Electronic equipment including a sealing layer and its manufacturing process

Abstract

Electronic equipment comprising a sealing layer and its manufacturing process. One aspect of the invention relates to electrical equipment comprising an electronic block 2 comprising a heat transfer surface 22 and a connection surface 20, an external connector 21 comprising a connector body 210 comprising a base extending from the connection surface 20. The electrical equipment 1 further comprises a sealing layer 3 comprising mainly an elastomer, based on Polydimethylsiloxane, covering the connection surface 20 by surrounding and being in contact with at least a part of the base of each connector body 210.The electrical equipment 1 comprises a thermal transfer film 4 covering the thermal transfer surface 22, having a thermal conductivity greater than or equal to 1 W / (m·K), and having a hardness greater than that of the sealing layer 3, comprising an edge 41 cross-linked with the sealing layer 3 and fibers and a binder comprising polydimethylsiloxane. Figure to be published with the abbreviation: Figure 1.

Description

Title of the invention: Electronic equipment comprising a sealing layer and its manufacturing process. TECHNICAL FIELD OF THE INVENTION

[0001] The technical field of the invention is that of the sealing of electrical equipment.

[0002] The present invention relates to a sealed electrical equipment and a method for sealing an electronic block. TECHNOLOGICAL BACKGROUND OF THE INVENTION

[0003] Various methods of sealing electrical equipment are known, such as encapsulating an electronic block with resin. However, this solution prevents disassembly and is therefore irreparable. Furthermore, resin encapsulation is only suitable for small electronic blocks due to its coefficient of thermal expansion. Another problem with resin encapsulation is the cooling of the electronic block, as the resin hinders efficient heat transfer from the block to the outside. There are, however, resins filled with metal oxides that improve heat transfer, but their thermal resistance is directly proportional to their thickness.

[0004] Equipment comprising a housing containing the electronic unit, which may be metallic to improve cooling of the electronic unit, and seals at various points on the housing, particularly around the electrical connectors, is also known. However, such a housing with this type of seal is not resistant to salt spray.

[0005] Indeed, salt spray is highly corrosive to most metals and, more importantly, due to its high salt content, is electrically conductive and can cause short circuits if it penetrates the electronic connectors of equipment. Electronic boards are generally tropicalized for protection, but this is obviously not possible for electrical connectors, which are not waterproof. Since salt spray is water saturated with salt, it is very fluid and can easily seep into the electronic equipment through the slightest mechanical gap due to capillary action, causing short circuits.

[0006] There is therefore a need for equipment that is impermeable to salt spray while also being able to be cooled efficiently. Summary of the invention

[0007] The invention offers a solution to the problems mentioned above, by encapsulating the equipment in an elastomer in order to isolate it from the external environment. by having a thermal film on a surface of the electronic block. In particular, the invention proposes a film and an elastomer comprising Polydimethylsiloxane so that the association of the very flexible and very adhesive elastomer with the thin thermal film crosslinks together in order to eliminate any possibility of gaps between them.

[0008] One aspect of the invention relates to electronic equipment comprising: • an electronic unit comprising at least: • a first heat transfer surface, and • a second connection surface, • at least one external connector projecting from the connection surface, comprising a connector body including a base extending from the connection surface, and • electrical connection plugs surrounded by the connector body, • a sealing layer comprising mainly an elastomer, based on Polydimethylsiloxane, the sealing layer comprising: • a first part covering the connection surface by surrounding and being in contact with at least part of the base of each connector body, • a thermal transfer film having a thermal conductivity greater than or equal to 1 W / (m K), covering the first thermal transfer surface, having a hardness greater than that of the sealing layer, comprising: • a cross-linked edge with the sealing layer, • fibers and a binder comprising Polydimethylsiloxane.

