JPS6287329A - Manufacture of electrical laminated sheet - Google Patents

Abstract

PURPOSE:To obtain a laminated sheet markedly excellent in moldability by a method wherein tetrafluoroethylene resin and fluoroplastic, the melting point of which is lower and the fluidity of which is better than those of tetrafluoroethylene resin, are used as the resin for the resin layer, with which a base material is impregnated. CONSTITUTION:The predetermined number of sheets of resin-impregnated base material, which is impregnated with fluoroplastic, are laminatingly molded under the state that fluoroplastic layer is interposed between each pair of the sheets of the resin-impregnated base material and further put onto the surfaces of both the outermost sheets of the resin-impregnated base material. As the fluoroplastic, with which the base material is impregnated and which is used in the fluoroplastic layer, tetrafluoroethylene resin and fluoroplastic, the melting point of which is lower and the fluidity of which is better than those of tetrafluoroethylene resin, are employed in the form of mixture of 0.5-100 parts, by weight of the fluoroplastic resin in 100 parts by weight of the tetrafluoroethylene resin.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for manufacturing electrical laminates used in electronic devices and the like.

[Background technology]

Electrical laminates are generally made of resin-impregnated base material (prepreg).
It is made by laminating and molding a predetermined number of sheets together with metal foil if necessary.

[Purpose of the invention]

An object of the present invention is to provide a method for manufacturing an electrical laminate that can produce an electrical laminate with extremely excellent moldability.

[Disclosure of the invention]

The inventor conducted repeated research in an attempt to achieve the above object by improving the conventional manufacturing method. As a result, as the fluororesin to be impregnated into the base material, we used tetrafluoroethylene resin and a fluororesin that has a lower melting point and better fluidity than tetrafluoroethylene resin, and used resin impregnation between the resin-impregnated base materials and the outermost layer. If a fluororesin layer is provided on the outside of the base material, and the resin for the fluororesin layer is polytetrafluoroethylene resin, or a fluororesin with a lower melting point and better fluidity than tetrafluoroethylene resin is used for lamination molding. They discovered that the molding properties were further improved, including excellent moldability, and completed this invention.

Therefore, this invention provides a resin-impregnated base material made by impregnating a fluororesin-based material (4) with a fluororesin layer interposed therebetween, and also provides a fluororesin layer on the outside of both resin-impregnated base materials. A method for manufacturing an electrical laminate in which a predetermined number of sheets are laminated and molded in a manner such that the base material is impregnated with a fluororesin and the resin of the fluororesin layer is a tetrafluoroethylene resin or a tetrafluoroethylene resin. The gist of this paper is a method for manufacturing electrical laminates, which is characterized by using a fluororesin that has a low melting point and good fluidity.

The present invention will be explained in detail below.

Here, "excellent formability" means that there are no unmelted (opaque) parts in appearance and that the plate thickness accuracy is excellent.

Tetrafluoroethylene resin (hereinafter referred to as "PT") used in this invention
Examples of fluororesins that have a lower melting point and better fluidity than ``FE'') include, but are not particularly limited to, tetrafluoroethylene-hexafluoropropylene copolymer resins (hereinafter referred to as ``r'').
FEPJ), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (rPFAJ), polychlorotrifluoroethylene (PCTFF)
.

), polyvinylidene fluoride (PVDF), polyvinyl fluoride (PVF), tetrafluoroethylene-ethylene copolymer (ETFB), chlorotrifluoroethylene-ethylene copolymer (ECTFE), etc. It can be used alone or as a mixture of two or more. Among these, FEP and PFA are preferable because they have properties other than melting point that are close to those of PTFE.

