Sintering apparatus and method

Abstract

The present invention relates to a sintering apparatus (10) and a method for simultaneously joining a plurality of side-by-side arranged electronic devices (22) by pressure sintering. The sintering apparatus has an upper die (12) and a lower die (14), comprising a plurality of first stamping heads (16) disposed on the upper die (12) and at least one, particularly a plurality of, second stamping heads (18) disposed on the lower die (14), with the devices (22) housed between these stamping heads. For this purpose, each first stamping head (16) and / or each second stamping head (18) is provided with a driving device (28, 28.1, 28.2) configured to apply pressure to one of the devices (22) by axially moving the corresponding first stamping head (16) and / or the corresponding second stamping head (18) in the direction of pressure (P). The present invention proposes that the first stamping heads (16) are placed on the devices (22) before the pressurization operation begins, and that the devices (22) are pressed against the at least one second stamping head (18) during the application of the pressure.

Description

Technical Field

[0001] The present invention relates to a sintering apparatus and a method for simultaneously connecting multiple side-by-side electronic devices by pressure sintering. Background Technology

[0002] In pressure sintering, two or more components, particularly electronic components and substrates, can be interconnected in a conductive and / or thermally conductive manner using bonding materials, wherein the bonding materials to be joined are sintered. In this case, the components to be joined are uniaxially pressed between an upper mold and a lower mold to provide bonding pressure.

[0003] It has been proven that joining under process atmospheres, particularly negative pressure or vacuum, is especially advantageous to prevent unwanted chemical reactions (such as oxidation), gas inclusions, and impurities. The heat required for sintering is typically transferred to the components via upper and lower dies, but can also be applied as radiant heat from the bottom and / or top sides. Multiple components, which may differ in their lateral extension and height, are usually arranged on a shared substrate. To ensure uniform pressure transfer, multiple stamping heads can be provided on the upper and / or lower dies, their dimensions being coordinated with the components to be joined.

[0004] If different types of components are to be processed on a single machine, the layout of the stamping heads on the upper or lower die needs to be adapted periodically. This adaptation is time-consuming and difficult because the die and / or stamping heads can get hot. Furthermore, dies, especially stamping heads, are typically made of metal because they must withstand high pressures. Therefore, these dies are heavy, cool slowly, and are expensive. In addition, precise alignment of the die or stamping head with respect to the components to be connected is required.

[0005] The purpose of this invention is to provide a sintering apparatus and a corresponding method that can quickly and reliably arrange the stamping head to be adapted to the components to be connected. Summary of the Invention

[0006] A sintering apparatus according to the invention for simultaneously joining multiple side-by-side electronic devices by pressure sintering includes an upper die and a lower die, wherein a plurality of first stamping heads may be disposed in the upper die, and at least one, particularly a plurality of second stamping heads are disposed in the lower die. The devices are disposed between these first stamping heads and the at least one, particularly a plurality of second stamping heads, wherein each first stamping head and / or each second stamping head is provided with a driving device configured to apply pressure to one of the devices by axially moving the corresponding first stamping head and / or the corresponding second stamping head in the direction of pressure application.

[0007] The present invention proposes that, before the pressurization operation begins, a first stamping head is placed on these devices, that is, before the sintering process begins, the first stamping head is placed outside the sintering apparatus, and during the application of pressure, the devices are pressed against at least one second stamping head.

[0008] Unlike conventional sintering apparatuses where the first punches acting on the top side of the components are securely or replaceably fixed to the upper die, the first punches acting on the top side of the components are loosely placed onto these components or their assemblies. Preferably, the first punches are placed onto these components outside the sintering apparatus so that they can be inserted together with the components during the necessary step of inserting the components into the sintering apparatus. When the first or second punches are moved by the drive mechanism to apply pressure, the first punches, along with the components of these components located below the first punches, are pressed against a pressure plate arranged above these components or against a corresponding drive mechanism of the upper die, which is, for example, stably fixed to the frame of the sintering apparatus. Alternatively, the first or second punches may be supported on a pressure plate of the lower die, with the first punches of the upper die pressing the components relative to the pressure plate or the second punches of the lower die. Thus, the pressure plate or the corresponding opposing drive mechanism applies a reaction force opposite to the pressure. Preferably, the pressure plate or drive mechanism of the lower die and / or upper die can be temperature-controlled by corresponding heating and / or cooling devices to transfer heat to or from the components through the first and / or second stamping heads. This heating and / or cooling device is preferably located at least in the lower die to heat the substrate of the device, while the first stamping head of the upper die is preheated (e.g., before or after placement) so that a separate heating or cooling device in the upper die can be omitted if necessary.

