JP2012178487A - Led lamp - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an LED lamp in which an LED chip is mounted on a substrate having high heat radiating effects.SOLUTION: An LED lamp comprises a substrate formed from an electro-conductive and thermo-conductive material, a wiring layer formed on a surface of the substrate via an insulating layer, an exposed portion, which is formed from the surface of the substrate, exposed from a bottom face of an opening formed in the insulating layer and the wiring layer, and an LED chip in which a first electrode and a second electrode are formed. The first electrode is connected to the exposed portion and the second electrode is connected to the wiring layer, thereby mounting the LED chip on the substrate.

Description

  The present invention relates to an LED lamp.

In recent years, LED lamps having excellent heat dissipation have been demanded as the output of LED chips has increased.
As such an LED lamp, there is one in which an LED chip is mounted on a substrate in which a wiring layer is formed on the surface of a core material containing a conductive and thermally conductive material via an insulating layer (see Patent Document 1). .
In addition, a technique is disclosed in which a clad material having a structure in which layers made of materials having different thermal expansion coefficients and thermal conductivities are alternately stacked is used as a heat dissipation substrate for a semiconductor device (see Patent Document 2).

Special table 2007-509505 JP 2010-56148 A

  In the technique of Patent Document 1, since the thermal expansion coefficient of the substrate is larger than the thermal expansion coefficient of the sealing material for sealing the LED chip mounted on the substrate, the sealing material and the substrate do not adhere to each other. There is a risk that peeling or distortion or cracking may occur in the sealing material, and high reliability cannot be obtained.

By the way, when a synthetic resin material is used as the sealing material, it is difficult to increase the output of the LED chip because the synthetic resin material may be discolored by the light of the LED chip.
Therefore, it is possible to increase the output of the LED chip by using a glass material that is not easily discolored by light as the sealing material. However, if the output of the LED chip is increased, the amount of heat generated increases. The above problem due to the difference in the coefficient of thermal expansion between the substrate and the substrate becomes more apparent.

Therefore, it is required to enhance the heat dissipation effect of the substrate on which the LED chip is mounted.
The present invention has been made to satisfy the above-described requirements, and an object thereof is to provide an LED lamp in which an LED chip is mounted on a substrate having a high heat dissipation effect.

  As a result of intensive studies in order to solve the above-mentioned problems, the present inventors have arrived at each aspect of the present invention as follows.

<First aspect>
The first aspect of the present invention is:
A substrate made of a conductive and thermally conductive material;
A wiring layer formed on the surface of the substrate via an insulating layer;
An exposed portion composed of the surface of the substrate exposed from the bottom surface of the opening formed in the insulating layer and the wiring layer;
An LED lamp comprising an LED chip on which a first electrode and a second electrode are formed,
In the LED lamp, the LED chip is mounted on the substrate by connecting the first electrode to the exposed portion and connecting the second electrode to the wiring layer.

According to the first aspect, since the substrate made of a conductive and thermally conductive material can be used as the first side electrode of the LED chip, the heat dissipation effect of the substrate can be enhanced.
As a result, since the thermal expansion of the substrate can be suppressed, the adhesion between the sealing material and the substrate is prevented, and the sealing material is prevented from being distorted or cracked. Can be improved.

<Second aspect>
According to a second aspect of the present invention, in the first aspect,
The first electrode connected to the exposed portion is an LED lamp that is electrically and thermally connected to the outside through the entire back surface side of the substrate.

According to the second aspect, since the entire back surface of the substrate can be used as the first electrode of the LED chip, both the electrical resistance and the thermal resistance of the first electrode of the LED chip can be reduced.
As a result, the heat generated when a large current is passed through the high-power LED chip can be quickly dissipated from the entire back surface of the substrate to the outside, and the amount of heat generated by the LED lamp can be suppressed. The effects and effects of this aspect are further enhanced.

