Pressing machine for pressing components onto a substrate, particularly a printed circuit board or support board, with substrate placement

Abstract

A machine (10) for pressing electrical, electronic, mechanical and / or electromechanical components onto a substrate (31), in particular onto a printed circuit board or carrier board (32), and a method therefor, comprising: - a movable unit (24), comprising a receptacle (26) for a substrate (31, 32) and with which the substrate (31, 32) can be moved in a plane, which is traversed by an x-axis (34) and a y-axis (36), and can be placed in a pressing position in which one or more components are pressed onto the substrate (31, 32), - a lower tool (16), which rests against the underside of the substrate (31, 32) before or during pressing, - an upper tool (20), which can be moved against the component to press the component along the z-axis (18) towards the substrate (31, 32), - a control unit (45) for controlling the movable unit (24), and - a sensor (48) for detecting at least one reference mark (50, 52,47) present in the substrate (31, 32), wherein the control unit (45) is configured and designed to control the moving unit (24) based on the detected reference mark (50, 52, 47) so that the substrate (31, 32) is placed between the lower tool (16) and the upper tool (20) in the pressing position. (Fig. 2).

Description

The invention relates to a pressing machine for pressing electrical, electronic, mechanical and / or electromechanical components onto a substrate, in particular onto a printed circuit board or carrier board. BACKGROUND OF THE INVENTION These pressing machines are commonly used in the production of large numbers of identical printed circuit boards or carrier boards equipped with electrical, electronic, mechanical, and / or electromechanical components. Pressing components onto printed circuit boards or carrier boards is a particularly effective alternative to soldering. Specifically, it offers the advantage of eliminating the need to melt solder, venting the resulting process gas, and generally resulting in a comparatively lower energy consumption. The pins of electrical, electronic, mechanical, and / or electromechanical components are pressed into the metallized holes or bores of the substrate. Any overpressure generated during pressing can be absorbed by deformation of the metallized hole or by deformation of the pin itself. Generally, this results in a reliable and stable connection. Pressing can be performed, in particular, to join the metal parts by cold welding. It has been found that the requirements for pressing components onto a substrate, such as printed circuit boards or carrier boards, are becoming increasingly stringent. In particular, the placement of the substrates with the components in the pressing position, where the components are pressed onto the substrates, must be performed with relative precision to ensure a functionally reliable pressing of the components. In this context, it should be noted that the component leads may penetrate the substrates during pressing and that the free ends of the leads often protrude from the side of the substrate opposite the components during or after pressing. QCOC Ln / Zznz / E / YIAI It has also been found that it is desirable to use pressing machines flexibly, in particular to press different components on the same substrate, or also on different substrates. In particular, when different substrates with different components are to be joined in a pressing machine, it is necessary that the individual substrates be placed in a pressing position that will be defined in each case before the respective pressing operation in the machine. The object of the present invention is to allow the placement of substrates in the pressing machine in a simple manner. BRIEF DESCRIPTION OF THE INVENTION The object is obtained by means of a pressing machine for pressing electrical, electronic, mechanical and / or electromechanical components that has the characteristics of claim 1. The pressing machine comprises, in particular, a movable unit comprising a receptacle for a substrate, whereby the substrate can be moved in a substrate plane intersected by an xy axis and a y axis, and can be placed in a pressing position in which one or more components are pressed into the substrate. The xy axis and the y axis are arranged orthogonally to each other and lie in a horizontal plane. In addition, a lower tool is provided that can move along a z-axis against the underside of the substrate during or before pressing. Specifically, the z-axis is orthogonal to the plane of the substrate, i.e., orthogonal to the xy-axis. The lower tool can also be rigid, and the substrate with the components to be pressed