ADJUSTABLE HEAT PIPE THERMAL UNIT
Assemblies and methods are described. One assembly includes a first plate and a second plate. The assembly also includes an adjustable heat pipe positioned between the first plate and the second plate, the adjustable heat pipe being in thermal contact with the first plate and the second plate. In another aspect, a plurality of springs may be positioned between the first plate and the second plate. Other embodiments are described and claimed.
As electronic devices become smaller and more complex, heat dissipation becomes a significant issue in a variety of situations, such as testing.
Embodiments are described by way of example, with reference to the accompanying drawings, which are not necessarily drawn to scale.
In order to show features of various embodiments most clearly, the drawings included herein include a representation of various electronic and/or mechanical devices. The actual appearance of the fabricated structures may appear different while still incorporating the claimed structures of the illustrated embodiments. Moreover, the drawings may show only the structures necessary to understand the illustrated embodiments. Additional structures known in the art have not been included to maintain the clarity of the drawings.
Certain embodiments relate to a system for thermal control including a thermal unit comprising a main plate and one or more contact plates coupled to the main plate through springs, and adjustable heat pipes positioned between the contact plates and the main plate to facilitate heat transfer therebetween.
The heat pipes 18 are be configured to be adjustable so that a good thermal contact can be maintained despite variations in the vertical position of a surface or of adjacent surfaces. Both the heat pipes 18 and springs 16 provide sufficient compliance to accommodate die height (vertical position) variations. Such variations may occur for a number of reasons, including, but not limited to, manufacturing variations, warpage or deformations arising during testing. Such variations may result, for example, in die structures having a curved surface or multiple die structures having different heights.
As illustrated in
Embodiments may include varying numbers of contact plates 12, springs 16, and heat pipes 18. By having individual contact plates 12 that are independently actuated and can adjust to changes in die height, effective temperature regulation of die structures at different heights, for example, in a package such as a multi-chip electronic package (MCP), can be carried out simultaneously because each contact plate can make a stable mechanical and thermal contact with the die, regardless of differences in die height (vertical position) or changes in the die height. This enables testing of such MCP packages to be efficiently carried out.
The main plate 10 may comprise any suitable structure for transferring heat and may in certain embodiments be formed from a block of material such as a nickel (Ni) coated copper (Cu) plate. The main plate 10 may have pathways positioned therein for fluid flow and may also include various components for controlling the temperature therein.
The contact plates 12, 12′ may comprise any suitable structure for transferring heat and may in certain embodiments also be formed from a block of material such as Ni coated Cu. The springs 16 may be formed from any suitable material, including, but not limited to, metals. The heat pipes 18 may comprise any suitable structure for transferring heat and may in certain embodiments be formed from a Cu tube having a heat transfer mechanism therein. One example of such a heat transfer mechanism is a fluid (for example, water) positioned within the tube that can boil, travel up the tube towards the main plate, then cool and condense near the main plate and drip back down the tube towards the contact plate. Certain embodiments may also include a wicking structure within the tube. Other configurations for the heat pipes 18 are also possible, and the structure does not necessarily have to be tubular.
As illustrated in
In certain embodiments, the heat pipe 18 operates within the assembly over a range of distances of up to about 1 mm. Using the structure illustrated in
While certain embodiments utilize a substantially C-shaped heat pipe 18, other shapes for the heat pipe are also possible, including, but not limited to, a helical or spring shape 18′ as illustrated in
The springs may in certain embodiments be attached to one or both of the contact plate 12 and the main plate 10 (as seen in
Thermal unit assemblies such as described above may be useful in a variety of applications, including device testing. Embodiments as described herein enable efficient testing of thin electronic packages including, for example, sub-200 micron thick core packages and coreless packages that include multiple die structures.
In one example thermal unit assembly, a Cu heat pipe approximately 9 mm long and 4 mm in diameter was used. Water was used as a working fluid in the Cu heat pipe. The Cu heat pipe was attached to both the main plate and the contact plate, with approximately 4 mm of the heat pipe on each end being used for the attachment to the main plate and to the contact plate. Under an operating temperature of 60° C., the maximum heat removal capability was approximately 150 watts.
It should be appreciated that many changes may be made within the scope of the embodiments described herein. For example, in certain embodiments heat may be supplied to a DUT from the thermal unit. The term die as used herein refers to a workpiece that is transformed by various process operations into a desired electronic device. A die is usually singulated from a wafer, and may be made of semiconducting, non-semiconducting, or combinations of semiconducting and non-semiconducting materials. Terms such as “first”, “second”, and the like, if used herein, do not necessarily denote any particular order, quantity, or importance, but are used to distinguish one element from another. Terms such as “top”, bottom”, “upper”, “lower”, “over”, “under”, “vertical” and the like, if used herein, are used for descriptive purposes and to provide a relative position and are not to be construed as limiting. Embodiments may be manufactured, used, and contained in a variety of positions and orientations.