[0009] Thanks to the invention, the electronic block is sealed and has an efficient heat exchange surface thanks to the thermal film. Polydimethylsiloxane cross-links the elastomer and the waterproof film, making them impermeable to salt spray. Cross-linking the two edges (gel and thermal film) means bonding the gel to the thermal film by creating intermolecular chemical bonds at the two interfaces of the thermal film and the gel, forming a composite. The elastomer has the particularity of easily coating surfaces during application, making them watertight, and in particular the base of each connector, to prevent salt spray from passing between the connector base and the connection surface of the electronic block.Even though some elastomers contain fillers to improve heat transfer, it would be very difficult, if not impossible, to achieve a sufficiently thin sealing layer with an elastomer to obtain a heat transfer coefficient equivalent to that of a thermal film. Furthermore, the flexibility of the elastomer prevents proper [application / application]. Securing the equipment to a support, particularly with screws that cannot maintain the required torque when tightened onto the elastomer, is challenging. The thermal film allows for a very thin profile for efficient heat exchange, and its greater hardness compared to the elastomer ensures secure mounting of the electrical equipment and good heat transfer to the support surface.

[0010] In addition to the characteristics mentioned in the preceding paragraph, the electrical equipment according to one aspect of the invention may have one or more additional characteristics from among the following, considered individually or in all technically possible combinations: • According to one example, the first heat transfer surface has the shape of a part of a cylindrical surface or a cylindrical surface. • According to another example, the first heat transfer surface has the shape of a portion of a spherical surface and • According to another example, the first heat transfer surface has the shape of a part of a flat surface or a flat surface. • According to one example, the second connecting surface has the shape of a part of a cylindrical surface or a cylindrical surface. • According to another example, the second connecting surface has the shape of a part of a spherical surface and • According to another example, the second connecting surface to the shape of a part of a flat surface or a flat surface. • According to one example, the first heat transfer surface is smooth. By smooth, we understand that it does not include any protrusion visible to the naked eye. • According to one embodiment, the electronic block further comprises the first surface and of the second surface, at least one other surface, each other surface is coated by the sealing layer; This prevents any gap between the elastomer and a wall of the electronic block and thus provides a seal against salt spray. • According to one embodiment, the binder further comprises mainly silicone filled with metal oxide or nitride, and the fibers are arranged in a mesh. The mesh increases the hardness of the film, and the binder filling increases the heat transfer coefficient; • According to one embodiment, the thermal film has a thickness between 0.1 and 0.5mm; • According to one embodiment, the sealing layer comprises a Young's modulus E such that E < 0.1 GPa and a hardness between 20 shore OO and 70 shore OO; • According to one embodiment, the thermal film includes at least one hole, and the electronic block includes at least one mounting tab including a hole opposite the hole in the thermal film to receive a screw.

[0011] Another aspect of the invention relates to a method for manufacturing electronic equipment according to the aspect of the previous invention, with or without the various examples described above, the method comprising: • A step of supplying a mold comprising a fixing wall including an internal surface corresponding to the first heat transfer surface, a part of the internal surface having a chemical property that is non-reactive with Polydimethylsiloxane, • a step of supplying a thermal transfer film corresponding to the thermal transfer surface of the electronic block, • a step of fixing the electronic block to the first wall of the mold by sandwiching the thermal transfer film between the first thermal transfer surface and the internal surface, • a step of injecting a gel comprising the sealing layer materials onto the connection surface of the electronic block in the mold, forming a first assembly, the gel flowing over the connection surface until it comes against the edge of the thermal transfer film and until it completely covers the connection surface by being in contact with at least part of the base of each connector body, • a step of heating the first assembly to a temperature between 90 and 110°C for a period of at least 1 hour and 40 minutes, at ambient pressure, allowing the gel to crosslink with the sealing layer and the gel / sealing layer to crosslink with the edge of the thermal film in contact with each other, and • a demolding step for the electronic equipment.

[0012] By non-reactive, it is understood that the materials do not have chemical properties to crosslink by chemical reaction.

[0013] According to one example, the step of supplying the thermal transfer film includes a substep of arranging the thermal transfer film beforehand on the mold wall opposite the thermal transfer surface of the electronic block. This is simpler to carry out in the case of a mold assembled wall by wall. It will then remain on the thermal transfer surface of the electronic block.

