JP2003101121A - Semiconductor light emitting device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a semiconductor light emitting device which suppresses the short circuit being caused by adhesive material sticking out to an unnecessary region when connecting the electrode of a light emitting element chip with the conductive layer of a mount member. SOLUTION: In a semiconductor light emitting device, a light emitting element chip 10 equipped with an electrode 4 at its surface is mounted in such manner that the above electrode 4 and the above conductive layer 5 face each other, on the mount member 20 equipped with the conductive layer 5 at its surface. A first groove 9a and a second groove 9b are made apart with the above conductive layer 5 in-between at the above mount member 20. The total dimensions (W1a +W1b +W1c ) of the width (W1a ) of the above first groove 9a, the width (W1c ) of the above second groove 9b, and the interval (W1b ) between the above first groove and the above second groove is made smaller than the width (W2 ) of the above electrode 4 of the above light emitting element chip 10.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor light emitting device in which a light emitting diode (LED), a semiconductor laser (LD), and a light emitting element chip such as an array element thereof are mounted on a mount member.

[0002]

2. Description of the Related Art FIG. 5 is a sectional view showing the structure of a conventional semiconductor light emitting device. This semiconductor light emitting device has a structure in which a light emitting element chip 10 is mounted on a mount member 20. In the light emitting element chip 10, the semiconductor substrate 2
An epitaxial layer 1 is formed on the upper side, and an electrode 4 is formed on the epitaxial layer 1. Epitaxial layer 1 includes n-type conductive layer 1b, active layer 1a and p-type conductive layer 1c. That is, this is an example in which a semiconductor laser element is mounted as a light emitting element chip. Further, in the mount member 20, the conductive layer 5 is formed on the substrate 3. The light emitting element chip 10 is mounted on the mount member 20 so that the electrode 4 faces the conductive layer 5, and the electrode 4 and the conductive layer 5 are connected via an adhesive material 6 such as solder.

FIG. 6 is a sectional view showing another structure of a conventional semiconductor light emitting device. In this semiconductor light emitting device, a light emitting element chip 11 which is a semiconductor laser array element in which a plurality of light emitting elements are integrated in the same chip is used, and this is mounted on a mount member 20. In the light emitting element chip 11, each light emitting element has an epitaxial layer 1 (including an n-type conductive layer 1b, an active layer 1a and a p-type conductive layer 1c) formed on a semiconductor substrate 2, and each epitaxial layer. An electrode 4 is formed on the layer 1. In addition, in the mount member 20, a plurality of conductive layers 5 are formed on the substrate 3 so as to correspond to the respective light emitting elements. The light emitting element chip 11 is mounted on the mount member 20 so that the electrode 4 faces the conductive layer 5, and the electrode 4 and the conductive layer 5 are connected via an adhesive material 6 such as solder.

According to these semiconductor light emitting devices, since the light emitting element chip is mounted with the epitaxial layer side facing the mount member, the heat dissipation of the light emitting element chip can be improved.

However, in the semiconductor light emitting device as described above, as shown in FIGS. 5 and 6, when the light emitting element chip is mounted on the mount member, variations in the amount or composition of the adhesive, and further mounting conditions. It is said that the adhesive 6 rises up on the side surface of the epitaxial layer 1 of the light emitting element chip due to the influence of variations in temperature (atmosphere, atmosphere, etc.) and causes a short circuit between the n-type conductive layer 1b and the p-type conductive layer 1c. There was a problem. Further, as shown in FIG. 6, when the light emitting element chip 11 in which a plurality of light emitting elements are integrated in the same chip is used, the adhesive 6 spreads in the lateral direction and short-circuits between the electrodes 4 of the adjacent light emitting elements. There was a problem of causing. In particular, when an array element or a monolithic multi-wavelength semiconductor laser is used, the above problem becomes a serious problem as the plurality of light emitting points are brought closer to each other.
Further, it has been a big problem also in a semiconductor light emitting device in which a plurality of p-type electrodes and n-type electrodes are arranged on the same surface of a substrate, as seen in a blue-violet semiconductor laser using a GaN-based material.

