This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2012-112747, filed on May 16, 2012; the entire contents of which are incorporated herein by reference.
Embodiments are related generally to a semiconductor light emitting device.
The semiconductor light emitting device are going to be widely used as small-sized and easily handled light source, which includes a semiconductor light emitting element and a fluorescent substance, and emits visible light such as white light or light in other wavelength bands. For example, most packages that house semiconductor light emitting elements have a resin body formed using a special metal mold and leads extending from the resin body. A plurality of resin bodies are formed on a single lead frame sheet and then, each individual semiconductor light emitting device is manufactured by bending and cutting their respective leads.
Thus, a space occupied by the leads that extend from the resin bodies restricts the number of semiconductor devices made from a single lead frame, thereby limiting the improvement of productivity and the reduction of cost. In addition, the cost of the special metal molds may occupy a large portion of the manufacturing cost. Therefore, it is necessary for the semiconductor light emitting device to have the package suitable for increasing the productivity and reducing the manufacturing cost.
According to an embodiment, a semiconductor light emitting device includes an insulating base and a semiconductor light emitting element and resin. The insulating base includes a first face, a second face on a side opposite to the first face, and a side face connecting to the first face and the second face, a recess portion being provided on the side face extending from the first face to the second face. The insulating base also includes a first metal layer provided on the first face and blocking an opening of the recess portion, a second metal layer provided on an inner face of the recess portion, and a third metal layer provided on the second face, the third metal being electrically connected to the first metal layer via the second metal layer. A semiconductor light emitting element is fixed on the first face; and resin covers the first face and seals the semiconductor light emitting element, the resin transmitting at least part of light emitted from the semiconductor light emitting element.
Embodiments of the invention will now be described with referring to the drawings. Note that like elements in the drawings are denoted with like numerals, and detailed descriptions thereof are appropriately omitted while describing different elements.
The semiconductor light emitting device 100 includes an insulating base 10, a semiconductor light emitting element 20, and resin 30 that seals the semiconductor light emitting element 20. In other words, the semiconductor light emitting device 100 has a configuration in which the semiconductor light emitting element 20 is housed in a package that includes the base 10 and the resin 30.
The base 10 includes a first face 10a, a second face 10b on a side opposite the first face 10a, and a side face 10c that contacts the first face 10a and the second face 10b. The side face 10c of the base 10 is provided with a recess portion 17 that extends from the first face 10a to the second face 10b.
As illustrated in
The outer electrode 7a is provided blocking an opening of the recess portion 17. A metal layer 33 (second metal layer), for example, is provided on an inner face of the recess portion 17 as described later. Also, the outer electrode 7b blocks an opening of a recess portion 17 provided on a side face 10d on a side opposite the side face 10c.
As illustrated in
The semiconductor light emitting element 20 is fixed to the mount bed 5a provided on the first face 10a. For example, electrically conductive paste or adhesive can be used for fixing (die bonding) the semiconductor light emitting element 20.
The semiconductor light emitting element 20 is for example a light emitting diode (LED), having a p electrode and an n electrode on the upper surface. In the following, a first electrode 20a and a second electrode 20b are indicated, but in each case they may be a p electrode and an n electrode. The first electrode 20a is connected to the electrode 3 via a metal wire 9a, and the second electrode 20b is connected to the electrode 5 via a metal wire 9b. Also, the first electrode 20a is electrically connected to the back side metal 13 via the outer electrode 7a and the metal layer 33 of the recess portion 17 (first recess portion). The second electrode 20b is electrically connected to the back side metal 15 via the outer electrode 7b and the metal layer 33 of the recess portion 17 (second recess portion).
In addition, the semiconductor light emitting element 20 is sealed in the resin 30 that covers the first face 10a. The resin 30 is a transparent resin that transmits at least a portion of the light emitted by the semiconductor light emitting element 20. Also, the resin 30 may include a fluorescent substance that emits fluorescent light, which is excited by the light emitted from the semiconductor light emitting element 20. Also, as illustrated in
Next, the resin 30 is formed on the substrate, to seal the semiconductor light emitting elements 20 (S03). For example, the resin 30 is formed to have a uniform thickness on the substrate using a silicone resin. Then, the substrate on which the resin 30 has been formed is cut using, for example, a dicing blade, and each individual semiconductor light emitting device 100 is cut out therefrom (S04). Then, the characteristics of the semiconductor light emitting devices 100 are individually checked, whereby selecting ones that satisfy a predetermined specification (S05).