[0009] As an alternative or supplementary method to placing the first stamping heads onto these devices before the start of the sintering process, as described in EP4 080 554 A2, at least some, and in particular all, of the first stamping heads are replacedly fixed in the upper die, particularly thermally clamped in a clamping device. This allows for flexible configuration of the first stamping heads. Thus, at a first temperature, the first stamping heads can be received, for example, in a movable manner within the upper die along the direction of pressure, on or within the retaining plate of the upper die; at a second temperature higher than the first temperature, these first stamping heads can be clamped onto or within the retaining plate or the upper die. This allows for particularly rapid and precise fitting of corresponding devices, where different components have different heights. Thus, at the first temperature, i.e., at a lower temperature, the first stamping heads can be brought close, for example, to the device to be connected or the corresponding alignment gauge, until all contact surfaces of the first stamping heads are in contact with the corresponding component. In this case, the punch head that contacts a relatively high component or part moves further than the punch head that contacts a relatively low component or part. With the punch head adapted to these components or parts in its longitudinal position, the retaining plate of the first punch head and the upper die is heated. This clamps the first punch head onto or within the clamping plate, thus fixing these first punch heads in their longitudinal or axial position. This clamping creates a press-fit between the first punch head and the retaining plate.

[0010] Advantageously, during sintering, a definable temperature gradient can be provided between the upper and lower punches by independently operable heating or cooling devices located in the lower and upper dies, particularly in the respective punches. The heat-sensitive upper component of the device (e.g., a power semiconductor component) typically faces the upper die, while the advantageously thermally conductive lower component (e.g., a heat sink) faces the lower die. Typically, a sintered connection should be established between the bottom side of the upper component and the lower component, provided that a sintering slurry interlayer is provided. To avoid exceeding the limiting temperature of the upper component, the upper die can be heated or cooled during sintering along a temperature profile that is lower than the temperature profile of the upper die at higher temperatures. For example, a temperature gradient of 50°C to 100°C can be established between the hotter lower second punch and the cooler upper first punch, at least until the sintering temperature is reached.

[0011] If a single drive unit is used in the upper and / or lower die, this drive unit can be configured, for example, as a single-acting hydraulic cylinder for the corresponding single or multiple first and / or second stamping heads. This single-acting hydraulic cylinder can have a large piston surface that substantially covers the layout surface of the components on the carrier frame. The single-acting hydraulic cylinder can be reset, for example, by a spring or another reset mechanism. In this respect, the hydraulic tension acting on the pressing plane and the use of complex double-acting hydraulic cylinders can be eliminated; instead, the single-acting hydraulic cylinder can move freely as a cylinder body, thus providing a hydraulic pressing device in a less cost-effective manner and placing lower demands on the hydraulic control device.

[0012] In an advantageous embodiment, the first punch head may abut against the pressure plate of the upper die, wherein at least one drive device of the lower die, particularly the corresponding drive device corresponding to each of the second punch heads, applies pressure towards the upper die in the direction of pressure application via at least one second punch head. Alternatively, at least one second punch head abuts against or is constituted by the pressure plate of the lower die, wherein at least one drive device of the upper die, particularly the corresponding drive device corresponding to each of the first punch heads, applies pressure towards the lower die in the direction of pressure application. In this embodiment, at least one drive device for applying pressure in the direction of application toward the lower or upper die may be arranged in the upper or lower die. If at least one drive device is provided in the upper die, pressure can be transmitted to the first punch head, for example, via the pressure plate in the direction of application toward the lower die. Alternatively, each individual corresponding drive device (multiple actuators) of the first punch head may also be arranged in the upper die, and these drive devices can individually apply pressure to the first punch head. In this case, the second punch head may, for example, be constructed as the pressure plate in the lower die. Alternatively, multiple statically fixed second punches in the lower die can abut against the lower die. Alternatively, at least one drive device can be provided in the lower die. This drive device can, for example, move a second punch that is configured as a pressure plate or multiple second punches statically connected to the drive device in the direction of pressure. However, each of the multiple second punches, particularly each corresponding to a first punch, can also have its own dedicated drive device (multi-actuator) arranged in the lower die, which can individually apply pressure to the second punch. In this respect, this embodiment provides a shared drive device or multiple actuators for the first or second punches in the upper or lower die.

[0013] As an alternative to the foregoing embodiments, in another advantageous embodiment, the driving device for the upper die can be disposed on a plurality of first stamping heads, and the driving device for the lower die can be disposed on a plurality of second stamping heads, wherein, due to the opposite directions of pressure application, both sides of each electronic device are acted upon by the driving devices of the upper and lower dies. In this embodiment, these devices are subjected to sandwich-type bidirectional pressing by at least one driving device of the upper and lower dies. The driving device of the upper die can be a single actuator, for example, distributing pressure to the first stamping heads placed on these devices via a pressure plate. Alternatively, a corresponding driving device can be provided separately for each first stamping head. The same applies to the driving device of the lower die. This driving device can be configured as a single actuator, which applies pressure, for example, via a second stamping head constructed as a pressure plate or a plurality of second stamping heads statically arranged on the driving device in the direction of application toward the upper die. Alternatively, a corresponding driving device can be provided separately for each second stamping head. Unlike the above implementation, these devices can be pressed against each other by a drive device that operates in opposite directions in the upper and lower molds, and individual temperature and pressure parameters can be controlled on adjacent devices. This is particularly advantageous for parallel sintering of different types of devices.