To solve this problem, as shown in FIG. 7, a groove 9 is provided on the surface of the substrate 3 in the mount member 20, and a region (projection) adjacent to the groove 9 is formed with the light emitting element chip 11. A structure has been proposed in which a conductive layer 5 is formed on the surface of the adhesive portion as an adhesive portion (Japanese Patent Laid-Open No. 6-310617). Further, the width of the adhesive portion is set smaller than the width of the electrode 4 of the light emitting element chip 11. According to such a structure, the protruding adhesive 6 flows into the groove 9,
Compared with the structure shown in FIGS. 5 and 6, the occurrence of short circuit can be suppressed.

[0007]

As described above, as shown in FIG.
According to the configuration shown in (1), the allowable range for the variation in the amount and composition of the adhesive and the variation in the mounting conditions can be somewhat relaxed, but it is not sufficient. In such a configuration, the adhesive may not flow well along the groove, and in such a case, a short circuit between the n-type conductive layer and the p-type conductive layer and adjacent light emission may occur. This is because a short circuit will occur between the electrodes of the device.

In view of the above situation, the present invention provides a semiconductor light emitting device in which the occurrence of a short circuit is suppressed due to variations in the amount and composition of the adhesive material connecting the mount member and the light emitting element chip, and variations in mounting conditions. The purpose is to provide.

[0009]

To achieve the above object, in a semiconductor light emitting device of the present invention, a light emitting element chip having an electrode on its surface is provided with the above electrode on a mount member having a conductive layer on its surface. A semiconductor light emitting device mounted such that the conductive layer faces each other, the electrode and the conductive layer are connected via an adhesive, on the surface of the mount member,
A first groove and a second groove are formed so as to be separated from each other with the conductive layer interposed therebetween, and the width of the first groove, the width of the second groove, and the first groove and the first groove. The total size of the distances from the two grooves is smaller than the width of the electrodes of the light emitting element chip.

With this structure, when the electrodes of the light emitting element chip and the conductive layer of the mount member are connected to each other, the conductive layer is affected by variations in the amount and composition of the adhesive and variations in mounting conditions. Even if the adhesive material squeezes out from the region where the ridge is formed, the squeezed adhesive material can be reliably poured into the groove on the surface of the mount member, and as a result, the occurrence of a short circuit can be suppressed.

In the semiconductor light emitting device, it is preferable that the first groove and the second groove are formed by etching the surface of the mount member. According to this preferable example, it is possible to improve the dimensional accuracy and the positional accuracy of the groove on the surface of the mount member,
As a result, it becomes possible to assemble fine chips and miniaturize array element chips.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described with reference to the drawings.

(First Embodiment) FIG. 1 is a sectional view showing an example of a semiconductor light emitting device according to the first embodiment of the present invention. The semiconductor light emitting device of the present invention can be manufactured by mounting the light emitting element chip 10 on the mount member 20.

As the light emitting element chip 10, for example, a chip including a light emitting element such as a semiconductor laser element or a light emitting diode can be used. Note that FIG. 1 illustrates a case where an edge emitting semiconductor laser device chip is used as the light emitting device chip.

The light emitting device chip 10 has an epitaxial layer 1 formed on a GaAs substrate 2, and an electrode 4 is formed on the epitaxial layer 1. The epitaxial layer 1 can have, for example, a structure in which an n-type conductive layer 1b, an active layer 1a including an active stripe, and a p-type conductive layer 1c are sequentially stacked from the substrate side. In addition, the epitaxial layer 1 may include another layer.

In the mount member 20, a first groove 9a and a second groove 9b are formed in the substrate 3, and a conductive layer 5 is formed on the surface of the substrate 3 between these grooves.
The first and second grooves 9a and 9b are, as shown in FIG.
It has a shape along a direction orthogonal to the light emitting surface of the light emitting element chip 10.

In the first and second grooves 9a and 9b, the total dimension (W1a + W1b + W1c) of the width (W1a, W1c) of each groove and the separation distance (W1b) between the grooves is the light emitting element chip 1
It is formed to be smaller than the width (W2) of the zero electrode 4.

In the example shown in FIG. 1, each of the above dimensions is
For example, the width W2 of the electrode 4 may be 250 μm, the widths W1a and W1c of the grooves 9 may be 30 μm, and the distance W1b between the grooves may be 140 μm. According to such an example, the difference between the electrode width of the light emitting chip and the total size of the groove width and the separation distance is 50 μm, so that the adhesive 6 surely holds the groove 9 in place.
It is possible to suppress the occurrence of short circuit. Further, it is possible to secure a sufficient margin of ± 20 μm or more as an assembly margin of the light emitting chip element and the mount member.

