RELATED APPLICATION
This application claims priority under 35 U.S.C. §119 to European Patent Application No. 10161436.0 filed in Europe on Apr. 29, 2010, the entire content of which is hereby incorporated by reference in its entirety.
FIELD
This disclosure relates to a mounting base for an electric component, for example, a mounting base which can conduct heat away from an electric component.
BACKGROUND INFORMATION
In known devices an electric component is attached to a first surface of a mounting base. In order to avoid heat generated by the electric component during use from raising the temperature excessively, a second surface of the mounting base is cooled. In this way heat generated by the electric component can be dissipated via the mounting base.
However, the heat load may not be evenly distributed over the mounting base. Therefore different parts of the base can have different temperatures.
In case the heat load is localized on the first surface of the base, for example, restricted to only a part of the surface area, the entire dissipation capacity of the second surface may not be efficiently utilized because of an uneven heat distribution.
U.S. Patent Application Publication No. 2003/0155102 A1 discloses a mounting base with a thermosyphon or a planar heat pipe which is used for distributing heat in various directions. A chamber is provided where a fluid can boil and condense. The pressure inside the chamber can increase to an extent than the mounting base bulges. In that case an electric component attached to the mounting base may be bent to an extent where damage occurs to the component.
SUMMARY
A mounting base for an electric component is disclosed including a first surface for receiving the electric component and for receiving a heat load generated by the electric component, a second surface for dissipating heat from the mounting base and evaporator channels arranged in the vicinity of the first surface for transferring the received heat load to a fluid in the evaporator channels, condenser channels in the vicinity of the second surface for transferring heat from the fluid in the condenser channels to the second surface, a first connecting part for passing the fluid from the condenser channels to the evaporator channels and a second connecting part for passing the fluid from the evaporator channels to the condenser channels.
BRIEF DESCRIPTION OF THE DRAWINGS
Exemplary embodiments will be described in closer detail by way of example and with reference to the attached drawings, in which
FIGS. 1 to 3 illustrate a first exemplary embodiment of a mounting base;
FIG. 4 illustrates a second exemplary embodiment of a mounting base; and
FIG. 5 illustrates an exemplary fluid distribution in a mounting base.
DETAILED DESCRIPTION
In an exemplary embodiment of the disclosure, evaporator channels and condenser channels can be arranged in the mounting base to make it possible to utilize a fluid in the mounting base for receiving and passing on a heat load generated by an electric component. In this way heat can be efficiently distributed due to the fluid. Therefore, the dissipation capacity of the second surface of the mounting base can be utilized efficiently.
FIGS. 1 to 3 illustrate a first exemplary embodiment of a mounting base 1. FIG. 1 is a side view of the mounting base 1, and FIGS. 2 and 3 are partial cross sections of the mounting base. The illustrated mounting base can be utilized with significant fluid pressures without any bulging that can damage components attached to the mounting base.
The mounting base 1 includes a first surface 2 for receiving one or more electric components 3 that generate a heat load during use. The mounting base 1 can be utilized for efficiently cooling a plurality of electric components that can be freely distributed over the first surface 2. When implemented in a drive for an electric motor, such as in a frequency converter, for example, the electric component (or electric components) may be a power semiconductor. The generated heat load can be received by the mounting base 1 via the first surface 2.
The heat load received by the mounting base 1 can be dissipated from the mounting base via a second surface 4 of the mounting base 1. Depending on the implementation, in various exemplary embodiments this second surface 4 can be provided by an apparatus or shaped in a way which enhances the dissipation. In FIGS. 1 to 3, for example, the second surface includes a heat sink 5 for dissipating heat into the ambient surroundings. Instead of a heat sink, a fin structure capable of dissipating heat into the ambient surroundings, may be utilized. The heat sink 5 can additionally include a plurality of fins which pass on heat into the surrounding air. If desired, in order to increase the cooling capacity, a fan may be utilized in order to generate an airflow 6 between the fins, as illustrated by way of example. The direction of the airflow can be as illustrated, or in any suitable direction.
In order for the heat load from the electric component 3 to be evenly distributed over the surface of the mounting base 1, the mounting base can, for example, include evaporator channels 7, condenser channels 8, a first connecting part 9 and a second connecting part 10 in order to circulate fluid in the mounting base 1.
The evaporator channels 7 can be arranged in the vicinity of the first surface 2 to receive the heat load from the electric component 3 via the first surface 2, and to pass the heat load into the fluid in the evaporator channels 7. The second connecting part 10, shown in the upper end of the mounting base 1 in the example of FIGS. 1 and 2, can receive the fluid from the evaporator channels 7 and pass the fluid on into the condenser channels 8.
