in the length direction of 3, the pitch between the electrodes can be widened. In accordance with this, the pitch between the electrode portions 52a of the wiring pattern 52 can be set wider.

The light emitting diode of the fifth embodiment is
As in the first or second embodiment, the underfill resin 16 or the anisotropic conductive paste
The entire periphery of the ED chip 53 and the LED chip 5
The gap between the lower surface of the substrate 3 and the surface of the substrate 51 is sealed. As in the conventional example, the entire periphery of the LED chip 53 is sealed and protected by a resin mold 6 such as an epoxy resin.

The light emitting diode of the fifth embodiment configured as described above is manufactured in the same manner as in the first or second embodiment, and has the same functions and effects. In addition, the light emitting diode of the fifth embodiment has the same effect as that of the third or fourth embodiment because a pair of positive and negative electrodes are arranged in the length direction of the LED chip 53.

FIG. 7 is a sectional view of a light emitting diode according to a sixth embodiment of the present invention.

The light emitting diode of the sixth embodiment uses an MID substrate as a substrate and is embodied as an MID light emitting diode. That is, as shown in FIG.
The light emitting diode of the sixth embodiment includes a substrate 61 having a predetermined wiring pattern 62 forming a pair of positive and negative electrodes;
The ED chip 63 is provided. The substrate 61 has the shape of a thick rectangular block and has a cone-shaped concave portion whose center on the upper surface side is reduced in diameter downward.
Are extended to form a cone-shaped reflecting surface 62a. Both wiring patterns 62 extend to the bottom surface of the recess. As the material of the substrate 61 and the wiring pattern 62, the same materials as in the first embodiment can be used. The same LED chip 63 as the LED chip 16 of the first embodiment can be used.

As in the first embodiment, the reflection layer 6 made of a metal layer such as an Au pad is provided on the lower surface of the LED chip 63.
4 is formed on the entire surface by metal evaporation or the like. Also,
The LED chip 63 has a pair of positive and negative electrodes (not shown) on the same surface side (the lower surface side in the figure), and the both electrodes are connected to the tips of both wiring patterns 62 of the substrate 61 by bumps 65 by flip chip bonding. To be electrically connected. The bump 65 is the bump 15 of the first embodiment.
The same can be used. Further, the light emitting diode of the sixth embodiment also includes an insulating underfill resin 66 for sealing at least a pair of the positive and negative electrodes of the LED chip 63. The underfill resin 66
Is made of the same material as the underfill resin 16 of the first embodiment, covers the entire periphery of the LED chip 63, and
The gap between the lower surface side of the LED chip 63 and the bottom surface of the concave portion of the substrate 61 is sealed. In the light emitting diode according to the sixth embodiment, the recess formed by the reflection surface 62a is filled with a casting resin 67 such as an epoxy resin to seal and protect the light emitting diode 63 and the like.

Next, a method of manufacturing the light emitting diode according to the sixth embodiment configured as described above and its operation will be described.

The light emitting diode of Embodiment 6
The substrate 61 is molded by a normal MID substrate molding technique such as a one-shot molding method, and a wiring pattern 62 is formed on the substrate 61. Next, in the same manner as in the first embodiment, the LED chip 63 is electrically connected to the wiring pattern 62 via the bump 65, and the underfill resin 66 is
The lower surface of the chip 6 is filled and hardened. Then, the substrate 6
The casting resin 67 is provided in the recess formed by the first reflection surface 62a.
Fill and cure. Thus, an MID light emitting diode as a final product shown in FIG. 7 is formed.

The light emitting diode thus formed exhibits the same effects as in the first embodiment. In addition, the substrate 61
The reflection surface 62a of the wiring pattern 62 of the LED chip 63
The light emitted laterally from is reflected upward. As a result, the luminous efficiency or luminance of the entire light emitting diode can be further increased.

The LED chips 43 and 53 of the light emitting diodes according to the fourth and fifth embodiments may be implemented as in the following example.

