Coreless substrate prepreg, coreless substrate, coreless substrate manufacturing method and semiconductor package

1. A prepreg for a coreless substrate, comprising a thermosetting resin composition containing (a) (meth)acrylic elastomer, (b) an amine compound having at least two primary amino groups, and (c) a maleimide compound having at least two N-substituted maleimide groups.

2. The prepreg for a coreless substrate according to claim 1 , wherein the content of (meth)acrylic elastomer (a) is 1 to 60 parts by mass with respect to 100 parts by mass of a solid content of the resin component in the thermosetting resin composition.

3. The prepreg for a coreless substrate according to claim 1 , wherein the (meth)acrylic elastomer (a) has one or more reactive functional groups selected from the group consisting of an epoxy group, a hydroxy group, a carboxy group, an amino group, and an amide group.

4. The prepreg for a coreless substrate according to claim 1 , wherein the thermosetting resin composition further contains (d) a thermosetting resin.

5. The prepreg for a coreless substrate according to claim 1 , wherein the thermosetting resin composition further contains (e) a curing accelerator.

6. The prepreg for a coreless substrate according to claim 1 , wherein the thermosetting resin composition further contains (f) an inorganic filler.

7. A coreless substrate comprising an insulating layer formed using the prepreg for a coreless substrate according to claim 1 .

8. A semiconductor package comprising a semiconductor element mounted on the coreless substrate according to claim 7 .

9. A method of manufacturing a coreless substrate in which a build-up layer is formed on a support and then the build-up layer is separated from the support,

wherein the build-up layer is formed by alternately stacking insulating layers and conductive layers, and

at least one layer of the insulating layers is formed using the prepreg for a coreless substrate according to claim 1 .