Power semiconductor module and method for combining the same with other materials

Abstract

The present invention discloses a power semiconductor module and a method for combining the arrangement material thereof, wherein the power semiconductor module is configured with a housing and a switch device for arrangement on a base element. The switch device comprises a circuit board having a second surface, the second surface being configured for arrangement on a corresponding third surface of the base element, other components being arranged on a side of the circuit board away from the second surface, the housing at least partially encapsulating the switch device on at least two mutually opposite sides, and fixing devices are arranged respectively therein, only one or at least one first fixing device comprises a first surface, the first surface being configured for arrangement parallel to and offset from the second surface and being recessed relative to the second surface from the direction of the third surface, and the fixing device comprising a stop element configured to withstand a first force, the first force compressing the first surface in the direction of the third surface without deforming the stop element, and further deforming the stop element in response to a second force acting in the same direction.

Description

Technical Field

[0001] The invention describes a power semiconductor module having a housing and a switch device for arrangement on a base element, wherein the switch device comprises a circuit board having a second surface, the second surface being arranged to face in the direction of a corresponding third surface of the base element. The invention also describes a method for material bonding the power semiconductor module to the base element. Background Art

[0002] Power semiconductor modules are known from the general prior art, which include a switch device for arrangement on a base element, which is generally configured as a cooling device, that is, generally configured as a heat sink. These switch devices are enclosed in a housing in a conventional manner according to the prior art, and the housing is generally of cup-shaped design. The housing includes a fixing device, which is generally configured in the form of a cutout according to the conventional manner of the prior art for the penetration of screws as fixing devices. When the power semiconductor module is combined with the heat sink by material, the surface of the housing facing the heat sink is arranged on the heat sink by the screws. In the presence of multiple cutouts for screw penetration, if the surface of the housing is configured with a gap to the surface of the heat sink (further, the surface of the housing is configured with a gap to the loose arrangement of the power semiconductor module on the heat sink), the threaded connection process (especially the initial tightening) will cause the housing to tilt, and in the case of further connection, it will cause the deflection of the switch device, or even damage the switch device.

[0003] With this knowledge in mind, the object of the present invention is to disclose a power semiconductor module with a housing and a switching device, and a method for arranging material bonding of said power semiconductor module on a base element, wherein any tilting of the housing during attachment is reduced. Summary of the invention

[0004] According to the invention, this object is achieved by a power semiconductor module and a method having the following features.

[0005] According to the present invention, a power semiconductor module is configured with a housing and a switching device for arrangement on a base element, wherein the switching device includes a circuit board having a second surface, the second surface being configured to be arranged on a corresponding third surface of the base element, wherein other components are arranged on a side of the circuit board facing away from the second surface, wherein the housing at least partially encloses the switching device on at least two sides opposite to each other, and fixing devices are arranged at the positions respectively, wherein only one or at least one first fixing device includes a first surface, which is configured to be arranged parallel to the second surface and offset and recessed relative to the second surface from the direction of the third surface, and wherein the fixing device includes a stop element, which is configured to be subjected to a first force, which compresses the first surface in the direction of the third surface without causing the stop element to be deformed, and further causes the stop element to be deformed in response to a second force acting in the same direction.

[0006] Preferably, the foot 162 of the stop element 16 is arranged in a recess 18 in the associated fixing device 14. The stop element is preferably configured integrally with the fixing device, and the fixing device is naturally configured integrally with the housing. In each case, the foot of the stop element is understood to be the region which forms the transition from the stop element to the fixing device or the foot of the stop element is arranged on the stop element.

[0007] The stop element itself is in particular configured cylindrically or frustoconically.

[0008] Preferably, the respective fixing device 14 , 12 comprises a through-cutout 146 , 126 for a fixing means 50 , which is in particular configured as a screw 54 .

