JPS5917669B2 - laminate board - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION -5 The present invention relates to a laminate having excellent flexibility, heat resistance, bending resistance, electrical insulation and adhesive properties.

Conventionally, flexible printed wiring boards have been made by bonding and integrating copper foil onto a polyester film or polyimide J0 film, or by bonding and integrating glass cloth and copper foil using an epoxy resin with excellent flexibility. It has been known.

However, a board made by bonding and integrating a polyester film and a copper foil has poor heat resistance; therefore, processing such as solder bath welding, which is the most effective method for connecting terminals, causes polyester to break due to heat. Because of this, when connecting terminals, methods such as careful welding with manual soldering or methods that apply mechanical force are used; This process requires a great deal of effort, and connections made in this way have the disadvantages of low reliability and high cost.
In addition, polyimide film that is made by bonding and integrating copper foil has a weak adhesive strength, and poly-15imide film is very expensive, so its uses are limited. A product made by bonding and integrating a glass cloth and a copper foil using resin has a disadvantage in that it has poor flexibility and bending resistance, and cannot satisfy the function of a flexible printed wiring board. This invention eliminates the above-mentioned conventional drawbacks.
In particular, the purpose is to provide a positive board that is suitable for flexible printed wiring boards. It is formed by laminating and integrating an inorganic fiber impregnated or coated with an organopolysiloxane composition consisting of a filler and platinum or a platinum compound, and a metal foil.

Next, to explain the present invention in more detail, various alkenyl group-containing diorganopolysiloxanes used in the present invention can be used as long as each molecule has an alkenyl group directly bonded to a silicon atom. However, in the present invention, in particular, (where RI represents a substituted or unsubstituted monovalent hydrocarbon group, R2 represents a hydroxyl group or a monovalent hydrocarbon group of the same or different kind, and m represents a positive integer)
0.000 of all organic groups directly bonded to silicon atoms
A diorganopolysiloxane in which 5 to 5 mol% is an alkenyl group and has a viscosity at 25°C of 1,000,000 centistotas or more and the general formula (wherein, R3 has the same meaning as R4 described above, R4 has the same meaning as R2 described above.

n represents a positive integer), 0.01 to 15 mol% of all organic groups directly bonded to silicon atoms are alkenyl groups, and the viscosity at 25°C is 100,000 centistokes or less. Preferably, an organopolysiloxane mixture consisting of an organopolysiloxane having the above general formula (
In the diorganopolysiloxane represented by 1), it is essential that 0,0005 to 5 mol%, preferably 0.005 to 3 mol% of the total organic groups directly bonded to silicon atoms be alkenyl groups such as vinyl groups. The viscosity at 25° C. is 1,000,000 centistokes or more, preferably in the range of 3,000,000 to 8,000,000 centistokes. In this diorganopolysiloxane, if the ratio of alkenyl groups to the total organic groups bonded to silicon atoms is less than 0.0005 mol%, the crosslinking density will be small and the resulting cured film will have poor mechanical strength. % or more, adhesiveness decreases and the resulting film has too high a crosslinking density, resulting in a hard and brittle film with poor flexibility. In addition, the above general formula (
In the diorganopolysiloxane represented by ), 0.01 to 15 mol%, preferably 0.1 to 5 mol% of the total organic groups directly bonded to silicon atoms are alkenyl groups such as vinyl groups. 6
In addition, the viscosity at 25° C. is preferably 100,000 centistokes or less, preferably 100 to 50,000 centistokes, and if the alkenyl group content is outside the above range, the purpose cannot be achieved for the same reason as above. Can not do it.

The mixing ratio of the above-mentioned organopolysiloxane is 95% of the diorganopolysiloxane represented by the above-mentioned general formula (1).
~50% by weight, preferably 90-60% by weight,
Diorganopolysiloxane 5 represented by the above general formula ()
-50% by weight, preferably 10-40% by weight, but this means that if the proportion of the diorganopolysiloxane represented by the general formula (1) exceeds 95% by weight,
If the composition exceeds 50% by weight, the composition will have poor wettability to the metal foil, and its adhesion and enclosing properties will decrease.On the other hand, if the composition exceeds 50% by weight, the wettability to the metal foil will improve, but the mechanical strength, especially the cohesive force, will deteriorate. As a result, cohesive failure occurs at the adhesive interface, resulting in significantly poor adhesive strength.

