JP2006103039A - Laminated sheet and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method of a laminated sheet stable in dimensional (change) characteristics, and the laminated sheet manufactured thereby. <P>SOLUTION: In the manufacturing method of the laminated sheet by laminating a predetermined number of prepregs impregnated with a resin and heating them under pressure, at least one prepreg is heat-treated once or a plurality of times at a temperature lower in 10-40°C than a temperature at which the melt viscosity of the resin infiltrated in the prepreg lowers maximally before lamination. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a laminate and a laminate produced by the method.

  Conventionally, the production of laminated plates is made by stacking copper foil, prepreg, and copper foil on the mirror plate, and then stacking the mirror plate on top of it, and repeating this to form a laminated structure composed of multiple configurations and mirror plates between the hot plates of the multi-stage press. A desired number of components are set and pressure is applied, and the hot plate is heated to a desired temperature and heated for a predetermined time to be laminated and pressurized to be integrated. As for the stability of dimensional characteristics, as shown in Japanese Patent Application Laid-Open No. 59-64350 and Japanese Patent Publication No. 05-57752, variation in dimensional characteristics can be achieved by aging the metal foil-clad laminate after lamination molding. A technique for reducing the above is known.

JP 59-64350 A Japanese Patent Publication No. 05-57752

  When the prepreg obtained in the prepreg manufacturing process is used as it is in the laminating process, the resin hardens and shrinks during the prepreg manufacturing drying process, and at the same time, the tension (tension) applied to the glass cloth or glass paper causes the prepreg to enter the prepreg. Since large strain (stress) remains and pressure is required in the lamination process, this strain (stress) is constrained and remains in the laminate, resulting in a difference in dimensional (change) characteristics. There is a problem. An object of the present invention is to solve the above-mentioned problems and to provide a method for producing a laminated plate having stable dimensional (change) characteristics and a laminated plate produced by the production method.

In order to solve the above problems, the present invention is configured as follows.
(1) In a method for producing a laminated board in which a predetermined number of prepregs impregnated with resin are laminated and heated and pressed, the melt viscosity of the resin impregnated with at least one prepreg before the laminated structure A method for producing a laminated board, characterized in that heat treatment is performed once or a plurality of times at a temperature 10 to 40 ° C. lower than the lowest temperature.
(2) A laminate produced by the laminate production method according to item (1).

  According to the present invention, it is possible to provide a method of manufacturing a laminated plate having stable dimensional (change) characteristics and a laminated plate manufactured by the manufacturing method.

  The present invention relates to a method for producing a laminated plate in which a predetermined number of prepregs impregnated with a resin are laminated and heated and pressed, and before the laminated constitution, at least one prepreg is melted with the resin impregnated in the prepreg. A method for producing a laminated board characterized by heat-treating once or a plurality of times at a temperature lower by 10 to 40 ° C. than a temperature at which the viscosity is lowest, and the laminated board produced by this production method. In addition, as a prepreg used for this invention, what impregnated resin to fiber base materials, such as glass fiber base materials, paper fiber base materials, resin fiber base materials, such as an aramid, is mentioned. Examples of the laminate of the present invention include a double-sided metal-clad laminate, a single-sided metal-clad laminate, a resin plate, and a wiring board.

  In the method for producing a laminate of the present invention, one or a plurality of prepregs may be laminated, and metal foil may be arranged on both sides or one side thereof to form a metal-clad laminate, or a resin that does not arrange metal foil. It may be a board, or may be a multilayer wiring board using an inner layer board. The resin impregnated in the prepreg is not particularly limited, and examples thereof include a thermosetting resin and a thermoplastic resin, and a thermosetting resin is preferable. Thermosetting resins include phenol resin, urea resin, melamine resin, alkyd resin, acrylic resin, unsaturated polyester resin, diallyl phthalate resin, epoxy resin, silicone resin, resin synthesized from cyclopentadiene, tris (2-hydroxyethyl) ) Resin containing isocyanurate, resin synthesized from aromatic nitrile, trimerized aromatic dicyanamide resin, resin containing triallyl trimetallate, furan resin, ketone resin, xylene resin, thermosetting containing condensed polycyclic aromatic Resin, benzocyclobutene resin, norbornene resin and the like can be used. Examples of the thermoplastic resin include polyimide resin, polyphenylene oxide resin, polyphenylene sulfide resin, aramid resin, and liquid crystal polymer. A filler may be added to the resin. Examples of the filler include silica, talc, aluminum hydroxide, aluminum borate, aluminum nitride, and alumina.