[0009] According to the method of the invention for bonding the above arrangement material of the power semiconductor module on the third surface 340 of the base element, the base element being configured in particular in the form of a cooling device, the method comprises at least the following process steps:

[0010] a) separately arranging the second surface 240 of the power semiconductor module 1 on the third surface 340 , wherein a gap 440 is provided between the third surface 340 and the first surface 140 ;

[0011] b) applying a first force 40 to the first fixing device 14, thereby bringing the contact surface 160 of the stop element 16, which faces the third surface 340, into contact with said third surface 340, without causing a deformation of the stop element 16; in this way, it is naturally understood that no significant deformation of the stop element occurs, but only the deformation necessary for the technical purpose; in step a), the contact surface may already be arranged separately on the third surface, or may only be brought into this position during this process step;

[0012] c) applying another force to another fixture 12;

[0013] d) Applying a second force 42 to the first fixing device 14, whereby the stop element 16 undergoes a deformation and the gap between the first surface 140 and the third surface 340 is correspondingly reduced.

[0014] Advantageously, as early as in step a), an intermediate layer 32 , which is in particular heat-conducting, is arranged between the second surface 240 and the third surface 340 .

[0015] In an advantageous configuration, the loading of the first fixing device 14 is achieved by means of a first fixing means 50, which is specifically configured as a screw 54, wherein the fixing means 50 protrudes through a cutout 146 in the associated fixing device 14 and engages with an abutment of the base element 30, in particular a blind hole with an internal thread.

[0016] In an alternative configuration, loading of the first fixing device 14 is achieved by means of first fixing means 50 , which are configured in particular as clamping devices 52 , wherein the fixing means engage with the abutment 36 of the base element 30 .

[0017] Advantageously, in step d) the first surface 140 is brought into contact with the third surface 340 .

[0018] In a preferred variant, the base 62 of the stop element 16 can be arranged in a groove 18 in the associated fixing device 14, and in step d), the stop element 16 can undergo a deformation so that a portion 164 of the stop element 16 is deformed (preferably deformed into the groove 18), and the portion 164 initially protrudes partially or completely from the first surface 140 in the direction of the third surface 340.

[0019] In the context of process step d), the subsection 142 of the first fixture 14 may undergo a reversible or irreversible deformation. A subsection is not necessarily to be understood as a strictly delimited area; rather, it may perform a continuous transition to a non-deformed section.

[0020] The method is particularly advantageous in that, in the case of two mutually opposed fixing devices, the first force is applied only to the fixing device comprising one or more stop elements. Thus, the fastening of the power semiconductor module is carried out at this point, wherein the power semiconductor module as a whole is subjected to a certain degree of tilting in the direction of the first fixing device, but this tilting is less than in the case of a power semiconductor module according to the prior art. By fastening the second fixing device, to which the second force can be applied in the same way, the tilting occurs in the opposite direction. By further fastening the first fixing device by means of the second force, a flat attachment of the power semiconductor module to the base element is achieved. In summary, it has been determined that, by means of the method according to the invention, the maximum tilting of the power semiconductor module relative to the base element is less than in the prior art. As a result, the risk of any damage to the power semiconductor module during attachment to the base element is significantly reduced.

[0021] For production engineering reasons or for other reasons, it is advantageous if not only one but a plurality and in particular all fixing devices comprise at least one stop element. It is particularly preferred that all fixing devices have the same design with respect to the stop element.

[0022] Of course, any feature (especially stop element) or feature group described in the singular may exist in the power electronic switching device according to the invention in the plural form, unless explicitly or essentially excluded, or contrary to the concept of the invention.

[0023] It should be understood that the various configurations of the present invention, whether they are described with respect to the power semiconductor module or with respect to the arrangement, can be implemented alone or in any desired combination to achieve improvements. In particular, the features shown and described above and below can be implemented not only in the indicated combinations, but also in other combinations or alone without departing from the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] From the following Figures 1 to 7 Further elaborations, advantageous features and properties of the invention can be found in the description of the exemplary embodiments of the invention schematically shown in the accompanying drawings or in its individual elements.

