JPH10272733A - Manufacture of metal-clad laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for manufacturing a metal-clad laminate in which a glass-woven cloth is used as a base and the dimension change rate is small in a heating process. SOLUTION: A glass-woven cloth is formed of glass yarns of the name of D450 1/0 specified in JIS R 3413, and the ratio of count number per 25 mm (number of warps/number of wefts)=1.0-1.2, and the weight per unit area is 55-65 g/m<2> . The glass-woven cloth of plane weave fabrics is used as a base, and the base is so impregnated with thermoset resin varnish as to set the solid adhesion amount of 45-60 wt.% and dried to manufacture a prepreg, and then metal foils are overlapped on the prepreg and heated and pressurized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing a metal-clad laminate.

[0002]

2. Description of the Related Art A printed wiring board is manufactured by subjecting a metal-clad laminate to circuit processing. This metal-clad laminate is prepared by impregnating and drying a base material with a thermosetting resin varnish and a metal foil. And laminated. Paper, paper,
Glass fiber woven fabric, glass fiber non-woven fabric and the like are used depending on the application. Printed wiring boards have also become thinner in response to miniaturization and higher integration of electronic components, and in such thin metal-clad laminates, glass woven fabrics having an excellent reinforcing effect are used.

[0003]

The printed wiring board is subjected to a heat treatment by soldering at the time of component mounting, secondary molding for multilayering, and the like. When subjected to such a heating step, the printed wiring board undergoes a dimensional change mainly in the shrinking direction. This change in size is more remarkable in a metal-clad laminate using a glass woven fabric as a base material, as the thickness becomes thinner.
In some cases, the dimensional change rate due to the heat treatment (hereinafter referred to as the dimensional change rate, and when the magnitude of the dimensional change rate is referred to as the absolute value thereof) is −0.10% or more. The inventions of claims 1 to 3 all provide a manufacturing method for obtaining a metal-clad laminate having a small dimensional change rate when placed in a heating step, using a glass woven fabric as a base material. .

[0004]

Means for Solving the Problems The invention of claim 1 is a JI.
The name of the yarn specified in SR3413 is D4501 /
0 glass thread, the ratio of the number of driven yarns per 25 mm is (number of warp yarns / number of weft yarns) = 1.0 to 1.2,
A thermosetting resin having a weight per unit area of 55 to 65 g / m ² and a plain-woven glass woven fabric as a base material, and having a solid content of 45 to 60% by weight on the base material. This is a method for producing a metal-clad laminate, which comprises impregnating and drying a varnish to form a prepreg, and then laminating a metal foil on the prepreg and heating and pressing.

[0005] A glass woven fabric used as a substrate has a thickness of 25 mm.
If the ratio of the number of driven yarns per hit is less than (the number of warp yarns / the number of weft yarns) = 1.0, the difference in the dimensional shrinkage ratio between the warp direction and the weft direction becomes large and the dimensional shrinkage ratio in the warp direction is 0.1%. Will be exceeded. If this ratio exceeds 1.2, the difference between the dimensional contraction rates in the vertical direction and the horizontal direction increases, and the dimensional contraction rate in the horizontal direction exceeds 0.1%. If the weight per unit area of the glass woven fabric used as the base material is less than 55 g / m ² , the volume occupied by the glass may be small and the dimensional shrinkage may increase. When the weight exceeds 65 g / m ² , the thickness of the prepreg increases. The fabric structure of the substrate is limited to plain weave.
This is because satin weave and twill weave are not preferable from the viewpoint of surface smoothness.

A prepreg is obtained by impregnating and drying a thermosetting resin varnish using such a glass woven fabric as a base material. When the thermosetting resin varnish is impregnated, the adhesion amount is determined by the solid adhesion amount after drying. Is 45 to 60% by weight. If the solid content after drying is less than 45% by weight, the resin content is insufficient, resulting in a missing portion of the resin. If it exceeds 60% by weight, the dimensional change rate cannot be reduced. . From this, when impregnating the thermosetting resin varnish, the adhesion amount is 50 to 55 as a solid adhesion amount after drying.
More preferably, it is set to be% by weight.

According to a second aspect of the present invention, in the first aspect, the glass woven fabric is a glass woven fabric having a coefficient of thermal expansion of 3 × 10 ⁻⁶ / ° C. or less. Thermal expansion coefficient is 3 × 1
It is preferable to use a glass woven fabric having a temperature of 0 ⁻⁶ / ° C. or less because the dimensional change rate can be further reduced.

