JPS5951913B2 - Continuous manufacturing method for laminates - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION ``The present invention relates to an improved method for continuous production of laminates.

Conventionally, laminates are produced by impregnating a base material with a varnish made by dissolving a resin component in a solvent, then drying the solvent to create a prepreg, cutting this into a certain size, stacking a large amount of these, and depending on the case. is manufactured using methods such as stacking metal foil and applying pressure and heat in a batch process, but the process is complicated, and because it is batch production, it is necessary to obtain it, which poses a major problem in productivity. It is.

In recent years, from this point of view, several proposals have been made to continuously produce laminates, but these have not been fully put into practical use. From this point of view, the present inventor has conducted intensive research on a method and apparatus for continuously manufacturing a laminate, and has arrived at the present invention. The inventor has already made some proposals,
This enables continuous production of these laminates.

In other words, continuous production can be achieved by appropriately controlling manufacturing conditions such as preliminary drying conditions for the base material, selection of resin liquid, conditions for impregnating the base material with the curable resin liquid, and curing conditions after laminating the cover film. This method ensures higher productivity than conventional batch production methods. The present invention is characterized in that productivity can be further improved in this continuous manufacturing method. The present inventor stacked the cover film in multiple stages by sandwiching the cover film on the upper surface, the lower surface, and between the sheet-like base materials,
By curing, it is possible to simultaneously manufacture a large number of laminates under almost the same drying time, impregnating time, and curing time as described above, and as a result, productivity can be dramatically improved. They discovered this and arrived at the present invention.
That is, in the present invention, a plurality of sheet-like substrates are continuously conveyed, and processes such as impregnation with a curable resin liquid, lamination of the impregnated substrates, lamination of a cover film, curing, and cutting into practical dimensions are carried out continuously. This continuous production method of a laminate is characterized in that a cover film is laminated in multiple stages on the upper surface, the lower surface of a sheet-like base material, and between them to obtain a large number of laminates at the same time.

The laminate in the present invention is particularly intended as an electrical laminate, and includes a laminate insulating board or a metal foil-covered laminate used as a substrate for various electronic components.For example, it is used as a printed circuit board. be exposed.

As the sheet-like base material in the present invention, well-known materials such as paper such as linter paper and kraft paper, glass cloth, asbestos cloth, and organic fiber nonwoven fabric can be used, but paper and glass cloth are particularly suitable for the base material. It is suitable for the present invention due to the mechanical strength of the material.

The present invention can be applied to any conventionally well-known curable resin liquid, especially thermosetting resin liquid, but in particular, substantially generates reaction by-products such as gas and liquid during the curing reaction process. It is a type of thermosetting resin liquid that does not contain any unnecessary removal components such as solvents during curing, and the entire resin liquid component can essentially become a component of the cured product. It is preferable to use a resin liquid that does not substantially generate reaction by-products such as condensed water and carbon dioxide gas during curing.

For example, there are radical polymerization type or addition reaction type materials such as unsaturated polyester resin, diallyl phthalate resin, epoxy resin liquid, etc., which can be molded without pressure, and the present invention suitable for Further, in the present invention, an unsaturated polyester resin that is liquid at room temperature, and in particular, one in which the crosslinking monomer is styrene is particularly preferred from the viewpoint of product performance or curing speed. The viscosity of the resin liquid is preferably 0.1 to 15 poise at room temperature, more preferably 0.
．． It is preferable to select a commercially available product with a glass transition point of about 100° C. or lower, which has a hardness of 5 to 10 poise. The cover film in the present invention includes various release papers and cellophane with a thickness of about 10 μm to 200 μm, various synthetic resin films such as Teflon and polyester, and various metal foils such as aluminum, copper, stainless steel, iron, and phosphor bronze. It is.

These cover films have effects such as preventing the resin from sticking to the equipment, ensuring the smoothness of the laminated surface, and blocking oxygen (air) that can prevent the resin from curing, but there is something even more surprising. Furthermore, it has been found that, as in the present invention, it plays a role as a separator when laminated in multiple stages. That is, it is possible to laminate base materials on both sides of the cover film, and it is possible to laminate in multiple stages to obtain a large number of laminates at the same time. Moreover, when the cover film is a metal foil, it can be peeled off after molding, and the metal foil-covered laminate can be bonded to either one of the laminates on both sides of the metal foil. You can also get . In this case, if necessary, an adhesive can be applied to one side of the metal foil in advance. In the manufacturing method of the present invention,
Laminating in multiple stages means that when the upper limit of the number of substrates that can be transported and the thickness of the substrate are specified, the substrates are laminated to a predetermined thickness, and a cover film is sandwiched between the layers. The number of laminates that can be stacked in multiple stages is defined by the upper limit number of substrates that can be transported and the thickness of one substrate.

