JP4759791B2 - Optical semiconductor device and manufacturing method thereof - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a light-emitting element that emits light by converting electricity into light, and an optical semiconductor element that is a light-receiving element that receives incident light and converts it into electricity, and a method for manufacturing the same. The present invention relates to an optical semiconductor element improved to prevent the optical semiconductor chip from tilting with respect to a base material or to improve the bonding strength, and a method for manufacturing the same.
[0002]
[Prior art]
In recent years, light-emitting elements using nitride semiconductors have attracted attention as light-emitting elements that can emit blue light. In this light emitting device using a nitride semiconductor, an n-type nitride semiconductor layer is grown on a sapphire substrate, and a p-type nitride semiconductor layer is grown directly or via the light emitting layer on the n-type nitride semiconductor layer. It has a layered structure.
[0003]
Further, in a nitride semiconductor light emitting device configured using a sapphire substrate that is an insulator, a p-electrode and an n-electrode are formed on a semiconductor layer on the same plane side. That is, the p-electrode is formed on the p-type nitride semiconductor layer, and the n-electrode is formed by removing the p-type nitride semiconductor layer at a predetermined position to expose the surface of the n-type nitride semiconductor layer. Formed on the physical semiconductor layer.
[0004]
For example, an optical semiconductor element having a pair of positive and negative electrodes formed on the same surface side, such as a light-emitting element using the above-described nitride semiconductor, is flip-chip bonded to a substrate having a lead electrode with the electrode surface facing down. In this case, the light emitting chip and the substrate on which the light emitting chip is mounted are connected to each electrode of the light emitting chip and the corresponding lead electrode using a bonding member such as solder.
[0005]
Here, when the amount of the bonding member increases, the bonding member turns not only to the electrode portion but also to the end face of the semiconductor layer. Therefore, the semiconductor layer and each electrode are shielded by an insulating protective film except for the exposed portion of the surface of each electrode. The way to do is taken. Thereby, an optical semiconductor element with high reliability can be obtained without occurrence of short circuit or leakage.
[0006]
[Problems to be solved by the invention]
However, optical semiconductor elements are being used in various fields as the functions and size of the semiconductor devices increase. And with the expansion of the field of use, it is in an environment with greater vibration, heat, etc., and it emits or receives light from ultraviolet to infrared with high brightness, while satisfying more stringent requirements, for a long time There is a demand for an optical semiconductor element that can be used with stable performance and has high reliability and mountability. Accordingly, the present invention is to solve the above-described problems and provide an optical semiconductor element with higher reliability and mountability.
[0007]
[Means for Solving the Problems]
The optical semiconductor device according to claim 1 of the present invention is a pair of first and second electrodes provided on the same surface side of the semiconductor, that is, a p-electrode and an n-electrode, and an exposed upper surface of each electrode. An optical semiconductor element having an insulating protective film covering the semiconductor and the electrodes except for a portion, and electrically connected to the p electrode or the p electrode and the n electrode, and the p electrode Alternatively, it has a third electrode which is larger than the exposed portion of the upper surface of the p electrode and the n electrode and is provided through a side surface and a space of the insulating protective film, and an outer side of the third electrode is the insulating protection The third electrode and the lead electrode on the substrate protrude from the outer side of the film. Made of conductive paste or solder It is connected via a joining member. In this case, when the third electrode is provided on the p-electrode, the joining member can be prevented from creeping up in the direction of the side surface of the insulating protective film, that is, the end face of the n-type semiconductor layer. It is possible to prevent a short circuit or a leak that occurs when the n-type semiconductor layer climbs toward the end face. Note that the term “via a space” as used herein includes an overlap between the side surface of the insulating protective film and the third electrode via the space.
