CN110836217A

CN110836217A - Joining method and system for connecting members

Info

Publication number: CN110836217A
Application number: CN201910753455.3A
Authority: CN
Inventors: O.兰格; A.勒希; M.普里斯; J.U.米勒; M.齐默曼
Original assignee: Volkswagen AG
Current assignee: Volkswagen AG
Priority date: 2018-08-15
Filing date: 2019-08-15
Publication date: 2020-02-25
Also published as: DE102018213719A1

Abstract

A joining method (80) for the pressure-loaded connection of a first component (10) to a second component (20) is disclosed, wherein the first component (10) is arranged between a punch (40) and the second component (20), and an ambient pressure (p) of the first component (10) is applied_Chamber) And the ambient pressure (p) of the second component (20)_i) Synchronously increasing the working pressure, maintaining the working pressure for a defined period of time after the working pressure is reached, or continuously reducing the ambient pressure (p) of the first component_Chamber) For generating a pressure difference. Further, a system (100) is disclosed.

Description

Joining method and system for connecting members

Technical Field

The invention relates to a joining method for the fixed connection of a first component to a second component under pressure loading and to a system for connecting a first component to a second component.

Background

There is a need in many technical fields to connect a plurality of components (in particular, material-fittingly) to one another. For example, in the case of electronic components, the component to be cooled can be connected to the heat sink in such a way that as low a loss of heat transport of the component in the heat sink as possible occurs. For this purpose, the respective component can be screwed, riveted, soldered or adhesively bonded to the cooling body. Such a component may be, for example, a semiconductor or a semiconductor module.

Depending on the material of the components to be connected to one another, however, a material-fit connection (verindung) that can be maintained over a long period of time may not be possible or only difficult to achieve by soldering or adhesive techniques. The components can thus be connected to one another by sintering with a material fit. Since a high contact pressure is applied to the connection point during the sintering process and the connection point is additionally heated to 180 to 300 ℃, the method is primarily limited to mechanically stable components, since the strength properties of the material are negatively influenced by the sintering process.

Document DE 102014114095B 4 describes a sintering device in the case of which an electronic assembly can be connected to a mechanically stable base (Unterlage) by sintering. The base simultaneously acts as a lower punch and is not deformable, so that the electronic assembly can be pressed shape-stably against the base with a pressure pad (Druckkissen).

However, the sintering devices and sintering methods known to date can lead to damage to the components to be joined when they are designed thinly or in a brittle manner. In the case of such components, the production of a material-to-material connection, such as, for example, friction welding, which occurs as a result of frictional heat, is also problematic.

Disclosure of Invention

The invention is based on the object of providing a method and a system for connecting components that are sensitive under pressure loading.

This object is achieved by the features specified in claim 1 and in claim 8. Further advantageous embodiments of the invention are described in the dependent claims.

According to one aspect of the invention, a joining method for the positionally fixed connection of a first component to a second component under pressure loading is provided. In one step, a first member is disposed between a punch and a second member. The ambient pressure of the first component and the ambient pressure of the second component are then simultaneously increased to the operating pressure. After the working pressure is reached, the working pressure is maintained for a defined duration or the ambient pressure of the first component is continuously reduced for generating the pressure difference.

The surrounding pressure of the components can be adjusted by means of a spatial separation and a hydraulic or pneumatic coupling of the respective receiving spaces of the components.

By reducing the ambient pressure of the first component, a controlled imbalance can additionally be created, by means of which the connection point between the first component and the second component is acted upon by a pressure difference. The first component can be pressed by a pressure difference between the punch and the second component. The punch may additionally be used for initial positioning or orientation of the first member relative to the second member.

Preferably, the region in which the ambient pressure of the first component acts is closely spaced from the region in which the ambient pressure of the second component acts. This may be designed by one or more optional seals or sealing profiles.

By means of the method according to the invention, shorter holding times for positioning the component to be fastened and shorter process times for the automatable connection of the components can be achieved.

After the loading of the two components with pressure, the connection point and the two interconnected components can be relieved, by continuously and uniformly reducing the ambient pressure on both sides of the connection point to atmospheric pressure.

In contrast to other solutions known to us, by this method it is possible, for example, to arrange electronic components to be cooled in or at the cooling profile without risking damage to the components or the cooling profile. The risk of corrosion or short circuits can be eliminated due to the corresponding spatial separation of the electronic components from the cooling medium.

