JPH05239738A - Glass fiber woven fabric and multilayer printed wiring board - Google Patents

Abstract

PURPOSE:To provide a multilayered printed wiring board of excellent dimensional stability by using the glass yarns of specific deniers as the warp and the weft and laminating and curing the glass fiber-woven cloths whose warp and weft densities are in specific relations. CONSTITUTION:Glass yarns of ECD 450-1/0 are used as the warp and weft yarns to make glass fiber fabrics where the warp density (y filaments/25mm) and the weft density (x filaments/25mm) satisfy the expressions: 65<=y<100 and x=0.757+ or -4. Then, the glass fabrics are impregnated with a thermosetting resin such as an epoxy resin, polyimide resin or bismaleimide resin to form pregregs. Then, they are laminated and cured to give the objective multilayer print wiring boards.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a woven glass cloth and a multilayer printed wiring board. For more details,
TECHNICAL FIELD The present invention relates to a glass woven fabric for a multilayer printed wiring board having a small dimensional change and a multilayer printed wiring board using the same.

[0002]

2. Description of the Related Art Generally, many printed wiring boards are manufactured by a known method using a copper clad laminate and performing drilling, cleaning in the hole, electroless copper plating and the like. It is generally known that the dimensions of the copper-clad laminate change during these processing steps, and a larger dimension change occurs in the multilayer printed wiring board due to the addition of the multilayer forming step.

JIS R 3423 treated glass cloth for electronic equipment is a major type of glass woven cloth used for such printed wiring boards, and its representative number is yarn count, weave density, nominal thickness, and mass. Is, for example, Table 1
In the case of using these cloths shown in Fig. 2 as a double-sided printed wiring board, the dimensional changes are almost at the same level. In addition, the thickness of the cloth of the conventional EPEL-10A is about 100μ.
m, and EPEL-18 and the like with a cloth thickness of about 180 μm are used alone for multilayer printed wiring boards, but EPEL-06 and the like with a cloth thickness of 40 to 70 μm are mainly used. Was used for adjusting the thickness and was rarely used alone for a multilayer printed wiring board.

[0004]

[Table 1]

[0005]

However, along with the trend toward lighter, thinner, shorter, and smaller electronic products, the thickness of the cloth is recently used for ultra-thin multilayer printed wiring boards used in IC cards, mobile phones, and the like. It has been investigated to use a film having a thickness of 40 to 70 μm alone. However, when a conventional woven cloth having a nominal thickness of 40 to 70 μm is used alone to perform multi-layer molding, a woven cloth having a cloth thickness of about 100 μm and a nominal cloth thickness of about 180 μm.
Compared to the case where multi-layer molding is performed by using a woven fabric of μm alone, a dimensional change occurs several times, and as a result, alignment of circuits between inner and outer layers and automatic mounting of parts are required. Was difficult.

For this reason, it has been a very serious problem to make the dimensional change smaller even in an ultra-thin multilayer printed wiring board using a glass cloth having a thickness of about 50 μm. The present invention has been made in view of the circumstances as described above. For an ultra-thin multilayer printed wiring board, alignment of circuits between inner and outer layers, automatic mounting of components, etc. can be performed by the same operation as the conventional one. An object of the present invention is to provide a glass woven fabric having a smaller dimensional change of the substrate when manufacturing a multilayer printed wiring board from a multilayer molding material such as a copper clad laminate or prepreg, and a multilayer printed wiring board using the same. I am trying.

[0007]

In order to solve the above problems, the present invention uses ECD450-1 / 0 glass yarn as warp and weave density (y) of warp (piece / 25 mm).
The present invention provides a glass woven fabric for a multilayer printed wiring board, characterized in that the relation between the weave density (x) of the weft and the weft density (book / 25 mm) satisfies 65 ≦ y <100 x = 0.757 y ± 4. The present invention also provides a multilayer printed wiring board characterized in that a glass woven cloth for a multilayer printed wiring board is impregnated with a thermosetting resin to form a prepreg, which is laminated and cured and processed.