FIG. 9 is a plan view showing an example of the shape of an LED chip of a light emitting diode according to Embodiment 4 of the present invention. FIG. 10 is a cross-sectional view showing the LED chip of FIG. 9 cut in a diagonal direction where electrodes are located.

This example of the shape shows an example of a specific configuration of the LED chip 43 of the fourth embodiment. The LED chip 43 of the examples of FIGS. 9 and 10 includes a semiconductor part 43a having a square planar shape. ing. In the diagonal direction on the same surface side (the upper surface side in FIG. 10) of the semiconductor portion 43a, a pair of positive and negative electrodes 4
3b and 43c are arranged. In addition, both electrodes 43b, 43
c is arranged in the semiconductor section 43a with a step. Electrode 4
3b is the electrode 4 of the surface (upper surface in FIG. 10).
It is covered with an insulating film 43d while leaving a part on the diagonal opposite side to 3c in a circular shape. The circular portion is a circular hole 4
3e, the surface of the electrode 43b is exposed from the circular hole 43e, and can be electrically connected to the outside. The insulating film 43d covers the entire surface from the surface to the side surface of the electrode 43b, and also covers the entire step surface (vertical surface in FIG. 10) of the semiconductor portion 43a adjacent to the electrode 43b. Thereby, the insulating film 43d completely secures electrical insulation between the electrode 43b and the electrode 43c.

As in the fourth embodiment, the distance between the circular hole 43e exposing the electrode 43b and the electrode 43c is the same as the distance between the tips of the electrode portions 42a of the substrate 41. Thereby, by aligning the center line of the LED chip 43 with the center line extending in the length direction of the substrate 41 and disposing the LED chip 43 in the center of the substrate 41, the exposed portion of the electrode 43b of the LED chip 43 from the circular hole 43e and An electrode 43c is disposed opposite to the tip of both electrode portions 42a of the wiring pattern 42. Then, the exposed portion of the electrode 43b of the LED chip 43 from the circular hole 43e and the electrode 43c can be electrically connected to the corresponding electrode portion 42a via the bump 45.

FIG. 11 is a plan view showing an example of the shape of the LED chip of the light emitting diode according to the fifth embodiment of the present invention. FIG. 12 is a cross-sectional view showing the LED chip of FIG. 11 cut in a length direction where electrodes are located.

This example of the shape shows an example of a specific configuration of the LED chip 53 of the fifth embodiment.
The LED chips 53A of the examples of FIGS.
It corresponds to the ED chip 53 and includes a semiconductor part 53a having a rectangular shape in a plane. A pair of positive and negative electrodes 5 is arranged in the longitudinal direction on the same surface side (the upper surface side in FIG. 12) of the semiconductor portion 53a.
3b and 53c are arranged. In addition, both electrodes 53b, 53
c is arranged in the semiconductor section 53a with a step. Electrode 5
3b is the electrode 5 of the surface (upper surface in FIG. 12).
The insulating film 5 is formed by leaving a part on the side opposite to the longitudinal direction of the insulating film 3c in a circular shape.
Coated with 3d. The circular portion is a circular hole 53
The surface of the electrode 53b is exposed from the circular hole 53e, and is electrically connectable to the outside. The insulating film 53d covers the entire surface from the surface to the side surface of the electrode 53b, and also covers the entire surface (horizontal plane in FIG. 12) and the entire step surface (vertical plane in FIG. 12) of the semiconductor portion 53a adjacent to the electrode 53b. doing. Thus, the insulating film 53d completely secures electrical insulation between the electrode 53b and the electrode 53c.

