Patent Publication Number: US-2023137203-A1

Title: Press-in machine for pressing components into a substrate, in particular into a printed circuit board or carrier plate, with changing unit

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application relates and claims priority to German Patent Application No. 10 2021 128 728.6 filed with the German Patent Office on Nov. 4, 2021, the entirety of which is hereby incorporated by reference. 
     BACKGROUND 
     The invention relates to a press-in machine for pressing electrical, electronic, mechanical and/or electromechanical components into a substrate, in particular into a printed circuit board or carrier board. 
     Such press-in machines are regularly used in the production of a large number of identical circuit boards populated with electrical, electronic, mechanical and/or electromechanical components. The pressing of the components into printed circuit boards represents in particular an alternative to soldering the components. In particular, it has the advantage that no melting of solder tin is required, that no resulting process gas has to be discharged and that overall the joining process is subject to a comparatively lower energy consumption. 
     The pins provided on the electrical, electronic, mechanical and/or electromechanical components are pressed into metallized holes provided in the substrate during pressing. An excessive pressing occurring during the pressing-in can be absorbed either by deformation in the metallized hole or by the deformation of the pin. Overall, a very reliable and also robust connection results. Pressing-in can be carried out in particular such that the metal partners are joined by cold welding. 
     It has been found desirable to use press-in machines flexibly, in particular for pressing-in different components into one and the same substrate or into different substrates. 
     In particular when different substrates with different components are to be joined in a press-in machine, it is necessary to use different tools for pressing-in different components. 
     SUMMARY OF THE INVENTION 
     The object of the present invention is to enable a tool change of the press-in tools in a simple manner. 
     The object is achieved by a press-in machine for pressing electrical, electronic, mechanical and/or electromechanical components into a substrate. 
     Such a press-in machine comprises in particular a lower tool which can, during or before pressing-in, be moved together with a lower pressing unit along a z-axis and against the underside of the substrate. The lower tool can also be provided in a stationary design, and the substrate with the components to be pressed-in can be placed on the lower tool. 
     Furthermore, an upper tool is provided which can be moved together with an upper pressing unit along the z-axis toward the substrate and against the component for pressing-in the component. Pressing-in is ultimately carried out by the upper tool, which presses the component into the substrate, against the underside of which the lower tool is in contact for deflecting the press-in forces. 
     Furthermore, a changing unit is provided for automatically changing the lower and/or upper tools, wherein the changing unit comprises a magazine in which a plurality of tools can be deposited, one or more tool-holders, wherein a tool is provided in or fastened on each of the tool-holders, a displacement unit with which the respective tool-holder can be moved along a displacement direction out of the magazine into a pressing receptacle of a pressing unit, and a locking device with which the respective tool-holder can be locked in the pressing receptacle. 
     By providing such a changing unit, an automated and reliable changing of the tools is possible in a simple manner. The tools can be the lower tools and/or also the upper tools. Depending on the component to be pressed in, it may be necessary to change the lower and the upper tools. By providing a magazine with a plurality of tools, different tools can be kept ready. The tool-holders, which provide the respective tool and/or in which the respective tool is fastened, can form a kind of adapter between the tools and the magazine. In particular, the interface between the tool-holders and the respective tools can be adapted to the respective tool. Different tool-holders can provide different interfaces. 
     It is also conceivable for the tool-holder and the tool to be formed in one piece and in one part; the respective tool then comprises the associated tool holder. 
     By provision of the displacement unit, the respective tool-holder together with the tool can be moved into and out of the pressing receptacle of the pressing unit in a simple manner. The tool-holder with that tool which is used for pressing-in can thereby be introduced into the pressing receptacle of the pressing unit and taken back out of it. 
     The locking device is provided for fixing the tool-holder together with the tool in the pressing receptacle. With said locking device, the tool-holder together with the tool is fixed with positional accuracy in the pressing receptacle. 
     Advantageously, the displacement unit is designed such that it pushes the respective tool-holder together with the tool out of the magazine and into the pressing receptacle. In order to ensure a reliable displacement, it is conceivable for guides to be provided for guiding the tool-holder. For example, linear guides can be provided, such as guide grooves. The displacement unit can comprise, for example, an electric motor, pneumatic cylinder or the like for implementing the sliding movement. 
     Furthermore, it is advantageous if the respective tool-holder has a coupling element and if the displacement unit comprises a coupling head, wherein the coupling head interacts with the coupling element in such a way that the coupling head pulls the coupling element out of the pressing receptacle and into the magazine. Such a pulling-out of the tool-holder together with the tool from the pressing receptacle and into the magazine can likewise be effected in a comparatively simple manner. 
