Cooling of an electronic device

Abstract

Cooling of an Electronic Device This description relates to an electronic device (100) comprising: an electronic chip (101) including an active area (107) on a first face (103), and a second face (105) opposite the first face (103); a substrate (111), the first face (103) of said chip (101) being mounted on a third face (113) of said substrate (111); and a thermally conductive cover (119) including a transverse portion (121; 403) extending at least above the second face (105) of said electronic chip (101), wherein the electronic device (100) further includes at least one thermally conductive pillar (127) connecting the second face (105) of the electronic chip (101) to said transverse portion (121) of said thermally conductive cover (119). Figure for the abbreviation: Fig. 1

Description

Description Title of the invention: Cooling of an electronic device technical field

[0001] — This description generally relates to electrical systems and devices tronics, and their means of protection and cooling. This description applies more specifically to the cooling methods of an electrical device electronics protected by a case. Previous technique

[0002] — Numerous techniques for cooling electrical systems and devices Protected electronic components housed in a casing are known. For example, it is known to use cases designed to dissipate the heat generated by the components and circuits of the electronic device or system.

[0003] — It is desirable to be able to improve, at least in part, the means of cooling- housing of electronic devices protected by a casing. Summary of the invention

[0004] There is a need for means of cooling electronic devices protected by a more efficient casing.

[0005] An embodiment overcomes all or part of the drawbacks of the cooling means Dismantling of known electronic devices.

[0006] — One embodiment provides for an electronic device comprising: - an electronic chip comprising an active area on one side, and a second face opposite to the first face; - a substrate, the first face of said chip being mounted on a third face of said substrate; and - a thermally insulated driver's hood comprising a transverse portion extending at least above the second side of said electronic chip, in which the electronic device further comprises at least one pillar thermally conductive linking the second side of the electronic chip to said transverse part of said driver's hood thermally.

[0007] According to one embodiment, said at least one thermally conductive pillar is a metal pillar.

[0008] According to one embodiment, said at least one thermally conductive pillar includes a first portion made of copper.

[0009] According to one embodiment, said at least one thermally conductive pillar includes at least a second portion made of a weldable metal alloy.