In the foregoing Detailed Description, various features are grouped together for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter may lie in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate preferred embodiment.
While certain exemplary embodiments have been described above and shown in the accompanying drawings, it is to be understood that such embodiments are merely illustrative and not restrictive, and that embodiments are not restricted to the specific constructions and arrangements shown and described since modifications may occur to those having ordinary skill in the art.
Claims
1-16. (canceled)
17. A method comprising:
- providing a first plate and a second plate coupled to the first plate through an adjustable heat pipe;
- positioning a surface of an electronic device into thermal contact with the second plate;
- generating heat on the surface of the electronic device; and
- transferring an amount of the heat through the second plate and through the adjustable heat pipe to the first plate.
18. The method of claim 17, wherein the providing further comprises providing a plurality of springs between the first plate and the second plate.
19. The method of claim 17, further comprising applying a mechanical force to thermally couple the second plate and the electronic device.
20. The method of claim 17, wherein the providing further comprises providing a third plate coupled to the first plate through an additional adjustable heat pipe, and further comprising:
- positioning an additional electronic device into contact with the third plate;
- generating heat on the surface of the additional electronic device; and
- transferring an amount of the heat through the third plate and through the additional adjustable heat pipe to the first plate.
21. A method comprising:
- providing a first plate;
- providing a second plate spaced apart from the first plate;
- providing an adjustable heat pipe between the first plate and the second plate, the second plate thermally coupled to the first plate through the adjustable heat pipe;
- providing a third plate spaced apart from the first plate and the second plate, the third plate thermally coupled to the first plate;
- thermally coupling a first die to the second plate, wherein the second plate is positioned between the first plate and the first die; and
- thermally coupling a second die to third plate, wherein the third plate is positioned between the first plate and the second die.
22. The method of claim 21, further comprising providing an additional adjustable heat pipe between the first plate and the third plate, the third plate thermally coupled to the first plate through the additional adjustable heat pipe.
23. The method of claim 21, further comprising providing the third plate with a greater thickness than that of the second plate.
24. The method of claim 21, further comprising configuring the adjustable heat pipe to be substantially C-shaped.
25. The method of claim 21, further comprising positioning the first die and the second die in a test rig, applying a current to the first die and the second die, transferring heat from the first die to the first plate through the second plate and the adjustable heat pipe, and transferring heat from the second die to the first plate through the third plate.
26. The method of claim 21, further comprising providing a plurality of springs between the first plate and the second plate.
27. The method of claim 21, further comprising providing the adjustable heat pipe with a tubular structure.
28. The method of claim 21, further comprising configuring the adjustable heat pipe to be adjustable in a range of up to 1 mm.
29. The method of claim 21, further comprising a plurality of additional adjustable heat pipes positioned between the first plate and the second plate.
30. The method of claim 21, wherein there are no adjustable heat pipes positioned between the first plate and the third plate.
31. The method of claim 21, further comprising providing a thermal interface material between the first die and the second plate.
32. The method of claim 31, further comprising providing a thermal interface material between the second die and the second plate, and between the second plate and the first plate.
33. A method comprising:
- providing a first plate;
- providing a second plate spaced apart from the first plate;
- providing an adjustable heat pipe between the first plate and the second plate, the second plate thermally coupled to the first plate through the adjustable heat pipe;
- providing a third plate spaced apart from the first plate and the second plate, the third plate thermally coupled to the first plate;
- providing a first die and a second die positioned on a substrate so that the first die extends outward from the substrate a different distance than that of the second die; and
- positioning the first die and the second die so that the first die is thermally coupled to the second plate, the second plate is positioned between the first plate and the first die, the second die is thermally coupled to the third plate, the third plate is positioned between the first plate and the second die, the first die is spaced apart from the first plate a first distance, the second die is spaced apart from the first plate a second distance, and the first distance is different than the second distance.
34. The method of claim 33, further comprising providing the third plate with a different thickness than that of the second plate.
35. The method of claim 33, further comprising providing a first plurality of additional adjustable heat pipes between the first plate and the second plate, and a second plurality of additional heat pipes positioned between the first plate and the third plate.
36. The method of claim 33, wherein there are no adjustable heat pipes positioned between the first plate and the third plate.
Type: Application
Filed: May 23, 2016
Publication Date: Sep 15, 2016
Inventors: Jin YANG (Hillsboro, OR), David SHIA (Hillsboro, OR)
Application Number: 15/162,513