The present disclosure relates to systems and methods for cooling electronic devices, and more particularly to systems and methods for actively cooling semiconductor devices including stacked diode laser assemblies through the use of an embedded thermoelectric cooler.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.
At the present time there is strong interest in improving the thermal management solution for a stacked diode laser assembly with lower stack pitch. By “stack pitch” it is meant the distance separating adjacent diode emitters making up the stacked diode laser assembly. Reducing the stack pitch improves the brightness of the beam generated by the stacked diode laser assembly. However, reducing the stack pitch, without suitable cooling, also contributes to increased heat.
Most of the previously conducted research and work related to cooling active electronic devices, including diode lasers, has been devoted to single phase and multi-phase fluid based active cooling approaches (e.g., see, “Active Cooling Solutions for High Power Laser Diodes Stacks”, Yoram Karni, Genady Klumel, Moshe Levy, Yuri Berk, Yaki Openhaim, Yaakov Gridish, Asher Elgali, Meir Avisar, Moshe Blonder, Hila Sagy, Alex Gertsenshtein, Semiconductor Devices; and also “Photonics Products: Laser-Cooling Equipment: Keep Your Laser-diode System Cool, Whatever the Power Laser Diodes Work Best When Cool—Different Cooling Approaches Work Best for Different Laser Powers”, John Wallace, Jan. 18, 2018.
Most of the present day approaches for cooling stacked diode laser assemblies have relied on channel based cooling, as illustrated in
Accordingly, there is a strong need in the art for cooling approaches and technologies which are well adapted for use with active electronic devices including, but not limited to, stacked diode laser assemblies. There is furthermore a strong need for cooling approaches and technologies which are well suited for use with active electronic devices, and particularly stacked diode assemblies, which do not involve any moving parts, and which provide innovative packaging configurations and materials that provide even smaller form factor solutions.
This section provides a general summary of the disclosure and is not a comprehensive disclosure of its full scope or all of its features.
In one aspect the present disclosure relates to a thermoelectric cooling (TEC) embedded electronics. The system may comprise a substrate having a first surface and a second surface and constructed of a thermally and electrically conductive material. A die may be included which is configured to be supported from the first surface of the substrate and in thermal contact with the substrate, with the die forming a heat generating component. A TEC material element may also be included which has a first surface and a second surface, and which is configured to be positioned at least partially against the second surface of the substrate. A heat pipe may be included which has a first portion and a second portion, where the first portion is configured to be in thermal contact with the second surface of the TEC material, and the second portion is configured to sink heat generated by the die and transmitted through the substrate and the TEC material.
In another aspect the present disclosure relates to a thermoelectric cooling (TEC) embedded electronics system. The system may comprise a thermally and electrically conductive substrate having an outer surface and an opening forming an inner surface. A die is included which is configured to be supported from the outer surface of the substrate and in thermal contact with the substrate. The die forms a heat generating semiconductor component. An N-type TEC material element is included which forms a continuous loop disposed within the opening of the thermally conductive substrate, and which has an outer surface and an inner surface. The outer surface of the N-type TEC material element is positioned in contact with the inner surface of the substrate. A heat pipe is included which has a first portion and a second portion. The first portion is configured to be disposed within the opening of the substrate and in thermal contact with the second surface of the TEC material. The second portion is configured to project outwardly from the opening and to sink heat generated by the die and transmitted through the substrate and the N-type TEC material. A TEC cooled heat sink is included which is in contact with the second portion of the heat pipe, to sink heat from the heat pipe.
In still another aspect the present disclosure relates to a method for cooling an electronics system. The method may comprise providing a die forming a heat generating component and using an electrically conductive material layer to support the die. The method may also include using a substrate having a first surface and a second surface and constructed of a thermally conductive material to support the electrically conductive material layer on the first surface, with the substrate including an opening. The method may further include using a TEC material element having a first surface and a second surface, which is configured to at least partially line the second surface of the substrate, to form a ground layer. The method may further include providing a current to the electrically conductive material layer and transmitting the current from the electrically conductive material layer to the substrate. The method may further include using the substrate to facilitate sinking heat generated by the die through the substrate and through the TEC material element, and using a heat pipe positioned at least partially within the opening, and in thermal contact with the TEC material element, to sink heat from the TEC material element.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustrative purposes only of selected embodiments and not all possible implementations, and are not intended to limit the scope of the present disclosure.
Corresponding reference numerals indicate corresponding parts throughout the several views of the drawings.
Example embodiments will now be described more fully with reference to the accompanying drawings.