[0010] According to one embodiment, said at least one thermally conductive pillar is surrounded by a first layer of a first thermally conductive material extending from said second face of the electronic chip to said transverse part of said thermally conductive hood. According to one embodiment, said first layer also covering, along at least one fourth lateral face of said electronic chip. According to one embodiment, said transverse part of said hood having a first portion of a first thickness extending above the second face of said electronic chip, and at least a second portion of a second thickness greater than the first thickness extending to the periphery of said electronic chip. According to one embodiment, the second portion extends to the level of the first face of said electronic chip. According to one embodiment, said second portion is connected to said third face of said substrate by at least one first thermally conductive bar. According to one embodiment, the hood further comprises at least one lateral part surrounding the electronic chip, and at least one extension extending from the lateral part of the hood to said fourth lateral face of said electronic chip. According to one embodiment, the space between said transverse part of said hood and said at least one extension is filled by a second thermally conductive material. According to one embodiment, said elongation is connected to said third face of said substrate by at least one second thermally conductive bar. According to one embodiment, the thermally conductive hood is a metallic hood. According to one embodiment, said at least one elongation comprises on its upper face at least one groove. One embodiment provides a method for manufacturing an electronic device comprising an electronic chip having an active area on a first face, and a second face opposite the first face, the method comprising the following successive steps: - form at least one thermally conductive pillar on said second face of said electronic chip; - mounting said electronic chip on a third face of a substrate, the first face of the chip being on the side of the third face of said substrate; and - to provide a thermally conductive hood comprising a transverse part extending over the second face of said electronic chip, said transverse part being in contact with said at least one thermally conductive pillar. According to one embodiment, said at least one thermally conductive pillar comprises a first portion of copper and at least a second portion of a solder metal alloy. Brief description of the drawings These features and advantages, as well as others, will be described in detail in the following description of particular embodiments, given by way of non-limiting example, in relation to the attached figures, among which: [Fig.1] includes a side cross-sectional view and a top cross-sectional view of an embodiment of an electronic device; [Fig.2] includes six side cross-sectional views illustrating steps in an implementation method of the manufacturing process of the embodiment of [Fig.1]; [Fig.3] includes a side cross-sectional view and a top cross-sectional view of another embodiment of an electronic device; [Fig.4] represents a side cross-sectional view of another embodiment of an electronic device; [Fig.5] represents a side cross-sectional view of another embodiment of an electronic device; [Fig.6] represents a side cross-sectional view of another embodiment of an electronic device; [Fig.7] represents a side cross-sectional view of another embodiment of an electronic device; [Fig.8] represents a side cross-sectional view of another embodiment of an electronic device; [Fig.9] represents a side cross-sectional view of another embodiment of an electronic device; [Fig.10] represents a side cross-sectional view of an embodiment of an electronic device according to another aspect. Figure 11 shows a side cross-sectional view of another embodiment of an electronic device; and Figure 12 comprises three side cross-sectional views illustrating steps in one implementation of the manufacturing process for the embodiment shown in Figure 10. Description of the embodiments The same elements have been designated by the same reference numerals in the different figures. In particular, structural and / or functional elements common to the different embodiments may have the same reference numerals and may have identical structural, dimensional and material properties. For the sake of clarity, only the steps and elements useful for understanding the modes are included. The implementations described have been represented and are detailed. Unless otherwise specified, when referring to two connected elements, this means directly connected without any intermediate elements other than conductors, and when referring to two coupled elements, this means that these two elements can be connected or linked through one or more other elements. In the description that follows, when referring to absolute positional qualifiers, such as the terms “front”, “back”, “top”, “bottom”, “left”, “right”, etc., or relative positional qualifiers, such as the terms “above”, “below”, “superior”, “inferior”, etc., or to orientational qualifiers, such as the terms “horizontal”, “vertical”, etc., it