JP2000015747A - Fluororesin laminated base - Google Patents

Abstract

PROBLEM TO BE SOLVED: To form a plated layer without the necessity to perform an etching treatment and enhance the economy and the productivity and further avoid the deterioration of electric insulating properties by filling a fluororesin with a hydrophilic solid inorganic matter weighing within a specific range to the weight of the fluororesin. SOLUTION: Fluororesin layers 12a, 12b are formed on both faces of a glass cloth 11 by impregnating the glass cloth 11 with the fluororesin layers 12a, 12b and baking the layers 12, 12b. That is, not only the fluororesin layers 12a, 12b are formed on both faces of the glass cloth 11 but also the glass cloth 11 is impregnated with part of the fluororesin layers 12a, 12b. In this case, each of the fluororesin layers 12a, 12b is filled with fluororesin and silica as a hydrophilic solid inorganic matter. That is, the blended content of the silica is 5-100 pts.wt. to 100 pts.wt. entire fluororesin contained in the fluororesin layers 12a, 12b. Thus a prepreg sheet 13 comprising the glass cloth 11 and the fluororesin layers 12a, 12b is constituted. The prepreg sheet 13 is, for example, of a five-layer laminate 14, on both faces of which copper foilds 15a, 15b are applied.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a fluororesin laminated substrate used for a copper-clad laminate.

[0002]

2. Description of the Related Art As is well known, fluororesin laminates used for electronic communication equipment have excellent high-frequency characteristics, heat resistance, weather resistance, chemical resistance, and water repellency, and are used for satellite broadcasting receivers, mobile phones, and the like. It is widely used in the technical fields. The fluororesin laminate is manufactured, for example, by laminating a plurality of prepregs repeatedly impregnated and fired with PTFE in a glass fiber cloth, laminating a copper foil on the outermost surface layer, performing a heat press, and performing thermal fusion. You.

[0003]

However, since the fluororesin has water repellency, the plating solution is not the exception, and the plating layer is made of the fluororesin laminate 1 as shown in FIG.
Does not adhere to the fluorine resin layer on the inner wall of the terminal fixing through hole 2 opened in the above. That is, fluorine (F) is exposed on the inner wall surface of the through hole 2, and this alienates formation of the plating layer.

Therefore, conventionally, after drilling holes, the inner wall of the through hole is treated with an etching solution in which metallic sodium is dissolved in tetrahydrafuran, and "etching treatment" for replacing fluorine on the surface with hydroxyl groups or the like is performed to eliminate water repellency. After plating, it is common practice to use a plating process (N
a and F react to break the connection between carbon C and fluorine).

However, since this etching process uses metallic sodium, there is a high risk of ignition (explosion) if it comes into contact with water accidentally, and it is necessary to pay close attention to handling and storage locations. In addition, since a large amount of organic solvent is used, there is a high risk of harm to the health due to inhalation by workers, and there are many problems such as post-treatment of used processing solutions. I was Further, there are problems that the above-mentioned steps are additionally required for imparting hydrophilicity to the fluororesin laminate, that the disposal of the treatment liquid is expensive, and that the productivity is low.

Japanese Unexamined Patent Publication (Kokai) No. 4-70310 has been known as a method for producing a prepreg for a fluorine-fluorine resin laminate, but in order to obtain a plating catalytic filler, plating is performed on aluminum potassium silicate. There is a problem that productivity is inferior because the number of steps for adsorbing a catalyst (palladium ion) is increased as compared with the present invention.

The present invention has been made in view of such circumstances, and a hydrophilic solid inorganic substance is added to a fluororesin.
By using a configuration in which 5 to 100 parts by weight is charged with respect to parts by weight, it is possible to form a plating layer without performing an etching process using metallic sodium as in the conventional case, and is excellent in economical efficiency and productivity. An object is to provide a laminated substrate.

The present invention also relates to a fluororesin base material layer in which one or both surfaces of a heat-resistant fiber cloth are impregnated with a fluororesin, and a hydrophilic solid inorganic substance provided on one or both surfaces of the fluororesin base material layer. 5 to 100 parts by weight of resin
By using a structure including a prepreg sheet formed by sintering a laminate with an inorganic impregnated layer filled by weight and a copper foil laminated on the prepreg sheet, an etching treatment using metallic sodium as in the related art is performed. An object of the present invention is to provide a fluorine resin laminated substrate which can form a plating layer without performing the method, is excellent in economy and productivity, and can avoid a decrease in electric insulation.

