| US 7,601,281 B2 | ||
| Production method of anisotropic conductive sheet | ||
| Toshiaki Masaki, Ibaraki (Japan); Kenichi Ikeda, Ibaraki (Japan); Osamu Maekawa, Toyohashi (Japan); Yasuo Nakatasuka, Ibaraki (Japan); and Masataka Tada, Ibaraki (Japan) | ||
| Assigned to Nitto Denko Corporation, Ibaraki-shi (Japan) | ||
| Filed on Sep. 26, 2005, as Appl. No. 11/236,249. | ||
| Claims priority of application No. 2004-279902 (JP), filed on Sep. 27, 2004. | ||
| Prior Publication US 2006/0065995 A1, Mar. 30, 2006 | ||
| Int. Cl. H01L 29/82 (2006.01); H01L 23/50 (2006.01); H01F 7/02 (2006.01); B29C 47/00 (2006.01); B29C 70/62 (2006.01) | ||
| U.S. Cl. 264—108 [264/427; 264/437] | 14 Claims |
| 1. A method of producing an anisotropic conductive sheet, which method comprises:
(a) placing a flowable insulating resin in a space of a sheet-like molding die, wherein the flowable insulating resin has
conductive magnetic particles dispersed therein,
(b) simultaneously performing, relative to the space of the sheet-like molding die, the processes of
(i) applying, in a sheet thickness direction, a first magnetic field to a position in the space of the sheet-like molding
die to locally collect the conductive magnetic particles together to form a conductive path, and
(ii) applying, in the sheet thickness direction, a second magnetic field to a region in the space of the sheet-like molding
die and moving the second magnetic field in the sheet surface expanding direction to move the conductive magnetic particles
in the region to the conductive path formed in process (i), and repeating processes (i) and (ii) on a different portion of
the flowable insulating resin, and
(c) solidifying the flowable insulating resin to produce an anisotropic conductive sheet comprising an insulating resin sheet
and conductive magnetic particles contained in the sheet, wherein the conductive magnetic particles are locally collected
together to form multiple conductive paths penetrating the insulating resin sheet in the thickness direction,
wherein the process (i) is performed by placing, according to the arrangement pattern of the conductive path, a first magnet
in or behind a first main wall surface of two main wall surfaces forming the space of the sheet-like molding die, when seen
from the space of the sheet-like molding die, and
the process (ii) is performed by placing a second magnet behind the first magnet or behind a second main wall surface opposite
the first main wall surface, when seen from the space of the sheet-like molding die, and moving the second magnet in the sheet
surface expanding direction.
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