ECD450-1 / 0 used in the present invention
The glass thread of No. 1 is a display based on JIS R3413, and shows that the filament diameter is about 5 μm and the count is 11.2 tex. As the glass fiber thread used in the present invention, various kinds can be used, but especially when the alkali content is 0.8
% Of E glass fibers is one of the preferred ones.

Further, the glass woven fabric is a plain woven fabric which is free from problems such as warping and twisting during processing, since the glass woven fabric is surface-treated with a silane coupling agent or the like after removing the sizing agent for weaving. Any thermosetting resin can be used as long as it is suitable for electrical applications, and epoxy resin, polyimide resin, bismaleimide resin and the like can be exemplified.

[0010]

In the case of the glass woven fabric of the present invention, the dimensional stability is remarkably improved by using it in the multilayer printed wiring board. There are various reasons for this, and although it is not clear from the assertion, one reason is that the thermosetting resin at the time of multilayer molding flows to the same level in the vertical and horizontal directions to minimize residual strain. It is thought that it has a woven structure.

Hereinafter, the present invention will be described in more detail with reference to examples.

[0012]

EXAMPLES Example 1 Mass 55 g / m ² , weave density, warp y = 70, and weft x
= 52, a glass woven fabric having a count z = 11.2 was produced.
As shown in Table 2, the numerical values y and x of this woven fabric were within the ranges satisfying the relational expressions of the present invention as described above.

Epicoat 50451, a brominated bisphenol A type epoxy resin manufactured by Yuka Shell Epoxy Co., Ltd.
00 parts, 4.0 parts of dicyandiamide as a curing agent, BD
An epoxy resin varnish containing 0.15 parts of MA and 60 parts of methyl cellosolve as a solvent was added to the glass woven cloth. However, the amount of this resin is added so as to be 55% by weight. Then, this glass woven cloth was heated and dried for 120 seconds to be cured. One piece of prepreg thus obtained was laminated with copper foil, and the temperature was 170 ° C. and the pressure was 40 kg /
Molding was carried out under the conditions of cm ² and heating time of 90 minutes to prepare a thin plate for the inner layer plate.

After dimensional change measurement points were attached to this inner layer plate according to JIS C6481, the entire surface was etched according to a conventional method. Next, a single layer of the above prepreg was formed on each of the upper and lower sides under conditions of 170 ° C., pressure of 40 kg / cm ² , and heating time of 30 minutes. The dimensional change of the cloth before and after the multilayer molding was measured according to JIS C6481.

The results of this measurement are also shown in Table 2. As is clear from Table 2 and Comparative Examples described later, the dimensional change rate was -0.069% in warp and -0.075% in weft, which were very small values. Example 2 Mass 64 g / cm ² , weave density warp y = 80 and weft x =
A glass woven fabric having a count of 61 and a count of z = 11.2 was manufactured. Table 2
As shown in Table 1, the numerical values y and x of this woven fabric also satisfied the above relational expressions. A thin plate for the inner layer plate was prepared in the same manner as in Example 1, and then multilayered.

The dimensional change of the cloth before and after the multilayer molding was measured in the same manner as in Example 1. The results of this measurement are also shown in Table 2. The dimensional change rate was -0.061% for warp and -0.066% for weft, which were very small values. Example 3 A glass woven fabric having a mass of 72 kg / cm ² , y = 90, x = 68 and z = 11.2 was produced. As shown in Table 2, y and x of this woven fabric also satisfied the above relational expressions. A thin plate for the inner layer plate was prepared in the same manner as in Example 1, and then multilayered.

The dimensional change of the cloth before and after the multilayer molding was measured in the same manner as in Example 1. The results of this measurement are also shown in Table 2. The dimensional change rate was -0.065% for warp and -0.059% for weft, which were very small values.