[0009]

Means for Solving the Problems The first invention of the present application is directed to a fluororesin laminated substrate in which a prepreg sheet formed by impregnating and firing a fluororesin on one or both sides of a heat-resistant fiber cloth and a copper foil are laminated. A fluorine resin laminated substrate characterized in that a fluorine resin is filled with a hydrophilic solid inorganic substance in an amount of 5 to 100 parts by weight based on 100 parts by weight of the fluorine resin.

The second invention of the present application is directed to a fluororesin substrate layer in which one or both surfaces of a heat-resistant fiber cloth are impregnated with a fluororesin, and a hydrophilic solid inorganic substance provided on one or both surfaces of the fluororesin substrate layer. 5 to 10 per 100 parts by weight of fluororesin
A fluororesin laminate substrate comprising: a prepreg sheet formed by firing a laminate of an inorganic impregnated layer filled with 0 parts by weight; and a copper foil laminated on the prepreg sheet.

In the present invention, examples of the hydrophilic solid inorganic substance include silica (SiO ₂ ) and titania (TiO ₂ ).
₂ ), alumina (Al ₂ O ₃ ), potassium titanate (K
₂ O · 6TiO _2), include barium oxide (BaO) is. Among them, silica is most preferable in terms of cost and hydrophilicity.

In the present invention, the hydrophilic solid inorganic substance is charged in an amount of 5 to 100 parts by weight based on 100 parts by weight of the fluororesin, and more preferably in the range of 10 to 50 parts by weight. If the amount of the hydrophilic solid inorganic substance is less than 5 parts by weight, the hydrophilicity is not sufficient, and there is a problem that plating is difficult in a plating step for making the fluororesin laminate substrate according to the present invention into a printed circuit board. On the other hand, when the amount of the hydrophilic solid inorganic substance exceeds 100 parts by weight, there is a problem that the characteristics (electrical characteristics, strength, etc.) of the fluororesin are not sufficient.

In the present invention, the fluorine resin includes:
For example, ethylene tetrafluoride resin (PTFE), ethylene tetrafluoride-propylene hexafluoride copolymer resin (PFEP),
Either one of ethylene tetrafluoroalkyl vinyl ether copolymer resins (PFA) or a mixed composition thereof may be used.

In the present invention, examples of the heat-resistant fiber cloth include glass fiber cloth and aromatic polyamide fiber cloth. [Operation] In the present invention, the filling of the fluororesin dispersion with a hydrophilic solid inorganic substance such as silica is carried out by placing the fluororesin dispersion in a container, setting it in a stirrer, adding a predetermined amount of the silica dispersion liquid thereto, and adding After the addition, stirring is continued for about one hour.

On the other hand, coating of a heat-resistant fiber cloth on a glass cloth or the like with a silica-filled fluorine resin dispersion is performed as follows. First, a glass cloth was immersed in a silica-filled fluororesin dispersion, and then lifted up for 1 hour.
After passing through an electric furnace at 00 to 200 ° C. for about 5 minutes to dry the water, and further passing through an electric furnace at 280 to 310 ° C. for about 5 minutes to remove impurities such as surfactants,
Firing in an electric furnace at a temperature of about 5 minutes for firing. This process is repeated a plurality of times until the content of the resin layer reaches the required amount (the same applies to unfilled dispersions).

[0016]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a fluorine resin laminated substrate according to an embodiment of the present invention. Embodiment 1 Referring to FIG. In FIG. 1, only one prepreg sheet is shown for convenience. Reference numeral 11 in the drawing denotes a glass cloth (JIS standard EP10) as a heat-resistant fiber cloth. On both surfaces of the glass cloth 11, fluorine resin layers 12a and 12b are provided by impregnating and firing the glass cloth 11. In other words, the fluorine resin layers 12a and 12b are formed not only on both sides of the glass cloth 11, but also partially in the glass cloth 11. Here, the fluorine resin layers 12a and 12b are filled with a fluorine resin and silica (not shown) as a hydrophilic solid inorganic substance, respectively. This silica is, as shown in Table 1 below,
10 parts by weight are filled with respect to 100 parts by weight of the fluorine resin. The glass cloth 11 and the fluorine resin layers 12a, 12b
A prepreg sheet 13 is formed. For example, copper foils 15a and 15b having a thickness of 18 μm are provided on both sides of a laminated body 14 in which five prepreg sheets 13 are laminated.