[0008]
An optical semiconductor element according to claim 2 of the present invention is a semiconductor device, wherein each of the semiconductor and each of the semiconductor devices except for a pair of p-electrode and n-electrode provided on the same surface side of the semiconductor and an exposed portion of the upper surface of each electrode. An optical semiconductor element having an insulating protective film covering an electrode, wherein the optical semiconductor element is electrically connected to the p electrode or the p electrode and the n electrode, and the upper surface of the p electrode or the p electrode and the n electrode A third electrode provided in contact with a part of the insulating protective film, the outer side of the third electrode protruding beyond the outer side of the insulating protective film, What is the third electrode and the lead electrode on the substrate? Made of conductive paste or solder It is connected via a joining member. Note that the term “contact” as used herein is different from the relationship between the bonding member and the insulating protective film in a state where the bonding member crawls up to the side surface of the insulating protective film, and a part of the third electrode touches the side surface of the insulating protective film. That means. That is, it means a state where the third electrode and the insulating protective film can be separated. Therefore, for example, even if the material constituting the third electrode is excessively used and a part of the third electrode comes into contact with the surface of the insulating protective film, the optical semiconductor element according to claim 2 of the present invention is the present invention. The same effect as that of the optical semiconductor device according to claim 1 is exhibited.
[0009]
Moreover, in the optical semiconductor element according to claim 1 or 2 of the present invention, the optical semiconductor element is preferably a flip chip type. In this case, when the third electrode is provided on the p electrode and / or the n electrode, the exposed member on the upper surface of the p electrode and / or the n electrode and the lead electrode on the substrate are directly bonded. Compared to the above, since the joining area of the joining member, the third electrode, and the lead electrode in the base material can be increased, the optical semiconductor chip and the base material can be joined more firmly. Moreover, by installing the third electrode on the p-electrode and / or the n-electrode, a space for filling the sealing resin between the optical semiconductor chip and the substrate can be easily secured, and accordingly The amount of the joining member can be reduced. Thereby, it is possible to more effectively prevent the joining member on the p-electrode side from creeping in the direction of the end face of the n-type semiconductor layer. Further, by providing the third electrode on each electrode without any difference in height, it is possible to prevent the optical semiconductor chip from being inclined with respect to the base material when the optical semiconductor chip is mounted on the base material. In this case, for example, in a light-emitting element that is one of optical semiconductor elements, light extraction efficiency can be increased. That is, the performance of the optical semiconductor element can be stabilized by eliminating the inclination of the optical semiconductor chip. Further, the ease of mounting is improved by reducing the height difference between the electrodes.
[0010]
In the optical semiconductor element according to claim 3 of the present invention, it is preferable that the outer side of the third electrode protrudes from the outer side of the insulating protective film. In this way, not only can the creeping of the joining member toward the end face direction of the n-type semiconductor layer on the p-electrode side be more effectively prevented, but also the joining area of the joining member, the third electrode, and the lead electrode in the base material Therefore, the bonding strength between the optical semiconductor chip and the base material can be further increased.
[0011]
In the optical semiconductor element according to any one of claims 3 to 4, the film thickness of the peripheral edge of the third electrode can be made larger than the film thickness of the central part. In this way, it is possible to more effectively prevent the joining member from creeping up on the p electrode and / or n electrode side.
[0012]
Moreover, in the optical semiconductor element according to any one of claims 3 to 5, the third electrode may have a concave shape having an open side facing the base material. You may have a so-called flip to prevent. If it does in this way, the creeping of a joining member can be prevented more effectively.
[0013]
In the optical semiconductor element according to any one of claims 3 to 6, it is preferable that the third electrode is Au or an alloy containing Au. In this case, since the surface state of Au is extremely stable even in a high humidity environment, the bonding surface condition is stabilized, and conduction failure caused by corrosion of the bonding surface due to the environment can be prevented. Au is also preferable from the viewpoint of heat dissipation and conductivity because it has relatively good thermal conductivity and conductivity.
[0014]
In the optical semiconductor element according to claims 3 to 7 of the present invention, it is particularly effective when at least the third electrode and the lead electrode on the substrate are connected via a joining member containing Ag. That is, when Ag is contained in the bonding member, Ag is very likely to migrate, but the protruding portion of the third electrode provided on the p-electrode prevents the creeping of the Ag n-type semiconductor layer in the end face direction. However, since the creepage gap is increased, the occurrence of leakage due to migration is prevented.
