JP2003282955A - Semiconductor light-emitting device having reflector case - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a semiconductor light-emitting device having a reflector case, which effectively prevents separation of a translucent resin from the reflector case. <P>SOLUTION: The semiconductor light-emitting device is provided with an insulating substrate 1, an electrode 2 formed on the surface of the insulating substrate 1, a semiconductor light-emitting element 3 mounted on the electrode 2, and the reflector case 5, which is arranged on the substrate 1, for reflecting the light from the element 3, with its inside being sealed with the translucent resin 6. A crepe 51 is formed at least at one portion of the contact face between the case 5 and the resin 6. From the viewpoint of suppressing unevenness in luminous intensity of the light emitted from the semiconductor light-emitting device, the crepe 51 may preferably be formed at least on the opposite areas of the side faces of the element 3. In order to further ensure that the resin 6 is prevented from separating from the case 5, the concavo-convex level difference in the crepe 51 should desirably be 12 μm or more, or the pitch between the crimps should desirably be 20 μm or below. <P>COPYRIGHT: (C)2004,JPO

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, and more particularly to a semiconductor light emitting device having a reflective case provided on an insulating substrate.

[0002]

2. Description of the Related Art In order to emit light from a semiconductor light emitting element such as a light emitting diode element in a specific direction, a reflection case may be provided around the semiconductor light emitting element. Figure 10
FIG. 1 is a side sectional view showing an example of a conventional semiconductor light emitting device in which the reflective case 5 is provided on the insulating substrate 1. In the conventional semiconductor light emitting device, the inside of the reflection case 5 is sealed with the translucent resin 6. A thermosetting resin such as an epoxy resin is generally used as the translucent resin 6. For this reason, after the translucent resin 6 is poured into the reflective case 5, the translucent resin 6 is cured by being heated to a hundred and several tens of degrees.

[0003]

However, most of the translucent resin 6 is not well compatible with the material of the reflective case 5. Therefore, when the translucent resin 6 is heat-cured in a reflow oven or the like, the translucent resin 6 is not cured. 6 may be peeled off from the reflective case 5 to become a defective product.

Further, in general, the light emitted from the corner of the semiconductor light emitting element 3 is weaker than the light emitted from the side surface, and as shown in the alignment characteristic diagram of FIG. 11, the light emitted from the device has uneven light intensity in plan view. It was

The present invention has been made in view of such conventional problems. Even when the translucent resin is not well compatible with the material of the reflective case, the translucent resin is reflected after being cured. It is an object of the present invention to provide a semiconductor light emitting device that does not peel off from the case.

Another object of the present invention is to suppress unevenness in luminous intensity of light emitted from a semiconductor light emitting device.

[0007]

To achieve the above object, in a semiconductor light emitting device of the present invention, a semiconductor light emitting element is mounted on an electrode portion formed on the surface of an insulating substrate, and light from this semiconductor light emitting element is emitted. In a semiconductor light emitting device in which a reflective case for reflecting the light is provided on the insulating substrate and the inside of the reflective case is sealed with a transparent resin, at least a part of the contact surface of the reflective case with the transparent resin is textured. Is formed.

Here, in order to suppress the unevenness of the luminous intensity of the light emitted from the device while improving the adhesion between the translucent resin and the reflective case, the wrinkles formed on the reflective case should at least face the side surface of the semiconductor light emitting element. It is desirable to form it in the region.

From the viewpoint of further preventing the translucent resin from being peeled off from the reflection case, it is preferable that the unevenness of the unevenness is 12 μm or more, or the pitch between the unevenness is 20 μm or less. In addition, as shown in FIG. 5, in the present invention, the uneven surface step of the grain is a ten-point average roughness, and the pitch is a distance between the convex portions.

From the viewpoint of improving the productivity of the device, the insulating substrate and the reflection case may be integrally formed.

Further, as the material of the reflection case, liquid crystal polymer is preferable from the viewpoint of heat resistance and low thermal expansion, and as the translucent resin, epoxy resin is preferable from the viewpoint of translucency.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION As a result of extensive studies, the present inventor has made extensive studies as to whether or not peeling of a translucent resin from a reflective case, which occurs when a translucent resin is heated and cured in a semiconductor light emitting device, can be prevented. By forming a grain on the contact surface of the reflective case with the translucent resin to increase the contact area between the reflective case and the translucent resin and at the same time allowing the translucent resin to enter into the concave portion of the grain, The present invention has been completed by finding that it is possible to effectively prevent peeling of the light-sensitive resin from the reflective case during heat curing. The semiconductor light emitting device of the present invention will be described below with reference to the drawings.