[0017]

[Table 1]

The fluorine resin laminated substrate according to the first embodiment is
It is manufactured as follows. First, on both surfaces of a glass cloth 11, copper foils 15a and 15b are formed on and under a laminated body 14 composed of, for example, five prepreg sheets 13 repeatedly impregnated with and baked with fluorine resin layers 12a and 12b filled with silica. Subsequently, the base material 16 thus obtained is disposed and laminated between three stainless steel plates 17 having a thickness of 1 mm as shown in FIG. Further, in this state, the heat-resistant cushioning material 18
Between the 3 mm-thick stainless steel plates 19a and 19b through a press set at 390 ° C.
It is held for about 30 minutes at kgf / cm ² and then cooled to obtain a fluorine resin laminated substrate.

According to the first embodiment, since the glass cloth 11 is provided on both surfaces with the fluorine resin layers 12a and 12b filled with 10 parts by weight of silica with respect to 100 parts by weight of the fluorine resin. A plating layer can be formed without performing an etching process using metallic sodium as in the related art. Further, since there is no treatment step using metallic sodium, there are advantages of low cost, excellent productivity, and excellent operator safety.

In fact, the electrical properties and the plating properties according to Example 1 are as shown in Table 1 above. However, in Table 1, the dielectric loss tangent must be 0.007 or less in a 5 GHz band. If it is larger than this, the circuit loss becomes large and it cannot be used as a high frequency substrate. The insulation resistance after boiling is 1
Greater than or equal to 0 ^{8 Ω} is essential. If it is lower than this, insulation reliability in a high humidity environment cannot be maintained. The symbol “性 の” of the plating adhesion means that the plating adheres to the entire surface of the through-hole portion in a normal plating step (base treatment, electroless plating, electrolytic plating). “O” of the plating adhesion means that a strength that does not easily peel off in the adhesive tape peeling test is obtained.

Examples 2 to 5 In each of Examples 2 to 5, except that the proportions of silica and titania as hydrophilic solid inorganic substances in the fluorine resin layer were as shown in Table 1 above. Has a configuration similar to that of the first embodiment.

(Embodiment 6) Referring to FIG. In FIG. 3, on both sides of a glass cloth 11 as a heat-resistant fiber cloth,
Fluororesin layers 21a and 21b are provided by impregnating and firing the glass cloth 11. Also in this case, similar to the first embodiment,
The fluororesin layers 12a and 12b are not only formed on both sides of the glass cloth 11, but also partially impregnated in the glass cloth 11. Here, the fluorine resin layer 21a,
Each of 21b is not filled with a hydrophilic solid inorganic substance. Fluororesin layers 23a and 23b filled with silica as a hydrophilic solid inorganic substance are formed on both sides of the fluororesin base layer 22 composed of the glass cloth 11 and the fluororesin layers 21a and 21b. Here, the blending amount of silica is 20 parts by weight with respect to 100 parts by weight of all the fluorine resin contained in the fluorine resin layers 21a and 21b and the fluorine resin layers 23a and 23b filled with silica. Further, five laminates 24 each composed of such a fluorine resin base material layer 22 and a fluorine resin layer 23a, 23b filled with an inorganic substance are laminated, and copper foils 15a, 15b having a thickness of 18 μm are provided on both surfaces thereof.

According to the sixth embodiment, the adhesion between the glass cloth 11 and the resin layer can be improved as compared with the first to fifth embodiments. That is, when the hydrophilic solid inorganic material is filled in the resin layer in contact with the glass cloth 11 as in Examples 1 to 5, the permeability of the fluorine resin between the glass fibers is inferior. Although there is a possibility that the adhesiveness may decrease or the water absorption may increase, when the resin layer in contact with the glass cloth does not contain a hydrophilic solid inorganic substance as in Example 6, the adhesiveness increases as compared with Examples 1 to 1. . Therefore, in the case of Example 6,
The insulation resistance tends to increase and the dielectric loss tangent tends to decrease.