As illustrated in
The dotted lines illustrated in
As illustrated in
Next, as illustrated in
Then, the metal layer 24 on the front surface 21a is processed to the pattern illustrated in
Next, as illustrated in
Next, the resin 30 and the substrate 120 are cut as illustrated in
Since the semiconductor light emitting device 100 is cut out to the size of its package, there is no space for the leads extending from the package. Therefore, the whole substrate 120 is effectively utilized, and it is possible to increase the yield of semiconductor light emitting devices 100. Also, since the special metal mold is not used in the manufacturing process, it is possible to reduce the manufacturing cost.
As illustrated in
As illustrated by the broken line in
In the substrate 140 illustrated in
Next, the process of mounting the semiconductor light emitting device 100 is described with reference to
As illustrated in
Also, the solder cream 36 climbs up along the surface of the metal layer 33 in the recess portion 17 and contacts the back face side of the outer electrode 7a, and forms a fillet 38 as illustrated in
In other words, it was difficult to form fillets 38 using the semiconductor light emitting device having mounting pads on the back face side, and therefore, difficult to improve the reliability of the mounting substrate and to carry out its repair. In this embodiment, the recess portion 17 provided in the side face of the base 10 makes it easy to form the fillet 38 in the substrate, on which the semiconductor light emitting device 100 is mounted, and may improve the reliability and the reparability thereof.
The semiconductor light emitting device 200 includes an insulating base 40, the semiconductor light emitting element 20, and resin 30 that seals the semiconductor light emitting element 20.
As illustrated in
The first electrode 20a of the semiconductor light emitting element 20 that is fixed on the mount bed 5a is connected to the electrode 3 via the metal wire 9a, and the second electrode 20b is connected to the electrode 5 via the metal wire 9b. Also, the first electrode 20a is electrically connected to the backside metal 13 via the outer electrode 7a and the metal layer 33 of the recess portion 17. The second electrode 20b is electrically connected to the backside metal 15 via the outer electrode 7b and the metal layer 33 of the recess portion 17.
The backside metal 13, 15, and 19 are provided on a second face 40b of the base 40. The backside metal 19 is provided separated from the backside metal 13 and 15, and is connected to the mount bed 43 via the through hole 35 (see
The semiconductor light emitting device 300 includes an insulating base 50, the semiconductor light emitting element 20, a protective element 55, and resin 30 that seals the semiconductor light emitting element 20 and the protective element 55. The protective element 55 is, for example, a Zener diode, that suppresses excess current flowing through the semiconductor light emitting element 20.
As illustrated in
The first electrode 20a of the semiconductor light emitting element 20 fixed on the mount bed 5a is connected to the electrode 3 via the metal wire 9a, and the second electrode 20b is connected to the electrode 5 via the metal wire 9b. Also, the first electrode 20a is electrically connected to the backside metal 13 via the outer electrode 7a and the metal layer 33 of the recess portion 17. The second electrode 20b is electrically connected to the backside metal 15 via the outer electrode 7b and the metal layer 33 of the recess portion 17.
The protective element 55 is mounted on the electrode 3, and a metal wire 9c is connected between an electrode 55a on the upper surface of the protective element 55 and the electrode 5. The protective element 55 operates by current flowing between the electrode 55a on the upper surface and a lower surface electrode. Therefore, the lower surface electrode of the protective element 55 is electrically connected to the electrode 3. Thereby, the resistance of the semiconductor light emitting device 300 to high voltages is improved, so it is possible to prevent failure due to static electricity surges.
The semiconductor light emitting device 400 includes an insulating base 60, the semiconductor light emitting element 20, the protective element 55, and resin 30 that seals the semiconductor light emitting element 20 and the protective element 55.
