JPH03130146A - Manufacture of laminated board - Google Patents

Abstract

PURPOSE:To reduce warpage by alternately superposing a plurality of long-sized fluoroplastic-impregnated base materials and fluor plastic films, stacking a long-sized metallic foil onto one-side outer surface of the laminate, and pressing and heating, laminating and unifying, cutting and quenching the laminate and metallic foil. CONSTITUTION:A plurality of long-sized fluoroplastic-impregnated base materials 10 and long-sized fluoroplastic films 70 are superposed alternately, a long-sized metallic foil 20 is stacked onto at least one-side outer surface of the laminate, and the laminate and metallic foil are 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 and quenched. 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 70 is composed of various fluoroplastics cited as the materials of the fluoroplastic-impregnated base material 10, the base material is not impregnated with the fluoroplastics, and materials acquired by previously molding fluoroplastics in a filmy shape are employed. Accordingly, a fluoroplastic laminated board having the low rate of warpage and excellent quality can be manufactured efficiently.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for manufacturing a laminate, and more specifically, a 7fi metal 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. The present invention relates to a method for manufacturing a laminate used in the field of manufacturing.

(Prior art) Conventionally, as a material for printed wiring circuit boards, copper is coated 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. A laminate plate made of laminated foil is used. Such laminates are widely used as materials for printed wiring circuit boards and other electronic parts into which electronic equipment, computers, communication equipment, etc. are incorporated.

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 heated and pressurized using a press device such as a multi-stage press machine to integrate the layers.

On the other hand, in order to improve the heat resistance and the like of the laminate, it has been proposed to use a fluorine resin having excellent heat resistance and the like as the 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 metal foil are stacked and heated under pressure using a press machine, residual stress is generated within the A-layer board due to uneven heating and pressure. When the stress and deformation are gradually released during the cooling stage after the pressurizing and heating process, warping may occur in the manufactured laminate, or the process may be uneven at the end of the pressing process. This is thought to be because the laminate, which is still in a softened state that is easily deformed at high temperatures, is deformed due to external force being applied during handling until it is cooled and hardened.

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 laminated NFi with excellent performance such as heat resistance as described above. It is in.

[Means to solve the problem]

A method for manufacturing a laminate of the present invention that solves the above problems is as follows:
A method for manufacturing a laminate having a metal foil layer on at least one side of a fluororesin layer, the method comprising: alternately stacking a plurality of elongated fluororesin-impregnated substrates and elongated fluororesin films; While running the shaku metal foils in layers, they are pressed and heated with a pair of upper and lower belts to form a laminated body, and then cut to a predetermined size.
Cool quickly.

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, Fluorinated chlorinated ethylene resin, etc. are used. As the base material to be impregnated with the fluororesin, for example, paper, glass cloth, glass paper, glass nonwoven fabric, base 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, a fluorine 4MJ resin that has been previously formed into a film is used. The thickness of the fluororesin film is
About 0.001 to 0.1 am 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 and integrated with the fluororesin-impregnated base material or fluororesin film simply by heating and pressing, 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, in a long length, and are laminated and integrated while being continuously run. Therefore, the process of impregnating and drying the base material with fluorocarbon resin, and the process of applying adhesive to gold B7g, etc., are carried out in sequence with the lamination process, etc. described later, while continuously running the long base material or metal foil. This can be done continuously on the line.

A device that uses a pair of upper and lower belts to press and heat to integrate the layers 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 material is passed through the belts! This is a device that applies pressure while heating the II layer material to integrate the layers, and on the back side of the belt, that is, on the opposite side of the surface that contacts the layered material, there is a pressure device that presses the belt toward the layered material side. and heating means for applying heat to the laminated material via the belt.

As a means of applying pressure, it is possible to first press a flat pressure plate directly against the back of the heald, or to arrange multiple pressure rollers on the back of the belt and apply pressure 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 oil is supplied to this sealed space to apply fluid pressure to the belt. A belt that rotates endlessly and moves,
If a pressure transmission mechanism or a sealing mechanism using a magnetic fluid is provided in the sliding part between the pressure plate and the pressure medium seal which are stationary at a fixed position, the magnetic fluid is FiF, has extremely low frictional resistance, and almost no seal leakage. This is preferable because it does not occur.

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 thermosetting 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 and integrated.

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 also be supplied and laminated at the same time.

The long laminates continuously obtained from the double belt press are cut into predetermined dimensions using a cutting device such as a normal cutter while still being heated, and then placed into water. The laminate is then rapidly cooled to complete the production of the laminate. As the quenching means, in addition to the above-mentioned water, other means such as pouring into a cooling tank containing a cooling liquid such as alcohol, or spraying cooling gas such as carbon dioxide gas, etc., can be adopted. In this quenching process, the laminate, which is still easily deformed at the end of the previous cutting process, is rapidly cooled to a temperature that is sufficiently hardened to release residual stress and prevent deformation from external forces. I'll do what I do. The specific cooling temperature and cooling rate are set to appropriate conditions depending on the thickness of the laminate, the material of the fluororesin, etc.

