Bonding Device

Abstract

Bonding device for producing bonding connections, in particular wire bonding connections, tape bonding connections and ball bonding connections, on carriers fixed outside the bonding device and having contact surfaces for the bonding connections, in different spatial directions with respect to the respective carrier, the bonding device comprising a base body, a bonding tool which is movable relative to the base body for applying a bonding force to a bonding means placed on the contact surface of the carrier to produce a material bond between the bonding means and the contact surface as a bonding connection, and bonding force generating means for generating a bonding force directed towards the contact surface when the bonding tool is placed on the carrier, wherein the bonding force generating means comprise a bonding force setting device for realizing a predetermined effective bonding force independently of its spatial direction of action.

Claims

1. Bonding device for producing bond connections, in particular wire bond connections, tape bond connections and ball bond connections, on carriers fixed outside the bonding device and having contact surfaces for the bond connections, in different spatial directions with respect to the respective carrier, the bonding device comprising a basic body, a bonding tool movable relative to the base body for applying a bonding force to a bonding material placed on the contact surface of the carrier to produce a material bond between the bonding material and the contact surface as a bonding connection and bonding force generating means for generating a bonding force directed to the contact surface when the bonding device is placed on the carrier, wherein said bonding force generating means comprises a bonding force setting means for realizing a predetermined effective bonding force independent of the spatial direction of action thereof.

2. Bonding device according to claim 1, designed as a hand-held or robot-guided device with a handle or coupling piece for connection to a robot arm on the base body.

3. Bonding device according to claim 1, designed as wire bonding device, with bonding wire feeding means for feeding a bonding wire as a bonding material onto the contact surface of the respective carrier, and an ultrasonic transducer mechanically connected to the bonding tool to generate ultrasonic vibrations acting on the bonding tool.

4. Bonding device according to claim 1, designed as ball bonding device, with bonding wire feeding means for feeding a bonding wire as a bonding material onto the contact surface of the respective carrier, and a wire melting device for melting a free end of the bonding wire to produce a bond ball.

5. Bonding device according to claim 1, designed as TAB bonding device, with bonding foil feeding means for feeding a bonding foil as a bonding material onto the contact surface of the respective carrier, and an ultrasonic transducer mechanically connected to the bonding tool to generate ultrasonic vibrations acting on the bonding tool.

6. A bonding apparatus according to claim 1, wherein the bonding force setting means comprises a position sensor for determining the spatial position of the direction of action of the bonding tool and a calculation unit connected on its input side to the position sensor for the position-dependent calculation of the bonding force to be applied by the bonding force generating means.

7. A bonding apparatus according to claim 1, wherein the bonding force setting means comprises a bonding wire deformation sensor for determining a deformation of the bonding wire under the effect of the set bonding force, and has a bonding force adjustment unit connected on the input side to the bonding wire deformation sensor for deformation-dependent adjustment of the bonding force to be applied by the bonding force generating means.

8. Bonding device according to claim 1, which has a bonding force sensor for detecting the effective bonding force acting on the bonding material in a bonding step for monitoring and/or controlling the bonding process.

9. Bonding device according to claim 1, wherein a bonding tool stop is provided in the base body of the bonding device for presetting a defined initial position of the bonding tool after the positioning of the bonding device with respect to the contact surface of a carrier and before the bonding step.

10. Bonding apparatus according to claim 9, which has a bonding step displacement sensor for detecting a path covered in the bonding step by the bonding tool with respect to the bonding tool stop to obtain a path signal for monitoring and/or controlling the bonding process.

11. Bonding device according to claim 9, which has a contact pressure force sensor for detecting a contact pressure force of the bonding device or bonding tool against the carrier before the start of the application of the bonding force in order to obtain a contact pressure force signal for at least one of monitoring and controlling the bonding process.

12. Bonding device according to claim 8, wherein the bonding force sensor is connected to a respective input of the bonding force setting device for providing an input signal for setting or adjusting the bonding force to be applied by the bonding force generating means.

13. Bonding device according to claim 10, wherein the bonding step displacement sensor is connected to a respective input of the bonding force setting device for providing an input signal for setting or adjusting the bonding force to be applied by the bonding force generating means.

14. Bonding device according to claim 11, wherein the contact pressure force sensor is connected to a respective input of the bonding force setting device for providing an input signal for setting or adjusting the bonding force to be applied by the bonding force generating means.