<Third aspect>
According to a third aspect of the present invention, in the first or second aspect,
The LED lamp is disposed and formed on the bottom surface of the LED chip so that the second electrode surrounds the first electrode.

  According to the third aspect, since it is possible to make the current distribution in the current path from each electrode through the LED chip uniform, it is possible to efficiently flow current to the LED chip and further increase the luminous efficiency of the LED lamp. be able to.

By the way, in order to increase the light emission area of the LED chip and increase the light emission efficiency of the LED lamp, the area of the anode side electrode pad (P electrode) is made larger than the area of the cathode side electrode pad (N electrode) of the LED chip. There is a need to.
Therefore, if the first electrode is an anode-side electrode pad, the anode-side electrode pad is connected to the exposed portion of the substrate, so that heat generated by the LED chip can be quickly transferred from the anode-side electrode pad having a large area to the substrate. Therefore, the heat generation of the LED chip can be effectively suppressed.

<Fourth aspect>
According to a fourth aspect of the present invention, in the first to third aspects,
The substrate is an LED lamp which is a clad material having a structure in which layers made of a first material and layers made of a second material having different coefficients of thermal expansion and thermal conductivity are alternately laminated.

  In the fourth aspect, since the structure of the substrate is the same as that of Patent Document 2, the same actions and effects as in Patent Document 2 can be obtained, and the thermal conductivity can be increased while reducing the thermal expansion coefficient of the substrate. Therefore, the action / effect of the first aspect is further enhanced.

<5th aspect>
According to a fifth aspect of the present invention, in the first to fourth aspects,
The LED lamp includes a sealing material made of a glass material that seals and covers the wiring layer and the LED chip on the surface side of the substrate.

According to the fifth aspect, since the sealing material is made of a glass material that is not easily discolored by light, it is possible to increase the output of the LED chip.
However, the higher the output of the LED chip, the greater the amount of heat generated. The problem that occurs is easy to manifest.
However, according to the fifth aspect, since the thermal expansion of the substrate can be suppressed as in the first to fourth aspects, it is possible to reliably prevent the problem from occurring.

<Sixth aspect>
According to a sixth aspect of the present invention, in the first to fifth aspects,
The LED lamp includes a reflector made of a glass ceramic material arranged and formed so as to surround the periphery of the LED chip on the surface side of the substrate.

According to the sixth aspect, since the thermal expansion of the substrate is suppressed as in the first to fourth aspects, the adhesion between the reflector and the substrate is prevented from being disturbed, and the distortion and cracks of the reflector are prevented. This can be prevented and the reliability of the LED lamp can be improved.
Further, according to the sixth aspect using the fifth aspect, the reflector made of the glass ceramic material has a thermal expansion coefficient close to that of the sealing material made of the glass material. Even if it thermally expands, it can prevent that the adhesiveness of a reflector and a sealing material is inhibited.

The principal part longitudinal cross-sectional view which shows schematic structure of the LED lamp 10 of 1st Embodiment which actualized this invention. FIG. 2A is a bottom view of the LED chip 30 of the first embodiment mounted on the LED lamp 10. FIGS. 2B to 2D are bottom views of the LED chip 30 showing first to third modification examples in which the arrangement of the electrode pads 31 and 32 in the LED chip 30 of the first embodiment is changed. The principal part longitudinal cross-sectional view which shows schematic structure of the LED lamp 100 of 2nd Embodiment which actualized this invention. The bottom view of LED chip 30 of a 2nd embodiment mounted in LED lamp 100. FIG. The principal part longitudinal cross-sectional view which shows schematic structure of the LED lamp 200 of 3rd Embodiment which actualized this invention. FIG. 6A is a bottom view of the LED chip 30 of the fourth embodiment embodying the present invention. FIG. 6B is a bottom view of the LED chip 30 showing a first modified example in which the arrangement of the electrode pads 31 and 32 in the LED chip 30 of the fourth embodiment is modified. FIGS. 7A and 7B are bottom views of the LED chip 30 showing second and third modified examples in which the arrangement of the electrode pads 31 and 32 in the LED chip 30 of the fourth embodiment is changed. The bottom view of LED chip 30 which shows the 4th modification which changed arrangement of electrode pads 31 and 32 in LED chip 30 of a 4th embodiment.

