FR3117286A1 - Electronic system and voltage converter comprising such an electronic system - Google Patents

Abstract

The present invention relates to an electronic system (100, 300,500) comprising: a box (160.560) comprising a bottom (161.561), a first radiator (140.540) fixed outside the box on a first wall (162.562), a first electronic card (155.555), placed inside the box (160.560 ), comprising an upper face (156,556) and a lower face (157,557), the first electronic card (155,555) comprising a first and a second electronic component (151, 152,551,552) on its upper face (156,556) a first heat pipe (110,510) in thermal contact with the first and second electronic components (151,152, 551,552), a first end of the first heat pipe (110, 510) passing through at least a part of the first radiator (140, 540) through a first orifice (181, 581) in the first wall (162, 562), Figure for abstract: Figure 3

Description

Electronic system and voltage converter comprising such an electronic system

The present invention relates to electronic systems for electric or hybrid motor vehicles and which comprises a cooling device. It also relates to a voltage converter comprising such an electronic system.

Voltage converters implemented in the automotive field include power components located on an electronic board. These power components are in operation traversed by high currents, for example of several hundred amperes, which generates a very significant heating of these components, which if they are not cooled can damage them irreversibly.

It is therefore appropriate to cool these power components during their use.

To do this, an electronic system is known from the prior art comprising electronic components placed in thermal contact with the bottom of a box 50. As described on the , the bottom of the case comprises in its thickness an inlet endpiece 10, an outlet endpiece 20 and a cooling channel 30, a cooling fluid, for example ethylene glycol, circulating in the cooling channel 30 of the input end piece 10 to the output end piece 20 so as to cool the electronic components. The cooling channel is made in the form of a cavity hollowed out in the bottom of the case, said cavity being closed by means of a lid 65 and a seal 60 (not shown in the figure) placed between the cavity and the cover 65. Screws 90 maintain the assembly of the cover 65 and the seal 60 with the box 50.

However, the tightness of such a cooling system is difficult to implement.

The object of the invention is to at least partially overcome this problem.

1. un boitier comprenant un fond
2. un premier radiateur fixés à l’extérieur du boitier sur une première paroi,
3. une première carte électronique, disposée à l’intérieur du boitier, comportant une face supérieure et une face inférieure, la première carte électronique portant un premier et un deuxième composant électronique sur sa face supérieure
4. un premier caloduc en contact thermique avec les premier et deuxième composants électroniques, une première extrémité du premier caloduc traverse au moins une partie du premier radiateur par un premier orifice dans la première paroi,

To this end, according to a first aspect of the invention, an electronic system is proposed comprising:

1. a box comprising a bottom
2. a first radiator fixed outside the box on a first wall,
3. a first electronic card, disposed inside the case, comprising an upper face and a lower face, the first electronic card carrying a first and a second electronic component on its upper face
4. a first heat pipe in thermal contact with the first and second electronic components, a first end of the first heat pipe passes through at least part of the first radiator through a first orifice in the first wall,

Thus the use of an electronic system according to the invention makes it possible to cool electronic components without using a cooling channel formed by a cavity in the bottom of the case and closed by a cover, which makes it possible to avoid a system of assembly and sealing complex to implement the electronic system.

The electronic system according to the first aspect of the invention may also have one or more of the characteristics of the particular embodiments below, considered individually or in all technically possible combinations.

In a particular embodiment of the invention, the electronic system comprises a second heat pipe in thermal contact with the lower face of the first electronic card, a first end of the second heat pipe passes through at least part of the first radiator via a second orifice.

In a particular embodiment of the invention, the first electronic card comprises on its lower face a third and a fourth electronic components.

In a particular embodiment of the invention, the electronic system comprises a second electronic card comprising an upper face and a lower face, carrying on its upper face a fifth and a sixth electronic components.

In a particular embodiment of the invention, the thermal contact is made with an electrically insulating thermal paste.

In a particular embodiment of the invention, the first fan is radial, axial, tangential.