can be placed on it. The lower tool absorbs the forces that arise during pressing. Additionally, an upper tool is provided that can be moved against the component to press it along the z-axis toward the substrates. The pressing is ultimately performed by the upper tool, which presses the component onto the substrate, against whose underside the lower tool rests to deflect the pressing forces. In addition, a control unit is provided to control the moving unit. Specifically, the control unit can be designed to also control the tool's movement. QCOC Ln / Zznz / E / YIAI upper and lower tool along the z-axis. In addition, a sensor is provided to detect at least one reference mark provided on the substrate. The control unit is configured and designed to control the moving unit based on a detected reference mark, positioning the substrate between the lower and upper tools in the pressing position. By detecting the reference mark, a defined reference position for the substrate can be determined. The pressing position can be specified relative to either the reference position or the reference mark. Therefore, when the reference position or reference mark is known, the substrate can be moved with positional accuracy to the pressing position, i.e., the target position. This positioning of the substrate in the pressing position can be done for each substrate received by the pressing machine. This ensures that the substrate is always positioned precisely for pressing before the pressing process begins. Overall, this can optimize the pressing and bonding processes. After pressing, the control unit can continue to control the moving unit so that it moves to a second or subsequent pressing position, where a second component or components placed on the substrate are pressed into place. Since the second or subsequent pressing positions are known relative to the first or previous pressing position, the control unit can precisely control the moving unit. Furthermore, it is advantageous if the lower tool has cavities on its upper side opposite the upper tool to receive the free ends of the component pins as they pass through the solder plate during pressing. By providing these cavities in the lower tool, the free ends of the pins can be submerged within them during the pressing process. This has the benefit of preventing the pressing process from being hindered by the free ends striking the lower tool. The quality of the press and the resulting joint can also be improved. Especially if the pins that penetrate the substrate protrude from the underside of the substrate after the pressing operation, precise positioning and placement of the substrate in the pressing position is required before pressing. Only in this way can it be ensured that the free ends of the pins can actually be inserted into the cavities in the upper part of the lower tool. QCOC Ln / Zznz / E / YIAI The upper tool can be adapted to the geometry of the component to be pressed on its underside, relative to the lower tool. However, it is also conceivable that the underside of the upper tool could be flat and without cavities. It has been found that it is advantageous for the reference mark to be an edge of the substrate. This allows the substrate to be fed into the pressing machine and the edge of the substrate to be detected by the sensor. Based on the detected reference mark, the substrate can then be positioned for pressing. It is also conceivable that the reference mark is a fiducial mark present on the substrate. Such reference marks are known on printed circuit boards to serve as optical reference points for automated machining of the printed circuit board, particularly for the insertion of holes or vias. An additional and particularly preferred embodiment of the invention provides that the reference mark detected by the sensor is a reference hole present in the substrate. The sensor is then designed to detect the reference points, and in particular the central axis or center point of the substrate. The reference hole may have, for example, a predefined diameter that can be detected by the sensor, allowing it to deduce the central axis or center point. After the detection of the reference hole, the substrate is preferably displaced so that the reference hole is located at the center of the sensor; that is, the central axis of the sensor and the central axis of the reference hole correspond or are aligned along a common straight line. The substrate then assumes its reference position.Next, the substrate, starting from the substrate reference position, can be moved with respect to the reference position to the pressing position. Additionally, it is desirable that the control unit be configured and designed so that, during the movement of