  The heating and pressing conditions are not particularly limited, but are desirably determined according to the characteristics of the prepreg (impregnated resin) used. Prior to the layered configuration, at least one prepreg of the layered prepreg is heat-treated, but when there are two or more layered prepregs, two or more prepregs are preferably heat-treated. More preferably, all prepregs to be processed are heat-treated. Note that the number of prepregs to be stacked during the heat treatment may be one prepreg or two or more prepregs, but is preferably the same as the number of stacked prepregs.

  The heat treatment of the prepreg before the laminated structure may be performed using a dryer or the like. The temperature of the heat treatment is a temperature that is 10 to 40 ° C. lower than the temperature at which the melt viscosity of the resin impregnated in the prepreg is lowest. If it is less than 10 degreeC, hardening will progress too much and it will become difficult to control the degree of hardening of a prepreg, and if it exceeds 40 degreeC, the effect of heat processing will be scarce. The time for the heat treatment is not particularly limited, but is preferably 10 to 600 seconds, more preferably 20 to 120 seconds, and particularly preferably 30 to 60 seconds. If it is less than 10 seconds, the effect of the heat treatment is poor, and if it exceeds 600 seconds, curing proceeds too much, and it becomes difficult to control the degree of curing of the prepreg. The number of heat treatments is one or more, but it is desirable to appropriately determine the heat treatment temperature, heat treatment time, resin characteristics, and the like. The method for cooling the prepreg after the heat treatment is not particularly limited, but it is preferable that the prepreg is naturally cooled gradually by air cooling or the like to room temperature (25 ° C.). Therefore, when the prepreg is laminated or is subjected to the next heat treatment, it is preferably performed after the prepreg returns to room temperature (25 ° C.). Heat treatment of the prepreg before the laminated structure, or heat treatment and further natural cooling gradually to room temperature (25 ° C.) can prevent the distortion (stress) from being different for each constituent position of the prepreg after the heat treatment. It becomes possible, and it becomes possible to reduce the strain (stress) remaining in the prepreg in the manufacturing process of the prepreg.

  The temperature at which the melt viscosity of the resin impregnated in the prepreg becomes the lowest can be obtained by collecting the resin from this prepreg and measuring the viscosity change curve using a commercially available flow tester or the like.

Next, the present invention will be specifically described with reference to examples. The present invention is not limited by the examples.
(Manufacture of prepreg)
Brominated epoxy resin (using Epicoat 5040B80 (trade name) manufactured by Yuka Shell Epoxy Co., Ltd.) 90 parts (parts by weight, the same applies hereinafter), cresol novolac type epoxy resin (Dainippon Ink Chemical Co., Ltd., N-673-) 10 parts of 80M (trade name)), 1.5 parts of dicyandiamide, 0.05 part of 2-ethyl-4-methylimidazole, and 50 parts of methyl ethyl ketone were mixed to prepare a resin varnish having a solid content of 69.6% by weight. . Using this resin varnish and a glass cloth base (glass fiber base), a glass cloth (MIL standard: 7629) having a basis weight of 210 g / m ² , a width of 510 mm, and a thickness of 0.2 mm, the resin solid content of the prepreg ( (Including inorganic filler) was adjusted to 45% by weight and passed through a drying furnace at 170 ° C. at a speed of 9 m / min to prepare a prepreg. A solid resin was collected from the prepreg, and a viscosity change curve was measured using a flow tester manufactured by Shimadzu Corporation. As a result, it was found that the temperature at which the melt viscosity was lowest was 120 ° C., and the minimum melt viscosity of the resin at that time was 45 Pa · s. The resin flow of this prepreg at 160 ° C. was 15.6% by weight, and the curing time was 96 seconds.

