JP2001203396A - Light irradiation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the heat radiation characteristic of a light irradiation device where an optical semiconductor element is fitted to a printed board, and to provide a high light-emission efficiency, small size, and high mountability of an optical semiconductor device. SOLUTION: The optical semiconductor element is sealed with a resin to be turned to a lens as an individual part 56, for improved mountability on a substrate 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light irradiation device.

[0002]

2. Description of the Related Art When it is necessary to irradiate a large amount of light, an electric lamp or the like is generally used. However, the optical element 2 may be mounted on the printed circuit board 1 as shown in FIG.

This optical element is mainly a light emitting diode (Light Emitting Diode) formed of a semiconductor, but a semiconductor laser or the like is also conceivable.

The light emitting diode 2 is provided with two leads 3 and 4, and one lead 3 has a back surface (anode electrode or cathode electrode) of the light emitting diode chip 5.
The other lead 4 is electrically connected to an electrode (cathode electrode or anode electrode) on the chip surface via a thin metal wire 6. Further, a transparent resin sealing body 7 for sealing the leads 3 and 4, the chip 5 and the fine metal wire 6 is formed also as a lens.

On the other hand, the printed circuit board 1 is provided with electrodes 8 and 9 for supplying power to the light emitting diode 2, and the leads 3 and 4 are provided in through holes provided therein.
Is inserted, and the light emitting diode 2 is fixed and mounted via solder or the like.

For example, Japanese Patent Application Laid-Open No. 9-252651 describes a light irradiation device using this light emitting diode.

However, the aforementioned optical semiconductor device 2
Is composed of a package in which the resin sealing body 7, the leads 3, 4 and the like are incorporated. Therefore, there is a disadvantage that the size of the mounted substrate 1 is large and the weight is heavy. In addition, there is a problem that the temperature rises as a whole because the heat radiation of the substrate itself is poor. For this reason, there has been a problem that the temperature of the semiconductor chip itself also rises, and the driving capability decreases.

The light emitting diode 5 emits light also from the side surface of the chip, and there is light traveling toward the substrate 1. However, since the substrate 1 is a printed circuit board, there is also a problem that high efficiency of emission of all light cannot be emitted upward.

Therefore, a structure as shown in FIG. 10 has been considered. This has already been filed in Japanese Patent Application No. 11-162508.

This structure prevents the temperature of the mounted light emitting diode 15 from increasing by employing the metal substrate 11.

Then, the light emitting diodes 15 are connected in series between the electrode 30 and the electrode 31,
Are constant.

[0012] Ten electrodes are formed between the electrode 30 and the electrode 31, and the back surface of the chip serving as the cathode electrode (or anode electrode) of the light emitting diode is fixed to the electrode 32, and the anode electrode (or cathode electrode) is fixed. And the electrode 30 are connected by the thin metal wire 17. The back surface of the chip of the second light emitting diode is fixed to the electrode 33, and the electrode on the chip surface and the electrode 32 are connected by a thin metal wire. That is, the electrode to which the chip back surface serving as the cathode electrode (or the anode electrode) is fixed is connected to the thin metal wire extending from the anode electrode (or the cathode electrode) of the next light emitting diode. By repeating this connection form, a series connection is realized. In addition, in order to use the electrode made of copper foil as a reflection plate, the surface is coated with Ni. Further, in order to make the entire substrate substantially a reflection plate, 12 electrodes from the right electrode 30 to the left electrode 31 are used. And is patterned so as to be substantially completely covered with.

According to this structure, the heat generated from the light emitting diode 15 is radiated through the metal substrate 11 and has a merit that a larger driving current for the light emitting diode 15 can be obtained. Furthermore, since the metal substrate 11 is covered with Ni to form the lens 19, the light emitted from the light emitting diode 15 can be efficiently emitted upward.