Furthermore, the organohydrodiene polysiloxane in the organopolysiloxane composition used in the present invention is 1
At least 2 hydrogen atoms directly bonded to silicon atoms in the molecule
There are no particular limitations on the structure of the polysiloxane, and therefore any conventionally known organohydrodiene polysiloxane with a linear, branched, or cyclic structure may be used. can also be used. The amount of the organohydrodiene polysiloxane used is preferably 1.2 to 6 hydrogen atoms directly bonded to a silicon atom per alkenyl group directly bonded to a silicon atom in the alkenyl group-containing organopolysiloxane.
If the amount is less than 1.2, the composition of the present invention will not cure well, resulting in decreased mechanical strength and extremely poor adhesive strength. Also 6
Even when the number of particles exceeds 1, it is not possible to perform a good curing, resulting in a decrease in adhesive strength.

The viscosity of this organohydrodiene polysiloxane does not need to be particularly limited as long as it has fluidity, but when considering workability etc., the viscosity at 25 ° C.
It is preferably 0 centistokes or less.

Specific examples of such organohydrodiene polysiloxanes include the following.

Furthermore, as the inorganic filler in the organopolysiloxane composition used in the present invention, specifically reinforcing fillers such as dry silica, wet silica, and silane-treated silica whose surface is treated with trichloromethylsilane etc. , zirconium silicate, glass fiber powder, aluminum silicate, diatomaceous earth, zinc oxide, zinc carbonate, etc. are added to provide flame retardant properties.
Talking about the specific surface area of 100
It is preferable to use dry silica of about 300 i/9, and two or more of these may be used in combination.

The amount of the inorganic filler used is in the range of 10 to 200 parts by weight, preferably 20 to 100 parts by weight, based on 100 parts by weight of the total amount of the alkenyl group-containing diorganopolysiloxane and organohydrodiene polysiloxane.

If it is less than 10 parts by weight, the composition will have poor adhesive properties, and the mechanical strength of the cured product will decrease;
This is because if the amount exceeds 0 parts by weight, the adhesiveness will be poor.

Furthermore, the platinum or platinum compound in the organopolysiloxane composition used in the present invention is one that is conventionally known as a catalyst for the addition reaction between a vinyl group-containing organopolysiloxane and an organohydrodiene polysiloxane. Common examples include chloroplatinic acid, alcohol-modified chloroplatinic acid, a complex of chloroplatinic acid and olefin, and solid platinum supported on a carrier such as platinum black, alumina, or silica.

The amount used is a catalytic amount, that is, usually 5 to 40% platinum based on the alkenyl group-containing diorganopolysiloxane.
Although ppm is sufficient, it is desirable to increase or decrease the amount as appropriate depending on the desired curing speed. The organopolysiloxane composition used in the present invention is produced by kneading the above-mentioned components using a roll kneader, Penn shell mixer, Banbury mixer, etc., but there is no particular restriction on the order of mixing these components.

However, since the composition may harden due to the action of the platinum compound during heating and kneading, it is advantageous to add the platinum compound last. At this time, if necessary, conventionally known platinum compound activity inhibitors such as organic phosphorus compounds, halocarbons, acetylene compounds, sulfoxide compounds, etc. may be added at the same time. Examples of metal foils that can be used in the present invention include copper, aluminum, and plated iron plates, and examples of inorganic fibrous materials include glass fibers, glass cloth, and asbestos cloth.

In order to obtain the laminate of the present invention, for example, the above-mentioned organopolysiloxane composition is diluted with an organic solvent as necessary to adjust the viscosity suitable for use, and the inorganic fibrous material is impregnated with this. After that, overlap it with metal foil,
Then, the metal foil and the inorganic fibrous material are overlapped in advance, and the organopolysiloxane composition is uniformly applied to the fibrous material.
Then, a method such as laminating and integrating in the same manner as above may be adopted, and the pressure in this case is 0.21<g/
The heating temperature should be at least CflL, and the heating temperature should be approximately 100~100℃.
It is said to be around 180°C.

Examples of the above-mentioned organic solvents include aliphatic or aromatic hydrocarbon solvents such as toluene, xylene, and mineral turbene, but these organic solvents may also be supplemented with up to an equal amount of ethanol, isopropyl alcohol, ethyl acetate-methyl ethyl ketone, Mixtures of hydrophilic organic solvents such as acetone, ethylene glycol monomethyl ether, and ethylene glycol monoethyl ether can also be used, and when these mixed solvents are used, wetting of the metal is particularly good, resulting in stable and uniform wetting. It is possible to obtain strong adhesive strength.

In addition, when laminating and integrating the metal foil and the inorganic fibrous material, the metal surface may be treated in advance with a conventionally known primer, which can further improve adhesion. Examples of this primer include those having a coupling effect mainly composed of aminosilane, vinylsilane, epoxysilane, or alkyl titanates.

