JPH02218195A - Manufacture of copper-clad laminated sheet - Google Patents

Abstract

PURPOSE:To made possible the use of a prepreg using a matrix resin and holding of the physical properties of the prepreg by a method wherein a copper foil is heated and pressed in such a way that its peel strength becomes that in a specified range to form a semicured resin copper-clad laminated sheet and after being cut in a prescribed dimension, the laminated sheet is postcured at a specified temperature. CONSTITUTION:In the manufacturing method of a continuous copper-clad laminated sheet using a double belt press method, a copper foil is heated and pressed in such a way that its peel strength is 0.2kg/cm or more and is confined within a range of 90% or less of its peel strength at the time of complete curing to form a semi-cured resin copper-clad laminated sheet, then, after being cut in a prescribed dimension, the laminated sheet is postcured at temperatures of 100 to 240 deg.C. Here, it is desirable that the peel strength of the copper foil is set in 0.3kg/cm or more and the postcuring is performed in an oxygen-free atmosphere. Thereby, a prepreg for multi-stage press use using a matrix resin by a continuous press can be used without changing substantially its composition and the like and at the same time, the formation of a copper-clad laminated sheet set to the physical properties of the prepreg in a desired range can be performed easily.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention improves productivity, dimensional stability, and
This is a new manufacturing method for copper-clad laminates that combines continuous pressing and post-curing to produce copper-clad laminates with excellent mechanical strength, etc. The copper-clad laminates produced by the manufacturing method of the present invention have high dimensional accuracy. Various uses as copper-clad laminates, such as printed wiring boards,
It is suitably used as an intermediate layer, an outer layer, etc. of a multilayer board.

[Conventional technology]

As one of the manufacturing methods for copper-clad laminates, a laminate consisting of a desired number of long resin-impregnated base materials and a long copper foil layered on one or both of the outermost surfaces is placed between a pair of belts. A method for producing a continuous copper-clad laminate using a double belt press method using heat and pressure is known (Japanese Unexamined Patent Publication No. 10456/1986, etc.).

This method usually involves supplying a resin-impregnated base material and copper foil at room temperature between a pair of belts, heating and pressing the resin to a pressure of 50 kg/Cr1 or more and a temperature of about 200°C in the pressure heating area of a double belt press. The copper-clad laminate is cured, then rapidly cooled in a pressurized cooling area, and the cooled copper-clad laminate is discharged from between a pair of belts. Although this continuous manufacturing method is an excellent method, various problems arise in pressurization due to the use of high pressure, and in order to ensure productivity equivalent to multistage press, heating and pressing There were problems such as the fact that the curing time had to be kept within a few minutes.

For the purpose of reducing the working pressure and improving dimensional accuracy, the present inventor previously developed a method for pre-fusion of laminated materials under vacuum (Japanese Patent Application No. 1983-3).
No. 03284), Utilization of preheating of laminated materials (Patent Application No. 1983)
-45771) was filed.

However, no description has been found regarding a method for producing a copper-clad laminate using the above-mentioned continuous press without substantially changing the composition of the conventional multi-stage prepreg.

[Issues with conventional technology]

The present inventor has intensively studied the characteristics (advantages and disadvantages) when comparing a continuous press and a multi-stage press regarding the practical use of the above-mentioned continuous press.

As a result, the continuous press does not require (1) cutting laminated materials such as base material and copper foil into predetermined lengths;

(2) Variations in the pressure, temperature, and time applied to the materials to be laminated in the pressure and heating zone depend only on the stability of the equipment.

Therefore, it is easier to integrate the prepreg manufacturing process in accordance with (1) and (2).

(2) Also, adhesive prepreg can be used.

From ① and ③, if you understand the curing characteristics of prepreg resin and the associated physical property values, it is easy to manufacture copper-clad laminates with the degree of curing and physical properties of the resin within the desired range, and
This condition setting has little effect on processing costs.

