Electric circuit system and assembling method thereof

Abstract

The present disclosure relates to an electric circuit system. The system includes a housing, a printed circuit board mounted within the housing, an electric component conductively mounted to the printed circuit board, and a cooling system for transferring heat away from of the electric component. The printed circuit board is compartmentalizing the inside of the housing into a first compartment and a second compartment, and the electric component is situated in the first compartment. The cooling system includes at least one first heat transferring element located adjacent to the electric component. The at least one first heat transferring element is secured to the housing surrounding the second compartment capable of forming a heat flowing path defined to transfer heat from the electric component to the housing via the at least one first heat transferring element.

Claims

1. An electric circuit system (100), comprising: a housing (103); a printed circuit board (PCB) mounted within the housing (103); an electric component (101a, 101b, 101c) conductively mounted to the printed circuit board (PCB); and a cooling system (110) for transferring heat away from of the electric component (101a, 101b, 101c); wherein the printed circuit board (PCB) is compartmentalizing the inside of the housing (103) into a first compartment (C1) in which the electric component (101a, 101b, 101c) is situated; and a second compartment (C2); characterized in that the cooling system (110) comprises at least one first heat transferring element (120) located adjacent to the electric component (101a, 101b, 101c); the at least one first heat transferring element (120) is secured to the housing (103) surrounding the second compartment (C2) and configured to form a heat flowing path (HP) defined to transfer heat from the electric component (101a, 101b, 101c) to the housing (103) via the at least one first heat transferring element (120).

2. The electric circuit system (100) according to claim 1, wherein the cooling system (110) further comprises at least one second heat transferring element (130) provided between the first heat transferring element (120) and the housing (103) surrounding the second compartment (C2), where the heat flowing path (HP) is defined to transfer heat from the electric component (101a, 101b, 101c) to the housing (103) via the first heat transferring element (120) and the second heat transferring element (130).

3. The electric circuit system (100) according to claim 2, wherein the at least one second heat transferring element (130) is provided as part of the housing (103).

4. The electric circuit system (100) according to claim 2, wherein two second heat transferring elements (130) are provided between the one single first heat transferring element (120) and the housing (103).

5. The electric circuit system (100) according to claim 2, wherein the housing (103) is a protective housing (103) protecting the inside of the housing (103) from an outdoor environment.

6. The electric circuit system (100) according to claim 1, wherein the at least one first or second heat transferring element (120, 130) extend through an opening (109) of the printed circuit board (PCB).

7. The electric circuit system (100) according to claim 1, wherein: the at least one second heat transferring element (130) extend through the opening (109) of the printed circuit board (PCB); the cooling system (110) comprises a connection system (CS) for connecting the first heat transferring element (120) and the second heat transferring element (130) to each other; the connection system (CS) comprises a first heat transferring surface (121a) provided in one end of the first heat transferring element (120) and a second heat transferring surface (131a) provided in one end of the second heat transferring element (130), the first and second heat transferring surfaces (121a, 131a) being in contact with each other.

8. The electric circuit system (100) according to claim 7, wherein the system (100) comprises an electric insulator (135) provided between the second heat transferring element (130) and the printed circuit board (PCB).

9. The electric circuit system (100) according to claim 7, wherein the connection system (CS) comprises: a U-shaped edge (121b) protruding from the first heat transferring surface (121a) and surrounding at least parts of the second heat transferring element (130).

10. The electric circuit system (100) according to claim 7, wherein the connection system (CS) comprises: a notch (131c) provided in the second heat transferring surface (131a); and a notch engaging element (121c) protruding from the first heat transferring surface (121c).

11. The electric circuit system (100) according to claim 1, wherein the connection system (CS) comprises: a through bore (121d) provided through the first heat transferring element (120); a fastener receiving bore (131d) provided in the second heat transferring element (130); and a fastener (140) inserted through the through bore (121d) and fastened to the fastener receiving bore (131d).

12. The electric circuit system (100) according to claim 1, wherein the first heat transferring element (120) comprises a planar heat transferring surface (122a) provided adjacent to the housing (103) surrounding the first compartment (C1) to form a further heat flowing path (HP) defined to transfer heat from the electric component (101a, 101b, 101c) to the housing (103) via the at least one first heat transferring element (120).