As in the fifth embodiment, the distance between the circular hole 53e exposing the electrode 53b and the electrode 53c is the same as the distance between the tips of the electrode portions 52a of the substrate 51. Thereby, the LED chip 53A is arranged at the center of the substrate 51 by aligning the center line extending in the length direction with the center line extending in the length direction of the substrate 51.
Exposed portion of the electrode 53b from the circular hole 53e and the electrode 53
“c” is disposed opposite to the tip of both electrode portions 52 a of the wiring pattern 52. Then, the exposed portion of the electrode 53b of the LED chip 53A from the circular hole 53e and the electrode 53c can be electrically connected to the corresponding electrode portion 52a via the bump 55.

In the examples of FIGS. 11 and 12, the electrode 5
The area of 3c is larger than the area of the exposed portion of the electrode 53b, and when the exposed portions of the electrode 53c and the electrode 53b are connected to the wiring pattern 52 by a single bump 55, the electrical connection area with the bump 55 is different. become. Therefore, in this case, as shown by a two-dot chain line in FIG. 11, a plurality of (for example, two) bumps 55 are formed on the electrode 53c having the larger area, and the electric connection area between the electrodes 53b and 53c is reduced. The difference may be absorbed.

FIG. 13 is a plan view showing another example of the shape of the LED chip of the light emitting diode according to the fifth embodiment of the present invention. FIG. 14 is a cross-sectional view of the LED chip of FIG. 13 cut along a length direction where electrodes are located.

Another example of the shape is also the LED of the fifth embodiment.
14 shows an example of a specific configuration of the chip 53. The LED chip 53B in the example of FIGS.
And has substantially the same configuration as the LED chip 53A of the example of FIG. 11 and FIG. That is, similarly to the LED chip 53A, the LED chip 53B includes a semiconductor portion 53a and a pair of positive and negative electrodes 53.
b, 53c. On the other hand, the LED chip 53B
The disk-shaped interposed conductive material 53f is placed and fixed on the exposed portion of the electrode 53b (the portion corresponding to the circular hole 53e).
The surface of the electrode 53b (upper surface in FIG. 14) is covered with an insulating film 53g except for the interposed conductive material 53f. The insulating film 53g covers the peripheral portion of the surface (the striation in FIG. 14) of the interposed conductive material 53f, and forms a circular hole 53h. The interposed conductive material 53 is inserted through the circular hole 53h.
The f surface is exposed, and can be electrically connected to the outside. The insulating film 53g covers the entire surface from the surface to the side surface of the electrode 53b, and also covers the entire surface (horizontal plane in FIG. 14) and the entire step surface (vertical plane in FIG. 14) of the semiconductor portion 53a adjacent to the electrode 53b. doing. Thus, the insulating film 53g completely secures electrical insulation between the electrode 53b and the electrode 53c.

As in the fifth embodiment, the circular hole 53h exposing the interposed conductive material 53f connected to the electrode 53b and the electrode 53
The interval between the electrodes c and c is the same as the interval between the tips of the electrode portions 52a of the substrate 51. Thereby, the LED chip 53B
The center line extending in the length direction is made coincident with the center line extending in the length direction of the substrate 51, and is disposed at the center of the substrate 51, so that the interposed conductive material 53f of the LED chip 53B is exposed from the circular hole 53h. The part and the electrode 53c are arranged to face the distal ends of both electrode parts 52a of the wiring pattern 52.
Then, the exposed portion of the interposed conductive material 53f of the LED chip 53B from the circular hole 53h and the electrode 53c can be electrically connected to the corresponding electrode portion 52a via the bump 55, respectively. At this time, the electrode 53b is
By f, it is electrically connected to the corresponding electrode part 52a via the bump 55.

As in the case of the LED chip 53A,
When the area of the electrode 53c is larger than the exposed area of the interposed conductive material 53 and the electrical connection area with the bump 55 is different,
13, a plurality of bumps 55 may be formed on the electrode 53c having a larger area.

Incidentally, the LEs of the third and fourth embodiments are used.
The D chips 33 and 43 may have a substantially rectangular plate shape, and may have a rectangular plate shape or the like other than the square plate shape. Also in this case, since the pair of positive and negative electrodes is arranged in the diagonal direction of the LED chips 33 and 43, the pitch between the electrodes can be made larger than when the electrodes are arranged in the length direction, and the same effect is obtained.