1. Un système électronique selon le premier aspect de l’invention
2. Un interrupteur électronique par exemple un, un transistor, une diode un transistor bipolaire, un transistor MOSFET, ou un transistor IGBT ledit premier composant électronique à refroidir étant ledit interrupteur électronique

The invention also relates, according to a second aspect, to a voltage converter comprising:

1. An electronic system according to the first aspect of the invention
2. An electronic switch, for example a transistor, a diode, a bipolar transistor, a MOSFET transistor, or an IGBT transistor, said first electronic component to be cooled being said electronic switch

Optionally, the voltage converter is a DC-DC voltage converter or an AC-DC voltage converter or else a DC-AC voltage converter

represents the outer face of the bottom of a case of an electronic system according to the prior art.

shows a box of an electronic system in a first embodiment of the invention in top view.

shows a cross-sectional view of a box of an electronic system in a first embodiment of the invention.

shows a cross-sectional view of a box of an electronic system in a third embodiment of the invention.

shows a cross-sectional view of a box of an electronic system in a fifth embodiment of the invention.

With reference to Figures 2 and 3, a voltage converter 100 according to a first embodiment of the invention will be described. The voltage converter 100 is for example used in a motor vehicle.

The voltage converter 100 includes an electronic system. This electronic system comprises a box 160, a first electronic card 155 carrying at least a first and a second electronic component 151, 152 to be cooled, a first radiator 140, a first fan 120, a first heat pipe 110 and a second heat pipe 115.

The first electronic card 155 has an upper face 156 and a lower face 157, the upper face bearing at least a first and a second electronic component 151, 152. The first electronic card 155 is arranged parallel to the bottom 161 of the box 160.

In the context of the invention, the upper face 156 is the face on which the first and second electronic components 151,152 are arranged. The lower face 157 is the face opposite that where the first and second electronic components 151,152 are arranged.

More precisely, the lower face 157 is the one which is arranged facing the bottom 161 of the box 160. The upper face is the face which is opposite to the face which is opposite the bottom 161 of the box 160.

The first electronic component 151 is for example an electronic switch such as a MOSFET or an IGBT forming part of a switching arm of the voltage converter 100.

The second electronic component 152 is for example an inductor. It will be noted that in the example described here, the first electronic component 151 dissipates in operation more heat than the second electronic component 152.

The first heat pipe 110 is in the form of a closed tube of circular section, for example made of copper, in which a heat transfer fluid circulates. This heat transfer fluid is preferably a two-phase fluid which can be acetone, ammonia, methanol, toluene or even water. In known manner, the first heat pipe 110 comprises a first end where the fluid vaporizes by absorbing thermal energy and a second end where the fluid condenses to return to the liquid state, the circulation of the fluid within the first heat pipe 110 being done for example by capillarity. The second heat pipe 115 operates identically to the first heat pipe 110.

In the example described, the box 160 is a rectangular parallelepiped comprising a bottom 161 surrounded by a first 162, a second 163, a third and a fourth wall. The length of the first and second wall defines the width of the housing, and the length of the third and fourth wall defines the length of the housing. The bottom 161 and the four walls of the box 161 further define an interior housing of the box.

In the example described, the box 160 is a metal box, for example aluminum.

Preferably, the first electronic component 151 which dissipates more heat than the second electronic component 152 is placed close to the first end of the first heat pipe 110 located inside the case 160. In other words the first component electronic component 151 is placed so that it is furthest from the first wall 162 than is the second electronic component 152 which is placed closer to the first wall 162 than the first electronic component 151, the first and second electronic components 151, 152 still being in thermal contact with the first heat pipe 110. The first and second electronic components 151, 152 are in thermal contact via an electrically insulating thermal paste.

The second heat pipe 115 is arranged so as to be in thermal contact with the lower face 157 of the first electronic card 155 and opposite the first and second electronic components 151,152. The second heat pipe 115 is also arranged so that its first end is inside the case 160 and in thermal contact with the lower face 157 of the electronic card 155 and its second end is partly arranged outside the box 160 through the second wall 162 by a second orifice 181.

The first radiator 140 is composed of a stack of rectangular metal fins. The metal fins are separated by a space to allow the passage of an air flow between them.

The first radiator 140 and the first fan 120 are fixed outside the box 160, i.e. outside the interior housing of the box 160, on the first wall 162. The first fan 120 is also fixed on the first wall 162 so as to cool the first radiator 140. In other words, the first fan 120 and the first radiator 140 are fixed on the first wall 162 so that the metal fins of the first radiator 140 are parallel to the first wall 162 and that the first fan, when it is in operation, generates a flow of air passing between said metal fins, thus allowing them to be cooled.