From (2) and (2), if the stability of the device is good, the accuracy of thickness, dimensions, etc. will be improved compared to the multi-throw press.

However, in order to obtain productivity equivalent to that of multistage presses, the lamination molding time must be within a few minutes.

(2) Therefore, when producing a normal copper-clad laminate, it is necessary to use an instant-curing prepreg, but if a conventional prepreg is immediately cured by adding a catalyst, etc., it has the disadvantage of poor physical properties.

It has become clear that it has the following drawbacks.

Therefore, the inventor of the present invention conducted extensive studies on a method of utilizing the features of continuous press as described above, and as a result, completed the present invention.

[Means to solve the problem]

That is, the present invention heats and presses between a pair of belts a laminated material composed of one or more long resin-impregnated base materials and a long copper foil layered on one or both of the outermost surfaces thereof. In the method for manufacturing continuous copper-clad laminates using the double belt press method, semi-cured resin copper is heated and pressed so that the peel strength of the copper foil is 0.2 kg/cm or more and 90% or less of fully cured. This is a method for producing a copper-clad laminate, which is characterized by producing a clad laminate, cutting it into a predetermined size, and then post-curing at a temperature of 100 to 240°C. More preferably, the peel strength of the copper foil is 0. .3 kg/am or more, and post-curing is performed in an oxygen-free atmosphere.

The configuration of the present invention will be explained below.

First, the continuous press of the present invention is typified by a conventionally known double belt press.

Here, the pressurization and heating conditions may be the same as conventional ones, but preliminary fusion of laminated materials under vacuum (Japanese Patent Application No. 62-303284)
, the use of preheating of laminated materials (Japanese Patent Application No. 63-45771), and other appropriate combinations are used.

The semi-cured resin copper-clad laminate manufactured by the continuous press of the present invention is composed of a normal thermosetting resin (=matrix resin) and a base material (=base material, reinforcing base material) as its insulating layer. be.

Examples of matrix resins include phenol resins, epoxy resins, unsaturated polyester resins, cyanato resins, and other thermosetting resins, compositions formed by appropriately blending two or more of these, and furthermore, these thermosetting resins, and two or more of these. Compositions containing more than one species modified with polyvinyl butyranohyl acrylonitrile-butadiene rubber, polyfunctional acrylate compounds and other known resins, additives, etc.; cross-linked polyethylene, cross-linked polyethylene/epoxy resin, cross-linked polyethylene/cyanate Examples include crosslinked curable resin compositions made of resin, polyphenylene ether/epoxy resin, polyester carbonate/cyanate, and other modified thermoplastic resins.

In addition, base materials include kraft paper, linter paper, glass (E, D, S, T, quartz and other various glass fibers) woven and non-woven fabrics, fully aromatic polyamide, polyphenylene sulfide, polyether ether ketone, Examples include woven and nonwoven fabrics made of heat-resistant engineering plastic fibers such as polyetherimide and polytetrafluoroethylene, as well as long composite fabrics and nonwoven fabrics made by appropriately mixing or combining these materials.

This elongated base material is impregnated with the above-mentioned matrix resin, coated, etc., and dried as appropriate to produce the prepreg for laminate molding of the present invention. In the present invention, it is possible to use the same components as in the case of conventional multi-stage pressing, but naturally the type of catalyst, increase/decrease in the amount added, degree of preliminary reactivity, etc. It is preferable that the material be adapted in consideration of the manufacturing process of manufacturing and subsequent curing.

Copper foils include long electrolytic copper foils, rolled copper foils, etc., as well as those whose back surfaces (adhesive side) have been treated for adhesion and an adhesive layer has been formed on the back surface, etc. It can be used and is appropriately selected depending on the type of resin of the resin-impregnated base material described above.

A semi-cured resin copper-clad laminate is produced using the above, cut into predetermined dimensions, and then post-cured.