     In particular, the coupling element is magnetizable and the coupling head comprises a magnetic element, preferably an electromagnet, which can be energized to activate the coupling head. An energization thus preferably takes place when the tool-holder is to be pulled out of the pressing receptacle by the magnetic element. If the tool-holder is to be inserted into the pressing receptacle, the magnetic element can be deactivated or deenergized. 
     The magazine preferably has a plurality of sliding receptacles running parallel to one another, into which the respective tool-holder can be inserted and pulled out. Here, the sliding receptacles can be designed in the manner of a groove and the tool-holder can be formed in the manner of a T-piece so that the section of the tool-holder formed in the manner of a T-piece can be inserted into the groove of the respective sliding receptacle. As a result, a large number of different tools can be arranged next to one another in a comparatively space-saving manner in the magazine. 
     Furthermore, it is advantageous if the magazine is guided by means of a magazine drive displaceably along a magazine guide extending transversely to the displacement direction. This embodiment has the advantage that the displacement unit can be arranged to be stationary. By moving the magazine along the magazine guide, the tool-holder with the tool that is to be used for the pressing-in can be moved in the displacement range of the displacement unit and can finally be inserted by the displacement unit into the pressing receptacle. 
     Furthermore, it is conceivable for the pressing receptacle to be provided on a rotary element mounted rotatably about an axis of rotation and for a rotary drive to be provided for rotating the rotary element. This has the advantage that the tool-holder together with the tool can be aligned by rotating toward the component to be pressed in. The tool can consequently be oriented according to the component to be pressed in. 
     A further development of the invention provides that the locking device comprises a locking bolt which is displaceable axially between a locking position and a release position and interacts on the side of the tool-holder facing away from the tool with the tool-holder in order to lock the tool-holder in the pressing receptacle. Then, when the locking bolt is in the release position, the tool-holder can be retracted into the pressing receptacle or moved out. Then, if a tool-holder is present in the pressing receptacle, it can be fixed there by moving the locking bolt into the locking position. On its side facing away from the tool, the tool-holder can provide a recess, a hole, a cone or the like with which the locking bolt interacts in the pressing receptacle for securing the position and locking the tool-holder. In order to move the locking bolt between the locking position and the release position, a bolt drive is preferably provided which can be designed, for example, as an electric motor, pneumatic cylinder or the like. 
     In order to enable a rotation of the pressing receptacle about the axis of rotation despite the provision of the locking bolt, the locking bolt is preferably arranged along the axis of rotation of the pressing receptacle or the rotary part. A rotation of the pressing receptacle is then possible without hindering the locking bolt. 
     Furthermore, it is advantageous if a readable coding is provided on the tool-holder for identifying the tool and if a reading unit for reading the coding is provided on the displacement unit. As a result, it can be ensured that prior to the introduction of the respective tool-holder together with the tool into the pressing receptacle, it is possible to check which tool is present for introduction into the pressing receptacle. Thus it can consequently be ruled out that a tool which is not suitable for pressing-in the component to be pressed-in is introduced into the pressing receptacle. 
     Furthermore, when a plurality of different tools is present, it is advantageous for interfaces between the tool-holders and the respective tools to have different designs. The background for this is that tools from different manufacturers can be used; in particular, in the case of pressing-in, tools are regularly supplied or prescribed by the component manufacturers of the components that are to be pressed in. The individual tool-holders then serve as adapters between the tools and the changing unit. 
     In addition, it is advantageous if, when a plurality of different tools is present, the tool-holders each have different heights extending in the z axis. Consequently, the tool-holders can provide height compensation if the tools require different heights. A height compensation is also necessary in particular when other components are already present on the substrate next to the components to be pressed-in and have a certain height. 
     Furthermore, it is advantageous if a moving unit is provided which comprises a receptacle for the substrate with which the substrate can be moved in a plane which is defined by an x-axis and a y-axis and can be placed in a press-in position in which one or more components are pressed into the substrate. The x-axis and the y-axis are arranged orthogonally to one another and lie in particular within a horizontal plane. Such a moving unit has the advantage that the tools can be arranged so as to be movable only in the z-direction. 
     Furthermore, it is advantageous if a control unit is provided which is provided for controlling the individual units, such as for example the lower pressing unit, the upper pressing unit, the displacement unit, the locking device, the magazine drive, the rotary drive and/or the moving unit. By providing such a control unit, an automated change of the tools in the press-in machine can be effected. 