the receptacle along the x-axis in the direction of travel, the sensor detects, for example, a substrate edge in the receptacle located in front of it with respect to the direction of travel. Based on the detected substrate edge, the moving unit is then controlled to move the receptacle in the plane of the substrate along the xy-axis or the y-axis so that the reference mark is within the sensor's detection region. It is desirable that the position and distance of the reference mark from the substrate edge be known. Once the substrate edge has been acquired, the reference mark can be searched for in a predetermined region using the corresponding region output. QCOC Ln / Zznz / E / YIAI Therefore, several steps are possible: In the first step, the substrate edge is detected. Specifically, it can be detected that a substrate has been introduced into the pressing machine and is present. Especially when the location of the reference mark on the substrate relative to its edge is stored, the substrate can be moved in a second step so that the reference mark is within the sensor's detection range. The reference mark can then be detected in a third step, and, starting from the reference mark, the substrate can be moved in a fourth step to the target or pressing position by means of the moving unit. In a subsequent step, the pressing can be performed. Furthermore, it is advantageous for the substrates to have metallized through-holes, where the reference hole in the substrate is produced during the machining operation for the substrate where through-holes are created to receive the component pins. This has the advantage that both the through-holes and the reference hole are produced in the same machining operation, and specifically in the same substrate fixture. This ensures that the positions of the reference hole relative to the through-holes are comparatively accurate. Therefore, the position of the through-holes can be reliably deduced from the position of the reference hole.In this way, if the substrate is placed in the pressing position, it is ensured that the through holes adopt an exact position with respect to the reference hole and that, ultimately, the pressing process can be carried out with a precisely positioned substrate. The sensor itself can be designed as either an optoelectronic sensor or a camera. Specifically, a light barrier sensor can be used as an optoelectronic sensor. In particular, a CCD camera can be used as a camera, where the reference position can be deduced using pattern recognition methods. Furthermore, it is advisable that the moving unit and / or the control unit be configured so that the acceleration and / or braking of the receptacle along the xy / y axis occurs in such a way that the components on the substrate do not change their position before being pressed during the acceleration and / or braking of the receptacle. Specifically, the acceleration and braking occur in such a way that the components do not tilt on the substrate before being pressed during the braking or acceleration process. This ensures secure placement and pressing of the components on the substrate. QCOC Ln / Zznz / E / YIAI The aforementioned object is also achieved by a method for operating a pressing machine for pressing components onto a substrate, in particular for operating a pressing machine in accordance with the invention having the features of claim 10. The method is characterized by the sensor detecting at least one reference mark on the substrate and by the movable unit being positioned between the lower and upper tools based on the detected reference mark. Consequently, the substrate's reference position is determined by detecting this reference mark. From either the reference position or the substrate's actual position, the substrate can be moved to the target position, i.e., the pressing position, and placed there for pressing. The reference mark can be a substrate edge, a fiducial mark, and / or a reference hole. Furthermore, it is convenient that, in a first step, when the substrate moves along the x-axis in the direction of displacement, for example, the leading edge of the substrate is detected in the direction of displacement. In a second step, depending on the detected substrate, the substrate is moved in the substrate plane along the xy-axis or the y-axis such that the reference mark is located within the sensor's detection region. In a third step, the reference mark can be detected, and in a fourth step, the substrate can be moved into the pressing position. In a fifth step, the pressing can be performed. In general, the substrate can therefore be reliably placed in the pressing machine for pressing. Further details and advantageous embodiments of the invention can be