JPH0577378A - Production of metal foil-coated laminate by wet continuous method - Google Patents

Abstract

PURPOSE:To obtain a production of a metal foil-coated laminate by a wet continuous method capable of improving productivity to a great extent without changing a line speed. CONSTITUTION:In a production of a metal foil-coated laminate by a wet continuous method, a substrate having a width approximately twice as long as a regular width is used as a base material. The base material is impregnated with a liquid-type curable resin. The materials are integrally laminated by two or more sheet. On at least one surface of the laminate, two sheets of metal foils 8 of a regular width are applied in parallel separately from each other. After being cured under pressure through a substantially non-pressure or double-belt press 11, this laminate is longitudinally equally cut into two parts along the center line thereof and cut into a predetermined length.

Description

Detailed Description of the Invention

[0001] Technical Field The present invention is a continuous process regarding one or both sides metal foil-clad laminate rigid type used in printed circuit board.

2. Description of the Related Art Conventionally, the production of metal foil-clad laminates has hitherto been carried out by impregnating a base material with a resin varnish, drying the prepreg on a required number of sheets and the metal foil, and compression-molding them. The batch type dry method was the mainstream, but the continuous method, which exhibits high productivity, is attracting attention.

As one of them, Japanese Patent Laid-Open No. 56-
126418 (Japanese Examined Patent Publication No. 62-6513) discloses a continuous thermosetting resin liquid which does not generate a volatile by-product in the curing reaction process, such as an unsaturated polyester resin liquid, which is impregnated into a plurality of continuous sheet-shaped base materials while being conveyed. Then, these are laminated and combined,
A method for producing a metal foil-clad laminate (wet pressureless continuous method) in which a metal foil is applied to a laminate and then continuously cured without applying a molding pressure is disclosed. However, with the recent development of electric and electronic devices, the performance required for a laminated plate is becoming more and more severe, and it is particularly desired to improve the characteristics when heated. For that purpose, it is effective to reduce the resin content of the laminated plate and increase the ratio of the base material, but this tends to be difficult to achieve in the pressureless continuous method because the molding pressure is not substantially applied during curing. Further, in the pressureless continuous method, since the relative movement between the metal foil and the base material layer is free at the initial stage of curing, slack, wrinkles, etc. of the metal foil may occur due to the difference in thermal expansion coefficient between the two and the vibration. Is likely to occur.

Therefore, the laminated product is sandwiched by a pair of endless belts from both sides, and the laminated product and the belt are synchronously moved in the same direction while being pressurized and heated to cure the laminated product. The wet method has been developed and is disclosed in Japanese Patent Laid-Open No. 56-144151 (Japanese Patent Publication No. 60-58031), and recently, Japanese Patent Laid-Open Nos. 2-6131, 2-59343 and 2-86441.

However, the pressureless or pressure continuous wet method requires a large capital investment and is required to further improve the productivity. One of the methods is to increase the line speed, but it takes a certain heating time to cure the resin, so increasing the line speed will increase the length of the line and further increase the equipment cost.

Therefore, the present invention proposes a method for producing a wet continuous type metal foil-clad laminate which can significantly improve the productivity without changing the line speed.

Solution The present invention is to laminate a plurality of sheet-like base materials impregnated with a liquid curable resin while continuously conveying them, laminate a metal foil on at least one side of the combined laminate, and then substantially In a method for producing a metal foil-clad laminate by a wet pressure continuous method including a step of sandwiching with no pressure or a double belt press, heating under pressure to cure, and cutting into a predetermined size, a width of about 2
Using a base material having a double width, after stacking, two metal foils with a standard width are placed in parallel and separated from each other, and after curing, bisected along the center line and cut into a predetermined length. Is provided.

According to the present invention, it is possible to approximately double the production amount of laminated plates per unit time and to reduce the equipment cost.

Preferred Embodiments Preferred embodiments of the present invention will be described with reference to the drawings. The layout of an example of the apparatus used for carrying out the method of the present invention shown in FIG. 1 is such that the preheating zone 10 is mainly installed in each endless belt loop 12 of the double belt press 11 and is integrated with the double belt press 11. And the apparatus disclosed in the above-cited Japanese Patent Application Laid-Open No. 56-144151, except that the post-curing furnace 15 is added. Therefore, the impregnated portion of the substrate is omitted in the drawing.