  Hereinafter, embodiments embodying the present invention will be described with reference to the drawings. In each embodiment, the same constituent members and constituent elements are denoted by the same reference numerals, and redundant description of the same content is omitted.

<First Embodiment>
FIG. 1 is a longitudinal sectional view of an essential part showing a schematic configuration of the LED lamp 10 of the first embodiment.
The LED lamp 10 includes a mounting substrate 11, a wiring layer 12, a connection material 13, a heat dissipation substrate 14, an exposed portion 14 a, an insulating layer 15, an opening portion 15 a, a wiring layer 16, an opening portion 16 a, bumps 17 and 18, and a sealing material 19. , LED chip 30, cathode side electrode pad 31, anode side electrode pad 32, and the like.

On the surface of the mounting substrate 11 made of an insulating material (for example, a ceramic material), a wiring layer 12 made of metal (for example, copper, aluminum, an alloy containing these) is formed.
The entire back surface of the heat dissipation board 14 is connected and fixed to the surface of the wiring layer 12 via a connecting material 13 made of a conductive material (for example, solder, metal-containing paste material).

  The heat dissipation substrate 14 is made of a conductive and thermally conductive material. For example, it is described in a core material such as metal (copper, aluminum, an alloy including these) and carbon described in Patent Document 1, and in Patent Document 2. Clad having a structure in which layers made of a first material (copper, silver, an alloy containing these) having different coefficients of thermal expansion and thermal conductivity and layers made of a second material (molybdenum, tungsten) are alternately laminated It is a material.

A wiring layer 16 is formed on the surface of the heat dissipation substrate 14 via an insulating layer 15.
For the insulating layer 15, for example, silicon oxide, silicon nitride, a composite material including an inorganic filler and a synthetic resin, and aluminum oxide or the like when the surface of the heat dissipation substrate 14 is made of aluminum are used.
The wiring layer 16 is made of a single layer film or a multilayer film of metal (for example, aluminum, titanium, nickel, gold, silver, copper, platinum, etc.).

  The insulating layer 15 and the wiring layer 16 are formed with openings 15a and 15b penetrating the laminated layers 15 and 16, and the surface of the heat dissipation substrate 14 is exposed from the bottom surfaces of the openings 15a and 16a. An exposed portion 14 a is formed from the exposed surface of the heat dissipation substrate 14.

The LED chip 30 is mounted on the heat dissipation substrate 14 by being flip-chip mounted on the heat dissipation substrate 14 and the wiring layer 16 using bumps 17 and 18.
That is, on the lower surface side of the LED chip 30, the cathode side electrode pad 31 connected to the N-type semiconductor layer (not shown) of the LED chip 30 and the P-type semiconductor layer (not shown) of the LED chip 30 are connected. An anode side electrode pad 32 is disposed and formed.

The cathode-side electrode pad 31 of the LED chip 30 and the exposed portion 14 a of the heat dissipation substrate 14 exposed from the openings 15 a and 16 a of the layers 15 and 16 are electrically and thermally connected by the bumps 17.
Further, the anode side electrode pad 32 of the LED chip 30 and the surface of the wiring layer 16 are electrically and thermally connected by the bump 18.
The bumps 17 and 18 are made of, for example, gold or solder.

Here, the P-type semiconductor layer of the LED chip 30 is formed on the entire lower surface side of the light emitting layer (not shown) of the LED chip 30.
The cathode side electrode pad 31 is formed on the entire lower surface side of the N-type semiconductor layer, and the anode side electrode pad 32 is formed on the entire lower surface side of the P-type semiconductor layer.

