Title of Invention

CIRCUIT ARRANGEMENT COMPRISING A POWER MODULE COMBINED WITH A PRINTED CIRCUIT BOARD

Abstract

A description is given of a circuit arrangement (10) comprising a power module (12) combined with a printed circuit board (14). The power module (12) and the printed circuit board (14) are provided between a heat sink (16) and a pressing device (18) and are contact-connected to one another by pressure contact elements (28). The power module (12) has at least one module board element (22) and a housing (24) formed with shafts (26) for the pressure contact elements (28). The shafts (26) open out from the base area (30) - facing the printed circuit board (14) - of the housing (24) at opening orifices (40). The base area (30) of the housing (24) is formed with orifice sealing ribs (42) around the opening orifices (40). Moreover, the base area (30) of the housing (24) can have a peripheral edge sealing rib (38) along its outer edge (36). Furthermore, a sealing area element (32) can be provided between the printed circuit board (14) and the base area (30) of the housing (24).

Full Text

FORM 2 THE PATENT ACT 1970 (39 of 1970) & The Patents Rules, 2003 COMPLETE SPECIFICATION (See Section 10, and rule 13) 1. TITLE OF INVENTION CIRCUIT ARRANGEMENT COMPRISING A POWER MODULE COMBINED WITH A PRINTED CIRCUIT BOARD APPLICANT(S) a) Name : b) Nationality : c) Address : SEMIKRON ELEKTRONIK GMBH & CO. KG GERMAN Company. POSTFACH 82 0251, 902 53 NUERNBERG, GERMANY PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed : - The invention relates to a circuit arrangement comprising a power module combined with a printed circuit board, the power module and the printed circuit board being provided between a heat sink and a pressing device and being pressure-contact-connected to one another by pressure contact elements, the power module having at least one module board element and a housing formed with shafts for the pressure contact elements, which are pressure-contact-connected to the at least one module board element and the printed circuit board, the shafts opening out from the base area - facing the printed circuit board - of the housing at opening orifices. In the case of circuit arrangements of this type, the occurrence of a failure of the circuit arrangement under extreme climate conditions, such as, for example, extreme exposure to moisture with dewing in the meantime, cannot be reliably precluded. Such failures are caused in particular by corrosion of the at least one module board element of the power module, of the pressure contact elements and/or of the printed circuit board. Therefore, the invention is based on the object of providing a circuit arrangement of the type mentioned in the introduction in which corrosion of the power module, of the pressure contact elements and/ or of the printed circuit board is prevented and a resultant failure of the circuit arrangement is avoided using simple means. In the case of a circuit arrangement of the type mentioned in the introduction, this object is achieved according to the invention by means of the features of claim 1, that is to say by virtue of the fact that the base area of the housing is formed with orifice sealing ribs around the opening orifices of the shafts provided for the pressure contact elements. Said orifice sealing ribs can be assigned to individual opening orifices or groups of opening orifices. Said orifice sealing ribs afford the advantage that penetration of moisture is prevented and corrosion is thus avoided on the printed circuit board, the pressure contact elements and/or the power module. The circuit arrangement according to the invention thus has an optimum operating reliability and service life. In the circuit arrangement according to the invention, the orifice sealing ribs can be composed of the material of the housing, that is to say be formed integrally with the housing in one production process. Another possibility is that the orifice sealing ribs provided at the opening orifices of the base area of the housing are composed of a compliant material. Such orifice sealing ribs of the last-mentioned type can be printed for example onto the base area of the housing; another possibility consists in producing the housing in a 2C injection method, the housing being composed of a dimensionally stable hard material and the orifice sealing ribs being composed of a compliant material and being produced in a common production process at the base area of the housing during the realization thereof. Irrespective of whether the orifice sealing ribs are produced integrally with the housing material or from a relatively compliant material that is different from the housing material, the orifice sealing ribs assigned to the individual opening orifices or groups of opening orifices result in good sealing between the base area of the housing of the power module and the printed circuit board adjacent thereto. A further improvement in the sealing properties of the circuit arrangement according to the invention results if the base area of the housing of the power module has a peripheral edge sealing rib along its outer edge. Said peripheral