[0015]
In addition, the method for manufacturing an optical semiconductor device according to the present invention includes a pair of p-electrode and n-electrode provided on the same side of the semiconductor, and the semiconductor and each of the semiconductor except for the exposed portion of the upper surface of each of the electrodes. In a method for manufacturing an optical semiconductor element having an insulating protective film covering an electrode, a step of forming a ball on the p electrode or the p electrode and the n electrode by, for example, ultrasonic thermocompression ball bonding; and Forming a third electrode by deforming, or forming a third electrode by bonding a plate-like conductor to the p electrode or the p electrode and the n electrode by lead bonding; and The third electrode and the lead electrode on the substrate Made of conductive paste or solder Including a step of connecting through a bonding member, wherein the outer side of the third electrode is formed to protrude from the outer side of the insulating protective film. If it does in this way, the 3rd electrode in the present invention can be formed easily.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
As a result of various experiments, the present inventor has found that by providing a third electrode having a specific shape on a pair of p-electrode and / or n-electrode, reliability and mountability are improved. It came to make.
[0017]
In other words, when an optical semiconductor element in which the bonding member has been raised to the side surface of the insulating protective film is actually used for a long period of time, a short circuit or a leak may occur even though the insulating protective film is provided. More specifically, for example, the side surface of the insulating protective film on the p electrode side is deteriorated, and the bonding member and the n-type semiconductor layer are in contact with each other at this deteriorated portion or the metal such as Ag contained in the bonding member is in the surrounding environment. In some cases, the ionized metal is migrated in the insulating protective film due to energization with the semiconductor, causing short circuit or leakage. In this case, not only the function of the semiconductor deteriorates but also the optical semiconductor element may be destroyed. In particular, a short circuit or leakage at the semiconductor junction is considered to have a particularly great influence on the optical semiconductor element. Further, when an optical semiconductor chip having a pair of positive and negative electrodes on the same surface side is flip-chip bonded to the base material, the optical semiconductor chip is in relation to the base material due to the amount of the joining member or the height difference of each electrode. There is a possibility of tilting. Therefore, the present invention prevents a short circuit or a leak that occurs when the bonding member crawls up toward the end face of the n-type semiconductor layer on the p-electrode side in spite of the provision of the insulating protective film. By improving the bonding strength with the base material or preventing the optical semiconductor chip from tilting with respect to the base material, an optical semiconductor element excellent in reliability and mountability is obtained. Such a problem is not only a light emitting element but also a light receiving element.
[0018]
Here, the optical semiconductor element referred to in this specification refers to a semiconductor element having a light emitting or light receiving function, and refers to a light emitting diode, a semiconductor laser, a photodetector, a solar cell, or the like.
[0019]
Hereinafter, specific embodiments of the present invention will be described.
[0020]
The flip chip type LED (light emitting diode) in the embodiment includes a base material having a lead electrode which is a predetermined wiring pattern, and an LED chip. An n electrode and a p electrode are formed on the lower surface of the LED chip. Furthermore, a third electrode is formed on the lower surface of the n electrode and / or the p electrode, and the light emitting diode is formed by bonding the electrode located on the lower surface of the LED chip and the lead electrode via a bonding member such as an Ag paste. To do.
[0021]
In the LED chip in the embodiment, an n-type nitride semiconductor layer and a p-type nitride semiconductor layer are sequentially formed on a sapphire substrate, and then the p-type nitride semiconductor layer is partially etched to form an n-type nitride. The surface of the physical semiconductor layer is exposed. Thereafter, a p-electrode is formed on the p-type nitride semiconductor layer via an entire surface electrode, and an n-electrode is formed on the n-type nitride semiconductor layer. Further, after forming the insulating protective film, a third electrode is formed on the lower surface of the n electrode and / or the p electrode.