The laminate according to the present invention has adhesive strength sufficient for practical use, is highly flexible, has heat resistance, bending resistance,
It has excellent electrical insulation properties, and even if this laminate is left in an atmosphere of 50°C and 90% relative humidity for 2 months or 105°C and relative humidity of 900% for 2 months, no decrease in adhesive strength will be observed. It has excellent adhesive strength.

Furthermore, this laminate is printed with a resist ink that is resistant to etching liquids and has poor alkali resistance, and then etched with a commonly used etching liquid containing ferric chloride as the main ingredient, and etched with 5% water. After washing off the resist ink with an aqueous sodium oxide solution, thoroughly rinsing with water, and drying, the adhesive strength, electrical insulation properties, etc. do not deteriorate at all, and the product maintains excellent performance in practical use. Because it allows easy formation of printed wiring and has excellent heat resistance,
It has good solder bath resistance, with almost no change in performance such as adhesive strength or electrical insulation even when heated at 300°C for 30 minutes, making it extremely easy and reliable to attach parts. It has advantages and is particularly suitable for flexible printed circuit boards. Example viscosity is 4,000,00
0 centistokes, 0,004 mol% of all organic groups directly bonded to silicon atoms are vinyl groups, and both ends of the molecular chain are capped with dimethylvinylsilyl groups. 10,000
mixed with vinyl group-containing dimethylpolysiloxane 4009, which is centistokes, 0.174 mol% of all organic groups directly connected to silicon atoms are vinyl groups, and both ends of the molecular chain are blocked with dimethylvinylsilyl groups, To this, dry silica fine powder (trade name Aerosil A-300; Nippon Aerosil Co., Ltd.) 5009 and dimethyldimethoxysilane 109 were added.
was added and heated to 180°C while mixing with a roller, kneaded at the same temperature for about 3 hours, cooled, further kneaded with a roller, and then mixed with xylene 15009.
and isopropyl alcohol 8509.

After adding chloroplatinic acid in an amount of 12 ppm based on the weight of platinum, methylhydrodiene polysiloxane (the amount of hydrogen gas generated in the presence of potassium hydroxide is 350 m1/9, 00 C, 1 atm, )
A 120 μm thick glass cloth (manufactured by Nitto Boseki Co., Ltd., WE-12-104) 100 μm was prepared by adding an amount such that the amount of hydrogen atoms per vinyl group was 1.5.
Impregnated so that the non-volatile content becomes 150 parts by weight,
Next, the copper foils were stacked and heated and pressed at a pressure of 0.21<9/Cdl temperature of 150° C. for 15 minutes to integrate the laminated layers to obtain a flexible printed wiring board having a total thickness of 240 μm.

When this product was examined for adhesive strength between copper foil and glass cloth, bending resistance, volume resistivity, surface resistance, and solder bath resistance, the results shown in the table below were obtained.

For comparison, the properties of commercially available copper-clad flexible printed wiring boards using polyester film, polyimide film, epoxy resin, and glass cloth instead of the composition used above are also listed in the same table.

In addition, commercially available copper-clad flexible pudding The total thickness of the substrate is as follows:

For wiring

Claims (1)

[Scope of Claims] 1 Alkenyl group-containing diorganopolysiloxane Impregnated or coated with an organopolysiloxane composition consisting of an organohydrodiene polysiloxane having a hydrogen atom directly bonded to a silicon atom, an inorganic filler, and platinum or a platinum compound. A laminate made by laminating and integrating inorganic fibers and metal foil. 2 The alkenyl group-containing diorganopolysiloxane has a) general formula ▲ mathematical formula, chemical formula, table, etc. ▼ (in the formula, R^1 is a substituted or unsubstituted monovalent hydrocarbon group, R^2 is a hydroxyl group or (represents the same or different types of monovalent hydrocarbon groups, m represents a positive integer), 0.0005 to 5 mol% of all organic groups directly bonded to silicon atoms are alkenyl groups, and The viscosity at is 1,0
b) General formula ▲ Numerical formula, chemical formula, table, etc. ▼ (In the formula, R^3 is a substituted or unsubstituted monovalent hydrocarbon group, and R^4 is represents a hydroxyl group or a monovalent hydrocarbon group of the same or different kind, n represents a positive integer), and 0.01 to 15 mol% of all organic groups directly bonded to silicon atoms are alkenyl groups, and Viscosity at 25°C is 100,
The laminate according to claim 1, which is an organopolysiloxane mixture comprising a diorganopolysiloxane having a diorganopolysiloxane of 000 centistokes or less.