[0014] According to a preferred embodiment, each drive unit can be individually controlled in terms of its travel distance and / or applied pressure, preferably in a hydraulic, electric, piezoelectric, or magnetostrictive manner. The corresponding first and / or second punch heads preferably correspond to corresponding devices or components. This allows for the application of uniform pressing pressure to different devices or individual components. In particular, it ensures that each device can be individually loaded with a preset pressing pressure. This avoids applying excessively high or low pressing pressure to individual devices, as is often the case with conventional solutions where only one common punch head acts on multiple components. Another advantage is that height tolerances of these devices or components can be compensated for or taken into account. For example, the required pressure can be adjusted by a corresponding force or pressure sensor or by a displacement sensor, where the applied pressure can be achieved directly by adjusting the working pressure or indirectly by adjusting the travel distance of the second punch head. Hydraulically controllable drive units can be formed, for example, by arranging double-acting pistons, which can be supplied from a common pressurized reservoir via corresponding control valves. However, in principle, each drive unit can also have an inherent fluid source for generating pressure, thus eliminating the need for valves. For example, electric control can be achieved through a drive unit with a spindle driver. Alternatively, a drive unit that operates piezoelectrically or magnetostrictively can also be provided.

[0015] According to another preferred embodiment of the invention, each first stamping head and / or second stamping head is connected to a corresponding drive device. Advantageously, the second stamping head is not placed on its corresponding drive device, but rather forms a unit with the corresponding drive device.

[0016] As an alternative or supplementary solution, each first and / or second stamping head may have a corresponding heating and / or cooling device. This heating and / or cooling device allows for individually controlled heat transfer to or from each second stamping head and each device in thermal contact with it. The heating and / or cooling device may be electrically operated and / or include corresponding fluid channels disposed in the second stamping head, these fluid channels being fluidly connected to a corresponding temperature-adjustable fluid source. The heating and / or cooling device is preferably constructed as a needle-contact heating and / or cooling device. Before the second stamping head contacts the entire surface of the device, heating or cooling temperature can be effectively transferred by a highly thermally conductive, flexible needle, particularly compensating for any alignment problems, such as surface parallelism compensation. Such heat-transferring needle contacts are described, for example, in WO 2016 / 091962 A1. These heat-transferring needle contacts have been used in heating chambers to heat devices, second stamping heads, and / or pressure plates. Preferably, in the combined temperature control of the heating and / or cooling devices, the temperatures of the first and second stamping heads are simultaneously controlled, and a predefined temperature gradient is maintained between the respective first and second stamping heads. This protects the temperature-sensitive components of these devices from thermal overload. Furthermore, even after multiple repeated sintering processes, the same temperature conditions can be maintained on the first and second stamping heads.

[0017] According to another preferred embodiment, a carrier frame is provided for insertion into a sintering apparatus. Components of these devices, preferably together with a placed first pressing head, are held in the carrier frame in a laterally guided manner. The carrier frame preferably has through-holes corresponding to the devices, through which a second pressing head can make mechanical and thermal contact with the devices. The devices are mounted laterally aligned via the carrier frame to match the arrangement of the second pressing head, where lateral alignment refers to alignment laterally to the pressing direction. That is, while the carrier frame prevents lateral movement of the components, it allows movement in the direction of pressure. These through-holes allow the second pressing head to lift these components from the carrier frame.

[0018] According to another preferred embodiment, at least one guide frame is preferably detachably arranged on the carrier frame for guiding the first punch head relative to the devices in a lateral direction. Therefore, the guide frame prevents relative movement of the placed punch head relative to the components of the devices and / or the carrier frame. To facilitate the configuration or reconfiguration of the carrier frame for different devices and / or punches, at least one guide frame can be plugged into or screwed to the carrier frame. For example, the guide frame can be arranged only after the components are inserted into the carrier frame, and then the first punch head can be inserted into the guide frame.