13. The electric circuit system (100) according to claim 1, wherein the first heat transferring element (120) comprise a side surface (123) facing the electric component (101a, 101b, 101c), where the side surface (123) is shaped according to the shape of the electric component (101a, 101b, 101c).

14. The electric circuit system (100) according to claim 1, wherein one single heat transferring element (120) is located adjacent to two or more electric components (101a, 101b, 101c).

15. The electric circuit system (100) according to claim 1, wherein the housing (103) is made of a thermally conducting material.

16. An assembling method of an electric circuit system, comprising the steps of: providing a first heat transferring element (120) and a second heat transferring element (130); providing a first housing section (103a) and a second housing section (103b), wherein the first and second housing sections (103a, 103b) together are defining a compartment (C), wherein the second heat transferring element (130) is protruding into the compartment (C) from the second housing section (103b); guiding the second heat transferring element (130) through an opening (109) of a printed circuit board (PCB), wherein an electric component (101a, 101b, 101c) is conductively mounted to the printed circuit board (PCB); securing the first heat transferring element (120) to the second heat transferring element (130); and enclosing the compartment (C) by mounting the first housing section (103a) to the second housing section (103b).

17. The method according to claim 16, wherein the step of securing the first heat transferring element (120) to the second heat transferring element (130) comprises the steps of: inserting a thermally conducting material (143) between the electric component (101a, 101b, 101c) and the second heat transferring element (130); placing the first heat transferring element (120) onto the second heat transferring element (130); and fastening the first heat transferring element (120) to the second heat transferring element (130) by means of a fastener (140).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Embodiments of the disclosure will now be described in detail with respect to the enclosed drawings, wherein:

(2) FIG. 1 shows a prior art housing of an outdoor power supply system, the housing being a cabinet;

(3) FIG. 2a illustrates a converter module used in the power supply system of FIG. 1;

(4) FIG. 2b illustrates a prior art passively cooled converter module;

(5) FIG. 2c illustrates a prior art power supply system with two such passively cooled converter modules; illustrates a converter module used in the power supply system of FIG. 1;

(6) FIG. 3a shows a front view of a first embodiment of an outdoor power supply system;

(7) FIG. 3b shows a rear view of the first embodiment;

(8) FIG. 4a corresponds to FIG. 3, wherein the upper part of the main housing and the upper part of the respective converter module housings have been removed;

(9) FIG. 4b shown an enlarged view of a converter module located within a converter module housing, where two heat conducting devices are shown;

(10) FIG. 5 illustrates a cross sectional view of a first embodiment;

(11) FIG. 6 illustrates a cross sectional view of a second embodiment;

(12) FIG. 7 illustrates a cross sectional view of a third embodiment;

(13) FIG. 8 illustrates a cross sectional view of a fourth embodiment;

(14) FIG. 9 illustrates a cross sectional view along line A in FIG. 4a;

(15) FIG. 10 illustrates a cross sectional perspective view along line A of FIG. 4b;

(16) FIGS. 11a and 11b illustrates openings in the printed circuit board;

(17) FIG. 12a is a perspective view of a first heat transferring element;

(18) FIG. 12b is an enlarged view of circle B in FIG. 12a;

(19) FIG. 12c is an enlarged perspective view of a second heat transferring element;

(20) FIG. 13a shows a bottom view of the first heat transferring element (from the PCB side);

(21) FIG. 13b shows a first side view of the first heat transferring element;

(22) FIG. 13c shows a top view of the first heat transferring element;

(23) FIG. 13d shows a second side view of the first heat transferring element;

(24) FIGS. 14a-e shows the steps of manufacturing the electric circuit system.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(25) An introduction of the embodiment of the present disclosure will now be described with reference to FIGS. 3a, 3b, 4a, and 4b. In FIG. 3a and FIG. 3b, the front side FS and rear side RS of a power supply system 1 are shown. The system 1 includes a main unit 10 including a protective main housing 11 and a distribution circuit 20 disposed in the protective main housing 11. The system further includes a converter module unit 30 including a protective module housing 31 and a converter module 40 disposed in the protective module housing 31. In the drawings, the system includes four such converter module units 30a, 30b, 30c, and 30d each including respective module housings 31a, 31b, 31c, 31d and converter modules 40a, 40b. However, the system may include only one, two, three or four such units 30, depending on the expected load connected to the power supply system 1.

