Title of Invention

POWER SEMICONDUCTOR MODULE WITH SEALING DEVICE TO THE SUBSTRATE CARRIER AND PRODUCTION METHOD THEREFOR

Abstract

The invention describes a power semiconductor module comprising a housing of a first plastic, at least one substrate carrier with a circuit arrangement constructed thereon and electric terminating elements coming from it, wherein the housing has attachment means for the permanent connection with the substrate carrier and wherein the housing has a permanently elastic sealing device of a second plastic which is constructed of one piece with the former and circulates and is directed towards a first inner main surface of the substrate carrier. The associated method exhibits the following essential steps: constructing a housing of a first mechanically stable plastic and a sealing device of a second permanently elastic plastic; arranging the at least one substrate carrier at the housing; permanently connecting the housing with the substrate carrier by means of the attachment means.

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 POWER SEMICONDUCTOR MODULE WITH SEALING DEVICE TO THE SUBSTRATE CARRIER AND PRODUCTION METHOD THEREFOR APPLICANT (S) a) Name b) Nationality c) Address SEMIKRON ELEKTRONIK GMBH & CO. GERMAN Company SIGMUNDSTRASSE 200, 90431 NUERNBERG, GERMANY KG PREAMBLE TO THE DESCRIPTION The following specification particularly describes the invention and the manner in which it is to be performed : - RWS Group Ltd, of Europa House, Marsham Way, Gerrards Cross, Buckinghamshire, England, hereby declares that, to the best of its knowledge and belief, the following document, prepared by one of its translators competent in the art and conversant with the English and German languages, is a true and correct translation of the accompanying German Patent Application No. 10 2007 034 848.9 filed on 26 July 2007. Signed this 17th day of June 2008 C. E. SITCH Managing Director - UK Translation Division For and on behalf of RWS Group Ltd Description The invention describes a power semiconductor module with a housing, at least one substrate carrier, preferably arranged in a recess of the housing and laterally enclosed by the housing, with a power- electronics circuit arrangement constructed thereon and electrical terminating elements coming from this. By way of example, a power semiconductor module of the said type is disclosed in DE 101 00 460 Al as has long been known in its basic embodiment. Such power semiconductor modules according to the prior art have a substrate carrier which forms the lower termination to the power semiconductor module. The housing of insulating material slightly protrudes above this substrate carrier on its longitudinal sides in order to enclose it. Such substrate carriers are frequently constructed as a flat moulded metal body, preferably of copper. This results in low thermal resistance with effective spreading of the heat for the heat transport from the power-electronics circuit arrangement to a cooling component. According to the prior art, it is also known that the substrate carrier is bonded to the housing in order to prevent, when the housing is filled with an insulating material which is liquid at this time, for example a silicone rubber, this silicone rubber from flowing out. Furthermore, the housing is connected to the substrate carrier by means of metallic rivet connections. These rivet connections are constructed as hollow bodies with a continuous recess in order to also enable the power semiconductor module to be attached to a cooling component by means of a screw connection. According to the prior art, these rivet connections are constructed as brass rivets since these, due to the lead component of the brass, provide for a certain deformation and thus provide for a rivet connection at all. On the substrate carrier itself, the circuit arrangement of the power arranged insulated from the semiconductor module is former. In this context, various circuit arrangements with power transistors, power diodes and/or power thyristors are known. The circuit arrangement is insulated from the substrate carrier by means of insulating substrates, for example DCB (direct copper bonding) substrates. 2 Variously designed terminating elements for load and auxiliary terminals must also be allocated to the prior art, for example control terminals for controlled power semiconductor components. In this context, various technologies for connected these terminating elements to the substrate or the power semiconductor components of the circuit arrangement are known. In this context, solder connections, pressure contact connections and/or sintered pressure connections are particularly preferred. The disadvantageous factor in power semiconductor modules according to the prior art is that the substrate carrier is bonded to the housing by means of an adhesive bond in order to ensure a tightness of the housing against flowing-out of the silicone rubber during the production process. The permanently durable 35 bond is additionally achieved by the rivet connection described above. The invention is thus based on the object of presenting a power semiconductor module with a substrate carrier, wherein the latter is joined to the housing of the power semiconductor module by means of bonding means and wherein the associated production method is susceptible to a cost-effective and automatable design. According to the invention, this object is achieved by a subject matter having the features of Claim 1 and by a method according to Claim 6. Preferred embodiments are described in the subclaims. The starting point of