[0014] According to one embodiment of the process: • the block comprises at least one molding wall (54a, 54b, 54c, 54d) corresponding to another surface of the electronic block, the fixing wall (52a) and at least one molding wall (54a, 54b, 54c, 54d) being contiguous each having at least a portion of an internal surface (520) not having a chemical crosslinking property with Polydimethylsiloxane and each internal surface of a molding wall is separated from a surface of the electronic block, • during the gel injection step, the gel thins inside the mold between each other surface of the electronic block and each internal surface of each molding wall, • During the heating stage, each edge of the thermal film in contact with the gel in the mold crosslinks with the gel

[0015] According to one embodiment, the entire internal surface of the mold fixing wall is devoid of a chemical crosslinking property with Polydimethylsiloxane.

[0016] According to one embodiment, the method further comprises: • a step of coating a mold block by molding wall, with an interface film between the mold block and the sealing layer, based on Polyvinyl Chloride on each internal surface of each block, forming the internal surface of each molding wall of the mold devoid of a chemical crosslinking property with Polydimethylsiloxane, and • The demolding stage includes a sub-step of dismantling the mold blocks and then a sub-step of removing the polyvinyl chloride-based films remaining on each part of the sealing layer.

[0017] By interface film, based on polyvinyl chloride, is meant a film sufficiently flexible to allow for wrapping a wall. For example, the interface film has a thickness of between 10 and 15 µm. Such a polyvinyl chloride (PVC)-based film lacks chemical crosslinking properties with PDMS; its thickness of between 10 and 15 µm provides flexibility so that it can be easily peeled off while serving as an interface between the sealing layer and the mold. The interface film may be made of polyvinyl chloride.

[0018] According to one embodiment: • The mold is formed by molding walls, each molding wall being removable from each other and a single fixing wall attaching to the other contiguous molding walls, the electronic block being fixed only to the fixing wall, • the process further includes a step of mounting each wall of the mold around the block including the step of fixing the fixing wall, the fixing by first fixing each molding wall contiguous to the fixing wall one after the other, then to each other, and then to each other covering each other faces of the electronic block.

[0019] According to an example, the substep of fixing one of the walls to the fixing wall is a bottom wall opposite the back surface and in that each other wall is fixed to the bottom wall.

[0020] According to one example, the fixing can be achieved by a screw passing through a hole in one wall and butting against its external surface and a tapping in the other wall coupled to the screw.

[0021] The invention and its various applications will be better understood by reading the following description and examining the accompanying figures. BRIEF DESCRIPTION OF THE FIGURES

[0022] The figures are presented for illustrative purposes only and are in no way limiting of the invention.

[0023] [Fig.1] represents a schematic diagram of an electrical equipment according to an embodiment of the invention.

[0024] [Fig.2] represents a schematic diagram of an electronic block of the equipment electric of the [Fig.l].

[0025] [Fig.3] represents a schematic diagram of a mold wall before and after a coating of an interface film, based on Polyvinyl Chloride.

[0026] [Fig.4] represents a schematic diagram of an assembly comprising a block electronics, a mold wall and a thermal film before assembly.

[0027] [Fig.5] represents a schematic diagram of the entire assembled [Fig.4].

[0028] [Fig.6] represents a schematic diagram of the entire [Fig.5] assembly with the mold entire.

[0029] [Fig.7] represents a schematic diagram of the entire [Fig.6] with a sealing layer.

[0030] [Fig.8] represents a schematic diagram of the entire [Fig.7], devoid of two walls of the mold;

[0031] [Fig.9] represents a schematic diagram of the entire [Fig.7], devoid of the mold. DETAILED DESCRIPTION

[0032] The figures are presented for illustrative purposes only and are in no way limiting of the invention.

[0033] [Fig.1] shows a schematic representation of an electronic assembly 1 comprising an electronic block shown alone on [Fig.2].