  The sealing material 19 is made of a transparent glass material, covers and covers each member (the wiring layer 16, the LED chip 30, and the bumps 17 and 18) formed on the surface side of the heat dissipation substrate 14, and the upper surface thereof is substantially spherical. It is formed in a shape.

FIG. 2A is a bottom view of the LED chip 30 of the first embodiment mounted on the LED lamp 10.
A circular cathode side electrode pad (N electrode) 31 is arranged and formed at a substantially central portion of the bottom surface on the square bottom surface of the LED chip 30, and an anode side electrode pad (P electrode) 32 is spaced from the cathode side. The electrode pad 31 is surrounded and formed up to the vicinity of the outer peripheral edge of the LED chip 30.

[Operations and effects of the first embodiment]
According to the LED lamp 10 of the first embodiment, the following actions and effects can be obtained.

  [1-1] In the LED lamp 10, the heat dissipation board 14 is made of a conductive and thermally conductive material, and the cathode-side electrode pad 31 (first electrode) of the LED chip 30 is bump 17 on the exposed portion 14 a of the heat dissipation board 14. The anode side electrode pad 32 (second electrode) of the LED chip 30 is connected via the bump 18 to the wiring layer 16 formed on the surface of the heat dissipation substrate 14 via the insulating layer 15. Thus, the LED chip 30 is mounted on the heat dissipation substrate 14.

Thereby, since it becomes possible to use the thermal radiation board | substrate 14 which consists of an electroconductive and heat conductive material as a cathode side electrode of the LED chip 30, the thermal radiation effect of the thermal radiation board | substrate 14 can be improved.
As a result, the thermal expansion of the heat dissipation substrate 14 can be suppressed, so that the adhesion between the sealing material 19 and the heat dissipation substrate 14 is prevented from being inhibited, and the sealing material 19 is prevented from being distorted or cracked. In addition, the reliability of the LED lamp 10 can be improved.

[1-2] The cathode-side electrode pad 31 of the LED chip 30 connected to the exposed portion 14a of the heat dissipation board 14 is connected to the wiring layer 12 that is outside through the connecting material 13 from the entire back surface of the heat dissipation board 14. ing.
The wiring layer 12 extending from the back surface of the heat dissipation substrate 14 onto the mounting substrate 11 is used as an external terminal (cathode side terminal) of the LED lamp 10.

As a result, the entire back surface of the heat dissipation substrate 14 can be used as the cathode side electrode of the LED chip 30, so that both the electrical resistance and thermal resistance of the cathode side electrode of the LED chip 30 can be reduced.
As a result, it is possible to quickly dissipate the heat generated when a large current is passed through the high-power LED chip 30 from the entire back surface of the heat dissipation board 14 via the wiring layer 12, and the heat generation of the LED lamp 10 Since the amount can be suppressed, the function and effect of [1-1] are further enhanced.

[1-3] In order to increase the light emission area of the LED chip 30 and increase the light emission efficiency of the LED lamp 10, it is necessary to increase the area of the anode-side electrode pad 32 of the LED chip 30.
In addition, a current flows through the LED chip 30 through a path of anode side electrode pad 32 → P-type semiconductor layer → light emitting layer → N-type semiconductor layer → cathode side electrode pad 31.
Therefore, in order to efficiently flow the current to the LED chip 30, the current distribution in the current path from the anode side electrode pad (P electrode) 32 through the LED chip 30 to the cathode side electrode pad (N electrode) 31 is made uniform. It is necessary to make it.

As shown in FIG. 2A, the anode-side electrode pad 32 (second electrode) surrounds the circular cathode-side electrode pad 31 (first electrode) disposed at the center of the bottom surface of the LED chip 30. Yes.
Then, on the bottom surface of the LED chip 30, the anode side electrode pad 32 is formed in most of the portion excluding the cathode side electrode pad 31.

Therefore, the area of the anode side electrode pad 32 can be increased, and the light emission area of the LED chip 30 can be increased to increase the light emission efficiency of the LED lamp 10.
In addition, the current distribution in the current path from the anode side electrode pad 32 through the LED chip 30 to the cathode side electrode pad 31 can be made uniform. The luminous efficiency of the lamp 10 can be further increased.

