BONDING TOOL, BONDING DEVICE AND BONDING METHOD

Abstract

The invention relates to a bonding tool for a bonding device for bonding at least one component by adhesives to a substrate, the bonding device including a circular disc-shaped main body lying in a main plane and having an opening and a receiving head connected to the main body for receiving and holding the components, an orthogonal projection of the receiving head onto the main plane lying within the opening so that the receiving head is freely accessible through the opening. The bonding tool has a lighting unit integrated in the bonding tool for curing the adhesive. The invention also relates to a bonding device for bonding at least one component by adhesives applied to a substrate located in an assembly position, and to a bonding method for bonding components by adhesives applied to a substrate.

Claims

1. A bonding tool for a bonding device for bonding at least one component by adhesives to a substrate, the bonding tool comprising: a circular disk-shaped base body lying in a base plane and having an opening and a receiving head connected to the circular disk-shaped base body for receiving and holding the at least one component, wherein an orthogonal projection of the receiving head onto the base plane lies within the opening, so that the receiving head can be accessed freely through the opening, wherein the bonding tool comprises a lighting unit, which is integrated in the bonding tool, for curing the adhesives.

2. The bonding tool according to claim 1, wherein the lighting unit is replaceable.

3. The bonding tool according to claim 1, wherein the lighting unit is a UV lighting unit or a UV LED unit.

4. The bonding tool according to claim 3, wherein the UV LED unit comprises at least two LEDs.

5. The bonding tool according to claim 1, wherein the lighting unit comprises a cooling unit, or cooling fins.

6. The bonding tool according to claim 1, wherein the lighting unit is electrically connected to the base body via an electrical interface.

7. The bonding tool according to claim 1, wherein the receiving head comprises a gripping unit and/or a vacuum unit.

8. The bonding tool according to claim 1, wherein the bonding tool comprises fastening elements for fastening to a bonding head of a bonding device.

9. The bonding tool according to claim 8, wherein the fastening elements comprise a a V-shaped groove, which is arranged on a circumference of the base body.

10. The bonding tool according to claim 1, wherein the bonding tool comprises at least one magnet and/or a ferromagnetic region for magnetically fastening the bonding tool to a bonding head of the bonding device.

11. The bonding tool according to claim 10, wherein the bonding tool comprises an adjusting device for setting an alignment of the bonding tool with respect to the bonding head.

12. The bonding tool according to claim 11, wherein the adjusting device comprises at least two setting screws, wherein the setting screws have a ball-like tip for engaging with a V-shaped setting groove in the bonding head.

13. The bonding tool according to claim 1, wherein the bonding tool has electrical contracts for an electrical connection to the bonding head.

14. The bonding tool according to claim 1, wherein the opening is circular.

15. The bonding tool according to claim 1, wherein the bonding tool comprises a spring assembly, which is arranged in the opening, wherein the receiving head is fastened to the spring assembly, so that the receiving head is resiliently connected to the circular disk-shaped base body.

16. The bonding tool according to claim 15, wherein the spring assembly comprises at least four leaf springs, which are arranged in a parallelogram-like manner.

17. The bonding tool according to claim 1, wherein the bonding tool comprises a sensor device for measuring a contact force of the at least one component on the substrate.

18. The bonding tool according to claim 17, wherein the sensor device is measures a deflection of the receiving head to the circular disk-shaped base body.

19. The bonding tool according to claim 17, wherein the sensor device comprises optical sensors, an ultrasonic assembly and/or strain gauges.

20. A bonding device for bonding at least one component by adhesives to a substrate located in an assembly position (M), comprising: a work plate extending along a work plane, and a base frame supporting the work plate; a displaceable bonding head comprising a bonding tool, wherein the bonding tool comprises a receiving head for receiving and holding the at least one component, a displaceable metering valve for applying adhesive to the substrate, wherein the bonding tool (9) has a lighting unit integrated in the bonding tool for curing the adhesive.