FIG. 11 shows a specific structure of the lens. In order to form the lens by solidifying the fluid resin and to form the lens in a convex shape, the flow preventing means 20 is formed in a ring shape, and the resin is placed in the ring-shaped flow preventing means 20. It was formed by coating. In addition, a second lens 22 is formed on the first lens 21 in order to efficiently collect light from the light emitting diode 15.

[0015]

However, in the above-described structure, the flow prevention means 20 is formed by applying a dispenser to each of the light emitting diodes 15 mounted on one metal substrate 11, and furthermore, the flow prevention means is formed. Since the resin constituting the lens is coated and cured in the dispenser 20 with a dispenser, the time required for this step is extremely long.

Further, when one of the light emitting diodes 15 fails, the entire substrate 11 must be replaced.

[0017]

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and firstly, an optical semiconductor element mounted on a substrate and a transparent element which seals the optical semiconductor element and serves as a lens. In a light irradiation device having a resin, the problem is solved by configuring the optical semiconductor element as individual components including the transparent resin.

Second, a first electrode and a second electrode provided on a substrate are electrically connected to a cathode electrode or an anode electrode on a back surface of the first electrode, and the first electrode and the second electrode are connected to the second electrode. In a light irradiation device including a plurality of optical semiconductor elements to which the anode or cathode electrode in the table is electrically connected, and a lens for condensing light emitted from the optical semiconductor element, the lens includes the lens. A first conductive electrode electrically connected to the cathode electrode or the anode electrode, the first conductive electrode being electrically connected to the cathode electrode or the anode electrode, and being electrically connected to the anode electrode or the cathode electrode. This is solved by exposing the connected second conductive electrode and fixing the first conductive electrode and the first electrode, and the second conductive electrode and the second electrode.

Third, a first electrode and a second electrode provided on a substrate, and a cathode electrode or an anode electrode on a back surface are electrically connected to the first electrode, and the second electrode is connected to the second electrode. In a light irradiation device including a plurality of optical semiconductor elements to which the anode or cathode electrode in the table is electrically connected, and a lens for condensing light emitted from the optical semiconductor element, the lens includes the lens. The optical semiconductor element and a cup-shaped reflecting means for reflecting the light of the optical semiconductor element upward are sealed to form an individual part, and the back surface is electrically connected to the cathode electrode or the anode electrode. A first conductive electrode, a second conductive electrode electrically connected to the anode electrode or the cathode electrode is exposed, and the first conductive electrode and the first electrode; the second conductive electrode and the second conductive electrode; Electrode Solves by being secured.

By preparing them as individual components, the manufacturing time of the light irradiation device can be greatly reduced. Also, even if some of the optical semiconductor elements mounted on the substrate are destroyed, each of the destroyed optical semiconductor elements can be individually replaced because they are prepared as individual components.

Further, by incorporating the reflecting means into the individual parts together, the manufacturing process of the light irradiation apparatus can be greatly simplified.

Fourth, the reflecting means includes a first reflecting electrode electrically connected to the cathode electrode or the anode electrode, and a second reflecting electrode electrically connected to the anode electrode or the cathode electrode. The first reflective electrode is fixed to a first conductive electrode, and the second reflective electrode is fixed to a second conductive electrode.

Fifth, the reflecting means includes a first reflecting electrode electrically connected to the cathode electrode or the anode electrode, and a second reflecting electrode electrically connected to the anode electrode or the cathode electrode. The first reflection electrode and the second reflection electrode are configured to be exposed by being exposed from the lens.

Sixth, the problem is solved by providing the side surface of the individual component with a horizontal plane for position recognition.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present light irradiating apparatus comprises a plurality of optical semiconductor elements having an anode electrode and a cathode electrode mounted on a substrate, and is connected in series with a light irradiating apparatus in which the optical semiconductor elements are connected in parallel. It is roughly divided into connected light irradiation devices.

First, a light irradiation device in which light emitting diodes 15 as optical semiconductor elements are connected in parallel will be described with reference to FIG. In this structure, the first electrode 13 and the second electrode 14 cover almost the entire area of the hybrid integrated circuit board 11, and a light emitting diode 15 is connected in parallel between the two electrodes 13 and 14. Have been.