[0022]
In order to perform die bonding, an Ag paste is provided on the lead electrode in advance. Next, the LED chip aligned at a predetermined position is pressed against the Ag paste, and then heated and cured, whereby the LED chip and the lead electrode can be bonded with good thermal conductivity. Thereafter, a sealing resin is injected and formed for the purpose of efficiently transmitting the light from the LED chip to the outside and protecting the LED chip from external force and dust.
[0023]
Hereinafter, each configuration of the present invention will be described in more detail.
(Base material)
The base material is provided with a lead electrode for arranging the LED chip and supplying an electric current from the outside to the LED chip. Therefore, a substrate having heat resistance or insulation is preferably used. As a material used for such a substrate, an insulating substrate made of glass epoxy, bismaleimide triazine (BT resin), polybutylene terephthalate resin (PBT resin), ceramics, liquid crystal polymer, or the like can be used.
(Lead electrode)
Since the lead electrode is to electrically connect the LED chip to the outside of the substrate, an electrode having excellent electrical conductivity is preferable. Copper and copper alloy are used for the lead electrode in the present invention, and the thickness of the lead electrode is about 10 to 300 μm. Further, smooth metal plating such as Ag, Al, Au or the like is applied as a metal thin film on the surface of the lead electrode. The metal thin film has an effect of preventing the formation of an oxide film on the surface of the bonding member in the bonding portion and improving the bonding property between the bonding member and the lead electrode.
(Joining member)
Usually, there are conductive pastes containing metal fillers such as Ag, Pd, Au and solders such as Pb—Sn, Sn—Bi, Sn—In, Sn—Ag—Cu alloy, etc. Any joining member can be used in the LED according to the above. In the present invention, it is particularly effective to use an Ag paste as the joining member. That is, when Ag is included in the bonding member, Ag is very likely to cause migration, but the protruding portion of the third electrode provided on the p-electrode side prevents the creep of Ag in the semiconductor layer end face direction, By increasing the creepage gap, leakage due to migration is prevented.
(LED chip)
The LED chip in the present invention is a light emitting device made of a nitride semiconductor. It can be formed of a nitride semiconductor having at least a semiconductor junction formed on a light-transmitting insulating substrate. Specifically, a nitride semiconductor can be formed on a sapphire substrate using MOCVD or HVPE. The translucent insulating substrate is made of sapphire (Al ₂ O _Three Spinel (MgAl) ₂ O _Four ), SiC, Si, ZnO, GaN, and the like. Further, examples of the semiconductor junction include a pn junction in addition to a MIS junction and a PIN junction, and a homo- or double-hetero structure can be formed depending on the characteristics of the LED chip. Furthermore, a single quantum well structure or a multiple quantum well structure can be used. Note that the sapphire substrate is used in the present invention in order to form a nitride semiconductor with good crystallinity. In addition, a light emitting device having excellent semiconductor characteristics can be configured by forming a buffer layer of GaN, AlN or the like on the sapphire substrate to reduce lattice mismatch and forming a nitride semiconductor thereon.
[0024]
A gallium nitride semiconductor exhibits n-type conductivity in a state where impurities are not doped. However, when a desired n-type gallium nitride semiconductor is formed, for example, to improve luminous efficiency, Si, Ge, Se, Te are used as n-type dopants. , C and the like are preferably introduced as appropriate. When a p-type gallium nitride semiconductor is formed, a p-type dopant such as Zn, Mg, Be, Ca, Sr, or Ba is doped. However, since the gallium nitride compound semiconductor is difficult to be p-type only by doping with a p-type dopant, it is preferable to lower the resistance by low-energy electron beam irradiation, plasma irradiation, annealing, or the like after introduction of the p-type dopant.
(electrode)
In order to form a pair of electrodes on the nitride semiconductor exposed surface side, each semiconductor layer is preferably etched into a desired shape. Etching includes dry etching and wet etching. Examples of dry etching include reactive ion etching, ion milling, focused beam etching, and ECR etching. As wet etching, a mixed acid of nitric acid and phosphoric acid can be used. However, it goes without saying that a mask is formed in a desired shape using a material such as silicon nitride or silicon oxide before etching.