the invention is formed by a power semiconductor module with a housing, at least one substrate carrier preferably arranged in a recess of the housing and laterally enclosed by the housing, preferably on all sides. On the substrate carrier, a power-electronics circuit arrangement is constructed from which electrical terminating elements for load and auxiliary terminals emanate. In this context, it is preferred if at least one connecting element is constructed as spring contact device. Furthermore, the housing has attachment means for a permanent connection with the substrate carrier. The substrate carrier thus forms an outside 3 facing the cooling component or the part of an outside of the power semiconductor module. According to the invention, the housing, preferably the recess of the housing, has a sealing device constructed of one piece with the latter. This sealing device is preferably arranged in the recess of he housing and is constructed circulatory and towards a first inner main surface of the substrate carrier. According to the invention, the sealing device is constructed of a second permanently elastic plastic. The method according to the invention for the producing following such a power semiconductor module has essential method steps: • Constructing a housing, preferably with at least one recess for an associated substrate carrier, in a two- component injection method of a first mechanically stable plastic and a sealing device of a second permanently elastic plastic. • Arranging the at least one substrate carrier at the housing, preferably in the associated recess of the housing. • Permanently connecting the housing with the substrate carrier by means of the attachment means. This connection is preferably constructed in that the attachment means consists of projections of the housing which reach through recesses in the substrate carrier and by establishing a rivet connection by deformation by means of the action of temperature and/or ultrasound of the ends of these projections. In this context, it is preferred if the sealing device at least partially encloses the attachment means of the substrate carrier and excludes them towards the recess. A tight construction of this rivet connection to the extent that it prevents a flowing-out when the power semiconductor module is filled with a silicone rubber, is thus unnecessary. 4 It can also be particularly preferred if the substrate carrier is replaced in its functionality by the substrate itself. In this context, the substrate forms the boundary of the power semiconductor module and, in turn, has the necessary recesses for the rivet connection. Particularly preferred developments of this semiconductor component are mentioned in the respective description of the illustrative embodiment. The inventive solution is also explained in greater detail with reference to the illustrative embodiments and Figures 1 to 4. Figure 1 shows a housing without substrate carrier of a power semiconductor module according to the invention in a three-dimensional view. Figure 2 shows a housing according to Figure 1 in a two-dimensional view. Figure 3 shows a cross section through a housing of a power semiconductor module according to the invention according to Figure 1. Figure 4 shows a part of the power semiconductor module according to the invention according to Figure 1 in cross section with substrate carrier arranged thereon. Figure 1 shows a housing (10), preferably of a plastic, which is tempera ure-stable up to about 150°C/ without substrate carrier of a power semiconductor module (1) according to the invention in a three-dimensional view. In this context, the housing (10) has on the side facing a cooling device, not shown, a recess (12) for receiving a substrate carrier, and two holes (16) for screw connections with the cooling component. This recess (12) advantageously has on the two longitudinal sides of the power semiconductor module (1) in each case a web (120) in order to enclose the arrangeable substrate carrier on all sides. 5 In the interior of the power semiconductor module (1), further holes (14) for arranging connecting elements, in this case auxiliary connecting elements constructed as contact springs, are shown. These auxiliary connecting elements are used for the external connection of a circuit arrangement which is arranged on a substrate carrier which can be arranged in the recess (12) of the housing (10). In the area of this recess (12)/ advantageously in its edge area (122) of the narrow sides, the housing (10) exhibits projections (20) preferably constructed of one piece with the former. These projections (20) are constructed to be pin like in this case and protrude above the housing (10) in the direction of the substrate carrier to be arranged. A sealing device (30) of an elastic plastic which was preferably produced jointly with the housing (10) in a two-component injection method is also shown. This sealing device (30) forms a sealing lip circulating in the edge area of the recess (12) of the housing (10) which in a preferred manner suitably encloses the projections (20) in such a manner that these projections (20) are outside the sealing area of the sealing up. Figure 2 shows a housing (10) of a power semiconductor module (1) according to Fig. 1 in a two-dimensional view, in this case in a top view of the recess (12) for the arrangement of the substrate carrier, without details in the interior of the recess. In this case, the housing (10) with the two holes (16) for the screw connection with an arrangeable cooling component is again shown. In the area of the recess (12), the