JPH06126920A - Cushioning material for forming laminated sheet and manufacture of laminated sheet - Google Patents

Abstract

PURPOSE:To obtain a laminated sheet which is excellent both in accuracy in sheet thickness and in surface irregularity without decreasing productivity. CONSTITUTION:In a manufacturing method of a laminated sheet wherein a prepreg of one sheet or a plurality of sheets of thermosetting resin impregnated base materials and metallic foils arranged on one side or both sides are pressurized, heated to form lamination, a cushioning material for forming the laminated sheet having a resin layer of 0.5-100mum in a thickness indicating fluidity in either temperature range of a glass transition temperature or higher of the resin for the laminated sheet or -50 deg.C or higher in melting point, is arranged between the metallic foil and the most exterior layer metallic plate to form the lamination.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cushion material used for manufacturing a laminated board and a method for manufacturing a laminated board using the cushion material.

[0002]

2. Description of the Related Art With the miniaturization of electronic devices using a printed wiring board, the printed wiring board has been reduced in size and increased in density. As a result, there has been a strong demand for improvement of the plate thickness accuracy, heat resistance, and surface irregularity of the laminated plate as the raw material.

In the manufacture of a laminated plate, a required number of prepregs, metal foils, cushion materials, metal plates, etc. are piled up to form a body to be pressured, and the body to be pressured is inserted between heating plates of a molding press and heated. Press to laminate. There is a problem that resin cracks called "measling" occur in the laminate due to hardening of the resin, shrinkage due to cooling, etc. during the lamination molding. As measures against this, a method of gradually cooling after heating and pressurizing lamination molding, a method of suppressing a temperature rising rate, and the like are used, but these have a problem of reducing productivity. Further, a cushion material made of kraft paper, felt material, aromatic polyamide paper, or the like is used so that the pressure of the molding press is uniformly applied to the body to be pressed. However, each had the following problems. The kraft paper has a cushioning property lower than the initial level during the heating and pressing process, and has almost no cushioning property during the cooling stage. The felt material has little change in the level of cushioning property during the heating and pressure molding process, but surface irregularities due to needle unevenness are likely to occur. Aromatic polyamide paper requires a high molding pressure because it has a large elastic modulus, which causes deterioration in appearance quality such as surface irregularities due to unevenness in paper making.

[0004]

Therefore, a cushioning material for laminate molding, which improves the formability, the thickness accuracy, and the surface irregularity at the time of laminate molding, and the laminated plate excellent in the thickness accuracy and the surface irregularity are obtained. A method of manufacturing a laminated plate for the above is provided.

[0005]

The first aspect of the present invention, which has been made in view of the above problems, is a cushioning material for laminated molding, which is characterized by the glass transition of the resin for the laminated board during molding of the laminated board. The second aspect of the present invention is to have a resin layer having a fluidity of 0.5 to 100 μm and having a fluidity at a temperature of not less than the temperature or a temperature of not less than −50 ° C. of the melting point. A prepreg of a curable resin-impregnated base material and a metal foil arranged on one side or both sides of the prepreg, in a method for producing a laminated plate by heat-pressing and laminating, the metal foil and the metal plate of the outermost layer as described above. It is characterized in that a cushion material having a resin layer is arranged and laminated.

The cushioning material for laminate molding of the present invention and the method for manufacturing a laminated board using this cushioning material will be described below.

The cushioning material for laminate molding used in the present invention has a glass transition temperature of the resin for the lamination plate or higher, or at any position on the surface and / or the intermediate layer of the cushioning material usually used for producing the lamination plate, or It has a resin layer having a thickness of 0.5 to 100 μm and showing fluidity in any of the temperature ranges of −50 ° C. or higher. The thickness of the resin layer is 0.5-10
0 μm is required. This is because if the thickness is less than 0.5 μm, the resin cracks generated in the resin portion in the laminated plate are the same as in the conventional case, and if it exceeds 100 μm, unevenness is generated on the surface of the laminated plate. The preferred thickness is 5 to 3
It is 0 μm. As the resin, in the case of a glass cloth base epoxy resin, the glass transition temperature (Tg) of the epoxy resin and the modified epoxy resin is in a temperature range of about 120 to 200 ° C., and a polyethylene resin or a polypropylene resin showing fluidity in this range. , Triacetate resin, polyester resin, polyvinyl fluoride resin, etc. can be used,
In the case of a glass cloth base polyimide resin, Tg of the polyimide resin is about 150 to 280 ° C., and therefore polyamide resin, polyetherimide resin, fluororesin, polyphenylene oxide resin and the like can be used in addition to the above resins.

As a method for forming the above-mentioned fluid resin layer on the cushion material, a cushion material is used as a constituent material between felt materials, aromatic polyamide materials and kraft paper, or on the outer surface of these materials. , A method of arranging a film made of the above-mentioned resin and heating and pressurizing to integrate it,
It can be formed by a method in which a resin solution obtained by dissolving the resin in a solvent is applied or coated to integrate the resin solution.

As the resin of the prepreg of the thermosetting resin base material, epoxy resin, polyimide resin, fluorine resin, polyphenylene oxide resin, unsaturated polyester resin,
It is possible to use a single phenol resin, a modified resin using these as a base resin, a combination resin of these resins, and the like. Further, these resins can be used by filling them with an inorganic filler such as alumina, silica, calcium carbonate, talc, clay, barium sulfate or aluminum hydroxide.

As the metal foil, a copper foil, an aluminum foil or the like can be appropriately selected and used with a thickness according to the application.