In the example described here, the first fan 120 is an axial fan. Alternatively, the first fan 120 can be a radial or tangential fan.

In addition, each of the metal fins of the first radiator 140 comprises an opening, these openings being sufficiently wide and positioned facing each other so as to allow the introduction, from outside the box 160, of the second end of the first heat pipe 110 through the first orifice 181 of the first wall 162. The first radiator 140 also comprises another opening allowing the introduction from outside the case 160 of the second end of the second heat pipe 115 through the second orifice 182.

Thus, the first heat pipe 110 crosses, before its introduction inside the box 160, the metal fins of the first radiator 140 and the first orifice 181 of the first wall 162 of the box 160. In the same way, the second heat pipe 115 crosses before its introduction inside the box 160, the metal fins of the first radiator 140 and the second orifice 182 of the first wall 162 of the box 160.

After its introduction, the first heat pipe 110 is arranged inside the case 160 so that its first end is in thermal contact with the first electronic component 151 and so that its second end is in thermal contact with the metal fins of the first radiator 140. The first heat pipe 110 may optionally be attached to the first radiator 140 by crimping.

After its introduction, the second heat pipe 115 is arranged inside the box 160 so that its first end is in thermal contact with the lower face 157 of the first electronic card 155 and its second end is in thermal contact with the fins metal of the first radiator 140. Thus, the second heat pipe 115 is in thermal contact with the lower face 157 of the first electronic card 155 via an electrically insulating thermal paste.

When the voltage converter 100 is running, the first and second electronic components 151, 152 heat up and their temperature increases. The thermal energy dissipated by the electronic components 151, 152 in operation is then drained via the thermal paste, towards the first end of the first heat pipe 110. At this first end, the heat transfer fluid of the first heat pipe 110 is vaporizes by absorbing the thermal energy emitted by the first and second electronic components 151, 152. The vapor then circulates in the first heat pipe 110 up to its second end located at the level of the metal fins of the first radiator 140 where it condenses to return in liquid state. During the condensation phase, the thermal energy is transmitted from the first heat pipe to the first radiator 140 cooled by the first fan 120.

The energy dissipated by the first and second electronic components 151,152 through the first electronic card 155 is drained via the thermal paste towards the first end of the second heat pipe 115. At this first end, the heat transfer fluid of the second heat pipe 115 vaporizes by absorbing the thermal energy emitted by the first and second electronic components 151, 152. The vapor then circulates in the second heat pipe 115 up to its second end located at the level of the metal fins of the first radiator 140 where it condenses back to a liquid state. During the condensation phase, the thermal energy is transmitted from the second heat pipe 115 to the first radiator 140 cooled by the first fan 120.

Optionally, the second heat pipe 115 is in thermal contact with the bottom of the case 161 via a thermal paste, thus making it possible to drain the energy dissipated by the first and second electronic components 151, 152 towards the bottom of the housing 161 improving heat dissipation.

In addition and optionally, the box 160 can be hermetically sealed. And in this case the box 160 comprises a lid and sealing means. These sealing means comprise for example a seal between the box 160 and its lid.

Sealing means are also arranged at the level of the first orifice 181 and the second orifice 181. These sealing means comprise for example an O-ring seal around the first heat pipe 110 and making contact with the first orifice 181 and also a another O-ring seal around the second heat pipe 115 and making contact with the second orifice 182. These sealing means can also be thermal paste placed in the first and second orifices 181, 182 around the first and second heat pipe 110 , 115.

Thus, the first heat pipe 110, the second heat pipe 115, the first radiator 140 and the first fan 120 constitute a device for cooling the first and second electronic components 151, 152.

With reference to the , a voltage converter 300 according to a second embodiment of the invention will now be described. The elements identical to the first embodiment of FIGS. 2 and 3 retain the same references and will not be described again.

The voltage converter 300 differs from the voltage converter 100 previously described in that the first electronic card 155 comprises a third and a fourth electronic components 153, 154 on the lower face 157 of the first electronic card 155.

The fourth electronic component 154 is for example an electronic switch such as a MOSFET or an IGBT forming part of a switching arm of the voltage converter 300.