[0034] The electronic block 2 comprises a first heat transfer surface 22, a second connection surface 20. In this example, it has the shape of a parallelepiped but could have another shape, such as a half-cylinder, a cylinder, a sphere, a hemisphere, a polygon, etc. The electronic block 2 therefore comprises, in this example, a third and fourth lateral surfaces 24a, 24b, a rear surface 24c and a bottom surface 24d. In this example, the lateral surfaces, 24a, 24b, the rear surface 24c and the bottom surface 24d are each a face of the electronic block formed by a wall of the electronic block.

[0035] In this example, the second connection surface 20 is contiguous with the first heat transfer surface 22, but the first heat transfer surface 22 can also be located opposite the second connection surface 20. In this example, the electronic block 2 has only one connection surface 20 (from which connectors protrude), but could have more than one; for example, one of the lateral surfaces 24a, 24b could be a connection surface. In this example, the electronic block 2 has only one heat transfer surface, but could have two opposite each other.

[0036] The electronic block 2 therefore comprises walls forming the aforementioned surfaces and forming an internal housing containing electronic boards of the electronic block, which may be tropicalized. The electronic block 2 includes at least one external connector 21 projecting from the connection surface 20. In this case, the electronic block 2 comprises seven external connectors 21, one of which is cylindrical and the others rectangular, of type DB for example.

[0037] Each external connector 21 comprises a connector body 210, in this case one for the cylindrical connector and four for DB type connectors.

[0038] Each connector body 210 includes a base extending from the connection surface 20. In this example, each connector body 210 includes a plate in contact with the connection surface 20 of the electronic block 2. Each connector body 210 further includes electrical connection plugs 211 surrounded by the connector body 210.

[0039] The electronic assembly 1 further comprises a sealing layer 3 comprising mainly or predominantly by mass an elastomer based on polydimethylsiloxane. The expression "based on" means that it comprises at least 50% by mass. By predominantly by mass, it is understood that at least 50% by mass of the sealing layer is the elastomer. By predominantly, it is understood that the material has the highest percentage by mass of the compound; for example, "mainly composed of A" could mean comprising 45% by mass of A, 20% of B, 10% of C, and 25% of D. As an example, the polydimethylsiloxane comprises vinyl groups, enabling the crosslinking of the gel into a waterproof layer forming the sealing layer 3. The sealing layer 3 comprises a first portion completely covering the connection surface 20 by surrounding and being in contact with at least a portion of the base of each connector body 21.In this example, the sealing layer includes a Young's modulus E such that E < 0.1 GPa and a hardness between 20 Shore OO and 70 Shore OO.

[0040] The electronic assembly 1 further comprises a thermal transfer film 4 covering the first thermal transfer surface 22. The film 4 has a thermal conductivity greater than or equal to 1 W / (m-K) and a hardness greater than that of the sealing layer 3. The thermal transfer film 4 comprises an edge 41 cross-linked with the sealing layer 3. The film 4 comprises fibers and a binder comprising polydimethylsiloxane. An enlargement of the corner between the edge 41 and the sealing layer 3 is shown. A schematically represented weld 43, formed by the cross-linking between the film 4 and the sealing layer 3, can be seen. This cross-linking prevents the formation of a gap between the film 4 and the sealing layer 3.

[0041] In this embodiment, all the lateral surfaces, 24a, 24b, the rear surface 24c, and the bottom surface 24d are covered by the sealing layer 3. The binder of the thermal film 4 is also waterproof. In this example, it mainly comprises silicone filled with metal oxide or nitride. In this example, the fibers of the thermal film 4 are arranged in a weave. The thermal film 4 has a thickness between 0.1 and 0.5 mm.

[0042] As can be seen, the electronic block 2 includes two mounting tabs 28a, 28b, each comprising a hole 26a, 26b, in this case through and smooth (not tapped) opening onto the first heat transfer surface 22 and onto an opposite face of the corresponding mounting tab 28a, 28b.