refers, unless otherwise specified, to the orientation of the figures. Unless otherwise specified, the expressions 'approximately', 'roughly', 'significantly', and 'on the order of' mean within 10%, preferably within 5%. Figure 1 comprises two cross-sectional views (A) and (B) illustrating an embodiment of an electronic device 100. View (A) is, more particularly, a side cross-sectional view of the device 100 along axis AA shown in view (B). View (B) is, more particularly, a top cross-sectional view of the device 100 along axis BB shown again in view (A). The electronic device 100 comprises an electronic chip 101 including one or more components (not shown in [Fig. 1]) formed in and / or on a substrate wafer, for example, a silicon substrate. The chip 101 includes a face 103 and a face 105 opposite face 103. The chip 101 is, for example, parallelepiped in shape. On the side of face 103 is the active area 107 of the chip 101, shown by hatching in [Fig. 1]. The active area of ​​an electronic chip is defined here as the part of the electronic chip in which most of the chip's electronic components and the electrical contacts that allow the chip to be used are formed. The chip 101 also includes lateral faces 109. The electronic device 100 further comprises a substrate 111 on which the chip 101 is mounted. The substrate 111 is, for example, a printed circuit board, a succession of conductive and insulating layers forming metallization levels, a plate traversed by electrically conductive vias, etc. More precisely, the face 103 of the chip 101 is mounted on a face 113 of the substrate 111 by means of electrical connectors 115 linking electronic contacts of the active area 107 of the chip 101 to electrical contacts formed at the face 113 of the substrate 111. The contacts of the active area 107 and the face 113 are not shown in [Fig. 1]. The electrical connectors 115 are, for example, conductive balls, such as solder balls. The electrical connectors 115 are embedded in a filler material 117 to protect them. This material The filling material 117 is an electrically insulating material. For example, it may be a material known by the trade names XS8410-302SNS8AG or U8410-399F (Namics company). Furthermore, the substrate may include contacts (not shown in [Fig. 1]) on its underside 114, i.e., the side opposite face 113, to allow the electronic device 100 to be connected to other electronic devices. These contacts may be electrically connected to other contacts via solder balls, also not shown in [Fig. 1]. The electronic device 100 further comprises a cover 119 made of a thermally conductive material. For example, the cover 119 is a metallic cover, preferably made of copper. The cover 119 comprises a transverse portion 121 extending substantially parallel to the faces 103 and 105 of the chip 101 and to the face 113 of the substrate 111, and lateral portions 123 extending substantially parallel to the faces 109 of the chip 101. For example, the transverse portion 121 and the lateral portions 123 are each plates of substantially constant thickness, for example, having a thickness between 0.3 mm and 1 mm, for example, on the order of 0.5 mm. According to one example, the hood 119 is made of a single piece comprising parts 121 and 123, but according to a variant parts 121 and 123 may be pieces fixed to each other to form the hood 119, for example fixed by gluing. The cover 119 is arranged on the chip 101 so as to protect the faces 105 and 109 of the chip 101. The cover 119 is fixed to the face 113 of the substrate 111, for example, by means of a layer of glue 125 disposed between the end of the lateral parts 123 of the cover 119 and the face 113 of the substrate 111. The electronic device 100 further includes one or more, preferably several, thermally conductive pillars 127 extending from the face 105 of the chip 101 to the transverse part 121 of the cover 119. According to one embodiment, a first end of each pillar 127 is in direct contact with the face 105, and a second end, opposite to the first end, is in direct contact with the transverse part 121 of the cover 119. The pillars 127 are distributed on the face 105 of the chip 101 (see view (B)). According to one embodiment, the pillars 127 are concentrated in the areas of the chip 101 that give off the most heat. According to one embodiment, the pillar(s) 127 are metallic pillars. In one embodiment, the pillar(s) 127 comprise at least one portion made of a first metal, for example, copper or an alloy containing copper, and at least one second portion made of two metals, for example, a metal alloy, such as a metal alloy intended for welding. In one example, the first end corresponds to the first portion of the pillar 127, and the second end corresponds to the second portion of the pillar 127. A device 100 may include Pillars 127 of different shapes, Pillars 127 can have a tubular shape with an oblong or even round section (see view (B)). The substrate 111, the hood 119 and the pillar(s) 127 form the protective housing of the chip 101 in the electronic device 100. According to one embodiment, the electronic device 100 has a length and width between 13 mm and 55 mm, for example, a length of approximately 45 mm and a width of approximately 45 