[0018]

[Table 2]

Comparative Example 1 Mass of 48 g / m ² , y = 60, x = 46, z = 11.2
I prepared a glass woven fabric. As shown in Table 3,
The y and x of this woven fabric did not satisfy the above relational expression. Using this glass woven fabric, a thin plate for an inner layer plate was prepared in the same manner as in Examples 1 to 3 and then multilayered. Further, the dimensional change was measured in the same manner as in Examples 1 to 3.

The results of this measurement are also shown in Table 3. The dimensional change rate was -0.191% for warp and -0.113% for weft, which were very large values. Comparative Example 2 A glass woven fabric having a mass of 72 g / m ² , y = 80, x = 80, and z = 11.2 was prepared. As shown in Table 3, the numerical values y, x, z of this woven fabric did not satisfy the above relational expression.

Using this glass woven fabric, a thin plate for an inner layer plate was prepared in the same manner as in Examples 1 to 3, and then multilayered. Further, the dimensional change was measured in the same manner as in Examples 1 to 3. The measurement results are shown in Table 3. The rate of dimensional change is
At 0.101%, the latitude was -0.032%, which was a very large value. Comparative Example 3 A glass woven fabric having a mass of 63 g / m ² , y = 90, x = 50, and z = 11.2 was prepared. As shown in Table 3, the numerical values y and x of this woven fabric did not satisfy the above relational expression.

Using this glass woven fabric, a thin plate for an inner layer plate was prepared in the same manner as in Examples 1 to 3 and then multilayered. Further, the dimensional change was measured in the same manner as in Examples 1 to 3. The results of this measurement are also shown in Table 3. The rate of dimensional change is
At 0.041%, the latitude was -0.115%, which was a very large value.

[0023]

[Table 3]

Comparative Example 4 A woven cloth having a cloth thickness of 40 to 70 μm, which is the object of the present invention, was used, and a thick glass woven cloth having a cloth thickness of about 100 μm was used. A comparison was made. The glass woven cloth of this thickness has been conventionally used alone for a multilayer wiring board.

As shown in Table 4, the glass woven fabric has a J
A glass woven fabric of IS product number EPEL-10A, that is, a mass of 107 g / m ² , y = 60, x = 58, and z = 22.5. Using this glass woven fabric, a thin plate for an inner layer plate was prepared in the same manner as in Examples 1 to 3 and then multilayered. Further, the dimensional change was measured in the same manner as in Examples 1 to 3.

The results of this measurement are also shown in Table 4. The dimensional change rate was -0.091% for warp and -0.053% for weft.

[0027]

[Table 4]

Comparing the above example with the comparative example, the dimensional change rate of the multilayer printed wiring boards prepared in the comparative examples 1 to 3 is -0.101% to -0.19 when the larger value is observed.
Very large at 1%. On the other hand, the dimensional change rate of the multilayer printed wiring boards prepared in Examples 1 to 3 of the present invention is -0.065% to -0.07 when viewed in terms of the larger history.
It is very small at 5%, which is 1/2 or less compared to the comparative example.

Further, regarding the dimensional change rate of the multilayer printed wiring board according to the present invention, the thickness of the cloth of Comparative Example 4 is about 10.
It is at the same level as when using a 0 μm one, and the plate thickness is thin.

[0030]

As described in detail above, according to the present invention, the maximum value of the dimensional change rate of the ultra-thin plate (the value with the larger history) is less than half that of the conventional product, and the same operation as the conventional one causes problems. Instead, it is possible to align the inside and outside layers and automatically mount parts. As a result, a multilayer printed wiring board with high dimensional stability is realized.

Claims (2)

[Claims] 1. A glass yarn of ECD450-1 / 0 is used for the warp and the relationship between the weave density (y) of the warp (pieces / 25 mm) and the weave density of the weft (x) (pieces / 25 mm) is as follows. A glass woven fabric for a multilayer printed wiring board, which satisfies the formula. 65 ≦ y <100 x = 0.757 y ± 4 2. A prepreg is formed by impregnating a glass woven fabric for a multilayer printed wiring board according to claim 1 with a thermosetting resin,
A multilayer printed wiring board, which is obtained by laminating and hardening this and processing it.