[0019] The coefficient of thermal expansion of the guide frame is preferably higher than that of the upper components of these devices. The devices to be sintered can be stacked from individual components, such as a power semiconductor component as the upper component and a heat sink as the lower component, and these components can have different coefficients of thermal expansion. Therefore, the coefficient of 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 experience undesirable relative displacements relative to each other. In further processing steps, precise and correct alignment of the individual stacked components of the devices relative to each other is crucial; therefore, the guide frame can advantageously thermally expand to compensate for undesirable thermal relative displacements of the device components relative to each other, for example, thermal displacement of the upper component relative to the lower component in the same manner. Advantageously, the coefficient of thermal expansion of the guide frame can be higher than that of the upper component of the device housed therein and, in particular, can be made of aluminum. The lower component of the device can be, for example, a heat sink and can be made of copper or a similar material with good thermal conductivity. This material expands with heat, with the upper components of these devices (e.g., the power semiconductor component) expanding less. To achieve precise sintering of power semiconductor components onto the heat sink, the guide frame can have a high coefficient of thermal expansion to align the upper and lower components of the device during heating. For this purpose, the guide frame is suitable for use with aluminum, while the lower components of the device are made of copper. Thus, in subsequent process steps, such as a power supply board with interconnecting contacts, the power semiconductor components (preferably converter components for power conversion, such as IGBTs) sintered on a common or separate heat sink are precisely connected in the correct positions.

[0020] According to another preferred embodiment, each first and / or second punch has a punch body that is axially movable in the direction of pressure and a contact surface that can contact components of the device, wherein the contact surface is configured to be tiltable relative to the punch body about at least one spatial axis. However, the contact surface is preferably tiltable about two Cartesian spatial axes, wherein a third spatial axis of the Cartesian spatial axis system extends in the direction of pressure. Therefore, the contact surface can be said to be omnidirectionally movable relative to the punch body, allowing it to uniformly abut against the component it contacts. Unlike rigidly aligned contact surfaces that are tiltable relative to the component they contact, this avoids force peaks or force gradients within the component and distributes pressure evenly. In this case, the contact surface is automatically aligned. For example, tiltable mounting of the contact surface relative to the punch body can be achieved through an elastic balancing layer. The corresponding punch may also be divided into two parts, including, in addition to the aforementioned punch body, another punch body having the aforementioned contact surface, wherein the two parts of these punch bodies are connected by the aforementioned elastic balancing layer or provided with another tiltable mounting structure.

[0021] According to another preferred embodiment, a plurality of first stamping heads arranged side by side correspond to a corresponding second stamping head. Alternatively, a plurality of second stamping heads arranged side by side correspond to a corresponding first stamping head. These first or second stamping heads, corresponding to the second or first stamping heads, can in particular have different heights. This allows, for example, the sintering of devices with multiple components of different heights arranged on a planar substrate. The heights of the first and second stamping heads are determined in a way that the contact surfaces of these first and second stamping heads facing the pressure plate are in a common plane.

[0022] Advantageously, in assembly line operations, these first stamping heads can be transported from the unloading station after the sintering unit back to the loading station before the sintering unit via a conveyor, especially when the sintering process is bypassed after completion, as described, for example, in WO 2021 / 069328 A1. This ensures a high-cycle sintering process for large quantities of parts to be joined.

[0023] According to the invention, a method for simultaneously joining an assembly of multiple side-by-side arranged electronic devices by pressure sintering in a sintering apparatus, the sintering apparatus being particularly designed according to the foregoing embodiment or a preferred embodiment of the invention, wherein the sintering apparatus includes a plurality of first stamping heads and at least one second stamping head, particularly a plurality of second stamping heads, with devices disposed between these stamping heads, wherein each first stamping head and / or the at least one second stamping head can be axially moved along the direction of pressure application by a corresponding driving device to apply pressure to one of these devices, the method comprising the following steps

[0024] - Place the first stamping head onto these devices.

[0025] - Insert these components, along with the first stamping head, into the sintering apparatus and align them with the second stamping head, and

[0026] - The sintering process is carried out by manipulating the drive device to move the first punches and / or the at least one second punch from the rest position to the working position to generate pressing pressure, in which the devices are jointly pressed between the first punches and the at least one second punch, the at least one second punch being arranged opposite to the first punches to apply a reaction force.

[0027] The first stamping heads can be configured in a simple manner by placing them on the devices and inserting them together into the sintering apparatus. This includes both arranging the first stamping heads to the appropriate size and precisely aligning them with respect to the layout geometry of the devices or indirectly with respect to the second stamping heads.

[0028] Advantageously, these devices, along with the first punches, can be inserted into the sintering apparatus via a carrier frame, the components of which, together with the placed punches, are held in the carrier frame in a laterally guided manner. The carrier frame preferably has through-holes corresponding to the devices, through which the second punches can make mechanical and thermal contact with the devices. When the second punches are moved to the working position, the devices can be lifted from the carrier frame. To prevent the first punches from sliding laterally or laterally during lifting before contacting the pressure plate and being secured by the generated pressure, the carrier frame may have a guide frame configured to guide the first punches laterally relative to the devices. This guide frame ensures that the first punches can move axially in the direction of pressure.

