| abstract |
The first invention is directed to a composite sheet of given thickness in semi-cured form, comprising a semi-cured binder (B1) and, incorporated therein, a magnetic fibrous filler (A), and said semi-cured binder (B1) comprising a thermosetting component and a component resulting from curing of a photocuring component, the magnetic fibrous filler (A) orientated in the direction of the thickness of the semi-cured composite sheet. The second invention is directed to a composite sheet of given thickness comprising a binder and a magnetic fibrous filler (A), the magnetic fibrous filler (A) orientated in the binder in the direction of the thickness of the composite sheet, the orientated magnetic fibrous filler (A) constituting a plurality of bundles. The third invention is directed to a composite sheet of given thickness comprising a binder and a magnetic fibrous filler (A), the magnetic fibrous filler (A) orientated in the binder in the direction of the thickness of the composite sheet, the composite sheet having projections on at least one side thereof. The fourth invention is directed to a composite sheet of given thickness comprising a magnetic fibrous filler (A), a binder cured by heating and/or light irradiation, and organic fine particles or inorganic fine particles (C), the magnetic fibrous filler (A) orientated in the direction of the thickness of the composite sheet. The fifth invention is directed to a composite sheet of given thickness to be interposed between a semiconductor element and a circuit substrate, comprising a magnetic fibrous filler (A) orientated in the direction of the thickness of the composite sheet, at least 80% of the, magnetic fibrous filler (A) having a fiber length L1 satisfying the relationship: 0.5xD < L1 < (L2<2>+D<2>)<1/2> (I), wherein L1 represents a fiber length of magnetic fibrous filler (A), D represents a thickness of composite sheet, and L2 represents a minimum distance between neighboring electrodes among neighboring electrode distance with respect to electrodes arranged on a semiconductor element on its composite sheet side or neighboring-electrode distance with respect to electrodes arranged on a circuit substrate on its composite sheet side. |