The third electronic component 153 is for example an inductance. It will be noted that in the example described here, the fourth electronic component 154 dissipates in operation more heat than the third electronic component 153.

Preferably, the fourth electronic component 154 which dissipates more heat than the third electronic component 153 is placed close to the first end of the second heat pipe 115 located inside the case 160. In other words the fourth component electronic component 154 is placed so that it is furthest from the first wall 162 than is the third electronic component 153 which is placed closer to the first wall 162 than the fourth electronic component 154, the third and fourth electronic components 153,154 still being in thermal contact with the second heat pipe 115. The third and fourth electronic components 153,154 are in thermal contact with the second heat pipe 115 via an electrically insulating thermal paste.

The second heat pipe 115 is placed in thermal contact with the third and fourth electronic components 153,154. The second heat pipe 115 is also arranged so that a first end of the heat pipe 115 is inside the case 160 and in thermal contact with the third and fourth electronic component 153, 154 of the lower face 157 of the first card. electronic 155 and a second end is outside the box 160 through the second wall 262 by a second orifice 182.

The first heat pipe 110 crosses, before its introduction inside the box 160, the metal fins of the first radiator 140 and the first orifice 181 of the first wall 162 of the box 160. In the same way, the second heat pipe 115 crosses before its introduction inside the case 160, the metal fins of the first radiator 140 and the second orifice 182 of the first wall 162 of the case 160.

After its introduction, the first heat pipe 110 is arranged inside the case 160 so that its first end is in thermal contact with the first electronic component 151 and so that its second end is in thermal contact with the metal fins of the first radiator 140. The first heat pipe 110 may optionally be attached to the first radiator 140 by crimping.

After its introduction, the second heat pipe 115 is arranged inside the box 160 so that its first end is in thermal contact with the third and fourth electronic component 153,154 of the lower face 157 of the first electronic card 155 and that its second end is in thermal contact with the metal fins of the first radiator 140. Thus, the second heat pipe 115 is in thermal contact with the third and fourth electronic components 153,154 of the lower face 157 of the electronic card 155 via a paste electrically insulating thermal.

When the voltage converter 300 is running, the first, second, third, fourth electronic components 151, 152, 153, 154 heat up and their temperature increases.

The thermal energy dissipated by the first and second electronic components 151, 152, in operation is then drained via the thermal paste, towards the first end of the first heat pipe 110. At this first end, the heat transfer fluid of the first heat pipe 110 vaporizes by absorbing the thermal energy emitted by the first and second electronic components 151, 152. The vapor then circulates in the first heat pipe 110 up to its second end located at the level of the metal fins of the first radiator 140 where it condenses back to a liquid state. During the condensation phase, the thermal energy is transmitted from the first heat pipe to the first radiator 140 cooled by the first fan 120.

The thermal energy dissipated by the third and fourth electronic components 153, 154, in operation is then drained via the thermal paste, towards the first end of the second heat pipe 115. At this first end, the heat transfer fluid of the second heat pipe 115 vaporizes by absorbing the thermal energy emitted by the third and fourth electronic components 153, 154. The vapor then circulates in the second heat pipe 115 up to its second end located at the level of the metal fins of the first radiator 140 where it condenses back to a liquid state. During the condensation phase, the thermal energy is transmitted from the second heat pipe to the first radiator 140 cooled by the first fan 120.

Optionally, the second heat pipe 115 is in thermal contact with the bottom of the case 161 via a thermal paste, thus making it possible to drain the energy dissipated by the third and fourth electronic components 153, 154 towards the bottom of the case. 161 further improving heat dissipation.

Optionally, the box 160 can be hermetically sealed. And in this case the box 160 comprises a lid and sealing means. These sealing means comprise for example a seal between the box 160 and its lid.

Sealing means are also arranged at the level of the first orifice 181 and the second orifice 181. These sealing means comprise for example an O-ring seal around the first heat pipe 110 and making contact with the first orifice 181 and also a another O-ring seal around the second heat pipe 115 and making contact with the second orifice 182. These sealing means can also be thermal paste placed in the first and second orifices 181, 182 around the first and second heat pipe 110 , 115.

Thus, the first heat pipe 110, the second heat pipe 115, the first radiator 140 and the first fan 120 constitute a device for cooling the first, second, third, fourth electronic components 151, 152, 153, 154.