The semi-cured resin copper-clad laminate of the present invention can be manufactured using a copper foil with a peel strength of 0.2 kg/cm or more, more preferably a copper foil with a peel strength of 0.3 kg/cm or more, and a peel strength after complete curing. A semi-cured resin copper-clad laminate is manufactured by heating and pressurizing the copper clad laminate so that it is within 90% of the above range. When a thermosetting resin composition is used as the matrix resin, the standard for this copper foil peel strength can also be determined from the glass transition temperature of the matrix resin.
C)/glass transition temperature Tg'''C) of the matrix resin after complete curing corresponds to the range of 0.55 to 0.90.

If the copper foil peel strength is less than 0.2 kg/mark, it is undesirable and may easily cause peeling of the edges of the copper foil or other defects when cutting the obtained semi-cured resin copper-clad laminate. It is not necessary to cure to more than 90% of the peel strength after curing.

The method of continuous lamination molding while controlling the peel strength of copper foil within the above range is based on the method of measuring the peel strength in advance when the prepreg for lamination molding and the copper foil are heat treated at a predetermined temperature. It may also depend on the behavior of the glass transition temperature, and the heating temperature and heating time of the continuous press may be set according to this condition. For example, when using glass epoxy prepreg for normal multi-stage presses,
At 200℃, the peel strength of copper foil decreases to 0 after heating for 1 to 3 minutes.
．． 3 to 1.5 kg/cm (copper foil peel strength after complete hardening 2, Qkg/cm or more), Tg'/Tg' = 0.70
~0.85, and at 180°C, the peel strength of copper foil is 0.4~1.0 kg/ after heating for 2~4 minutes.
cm, Tgs/Tg' = about 0.60 to 0.75, and it is possible to manufacture a semi-cured resin copper-clad laminate in a normal continuous press time. In addition, in the above, the copper foil peel strength is 0.2 kg/a
If it is at least m, there will be virtually no cause for defects, especially during subsequent handling. Therefore, it is possible to use a semi-cured resin copper-clad laminate with an insulating layer having different properties inside and near the copper foil bonding part, and the properties include: (1) changing the glass transition temperature of the matrix resin; ■Changing the content of matrix resin or forming a resin layer. ■Changing the type of matrix resin [methods such as using a prepreg containing a radical polymerization component such as polyester, a crosslinkable thermoplastic resin such as crosslinked polyethylene, or a crosslinkable rubber near the copper foil bonding area]. ■ Types of base materials (combinations of woven fabrics, non-woven fabrics, combinations of different base materials such as glass/paper, glass/heat-resistant engineering plastics, etc.). Also, each of the combinations of (1) and (2) to (2) may be selected. The semi-cured resin copper-clad laminate of the present invention is characterized by the above-mentioned structure, but a long releasable film is further inserted between the prepregs to form a single-sided copper-clad semi-cured resin laminate. To manufacture this binding board, use a board with a number of holes in predetermined positions, and to make a binding board that is partially bonded.A continuous laminate or metal film cured between adhesive-coated copper foil or prepreg. This also includes manufacturing a semi-cured resin copper-clad laminate having a hardened insulating layer or metal layer by inserting a hardened insulating layer or metal layer.

Next, the obtained semi-cured resin copper-clad laminate is cut into a predetermined size and then post-cured. The conditions for post-curing are usually preferably the heating temperature and time used for laminated molding in a multi-stage press;
The temperature is selected from the range of 0 to 240°C and 0.5 to 5 hours.

In addition, it is preferable to use a deoxidized atmosphere as the post-curing atmosphere, and the post-curing tank may be replaced with nitrogen or the like, or a large number of semi-cured copper clad laminates may be stacked on top and bottom, and if necessary, on the side walls. Examples include a method of covering the material with heat-resistant resin, metal foil, etc.

〔Example〕

The present invention will be explained below with reference to Examples.

Note that the glass transition temperature in the examples was measured by O5C.