[0029] Advantageously, the guide frame and / or the carrier frame have complementary alignment components, such as guide pins, guide slots, guide sockets, or similar components, to position the guide frame correctly on the carrier frame. When assembling devices onto the carrier frame, for example, lower components of these devices (such as heat sinks) may be placed on or within the carrier frame, the heat sink also serving as a lower component of a plurality of placed upper components of the device. The guide frame can then be positioned and aligned onto the carrier frame using the alignment components. The guide frame may have through-holes into which the upper components of these devices (such as power semiconductor components) are inserted via a placed first punch.

[0030] According to a preferred embodiment of the method, the sintering process includes at least heating and / or cooling a first stamping head and / or at least one, particularly multiple, second stamping heads. This allows the heat required for sintering to be transferred to the device via the stamping heads, and, where appropriate, targeted cooling. To prevent the upper components of the device (such as power semiconductor components) from exceeding a critical temperature, the first upper stamping head is preferably maintained at a lower temperature level than the second lower stamping head, for example, facing a heat sink, during the sintering process. Heat transfer is preferably performed via, for example, an elastic heat transfer device known as WO2016 / 091962A1. The first stamping heads are preferably preheated before or after placement onto the devices, and they maintain a predetermined temperature level based on their heat storage capacity. Therefore, heating and / or cooling devices in the upper die may be omitted, depending on the situation.

[0031] According to another preferred embodiment of the method, different drive devices for moving the first and / or second stamping heads to the working position are activated in a time-delayed manner. The different drive devices can be activated in the same time sequence, simultaneously, or in reverse time sequence to move the first and / or second stamping heads back from the working position to the rest position.

[0032] According to another advantageous technical solution of the method, different drive devices are activated in a staggered manner in a certain way, so that at least one drive device arranged in the central region is activated first, and the drive devices located further out are activated after a certain time interval. In the case of arranging nine stamping heads in three rows of three, for example, the middle stamping head can be moved first, followed by the outermost stamping heads surrounding the middle stamping head. By raising the central member or central device in advance, the guide frame, together with all the raised upper stamping heads or the upper parts of the devices with upper stamping heads housed therein, can be advantageously raised and centered before the other surrounding stamping heads press. This allows for the advance alignment of these devices relative to the upper and lower stamping heads or the upper and lower drive devices. Advantageously, the guide frame includes three groups of devices, each with three devices, or it may include four groups of devices, each with three devices, in which the corresponding intermediate drive device in one group can raise the intermediate device with the upper stamping head and the guide frame from the carrier frame in advance.

[0033] Preferably, at least the sintering process is carried out in a process atmosphere, especially in an oxygen-free process atmosphere that avoids oxidation, and preferably under negative pressure, especially under vacuum.

[0034] Advantageously, for the calibration and / or verification of the sintering apparatus and sintering process, a measuring carrier frame may be provided, which may also include a measuring guide frame and geometrically replicated devices arranged in the correct positions. Pressure and / or temperature sensors may be placed in or on these replicated devices, for example, during the setup or calibration of the sintering apparatus, such as by first passing these sensors through the sintering apparatus and applying default sintering pressure and temperature to it, in order to verify and calibrate the sintering process. Data from the pressure and / or temperature sensors can be used to adjust process parameters and test the normal functioning of the sintering apparatus.

[0035] Heating and / or cooling temperature transfer is preferably achieved through mechanical contact coolers. Depending on the circumstances, radiative heat transfer (e.g., via induction heaters, infrared radiation heaters) or convective temperature transfer via process gas circulation may also be used. Attached Figure Description

[0036] Other advantages are illustrated in the accompanying drawings and related descriptions. These drawings depict embodiments of the invention. The drawings, description, and claims encompass numerous combinations of features. Those skilled in the art can also advantageously consider these features individually and combine them into other advantageous combinations. In particular, those skilled in the art will also apply the features described in relation to embodiments of the sintering apparatus to the technical solutions of the method according to the invention, and vice versa.

[0037] in:

[0038] [ Figure 1 This is a longitudinal cross-sectional schematic diagram of the sintering apparatus according to the first embodiment;

[0039] [ Figure 2 ]for Figure 1 A perspective view of the carrier frame of the sintering apparatus with the inserted components.

[0040] [ Figure 3 ]for Figure 2 The perspective view of the carrier frame shown also includes a first stamping head and a guide frame.

[0041] [ Figure 4 ]to[ Figure 7 ]for Figure 1 The sintering apparatus shown is illustrated in cross-sectional views at different operating positions.

