JPH03130145A - Manufacture of laminated board - Google Patents

Abstract

PURPOSE:To reduce warpage by alternately superposing a plurality of long-sized fluoroplastic-impregnated base materials and fluoroplastic films, stacking a long-sized metallic foil onto one-side outer surface of the laminate, pressing and heating the laminate and metallic foil, laminating and unifying them and cutting them. CONSTITUTION:A plurality of long-sized fiuoroplastic-impregnated base materials 10 and long-sized fluoroplastic films 70 are superposed alternately, and a long- sized metallic foil 20 is stacked onto at least one-side outer surface of the laminate, pressed by a pair of upper and lower belts 41, 41 while being made to travel, and heated and laminated and unified, and cut in specified size. The same base material as one for manufacturing a normal fluoroplastic laminated board is used as the fluoroplastic-impregnated base material 10. The fluoroplastic film is composed of various fiuoroplastics cited as the materials of the fluoroplastic-impregnated base materials 10, the base materials are not impregnated with the fluoroplastics, and materials acquired by previously molding fluoroplastics in a filmy shape are used. Accordingly, a fluoroplastic laminated board having the low rate of warpage and excellent quality can be manufactured.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a laminate, and more specifically, a method for manufacturing a laminate, in which a metal foil layer is laminated on one or both sides of a resin layer, and is used for manufacturing electronic components such as printed wiring circuit boards. of! ! ! The present invention relates to a method for manufacturing laminates used in the manufacturing field.

[Conventional technology]

Conventionally, as a material for printed circuit boards, copper foil was laminated on one or both sides of an insulating substrate obtained by impregnating a base material such as paper or glass cloth with thermosetting resin such as epoxy resin. Laminated plates are used. Such A-layer boards are widely used as printed wiring circuit boards and other electronic component materials incorporated into electronic equipment, computers, communication equipment, and the like.

The method for manufacturing the above-mentioned laminates is usually to stack a plurality of substrates impregnated with a thermosetting resin, that is, resin-impregnated substrates cut to a fixed size, and to have the same cut to a fixed size on one or both sides. After stacking the copper foils, they were laminated by heating and pressurizing them with a press device such as a multi-stage press machine.

On the other hand, in order to improve the heat resistance of the laminate, it has been proposed to use a fluororesin, which has excellent heat resistance, as a resin material.

[Problem to be solved by the invention]

However, when a fluororesin laminate is manufactured using the conventional manufacturing method described above, there is a problem in that the warp becomes large, which is not preferable for applications such as printed wiring circuit boards.

This is because when the fluororesin-impregnated base material and the metal foil are stacked and heated and pressed using a press machine, the heating and pressure are not uniformly applied, resulting in residual stress being generated within the laminate. This is thought to be due to uniform deformation, which causes warpage in the manufactured laminate.

Therefore, an object of the present invention is to provide a method for manufacturing a laminate of good quality by reducing warping when manufacturing a fluororesin laminate with excellent performance such as heat resistance as described above. be.

[Means to solve the problem]

A method for manufacturing a laminate of the present invention that solves the above problems is as follows:
A blade-shaped laminate for producing a laminate having a metal foil layer on at least one side of a fluororesin layer, wherein a plurality of long fluororesin-impregnated substrates and long fluororesin films are alternately stacked, and further on at least one outer surface of the laminate. While the long metal foils are overlapped and run, they are pressed and heated with a pair of upper and lower belts to form a laminated film, and then cut into predetermined dimensions.

The fluororesin-impregnated base material used is the same as the base material for manufacturing ordinary fluororesin laminates. Examples of the fluororesin include tetrafluoroethylene resin, tetrafluoroethylene perfluorovinyl ether copolymer resin, tetrafluoroethylene hexafluoropropylene copolymer resin, tetrafluoroethylene ethylene copolymer resin, and trifluoroethylene ethylene copolymer resin. Ethylene chloride resin or the like is used. As the base material to be impregnated with the fluororesin, for example, paper, glass cloth, glass paper, glass nonwoven fabric, synthetic fiber cloth, etc. are used.

In order to produce a fluororesin-impregnated base material, the base material is impregnated with a fluororesin liquid (emulsion) and then dried.

The amount of fluororesin liquid impregnated is preferably such that the amount of resin after drying is about 40 to 60% by weight.

The fluororesin film is made of the various fluororesins listed as the materials for the fluororesin-impregnated base material, and instead of being impregnated into the base material, the fluororesin is pre-shaped into a film shape. The thickness of the fluororesin film is approximately 0.
．． 001 to Q, about 1 mm can be used.

As the metal foil, various conductive metals or non-conductive metals can be used depending on the intended use of the laminate.

