Semiconductor device manufacturing: process – Packaging or treatment of packaged semiconductor
Reexamination Certificate
2000-04-17
2001-11-27
Nelms, David (Department: 2818)
Semiconductor device manufacturing: process
Packaging or treatment of packaged semiconductor
C257S678000
Reexamination Certificate
active
06323059
ABSTRACT:
The present invention relates to a semiconductor device including a semiconductor element disposed on a mounting board and a package having the mounting board, and fabrication methods thereof.
At present, semiconductor light emitting devices are being used in various industrial fields. Such a semiconductor light emitting device is generally configured such that a semiconductor light emitting element is contained in a package. The package is adapted to achieve simple handling and protection of the light emitting element, and to efficiently radiate heat generated in the light emitting element upon operation of the light emitting device. In recent years, there have been strong demands to develop a high output semiconductor light emitting device, and to develop a semiconductor light emitting device for emission of green light using a compound semiconductor composed of a compound containing a group II element and a group VI element or a semiconductor light emitting device for emission of blue color using a compound semiconductor composed of a nitride containing nitrogen and a group III element. To meet such demands, a power supplied to the light emitting element tends to be increased, with a result that the amount of heat generation from the light emitting element becomes far larger. From this viewpoint, it is expected to enhance the heat radiation effect by means of the package for radiating the heat generation from the light emitting element.
FIG. 1
shows a related art semiconductor light emitting device having a configuration in which a semiconductor light emitting element
2220
is disposed via a sub-mount
2219
made from an insulator on a conductive mounting board
2213
made from a metal (see Japanese Patent Laid-open No. Hei8-321655). Such a semiconductor light emitting device is advantageous in that electrical connection to the semiconductor light emitting element can be easily performed by providing suitable wires on the sub-mount
2219
. Specifically, the technique disclosed in this document is particularly effective for a semiconductor light emitting device in which a semiconductor light emitting element using a compound semiconductor composed of a nitride containing a group III element is formed on an insulating substrate and a p-side electrode and an n-side electrode are both provided on the side, opposed to the insulating substrate, of the light emitting element. Since the sub-mount
2219
is connected to the semiconductor light emitting element
2110
, the p-side electrode and the n-side electrode may be connected to pins by way of the sub-mount
2219
, to thereby make the area required for wire bonding large on the sub-mount
2219
. A current can be injected into the semiconductor light emitting device from the p-side electrode and the n-side electrode connected to the two pins shown in
FIG. 1
via the sub-mount
2219
.
FIG. 2
shows an other related art method for electrical connection of a semiconductor light emitting device including a semiconductor light emitting element using a compound semiconductor composed of a nitride containing a group III element. Referring to
FIG. 2
, a p-side electrode of the semiconductor light emitting device is connected to a left pin and an n-side electrode thereof is connected to a third pin (not shown) via a sub-mount
2129
and a conductive mounting board
2121
. With this electrical connection, a current can be injected into the semiconductor light emitting device. Further, a photodetector (not shown) for monitoring optical output of the semiconductor light emitting device is disposed on the conductive mounting board
2121
, wherein a first electrode of the photodetector is connected, together with the semiconductor light emitting device, to the common third pin not shown, and a second electrode of the photodetector is connected to a right pin. With this configuration, the optical output of the semiconductor light emitting device can be monitored by the photodetector.
The above-described technique, however, has a problem. Since an insulator is lower in both thermal conductivity and electrical conductivity than a metal, the p-side electrode and the n-side electrode provided on the same side are prevented from being short-circuited by using the insulating sub-mount
2219
or
2129
, however, the heat radiation characteristic of the device is reduced. As a result, the temperature of the semiconductor light emitting element is raised, thereby degrading the stable operation and reliability of the device for a long-period of time.
A known semiconductor device of this type is configured such that a wiring portion is formed on a flat surface of a conductive board via a thin insulating film, and a p-side electrode of a semiconductor light emitting element is connected to the conductive board and an n-side electrode of the element is connected to the wiring portion. Such a semiconductor device, however, is disadvantageous in that since the wiring portion is formed on the conductive board via the thin insulating film, it is impossible to ensure the sufficient insulation of the wiring portion from the conductive board.
SUMMARY OF THE INVENTION
An object of the present invention is to provide a semiconductor device and a package, which are capable of ensuring a high heat radiation effect while preventing short-circuit between electrodes, and fabrication methods thereof.
To achieve the above object, according to a first aspect of the present invention, there is provided a semiconductor device including a conductive mounting board having a recessed portion and a projecting portion disposed on said conductive mounting board; an insulating mounting board disposed on said recessed portion of said conductive mounting board; and a semiconductor element having one portion disposed on said conductive mounting board and the other portion disposed on said insulating mounting board. With this configuration, it is possible to ensure electrical insulation of the semiconductor element and radiate heat generated in the semiconductor element via the conductive mounting board, and hence to suppress temperature rise of the semiconductor element and thereby ensure a stable operational state of the device for a long-period of time. As a result, it is possible to improve the reliability of the semiconductor device.
In this semiconductor device, preferably, the first electrode is disposed on a portion, on the side where the active layer is provided, of the first conduction type semiconductor layer and the second electrode is disposed on a portion, on the side opposed to the active layer, of the second conduction type semiconductor layer; and also the first electrode is disposed on the insulating mounting board and the second electrode is disposed on the conductive mounting board. With this configuration, it is possible to shorten the distance between the active layer and the conductive mounting board and hence to positively radiate heat generated in the active layer via the conductive mounting board. As a result, it is possible to suppress temperature rise of the semiconductor element and to prevent short-circuit between the first electrode and the second electrode of the semiconductor element.
In the semiconductor device, preferably, the semiconductor element is configured such that a plurality of the light emitting portions are formed on the same substrate. With this configuration, it is possible to radiate heat generated in each active layer via the conductive mounting board, and hence to suppress thermal interference between the light emitting portions. As a result, it is possible to suppress an increase in threshold current and a reduction in luminous efficiency in each light emitting portion, and hence to ensure a high quality of the device for a long-period of time.
In the semiconductor device, a separating portion is preferably provided on the conductive mounting board at a position between the recessed portion and the projecting portion. With this configuration, it is possible to more effectively ensure the insulation of the semiconductor element.
In
Ozawa Masafumi
Tojo Tsuyoshi
Yoshida Hiroshi
Nelms David
Sonnenschein Nath & Rosenthal
Sony Corporation
Vu David
LandOfFree
Method of fabricating a semiconductor device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of fabricating a semiconductor device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of fabricating a semiconductor device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2618208