[0042] [ Figure 8 [A longitudinal cross-sectional view of the sintering apparatus according to the second embodiment; and]

[0043] [ Figure 9 This is a longitudinal cross-sectional schematic diagram of the sintering apparatus according to the third embodiment.

[0044] Implementation

[0045] Figure 1 and Figures 4 to 7 A sintering apparatus 10 according to a first embodiment is shown, the sintering apparatus including an upper die 12 and a lower die 14. In the first embodiment, considering the sintering apparatus 10, a first punch 16 is statically supported against a pressure plate 20 of the upper die 12, and a plurality of second punches 18 of the lower die 14 can be displaced by separate drive devices 28, 28.2.

[0046] The sintering apparatus 10 may include a robust press body that defines a vacuum-ejectable process chamber, wherein the upper mold 12 and the lower mold 14 are supported on the press body.

[0047] The upper die 12 includes a flat pressure plate 20, which may have heating and / or cooling devices (not shown). The lower die 14 includes a row of second stamping heads 18, each of which corresponds to a drive device 28. The drive devices 28 may be designed, for example, as hydraulically operated piston-cylinder assemblies, which are operated by pressurized hydraulic fluid to raise or lower the corresponding second stamping head 18. The second stamping heads 18 may also have heating and / or cooling devices, such as fluid channels for the flow of temperature-adjustable fluid or infrared-based heating components, electric heating components, or induction heating components.

[0048] A working cavity 40 is defined between the second punch head 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 the components of the device 22 to be connected can be supported on the carrier frame.

[0049] Combination Figure 2 and Figure 3 The working principle of the carrier frame 30 is described in detail. The carrier frame 30 includes an outer frame 34 with a central opening, in which an inner frame 36 is disposed. In this embodiment, a total of five substrates 24 are inserted into the inner frame 36 and held in a laterally guided manner. These substrates are, for example, heat sinks or carriers for power semiconductor components, on which three components 26, such as semiconductor cells or so-called molds, are placed, wherein multiple semiconductor components have been pre-bonded and packaged. Corresponding first stamping heads 16 are then placed onto the components 26, wherein the three first stamping heads 16 corresponding to the respective substrate 24 are supported in a laterally guided manner in a guide frame 32. Thus, each guide frame 32 extends beyond the corresponding substrate 24.

[0050] The carrier frame 30 has openings or through holes covered by the substrate 24, through which the second punch head 18 can directly contact the device 22 or the substrate 24.

[0051] Using the exemplary sintering apparatus 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. Correspondingly, the second stamping heads 18, together with their corresponding drive devices 28, are arranged in a matrix of five rows, each comprising either three second stamping heads 18 or three drive devices 28. The placed first stamping heads 16, components 26, second stamping heads 18, and drive devices 28 are aligned with each other, i.e., the components are located in each of fifteen stacks in the top view, i.e., stacked vertically along the direction of pressure P.

[0052] Preferably, the carrier frame 30 is assembled with the components 22, guide frame 32, and first stamping head 16 outside the sintering apparatus 10. After assembly, the carrier frame 30, along with the components arranged on it, is inserted into the sintering apparatus 10. The corresponding rest positions are as follows: Figure 1 As shown, the sintering apparatus 10 is shown in a longitudinal cross-sectional view, thus a total of five stamping heads 16, 18, and corresponding five devices 22 and five drive devices 28 can be seen there. In contrast, Figures 4 to 7 The cross-sectional view shown is a cross section, so only one device 22 can be seen here, which has a substrate 24 and three placed components 26. Accordingly, only three stamping heads 16, 18 and three drive devices 28 are shown.

[0053] like Figure 4 As shown, the second punch head 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 46 is constructed as a spherical surface, and the upper punch body 44 in contact with the device 22 can be automatically aligned on its bottom side by a slight sliding movement along the spherical surface. This avoids pressure peaks within the device 22.

[0054] According to a technical solution of the operation method of the sintering apparatus 10, such as Figure 4 As shown, first only the central second stamping head 18 corresponding to the corresponding device 22 is raised. (As shown...) Figure 5 As shown, the outer second stamping head 18 is raised with a time delay, causing a temporary height offset between the top sides of the second stamping head 18. Once the second stamping head 18 contacts 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 pressure, and the placed first stamping head 16 is lifted from the corresponding guide frame 32.

[0055] like Figure 6As shown, as the first punch head 16 rises further, it contacts the pressure plate 20, where a reaction force is formed in the opposite direction to the pressure P generated by the drive device 28, thereby causing a pressure increase within the device 22. The heat required for pressure sintering is provided by heating the pressure plate 20 or the second punch head 18.

[0056] The sintering apparatus 10 is held in place for the predetermined duration. Figure 6 The working position is shown until a sintered connection is formed between the components of device 22.