[0043] Furthermore, the wall of the electronic block forming the first heat transfer surface 22 includes two mounting holes 26c, 26d, smooth or threaded. According to another example, the wall includes a mounting base mounted in an external recess of the wall, comprising a surface forming part of the first internal surface, the base including the mounting holes. The base can simply be placed in position and then held in place by the sealing layer and / or the heat transfer film. In the case of a smooth hole, screws are first inserted inside, bearing against and preventing rotation against an internal surface of the wall, allowing the screw to pass through a smooth hole in another wall (of a mold or a heat exchanger) to secure them together with a nut.

[0044] Each tapped hole 26c, 26d is aligned along an edge with the corresponding through hole 26b, 26a, allowing, in particular, the attachment of a heat exchanger to press a surface of the heat exchanger against the heat exchange surface 22 in order to achieve good heat transfer between them. For example, the screws 6a, 6b, 6c, 6d visible in [Fig. 3] can be used to attach the heat exchanger.

[0045] The thermal film 4, as seen in [Fig. 3], therefore includes in this example a through hole 46a, 46b at the level of the mounting tabs 28a, 28b, opposite the hole 28a, 28b of the corresponding fixing bracket 28a, 28b and holes 46c, 46d opposite holes 56c, 56d allowing screws 6c, 6d to be fixed there.

[0046] In this example, the fixing tabs 28a, 28b are coated by the sealing layer 3 but they may not be.

[0047] The manufacturing process for electronic equipment 1 will now be described.

[0048] The process includes a step of supplying a mold 5 comprising a fixing wall 52a and at least one molding wall, here in the case of molding walls 54a, 54b, 54c, 54d.

[0049] In this example, the mold 5 is formed by four molding walls 54a, 54b, 54c, 54d, which are detachable from one another, and a single fixing wall 52a that is fixed to the other contiguous molding walls 54a, 54b, 54c. Of the four molding walls 54a, 54b, 54c, 54d: • a first is a bottom wall 54c, opposite the connection surface 20, comprising an internal surface pressed against the rear flank of the fixing wall 52a, • Two of the walls adjacent to the fixing wall 52a are respectively a first lateral wall 54a and a second lateral wall 54b, and • the last molding wall, opposite the fixing wall is called in this example opposite wall 54d.

[0050] The electronic block 2 is fixed only to the fixing wall 52a in this example.

[0051] In this case, as seen in [Fig. 5], each screw 6a, 6b, whose head abuts against the corresponding fixing lug 28a, 28b, passes through the hole 26a, 26b and the corresponding hole 46a, 46b and is screwed into the corresponding tapped hole 56a, 56b of the fixing wall 52a. According to another example, each screw 6a, 6b abuts against the external surface of the fixing wall 52a, and passes through the hole 56a, 56b by being screwed into the corresponding tapped hole 26a, 26b of the fixing lug 28a, 28b.

[0052] Each screw 6c, 6d passes through the corresponding hole 56c, 56d in the mounting wall 52a and is screwed into the corresponding tapped hole 26c, 26d. The mounting wall 52a and each molding wall 54a, 54b, 54c, 54d each have at least a portion of an internal surface 520 having a chemical property that prevents crosslinking with polydimethylsiloxane. In this example, the electronic block 2 is housed in the mold 5, as seen in [Fig. 6], such that only the connection surface 20 is visible through an opening in the mold 5.

[0053] The fixing wall 52a and each molding wall 54a, 54b, 54c, 54d have an external surface opposite the internal surface 520 and flanks connecting the internal surface to the external surface.

[0054] The fixing wall 52 includes in this example tapped holes 565 opening onto each side flank and tapped holes not shown opening onto the rear flank not shown.