     Further details and advantageous embodiments of the invention can be found in the following description, on the basis of which an exemplary embodiment of the invention is described and explained in more detail. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings show: 
         FIG.  1    a press-in machine; 
         FIG.  2    a changing unit of the press-in machine according to  FIG.  1    having a magazine in the parked position; 
         FIG.  3    the changing unit according to  FIG.  2    having the magazine in a changing position; 
         FIG.  4    an isometric view of the magazine and of a displacement unit of the changing unit according to  FIGS.  2  and  3   ; 
         FIG.  5    the lower pressing unit of the press-in machine according to  FIG.  1   ; and 
         FIG.  6    a longitudinal section through the upper part of the pressing unit according to  FIG.  5   . 
     
    
    
     DETAILED DESCRIPTION 
       FIG.  1    shows a press-in machine  10  which has a base body  12  and a gantry  14 . A lower tool  16  is provided on the base body  12  which with a lower pressing unit  17  is movably arranged along a vertically running z-axis  18 . An upper tool  20  which interacts with the lower tool  16  during the pressing-in process is shown on the gantry  14 , said upper tool  20 , which together with an upper pressing unit  22  which engages in the gantry  14 , being movable along the z-axis  18  toward a substrate  32  in the form of a printed circuit board or carrier board. 
     The press-in machine  10  comprises a moving unit  24  which provides a receptacle  26  for the substrate  32  to be processed. 
     On the substrate  32  there are in particular electrical, electronic, mechanical and/or electromechanical components (not shown in the figures) with pins which are pressed by the press-in machine  10  into the substrate  32 . The pins of the components can be plugged into or slightly inserted into metallized through-holes which are provided in the substrate  32 . 
     With the moving unit  24 , the substrate  32  can be moved along an x-axis  34  and a y-axis  36 , which are arranged perpendicular to the z-axis  18 , into a press-in position. After reaching the press-in position, the lower tool  16  is moved along the z-axis against the underside of the substrate  32 , so that the tool  16  comes into contact against the substrate  32 . The pressing-in is finally carried out by the upper tool  20 , that the component is pressed into the substrate  32 , while on the underside of the substrate  32  the lower tool  16  deflects press-in forces into the base body  12 . Consequently, one or more components placed on the substrate  32  can be pressed into different press-in layers by means of the tools  16  and  20  simultaneously or sequentially by moving the substrate  32  into different press-in layers in the substrate  32 . 
     Furthermore, a control unit  45 , for example a PLC controller, is provided, which is configured for driving the moving unit  24  along the x-axis  34  and the y-axis  36 . With the control unit  45 , the upper tool  20  and the lower tool  16  can also be moved along the z-axis  18  independently of one another and away from one another. 
       FIG.  2    shows a changing unit  60  for changing the lower tool  16 . The changing unit  60  is provided on the base body  12  and comprises a magazine  62  and a displacement unit  64 . A plurality of tools  66  is stored in the magazine  62 . The tools  66  are each rigidly fastened to a tool-holder  68 . In  FIG.  2   , the magazine  62  with tools  66  is located in a parked position. The tool  16  is located in a pressing receptacle  70  of the pressing unit  17 , where it is fixed by means of a locking device  98 , which is shown in  FIG.  6    and is described further below. 
     The magazine  62  has a plurality of sliding receptacles  72  running parallel to one another, wherein in  FIG.  2    only one sliding receptacle  74  is free and the other sliding receptacles  72  are occupied by the tools  66 . 
     To replace the tool  16  that is present in the pressing receptacle  70  for one of the tools  66 , the magazine  62  can be moved by means of a magazine drive  76 , which can be seen in  FIG.  3   , from the parked position shown in  FIG.  2    along a magazine guide  78  into a changing position shown in  FIG.  3   . 
     In  FIG.  3    the magazine  62  is consequently located in the changing position, in which the free sliding receptacle  74  is oriented toward the pressing receptacle  70 . In order now to move the tool  16  into the free sliding receptacle  74 , the displacement unit  64  can be actuated in such a way that a coupling head  80  of the displacement unit  64 , which can be clearly seen in  FIG.  4   , is displaced along a displacement direction  82  from a retracted position shown in  FIGS.  2  and  3    into an extended position, so that the coupling head  80  acts against a coupling element  84  present on the tool-holder  68 . The coupling element  84  can, for example, be a magnetizable plate which is provided on the respective tool-holder  68 . For moving the coupling head  80  between the retracted position and the extended position, it is conceivable for the moving unit to comprise a drive, for example a pneumatic drive with a piston-cylinder unit. 