edge sealing rib - like the orifice sealing ribs - can be composed of the material of the housing and be formed integrally with the housing material, or the peripheral edge sealing rib is composed of a compliant material and is provided at the outer edge of the base area of the housing of the power module. The explanations given above with respect to the orifice sealing ribs correspondingly hold true with regard to the peripheral edge sealing rib. Sealing properties improved even further or optimum sealing result(s) in the circuit arrangement according to the invention if a sealing area element is provided between the printed circuit board and the base area of the housing, said sealing area element being formed with cutouts for the pressure contact elements. The searing area element is preferably formed by a plastic film. Said film can be a PTFE film, for example, which can be used in the temperature range of between -20 and +260°C, is acid-, alkali-, petrol- and oil-resistant and non-flammable and thus corresponds to the fire behaviour UL94VO. It goes without saying that the sealing area element can also be composed of some other suitable material. The sealing area element is expediently formed with external dimensions corresponding to the edge dimensions of the base area of the housing of the power module, that is to say external dimensions which are the same size as or slightly larger than the base area of the housing. Further details, features and advantages emerge from the following description of an exemplary embodiment of the circuit arrangement according to the invention that is illustrated schematically in the drawing, and essential details thereof. In the figures -: Figure 1 shows one embodiment of the circuit arrangement partially in a side view in a manner not true to scale, Figure 2 shows a view in the viewing direction of the arrows II-II in figure 1 of a portion of the base area of the housing of the power module of the circuit arrangement, Figure 3 shows a partial plan view - similar to figure 2 - of another embodiment of the housing of the power module of the circuit arrangement, Figure 4 shows a section along the sectional line IV-IV in figure 2 on a larger scale, Figure 5 shows a section along the sectional line V-V in figure 2 on a larger scale, Figure 6 shows a partial sectional illustration - similar to figure 5 - of another embodiment of the circuit arrangement, Figure 7 shows a partial sectional illustration - similar to figure 4 - of the embodiment of the circuit arrangement in accordance with figure 6, Figure 8 shows a perspective view of a sealing area element of a circuit arrangement in accordance with figures 6 and 7, Figure 9 shows a view of the sealing area element in a viewing direction from above, Figure 10 shows a perspective view of an embodiment of the housing of the power module of the circuit arrangement, and Figure 11 shows a view of the housing in accordance with figure 1 in a viewing direction from above. Figure 1 schematically sectionally illustrates in a side view an embodiment of the circuit arrangement 10 comprising a power module 12 combined with a printed circuit board 14. The power module 12 and the printed circuit board 14 are provided between a sectionally depicted heat sink 16 and a pressing device 18 and are pressure-contact-connected to one another in a manner known per se. For pressing the printed circuit board 14 together with the power module 12, the pressing device 18 is braced with the heat sink 16. This bracing is effected for example with the aid of at least one screw, illustrated schematically by a dash-dotted line 20 in figure 1. The power module 12 has, in a manner known per se, at least one module board element 22 and a cup-shaped housing 24. The cup-shaped housing 24 is formed with shafts 26 (see figures 2, 3, 4, 10 and 11). The shafts 26 are provided for pressure contact elements 28 (see figures 2, 3, 4, 7 and 11). The pressure contact elements 28 serve for the pressure contact-connection - known per se - of the at least one module board element 22 to the printed circuit board 14. In order to bring about a reliable sealing against the ingress of moisture between the power module 12 and the printed circuit board 14, a sealing 31 is provided between the printed circuit board 14 and the base area 30 - facing the latter - of the cup-shaped housing 24. Said sealing 31 is formed by orifice sealing ribs 42 (see figures 2, 3, 4, 7, 10 and 11) which are in each case provided around opening orifices 40 of the shafts 26 provided for the pressure contact elements 28. In this case, the orifice sealing ribs 42 can be assigned in each case to individual shafts 26 (see figure 2) or groups of shafts 26 (see figure 3). In this case, the orifice sealing ribs 42 bear directly and immediately closely against the printed circuit board 14, or a sealing area element 32 is provided between the printed circuit board 14 and the base area 30 of the cup-shaped housing 24 (see figures 6 to 9). The sealing 31 between the printed circuit board 14 and the cup-shaped housing 24 of the power module 12 can additionally be improved by an edge sealing lip 38 (see