[0025]
After the exposed surfaces of the p-type semiconductor and the n-type semiconductor are formed by etching, each electrode is formed on the semiconductor layer using a sputtering method, a vacuum evaporation method, or the like. The entire surface electrode according to the present invention has translucency and is in ohmic contact with the p-type nitride semiconductor layer, and is specifically made of Ni / Pt or Ni / Pt. Further, the p-electrode is formed by sputtering so as to be in contact with the entire surface electrode. The material used for the p-electrode is mainly composed of Pt, Au, or Ni, and good light emission can be secured by heat treatment at a predetermined temperature (400 ° C. to 700 ° C.). When Pt is used for the p-electrode, a rapid diffusion phenomenon does not occur, and alloying of the p-electrode and solder, that is, leakage proceeds, so that only the surface of the p-electrode is alloyed with the bonding member. Stable connection and conduction can be obtained between the joining member and the lead electrode. Further, an n-type electrode made of W / Al or Ti / Al is formed on the exposed surface of the n-type nitride semiconductor layer.
(Insulating protective film)
An insulating protective film is formed on the LED chip on which the electrodes are formed as described above except for the bonding surface of each electrode. The insulating protective film can prevent the semiconductor layer from being scratched or cracked, and is effective in preventing a short circuit or leakage. Furthermore, it is preferable to form on the electrode because it can prevent the electrode from peeling off. Although the film thickness of an insulating protective film is not specifically limited, It is 0.1-5 micrometers. In the present invention, the material of the insulating protective film is SiO ₂ TiO ₂ , Al ₂ O _Three , Si _Three N _Four Etc. can be used.
(Third electrode)
An insulating protective film is formed except for the bonding surface of each electrode, and then a third electrode made of Au or an alloy containing Au is formed on the p electrode and / or the n electrode. As a material used for the third electrode, Cu, Al, or an alloy containing them can be used in addition to Au or an alloy containing Au. When Au is used for the third electrode, the surface state of Au is extremely stable even in a high-humidity environment, so that the bonding surface condition is stable and conduction failure caused by corrosion of the bonding surface due to the environment is prevented. Is done.
[0026]
Next, an example of the manufacturing method of the 3rd electrode in this invention is demonstrated.
(1) First, an Au ball is bonded to the p electrode and / or the n electrode by thermocompression bonding with ultrasonic waves or the like.
(2) Next, the Au ball is deformed by pressing, for example, using a pressing piece to form a third electrode.
[0027]
In the step (2), when the third electrode is formed on both the p electrode and the n electrode, the third electrode in each electrode is formed without any difference in height by adjusting the height of the pressing piece. be able to. If it does in this way, the 3rd electrode of the present invention can be formed easily. Further, by providing the third electrode, a space between the optical semiconductor chip and the base material can be easily secured, and the amount of the joining member used can be reduced accordingly. Furthermore, since the third electrode has the protruding portion, it is possible to effectively prevent creeping in the end face direction of the semiconductor layer of the bonding member. In addition, in the case where the third electrode is provided as compared with the case where the p electrode or the n electrode and the bonding member are directly bonded, the bonding area with the bonding member can be increased, so that the optical semiconductor chip and Bonding strength with the substrate can be further increased.
[0028]
Furthermore, the 3rd electrode which has various shapes can be formed by making a press piece into arbitrary shapes. Next, a more specific method of forming the third electrode, the shape obtained thereby, and the effect thereof will be described with reference to FIG. In FIG. 6, the third electrode is provided only on the p electrode 7. However, the present invention is not limited to this, and the third electrode may be formed on both the p electrode 7 and the n electrode 6. Further, the shape of the pressing piece that can be used in the present invention is not limited to the shape of the pressing piece shown in FIG.
As shown in FIG. 6 (A), the pressing piece having a shape like 19 is lowered straight (arrow 1), the Au ball is deformed, and then the pressing piece 19 is returned straight upward ( By the arrow (2)), the third electrode 17 having a shape in which the peripheral portion has a thickness as compared with the central portion as shown in FIG. 4 is formed. By forming the third electrode in such a shape, it is possible to effectively prevent the joining member from creeping in the end face direction of the semiconductor layer.
