JP2001177244A - Method of manufacturing multilayered board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing an asymmetric, less-warped multilayered board. SOLUTION: In this method of manufacturing the asymmetric multilayered board, in which a difference occurs between the amounts of expansion and contraction of prepregs put on and under each inner-layer circuit board, panel boards having different coefficients of thermal expansion are respectively arranged, on and under multiple laminating materials at laminating of the materials upon another.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer laminating method for producing a multilayer board.

[0002]

2. Description of the Related Art In recent years, due to the tendency of printed wiring boards to have higher densities, higher multi-layers, and thinner and lighter weights, production by a build-up method or by a lamination method in which two types of circuit boards are laminated and integrated are increasing. I've been. In particular, in the laminating method, the thickness of the prepreg interposed above and below the inner circuit board,
In many cases, a four-layer plate or a three-layer plate with an asymmetric configuration having different performances are used. The thickness of the prepreg interposed between the upper and lower portions of the inner layer circuit board and the four-layer plate having an asymmetrical configuration having different performances cause a difference in the amount of expansion and contraction between the upper and lower prepregs during lamination molding. The warpage is larger than that of a four-layer plate having a symmetrical configuration arranged symmetrically, and warpage is a problem when finishing and processing. The warpage of the multilayer board can increase the size reading error when machining the guide holes,
This causes troubles on automated cutting and edge finishing lines, and also causes errors in automatic thickness inspection. Until now, as a countermeasure against warping caused by warping, the multilayer board was sandwiched between two parallel plates or heated between the convex and concave molds, and the warpage was corrected by manual work or machine before line introduction. Has been done.

[0003]

However, such measures require time and effort for correction, and
It is necessary to pay attention to the handling of the product, and there is a concern that defective defects may occur due to improper handling. Further, modification by a conventional method induces deformation, breakage, and the like. Also,
There was a problem that it was not a fundamental measure for sleds. One of the causes of the warpage of the asymmetrically configured multilayer board is that the difference in the amount of expansion and contraction of the prepreg interposed between the top and bottom of the inner layer circuit board during heating and pressing is one of the factors, and it is necessary to reduce the difference in the amount of expansion and contraction. . The present invention has been made from such a viewpoint,
An object of the present invention is to provide a method of manufacturing a multilayer board having an asymmetric configuration with less warpage.

[0004]

That is, the present invention relates to a method of manufacturing a multilayer board having an asymmetrical structure in which the amount of expansion and contraction of a prepreg arranged above and below an inner circuit board is different. The present invention relates to a method for manufacturing a multilayer board, comprising arranging end plates having different coefficients and laminating them.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A head plate used in the present invention is a commercially available SUS301 or SUS for forming a laminated plate.
A material such as 630 may be made of another material according to the amount of expansion and contraction of the material used. The difference between the thermal expansion coefficients of the head plates is 10.5-11.
Thermal expansion coefficient of 2 × 10- ⁶ and SUS630 14.6-1
It is preferred that 3 × 10- ⁶ or more in consideration of 6.8 × 10- ⁶ but may even lower than this, depending on the material used.
Further, it is preferable to adjust the coefficient of thermal expansion by a method such as changing the material of the head plate according to the amount of change in expansion and contraction of the prepreg. As the prepreg used in the present invention, conventionally known ones can be appropriately used.Specifically, as a substrate, a glass woven fabric, a glass nonwoven fabric, or the like can be used, and as the resin to be impregnated into the substrate, Epoxy resin, polyimide resin, triazine resin, phenol resin, unsaturated polyester resin, melamine resin, and modified resins of these resins can be used. Further, two or more kinds of the above resins may be used in combination, or if necessary, various known curing agents and curing accelerators may be used in combination. The inner layer circuit board used in the present invention is not particularly limited, but may be a circuit board processed by etching copper of a copper-clad laminate from the viewpoint of economy and electrical reliability. The prepreg is used for bonding the inner layer circuit board and the outer layer metal foil at a temperature of 150 ° C to 2 ° C.
The multilayer printed wiring board is formed by heating and pressing at a temperature of 00 ° C. and a pressure of about 1 to 6 MPa. The selection of a head plate for a prepreg to be used is based on a head plate having a small thermal expansion coefficient on the side where the expansion and contraction change is large, and a head plate having a large thermal expansion coefficient on the side where the expansion and contraction change is small. In this way, by controlling the amount of expansion and contraction of the prepreg by utilizing the difference in the coefficient of thermal expansion between the head plates, it is possible to manufacture an asymmetric multilayer board with less warpage. Less than,
The present invention will be specifically described with reference to the drawings showing embodiments, but the present invention is not limited to these.

