Sintering device and method

Abstract

The invention relates to a sintering device (10) and a method for simultaneously connecting an assembly of a plurality of electronic components (22) arranged next to one another by pressure sintering. The invention relates to a sintering device (10) having an upper die (12) and a lower die (14), comprising a plurality of first punching heads (16) which can be arranged on the upper die (12) and at least one, in particular a plurality of second punching heads (18) which are arranged on the lower die (14), between which the components (22) are accommodated. For this purpose, each first punch (16) and / or each second punch (18) is associated with a drive (28, 28.1, 28.2) which is arranged to apply pressure to one of the devices (22) by axially moving the associated first punch (16) and / or the associated second punch (18) in the direction of action of the pressure (P). According to the invention, the first punch heads (16) are placed on the devices (22) before the start of a pressing operation and press the devices (22) against the at least one second punch head (18) during the application of the pressure.

Description

Technical Field

[0001] The present invention relates to a sintering device and a method for simultaneously connecting a plurality of electronic components arranged side by side by pressure sintering. Background Art

[0002] In pressure sintering, two or more components, in particular electronic components and substrates, can be connected to one another in an electrically and / or thermally conductive manner via a joining material, wherein the joining material to be joined is sintered. In this case, the joined components are pressed uniaxially between an upper die and a lower die to provide the joining pressure.

[0003] It has proven to be particularly advantageous to carry out the connection under a process atmosphere, in particular under negative pressure or under vacuum, in particular to prevent undesired chemical reactions such as oxidation, the formation of gaseous inclusions and impurities. The heat required for sintering is usually transferred to the component via the upper and lower dies, but the required heat can also be applied as radiant heat from the bottom and / or top side. Generally, a plurality of components should be arranged on a shared substrate, which components can differ from one another in terms of their lateral extension and their height. In order to ensure uniform pressure transmission, a plurality of punches can be provided on the upper and / or lower dies, which punches are coordinated in terms of their size with the components to be connected.

[0004] If different components of different types are to be processed on one machine, the punch layout on the upper or lower die needs to be adapted regularly. This adaptation is time-consuming and difficult to carry out, since the die and / or punch may be hot. In addition, the die, and in particular the punch, are usually made of metal, since they have to withstand high pressures. As a result, such dies are heavy, cool slowly and are more expensive. Furthermore, precise position alignment of the die or punch relative to the component to be connected is required.

[0005] The object of the present invention is to provide a sintering device and a corresponding method which allow a punch head to be arranged quickly and reliably to be adapted to the components to be connected. Summary of the invention

[0006] The solution to the above-mentioned object according to the invention consists in a sintering device having the features of claim 1 and a method having the features of the independent claim. Preferred embodiments are given in the dependent claims.

[0007] The sintering device for connecting a plurality of electronic components arranged side by side by pressure sintering according to the present invention comprises an upper die and a lower die, wherein a plurality of first punch heads can be arranged on the upper die, and at least one, in particular a plurality of second punch heads are arranged on the lower die. The components are accommodated between the first punch heads and the at least one, in particular a plurality of second punch heads, wherein each first punch head and / or each second punch head is provided with a driving device, and the driving device is configured to apply pressure to one of the components by axially moving the corresponding first punch head and / or the corresponding second punch head in the direction of action of the pressure.

[0008] The invention proposes that a first punch is placed on the components before the pressing operation begins, ie before the sintering process begins, the first punch is placed outside the sintering device and the components are pressed against at least one second punch during the application of pressure.

[0009] The difference from the conventional sintering device in which the punch acting on the top side of the device is firmly or replaceably fixed on the upper die is that the first punch acting on the top side of the device is only loosely placed on these devices or their components. Preferably, the first punch is placed on these devices outside the sintering device so that the first punch can be inserted together with these components in the necessary step of inserting the components into the sintering device. When the one or these drive devices move the one or these second punches to apply pressure, the first punch together with the components of these devices located below the first punches are pressed against the pressing plate arranged above these devices or relative to the corresponding drive device of the upper die, which is, for example, stably fixed on the frame of the sintering device. As an alternative, the one or these second punches can be supported on the pressing plate of the lower die, and the first punch of the upper die presses these devices relative to the pressing plate or the second punch of the lower die. Therefore, the pressing plate or the corresponding relative drive device applies a reaction force opposite to the pressure. Preferably, the pressure plate or the drive device of the lower die and / or the upper die can be temperature-controlled by means of corresponding heating and / or cooling devices, so that heat can be transferred to or from the components through the first and / or second punch. The heating and / or cooling device is preferably provided at least in the lower die in order to heat the substrate of the component, while the first punch of the upper die is thermally heated beforehand (e.g. before or after placement), so that a separate heating or cooling device in the upper die can be omitted as appropriate.