The shape of each groove is not particularly limited, and for example, a shape having a rectangular cross section, a shape having a V-shaped cross section, a shape having a trapezoidal cross section as shown in FIG. 1 is adopted. be able to.

The substrate 3 is, for example, SiC,
Si, AlN, diamond, Mo-based material, W-based material, etc. can be used. Further, as the conductive layer 5,
For example, Au, Al, AuSn or the like can be used.

Such a mount member 20 is, for example,
Producing by forming a conductive material on the surface of the substrate 3, patterning the conductive material to form the conductive layer 5, and then forming the first groove 9a and the second groove 9b on both sides of the conductive layer 5. You can In this embodiment, the grooves 9a and 9b
Dicing can be adopted as a method of forming the.

The light emitting element chip 10 is mounted on the mount member 20. At this time, the light emitting element chip 10
The electrode 4 is mounted on the mount member 20 so as to face the conductive layer 5, and the electrode 4 and the conductive layer 5 are connected by the adhesive material 6. As the adhesive material 6, for example, solder or the like can be used.

To mount the light emitting element chip 10 on the mount member 20, for example, after solder is formed on the conductive layer 5 of the mount member 20, the light emitting element chip 10 is aligned and mounted on the mount member 20, In this state, the temperature is raised to melt the solder, and the light emitting element chip 10 is pressed against the mount member 20.

In the above description, the case where the semiconductor laser element chip is used as the light emitting element chip has been exemplified.
The present invention is not limited to this. For example, an array element chip in which a plurality of light emitting elements are integrated in the same chip can be used as the light emitting element chip.

FIG. 2 is a sectional view showing a semiconductor light emitting device using an array element chip, and illustrates a case where an edge emitting semiconductor laser array element is used. This semiconductor light emitting device can be manufactured by mounting the light emitting element chip 11, which is an array element chip, on the submount member 20.

The light-emitting element chip 11 has a plurality of light-emitting elements, and each light-emitting element is formed on a substrate 2 by an epitaxial layer 1 (n-type conductive layer 1b, active layer 1a and p-type conductive layer 1).
Including c. ) And the electrode 4 formed thereon. Further, in the mount member 20, a plurality of conductive layers 5 are formed on the substrate 3 so as to correspond to the respective light emitting elements, and grooves 9 a and 9 b are formed on both sides of each conductive layer 5. Similar to the example of FIG. 1, this groove is formed such that the total dimension (W1a + W1b + W1c) of the width of the groove and the separation distance is smaller than the width (W2) of the electrode 4. The light emitting element chip 11 is mounted on the mount member 20 so that the electrode 4 faces the conductive layer 5, and the electrode 4 and the conductive layer 5 are mounted.
And are connected via an adhesive material 6 such as solder.

According to the semiconductor light emitting device of the present embodiment, as shown in FIGS. 1 and 2, even when the adhesive material protrudes from the conductive layer when the light emitting element chip is mounted on the mount member. Since the protruding adhesive material surely flows into the groove, it is possible to prevent the adhesive material from adhering to the side surface of the light emitting element chip and suppress the occurrence of a short circuit.

(Embodiment 2) In the semiconductor light emitting device of the present invention, it is preferable that the groove on the surface of the mount member is formed by photolithography and etching. Such an example will be described as a second embodiment.

FIG. 3 is a sectional view showing an example of a semiconductor light emitting device according to Embodiment 2 of the present invention. Note that FIG. 3 exemplifies a case where an edge-emitting semiconductor laser element chip is used as the light emitting element chip. The structure of the light emitting element chip 10 is the same as that of the first embodiment.

In the mount member 20, the first groove 9a and the second groove 9b are formed in the substrate 3, and the conductive layer 5 is formed on the surface of the substrate 3 between these grooves.
Similar to the first embodiment, the first and second grooves 9a and 9b have the width (W1a, W1c) of each groove and the distance (W) between the grooves.
1b) and the total size (W1a + W1b + W1c) are set to be smaller than the width (W2) of the electrode 4 of the light emitting element chip 10.