21. The bonding device according to claim 20, wherein the bonding tool is rotatably supported on the bonding head.

22. The bonding device according to claim 20, wherein the bonding tool comprises electrical contacts and the bonding head comprises electrical counter contacts for an electrical connection.

23. The bonding device according to claim 20, wherein the bonding device comprises a camera system directed to an assembly position for measuring an alignment of the component in relation to the substrate.

24. The bonding device according to claim 20, wherein the bonding device comprises a distance sensor for determining a distance of the component to the substrate.

25. A bonding method for bonding components by adhesives to a substrate, comprising the steps of: receiving a component to be bonded in a receiving position by a bonding tool arranged on a bonding head of a bonding device; applying, at the same time or following the receiving the component to be bonded in the receiving position, an adhesive to the substrate; to which the component is to be applied, at an assembly position; displacing the bonding head to the assembly position with the bonding tool and the received component; placing and holding, the component onto an adhesive structure with a specified height and/or contact force; and activating a lighting unit integrated in the bonding tool to cure the adhesive, and then moving the bonding head back to a starting position.

26. The bonding method according to claim 25, wherein alignment with the substrate takes place via a camera system through an opening of the bonding tool from a top onto the component.

27. The bonding method according to claim 25, wherein prior to the activating the lighting unit, verification and/or measuring steps are performed for a proper assembly of the component on the substrate.

28. The bonding method according to claim 25, wherein for aligning purposes, the bonding tool is rotated in the bonding head and/or the bonding head is displaced in a work plane.

29. The bonding method according to claim 25, wherein the substrate is displaced out of the assembly position or a further component is bonded to the substrate.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The invention will be described in more detail below on the basis of exemplary embodiments in connection with the drawings, in which

[0038] FIG. 1 shows a schematic side view of a bonding device.

[0039] FIG. 2a shows a side view of a bonding tool.

[0040] FIG. 2b shows a longitudinal section through the bonding tool from FIG. 2a.

[0041] FIG. 2c shows a perspective view of the bonding tool from FIGS. 2a and 2b.

[0042] FIG. 2d shows a perspective exploded drawing of the bonding tool from FIGS. 2a to 2c.

DETAILED DESCRIPTION OF THE INVENTION

[0043] Identical reference numerals are used in the figures for elements of the invention, which are identical, or which act identically. For the sake of clarity, only reference numerals, which are required for the description of the respective figure, are illustrated in the individual figures.

[0044] FIG. 1 shows a schematic side view of a bonding device 1 for bonding at least one component by adhesives to a substrate 2 located in an assembly position M. The bonding device 1 comprises a work plate 3 and a base frame 4 supporting the work plate 3. The top side of the work plate 3 thereby defines a work plane E.

[0045] The substrate 2, to which the component or the components, respectively, are to be bonded, is located in the center of the work plate 3, in the assembly position M. A control unit 5 of the bonding device 1, which controls the units of the bonding device 1, is only indicated.

[0046] A camera system 6, here, for example, comprising two cameras 7, is arranged above the assembly position M. A bonding head 8 comprising a bonding tool 9 as well as a metering valve 10 for adhesive are arranged above the work plate 3. The bonding head 8 as well as the metering valve 10 can be displaced in the work plane E and perpendicular to the work plane E.

[0047] For bonding a component by adhesives to the substrate 2, the component is initially received by a receiving station 12 by a receiving head 11 of the bonding tool 9. At the same time or following this, adhesive is applied to the substrate 2 at specified locations at the assembly position M by the metering valve 10. The bonding head 8 is then displaced to the assembly position M with the bonding tool 9 and the received component.

