Patent Application
20110268150
Embodiments presented herein relate generally to the area of semiconductor devices. More specifically, embodiments presented herein relate to the area of high power semiconductor device systems.
An extant galvanometric method of measuring temperature of a semiconductor junction involves use of a thermocouple that is in thermal communication with the semiconductor junction. However, the employability of this method may be limited due to electromagnetic interference between the thermocouple (which in order to provide a read-out needs to be biased), and for example, the semiconductor junction. In particular, the ability to operate the semiconductor device reliably at high voltage levels (that is, at voltage levels approaching the voltage level at which peak output of the semiconductor device is obtained) may be compromised when a thermocouple is used to monitor the temperature of the semiconductor junction. Furthermore, the presence of metallic thermocouple components in the vicinity of the semiconductor device can introduce a risk of inadvertent electrical shorting of portions of the semiconductor device.
Another extant galvanometric method of measuring temperature of a semiconductor junction involves the measurement of forward voltage changes of the semiconductor junction. However, the employability of this method may be limited since the operation of the semiconductor device needs to be interrupted in order to make the forward voltage change measurements. Furthermore, the smallness of the forward voltage changes imposes practical difficulties on their accurate measurement.
Another extant method of measuring temperature of a semiconductor junction involves the measurement of temperature of the base plate of the semiconductor device. However, the employability of this method may be limited unless an accurate thermal model of the heat conduction between the semiconductor junction and base plate is available. Furthermore, in the event of any change in the thermal link between the semiconductor device and base plate (for example, if the semiconductor device lifts off of the base plate), the accuracy of the model may be compromised.
Another extant method of measuring temperature of a semiconductor junction involves the use of an infra red camera to obtain a thermal image of the semiconductor junction. However, the employability of this method may be limited since immediate access to the semiconductor junction is usually required, which requirement imposes the condition that the semiconductor device not be encapsulated within a protective housing.
A system via which one is able to reliably monitor the temperature of a semiconductor junction without compromising the ability to operate the semiconductor device, and which system has a design that is amenable to being retro fitted within existing installations of semiconductor devices which would benefit from such monitoring, would therefore be highly desirable.
Embodiments presented herein are directed to a system comprising, a semiconductor device including a semiconductor junction, an optical fiber, a proximal end of said optical fiber in electromagnetic communication with said semiconductor junction, and a processing unit in electromagnetic communication with a distal end of said optical fiber, said processing unit capable of receiving electromagnetic information available at said distal end and processing the electromagnetic information.
Embodiments presented herein are directed to a method comprising, collecting electromagnetic information from a semiconductor junction of a semiconductor device via a proximal end of an optical fiber for transmission therealong to a processing unit via a distal end of said optical fiber, and processing, within said processing unit, the electromagnetic information received via said distal end of said optical fiber.
Embodiments presented herein are directed to a method comprising, providing an optical fiber having opposing proximal and distal ends, disposing said proximal end of said optical fiber in contact with a semiconductor junction of a semiconductor device in a manner that electromagnetic information from said semiconductor junction is received at said proximal end so as to propagate along said optical fiber, providing a processing unit configured to receive the electromagnetic information via said distal end of said optical fiber, and processing the electromagnetic information within said processing unit to estimate a temperature of said semiconductor junction.
These and other advantages and features will be more readily understood from the following detailed description that is provided in connection with the accompanying drawings.
In the following description, whenever a particular aspect or feature of an embodiment is said to comprise or consist of at least one element of a group and combinations thereof, it is understood that the aspect or feature may comprise or consist of any of the elements of the group, either individually or in combination with any of the other elements of that group.
As described in detail below, embodiments presented herein may enable monitoring of the temperature of the semiconductor junction within a semiconductor device. For example, embodiments may allow for the monitoring of semiconductor junction temperature while the semiconductor device is in operation with no untoward burden being placed upon the semiconductor device due the monitoring. The temperature of the semiconductor junction within a semiconductor device can, in some cases, provide an indication of the health of a semiconductor device and/or of the system incorporating the semiconductor device.
Quite generally therefore, embodiments of the invention include semiconductor device systems (for instance, of type 100) capable at least of obtaining and monitoring parameters related to the health of its constituent components. The semiconductor device system can include a semiconductor device (for instance, of type 102) including a semiconductor junction (for instance, of type 114). The semiconductor device system can further include an optical fiber (for instance, of type 112). The proximal end (for instance, of type 116) of said optical fiber can be in electromagnetic communication with said semiconductor junction (the immediately preceding mention of “electromagnetic communication” refers, in one instance, to the collection by the proximal end 116 of the optical fiber 112 of portion 119 of electromagnetic radiation 120 emitted by the semiconductor junction 114 as is discussed at least in context of
The proximal end 116 of the optical fiber 112 may be disposed so as to be in electromagnetic communication with the semiconductor junction 114. For example, the proximal end 116 of the optical fiber 112 may be disposed so as to be able to collect and transmit a portion 119 of electromagnetic radiation 120, which may be emitted by the semiconductor junction 114 during operation of the semiconductor device 102. In some embodiments, the proximal end 116 of the optical fiber 112 may be disposed so as to be in direct physical contact with the semiconductor junction 114.