The method for manufacturing an electrical laminate according to the present invention uses a resin-impregnated base material obtained by impregnating a base material with PTFE and a fluororesin having a lower melting point and better fluidity than PTFE. Specifically, such a resin-impregnated base material is, for example, a resin dispersion made by mixing PTFE and a fluororesin having a lower melting point than PTFE and good fluidity, or a PTFE dispersion. P T F E to John
PTFE and P
A resin dispersion made by mixing a fluororesin with a lower melting point than P'rFg and better fluidity than TFE, or a fluororesin with a lower melting point and better fluidity than P'rFg in a PTFFE dispersion. After impregnating the base material with a fluororesin that has a lower melting point and better fluidity than PTR"FE and PTFE, by coating the base material with a mixture of dispersion, etc., the base material is It can be obtained by heating and drying, or by melting (firing) a fluororesin and PTFE, which have a lower melting point and better fluidity than PTFE, but are not limited to these methods.

The fluororesin used in this invention to be impregnated into the base material is not particularly limited as long as it is PTFE or a fluororesin that has lower proof stress and better fluidity than PTFE, but PTF
P for 100 parts by weight (hereinafter abbreviated as "parts") of E
A mixture of 0.5 to 100 parts of a fluororesin having a lower melting point and better fluidity than TFE is preferred. If the proportion is less than the lower limit of the range, the improvement in moldability may not be achieved, and if the proportion is greater than the lower limit, the overall melting point may decrease and heat resistance may deteriorate.

As the base material used in this invention, cloth such as glass cloth, nonwoven paper such as glass nonwoven fabric, and other materials commonly used for manufacturing electrical laminates are used.

A predetermined number of resin-impregnated base materials as described above are stacked one on top of the other with a fluororesin layer interposed between the resin-impregnated base materials, and fluororesin layers are also provided on both outer surfaces of the resin-impregnated base materials. Then, if necessary, a metal foil such as copper foil is overlaid on at least one side of the laminate and laminated to form an electrical laminate.

As the resin for the fluororesin layer used in this invention, PTI
A fluororesin having a lower melting point and better fluidity than PTFE and PTFE is used, and when looking at the fluororesin layer individually, either one or both of them are used (or a mixture of the two is used). (or both may be bonded to each other in separate layers.), ] Both of these may be used in an electrical laminate as a whole. Note that the fluororesin layer can be formed by coating or the like, but it is preferably used in the form of a film (fluorine-based film) or the like. Phil J.
This is because it is easier to adjust the thickness of the fluororesin layer if it is used in this form. The film is made using a cutting method.

It can be prepared and used by the calendar method 7 casting method, etc., or a commercially available product can be used. When using a film, the number of films made of a fluororesin that has a lower melting point and better fluidity than I) T F F depends on the thickness of the film and the number of resin-impregnated base materials used.
It is effective within the range of 1 or more - 1 = the number of resin-impregnated substrates. I) TFE If the number of films made of fluororesin having a lower melting point and better fluidity than E is used, it may be installed at any position, but if moldability is important, The closer to the surface of the electrical laminate the film made of fluororesin, which has a lower melting point and better fluidity than PTFE, is provided, the greater the effect. For example, a film made of a fluororesin, which has a lower melting point and better fluidity than PTFE, is placed outside the resin-impregnated base material on both outer surfaces and/or between the resin-impregnated base material and the resin-impregnated base material immediately inside the resin-impregnated base material ( If only two resin-impregnated substrates are used, it is preferable to provide the resin-impregnated substrate between them, but the invention is not limited thereto.

The conditions for lamination molding are not particularly limited, but the temperature is 340 to 4
00℃, pressure 1-100kg/aJ, time 10-180
Minutes are preferred.

According to the method for manufacturing an electrical laminate of the present invention, the resin-impregnated base material as described above is used, the fluororesin layer as described above is interposed between the resin-impregnated base materials, and the resin-impregnated base materials on both outer surfaces are used. Since the above-mentioned fluororesin layer is also provided on the outside of the material for laminated molding, there are no unmelted and opaque parts, and the thickness accuracy has been improved, in other words, the moldability is extremely high. An excellent electrical laminate can be obtained. The obtained electrical laminate has good punching workability.

Other properties such as moisture resistance, heat resistance, and electrical properties are also improved.