Specifically, in the case of printed wiring boards and the like, circuit conductor metals such as copper and aluminum are preferably used. If an adhesive layer is formed on the surface of the metal foil to be bonded to the fluororesin-impregnated base material or fluororesin film, the bonding force between the metal foil and the fluororesin-impregnated base material will be increased. However, if the metal foil can be laminated by simply heating and pressing the fluororesin-impregnated base material or the fluororesin film, it can be carried out without an adhesive layer.

The fluororesin-impregnated base material, the fluororesin film, and the metal foil are all manufactured in a continuous band shape, that is, a long length, and the lamination process is performed while continuously running the strips. The impregnation and drying process of fluororesin and the process of applying adhesive to metal foil are carried out continuously on a series of lines, such as the lamination process described later, while the long base material and metal foil are continuously run. It can be carried out.

A device that performs lamination and lamination by applying pressure and heat using a pair of upper and lower belts is generally called a double belt press device.

Its structure is such that the material to be laminated is sandwiched between a pair of endlessly rotating belts, and the laminated material is heated and pressurized through the belts to form a laminated material. On the side opposite to the surface that contacts the laminated material, there is provided a pressure means for pressing the heald toward the laminated material, and a heating means for applying heat to the laminated material via the belt.

As the pressure means, first, a flat pressure plate can be directly pressed against the back of the belt, or multiple pressure rollers can be arranged on the back of the belt and pressure can be applied while rotating the pressure rollers. .

In this case, the pressurizing mechanism that applies the pressurizing force includes a cam, link mechanism, spring mechanism, hydraulic cylinder, electromagnetic cylinder, etc.
The same mechanism as a normal mechanical device can be adopted. Also used is one in which a certain sealed space is provided on the back side of the belt, and a pressure medium such as steam or bending is supplied to this sealed space to apply fluid pressure to the heald. If a pressure transmission mechanism or a sealing mechanism using magnetic fluid is provided in the sliding part between the belt that rotates endlessly and the pressure plate or pressure medium seal that is stationary at a fixed position, the magnetic fluid will reduce frictional resistance. This is preferable because it has extremely low resistance and almost no seal leakage occurs.

Examples of heating means include those with a built-in heater inside the pressure plate or pressure roller that serves as the pressure means, those that heat the entire atmosphere by storing the area around the pressure roller and belt inside a heating chamber, and heating means. It is possible to use the same heating means as in ordinary mechanical devices, such as one that heats the chamber or pressure roller with heated steam or oil, or one that supplies a heated pressure medium as the pressure medium.

A plurality of the fluororesin-impregnated substrates and fluororesin films described above are alternately stacked on top of each other, and metal foil is stacked on one side or both sides of the double belt press device, and during a certain running section, By thermally curing the fluororesin-impregnated base material by applying pressure and heating at the same time, a plurality of base materials, films, and metal foils are laminated.

The specific heating temperature, heating time, running speed, etc. at this time are appropriately set depending on conditions such as the curing temperature of the fluororesin and the number of laminated base materials. Note that it is preferable that the fluororesin-impregnated base material and the fluororesin film are arranged alternately so that the fluororesin film is disposed on the outermost surfaces of both sides, that is, the surface that is laminated with the metal foil. Furthermore, in addition to the fluororesin-impregnated base material, fluororesin film, and metal foil, a release film or the like can be simultaneously supplied and laminated.

The elongated laminate continuously obtained from the double belt press device is cut into a predetermined size using a cutting device such as an ordinary cutter to produce a laminate of fixed size.

[For production]

By running the fluororesin-impregnated substrate, fluororesin film, and metal foil in a long length and applying pressure and heating with a pair of belts, the heating and pressure will be applied evenly.
It is believed that uneven deformation, generation of residual stress, etc. that cause warping can be prevented, and the warpage of the obtained laminate is reduced.

In particular, since a portion of the fluororesin layer includes a pre-formed fluororesin film, the molding time for the entire fluororesin layer is short, and the laminate can be manufactured efficiently.

〔Example〕

Next, embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 schematically shows a specific example of an apparatus used for carrying out the present invention. First, on the left side of the figure, a plurality of winding roll parts 11 of the long fluororesin-impregnated base material 10 and a plurality of winding roll parts 71 of the long fluororesin film 70 are arranged alternately, and furthermore, on the outside thereof, a long metal A winding roll portion 21 of the foil 20 is arranged. The metal foil 20 used has an adhesive coated on its bonding surface with the outermost fluororesin film 70. Winding roll part 11.21.7
A long fluororesin-impregnated base material lO pulled out from 1;
The fluororesin film 70 and the metal foil 20 are superimposed on each other by a guide roll 30 or the like and are supplied to the double belt press device 4o.