(Example 1)
The prepreg prepared above is cut into dimensions of 510 mm in length and 510 mm in width, and the prepreg is 30 in a dryer set at 110 ° C. so that it becomes 10 ° C. lower than the temperature at which the resin viscosity is lowest (120 ° C.). Heat-treatment for 2 seconds and natural cooling to room temperature (25 ° C.) once were performed, and a 35 μm thick copper foil was placed on each end plate (material SUS304), and the heat-treated prepreg was placed thereon. Place one sheet, put a 35μm thick copper foil on it, stack a mirror plate, and repeat the process 10 times. Load the components between the hot plates and heat them at the lamination temperature of 185 ° C and the pressure of 2.5MPa. Then, pressurization was started and heating was performed for 100 minutes to produce a glass substrate double-sided copper-clad laminate having a thickness of 0.2 mm.

(Example 2)
The prepreg produced above is cut into dimensions of 510 mm in length and 510 mm in width, and the prepreg is 30 in a dryer set at 80 ° C. so that the temperature of the resin becomes 40 ° C. lower than the lowest temperature (120 ° C.). A glass substrate double-sided copper-clad laminate having a thickness of 0.2 mm was prepared in the same manner as in Example 1 except that the heat treatment for 2 seconds and the process of natural cooling to room temperature (25 ° C.) were repeated three times. Produced.

(Example 3)
The prepreg produced above is cut into a dimension of 510 mm in length and 510 mm in width, and the three prepregs are overlapped, and the prepreg is adjusted to 110 ° C. so that the temperature becomes lower by 10 ° C. than the temperature at which the resin has the lowest viscosity (120 ° C.). Heat treatment for 30 seconds in the set dryer and natural cooling to room temperature (25 ° C) once were put on each end plate (material SUS304) with a 35 μm thick copper foil. Three heat-treated prepregs are placed on top, a 35 μm thick copper foil is placed thereon, a mirror plate is further stacked, and a component obtained by repeating this 10 times is loaded between the hot plates, and the lamination temperature is 185 ° C. Heating and pressurization were started under conditions of a pressure of 2.5 MPa, and heating was performed for 100 minutes to produce a glass substrate double-sided copper-clad laminate having a thickness of 0.6 mm.

(Example 4)
The prepreg produced above is cut into a dimension of 510 mm in length and 510 mm in width, the three prepregs are overlapped, and the prepreg is heated to 80 ° C. so that it is 40 ° C. lower than the temperature at which the resin viscosity is lowest (120 ° C.). A process of heat treatment for 30 seconds in a set dryer and natural cooling to room temperature (25 ° C.) was repeated 5 times, and a 35 μm thick copper foil was placed on each end plate (material SUS304). Three heat-treated prepregs are placed on top, a 35 μm thick copper foil is placed thereon, a mirror plate is further stacked, and a component obtained by repeating this 10 times is loaded between the hot plates, and the lamination temperature is 185 ° C. Heating and pressurization were started under conditions of a pressure of 2.5 MPa, and heating was performed for 100 minutes to produce a glass substrate double-sided copper-clad laminate having a thickness of 0.6 mm.

(Comparative Example 1)
The prepreg produced above is cut into dimensions of 510 mm in length and 510 mm in width, and a copper foil with a thickness of 35 μm is placed on the end plate (material SUS304), one prepreg is placed thereon, and a thickness of 35 μm is placed thereon. Put the copper foil on top, and stack the end plate, and repeat the process 10 times. Load the components between the hot plates and start heating and pressurization under the conditions of a lamination temperature of 185 ° C and a pressure of 2.5 MPa. Heat for 100 minutes. Thus, a glass substrate double-sided copper-clad laminate having a thickness of 0.2 mm was produced.