Further, the invention of claim 3 is the invention according to claim 1 or 2, wherein the metal foil has a hot elongation at 180 ° C. (hereinafter, simply referred to as a hot elongation) of 10% to 5%.
0% of the metal is solid. By using a metal foil having a hot elongation of 10% or more as a metal foil, the dimensional change rate can be further reduced. However, if the hot elongation exceeds 50%, the handleability is poor, and folds and wrinkles are liable to occur when laminating. Therefore, it is necessary to handle very carefully, resulting in an increase in the number of manufacturing steps. The hot elongation is defined by cutting a test piece from a metal foil to be measured into a rectangle, pulling the test piece at a temperature of 180 ° C by a tensile tester, and elongating the test piece when it breaks. It is expressed in%.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A glass yarn having a name of D450 1/0 specified in JIS R 3413 has a diameter of 5 ±
It is a single yarn in which 200 ± 10 1.5 μm glass filaments are bundled. The weight per unit area of glass woven fabric is
It is adjusted by the weaving density, that is, the number of shots per 25 mm. Therefore, the glass woven fabric used as a substrate in the present invention has a warp yarn number / weft yarn number of 1.0 to 1.0 within a range of a weaving density for obtaining a weight per a predetermined unit area.
It is woven so as to be 1.2. The fabric structure may be a plain weave, and there is no particular limitation on the loom for weaving.
Further, in order to improve the affinity with the thermosetting resin, it is preferable to perform treatment with a silane coupling agent. Also,
As a glass woven fabric having a thermal expansion coefficient of 3 × 10 ⁻⁶ / ° C. or less, an S glass woven fabric (thermal expansion coefficient = 2.8 × 10 ⁻⁶ / ° C.)
And the like.

[0010] Thermosetting resins used for prepreg include epoxy resins, polyimide resins, unsaturated polyester resins, bismaleimide-triazine resins, and the like, which are conventionally used for laminated boards. Is mentioned. As a solvent used when these thermosetting resins are used as a varnish, conventionally known solvents can be used,
Further, the method conditions for producing the prepreg can be the same as the conventional method conditions.

As the metal foil used to obtain the metal-clad laminate, copper foil is usually used. Examples of the copper foil having a hot elongation of 10% to 50% include, for example, HTE foil from Mitsui Kinzoku Kogyo Co., Ltd. and HG from Nihon Electrolysis Co., Ltd.
Copper foil which is commercially available under the trade names R foil and MGR foil, respectively, may be mentioned.

The method conditions for producing a metal-clad laminate from a prepreg and a metal foil can be the same as those in the conventional method. That is, the number of layers corresponding to the thickness of the metal-clad laminate for which the prepreg is to be manufactured is overlapped, a metal foil is laminated on the outside (usually both sides), heated and pressed with a stainless steel end plate, and Get.

The metal-clad laminate produced by the production method of the present invention is also suitable as an inner layer of a multilayer printed wiring board. That is, the metal-clad laminate manufactured by the manufacturing method of the present invention is subjected to circuit processing and used as an inner layer board.
Further, the single-sided metal-clad laminate can be used as an outer layer of a multilayer printed wiring board by the production method of the present invention.
When these multilayer printed wiring boards are manufactured, it is preferable to use the prepreg used in the manufacturing method of the present invention as a bonding prepreg in order to reduce the dimensional change rate of the multilayer printed wiring board. As the adhesive prepreg, it is preferable to set the solid content after drying to a relatively large value, for example, 55 to 60% by weight.

[0014]

EXAMPLES Preparation of epoxy resin varnish 1,000 parts (parts by weight, the same applies hereinafter) of bisphenol A, 220 parts of 37% formalin, and 10 parts of oxalic acid were charged into a reaction vessel, reacted for 2 hours, and then dehydrated and concentrated. Thus, bisphenol A novolak resin was prepared. 60 parts of prepared bisphenol A novolak resin, bisphenol A
Novolak type epoxy resin (Epiclon N-865 (trade name) manufactured by Dainippon Ink and Chemicals, Inc.)
100 parts and 1-cyanoethyl-2-ethyl-4-methylimidazole 0.5 part
The epoxy resin varnish was obtained.

Example 1 The yarn name specified in JIS R 3413 is D450
The ratio of the number of driving of 1/0 glass thread per 25 mm is (number of warp / number of weft) = 1.17,
A plain woven glass woven fabric having a weight per unit area of 58 g / m ² and a coefficient of thermal expansion of 5.0 × 10 ⁻⁶ / ° C. is used as a base material, and the epoxy resin varnish is used as the base material. Was impregnated so that the resin content was 52% by weight after drying, and dried to prepare a prepreg having a thickness of 0.55 mm. 18 μm thick on both sides of one prepreg prepared,
A copper foil having a hot elongation of 1.7% is overlaid, and the temperature is reduced to 1 at a reduced pressure.
A copper-clad laminate was produced by heating and pressing at 75 ° C. and a pressure of 3 MPa for 60 minutes.

Example 2 Copper foil having a hot elongation at 180 ° C. of 30.4% (HTE foil (trade name, manufactured by Mitsui Kinzoku Kogyo KK))
Was used in the same manner as in Example 1 except that the copper-clad laminate was used.

