Grease rework applicator

#The present invention relates in general to methods and apparatus for applying a controlled thickness of semi-viscous material to a surface.

#The power density and thermal specification of present high performance processor integrated circuits (ICs) has been driving up the cost and performance of their corresponding heat sink assemblies. As a result, heat sink technology as well as the thermal interface material required between the heat sink and a corresponding integrated circuit have changed. Current thermal solutions used for high performance IC processors require the use of semi-viscous thermal greases to increase thermal conductivity between the IC and its heat sink. These thermal greases create manufacturing problems as well as human factor concerns.

#Typically, a heat sink assembly is supplied from a heat sink vendor with a controlled amount of thermal grease applied to the base of the heat sink. The thermal grease may have a specification that requires the thickness of the thermal grease to be 0.005 inch thick with a variation of plus or minus 0.001 inch. The system assembly vendor doing the final board assembly and test would normally attach the heat sink to a corresponding IC. While applying a thickness of thermal grease to the heat sink with high accuracy may be easy to achieve at the heat sink vendor's manufacturing line, any rework required at the system assembly vendor or later in the field makes reproducing the required thermal grease thickness very difficult.

#For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawings, in which:

#FIG. 1 illustrates a base unit of a grease applicator;

#FIG. 2 illustrates a cap unit of a grease applicator;

#In the following description, numerous specific details are set forth to provide a thorough understanding of the present invention. However, it will be obvious to those skilled in the art that the present invention may be practiced without such specific details. In other instances, well-known processes have been shown in block diagram form in order not to obscure the present invention in unnecessary detail. For the most part, details concerning manufacturing processes and materials composition and the like have been omitted in as much as such details are not necessary to obtain a complete understanding of the present invention and are within the skills of persons of ordinary skill in the relevant art.

#Refer now to the drawings wherein depicted elements are not necessarily shown to scale and wherein like or similar elements are designated by the same reference numeral through the several views.

#FIG. 1 illustrates base unit 100 of the grease applicator 400 (see FIG. 4). Base unit 100 has a window 101 with a predetermined area and depth corresponding to a particular volumetric shaped amount of grease to be applied to a particular heat sink (e.g., heat sink 601, shown in FIG. 6). Base unit 100 has three distinct surfaces, base top surface 107, base bottom surface 108 and cavity bottom surface 106. Base unit 100 also has three locator slots, 103-105. These locating slots match corresponding location tenons 202-204 in the cap unit 200 (see FIG. 2) and are used to locate base unit 100 and cap unit 200 with respect to each other. Extension 102 forms a ledge that is mated to one edge of its matching heat sink and functions to locate window 101 so that the grease will be applied on a particular area of the heat sink surface (e.g., surface 603, shown in FIG. 6). Window 101 has a depth corresponding to the thickness of the material between cavity bottom surface 106 and base bottom surface 108.