| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a ball grid array capable of obtaining excellent high frequency transfer characteristic without deteriorating a mechanical strength. <P>SOLUTION: The ball grid array 1 is provided on the rear surface thereof with first solder balls 2 arranged from the outer periphery of the array across two rows and second solder balls 3 having a ball diameter smaller than that of the first solder ball 2 and arranged inside of the first solder balls 2. The pitch of the second solder balls 3 is specified so as to be smaller compared with that of the first solder balls 2. The rear surface of the ball grid array 1 is provided at the arranged position of the second solder balls 3 with a protruded part 4 for absorbing the difference of levels due to the difference in diameters between the first solder balls 2 and the second solder balls 3. <P>COPYRIGHT: (C)2003,JPO</p> |
