JPH0722731A - Manufacture of laminated sheet copper-clad on both-sides - Google Patents

Abstract

PURPOSE:To decrease a deflection of a printed wiring board for high-frequency circuit by making the thickness of a copper foil for circuit forming to be laid on the top side to be less than 52% of the thickness of a copper foil for ground ing to be laid on the bottom, in hot molding. CONSTITUTION:A copper foil 1a for circuit forming touches the upper side of a prepreg 4a on the uppermost surface, and a copper foil 1b for grounding touches the lower side of a prepreg 4b at the lowermost surface. The thickness of the copper foil 1a for circuit forming is 52% less than that of the copper foil 1b for grounding. After heat molding, this constitution produces a protrusion on the copper foil side for circuit forming to be laid on the upper side, but when it is used as a high-frequency printed circuit board, upon etching the copper foil 1a for circuit forming, it works to make a deflection of a laminated sheet protrude on the copper foil side for earthling. Forces of equal magnitude are applied to both surfaces in mutually opposite direction, thus diminishing the deflection.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a double-sided copper-clad laminate, and more particularly to a method for producing a double-sided copper-clad laminate for high frequency printed wiring boards used in electronic equipment and electric equipment.

[0002]

2. Description of the Related Art In the production of a double-sided copper-clad laminate for a high-frequency printed wiring board, for example, a base material is impregnated with an epoxy resin and a plurality of semi-cured prepregs are piled up to form the outermost prepreg. Laminating copper foil on the outer surface of both prepregs,
This laminated body is sandwiched between molding plates and heated and pressed to be molded. The double-sided copper-clad laminate thus obtained is
When the copper foil for forming a circuit is etched after completion of molding, warpage occurs. It is presumed that the above-mentioned warpage occurs when one side is etched because the copper foils disposed on both sides have the same thickness. However, when the copper foil for circuit formation is etched in this way, warpage occurs. However, when used in a printed wiring board for high frequency circuits, there is a problem in that the dimensional accuracy is insufficient.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and it is an object of the present invention to provide a double-sided copper-clad laminate having a small warp used for a printed wiring board for high frequency circuits. It is to provide a manufacturing method.

[0004]

According to a first aspect of the present invention, there is provided a method for producing a double-sided copper-clad laminate, wherein a plurality of prepregs are stacked and a copper for forming a circuit is formed on an outer surface of both outermost prepregs of the prepreg. Foil, in the method for producing a double-sided copper-clad laminate in which a copper foil for grounding is disposed on the lower side and heat-molded, the thickness of the copper foil for circuit formation disposed on the upper side during heat-molding, 52 of the thickness of the copper foil for grounding arranged on the lower side
It is less than%.

A method for manufacturing a double-sided copper-clad laminate according to a second aspect of the present invention comprises stacking a plurality of prepregs, a copper foil for forming a circuit on the upper side of the outermost prepreg outer surfaces of the prepreg, and a lower side of the prepreg. In the method for producing a double-sided copper-clad laminate in which a copper foil for grounding is arranged and heat-molded, the amount of resin on the uppermost surface of the prepreg is 10% by weight compared to the amount of resin on the lowermost surface.
It is characterized by containing a large amount as described above.

[0006]

According to the method for producing a double-sided copper-clad laminate according to claim 1 of the present invention, a plurality of prepregs are stacked, and a copper foil for forming a circuit is formed on the lower side of the outermost prepreg outer surfaces of the prepreg. In the method for producing a double-sided copper-clad laminate in which a copper foil for grounding is disposed on and heat-molded, the thickness of the circuit-forming copper foil disposed on the upper side during heat-molding is disposed on the lower side. Since the thickness is less than 52% of the thickness of the copper foil for grounding, this structure has a convex shape on the copper foil surface for circuit formation disposed on the upper side after heat molding, but when used as a high frequency printed wiring board. , When etching the copper foil for circuit formation,
It works to make the warpage of the laminated board convex to the side of the copper foil for grounding, applying the same force to both sides in opposite directions,
Therefore, the warpage is reduced.