  [1-4] The heat dissipation board 14 has a structure in which layers made of a first material and layers made of a second material having different thermal expansion coefficients and thermal conductivities are alternately laminated, as in the technique of Patent Document 2. When the clad material is used, the same operation and effect as in Patent Document 2 can be obtained, and the thermal conductivity can be increased while the thermal expansion coefficient of the heat dissipation substrate 14 is reduced. The effect is further enhanced.

[1-5] Since the sealing material 19 is made of a glass material that is not easily discolored by light, the output of the LED chip 30 can be increased.
However, since the amount of heat generation increases when the LED chip 30 has a high output, the difference in thermal expansion coefficient between the sealing material 19 and the heat dissipation substrate 14 impedes the adhesion between the sealing material 19 and the heat dissipation substrate 14. The problem of distortion and cracks occurring in the sealing material 19 tends to become obvious.
However, according to the LED lamp 10, since the thermal expansion of the heat dissipation substrate 14 can be suppressed as described above, it is possible to reliably prevent the problem from occurring.

[1-6] FIGS. 2B to 2D are bottom views of the LED chip 30 showing first to third modification examples in which the arrangement of the electrode pads 31 and 32 in the LED chip 30 of the first embodiment is changed. FIG.
Also in the first to third modified examples, the anode side electrode pad (P electrode) 32 surrounds the cathode side electrode pad (N electrode) 31 as in the example shown in FIG.

  And according to the 1st-3rd modification, compared with the example shown in FIG. 2 (A), the current distribution in the current path from the anode side electrode pad 32 through the LED chip 30 to the cathode side electrode pad 31 Therefore, it is possible to further increase the light emission efficiency of the LED lamp 10 by efficiently passing a current through the LED chip 30.

In the first modification shown in FIG. 2B, the cathode-side electrode pad 31 has a circular first portion arranged and formed substantially at the center of the bottom surface of the LED chip 30, and the bottom surface of the LED chip 30 from the first portion. And a second portion having a long rectangular shape with a constant width extending toward the four corners.
Note that the second portions of the cathode-side electrode pads 31 are not limited to the four pieces shown in FIG. 2B, and may be equally arranged with an appropriate number of three pieces or five pieces or more.

In the second modified example shown in FIG. 2C, two cathode-side electrode pads (N electrodes) 31 having a long rectangular shape are arranged in parallel and evenly.
A substantially circular pad portion for connecting to the bump 17 is formed at both ends of each cathode-side electrode pad 31.
The cathode-side electrode pads 31 are not limited to the two shown in FIG. 2C, and may be equally arranged with an appropriate number of three or more.

In the third modification shown in FIG. 2D, 16 circular cathode-side electrode pads 31 are equally arranged and formed in the vertical and horizontal directions on the bottom surface of the LED chip 30.
The number of cathode-side electrode pads 31 is not limited to 16 shown in FIG. 2D, and may be evenly arranged with an appropriate number of four or more.

Second Embodiment
FIG. 3 is a longitudinal sectional view of an essential part showing a schematic configuration of the LED lamp 100 of the second embodiment.
The LED lamp 100 includes a mounting substrate 11, a wiring layer 12, a connecting material 13, a heat dissipation substrate 14, an exposed portion 14 a, an insulating layer 15, an opening portion 15 a, a wiring layer 16, an opening portion 16 a, bumps 17 and 18, and a sealing material 19. , LED chip 30, cathode side electrode pad 31, anode side electrode pad 32, and the like.

  The LED lamp 100 is different from the LED lamp 10 of the first embodiment in that the cathode side electrode pad 31 of the LED chip 30 is connected to the surface of the wiring layer 16 by the bump 18, and the anode side electrode pad 32 is connected to the heat dissipation substrate 14. It is only a point connected by the exposed part 14a and the bump 17.

