JP2500398C - - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for continuously producing a metal foil-clad laminate used for a printed wiring board or the like. 2. Description of the Related Art Metal foil used in a conventional method for continuously manufacturing a metal foil-clad laminate has a small elongation at high temperatures. For example, the elongation at 180 ° C. is about 1 to 8%. For this reason, the resin-impregnated base material cannot follow the movement of the resin such as curing shrinkage and thermal expansion of the resin when the resin becomes the insulating layer, and distortion is easily generated inside the insulating layer. This distortion causes the metal foil-clad laminate to warp or twist. In particular, in metal foil-clad laminates manufactured continuously using long metal foils, the metal foil is always laminated while being stretched during the manufacturing process. And cause a twisting phenomenon. Further, in the case of a double-sided metal foil-clad laminate, if only one side of the metal foil is removed, the warpage and torsion increase due to distortion of the insulating layer. In addition, there is a problem that the dimensional change rate when the metal foil is removed due to distortion inside the insulating layer becomes large. [0003] An object of the present invention is to provide a continuous production method for obtaining a metal foil-clad laminate having less warpage and twist and excellent dimensional stability. [0004] The present invention has been made in view of the above points. The present inventors stack a long metal foil on one side of a required number of long resin-impregnated base materials and a long release film or a long metal foil on the other side, and dispose them vertically. In a method of manufacturing a metal-foil-clad laminate by cutting to a required size after curing while continuously moving a long strip-shaped laminate that has been laminated through a laminator roll, the metal foil at 150 to 200 ° C. An object of the present invention is to provide a method for manufacturing a metal foil-clad laminate, wherein a metal foil having an elongation percentage of 10 to 50% is always used while being laminated while being stretched. Hereinafter, the present invention will be described in detail. As the metal foil of the present invention, elongation at 150 to 200 ° C. is 10 to 50%, and preferably, elongation at 180 ° C. is 15 to 30%, such as copper, aluminum, iron, nickel, and zinc alone, alloy, A composite foil is used, and if necessary, an adhesive layer may be provided on one side of the metal foil to further improve the adhesion to the insulating layer described below. The thickness of the metal foil, such as 12, 18, 35, and 70 μm, which is commonly used, can be used as it is. The elongation percentage of the metal foil was measured according to the IPC standard, and the test piece length was 15
2.4 mm, width 12.7 mm, distance between chucks 50 mm, test speed 50 mm / min, ambient temperature was measured at a predetermined temperature. The resin-impregnated base material is obtained by impregnating a base material with a resin, and can be cured later to form an insulating layer. As the base material, woven fabric, nonwoven fabric, mat or paper made of inorganic fibers such as glass, polyester, polyacryl, polyvinyl alcohol, polyamide, polyimide, polyphenylene sulfite, organic synthetic fibers such as urethane and natural fibers such as cotton, or , A combination of these substrates can be used. As the resin to be impregnated into the base material, an unsaturated polyester resin, an epoxy resin, a polyimide resin, a fluorine resin, a phenol resin, a polyphenylene oxide resin, or the like alone, a modified product, or a mixture having a resin amount of 40 to 60% by weight (hereinafter simply referred to as% To be described). The resin impregnation is preferably carried out by performing the primary impregnation with the same resin or a low-viscosity resin of a different resin, since the more uniform impregnation can be achieved. Further, a filler such as aluminum hydroxide, talc, silica, alumina or the like can be added to the resin as required. Further, the resin may be used as it is, but is preferably used after defoaming under reduced pressure in order to suppress the generation of bubbles in the resin-impregnated base material. As the laminator roll, a metal, rubber, synthetic resin, or a metal roll surface coated with rubber or synthetic resin can be appropriately used. For the curing of the long strip-shaped laminate, the curing temperature and the curing time can be selected depending on the type of the