[0010] As an alternative or supplement to placing the first punch on these components before the start of the sintering process, as described in EP4 080 554 A2, at least a portion of the first punches, in particular all of the first punches, are fixed in the upper die in a replaceable manner, in particular hot clamped in a clamping device. In this way, the first punches can be flexibly configured. Therefore, at a first temperature, the first punches can be accommodated on or in the retaining plate of the upper die in a manner that can be moved in the upper die along the direction of action of the pressure, for example, and at a second temperature higher than the first temperature, these first punches can be clamped on or in the retaining plate or the upper die. In this way, the corresponding components can be adapted quickly and accurately, in particular, different components have different heights. Therefore, at a first temperature, that is, at a lower temperature, for example, the first punch can be brought close to the component to be connected or the corresponding alignment gauge until all contact surfaces of the first punch are in contact with the corresponding component. In this case, the punches that come into contact with relatively high components or members move further than the punches that come into contact with relatively low components or members. In the case where the punches are adapted to these components or devices in terms of their longitudinal position, the first punches and the holding plate of the upper die are heated. As a result, the first punches are clamped on or in the clamping plate, so that these first punches are fixed in their longitudinal or axial position. By this clamping, a press fit is formed between the first punches and the holding plate.

[0011] Advantageously, during the sintering process, a definable temperature gradient can be provided between the upper punch and the lower punch by means of a heating or cooling device which can be operated separately in the lower die and the upper die, in particular in the associated punch. The heat-sensitive upper part of the device, such as a power semiconductor component, is usually oriented toward the upper die, while the lower part of the device, which is advantageously a good heat conductor, such as a heat sink, is oriented toward the lower die. The sintering connection should usually be established between the bottom side of the upper part of the device and the lower part with the provision of an intermediate layer of sintering slurry. In order not to exceed the limit temperature of the upper part, during the sintering process, the upper die can be heated or cooled along a temperature curve which has a lower temperature curve compared to the temperature curve of the higher temperature of the upper die. For example, a temperature gradient of 50° C. to 100° C. can be set between the hotter lower second punch and the cooler upper first punch, at least when the sintering temperature is reached.

[0012] If a single drive is used in the upper die and / or the lower die, the drive can be designed, for example, as a single-acting hydraulic cylinder for the corresponding single or multiple first and / or second punches. The single-acting hydraulic cylinder can have a large piston surface, which can essentially cover the layout surface of the components on the carrier frame. The single-acting hydraulic cylinder can be reset, for example, by a spring element or another reset mechanism. In this regard, it is possible to dispense with the hydraulic tensioning action on the pressing plane and the use of complex double-acting hydraulic cylinders; instead, the single-acting hydraulic cylinder can be freely movable as a cylinder block, so that the hydraulic pressing device can be provided in a cost-effective manner and lower requirements are placed on the hydraulic control device.

[0013] In an advantageous embodiment, the first punch head can be against the pressing plate of the upper die, wherein at least one drive device of the lower die, in particular the corresponding drive device corresponding to each second punch head, applies pressure in the direction of the upper die through at least one second punch head along the direction of action of the pressure. As an alternative, at least one second punch head is against the pressing plate of the lower die or is formed by the pressing plate, wherein at least one drive device of the upper die, in particular the corresponding drive device corresponding to each first punch head, applies pressure in the direction of action of the pressure in the direction of the lower die. In this embodiment, at least one drive device for applying pressure in the direction of action toward the lower die or the upper die can be arranged in the upper die or the lower die. If at least one drive device is provided in the upper die, the pressure can be transmitted to the first punch head, for example, through the pressing plate in the direction of action toward the lower die. As an alternative, each corresponding drive device (multiple drives) corresponding to each individual in the first punch head can also be arranged in the upper die, and these drive devices can apply pressure to the first punch head individually. In this case, the second punch head can be constructed as a pressing plate in the lower die, for example. As an alternative, a plurality of second punch heads statically fixed in the lower die can press these devices against the lower die. As an alternative, at least one drive device can be provided in the lower die. The drive device can, for example, move the second punch head constructed as a pressure plate or a plurality of second punch heads statically connected to the drive device in the direction of action of the pressure. However, each of the plurality of second punch heads, in particular, the corresponding drive device (multiple drives) corresponding to each second punch head individually corresponding to the first punch head can also be arranged in the lower die, and the drive device can apply pressure to the second punch head individually. In this regard, this embodiment provides a shared drive device or multiple drives for the first or second punch head in the upper die or lower die.

[0014] As an alternative to the aforementioned embodiment, in another advantageous embodiment, the drive device of the upper die can be provided on a plurality of first punching heads, and the drive device of the lower die can be provided on a plurality of second punching heads, wherein due to the opposite directions of the pressure, both sides of each electronic device are acted upon by the drive devices of the upper die and the lower die. In this embodiment, the devices are subjected to sandwich bidirectional pressing by at least one drive device of the upper die and the lower die. The drive device of the upper die can be used as a single drive to distribute the pressure to the first punching heads placed on the devices, for example, through a pressure plate. As an alternative, a corresponding drive device can also be provided for each first punching head individually. The same is true for the drive device of the lower die. The drive device can be provided as a single drive device, which applies pressure in the direction of action toward the upper die, for example, by a second punching head constructed as a pressure plate or a plurality of second punching heads statically arranged on the drive device. As an alternative, a corresponding drive device can be provided for each second punching head individually. Different from the above embodiment, the components can be pressed against each other by driving devices in the upper and lower molds operating in opposite directions, and individual temperature and pressure parameters can be controlled on adjacent components, which is particularly advantageous for parallel sintering of different types of components.