mm, and a thickness between 1.5 mm and 4 mm, for example, approximately 2.5 mm. For such an electronic device, the chip 101 can have a length and width between 10 mm and 20 mm, for example, a length of approximately 15 mm and a width of approximately 15 mm, and a thickness between 150 mm and 400 mm, for example, approximately 300 mm. In this case, the pillars 127 can have a width between 30 and 100 µm, for example, approximately 60 or 80 µm, and a height between 50 and 120 µm. One advantage of this embodiment is that it effectively dissipates the heat emitted by the chip 101 during operation. In other words, the housing formed by the substrate 111, the cover 119, and the pillar(s) 127 extracts heat from the chip 101. Indeed, during operation, the chip 101 can generate heat. Since the pillars 127 are thermally conductive, they guide the heat emitted by the chip 101 towards the cover 119, which is itself thermally conductive, in order to dissipate as much heat as possible to the outside of the electronic housing. Another advantage of this embodiment is that the concentration of pillars can be increased at the hot spots of the chip 101, i.e., the areas of face 103 that generate the most heat. This is not the case with a uniform layer of a thermally conductive material. [Fig.2] includes six cross-sectional views (A), (B), (C), (D), (E), and (F) each illustrating a step in an implementation method of a manufacturing process for device 100 described in relation to [Fig.1]. The steps illustrated in [Fig.2] are performed while the chips are still in wafer form. For simplicity, only a 201 chip is shown in [Fig.2]. At the viewing stage (A), the various chips 201 include an active area 203 arranged on the side of a face 205, opposite a face 207, at the scale of the wafer. In step (B), connectors 209 of the type of connectors 115 in [Fig. 1] are formed at the contacts of the active area 203 of the chip 201. The wafer is then turned over so that its face 207 is accessible. The wafer is then thinned to the desired thickness. At the viewing stage (C), the plate 201 is fixed to a temporary support 211 by means of a temporary fixing layer 213 disposed at the level of the connectors 209. In the viewing step (D), one or more, preferably several, thermally conductive pillars 215 are formed on the face 207 of the individual chips 201 of the wafer. In one embodiment, a metallic portion 217 is formed first, and then a second metallic portion 219 is formed on top of it. For example, the pillars are formed by electrolytic deposition. At the viewing stage (E), the temporary support is removed. The fabrication of the unit chips 201 is, for example, completed by a singularization stage. At the view stage (F), the chip 201 is fixed to a substrate 221 of the type of substrate 111 of [Fig.1] via the connectors 209. A filler material 223 is then disposed between the active area of ​​the chip 201 and a face 225 of the substrate 991; Next, a cover 227 of the type of cover 119 in [Fig. 1] is placed on the chip 201. For this purpose, lateral parts of the cover 227 are attached, for example by gluing, to the face 225 of the substrate 221. The gluing is, for example, carried out by depositing a layer of glue 229. As an example, if the cover 227 is composed of several parts glued together, the cover 227 can be assembled around the chip 201. Figure 3 includes two cross-sectional views (A) and (B) illustrating an embodiment of an electronic device 300. View (A) is, more particularly, a side cross-sectional view of the device 300 along axis AA shown in view (B). View (B) is, more particularly, a top cross-sectional view of the device 300 along axis BB shown again in view (A). Furthermore, electronic device 300 shares common features with electronic device 100 described in relation to [Fig. 1]. These common features are not described again in detail here, and only the differences between devices 100 and 300 are highlighted. The electronic device 300 differs from the device 100 in that a layer 301 of a thermally conductive material is formed around the pillar(s) 127. The layer 301 extends over the entire height of the pillar(s) 127, i.e. from the layer 105 of the chip 101 to the transverse part 121 of the cover 119. More particularly, according to one embodiment, a lower face of the layer 301 is in direct contact with the face 105, and an upper face, opposite the lower face, is in direct contact with the transverse part 121 of the cover 119. According to one embodiment, layer 301 may extend over one or more portions (see view (B)) of face 105 of chip 101, but may, according to another variant, extend over the entire face 105 of chip 101. According to one example, layer 301 is formed at one or more hot spots of chip 101. As previously mentioned, layer 301 is made of a thermally conductive material. mically. According to an example, this material is chosen by the group comprising: the material bearing the reference SE4450 marketed by the company Dow Corning, and the material bearing the reference TC3040 marketed by the company Dow Corning. One advantage of this embodiment is that layer 301 improves heat transfer from the chip to the outside of the package. Device 300 also has the same advantages as device 100 described in