[0025] Figures 1 to 3 A first configuration of a power semiconductor module according to the invention is shown in various stages of the method according to the invention, which is arranged on a base element which is configured as a cooling device.

[0026] Figure 4 A second configuration of a power semiconductor module according to the invention is shown, which is arranged on a cooling device.

[0027] Figures 5 to 7A third configuration of a power semiconductor module according to the invention is shown, which is illustrated in various views. DETAILED DESCRIPTION

[0028] Figures 1 to 3 A first configuration of a power semiconductor module 1 according to the invention is shown in various stages of the method according to the invention, arranged on a base element 30 configured as a cooling device 34 .

[0029] A portion of a cooling device 34 is shown in each case, in this case an air cooling device. On one surface, namely the third surface 340 , of the air cooling device, a power semiconductor module 1 is arranged, which is likewise only a portion shown.

[0030] For this purpose, a thermally conductive paste 32 is applied to the third surface 340, whereby the circuit board 22 of the power semiconductor module 1 is arranged thereon. The circuit board 22 comprises a first metal layer 24 having a second surface 240, which is positioned in direct contact with the thermally conductive paste 32. In the direction outward from the cooling device 34, the metal layer 24 is followed by a layer of insulating material 26, and then by a second metal layer 28. In a conventional manner according to the prior art, the second metal layer 28 constitutes a printed conductor of the power semiconductor module 1, on which a power semiconductor element not shown is arranged. The circuit board 22, the power semiconductor element and other components (including connection elements and terminal elements not shown) constitute the switching device 20 of the power semiconductor module 1.

[0031] A side of the housing 10 of the power semiconductor module 1 is further shown, on which a first fixing device 14 is arranged. The first fixing device 14 is formed integrally with the housing 10 and thus constitutes an element of the housing. In this case, a subsection 142 of the fixing device 14 is configured as a deformable design and can be moved within certain limits relative to the rest of the housing.

[0032] The fixture 14 comprises a first surface 140, which faces the third surface 340 of the cooling device 34. From this first surface 140, a recess 18 extends into the interior of the first fixture 14. A stop element is arranged in this recess 18, in which case the stop element protrudes from the bottom surface of the recess 18 and is configured integrally with the fixture 14. Thus, a foot 162 of the stop element 16, i.e. the part of the fixture 14 forming the transition to the stop element 16, is arranged in this recess 18. The stop element 16 also comprises a contact surface 160, which is configured to be in contact engagement with the third surface 340. The stop element 16 itself is configured in the shape of a truncated cone.

[0033] Figure 1The arrangement of the power semiconductor module 1 and the cooling device 34 according to process step a) is shown. The first surface 140 is oriented parallel to the third surface 340 and is therefore also oriented parallel to the second surface 240. However, the first surface 140 is configured with a gap 440 from the third surface 340 and is therefore recessed relative to the second surface 240 in the outward direction of the third surface 340. In this configuration, although in principle not necessary, the contact surface 160 of the stop element 16 is also arranged with a gap from the third surface 340.

[0034] Figure 2 The arrangement according to process step b) is shown. Here, the fixture 14 is loaded with a first force 40 in the direction of the cooling device 30, more specifically in the direction of its third surface 340, by the action of a fixing device 50, which in this case is a clamping device 52, more specifically a spring clamping device. In order to introduce the force, the cooling device 34 comprises an abutment 36 for the clamping device 52. By loading the fixture 14 with the first force 40, the contact surface 160 of the stop element 16 is pressed against the third surface 340. As far as technically feasible, the stop element 16 is not deformed.

[0035] At the same time, the fixing device 14 is at least slightly inclined relative to the rest of the housing, whereby the first surface 140 (at least in a portion thereof) is close to the third surface 340 but does not contact the third surface 340. The housing 10 of the switch device 20 may also be slightly inclined relative to the third surface 340 as a whole.

[0036] Process step b) shown here is followed by process step c), in which a further force is applied to a further fixing device (not shown), which is preferably arranged opposite the first fixing device, see Figure 5 and Figure 6 .