found in the following description, which describes and explains in more detail an exemplary embodiment of the invention. DESCRIPTION OF THE FIGURES The drawings show: Fig. 1 a pressing machine; Fig. 2 the mobile unit of the pressing machine according to Fig. 1; and Fig. 3 a lower tool of the pressing machine according to Fig. 1 in a side view and a plan view. QCQQI η / 77Π7 / Β / YILI DETAILED DESCRIPTION OF THE INVENTION Figure 1 shows a pressing machine 10 having a base body 12 and a gantry 14. On the base body 12 is a lower tool 16, which is movably arranged with a lower pressing unit 17 along a vertical z-axis 18. On the gantry 14 is shown an upper tool 20 that interacts with the lower tool 16 during the pressing process, said upper tool 20 being movable along the z-axis 18 towards a substrate 31 in the form of a carrier board or printed circuit board 32 with an upper pressing unit 22 that is coupled to the gantry 14. The pressing machine 10 comprises a mobile unit 24, which provides a receptacle 26 for the substrate 31 or the printed circuit board 32. The mobile unit 24, shown in Fig. 2, has an input 28 and an output 30, in which the printed circuit board 32 shown in Fig. 2 can be moved between the input 28 and the output 30 along an x-axis 34 by means of a transport drive 37 having two motors. The transport drive 37 drives the conveyor belts 40 on which the printed circuit board 32 rests. The belts 40 are guided by transport rails 42. When the printed circuit boards 32 are moved to entry 28, there are electrical or electronic components on the printed circuit board 32, which are pressed into the printed circuit board 32 with the pressing machine 10. Such components are not shown in Fig. 2; the pins of the components may be placed in metallized through holes, which are provided in the printed circuit board 32, or they may be inserted in some other way. For the supply of the printed circuit boards 32, it is conceivable that a feeding device be provided above the inlet 28 with which the printed circuit boards 32 are supplied. To unload the printed circuit boards 32 after the pressing operation, it is conceivable that an unloading unit be connected below the outlet 30. With the movable unit 24, the printed circuit board 32 can be moved along the x-axis 34 and along a y-axis 36, which is arranged perpendicular to the x-axis 34 and perpendicular to the z-axis 18. The printed circuit board 32 can therefore be moved with the movable unit 24 in a plane, which is crossed by the x-axis 34 and the y-axis 36. An x-axis drive is provided to move the printed circuit board in receptacle 26 in the x-direction. By properly controlling the x-axis drive, the QCOC Ln / Zznz / E / YIAI q Receptacle 26 together with the printed circuit board can be moved accordingly in the x 34 direction. The mobile unit 24 also provides a y-axis drive 44, by which the transport rails 42, and therefore the printed circuit board 32, can be moved in the y-direction 36. Depending on the x-drive control 38 and the y-drive 44, the printed circuit board 32 can consequently move freely in the plane defined by the x-axis 34 and the y-axis 36. In addition, a control unit 45, for example a PLC controller, is provided, which is shown schematically in Fig. 2 and serves to control the drive of the x-axis 38 and the drive of the y-axis 44. With the control unit 45, the upper tool 20 and the lower tool 16 can also move along the z-axis 18 independently of each other and away from each other. In Fig. 2, a stop sensor 46 is arranged in the region of one of the transport lanes 42. The stop sensor 46, which can be designed, for example, as a light barrier, detects the entry of a leading edge 47 of the printed circuit board 32 during the movement of the printed circuit board from entry 28 to exit 30. Fig. 2 shows another sensor 48, a position sensor, with which a reference mark 50 present on the printed circuit board 32 can be detected. The reference mark 50 can be, for example, the front edge 47 or a reference hole 52 on the printed circuit board 32 or a fiducial mark on the printed circuit board 32. Both the stop sensor 46 and the position sensor 48 are connected to the control unit 45 and supply generated sensor signals to the control unit 45. To transport a printed circuit board 32 from input 28 to output 30, the transport drive 37 is controlled by the control unit 45 so that the printed circuit board 32 moves toward output 30. As soon as the stop sensor 46 detects the leading edge 47 of the printed circuit board 32, the transport drive 37 stops. Since the stop is not abrupt to prevent components from falling, the printed circuit board moves slightly past the stop sensor 46 before finally coming to a halt. QCQQI η / 77Π7 / Β / YILI