Examples 1 to 5 Epoxy resin faces were prepared using dicyandiamide as a curing agent, 2-ethyl-4-methylimidazole as a curing accelerator, and acetone as a diluting solvent for a brominated epoxy resin. This festival has a long width of 52
Impregnated a glass woven fabric with a thickness of 5 mm and a thickness of 0.2 mark, dried it, gel time on a 170°C heating plate was 30 seconds, and the amount of resin was 40.
% long prepreg (hereinafter referred to as PPI) was obtained.

The 8 sheets of PPI obtained above were stacked, and copper M (hereinafter referred to as Cu1) with a thickness of 35 cm was stacked on the outermost layer on both sides, and heated and pressure molded by continuous feeding into a double belt press. . The molding temperature was 200°C, the molding pressure was 50 kg/cd, and the molding time was set to the time shown in Table 1 by varying the running speed of the double belt.

The long copper-clad laminate after molding was cut into a predetermined length using a double belt, and at the same time, the ears on both sides were also cut and removed to obtain a semi-cured resin copper-clad laminate.

Next, this semi-cured resin copper-clad laminate was replaced with nitrogen gas.
It was heated for 1 hour in a hot air dryer maintained at 00°C for post-curing.

Table 1 shows the properties of the semi-cured resin copper-clad laminate obtained above and the properties of the post-cured copper-clad laminate.

Example 6 The same procedure as in Example 2 was carried out except that an adhesive-coated copper foil having an average thickness of 20 mm was used as the copper foil.

Table 1 shows the properties of the copper clad plate obtained.

Comparative Example 1 Prepreg (
PP2) was obtained, and a copper-clad laminate was obtained using a double belt press in the same manner as in Example 2. Note that post-curing was not performed.

Table 1 shows the properties of the copper clad plate obtained.

Comparative Example 2 Using the same festival as in Examples 1 to 5, a prepreg (hereinafter referred to as PP3) with a gel time of 2 minutes and 45 seconds on a 170° C. heating plate was prepared.

8 sheets of this prepreg cut into predetermined dimensions are stacked together.
Cul was layered on the outermost layer, heated using a multistage hot platen press at a temperature of 180° C. and a pressure of 50 kg/cut for 1 hour and 30 minutes, and cooled for 30 minutes to obtain a copper-clad laminate.

Table 1 shows the properties of the copper clad plate obtained.

Table 1-2 The description in Table 1 is as follows.

・Cu peel strength Measured according to JIS C-6481.

・Tg Nigaras transition temperature Measured at 08C.

・ΔL: Dimensional change rate Measured by MIL.

・PCT: Pressure test.

[Operation and effects of the invention]

As is clear from the above detailed description of the invention and examples, the method of manufacturing a semi-cured resin copper-clad laminate of the present invention and post-curing the copper-clad laminate does not meet the limitations of continuous press, that is, Productivity will be poor if an instantly curing prepreg is not used, and in that case it is difficult to maintain physical properties such as heat resistance. It also makes it possible to maintain the physical properties. Furthermore, the advantages of continuous press, such as dimensional stability and dimensional accuracy, can be further improved.

Moreover, since it does not require any special equipment to manufacture, it is clear that it is excellent in practical industrial terms.

Patent applicant: Mitsubishi Gas Chemical Co., Ltd.

Claims (1)

[Claims] 1. A laminate consisting of one or more long resin-impregnated substrates and a long copper foil layered on one or both of the outermost surfaces is heated between a pair of belts. In a method for manufacturing continuous copper-clad laminates using a double belt press method, semi-cured resin is heated and pressed so that the peel strength of the copper foil is 0.2 kg/cm or more and 90% or less of fully cured. After producing a copper-clad laminate and then cutting it to a predetermined size, it is heated to a temperature of 100~
A method for producing a copper-clad laminate, characterized by post-curing at 240°C. 2. The method for producing a copper-clad laminate according to claim 1, wherein the copper foil has a peel strength of 0.3 kg/cm or more. 3. The method for producing a copper-clad laminate according to claim 1, wherein the post-curing is performed in an oxygen-free atmosphere.