The light emitting diode of the sixth embodiment is
As in the second embodiment, the anisotropic conductive paste 21 is provided on the lower surface side of the LED chip 63 instead of the underfill resin 66.
And the same effect may be imparted. Further, the light emitting diode of Embodiment 6 may be implemented in combination with any of Embodiments 3 to 5. For example, as in the third or fourth embodiment, a pair of positive and negative electrodes are arranged in a diagonal direction of the light emitting diode 63, and the pattern shape of the wiring pattern 62 (particularly, the tip shape corresponding to the electrode portions 32a and 42a) is implemented. As in the form 3 or 4, electrical insulation between both electrodes of the LED chip 63 may be ensured to further improve operation reliability. Alternatively, as in Embodiment 5,
The light emitting diode 63 may have a rectangular plate shape to similarly improve the operation reliability.

[0067]

As described above, the light-emitting diode according to the first aspect of the present invention has a substrate having a pair of wiring patterns and a pair of positive and negative electrodes on the same surface side, and the two electrodes are connected to both wiring patterns of the substrate. L electrically connected via each bump
An ED chip.

Therefore, since the pair of positive and negative electrodes of the LED chip are located on the lower surface opposite to the light emitting surface, there is no shadow on the upper surface, which is the light emitting surface, to block the light.
The entire upper surface of the D chip is a light emitting area. As a result, LE
The light extraction efficiency from the D chip can be increased, and the luminous efficiency or luminance can be improved. Further, since electrical connection between both electrodes of the LED chip and both wiring patterns of the substrate is performed by flip-chip bonding via bumps, a space for wire bonding as in the related art is unnecessary, and the entire light emitting diode can be miniaturized. be able to. Furthermore, since both electrodes of the LED chip can be directly connected to both wiring patterns of the substrate, the heat dissipation during driving of the LED chip is improved, and the reliability and durability of the light emitting diode are improved.

According to a second aspect of the present invention, there is provided a light emitting diode having a substrate having a pair of wiring patterns and a pair of positive and negative electrodes on the same surface side, wherein both electrodes are electrically connected to both wiring patterns of the substrate via bumps. And an electrically insulating underfill resin for sealing between at least both electrodes of the LED chip.

Therefore, since the pair of positive and negative electrodes of the LED chip is located on the lower surface side opposite to the light emitting surface, there is no shadow on the upper surface, which is the light emitting surface, and there is no shadow.
The entire upper surface of the D chip is a light emitting area. As a result, LE
The light extraction efficiency from the D chip can be increased, and the luminous efficiency or luminance can be improved. Further, since electrical connection between both electrodes of the LED chip and both wiring patterns of the substrate is performed by flip-chip bonding via bumps, a space for wire bonding as in the related art is unnecessary, and the entire light emitting diode can be miniaturized. be able to. Furthermore, since both electrodes of the LED chip can be directly connected to both wiring patterns of the substrate, the heat dissipation during driving of the LED chip is improved, and the reliability and durability of the light emitting diode are improved. In addition, LE with underfill resin
Electrical insulation between both electrodes of the D chip is ensured, and operation reliability is improved.

A light emitting diode according to a third aspect of the present invention has a substrate having a pair of wiring patterns and a pair of positive and negative electrodes on the same surface side, and the two electrodes are electrically connected to both wiring patterns of the substrate via bumps. And an anisotropic conductive paste for sealing at least between both electrodes of the LED chip.