The printed circuit board 32 is then fixed to the movable unit 24 by means of fastening means 54, so that it cannot escape upwards or downwards in the z direction 18. The fastening means 54 may be clamping elements or clamping springs, which act against the printed circuit board 32. In a subsequent step, the printed circuit board 32 is moved in the x direction 34 and in the y direction 36 until the sensor 48 detects the reference mark 50. Since the distance between the leading edge 47 and the reference mark 50 is known, the printed circuit board 32 can be selectively moved with the movable unit 24 to the region where the reference mark 50 is located. The sensor 48 can be, for example, an optoelectronic sensor, such as a light barrier or a camera, which detects the reference mark 50. If the sensor 48 has detected the reference mark 50, a defined reference position or the actual position of the printed circuit board 32 is known. Starting from this reference position, the printed circuit board 32 can be moved in a subsequent step in the x direction 34 and in the y direction 36 to a desired position, i.e., to the pressing position, where the components on the printed circuit board 32 are pressed in using tools 16 and 20. This is possible because the pressing position relative to the reference position or reference mark is known and stored accordingly.Thus, the control unit 45 is configured in such a way that it controls the x drive 38 and the y drive 44 in such a way that the printed circuit board 32 is placed from the reference position between the lower tool 16 and the upper tool 20 in the pressing position that is known in relation to the reference position. Once the pressing position is reached, the lower tool 16 moves along the z-axis against the underside of the printed circuit board 32, so that tool 16 rests on the printed circuit board 32. Ultimately, the upper tool 20 performs the pressing, pressing the component onto the printed circuit board 32, while the lower tool 16 diverts the pressing forces to the base body 12 on the underside of the circuit board 32. Consequently, one or more components placed on the printed circuit board 32 can be pressed onto the printed circuit board 32 by means of tools 16 and 20 simultaneously or sequentially by moving the printed circuit board 32 to different pressing positions. Although Fig. 2 shows two different sensors 46 and 48, it is conceivable that sensor 48 also assumes the task of the stop sensor 46, i.e., that it determines whether the leading edge 47 has passed over sensor 48, so that the transport drive 37 is then stopped. QCQQI η / 77Π7 / Β / YILI As previously mentioned, reference mark 50 can be the leading edge 47 of the printed circuit board. However, it has been shown that printed circuit boards 32 can have production-related size deviations of a few tenths of a millimeter, and that this is too imprecise for accurate pressing positioning. Therefore, it is convenient to provide a reference hole 52 as a reference mark, whose position relative to the metallized through-holes on the printed circuit board 32, into which the electronic component pins are inserted, is comparatively accurate. In particular, the position of reference hole 52 relative to the through-holes of the printed circuit board 32 is very accurate when reference hole 52 is created in the same machining operation as the through-holes of the printed circuit board 32. Figure 3 shows the lower tool 16 as a single piece in a side view (Fig. 3a) and in a plan view (Fig. 3b). On its upper face 55, facing the upper tool 20, the lower tool 16 has cavities 56 in the form of blind holes with a diameter of 1 / 10 to 1.5 millimeters. The cavities 56 serve to receive the free ends of the pins of the electronic components that pass through the printed circuit board 32 during pressing. By providing the cavities 56, it is ensured that the free ends do not impede the pressing operation when the components are pressed onto the printed circuit board 32, but rather can be submerged in the cavity 56.Therefore, since it is also ensured that during the pressing process the free ends of the pins can be submerged into the cavities 56, it is necessary to move the printed circuit board 32 with relative precision to the pressing position before pressing and place it there. The mobile unit 24 or the drives 38 and 44 thereof are controlled by the control unit 45 in such a way that the acceleration and braking of the receptacle 24 take place in such a way that the components present on the printed circuit board 32 do not change their position on the printed circuit board before being pressed during the acceleration and / or during the braking of the receptacle 24, and in particular they do not tip over.

