JPH04262318A - Continuous manufacture of electrical laminated plate - Google Patents

Abstract

PURPOSE:To remove any excessive resin solution, so as not to contaminate environment during the processes of lamination and pressurization, so as to reduce loss and equalize the distribution, by individually passing a plurality of resin impregnated base materials through a roll line in which at least one pair of rolls stand still or reversely rotate. CONSTITUTION:Respective impregnated base materials 1 such as unwoven cloth or the like which have exited from an impregnating chamber 5, in which a resin solution of an unsaturated polyester resin or the like staying in liquid state at room temperature and hardening without generating any volatile by- product, is impregnated therein; are individually conveyed through a roll line 50 comprising a plurality of rolls 51 to 55, and are incorporated in a laminating roll 6. Among rolls, at least one roll making contact with the top surface and the under surface of the base materials respectively, e.g. a roll 51 or 53 and a roll 52 or 54, are stopped or rotated in opposite direction relative to the base material conveying direction, and the other rolls are used as idle rolls. Consequently, the excessive resin is removed from both surfaces of the base materials by the friction of rolls, and concurrently bending motions are given so that inward impregnation can be promoted.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously producing electrical insulating laminates or metal foil-clad laminates for printed circuits. The term "electrical insulating laminate" here refers to a laminate used as a substrate or support plate for various electronic components or devices, and the term "metal foil-clad laminate for printed circuits" refers to a laminate used for mounting electronic circuit components, etc. A single-sided or double-sided printed circuit board that constitutes a printed circuit, both of which are of the rigid type.

0002

[Prior Art] Japanese Patent Application Laid-open No. 55-126418 (
Japanese Patent Publication No. 62-6513) discloses a method for transporting a thermosetting resin liquid (for example, an unsaturated polyester resin liquid) that does not generate volatile by-products during the curing reaction and is liquid at room temperature onto a long sheet-like substrate. A method for manufacturing an electrical laminate is disclosed in which a large number of electrical laminates are impregnated, laminated, both sides of the laminate are coated with metal foil and/or a release film, and the laminate is continuously cured substantially under no pressure. In this method, since no pressure is applied during curing, it has been difficult to increase the proportion of reinforcing base material in the product and improve its properties under heat. In addition, in the case of single-sided or double-sided metal foil-covered laminates, the relative movement between the metal foil and the base material layer is free in the early stage of curing, so the difference in thermal expansion coefficient between the two and vibration may cause The disadvantage is that the metal foil tends to sag and wrinkle.

[0003] Therefore, the present applicant's Japanese Patent Application Laid-Open No. 14415/1983
1 (Special Publication No. 60-58031), a laminate is sandwiched between a pair of endless belts that run synchronously with the laminate,
We proposed a method of thermosetting the endless belt while applying pressure from a direction perpendicular to the surface of the laminate. It has been found that in the wet pressurized continuous method using such a double belt, consideration must be given to the amount of resin impregnated into the base material before lamination, which is different from that in the pressureless continuous method. In other words, in the pressureless continuous method, no pressure is applied during curing, so air is likely to be trapped between each base material layer and between the base material and metal foil, and to prevent this, excessive resin liquid is supplied to form an interlayer resin layer. However, in the continuous pressure method using a double belt, excess resin liquid is squeezed out by pressure and contaminates the device and release sheet, which is not preferable.

0004

Disclosure of the Invention The present invention involves impregnating a plurality of continuously conveyed long base materials with a thermosetting resin liquid that is itself liquid at room temperature and does not generate volatile byproducts during the curing reaction process. In a continuous manufacturing method for electrical laminates, which involves laminating impregnated substrates and heating and pressurizing uncured laminates, optionally covered with metal foil, in a double belt press, a plurality of resin liquid impregnated substrates are laminated. The material is individually conveyed through a row of rolls arranged such that their upper and lower surfaces are in alternating contact with each other,
Among the roll rows, at least one pair of rolls that contact the upper and lower surfaces of the substrates are stationary rolls and/or rolls that rotate in the opposite direction to the substrate, and excess resin liquid is removed from each substrate before lamination. The method is characterized in that:

According to the present invention, when laminating resin-impregnated base materials and pressurizing the laminate with a double belt press, excess resin liquid is not squeezed out from the base materials and contaminates the surroundings, while the resin liquid There is an advantage that there is less loss of resin and no voids are observed due to lack of resin in the product.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An apparatus for carrying out the present invention is shown in FIGS. 1, 2, and 3. This device, except for the resin liquid control section shown in FIG.
The same device as shown in No. 9 etc. may be used. The first one showing the impregnated part
Referring to the figure, a long base material 1 such as a cellulose base material such as linter paper or kraft paper, a glass cloth, a glass paper, a mixed paper, a non-woven fabric, etc. is pulled out from a roll 2, a pre-impregnating bath 3, a drying chamber 4, etc. It enters the impregnation chamber 5 through it. In the impregnation chamber 5, the substrate 1 is impregnated with a thermosetting resin that is liquid at room temperature and hardens without generating volatile by-products, such as unsaturated polyester resin, epoxy resin, epoxy acrylate resin, etc. The resin passes through the resin liquid control section, enters the lamination curing section shown in FIG. 3, and is combined by a lamination roll pair 6. Thereafter, the metal foil 8 is applied to the laminate by a roll 9 to both sides in the case of a double-sided metal foil clad board, or to one side in the case of a single-sided metal foil laminate.
is stretched. In the case of unclad boards and single-sided metal-clad boards, a release film such as cellophane or polyester film may be applied to the surface not covered with metal foil using a roll 9 and peeled off from the laminate after curing, or a double belt press may be used. The belt 12 can also be used as a release film. In addition, after the metal foil was stretched, a similar release film was supplied between the metal foil 8 and the belt 12 from a roll (not shown) to protect the metal foil from direct contact with the belt 12 of the double belt press. Good too. In the present invention, the phrase "pasting metal foil if necessary" includes all such cases. The metal foil can be electrolytic copper foil, rolled copper foil, aluminum foil, etc., and becomes part of the structure of the final product.