relation to [Fig.1]. Fig. 4 is a side cross-sectional view illustrating one embodiment of an electronic device 400. The electronic device 400 shares common features with the electronic device 300 described in relation to [Fig. 3]. These common features are not described again in detail here, and only the differences between devices 400 and 300 are highlighted. The electronic device 400 differs from the device 300 in that the layer 301 is replaced by a layer 401 made of a thermally conductive material formed around the pillar(s) 127. Like the layer 301, the layer 401 extends over the entire height of the pillar(s) 127, i.e. from the layer 105 of the chip 101 to a transverse part 403 of the cover 119. In addition, according to one embodiment, the layer 401 also covers all or part of the lateral faces 109 of the chip 101. Furthermore, like layer 301, layer 401 can extend over one or more portions (see view (B)) of faces 105 and 109 of chip 101, but can, according to a variant, extend over the entire face 105 of chip 101 and over all faces 109 of chip 101. According to one example, layer 401 is formed at hot spots of chip 101. As previously mentioned, layer 401 is made of a thermally conductive material. For example, this material is chosen by the group comprising: the material with the reference SE4450 marketed by Dow Corning, and the material with the reference TC3040 marketed by Dow Corning. The electronic device 400 differs further from the device 300 in that the cover 119 comprises a transverse portion 403 that differs from the transverse portion 121 described in relation to [Fig. 1]. The transverse portion 403 comprises sections of different thicknesses; more specifically, the transverse portion 403 comprises: - a portion 405 of thickness P1 extending above chip 101; and - at least a portion 407 of thickness P2 extending around, that is to say on the periphery of the chip 101. According to one embodiment, the thickness Pl is less than the thickness P2. In practice, the thickness P2 is large enough that the portion 407 extends at least as far as the face 103 of the chip 101. In this way, the lateral faces 109, and more specifically the portions of layer 401 covering them are in contact with portion 407 of the transverse part 403 of the hood 119. Thus, according to one embodiment, an upper face of layer 401 is in direct contact with face 105 and faces 109, and a lower face, opposite to the upper face, is in direct contact with the transverse part 403 of the hood 119. One advantage of this embodiment is that layer 401 and portion 407 of the transverse part 403 of the hood 119 allow the heat emitted from the lateral faces 109 of the chip 101 to be evacuated. Device 400 also has the same advantages as device 300 described in relation to [Fig.3]. Fig. 5 is a side cross-sectional view illustrating one embodiment of an electronic device 500. Furthermore, the electronic device 500 shares common features with the electronic device 400 described in relation to [Fig. 4]. These common features are not described again in detail here, and only the differences between devices 400 and 500 are highlighted. The electronic device 500 differs from the device 400 in that the device 500 comprises one or more, preferably several, thermally conductive bars 501 arranged between the portion 407 of the transverse part 403 of the hood 119 and the face 113 of the substrate 111. More particularly, according to one embodiment, the bar(s) 501 are in direct contact with the portion 407 of the transverse part 121 of the hood 119 and with the face 113 of the substrate 111. According to one embodiment, the thermally conductive bar(s) 501 extend over all or part of the face 113. The bar(s) 501 have a width between 50 µm and 100 µm, for example on the order of 80 µm. According to one embodiment, the thermally conductive bar(s) 501 are metallic bars, for example bars made of copper or of a metallic alloy comprising copper. One advantage of this embodiment is that the bar(s) 501 allow some of the heat released by the chip 101 to be dissipated into the substrate 111. Device 500 also has the same advantages as device 400 described in relation to [Fig.4]. Fig. 6 is a side cross-sectional view illustrating one embodiment of an electronic device 600. Furthermore, the electronic device 600 shares common features with the electronic device 100 described in relation to [Fig. 1]. These common features are not described again in detail here, and only the differences between devices 100 and 600 are highlighted. The electronic device 600 differs from the device 100 in that the device 600 includes the layer 401 in a thermally conductive material described in relation to [Fig.4]. The electronic device 600 differs from the device 100 in that the device 600 further comprises one or more, preferably several, extensions 601 at the lateral portions 123 of the cover 119. More specifically, the extensions 601 extend from the lateral portions 123 of the cover 119 to the lateral faces 109 of the chip 101, and more precisely to the portions of the layer 401 covering them. As an example, the extensions 601 have a thickness on the order of the thickness of the chip 101. The extensions 601 may have a greater thickness than the chip. They may also