Measuring and testing – Dynamometers – Responsive to force
Patent
1996-11-04
1998-06-23
Raevis, Robert
Measuring and testing
Dynamometers
Responsive to force
219 8651, B23K 1124
Patent
active
057708070
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to an apparatus for taking up and guiding a tool device, especially a connection device.
2. Discussion of the Related Art
To automate the production of electrically conducting connections between contact elements, such as, for instance, the contact areas of a chip and the leads connected thereto, pneumatic apparatuses were previously used for this as a rule. The actual connection device here can be designed, for instance, as a thermo-compression device, and it is moved along a feed axis of the apparatus toward the connection point of the contact elements. In the case of a thermo-compression device, the action of pressure and temperature will thus make a solder or weld joint between the contact elements. Adjusting the force with which the connection device is moved toward the connection point, so as to produce the connection pressure there, represents an optimization problem. On the one hand, if a thermo-compression process is involved, a connection pressure matched to the connection temperature must be set; on the other hand, the connection pressure may not exceed a given maximum, so as to prevent mechanical damage to sensitive micro-electronic components.
In a well-known apparatus, the connection device is moved by means of a pneumatic positioning cylinder toward the connection point, such that the positioning cylinder at the same time also creates the necessary connection pressure. The pneumatic positioning cylinder consists of a piston/cylinder unit, in which mechanical friction forces are created due to the piston being guided in the cylinder. In addition, these friction forces vary over the piston stroke. The result of this is that, even if the air pressure is adjusted to be constant, the connection force that is actually exerted on the connection point by the pneumatic positioning cylinder will vary. To this must be added compressibility effects of the air, so that the known apparatus cannot produce an exactly reproducible force at the connection point and a corresponding connection pressure. In mass production of such connections, this results in a relatively high reject rate.
The EP-A-0 476 912 describes an apparatus for taking up and guiding a tool device which has a take-up device for taking up the tool device, said take-up device being movable by means of a servo-element along a feed axis through a feed device, as well as a force measuring device. In the known apparatus, the force measuring device is an integral component of the take-up device.
The SU-A-1 574 405 describes an apparatus which makes possible a deformation measurement in a wire conductor subject to a welding process.
It is an object of the present invention to create an apparatus of the type mentioned in the introduction, which makes it possible to set a precisely reproducible connection force at a connection point and which thus reduces significantly the reject rate in the production of such connections.
This object is achieved by an apparatus that comprises a feed device that can move along a feed axis by means of a servo-element, and a take-up device which can move along a motional axis in such a way that the take-up device can move relative to the feed device, a force measuring device being disposed on the feed device and an elastic element being disposed between the force measuring device and the take-up device in such a way that the elastic element is deformed when a relative motion takes place between the force measuring device and the take-up device.
The inventive apparatus makes it possible for the connection device to execute a feed motion toward the connection point, which depends directly on the force. At the same time, the inventive apparatus makes it possible, by means of the elastic element connected between the force measuring device and the take-up device, to attenuate the impact shock, when the connection device strikes the connection point. The elastic element makes it possible to decouple the mass between the take-up device and
REFERENCES:
patent: 4229637 (1980-10-01), Dederer et al.
patent: 4914602 (1990-04-01), Abe et al.
patent: 5074038 (1991-12-01), Fath
patent: 5138127 (1992-08-01), Fries et al.
Finn David
Rietzler Manfred
LandOfFree
Apparatus for taking up and guiding a connection device does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Apparatus for taking up and guiding a connection device, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Apparatus for taking up and guiding a connection device will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1396122