FIG. 1 is a sectional view showing an example of a semiconductor light emitting device of the present invention. A pair of electrode portions 2, on the insulating substrate 1.
2 ′ is formed, the semiconductor light emitting element 3 is mounted on one of the electrode portions 2, and the upper surface electrode of the semiconductor light emitting element 3 and the other electrode portion 2 ′ are connected by the bonding wire 4. Then, a reflection case 5 having an opening on the upper surface is mounted on the insulating substrate 1 so as to cover the semiconductor light emitting element 3, the bonding wire 4, and a part of the electrode portions 2 and 2 ′. The transparent resin 6 is filled in and heat-cured.

A wrinkle 51 is formed on the inner wall of the reflection case 5 used here. This grain 51 is a reflective case 5.
However, in order to suppress the unevenness of the luminous intensity of the light emitted from the semiconductor light emitting device,
It is desirable to form at least in the opposing region on the side surface of the semiconductor light emitting device. FIG. 2 shows a plan view of a semiconductor light emitting device in which the embossments 51 are formed in the opposing region of the side surface of the semiconductor light emitting element of the reflection case 5. Then, FIG. 3 shows the alignment characteristics of luminous intensity in a plan view of this device. As is clear from a comparison between FIG. 3 and FIG. 11, the semiconductor light emitting device of FIG. 2 in which the embossment 51 is formed in the opposing region of the side surface of the semiconductor light emitting element of the reflective case 5 is more difficult than the conventional semiconductor light emitting device of FIG. The uneven brightness is suppressed. Of course, in order to effectively prevent the translucent resin 6 from peeling off from the reflective case 5, the reflective case 5
It is desirable that the wrinkles 51 are formed on the entire area of the contact surface with the translucent resin 6.

The unevenness of the embossment 51 is preferably 12 μm or more. If the unevenness is smaller than 12 μm, a sufficient contact area cannot be secured and peeling of the translucent resin may not be completely prevented. In addition, light from the semiconductor light emitting element may not be sufficiently diffused to cause uneven light intensity. This is because there is a possibility that the

The pitch between the textures is preferably 20 μm or less. If the pitch is larger than 20 μm, a sufficient contact area cannot be secured and peeling of the translucent resin may not be completely prevented. In addition, the light from the semiconductor light emitting element may not be sufficiently diffused to suppress uneven light intensity. This is because there is a risk that it will not be possible. The lower limit of the pitch between the textures is not particularly limited, but if it is less than 12 μm, the convex portion may have an acute angle and peeling of the light-transmitting resin may be caused.
12 μm or more is desirable.

To form a grain on the surface of the reflective case,
A conventionally known method can be used. For example, a method of forming a reflection case by using an injection molding die having fine irregularities by surface processing, a method of blasting after forming the reflection case and forming a wrinkle on the surface of the reflection case, and the like can be mentioned. Among these, from the viewpoint of productivity and the like, a method of injection molding the reflection case using a surface-treated injection molding die is preferable. Examples of the surface processing method for forming the texture on the surface of the die include methods such as etching and electroforming.

The material of the reflection case used in the present invention is not particularly limited as long as it has heat resistance, low thermal expansion and electric insulation, and conventionally known materials can be used.
Among them, a liquid crystal polymer which is excellent in heat resistance, low thermal expansion property and electric insulation property is preferable. Examples of such liquid crystal polymers include polyester-based, polyester-amide,
Examples thereof include polyazomethine. Among these, aromatic polyester liquid crystal polymers are preferable.

In the device of FIG. 1, in order to emit light in the upward direction, the reflection case 5 having an opening on the upper surface is used, but the shape of the reflection case 5 is not particularly limited.
The shape may be such that an opening is provided in the direction in which light is desired to be emitted. FIG. 4 is a sectional view showing an example of a semiconductor light emitting device that emits light in the side direction. In each of the devices of FIG. 4, light is emitted to the right. A wrinkle 51 is formed on the entire inner peripheral surface of the reflective case 5 ′, 5 ″, which is in contact with the translucent resin 6.