have a smaller thickness, but at the expense of the heat dissipation effect. According to one embodiment, the extensions 601 are made of the same material as the cover 119. Furthermore, as described in relation to [Fig. 1], the cover 119 can be made of a single piece comprising parts 121 and 123, and the extensions 601, but according to another variant, parts 121 and 123 and the extensions 601 can be pieces fixed together to form the cover 119. These pieces can be fixed together by gluing, i.e., for example, by means of one or more layers of glue 603. A person skilled in the art will be able to imagine several combinations of parts for obtaining the cover 119 of the device 600. One advantage of this embodiment is that the extensions 601 of the hood 119 allow the heat emitted from the side faces 109 of the chip 101 to be evacuated. Device 600 also has the same advantages as devices 100 described in relation to [Fig.1]. Fig. 7 is a side cross-sectional view illustrating one embodiment of an electronic device 700. Furthermore, the electronic device 700 shares common features with the electronic device 600 described in relation to [Fig. 6]. These common features are not described again in detail here, and only the differences between devices 600 and 700 are highlighted. The electronic device 700 differs from the device 600 in that the device 700 comprises one or more, preferably several, thermally conductive bars 501 as described in relation to [Fig. 5]. In the device 700, the bar(s) 501 are arranged between the extension(s) 601 of the cover 119 and the face 113 of the substrate 111. More particularly, according to one embodiment, the bar(s) 501 are in direct contact with the extension(s) 601 of the cover 119 and with the face 113 of the substrate 111. The 700 device offers the same advantages as the 500 and 600 devices. described in relation to figures 5 and 6. Fig. 8 is a side cross-sectional view illustrating one embodiment of an electronic device 800. Furthermore, the electronic device 800 shares common features with the electronic device 600 described in relation to [Fig. 6]. These common features are not described again in detail here, and only the differences between devices 600 and 800 are highlighted. The electronic device 800 differs from the device 600 in that the space, or cavity, 802 formed between the extensions 601 and the transverse portion 121 of the cover 119 is filled with a thermally conductive material 801. More specifically, the material 801 is a material with a thermal conductivity greater than 2 W / mK, or even 3 W / mK. The material 801 is, for example, selected from the group comprising: the material known by the trade name SE4450 from Dow Corning, and the material known by the trade name TC3040 from Dow Corning. The use of materials known by the trade name TIM is also possible. According to one embodiment, the material 801 is injected into the space 802 via a cavity 803 formed through the transverse part 121 of the hood 119. One advantage of this embodiment is that the presence of material 801 improves heat dissipation in the hood 119. Device 800 also has the same advantages as device 600 described in relation to [Fig.6]. Fig. 9 is a side cross-sectional view illustrating one embodiment of an electronic device 900. Furthermore, the electronic device 900 shares common features with the electronic device 800 described in relation to [Fig. 8]. These common features are not described again in detail here, and only the differences between devices 800 and 900 are highlighted. Device 900 differs from device 800 in that device 900 comprises one or more, preferably several, thermally conductive bars 501 as described in relation to [Fig. 5]. In device 900, the bar(s) 501 are arranged between the elongation(s) 601 of the cover 119 and the face 113 of the substrate 111. More particularly, according to one embodiment, the bar(s) 501 are in direct contact with the elongation(s) 601 of the cover 119 and with the face 113 of the substrate 111. Device 900 has the same advantages as devices 500 and 800 described in relation to figures 5 and 8. Fig. 10 is a side cross-sectional view illustrating one embodiment of an electronic device 1000 according to another aspect. The electronic device 1000 shares common features with the electronic device 600 described in relation to [Fig. 6]. These common features are not described again in detail here, and only the differences between devices 1000 and 600 are highlighted. Device 1000 differs from device 600 in that device 1000 does not include a thermally conductive pillar 127 between the face 105 of the chip 101 and the transverse part of the metal cover 119. Instead, the device 1000 includes a layer 1001 made of a thermally conductive material. The layer 1001 extends from the face 105 of the chip 101 to the transverse part 121 of the cover 119. More particularly, according to one embodiment, a lower face of the layer 1001 is in direct contact with the face 105, and an upper face, opposite the lower face, is in direct contact with the transverse part 121 of the cover 119. According to one embodiment, the layer 1001 can extend over the entire face 105 or over one or more portions of the face 105 of the chip 101, as described for the