JPH0691300B2 - Method for manufacturing electrical laminate - Google Patents

Description

Detailed Description of the Invention [Industrial applications]

TECHNICAL FIELD The present invention relates to a method for manufacturing an electric laminate, which is processed into a printed wiring board and used.

[Prior art]

Printed wiring boards used for electrical equipment and electronic equipment,
It is created by processing an electrical laminate with a metal foil attached. That is, by stacking a plurality of prepregs, further stacking a metal foil such as a copper foil on one or both sides of the prepreg, and heating and pressurizing the metal foil for lamination molding, an electrical laminate can be manufactured. The printed wiring board can be finished by performing processing such as etching the metal foil of the electrical laminate to create a circuit pattern. Recently, in such printed wiring boards, there is an increasing demand for fine patterns in which circuits are finely and densely arranged. However, in the fine patterns, the distance between the circuits is narrow, so that the impedance between the patterns is low. Therefore, there is a problem that noise interference occurs. When the electric laminate of the printed wiring board having a high dielectric constant has a low impedance and causes a large noise disturbance, use of an electric laminate having a low dielectric constant has been studied. Here, in the electrical laminate, the permittivity is governed by the base material and the resin constituting the laminate, that is, the permittivity is governed by the prepreg formed by impregnating the base material with the resin. It will be. For example, the dielectric constant (ε) of various prepregs is: -Paper base material phenol resin prepreg ... 4.3-Paper base material epoxy resin prepreg ... 4.3-Glass cloth base material epoxy resin prepreg ... 4.8-Glass cloth base material polyimide prepreg ... 4.5-Glass Cloth-based polyphenylene oxide prepreg 3.
5 ・ Glass cloth base material fluororesin prepreg ... 2.7, and electrical laminates made using these prepregs have a specific dielectric constant for each prepreg. Therefore, when forming a circuit with a fine pattern, it is possible to reduce the occurrence of noise interference between circuits by using an electrical laminate made of a prepreg having a low dielectric constant. . However, since a prepreg with a small dielectric constant is generally expensive, for example, when it is necessary to form a circuit with a particularly high fine pattern, a glass cloth-based fluororesin prepreg with a dielectric constant of 2.7 is used. When a circuit is formed with a fine pattern, a glass cloth base material polyphenylene oxide prepreg with a dielectric constant of 3.5 is used, and if the fine pattern is not very high, another prepreg is used. The prepreg to be used is selected according to.

[Problems to be Solved by the Invention]

However, since the dielectric constant of each prepreg has a specific numerical value, the dielectric constant of the electrical laminate produced using the prepreg can only be a specific numerical value corresponding to the prepreg, and the fine pattern of There is a problem that the permittivity of the electrical laminate cannot be freely designed according to the degree. The present invention has been made in view of the above points, and an object of the present invention is to provide a method for manufacturing an electrical laminate, which allows the dielectric constant of the electrical laminate to be freely designed.

[Means for Solving the Problems]