[0015] According to a preferred embodiment, each drive device can individually control its movement distance and / or the pressure applied, preferably in a hydraulic, electric, piezoelectric or magnetostrictive manner. The corresponding first and / or second punch head preferably corresponds to the corresponding device or component. In this way, a uniform pressing pressure can be applied to different devices or individual components. In particular, it is ensured that each device can be individually loaded with a preset pressing pressure. This avoids applying too high or too low pressing pressure to a single device, such as when conventional solutions are adopted, in which only one common punch head acts on multiple components. Another advantage is that the height tolerances of these devices or components can be compensated or taken into account. For example, the required pressure can be adjusted by the corresponding force sensor or pressure sensor or by the displacement sensor, wherein the applied pressure can be achieved directly by adjusting the working pressure or indirectly by adjusting the movement distance of the second punch head. The hydraulically controllable drive device can be formed, for example, by arranging a double-acting piston, which can be supplied from a common pressurized reservoir by a corresponding control valve. However, in principle, each drive device can also have an inherent fluid source for generating pressure, so that the valve can be omitted. For example, electric control can be realized by a drive device with a spindle drive. In addition, a drive device that operates piezoelectrically or magnetostrictively can also be provided.

[0016] According to another preferred embodiment of the present invention, each first punch head and / or second punch head is connected to a corresponding drive device. The second punch head is advantageously not placed on the corresponding drive device, but forms a unit with the corresponding drive device.

[0017] As an alternative or supplementary solution, each first and / or second punch head may have a corresponding heating and / or cooling device. The heating and / or cooling device can be used to transfer heat to or from each device that is in thermal contact with each second punch head and each device that is in thermal contact with the device. The heating and / or cooling device can be electrically operated and / or include corresponding fluid channels arranged in the second punch head, which are connected to corresponding temperature-adjustable fluid sources. The heating and / or cooling device is preferably constructed as a pin-contact heating and / or cooling device. Before the second punch head contacts the entire surface of the device, the heating or cooling temperature can be effectively transferred by a highly thermally conductive elastic needle, in particular, any alignment problem can be compensated, such as surface parallelism compensation. Such heat transfer pin contacts have been described, for example, in WO 2016 / 091962 A1. These heat transfer pin contacts can be used in a heating chamber to heat the device, the second punch head and / or the pressing plate. Preferably, in the combined temperature control of the heating and / or cooling device, the temperature of the first and second punches is controlled simultaneously and a predefinable temperature gradient is maintained between the respective first punch and the corresponding second punch. In this way, temperature-sensitive components of the device can be protected from thermal overload. In addition, even after multiple repetitions of the sintering process, the same temperature conditions can be maintained at the first and second punches.

[0018] According to another preferred embodiment, a carrier frame is provided which can be inserted into the sintering device, in which the components, preferably together with the placed first punch, are held in a manner guided in the transverse direction, wherein the carrier frame preferably has through-holes corresponding to the components, through which the second punch can be mechanically and thermally contacted with the components. The components are mounted in transverse alignment via the carrier frame to match the arrangement pattern of the second punch, wherein transverse alignment refers to alignment transverse to the pressing direction. That is, although the carrier frame prevents lateral movement of the components, it allows movement in the direction of action of the pressure. The through-holes enable the second punch to lift the components from the carrier frame.

[0019] According to another preferred embodiment, at least one guide frame is preferably detachably arranged on the carrier frame, the guide frame being used to guide the first punch head in a transverse direction relative to the components. The guide frame thus prevents a relative movement of the placed punch head relative to the components of the components and / or the carrier frame. In order to facilitate the assembly or reconfiguration of the carrier frame for different components and / or punch configurations, at least one guide frame can be plugged into the carrier frame or can also be screwed to the carrier frame. For example, the guide frame can only be arranged after the components have been inserted into the carrier frame, and then the first punch head can be inserted into the guide frame.

