JPH0974255A - Glass fiber fabric for printed wiring boards - Google Patents

Abstract

(57) [PROBLEMS] To provide a glass fiber woven fabric for a printed wiring board, which has characteristics of low dielectric constant and low dielectric loss tangent and is excellent in drilling processability and water resistance when used as a substrate. SOLUTION: By weight%, SiO ₂ 50 to 60%, Al ₂
O ₃ 10-20%, B ₂ O ₃ 20-30%, CaO 0
~5%, 0~4% MgO, Li 2 O + Na 2 O + K 2
A glass fiber woven fabric for a printed wiring board, which is woven from glass fibers having a composition of 0 to 0.5% O and 0.5 to 5% TiO ₂ .

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass fiber woven fabric for a printed wiring board, and more particularly to a glass fiber woven fabric suitable for strengthening a high density printed wiring board required to have a low dielectric constant and dielectric loss tangent.

[0002]

2. Description of the Related Art In recent years, with the advent of an advanced information society, communication devices such as satellite broadcasting and mobile radio have tended to be digitized and have high-speed signal processing. High density and high speed processing are also required for the board, and as a result, low dielectric constant and low dielectric loss tangent are desired for the reinforcing material that constitutes the material of the printed wiring board. There is. As a reinforcing material,
Although glass fibers are used, E-glass is known as a commercially produced glass fiber of this type. In general, when an alternating current is passed through the glass, the glass absorbs the alternating current as energy and absorbs it as heat.
The absorbed dielectric loss energy is proportional to the dielectric constant and the dielectric loss tangent determined by the composition and structure of glass, and is represented by the following formula. W = kfv ² × εtan δ W is the dielectric loss energy, k is a constant, f is the frequency, v ²
Is a potential gradient, ε is a dielectric constant, and tan δ is a dielectric loss tangent.
From this equation, it can be seen that the dielectric loss increases as the dielectric constant and the dielectric loss tangent increase, and the frequency increases.

However, since the E-glass has a relatively high dielectric constant and dielectric loss tangent, the printed wiring board using the E-glass cannot sufficiently meet the demands for high density and high-speed signal processing. . Therefore, a glass having a lower dielectric constant and dielectric loss tangent than E glass is desired, but a glass called D glass has been developed as one of the glasses. D glass is, as an example, SiO ₂ 73%,
Al ₂ O ₃ 1.0%, B ₂ O ₃ 22%, CaO 0.6
%, MgO 0.5%, Li ₂ O 0.6% Na ₂ O
It is a glass having a composition of 1.2% K ₂ O 1.1%.

[0004]

However, the D glass is
1) Due to poor water resistance, peeling from the resin in the printed wiring board is likely to occur, and high reliability cannot be obtained when a printed wiring board is formed using this glass fiber woven fabric. 2) Further, a printed wiring board material using this glass fiber woven fabric has poor drilling workability such that the drill is greatly worn and damaged during drilling and the drilling position is easily displaced. 3) Furthermore, since the meltability is poor and striae and bubbles are likely to occur, there is a problem that glass fibers are often cut in the spinning process, resulting in poor productivity and workability.

The present invention has been made in view of the above circumstances, and as a printed wiring board material, a glass fiber woven fabric which has a low dielectric constant and a low dielectric loss tangent and is excellent in water resistance and drill workability is also provided. The purpose is to provide.

[0006]

The inventors of the present invention have conducted various studies in order to achieve the above-mentioned object, and as a result, in the composition of glass fiber, especially SiO ₂ is 60% or less, TiO ₂
Is set to 0.5 to 5%, and the solubility of glass is improved, while the total of Li ₂ O, Na ₂ O, and K ₂ O is set to 0.5% or less, whereby a low dielectric constant and a low dielectric loss tangent are obtained. It has been found that it is possible to obtain a glass fiber woven fabric for a printed wiring board which is water resistant and has good drilling workability, and has completed the present invention.

That is, the glass fiber woven fabric for a printed wiring board according to the present invention has a SiO ₂ content of 50 to 60% and an Al ₂ content of ₂ % by weight.
O ₃ 10-20%, B ₂ O ₃ 20-30%, CaO 0
~5%, 0~4% MgO, Li 2 O + Na 2 O + K 2
It is characterized by being woven with glass fibers having a composition of O 0 to 0.5% and TiO ₂ 0.5 to 5%.

The glass fiber fabric of the present invention is preferably
% By weight, SiO ₂ 50-56%, Al ₂ O ₃ 14-1
_{8%, B 2 O 3 24~28} %, CaO 0~2.5%,
_{MgO 0~2.5%, Li 2 O 0~0.15} %, N
a ₂ O 0 to 0.15%, K ₂ O 0 to 0.15%, T
It is woven with glass fibers having an iO ₂ 1 to 4% of the composition.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The glass fiber woven fabric of the present invention is usually surface-treated with a silane coupling agent. The silane coupling agent used for the surface treatment is optional, and conventionally known ones can be used. For example, vinyltrichlorosilane, vinyltris (2-methoxy) silane, γ-glycidoxypropyltrimethoxysilane, methacryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ- (2-aminoethyl) aminopropyltrimethoxysilane. Silane, N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltri Methoxysilane, vinyltriethoxysilane and β- (3,4epoxycyclohexyl) ethyltrimethoxysilane can be used.

