JPS59190846A - Continuous manufacture of metallic foil lined laminated board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for the continuous production of single-sided or double-sided metal foil laminates for electrical printed wiring boards.

Conventionally, these metal foil-clad laminates have been manufactured by impregnating a base material with resin varnish and drying it to create a prepreg, laminating the required number of sheets of prepreg and metal foil, and pressing and heating with a press. Since this method is a batch method, it requires a lot of labor and has low productivity.

Therefore, the present inventors proposed a continuous manufacturing method for metal foil-clad laminates in Japanese Patent Application Laid-Open No. 55-4838.

This method involves laminating sheet-like substrates impregnated with a thermosetting resin while continuously conveying them, or at the same time or after the lamination, a long sheet is coated with a thermosetting adhesive on one or both sides of the laminate. Metal foils are successively laminated and then continuously cured under substantially pressureless conditions. For electrical printed wiring boards, it goes without saying that the properties of the insulating layer formed by laminating multiple base materials are important, but the solder heat resistance and peel strength of the metal foil and adhesive layer are also important properties. Therefore, in the continuous method, the step of applying an adhesive to the metal foil and, if necessary, semi-curing it before bonding, must be carried out under conditions that satisfy these requirements.

The present invention is directed to the continuous method, in which a long metal foil coated with an adhesive on one side and a required number of resin-impregnated base materials are layered and cured while continuously conveying the metal foil. The continuous manufacturing method for stretched laminates is characterized by using a long adhesive-precoated metal foil which is coated with an adhesive in advance in a separate step and wound into a roll.

According to the present invention, in a line separate from the main metal foil-clad laminate production line in which metal foil is laminated onto a laminate of resin-impregnated base materials and subsequently cured, adhesive is applied to a long length of metal foil in advance. The adhesive is applied, semi-cured if necessary, and wound up into a roll to prepare adhesive pre-coated metal foil, which is used in the main production line. Therefore, the process of pre-coating the metal foil with adhesive and the process of curing the metal foil-clad laminate can be carried out separately, so each process can be carried out at the optimum line speed. It is now possible to strictly control the thickness of the adhesive and the degree of curing, and the surface of the metal foil can be coated with silane, for example, before applying the adhesive to the metal foil in order to improve the soldering heat resistance and peel strength of the metal foil. It becomes easy to add steps such as surface treatment with a coupling agent. Furthermore, since the process is divided into two processes and simplified, process troubles are reduced and total production efficiency is improved. The effect is particularly remarkable when producing a double-sided metal foil-clad laminate. This is because in this case the applied adhesive layer must be uniform on both sides, and this can be easily achieved using adhesive pre-coated metal foil.

The metal foil used in the present invention is a long foil made of aluminum, iron, brass, copper, etc. and having a thickness of 7 to 100 μm. In particular, electrolytic copper foil and rolled copper foil with a thickness of 18 to 40/1 m are most suitable as metal foils for printed wiring boards.

As the base material used in the present invention, asbestos paper, cloth or non-woven fabric made of organic fibers such as Tetron can also be used, but in general, kraft paper, linter paper, cotton cloth, glass cloth, glass cloth, etc., whose main component is cellulose fiber, Matte, glass paper, etc. are often used.

When the base material is cellulose fiber, in order to improve the electrical properties, heat resistance and weaving properties of the laminate, the base material may be urea resin, cyclic urea resin, melamine resin, guanamine resin, N
- Pre-impregnation with methylol acrylamide etc. is effective. In addition, the present inventors have published JP-A-55-144159.
Also effective are resins obtained by modifying the above-mentioned resins as proposed in JP-A No. 56-43329.

When the base material is glass fiber, it is preferable to treat the base material with a silane coupling agent suitable for the resin with which the base material is impregnated, from the viewpoint of electrical properties, heat resistance, and mechanical properties of the metal foil-clad laminate.

In the present invention, the resin to be impregnated into the base material is a resin that is liquid at room temperature and does not generate gas or liquid reaction by-products during the curing reaction process, such as unsaturated polyester resin, vinyl ester resin, diallyl phthalate resin, or epoxy resin. It will be done. The resin can be continuously impregnated into a long base material that is unwound and conveyed in a continuous manner, and subsequently, after laminating metal foil, it can be cured and molded under substantially no pressure. Because I can,
It is particularly preferred for continuously manufacturing rigid type laminates.

In the present invention, it is preferable that the metal foil precoated with an adhesive be slightly cured to the B stage before being wound up into a roll.

