| 摘要 |
ACCORDING TO THE PACKAGE BOARD (200) OF THE PRESENT INVENTION EACH SOLDERING PAD (75U) FORMED ON THE TOP SURFACE OF THE PACKAGE BOARD (200), ON WHICH AN IC CHIP IS TO BE MOUNTED, IS SMALL (133 TO 170 μM IN DIAMETER), SO THE METALLIC PORTION OCCUPIED BY THE SOLDERING PADS (75U) ON THE SURFACE OF THE PACKAGE BOARD (200) IS ALSO SMALL. ON THE OTHER HAND, EACH SOLDERING PAD (75D) FORMED ON THE BOTTOM SURFACE OF THE PACKAGE BOARD (200), ON WHICH A MOTHER BOARD, ETC. ARE TO BE MOUNTED, IS LARGE (600 μM IN DIAMETER), SO THE METALLIC PORTION OCCUPIED BY THE SOLDERING PADS (75D) ON THE SURFACE OF THE PACKAGE BOARD (200) IS ALSO LARGE. CONSEQUENTLY, A DUMMY PATTERN 159 IS FORMED BETWEEN CONDUCTOR CIRCUIT (58U) FOR FORMING SIGNAL LINES ON THE IC CHIP SIDE SURFACE OF THE PACKAGE BOARD (200) THEREBY TO INCREASE THE METALLIC PORTION ON THE SURFACE AND ADJUST THE RATE OF METALLIC PORTION BETWEEN THE IC CHIP SIDE AND THE MOTHER BOARD SIDE OF THE PACKAGE BOARD (200), PROTECTING THE PACKAGE BOARD FROM WRAPPING IN THE MANUFACTURING PROCESSES, AS WELL AS DURING OPERATION. (FIG. 10) |