If necessary, the laminate covered with metal foil is pressurized and heated by a double belt press 11, and then transferred to a post-hardening furnace 1.
5 and is cured into a product 20.

As shown in the figure, the double belt press 11 consists of a pair of upper and lower endless belt devices consisting of a steel belt 12 stretched between rolls 13 and 13', with a laminate 20 to be pressurized sandwiched between them. It is driven synchronously with the transport speed. A hydraulic box 14 is provided on the opposite side of the laminated plate at the portion of each endless belt 12 that is in contact with the laminated plate. The hydraulic box is divided into a plurality of sections by partition plates, and the edges thereof in contact with the endless belt 12 are provided with sealing members to prevent oil leakage. Instead of a hydraulic box divided into multiple sections, a plurality of independent hydraulic boxes may be installed in parallel to individually control temperature and/or pressure. The pressure applied to the laminate is generally 20Kg/
cm2 or less, preferably in the range of 1 to 10 Kg/cm2.

Next, the resin liquid control section, which is a characteristic part of the present invention, will be explained with reference to FIG. They are conveyed through the stack, reach the lamination roll 6, and are combined. This roll row 50 includes a plurality of rolls 51 to 51 arranged such that the upper and lower surfaces of each base material are in alternate contact with each other.
Consists of 55.

According to the present invention, at least one of the rolls 51 to 55, for example, roll 51 or 53 and roll 52 or 54 is a stationary roll and/or a roll that rotates in the opposite direction to the substrate conveyance direction, and the other rolls are idle rolls, so that excess resin is removed from both sides of the substrate by friction with the stationary or counter-rotating rolls. At the same time, a bending motion is applied to the base material to promote impregnation of the resin liquid into the inside of the base material.

Furthermore, when laminating a plurality of impregnated base materials 1,
The roll 6 is a squeeze roll, and if necessary, a separate squeeze roll 7 is installed downstream of the laminated roll 6 (Fig. 3).
Preferably, the laminate is compressed in one or multiple stages to squeeze out excess resin liquid. Therefore, each base material 1 leaving the last roll 55 of the roll row 50 is conveyed toward the roll 6 in an upward slope. Thereby, it is possible to reduce the amount of resin liquid squeezed out by the roll 6 being carried into the lamination curing section.

[0012] The illustrated apparatus can be equipped with conventional feedback devices if desired. For example, post-curing furnace 15
It is also possible to continuously detect the thickness of the product laminate 20 that has come out and feed it back to the pressure of the double belt press 11, or to detect the amount of resin protruding when pressurized by the double belt press 11, and to It is also possible to feed back the squeeze pressure.

As described above, according to the present invention, contamination of the equipment by the resin liquid squeezed out during lamination of resin-impregnated base materials and pressurization of the laminate by a double belt press can be prevented, and the amount of loss of resin liquid can be reduced. It is possible to obtain a laminate of excellent quality with a uniform distribution of resin amount in the thickness direction while reducing the amount of resin.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an impregnating section for carrying out the invention.

FIG. 2 is a schematic diagram of a resin liquid control section for implementing the present invention.

FIG. 3 is a schematic diagram of a laminated hardening section for implementing the present invention.

[Explanation of symbols]

1 Base material 5 Impregnation chamber 50 Roll row 6 Laminated roll 8 Metal foil and/or release film 9
Laminating roll 11 Double belt press 20 Laminated plate

Claims (3)

[Claims] [Claim 1] A thermosetting resin liquid that is liquid itself at room temperature and does not generate volatile byproducts during the curing reaction process is impregnated into a plurality of long base materials that are continuously conveyed, and the impregnated base material is In the continuous production method for electrical laminates, which involves laminating uncured laminates and, if necessary, applying pressure and heat on a double belt press, uncured laminates are covered with metal foil. is conveyed through a row of rolls arranged such that their upper and lower surfaces are alternately in contact with each other, and at least one pair of rolls in the roll row that contacts the upper and lower surfaces of the base material is a stationary roll and/or a base material. The method described above is characterized in that rolls rotate in opposite directions to remove excessively adhered resin liquid from each substrate before lamination. 2. The method according to claim 1, further comprising the step of compressing the laminate with a squeeze roll to remove excess resin liquid when laminating a plurality of substrates impregnated with resin liquid. 3. A plurality of resin-impregnated substrates are conveyed toward the squeeze roll while forming an upward slope.
the method of.