[0048] Before the component is laid down on the substrate 2, it is detected by the cameras 7 of the camera system 6 through an opening in the bonding tool 9 and is evaluated in the control unit 5 by an image processing software. The measured position of the component with respect to the substrate 2 is compared to the predetermined, i.e., desired, position of the component with respect to the substrate 2. If these positions correspond, the component is laid down on the substrate 2. If, in contrast, the positions do not correspond, the position of the component is corrected. For this purpose, the bonding head 8 is displaced with the bonding tool 9 and the received component in the work plane E and/or the bonding tool 9 is rotated in the bonding head 8. The component is now detected again by the camera system 6 and is evaluated by the image processing software. If the actual position of the component with respect to the substrate 2 now corresponds to the specified position, the component is laid down on the substrate 2, or else the position is corrected once again.

[0049] If the position of the component with respect to the substrate 2 is now correct, the component is laid down on the substrate 2 and is held at a predefined distance from the substrate 2. This distance is thereby measured by a distance sensor 13, which is illustrated as optical sensor here and which is arranged close to the assembly position M. The optical sensor is thereby directed to an edge of the component, parallel to the work plane E. Yet a further optical sensor, which is directed to another edge of the component, is preferably provided, so that inclines of the component can also be recognized.

[0050] The measured distance is compared to a predetermined distance by the control unit 5, and the bonding head 8 is moved perpendicular to the work plane E until the measured distance corresponds to the specified distance.

[0051] As an alternatively to the holding of the component above the substrate 2, the component can also be pressed onto the substrate 2 with a specified contact force. This contact force is measured by a sensor, which is not illustrated in this figure. Also in this case, the bonding head 8 is moved perpendicular to the work plane E until the measured contact force corresponds to the predetermined contact force.

[0052] If the distance of the component from the substrate 2 or the contact force of the component on the substrate 2, respectively, now correspond to the predetermined values, the position of the component with respect to the substrate 2 is detected by the camera system 6 once again to be on the safe side and is evaluated in the control unit 5. Possible deviations are corrected, in turn, by displacing the bonding head 8 in the work plane E or by rotating the bonding tool 9 in the bonding head 8.

[0053] When all positions, distances and/or contact forces are correct, a lighting unit integrated in the bonding tool 9 is activated for curing the adhesive. This lighting unit is thereby arranged in such a way that it can apply light to the adhesive between the substrate 2 and the component. The duration of the application with light is thereby dependent on the type and thickness of the adhesive and on the intensity of the light, among other things.

[0054] After the illumination of the adhesive has ended, the component, which is bonded to the substrate 2, is released from the receiving head 11 of the bonding tool 9, and the bonding head 8 is moved back, preferably to the receiving station 12. The receiving head 11 can now receive a further component and can bond it to the substrate 2 as described above. These steps are repeated so often, until all of the components to be bonded to the substrate 2 have been bonded to the substrate 2. The substrate 2 is subsequently displaced out of the assembly position M, and a further substrate 2 is preferably moved into the assembly position M.

[0055] The bonding tool 9 according to the invention will be described in more detail on the basis of FIGS. 2a to 2d. FIG. 2a thereby shows the bonding tool 9 in a side view, FIG. 2b in a longitudinal section, FIG. 2c in a perspective view, and FIG. 2d in a perspective exploded drawing.

[0056] The bonding tool 9 has a circular disk-shaped base body 14, which lies in a base plane G. Arranged on the circumference of the circular disk-shaped base body 14 is a V-shaped groove 15, with which double frustoconical holding elements of the bonding head 8 engage. The bonding tool 9 is thus fastened to the bonding head 8 via the double frustoconical holding elements of the bonding head 8. The double frustoconical holding elements are further rotatable, so that a rotation of the bonding tool 9 with respect to the bonding head 8 is affected by a rotation of the double frustoconical holding elements. The orientation of the component with respect to the substrate 2 can be changed by such a rotation, so that the predetermined orientation is attained.

[0057] Alternatively, or in addition to the fastening of the bonding tool 9 to the bonding head 8 by the V-shaped groove 15, the bonding tool 9 can also be fastened to the bonding head 8 via magnetic force. For this purpose, the bonding tool 9 has at least one magnet, and the bonding head 8 has a corresponding ferromagnetic region and/or the bonding tool 9 has a ferromagnetic region, and the bonding tool 8 has a corresponding magnet.