As illustrated in
The first electrode 20a of the semiconductor light emitting element 20 fixed on the mount bed 5a is connected to the electrode 3 via the metal wire 9a, and the second electrode 20b is connected to the electrode 5 via the metal wire 9b. Also, the first electrode 20a is electrically connected to the backside metal 13 via the outer electrode 7a and the metal layer 33 of the recess portion 17. The second electrode 20b is electrically connected to the backside metal 15 via the outer electrode 7b and the metal layer 33 of the recess portion 17.
The protective element 55 is mounted on the electrode 5, and the metal wire 9c connects between the electrode 55a on the upper surface of the protective element 55 and the electrode 3. The protective element 55 operates by current flowing between the electrode 55a on the upper surface and a lower surface electrode. Therefore, the lower surface electrode of the protective element 55 is electrically connected to the electrode 5. Thereby, the resistance of the semiconductor light emitting device 400 to high voltages, for example, is improved, so it is possible to prevent failure due to static electricity surges.
The semiconductor light emitting device 500 includes an insulating base 70, a semiconductor light emitting element 25, and resin 30 that seals the semiconductor light emitting element 25. The semiconductor light emitting element 25 emits light when current is passed between an upper surface electrode 25a and a lower surface electrode.
As illustrated in
The semiconductor light emitting element 25 is fixed to the mount bed 5a with electrically conductive paste 53. In this way, the lower surface electrode is connected to the electrode 5 via the mount bed 5a. The upper surface electrode 25a of the semiconductor light emitting element 25 is connected to the electrode 3 via the metal wire 9a. Also, the upper surface electrode 25a is electrically connected to the backside metal 13 via the outer electrode 7a and the metal layer 33 of the recess portion 17.
As illustrated in
In addition, in this embodiment, the heat of the semiconductor light emitting element 25 can be dissipated via the through hole 35, enabling high current and high output operation.
The semiconductor light emitting device 600 includes an insulating base 80, a semiconductor light emitting element 45, and resin 30 that seals the semiconductor light emitting element 45.
The semiconductor light emitting element 45 has a flip-chip construction with the first electrode and the second electrode (not illustrated in the drawings) on the lower surface of the semiconductor light emitting element 45.
As illustrated in
The semiconductor light emitting element 45 is flip-chip bonded to the electrode 3 and the electrode 5. For example, the semiconductor light emitting element 45 is fixed to the electrode 3 and the electrode 5 via solder balls or the like. In other words, the electrode 3 is connected to the first electrode via a solder ball, and the electrode 5 is connected to the second electrode via a solder ball. The first electrode is electrically connected to the backside metal 13 via the outer electrode 7a and the metal layer 33 of the recess portion 17, and the second electrode is electrically connected to the backside metal 15 via the outer electrode 7b and the metal layer 33 of the recess portion 17.
In this embodiment, there are no connections using metal wire, so the thickness of the resin 30 can be reduced. Therefore, the height of the package can be reduced.
The semiconductor light emitting device 700 includes an insulating base 90, the semiconductor light emitting element 25, and resin 30 that seals the semiconductor light emitting element 25. The semiconductor light emitting element 25 emits light when current is passed between an upper surface electrode 25a and a lower surface electrode.
As illustrated in
The semiconductor light emitting element 25 is fixed to the mount bed 5a with electrically conductive paste 53. In this way, the lower surface electrode is connected to the electrode 5 via the mount bed 5a. The upper surface electrode 25a of the semiconductor light emitting element 20 is connected to the electrode 3 via the metal wire 9a.
In the embodiment, the electrode 3 and the outer electrode 7a are separated, so there is no current path to the backside metal 13 via the outer electrode 7a and the recess portion 17. Also, the electrode 5 and the outer electrode 7b are separated, so there is no current path to the backside metal 15 via the outer electrode 7b and the recess portion 17. Therefore, the base 90 has the through hole 35 below the mount bed 5a as illustrated in
In the embodiment, the outer electrode 7a and the electrode 3 are separated from each other, and the outer electrode 7b and the electrode 5 are separated from each other. As a result, the adhesion at the interface between the resin 30 and the first face 90a of the base 90 is improved, and it is possible to suppress a penetration of solder or flux. As a result, it is possible to prevent peeling of the metal wire 9a and degradation of the semiconductor light emitting element 25.