[0055] In this example, the surfaces of the walls 54a, 54b, 54c, 54d of the mold 5 and the surfaces of the retaining wall 52a do not have a chemical property to crosslink with polydimethylsiloxane. In this example, each wall 54a, 54b, 54c, 54d, 52a of the mold 5 comprises a block 52, the retaining wall 52a being shown in [Fig. 3], for example, a metallic block covered with an interface film 7 shown in [Fig. 3] by a roll of film which, in this case, is based on polyvinyl chloride (PVC). The interface film 7 provides an interface between the mold block and the sealing layer 3 in order to prevent tearing of the sealing layer bonded to the mold block when the mold block is removed.The process can therefore include a step of coating each mold block with interface film 7, based on polyvinyl chloride, either on only the inner face or, as in this example, on each inner surface of each block by wrapping it with interface film 7. Interface film 7 lacks a chemical crosslinking property with polydimethylsiloxane. Preferably, interface film 7 has a thickness between 10 and 15 µm, giving it sufficient flexibility to easily detach from the sealing layer 3, as explained later, while tearing or peeling during mold removal. Interface film 7 thus forms an interface between the sealing layer and the mold for removal. Interface film 7 can be made entirely of polyvinyl chloride.

[0056] The method further includes a step of supplying the thermal transfer film 4 corresponding to the thermal transfer surface of the electronic block 2 and a step of fixing the electronic block 2 to the fixing wall 52a of the mold 5 by sandwiching the thermal transfer film 4 as shown in [Fig.4] before fixing and in [Fig.5] once the fixing wall 52a of the mold 5 has been fixed to the electronic block 2 by means of the screws 6a, 6b, 6c, 6d to fix and compress the thermal transfer film 4 between the fixing wall 52a of the mold 5 and the electronic block 2.

[0057] The method in this example further includes a step of mounting each other wall 54a, 54b, 54c, 54d, of the mold 5 around the electronic block 2 comprising a substep of fixing at least one of the walls 54a, 54b, 54c, 54d to the fixing wall 52a, then the other walls 54a, 54b, 54c, 54d, to at least one of the fixed walls 54a, 54b, 54c, 54d, each covering the other faces of the electronic block 2.

[0058] In this example, the substep of fixing one of the walls 54a, 54b, 54c, 54d, to the fixing wall 52a is the bottom molding wall 54c opposite the back surface 24c and in that each wall 54a, 54b, 54d, is then fixed to the bottom wall 54c.

[0059] In [Fig. 8], smooth through holes 552 can be seen, each allowing the passage of a screw (not shown) with its head abutting an external surface of the bottom wall 54c. Each screw is screwed into a tapped hole on a rear side of the fixing wall 52a, or into a tapped hole on a rear side of the corresponding first and second side walls 54a, 54b, or into a tapped hole on a rear side of the opposite wall 54d. This ensures that the mold walls 54a, 54b, 54d, 52a are pressed against the surface of the bottom wall 54c to prevent gel leakage.

[0060] Optionally, in this example, the first and second side walls 54a, 54b (in this case, only the first side wall 54a is shown with this option) include through holes through which screws 65 pass, screwed into the tapped holes 565 in the side flank of the fixing wall 52a and into a side flank of the opposite wall 54d. This prevents gel leakage by ensuring a seal between each molding wall. The advantage of such a mold comprising a plurality of removable walls is to facilitate demolding by dismantling wall by wall to avoid disrupting the gel layers and, optionally, the application of a mold block-sealing layer interface film, based on polyvinyl chloride, as explained below.

[0061] The assembly order of the molding walls is therefore: • the fixing wall 52a to block 2, then for example • the bottom wall 54c to the fixing wall, then the other molding walls Next.

[0062] For example, the order then is: • the second side wall 54b to the bottom wall 54c and optionally to the fixing wall 52a, then • the opposite wall 54d of the mold 5 to the bottom wall 54c and then possibly to the second side wall 54b and finally • the first side wall 54a to the bottom wall 54c, and optionally to the fixing wall 52a and to the opposite wall 54d.

[0063] The process then includes a step of injecting a gel comprising the materials of the sealing layer onto the connection surface 20 of the electronic block 2 housed in the mold 5, forming a first assembly 6.

