JPH05286093A - Manufacture of laminated board - Google Patents

Abstract

PURPOSE:To bend a laminated board inwards without forming creases, and to bend the laminated board outwards without forming a crack. CONSTITUTION:5-50 pts.wt. inorganic fillers having mean particle size of 1mum or less and maximum particle size of 2.5mum of are compounded with a 100 pts.wt. flexible thermosetting resin. A base material is impregnated with the inorganic filer-filled flexible thermosetting resin whilc a required number of the base materials are superposed and laminated. The flexibility of the flexible thermosetting resin can be inhibited by adding the inorganic fillers.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a laminated board which can be bent into a multifaceted shape.

[0002]

2. Description of the Related Art As electronic devices have become lighter, thinner, shorter, and smaller, it has been devised to arrange printed wiring boards in a multi-sided shape so as to reduce the installation space. For example, by connecting a rigid printed wiring board based on a conventionally used glass cloth etc. with a connector via a flexible wiring board based on a polyimide film or a polyester film, and bending the flexible wiring board. A plurality of rigid printed wiring boards are arranged in a polyhedral shape.

However, when such a rigid printed wiring board is connected by a flexible wiring board, the printed wiring board itself is formed to be bendable because of problems of connection reliability and cost. Is being attempted. In this product, a flexible thermosetting resin is impregnated into a base material such as a glass cloth, and a plurality of the base materials are laminated and laminated to give flexibility to the laminated plate so that it can be bent. It is a thing.

[0004]

However, in this laminated plate having flexibility, since the flexible thermosetting resin has too high flexibility, when the laminated plate is bent, an internal bending portion is not formed. There is a problem that wrinkles may be formed on the inner surface and wrinkles may occur in the circuit, resulting in disconnection. The present invention has been made in view of the above points, and an object thereof is to provide a method for manufacturing a laminated plate that can be bent inward without wrinkles and can be bent outward without cracks. To do.

[0005]

A method for manufacturing a laminated board according to the present invention comprises an inorganic filler having an average particle size of 1 μm or less and a maximum particle size of 2.5 μm or less in 100 parts by weight of a flexible thermosetting resin. Is mixed in an amount of 5 to 50 parts by weight, the base material is impregnated with the flexible thermosetting resin containing the inorganic filler, and a required number of the layers are laminated to form a laminate.

The present invention will be described in detail below. The flexible thermosetting resin may be an epoxy resin, a vinyl ester resin, an unsaturated polyester resin, a polyphenylene oxide resin, etc., in which linear molecules are incorporated, the crosslink density is reduced, or a rubber or the like is used. It is obtained by making it flexible by modifying it with a flexible material or adding a flexible material. Use the commercially available flexible thermosetting resin as it is. You can

As the inorganic filler, antimony trioxide, aluminum hydroxide, alumina, silica or the like can be used, and in the present invention, the average particle size is 1
The maximum particle size is 2.5 μm or less. Then, this inorganic filler is added to the flexible thermosetting resin and diluted with a solvent to prepare a resin varnish. The addition amount of the inorganic filler is set in the range of 5 to 50 parts by weight with respect to 100 parts by weight of the resin solid content of the flexible thermosetting resin.

Thus, a woven or non-woven fabric made of glass fiber is used as a substrate, the substrate is impregnated with the above-mentioned flexible thermosetting resin containing an inorganic filler, and a required number of the resin-impregnated substrates are stacked, Further, if necessary, a metal foil such as a copper foil is laminated on one side or both sides thereof, and this is laminated and molded to cure the flexible thermosetting resin, whereby a laminated plate can be obtained. Here, a long base material such as glass cloth is used, and the base material is continuously fed to impregnate the base material with a flexible thermosetting resin. It is possible to use a method in which a required number of laminated sheets are continuously fed to a heating furnace and passed therethrough to cure the flexible thermosetting resin to continuously produce laminated plates.

In the laminated board according to the present invention manufactured as described above, since the laminated board is made of a flexible thermosetting resin, the laminated board can be easily bent into a multi-sided shape. . Since the flexible thermosetting resin contains an inorganic filler, the flexibility of the flexible thermosetting resin can be suppressed, and when the laminated plate is bent inward, wrinkles are formed on the inner periphery thereof. It is designed so that it can be prevented from entering. In order to prevent the occurrence of wrinkles, it is necessary to add the inorganic filler in an amount of 5 parts by weight or more based on 100 parts by weight of the flexible thermosetting resin. However, since the elongation percentage of the flexible thermosetting resin decreases due to the addition of the inorganic filler, if the addition amount is too large, a crack may occur on the outer periphery of the laminate when the laminate is bent outwardly. It is necessary to set the addition amount to 50 parts by weight or less based on 100 parts by weight of the flexible thermosetting resin. If the particle size of the inorganic filler is large, the effect of lowering the elongation of the flexible thermosetting resin tends to increase, and cracks may occur on the outer periphery of the laminated plate when it is bent outward. Therefore, in order to secure the elongation rate which is the basic characteristic of the flexible thermosetting resin,
It is necessary to use an inorganic filler having an average particle size of 1 μm or less and a maximum particle size of 2.5 μm or less.
By adding the inorganic filler to the flexible thermosetting resin as described above, the flame retardancy can be enhanced, and the inorganic filler serves as an extender, which leads to cost reduction.

