| 摘要 |
PURPOSE:To cut down assembly manhour by connecting two kinds of bare chips to a printed wiring board with solder bumps directly in a downface state. CONSTITUTION:A, B chip mount parts of a printed wiring board 1 is supplied with flux, and then A, B chips 2, 3 are mounted to subject wiring board pads and chip electrodes to positioning. After flux is hardened, bumps are soldered and flux remains are cleaned. Next, electrodes 5 of the A chip 2 connected to pads of A chip patterns 8 on the wiring board 1 with gold wires 9. Thus, signals input in the B chip 3 are input into the A chip 2 and output to the A chip pattern 8. This process cuts down assembly manhour due to connection made by wire bonding and prevents defects such as disconnection, thereby improving electric reliability. |
