JPS6147698A - Method of producing flexible both-side copper-lined 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 [Technical Field of the Invention] The present invention relates to a novel method for manufacturing a flexible double-sided copper clad board used for printed circuit boards.

[Prior art]

Conventionally, this type of copper-clad board has generally been manufactured by coating copper foil with epoxy prepreg or polyimide prepreg containing a glass cloth base material, and then hot pressing. However, with the above method, air bubbles are easily trapped, and the reliability of withstand voltage is poor.
It has drawbacks such as difficulty in continuous production.

[Summary of the invention]

The present invention was made for the purpose of solving the above-mentioned drawbacks, and consists of two long copper plates with an insulating layer formed on one side by electrodeposition coating, and then bonded or fused together by overlapping the insulating layer surfaces. By doing so, we propose a manufacturing method for flexible double-sided copper-clad plates that is economical, highly reliable, and capable of continuous production.

[Structure of the invention]

In the present invention, a precipitated layer is formed on one side of a copper foil by electrodeposition, using a mixture of a water-dispersed electrodeposition paint that can be cured by heating or a water-dispersion type electrodeposition paint that does not harden by heating as an electrodeposition paint. After the deposited layer is immersed in an organic solvent, the moisture and organic solvent in the deposited layer are evaporated by heating to form a continuous insulating layer. Then, the obtained two single-sided copper-clad boards are stacked with their insulating layers on top of each other and bonded together using a hot press to form a double-sided copper-clad board. With this method, the adhesive strength at the interface between the copper foil and the insulating layer is much higher than that of normal brief leg bonding, so excellent adhesion strength can be obtained not only with electro-field copper foil but also with rolled copper foil. It will be done.

When forming a continuous film, it is necessary to bring the film to a so-called B stage state rather than completely curing it.
Therefore, the heating conditions are preferably 100 to 200° C. for 10 to 30 minutes, although it depends on the type of electrodeposition paint. When bonding two single-sided copper-clad boards obtained in this way by hot pressing, the preferred conditions are 200 to 300
℃ for 10 to 30 minutes at a pressure of 2 kg/cJ or more. These are below 150℃, less than 10 minutes, or 2kg/
If it is less than C♂, the adhesion between the insulating film and the copper foil is poor;
Not practical. Even when adhering by hot roll, it is desirable that the roll pressure is 5 kg/c+f or more,
Even after passing through the rolls, it is desirable to post-cure in a heating furnace set at 200° C. or higher. Furthermore, when bonding two single-sided copper-clad boards together, a fibrous base material may be inserted into the bonding surface to provide a reinforcing effect.

Furthermore, when adhesive is applied to a single-sided copper-clad board, there is no need to bring the insulating film into a B-stage state, and there is an advantage that the curing conditions can be freely selected.

As the fibrous base material used here, glass or polyamide can be used, and a suitable example is glass cloth (Arisawa Seisakusho, EPCO50, EPC102, EPC16'
0. LPCO70, LPCllo) and aromatic polyamide (Kanebo Glass Fiber Co., Ltd., Kevlar 49-1・20
．． ni-220, ni-18L K-281), etc. The base material is usually used in the form of a cloth, but it may also be a nonwoven fabric.

Although there is no limit to the thickness, if no adhesive is used, the thickness of the electrodeposited insulating film must be sufficiently larger than the thickness of the cloth. The adhesive is not particularly limited, and acrylic, epoxy, phenol, rubber, and the like can be used.

The thermosetting water-dispersed electrodeposition paint used in the present invention includes:
Acrylic-modified epoxy-based electrodeposition paints, polyesterimide-based electrodeposition paints, etc. can be used, but when used on printed circuit boards etc., paints with excellent heat resistance in terms of solder heat resistance (high temperature, short-time solder resistance ) is desirable.