Claims

1. A pressing machine (10) for pressing electrical, electronic, mechanical, and / or electromechanical components onto a substrate (31), in particular onto a printed circuit board or carrier board (32), characterized in that it comprises: a movable unit (24), comprising a receptacle (26) for the substrate (31, 32) and by which the substrate (31, 32) can be moved in a plane that is traversed by an x-axis (34) and a y-axis (36) and can be placed in a pressing position in which one or more components are pressed onto the substrate (31, 32); a lower tool (16), which rests against the underside of the substrate (31, 32) before or during pressing; an upper tool (20), which can be moved against the component to press the component along a z-axis (18) toward the substrate (31, 32); a control unit (45) for controlling the movable unit (24); and a sensor (48) to detect at least one reference mark (50, 52,47) present in the substrate (31,32), wherein the control unit (45) is configured and designed in such a way that it controls the moving unit (24) based on the detected reference mark (50, 52, 47) so that the substrate (31, 32) is placed between the lower tool (16) and the upper tool (20) in the pressing position.

2. The pressing machine (10) according to claim 1, characterized in that the lower tool (16) has cavities (56) on its upper side (55) facing the upper tool (20) to receive the free ends of the component pins that pass through the substrate (31,32) when they are pressed in.

3. The pressing machine (10) according to claim 1 or 2, characterized in that the reference mark (50, 47) detected by the sensor (48) is a substrate edge.

4. The pressing machine (10) according to claim 1, 2 or 3, characterized in that the reference mark (50, 52) detected by the sensor (48) is a fiducial mark present on the substrate (31, 32).

5. The pressing machine (10) according to any of the preceding claims, characterized in that the reference mark (50) detected by the sensor (48) is a reference hole (52) present in the substrate (31,32).

6. The pressing machine (10) according to any of the preceding claims, characterized in that the control unit (45) is further configured and designed such that the sensor detects a substrate edge (47) of a substrate (31, 32) present in the receptacle (26) during the movement of the receptacle (26) along the x-axis (34), and in that, depending on the detected substrate edge (47), the movable unit (24) is also controlled so that the receptacle (26) is moved in the plane of the substrate along the x-axis (34) and / or the y-axis (36) so that the reference mark (50, 52, 47) is located in the detection region of the sensor (48).

7. The pressing machine (10) according to claim 5 or 6 and the substrate (31, 32) with through holes, characterized in that the reference hole (52) in the substrate (31, 32) is such that it has been produced in the machining operation of the substrate (31, 32) where the holes for receiving the pins of the components in the substrate (31, 32) have been introduced.

8. The pressing machine (10) according to any of the preceding claims, characterized in that the sensor (48) is designed as an optoelectronic sensor or as a camera.

9. The pressing machine (10) according to any of the preceding claims, characterized in that the movable unit (24) and / or the control unit (45) are configured in such a way that acceleration and / or braking of the receptacle (26) occurs in such a way that the components present in the substrate (31, 32) do not change their position in the substrate (31, 32) before pressing during acceleration and / or braking of the receptacle (26).

10. A method for operating a pressing machine (10) for pressing electrical, electronic, mechanical, and / or electromechanical components onto a substrate (31, 32), in particular a pressing machine (10) as claimed in any of the preceding claims, wherein the pressing machine (10) comprises: a movable unit (24), comprising a receptacle (26) for the substrate (31, 32) and with which the substrate (31, 32) can be moved in a plane, which is traversed by an x-axis (34) and a y-axis (36) and can be placed in a pressing position, a lower tool (16), which rests against the underside of the substrate (31, 32) before or during pressing, an upper tool (20), which can be moved against the component to press the component along a z-axis (18) into the substrate (31, 32), and a sensor (48) for detecting at least one reference mark (50, 52, 47) present in the substrate (31,32),wherein the method is characterized in that at least one reference mark (50, 52, 47) present on the substrate (31, 32) is detected by the sensor (48), and in that the movable unit (24) is placed in the pressing position according to the detected reference mark (50, 52, 47) between the lower tool (16) and the upper tool (20).

11. The method according to claim 10, characterized in that a printed circuit board edge (47), a fiducial mark and / or a reference hole (52) are detected as a reference mark (50).

12. The method according to claim 10 or 11, characterized in that, in a first step, a substrate edge (47) is detected when the substrate (31, 32) is displaced along the x-axis (34) in the displacement direction, wherein in a second step, based on the detected substrate edge (47), the substrate (31, 32) is displaced in the plane such that the reference mark (50, 52, 47) is located in the sensor's detection region (48), wherein, in a third step, the reference mark (50, 52, 47) is detected, wherein, in a fourth step, the substrate (31, 32) is displaced to the pressing position, and wherein, in a fifth step, the component is pressed into the substrate (31, 32).

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