The reasons for limiting the glass composition of the glass fiber woven fabric of the present invention are as follows. SiO ₂ is Al
It is a component that forms a glass skeleton together with ₂ O ₃ and B ₂ O ₃ , but if it is less than 50%, the dielectric constant becomes too large. If it exceeds 60%, the drill workability becomes too poor. Further, the viscosity becomes too high, the amount of elution becomes low during spinning, and the productivity decreases, and in some cases, fiberization becomes difficult. It is preferably 50 to 56%.

If Al ₂ O ₃ is less than 10%, a phase separation is likely to occur, resulting in poor water resistance. If it exceeds 20%, the liquidus temperature rises and the spinnability deteriorates. Therefore, Al ₂ O ₃ is limited to 10 to 20%, preferably 14 to 18%.

B ₂ O ₃ is a component used as a fluxing agent to lower the viscosity and facilitate melting, but if it is less than 20%, the dielectric loss tangent becomes too large. If it exceeds 30%, the water resistance and the drilling workability are deteriorated too much. Therefore B ₂ O ₃
Is limited to 10 to 20%, preferably 24 to 28%.

CaO and MgO are both components that improve water resistance. However, when CaO exceeds 5% and MgO exceeds 4%, the dielectric constant and dielectric loss tangent become too large, so CaO is 0 to 5%, and MgO is It is limited to 0 to 4%, preferably C
aO is 0 to 2.5% and MgO is 0 to 2.5%.

Li ₂ O, Na ₂ O and K ₂ O are all used as fluxing agents, but if the total amount of these exceeds 0.5%, the dielectric loss tangent becomes too high and the water resistance becomes poor. Thus _{Li 2 O + Na 2 O +} K 2 O is limited to 0 to 0.5%, preferably Li ₂ O0~0.15%, Na ₂ O
It is 0 to 0.15% and K ₂ O is 0 to 0.15%.

TiO ₂ is effective for lowering the viscosity and the dielectric loss tangent, but if it is less than 0.5%, striae and unmelting may occur during spinning, resulting in poor meltability.
The dielectric loss tangent becomes high. On the other hand, if it exceeds 5%, phase separation is likely to occur, resulting in poor chemical durability. Therefore, TiO ₂ is less than 0.
It is limited to 5 to 5%, preferably 1 to 4%.

In the present invention, other than the above components, ZrO ₂ , As ₂ O ₃ and Sb are added to the extent that glass properties are not impaired.
₂ O ₃ , ZnO, SrO, Fe ₂ O ₃ , Cr ₂ O ₃ , P
It is possible to contain up to 3% of components such as ₂ O ₅ , F ₂ , Cl ₂ , SO ₃ .

[0017]

EXAMPLES The glass fiber woven fabric of the present invention will be described in detail based on examples. 1) A batch prepared to have a glass composition shown in Table 1 was placed in a platinum crucible and placed in an electric furnace at 1500 to 1550 ° C.
It melted for 8 hours under stirring. Next, this molten glass was cast on a carbon plate to prepare a glass cullet. This glass cullet is put into a glass fiber manufacturing furnace, melted at 1300 to 1400 ° C., spun,
Glass fiber was produced. During production, no large amount of volatilization of boric acid (B ₂ O ₃ ) generated when spinning D glass was observed, and spinning could be performed without any inconvenience.

2) Using this glass fiber (fiber diameter 7 μm), the following glass fiber woven fabric was woven in accordance with glass cloth type EP10A specified in JIS R3414. <Type of glass cloth> Glass thread used: E225 1/0 1Z Density: 60 warps / 25mm, 58 wefts / 25mm horizontal Thickness: 0.1mm Mass: 105g / mm ² Weave: Plain weave

3) Next, after heat cleaning treatment, 1% by weight of N-β- (N-vinylbenzylaminoethyl) -γ-aminopropyltrimethoxysilane hydrochloride as a silane coupling agent. In addition to the acetic acid aqueous solution of
The glass fiber woven fabric was dipped in a treatment solution obtained by dissolving it so as to have a concentration of 7 g / l, squeezed with a mangle so that a pickup amount was 28% by weight, and then dried at 110 ° C. for 5 minutes to be treated. A glass fiber woven fabric was obtained.

4) The obtained treated glass fiber woven fabric was impregnated with an epoxy varnish of NEMA standard FR-4 composition shown below and dried at 130 ° C. for 6 minutes to obtain a prepreg. <Composition of epoxy varnish (FR-4)> 100 parts by weight of brominated epoxy resin (Epicote 5046-b-8, manufactured by Yuka Shell Epoxy Resin Co., Ltd.) 20 parts by weight of novolac type epoxy resin (Epicote 154 , Yuka Shell Epoxy Resin Co., Ltd.) Dicyandiamide 4 parts by weight 2-ethyl-4-methylimidazole 0.2 parts by weight Methylethylketone 15 parts by weight Dimethylformamide 30 parts by weight

5) Two kinds of the obtained prepregs were prepared, that is, 4 sheets and 16 sheets were piled up, and copper foils were piled up and down respectively, and 175 ° C. under a load of 30 kg / cm ^2.
And heated for 90 minutes to prepare a laminated plate. As the test piece, a copper-clad laminate obtained by removing copper by etching was used. Of these, the test piece with four prepregs stacked was used for the solder heat resistance, water absorption, and chemical resistance tests, and the test piece with 16 prepregs was used for the dielectric constant, dielectric loss tangent, and drill workability tests. . The main test methods are shown below. The results of these tests are shown in Table 1.

