Manufacturing method for a magnetic material core-embedded resin multilayer board

Patent metadata

Field	Value
Publication number	US-9748652-B2
Application number	US-201414572991-A
Country	US
Kind code	B2
Filing date	Dec 17, 2014
Priority date	Jan 24, 2013
Publication date	Aug 29, 2017
Grant date	Aug 29, 2017

Abstract

An antenna device includes a resin multilayer board in which a plurality of resin sheets are stacked, and a coil conductor provided in the resin multilayer board. A plurality of line portions of the coil conductor are provided on a lower surface of the resin sheet. When a magnetic material core is preliminarily pressure-bonded to the resin sheet, the magnetic material core is fractured along the line portions and cracks occur. Thus, the resin sheet with the magnetic material core in which the cracks have been formed is fully pressure-bonded together with the other resin sheets.

First claim

What is claimed is:

1. A manufacturing method for a magnetic material core-embedded resin multilayer board, comprising:
a preliminary pressure-bonding step of preliminarily pressure-bonding a magnetic material core, which is a sintered body, to at least one resin sheet to form a magnetic material core-equipped resin sheet; and
a full pressure-bonding step of stacking a plurality of resin sheets including a resin sheet including a conductor pattern formed thereon, a resin sheet including an aperture formed therein, and the magnetic material core-equipped resin sheet, in a state in which the magnetic material core is disposed in a cavity formed by the aperture, and fully pressure-bonding the plurality of resin sheets; wherein
in the preliminary pressure-bonding step or the full pressure-bonding step, a crack is formed in the magnetic material core along a conductor pattern formed on a resin sheet that directly faces the magnetic material core or on a resin sheet that indirectly faces the magnetic material core via another resin sheet.

2. The manufacturing method for the magnetic material core-embedded resin multilayer board according to claim 1 , further comprising a crack positioning step of decreasing a thickness of the magnetic material core at a position where the crack is to be formed, before the preliminary pressure-bonding step or the full pressure-bonding step.

3. The manufacturing method for the magnetic material core-embedded resin multilayer board according to claim 2 , wherein the magnetic material core includes a plurality of grooves where cracks are to be formed in the crack positioning step.

4. The manufacturing method for the magnetic material core-embedded resin multilayer board according to claim 3 , wherein the conductor pattern includes line portions that define and function as fulcrums during when the magnetic material core is fractured at positions of the plurality of grooves.

5. The manufacturing method for the magnetic material core-embedded resin multilayer board according to claim 1 , wherein the conductor pattern includes line portions that define and function as fulcrums during the preliminary pressure-bonding step.

6. The manufacturing method for the magnetic material core-embedded resin multilayer board according to claim 5 , wherein the line portions are located on a lower surface of a resin sheet at a position where the magnetic material core overlaps in a plan view.

Assignees

• Murata Manufacturing Co

Inventors

• Yosui Kuniaki
• Gouchi Naoki

Classifications

• H05K3/4602

  characterized by a special circuit board as base or central core whereon additional circuit layers are built or additional circuit boards are laminated · CPC title

• H05K2203/063

  of preperforated insulating layer · CPC title

• H01Q1/243

  with built-in antennas · CPC title

• G06K19/07794

  the record carrier comprising a booster or auxiliary antenna in addition to the antenna connected directly to the integrated circuit · CPC title

• H05K1/0239

  Signal transmission by AC coupling · CPC title