On the other hand, the translucent resin used in the present invention is not particularly limited as long as it is translucent. For example, epoxy resin, unsaturated polyester resin, silicone resin, urea.
Melamine resin etc. are mentioned. Among these, an epoxy resin can be more preferably used in terms of translucency. The epoxy resin is not particularly limited as long as it has two or more epoxy groups in one molecule and is used as an epoxy resin molding material, and a phenol novolac type epoxy resin and an orcresol novolac type epoxy resin are represented. Epoxidized novolak resin of phenols and aldehydes, diglycidyl ethers such as bisphenol A, bisphenol F, bisphenol S, hydrogenated bisphenol A, polybasic acids such as phthalic acid and dimer acid, and epichlorohydrin Diglycidyl ester type epoxy resin, diaminodiphenylmethane, glycidyl amine type epoxy resin obtained by reaction of polyamine such as isocyanuric acid with epichlorohydrin, obtained by oxidizing olefin bond with peracid such as peracetic acid. That flocculent aliphatic epoxy resins, and alicyclic epoxy resins and the like can be mentioned, and these can be used alone or as a mixture of two or more.
These epoxy resins are sufficiently purified and may be liquid or solid at room temperature, but it is preferable to use those which are as transparent as possible in appearance when liquefied.

The device of the present invention is manufactured, for example, as follows. First, an insulating substrate is manufactured as follows. After forming a plurality of slits 8 (shown in FIG. 6) with a die or a router on an insulating substrate having copper foil adhered on both sides to form a plurality of crosspieces 7 (shown in FIG. 6), a photoresist By performing coating, exposure, and development, the electrode pattern portions serving as the upper surface portion and the lower surface portion of the electrode portions 2 and 2 '(shown in FIG. 6) are covered with a photoresist, and this resist pattern is used as an etch resist for unnecessary portions of copper. The foil is removed by etching. And
After the Cu layer is formed on the side surface of the crosspiece 7 which is the side surface of the electrode portion by electroless plating, each layer of Cu, Ni, and Au is laminated on the electrode pattern portion including the side surface of the crosspiece 7 by electrolytic plating to insulate. Substrate 1 is used.

Next, as shown in the plan view of FIG. 6, the semiconductor light emitting element 3 is bonded to the produced insulating substrate 1 on the upper surface of one electrode portion 2 of each crosspiece 7. . Then, the upper surface electrode of each semiconductor light emitting element 3 and the upper surface portion of the other electrode portion 2 ′ are connected by a bonding wire.

The mounting of the reflection case and the sealing with the translucent resin are carried out, for example, as follows. FIG. 7 shows a cross-sectional view (cross-sectional view taken along the line AA) of the crosspiece 7 in FIG. 6 in the longitudinal direction. The reflection case continuum 5 in which the hole 53 having a depth sufficient to completely include the bonding wire fixed to the upper surface of the semiconductor light emitting element 3 is formed corresponding to the semiconductor light emitting element 3
2 is fixed on the insulating substrate 1 with an adhesive (FIG. 7).
(A)). Next, an epoxy resin, which is a translucent resin, is poured into the hole 53 of the continuous reflective case body 52 (FIG. 2B).
Then, after the epoxy resin is cured at a predetermined temperature ((c) in the figure), the portion indicated by the broken line is cut by dicing or the like to obtain the semiconductor light emitting device of the present invention ((d) in the figure).

In the semiconductor light emitting device of FIG. 1, an insulating substrate and a reflective case were prepared respectively and fixed to each other with an epoxy adhesive or the like. The case may be integrally molded. Figure 8
FIG. 9 shows an example of a semiconductor light emitting device in which an insulating substrate and a reflection case are integrally molded, and FIG. 9 shows an example of a manufacturing process diagram of this semiconductor light emitting device.