With reference to the , a voltage converter 500 according to a third embodiment of the invention will be described. The voltage converter 500 is for example used in a motor vehicle.

The voltage converter 500 includes an electronic system. This electronic system comprises a box 560, a first electronic card 555 comprising at least a first and a second electronic component 551, 552 to be cooled, a second electronic card 575 comprising at least a fifth and a sixth electronic component 553, 554 a first radiator 540, a first fan 520 a first heat pipe 510.

The first electronic card 555 has an upper face 556 and a lower face 557, the upper face 556 comprising at least a first and a second electronic components 551, 552.

The first electronic card 555 is arranged parallel to the bottom 561 of the box 560.

In other words, the upper face 556 is the face on which the first and second electronic components 551,552 are arranged. The lower face 557 is the face opposite that where the first and second electronic components 551,552 are arranged.

Still in other words, the lower face 557 is the one facing the bottom 561 of the box 560. The upper face is the face that is opposite the face that faces the bottom 561 of the box 560.

The second electronic card 575 has an upper face 576 and a lower face 577, the lower face comprising at least a fifth and a sixth electronic components 553, 554. The second electronic card 575 is also arranged parallel to the bottom 561 of the box 560 .

In other words, the lower face 577 of the second electronic card is the face on which the fifth and sixth electronic components 553,554 are arranged. The lower face 577 of the second electronic card is the face facing the upper face 556 of the first electronic card 555. The upper face 576 of the second electronic card 575 is the face opposite to the face on which the fifth and sixth electronic components are arranged.

The first electronic component 551 is for example an electronic switch such as a MOSFET or an IGBT forming part of a switching arm of the voltage converter 500.

The second electronic component 552 is for example an inductance. It will be noted that in the example described here, the first electronic component 551 dissipates in operation more heat than the second electronic component 552.

The fifth electronic component 553 is for example an inductor. It will be noted that in the example described here, the sixth electronic component 554 dissipates in operation more heat than the fifth electronic component 553.

The sixth electronic component 554 is for example an electronic switch such as a MOSFET or an IGBT forming part of a switching arm of the voltage converter 500.

The first heat pipe 510 is in the form of a closed tube of circular section, for example made of copper, in which a heat transfer fluid circulates. This heat transfer fluid is preferably a two-phase fluid which can be acetone, ammonia, methanol, toluene or even water. In known manner, the first heat pipe 510 comprises a first end where the fluid vaporizes by absorbing thermal energy and a second end where the fluid condenses to return to the liquid state, the circulation of the fluid within the first heat pipe 510 being done for example by capillarity.

In the example described, the box 560 is a rectangular parallelepiped comprising a bottom 561 surrounded by a first 562, a second 563, a third and a fourth wall. The length of the first and second wall defines the width of the case, and the length of the third and fourth wall defines the length of the case. The bottom 561 and the four walls of the box 561 further define an interior housing of the box.

In the example described, the box 560 is a metal box, for example aluminum.

Preferably, the first and sixth electronic components 551, 554 which dissipate more heat than the second and fifth electronic components 552, 553 are placed close to the first end of the first heat pipe 510 located inside the box 560. In other words, the first and sixth electronic components 551,554 are placed so that they are furthest from the first wall 562 than are the second and fifth electronic components 552, 553 which are placed closer. of the first wall 562 than the first and sixth electronic components 551, 554. The first, second, fifth and sixth electronic components 551, 552, 553, 554 still being in thermal contact with the first heat pipe 510. The first, second, fifth and sixth electronic components 551, 552, 553, 554 are in thermal contact via an electrically insulating thermal paste.

The first 540 radiator is made up of a stack of rectangular metal fins. The metal fins are separated by a space to allow the passage of an air flow between them.

The first radiator 540 and the first fan 520 are attached to the outside of the case 560, i.e. outside the interior housing of the case 560, on the first wall 562. The first fan 520 is also fixed on the first wall 562 so as to cool the first radiator 540. In other words, the first fan 520 and the first radiator 540 are fixed on the first wall 562 so that the metal fins of the first radiator 540 are parallel to the first wall 562 and that the first fan, when it is in operation, generates a flow of air passing between said metal fins, thus allowing them to be cooled.