Next, Examples and Comparative Examples will be shown.

(Example 1) A glass cloth (Nitto Boseki @ WE 05 F) was impregnated with fluororesin mixed in the proportions shown in Table 1 and then fired to obtain a resin with a resin content of 60%, W, and 0.061 mm. A resin-impregnated base material was created. Using this resin-impregnated base material, the first
As shown in the figure, one film (thickness: 0.030 + u) made of PTFE is interposed between the resin-impregnated base material 1, and PTF is placed on the outside of the resin-impregnated base material 1 on both outer surfaces.
10 sheets of the resin-impregnated base material 1 were prepared by providing one film 3 made of R and one film 2 made of PFA (thickness 0.0251-) on the outside thereof.
Two films 2 made of P FA, 11 films 3 made of P T F E, and 114 foil (thickness 0
．． 018 Dragon) 4 stacked on top of each other and heated to 360"C.
, a pressure of 20 kg/cd and a time of 30 minutes to produce an electrical laminate.

(Example 2) A glass cloth (Nitto Boseki @ WE 05 F) was impregnated with fluororesin mixed in the ratio shown in Table 1, and then fired to obtain a resin-impregnated cloth with a resin content of 50% and a thickness of 1.05 mm. A base material was made.Using this resin-impregnated base material, as shown in Fig. 2, a film (thickness 0.0301*) 3 made of PTFF was interposed between each resin-impregnated base material 1, and , PFA is applied to the outside of the resin-impregnated base material 1 on the inside and outside surfaces.
One film (thickness: 0.025 mm) 2 made of PTFE is provided, and one film 3 made of P T F E is provided on the outside of the film 2.
0 sheets, 2 sheets of film 2 made of PFA, 11 sheets of film 3 made of PTFE, and copper foil (thickness 0.01
81) Stack two sheets of 4 and heat to 360℃.

Laminate molding under the conditions of a pressure of 20 kg/cJ and a time of 30 minutes,
We made electrical laminates.

(Example 3) Glass cloth (Nitto Boseki WE 05 B) was impregnated with fluororesin mixed in the proportions shown in Table 1, and then fired.
Resin: A resin-impregnated base material with 50% resin content and a thickness of 0.05 mm was prepared. Using this resin-impregnated base material, as shown in FIG. 3, a film made of PFA (with a thickness of 0
．． A film made of PTFE (thickness 0
．． 030 Tsuru) 3 was interposed one by one, and P T F I? on the outside of the resin-impregnated base material l on both sides. , 10 sheets of resin-impregnated base material 1, 2 sheets of film 2 of PFA, PT
9 sheets of FE film J, 3 and 2 sheets of copper foil (thickness 0.018 m5) 4 were stacked at a temperature of 360
℃, a pressure of 29 kg/cJ, and a time of 30 minutes to produce an electrical laminate.

(Comparative example) As shown in Table 1, a glass cloth ([1 Tobo @ wEo 5E) was impregnated with a fluororesin containing only PTFF, and then fired, resulting in a resin content of 60% and a thickness of 0.06 mm.
A resin-impregnated base material was prepared. Using this resin gold-immersed base material,
As shown in FIG. 4, instead of using a film made of PFA, a film made of PTFE (
Ten resin-impregnated base materials 1 were prepared by interposing one film 3 having a thickness of 0.0301 mm) and also providing one film 3 made of PTFE on the outside of the resin-impregnated base material 1 on the inner and outer surfaces. Eleven films 3 made of PTFE and two sheets of copper foil (thickness 0.018 mm) 4 were stacked together at a temperature of 370°C and a pressure of 'l Q kg/cl.
Laminate molding was carried out under conditions of a2 hours and 50 minutes to produce an electrical laminate.