A material-fit connection between the first component and the second component can be established in a versatile manner when the first component is arranged directly on the second component or by means of a joining material on the second component, that is to say between the first component and the second component. For example, a fusible solder layer, an activatable or hardenable adhesive layer or a sintered material layer can be arranged as a joining material between the first component and the second component. The joining material arranged between the components thus forms the connection points of the components. A uniform force distribution along the connecting point can be established by the application of pressure to the components on both sides of the pressure force, which is directed in the direction of the connecting point, as a result of which a particularly stable and retainable material-fit connection occurs.

The first component to be fastened is acted upon by a force (Flä) which is proportional to the ambient pressure of the second component at any time by means of an inversely proportional control of the pressure, the resulting force balance prevents damage to the first component.

Preferably, the area of the pressing chamber, projected onto the second component, in which the ambient pressure of the first component acts is only insignificantly larger than the first component to be fixed. Furthermore, the area difference can be compensated by a adaptable pressure guidance in the spatially separated chambers for the first and second component. Preferably, the respective ambient pressure can be measured and adjusted via the control unit. The control unit can be designed as a process control (processstauung) for the method.

The pressure in the respective chamber can be reduced or adapted to atmospheric pressure before the respective component is loaded with an overpressure (Überdrive), the first component to be fastened is prevented from deforming by simultaneous force loading of the punch, which is designed to press against the punch, thereby reducing the risk of damage caused by deformation.

According to a further embodiment, the second component is a hollow body and/or an extruded profile, wherein the internal pressure of the second component corresponds to the ambient pressure of the second component. The second component can thus be a heat sink and in particular an extruded profile, which can also have a hollow space. Such extruded profiles can be deformed by the pressure loading required for the sintering process and thus make a material-fit connection difficult or prevent it. The deformation of the components to be connected to one another can be prevented or at least reduced by a uniform and simultaneous loading of the components. In this way, thin-walled and easily deformable components can also be connected to one another under pressure by the method according to the invention.

The first component can be mounted directly on one outer side of the extrusion geometry or the second component, wherein the liquid-conducting region of the extrusion geometry is located inside. The extrusion geometry can consist of, for example, extrusion-capable materials such as aluminum, copper, brass and the like. However, it is also possible to use gaseous coolants, such as, for example, air, in addition to the liquid-conducting medium. The extrusion geometry may also have a surface-increasing geometry or contouring (Konturierung) in the region of the coolant contact.

Such geometries of the second component or of the extruded profile can also be produced by another production method, such as, for example, 3D printing, casting methods or stamping and bending methods.

After the synchronous establishment of the operating pressure or after the reduction of the ambient pressure of the first component, according to one embodiment, the joining region or the joining material between the first component and the second component is acted upon with heat or radiation for producing a material-fit connection. A sintering process or any other joining process, which is pressure-balanced at all times, can be carried out under the influence of pressure and temperature by pressure guidance adapted to the method via hydraulic or pneumatic or fluids formed from solid substances (e.g. paste or sand) in the chambers of the respective components. The corresponding ambient pressure can be adapted accordingly to the fluid heating and the resulting volume expansion in order to compensate for the local excess pressure.

The heat can be brought in by heating the punch, by local or complete heating of the second component and/or by irradiating the connecting point with a laser. After the joining process has been carried out or after the heat input has ended, the pressure of the two components can be synchronously reduced.

According to a further embodiment, the first component and/or the second component is/are loaded with a movement for generating frictional heat after the working pressure has been reached or after the ambient pressure of the first component has been reduced. Relative movement can thereby be generated, which generates frictional heat. Due to the frictional heat, the joining material can either be temporarily melted or the material boundary in the connecting region between the first member and the second member can be melted. It is thereby possible to connect the components to one another in a positive manner by friction welding or contact welding.

The relative movement can be caused, for example, by the punch or the component receptacle of the second component.

According to another aspect of the invention, a system for connecting a first member with a second member and for carrying out a method according to the invention is provided. The system has an engagement device with a pressing chamber and a component chamber, wherein the pressing chamber has a punch for contacting the first component on one side. According to the invention, the pressing chamber and the component chamber can be acted upon independently of one another with an overpressure, wherein the first component can be arranged in the pressing chamber and the second component in the component chamber in such a way that the second component separates the pressing chamber from the component chamber in an air-tight manner.