・ As shown in FIG. 6 (B), the peripheral portion as shown in FIG. 1 and FIG. The third electrode 13 to the third electrode 15 having a thickness compared to the portion and having a depression at the center are formed. Since the third electrode having such a shape is easier to secure the thickness than the third electrode 17 shown in FIG. 4, the amount of the joining member can be reduced, and accordingly, the semiconductor layer of the joining member is used. It is possible to more effectively prevent the scooping up in the end face direction. Furthermore, since it has a hollow in the center part, since the contact area of a 3rd electrode and a joining member can be taken more, the joining strength of an optical-semiconductor chip and a base material can be raised more.
[0029]
Also, the third electrode in the present invention can be formed as follows.
[0030]
That is, the third electrode in the present invention can be formed by bonding a plate-like conductor to the p electrode and / or the n electrode by lead bonding. Furthermore, if a conductor having an arbitrary shape is used, third electrodes having various shapes can be easily formed.
[0031]
For example, as shown in FIG. 7, a bonding tool having a shape like 22, that is, a vibration pressing piece, is used to join the Au piece 21 having a concave shape with the side facing the substrate open to the p-electrode 7. Thus, the third electrode 16 having a shape as shown in FIG. 3 is formed. The third electrode having such a shape can more effectively prevent the joining member from creeping in the direction of the end face of the semiconductor layer. In FIG. 7, the third electrode is provided only on the p electrode 7. However, the present invention is not limited to this, and the third electrode may be formed on both the p electrode 7 and the n electrode 6. The shape of the bonding tool that can be used in the present invention is not limited to the shape of the bonding tool shown in FIG.
(Sealing resin)
The sealing resin formed so as to cover the LED chip is for protecting the LED chip, the joint between the LED chip and the lead electrode, and the like according to the use application of the light emitting diode. As a specific material of the sealing resin, a translucent resin or glass having excellent weather resistance such as an epoxy resin, a urea resin, or a silicone resin is preferably used.
[0032]
Further, by adding a diffusing agent to the sealing resin material, the directivity from the LED chip can be relaxed and the viewing angle can be increased. As a material for the diffusing agent, barium titanate, titanium oxide, aluminum oxide, silicon oxide, or the like is used.
[0033]
【Example】
Hereinafter, examples of the present invention will be described in detail, but the present invention is not limited thereto.
[Example 1]
The LED shown in FIG. 1 was formed.
[0034]
First, a nitride semiconductor was formed by MOCVD using the cleaned C-plane of the sapphire substrate 2 as the film formation surface. An n-type nitride semiconductor layer 3, an active layer (not shown in the present specification), and a p-type nitride semiconductor layer 4 were formed through a buffer layer (not shown in the present specification).
[0035]
Ni / Pt with a thickness of 500 mm was formed by sputtering as a full-surface electrode 5 in contact with the p-type nitride semiconductor layer 4 and covering the entire surface thereof. On this whole surface electrode 5, the p electrode 7 was formed into a film thickness of 7000 mm using Au or Pt. Further, a tungsten / aluminum film having a thickness of 200/7000 mm was formed as an n-electrode 6 on the n-type nitride semiconductor layer 3. Thereby, the p-electrode 7 and the n-electrode 6 were formed on the same plane side on the nitride semiconductor. Further, except for the bonding surfaces of the p-electrode 7 and the n-electrode 6, the insulating protective film 8 is made of SiO. ₂ Was deposited.
[0036]
Next, the formed semiconductor wafer is fully cut directly by a dicing saw with a blade having a diamond blade edge or a groove having a width wider than the blade edge width is cut (half cut), and then the semiconductor wafer is applied by an external force. Break. Alternatively, an LED chip can be obtained by drawing a very thin scribe line (meridian line) on the semiconductor wafer, for example, in the shape of a base by a scriber in which the diamond needle at the tip moves back and forth, and then cutting the wafer into chips from the semiconductor wafer by external force. 1 is formed.
