Shape-Dependent Transmittable Tangential Force of Wire Bond Tools

Althoff, Simon; Meyer, Tobias; Unger, Andreas; Sextro, Walter; Eacock, Florian

doi:10.1109/ectc.2016.234

Cited by 5 publications

(7 citation statements)

References 12 publications

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“…The gap between both designs even widens up to 35% for high softening status. The conical form fit is preventing the tool from gross slippage at the top of the connector pin due to high clamping force as already described in [5]. Thus, the tangential motion is transmitted mainly via form fit, not force fit.…”

Section: Tangential Force Transmissionmentioning

confidence: 87%

“…6) pin material as well as for the final softening status of USS=0.3 (dashed line in fig. 6) as suggested in [5]. Using the conical tool an up to 25% higher tangential force can be transmitted compared to a flat tool.…”

Section: Tangential Force Transmissionmentioning

confidence: 97%

“…These adoptions are reducing the computing time due to the reduced number of elements and nodes. The vertical displacement is determined by considering the softening of the copper pin as described in [5]. Constant normal force is applied on the topside of the tool.…”

Section: Modelling Contact Section Tool/pinmentioning

confidence: 99%

“…A vibration amplitude of 5 µm was chosen for this tangential deflection of the tool, which was measured by the help of laser vibrometry for copper wire bonding [2]. The coefficient of friction between tool and pin is set to 0.37 and between pin and substrate to 0.3 [5]. The normal force F y is set to 150 N.…”

Section: Modelling Contact Section Tool/pinmentioning

confidence: 99%

“…Therefore, a proper bond tool and suitable connector pin geometry have to be designed. Such a tool has to fulfill various functional requirements named in [1], [2] and [5]:  Fix the connector pin while the vibration system moves to the bond location.  Avoid damages at the connector pin.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Multi-dimensional Ultrasonic Copper Bonding – New Challenges for Tool Design

Eichwald

Althoff

Schemmel

et al. 2017

International Symposium on Microelectronics

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In power electronics, copper connector pins are e.g. used to connect control boards with power modules. The new chip generation based on SiC and GaN technology increase the power density of semiconductor modules significantly with junction temperatures reaching 200°C. To enable reliable operation at such high temperature, the soldering of these connector pins should be substituted by a multi-dimensional copper-copper bonding technology. A copper pin welded directly on DBC substrate also simplifies the assembly. With this aim, a proper bond tool and a suitable connector pin geometry are designed. This paper presents a two-dimensional trajectory approach for ultrasonic bonding of copper pieces, e.g. connector pins, with the intention to minimize mechanical stresses exposed to the substrate. This is achieved using a multi-dimensional vibration system with multiple transducers known from flip chip bonding. Applying a planar relative motion between the bonding piece and the substrate increases the induced frictional power compared to one-dimensional excitation. The core of this work is the development of a new tool design which enables a reliable and effective transmission of the multidimensional vibration into the contact area between nail-shaped bonding piece and substrate. For this purpose, different bonding tool as well as bonding piece designs are discussed. A proper bonding tool design is selected based on the simulated alternatives. This tool is examined in bonding experiments and the results are presented. In addition, different grades of hardness for bonding piece and substrate are examined as well as different bonding parameters. Optical inspection of the bonded area shows the emergence of initial micro welds in form of a ring which is growing in direction of the interface boundaries with increasing bonding duration.

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Section: Tangential Force Transmissionmentioning

confidence: 87%

Section: Tangential Force Transmissionmentioning

confidence: 97%

Section: Modelling Contact Section Tool/pinmentioning

confidence: 99%

Section: Modelling Contact Section Tool/pinmentioning

confidence: 99%