(26) The distribution circuit 20 includes cable connectors, circuit breakers/relays, a controller for controlling power through the converter(s) etc., while the converter module 40 includes an AC/DC converter, a DC/DC converter, and/or an DC/AC converter, depending on the input power and load requirement. UPS functionality may also be provided by connecting a rechargeable battery to the distribution circuit 20.

(27) In FIG. 4b, an electric circuit system 100 is shown. The electric circuit system 100 is here one of the converter modules 40. However, it should be noted that the principles of the present disclosure are not limited to electric power converters.

(28) The electric circuit system 100 will now be described with reference to FIG. 5, which is a simplified cross-sectional view along line A of FIG. 4b.

(29) In FIG. 5, it is shown that a housing 103 includes a first housing section 103a and a second housing section 103b connected to each other at an interface 105. A printed circuit board PCB is mounted within the housing 103. A dashed line through the printed circuit board PCB is referred to as a PCB plane.

(30) The housing 103 is defining a compartment indicated with a dashed line C in FIG. 5. The printed circuit board PCB is compartmentalizing the inside of the housing 103 into two sub-compartments of the compartment C: a first compartment C1 and a second compartment C2.

(31) An electric component 101 is shown conductively mounted to the printed circuit board PCB by means of a soldering S. The electric component 101 is provided in the first compartment C1 and the soldering is provided in the second compartment C2. However, the electric component 101 may also be a surface mounted device electrically mounted to the first compartment C1 facing side of the printed circuit board PCB.

(32) When supplied with electric power, the electric component 101 produces heat, which must be removed from the compartment C to prevent overheating.

(33) The system 100 therefore includes a cooling system generally referred to as 110. In an embodiment, the cooling system 110 includes a passive cooling system. The housing 103 may be a part of the cooling system 110, where heat is dissipated from the housing 103 to the environment. The housing 103 is therefore made of a thermally conducting material, such as a metal. In one aspect, the cooling system 110 includes cooling fins 104 provided on the outer surface of the housing 103 (not shown in the simplified illustrations in FIG. 5-8, but shown in FIGS. 9 and 10).

(34) Preferably, the system 100 is designed for outdoor use. In such a case, the housing 103 is a protective housing 103 protecting the inside (i.e. the PCB and the electric component 101) of the housing 103 from an outdoor environment. The system 100 may for example have an IP65 classification.

(35) Preferably, the housing 103 is made of aluminum or an aluminum alloy. The cooling fins of the passive cooling system may be manufactured together with the converter module housing in a die casting process or a machining process.

(36) Different embodiments will now be described further in detail below.

First Embodiment

(37) It is referred to FIG. 5 again. Here, the cooling system 110 includes a first heat transferring element 120 located adjacent to the electric component 101. The first heat transferring element 120 is secured to the housing 103 surrounding the second compartment C2, i.e. the first heat transferring element 120 is secured to the second housing section 103b, and configured to form a heat flowing path HP defined to transfer heat from the electric component 101 to the housing 103 via the at least one first heat transferring element 120.

(38) In this embodiment, the first heat transferring element 120 is secured directly to the second housing section 103b.

(39) Hence, heat generated by the electric component 101 is transferred from the first compartment C1 on one side of the printed circuit board PCB to the second compartment C2 on the opposite side of the printed circuit board PCB and further to the second housing section 103b.

(40) In FIG. 5, and also in FIG. 4b, it is shown that there are two such first heat transferring elements 120, one on each side of the electric component 101 (FIG. 5) or components 101a, 101b, 101c (FIG. 4b).

(41) In FIG. 5, the first heat transferring element 120 is extending through an opening 109 of the printed circuit board PCB. This will be described further in detail below.

Second Embodiment

(42) It is now referred to FIG. 6. This embodiment corresponds substantially to the embodiment of FIG. 5, and these corresponding features will not be repeated here. Here, it is shown that the first heat transferring element 120 includes a planar heat transferring surface 122a provided adjacent to the housing 103 surrounding the first compartment C1, i.e. the first housing section 103a, capable of forming a further heat flowing path HP defined to transfer heat from the electric component 101a, 101b, 101c to the housing 103 via the at least one first heat transferring element 120.