The above-mentioned hybrid integrated circuit board 11 is made of Al,
The reason why Cu or Fe or the like is considered and the above-mentioned metal material is used as the hybrid integrated circuit board is as follows. First, the heat generated from the optical semiconductor element can be efficiently released to the outside. The feature is that the temperature rise of the optical semiconductor element can be prevented and the driving capability can be improved. Second
In addition, due to the flatness and smoothness of the substrate, light other than light emitted upward can be efficiently reflected and directed upward. Thirdly, it is excellent in processing of screw holes for mounting, processing of parabolic surfaces and the like.

In the present invention, Al is adopted in consideration of workability and lightness. In this case, an oxide is formed on the surface by anodic oxidation to improve insulation, and an insulating resin 12 is formed thereon. The oxide film may be omitted, or may be covered with an insulating film made of another inorganic substance instead of the oxide. Hybrid integrated circuit board 1
1 has conductivity, the insulating resin 12 is applied to the entire surface in consideration of a short circuit with the first electrode 13 and the second electrode 14 provided thereon, and the slit SL is substantially 1 mm or less. Is formed.

The electrodes 13, 14 are made of, for example, Cu, and function as wiring, lands, bonding pads, fixing pads for external leads, and the like. And the first
A light emitting diode 15 prepared as an individual component of the present invention is fixed between the electrode 13 and the second electrode 14.
The light emitting diode 15 as an individual component will be described later. The back surface of the light emitting diode 15 has two types, a cathode type and an anode type. FIG. 7 shows a cathode type. In this case, it is possible to mount an optical semiconductor device having an anode on the back surface only by changing the direction of the DC power supply.

Here, a plurality of light emitting diodes 15 are scattered on the metal substrate in order to function as an irradiation device.

Although the driving circuit of the light emitting diode is realized on another substrate, the driving circuit may be formed on the metal substrate 11. In this case, wiring, lands, bonding pads, external electrical connection pads, and the like are patterned around the substrate, particularly at the corners and in the vicinity thereof, and components such as chip capacitors, chip resistors, and printed resistors are provided between the wirings. A transistor, a diode, an IC, and the like are provided.
Here, a packaged element may be mounted, but a bare chip is superior in terms of heat dissipation and mounting area.

This circuit element is electrically fixed via solder, silver paste, or the like, or a printed resistor is formed by screen printing or the like. Further, in order to electrically connect the semiconductor chip and wiring, a thin metal wire is used between an electrode on the chip and a bonding pad. External leads are electrically connected to the pads via solder if necessary. Also, due to implementation issues,
At least two screw holes may be provided on both sides of the substrate.

The pattern of Cu on the metal substrate 11 is
The flexible sheet may be attached to an insulating flexible sheet, and the flexible sheet may be attached to a hybrid integrated circuit board.

As described above, a film of the insulating resin 12 is applied on the entire surface of the metal substrate 11, and the two electrodes 13 and 14 are provided so as to bisect the metal substrate 11.
i has been deposited. Since the light reflection efficiency is reduced due to the prevention of Cu oxidation and the oxidation of Cu, it is relatively hard to be oxidized, has excellent light reflectivity, and in consideration of the bonding property with a fine metal wire, glossy Ni is employed. . With this structure, the entire area of the metal substrate 11 is used as a light reflecting plate.

Accordingly, a predetermined voltage is applied to the light emitting diode 15 prepared as an individual component, and the light emitting diode 1
When a current flows through 5, the light emitting diode 15 emits light, and can emit light upward including light reflected from a metal substrate serving as a light reflecting plate.

As shown in FIG. 7, the light emitting diodes 15 are connected in parallel between the first electrode 13 and the second electrode 14. However, since the surface of the second electrode 14 employs Ni, this parallel type has a problem that the contact resistance of the thin metal wire 17 varies. Therefore, there is a problem that current concentrates on the light emitting diode having a small contact resistance among the many light emitting diodes 15, and a specific light emitting diode becomes abnormally bright or is broken.