According to the method for producing a double-sided copper-clad laminate according to claim 2 of the present invention, a plurality of prepregs are stacked, a copper foil for forming a circuit is formed on the lower side of the outermost prepreg outer surfaces of the prepreg, and a lower side is formed on the lower side. In the method for producing a double-sided copper-clad laminate in which a copper foil for grounding is provided and heat-molded, the resin amount on the uppermost surface of the prepreg contains more than 10% by weight as compared with the resin amount on the lowermost surface. , This structure has a convex shape on the copper foil side for circuit formation that contacts the upper side of the uppermost surface of the prepreg after heat molding, but when used as a high-frequency printed wiring board,
When the copper foil for circuit formation is etched, it works to make the warp of the laminated plate convex to the side of the grounding copper foil contacting the lower side of the lowermost surface of the prepreg, and the same amount of force is applied to both sides. They join in opposite directions, thus reducing the sled.

The present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the constituent materials of a double-sided copper-clad laminate according to an embodiment of the present invention separately.

The method for producing a double-sided copper-clad laminate according to the present invention comprises:
As shown in FIG. 1, a base material is impregnated with a resin, semi-cured, and several prepregs (4) obtained by cutting are stacked, and copper is applied to the outer surfaces of both outermost prepregs (4) of these prepregs (4). The foils (1) are arranged and laminated. The laminated body is sandwiched between molding plates, and the resin in the substrate is cured by heating and pressing.

Examples of the above resin include epoxy resin,
Examples include polyimide. Examples of the base material include woven fabrics, non-woven fabrics, mats or papers composed of inorganic fibers such as glass and asbestos, organic synthetic fibers such as polyester, polyamide, polyvinyl alcohol and acrylic, and natural fibers such as cotton, or a combination thereof. Wood is used.

As shown in FIG. 1, the circuit-forming copper foil (1a) used in the above-mentioned double-sided copper-clad laminate is in contact with the uppermost prepreg (4a) from above, and the grounding copper foil (1a).
b) is in contact with the lowermost prepreg (4b) from below. The thickness of the copper foil (1a) for forming a circuit is less than 52% as compared with the thickness of the copper foil (1b) for grounding. The copper foil (1a) for forming the circuit and the copper foil (1b) for grounding may be of any type. This structure has a convex shape on the side of the copper foil for circuit formation to be placed on the upper side after heat molding, but when used as a high-frequency printed wiring board, when the copper foil for circuit formation is etched, the warpage of the laminated board Acts as a convex on the side of the copper foil for grounding, and forces of the same magnitude are applied in opposite directions on both sides, thus reducing warpage.

Further, as shown in FIG. 1, among the prepregs (4) used in the above-mentioned double-sided copper-clad laminate, the prepreg (4a) on the uppermost surface in contact with the copper foil (1a) for forming a circuit contains the amount of resin. Is the most common. On the other hand, of the prepregs (4), the lowermost prepreg (4b) in contact with the grounding copper foil (1b) contains the least amount of resin. And
The amount of resin on the uppermost surface of the prepreg is 10% by weight or more as compared with the amount of resin on the lowermost surface. When three or more prepregs (4) are used, copper foil (1a) for circuit formation
The remaining prepreg (4) sandwiched between the uppermost prepreg (4a) in contact with and the lowermost prepreg (4b) in contact with the grounding copper foil (1b) is the resin content of the prepreg (4). From the top surface (4a) to the bottom surface (4
It is loaded with a structure in which the content is the same or gradually decreases toward b). This structure, after heat molding, becomes convex on the copper foil surface side for circuit formation in contact with the upper side of the uppermost surface of the prepreg, but when used as a high frequency printed wiring board, when the copper foil for circuit formation is etched, It functions to make the warp of the laminated plate convex to the side of the grounding copper foil contacting the lower side of the lowermost surface of the prepreg, and the same magnitude of force is applied to both sides in opposite directions, thus reducing the warp.

After taking out a laminate comprising the copper foil (1) and the prepreg (4), which are obtained by curing the resin in the prepreg (4) by heating and pressing, from the molding plate, a double-sided copper-clad laminate is obtained.

