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US 5,093,545 AGranted
Method, system and composition for soldering by induction heating
AssigneeMetcal, Inc.
InventorThomas H. McGaffigan
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AssigneeMetcal, Inc.
InventorThomas H. McGaffigan
Estimating the term…
This invention provides a method for soldering using induction heating, which is accomplished by the use of lossy heating particles in or on the solder. The method of this invention provides direct heating of the solder itself through induction heating of the magnetic particles in an alternating magnetic field. The magnetic particles useful in this invention can be ferromagnetic particles or ferrimagnetic particles, preferably ferrites, which have a Curie temperature at least equal to the flow temperature of the solder. Selection of the magnetic lossy heating particles with the appropriate Curie temperature for the system in which the particles are being used provides a system in which the temperature is self-regulating when the alternating magnetic field is applied. This self-regulation feature prevents overheating of the solder in the articles being soldered. The invention also discloses the selection of particles with surface properties whereby the particles can either be wetted by the solder and remain in the solder when the solder flows or it can be nonwettable by the solder whereby the particles separate from the solder when the solder flows. The surface properties can also be provided by coatings on the particles. This invention also discloses solder compositions comprising solder and lossy heating particles which produce the desired heat in an alternating magnetic field. The invention also provides systems and assemblies for the use of the above method and composition.
A method for soldering an article comprising:
A solder composition comprising in combination a solder material and ferrimagnetic lossy heating particles which have a Curie temperature at least equal to the flow temperature of the solder and which are sufficiently lossy to produce sufficient heating for flowing the solder when subjected to an alternating magnetic field.
A solder composition comprising in combination (a) a solder material, (b) ferromagnetic lossy heating particles which have a Curie temperature in the range between about the flow temperature of the solder and up to about 300.degree. C. above the flow temperature of the solder and which are sufficiently lossy to produce sufficient heating for flowing the solder when subjected to an alternating magnetic field and (c) nonlossy particles having a high permeability and being capable of providing magnetic circuit coupling when the ferromagnetic lossy heating particles are at or near their Curie temperature.
An article suitable for connection to another article having deposited thereon at the point of connection a solder composition comprising in combination a solder material and lossy heating particles in thermal contact with the solder material which particles have a Curie temperature at least equal to the flow temperature of the solder wherein the lossy heating particles (a) comprise ferrimagnetic particles or (b) comprise ferromagnetic particles and nonlossy particles having a high permeability and being capable of providing magnetic circuit coupling through the ferromagnetic lossy heating particles and wherein the lossy heating particles are sufficiently lossy to produce sufficient heating for flowing the solder when subjected to an alternating magnetic field.
A cored solder wire comprising lossy heating particles in the core thereof wherein the lossy heating particles have a Curie temperature at least equal to the flow temperature of the solder and which are sufficiently lossy to produce sufficient heating for flowing the solder when subjected to an alternating magnetic field wherein the lossy heating particles (a) comprise ferrimagnetic particles or (b) comprise ferromagnetic particles and nonlossy particles having a high permeability and being capable of providing magnetic circuit coupling through the ferromagnetic lossy heating particles.
An autoregulating system for soldering an article comprising:
An assembly comprising:
Dependencies are inferred from the claim text.