projections (20) of the housing (10) for the rivet connection with the arrangeable substrate carrier are also shown. In the interior of the recess (12), the sealing device (30) according to the invention is arranged. This is advantageously arranged in such a manner that it leaves open connecting means such as the projections (20). The projections (20) are thus located in an area of the recess (12) which is not sealed towards the substrate carrier by the 6 sealing device (30). This is advantageous since, as a result, the rivet connection between the projections (20) and the substrate carrier does not have to meet any special requirements for the tightness. However, it may also be preferred to exclusively or additionally arrange connecting means in the area of the surface of the substrate carrier to be sealed, as a result of which the requirements for the rivet connection rise to the extent that it must be constructed to be tight. An electrically insulating casting compound which is introduced into the interior of the power semiconductor module during the production process and at least partially fills the former is still liquid at this time according to the prior art and could thus emerge in the area of the rivet connections. Figure 3 shows a cross section through a housing (10) of a power semiconductor module (1) according to the invention according to Fig. 1. It shows the housing (10) with the recess (20) and, arranged in the area of this recess, a connecting means (20) for the rivet connection with a substrate carrier in the form of a projection of the housing (10) and a hole (14) for arranging an auxiliary connecting element constructed as contact spring. The recess (12) itself is bounded laterally with respect to the longitudinal sides of the power semiconductor module (1) by two webs (120) which form stop means for a substrate carrier to be arranged. The sealing device (30) is arranged directly adjacently to these webs (120) in the interior of the recess (12). According to the method described, this sealing device (30) is constructed of a second permanently elastic plastic and produced of a first plastic, together with the housing (10), in a two-component injection method. Figure 4 shows, in cross section, a part of the power semiconductor module according to Figure 1 according to the invention with the substrate carrier arranged. In this context, the substrate carrier (40) is designed as a surface-finished copper plate. This substrate carrier (40) exhibits recesses (42) which are continuous flush with the projections (20) of the housing (10). To achieve the rivet connection of the substrate carrier with the housing, these projections have been deformed by means 7 of temperature and/or ultrasound application in such a manner that they no longer protrude over the outer main surface (46) of the substrate carrier (40). The power-electronics circuit arrangement (50) is arranged on the inner main surface (44) of the substrate carrier, facing the interior of the power semiconductor module (1), and electrically insulated from the former. 8 WE CLAIM: 1. Power semiconductor module (1) comprising a housing (10) of a first plastic, at least one substrate carrier (40 ) with a circuit arrangement (50) constructed thereon and electric terminating elements (60) coming from it, wherein the housing (10) has attachment means (20) for the permanent connection with the substrate carrier (40) and wherein the housing (10) has a permanently elastic sealing device (30) of a second plastic which is constructed of one piece with the former and circulates and is directed towards a first inner main surface (44) of the substrate carrier (40). 2. Power semiconductor module according to Claim 1, wherein the substrate carrier (40) is designed as a surface-finished copper plate, on the inner main surface (44) of which a power-electronics circuit arrangement'(50), built up electrically insulated to the copper plate, is arranged. 3. Power semiconductor module according to Claim 1, wherein the substrate carrier (40) is arranged in a recess (12) of the housing (10) and is laterally enclosed by the housing (10) and the permanently elastic sealing device (30) is arranged in this recess (12). 4. Power semiconductor module according to Claim 1, wherein at least one connecting element (60) is constructed as spring contact device. 5. Power semiconductor module according to Claim 1, wherein the sealing device (30) at least partially encloses the attachment means (20) of the substrate carrier (40) and excludes them towards the recess (12). 6. Method for producing a power semiconductor module (1) according to Claim 1, comprising the method steps: 9 • Constructing a housing (10) of a first mechanically stable plastic and a sealing device (30) of a second permanently elastic plastic. • Arranging the at least one substrate carrier (40) at the housing (10). • Permanently connecting the housing (10) with the substrate carrier (40) by means of the attachment means (20). 7. Method according to Claim 6, wherein the attachment means (20) consists of projections of the housing (10) which reach through recesses (42) in the substrate carrier (40) and wherein a rivet connection is established by deformation by means of the action of temperature and/or ultrasound of the ends of these projections (20). 8. Method according to Claim 6, wherein subsequently the internal space of the power semiconductor module (1) is filled at least partially with an electrically insulating casting compound. Dated this 10th day of July, 2008 HIRAL CHANDRAKANT JOSHI AGENT FOR SEMIKRON ELEKTRONIK GMBH & CO. KG 10