(43) Hence, heat generated by the electric component 101 is transferred both to the first and the second housing sections 103a, 103b.

(44) To further improve the heat transfer, the cooling system 110 includes a thermally conducting material 142 provided between the planar heat transferring surface 122a and the housing 103 surrounding the first compartment C1.

(45) Again, to further improve the heat transfer, the cooling system 110 includes a thermally conducting material 143 provided between the electric component 101 and the first heat transferring element 120.

(46) The above thermally conducting material may for example be a thermally conducting pad, a thermally conducting gap filler or a solidified liquid gap filler.

Third Embodiment

(47) It is now referred to FIG. 7. This embodiment corresponds substantially to the embodiments of FIGS. 5 and 6, and these corresponding features will not be repeated here. In FIG. 7, the thermally conducting material 142, 143 have been removed for the sake of simplicity.

(48) Here, the cooling system 110 further includes a second heat transferring element 130 provided between the first heat transferring element 120 and the housing 103 surrounding the second compartment C2, i.e. the second housing section 103b, where the heat flowing path HP is defined to transfer heat from the electric component 101a, 101b, 101c to the housing 103 via the first heat transferring element 120 and the second heat transferring element 130.

(49) In this embodiment, the second heat transferring element 130 is an element separate from the housing 103, the element being connected between the at least one first heat transferring element 120 and the housing 103.

(50) The cooling system 110 includes a connection system CS for connecting the first heat transferring element 120 and the second heat transferring element 130 to each other. In this embodiment, the connection system CS is located in the second compartment C2.

Fourth Embodiment

(51) It is now referred to FIG. 8. This embodiment corresponds substantially to the embodiment of FIG. 7, and these corresponding features will not be repeated here.

(52) Here, the connection system CS is located in the first compartment C1. This is also the case for the embodiment shown in FIGS. 9 and 10. Hence, it is the second heat transferring element 130 which is extending through an opening 109 of the printed circuit board PCB.

(53) Here, the second heat transferring element 130 is provided as part of the housing 103.

(54) In the embodiment shown in FIG. 9, the electric circuit system 100 further includes an electric insulator 135 provided between the second heat transferring element 130 and the printed circuit board PCB.

(55) One embodiment of the connection system CS will now be described in detail with reference to FIGS. 12a, 12b, and 12c. First, it should be noted that FIGS. 12b and 12c are not shown in the same scale.

(56) The connection interface CS includes a first heat transferring surface 121a provided in one end of the first heat transferring element 120 and a second heat transferring surface 131a provided in one end of the second heat transferring element 130, the first and second heat transferring surfaces 121a, 131a being in contact with each other when the system 100 is assembled. One purpose of these heat transferring surfaces 121a, 131a is to ensure an efficient heat transfer between the first and second heat transferring elements 120, 130. The heat transferring surfaces are preferably oriented in a plane parallel to the printed circuit board PCB plane.

(57) The connection system CS further includes U-shaped edge 121b protruding from the first heat transferring surface 121a and surrounding at least parts of the second heat transferring element 130 when the system 100 is assembled.

(58) The connection system CS further includes a through bore 121d provided through the first heat transferring element 120 and a fastener receiving bore 131d provided in the second heat transferring element 130. The fastener receiving bore 131d is aligned with the through bore 121d. In addition, the connection system CS includes a fastener 140 (FIG. 4b) inserted through the through bore 121d and fastened to the fastener receiving bore 131d. The fastener 140 may be a screw for fastening to threads provided in the fastener receiving bore 131d. However, other alternate fasteners may also be used.

(59) The connection system CS further includes a notch 131c provided in the second heat transferring surface 131a; and a notch engaging element 121c protruding from the first heat transferring surface 121c. One purpose of the edge 121b and the notch 131c engaging the element 121c is to enable a manufacturing machine to place or set the first heat transferring element 120 onto the second heat transferring element 130 while ensuring that the bores 121d, 131d are aligned correctly to allow the manufacturing machine to insert the fastener and fasten the first heat transferring element 120 to the second heat transferring element 130.

