Cooling structure for heat generating electronic components mounted on a substrate

Abstract: The cooling structure for heat-generating electronic com­ ponents (2) mounted on a substrate (1) comprises a cold plate (7) fixed on the substrate and provided with through holes (5) opposed to the respective upper surfaces of the heat-generating electronic components. Flow paths (6) are formed within the cold plate (7) for circulating a coolant from an inlet (10) provided on a side of the cold plate to an outlet (11) provided on a side of the cold plate. Pistons or plugs (4) are inserted through and held within the through holes (5) so that the lower surfaces of these pistons or plugs come into contact with the upper surfaces of the heat-generating electronic components (2). An intermediate member (3) made of a heat-conductive material is interposed between the lower surfaces of the pistons (4) and the upper surfaces of the electronic components (2).

Description: Background of the Invention The invention relates to a cooling structure for heat generating electronic components, such as integrated circuit (IC) chips. U.S. Patent US-A-3 405 323 and our U.S. Patent US-A-4 628 990 (= FR-A-2 569 306) disclose examples of prior art cooling structures for IC chips. The present invention is concerned with improvements in the cooling structures of these prior patents. Summary of the Invention The invention is defined in claim 1 below to which reference should now be made. Advantageous features of the invention are defined in the sub-claims. Brief Description of the Drawings : The invention will now be described by way of example, in the following detailed description when taken in conjunction with the accompanying drawings, in which: Fig. 1 shows a perspective view with a partially exploded section of an embodiment of the invention; Fig. 2 shows a cross-sectional view of the embodiment; and Figs. 3A and 3B are plan and side views, respectively, of a piston used in the embodiment. Detailed Description of the Preferred Embodiment The embodiment shown in Figs. 1 and 2 comprises a substrate 1, IC chips 2 mounted on the substrate 1, heat-conductive plates 14 of metal attached on the upper surfaces of the chips 2 with an adhesive agent 15, pistons 20 in contact with the plates 14, and a cold plate 7 having flow paths 6 and a plurality of holes 5 for insertion of the pistons 20. The plate 7 cools the pistons 20 inserted in the holes 5 with a coolant 6a circulating through the flow paths 6. The heat generated from each chip 2 is transmitted through a path, shown by a broad arrow in Fig 2, extending from the adhesive agent 15 via the plate 14, the piston 20 and the plate 7 to the coolant 6 a . The plate 7 is provided with an inlet 10 and an output 11 for the coolant 6a on one side thereof. The plate 7 is spaced from the substrate 1 by a predetermined distance by stiffeners 12. The plate 7, the stiffeners 12 and the substrate 1 are fixed with screws 8. The plate 7 may be made integrally with the stiffeners 12. Referring to Figs 3A and 3B, each of the pistons 20 has a longitudinal slit 9 extending through the centre of the piston, a through hole 19 at the centre of the piston, and a threaded screw hole 17 extending through the slit near the through hole 19 and to the side of the through hole which is towards the open end of the slit, as shown. The pistons 20 are inserted into the holes 5 of the cold plate 7 to come into contact with the upper surfaces of the plates 14, respectively. First threaded screws 13 are driven into the through holes 19 of the pistons 20 to be engaged with threaded screw holes 16 formed in the heat conductive plates 14, until flanges formed at the tops of the screws 13 abut against the upper surfaces of the pistons 20, respectively. This fixes the pistons 20 on the plates 14. Then second threaded screws 18 are mated with the screw holes 17 of the pistons 20. By tightening the screws 18 in the screw holes 17, the slits on the pistons 20 are expanded to fix the pistons 20 snugly in the holes 5 of the cold plate 7 through friction.

Claims: A cooling structure for heat-generating electronic components (2) mounted on a substrate (1), comprising: a cold plate (7) fixed on said substrate, which cold plate is provided with first through holes (5) aligned with the upper surfaces of the heat-generating electronic components on said substrate; flow paths (6) formed within said cold plate for circulation of coolant; an inlet (10) provided on a side of said cold plate for supplying said coolant into said flow paths; an outlet (11) provided on a side of said cold plate for exhausting said coolant from said flow paths; pistons (20) inserted through and held within said first through holes; and an intermediary member (14) made of a heat-conductive material interposed between each of said lower surfaces of said pistons and a corresponding one of the upper surfaces of the electronic components to provide a heat-conducting path therebetween, said intermediary member having a first threaded hole (16); and each of said pistons including: a longitudinal slit (9); a second through hole (19) provided at the centre of the piston; a first screw (13) inserted through said second through hole (19) to be engaged with said first threaded hole (16); a second threaded hole (17) formed within said slit at a position near said second through hole; and a second screw (18) inserted into said second threaded hole (17) so as to expand said slit for causing the wall surface of the first through hole (5) in which the piston (20) is inserted to come into contact with the outer surface of the piston. A cooling structure as claimed in Claim 1, wherein said pistons are cylindrical. A cooling structure as claimed in Claim 1 or 2, wherein said heat-conductive material is metal. A cooling structure as claimed in claim 3, wherein said intermediary member (14) is attached to the upper surfaces of the heat-generating electronic components by an adhesive agent (15). A cooling structure as claimed in any preceding claim, wherein said longitudinal slit (9) extends through the centre of the piston (20).

Inventors: MINE SHINJI C O NEC CORPORATIO, SHIMONISHI TERUMI C O NEC CORP, MINE, SHINJI C/O NEC CORPORATION, SHIMONISHI, TERUMI C/O NEC CORPORATION
Applicants: NIPPON ELECTRIC CO, NEC CORPORATION
Application year: 1988
Main classification: H01L23
IPC codes: H01L23