[0058] A location of the circumference of the circular disk-shaped base body 14 furthermore has a V-shaped notch 16, which runs perpendicular to the V-shaped groove 15 and perpendicular to the base plane G. An engagement element of the bonding head 8 engages with this V-shaped notch 16, so that the alignment of the bonding tool 9 with respect to the bonding head 8 can be recognized by the bonding head 8.

[0059] The incline of the bonding tool 9 to the bonding head 8 can be set via an adjusting mechanism 17 comprising three setting screws 18. The setting screws 18 thereby comprise ball-like tips 19, which in each case engage with a V-shaped setting groove in the bonding head 8. By unscrewing or screwing in, respectively, the setting screws 18, the incline of the bonding tool 9 to the bonding head 8 is changed. The distance of the bonding tool 9 from the bonding head 8 can furthermore also be set to a small extent. The incline of the bonding tool 9 is thereby preferably set so that the base plane G comes to rest parallel to the work plane E.

[0060] The bonding tool 9 furthermore comprises electrical contacts 20, which are arranged on a top side of the bonding tool 9. These electrical contacts 20 come into contact with electrical counter contacts of the bonding head 8, and thus establish an electrical connection between the bonding tool 9 and the bonding head 8. The bonding tool 9 is controlled and supplied with electrical energy via this electrical connection. Separate cables are thus not necessary for this. The bonding tool 9 furthermore has a negative pressure connection 21, via which the receiving head 11 is supplied with negative pressure, so that components 22 can be received therewith.

[0061] The circular disk-shaped base body 14 of the bonding tool 9 furthermore comprises an opening 23, wherein the opening 23 is arranged essentially in a circular manner and concentrically with the circular disk-shaped base body 14. The receiving head 11 of the bonding tool 9 is thereby arranged so that an orthogonal projection of the receiving head 11 onto the base plane G lies within the opening 23. This means that perpendicular to the base plane G, thus viewed from the top or from the bottom, the receiving head 11 lies within the opening 23. The receiving head 11 can thus be accessed freely through the opening 23, for example for measurements by the camera system 6.

[0062] On its lower end, the receiving head 11 comprises a vacuum unit 24, which, when it is supplied with negative pressure via the negative pressure connection 21, can receive and hold a component 22. In the alternative, the receiving head 11 can comprise a gripping unit, by which components 22 can be gripped. In the case of such a receiving head 11, the negative pressure connection 21 can also be omitted. Due to the fact that the bonding tool 9 is arranged in a replaceable manner on the bonding head 8, it is also conceivable to use a bonding tool 9 comprising a receiving head 11 comprising a vacuum unit 24 for some applications, and a bonding tool 9 comprising a receiving head 11 comprising a gripping unit for other applications.

[0063] The receiving head 11 is resiliently connected to the base body 14 via a spring assembly 25. This resilient connection serves the purpose of weakening impacts and vibrations, which can appear, for example, when displacing the bonding head 8. Moreover, the resilient connection can be used to measure the contact force of the component 22 on the substrate 2.

The spring assembly 25 thereby comprises four leaf springs 26, which are arranged in a parallelogram-like manner Two of the leaf springs 26 thereby extend approximately in a semi-circular manner along the one inner side of the opening 23, while the other two leaf springs 26 extend approximately in a semi-circular manner along the other inner side of the opening 23. The respective two leaf springs 26 are thereby spaced apart from one another in a direction perpendicular to the base plane G. The one end of the leaf springs is thereby firmly connected to the base body 14, and the other end is firmly connected to the receiving head 11. Due to the parallelogram-like arrangement of the leaf springs 26, the orientation of the receiving head 11 to the base body 14 does not change when a force is exerted on the receiving head 11 and thus on the spring assembly 25. Due to the fact that the leaf springs 26 are arranged along the inner side of the opening 23, the accessibility of the receiving head 11 through the opening 23 is moreover only slightly limited.