For this reason, as shown in FIG. 8, a series connection structure has been considered. Light emitting diodes 15..., Which are individual components, are connected in series between the electrode 30 and the electrode 31 to keep the current value passing through the light emitting diodes 15.

[0038] Ten electrodes are formed between the electrode 30 and the electrode 31, and a cathode electrode (or an anode electrode) of the light emitting diode is electrically connected to the electrode 32, and the anode electrode (or the cathode electrode) is connected. It is electrically connected to the electrode 30. Further, the cathode (or anode) of the second light emitting diode is electrically connected to the electrode 33, and the anode (or cathode) is electrically connected to the electrode 32. That is, the electrode on the substrate to which the electrode on the back surface of the individual component serving as the cathode electrode (or the anode electrode) is fixed is connected to the electrode of the individual component serving as the anode electrode (or the cathode electrode) of the next light emitting diode. By repeating this connection form, a series connection is realized. Also in this case, since the electrode made of copper foil is used as a reflection plate, the surface is coated with Ni, and in order to make the entire substrate substantially a reflection plate, 12 electrodes from the right electrode 30 to the left electrode 31 are used.
It is patterned so as to be completely covered by the individual electrodes. Of course, some gaps (slits SL) are formed so that they are separated in a pattern.

According to this structure, the current flowing in each of the light emitting diodes connected in series theoretically has the same value, so that all the light emitting diodes emit the same light.

The connection mode of the parallel connection and the series connection has been described above. Conventionally, as described with reference to FIG. 11, after the flow prevention means 20 is formed on the metal substrate 11, the flow prevention means 20 is formed. Are formed by applying the transparent resin of the lenses 21 and 22 to the inside. However, since the number of the light emitting diodes 15 is large and the size of the metal substrate 11 is large, there is a problem that the manufacturing process becomes extremely long.

In view of this point, the present invention has realized the shortening of the manufacturing time by preparing individual parts as shown in FIGS. If previously prepared as individual parts, as shown in FIGS. 7 and 8, the electrodes 14, 15 or the electrodes 30.
When the individual components are mounted on the metal substrate on which is formed, the light irradiation device can be manufactured in a short time.

FIG. 1 will now be described. 1A is a plan view, and FIG. 1B is a cross-sectional view taken along line AA. Code 5
Reference numeral 0 denotes a first conductive electrode to which the back surface of the optical semiconductor element 52 is fixed, and reference numeral 53 denotes a second conductive electrode to which a thin metal wire 54 connected to the surface of the optical semiconductor element 52 is connected. The first conductive electrode 50, the second conductive electrode 53, the optical semiconductor element 52, and the fine metal wire 54
The optical semiconductor device 56 is covered with a resin 55 that transmits light emitted from the optical device 2 and is an individual component. This optical semiconductor device 5
6, the back surface of the first conductive electrode 50 and the back surface of the second conductive electrode 53 are exposed, and the resin 55 is convex upward in order to collect as much light from the optical semiconductor element 52 as possible and emit the light upward. Lens shape. Therefore, as shown in FIG. 1a, when viewed from above, it has a substantially circular shape.

FIG. 2 shows the resin 55 of FIG. 1 having a planar shape. This plane is formed by a plane perpendicular to the metal substrate, and by doing so, the mounting apparatus holding the individual components can recognize the position of this plane, thereby increasing the mounting accuracy on the mounting board. it can. Except for this, the configuration is substantially the same as that of FIG.

FIG. 3 shows a structure in which four surfaces perpendicular to the metal substrate are provided so that the component holding means of the mounting apparatus can easily hold the components. The portion that seals the optical semiconductor element 52 is formed of a rectangular parallelepiped, on which a hemispherical lens 55 is integrally formed.