figures 2, 3, 5, 6,10 and 11) running peripherally at the outer edge 36 of the base area 30 of the cup-shaped housing 24. The sealing area element 32 is formed with cutouts 34 which are provided congruently with the opening orifices 40 of the shafts 26 and through which the pressure contact elements 28 extend and are pressure-contact-connected to the printed circuit board 14. Identical details are in each case designated by the same reference numerals in figures 1 to 11, such that it is unnecessary to describe all the details in each case in detailed fashion in conjunction with all of the figures. List of reference numerals-: 10 Circuit arrangement 12 Power modules (of 10) 14 Printed circuit board (of 10) 16 Heat sink (of 10) 18 Pressing device (for 12 and 14) 20 Dash-dotted line/screw (between 18 and 16) 22 Module board element (of 12) 24 Cup-shaped housing (of 12 for 22) 26 Shafts (in 24 for 28) 28 Pressure contact elements (between 12 and 14) 30 Base area (of 24) 31 Sealing (between 14 and 12) 32 Sealing area element (between 12 and 14) 34 Cutouts (in 32) 36 Outer edge (of 24 or 30) 38 Edge sealing rib (at 36) 40 Opening orifices (of 26 at 30) 42 Orifice sealing ribs (at 40) WE CLAIM: 1. Circuit arrangement (10) comprising a power module (12) combined with a printed circuit board (14), the power module (12) and the printed circuit board (14) being provided between a heat sink (16) and a pressing device (18) and being pressure-contact-connected to one another by pressure contact-connection elements (28), the power module (12) having at least one module board element (22) and a housing (24) formed with shafts (26) for the pressure contact elements (28), which are pressure-contact-connected to the at least one module board element (22) and the printed circuit board (14), the shafts (26) opening out from the base area (30) - facing the printed circuit board (14) - of the housing (24) at opening orifices (40), characterized in that the base area (30) of the housing (24) are formed with orifice sealing ribs (42) around the opening orifices (40) of the shafts (26) provided for the pressure contact elements (28). 2. Circuit arrangement according to Claim 1, characterized in that the orifice sealing ribs (42) are assigned to individual opening orifices (40) and/or groups of opening orifices (40). 3. Circuit arrangement according to Claim 1 or 2, characterized in that the orifice sealing ribs (42) are composed of the material of the cup-shaped housing (24) and are formed in material-integral fashion with the cup-shaped housing (24). 4. Circuit arrangement according to Claim 1 or 2, characterized in that the orifice sealing ribs (42) are composed of a compliant material and are provided at the opening orifices (40) of the base area (30) of the cup-shaped housing (24). 5. Circuit arrangement according to one of Claims 1 to 4, characterized in that the base area (30) of the cup-shaped housing (24) has a peripheral edge sealing rib (38) along its outer edge (36). 6. Circuit arrangement according to Claim 5, characterized in that the peripheral edge sealing rib (38) is composed of the material of the cup-shaped housing (24) and is formed in material-integral fashion with the cup-shaped housing (24). 7. Circuit arrangement according to Claim 5, characterized in that the peripheral edge sealing rib (38) is composed of a compliant material and is provided at the outer edge (36) of the base area (30) of the cup-shaped housing (24). 8. Circuit arrangement according to one of Claims 1 to 7, characterized in that a sealing area element (32) is provided between the printed circuit board (14) and the base area (30) of the cup-shaped housing (24), said sealing area element being formed with cutouts (34) for the pressure contact elements (28). 9. Circuit arrangement according to Claim 8, characterized in that the sealing area element (32) has external dimensions corresponding to the edge dimensions of the base area (30) of the cup-shaped housing (24). 10. Circuit arrangement according to Claim 8, characterized in that the sealing area element (32) is formed by a plastic film. ABSTRACT A description is given of a circuit arrangement (10) comprising a power module (12) combined with a printed circuit board (14). The power module (12) and the printed circuit board (14) are provided between a heat sink (16) and a pressing device (18) and are contact-connected to one another by pressure contact elements (28). The power module (12) has at least one module board element (22) and a housing (24) formed with shafts (26) for the pressure contact elements (28). The shafts (26) open out from the base area (30) - facing the printed circuit board (14) - of the housing (24) at opening orifices (40). The base area (30) of the housing (24) is formed with orifice sealing ribs (42) around the opening orifices (40). Moreover, the base area (30) of the housing (24) can have a peripheral edge sealing rib (38) along its outer edge (36). Furthermore, a sealing area element (32) can be provided between the printed circuit board (14) and the base area (30) of the housing (24). (Figure 1) To The Controller of Patents The Patent Office Mumbai