The condenser channels 8 can be arranged in the vicinity of the second surface 4 in order to transfer heat from the fluid in the condenser channels to the second surface 4. The first connecting part 9, shown in the lower end of the mounting base 1 in the example of FIGS. 1 and 2, can receive the fluid from the condenser channels 8 and pass the fluid on into the evaporator channels 9.
In FIGS. 1 and 2, the mounting base is utilized in a position where the second connecting part 10 is located higher than the first connecting part 9, and the circulation of the fluid will take place due to gravity and condensation/evaporation of the fluid. See EP 2 031 332 A1 and EP 2 119 993 A1, for example. No pump is therefore needed in order to circulate the fluid. The evaporation in the evaporator channels 7 can cause an upward movement of the fluid in the evaporator channels 7, and gravity can cause a downward movement of the fluid in the condenser channels 8. Such a circulation can be achieved at least as long as the first connecting part 9 is not located above the level of the second connecting part 10. In that case, the first and second connecting parts 9 and 10 can be designed to pass on fluid from any evaporator channel to any condenser channel and vice versa. Fluid from different evaporator channels and different condenser channels may also be permitted to be mixed up with each other in the first and the second connecting parts before they are passed on.
From FIG. 3 it can be seen that the evaporator channels 7 and the condenser channels 8 can be grouped together into at least a first group 11 and a second group 12, though the number of groups is sixteen in the illustrated example. Each group can include at least one evaporator channel and at least one condenser channel. Such a structure can be accomplished by extruding the mounting base 4 of an aluminum alloy, for example, in which case the mounting base can include a single block having the evaporator channels and the condenser channels formed in it already after the extrusion phase. However, in FIG. 3 it is by way of example assumed that the mounting base 1 includes two plates 13 and 14. The first plate can be manufactured with grooves, into which pipes can be fitted. The pipes can include longitudinal internal walls that separate the evaporator channels and the condenser channels from each other. The second plate 14 can be attached to the first plate 13 to form the mounting base 1. The first and second plate 13 and 14, the fins of the heat sink 5 and the pipes may be attached to each other by providing for example, a solder on the surfaces of these parts that come into contact with each other. In this way, after the parts have been arranged to contact each other in the illustrated positions, the solder can be melted in an oven, in which case the solder melts and subsequently, when cooled, attaches the parts to each other.
In order to facilitate attachment of the electric component to the mounting base by screws, for example, some of the evaporator channels of FIG. 3 can be omitted. In that case the material thickness of the mounting base is bigger at these locations, which makes it possible to use these locations for attaching said screws, for example. The solid base material at these attachment locations can conduct heat for short distances, and therefore such attachment locations can be arranged in different parts of the mounting base in advance (before knowing exactly the components and the sizes of the components that will be attached to this particularly mounting base), while only those attachment locations that are actually needed are subsequently used by providing attachment holes into them, for example. Consequently the attachment of components to the mounting base can be very simple and flexible.
FIG. 4 illustrates a second exemplary embodiment of a mounting base 1′. The embodiment of FIG. 4 is similar to the one explained in connection with FIGS. 1 to 3. Therefore, the embodiment of FIG. 4 will be explained also by pointing out the differences between these embodiments.
In FIG. 4, several subsequent pipe structures 15′ can be utilized. The first and second connecting parts 9′ and 10′ can be designed to pass on fluid between these different pipe structures. Similarly to the previous embodiment, a heat sink can be provided on the second surface 4′ of the mounting base 1′ for dissipating heat.
FIG. 5 illustrates fluid distribution in a mounting base, such as the one illustrated in FIGS. 1 to 3. In this figure only the electric component 3, the first connecting part 9 and the second connecting part 10 are shown. The evaporator channels and the condenser channels are located on top of each other.
FIG. 5 illustrates a situation where the first and second connecting parts 9 and 10 have a structure that allows fluid from different evaporator channels, and correspondingly, different condenser channels, to mix up with each other and to be passed on via any one of the condenser channels, and correspondingly, evaporator channels. It can be seen that as the fluid also circulates sideways, the cooling capacity of the entire second surface can be utilized efficiently. In this way the dimensions of the mounting base can be increased both longitudinally and transversally. The spaces between the channels may be dimensioned in such a way that electric or other components can be attached by screws, for instance, in the spaces between the channels.
In the previous explanation the term ‘fluid’ has been used generally to indicate any medium suitable for use in the described mounting base. The fluid may be a liquid or a gas, and in many implementations, the fluid can be in liquid state in certain parts of the mounting base while it can be in a gas state in other parts of the mounting base.
Thus, it will be appreciated by those having ordinary skill in the art that the present disclosure can be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The presently disclosed embodiments are therefore considered in all respects to be illustrative and not restricted. The scope of the disclosure is indicated by the appended claims rather than the foregoing description and all changes that come within the meaning and range and equivalence thereof are intended to be embraced therein.
Patent Application
20110265975
