Method of connecting circuit boards

A method of bonding metal, comprising:

• a method connecting a metal first wiring connector on a first circuit board and a metal second wiring connector on a second circuit board, comprising:
• disposing first wiring connector and second wiring connector on said first circuit board and said second circuit board respectively, said first wiring connector being disposed opposite said second wiring connector, metal on said first circuit board and metal on said second circuit board have a hydrocarbon compound interposed therebetween, said hydrocarbon having a C—H bond disassociation energy less than 950 kJ/mol;
• and
• applying a pressure to said metal first wiring connector and second wiring connector on said first circuit board and said second circuit board;
• heating said metal on said first circuit board and said metal on said second circuit board to a point lower than a lowest melting point of said metals to decompose said hydrocarbon compound to form a radical by separating hydrogen form said hydrocarbon compound due to said heating of said hydrocarbon compound, said radical formed from said hydrocarbon compound reducing oxide films on a surface of said metals while bonding said metals by means of mutual diffusion, wherein
• the hydrocarbon compound is selected from a group consisting of binary alicyclic formula hydrocarbon, tertiary straight chain formula hydrocarbon, alicyclic formula hydrocarbon containing tertiary allyl position hydrogen, and alicyclic formula hydrocarbon containing binary benzylic position hydrogen both sides.

A method of manufacturing a multiple circuit board having a printed circuit board and a flexible circuit board which are connected together, the printed circuit board having a base plate and a plurality of printed wire terminals which are bonded to a surface of the base plate and the flexible circuit board having a film of thermoplastic resin and a plurality of conductive thick-film terminals which are bonded to the surface of the film, the method comprising:

• applying an alkane group to at least a portion of a surface of the printed circuit board where the printed wire terminals exist or a portion of a surface of the flexible circuit board where the conductive thick-film terminals exist in an alkane application step;
• and
• heat-press-bonding the flexible circuit board to the printed circuit board in a heat-press-bonding step, said heat-press-bonding occurring while positioning the printed wire terminals and the conductive thick-film terminals to face one another, wherein
• the hydrocarbon compound is selected from a group consisting of binary alicyclic formula hydrocarbon, tertiary straight chain formula hydrocarbon, alicyclic formula hydrocarbon containing tertiary allyl position hydrogen, and alicyclic formula hydrocarbon containing binary benzylic position hydrogen both sides.

A method of connecting a first wiring connector on a first circuit board and a second wiring connector on a second circuit board, comprising:

• disposing said first wiring connector on said first circuit board and said second wiring connector on said second circuit board, said first wiring connector disposed opposite said second wiring connector, said first wiring connector on said first circuit board composed of metal and said second wiring connector on said second circuit board composed of metal and having a hydrocarbon compound interposed therebetween, said hydrocarbon having a C—H bond disassociation energy less then 950 kJ/mol;
• and,
• decomposing said hydrocarbon compound to form a radical, said hydrocarbon being decomposed by separating hydrogen from said hydrocarbon compound by heating said hydrocarbon compound, said radical formed from said hydrocarbon compound and reducing oxide film on a surface of said metal of said first wiring connector and said second wiring connector while bonding the first wiring connector and second wiring connector on said first circuit board and said second circuit board respectively by fusion or diffusion, wherein
• the C—H bond disassociation energy is within a range between 890-950 KJ/mol.

A method of bonding metal, comprising:

• a method of connecting a metal first wiring connector on a first circuit board and a metal second wiring connector on a second circuit board, comprising:
• disposing first wiring connector and second wiring connector on said first circuit board and said second circuit board respectively, said first wiring connector being disposed opposite said second wiring connector, metal on said first circuit board and metal on said second circuit board have a hydrocarbon compound interposed therebetween, said hydrocarbon having a C—H bond disassociation energy less than 950 kJ/mol;
• and
• applying a pressure to said metal first wiring connector and second wiring connector on said first circuit board and said second circuit board;
• heating said metal on said first circuit board and said metal on said second circuit board to a point lower than a lowest melting point of said metals to decompose said hydrocarbon compound to form a radical by separating hydrogen from said hydrocarbon compound due to said heating of said hydrocarbon compound, said radical formed from said hydrocarbon compound reducing oxide films on a surface of said metals while bonding said metals by means of mutual diffusion, wherein
• the C—H bond disassociation energy is within a range between 890-950 KJ/mol.

A method of manufacturing a multiple circuit board having a printed circuit board and a flexible circuit board which are connected, the printed circuit board having a base plate and a plurality of printed wire terminals which are bonded to a surface of the base plate and the flexible circuit board having a film of thermoplastic resin and a plurality of conductive thick-film terminals which are bonded to the surface of the film, the method comprising:

• applying an alkane group to at least a portion of a surface of the printed circuit board where the printed wire terminals exist or a portion of a surface of the flexible circuit board where the conductive thick-film terminals exist in an alkane application step;
• and
• heat-press-bonding the flexible circuit board to the printed circuit board in a heat-press-bonding step, said heat-press-bonding occurring while positioning the printed wire terminals and the conductive thick-film terminals to face one another, wherein
• the C—H bond disassociation energy is within a range between 890-950 KJ/mol.