(60) It is now referred to FIG. 12a and FIGS. 13a-d, showing details of the first heat transferring element 120 of FIG. 4b. Here it is shown that one first heat transferring element 120 includes a side surface 123 facing three electric components 101a, 101b, 101c, where the side surface 123 is shaped according to the shape of the electric components 101a, 101b, 101c to improve heat transfer between the electric components and the first heat transferring element 120.

(61) It is also shown here that one first heat transferring element 120 is connected to two second heat transferring elements 130 by means of two connection systems CS. Hence, two fasteners 140 are used to secure the first heat transferring element 120 to the two second heat transferring elements 130.

(62) It is now referred to FIGS. 11a and 11b. In FIG. 11a it is shown that the PCB includes four circular or oval openings 109a. Preferably, the openings 109a are adapted to the shape of the second heat transferring element 130. In FIG. 11b it is shown that the opening 109 can include an elongated aperture 109b, i.e. one opening 109 for two or more second heat transferring elements 130. It is also shown that the opening 109 may include a notch 109c provided from one of the sides of the printed circuit board PCB.

(63) Assembly Method

(64) The assembly of the electric circuit system 100 will now be described with reference to FIGS. 14a-14e. The assembly may easily be done by means of a manufacturing robot or a number of manufacturing robots located adjacent to an assembly line.

(65) Initially, the different parts have been manufactured and are located near the assembly site. Hence, the first and second housing sections 103a, 103b are stored or provided near the assembly line together with the first heat transferring element.

(66) In a first step shown in FIG. 14a, the second housing section 103b is oriented with the opening to the second compartment C2 facing upwards. The second heat transferring element 130 is also protruding upwardly. In this embodiment, the second heat transferring element 130 is provided as part of the second housing section 103b. As shown, there are two such second heat transferring elements 130, for the purpose of transferring heat from both sides of the electric component 101.

(67) The printed circuit board PCB has already been manufactured and electric components are conductively mounted to the printed circuit board PCB. Only one such electric component 101 are shown in FIG. 14a. The printed circuit board PCB are here lowered into the second compartment C2, where the upwardly facing second heat transferring elements 130 are inserted through openings 109 of the printed circuit board PCB and may be used to guide the printed circuit board PCB to its correct position. As shown in FIG. 12c, the second heat transferring element 130 may be at least partially conical for this purpose.

(68) In FIG. 14b, the printed circuit board PCB are in its desired location and the first heat transferring element 120 are lowered towards the second heat transferring elements 130. Due to the connection system CS, the first heat transferring element 120 will not easily fall off the second heat transferring element.

(69) In FIG. 14c, thermally conducting materials 142, 143 are inserted in place. This may preferably take place before the fastener 140 is used to secure the first heat transferring element 120 to the second heat transferring element.

(70) In FIG. 14c, it is also shown that the distal end of the electric component 101 with respect to the printed circuit board (PCB) aligned with the distal end of the first heat transferring elements 120 with respect to the printed circuit board PCB, as indicated by the dashed line indicating an aligning plane AP. Hence, as these distal ends are aligned with respect to the first housing section 103a, it is easy from a manufacturing point of view and efficient from a cooling point of view to provide a heat conducting material in the aligning plane AP to transfer heat from the electric component 101 and the first heat transferring elements 120 to the first housing section 103a. The aligning plane AP is also indicated in FIG. 9.

(71) In FIG. 14d, the first housing section 103a is lowered towards the second housing section 103b. A sealing element 105a (FIG. 10) is used to protect the compartment C from the outside of the housing 103.

(72) In FIG. 14e, the first housing section 103a is secured to the second housing section 103b for example by means of fasteners inserted in openings 105b (FIG. 10). Hence, the compartment C is now enclosed by the first and second housing sections 103a, 103b.

(73) As many heat generating electric components are located in the first compartment C1, also most of the heat will be generated in the first compartment C1. A printed circuit board PCB is typically not a very good heat conductor. According to the embodiments described above, heat may be transferred efficiently from an electric component on one side of the printed circuit board PCB to the opposite side of the printed circuit board PCB and hence, a more distributed cooling is achieved.