[0020] The thermal expansion coefficient of the guide frame is preferably higher than that of the upper parts of the devices. The device to be sintered can be stacked from individual parts, such as a power semiconductor component as the upper part of the device and a heat sink as the lower part of the device, which parts can have different thermal expansions. Therefore, the thermal expansion of the power semiconductor component is lower than that of the heat sink. When heated to the sintering temperature, the stacked devices may undergo undesirable relative displacements relative to each other. In further processing steps, the precise and correctly positioned alignment of the individual stacked parts of the device relative to each other is very important, so the guide frame can advantageously thermally expand to compensate for the undesirable thermal relative displacement of the device parts relative to each other, for example, thermally displacing the upper part relative to the lower part in the same way. Advantageously, the thermal expansion of the guide rail frame can be higher than that of the upper part of the device accommodated therein and can in particular be composed of aluminum. The lower part of the device can be, for example, a heat sink and can be composed of copper or a similar material with good thermal conductivity. This material expands thermally, wherein the upper parts of the devices (such as power semiconductor components) expand thermally to a lesser extent. In order to achieve accurate sintering of the power semiconductor components on the heat sink, the guide frame can have a high thermal expansion coefficient so that the upper and lower parts of the device are aligned with each other when heated. For this purpose, the guide frame is suitable for using aluminum material, while the lower part of the device is made of copper material. Therefore, in the subsequent process steps, for example, a power supply plate with connecting contacts will accurately connect the power semiconductor components (preferably converter components for power conversion, such as IGBT) sintered on a common heat sink or a separate heat sink in the correct position.

[0021] According to another preferred embodiment, each first and / or second punch head has a punch body that can be axially moved in the direction of action of the pressure and a contact surface that can contact the component of the device, wherein the contact surface is arranged to be tiltable about at least one spatial axis relative to the punch body. However, the contact surface is preferably tiltable around two Cartesian spatial axes, wherein the third spatial axis of the Cartesian spatial axis system extends along the direction of action of the pressure. Therefore, the contact surface can be said to be universally movable relative to the punch body, so that the contact surface can be evenly attached to the component in contact with it. Unlike the rigidly aligned contact surface that can be tilted relative to the component in contact with it, this can avoid the peak force or force gradient inside the component and evenly distribute the pressure. In this case, the contact surface is automatically aligned. For example, the tiltable installation of the contact surface relative to the punch body can be achieved by an elastic balancing layer. The corresponding punch head can also be divided into two parts, for example, in addition to the above-mentioned punch body, it also includes another punch body, which has the above-mentioned contact surface, wherein the two parts of these punch bodies are connected by the above-mentioned elastic balancing layer or provided with another mounting structure that allows tilting.

[0022] According to another preferred embodiment, a plurality of first punch heads arranged side by side correspond to a corresponding second punch head. As an alternative, a plurality of second punch heads arranged side by side correspond to a corresponding first punch head. These first or second punch heads corresponding to the second or first punch heads can in particular have different heights. Thus, for example, a device in which a plurality of components with different heights are arranged on a planar substrate can also be sintered. The heights of the first and second punch heads are determined in such a way that the contact surfaces of these first and second punch heads facing the pressure plate are in a common plane.

[0023] Advantageously, in a flow operation, these first punches can be transported from a discharge station after the sintering device back to a loading station before the sintering device by a conveying device, in particular when the sintering device is bypassed after the sintering process is completed, as described, for example, in WO 2021 / 069328 A1. This ensures a mass production process in which a large number of parts to be connected can be sintered at a high cycle rate.

[0024] According to the method of the present invention for simultaneously connecting a plurality of electronic device components arranged side by side by pressure sintering in a sintering device, the sintering device is particularly designed according to the aforementioned embodiment of the present invention or a preferred embodiment, wherein the sintering device comprises a plurality of first punch heads and at least one second punch head, particularly a plurality of second punch heads, and devices are accommodated between the punch heads, wherein each first punch head and / or the at least one second punch head can be axially moved in the direction of action of the pressure by a corresponding driving device to apply pressure to one of the devices, and the method comprises the following steps

[0025] - placing a first punch onto the devices,

[0026] - inserting the components together with the first punch into the sintering device and aligning it with the second punch, and

[0027] -The sintering process is carried out by operating the drive device so as to move these first punches and / or the at least one second punch from the rest position to the working position to generate the pressing pressure, in which working position, these components are pressed together between these first punches and the at least one second punch, and the at least one second punch is arranged opposite to these first punches to apply a reaction force.

[0028] By placing the first punches onto the components and inserting the components together into the sintering device, the first punches can be configured in a simple manner, which includes both arranging the first punches of appropriate dimensions and accurately aligning the first punches relative to the components or indirectly relative to the layout geometry of the second punches.

[0029] The components together with the first punches can advantageously be inserted into the sintering device via a carrier frame, in which the assembly of the components together with the placed punches is held in a laterally guided manner. The carrier frame preferably has through-holes corresponding to the components, through which the second punches can be brought into mechanical and thermal contact with the components. When the second punches are moved into the working position, the components can be lifted from the carrier frame. In order to prevent the first punches from sliding sideways or transversely during the lifting process before they come into contact with the pressure plate and are fixed by the pressure generated, the carrier frame can have a guide frame, which is arranged to guide the first punches laterally relative to the components. The guide frame ensures that the first punches can be moved axially in the direction of action of the pressure.