[0057] like Figure 7 As shown, after the sintering process is completed, the drive device 28 is manipulated to lower the second punch head 18 in the opposite direction to the direction of the pressure P. This also lowers the device 22 along with the punch head 16 and allows it to fall back into the carrier frame 30 or guide frame 32. After the descent process is completed, the carrier frame 30 with the sintered device 22 can be removed from the sintering apparatus 10 and inserted into another carrier frame 30 with the device 22 to be sintered, so that the sintering process can be performed again.

[0058] Figure 8 and Figure 9 Alternative second and third embodiments of the sintering apparatus 10 are shown, wherein a multi-actuator comprising multiple drive units 28, 28.1 and 28.2 is arranged in the upper mold 12 (see...). Figure 8 The second embodiment shown, or simultaneously arranged in the upper mold 12 and the lower mold 14 (see the second embodiment shown). Figure 9 The third embodiment shown. Figure 8 , Figure 9 The second and third embodiments shown are based in principle on the already combined Figures 1 to 7 The technical solution of the first embodiment is described in detail below. Therefore, only the distinguishing features will be described below.

[0059] Figure 8 Implementation method 10 shown Figure 1The difference in the illustrated embodiment is that each first stamping head 16 is equipped with a separate drive device 28.1 and is arranged in the upper die 12. A pressure plate 20 is provided in the lower die, which serves as a second stamping head 18. During sintering, the pressure plate 20 supports the device 22 in the lower die 14. Once the carrier frame 30, carrying the device 22 and the guide frame 32 with the placed first stamping heads 16, is inserted into the working chamber 40, for example, during a continuous operation via a conveyor (not shown), from the preheating chamber to the vacuum-ejectable process chamber of the sintering apparatus 10, the drive device 28.1 can be placed on the top side of the first stamping head 16 and apply pressure P to the device 22 in the direction of action toward the lower die 14. A suitable conveyor is known, for example, from WO2021 / 069328 A. The preheating chamber is preferably capable of induction heating, particularly for the lower part of the device, preferably the heat sink. For this purpose, the preheating chamber may include conductive induction coils that are spaced at a small distance from the inductively heatable area of ​​the device and / or the carrier frame 30.

[0060] Figure 9 The third embodiment 10 is shown, which is essentially combined with Figure 1 and Figure 8 The embodiment shown. In Figure 1 In the middle, the first punch head 16 of the first embodiment is supported by the pressure plate 20 in the upper die 12, while Figure 8 In the middle, the second stamping head 18 is constructed as the pressure plate 20 in the lower die 14, and Figure 9 The third embodiment shown omits the pressure plate. Multiple drive devices 28.1 are arranged in the upper die 12, each corresponding to one of the first stamping heads 16. Multiple drive devices 28.2 are arranged in the lower die 14, each driving the movement of a second stamping head 18. For this purpose, the carrier frame 30 has through holes 52 through which the second stamping heads 18 can pass. The stamping heads 18 have resilient needle-contact heat transfer devices 50 to achieve rapid heat transfer and to compensate for unevenness and non-parallelism between the surface of the stamping head 18 and the bottom side of the device 22.

[0061] Each device 22 is sandwiched between drive units 28.1 and 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 the parallel sintering of heterogeneous devices 22.

[0062] The process atmosphere in the sintering apparatus 10 is preferably adjustable, so it can be flushed with cleaning gases such as formic acid, or oxygen can be removed to prevent oxidation, until a vacuum is achieved.

[0063] List of reference numerals

[0064] 10: Sintering apparatus

[0065] 12: Upper mold

[0066] 14: Lower mold

[0067] 16: First stamping head

[0068] 18: Second stamping head

[0069] 20: Pressure plate

[0070] 22: Devices

[0071] 24: Substrate

[0072] 26: Components

[0073] 28, 28.1, 28.2: Drive unit, upper mold drive unit, lower mold drive unit

[0074] 30: Carrier Frame

[0075] 32: Guiding Framework

[0076] 34: Outer frame

[0077] 36: Inner Frame

[0078] 40: Working chamber

[0079] 42: Punch body

[0080] 44: Upper punch body

[0081] 46: Lower punch body

[0082] 48: Contact surface

[0083] 50: Needle-type heat transfer device

[0084] 52: Through holes in the carrier frame

[0085] P: Direction of pressure

Claims

1. A sintering apparatus (10) for simultaneously connecting a plurality of side-by-side arranged electronic devices (22) by pressure sintering, having an upper die (12) and a lower die (14), the sintering apparatus comprising a plurality of first stamping heads (16) disposed on the upper die (12) and at least one or more second stamping heads (18) disposed on the lower die (14), wherein the devices (22) are disposed between the stamping heads, wherein, Each first stamping head (16) and / or at least one second stamping head (18) is provided with a drive device (28, 28.1, 28.2) configured to apply pressure to one of the devices (22) by axially moving the corresponding first stamping head (16) and / or at least one corresponding second stamping head (18) in the direction of the pressure (P). The device is characterized in that, before the pressurization operation begins, the first stamping head (16) may be loosely placed on the devices (22) outside the sintering apparatus (10) so that when the device (22) is inserted into the sintering apparatus (10), the first stamping head (16) can be inserted together with the device (22), and during the application of the pressure, the first stamping head (16) presses the devices (22) against the at least one or more second stamping heads (18).

