Method for connecting printed circuit boards and connected printed circuit boards

A method for connecting a pair of printed circuit board comprising steps of:

• preparing a first printed circuit board by forming a first conductive pattern, which includes a first land, on a first insulating board substantially made of thermoplastic resin;
• preparing a second printed circuit board by forming a second conductive pattern, which includes a second land, on a second insulating board;
• forming a solder on one of the first and second lands;
• overlapping the first and second printed circuit boards such that the first and second lands confront each other;
• heat pressing an overlapped portion of the first and second printed circuit boards with a heat-pressing tool having a plurality of projections at a temperature higher than the glass transition temperature of the thermoplastic resin such that the thickness of the first insulating board is smaller at areas pressed by the projections than the maximum thickness of the first insulating board at areas between the areas pressed by the projections, wherein the first and second lands are electrically connected with the solder and the thermoplastic resin is softened and plastically deformed to bond the first insulating board to the second insulating board at the step of heat pressing.

A method for connecting a pair of printed circuit board comprising steps of:

• preparing a first printed circuit board by forming a first conductive pattern, which includes a first land, on a first insulating board substantially made of thermoplastic resin;
• preparing a second printed circuit board by forming a second conductive pattern, which includes a second land, on a second insulating board;
• overlapping the first and second printed circuit boards such that the first and second lands confront each other;
• heat pressing an overlapped portion of the first and second printed circuit boards with a heat-pressing tool at a temperature higher than the melting point of the thermoplastic resin while the first insulating board is cooled at an area adjacent to an area pressed by the heat-pressing tool during the step of heat pressing such that the temperature of the first insulating board is kept lower than the melting point at the area adjacent to the area pressed by the heat-pressing tool, wherein the first and second lands are electrically connected with the solder and the thermoplastic resin is softened and plastically deformed to bond the first insulating board to the second insulating board at the step of heat pressing.