[0030] Advantageously, the guide frame and / or the carrier frame have complementary alignment components, such as guide pins, guide grooves, guide sockets or similar components, to arrange the guide frame in the correct position on the carrier frame. When assembling the components on the carrier frame, for example, the lower parts of these components, such as heat sinks, can be placed on or in the carrier frame, and the heat sinks can also serve as the lower parts of multiple placed upper parts of the components. The guide frame can then be placed on the carrier frame in an aligned position by means of the alignment components. The guide frame can have through holes, into which the upper parts of the components, such as power semiconductor components, are inserted by means of a placed first punch.

[0031] According to a preferred technical solution of the method, the step of implementing the sintering process includes at least heating and / or cooling the first punch head and / or at least one, in particular multiple second punch heads. In this way, the heat required for sintering can be transferred to the device through the punch head and targeted cooling can be performed as appropriate and supplementary. In order to prevent the upper part of the device (such as a power semiconductor component) from exceeding the critical temperature, the first upper punch head can preferably maintain a temperature level lower than the second lower punch head during the sintering process, and the second lower punch head is, for example, facing the heat sink. Preferably, heat transfer is performed by an elastic heat transfer device known, for example, from WO2016 / 091962A1. Preferably, the one or more second punch heads are heated or cooled, wherein the first punch heads are preheated before or after being placed on the devices, and the first punch heads maintain a predeterminable temperature level based on their heat storage capacity. Therefore, the heating and / or cooling device in the upper mold can be omitted as appropriate.

[0032] According to another preferred technical solution of the method, different drive devices for moving the first and / or second punch head to the working position are activated in a time-delayed manner. Different drive devices can be activated in the same time sequence, simultaneously or in a reverse time sequence to move the first and / or second punch head back from the working position to the rest position.

[0033] According to another advantageous technical solution of the method, the different drive devices are started in a time-staggered manner in a certain manner, so that at least one drive device arranged in the central area is started first and the drive devices located further outward are started after a certain time interval. In the case where nine punch heads are arranged in three rows of three, for example, the middle punch head can be moved first, and then the punch heads located further outward surrounding the middle punch head can be moved. By lifting the central component or central device in advance, the above-mentioned guide frame together with all the upper punch heads or the upper parts of the devices with upper punch heads that are lifted and centered before the other punch heads in the periphery are pressed. In this way, the early alignment of these devices relative to the upper and lower punch heads or the upper and lower drive devices can be achieved. Advantageously, the guide frame includes three groups of devices, each of which has three devices, and can also include four groups of devices, each of which has three devices, wherein the corresponding intermediate drive device in one group can lift the intermediate device with the upper punch head and the guide frame from the carrier frame in advance.

[0034] Preferably, at least the sintering process is carried out in a process atmosphere, in particular in an oxygen-free, oxidation-avoiding process atmosphere, preferably under reduced pressure, in particular under vacuum.

[0035] Advantageously, for calibration and / or verification of the sintering device and the sintering process, a measuring carrier frame can be provided, which can optionally also include a measuring guide frame and geometrically replicated components arranged in geometrically correct positions, wherein pressure sensors and / or temperature sensors can be arranged in or on these replicated components, for example, when setting up or calibrating the sintering device, for example, these sensors are first passed through the sintering device and subjected to a default sintering pressure and sintering temperature in order to verify and calibrate the sintering process. The data of the pressure and / or temperature sensors can be used to adjust the process parameters and to test the correct functioning of the sintering device.

[0036] The heating and / or cooling temperature transfer is preferably carried out by mechanical contact coolers. Heat radiation transfer (eg by induction heaters, infrared radiation heaters) or convective temperature transfer by process gas circulation may also be used as appropriate. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] For further advantages, see the drawings and the associated description of the drawings. These drawings show exemplary embodiments of the invention. The drawings, the description and the claims contain a number of combinations of features. A person skilled in the art can also advantageously consider these features individually and combine them into other advantageous combinations. A person skilled in the art can also use the features described in relation to the embodiments of the sintering device for the technical solution of the method according to the invention and vice versa.

[0038] in:

[0039] [ Figure 1 ] is a schematic longitudinal cross-sectional view of a sintering device according to a first embodiment;

[0040] [ Figure 2 ]for Figure 1 A schematic perspective view of a carrier frame of the sintering device with inserted components;

[0041] [ Figure 3 ]for Figure 2 A perspective view of the carrier frame shown, which also has the first punch head and guide frame placed therein;

[0042] [ Figure 4 ]to[ Figure 7 ]for Figure 1 Schematic cross-section of the sintering device shown in different operating positions;

[0043] [ Figure 8 ] is a schematic longitudinal cross-sectional view of a sintering device according to a second embodiment; and

[0044] [ Fig. 9 ] is a schematic longitudinal cross-sectional view of a sintering device according to the third embodiment.

