| 摘要 |
PURPOSE: To join the laminated sheets of a multilayer wiring board to each other at a temperature capable of the heat resistance of the sheet being secured and obtain a junction organization with a larger heat resistance than solders, by bonding to each other with resin the portions other than the Au-Sn junctions of the electrode portions of the sheets. CONSTITUTION: Onto the copper conductor of the junction portion of one side of a board, an Sn plating of 1-3μm, preferably 3μm, in thickness is applied, and onto the copper conductor of the other side of the board, an Au plating of 0.3μm in thickness is applied, and double-sided conductor forming films are superimposed on each other in multilayer. Then, in either of the atmosphere, an inert gas atmosphere and a reducing gas atmosphere of 300-350 deg.C in maximum temperature and 10-20MPa in pressure, the junction portions of the double-sided conductor films are joined with metal to each other by a thermo-compression bonding, and the portions other than these Au-Sn junction portions are bonded with resin to each other to be hardened. In the interlayer connective bonding of this multilayer wiring board, when a liquid phase is formed in case of the Au-Sn joining, it is apt to generate bridging faults because of the flowings of alloys into its electrodes. Therefore, by so using bonding resins 5 in the bonding portions other than the metallic junction portions as for them to be bonded to each other and be hardened, the bridging faults are prevented. |