[0006]

EXAMPLE An epoxy resin copper-clad laminate of glass cloth base material (FR-4, 0.
After laminating a photosensitive film generally used by an etched foil method on a 14 mm, 18 μm copper foil) and performing printing (exposure) using a negative film for forming a circuit, etching treatment and oxidation treatment of the circuit surface are performed. To obtain an inner circuit board. Next, as shown in FIG. 1, a 0.06 mm-thick glass cloth-epoxy prepreg 2 (trade name: GE-67, manufactured by Hitachi Chemical Co., Ltd.) is provided on the upper side (F side) of the inner circuit board 1.
L), a 12 μm copper foil 4 on the prepreg 2, a mirror plate 6 made of SUS630 thereon, and a glass cloth-epoxy prepreg 3 (0.10 mm thick) on the lower side (side B) of the inner circuit board 1 ( Product name: GE-67, manufactured by Hitachi Chemical Co., Ltd.
3NA5L), a standard configuration except that an 18 μm copper foil 5 under the prepreg 3 and an end plate 7 made of SUS301 under the copper foil 5, under a reduced pressure atmosphere, 40 kg / cm ² , 17
After heating and pressing at 0 ° C. for 90 minutes, the mixture was cooled for 30 minutes to obtain a four-layer plate having a product size of 600 × 500 mm.

Comparative Example 1 A four-layer plate was obtained in the same manner as in the example except that the upper and lower end plates were made of SUS301.

Comparative Example 2 A four-layer plate was obtained in the same manner as in the example except that the upper and lower end plates were made of SUS630.

Examples 4 and 4 prepared according to Comparative Examples 1 and 2
The warpage of the layer plate and the effect on workability were evaluated. Table 1 shows the results. In Table 1, the amount of warpage was set on the surface plate with the sled surface facing down, and the maximum jump size of the surface plate and the end of the product was measured with a dial gauge. In addition, the trouble on the line refers to a phenomenon in which the line stops or the product is damaged due to contact with other equipment when the product is transported for warpage.

[0010]

[Table 1]

[0011]

According to the manufacturing method of the present invention, it is possible to obtain a multilayer board having an asymmetric configuration with a small warpage, without the need for a re-warping operation, and to reduce troubles caused by the warping and finishing work. can do.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a configuration of an embodiment of the present invention at the time of multi-layer lamination.

[Explanation of symbols]

 Reference Signs List 1 inner layer circuit board 2 thickness 0.06 mm prepreg 3 thickness 0.10 mm prepreg 4 thickness 12 μm copper foil 5 thickness 18 μm copper foil 6 SUS630 end plate 7 SUS301 end plate 8 cushion material 9 upper plate 10 feed plate 11 hot plate

Claims (3)

[Claims] 1. A method for manufacturing a multilayer board having an asymmetric configuration in which a difference in the amount of expansion and contraction of prepregs arranged above and below an inner circuit board is provided, wherein mirror plates having different thermal expansion coefficients are arranged above and below a multilayer material to be multilayered. A method for producing a multilayer board, comprising forming. 2. The method according to claim 1, wherein the difference between the thermal expansion coefficients of the head plates used up and down is 3
Method for manufacturing a multilayer board according to claim 1, wherein the certain × 10- ⁶ or more. 3. A head plate having a small thermal expansion coefficient is disposed on a side of the prepreg having a large expansion and contraction change via an inner circuit board, and a head plate having a large thermal expansion coefficient is disposed on a side of a small expansion and contraction change. 3. The method for producing a multilayer board according to 2.