JPS602182B2 - Manufacturing method for metal foil-clad laminates - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a metal foil-clad laminate that has excellent warpage characteristics, dimensional stability, etc., and has good low-temperature punching properties.

In recent years, with the remarkable development of the electronics industry, the manufacturing and usage conditions of printed wiring boards have become more basic, and there has been a growing trend to improve the physical properties required of laminates.

That is, the insertion of parts has also shifted to automation, and dimensional accuracy and warp characteristics of the laminate have become more important. Furthermore, with the production of dense hole printed wiring boards, the quality requirements for laminates with good low-temperature punching properties are becoming even stronger. The present invention was completed as a result of intensive research to obtain a metal foil-clad laminate that satisfies these quality requirements. That is, the present invention impregnates a reinforcing base material with a thermosetting resin and reinforces a mixed solution of dried prepreg (1), acrylonitrile-butadiene rubber latex (hereinafter referred to as NBR latex), and a water-droppable phenolic resin resol. After pre-mixing and drying the base material, use the prepreg (B) impregnated with a thermosetting resin composition and dried, stack one or two or more sheets of prepreg (1), and coat one or both sides with the prepreg (D). ), then layer metal foil on one or both sides, heat and heat.
The present invention relates to a method for manufacturing a metal foil-clad laminate, which is characterized by lamination molding under pressure.

As thermosetting resins used in the present invention, curable resins such as phenol resins, modified phenolic resins, polyester resins, diallyl phthalate resins, alkyd resins, epoxy resins, cyanate ester resins, compositions thereof, modified products, etc. and those modified with oils such as tung oil and ojin, other resins such as acrylic resin, melamine resin, and thermoplastic resin, curing agents, catalysts, retardants, flexibility imparting agents,
Products with added inorganic fillers, pigments, dyes, etc.
Examples include those modified using thermosetting resins such as phenol, melamine, polyester, cyanate ester, polyimide, and acrylic as modifiers.

Reinforcing base materials include cotton linter paper, kraft paper, linter kraft Kaji paper, paper glass moat paper, glass wood woven fabric,
Glass cloth etc. can be used.

The NBR latex used in the present invention is a modified NBR latex with medium nitrile, high nitrile, hydroxyl group, carboxyl group, etc. introduced, and usually has a solid content concentration of 35
~6 skin t%. The water-soluble phenolic resin resol used in the present invention combines phenol, m-cresol, etc. with calcium hydroxide, magnesium hydroxide, ammonia,
It is a water-soluble resol type phenolic resin made by reacting an aqueous formaldehyde solution in the presence of a catalyst such as triethylamine. As the metal foil used in the present invention, copper foil, iron foil, aluminum foil, etc. are usually used.

Depending on the type of resin used for the prepreg that is bonded to the metal foil, the adhesive strength may be insufficient, in which case metal foil with adhesive or adhesive film,
By a method such as using a combination of a sheet or the like and metal foil. Prepreg (1), which is a reinforcing base material impregnated with a thermosetting resin and dried, is manufactured in the same manner as the manufacturing method of ordinary prepreg for laminates, and the total amount of resin in the prepreg is 3.
It is preferable to adjust the content to 5 to 55% by weight.

Further, depending on the type of reinforcing base material and other conditions, a pre-impregnation method such as a method of pre-treating the paper base material with water-soluble monophenol or melamine resin may be used, but this method is also used in the present invention. You may.

When manufacturing a prepreg (b) by pre-mixing a mixed solution of NBR latex and water-soluble phenolic resin into a reinforcing base material, drying it and impregnating it with a thermosetting resin, NBR latex and water-soluble phenolic resin are mixed together. The amount of soaking in the prepreg is adjusted so that the solid resin content is 3 to 35% by weight of the prepreg, and the amount of NBR latex in the mold is 30 to 35% by weight of the prepreg.
It is preferable to mix it so that it is 70% by weight.

After drying, the preliminary soaked reinforced base material obtained in this way is impregnated with a thermosetting resin and dried to adjust the total resin amount to 35 to 55% by weight of the obtained prepreg. Comparing the heating dimensional shrinkage rates of the laminates obtained by laminating prepregs (1) and (0) obtained as above and heating and pressurizing them, it was found that the laminates using prepreg (D) were It was found that the dimensional shrinkage rate was extremely small.

