Metal fusion bonding – Process – With condition responsive – program – or timing control
Patent
1989-04-04
1990-06-12
Ramsey, Kenneth J.
Metal fusion bonding
Process
With condition responsive, program, or timing control
226 43, 226 45, 228 41, B23K 306
Patent
active
049325817
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to a method of and a device for metering quantity of solder material by an automatic forward feed of a predetermined length of a solder wire to be melted in a soldering device. A soldering device with automatic forward feed of a predetermined length of a solder wire to be melted at the soldering location during every soldering process is already known from the DE-OS 24 27 390 (U.S. Pat. No. 3,830,420). In particular, this device comprises a carriage which can be moved toward and away from a soldering location by a drive motor. An electromechanically controlled wire forward feed device is arranged at the carriage. A control system with object feeling switches for the drive motor of the carriage ensures that the carriage arrives in its soldering position. A predetermined length of solder wire to be melted is then fed to a heated soldering location, and the carriage is returned after the soldering of the solder wire is accomplished. Accordingly, it is ensured that the device works in an automatically controlled time sequence, wherein the same quantity of solder wire is always fed to the soldering location during every soldering process. The nature of the solder wire employed, i.e. its thickness, material composition, melting capability and the like, is not taken into account in the known device.
SUMMARY OF THE INVENTION
The object of the invention is to provide a method of metering a quantity of a solder wire in which a maximum uniform soldering quality can be maintained accurately in a simple manner, even when one or more soldering parameters change or disturbing influences occur. Such disturbance factors are e.g. temperature changes in the heat source resulting from current fluctuations, impurities or, when using gas burners, from changes in the slow rate of gas. The soldering parameters which can change are particularly the size, material and mass of the parts to be soldered together, their initial temperature, and the composition and thickness of the solder wire. As a result of all of these components, the soldering time changes, i.e. the time span required by a given quantity of solder wire in order to melt after placement on the soldering location. The proposed method automatically compensates for heating errors by regulating the forward feed force or the forward feed speed of the solder wire and, in this way, moreover, prevents a bending of the end of the solder wire when placed in the soldering location. This regulation of melting of the solder wire in a manner which is sensitive to force is particularly important when using very soft and/or very thin solder wires for fine soldering. The described characteristics make a soldering device constructed according to the method of the invention, particularly suitable for use in automatic soldering stations in which the device is arranged in a programmable manipulator. Moreover, it must be mentioned that the proposed method requires no additional feelers for detecting the temperature at the soldering location. This makes it possible to build particularly reliable and sturdy automatic soldering machines.
Particularly simple and accurate regulation of force can be achieved by converting the magnitude of the contact pressure force occurring at the end of the solder wire into proportional electric signals which are supplied as actual values to a regulating circuit which determines the speed of an electric motor for the forward feed of the solder wire. In order to obtain a control which is as sensitive as possible during the forward feed as well as during placement and melting of the solder wire, it is further proposed that the weighting of the electric signal derived from the contact pressure force occurring at the end of the solder wire be variable. A further improvement consists in that the weight factor of the parts of the soldering device which participate in determining the contact pressure force of the solder wire is eliminated before every soldering cycle by balancing means. The value of the remaining
REFERENCES:
patent: 3830420 (1974-08-01), Milana
patent: 3940046 (1976-02-01), Fern
patent: 4107508 (1978-08-01), Izumi et al.
patent: 4530456 (1985-07-01), Michelotti
Ohle Eckhard
Reschnar Wilfried
Ramsey Kenneth J.
Robert & Bosch GmbH
Striker Michael J.
LandOfFree
Method of and device for metering a solder material in a solderi does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method of and device for metering a solder material in a solderi, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method of and device for metering a solder material in a solderi will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-611288