15. Bonding device according to claim 1, having a camera and downstream image processing device for recording an image of a bond site and of its surroundings for evaluating the recorded image with respect to a comparison image stored in an image storage unit, and a bonding tool adjusting device for fine adjustment of the position of the bonding tool and/or its direction of action as a result of the image processing.

16. Bonding arrangement with a bonding device according to claim 1 and, separately from the bonding device, with a camera and downstream image processing device for recording an image of a bond site and of its surroundings for evaluating the recorded image with respect to a comparison image stored in an image storage unit, and a bonding tool adjusting device for fine adjustment of the position of the entire bonding device or of the bonding tool and/or of its direction of action as a result of the image processing.

17. Bonding arrangement according to claim 16, wherein the camera and the downstream image processing device are designed to record a larger spatial region beyond the bond site and its surroundings and to evaluate the recorded image with respect to a comparison image of that larger spatial region stored in an image storage unit, and the arrangement comprises an adjusting device for adjusting the position of a robot arm holding the bonding device and/or the orientation of the bonding device by means of the robot as a result of the comparison image processing.

Description

[0029] This FIGURE shows a sketch of the principle of the internal structure of an exemplary bonding device 1 in operation, i.e. when a wire bond connection is made to a substrate 2A by means of a bonding wire 2B through a bonding tool (wedge) 3. The bonding tool 3 is mounted in a movable bonding head 4 in a familiar manner. The bonding head 4, flexibly suspended in joint parts 4a, 4b, accommodates the actual bonding unit 5, which comprises the ultrasonic transducer 6 acting on the bonding tool 3 and the bonding tool 3.

[0030] The bonding unit 5 is pressed onto the substrate 2A by a resulting total force, into which first the intrinsic mass of the bonding unit 5 or, in the case of the non-vertical direction of action with respect to a substrate assumed in the context of the invention, its direction-dependent gravity component is incorporated. Furthermore, a tension spring 7 acts, which is arranged inside the bonding head 4 and applies a fixed spring preload to the bonding unit. Finallyonly during the bonding stepa so-called voice coil 8 acts on the bonding unit 5. The resultant of the above-mentioned forces leads first to the setting of a defined relative position of the bonding unit 5 in relation to the bonding head 4.

[0031] A downward movement of the bond head along its direction of actionin the FIGURE of the z-axisfinally leads to an impact on a bond site on the substrate 2A, and this impact is registered by a touchdown and deformation sensor 9.

[0032] From this powerless contact state, the bonding head 4 is then moved further by a defined distance until the bonding unit 5 is released from a stop 10 provided in the area of the pretension spring 7. This additional movement is necessary to give the bonding tool 3 the necessary freedom of movement to exert a force effect on the bonding wire 2B and deform it (and, in conjunction with the ultrasonic energy from the transducer 6, to form a material bond with the substrate 2A at the bonding point).

[0033] In the version shown, an additional stop 11 is fixed to the bond head 4, which presses on the substrate (component) with a much greater force than the bond force acting in the bonding step. This stop 11 is used to stabilize the position of the bonding unit and the bonding tool relative to the substrate (component). It makes it possible to detect the deformation of the bonding wire 2B in the bonding step by a deformation sensor 9 and to track it over time without the measurement result being distorted by a possible evasive movement of the substrate 2A during the application of the bonding force in the bonding step. In addition, a force sensor (not shown) can be assigned to the stop 11, which detects the stop on the substrate 2A or can signal a possible release of the substrate from the stop.

[0034] The illustrated version of wire bonder 1 works as follows:

[0035] In a first step, the entire bonding head 4 is brought up to the substrate 2A until it hits the substrate (which in the illustration shown would mean lowering, but in the case of overhead bonding it would mean lifting). The impact is registered by the touchdown sensor 9, and the force acting on the substrate, which is derived from the or similar The force acting on the substrate, which is composed of the components mentioned above, is determined using signals from the deformation sensor 9 or a position sensor 12 and, if necessary, readjusted using the voice coil 8.

[0036] Then the bonding unit is moved on against the spring force of the spring 7 to gain the necessary movement space for the bonding tool 3 to deform the bonding wire 2B. Finally, the bonding step takes place, in which a higher pressure force is generated by the voice coil 8, depending on the direction of action of the bonding unit and the bonding tool detected by the position sensor.

[0037] The implementation of the invention is not limited to this example and the aspects highlighted above, but possible also in manifold modifications and combinations within the scope of the pending claims.