As a result, the adhesive loses its tackiness and can be rolled up without sandwiching release paper or the like in between. However, even with adhesive pre-coated metal foil obtained by drying and removing the solvent after applying an adhesive, if you roll it up with release paper etc. in between, the adhesive will be able to reach the coated surface of the metal foil. Adhesion can be prevented.

The adhesive used in the present invention is Bisfe/-
Epoxy resins such as L-A type epoxy resin, bispheno-/L'F-type epoxy resin, novolak type epoxy resin, alicyclic type epoxy resin, or mixtures thereof can be used. As the curing agent for the epoxy resin, known amine-based and acid anhydride-based curing agents can be used. In particular, aromatic amine-based, acid anhydride-based, and dicyandiamide-based curing agents are preferred because they have a long shelf life when cured to the B stage. Paper phenol metal foiling 7 - Phenolic adhesives widely used for laminates can also be used. In addition to those mentioned above, polyurethane adhesives, vinyl ester adhesives, and acrylic adhesives can also be used. These adhesives include fillers, nitrile rubber, nylon, phenoxy resin,
Flexibility agents such as polyvinyl acecool, coloring agents,
Additives such as flame retardants may be included.

According to the present invention, after the bonded surfaces of long metal foils are treated with a silane coupling agent as necessary, the adhesive is applied, dried or cured to the B stage as necessary, and wound onto a roll. . The thickness of the adhesive is preferably 10 to 120 mm, particularly 20 to 80 mm. A different type of adhesive can be applied on top of the first applied adhesive and dried or heat cured as required.

When the adhesive-precoated metal foil wound into a roll in this way is laminated onto a resin-impregnated substrate in a separate line, it is preferable to heat-treat the adhesive layer of the metal foil to dry or further harden it immediately before lamination. There is also. For example, in the case of polyvinyl acetal modified phenolic resin, which is widely used for paper phenol resin wiring boards, the temperature is 100°C to 160°C.
By performing heat treatment at C for 1 to 5 minutes, the heat sealing properties are improved by half.

Further, it may be more preferable to apply an epoxy resin on the adhesive prior to the adhesive heat treatment immediately before laminating the pre-coated metal foil. -For example,
When the combination of the adhesive and the base impregnating resin is a polyvinyl acetal-modified phenolic resin and an unsaturated polyester resin, an epoxy resin solid at room temperature, such as Epicor 1004, and an amine-based curing agent are added on top of the adhesive. 1 to 5 μm after drying the flexibility imparting agent solution depending on the
After coating to a thickness of 100°C to 160°
It is possible to dry and remove the solvent and cure the adhesive by heating at C for 1 to 5 minutes. In this case, the epoxy resin can further improve the adhesion between the phenolic adhesive and the unsaturated polyester resin, and can further improve the metal foil peel strength and solder heat resistance of the metal foil-clad laminate. The above is just an example, and the type of adhesive resin and handle material aθ to be combined with it
Depending on the type of resin, choose the most suitable one for the specific combination from epoxy resin, urea resin, phenol resin, melamine resin, nitrile butadiene rubber, polyvinyl acetal resin, polyurethane resin. It can be used in

When using the adhesive Preco-j and metal foil according to the present invention, especially when the adhesive is semi-cured to the B stage, the entire hardening of the layer after the metal foil is pasted is difficult because the base material impregnated resin is tacky. At the stage when it has reached the stage where it does not lose its elasticity and has self-supporting ability, the curing carried out under continuous transport is stopped, and at that point the long semi-finished product is cut to the required size, and the cut semi-finished product is cut into the required size. For example, 80 to 1
1-72 hours at 60°C humidity, preferably 100°C
It can be post-cured batchwise at ~140°C for 8-30 hours. This is preferable since it is possible to downsize the tunnel type hardening furnace used for continuous hardening or to increase the line speed.

Next, the present invention will be explained in more detail with reference to Examples.Example 1 A long adhesive precoated electric HtH copper foil coated with a polyvinyl acetal-modified phenolic resin adhesive to a thickness of about 30/1 m was obtained as a roll.

Five long pieces of raft paper are continuously fed out and conveyed separately, pre-impregnated with a methylolmelamine resin solution, the solvent is dried and removed, then impregnated with an unsaturated polyester resin liquid, and then continuously fed. The resin-impregnated paper substrates were combined and laminated, and then the adhesive pre-coated copper foil was applied to the upper surface of the layered body, and a polyester film was applied to the lower surface as a cover sheet, and l"cinel was applied. By passing through a mold hardening furnace at 100°C for 10 minutes (y, 1
This was then heated and cured at 1.50°C for 10 minutes to obtain a single-sided copper foil-clad laminate. The solder heat resistance and copper foil peel strength of this laminate based on JIS C6481 are 44, respectively.
seconds and], 68 Kg/h.