The ambient pressure in the pressing chamber and the component chamber can be adjusted and regulated by the control unit alone. In the case of the second component used in the component chamber, a fluid-tight seal (absschluss) can be created, which seals the two chambers from one another. Different or identical pressures can thereby be set in the chambers in order to overcome the deformation of the component. In particular, a deformation of the second component, which can be designed to be thin-walled, can be prevented.

A joining process that is pressure-balanced at any time, such as, for example, a sintering process, can be performed by means of a matched pressure guidance via the component chamber and a suitable fluid that is pressed against the chamber. In addition to the pressure application, the components and/or the chambers can be applied with a defined temperature.

By means of the system, for example, electronic components, such as semiconductor modules, can be arranged on the hollow body in a material-fitting manner. The hollow body or the second component can be designed as an extruded profile and serve as a cooling channel for cooling the first component.

When the pressing chamber has a seal for forming the end side of the sealing region, the two chambers can be separated from one another particularly efficiently by the second component. Preferably, the sealing element can be dimensioned such that a surface pressure on the connection point is achieved by pressing in the sealing element. Furthermore, production tolerances can be balanced by the seal.

According to one embodiment, the punch is not movably designed or designed as a pressing punch with an adjustable pressing force. Here, the first member may be pressed by the second member against a passively (passiv) designed punch. Alternatively, the punch can be designed as an active punch, which can exert a separate pressing force on the first component. The pressing force can be realized in parallel to the pressure loading in the pressing chamber.

Preferably, the first member may be arranged at the or the second member inside or outside the extruded cooling profile. This makes it possible to connect the first component to the second component in a particularly space-saving manner.

By means of the system and the method, for example, electronic components that require cooling can be connected in a material-fitting manner to the corresponding cooling structure. They can be used, for example, in the field of motor vehicles, electronic control units, commercial vehicles, motorcycles, cogeneration plants, electronic appliances and the like.

Drawings

Embodiments of the invention are explained in more detail subsequently with the aid of the figures. Wherein:

figure 1 shows a schematic illustration of a system according to an embodiment of the invention,

FIG. 2 shows a schematic illustration of a system according to another embodiment of the invention, an

Fig. 3 shows a flow chart for elucidating the joining method in accordance with one embodiment of the invention.

List of reference numerals

10 first component/semiconductor module

11 bonding/sintering material

20 second component/extruded profile

21 hollow space of second member

30 joining device

31 pressing chamber

32 member chamber

33 fluid line pressed against the chamber

34 fluid line of component chamber

35 sealing profile

36 sealing element

40 punch

41 punch driver

50 first hydraulic system

51 second hydraulic system

52 third Hydraulic System

60 controller for a first hydraulic system

61 controller of second hydraulic system

62 controller for third hydraulic system

63 central controller

70 connection region

80 joining method

100 system

A_ChamberSurface section of the second component

D press-in distance of seal 36

F_{Press against}The pressing force being caused by the punch

F_{p _ interior}By the ambient pressure p_iInduced compressive force (Druckkraft)

F_{p _ Chamber}By the ambient pressure p_ChamberInduced compressive force

p_ChamberAmbient pressure in the pressing chamber

p_iAmbient pressure in component chamber

p_StThe pressure caused by the punch.

Detailed Description

Fig. 1 shows a schematic illustration of a system 100 for connecting a first component 10 with a second component 20 according to an embodiment of the present invention.

The first component 10 is designed as a semiconductor module, which is mounted on the second component 20. The second component 20 is embodied as a tubular, partially open extruded profile with a hollow space 21.

A bonding material 11 is disposed between the first member 10 and the second member 20. According to the present embodiment, the bonding material 11 is a sintered material.

The first component 10 and the second component 20 can be designed to be thin-walled and/or mechanically unstable and have any desired shape.

The system 100 has an engagement device 30 with a pressing chamber 31 and a component chamber 32. The pressing chamber 31 has a punch 40 which can be controlled via a drive 41 for pressing the pressing force F_{Press against}Is applied to the first member 10. The driver 41 can thus generate the surface pressure p by means of the punch 40_St. The ram 40 is connected in a fluid-conducting manner to the first hydraulic system 50 and can therefore absorb energy in the form of hydraulic pressure for operating the drive 41.

The pressing chamber 31 is connected to the second hydraulic system 51 via a fluid line 33. The component chamber 32 is coupled with the third hydraulic system 52 via a further fluid line 34. The

hydraulic systems

51,52 can thus fill the

respective chambers

31,32 with hydraulic fluid or a hydraulic fluid can be used indirectly for adjusting the ambient pressure p in the

chambers

31,32_Chamber,p_i. Alternatively, the ambient pressure p in the

respective chambers

31,32_Chamber,p_iCan be adjusted by a pneumatic system.

