COOLING BODY FOR SEMI-CONDUCTOR COMPONENTS, PROCESS FOR ITS PRODUCTION AND MOULDING TOOL FOR THIS

Canadian Intellectual Property Office An Agency of Industry Canada Office de la Propri,t, Intellectuelle du Canada Un organisme d'Industrie Canada <¹¹> CA 2 355 591 (¹³) A1(40) 28.02.2002 (43) 28.02.2002(12)(21) 2 355 591(22) 23.08.2001(51) Int. CI.⁷:H01L 23/36(30) 100 42 124.5 DE 28.08.2000 (72) 100 53 240.3 DE 26.10.2000GRAF, WERNER (DE). BOCK, UWE (DE). (71) ALUSUISSE TECHNOLOGY & MANAGEMENT LTD., (M) CH-8212, NEUHAUSEN AM RHEINFALL, XX (CH).SWABEY OGILVY RENAULT(30) 100 42 124.5 DE 28.08.2000 (72) 100 53 240.3 DE 26.10.2000GRAF, WERNER (DE). BOCK, UWE (DE). (71) ALUSUISSE TECHNOLOGY & MANAGEMENT LTD., (M) CH-8212, NEUHAUSEN AM RHEINFALL, XX (CH).SWABEY OGILVY RENAULT (54) ELEMENT DE REFROIDISSEMENT POUR LES COMPOSANTES DES SEMICONDUCTEURS, PROCEDE DE PRODUCTION ET OUTIL DE MOULAGE CONNEXE (54) COOLING BODY FOR SEMI-CONDUCTOR COMPONENTS, PROCESS FOR ITS PRODUCTION AND MOULDING TOOL FOR THIS (57) In a cooling body (10) of metal material, in particular a light metal alloy, for semi-conductor elements or similar components, plate-like cooling ribs (20, 20e) projecting from a base plate (12) at intervals (f) and approximately parallel to each other, protrude with a connection strip (24) into the base plate in which they are cast. A moulding tool designed for production of this cooling body (10) is formed as a casting mould (30) with a mould chamber for the base plate (12) and this mould chamber contains an area to receive the connection strips (24) of the cooling ribs (20, 20e). Two parallel side walls (34) of the casting mould (30) and intermediate layers (28) arranged parallel between them, each bordering a receiver gap (29), are arranged displaceably on at least one shaft (19) passing through them and can be moved on this to produce the compact casting mould (30) after insertion of the cooling ribs (20, 20e) in the receiver gaps (29).

1*1 Office de la Propriété Intellectuelle du Canada Un organisme d'Industrie Canada Canadian Intellectual Property Office An agency of Industry Canada CA 2355591 A1 2002/02/28 (2D 2 355 591 (12) DEMANDE DE BREVET CANADIEN CANADIAN PATENT APPLICATION (13) A1 (22) Date de dépôt/Filing Date: 2001/08/23 (41) Mise à la disp. pub./Open to Public Insp.: 2002/02/28 (30) Priorités/Priorities: 2000/08/28 (100 42 124.5) DE; 2000/10/26 (100 53 240.3) DE (51) Cl.lnt.⁷/lnt.CI.⁷H01L 23/36 (71)Demandeur/Applicant: ALUSUISSE TECHNOLOGY & MANAGEMENT LTD., CH (72)Inventeurs/lnventors: BOCK, UWE, DE; GRAF, WERNER, DE (74) Agent: SWABEY OGILVY RENAULT (54) Titre : ELEMENT DE REFROIDISSEMENT POUR LES COMPOSANTES DES SEMICONDUCTEURS, PROCEDE DE PRODUCTION ET OUTIL DE MOULAGE CONNEXE (54) Title: COOLING BODY FOR SEMI-CONDUCTOR COMPONENTS, PROCESS FOR ITS PRODUCTION AND MOULDING TOOL FOR THIS (57) Abrégé/Abstract: In a cooling body (10) of metal material, in particular a light metal alloy, for semi-conductor elements or similar components, plate­like cooling ribs (20, 20e) projecting from a base plate (12) at intervals (f) and approximately parallel to each other, protrude with a connection strip (24) into the base plate in which they are cast. A moulding tool designed for production of this cooling body (10) is formed as a casting mould (30) with a mould chamber for the base plate (12) and this mould chamber contains an areata receive the connection strips (24) of the cooling ribs (20, 20e). Two parallel side walls (34) of the casting mould (30) and intermediate layers (28) arranged parallel between them, each bordering a receiver gap (29), are arranged displaceably on at least one shaft (19) passing through them and can be moved on this to produce the compact casting mould (30) after insertion of the cooling ribs (20, 20e) in the receiver gaps (29).