For example, if the upper limit of the number of substrates that can be conveyed using kraft paper with a thickness of 250 μm is 30 sheets, the thickness of kraft paper is 0.5 m.
It is possible to produce 15 laminates with a thickness of 1.5 mm, and approximately 4 laminates with a thickness of 1.6 mm.Since these numbers can be manufactured simultaneously, productivity increases by 15 times or 4 times, respectively. . Therefore, the present invention can be particularly effectively applied to the production of thin laminates. Normally, when using Taraft paper with a basis weight of about 150 g or 7 glass cloth with a thickness of about 100 to 200 μm, two stages are used to produce a 1.6 mm thick one, and a 0.5 mm thick one is used. If you do, 2 steps~
A preferred embodiment is about 5 stages. The length that can be manufactured in the transverse direction, that is, in the width direction, can be arbitrarily set to 0 depending on the product width of the long base material to be obtained, but usually, for example, from 0.1 to 0.
It is easy to manufacture a width of about 4 m. Generally speaking, a width of 1 meter is advantageous.

As an example of implementation, when manufacturing a 35 μm thick copper foil laminate made of unsaturated polyester resin and paper and having a thickness of 1.6 mm, for example, in the middle of the paper base material impregnated with the unsaturated polyester resin, Pre-dried cellophane is laminated, base materials of a predetermined thickness are laminated on the top and bottom, copper foil is applied as a cover film, and by lamination, two single-sided copper foil-covered laminates are created at the same time. In this case, the productivity is twice as high as that of a normal continuous manufacturing method, and therefore, the effects of the present invention are great.

Also, when manufacturing continuously using the above method using a metal box such as copper foil instead of cellophane in the middle of the base material, the metal foil such as copper foil can be used as a substitute for the cover film, and one side of the copper A foil-covered laminate and a double-sided metal foil-covered laminate can be produced simultaneously, and productivity is also improved in this case. Furthermore, although it is common practice to manufacture laminates of various thicknesses depending on the application, according to the present invention, various types of laminates with different thicknesses can be manufactured at the same time. This is advantageous because it prevents productivity from decreasing.

As described above, the present invention dramatically improves the productivity of the second laminate in the continuous manufacturing method, but compared to the case of manufacturing by stacking one layer, the present invention is particularly effective during curing or when adapting to practical dimensions. Some care must be taken when cutting the material.

That is, during curing, since the overall thickness of the laminate to be molded is thick, conditions such as heating efficiency during curing, heat transfer of hardening reaction heat, and heat radiation change. A heating furnace is used in which heating, heat generation, heat transfer, heat radiation, etc. can be precisely controlled depending on the number of stages, such as a furnace whose interior is divided into several blocks and whose temperature can be controlled appropriately. In addition, when using a catalyst or curing agent in unsaturated polyester resin, for example, in consideration of the heat generated during the curing reaction, it is necessary to place the catalyst or curing agent more centrally than in the impregnated resin liquid of the impregnated base material located on the outside. It is desirable to impregnate the parts to be coated with a resin liquid containing a reduced amount of catalyst, etc. A millimeter cutter is convenient for cutting, but if the thickness is difficult to cut using this cutter, it is better to install a movable slicer, for example. After cutting, it is preferable in terms of product performance to perform heat treatment if necessary. In addition, if necessary, it is possible to connect a cover sheet winding device, an adhesive coating device for metal foil, an after-cure device, or other necessary devices in the production of metal foil-clad laminates. do not have.

[Brief explanation of the drawing]

FIG. 1 is a schematic explanatory diagram showing an example of an apparatus for implementing the present invention, and FIG. 2 is a partially enlarged view of section A in FIG. 1. 1. Sheet-like base material such as glass cloth or paper, 2.
...Cover film such as cellophane, 3...
・Resin impregnation device, 4...Cover film such as metal foil, 5...Lamination device, 6...
Hardening device, 7...Bow I removal device, 8...
- Cutting machine, 9...Cut laminate.

Claims (1)

[Scope of Claims] 1. Using a curable resin liquid that does not substantially contain components removed by drying such as a solvent and does not substantially generate reaction by-products such as gas or liquid during the curing reaction process, Manufacture of a laminate in which multiple sheet-like substrates are continuously transported and impregnated with a curable resin liquid, etc., laminated with the containing substrates, laminated with a cover film, cured, and cut into practical dimensions, etc. In the method, the cover film is placed on the top surface of the laminated sheet-like substrate;
1. A continuous manufacturing method for electrical laminates, characterized by laminating them in multiple stages on the lower surface and between them to obtain a large number of laminates at the same time. 2. The manufacturing method according to claim 1, wherein the molding pressure during curing is substantially no pressure. 3. The manufacturing method according to claim 1, wherein the cover film is a synthetic resin film. 4. The manufacturing method according to claim 1, wherein part or all of the cover film is a metal foil, and the other part of the cover film is a synthetic resin film. 5. The manufacturing method according to claim 4, wherein part or all of the metal foil is an electrolytic copper foil.