| 摘要 |
PROBLEM TO BE SOLVED: To provide an electronic component built-in substrate which can be filled with resin reliably, while narrowing the arrangement pitch of conductive balls.SOLUTION: An electronic component built-in substrate comprises: a lower wiring board 5; electronic components 40 and 50 mounted on the lower wiring board 5; an intermediate wiring board 6 arranged around the electronic components 40 and 50 while having an aperture 6a for housing the electronic components 40 and 50, and connected with the lower wiring board 5 via conductive balls 28; an upper wiring board 7 arranged above the electronic components 40 and 50 and intermediate wiring board 6, and connected with the intermediate wiring board 6 via conductive balls 29; and a resin 38 filling the regions between the lower wiring board 5, intermediate wiring board 6 and upper wiring board 7, and sealing the electronic components 40 and 50. The conductive balls 28 and 29 being arranged on the upper and lower sides of the intermediate wiring board 6 are arranged at positions shifted from each other. |