[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 addition, after the belt pressurizes and heats the laminate and it is cut into predetermined dimensions, the laminate, which is still hot and easily deformed, is rapidly cooled to release the residual stress in the laminate and prevent warping. It is rapidly cooled to a sufficiently hardened state without any hardening. After that, even if an external force is applied to the laminate, the laminate will not deform.

Furthermore, since a portion of the fluororesin layer includes a fluororesin film whose bottom shape has been shaped in advance, 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 7o 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 2o 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 10 drawn from D.
The fluororesin film 70 and the metal Ffi 20 are superimposed on each other by a guide roll 30 or the like and are supplied to the double belt press device 40.

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. The fluororesin-impregnated base material 10, the fluororesin film, and the metal foil 20 are supplied in a stacked state between the upper and lower bells) 41 and 41. 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, so that the upper and lower bells 1-41°41 are The sandwiched fluororesin-impregnated base material 10, fluororesin film 70, and metal foil 20 are pressurized via the healds 41 and 41. Further, the double belt press device 40 is connected to the fluororesin-impregnated base material IO and the fluororesin film 70 via the belt 41.
A heating means (not shown) for heating the metal foil 20 is 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 cutter 50 or the like. After cutting it into a predetermined size using a mechanism, it is put into the cooling water tank 60. After the laminate S is cooled to a sufficiently hardened state in the cooling water tank 60, the cooling water tank 60
When the laminate S is taken out, the production of the laminate S is completed. FIG. 2 shows the cross-sectional structure of the laminate S manufactured in this way. The fluororesin-impregnated base material 10, . . . , the fluororesin film 70, the adhesive 21, and the metal foil 20 are sequentially laminated. In the figure, the fluororesin-impregnated base material 10 and the fluororesin film 70 are shown as separate layers, but in reality, they are fused together to form one fluororesin layer.

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

A long glass cloth with a width of 1050 mm and a thickness of 0.1 am was impregnated with tetrafluoroethylene resin (trade name: Polyflon Dispersion, manufactured by Daikin Industries, Ltd.) so that the amount of resin after drying was 45% by weight. , and dried to produce a Brebrig, that is, a fluororesin-impregnated base material 10. Further, as the fluororesin film 70, a tetrafluoroethylene resin film (trade name: Polyflon film, manufactured by Daikin Industries) with a thickness of 0.01+n was prepared.A long prepreg 1
0 and five fluororesin films 70 are stacked alternately so that the fluororesin films 70 are placed on both outer surfaces, and the adhesive-coated copper foils 20 are stacked above and below the fluororesin films 70 to form a double belt. It was supplied to the press device 40. copper foil 20
The thickness of the adhesive 21 was 35 μl. The pressing force of the dub/upper belt press device 40 is 20 kg/cII! The heating temperature was set at 350° C., and as the bleep rig 10 and copper foil 20 ran, they were pressurized and heated for 5 minutes each. The obtained laminate S has a length of 1000 m in the longitudinal direction.
The laminate S is cut into pieces of m each, and is also trimmed in the width direction so that the width is 1000 + n.Then, the laminate S is put into a cooling water tank 60 and rapidly cooled to 60°C.
The production of the laminate S was completed by taking it out from scratch.

In order to compare with the laminate S of the above example, four veneer prepregs cut into 1050+u angle from the same long prebrig 10, and five pieces of fluororesin film 70 cut into a fixed size in the same way were used. , also a single plate of 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/cJ and 350° C. for 5 minutes, the sheets were trimmed and cut to 1000×1000 +n, and rapidly cooled in a cooling water tank 60 to produce an 8 yen laminate of Comparative Example 1. Further, in the above example, after the cutting process, the N-laminated plate of Comparative Example 2 was manufactured by cooling in the atmosphere without performing the quenching process using the cooling water tank 60.

The warpage percentages of the laminates S of the above-mentioned Examples and Comparative Examples were measured and were as shown in Table 1 below.

As a result, it was confirmed that according to the manufacturing method of the present invention, a high quality laminate with a low warpage rate could be manufactured.

[Effects of the Invention] As described above, the laminate according to the present invention! ! According to the coined method, a pair of upper and lower endlessly rotating belts
To efficiently produce a high-quality fluororesin m-layer board with a low warpage rate by laminating a long fluororesin-impregnated substrate, a fluororesin film, and a metal foil by continuously applying pressure and heating. be able to.

In addition, at the stage where the laminated plates laminated by pressure and heating are cut into predetermined dimensions, the laminated plates are still hot and easily deformed. The fluororesin laminate can be cooled to a sufficiently cured state, and a fluororesin laminate with a lower warpage rate and better quality can be obtained.

Furthermore, by forming the fluororesin layer by alternately stacking fluororesin-impregnated substrates and fluororesin films, the resin lamination and curing time can be 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. 10...Fluororesin impregnated base material 2o...Metal foil 4
0...Double belt press device 4■...Held
60... Cooling water tank 70... Fluororesin film
S...Laminated board

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, characterized in that long metal foils are stacked and run while being pressed and heated with a pair of upper and lower belts to integrate the laminate, then cut to a predetermined size, and then rapidly cooled.