BUMP FORMATION METHOD

摘要

A METHOD FOR FORMING BUMPS IN AN LSI PACKAGE IN WHICH: SEMICONDUCTOR CHIPS ARE MOUNTED ONTO A FLEXIBLE PRINTED CIRCUIT BOARD; ELECTRICALLY CONDUCTIVE BALLS ARE TEMPORARILY FIXED BY USING ELECTRICALLY CONDUCTIVE PASTE SELECTED FROM FLUX, SOLDER PASTE AND A FIXING LIQUID CONTAINING AN ELECTRICALLY CONDUCTIVE ADHESIVE AGENT, ONTO PADS WHICH ARE PROVIDED ON THE FLEXIBLE PRINTED CIRCUIT BOARD SO AS TO BE ELECTRICALLY CONNECTED TO THE SEMI- CONDUCTOR CHIPS; THE FLEXIBLE PRINTED CIRCUIT BOARD HAVING THE ELECTRICALLY CONDUCTIVE BALLS TEMPORARILY FIXED THERETO IS WOUND UP ONTO A REEL; THE FLEXIBLE PRINTED CIRCUIT BOARD HAVING THE ELECTRICALLY CONDUCTIVE BALLS TEMPORARILY FIXED THERETO IS FED OUT FROM THE REEL AND HEATED TO THEREBY FORM BUMPS THEREON; AND THE FLEXIBLE PRINTED CIRCUIT BOARD HAVING THE BUMPS FORMED THEREON IS WOUND UP ONTO ANOTHER REEL; AND THE FLEXIBLE PRINTED CIRCUIT BOARD IS CLEANSED AND TRIMMED TO THEREBY FORM LSI PACKAGES. (FIGURE 1)