In the above embodiment, the number of prepreg sheets constituting the laminated substrate, the material and thickness of other components, and the like are merely examples, and are not limited thereto.

(Comparative Examples 1 to 3)
Except that the mixing ratio of silica as the hydrophilic solid inorganic substance in the fluororesin is as shown in Table 1, the configuration is the same as that of Example 1.

[0026]

As described above in detail, according to the present invention, the fluororesin is filled with 5-100 parts by weight of a hydrophilic solid inorganic substance per 100 parts by weight of the fluorine resin.
It is possible to provide a fluorine resin laminated substrate which can form a plating layer without performing an etching process using metallic sodium as in the related art, and is excellent in economic efficiency and productivity.

According to the present invention, there is also provided a fluororesin substrate layer impregnated with a fluororesin on one or both sides of a heat-resistant fiber cloth, and a hydrophilic solid inorganic material provided on one or both sides of the fluororesin substrate layer. A prepreg sheet obtained by firing a laminate of an inorganic material-filled layer filled with 5 to 100 parts by weight with respect to 100 parts by weight of a fluororesin, and a copper foil laminated on the prepreg sheet. ,
It is possible to provide a fluorine resin laminated substrate that can form a plating layer without performing an etching process using metallic sodium as in the related art, is excellent in economy and productivity, and can avoid a decrease in electrical insulation.

[Brief description of the drawings]

FIG. 1 is a sectional view of a fluororesin laminate substrate according to a first embodiment of the present invention.

FIG. 2 is an explanatory diagram of a use state of a mold when manufacturing the fluororesin laminated substrate according to the first embodiment.

FIG. 3 is a sectional view of a fluorine resin laminated substrate according to a sixth embodiment of the present invention.

FIG. 4 is a view for explaining a problem of a conventional fluorine resin laminated substrate.

[Explanation of symbols]

11: glass cloth (heat-resistant fiber cloth), 12a, 12b, 23a, 23b: fluorine resin layer filled with silica, 13, 24: prepreg sheet, 14: laminate, 15a, 15b: copper foil, 17, 19a, 19b: stainless steel plate, 18: heat-resistant cushion material, 21a, 21b: fluorine resin layer, 22: fluorine resin base layer.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C08L 27/12 C08L 27/12 H05K 1/03 610 H05K 1/03 610R (72) Inventor Reiji Hara Nagasaki 200, Hirao, Izumi, Izumi, Chora-cho, Matsuura-shi Chuo Kasei Kogyo Co., Ltd. (72) Inventor Keiji Kawamoto, 200, Hirao, Izumi, Hirao-cho, Matsukawa, Matsuura, Nagasaki Pref. 4F100 AA01B AA01C AA01H AA18B AA18C AA18H AA19B AA19C AA19H AA20B AA20C AA20H AA21B AAAB AAB AAB AB17A AB AB17 BA05 BA06 BA07 BA10A BA10D BA10E BA13 CA23B CA23C DG11A DG12 DH01 EJ48B EJ48C EJ82B EJ82C GB43 JB05B JB05C JB05H JG 04 JJ03A JL01 YY00B YY00C YY00H 4J002 BD151 DE096 DE136 DE146 DE186 DJ016 FD016 GF00 GQ01

Claims (3)

[Claims] 1. A fluororesin laminated substrate in which a prepreg sheet obtained by impregnating and baking a fluororesin on one or both sides of a heat-resistant fiber cloth and a copper foil are laminated on a fluororesin. 5 to 1 parts by weight
A fluorine resin laminated substrate filled with 00 parts by weight. 2. A fluororesin base material layer in which one or both sides of a heat-resistant fiber cloth are impregnated with a fluororesin, and a hydrophilic solid inorganic substance provided on one or both sides of the fluororesin base material layer and containing 100 parts by weight of the fluororesin. 1. A fluorine resin laminated substrate, comprising: a prepreg sheet obtained by firing a laminate of an inorganic impregnated layer filled with 5 to 100 parts by weight of the prepreg sheet; and a copper foil laminated on the prepreg sheet. 3. The fluororesin laminate substrate according to claim 1, wherein the hydrophilic solid inorganic substance is any one of silica, titania, alumina, potassium titanate, and barium oxide.