Specifically, 8 sheets of prepreg (1) obtained by pre-soaking 10 mils kraft paper with water-soluble phenol resin and co-soaking with modified phenol resin are laminated and heated and pressurized.

On the other hand, 8 sheets of prepreg (0) obtained by pre-impregnating the same kraft paper with NBR latex so that the weight of the prepreg was 3% by weight and impregnating it with the same modified phenol resin, and heated and Press.

Furthermore, prepreg (0) containing 7% by weight of NBR latex solid content in the prepreg is heated and pressurized in the same machine using the same method. The above three types of laminates were heated for 150q0l0 minutes and the dimensional shrinkage rates were measured: 0.07% for prepreg (1), 0.04% for prepreg (0) NBR latex solid content 3%, prepreg (0)NBR
In the case of latex solid content of 7%, it was 0.03%. N.B.
When the amount of R latex is increased, the heating dimensional shrinkage rate tends to further decrease, and the amount of NBR latex can be changed depending on the purpose of use. Metal foil-clad laminates warp due to substrate dimensional shrinkage due to heating, but by using prepreg (0), which has a small heating dimensional shrinkage, to reduce the heating dimensional shrinkage of the substrate, the warpage value can be reduced. Serve.

The metal foil-clad laminate of the present invention is manufactured using the prepreg (0) (0) obtained as described above and metal foil. The prepregs (1), (0), and metal foil of the present invention are made by stacking one or more sheets of prepreg (1) as described above, stacking one or more sheets of prepreg (0) on one or both sides, and then stacking one or more sheets of prepreg (0) on one or both sides. Laminated and molded with metal foil layered on top.

To explain this with a more specific example, when manufacturing a single-sided metal foil-clad laminate with small warpage, seven sheets of prepreg (1) made of kraft paper are stacked on top of each other, and a layer of kraft paper is placed on the substrate side. Laminate one sheet of prepreg (0),
Copper foil with adhesive is layered on the opposite side and laminated by heating and pressure. The warpage in the test pattern of the obtained product was 1/2 that of the case using 8 prepregs (1) made of kraft paper, which is preferable for processing printed circuit boards.
6 sheets of prepreg (1) made of kraft paper, 1 sheet of prepreg (1) made of kraft linter paper on the adhesive-coated steel foil side, and 1 sheet of prepreg (0) made of kraft paper on the board side. The warpage in the test pattern of a single-sided steel foil-clad laminate obtained by lamination molding by heating and pressurizing is in the opposite direction, and the warpage is small and is preferable for printed circuit board processing under severe heating conditions. One prepreg (1) made of linter paper is used on the copper foil side, then six prepregs (1) made of kraft paper are stacked, and then kraft paper is used on the board side.
Layer one sheet of prepreg (0) made of linter mixed paper,
A single-sided copper foil-clad laminate obtained by heating and pressurizing also warps in the opposite direction and exhibits a similar tendency.

One sheet of prepreg (B) made of paper mixed with kraft and linter was used on the copper foil side, then six sheets of prepreg (1) made of kraft paper were stacked, and then prepreg (0) made of kraft paper was used on the board side. The warpage in the test pattern of a single-sided steel foil-clad laminate obtained by stacking one sheet and applying heat and pressure is 1/3 compared to that using 8 sheets of prepreg (1) made of kraft paper. . One sheet of prepreg (0) made of linter paper was used on the steel foil side, then six sheets of prepreg (1) made of kraft paper were stacked, and then one prepreg (0) made of paper mixed with kraft linter was used on the substrate side. Layering, heating,
A single-sided steel foil-clad laminate obtained by pressurizing also exhibited the same problems as above, and the warpage was 1/2.