In the example shown in FIG. 3, each of the above dimensions is
For example, the width W2 of the electrode 4 is 80 μm, the widths W1a and W1c of the grooves 9 are each 10 μm, and the separation distance W1b between the grooves is 2 μm.
It can be 0 μm. According to such an example, the difference between the electrode width of the light emitting chip and the total size of the groove width and the separation distance is 40 μm, and the adhesive 6 can surely flow into the groove 9 and suppress the occurrence of a short circuit. . Also, as an assembly margin of the light emitting element array and the mount member,
A sufficient margin of ± 20 μm can be secured.

Regarding the shape of the groove, as in the first embodiment,
It is not particularly limited. For example, in addition to the V-shaped cross section shown in FIG. 3, a rectangular cross section can be adopted.

As the material of the substrate 3 and the conductive layer 5, the same material as in the first embodiment can be used.

As a method of manufacturing the mount member 20 and a method of mounting the light emitting element chip 10 on the mount member 20, the same method as in the first embodiment can be adopted. However, in this embodiment, the grooves 9a and 9b of the mount member 20 are formed by photolithography and etching. In particular, it is preferable to use Si as the substrate 3 of the mount member 20 and to form the grooves 9a and 9b by anisotropic etching.

Further, in the above description, the case where the semiconductor laser element chip is used as the light emitting element chip is illustrated, but the present invention is not limited to this. For example, an array element chip can be used as the light emitting element chip. FIG. 4 is a cross-sectional view showing such a semiconductor light emitting device. This semiconductor light emitting device has the same structure as that shown in FIG. 2 except that the groove of the mount member is formed by photolithography and etching.

According to the semiconductor light emitting device of this embodiment, as in the case of the first embodiment, when the light emitting element chip is mounted on the mount member, the adhesive protruding from the conductive layer adheres to the side surface of the light emitting element chip. This can be avoided, and the occurrence of short circuit can be suppressed. Further, since it is possible to prevent the adhesive material protruding from the conductive layer from spreading in the lateral direction, in a semiconductor light emitting device using a light emitting element chip having a plurality of light emitting elements, a short circuit between adjacent light emitting elements is caused. Can also be suppressed.

Further, according to the present embodiment, the groove is formed by a method suitable for fine processing such as photolithography and etching, so that the dimensional accuracy and the positional accuracy of the groove are higher than those formed by dicing. Therefore, for example, when an array element is used as the light emitting element chip, the light emitting points can be close to each other.

[0038]

As described above, according to the semiconductor light emitting device of the present invention, when the electrode of the light emitting element chip and the conductive layer of the mount member are connected to each other from the region where the conductive layer is formed, Even if the adhesive material for connecting the two is protruding, the protruding adhesive material can be poured into the groove on the surface of the mount member, and as a result, the occurrence of short circuit can be suppressed.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing an example of a semiconductor light emitting device according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing another example of the semiconductor light emitting device according to the first embodiment of the invention.

FIG. 3 is a sectional view showing an example of a semiconductor light emitting device according to a second embodiment of the invention.

FIG. 4 is a sectional view showing another example of the semiconductor light emitting device according to the second embodiment of the invention.

FIG. 5 is a cross-sectional view showing a conventional semiconductor light emitting device.

FIG. 6 is a cross-sectional view showing a conventional semiconductor light emitting device.

FIG. 7 is a cross-sectional view showing a conventional semiconductor light emitting device.

[Explanation of symbols] 1 Epitaxial layer 2 Semiconductor substrate 3 substrates 4 electrodes 5 Conductive layer 6 adhesive 9a, 9b groove 10, 11 Light emitting element chip 20 Mount member

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Tatsuya Nakamori             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Masahiko Nishimoto             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5F041 AA25 CA46 CA74 DA02 DA04                       DA13                 5F073 CB02 DA21 EA27 FA12 FA21

Claims (2)

[Claims] 1. A light emitting device chip having electrodes on its surface,
A semiconductor light emitting device, wherein the electrode and the conductive layer are mounted so as to face each other on a mount member having a conductive layer on the surface, and the electrode and the conductive layer are connected via an adhesive, A first groove and a second groove are formed on the surface of the mount member so as to be separated from each other with the conductive layer interposed therebetween. The width of the first groove, the width of the second groove, and the width of the second groove are formed. A semiconductor light emitting device characterized in that the total distance between the first groove and the second groove is smaller than the width of the electrode of the light emitting element chip. 2. The semiconductor light emitting device according to claim 1, wherein the first groove and the second groove are formed by etching the surface of the mount member.