[0064] In this example, the mold walls 54a, 54b, 54c, 54d are slightly separated from the surfaces of the electronic block 2, allowing the gel to flow between them. Thus, during this injection step, the mold 5 and the electronic block 2 are oriented such that the third mold wall 54c, visible in [Fig. 8], covers the back surface 24c of the block 2 and is resting on the ground. By gravity, the gel thus enters the gaps between the mold walls 54a, 54b, 54c, 54d and the surfaces 24a, 24b, 24c, 24d of the electronic block 2, which they cover.

[0065] The gel thus flows over the connection surface 20 until it comes against the edge 41 of the thermal transfer film 4 until it completely covers the connection surface 20. The gel also comes into contact with the base of each connector body 210, here in this case by covering each plate in contact with the connection surface 20 of the electronic block 2.

[0066] The process further includes a step of heating the first assembly 6 to a temperature between 90 and 110°C for a period of at least 1 hour and 40 minutes, at ambient pressure, allowing on the one hand the gel to crosslink in the sealing layer 3 and on the other hand the gel / thermal layer 3 to crosslink with the edge 41 of the thermal film 4 in contact with the gel in the mold 5. Once the gel has crosslinked (hardened), the electronic block 2, the sealing layer 3 and the thermal transfer film 4 together form the electronic equipment 1.

[0067] Finally, the process includes a demolding step of the electronic equipment 1. The demolding step of the equipment therefore includes a step of dismantling each wall block 52 of the mold 5 from one another. In this case, during this dismantling step of each block 52, the interface film 7 tears or peels away, leaving a portion covering the mold block 52, and a part or all of the internal surface of this block remains bonded to the sealing layer 3 or to the heat transfer film 4. For example, as shown in [Fig.[8], the blocks of the first molding side wall 54a and the fixing wall 52a were disassembled, leaving on the one hand a remnant of interface film 7 bonded against the sealing layer 3 of the side face 24a, together forming a covered sealing layer 37, and on the other hand a remnant of interface film 7 bonded against the thermal transfer film 4, together forming a covered thermal transfer film 47. In this example, the thermal transfer film 4 was bonded to the fixing wall 52a and therefore to the film 7 covering the block 52 of the fixing wall 52a, but it could be unbonded; in this case, the fixing wall 52a can be detached without tearing the interface film 7, or only at the weld zone between the sealing layer and the thermal transfer film 4.

[0068] Once the sub-step of dismantling the blocks has been carried out, in this example the demolded assembly includes the electrical equipment 1 and the mold block-sealing layer interface film on each sealing layer 3 as seen in [Fig.9], since these have each stuck to the sealing layer 3 when the gel has crosslinked.

[0069] In this example, the demolding step includes a substep of removing each remnant of the mold block-sealing layer interface film, based on polyvinyl chloride, which remains bonded to the sealing layer 3 after the demolding step, in order to obtain the electrical equipment such as that of [Fig. 1]. Here in In this instance, the demolding step further includes a sub-step of removing the remaining interface film 7 stuck against the thermal transfer film 4.

[0070] Unless otherwise specified, the same element appearing on different figures has a unique reference.

Claims

Demands

1. Electronic equipment (1) comprising: - an electronic block (2) comprising at least: • a first heat transfer surface (22), and • a second connection surface (20), • at least one external connector (21) projecting from the connection surface (20), comprising a connector body (210) comprising a base extending from the connection surface (20), and - a sealing layer (3) comprising predominantly a polydimethylsiloxane-based elastomer, the sealing layer (3) comprising a first portion covering the connection surface (20) by surrounding and being in contact with at least a portion of the base of each connector body (210), - a heat transfer film (4) covering the first heat transfer surface (22), having a thermal conductivity greater than or equal to 1 W / (m-K), and having a hardness greater than that of the sealing layer (3),comprising: - an edge (41) cross-linked with the sealing layer (3), - fibers and a binder comprising Polydimethylsiloxane.

2. Electronic equipment according to the preceding claim, wherein the electronic block (2) comprises, in addition to the first surface (20) and the second surface (22), at least one other surface (24a, 24b, 24c, 24d), each other surface (24a, 24b, 24c, 24d) being totally encapsulated by the sealing layer (3).