The double belt press device 40 includes a pair of drive rolls 42
．． A belt 41 stretched across the belt 42 rotates endlessly as the drive roll 42 rotates, and a pair of such belts 41 are provided vertically with an interval between them. Between the upper and lower belts 41□ 41, the fluororesin-impregnated base material 10, the fluororesin film, and the metal foil 2o are supplied in a stacked state. A large number of pressure rolls 43 are lined up on the back side of each belt 41, and the pressure rolls 43 apply pressing force to the belt 41 while rotating, and are sandwiched between the upper and lower belts 41 and 41. The fluororesin-impregnated base material 10, the fluororesin film 70, and the metal foil 2o are pressurized via the bell 1-41.41.

Further, the double belt press device 40 is connected to the fluororesin-impregnated base material 10 and the fluororesin film 7 via a belt 41.
Heating means (not shown) for heating the metal foil 20 and the metal foil 20 are also provided.

The fluororesin-impregnated base material 10, the fluororesin film 70, and the metal foil 20 heated and pressurized by the double belt press device 40 are bonded to each other and integrated into a laminated plate S, which is then cut using a cutting mechanism such as a cutter 50. If it is cut into predetermined dimensions and recovered, the production of the laminate S is completed.

FIG. 2 shows the cross-sectional structure of the laminate S manufactured in this way, and from the top layer, metal m20, adhesive 21, fluororesin film 70, fluororesin-impregnated base material 10, . . . , fluororesin film 70, Although the fluororesin-impregnated base material 10 and the fluororesin film 70 are shown as separate layers in Figure 0, in which the adhesive 21 and the metal foil 20 are sequentially laminated, in reality, they are fused and integrated into one. constitutes a fluororesin layer.

Next, a specific example in which a laminate S was manufactured using the apparatus and method described above will be described.

A long glass cloth with a width of 10,501 mm and a thickness of 0.1 mm was coated with 4/7 ethylene resin (trade name: Polyflon Dispersion, manufactured by Daikin Industries), and the amount of resin after drying was 45% by weight.
It was impregnated so as to have the following properties and dried to produce a prebrig, that is, a fluororesin-impregnated base material 1o. Further, as the fluororesin film 70, a tetrafluoroethylene resin film (trade name: Polyflon Film, manufactured by Daikin Industries@) having a thickness of 0.01 am was prepared. Long preprig 1
0 and 5 fluororesin films 70 are stacked alternately so that the fluororesin films 70 are placed on both outer surfaces, and the adhesive rolled copper 7F320 is stacked above and below them, and a double belt press machine is used. 40. The thickness of the copper foil 20771 M contact agent 21 was 35 μm. Pressure force with double belt press device 40 is 20 kg/cut
The heating temperature was set at 350° C., and as the bleb rig 10 and copper foil 20 traveled, they were pressurized and heated for 5 minutes each. The obtained laminate S has a thickness of 100 in the longitudinal direction.
In addition to cutting every 0 mm, also cut 1000 degrees in the width direction.
After trimming and cutting so as to be +n, the laminate S was completed by being allowed to cool.

In order to compare with the laminate S of the above example, four pieces of the same long Breblig 10 to 1050** were cut into squares, and five pieces of fluororesin film 70 were similarly cut to size. And the same veneer copper foil with adhesive 20
stacked on top of each other and using a conventional press device, 20
After laminating under the same heating and pressing conditions of kg/c++t, 350° C., and 5 minutes, a laminate of a comparative example was manufactured by cutting to a size of 1000×1000 fl.

Regarding the laminate S of the above-mentioned examples and comparative examples, the warpage rate %
When measured, it was 9% in the comparative example, while it was 3.5% in the example, which was an extremely low value. As a result, it was demonstrated that according to the manufacturing method of the present invention, a high-quality laminate with a low warpage rate could be manufactured.

〔Effect of the invention〕

As described above, according to the method for manufacturing a laminate according to the present invention, a long fluororesin-impregnated substrate, a fluororesin film, and a metal foil are continuously processed by a pair of upper and lower endlessly rotating belts. By laminating under pressure and heat, a fluorine resin laminate with a low warpage rate and good quality can be efficiently produced.

In particular, by forming the fluororesin layer by alternately stacking fluororesin-impregnated substrates and fluororesin films,
The resin lamination and curing time is shortened, improving manufacturing efficiency.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of the configuration of an apparatus showing an embodiment of the present invention, and FIG.
The figure is a cross-sectional structural diagram of the manufactured laminate.

Claims (1)

[Claims] 1. A method for producing a laminate having a metal foil layer on at least one side of a fluororesin layer, the method comprising: alternatingly stacking a plurality of long fluororesin-impregnated substrates and long fluororesin films, and further forming a layer on at least one outer surface thereof. A method for manufacturing a laminate, which comprises stacking and running long metal foils while applying pressure and heating with a pair of upper and lower belts to integrate the laminate, and then cutting the foils into a predetermined size.