[0037] Figure 3The arrangement according to process step d) is shown. Here, by the action of the clamping device 52, a second force 42 is applied to the fixing device 14 in the direction of the cooling device 34 (in particular, in the direction of its third surface 340), and the second force 42 is greater than the first force. By loading the fixing device 14 with the second force 42, the contact surface 160 of the stop element 16 is pressed against the third surface, so that the body of the stop element 16 is deformed. This deformation occurs essentially in the groove 18 of the fixing element 14, whereby the section 164 of the stop element 16 is almost completely deformed in the groove 18. By this deformation, the element of the first surface 140 (its edge when viewed three-dimensionally) is in contact with the third surface 340. In addition, for this process step d) and the previous process step c), the power semiconductor module 1 (in particular, its second surface 240) is in planar contact with the third surface 340 of the cooling device 34, and its cooperation with the cooling device 34 is completed.

[0038] Figure 4 FIG. 2 shows a second configuration of a power semiconductor module 1 according to the invention, which is likewise arranged on a cooling device 34. Essentially the same components as Figure 3 . The process steps performed here are similar to step d). In this case, the difference from the first configuration is that the first surface 140 of the first fixing device 14 (which is further loaded with the second force 42) is engaged with the third surface 340 of the cooling device 34 in a planar arrangement. This planar engagement is achieved by further configuring the connection of the first fixing device 14 and another fixing device (not shown) with the rest of the housing (e.g. similar to the third configuration). Here too, the fixing device 14 is configured integrally with the rest of the housing.

[0039] Figures 5 to 7 A third configuration of a power semiconductor module 1 according to the invention is shown in various views. Figure 5 The power semiconductor module 1 is shown in a plan view from above, ie in the direction of a third surface (not shown) of the base element. Figure 6 A plan view of the power semiconductor module 1 is shown from below, ie a view of the second surface 240 of the power semiconductor module 1 . Figure 7 A three-dimensional detail of a power semiconductor module 1 is shown from below.

[0040] The power semiconductor module 1 comprises a housing 10 with a plurality of penetrations 100, the function of which is the penetration of terminal elements, for example in the form of press-fit pin contact elements, which, however, are not shown themselves. In a substantially conventional manner according to the prior art, the housing 10 comprises a switch device 20, which comprises a circuit board 22 of conventional design according to the prior art, for example in the form of a DCB substrate. The circuit board 22 comprises a second surface 240 for arrangement on a base element, which is typically a cooling device according to the prior art.

[0041] On two opposite narrow sides 200, 202 of the switching device 20, the housing 10 comprises fixing devices 12, 14, respectively. Based on the ease of manufacturing, the fixing devices 12, 14 are configured as mirror images, but have the same design. These fixing devices 12, 14 are partially released from the rest of the housing by longitudinal grooves 122 in the area adjacent to the switching device. Therefore, this area of ​​the fixing devices 12, 14 includes cutouts 126, 146 for the penetration of the fixing device 50, more specifically, in this case, the screw 54 can be moved in the direction of the third surface. For this purpose, the housing 10 includes a sub-section 142, which is associated with the fixing devices 12, 14 and is configured as a deformable design.

[0042] The fixture 12, 14 further comprises two recesses 18, which originate from their first surface 140, respectively, and are arranged adjacent to the cutouts 146, 126 and, in this case, symmetrically with respect to the longitudinal axis of the power semiconductor module 1. The foot of the stop element 16 is arranged on the corresponding bottom surface of the recess 18. Of course, the two recesses 18 associated with the fixture 12, 14 can also be reduced to a single one. In one or more recesses, one, two or more stop elements 16 can be arranged, respectively. The stop element 16 shown here is of truncated conical design.