In order to perform the temperature loading of the joining material 11, the punch 40 and/or the joining device 30 can be designed to be heatable.

The pressing chamber 31 has a sealing contour 35 on the end side. The second component 20 is arranged in the component chamber 32 in such a way that it is pressed against the sealing contour 35, whereby the second component 20 acts as a tight separating wall between the component chamber 32 and the pressing chamber 31. In particular, the surface section A of the second component 20_ChamberServing as a partition wall.

The

hydraulic systems

50,51,52 can be operated independently of one another and have three controllers60,61,62, which are designed to control and regulate the

hydraulic systems

50,51, 52. The

controllers

60,61,62 may communicate with each other and adjust the optimized pressure profile between the component chamber 32, the pressing chamber 31 and the punch 40 according to the present embodiment. Preferably, the optimized pressure distribution is characterized by no or minimal deformation of the first and

second members

10, 20. Here, the initial shape and contour of the

components

10,20 can also be maintained at elevated pressure and elevated temperature. For example, it is necessary for the sintering process to apply, for example, 20N/mm in addition to heat²The pressure of (a). In order to ensure that the second component 20 does not change its shape, elastically deforms or even plastically bends or in the extreme case breaks when the first component 10 is placed, a corresponding pressure loading is carried out in such a way that the second component 20 even when the contact pressure p is applied_StWithout changing its shape.

To maintain the shape of the second member 20, the

controller

60,61,62 may adjust the compressive force of the system 100 according to the following equation:

F_{p _ interior}=F_{Press against}+F_{p _ Chamber}

In this case, the ambient pressure p in the component chamber 32 is used_iInduced compressive force F_{p _ interior}Corresponding to the biasing force F caused by the punch 40_{Press against}And by the ambient pressure p in the pressing chamber 31_ChamberInduced compressive force F_{p _ Chamber}The resulting sum. Compressive force F_{p _ interior},F_{p _ Chamber}Here essentially acting on the surface section a of the second component 20_ChamberAnd point towards each other. Depending on the size of the punch 40, it can act at least partially on the surface portion a of the second component 20_ChamberThe above.

In an alternative embodiment, the punch 40 can be driven mechanically perpendicularly to the pressure direction, as a result of which a relative movement can be generated between the

components

10, 20. By means of this relative movement, frictional heat can be generated and the

components

10,20 can be connected to one another directly in a material-fit manner, for example by welding.

A schematic illustration of a system 100 according to another embodiment of the present invention is set forth in fig. 2. In contrast to the system 100 according to the embodiment shown in fig. 1, the punch 40 is designed in a particularly rigid manner. In this case, the punch 40 is embodied as an immovable component of the joining device 30. Since the active loading of the first component 10 by the punch 40 is omitted, the equation for the optimal pressure distribution for the two

components

10,20 changes:

F_{p _ interior}=F_{p _ Chamber}

Depending on the joining method, the compressive force F can also be adjusted_{p _ interior},F_{p _ Chamber}Thereby squeezing the first member 10 and the joining material 11 together between the punch 40 and the second member 20. By pressing the first component 10 together with the second component 20, a connecting region 70 is produced by the heat-activatable joining material 11, which connects the

components

10,20 to one another in a material-fit manner.

According to the present embodiment, the

hydraulic systems

50,52 are connected to a central controller 63, which coordinates the

hydraulic systems

50, 52.

In order to be able to press the first component 10 together between the punch 40 and the second component 20, a seal 36 is provided between the pressing chamber 31 and the second component 20, which seal can be pressed in over the distance D.

A flow chart illustrating a bonding method 80 according to one embodiment of the present invention is shown in fig. 3. Here, the system 100 shown in fig. 1 is used to implement the method 80.

In a first step I, an ambient pressure p in the component chamber 32 is achieved_iAnd ambient pressure p in the pressing chamber 31_ChamberBuild-up of synchronization to the same pressure level. The wrapped portion of the second member 20 is pressure balanced at all locations and thus does not deform.

In a further step II, a holding time of this pressure level can be implemented in order to position or orient the first component 10 to be fixed.

