To provide a circuit board using conductive constituent materials which exhibit superior electrical reliability and high junction strength at the junction interface even under the severe condition involving environmental variations such as temperature and vibration, etc.
The circuit board is made up of materials including metal powders comprising a silver powder with a particle size of 0.5 to 60 μm and a tin powder with a particle size of 0.5 to 60 μm as well as a dispersing agent, wherein the tin powder has a grain in the spherical shape, and a rate of metal powder contents to the entire weight is 85 through 93 wt.%, while a compounding ratio of the silver powder and tin powder is 65 through 50 to 35 through 50 in the weight ratio. The dispersing agent is a single or mixture solvent which is selected from polyhydric alcohol, hydrocarbon, or alcohol ester, and has a boiling point of 200°C or higher. The conductive constituent materials are used for the circuit fabrication by means of the screen printing. By the pattern printing of those materials on a copper plate through the screen printing, a pattern paint film is formed, on which a copper foil is placed to apply the load for the thermal treatment, thus forming an alloy layer at the junction interface between the copper plate and the copper foil.
COPYRIGHT: (C)2007,JPO&INPIT
Michio Yukimatsu
Arrow saki Hotaro
Yoshihiko Shiraishi
Koji Kondo
Toshikazu Harada
Tomohiro Yokochi
福田金属箔粉工業株式会社
| JP52066540A | ||||
| JP2001101925A |
Uemura Yoshinaga