[0037]
Next, the third electrode 13 was formed as shown in FIG.
[0038]
The base material 10 was formed by placing a pre-formed lead electrode 11 in a mold and injecting and curing a glass epoxy resin. The formed substrate 10 has a smooth surface with a part of the lead electrode 11 exposed on the upper surface thereof.
[0039]
Next, the LED chip 1 is mounted on the substrate 10 by stamping or dispensing Ag paste on the lead electrode portion on the upper surface of the substrate corresponding to the n electrode 6 and the third electrode 13 of the LED chip 1. Then, dots having a diameter about 10% larger than the p-electrode 7 and the n-electrode 6 of the LED chip 1 and a thickness of about 10 to 30 μm are formed. Here, the diameter or thickness of the dots is preferably larger from the viewpoints of the bonding strength, heat dissipation, and conductivity after curing, as long as the bonding members in each electrode come into contact with each other and no short circuit occurs. Next, the LED chip 1 is mounted on the dots while being pressed with an appropriate force. Thereafter, the Ag paste is heated to be cured and the LED chip 1 is bonded.
[0040]
Further, the periphery of the chip is sealed with a sealing resin 12. The sealing resin used here is a silicone resin.
[0041]
Next, for the comparison shown in FIG. 5, the LED of Example 1 having the third electrode 13 completed as described above and the LED of Example 1 except that the third electrode 13 is not provided. Using LEDs, changes in manufacturing yield due to leakage were investigated.
[0042]
First, the LED of Example 1 and the LED for comparison were mass-produced by 1000 pieces each. Next, an energization test was conducted for 1000 hours at a current of 40 mA under a high temperature and high humidity environment of 85 ° C. and 85%. Then, when a voltage of 5 V was applied in the reverse direction and the occurrence of leakage (determined based on the criterion of 20 μA ≦ leakage current) was investigated, the LED of Example 1 met the above-described criterion for the occurrence of leakage. While there were no objects, 6 out of 1000 LEDs for comparison met the above criteria.
[Example 2]
The LED in FIG. 2 is configured in the same manner as the LED of Example 1 except that the third electrodes 15 and 14 are provided on both the p electrode 7 and the n electrode 6 without any difference in height. The third electrodes 15 and 14 were formed as shown in FIG.
[Example 3]
The LED in FIG. 3 is configured in the same manner as the LED of Example 1 except that the third electrode 16 has a concave shape with the side facing the base material opened. The third electrode 16 was formed as shown in FIG.
[Example 4]
The LED in FIG. 4 is configured in the same manner as the LED of Example 1 except that a third electrode having a shape like 17 is provided. The third electrode 17 was formed as shown in FIG.
[0043]
【The invention's effect】
As is apparent from the above description, according to the optical semiconductor element of the present invention, it is possible to effectively prevent the joining member on the p-electrode side from creeping in the direction of the end surface of the n-type semiconductor layer. It is possible to increase the bonding area between the three electrodes and the lead electrode in the base material. Moreover, the inclination of the optical semiconductor chip with respect to the base material can be eliminated by providing the third electrode without difference in height between both the p electrode and the n electrode.
[0044]
Therefore, the occurrence of short circuit or leakage can be prevented, and the bonding strength between the optical semiconductor chip and the substrate can be improved. Moreover, since the inclination of the optical semiconductor chip with respect to the substrate can be eliminated, stable performance can be obtained. From these effects, an optical semiconductor element excellent in reliability and mountability can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic cross-sectional view showing the structure of an LED of Example 1 according to the present invention.
FIG. 2 is a schematic cross-sectional view showing the structure of an LED of Example 2 according to the present invention.
FIG. 3 is a schematic cross-sectional view showing the structure of an LED of Example 3 according to the present invention.
FIG. 4 is a schematic cross-sectional view showing the structure of an LED of Example 4 according to the present invention.
