| abstract |
PROBLEM TO BE SOLVED: To propose a multilayer printed wiring board that can be directly electrically connected to an IC chip without using lead parts. In a multilayer printed wiring board, an IC chip 20 is built in a core substrate 30 in advance, and a first thin film layer 33, a second thin film layer 36, a thickening film are provided on a copper die pad 24 of the IC chip 20. A transition layer 38 made of 37 is disposed. For this reason, the electrical connection between the IC chip and the multilayer printed wiring board can be established without using lead parts or sealing resin. Further, by providing the transition layer 38 composed of a plurality of layers on the die pad 24, the connectivity and reliability between the die pad 24 and the via hole 60 are improved. [Selection] Figure 6 |