The present disclosure is related to a thermoelectric cooler (“TEC”) system which makes use of an embedded TEC subassembly that can be used in connection with semiconductor devices, for example and without limitation, stacked diode laser assemblies, to actively, effectively cool one or more dies each forming electronic and/or electro-optical components. The TEC material of the TEC system acts as an active cooler. The packaging configuration of the TEC system, which makes use of one or more TEC subassemblies, allows cooling of the entire die(s) without use of fluid, and importantly without the need for forming cooling fluid flow channels between adjacent dies. This elimination of cooling channels enables the pitch of a stacked diode laser to be reduced, resulting in improved brightness of the beam produced by a stacked diode laser assembly. The manner of constructing the TEC assembly is fully compatible with present day thin film TEC materials. A manufacturing process used to construct/integrate the TEC subassemblies with the dies(s) to form a larger, fully integrated TEC system, as explained herein, is fully compatible with present day semiconductor manufacturing processes. Solder hierarchy is also the same as the conventional solder hierarchy when using AuSn or AuIn. The substrate in contact with a GaAs of the die is preferably CTE (coefficient of thermal expansion) matched, as with present day active cooling systems and designs.
Referring now to
Each of the TEC subassemblies 102a-102d are in contact a TEC cooled heatsink 106 (
In this example the dies 104a-104c each form heat generating components in the form of diode lasers. The dies 104a-104c each have an associated facet 104a1, 104b1 and 104c1, which is shown formed at an end of the dies 104a-104c, respectively. The dies 104a-104c may be formed from any suitable material used to construct semiconductor diode lasers, but a typically used material is GaAs. The facets 104a1-104c1 each project a beam of light 104a2-104c2, respectively, out from its associated diode laser 104a-104c. It will be appreciated, however, that a stacked diode laser is only one example of a semiconductor-based system that the TEC system 100 can be used to help form. The TEC system 100 can be integrated into the construction of virtually any type of semiconductor-based component or system (e.g., memory, processor, switching, communications, etc.), and possibly other types of electronic, electro-optical or other heat generating devices, where active cooling is desired.
Referring further to
Referring to
The ground layer 110 may be formed using any suitable N-type TEC material, for example and without limitation, La doped Strontium Titanate (SrTiO3), InSb, etc. The ground layer 110 forms the “N” portion of the N/P TEC subassembly 102, and thus helps to “sink” or draw heat from the substrate 108 into the heat pipe assembly 112 during operation of the assembly 100.
With brief reference to
The substrate 108 preferably is formed from a material which is tuned to match the CTE of the die 104a-104c CTE. The substrate 108 may be formed from a custom material, for example and without limitation, from Si/Cu. The Cu material operates to add an additional path for current flow while the Si material contributes toward local thermoelectrical cooling. Alternatively, the substrate 108 may be constructed from a more commonly used material such as, without limitation, CuW, CuD or AIN. These materials are all compatible with current material configurations currently in use with TEC cooled devices.
With specific reference to
The dies 104a/104b are electrically coupled, for example by eutectic solder (e.g., AuSn, AuIn) to their respective electrically conductive material layers 116a/116b. As noted in
The construction of the TEC subsystem 102a is not limited by the magnitude of joules heating created by the active electronic components it is used with. Put differently, the TEC subassembly 102 can be engineered to handle the expect level of Joules heating created by the active electronic components which the TEC subsystems 102a-102d are used with, and thus which help form the complete TEC system 100.
Referring now to
Referring to
The various embodiments of the present disclosure thus provide a means to construct even more dense, more compact, TEC stacked semiconductor assemblies, and particularly stacked diode laser assemblies. Moreover, the teachings of the present disclosure are not limited to just the construction of stacked diode laser assemblies, but are readily adaptable to create other TEC embedded electronic/optical systems. The teachings of the present disclosure also do not require significant modifications to present day, actively cooled semiconductor manufacturing processes, and can be used to cost effectively create embedded TEC electronic devices and systems for a wide variety of applications.
The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.
Example embodiments are provided so that this disclosure will be thorough, and will fully convey the scope to those who are skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, and methods, to provide a thorough understanding of embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms and that neither should be construed to limit the scope of the disclosure. In some example embodiments, well-known processes, well-known device structures, and well-known technologies are not described in detail.
The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms “a,” “an,” and “the” may be intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises,” “comprising,” “including,” and “having,” are inclusive and therefore specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order discussed or illustrated, unless specifically identified as an order of performance. It is also to be understood that additional or alternative steps may be employed.
When an element or layer is referred to as being “on,” “engaged to,” “connected to,” or “coupled to” another element or layer, it may be directly on, engaged, connected or coupled to the other element or layer, or intervening elements or layers may be present. In contrast, when an element is referred to as being “directly on,” “directly engaged to,” “directly connected to,” or “directly coupled to” another element or layer, there may be no intervening elements or layers present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items.
Although the terms first, second, third, etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections should not be limited by these terms. These terms may be only used to distinguish one element, component, region, layer or section from another region, layer or section. Terms such as “first,” “second,” and other numerical terms when used herein do not imply a sequence or order unless clearly indicated by the context. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of the example embodiments.
Spatially relative terms, such as “inner,” “outer,” “beneath,” “below,” “lower,” “above,” “upper,” and the like, may be used herein for ease of description to describe one element or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Spatially relative terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” or “beneath” other elements or features would then be oriented “above” the other elements or features. Thus, the example term “below” can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly.
This invention was made with Government support under Contract No. DE-AC52-07NA27344 awarded by the United States Department of Energy. The Government has certain rights in the invention.