FIG. 5 is a schematic cross-sectional view showing the structure of an LED formed for comparison with the LED according to the present invention.
FIG. 6 is an enlarged view schematically showing a part of the manufacturing process of the LED according to the present invention.
FIG. 7 is a diagram schematically showing an enlarged part of another manufacturing process of the LED according to the present invention.
[Explanation of symbols]
1 ... LED chip
2 ... Sapphire substrate
3 ... n-type nitride semiconductor layer
4 ... p-type nitride semiconductor layer
5 ... Full-surface electrode
6 ... n electrode
7 ... p electrode
8 ... Insulating protective film
9 ... Ag paste
10 ... Base material
11 ... Lead electrode
12 ... Sealing resin
13, 14, 15, 16, 17 ... third electrode
18 ... Au ball
19, 20 ... Pressing piece
21 ... Au piece
22 ... Bonding tool

Claims (10)

An optical semiconductor element having a pair of p-electrode and n-electrode provided on the same surface side of a semiconductor, and an insulating protective film covering the semiconductor and the electrodes except for an exposed portion of the upper surface of each electrode And being electrically connected to the p electrode or the p electrode and the n electrode, being larger than the exposed portion of the upper surface of the p electrode or the p electrode and the n electrode, and of the insulating protective film. A third electrode provided through a side surface and a space;
The outer side of the third electrode protrudes from the outer side of the insulating protective film,
The optical semiconductor element, wherein the third electrode and the lead electrode in the substrate are connected via a joining member made of a conductive paste or solder . An optical semiconductor element having a pair of p-electrode and n-electrode provided on the same surface side of a semiconductor, and an insulating protective film covering the semiconductor and the electrodes except for an exposed portion of the upper surface of each electrode And being electrically connected to the p electrode or the p electrode and the n electrode, being larger than the exposed portion of the upper surface of the p electrode or the p electrode and the n electrode, and of the insulating protective film. A third electrode provided in contact with a portion;
The outer side of the third electrode protrudes from the outer side of the insulating protective film,
The optical semiconductor element, wherein the third electrode and the lead electrode in the substrate are connected via a joining member made of a conductive paste or solder . The optical semiconductor element according to claim 1, wherein the optical semiconductor element is a flip chip type. 4. The optical semiconductor element according to claim 3, wherein a film thickness of a peripheral portion of the third electrode is larger than a film thickness of a central portion of the third electrode. 5. The optical semiconductor element according to claim 3, wherein the third electrode has a concave shape having an opening on a side facing the base material. The optical semiconductor element according to claim 3, wherein the third electrode is made of Au or an alloy containing Au. 7. The optical semiconductor element according to claim 3, wherein at least the third electrode and the lead electrode of the substrate in the optical semiconductor element are connected via a bonding member containing Ag. An optical semiconductor device having a pair of p-electrode and n-electrode provided on the same surface side of a semiconductor, and an insulating protective film covering the semiconductor and the electrodes except for an exposed portion of the upper surface of the electrodes A manufacturing method comprising: forming a ball by ball bonding on the p-electrode or the p-electrode and the n-electrode; forming a third electrode by deforming the ball; and the third electrode and the base An optical semiconductor element including a step of connecting a lead electrode in the material via a joining member made of a conductive paste or solder , wherein the outer side of the third electrode protrudes beyond the outer side of the insulating protective film Manufacturing method. 9. The method of manufacturing an optical semiconductor element according to claim 8, wherein the ball bonding is ultrasonic thermocompression bonding. An optical semiconductor device having a pair of p-electrode and n-electrode provided on the same surface side of a semiconductor, and an insulating protective film covering the semiconductor and the electrodes except for an exposed portion of the upper surface of the electrodes A manufacturing method, comprising: forming a third electrode by bonding a plate-like conductor by lead bonding on the p electrode or the p electrode and the n electrode; and the lead electrode in the third electrode and the substrate And a connecting member made of a conductive paste or solder, and the outer side of the third electrode is formed so as to protrude from the outer side of the insulating protective film.

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