(Comparative Example 2)
The prepreg prepared above is cut into dimensions of 510 mm in length and 510 mm in width, and a copper foil with a thickness of 35 μm is placed on a mirror plate (material SUS304), three prepregs are placed on it, and a thickness of 35 μm is placed thereon. Put the copper foil on top, and stack the end plate, and repeat the process 10 times. Load the components between the hot plates and start heating and pressurization under the conditions of a lamination temperature of 185 ° C and a pressure of 2.5 MPa. Heat for 100 minutes. Thus, a glass substrate double-sided copper-clad laminate having a thickness of 0.6 mm was produced.

About the glass base-material double-sided copper clad laminated board and prepreg produced in Examples 1-4 and Comparative Examples 1 and 2, the characteristic was measured as follows. The results are shown in Table 1.
(Dimensional characteristics of glass substrate double-sided copper-clad laminate)
Regarding the dimensional characteristics of the glass-based double-sided copper-clad laminate, holes were made in four corners of a sample size of 330 mm × 250 mm, and the dimensional change rate in the vertical direction and the horizontal direction was measured. The dimensional change rate was calculated from the dimensional change after etching the entire surface (remaining copper ratio 0%) and drying at 170 ° C. for 30 minutes, based on the normal state. In this example, the warp direction is parallel to the fiber direction of the glass cloth of the double-sided copper-clad laminate of the glass substrate, and the weft direction is perpendicular to the fiber direction.

(Performance characteristics of prepreg)
The performance characteristics of the prepreg were determined from the heat-treated prepreg (Examples 1 to 4) and the unheated prepreg (Comparative Examples 1 and 2). The resin flow test condition, which is a performance characteristic of the prepreg, was prepared by cutting three prepregs into 150 mm square biases and superposing three sheets, heating and pressing at 160 ° C. and 1 MPa for 10 minutes, and pressing a 150 mm square sample. It was calculated from the weight change before and after. The curing time, which is a performance characteristic of prepreg, is inserted between hot plates held at 160 ° C ± 1 ° C, with multiple prepregs cut to 50 mm square bias so that the total weight is about 15 g. Then, pressurization was performed at 1 MPa for 10 seconds, and then the hot plate was opened, and the time until the resin that had flowed out hardened on the hot plate.

(Formability of glass substrate double-sided copper-clad laminate)
The copper of the glass-based double-sided copper-clad laminate was etched all over, and the presence or absence of blurring and voids in the laminate was confirmed. ○: Blurring, no generation of voids, X: Hazing, generation of voids.

  In the case of a laminated plate having a plate thickness of 0.2 mm, as shown in Examples 1 and 2, compared with Comparative Example 1, the dimensional change rate is -0.0202% to -0.0172 in the vertical direction. % To −0.0182%, and in the transverse direction, from −0.0176% to −0.0148% and −0.0162%, the dimensional change rate is 8 to 16 by heat treatment. % Was found to be reduced. Similarly, in the case of a laminated plate having a plate thickness of 0.6 mm, it was found that the dimensional change rate was reduced by 10 to 16% by comparing Examples 3 and 4 with Comparative Example 2.

Moreover, it turns out that the performance characteristic of a prepreg and the moldability of a glass base material double-sided copper clad laminated board hardly fall by the heat processing of this invention.

Claims (2)

  In a method of manufacturing a laminated board in which a predetermined number of prepregs impregnated with resin are laminated and heated and pressed, at least one of the prepregs impregnated with the prepreg has the lowest melt viscosity before being laminated. The manufacturing method of the laminated board characterized by heat-processing 1 time or several times at the temperature 10-40 degreeC lower than the temperature to become. The laminated board manufactured by the manufacturing method of the laminated board of Claim 1.