In a further step III, the pressure chamber p is pressed_ChamberThe pressure in (b) is reduced to atmospheric pressure. To be fixedThe first fixed component 10 is synchronized with the ambient pressure p via the pressure ram 40_ChamberIs reduced by a pressure p_StTo load. By the surface pressure F at the component 10 to be fixed_{Press against}And pressure F against the interior of the chamber_{p _ Chamber}The resulting sum is at any time equal to the internal pressure F at the component chamber 32_{p _ interior}. The resulting force balance prevents damage to the

components

10, 20.

In a further step IV, a pressing force F is generated_{Press against}And a member internal pressure p in the second member 20_iGenerated force F_{p _ interior}Complete force balance of the composition. In this phase, the component 10 to be fixed is sintered onto the second component 20 by temperature loading. The method 80 is designed such that the pressure required for sintering (Pressung) is achieved.

In a further step V, the pressure p in the pressing chamber 31 is adjusted_ChamberIncreasing the component internal pressure p to the second component 20_iThe above. This is followed by a simultaneous reduction of the force loading of the component 10 to be fixed via the pressure against the punch 40. By the surface pressure F at the component 10 to be fixed_{Press against}And by pressing against the internal pressure F of the chamber_{p _ Chamber}The resulting sum of the forces induced is at any time equal to the internal pressure p prevailing in the component chamber 32_iInduced force F_{p _ interior}. The resulting force balance prevents damage to the second component 20.

In a further step VI, which may be designed as a final step, the internal pressure p is achieved_iAnd chamber pressure p_ChamberSimultaneous discharge to atmospheric pressure. The wrapped portion of the second member 20 is pressure balanced at all locations and thus does not deform.

Claims

1. Joining method (80) for the positionally fixed connection of a first component (10) to a second component (20) under pressure loading,

-arranging the first member (10) between a punch (40) and the second member (20),

-bringing the ambient pressure (p) of the first member (10)_Chamber) And the ambient pressure (p) of the second component (20)_i) The increase to the working pressure is synchronized and,

-maintaining the working pressure for a defined duration or continuously reducing the ambient pressure (p) of the first component after reaching the working pressure_Chamber) For generating a pressure difference.

2. Method according to claim 1, wherein the first component (10) is arranged directly on the second component (20) or on the second component (20) by means of a joining material (11).

3. Method according to claim 1 or 2, wherein the ambient pressure (p) of the first component (10) is continuously reduced_Chamber) In the case of performing a pressing pressure (p) by means of the punch (40)_St) And conversely proportionally higher.

4. Method according to claim 3, wherein, when carrying out the method (80), the pressing force (F) caused by the punch (40) is_{Press against}) And an ambient pressure (p) through the first component (10)_Chamber) Induced force (F) onto the first component (10)_{p _ Chamber}) The sum of the compositions corresponds to the ambient pressure (p) passing through the second component (20)_i) Induced force (F)_{p _ interior})。

5. Method according to one of claims 1 to 4, wherein the second component (20) is a hollow body and/or an extruded profile, wherein the internal pressure of the second component (20) corresponds to the ambient pressure (p) of the first component (10)_i)。

6. Method according to any one of claims 1 to 5, wherein the ambient pressure (p) of the first component (10) or after the working pressure is reached_Chamber) After the reduction, by heat or radiation for producing a material-fit connection-loading the joining material (11) or the connecting region (70) between the first component (10) and the second component (20).

7. Method according to any one of claims 1 to 6, wherein the ambient pressure (p) of the first component (10) or after the working pressure is reached_Chamber) After the reduction, the first component (10) and/or the second component (20) is loaded with a movement for generating frictional heat.

8. System (100) for connecting a first component (10) to a second component (20) and for carrying out a method (80) according to one of the preceding claims, having an engagement device (30) with a pressing chamber (31) and a component chamber (32), wherein the pressing chamber (31) has a punch (40) for the one-sided contact of the first component (10), characterized in that the pressing chamber (31) and the component chamber (32) can be loaded independently of one another with overpressure and the first component (10) can be arranged in the pressing chamber (31) and the second component (20) can be arranged in the component chamber (32) in such a way, such that the second component (20) separates the pressing chamber (31) from the component chamber (32) in an air-tight manner.

9. System according to claim 8, wherein the pressing chamber (31) has seals (35,36) for configuring the end sides of the sealing zones.

10. System according to claim 8 or 9, wherein the punch (40) is non-movably designed or designed with an adjustable pressing force (F)_{Press against}) Against the punch.