FIG. 4 shows a case where light from the optical semiconductor element 52 is condensed,
The reflecting means RF is employed for the purpose of firing upward. 4A is a plan view, and FIG. 4B and FIG.
FIG. 4B is a cross-sectional view corresponding to line AA of FIG. 4A, in which electrodes exposed from the sealing body are slightly different. FIG. 4
d is a perspective view for explaining the structure of the reflection means RF.

First, the reflecting means RF has a cup-like shape, and the side face of the reflecting means RF is inclined to reflect light emitted from the side face of the optical semiconductor element 52 upward. Then, the optical semiconductor element 52 is mounted in the reflection means RF, and the reflection means RF is used as an electrode. Therefore, the reflection means RF includes the first reflection electrode 60 and the second reflection electrode 61.
It consists of two. The first reflection electrode 60 is electrically fixed on the back surface of the optical semiconductor element with a brazing material, a conductive paste, or the like, and the second reflection electrode 61 is a thin metal wire connected to the electrode on the front surface of the optical semiconductor element. 54 are electrically connected.

As described above, the first reflection electrode 60 and the second reflection electrode 61 are electrically separated from each other, and the whole is formed in a cup shape, so that individual parts including the reflection means RF can be formed. .

FIG. 4B shows that the first conductive electrode 50 and the second conductive electrode 53 are exposed from the back surface of the individual component, and the first reflective electrode 60 is formed on the first conductive electrode 50 by a brazing material or the like. The second reflective electrode 61 is electrically fixed on the second conductive electrode 53 with a conductive paste or the like.

On the other hand, FIG. 4C shows a case where the first conductive electrode 50 and the second conductive electrode 53 are omitted, and the first reflective electrode 60 and the second reflective electrode 61 are exposed from the back surface of the individual component. It is.

In FIG. 4, since the connecting portion of the thin metal wire 54 and the reflecting surface are integrally formed, it is necessary to electrically separate the connecting portion and the reflecting surface is provided with a slit. However, since this slit does not contribute as a reflection surface, there is a problem that the light emission intensity is reduced.

FIG. 5 is a view in which the slit is removed from the reflecting surface in consideration of the above problem. That is, the pad electrode 70 is formed in an island shape on the bottom surface of the reflection means RF, and the thin metal wire 54 is connected to the pad electrode 70. In this way, since no slit is formed on the reflection surface of the reflection means RF, the reflection efficiency can be increased accordingly.

In FIGS. 4 and 5, if a structure is used in which the resin is not provided on the back surface of the reflection means RF and the structure is exposed to the outside atmosphere, the heat of the optical semiconductor element can be released through the reflection surface. Can be.

Finally, a mounting method will be described with reference to FIG. Reference numeral 56 denotes an individual component (optical semiconductor device) in FIG. 3, and the first conductive electrode 50 and the second conductive electrode 53 of the first optical semiconductor device 56a are connected to the electrodes 80 and 8 on the metal substrate 11.
Connected to 1. Also, the first optical semiconductor device 56b
Conductive electrode 50 and second conductive electrode 53 are
Connected to upper electrodes 81 and 82. Further, the first conductive electrode 50 and the second conductive electrode 53 of the third optical semiconductor device 56b are connected to the electrodes 82 and 83 on the metal substrate 11. Further, the interval between the first conductive electrode 50 and the second conductive electrode 53 is formed wider than the interval between the slits SL on the substrate, thereby preventing a short circuit.

[0054]

As is apparent from the above description, since the optical semiconductor elements are arranged in a matrix on a metal substrate and used as a light irradiation device, the optical semiconductor elements are prepared as individual parts. Is fixed, the manufacturing process is simplified, and the manufacturing time can be greatly reduced.

Further, by forming a surface for position recognition on the individual component, the mounting accuracy by the mounting apparatus can be improved.

Further, since the lens and the reflecting means can be integrally formed, most of the light can be emitted upward, and a light irradiation device having excellent luminous efficiency can be realized.

Further, conventionally, if at least one of a plurality of optical semiconductor devices mounted on a substrate fails, it is necessary to replace the entire substrate. In the present invention, however, the optical semiconductor device is an individual component. Therefore, only the corresponding optical semiconductor device on the metal substrate can be replaced.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating individual components of the present invention.