Example 2 In Example 1, a solution of Epicoat], 004, an amine curing agent, and a polyamide resin dissolved in methyl ethyl ketone was applied onto the adhesive and heated at 145°C. A step of drying the stool for 3 minutes was added. The solder heat resistance and copper foil peel strength of the obtained laminate based on JISC6481 were 83 seconds and 1.85.
Kg/cm.

Example 3 Epoxy resin (Epicote 828. Shell Chemical Co., Ltd.) 10
0 parts by weight, 80 parts by weight of methylnadic anhydride, 0.5 parts by weight of benzyldimethylamine, carboxylic NB
An epoxy resin adhesive consisting of 40 parts by weight of R and 150 parts by weight of methyl ethyl ketone was applied to a 35) 1 m thick electrolytic copper foil using a roll coater, heated at 150°C for 10 minutes in a tunnel furnace, and the solvent was removed. At the same time, the adhesive was cured to the B stage and wound up into a roll. Using this adhesive pre-coated copper foil, a single-sided copper foil-clad laminate was obtained under the same conditions as in Example 1. JIS of the obtained laminate
Solder heat resistance and copper foil peel strength based on C6481 were 12-7/m at 67 seconds and 1.77.

Example 4 Epoxy resin (Ebiko) 828. shell chemistry fjj
) 100 parts by weight, 30 parts by weight of 4,4-diaminodiphenylsulfone, 0.8 parts by weight of BF3-monoethylamine, 40 parts by weight of alcohol-soluble nylon, 100 parts by weight of trichlorethylene! A single-sided copper foil-clad laminate having a thickness of 1.6 mm was obtained in the same manner as in Example 3 using an epoxy resin adhesive consisting of 100 parts by weight of ethanol and 60 parts by weight of methyl ethyl ketone.

The solder heat resistance and copper foil peel strength of the obtained laminate based on JIS C6481 were 53 seconds and ], respectively.
, 96 K9/太.

Patent applicant Kanebuchi Chemical Industry Co., Ltd. Agent Patent Attorney Aka Oka Akio

Claims (1)

[Scope of Claims] (1) A metal foil-covered laminate in which a long metal foil coated with an adhesive on one side and a required number of base materials impregnated with a resin are laminated while being continuously conveyed and cured. A continuous manufacturing method for a metal foil-clad laminate, characterized in that the continuous manufacturing method uses a long adhesive-precoated metal foil that is coated with an adhesive on the metal foil in a separate process and wound up into a roll. (2) The method according to claim 1, wherein the adhesive applied to the metal foil in advance is semi-cured to B stage. (3) The method according to claim 1 or 2, wherein the adhesive is an epoxy resin adhesive. (4) The method according to claim 3, wherein the curing agent for the epoxy resin is an aromatic amine. (5) The method according to claim 3, wherein the curing agent for the epoxy resin is an acid anhydride. (6) The method according to claim 3, wherein the curing agent for the epoxy resin is dicyandiamide. (7) The method according to claim 1 or 2, wherein the adhesive is a phenolic resin adhesive. (8) The method according to any one of claims 1 to 7, wherein the adhesive layer of the adhesive precoated metal foil is continuously heated immediately before lamination with the resin-impregnated base material. (9) Immediately before laminating with the resin-impregnated base material, an epoxy resin is continuously applied on the adhesive layer of the adhesive pre-coated metal foil and heated.
Either way. 00 The method according to any one of claims 1 to 9, wherein the resin impregnating the base material is liquid at room temperature and does not generate gas or liquid by-products during the curing reaction process. (10 The method according to any one of claims 1 to 10, wherein the base material is made of cellulose fiber and/or glass fiber. The method of curing according to any one of claims 1 to 11. +13) Continuously curing the laminate until it has self-supporting ability and can be cut with a cutter, and then cut to the required size with a cutter. Claims 1 to 12, in which a large number of cut laminates are post-cured in a batch manner after cutting.
Either way. (14) The method according to any one of claims 1 to 13, wherein metal foil is laminated on both sides of the laminate. (15) The method according to any one of claims 1 to 14, wherein the metal foil is an electrolytic copper foil or a rolled copper foil.