2. Each of the electrical laminates obtained in the above Examples and Comparative Examples was tested for the unmelted ratio, thickness accuracy, formability, moisture resistance,
Insulation resistance, heat resistance and punching workability were investigated, and the results were evaluated first.
It is also shown in the table. The electrical properties are represented by Insulation II (resistance).The unmelted ratio is the approximate area ratio [%] with the semi-transparent part as the unmelted part, excluding the copper foil on both sides of each electrical laminate after molding. The plate thickness accuracy was determined when each electrical laminated plate 5 was made with a thickness of 0.8 mm.
The variation in plate thickness for each piece is shown in millimeters. Moisture resistance was examined at 90° C. and 65% RH for 96 hours. The processing conditions before measuring insulation resistance were D-2/100. Heat resistance was determined by keeping the product in an oven for 30 minutes and showing the temperature at which no abnormality occurred and the temperature at which abnormality occurred at 10°C intervals.

As shown in Table 1, the electrical laminates obtained in Examples 1 to 3 had an unmelted ratio of 0%, whereas those of the comparative examples had an unmelted ratio of 10% to 95%. Moreover, the plate thickness accuracy is improved compared to that of the comparative example. That is, the moldability is very excellent. The electrical laminates obtained in Examples 1 to 3 also have improved moisture resistance, insulation resistance, heat resistance, and punching workability compared to those of comparative examples.

〔Effect of the invention〕

As described above, the method for producing an electrical laminate of the present invention includes a fluororesin impregnated with a group H, a resin-impregnated base material interposed between the resin-impregnated base materials, and a resin-impregnated base material on both sides. As the fluororesin of the fluororesin layer provided on the outside of I)
T F E and I) Since a fluororesin with a lower melting point and better fluidity than T F R is used, this manufacturing method eliminates any unmelted and opaque parts, and improves plate thickness accuracy. It is possible to obtain an electrical laminate having a l-. The obtained electrical laminates have improved punching workability, moisture resistance, heat resistance, Length, and electrical properties in addition to their formability.

[Brief explanation of drawings]

Figures 1 to 3 are side views schematically showing the configuration when making an electrical laminate in an example, and Figure 4 is a schematic side view showing the configuration when making an electrical laminate in a comparative example. FIG. 1...Resin-impregnated base material 2...Film made of PFA 3...Film made of PTFE Agent Patent attorney Takehiko Matsumoto G

Claims (5)

[Claims] (1) A resin-impregnated base material obtained by impregnating a base material with a fluororesin, with a fluororesin layer interposed between them, and a fluororesin layer also provided on the outside of the resin-impregnated base material on both outer surfaces, in a predetermined number of sheets. A method for manufacturing an electrical laminate by lamination molding, wherein the fluororesin impregnated into the base material and the resin of the fluororesin layer have a lower melting point and fluidity than the tetrafluoroethylene resin and the tetrafluoroethylene resin. A manufacturing method for electrical laminates characterized by using a high-quality fluororesin. (2) As the fluororesin to be impregnated into the base material, 0.00 parts of a fluororesin, which has a lower melting point and better fluidity than the tetrafluoroethylene resin, is added to 100 parts by weight of the tetrafluoroethylene resin.
A method for producing an electrical laminate according to claim 1, using a mixture of 5 to 100 parts by weight. (3) Claims 1 or 2 in which the fluororesin layer comprises a film made of a tetrafluoroethylene resin and a film made of a fluororesin that has a lower melting point and better fluidity than the tetrafluoroethylene resin. The method for manufacturing the electrical laminate described. (4) A film made of a fluororesin that has a lower melting point and better fluidity than tetrafluoroethylene resin is applied to the outside of the resin-impregnated base material on both outer surfaces, or to the resin-impregnated base material and the resin-impregnated base material immediately inside it. Claim 3 provided between
Method for manufacturing electrical laminates as described in Section 1. (5) Fluororesins with a lower melting point and better fluidity than tetrafluoroethylene resins are a group consisting of tetrafluoroethylene-hexafluoropropylene copolymer resins and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resins. Claim 1 which is at least one kind selected from
A method for producing an electrical laminate according to any one of items 1 to 4.