     The coupling head  80  can be switched between a magnetized state and a non-magnetized state by means of a magnetic element (not shown), in particular an electromagnet. If the tool  16  is now to be moved out of the pressing receptacle  70  into the free sliding receptacle  74 , the coupling head  80  in the magnetized state will move against the magnetizable coupling element  80  provided on the tool-holder  68 . After the locking device  98 , which locks the tool-holder  68  in the pressing receptacle  70 , is released, the tool-holder  68  together with the tool  16  can be moved out of the pressing receptacle  70  along the displacement direction  82  into the sliding receptacle  74  by moving the coupling head  80  back from the extended position into the retracted position. The coupling head  80  or its magnetic element pulls the tool-holder  68  out of the pressing receptacle  70  and into the free sliding receptacle  74 . 
     In order now to introduce a different tool  66  into the pressing receptacle  70 , the magazine  62  can be moved via the magazine drive  76  such that the tool  66  which is to be used is aligned along the displacement direction  82  and along the pressing receptacle  70 . In a next step, the respective tool  66  or its tool-holder  68  can be inserted into the pressing receptacle by means of the displacement unit  64  along the displacement direction  82 . For this purpose, the coupling head  80  is moved in the displacement direction against the coupling element  84  from the retracted position into the extended position until the respective tool-holder  68  has assumed its position in the pressing receptacle  70 . 
     To ensure that the correct tool  66  is inserted into the pressing receptacle  70 , readable codings are provided on the tool-holders  68  for identifying the respective tool  66 . Furthermore, a reading unit  86 , which can be clearly seen in  FIG.  4   , is provided on the displacement unit  64  and can be used to read the respective coding. The readable coding can in particular be a bar code, a QR code, an RFID code or the like. 
     As is clear from  FIGS.  5  and  6   , the pressing receptacle  70  is provided on a rotary element  90  mounted rotatably about an axis of rotation  88 . For this purpose, pivot bearings  94  are present between the rotary element  90  and an upper carrier  92  of the lower pressing unit  17 . Furthermore, a rotary drive  96  is provided with which the rotary element  90 , and thus the tool  16 , can be rotated about the axis of rotation  88 . As a result, the tool  16  or the tools  60  can be oriented toward the components to be pressed in. 
     In order to lock the respective tool-holder  68  in the pressing receptacle  70 , as is clear from the section according to  FIG.  6   , the locking device  98  is provided with a locking bolt  100  that can be displaced axially between a locking position and a release position. Here, the locking bolt in the locking position interacts with a recess  102  provided on the side of the tool-holder  68  facing away from the tool  16 . To displace the locking bolt  100  between the locking position and the release position, a bolt drive (not shown in more detail) is provided which can drive the locking bolt  100  either rotationally or axially for axial displacement. 
     As is clear from  FIG.  6   , the locking bolt  100  is arranged along the axis of rotation  88 . This has the advantage that rotation of the tool  16  about the axis of rotation  88  is possible independently of the presence or the position of the locking bolt  100 . 
     As is further apparent from  FIG.  6   , the tool  16  is rigidly fastened to the respective tool-holder  68  by means of fastening screws  104 . However, it is also conceivable for the particular tool  16  to be integrally formed with the respective tool-holder  68 . Depending on the components to be pressed in, different tools can be used. The interfaces between the tools  16 ,  20 ,  66  and the respective tool-holders  68  can also be designed differently, tool-specifically. However, the interfaces between the tool-holders  68  and the magazine  62  or the pressing receptacle  70  are preferably designed identically. In particular, the heights of the tools  16 ,  66  extending in the z-axis  18  and also of the tool-holders  68  can be different, depending on the components to be pressed in and depending on the given requirements. 
     The lower changing unit  60  for the respective lower tool  16  is shown in  FIGS.  2  to  6    and described in the foregoing. In accordance with the design of the lower changing unit  60 , as is indicated in  FIG.  1   , an upper changing unit  106  can also be provided which is designed in accordance with the lower changing unit  60 . 
     Consequently, the lower tools  16  and the upper tools  20  can be replaced automatically by means of the changing units  60  and  106 . In particular, different components successively placed on a substrate  32 , i.e., in particular on a printed circuit board or carrier board, can also be pressed-in with different tools  16 ,  20 . 
     Here the control unit  45  controls not only the movement of the pressing units  17  and  22  and the moving unit  24 , but also the locking device  98 , the magazine drive  76 , the rotary drive  96  and/or the bolt drive.