Abstract: A multi-layer printed wiring board is manufactured by forming a wiring pattern and a component mounting portion on a first substrate. An insulating spacer, formed with a first opening, is stacked over the first substrate with the first opening in registration with the component mounting portion. A second substrate is stacked over the spacer and the resulting assembly is bonded together. A second opening, continuing to the first opening, is formed in the second substrate, exposing the component mounting portion to the outside. An LSI is mounted on the component mounting portion, the first and second openings are filled with a synthetic resin mass, and then a third substrate is stacked over the second substrate to enclose the openings.

Abstract: A printed wiring board, in which an LSI is enclosed, is to be manufactured efficiently. To this end, a wiring pattern 17 is formed on a first substrate 11, and a component mounting portion 18 is formed in the first substrate 11. An insulating spacer 25 then is formed, in which there is formed a first opening 29 in registration with the component mounting portion 18 of the first substrate 11 for accommodating an LSI 39. A second substrate 19 is stacked on the spacer 25. The component units, thus stacked, are bonded together. A second opening 36 communicating with and continuing to the first opening 29 is formed in the second substrate 19 to expose the component mounting portion 18 to outside. The LSI 39 is mounted on the component mounting portion 18, exposed to outside, and synthetic resin 40 is charged in the first and second openings 29, 36. A third substrate 41 then is mounted for stopping the second opening 36.