In FIG. 9, first, metal members 91, 91 'having U-shaped cross-sections serving as electrode portions are placed in a lower mold M ₂ having a rectangular recess 92 serving as a substrate portion (see FIG. )). Then, the upper mold M ₁ in which the projection 94 having a diameter continuously reduced in the downward direction is formed at the center of the rectangular recess 93 is formed into the lower mold M _2.
(See FIG. 2B). At this time, irregularities corresponding to the wrinkles are formed at predetermined positions on the outer periphery of the protrusion 94. The resin injection hole 9 is provided in the space formed by the upper mold M ₁ and the lower mold M _2.
Resin is injected from 5 ((c) in the same figure). And after cooling,
The insulative substrate integrally formed with the reflection case is taken out from the mold ((d) in the figure). Next, the semiconductor light emitting element 3 is bonded to one metal member 91 exposed on the bottom surface of the mortar-shaped recess 96, and the upper electrode of the semiconductor light emitting element 3 and the other metal member 91 ′ are bonded by the bonding wire 4. Connect ((e) in the figure). Then, the translucent resin 6 such as an epoxy resin is poured into the mortar-shaped recess 96 and cured by heating ((f) in the same figure).

Applications of the semiconductor light emitting device of the present invention include:
Examples thereof include a backlight of a liquid crystal display device, a point light source in a device for optical fiber communication, a photocoupler, etc., and a display in a home electric appliance.

[0027]

In the semiconductor light emitting device of the present invention, since the wrinkles are formed on at least a part of the contact surface of the reflective case with the translucent resin, peeling of the translucent resin from the reflective case can be effectively prevented. .

By forming the embossments formed in the reflective case at least in the opposing region of the side surface of the semiconductor light emitting element, it is possible to suppress the unevenness of the luminous intensity of the light emitted from the device while improving the adhesiveness between the translucent resin and the reflective case. .

When the unevenness of the texture is 12 μm or more or the pitch between the textures is 20 μm or less, the translucent resin can be further prevented from peeling from the reflection case.

Further, if the insulating substrate and the reflection case are integrally formed, the productivity of the device can be improved.

If a liquid crystal polymer is used as the material of the reflective case and an epoxy resin is used as the translucent resin,
Excellent heat resistance and low thermal expansion are obtained, and further high translucency is obtained.

[Brief description of drawings]

FIG. 1 is a side sectional view showing an example of a semiconductor light emitting device of the present invention.

FIG. 2 is a plan view showing another example of the semiconductor light emitting device of the present invention.

FIG. 3 is a diagram showing an alignment characteristic of luminous intensity in a plan view of the semiconductor light emitting device of FIG.

FIG. 4 is a side sectional view showing another example of the semiconductor light emitting device of the present invention.

FIG. 5 is a diagram showing uneven steps and pitches of grain.

FIG. 6 is a plan view showing an intermediate body in the manufacturing process.

FIG. 7 is a process diagram showing mounting of a reflection case and sealing with a translucent resin.

FIG. 8 is a perspective view showing an example of a semiconductor light emitting device in which an insulating substrate and a reflection case are integrally molded.

FIG. 9 is an example of a manufacturing process diagram of the semiconductor light emitting device of FIG.

FIG. 10 is a side sectional view showing an example of a conventional semiconductor light emitting device.

FIG. 11 is a diagram showing an alignment characteristic of luminous intensity in a plan view of the semiconductor light emitting device of FIG.

[Explanation of symbols]

1 Insulating substrate 2,2 'electrode part 3 Semiconductor light emitting device 4 Bonding wire 5,5 ', 5 "reflective case 6 Translucent resin 51 grain

Claims (6)

[Claims] 1. A semiconductor light emitting device is mounted on an electrode portion formed on a surface of an insulating substrate, and a reflection case for reflecting light from the semiconductor light emitting device is provided on the insulating substrate. A semiconductor light-emitting device having an inside sealed with a translucent resin, wherein a wrinkle is formed on at least a part of a contact surface of the reflective case with the translucent resin. 2. The embossment is formed in at least a facing region of a side surface of the semiconductor light emitting element of the reflective case.
The semiconductor light-emitting device described. 3. The semiconductor light emitting device according to claim 1, wherein the unevenness of the unevenness is 12 μm or more. 4. The semiconductor light emitting device according to claim 1, wherein the pitch between the textures is 20 μm or less. 5. The semiconductor light emitting device according to claim 1, wherein the insulating substrate and the reflection case are integrally molded. 6. The semiconductor light emitting device according to claim 1, wherein a liquid crystal polymer is used as a material of the reflective case, and an epoxy resin is used as the translucent resin.