As shown in the figure, the double belt press 11 of the present invention comprises a laminate of a plurality of resin-impregnated base materials 1 which are united by a laminating roll 6 therebetween and, for example, a metal foil 8 laminated on the upper surface thereof. It includes a pair of upper and lower endless belt loops 12 that sandwich and run. Each endless belt loop 12 is made of a steel belt stretched between the rolls 13 and 13 ', and is driven in synchronization with the conveyance speed of the laminate. Meimei's Endless Belt Loop 1
A preheating zone 10, a pressure roll 7, and a pressure box 14 are provided in the inside of the unit 2. The preheating zone 10 is a heating chamber in which hot air or a heat medium circulates, and heats the laminated plate sandwiched between the belts 12 and 12. In combination with the preheating zone, the roll 13 upstream of the double belt press may be heated by hot air, heating medium or steam, which makes it possible to save the length of the preheating zone. The pressure roll 7 removes swelling, delamination, or the like caused by preheating. The pressure box 14 is preferably divided into a plurality of sections for enclosing the pressurized gas or liquid with a partition plate, and the temperature can be controlled independently. Instead of the pressure box divided into a plurality of sections, a plurality of independent pressure boxes may be installed in parallel to control the temperature and / or pressure. The laminate is heat cured under pressure while passing through the pressure zone by the pressure box. Instead of the pressure box, pressure may be applied by a plurality of roll pairs.

Laminate 20 exiting the double belt press 11
Passes through the post-curing furnace 15 in a pressureless state, and at least a part of internal stress is relaxed, and then cut into a predetermined size.

The specific example shown in FIG. 1 is for a single-sided metal foil-clad laminate, but in the case of a double-sided plate, the metal foil 8 is of course symmetrically laminated on the lower surface as well. An adhesive may be applied to the metal foil 8 immediately before lamination, but it is preferable to use a metal foil to which the adhesive has been applied off-line in advance.

The specific examples described above relate to the pressure continuous method, but the pressureless continuous method is described in detail in the above-mentioned Japanese Patent Application Laid-Open No. 56-126418 of the present application.

In the present invention, linter paper is used as the base material,
Cellulose-based materials such as kraft paper, glass cloth, glass paper, mixed paper, non-woven fabric and the like can be used. For these base materials, a plurality of continuous sheets thereof may be conveyed in parallel and individually impregnated with the resin liquid and then supplied in-line to the laminating roll 6, or instead of the base material once impregnated with the resin liquid. The continuous sheet may be prepared in another line and supplied to the laminating roll 6.

The features of the present invention are best illustrated in FIG. 2, which is a partial cross-sectional side view taken along line II-II of FIG. Generally, the standard width of a laminated board for a printed wiring board is defined as 1020 mm by the JIS standard. Therefore, as a base material, a width of 1050 is usually left with a margin of 10 to 20 cm left at the edge portion.
The thing of about mm is used.

In the present invention, a base material having a width about twice that of a base material having a standard width is used. After impregnating a plurality of these base materials with a curable resin solution and stacking and laminating them, two metal foils having a fixed width are separated from each other and stretched in parallel as shown in FIGS. 1 and 2. The gap between the metal foils is 1 to 20 mm, preferably 3 to 1
It is 0 mm. If the metal foils overlap each other, swelling may occur from that portion after pressure curing.

As for the metal foil, it is preferable to use a metal foil having a width about twice as large as the base material, but a metal foil having a width equal to twice the standard width is not common and is difficult to obtain. According to the method of the present invention, a metal foil-clad laminate can be manufactured by combining two metal foils having a fixed width and a base material having a double width.

After hardening, the laminated plate 20 is vertically divided into two parts by a circular saw or the like (not shown) along the center line in the gap, and further cut into a predetermined length by a guillotine cutter or the like.
Of course, this vertical and horizontal cutting order may be reversed.

As described above, according to the present invention, the production amount of the metal foil-clad laminate by the wet continuous method per unit time is about 2.
It will be possible to double.

[Brief description of drawings]

FIG. 1 is a schematic front view of a wet pressurizing continuous metal foil-clad laminate production line.

FIG. 2 is a partial cross-sectional side view taken along the line II-II in FIG.

[Explanation of symbols]

 1 Resin Impregnated Base Material 8 Metal Foil 11 Double Belt Press 20 Laminated Plate

Claims (1)

[Claims] 1. A plurality of sheet-shaped base materials impregnated with a liquid curable resin are continuously conveyed while being laminated, and a metal foil is applied to at least one surface of the combined laminate, and then substantially pressureless or double. In a method for producing a metal foil-clad laminate by a wet continuous method including a step of sandwiching a belt press, heating under pressure to cure, and cutting to a predetermined size, a base material having a width about twice the standard width is used. It is characterized in that after being laminated and laminated, two metal foils having a fixed width are separated from each other and juxtaposed in parallel, and after curing, they are bisected in the longitudinal direction along the center line and cut into a predetermined length. Method.