Canadahttp://opic.gc.ca[/a] • Ottawa-Hull Kl A 0C9 •http://cipu.gc.ca[/a]o PI C WW»rn CIPO OPIC-CIPO 191 CA 02355591 2001-08-23 ABSTRACT In a cooling body (10) of metal material, in particular a light metal alloy, for semi-conductor elements or similar components, plate-like cooling ribs (20, 20e) projecting from a base plate (12) at intervals (f) and approximately parallel to each other, protrude with a connection strip (24) into the base plate in which they are cast. A moulding tool designed for production of this cooling body (10) is formed as a casting mould (30) with a mould chamber for the base plate (12) and this mould chamber contains an area to receive the connection strips (24) of the cooling ribs (20, 20_e). Two parallel side walls (34) of the casting mould (30) and intermediate layers (28) arranged parallel between them, each bordering a receiver gap (29), are arranged displaceably on at least one shaft (19) passing through them and can be moved on this to produce the compact casting mould (30) after insertion of the cooling ribs (20, 20_e) in the receiver gaps (29). Fig. 7.

CA 02355591 2001-08-23 Cooling Body for Semi-Conductor Components, Process for its Production and Moulding Tool for This The invention concerns a cooling body of metallic material, in particular a light metal alloy, for semi-conductor elements or similar components, with cooling ribs projecting from a base plate parallel to each other and spaced apart, with approximately rod-like cross section, and which 10 protrude into the base plate with a connection strip. The invention also comprises a process for the production of these and a moulding tool for these. DE 35 18 310 C2 discloses a cooling body with a base plate of an AlMgSi alloy extruded in an extrusion die as a moulding tool, in the surface of which body are formed insert grooves for the plate-like cooling ribs made from a sheet or profile. The ribs have a base which, after insertion in one of the grooves, is distorted by a caulking process. With very close rib spacing and deep cooling ribs, the load on the caulking chisel is so great that it quickly kinks. In other known cooling bodies the cooling ribs can be glued or soldered in place. Gluing has the disadvantage that the glue causes a deterioration in the heat transmission from the base plate or plinth to the cooling rib. For soldering, again costly preliminary treatment is required. For another cooling body according to DE 25 02 472 C2, the base plate is also produced with grooves, the walls of which in their longitudinal direction are fitted with presged-out wall ribs. Cooling ribs with vertical fluting are pressed in these grooves by means of cold pressure welding. The necessary high forces which must be applied in the cold pressure welding process greatly limit the length of the cooling bodies to be produced, and a minimum thickness of cooling ribs is required in order to avoid their kinking during the cold pressure welding process.

CA 02355591 2001-08-23 - 2 - But it is not only the forces occurring which limit the length of the cooling body: the vertical fluting of the cooling ribs limits their length measured along the base plate due to the dimensions of the extrusion tool as the 5 pressing direction is the same as the fluting direction. In view of this state of the art, the inventors have faced the task of creating a cooling body which does not have the defects described. Also, the heat conductivity or control of 10 heat conduction is improved. The doctrine of the independent claims serves to solve this task; the subclaims disclose favourable developments. The scope of the invention also includes all combinations of at 15 least two of the features disclosed in the description, drawing and/or claims. According to the invention, the base plate consisting of metal material is cast onto the metallic cooling ribs in the 20 area of their connection strips, i.e. no subsequent insertion and deformation processes are required. The casting process also allows integration of inserts of heat conductive material to increase the conductivity and to control the heat conduction.

According to a further feature of thp invention at least one insert of good conductive material is cast into the base plate; as inserts, preferably heat pipes to control the heat conduction can be used. Favourably, several heat pipes are used as inserts which run parallel to each other and to the faces of the base plate. Also, the inserts extend between the parallel sides of the base plate. The scope of the invention includes a process for production of such a cooling body in which, to form cooling ribs, plate-like mouldings are arranged at intervals in a mould.