[0014]

Example 1 As a copper foil (1b) for grounding, a copper foil (1b) having a thickness of 35 μm was formed on the lower side.
Copper foil (manufactured by Nikko Gould Co., Ltd., trade name JTC) and circuit
As a copper foil (1a) for forming, copper having a thickness of 18 μm on the upper side
Using foil (manufactured by Nikko Gould Co., Ltd., trade name JTC)
It was The thickness of the copper foil (1a) placed on the upper side is
It is 51.4% of the thickness of the arranged copper foil (1b). Puri
As the prepreg (4), a glass cloth with a thickness of 180 μm
(Nitto Boseki, product name WE-116E) epoxy resin
Using a prepreg with a resin content of 75%
It was Next, as shown in FIG. 1, a copper foil (1
b), 4 pieces of prepreg (4) with a resin amount of 75%, thickness 18
The copper foil (1a) having a thickness of 1 μm is laminated in this order from the bottom, and this laminated body is
Sandwiched between molding plates, temperature 170 ℃, pressure 40kg / c
m ²After heating for 60 minutes, a double-sided copper-clad laminate was obtained.

Example 2 As a copper foil (1b) for grounding, a 70 μm thick layer was formed on the lower side.
Copper foil (manufactured by Nikko Gould Co., Ltd., trade name JTC) and circuit
As a copper foil (1a) for forming, copper having a thickness of 18 μm on the upper side
Using foil (manufactured by Nikko Gould Co., Ltd., trade name JTC)
It was The thickness of the copper foil (1a) placed on the upper side is
It is 25.7% of the thickness of the arranged copper foil (1b). Puri
As the prepreg (4), a glass cloth with a thickness of 180 μm
(Nitto Boseki, product name WE-116E) epoxy resin
Using a prepreg with a resin content of 75%
It was Next, as shown in FIG. 1, a copper foil (1
b), 4 pieces of prepreg (4) with a resin amount of 75%, thickness 18
The copper foil (1a) having a thickness of 1 μm is laminated in this order from the bottom, and this laminated body is
Sandwiched between molding plates, temperature 170 ℃, pressure 40kg / c
m ²After heating for 60 minutes, a double-sided copper-clad laminate was obtained.

Example 3 As a copper foil (1b) for grounding, a thickness of 105 μm on the lower side
As the copper foil (made by Nikko Gould Co., Ltd., trade name JTC) and the copper foil (1a) for forming a circuit, a copper foil having a thickness of 18 μm (made by Nikko Gould Co., Ltd., trade name JTC) was used on the upper side. The thickness of the copper foil (1a) arranged on the upper side is 17.1% of the thickness of the copper foil (1b) arranged on the lower side. As the prepreg (4), there was used a prepreg having a resin amount of 75%, which was obtained by impregnating a 180 μm-thick glass cloth (Nitto Boseki, trade name WE-116E) with an epoxy resin and semi-curing the resin. Next, as shown in FIG. 1, a copper foil (1
b), 4 pieces of prepreg (4) with a resin amount of 75%, thickness 18
A copper foil (1a) having a thickness of μm is laminated from the bottom, and the laminated body is sandwiched between molding plates, and the temperature is 170 ° C. and the pressure is 40 kg / c.
After heating at m ² for 60 minutes, a double-sided copper-clad laminate was obtained.

Example 4 As the copper foil (1a) for forming a circuit and the copper foil (1b) for grounding, a copper foil having a thickness of 18 μm (manufactured by Nikko Gould Co., Ltd., trade name JTC) was used on both sides. As the prepreg (4), a 180-μm-thick glass cloth (Nitto Boseki, trade name WE-116E) impregnated with an epoxy resin and semi-cured was used. next,
As shown in FIG. 1, a copper foil (1b) having a thickness of 18 μm and a resin amount of 7
One 0% prepreg (4), two 75% resin prepregs (4), one 80% resin prepreg (4),
A copper foil (1a) having a thickness of 18 μm is laminated in this order from the bottom, and the laminate is sandwiched between molding plates, and the temperature is 170 ° C. and the pressure is 40
After heating at kg / cm ² for 60 minutes, a double-sided copper-clad laminate was obtained.

Comparative Example 1 As the copper foil (1a) for forming a circuit and the copper foil (1b) for grounding, a copper foil having a thickness of 18 μm (manufactured by Nikko Gould Co., Ltd., trade name JTC) was used on both sides. As the prepreg (4), a glass cloth having a thickness of 180 μm (manufactured by Nitto Boseki Co., Ltd., trade name WE-116E) was impregnated with an epoxy resin and semi-cured, and a prepreg having a resin amount of 75% [prepreg (4 used in Example 1 )] Was used. Next, the copper foil (1), four prepregs (4), and the copper foil (1) are laminated in this order from the bottom, and the laminated body is sandwiched between molding plates, and the temperature is 170 ° C. and the pressure is 40 k.
After heating at g / cm ² for 60 minutes, a double-sided copper-clad laminate was obtained.