The method for manufacturing an electrical laminate according to the present invention is characterized in that a plurality of prepregs having different permittivities are superposed, a metal foil is further superposed on the prepregs, and these are integrally laminated. A prepreg is made by impregnating a base material such as paper or glass cloth with a varnish of various thermosetting resins (in some cases, a thermoplastic resin) and drying the varnish. The rate is set to a predetermined value depending on the type of base material and resin. Then, by stacking a plurality of these prepregs, a metal foil such as a copper foil is stacked on one or both sides of the prepreg, and by heat-pressing and laminating the laminated metal foil, an electrical laminate having a metal foil stretched on one or both sides is formed. Obtainable. In the present invention, a plurality of prepregs having different dielectric constants are combined and used. For example, as shown in FIG.
One sheet and four sheets of another type of prepreg 1b are alternately laminated, and the metal foil 2 is laminated on the sheet and heat-pressed to laminate to obtain an electric laminate, and as shown in FIG. As shown, four prepregs 1a of a certain type and two prepregs 1b of another type are alternately laminated, and a metal foil 2 is laminated and heat-pressed to form a laminate. By doing so, an electrical laminate can be obtained. Of course, the arrangement of the prepregs 1a and 1b is not limited to these and may be a random arrangement. Further, the prepregs may be used in combination of not only two kinds but three kinds or more kinds as described above. For example, if all glass cloth-based fluororesin prepregs are used as the prepreg, the dielectric constant (ε) of the laminate part of the electrical laminate will be 2.7, which is the same as that of this prepreg. If the base epoxy resin prepreg is used, the permittivity of the laminate part of the electrical laminate will be 4.8, which is the same as that of this prepreg, but the four prepregs 1a shown in FIGS. 1 and 2 are made of glass cloth. When the electrical laminate is manufactured by using the base fluororesin prepreg and the glass cloth base epoxy resin prepreg as the four prepregs 1b, the dielectric constant of the laminate of the electrical laminate is approximately (2.7 × 4 + 4.8 x 4)
÷ 8 = 3.7 to 3.8. If 6 glass cloth base fluororesin prepregs and 2 glass cloth base epoxy resin prepregs are used out of the total 8 prepregs, the permittivity of the laminated portion of the electrical laminate is approximately (2.7 × 6 + 4.8
× 2) ÷ 8 = 3.2 to 3.3. Therefore, it is possible to set the dielectric constant of the laminate part of the electrical laminate to an arbitrary value by combining and using which of the various types of prepregs having different permittivities. The degree of freedom in designing the dielectric constant according to the degree of the fine pattern is increased.

【Example】

The invention will now be illustrated by the examples. Example 1 A glass cloth base material epoxy resin prepreg having a dielectric constant of 4.8 was obtained by impregnating a glass cloth having a thickness of 0.15 mm with an epoxy resin so that the amount of resin after drying was 50% and drying. Further, a glass cloth having a thickness of 0.15 mm was impregnated with polyphenylene oxide (PPO) so that the amount of resin after drying was 50%, and dried to obtain a glass cloth-based polyphenylene oxide prepreg having a dielectric constant of 3.5. Next, four glass cloth base material epoxy resin prepregs and four glass cloth base material polyphenylene oxide prepregs were stacked in the arrangement shown in FIG.
By stacking 5mm copper foil and heating and pressurizing it under the conditions of 30kg / cm ² , 180 ℃, 90 minutes, 1.6m thickness is obtained.
A m electrical laminate was obtained. The dielectric constant of this electrical laminate was about 4.1. Conventional Example 1 An electric laminated board having a thickness of 1.6 mm was obtained by using only eight glass cloth-based epoxy resin prepregs obtained in Example 1 and then laminating the same. The dielectric constant of this electrical laminate was 4.8. Conventional Example 2 Eight glass cloth-based polyphenylene oxide prepregs obtained in Example 1 were used alone, and thereafter laminated in the same manner to obtain a 1.6 mm-thick electrical laminate. The dielectric constant of this electrical laminate was 3.5. Example 2 The amount of resin after drying polyimide on a glass cloth having a thickness of 0.15 mm is
A glass cloth base polyimide prepreg having a dielectric constant of 4.5 was obtained by impregnating it to 50% and drying. Next, the glass cloth base material polyphenylene oxide prepreg obtained in Example 1 and the glass cloth base material polyimide prepreg obtained in Example 1 in the arrangement shown in FIG. mm electrical laminate was obtained. The dielectric constant of this electrical laminate was about 4.0.

【The invention's effect】

As described above, in the present invention, a plurality of prepregs having different permittivities are stacked together with a metal foil, and the metal foil is further laminated and integrated. The dielectric constant of the electrical laminate can be set to an arbitrary value depending on how many kinds of materials are used in combination, and the degree of freedom in designing the dielectric constant according to the fine pattern of circuit formation can be set. Will be bigger.

[Brief description of drawings]

FIG. 1 and FIG. 2 are schematic exploded views showing the constitution of laminated molding, in which 1a and 1b are prepregs and 2 is a metal foil.

Claims (1)

[Claims] 1. A method for manufacturing an electrical laminate, comprising stacking a plurality of prepregs having different permittivities, further stacking a metal foil on the prepregs, and laminating and integrating the prepregs.