Claims

1. A power semiconductor module (1), comprising a housing (10) and a switch device (20) arranged on a base element (30), wherein the switch device (20) comprises a circuit board (22) having a second surface (240), the second surface (240) being configured to be arranged on a corresponding third surface (340) of the base element (30), other components being arranged on a side of the circuit board (22) facing away from the second surface (240), wherein the housing (10) at least partially encloses the switch device (20) on at least two mutually opposite side surfaces (200, 202), fixing devices (14, 12) being arranged on the side surfaces (200, 202), respectively, Only one or at least one first fixing device (14) includes a first surface (140), which is arranged to be parallel to and offset from the second surface (240) and recessed relative to the second surface (240) in a direction away from the third surface (340), and wherein the fixing device (14) includes a stop element (16), which is configured to be subjected to a first force (40), which compresses the first surface (140) in a direction toward the third surface (340) so that the stop element (16) does not undergo deformation, and further causes the stop element (16) to undergo deformation in response to a second force (42) acting in the same direction.

2. The power semiconductor module according to claim 1, characterized in that A foot (162) of the stop element (16) is arranged in a recess (18) in an associated fastening device (14).

3. The power semiconductor module according to claim 1, characterized in that The stopper element (16) is configured in a cylindrical or truncated cone shape.

4. The power semiconductor module according to claim 1 or 2, characterized in that The respective fixing device (14, 12) comprises a through-going cutout (146, 126) for a fixing means (50), which is in particular configured as a screw (54).

5. A method for bonding an arrangement material of a power semiconductor module (1) according to any one of the preceding claims on a third surface (340) of a base element (30), the method comprising the following process steps: a) separating and arranging the second surface (240) of the power semiconductor module (1) on a third surface (340), wherein a gap (440) is provided between the third surface (340) and the first surface (140); b) applying a first force (40) to the first fixing device (14), thereby causing a contact surface (160) of the stop element (16) facing the third surface (340) to contact the third surface (340) without causing deformation of the stop element (16); c) applying another force to another fixture (12); d) applying a second force (42) to the first fixing device (14), whereby the stop element (16) undergoes a deformation and the gap between the first surface (140) and the third surface (340) is correspondingly reduced.

6. The method according to claim 5, characterized in that: As early as in step a), the intermediate layer (32) is arranged between the second surface (240) and the third surface (340).

7. The method according to claim 6, characterized in that: The intermediate layer (32) is thermally conductive.

8. The method according to any one of claims 5 to 7, characterized in that: The loading of the first fixing device (14) is achieved by means of the first fixing means (50), wherein the fixing means (50) protrudes through a cutout (146) in the associated fixing device (14) and engages with an abutment of the base element (30).

9. The method according to claim 8, characterized in that: The first fixing device (50) is configured as a screw (54).

10. The method according to any one of claims 5 to 7, characterized in that: The loading of the first fixing device (14) is achieved by means of a first fixing means (50), wherein the fixing means engages with an abutment (36) of the base element (30).

11. The method according to claim 10, characterized in that: The first fixing means (50) is configured as a clamping device (52).

12. The method according to any one of claims 5 to 7, characterized in that: Applying a second force (42) is performed similarly to applying the first force (40), the second force (42) being greater than the first force.

13. The method according to any one of claims 5 to 7, characterized in that: In step d), the first surface (140) is brought into contact with the third surface (340).

14. The method according to any one of claims 5 to 7, characterized in that: The base (162) of the stop element (16) is arranged in a groove (18) in the associated fixing device (14), and in step d), the stop element (16) is subjected to a deformation so that a portion (164) of the stop element (16) is deformed, which initially protrudes partially or completely from the first surface (140) in the direction of the third surface (340).

15. The method according to claim 14, characterized in that: A section (164) of the stop element (16) is deformed into the groove (18).

16. The method according to any one of claims 5 to 7, characterized in that: The base element (30) is configured as a cooling device (34).

17. The method according to any one of claims 5 to 7, characterized in that: At least in process step d), the subsection (142) of the first fixing device (14) is reversibly deformed.

18. The method according to any one of claims 5 to 7, characterized in that: At least in process step d), the subsection (142) of the first fixing device (14) is irreversibly deformed.

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