Therefore, since the pair of positive and negative electrodes of the LED chip are located on the lower surface side opposite to the light emitting surface, there is no shadow on the upper surface, which is the light emitting surface, and there is no shadow.
The entire upper surface of the D chip is a light emitting area. As a result, LE
The light extraction efficiency from the D chip can be increased, and the luminous efficiency or luminance can be improved. Further, since electrical connection between both electrodes of the LED chip and both wiring patterns of the substrate is performed by flip-chip bonding via bumps, a space for wire bonding as in the related art is unnecessary, and the entire light emitting diode can be miniaturized. be able to. Furthermore, since both electrodes of the LED chip can be directly connected to both wiring patterns of the substrate, the heat dissipation during driving of the LED chip is improved, and the reliability and durability of the light emitting diode are improved. In addition, LE with anisotropic conductive paste
While ensuring electrical insulation between both electrodes of the D chip,
Electrical conduction between the electrodes of the LED chips and the corresponding wiring patterns on the substrate is ensured. As a result, the operation reliability of the light emitting diode is further improved.

According to a fourth aspect of the present invention, in the light-emitting diode according to any one of the first to third aspects, the wiring pattern of the substrate has an electrode portion which is opposed to the substrate at an interval in the length direction of the substrate. The LED chip has a substantially rectangular plate shape and the pair of positive and negative electrodes are arranged in a diagonal direction of the LED chip, and the pair of positive and negative electrodes are disposed opposite to and electrically connected to both electrode portions of the wiring pattern. It is.

Therefore, in addition to the effect of any one of the first to third aspects, the pitch between the electrodes of the LED chip becomes larger. As a result, a short circuit between the electrodes can be effectively prevented, the operation reliability of the light emitting diode can be further improved, and the product quality can be further improved.

According to a fifth aspect of the present invention, in the light emitting diode according to any one of the first to third aspects, the wiring pattern of the substrate is opposed to the wiring pattern at an interval in a direction inclined with the length direction of the substrate. The LED chip has a substantially rectangular plate shape, and the pair of positive and negative electrodes is arranged in a diagonal direction of the LED chip. Connect.

Therefore, in addition to the effect of any one of the first to third aspects, the pitch between the electrodes of the LED chip becomes larger. As a result, a short circuit between the electrodes can be effectively prevented, the operation reliability of the light emitting diode can be further improved, and the product quality can be further improved. Further, the LED chip can be arranged on the substrate in a normal state (a state in which the center lines are aligned) only by changing the pattern shape of the wiring pattern. As a result, the operation of positioning or arranging the LED chips can be performed by a normal method.

According to a sixth aspect of the present invention, in the light emitting diode according to any one of the first to third aspects, the wiring pattern of the substrate has an electrode portion opposed to the substrate at an interval in the length direction of the substrate. The LED chip has a substantially rectangular plate shape, and the pair of positive and negative electrodes is disposed in the length direction thereof, and the pair of positive and negative electrodes is disposed opposite to the electrode portion of the wiring pattern to be electrically connected. It is.

Therefore, in addition to the effects of any one of the first to third aspects, the pitch between the electrodes of the LED chip becomes larger. As a result, a short circuit between the electrodes can be effectively prevented, the operation reliability of the light emitting diode can be further improved, and the product quality can be further improved.

According to a seventh aspect of the present invention, in the light emitting diode according to any one of the first to sixth aspects, the substrate is provided with an MI.
This is a D substrate. Therefore, in addition to the effect of any one of the first to sixth aspects, the wiring pattern of the substrate reflects upwardly light emitted laterally from the LED chip. As a result, the luminous efficiency or luminance of the entire light emitting diode can be further increased.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view illustrating an overall configuration of a light emitting diode according to Embodiment 1 of the present invention.

FIG. 2 is a cross-sectional view illustrating a main part of the light-emitting diode according to Embodiment 1 of the present invention.

FIG. 3 is a sectional view showing a main part of a light emitting diode according to a second embodiment of the present invention.

FIG. 4 is a plan view of a light emitting diode according to Embodiment 3 of the present invention.

FIG. 5 is a plan view of a light emitting diode according to Embodiment 4 of the present invention.