The manufacturing method may be one or a plurality of the above-mentioned laminates depending on the thickness of the laminate to be produced, a single-sided metal foil-clad laminate, a double-sided metal foil-clad laminate, a multi-layer metal foil-clad laminate, and the like. A cushioning material having a thermosetting resin-impregnated base material, a prepreg and an inner layer material, and one or a plurality of combinations in which a metal foil is arranged on one side or both sides thereof are stacked, and having a resin layer showing fluidity on the outside thereof. A pressure plate is formed by arranging a metal plate on the outside. 120 ~
Insert into the stage between the heating plates heated to 250 ℃, pressure 5 ~
It is possible to obtain a predetermined laminate by heat-pressure lamination molding under a normal condition of about 110 kg / cm ² .

[0012]

By heating and pressurizing at the time of lamination molding, the portion of the resin layer provided on the cushion material becomes fluid. The fluidized bed having a small thickness of the resin layer serves as a buffer layer for pressurizing the body to be pressed, and by leaving a state where the resin is interposed between the glass cloth and the glass cloth of the prepreg base material between the prepregs. It is possible to prevent the occurrence of a measling, which is a resin crack in the laminated plate. In addition, since the cushion material includes a layer that exhibits fluidity, it serves as a buffer layer for pressurizing the body to be pressed, and problems such as wave texture and surface unevenness of the laminate board that occur when forming a laminated board with only various conventional cushioning materials are also encountered. It can be improved significantly.

[0013]

【Example】

Examples 1 to 4 and Comparative Examples 1 to 2 The constituent materials used in Examples 1 to 4 and Comparative Examples 1 and 2 are common. FR-6 resin blend consisting of 100 parts by weight of bisphenol type brominated epoxy resin (average epoxy equivalent 400-500), 4 parts by weight of dicyandiamine and 0.2 parts by weight of 2E4MZ 7628 type glass cloth (Nitto Boseki Co., Ltd. Made WEA18
W) was impregnated and dried to a resin content of 45% to obtain a prepreg.

Table 1 shows the constitution of the pressure-sensitive body of each of the examples and comparative examples in which the required number of the prepreg, the copper foil, the cushioning material having the resin layer, the metal plate, and the like are overlapped.
It is shown in Table 2 in a simplified manner. Although the resin layer provided on the cushion material is shown separately from the cushion material, it is actually integrated. Specifications of 45% resin content 8628 pieces of 7628-type glass cloth base materials are stacked, and a combination of 18 μm copper foils is placed on both top and bottom sides of the SUS630, 1.2 mm thick metal plate. 1
The stacking position of the resin layer on the outer side of 0 sets, the type of resin of the resin layer, and the thickness of the resin layer of the resin layer of Example 1 were 5 μm for triacetate in Example 1, 15 μm for polypropylene in Example 2 and polyethylene for Example 3. Is 20 μm, Example 4 is 30 μm of polyester, and Comparative Examples 1 and 2 are cushion materials in which these resin layers are not provided and replaced with each other.
(Made of felt material, made by Ichikawa Kaori Co., Ltd.), and SU in the outermost layer
S630, 1.2 mm thick metal plate is arranged, each example,
The body to be pressed was a comparative example. Insert this pressed body between the hot plates of the molding press at a temperature of 130 ° C and a pressure of 5kg / cm ² for 30 minutes, and then heat from 130 to 170 ° C and pressurize from 5 to 40kg / cm ² in 5 minutes. After changing the temperature, the mixture was heated and pressed at a temperature of 170 ° C. and a pressure of 40 kg / cm ² for 90 minutes and then rapidly cooled to room temperature for 20 minutes to obtain a 1.6 mm double-sided copper-clad laminate. Since only Comparative Example 1 was gradually cooled to room temperature at 2 ° C./minute, the molding time was longer than that of the others.

Formability of the obtained double-sided copper-clad laminate,
The plate thickness accuracy, heat resistance, and surface irregularity were evaluated. The evaluation conditions are as follows.

The formability was judged by the appearance after etching the obtained double-sided copper-clad laminate. ⊚ indicates no abnormality, ∘ web indicates wave texture on the film unused side, Δ indicates slight wave texture, and x indicates wave texture.

The plate thickness accuracy is indicated by the dispersion of measured values.
The heat resistance was measured by a pressure cooker test. 131 ° C
The pressure cooker was treated for 120 minutes and 150 minutes, and then immersed in a solder bath at 260 ° C for 30 seconds, and the appearance was visually observed to determine the measling.

◯ indicates no abnormality, ● indicates small measling, and Δ indicates large measling.

The surface unevenness was determined by measuring the presence or absence of the undulation phenomenon on the copper foil surface of the double-sided copper-clad laminate with a three-dimensional measuring machine.

The above results are shown in Tables 1 and 2.

[0021]

[Table 1]

┘

[Table 2]

[0023]

According to the present invention, it is possible to obtain a laminated plate which is excellent in formability at the time of laminate molding, plate thickness accuracy of the laminated plate, and surface irregularity without lowering productivity.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location B32B 27/00 J 7258-4F H05K 1/03 H 7011-4E // B29K 105: 06

Claims (2)

[Claims] 1. When molding a laminate, a thickness showing fluidity of 0.5 to 100 μm at a glass transition temperature of the laminate resin or a melting point of -50 ° C. or more.
A cushioning material for forming a laminated board, which has the resin layer of. 2. A method for producing a laminated plate, which comprises heat-pressing and laminating one or a plurality of prepregs of a thermosetting resin-impregnated base material and a copper foil arranged on one side or both sides of the prepreg, wherein a metal is used. A method for producing a laminated plate, comprising: arranging the cushion material according to claim 1 between a foil and an outermost metal plate to laminate-mold.