A processing unit 122 can be in electromagnetic communication with the distal end 118 of the optical fiber 112. The processing unit 122 can be configured so as to be capable of receiving and processing electromagnetic information. For example, the processing unit 122 can include electromagnetic energy sensing elements, transducer elements, and a microprocessor disposed so as to convert able to convert and process the electromagnetic information available at said distal end 118. The distal end 118 of the optical fiber 112 may be disposed so that substantially the portion 119 of the electromagnetic radiation 120 that is transmitted through the optical fiber 112 can be presented, via the distal end 118, for reception by the processing unit 122. The processing unit 122 can then process the received electromagnetic radiation 119 to obtain for example, information about the temperature of the semiconductor junction 114.
Based on the discussions herein, those of skill in the art may recognize that semiconductor device systems (for instance, of type 100) disclosed herein are potentially capable of monitoring parameters related to the health of their constituent parts in a non-galvanometric manner. Such non-galvanometric measurements tend to present little if any electromagnetic interference burden onto the semiconductor device system on which the measurements are being made, potentially resulting thereby at least in an enhancement in one's ability to operate the semiconductor device reliably close to the design power upper limit of operation of a constituent semiconductor device of the semiconductor device system.
Embodiments of the semiconductor device system disclosed herein may present several potential enhancements over extant semiconductor device systems, as are now discussed with reference to
Since optical fibers (for instance, of type 112) can be made electrically insulating, and the protective tubing can also be electrically insulating, therefore the electrical insulation between different parts of the semiconductor device 102 may remain undisturbed at and around the location 113 wherein the protective tubing 110 and the optical fiber 112 pass through the protective layer 104. Similarly, the electrical insulation between different parts of the semiconductor device 102 may remain undisturbed at and around the location 109 wherein the protective tubing 110 and the optical fiber 112 pass through the housing 106.
Further, since the temperature of the semiconductor junction 114 is estimated based upon processing of information (that is, electromagnetic radiation; in one instance, of type 119) obtained directly from the semiconductor junction 114, and not based upon, for instance, indirect information about the semiconductor junction 114, the accuracy and reliability of the temperature measurement may be enhanced. For example, an extant method of estimating the temperature within a semiconductor device system 100 may perform an estimate of the temperature of a semiconductor junction based upon indirect measurements, such as for instance, via a thermometer that is in thermal contact with the semiconductor junction. Such an estimate would be dependent on the accuracy of the thermal model that is used to approximate the flow of heat energy between the semiconductor junction 114 and the thermometer, which accuracy may be limited by the practicalities and variability of the thermal contact condition.
Furthermore, and as also discussed earlier, since embodiments of the presently disclosed semiconductor device system are capable of monitoring parameters related to the health of their constituent parts in a non-galvanometric manner, hence the range over which the constituent semiconductor device 102 may be operated reliably when measurements (for the purposes of said monitoring) of health related parameters of any one or more parts of the semiconductor device system 100 are being performed may remain substantially unaltered from the range over which the semiconductor device 102 may be operated reliably when such measurements of health related parameters of the semiconductor device system 100 are not being performed. In other words, monitoring of health related parameters of, for instance, the semiconductor device 102, when performed via embodiments disclosed herein or their equivalents thereof, may not impose a burden on the range of operability of the semiconductor device 102. That is, the ability of the semiconductor device 102 to operate substantially across the design range of its operability may not be compromised when they are used within embodiments of the presently disclosed systems and methods. Again, the temperature of the semiconductor junction 114 may be estimated and monitored in real time enabling, in real time, the performance of corrective action in case of any eventuality related to the semiconductor device system 100.
Another potential advantage of some semiconductor device systems consistent with semiconductor device systems disclosed herein relates to the manner in which semiconductor device systems may be realized. For instance, such semiconductor device systems may be realized by retrofitting extant semiconductor device (for instance, of type 102) installations with protective tubing (for instance, of type 110) within which passes an optical fiber (for instance, of type 112) and disposing the optical fiber in a manner as discussed in context of
Quite generally therefore, embodiments presented herein include methods for obtaining health related parameters, such as for instance the temperature, of a semiconductor junction (for instance, of type 114) within a semiconductor device (for instance, of type 102).
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While only a limited number of embodiments have been described, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