3. Electronic equipment according to claim 1 or 2, wherein the binder further comprises predominantly silicone loaded with metal oxide or nitride and the fibers are arranged in a weft.

4. Electronic equipment according to any one of the preceding claims, wherein the thermal film (4) has a thickness between 0.1 and 0.5mm.

5. Electronic equipment according to any one of the preceding claims, wherein the sealing layer comprises a Young's modulus E

6.

7. such that E < 0.1 GPa and a hardness between 20 shore 00 and 70 shore 00. Electronic equipment according to any one of the preceding claims, wherein the thermal film (4) includes at least one hole, and the electronic block (2) includes at least one mounting tab (28) including a hole opposite the hole in the thermal film to receive a screw. A method for manufacturing electronic equipment according to any one of the preceding claims, comprising: - a step of supplying a mold (5) comprising a fixing wall (52a) comprising an internal surface corresponding to the first heat transfer surface (22), at least a part of the internal surface (520) devoid of a chemical crosslinking property with Polydimethylsiloxane, - a step of supplying a thermal transfer film (4) corresponding to the shape and size of the thermal transfer surface (22) of the electronic block (2), - a step of fixing the electronic block to the fixing wall (52a) of the mold (5) by sandwiching the thermal transfer film between the first thermal transfer surface and the internal surface, - a step of injecting a gel comprising the materials of the sealing layer (3) onto the connection surface (20) of the electronic block (2) in the mold (5), forming a first assembly (6), the gel flowing onto the second connection surface (20) until it comes against the edge (41) of the thermal transfer film (4) and until it completely covers the second connection surface (20) by being in contact with at least a part of the base of each connector body (31), - a step of heating the first assembly (6) to a temperature between 90 and 110°C for a period of at least 1 hour and 40 minutes, at ambient pressure, allowing on the one hand the gel to crosslink into a sealing layer (3) and on the other hand to crosslink an area of the gel and the waterproof layer (3) with the edge (41) of the thermal film (4) in contact together, and - a demolding step for the electronic equipment.

8. A method according to the preceding claim, wherein: - the block comprises at least one molding wall (54a, 54b, 54c, 54d) corresponding to another surface of the electronic block, the fixing wall (52a) and at least one molding wall (54a, 54b, 54c, 54d) being contiguous and each having at least a part of an internal surface (520) devoid of a chemical crosslinking property with Polydimethylsiloxane and each internal surface of a molding wall is separated from another surface (24a, 24b, 24c, 24d) of the electronic block (2), - during the gel injection stage, the gel thins inside the mold (5) between each other surface (24a, 24b, 24c, 24d) of the electronic block (2) and each internal surface of each molding wall (54a, 54b, 54c, 54d), - during the heating stage, each edge (41) of the thermal transfer film (4) in contact with the gel in the mold (5) crosslinks with the gel.

9. A method according to the preceding claim, further comprising: - a step of coating a mold block (52) (5) by a mold wall (54a, 54b, 54c, 54d, 52a) of the mold (5), with a mold block-sealing layer interface film, based on Polyvinyl Chloride, on each internal surface of each block, forming the internal surface of each mold wall and the fixing wall, each lacking a chemical crosslinking property with Polydimethylsiloxane, and - the demolding stage includes a sub-stage of dismantling the mold blocks and then a sub-stage of removing the Polyvinyl Chloride-based films remaining on each part of the sealing layer (3).

10. A method according to any one of the preceding claims 7 to 9, wherein: the mold (5) is formed by molding walls (54a, 54b, 54c, 54d), each molding wall being removable from the other walls of the mold and a single fixing wall (52a) being fixed to the other contiguous molding walls, the electronic block (2) being fixed only to the fixing wall (52a), The process further includes a step of mounting each wall of the mold around the block, comprising after the step of fixing the fixing wall, the fixing of each molding wall contiguous to the fixing wall one after the other, then to each other, each covering the other faces of the electronic block.

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