Comparative Example 2 As a copper foil (1b) for grounding, a copper foil having a thickness of 12 μm (manufactured by Nikko Gould Co., Ltd., trade name JTC) on the lower side and a copper foil (1a) for forming a circuit on the upper side. A 18 μm-thick copper foil (manufactured by Nikko Gould Co., Ltd., trade name JTC) was used. The thickness of the copper foil (1a) arranged on the upper side is 150% of the thickness of the copper foil (1b) arranged on the lower side. As the prepreg (4), there was used a prepreg having a resin amount of 75%, which was obtained by impregnating a 180 μm-thick glass cloth (Nitto Boseki, trade name WE-116E) with an epoxy resin and semi-curing the resin. Next, as shown in FIG. 1, a copper foil (1
b), 4 pieces of prepreg (4) with a resin amount of 75%, thickness 18
A copper foil (1a) having a thickness of μm is laminated from the bottom, and the laminated body is sandwiched between molding plates, and the temperature is 170 ° C. and the pressure is 40 kg / c.
After heating at m ² for 60 minutes, a double-sided copper-clad laminate was obtained.

COMPARATIVE EXAMPLE 3 A copper foil (1b) for grounding having a thickness of 18 μm on the lower side.
Copper foil (manufactured by Nikko Gould Co., Ltd., trade name JTC) and circuit
As a copper foil (1a) for forming, copper having a thickness of 12 μm on the upper side
Using foil (manufactured by Nikko Gould Co., Ltd., trade name JTC)
It was The thickness of the copper foil (1a) placed on the upper side is
It is 66.7% of the thickness of the arranged copper foil (1b). Puri
As the prepreg (4), a glass cloth with a thickness of 180 μm
(Nitto Boseki, product name WE-116E) epoxy resin
Using a prepreg with a resin content of 75%
It was Next, as shown in FIG. 1, a copper foil (1
b), 4 pieces of prepreg (4) with a resin amount of 75%, thickness 18
The copper foil (1a) having a thickness of 1 μm is laminated in this order from the bottom, and this laminated body is
Sandwiched between molding plates, temperature 170 ℃, pressure 40kg / c
m ²After heating for 60 minutes, a double-sided copper-clad laminate was obtained.

Next, the warpage of the double-sided copper-clad laminates obtained in Examples 1 to 4 and Comparative Examples 1 to 3 was evaluated by the following method.

Only the copper foil (1a) for forming a circuit arranged on the upper side of the double-sided copper-clad laminate cut into a vertical length of 300 mm × horizontal length of 300 mm is etched, dried, and then placed on a smooth surface plate for maximum The amount of floating was measured with a JIS class 1 metal gauge.

The results of the above-mentioned warpage measurement are shown in Table 1 and Table 2.
It was as shown in. Examples 1-4 are Comparative Examples 1-3
The warp value was smaller than that of No. 1, and the results were all good.

[0024]

[Table 1]

[0025]

[Table 2]

[0026]

According to the method for producing a double-sided copper-clad laminate of the present invention, a double-sided copper-clad laminate having a small warp, which is used in a high frequency printed wiring board, can be obtained.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing separated constituent materials of a double-sided copper-clad laminate according to an embodiment of the present invention.

[Explanation of symbols]

 1 Copper foil 4 Prepreg

Claims (2)

[Claims] 1. A double-sided copper-clad for stacking a plurality of prepregs, arranging a copper foil for forming a circuit on the upper side of the outermost outer surfaces of both prepregs of the prepreg and a copper foil for grounding on the lower side of the prepregs and heat-molding the prepregs. In the method for manufacturing a laminated board, at the time of heat forming, the thickness of the circuit forming copper foil provided on the upper side is less than 52% of the thickness of the grounding copper foil provided on the lower side. A method for producing a double-sided copper-clad laminate characterized by the above. 2. A double-sided copper-clad for stacking a plurality of prepregs, arranging a copper foil for circuit formation on the upper side of the outermost outer surfaces of both prepregs of the prepreg, and a copper foil for grounding on the lower side of the prepregs. In the method for manufacturing a laminated board, the amount of resin on the uppermost surface of the prepreg is 10% by weight compared to the amount of resin on the lowermost surface.
A method for producing a double-sided copper-clad laminate characterized by containing a large amount as described above.