Documents:

2183-MUM-2007-ABSTRACT(GRANTED)-(28-2-2012).pdf

2183-mum-2007-abstract.pdf

2183-MUM-2007-CANCELLED PAGES(22-11-2011).pdf

2183-MUM-2007-CLAIMS(AMENDED)-(22-11-2011).pdf

2183-MUM-2007-CLAIMS(GRANTED)-(28-2-2012).pdf

2183-mum-2007-claims.pdf

2183-mum-2007-correspondence(15-1-2008).pdf

2183-MUM-2007-CORRESPONDENCE(29-2-2012).pdf

2183-MUM-2007-CORRESPONDENCE(5-4-2010).pdf

2183-MUM-2007-CORRESPONDENCE(IPO)-(29-2-2012).pdf

2183-mum-2007-correspondence-received.pdf

2183-mum-2007-description (complete).pdf

2183-MUM-2007-DESCRIPTION(GRANTED)-(28-2-2012).pdf

2183-MUM-2007-DRAWING(1-11-2007).pdf

2183-MUM-2007-DRAWING(22-11-2011).pdf

2183-MUM-2007-DRAWING(GRANTED)-(28-2-2012).pdf

2183-mum-2007-drawings.pdf

2183-MUM-2007-ENGLISH TRANSLATION(22-11-2011).pdf

2183-MUM-2007-ENGLISH TRANSLATION(29-2-2012).pdf

2183-mum-2007-form 1(14-12-2007).pdf

2183-MUM-2007-FORM 2(GRANTED)-(28-2-2012).pdf

2183-MUM-2007-FORM 2(TITLE PAGE)-(1-11-2007).pdf

2183-MUM-2007-FORM 2(TITLE PAGE)-(GRANTED)-(28-2-2012).pdf

2183-MUM-2007-FORM 3(22-11-2011).pdf

2183-MUM-2007-FORM 5(22-11-2011).pdf

2183-mum-2007-form-1.pdf

2183-mum-2007-form-18.pdf

2183-mum-2007-form-2.pdf

2183-mum-2007-form-26.pdf

2183-mum-2007-form-3.pdf

2183-mum-2007-form-5.pdf

2183-MUM-2007-GENERAL POWER OF ATTORNEY(22-11-2011).pdf

2183-MUM-2007-GENERAL POWER OF ATTORNEY(29-2-2012).pdf

2183-MUM-2007-PETITION UNDER RULE 137(22-11-2011).pdf

2183-MUM-2007-REPLY TO EXAMINATION REPORT(22-11-2011).pdf

2183-MUM-2007-US DOCUMENT(22-11-2011).pdf

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