[Test method] 1) Drill workability Three test pieces were stacked, a drill diameter of 0.3 mm and a rotation speed of 60,0.
Under the conditions of 00 rpm and a feed rate of 50 μm / rev, the degree of wear of the drill after the number of drilling of 8000 holes, the inner wall roughness of the processed hole, and the hole position accuracy were comprehensively evaluated. The evaluation is “excellent” if it is about the same as E glass, and that there is a problem with drill workability, as compared with E glass that has been often used and is said to have no problem with drill workability. If it was about the same as the D glass seen, it was regarded as "not good". If it was about the middle of E glass and D glass, it was judged as “good”.

2) Soldering heat resistance and water absorption rate As for the soldering heat resistance, the test piece was cut into 4 cm squares, and 1
After putting it in a pressure cooker set to 21 ° C for a predetermined time, and then immersing it in a solder bath at 260 ° C for 20 seconds, visually observing the blister state (delamination) of the test piece,
The evaluation was made in three grades of ◯, Δ, and ×. In the evaluation, "○" means no blister. "△" has one small blister.
“X” indicates that there are two or more blisters. The water absorption rate was calculated from the weights of the test pieces before and after charging in a pressure cooker set at 121 ° C. for 105 minutes in the solder heat resistance test, using the following formula, to calculate the water absorption rate (%). . Water absorption rate (%) = (W ₂ −W ₁ ) × 100 / W ₁ Here, W ₁ indicates the weight of the test piece before the pressure cooker is charged, and W ₂ indicates the weight of the test piece after the pressure cooker is charged. .

3) Chemical resistance The test piece was immersed in boiling methylene chloride for 60 minutes, and the surface condition after immersion was visually evaluated. “Excellent” means that there was no change in appearance, and “Fail” means that there was a change in appearance, such as the surface being rough or the cross eyes appearing to float.

[0025]

[Table 1]

[Results] As shown in Table 1, the laminates of the examples using the glass fiber woven fabric of the present invention have a dielectric constant of about 3.
9, the dielectric loss tangent was about 17.6 × 10 ⁻⁴ , and Comparative Example 2
4.67 and 1 of the laminated plate using E glass of
It is lower than 8.24 × 10 ⁻⁴ and is 3.83 and 17.66 × 10 ^{−4 of} the laminated plate using the D glass of Comparative Example 1, respectively.
Shows low dielectric constant and low dielectric loss tangent. Further, the drill workability of the laminated plate of the example is superior to that of the D glass of the comparative example 1, and is about the same as that of the E glass of the comparative example 2. Further, the water absorption of the laminated plate of the example is D of the comparative example 1.
It is smaller than glass and has excellent water resistance. Furthermore,
The solder heat resistance of the laminated board of the example is superior to that of the D glass of the comparative example 1, and is about the same as that of the E glass of the comparative example 2. Furthermore, the chemical resistance of the laminate of the example is D of Comparative Example 1.
It is superior to the case of glass and is almost the same as that of the E glass of Comparative Example 2.

[0027]

Since the printed wiring board obtained by using the glass fiber woven fabric of the present invention has a low dielectric constant and a low dielectric loss tangent, it is particularly useful as a glass fiber woven fabric for a high density circuit printed wiring board. Are better. Further, it is also excellent in water resistance, solder heat resistance, and chemical resistance, and is unlikely to peel off from the resin constituting the printed wiring board when subjected to a heat load.
Further, in terms of drill workability, the drilling position is unlikely to shift and the drill wear is small, so that a highly reliable printed wiring board can be stably obtained.

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Claims (2)

[Claims] 1. The composition according to claim 1, wherein the content of SiO _{2 is} 50-60% by weight,
₂ O ₃ 10-20%, B ₂ O ₃ 20-30%, CaO
0-5%, MgO 0-4%, Li ₂ O + Na ₂ O + K
A glass fiber woven fabric for a printed wiring board, which is woven with a glass fiber having a composition of 0 to 0.5% of ₂ O and 0.5 to 5% of TiO ₂ . 2. By weight%, SiO ₂ 50-56%, Al
₂ O ₃ 14-18%, B ₂ O ₃ 24-28%, CaO
0-2.5%, MgO 0-2.5%, Li ₂ O 0-
_{0.15%, Na 2 O 0~0.15%} , K 2 O 0~
A composition having a composition of 0.15% and TiO _{2 of} 1 to 4%.
A glass fiber woven fabric for a printed wiring board, which is woven with the glass fiber according to 1.