[0045] Implementation

[0046] Figure 1 and Figures 4 to 7 A sintering device 10 according to a first embodiment is shown, which comprises an upper die 12 and a lower die 14. In the first embodiment, a sintering device 10 is considered, wherein a first punch 16 is statically supported against a platen 20 of the upper die 12, wherein a plurality of second punches 18 of the lower die 14 can be displaced by separate drive devices 28, 28.2, respectively.

[0047] The sintering device 10 may include a solid press body which may define an evacuable process chamber, wherein an upper mold 12 and a lower mold 14 are supported on the press body.

[0048] The upper die 12 includes a flat platen 20, which may have a heating and / or cooling device (not shown). The lower die 14 includes a row of second punch heads 18, wherein each second punch head 18 corresponds to a drive device 28. The drive device 28 can be designed as a hydraulically operated piston-cylinder assembly, for example, which is operated by a pressurized hydraulic fluid to achieve the raising or lowering of the corresponding second punch head 18. The second punch head 18 can also have a heating and / or cooling device, such as a fluid channel for a temperature-adjustable fluid to flow through, or an infrared-based heating component, an electric heating component, or an induction heating component.

[0049] A working chamber 40 is defined between the second punch 18 of the lower die 14 and the pressure plate 20 of the upper die 12 , into which the carrier frame 30 can be inserted or pushed, and on which the components of the components 22 to be connected can be supported.

[0050] Combination Figure 2 and Figure 3 The working principle of the carrier frame 30 is described in detail. The carrier frame 30 comprises an outer frame 34 with a central opening, in which an inner frame 36 is arranged. In this embodiment, a total of five substrates 24 are inserted into the inner frame 36 and held in a laterally guided manner, which are basically, for example, heat sinks or carriers for power semiconductor components, on which three components 26 are placed, such as semiconductor units or so-called molds, in which a plurality of semiconductor components have been previously joined together and packaged. The corresponding first punches 16 are placed on the components 26, wherein the three first punches 16 corresponding to the corresponding substrates 24 are supported in the guide frame 32 in a laterally guided manner. Therefore, each guide frame 32 extends over the corresponding substrate 24.

[0051] The carrier frame 30 has openings or through holes covered by the substrate 24 , through which the second punch 18 can pass to directly contact the device 22 or the substrate 24 .

[0052] By means of the exemplary sintering device 10 shown, a total of five devices 22 can be connected together by pressure sintering, wherein each device 22 includes a shared substrate 24 and three components 26 arranged in series on the substrate. Accordingly, the second punches 18 together with the corresponding drive devices 28 are arranged in a matrix with five rows, each of which includes three second punches 18 or three drive devices 28. The placed first punches 16, components 26, second punches 18 and drive devices 28 are aligned with each other, that is, the components are in each of the fifteen stacks in a top view, that is, vertically stacked along the direction of action of the pressure P.

[0053] The support frame 30 is preferably assembled with the device 22, the guide frame 32 and the first punch 16 outside the sintering device 10. After the assembly is completed, the support frame 30 together with the components arranged thereon is inserted into the sintering device 10. The corresponding rest position is as follows Figure 1 As shown, the sintering device 10 is shown in a longitudinal section, so that a total of five punches 16, 18 and corresponding five devices 22 and five drive devices 28 can be seen in a row. Figures 4 to 7 The cutaway view shown is a cross-section, so that only one component 22 can be seen here, which has a base plate 24 and three placed components 26. Accordingly, only three punches 16, 18 and three drive devices 28 are shown.

[0054] like Figure 4 As shown, the second punch 18 may have a two-part punch body 42, including an upper punch body 44 facing the pressure plate 20 and a lower punch body 46 facing the corresponding drive device 28. The contact surface 48 between the upper punch body 44 and the lower punch body 48 is constructed as a spherical surface, and the upper punch body 44 in contact with the component 22 can be automatically aligned on its bottom side by a slight sliding movement along the spherical surface. In this way, pressure peaks in the component 22 are avoided.

[0055] According to a technical solution of the method for operating the sintering device 10, as Figure 4 As shown, first only the central second punch head 18 corresponding to the corresponding device 22 is lifted. Figure 5 As shown, the outer second punch head 18 is lifted with a time delay, so that a certain height offset temporarily occurs between the top sides of the second punch heads 18. Once the second punch heads 18 come into contact with the bottom side of the corresponding substrate 24 of the device 22, the device 22 is lifted from the carrier frame 30 along the direction of the pressure, and the placed first punch heads 16 are lifted from the corresponding guide frame 32 at the same time.

[0056] like Figure 6As shown, as the first punch 16 is further lifted, it contacts the press plate 20, where a reaction force is formed in the opposite direction to the pressure P generated by the drive device 28, thereby causing pressure increase in the device 22. The heat required for pressure sintering is provided by heating the press plate 20 or the second punch 18.

[0057] During the predetermined duration, the sintering device 10 is maintained as Figure 6 The working position shown is continued until a sintered connection is formed between the components of the device 22 .