layer 301 in relation to [Fig. 3]. According to one example, layer 1001 is formed at one or more hot spots of chip 101. In addition, like layer 401 described in relation to [Fig.4], layer 1001 can, furthermore, cover all or part of the lateral faces 109 of chip 101.For example, layer 1001 is made of a material chosen from the group comprising: the material bearing the reference SE4450 marketed by Dow Corning, and the material bearing the reference TC3040 marketed by Dow Corning. Device 1000 differs further from device 600 in that the elongations 601 of the hood 119 of device 1000 include at least one groove 1003, or trench 1003, surrounding the chip 101. More specifically, the groove 1003 is formed from a top face of the elongation 601, for example, a face of the elongation directed towards the side of the transverse part of the hood 119. The groove 1003 is, for example, located at a distance from the chip 101 of between 500 µm and 2 mm, for example, on the order of 1 mm. In one example, the groove has a depth of between 30 µm and 150 µm, for example, on the order of 70 µm, and a width of between 500 µm and 1.5 mm, for example, on the order of 1 mm. According to one embodiment, the elongations 601 may include more than one groove 1003, for example grooves 1003 parallel to each other and / or concentric. One advantage of this embodiment is that said groove makes it possible to slow down, or even prevent, the migration of layer 1001 during the operation of the chip. Figure 11 is a side cross-sectional view illustrating one embodiment of a electronic device 1100 according to another aspect. Furthermore, the electronic device 1100 shares common features with the electronic device 1000 described in relation to [Fig. 10]. These common features are not described again in detail here, and only the differences between devices 1100 and 1000 are highlighted. Device 1100 differs from device 1000 in that device 1100 does not include layer 1001 but layer 401 described in relation to [Fig.4] and pillars 127 described in relation to [Fig.1]. Device 1100 has the same advantages as devices 600 and 1000 described in relation to figures 6 and 10. Figure 12 comprises three cross-sectional views (A), (B), and (C), each illustrating a step in an implementation method for a manufacturing process of device 1000 described in relation to Figure 10. An implementation method for a manufacturing process of device 1100 described in relation to Figure 11 will be deduced from the combination of the manufacturing process described in relation to Figure 2 and the manufacturing process described below. In the view step (A), a chip 1201 was mounted on a substrate 1203. For this, connectors 1204 were formed on a face 1205 corresponding to the active area of ​​the chip 1201. The connectors 1204 were embedded in a filler material 1209 on the upper face 1207 of the substrate 1203. In step (A), a first portion of a thermally conductive hood of the type of hood 119 described in relation to [Fig. 10] is arranged around the chip 1201. The hood portion includes side portions 1211 of the hood, of the type of the portions 123 described in relation to [Fig. 1], and elongations 1213, of the type of the elongations 601 described in relation to [Fig. 6]. Like the elongations 601, the elongations 1213 include one or more grooves 1215 formed from a top face of the elongations 1213. In one example, the grooves 1215 are formed in the elongations 1215 in step (A) or are preformed. In one example, this portion of the hood is made in one piece. According to one variant, this part of the hood is made of several parts assembled together, for example by gluing. The hood part is fixed to the upper face 1207 of the substrate 1203, for example, by means of a layer of glue 1217. In the viewing step (B), a layer 1219 of a thermally conductive material is formed on all or part of a face 1221 of the chip 1201, opposite the face 1205. The layer 1219 is deposited up to the groove 1215 of the elongations 1213. The layer 1219 may, for example, cover all or part of the lateral faces 1223 of the chip 1201. The layer 1219 is, for example, made of a material selected from the group including: the material bearing the reference SE4450 marketed by Dow Corning, and the material bearing the reference TC3040 marketed by Dow Corning. In the step shown in view (C), the last part of the hood is formed on the chip 1201. According to the example illustrated in view (C), the last part of the hood is a side part 1225 of the type of the side part 121 described in relation to [Fig. 1]. The part 1225 is, for example, a plate of material attached to the layer 1219 by means of an adhesive layer 1227 to the previously attached side parts 1211 of the hood. In one example, the layer 1219 and the adhesive layer 1227 have substantially equal thicknesses. Various embodiments and variations have been described. A person skilled in the art will understand that some features of these various embodiments and variations could be combined, and other variations will become apparent to a person skilled in the art. Finally, the practical implementation of the described methods and variants is within the reach of the person in the trade, based on the functional indications given above.