Documents:

1444-MUM-2008-ABSTRACT(1-7-2013).pdf

1444-mum-2008-abstract.doc

1444-mum-2008-abstract.pdf

1444-MUM-2008-CANCELLED PAGE(6-12-2012).pdf

1444-MUM-2008-CLAIMS(AMENDED)-(1-7-2013).pdf

1444-MUM-2008-CLAIMS(AMENDED)-(6-12-2012).pdf

1444-mum-2008-claims.doc

1444-mum-2008-claims.pdf

1444-MUM-2008-CORRESPONDENCE(10-7-2008).pdf

1444-MUM-2008-CORRESPONDENCE(18-3-2010).pdf

1444-MUM-2008-CORRESPONDENCE(25-08-2008).pdf

1444-MUM-2008-CORRESPONDENCE(6-12-2012).pdf

1444-MUM-2008-CORRESPONDENCE(8-6-2012).pdf

1444-mum-2008-correspondence.pdf

1444-mum-2008-description(complete).doc

1444-mum-2008-description(complete).pdf

1444-mum-2008-drawing.pdf

1444-MUM-2008-FORM 1(25-08-2008).pdf

1444-mum-2008-form 1.pdf

1444-mum-2008-form 18.pdf

1444-mum-2008-form 2(title page).pdf

1444-mum-2008-form 2.doc

1444-mum-2008-form 2.pdf

1444-MUM-2008-FORM 26(1-7-2013).pdf

1444-MUM-2008-FORM 3(1-7-2013).pdf

1444-MUM-2008-FORM 3(6-12-2012).pdf

1444-mum-2008-form 3.pdf

1444-mum-2008-form 5.pdf

1444-MUM-2008-MARKED COPY(1-7-2013).pdf

1444-MUM-2008-OTHER DOCUMENT(1-7-2013).pdf

1444-MUM-2008-PETITION UNDER RULE-137(6-12-2012).pdf

1444-mum-2008-power of attorney.pdf

1444-MUM-2008-REPLY TO EXAMINATION REPORT(6-12-2012).pdf

1444-MUM-2008-REPLY TO HEARING(1-7-2013).pdf

1444-MUM-2008-SPECIFICATION(AMENDED)-(1-7-2013).pdf

1444-MUM-2008-US DOCUMENT(6-12-2012).pdf