2. The sintering apparatus (10) as claimed in claim 1, characterized in that, The first stamping 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) applies pressure toward the upper die (12) in the direction of the action of the pressure (P) via the at least one second stamping head (18), or the at least one second stamping head (18) abuts against the pressure plate (20) of the lower die (14) or is constituted by the pressure plate, wherein at least one drive device (28, 28.1) of the upper die (12) applies pressure toward the lower die (14) in the direction of the action of the pressure (P).

3. The sintering apparatus (10) as claimed in claim 1, characterized in that, The drive device (28, 28.1) of the upper die (12) is disposed on the plurality of first stamping heads (16), and the drive device (28, 28.2) of the lower die (14) is disposed on the at least one or more second stamping heads (18), wherein, since the pressure (P) acts in opposite directions, both sides of each electronic device (22) are acted upon by the drive devices (28, 28.1, 28.2) of the upper die (12) and the lower die (14).

4. The sintering apparatus (10) as claimed in claim 1, characterized in that, Each drive unit (28, 28.1, 28.2) can be individually controlled in terms of its travel distance and / or the applied pressure (P).

5. The sintering apparatus (10) according to claim 1, characterized in that, Each of the plurality of second stamping heads (18) is connected to its corresponding drive device (28, 28.2) and / or has a corresponding heating and / or cooling device.

6. The sintering apparatus (10) according to claim 1, characterized in that, A carrier frame (30) is provided for insertion into the sintering apparatus (10), in which at least the components of the devices (22) are held in the carrier frame in a manner guided in the lateral direction, wherein the carrier frame (30) has through holes (52) corresponding to the devices (22), through which at least one second stamping head (18) can make mechanical and thermal contact with the devices (22).

7. The sintering apparatus (10) as claimed in claim 6, characterized in that, At least one guide frame (32) is detachably arranged on the carrier frame (30) for guiding the first stamping head (16) relative to the device (22) in the lateral direction.

8. The sintering apparatus (10) according to claim 1, characterized in that, Each first punch and / or at least one second punch (18) has a punch body (42) that is axially movable in the direction of the pressure (P) and a contact surface (48) that can contact the components of the device (22), wherein the contact surface (48) is configured to be tiltable about at least one spatial axis relative to the punch body (42).

9. The sintering apparatus (10) according to claim 1, characterized in that, A plurality of first stamping heads (16) arranged side by side correspond to at least one second stamping head (18), or the plurality of second stamping heads (18) arranged side by side correspond to a plurality of first stamping heads (16).

10. A method for simultaneously connecting a plurality of side-by-side electronic devices (22) by pressure sintering in a sintering apparatus (10) according to any one of the preceding claims, wherein the sintering apparatus (10) includes a plurality of first stamping heads (16) and the at least one or more second stamping heads (18), wherein the devices (22) are disposed between the stamping heads, wherein each first stamping head (16) and / or the at least one second stamping head is axially movable in the direction of 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. The first stamping head (16) is loosely placed onto the device (22) outside the sintering apparatus (10). b. Insert the device (22) together with the placed first stamping head (16) into the sintering apparatus (10) and align it with the at least one or more second stamping heads (18). c. The sintering process is carried out by manipulating the drive device (28, 28.1, 28.2) to move the first punch (16) and / or the at least one second punch (18) from the rest position to the working position to generate pressing pressure, in which the devices (22) are pressed together between the first punch (16) and the at least one second punch (18), the second punch being arranged opposite to the first punch (16) to apply a reaction force.

11. The method of claim 10, wherein the step of carrying out the sintering process includes at least heating and / or cooling the first stamping head (16) and / or the at least one second stamping head (18), wherein the first stamping head (16) is maintained at a temperature level lower than that of the second stamping head (18).

12. The method of claim 10, wherein the different drive devices (28, 28.1, 28.2) for moving the first stamping head (16) and / or the second stamping head (18) to the working position are activated in a time-delayed manner.

13. The method of claim 12, wherein the different drive devices (28, 28.1, 28.2) are activated in a time-delayed manner, such that at least one drive device (28, 28.1, 28.2) arranged in the central region is activated first, and the drive devices (28, 28.1, 28.2) located on the outer side are activated after a certain time interval.

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