Thermal attach and detach methods and system for surface-mounted components

A method of heating a selected area of a substrate on which SMCs may be mounted, comprising:

• providing a planar-heater which generates heat in response to an electrical current, said heater's resistance varying with its temperature;
• providing a cartridge to which said planar-heater is affixed;
• providing a thermally conductive platen;
• affixing said platen to said planar-heater;
• placing a selected area of a substrate to be heated into contact with said platen, said heater and platen arranged such that said platen conducts heat generated by said heater to said selected area;
• and
• providing an electrical current to said planar-heater such that heat sufficient to heat said selected area is generated.

A method of heating a substrate on which integrated circuits may be mounted, comprising:

• providing a planar-heater which generates heat in response to an electrical current, said heater's resistance varying with its temperature;
• providing a cartridge to which said planar-heater is affixed;
• providing a containment box;
• placing said substrate within said containment box;
• placing a plurality of thermally conductive balls into said containment box and on said substrate, said balls sized so as to conform to irregularities in the surface of said substrate;
• placing said planar-heater beneath said containment box such that heat generated by said heater is uniformly distributed over said substrate by said balls;
• and
• providing an electrical current to said planar-heater such that heat sufficient to heat said substrate is generated.

A surface-mounted component (SMC) attachment/detachment system for attaching or detaching an SMC to or from a substrate, comprising:

• a planar-heater which generates heat in response to an electrical current, said heater's resistance varying with its temperature;
• a cartridge to which said planar-heater is affixed;
• a means for gripping an SMC such that its input/output (I/O) contacts are heated by thermal conduction from said planar-heater through and/or along the side-walls of the SMC;
• a means for providing electrical current to said planar-heater such that heat sufficient to attach/detach said SMC's I/O pins to or from a substrate is generated;
• and
• a means for reading the resistance of said heater to determine the temperature of said heater and thereby said SMC;
• said system arranged such that said gripping, heating, resistance monitoring and temperature determination occur simultaneously.

A system for heating a selected area of a substrate on which integrated circuits may be mounted, comprising:

• a planar-heater which generates heat in response to an electrical current, said heater's resistance varying with its temperature;
• a thermally conductive platen affixed to said planar-heater, said platen placed into contact with a selected area of a substrate to be heated, said heater and platen arranged such that said platen conducts heat generated by said heater to said selected area;
• a means for providing an electrical current to said planar-heater such that heat sufficient to heat said substrate is generated;
• a temperature sensor which provides an output that varies with the temperature of said planar-heater;
• a means for comparing said sensed temperature with a preset value which represents a desired planar-heater temperature;
• and
• a means for increasing or decreasing said electrical current so as to drive the difference between said sensed temperature and said preset value toward zero.

A system for heating a substrate on which integrated circuits may be mounted, comprising:

• a planar-heater which generates heat in response to an electrical current, said heater's resistance varying with its temperature;
• a containment box into which a substrate to be heated is placed;
• a plurality of thermally conductive balls placed within said containment box and on said substrate, said balls sized so as to conform to irregularities in the surface of said substrate;
• said planar-heater located beneath said containment box such that heat generated by said heater is uniformly distributed over said substrate by said balls;
• a means for providing an electrical current to said planar-heater such that heat sufficient to heat said substrate is generated;
• and
• a means for creating a magnetic field which prevents said balls from migrating;
• a temperature sensor which provides an output that varies with the temperature of said planar-heater;
• a means for comparing said measured temperature with a preset value which represents a desired planar-heater temperature;
• and
• a means for increasing or decreasing said electrical current so as to drive the difference between said measured temperature and said preset value toward zero.