[0058] like Figure 7 As shown, after the sintering process is completed, the drive device 28 is operated to lower the second punch 18 in the direction opposite to the direction of action of the pressure P. As a result, the component 22 is also lowered together with the punch 16 and falls back into the carrier frame 30 or the guide frame 32. After the lowering process is completed, the carrier frame 30 with the sintered component 22 can be removed from the sintering device 10 and another carrier frame 30 with the component 22 to be sintered can be inserted to perform the sintering process again.

[0059] Figure 8 and Fig. 9 An alternative second and third embodiment of the sintering device 10 is shown, in which a multi-drive comprising a plurality of drive devices 28, 28.1 and 28.2 is arranged in the upper mold 12 (see Figure 8 The second embodiment shown in FIG. 1 ) or arranged in the upper mold 12 and the lower mold 14 at the same time (see FIG. 1 ). Fig. 9 The third embodiment shown). Figure 8 , Fig. 9 The second and third embodiments shown are based in principle on the combined Figures 1 to 7 The technical solution of the first embodiment is described in detail. Therefore, only the distinguishing features will be described below.

[0060] Figure 8 Embodiment 10 shown and Figure 1The embodiment shown differs in that each first punch 16 is equipped with a separate drive 28.1 and is arranged in the upper die 12. A pressure plate 20 is provided in the lower die, which serves as the second punch 18. During the sintering process, the pressure plate 20 supports the component 22 in the lower die 14. As soon as the carrier frame 30 with the component 22 and the guide frame 32 with the placed first punch 16 is inserted into the working chamber 40, for example, in the process of conveying from the preheating chamber to the evacuable process chamber of the sintering device 10 in a flow-line operation by a conveying device (not shown), the drive device 28.1 can be placed on the top side of the first punch 16 and exert a pressure P on the component 22 in the direction of action of the lower die 14. A suitable conveying device is known, for example, from WO2021 / 069328 A. The preheating chamber can preferably realize inductive heating, especially heating of the lower part of the device, preferably the heat sink. To this end, the preheating chamber can include conductive induction coils, which are spaced a short distance from the inductively heatable areas of the device and / or the carrier frame 30.

[0061] Fig. 9 A third embodiment 10 is shown, which essentially combines Figure 1 and Figure 8 The embodiment shown. Figure 1 In the embodiment, the first punch head 16 of the first embodiment is supported by the pressing plate 20 in the upper die 12, and Figure 8 In the embodiment, the second punch head 18 is constructed as a pressing plate 20 in the lower die 14, and Fig. 9 The third embodiment shown omits the pressing plate. A plurality of drive devices 28.1 are arranged in the upper die 12, which correspond to each first punch 16. A plurality of drive devices 28.2 are arranged in the lower die 14, which drive the movement of the second punch 18 respectively. For this purpose, the carrier frame 30 has through holes 52, through which the second punch 18 can pass. The punch 18 has an elastic pin-contact heat transfer device 50, so as to achieve rapid heat transfer and to compensate for unevenness and non-parallelism between the surface of the punch 18 and the bottom side of the device 22.

[0062] Each device 22 is sandwich-pressed by the drive device 28.1 and the drive device 28.2, wherein parameters such as temperature, pressure, and movement distance can be adjusted individually for each device 22. The third embodiment is particularly suitable for parallel sintering of heterogeneous devices 22.

[0063] The process atmosphere in the sintering device 10 is preferably adjustable, so that it can be flushed with a purge gas such as formic acid, and oxygen can also be advantageously pumped away to prevent oxidation until a vacuum is achieved.

[0064] List of Reference Numerals

[0065] 10: Sintering device

[0066] 12: Upper mold

[0067] 14: Lower die

[0068] 16: First punch head

[0069] 18: Second punch head

[0070] 20: Pressure plate

[0071] 22: Devices

[0072] 24: Substrate

[0073] 26: Component

[0074] 28, 28.1, 28.2: Driving device, driving device of upper die, driving device of lower die

[0075] 30: Carrier frame

[0076] 32: Guidance frame

[0077] 34: Outer frame

[0078] 36: Inner frame

[0079] 40: Working chamber

[0080] 42: Punch body

[0081] 44: Upper punch body

[0082] 46: Lower punch body

[0083] 48: Contact surface

[0084] 50: Needle contact heat transfer device

[0085] 52: Through hole in carrier frame

[0086] P: Direction of pressure

Claims

1. A sintering device (10) for simultaneously connecting a plurality of electronic devices (22) arranged side by side by pressure sintering, comprising an upper die (12) and a lower die (14), the sintering device comprising a plurality of first punches (16) arranged on the upper die (12) and at least one, in particular a plurality of, second punches (18) arranged on the lower die (14), the devices (22) being accommodated between the punches, wherein: Each first punch head (16) and / or each second punch head (18) is equipped with a drive device (28, 28.1, 28.2), which is configured to apply pressure to one of the devices (22) by axially moving the corresponding first punch head (16) and / or the corresponding second punch head (18) along the direction of action of the pressure (P), characterized in that before the pressurizing operation begins, the first punch head (16) is placed on these devices (22) and during the application of the pressure, these devices (22) are pressed against the at least one second punch head (18).