CA 02355591 2001-08-23 - 3 - approximately parallel to each other so that their connection strips of specific height protrude into the chill mould chamber for the base plate, and this mould chamber is filled with the metallic material as a casting compound; 5 when this hardens, the connection strips are held firmly by the base plate and subsequently form a unit with this. To simplify the casting process, by the use of intermediate layers parallel to each other receiver gaps for the plate-10 like mouldings are produced and the latter inserted in the receiver gaps, whereupon two side walls parallel to the intermediate layers are brought together under pressure in order to create a compact mould for preparation of the casting.

According to a further feature of the invention, before filling with the hot casting compound, inserts of heat conductive material are arranged in the mould chamber in order to be cast into the base plate.

As a moulding tool according to the invention, a casting mould is used with a mould chamber for the base plate or plinth, to which, before the actual casting process, are allocated the parallel cooling ribs made from a sheet or profile so that their foot edges and adjacent connection strips protrude into the area established for the casting compound and are there held by the latter during the casting process; after hardening of the casting compound, the cooling body with metal constituents connected internally is 30 then ready for use. «. In the moulding tool according to the invention, two parallel side walls, and intermediate layers between them and also parallel, are arranged displaceably on at least one 35 shaft passing through them; the plate-like mouldings are pressed into the receiver gaps bordered by the intermediate layers until they contact the shaft(s), the side walls are then compressed in the shaft direction until a compact CA 02355591 2001-08-23 _ 4 _ casting mould is achieved. Its mould base is substantially determined by the foot edges of the intermediate layers. Further advantages, features and details of the invention 5 arise from the description of preferred design examples below and using the drawing; these show: Fig.l: a perspective view onto a cooling body with parallel cooling ribs protruding from a base 10plate; Fig.2: a top view onto a mould as a device for production of the cooling body; Fig.3 to Fig.5: a perspective view under the base plate of three different embodiments of the cooling body; 15 Fig.6: a perspective view onto the mould for production of the cooling body; Fig.7: an enlarged section of Fig. 6 in front view.

A longitudinally approximately comb-like cooling body 10 of an aluminium alloy, for example an AlMgSi alloy, for semi­conductor elements, not shown further in the drawings for the sake of clarity, has a base plate 12 of length a, width b and height e with plate-like cooling ribs 20 of free height h projecting from its surface 14 at close intervals 25 f. The distance between a plane E determining the surface 14 of the base plate 12 and the upper, contour of a shaft 42 visible in Fig. 2 in the casting position shown, and which runs parallel to the base plate 12, is marked t. The two end cooling ribs 20_e each run to the adjacent end face 16 of the base plate 12 at distance i, the length of which corresponds almost to plate height e. The side edges 22 of the cooling ribs 20, 20_e align with the side surface 18 of the base plate 12.

To produce the cooling body 10, the cooling ribs 20, 20_e made from sheets or profiles and of total height h-^ and in between intermediate layers 28 determining their rib spacing CA 02355591 2001-08-23 - 5 - f (see Fig. 7), are laid in a mould 30 of steel so that in each case a short connection strip 24 of height n starting from the foot edge 23 of cooling ribs 20, 20_e protrudes into a mould chamber 32 of the mould 30, the base of which is 5 determined by the said plane E and the height of which e^ corresponds to a multiple of the height n of the said connection strip 24. Figs. 6 and 7 show particularly clearly that the mould 30 has two side walls 34 and several parallel intermediate layers 28 bordering between them receiver gaps 29 of width f, where the number of intermediate layers is lower than the number of cooling ribs 20, 20_e. The side walls 34 and the intermediate layers 28 can be displaced on the shaft 19 passing through them so that thickness tolerances of the cooling ribs 20, 20_e can be compensated. The latter, starting from the top in Figs. 6, 7, are pressed between the intermediate layers 28 until their crest edges 26 lie on the shafts 19. The mould or chill mould 30 is then compressed in 20 the shaft direction by pressure means, not shown, i.e. closed downwards. At the free face ends cover plates 36 are applied as bordering walls. Moulding strips 34_a, 36_a of one piece with the side walls 34 and the face walls or cover plates 36 form the border of the fully enclosed chill mould chamber 32 of a base plate or plinth mould into which, as stated, the cooling ribs 20, 20_e protrude by the said dimension n, where in contrast the adjacent foot edges 27 of the intermediate layers 28 run in the said plane E i.e. they form the substantial part of the mould base. When this mould 30 chamber 32 is evacuated, the cooling ribs 20, 20e are. firmly connected with the base plate 12. The chill mould chamber 32 is shown in the upper part of Fig. 2 within the moulding strips 34_a, 36_a of the mould 30 which determine it. The height q at least of the side walls 34 is dimensioned such that in the casting position sketched in Fig. 2 these extend with their wall face edges 38 beyond the crest edges 26 of the cooling ribs 20, 20_e. The CA 02355591 2001-08-23 - 6 - evacuation of the chill mould chamber 32, as shown in particular in Fig. 7, produces the base plate 12 of the valve body 10 in which are cast - and subsequently established after hardening - the cooling ribs 20, 20_e with their feet sections or connection strips 24. Depending on the arrangement of the electronic components, before the casting process, plate-like - flat or curved -parts 40 or 40_a of particularly good heat conduction material can be laid in the mould chamber 32 which increase the conductivity or control the heat distribution; these inserts 40, 40_a are cast into the base plate 12 according to Figs 3, 4. Instead of the plate-like inserts 40, 40a heat pipes 42 can be inserted to control the heat conduction. In Fig. 5 heat pipes 42 run in the base plate 12 parallel to each other and to the faces 16 of the base plate 12. Like the plate-like inserts 40, 40_a, they extend between the parallel side surfaces 18 of the base plate 12.