FIG. 2 is a diagram illustrating individual components of the present invention.

FIG. 3 is a diagram illustrating individual components of the present invention.

FIG. 4 is a diagram illustrating individual components of the present invention.

FIG. 5 is a diagram illustrating individual components of the present invention.

FIG. 6 is a diagram illustrating a mounting structure of an individual component.

FIG. 7 is a diagram illustrating a mounting structure of an individual component.

FIG. 8 is a diagram illustrating a mounting structure of an individual component.

FIG. 9 is a diagram illustrating a conventional light irradiation device.

FIG. 10 is a diagram illustrating a conventional light irradiation device.

FIG. 11 is a diagram illustrating a mounting structure of a conventional optical semiconductor element.

[Explanation of symbols]

 Reference Signs List 11 metal substrate 13 first electrode 14 second electrode 15 light emitting diode 19 lens 50 first conductive electrode 52 optical semiconductor element 53 second conductive electrode 60 first reflective electrode 61 second reflective electrode 70 pad electrode RF Reflecting means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5E315 AA03 CC01 CC15 DD25 GG01 5E336 AA04 BB01 CC32 CC57 EE07 GG03 GG25 5F041 AA33 AA42 DA02 DA03 DA07 DA12 DA20 DA43 DB09 DC07 DC23 DC66 DC84 EE17 EE23 FF16

Claims (6)

[Claims] 1. A light irradiation device comprising an optical semiconductor element mounted on a substrate and a transparent resin that seals the optical semiconductor element and serves as a lens, wherein the optical semiconductor element also includes a transparent resin. A light irradiation device characterized by being constituted by individual parts, including: 2. A first electrode and a second electrode provided on a substrate, and a cathode electrode or an anode electrode on a back surface is electrically connected to the first electrode. A light irradiation device comprising: a plurality of optical semiconductor elements to which an anode electrode or a cathode electrode is electrically connected; and a lens for condensing light emitted from the optical semiconductor element, wherein the lens is the optical semiconductor A first conductive electrode electrically connected to the cathode electrode or the anode electrode, and a rear surface of the lens is electrically connected to the anode electrode or the cathode electrode. A light irradiation device, wherein the second conductive electrode is exposed, and the first conductive electrode and the first electrode are fixed, and the second conductive electrode and the second electrode are fixed. 3. A first electrode and a second electrode provided on a substrate, and a cathode electrode or an anode electrode on a back surface is electrically connected to the first electrode. A light irradiation device comprising: a plurality of optical semiconductor elements to which an anode electrode or a cathode electrode is electrically connected; and a lens for condensing light emitted from the optical semiconductor element, wherein the lens is the optical semiconductor The device and a cup-shaped reflecting means for reflecting the light of the optical semiconductor device upward are sealed to form an individual component, and on the back surface, a first electrode electrically connected to the cathode electrode or the anode electrode. A conductive electrode, a second conductive electrode electrically connected to the anode electrode or the cathode electrode is exposed, the first conductive electrode and the first electrode, the second conductive electrode and the second electrode But solid Light irradiation apparatus characterized in that it is. 4. The reflection means includes: a first reflection electrode electrically connected to the cathode electrode or the anode electrode;
A second reflective electrode electrically connected to the anode electrode or the cathode electrode; the first reflective electrode is fixed to a first conductive electrode; and the second reflective electrode is a second reflective electrode. The light irradiation device according to claim 3, wherein the light irradiation device is fixed to the conductive electrode. 5. The reflection means includes: a first reflection electrode electrically connected to the cathode electrode or the anode electrode;
A second reflection electrode electrically connected to the anode electrode or the cathode electrode, wherein the first reflection electrode and the second reflection electrode are exposed from the lens. Item 4. A light irradiation device according to Item 3. 6. The light irradiation device according to claim 1, wherein the side surface of the individual component has a horizontal plane for position recognition.