Example 3 The yarn name specified in JIS R 3413 is D450
The ratio of the number of driving of 1/0 glass thread per 25 mm is (number of warp / number of weft) = 1.17,
The same procedure as in Example 2 was carried out except that a plain woven glass woven fabric having a weight per unit area of 58 g / m ² and a coefficient of thermal expansion of 2.8 × 10 ⁻⁶ / ° C. was used as a base material. A copper-clad laminate was produced.

Comparative Example 1 The yarn name specified in JIS R 3413 is D450
The ratio of the number of driving of 1/0 glass yarn per 25 mm is (number of warp yarns / number of weft yarns) = 1.25,
A plain woven glass woven fabric having a weight per unit area of 48 g / m ² and a coefficient of thermal expansion of 5.0 × 10 ⁻⁶ / ° C. is used as a base material, and the resin content is 58% by weight after drying. Then, a copper-clad laminate was produced in the same manner as in Example 1 except that a prepreg having a thickness of 0.055 mm was produced by drying.

Comparative Example 2 The yarn name specified in JIS R 3413 is D450
The ratio of the number of driving of 1/0 glass yarn per 25 mm is (number of warp yarns / number of weft yarns) = 1.25,
A plain woven glass woven fabric having a weight per unit area of 48 g / m ² and a coefficient of thermal expansion of 2.8 × 10 ⁻⁶ / ° C. is used as a base material, and the resin content is 58% by weight after drying. Then, a copper-clad laminate was produced in the same manner as in Example 1 except that a prepreg having a thickness of 0.055 mm was produced by drying.

The dimensional change rate and the coefficient of thermal expansion of the copper-clad laminate prepared as described above were examined as described below. The results are shown in Table 1.

Dimensional change rate (based on JIS C 6481 "Test method for copper-clad laminate for printed wiring boards"): A test piece having a length of 300 mm and a width of 300 mm is cut out from the copper-clad laminate, and reference marks are formed at the four corners. Attached. After leaving the test piece in a room at a temperature of 20 ° C. and a relative humidity of 60 to 70% for 24 hours, the reference mark interval in the length and width directions is measured, and this is defined as ₁₀ . Next, the copper foil of the test piece was entirely etched, rinsed and dried, dried at 80 ° C. for 15 minutes, and then left in a room at a temperature of 20 ° C. and a relative humidity of 60 to 70% for 11 hours. After maintaining at a temperature of 170 ° C. for 30 minutes and cooling to room temperature, the reference mark interval in the length and width directions is measured, and this is set to l _1, and calculated by the equation (1).

## EQU1 ## Dimensional change rate = (l ₀ −l ₁ ) × 100 / l ₀

Thermal expansion coefficient (based on JIS C 6481 "Test method for copper-clad laminates for printed wiring boards"): A test piece having a size of 6 mm square is cut out from the copper-clad laminate, and copper foil is removed by etching the entire surface. Dry and use a thermal analyzer (TM
A), set at 10 ° C from room temperature to 120 ° C
/ Minute, and elongation or shrinkage in the thickness direction during that time is measured and calculated.

[0023]

[Table 1]

Table 1 shows that Example 1 has a significantly smaller dimensional change rate than Comparative Example 1. Further, in Example 2 using a copper foil having a hot elongation of 30.4%, it was shown that the dimensional change rate was smaller than that in Example 1, and the coefficient of thermal expansion was 2. In Example 3 using the glass woven fabric of 8 × 10 ⁻⁶ / ° C., it is shown that the dimensional change rate is smaller than that of Example 2.

[0025]

According to the first aspect of the present invention, it is possible to manufacture a metal-clad laminate having a small dimensional change rate, and according to the second and third aspects, it is possible to manufacture a metal-clad laminate. Also, a metal-clad laminate having a smaller dimensional change rate can be manufactured.

Claims (3)

[Claims] 1. A yarn specified in JIS R 3413 having a name of D450 1/0 and a ratio of the number of driving yarns per 25 mm (the number of warp yarns / the number of weft yarns) =
1.0 to 1.2, and the weight per unit area is 55 to 6
5 g / m ² , using a plain-woven glass woven fabric as a base material, and impregnating and drying a thermosetting resin varnish on the base material so as to have a solid content of 45 to 60% by weight to obtain a prepreg. Then, a metal foil is laminated on the prepreg and heated and pressed, and a method for producing a metal-clad laminate is provided. 2. The glass woven fabric has a coefficient of thermal expansion of 3 × 10 ^−6.
The method for producing a metal-clad laminate according to claim 1, wherein the metal-clad laminate is a glass woven fabric having a temperature of / C or lower. 3. The method for producing a metal-clad laminate according to claim 1, wherein the metal foil is a metal foil having a hot elongation of 10 to 50% at 180 ° C.