[0010]

The invention will now be illustrated by the examples. (Example 1) A flexible unsaturated polyester resin ("Polymer 6320F" manufactured by Takeda Pharmaceutical Co., Ltd.) was mixed by adding an antimony trioxide having a particle size shown in Table 1 as an inorganic filler in an addition amount shown in Table 1. did. And a non-woven fabric substrate made of long polyester and glass fibers (thickness: 0.35 m)
m) Two sheets were impregnated with the above resin varnish containing an inorganic filler so that the amount of impregnated resin was 50% by weight, and a long glass woven fabric substrate (“WE-05E” manufactured by Nitto Boseki Co., Ltd.)
Similarly, the resin varnish containing the inorganic filler was impregnated so that the amount of the impregnated resin was 50% by weight. The resin-impregnated glass woven base material is placed on both sides of the resin-impregnated polyester / glass fiber mixed nonwoven fabric base material, and 35 μm-thick long copper foil is placed on both sides of the resin-impregnated polyester / glass fiber mixed nonwoven fabric base material, and a pair of these are laminated It was continuously fed between rolls and laminated at low pressure. Next, these were continuously sent to a curing furnace and cured by heating at 100 ° C. for 20 minutes, and further after-cured at 160 ° C. for 20 minutes to obtain a copper-clad laminate having a thickness of 1.6 mm.

(Examples 2 and 3) Table 1 as an inorganic filler
A copper-clad laminate having a thickness of 1.6 mm was obtained in the same manner as in Example 1 except that antimony trioxide having a particle size shown in Table 1 was used and the addition amount shown in Table 1 was added. (Comparative Examples 1 to 3) A thickness of 1.6 mm was obtained in the same manner as in Example 1 except that antimony trioxide having a particle size shown in Table 1 was used as the inorganic filler and the addition amount shown in Table 1 was added. To obtain a copper-clad laminate.

(Comparative Example 4) A thickness of 1.6 m was obtained in the same manner as in Example 1 except that the inorganic filler was not added.
m copper-clad laminate was obtained. Outer bendability and inner bendability of the copper-clad laminates obtained in Examples 1 to 3 and Comparative Examples 1 to 4 were measured. The outward bendability was measured by measuring the minimum bend radius at which a crack does not occur on the outer periphery of the bent portion when the copper clad laminate is bent 180 ° so as to be wound around a core rod having a predetermined radius. In addition, the internal bending property is measured by etching the copper foil of the copper-clad laminate to a width of 1
This was performed by measuring a minimum bending radius at which a wrinkle does not occur in the circuit on the inner circumference of the bent portion when a circuit of mm is formed and the portion provided with this circuit is bent in the same manner by 180 °. The results are shown in Table 1.

[0013]

[Table 1]

As can be seen from Table 1, it is confirmed that, in each of the examples, the addition of the inorganic filler has good outward bendability and inward bendability. On the other hand, in Comparative Examples 1 and 3 using an inorganic filler having a large particle diameter and in Comparative Example 2 in which the amount of the inorganic filler added is too large, the outer bendability is lowered,
Further, in Comparative Example 4 in which the inorganic filler was not added, the inward bendability was poor.

[0015]

As described above, according to the present invention, 100 parts by weight of a flexible thermosetting resin is mixed with 5 to 50 parts by weight of an inorganic filler having an average particle size of 1 μm or less and a maximum particle size of 2.5 μm or less. As a result, the flexibility of the flexible thermosetting resin can be suppressed by the addition of the inorganic filler, and the laminated plate can be bent inward without wrinkling, and the particle size of the inorganic filler can also be increased. It is possible to prevent cracks from occurring when the laminated plate is bent outwardly by adjusting the amount and the compounding amount.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Internal reference number FI Technical display location C08J 5/10 7188-4F H05K 1/03 F 7011-4E // B29K 105: 06 (72) Invention Tetsuro Mitsuto 1048, Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Works Co., Ltd.

Claims (1)

[Claims] 1. 100 parts by weight of a flexible thermosetting resin are mixed with 5 to 50 parts by weight of an inorganic filler having an average particle size of 1 μm or less and a maximum particle size of 2.5 μm or less, and the inorganic filler containing the inorganic filler is mixed. A method for manufacturing a laminated plate, characterized in that a base material is impregnated with a flexible thermosetting resin, and a required number of the layers are laminated to form a laminate.