resin, but it is important that the curing is performed at no pressure to 20 kg / cm ² . After cutting, it is preferable that after baking is performed at a temperature equal to or higher than the thermal deformation temperature of the used resin and then cooled to a temperature equal to or lower than the thermal deformation temperature in order to reduce warpage and twist. It is particularly preferred to quench the cooling. When a release film is used, warping can be further reduced by removing the release film after cooling. Since the metal foil has a large elongation at a high temperature, the metal foil flexibly copes with the tension of the long metal foil, and the metal foil follows the thermal expansion and the curing shrinkage of the resin. Therefore, stress does not accumulate inside the insulating layer. Since stress does not accumulate, distortion is reduced, and after complete curing, the resulting laminate has less warpage and twist. Further, since the distortion inside the insulating layer is small, the dimensional change is small even when the metal foil is removed by etching or the like. Example 1 As a resin, a commercially available vinyl ester resin (R-806DA manufactured by Showa Kogyo KK) 10
0 parts by weight, 1 part by weight of cumer hydroperoxide and styrene added so that the viscosity at 25 ° C. becomes 5 poises, and this is used as a glass cloth base material (WE-18K-BS manufactured by Nitto Boseki Co., Ltd.). Two sheets and three sheets of glass nonwoven fabric substrate (EP-4035 manufactured by Japan Vilene Co., Ltd.) of the same shape were continuously impregnated so that the resin amount became 45%. At the time of impregnation, a glass cloth substrate is placed on both sides of the three glass non-woven fabric substrates, and further, an 18 μm thick copper foil with an adhesive having a 10% elongation at 180 ° C. and a thickness of 18 μm is bonded to both outer sides thereof. These were continuously fed between a pair of laminating rolls with the agent side placed inside, and laminated at low pressure. This is sent to a curing oven at 100 ° C,
The composition was cured by heating at a low pressure for 20 minutes, and after-cured at 160 ° C. for 20 minutes to obtain a copper-clad laminate having a thickness of 1.6 mm. Example 2 A 1.6 mm copper-clad laminate was obtained in the same manner as in Example 1 except that the copper foil of Example 1 was replaced with one having an elongation of 30% at 180 ° C. Example 3 A 1.6 mm copper-clad laminate was obtained in the same manner as in Example 1 except that the copper foil of Example 1 was replaced with one having an elongation of 50% at 180 ° C. Comparative Example 1 Example 1 was repeated except that the copper foil of Example 1 was replaced with one having an elongation of 1.5% at 180 ° C.
In the same manner as in the above, a 1.6 mm copper-clad laminate was obtained. Comparative Example 2 A 1.6 mm copper-clad laminate was obtained in the same manner as in Example 1 except that the copper foil of Example 1 was replaced with one having an elongation of 7% at 180 ° C. What is obtained by cutting the double-sided copper-clad laminate obtained above into a size of 300 × 250 mm,
Further, the copper foil on one side was removed by etching at this size, treated with a dryer at 130 ° C. for 1 hour, and then cooled, and the warpage was measured. The results are shown in Table 1. Further, the dimensional change rate is obtained by cutting the obtained double-sided copper-clad laminate into a size of 250 × 250 mm, and measuring the change under each condition with an initial value between holes formed at four corners at intervals of 200 mm. Table 1 shows the results of the change rates. From Table 1, it was confirmed that the example was smaller in warpage and dimensional change rate than the comparative example. According to the present invention, a metal foil-clad laminate having less warpage and twist in a metal foil-clad laminate and a printed wiring board and having further excellent dimensional stability can be obtained. [Table 1]

Claims (1)

Claims: 1. A required number of long resin-impregnated substrates are laminated with a long metal foil on one side and a long release film or a long metal foil on the other side. In a method of manufacturing a metal foil-clad laminate by cutting a required length after curing while continuously moving a long band-shaped laminate laminated by passing between laminator rolls disposed above and below, 150 to 200 ° C. A method for manufacturing a metal-foil-clad laminate, wherein the metal foil having an elongation percentage of 10 to 50% is always stretched and laminated and integrated .