In the example described here, the first fan 520 is an axial fan. Alternatively, the first fan 520 can be a radial or tangential fan.

In addition, each of the metal fins of the first radiator 540 comprises an opening, these openings being sufficiently wide and positioned facing each other so as to allow the introduction, from outside the box 560, of the second end of the first heat pipe 510 through a first orifice 581 of the first wall 562.

Thus, the first heat pipe 510 crosses, before its introduction inside the box 560, the metal fins of the first radiator 540 and the first orifice 581 of the first wall 562 of the box 560.

After its introduction, the first heat pipe 510 is arranged inside the box 560 so that its first end is in thermal contact with the first and sixth electronic components 551, 554 and so that its second end is in thermal contact with the metal fins of first heat sink 540. First heat pipe 510 may optionally be attached to first heat sink 540 by crimping.

When the voltage converter 500 is in operation, the first, second, fifth and sixth electronic components 551, 552, 553, 554 heat up and their temperature increases. The thermal energy dissipated by the electronic components 551, 552, 553, 554 in operation is then drained via the thermal paste, towards the first end of the first heat pipe 510. At this first end, the heat transfer fluid of the first heat pipe 510 vaporizes by absorbing the thermal energy emitted by the first second, fifth and sixth electronic components 551, 552, 553, 554. The vapor then circulates in the first heat pipe 510 up to its second end located at the level of the fins metals of the first radiator 540 where it condenses to return to the liquid state. During the condensation phase, the thermal energy is transmitted from the first heat pipe to the first radiator 540 cooled by the first fan 520.

Optionally, the second electronic card 575 is in thermal contact with the bottom of the box 561 via a thermal paste, thus making it possible to drain the energy dissipated by the fifth and sixth electronic components 553, 554 towards the bottom. of the box 561 improving heat dissipation.

In addition and optionally, the box 560 can be hermetically sealed. And in this case the 560 box includes a lid and sealing means. These sealing means comprise for example a seal between the box 560 and its lid.

Sealing means are also arranged at the level of the first orifice 581. These sealing means comprise for example an O-ring seal around the first heat pipe 510 and making contact with the first orifice 181. These sealing means can also be thermal paste placed in the first orifice 581 around the first heat pipe 510.

Thus, the first heat pipe 510, the first radiator 540 and the first fan 520 constitute a device for cooling the first, second, fifth and sixth electronic components 551, 552, 553, 554.

Claims (8)

Electronic system (100, 300,500) comprising:

1. a box (160.560) comprising a bottom (161.561),
2. a first radiator (140.540) fixed outside the box on a first wall (162.562),
3. a first electronic card (155.555), arranged inside the case (160.560), comprising an upper face (156.556) and a lower face (157.557), the first electronic card (155.555) comprising a first and a second electronic component ( 151, 152,551,552) on its upper face (156,556)
4. a first heat pipe (110,510) in thermal contact with the first and second electronic components (151,152, 551,552), a first end of the first heat pipe (110, 510) passes through at least a part of the first radiator (140, 540) through a first orifice (181, 581) in the first wall (162, 562),

Electronic system (100,300) according to claim 1 comprising:
a second heat pipe (115, in thermal contact with the lower face (157, 557) of the first electronic card (155, 555), a first end of the second heat pipe passes through at least a part of the first radiator (140) via a second orifice (182, 582) Electronic system (300) according to Claim 2, in which the first electronic card (155, 555) comprises on its lower face (157, 557) a third and a fourth electronic component (153, 154). Electronic system (500) according to Claim 1, in which the electronic system comprises a second electronic card (575) comprising an upper face (576) and a lower face (577), bearing on its upper face (576) a fifth and a sixth electronic components (553,554) Electronic system (100,300,500) according to claims 1 to 4 in which the thermal contact is made with an electrically insulating thermal paste Electronic system (100) according to one of the preceding claims comprising a first axial, radial or tangential fan (120). Voltage converter including:

1. An electronic system (100,300,500) according to claims 1 to 6
2. An electronic switch, for example a transistor, a diode, a bipolar transistor, a MOSFET transistor, or an IGBT transistor, said first electronic component to be cooled being said electronic switch

A voltage converter according to claim 7 wherein said voltage converter is a DC-DC voltage converter or an AC-DC voltage converter