2. The sintering device (10) according to claim 1, characterized in that The first punch head (16) abuts against the pressure plate (20) of the upper die (12), wherein at least one drive device (28, 28.2) of the lower die (14), in particular the corresponding drive device (28, 28.2) corresponding to each second punch head (18) applies pressure in the direction of action of the pressure (P) toward the upper die (12) through the at least one second punch head (18), or the at least one second punch head (18) abuts against the pressure plate (20) of the lower die (14) or is composed of the pressure plate, wherein at least one drive device (28, 28.1) of the upper die (12), in particular the corresponding drive device (28, 28.1) corresponding to each first punch head (16) applies pressure in the direction of action of the pressure (P) toward the lower die (14).

3. The sintering device (10) according to claim 1, characterized in that The driving device (28, 28.1) of the upper die (12) is arranged on the plurality of first punching heads (16), and the driving device (28, 28.2) of the lower die (14) is arranged on the plurality of second punching heads (18), wherein, since the pressure (P) acts in opposite directions, both sides of each electronic device (22) are acted upon by the driving devices (28, 28.1, 28.2) of the upper die (12) and the lower die (14).

4. The sintering device (10) according to any one of claims 1 to 3, characterized in that Each drive device (28, 28.1, 28.2) can be individually controlled in terms of its moving distance and / or applied pressure (P), preferably in a hydraulic, electric, piezoelectric or magnetostrictive manner.

5. The sintering device (10) according to any one of the preceding claims, characterized in that Each second punching head (18) is connected to the corresponding driving device (28, 28.2) and / or has a corresponding heating and / or cooling device, preferably a pin-contact heat transfer device.

6. The sintering device (10) according to any one of the preceding claims, characterized in that A carrier frame (30) is provided which can be inserted into the sintering device (10), wherein at least the components of the devices (22), preferably together with the placed first punches, are held in the carrier frame in a manner guided in a lateral direction, wherein the carrier frame (30) preferably has through holes (52) corresponding to the devices (22), through which the second punches (18) can pass to establish mechanical and thermal contact with the devices (22), wherein the thermal expansion coefficient of the carrier frame (30) is preferably higher than that of the upper parts of the devices (22).

7. The sintering device (10) according to claim 6, characterized in that At least one guide frame (32) is preferably detachably arranged on the carrier frame (30) and is used to guide the first punching head (16) in a transverse direction relative to the component (22).

8. The sintering device (10) according to any one of the preceding claims, characterized in that Each first and / or second punch (18) has a punch body (42) that can be axially moved along the direction of action of the pressure (P) and a contact surface (48) that can contact a component of the device (22), wherein the contact surface (48) is arranged to be tiltable around at least one spatial axis relative to the punch body (42).

9. The sintering device (10) according to any one of the preceding claims, characterized in that A plurality of first punching heads (16) arranged side by side corresponds to a corresponding second punching head (18), or a plurality of second punching heads (18) arranged side by side corresponds to a corresponding first punching head (16).

10. A method for simultaneously connecting a plurality of electronic devices (22) arranged side by side by pressure sintering, in particular in a sintering device (10) according to any one of the preceding claims, wherein the sintering device (10) comprises a plurality of first punches (16) and at least one, in particular a plurality of second punches (18), between which the devices (22) are accommodated, wherein each first punch (16) and / or each second punch can be axially moved in the direction of action of a pressure (P) by a corresponding drive device (28, 28.1, 28.2) to apply pressure to one of the devices (22), the method comprising the following steps a. placing the first punch head (16) onto the device (22), b. inserting the device (22) together with the first punch into the sintering device (10) and aligning it with the second punch (18), c. The sintering process is carried out by operating the driving device (28, 28.1, 28.2) so as to move the first punch (16) and / or the second punch (18) from a rest position to a working position to generate a pressing pressure, in which the components (22) are pressed together between the first punch (16) and the second punch (18), and the second punch is arranged relative to the first punches (16) to apply a reaction force.

11. A method as claimed in claim 10, wherein the step of implementing the sintering process includes at least heating and / or cooling the first punch head (16) and / or the second punch head (18), wherein preferably the first punch head (16) is maintained at a temperature level lower than that of the second punch head (18).

12. A method as claimed in claim 10 or 11, wherein different drive devices (28, 28.1, 28.2) for moving the first punch (16) and / or the second punch (18) into the working position are started in a time-delayed manner.

13. A method as claimed in claim 12, wherein different drive devices (28, 28.1, 28.2) are started in a time-delayed manner, so that at least one drive device (28, 28.1, 28.2) arranged in a central area is started first, and the drive devices (28, 28.1, 28.2) located further outward are started after a certain time interval.

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