Claims

Demands

1. Electronic device (100; 300; 400; 500; 600; 700; 800; 900) including: - an electronic chip (101) includes an active area (107) on a first face (103), and a second face (105) opposite the first face (103); - a substrate (111), the first face (103) of said chip (101) being mounted on a third face (113) of said substrate (111); and - a thermally conductive hood (119) comprising a part transverse (121; 403) extending at least above the second face (105) of said electronic chip (101), in which the electronic device (100; 300; 400; 500; 600; 700; 800; 900) includes, in addition, at least one thermally conductive pillar (127) magically connecting the second face (105) of the electronic chip (101) to said transverse part (121; 403) of said hood (119) driver thermally.

2. Device according to claim 1, wherein said at least one pillar (127) thermally conductive is a metallic pillar.

3. Device according to claim 1 or 2, wherein said at least one thermally conductive pillar (127) comprises a first portion in a spoon.

4. Device according to any one of claims 1 to 3, in which said at least one thermally conductive pillar (127) includes at less a second portion in a weldable metal alloy.

5. Device according to any one of claims 1 to 4, wherein said at least one thermally conductive pillar (127) is surrounded of a first layer (301; 401) in a first conductive material thermally extending from said second face (105) of the electronic chip- tronic (101) to said transverse part (121; 403) of said hood (119) thermally conductive.

6. Device according to claim 5, wherein said first layer (401) by covering, moreover, along at least a fourth face side (109) of said electronic chip (101).

7. A device according to any one of claims 1 to 6, in which said transverse part (403) of said hood (119) having a first portion (405) of a first thickness (P1) extending above the second face (105) of said electronic chip (101), and at least one second portion (407) of a second thickness (P2) greater than the first thickness (P1) extending to the periphery of said electronic chip- tronics (101).

8. Device according to claim 7, wherein the second portion (407) extends to the level of the first face (103) of said chip electronics (101).

9. Device according to claim 8, wherein said second portion (407) is connected to said third face (113) of said substrate (111) by the less a first thermally conductive bar (501).

10. Device according to any one of claims 1 to 6, wherein the hood (119) further comprises at least one side part (123) surrounding the electronic chip (101), and at least one extension (601) extending from the side part (123) of the hood (119) to the said fourth lateral face (109) of said electronic chip (101).

11. Device according to claim 10, wherein the space (802) between said transverse part (121) of said hood (119) and said at least one al- The length (601) is filled by a second conductive material (801). thermally.

12. Device according to claim 10 or 11, wherein said elongation (801) is connected to said third face (113) of said substrate (111) by the less a second thermally conductive bar (501).

13. Device according to any one of claims 1 to 12, wherein The thermally conductive hood (119) is a metallic hood.

14. Device according to any one of claims 10 to 13, in which said at least one elongation (601) comprises on its su- face perpendicular to at least one groove (1003).

15. Method of manufacturing an electronic device comprising a chip electronic (201) having an active area (203) on a first face (205), and a second face (207) opposite the first face (205), the process comprising the following successive steps: - form at least one thermally conductive pillar (215) on said second face (207) of said electronic chip (201); - mount said electronic chip (201) on a third face (225) of a substrate (221), the first face (205) of the chip (201) being on the side of the third face (225) of said substrate (221); and - to have a thermally conductive hood (227) comprising a transverse part extending above the second face (207) of said electronic chip (201), said transverse part being in contact with said at least one thermally conductive pillar (127).

16. Method according to claim 15, wherein said at least one pillar (215) thermally conductive comprises a first portion in copper and at least a second portion in a metallic alloy of welding.