FIG. 4 is a bottom view of the LED chip 30 of the second embodiment mounted on the LED lamp 100.
An anode side electrode pad (P electrode) 32 having a shape in which the four corners are rounded at the bottom surface of the square shape of the LED chip 30 is disposed and formed at the center of the bottom surface, and the cathode side electrode pad having a substantially square frame shape. The (N electrode) 31 is disposed and formed so as to surround the anode side electrode pad (P electrode) 32 with a gap.
In addition, substantially fan-shaped pad portions for connecting to the bumps 17 are formed at the four corners of the cathode side electrode pad 31.

[Operation and Effect of Second Embodiment]
According to the LED lamp 100 of the second embodiment, in addition to the operations and effects of [1-4] and [1-5] of the first embodiment, the following operations and effects can be obtained.

  [2-1] In the LED lamp 10, the heat dissipation board 14 is made of a conductive and heat conductive material, and the anode side electrode pad 32 (first electrode) of the LED chip 30 is bump 18 on the exposed portion 14 a of the heat dissipation board 14. The cathode side electrode pad 31 (second electrode) of the LED chip 30 is connected via the bump 17 to the wiring layer 16 formed on the surface of the heat dissipation board 14 via the insulating layer 15. Thus, the LED chip 30 is mounted on the heat dissipation substrate 14.

  As a result, the heat dissipation substrate 14 made of a conductive and thermally conductive material can be used as the anode side electrode of the LED chip 30, so that the heat dissipation effect of the heat dissipation substrate 14 is enhanced and the thermal expansion of the heat dissipation substrate 14 is increased. It can suppress and can improve the reliability of LED lamp 10. FIG.

[2-2] The anode-side electrode pad 32 of the LED chip 30 connected to the exposed portion 14a of the heat dissipation board 14 is connected to the wiring layer 12 which is the outside through the connecting material 13 from the entire back surface of the heat dissipation board 14. ing.
The wiring layer 12 extending from the back surface of the heat dissipation substrate 14 onto the mounting substrate 11 is used as an external terminal (anode side terminal) of the LED lamp 10.

  Accordingly, since the entire back surface of the heat dissipation substrate 14 can be used as the anode side electrode of the LED chip 30, both the electrical resistance and thermal resistance of the anode side electrode of the LED chip 30 can be reduced. ] Is further enhanced.

[2-3] As shown in FIG. 4, the periphery of the anode side electrode pad 32 (first electrode) having a shape in which the four corners arranged at the center of the bottom surface of the LED chip 30 are rounded is formed on the cathode side. The electrode pad 31 (second electrode) is surrounded.
Then, on the bottom surface of the LED chip 30, the anode side electrode pad 32 is formed in most of the portion excluding the cathode side electrode pad 31.
Therefore, also in 2nd Embodiment, the effect | action and effect similar to said [1-3] of 1st Embodiment are acquired.

  [2-4] In order to increase the light emission area of the LED chip 30 and increase the light emission efficiency of the LED lamp 10, the anode side electrode pad (P electrode) 32 is larger than the area of the cathode side electrode pad (N electrode) 31. The area has been increased.

In the first embodiment, since the cathode-side electrode pad 31 is connected to the exposed portion 14a of the heat dissipation substrate 14, the heat generated by the LED chip 30 is transmitted from the cathode-side electrode pad 31 having a small area to the heat dissipation substrate 14. Yes.
On the other hand, in the second embodiment, since the anode side electrode pad 32 is connected to the exposed portion 14a of the heat dissipation substrate 14, the heat generated by the LED chip 30 is transferred from the anode side electrode pad 32 having a large area to the heat dissipation substrate 14. Communicating to
Therefore, compared with the first embodiment, the heat generated by the LED chip 30 can be more quickly transmitted to the heat dissipation substrate 14 in the second embodiment, and thus the heat generation of the LED chip 30 can be effectively suppressed.

