Apparatus and test device for the application and measurement of prescribed, predicted and controlled contact pressure on wires
View Patent ↗The mechanical behavior of wires subjected to axial loading and experiencing bending deformation is used to ensure effective control of the contact pressure in mechanical and/or heat removing devices, and similar structures and systems. An apparatus for taking advantage of the characteristics of wires in packaging of a device, such as a semiconductor device, is disclosed, as well as a test device for identifying the accurate contact pressure required in same. Methods for the prediction of such a behavior for pre-buckling, buckling, and post-buckling conditions in wires, carbon nanotubes (CNTs), and similar wire-grid-array (WGA) structures, for example are also disclosed.
1. An apparatus for the efficient removal of heat from a hot surface, the apparatus comprises: an anchoring surface wherein the root portions of each of a plurality of wires is anchored to said anchoring surface; a base inside of which said anchoring surface is mounted; a low modulus continuous medium (LMM), said plurality of wires being at least partially embedded within said LMM; a support structure designed to support said plurality of wires placed in said LMM; and, means for applying axial forces to the free ends of said plurality of wires, when said base is forced against said hot surface; wherein said axial forces cause the bending deformation of at least one of said plurality of wires against said hot surface thereby increasing at least one of; the number of wires from said plurality of wires having thermal contact to said hot surface, the thermal contact area between said hot surface and said at least one of said plurality of wires, and wherein an upper portion of said at least one of said plurality of wires is coated with a material resistant to wetting, said wetting resistant material comprising a creep barrier for said LMM.
2. An apparatus for the efficient removal of heat from a hot surface, the apparatus comprises: an anchoring surface wherein the root portions of each of a plurality of wires is anchored to said anchoring surface; a base inside of which said anchoring surface is mounted; and, means for applying axial forces to the free ends of said plurality of wires, when said base is forced against said hot surface; wherein said axial forces cause the bending deformation of at least one of said plurality of wires against said hot surface thereby increasing at least one of: the number of wires from said plurality of wires having thermal contact to said hot surface, the thermal contact area between said hot surface and said at least one of said plurality of wires, wherein contact of pressure a wire against said hot surface is a result of at least one of said axial forces and is only a function of the ratio between the length and the diameter of said at least one of said plurality of wires, and wherein said contact pressure is in the range between 20 and 60 psi.
3. The apparatus of claim 2 , wherein the ratio between the length and the diameter of said at least one of said plurality of wires is between 400 and 1,200.
4. An apparatus for the efficient removal of heat from a hot surface, the apparatus comprises: an anchoring surface wherein the root portions of each of a plurality of wires is anchored to said anchoring surface; a base inside of which said anchoring surface is mounted; a low modulus continuous medium (LMM), said plurality of wires being at least partially embedded within said LMM; a support structure designed to support said plurality of wires placed in said LMM; and, means for applying axial forces to the free ends of said plurality of wires, when said base is forced against said hot surface; wherein said axial forces cause the bending deformation of at least one of said plurality of wires against said hot surface thereby increasing at least one of: the number of wires from said plurality of wires having thermal contact to said hot surface, the thermal contact area between said hot surface and said at least one of said plurality of wires, wherein said at least one of said plurality of wires being subjected to a lateral loading, wherein said lateral loading is achieved by means of coating said at least one of said plurality of wires, and wherein said coating is of a sufficient weight to bring said at least one of said plurality of wires up to, but less than, a buckling condition of said at least one of said plurality of wires.