CA 02355591 2001-08-23 _ 7 _ CLAIMS 1.Cooling body of metallic material, in particular a light metal alloy, for semi-conductor elements or similar components, with cooling ribs (20, 20_G) projecting from a base plate (12) parallel to each other, spaced by distance (f) and with approximately rod-like cross section, and which protrude into the base plate with a connection strip (24), characterised in that the base plate (12) is cast onto the connection strips (24) of the cooling ribs (20, 20_e). 2.Cooling body according to claim 1, characterised in that in the base plate (12) is cast at least one insert (40, 40a, 42) of highly heat-conductive material. 3.Cooling body according to claim 2, characterised in that the insert is a heat pipe (42). 4.Cooling body according to claim 2 or 3, characterised by several heat pipes (42) as inserts which run parallel to each other and to the faces (16) of the base plate (12). 5.Cooling body according to any of claims 2 to 4, characterised in that the inserts (40, 40_a, 42) extend between the parallel sides (18) of the base plate (12). 6.Process for production of a cooling body according to any of claims 1 to 5, characterised in that to form cooling ribs (20, 20e), plate-like mouldings are arranged at intervals (f) in a mould (30), approximately parallel, so that their connection strips (24) protrude, with a height (n) which is lower than height (ei) of a chill mould chamber (32), into the chill mould chamber for the base plate (12), and this is filled with metal material as a casting compound.

CA 02355591 2001-08-23 - 8 - where after hardening the connection strips are firmly held by the base plate. 7.Process according to claim 6, characterised in that receiver gaps (29) with intermediate layers (28) parallel to each other are produced for the plate-like mouldings (20, 20_e) and pressed into the receiver gaps, whereupon two face walls (34) parallel to the intermediate layers are brought together under pressure. 8.Process according to claim 6 or 7, characterised in that before filling with the hot casting compound, inserts (40, 40_a, 42) of heat conductive material are established in the chill mould chamber (32). 9.Moulding tool for production of a cooling body (10) with a base plate (12) and cooling ribs (20, 20_e) projecting approximately parallel from this and of approximately rod-like cross section according to any of claims 1 to 5, characterised in that the moulding tool is formed as a casting mould (30) with a chill mould chamber (32) for the base plate (12) and this chill mould chamber contains an area to receive the connection strips (24) of the cooling ribs (20, 20_e), the height (n) of which is less, than the height (e) of the chill mould chamber. 10.Moulding tool according to claim 9, characterised in that two parallel side walls (34) and intermediate layers (28) arranged parallel between them are arranged displaceably on at least one shaft (19) passing through them. 11.Moulding tool according to claim 10, characterised in that the base (E) of the chill mould chamber (32) is substantially formed by the foot edges (27) of the intermediate layers (28).

CA 02355591 2001-08-23 - 9 - 12. Moulding tool according to claim 10 or 11, characterised in that the shaft(s) (19) form a stop for the mouldings (20, 20e) inserted in the receiver gaps (29) bordered by the intermediate layers (28), where their insertion depth (t) is less than their total height (hi).

CA 02355591 2001-08-23 AL-2290 1/2 U2 U2 CA 02355591 2001-08-23 AL-2290 2/2