[0064] Due to the fact that the receiving head 11 is arranged in a movable manner with respect to the base body 14, the electrical connection and/or the negative pressure connection of the receiving head 11 to the base body 14 takes place via a flexible connecting element 27.

[0065] The bonding tool 9 furthermore has a replaceable lighting unit 28, which is integrated in the bonding tool 9. The adhesive, which was applied to the substrate 2, is cured by this lighting unit 28. The energy supply of the lighting unit 28 thereby takes place via an electrical interface 29, which is connected to the circuit of the base body 14, and thus to the circuit of the bonding head 8.

[0066] The lighting unit 28 is thereby a UV LED unit, because LEDs are particularly efficient and have a comparatively low heat development. To discharge the heat, which arises nonetheless, corresponding heat conducting ducts, which are not illustrated here, and a cooling unit 30 are provided. The cooling unit 30 thereby comprises a plurality of cooling fins 31, so that the heat can be discharged quickly to the ambient air via the large surface of the cooling fins 31.

A recess 32 is provided around the receiving head 11 in the lighting unit 28, so that the receiving head 11 can still be accessed freely through the opening 23 and the recess 32, in particular for the camera system 6.

[0067] Four UV LEDs 33 are arranged adjacent to the recess 32, wherein the LEDs 33 are arranged evenly around the receiving head 11. These LEDs 33 are moreover aligned obliquely downward in such a way that they optimally illuminate the assembly position M, at which the component 22 to be bonded is located. Due to the fact that the illumination takes place from four sides, the assembly position M is also illuminated largely evenly, so that the adhesive cures evenly.

[0068] Due to the fact that the lighting unit 28 is integrated in the bonding tool 9, a complex adjustment of the lighting unit 28 to the bonding tool 9 or to the assembly position M, respectively, is omitted. The free accessibility of the receiving head 11 can furthermore be maintained, without the lighting unit 28 and the camera system 6 being in each other's light path.

[0069] Due to the replaceability of the lighting unit 28, it is additionally possible to exchange a defective lighting unit 28 for a functional lighting unit 28 in an uncomplicated manner. Different lighting units 28 can furthermore be used at the same bonding tool 9, for example with a different arrangement of the LEDs 33 or with LEDs 33, which radiate light with different spectra, in each case adapted to the component 22 to be bonded or the used adhesive, respectively.

[0070] A sensor unit, which is not shown here, can furthermore be provided for measuring the contact force of the component 22 on the substrate 2. This sensor unit is required when the component 22 is to be pressed onto the substrate 2 with a predefined contact force during the bonding. The sensor unit thereby preferably utilizes the deflection, which is caused by the contact pressure, of the receiving head 11, which is connected to the base body 14 via the spring assembly 25. This is so, because the contact force can be calculated easily via the deflection and the known spring constant of the spring assembly 25. The deflection can thereby be determined, for example, by optical sensors, by an ultrasonic assembly and/or by strain gauges.

LIST OF REFERENCE NUMERALS

[0071] 1 bonding device [0072] 2 substrate [0073] 3 work plate [0074] 4 base frame [0075] 5 control unit [0076] 6 camera system [0077] 7 camera [0078] 8 bonding head [0079] 9 bonding tool [0080] 10 metering valve [0081] 11 receiving head [0082] 12 receiving station [0083] 13 distance sensor [0084] 14 base body [0085] 15 V-shaped groove [0086] 16 notch [0087] 17 adjusting mechanism [0088] 18 setting screw [0089] 19 ball-like tip [0090] 20 electrical contact [0091] 21 negative pressure connection [0092] 22 component [0093] 23 opening [0094] 24 vacuum unit [0095] 25 spring assembly [0096] 26 leaf spring [0097] 27 connecting element [0098] 28 lighting unit [0099] 29 electrical interface [0100] 30 cooling unit [0101] 31 cooling fins [0102] 32 recess [0103] 33 LED [0104] E work plane [0105] G base plane [0106] M assembly position