JPS63102297A - Manufacture of shielded multilayer board - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Industrial Application Field The present invention relates to a method for manufacturing a shield layer board, that is, a multilayer printed wiring board having a shield plate having a shielding effect as an inner layer.

2. Prior Art FIG. 3 shows a general example of a conventional method for manufacturing this type of multilayer board. 1 is a printed wiring board with non-etched copper foil on both sides, prepregs 2, 2 are laminated on both sides, copper foils 3, 3 are laminated on both outer sides, and mold release is applied on the outside. By placing the mirror plates 5, 5 through the film 4.4 and press-molding them with the hot plates 6, 6, one four-layer shield multilayer board is obtained. Note that 7 is a cushion sheet and 8 is a feed plate.

<The problem that the invention seeks to solve> The shield multilayer board manufactured by the above method has a small shielding effect because copper foil is used as the shield plate, and may not be able to achieve the intended purpose depending on the place of use. There were times when I couldn't do it.

This invention is applicable to such a period 2. This was done for the purpose of obtaining a shield multilayer board with a high shielding effect.

Means for Solving the Problems> In order to achieve the above object, the present invention forms a ferromagnetic layer on a conductive carbon sheet by ion plating, and further uses this as an inner layer on both sides of the sheet. The crucible foil is laminated by pressing through the prepreg.

Effect> Since a shield layer made of a ferromagnetic material is formed on the inner layer of the X-layered multilayer board, a shield multilayer board with a high shielding effect can be obtained.

<Example> Next, an example shown in the drawings will be described. Figure m1 is a diagram showing the state of press lamination, and Figure 2 is a diagram showing the manufacturing procedure of the shield plate. The same parts as in Figure 3 are indicated by the same symbols, and only the different parts will be explained.

Reference numeral 11 denotes a shield plate having a shield layer made of a ferromagnetic material, and is manufactured by the process shown in FIG. First of all,
Ferromagnetic materials such as iron, cobalt, nickel, or an alloy thereof are prepared and placed in a crucible 12. Further, a conductive carbon sheet 11' is separately prepared, and this and the above-mentioned crucible 12 are placed in the ion plating tank 13 in the arrangement as shown in FIG.

This ion plating tank 13 is filled with argon gas 14 in advance, and the gas is evacuated to 1/102
While maintaining a vacuum of ~1/103 torr, a DC voltage of several thousand volts was applied between the carbon sheet 11 and the metal in the crucible 12 by the power supply 15, and an AC voltage was applied to the crucible 12 by the power supply 15. The ferromagnetic metal in the crucible 12 is melted. As a result, ionized vaporized metal 17a is generated from molten gold Xx17, and vaporized metal 17a
is attracted to the carbon sheet 11' by the potential difference, and a plating layer, that is, a ferromagnetic layer 17b is formed around it. This layer 17b can be easily made to have a thickness of 5 to 8 μm by, for example, 1 minute of ion plating treatment, and by this treatment, the shield plate 11 having ferromagnetic material /1i17b on both surfaces can be formed. You get it.

Next, prepregs 2, 2 are laminated on both sides of this shield plate 11 as shown in FIG. Place mirror plates 5 and 5 through 4 and 4, and
), this is hot-press molded using hot plates 6, 6 to obtain one 3W1 shield multilayer board.

! In the fSi diagram and Figure 2, the thickness of the prepreg 2 is 100 [μ
m1 is common, and the thickness of the mirror plate 5 is 25 to 70 [μm1
It is.

A shield plate 1 is included in the inner layer of the multilayer board manufactured in this way.
1 are stacked in a sandwich-like manner, and a shield layer consisting of a ferromagnetic material layer 17b of a predetermined thickness is formed on both the front and back sides, so compared to a shield plate using copper foil, This results in a multilayer printed wiring board that exhibits a high shielding effect.

In each figure, the thickness of each layer and the size of particles are shown enlarged.

<Effects of the Invention> As is clear from the above embodiments, the method for manufacturing a shield multilayer board of the present invention involves forming a ferromagnetic layer on a conductive carbon sheet by ion plating, and further forming an inner layer on the conductive carbon sheet. Copper foil is press laminated on both sides of the shield via prepreg, and the shield layer is made of a ferromagnetic material with a relative magnetic permeability much higher than 1 and a strong degree of magnetization. Easy 5i shield multilayer board with high shielding effect! It can be left behind.

[Brief explanation of the drawing]

PIS Figures 1 and 2 show one embodiment of the present invention, and Figure 1 (,) is a perspective view showing the structure of the layers, Figure 1 (b) is a diagram showing the state of press lamination, and Figure 2 The diagram shows the shield plate! FIG. 3(a) is a perspective view showing the layer structure of a conventional example, and FIG. 3(b) is a diagram showing the state of press lamination. 2... Prepreg, 3... Copper foil 4... Release film, 6... Hot plate 11... Shield plate
, 11゛... Carbon sheet 12... Crucible
, 13... Ion plating tank 17... Molten metal of ferromagnetic material, 17a... Vaporized metal 17b... Layer of ferromagnetic material

Claims (1)

[Claims] 1. A shield multilayer characterized by forming a layer of ferromagnetic material on both surfaces of a conductive carbon sheet by ion plating, and then press laminating copper foil on both sides using prepreg as an inner layer. Substrate manufacturing method.