<Third Embodiment>
FIG. 5 is a longitudinal sectional view of an essential part showing a schematic configuration of the LED lamp 200 of the third embodiment.
The LED lamp 200 includes a mounting substrate 11, a wiring layer 12, a connection material 13, a heat dissipation substrate 14, an exposed portion 14 a, an insulating layer 15, an opening portion 15 a, a wiring layer 16, an opening portion 16 a, bumps 17 and 18, and a sealing material 19. , LED chip 30, cathode side electrode pad 31, anode side electrode pad 32, reflector 201, and the like.

The LED lamp 200 differs from the LED lamp 10 of the first embodiment only in that a reflector 201 is provided.
The reflector 201 is made of a glass ceramic material, and is mounted and fixed on the surface side of the heat dissipation substrate 14 so as to surround each member (the LED chip 30 and the bumps 17 and 18).
In the reflector 201, the inner peripheral surface of the recess 201a is an inclined surface inclined toward the opening 201b, and can reflect the light from the LED chip 30 and efficiently emit the light from the opening 201b.
The sealing material 19 is filled in the recess 201 a of the reflector 201.

Since the reflector 201 made of a glass ceramic material has a thermal expansion coefficient close to that of the sealing material 19 made of glass material, the reflector 201 and the sealing material 19 are sealed even if the reflector 201 and the sealing material 19 are thermally expanded due to heat generated by the LED chip 30. It can prevent that the adhesiveness of the material 19 is inhibited.
In addition, since the thermal expansion of the heat dissipation board 14 is suppressed as described above, the adhesion between the reflector 201 and the heat dissipation board 14 is prevented from being inhibited, and the reflector 201 is prevented from being distorted or cracked. The reliability of the LED lamp 10 can be improved.

<Fourth embodiment>
FIG. 6A is a bottom view of the LED chip 30 of the fourth embodiment.
The fourth embodiment is different from the first embodiment only in the size and shape of the LED chip 30 and the arrangement of the electrode pads 31 and 32 in the LED chip 30.

  The bottom surface of the LED chip 30 of the fourth embodiment has a long rectangular shape, and a cathode electrode pad (N electrode) 31 having a long rectangular shape is disposed at one end of the bottom surface along the longitudinal direction of the bottom surface. An anode-side electrode pad (P electrode) 32 that is formed and has a long rectangular shape is arranged and formed on most of the portion excluding the cathode-side electrode pad 31 on the bottom surface.

Thereby, also in 4th Embodiment, the effect | action and effect similar to 1st Embodiment are acquired.
The LED chip 30 of the fourth embodiment is suitable for a side view type LED lamp (side light emitting device), and can be used for a thin light emitting device used for a backlight of a liquid crystal display or the like.

FIGS. 6B, 7 </ b> A, 7 </ b> B, and 8 are respectively LED chips showing first to fourth modified examples in which the arrangement of the electrode pads 31 and 32 in the LED chip 30 of the fourth embodiment is changed. FIG.
In these first to fourth modified examples, the same operation and effect as in the first embodiment can be obtained.

  In the first modification shown in FIG. 6B, cathode-side electrode pads 31 having a long rectangular shape are arranged and formed at both ends in the longitudinal direction of the bottom surface, and anode-side electrode pads 32 having a long rectangular shape are formed. The bottom surface is arranged and formed in most of the portion excluding the cathode side electrode pad 31.

In the second modified example shown in FIG. 7A, as in the first modified example, cathode-side electrode pads 31 having a long rectangular shape are arranged and formed at both ends in the longitudinal direction of the bottom surface of the LED chip 30, A rectangular anode-side electrode pad 32 is disposed and formed on most of the portion excluding the cathode-side electrode pad 31 on the bottom surface.
A substantially semicircular pad portion for connection to the bump 17 is formed at a substantially central portion of each cathode side electrode pad 31.

