| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To suppress reduction of the number of pins to the minimum while occurrence of crack peeling is prevented. <P>SOLUTION: Ball lands 20 to which solder balls are bonded are formed in lattice shapes on a ball face of BGA 10. The ball lands 20 are divided into first ball lands 20a constituting a first lattice 35 on an outermost side and second ball lands 20b constituting a second lattice 36 surrounded by the first lattice 35. The first ball lands 20a are formed in positions except for four corners of the first lattice 35 at the same pitch as the second ball lands. Both adjacent first ball lands 20a at the four corners of the first lattice 35 are formed in positions dislocated from a direction toward the first ball lands 20a in an opposite direction of the four corners of the first lattices 35 by half pitch. Since the first ball lands 20a are formed outside four corner parts 38 to which stress is concentrated, occurrence of crack peeling in a solder bonding part with the solder balls at the time of a temperature cycle test is prevented and reduction of the number of pins is suppressed to the minimum. <P>COPYRIGHT: (C)2007,JPO&INPIT</p> |
