| 摘要 |
PROBLEM TO BE SOLVED: To improve the reliability of electrical connection by a flip-chip connection by setting the size and number of voids existing on the outermost surface of an Sn-plated layer on a flip connection type wiring board to be within a specified range. SOLUTION: This wiring board has an electrode pad group 11 for electrically connecting an integrated circuit chip of a flip-chip connection type and an Sn-plated layer 6 on the outermost surface of a conductor layer to be each electrode pad 11, the number of voids having the longest diameter of 0.3μm or larger existing on the surface of the Sn-plated layer 6 is set to 50 or less per 100μm<2> or less, the thickness of the void-controlled Sn-plated layer 6 is set to a range of 1-6μm. The wiring board uses a ceramics wiring board. the electrode pads 11 consist of a plurality of Ti4a-Cu4b-Au5b thin films and plated film having a Cu5a-Au-Sn6 multilayer structure. As a result, a flip-chip connection having good bond strength is enabled. |