FIG. 6 is a plan view of a light emitting diode according to a fifth embodiment of the present invention.

FIG. 7 is a sectional view of a light emitting diode according to a sixth embodiment of the present invention.

FIG. 8 is a sectional view showing a light emitting diode disclosed in Japanese Patent Application Laid-Open No. Hei 9-135040.

FIG. 9 is a plan view showing a shape example of an LED chip of a light emitting diode according to a fourth embodiment of the present invention.

FIG. 10 is a cross-sectional view showing the LED chip of FIG. 9 cut in a diagonal direction where electrodes are located.

FIG. 11 is a plan view showing a shape example of an LED chip of a light emitting diode according to a fifth embodiment of the present invention.

FIG. 12 is a cross-sectional view of the LED chip of FIG. 11 cut along a length direction where electrodes are located.

FIG. 13 is a plan view showing another example of the shape of the LED chip of the light emitting diode according to the fifth embodiment of the present invention.

FIG. 14 is a cross-sectional view showing the LED chip of FIG. 13 cut along a length direction where electrodes are located.

[Explanation of symbols]

11, 31, 41, 51, 61, substrate 12, 32, 42, 52, 62 wiring pattern 13, 33, 43, 53, 53A, 53B, 63L
ED chip 15, 35, 45, 55, 65 Bump 16 Underfill resin 21 Anisotropic conductive paste 32a, 42a, 52a Electrode

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Toshiya Uemura 1 Ochiai Nagahata, Kasuga-cho, Nishi-Kasugai-gun, Aichi Prefecture Inside Toyota Gosei Co., Ltd. Toyoda Gosei Co., Ltd.

Claims (7)

[Claims] 1. A substrate having a pair of wiring patterns, and an LED chip having a pair of positive and negative electrodes on the same surface side, wherein both electrodes are electrically connected to both wiring patterns of the substrate via bumps, respectively. A light-emitting diode comprising: 2. A substrate having a pair of wiring patterns, and an LED chip having a pair of positive and negative electrodes on the same surface side and electrically connecting both electrodes to both wiring patterns of the substrate via bumps, respectively. A light-emitting diode, comprising: an electrically insulating underfill resin that seals at least between both electrodes of the LED chip. 3. A substrate having a pair of wiring patterns, and an LED chip having a pair of positive and negative electrodes on the same surface side and electrically connecting both electrodes to both wiring patterns of the substrate via bumps, respectively. A light-emitting diode, comprising: an anisotropic conductive paste for sealing at least between both electrodes of the LED chip. 4. The wiring pattern of the substrate has electrode portions which are opposed to each other at intervals in the longitudinal direction of the substrate, and the LED chip has a substantially rectangular plate shape and the pair of positive and negative electrodes is arranged diagonally. 4. The electrode according to claim 1, wherein the pair of positive and negative electrodes are disposed so as to be opposed to both electrode portions of the wiring pattern and are electrically connected to each other. 5. Light emitting diode. 5. The wiring pattern of the substrate has electrode portions that are opposed to each other at intervals in a direction oblique to the length direction of the substrate, and the LED chip has a substantially rectangular plate shape and a diagonal direction thereof. 4. The method according to claim 1, wherein the pair of positive and negative electrodes is disposed on the first electrode, and the pair of positive and negative electrodes are disposed opposite to the electrode portion of the wiring pattern to be electrically connected. A light-emitting diode according to the item. 6. The wiring pattern of the substrate has electrode portions which are opposed to each other at intervals in the length direction of the substrate, and the LED chip has a substantially rectangular plate shape and the positive and negative electrodes are arranged in the length direction. 4. The device according to claim 1, wherein a pair of electrodes are disposed, and the pair of positive and negative electrodes are disposed to face and electrically connect to the electrode portion of the wiring pattern. 5. Light emitting diode. 7. The light emitting diode according to claim 1, wherein the substrate is an MID substrate.