Although specific examples of the same plate thickness have been described above, various methods can be used depending on the combination with the base material used.
A similar method can be used when the plate thickness is thin. Conversely, it is also possible to increase the warpage by using the opposite method. In the case of double-sided metal foil-clad laminates, the same procedure as for single-sided metal foil-clad laminates can be followed, but from the point of view of minimizing warping, it is preferable to use prepreg (0) of the same base material on both sides of the metal foil side. use

In addition, in order to create a difference between the front and back sides, use different types of prepreg (0) or change the number of sheets of the same base material prepreg (b). This is normally pressure 30-150k9/ground temperature 14-1
The final product, a metal foil-clad laminate, is obtained by heating and pressurizing the molding material at 80° C. for 30 to 120 minutes.

Incidentally, fillers, pigments, dyes, flame retardants, etc. can be appropriately blended into the resin for the laminate of the present invention, if necessary.

Next, the present invention will be specifically explained with reference to Examples.

Parts and percentages are by weight unless otherwise indicated. Reference example 1)
Production of water-soluble phenolic resin resol Phenol 35
A reaction vessel was charged with 50 parts of a 37% formaldehyde aqueous solution and 6 parts of triethylamine, and the mixture was reacted at 70°C for 2 hours. After dehydration under reduced pressure, ethanol was added to prepare a water-soluble phenolic resin resol with a non-volatile content of 60%. was manufactured.

(Resin A) 2) Production of tung oil-modified stylene-phenol resin resol Mesitylene resin (methysylene content 9% by weight, average molecular weight 554, oxygen content 11.4%)
200 parts of phenol, 60 parts of Ikarikuo, 16 parts of tung oil, and 1 part of p-toluene sulfonic acid were charged into a reaction vessel, and the temperature was heated to 130°C.
to react for 1 hour, and then cooled the reaction solution to 37°C.
% formaldehyde aqueous solution and 6 parts of hexamethylenetetramine were added, heated under reflux for 2 hours, dehydrated under reduced pressure, and methanol was added to produce a tung oil-modified mesitylene-phenol resin resol with a nonvolatile content of 60%.

(Resin B) Example 1 Resin A: NBR latex (manufactured by Nippon Zeon ■, Nipole 1571 solid content 40%) = 60:40 (solid content), pre-soaked on kraft paper, It was dried and adjusted so that the amount of undercoat resin was 6% of the prepreg, and then mixed with resin B to obtain a prepreg (b) with a total resin amount of 48% in the prepreg.

Resin A: Resin B was blended in a ratio of 10:90 (solid content), impregnated into kraft paper, and dried to obtain prepreg (1) with a total resin content of 48%. Prepreg (1
), 2 sheets of prepreg on one side and steel foil with adhesive on the other side, press-formed for 80 minutes at 155°C and 100k9/ground to a thickness of 1.6 mm/skin copper. A stretched laminate was obtained. The properties of the obtained laminate are shown in Table 1. Example 2 Same prepreg (B) and prepreg (1) as Example 1
get.

6 sheets of prepreg (1) are stacked, and prepreg (
□) one by one, and one side is covered with adhesive-coated steel foil 15
A steel clad laminate having a thickness of 1.6 skin/m was obtained by press forming for 80 minutes under the conditions of 5q0, 100k9/ground.

The properties of the obtained laminate are shown in Table 1. Comparative Example 8 sheets of the same prepreg (1) as in Example 1 were layered, adhesive-coated copper foil was layered on one side, and press-molded for 80 minutes under conditions of 155 qo, 100 k9/base to form a copper plate with a thickness of 1.6 legs. A stretched laminate was obtained.

The properties of the obtained laminate are shown in Table 1.

Table 1 Note) * Perform punching using the test die and check the shape of the punch and the condition of the cut surface.

Claims (1)

[Claims] 1 Impregnating the reinforcing base material with thermosetting resin, pre-impregnating the reinforcing base material with a mixed solution of dried prepreg (I), acrylonitrile-butadiene rubber latex, and water-soluble phenolic resin resol, drying, and then applying thermosetting resin. Using prepreg (II) impregnated with a resin composition and dried, one or more sheets of prepreg (I) are layered, one or more sheets of prepreg (II) is layered on one or both sides, and metal foil is further layered on one or both sides. A method for manufacturing metal foil-clad laminates, which is characterized by stacking and forming layers by heating and pressurizing.