The semiconductor light emitting device 800 includes the insulating base 10, the semiconductor light emitting element 25, and resin 30 that seals the semiconductor light emitting element 25. The semiconductor light emitting element 25 emits light when current is passed between an upper surface electrode 25a and a lower surface electrode 25.
In addition, in the embodiment, a resin layer 63 is provided between the first face 10a of the base 10 and the resin 30. The resin layer 63 is provided along the outer edge of the base 10, and has greater adhesion to the first face 10a than the resin 30.
The semiconductor light emitting element 25 is fixed to the mount bed 5a with electrically conductive paste 53. Also, the upper surface electrode 25a of the semiconductor light emitting element 25 is connected to the electrode 3 via the metal wire 9a. The electrode 3 is electrically connected to the backside metal 13 via the outer electrode 7a and the recess portion 17. On the other hand, the lower surface electrode of the semiconductor light emitting element 25 is electrically connected to the mount bed 5a via the electrically conductive paste 53. The mount bed 5a is electrically connected to the backside metal 15 via the electrode 5, the outer electrode 7b and the recess portion 17.
In the embodiment, adhesion is improved by interposing the resin layer 63 between the resin 30 and the base 10, so it is possible to suppress the penetration of solder or flux into the package.
The semiconductor light emitting device 850 includes the insulating base 10, the semiconductor light emitting element 25, and resin 30 that seals the semiconductor light emitting element 25. The semiconductor light emitting element 25 emits light when current is passed between an upper surface electrode 25a and a lower surface electrode 25.
In the embodiment, a resin layer 65 is provided between the first face 10a of the base 10 and the resin 30 covering the large part of the first face 10a of the base 10, apart from a mounting portion of the semiconductor light emitting element 25 and a bonding portion of the metal wire 9a to the electrode 3. The resin layer 65 is a white resin that includes titanium oxide or the like, that reflects light emitted from the semiconductor light emitting element 25. Also, the electrical connections between the semiconductor light emitting element 25 and the base 10 are the same as those for the semiconductor light emitting device 800.
In the embodiment, adhesion is improved by interposing the resin layer 65 between the resin 30 and the base 10, so it is possible to suppress the penetration of solder or flux into the package. In addition, the brightness may be improved by the resin layer 65 reflecting the light emitted from the semiconductor light emitting element 25.
As illustrated in
As illustrated in
An upper surface electrode of the semiconductor light emitting element 25a is connected to the electrode 71 via the metal wire 9a. On the other hand, a lower surface electrode of the semiconductor light emitting element 25a is connected to the electrode 73 via the mount bed 79, and is also connected to the backside metal 85 via the recess portion 17. Also, the semiconductor light emitting elements 25b, 25c, and 25d are connected in series between the electrode 75 and the electrode 77 via the metal wires 9b, 9c, and 9d.
For example, it is possible to control the light emitted from the semiconductor light emitting element 25a by controlling the current supplied between the backside metal 83 that is connected to the electrode 71, and the backside metal 85 that is connected to the electrode 73. Also, it is possible to control the light emitted from the semiconductor light emitting elements 25b, 25c, and 25d by controlling the current supplied between the backside metal 93 that is connected to the electrode 75, and the backside metal 95 that is connected to the electrode 77.
In this way, a plurality of semiconductor light emitting elements 25a to 25d is provided as desired, and the light emission of each may be controlled as desired via the backside metal 83, 85, 93, and 97.
As described above, the semiconductor light emitting device as illustrated in the first embodiment through the eighth embodiment can be manufactured by fixing a semiconductor light emitting element to a base, resin-sealing it, and cutting it using, for example, a dicing blade. In this way it is possible to reduce the manufacturing cost and increase the productivity. Also, it is possible to easily electrically connect an electrode provided on the first face and backside metal provided on the second face by forming the recess portion on a side face of the insulating base. In addition, a fillet can be easily formed when mounting the semiconductor light emitting device on the substrate, so it is possible to improve the reliability of the mounting. Also, it is possible to remove a device with a fault by melting a solder with heat providing through the fillet, and it is possible to repair the mounting substrate.
While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel embodiments described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the embodiments described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the invention.
Number | Date | Country | Kind |
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2012-112747 | May 2012 | JP | national |