In the third modified example shown in FIG. 7B, three cathode-side electrode pads 31 having a long rectangular shape are arranged and formed at both ends and the center of the bottom surface of the LED chip 30 to form a long rectangular shape. Two anode-side electrode pads 32 having a shape are arranged between the individual cathode-side electrode pads 31 on the bottom surface.
A substantially semicircular pad portion for connecting to the bump 17 is formed at a substantially central portion of the cathode-side electrode pad 31 disposed at both ends of the bottom surface of the LED chip 30.
In addition, a substantially circular pad portion for connecting to the bump 17 is formed at a substantially central portion of the cathode-side electrode pad 31 disposed at the central portion of the bottom surface of the LED chip 30.

  In the fourth modified example shown in FIG. 8, five cathode-side electrode pads 31 having a long rectangular shape are arranged and formed at both ends in the longitudinal direction of the bottom surface of the LED chip 30 and at a portion obtained by dividing the longitudinal direction into four parts. Four anode-side electrode pads 32 having a long rectangular shape are disposed between the individual cathode-side electrode pads 31 on the bottom surface.

  If a plurality of cathode-side electrode pads 31 are arranged with respect to the longitudinal direction of the bottom surface of the LED chip 30 as in the first to fourth modified examples, the anode side can be obtained even when the bottom surface of the LED chip 30 is long. Since the current distribution in the current path from the electrode pad 32 through the LED chip 30 to the individual cathode-side electrode pads 31 can be made uniform, a current is efficiently passed through the LED chip 30 and the LED lamp. The luminous efficiency of 10 can be increased.

By the way, the embodiments described above may be implemented in combination as appropriate, and in that case, the actions and effects of the combined embodiments can be combined or a synergistic effect can be obtained.
The present invention is not limited to the description of each aspect and each embodiment. Various modifications are also included in the present invention as long as those skilled in the art can easily conceive without departing from the scope of the claims. The contents of papers, published patent gazettes, patent gazettes, etc. specified in this specification are incorporated by reference in their entirety.

10, 100, 200 ... LED lamp 11 ... Mounting board 12 ... Wiring layer (external)
DESCRIPTION OF SYMBOLS 13 ... Connection material 14 ... Radiation board 14a ... Exposed part 15 ... Insulating layer 15a ... Opening part of the insulating layer 15 16 ... Wiring layer 16a ... Opening part 17 of the wiring layer 16 17, 18 ... Bump 19 ... Sealing material 30 ... LED chip 31 ... Cathode side electrode pad (first electrode for LED lamps 10 and 200, second electrode for LED lamp 100)
32 ... Anode-side electrode pad (second electrode for LED lamps 10 and 200, first electrode for LED lamp 100)
201 ... Reflector

Claims (6)

A substrate made of a conductive and thermally conductive material;
A wiring layer formed on the surface of the substrate via an insulating layer;
An exposed portion composed of the surface of the substrate exposed from the bottom surface of the opening formed in the insulating layer and the wiring layer;
An LED lamp comprising an LED chip on which a first electrode and a second electrode are formed,
An LED lamp in which the LED chip is mounted on the substrate by connecting the first electrode to the exposed portion and connecting the second electrode to the wiring layer.   2. The LED lamp according to claim 1, wherein the first electrode connected to the exposed portion is electrically and thermally connected to the outside through the entire back surface side of the substrate.   The LED lamp according to claim 1, wherein the LED lamp is disposed and formed on the bottom surface of the LED chip so that the second electrode surrounds the first electrode.   The said board | substrate is a clad material of the structure which laminated | stacked the layer which consists of a 1st material from which a thermal expansion coefficient and thermal conductivity differ, and the layer which consists of a 2nd material alternately. LED lamp of description.   The LED lamp of any one of Claims 1-4 provided with the sealing material which consists of a glass material which seals and covers the said wiring layer and the said LED chip on the surface side of the said board | substrate. The LED lamp according to any one of claims 1 to 5, further comprising a reflector made of a glass ceramic material arranged and formed so as to surround the periphery of the LED chip on the surface side of the substrate.

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