The thermoplastic water-dispersed electrodeposition paint used in the present invention includes:
Phenoxy resin, polyphenylene sulfide, polyether sulfone, etc. are used, and one example of an electrodeposition coating is a method in which the resin is pulverized to 30 μm or less and dispersed in water containing a surfactant. As the surfactant used here, if the above-mentioned thermosetting water dispersion paint is anionic, an anionic surfactant is used, and preferred examples include sodium lauryl benzene sulfonate and sodium lauryl sulfate ester. can be given.

The concentration of the electrodeposition paint is preferably about 5 to 20%; if it is less than 5%, it takes time to obtain the desired film thickness, and
If it is 0% or more, steps such as washing the electrodeposited layer with water before heating are required, which is not preferable. Of course, when using the above electrodeposition paint, in order to obtain an even smoother insulating film, a small amount (0.01 to 0.1%) of a fluorocarbon-based surface fouling agent that provides a leveling effect may be added to the paint. It is possible.

When the electrodeposited layer obtained in this way is immersed in an organic solvent for a short time, the water-dispersed particles of the deposited layer are partially swollen by the organic solvent, and a continuous film without pinholes can be formed by heating. .

[Embodiments of the invention]

The figure is a system diagram showing one embodiment of the present invention. In the figure, (1) is a copper foil, (2) is a fibrous base material, (3) is an electrodeposition tank, (4) is a counter electrode, ( 5) is an electrodeposition paint, (6) is an organic solvent vapor tank, (7) is a secondary baking furnace, (8) is a hot roller, (9) is a secondary baking furnace, and (10) is a winding machine. .

The manufacturing method of flexible double-sided copper clad board is to use electrodeposition paint (5
) A continuous copper foil (1) is introduced into an electrodeposition tank (3) filled with 30% of the electrodeposition tank (3), and a voltage is applied between the copper foil side as an anode and the counter electrode (4) provided in the electrodeposition tank (3). A precipitated layer is formed by electrocoating. Next, the copper foil (1) is placed in an organic solvent vapor bath (6).
After organic solvent vapor treatment through
Heat it through a primary incineration furnace (7) at 00°C, and then sandwich the fibrous base material (2) with or without sandwiching the electrodeposited surfaces and heat with hot rollers at a temperature of 200 to 400°C. (8) Heat fusion. The adhesive sharpener may be applied before entering the hot roller (8) or, if a fibrous substrate (2) is used, the adhesive may be applied to the substrate beforehand. The obtained laminate is further cured in a secondary baking furnace (9) if necessary, and the obtained flexible double-sided copper-clad substrate is wound up in a winder (10). When using a press instead of the hot roller (8), cut the single-sided copper clad plate that comes out of the primary baking furnace (7) into a certain length, and
The sheet membranes may be overlapped and pressed, or a method may be used in which pressing is repeated while extruding a long piece like a hot roll.

Reference examples and examples will be described below.

Reference Example 1 1,900 g of ion-exchanged water and 2.4 g of lauryl sulfate ester soda were placed in a four-necked flask, and N2 gas was passed through the flask for about 30 minutes while stirring.

Next, the flow of N2 gas was stopped, and the temperature was raised to 70°C. Next, 2.0 g of ammonium persulfate.

After adding a solution of 0.7 g of sodium bisulfite dissolved in 100 g of ion-exchanged water, immediately add 2 ml of acrylonitrile.
4.0 g, α-methylstyrene 60g, styrene 60
g, methacrylic acid 20g, glycidyl methacrylate 2
Drop 0g of the mixed solution over about 30 minutes, and after dropping 7
The mixture was reacted at 0° C. for 3 hours to produce a thermosetting water-dispersed electrodeposition paint (A) with a non-volatile content of 19.5%.

Reference example 2 206g of diaminodiphenylmethane in the fourth flask,
After charging 400 g of anhydrous trimellit and 600 g of m-cresol and reacting at 150°C for 1 hour, the temperature was raised to 200°C, and 400 g of polyethylene terephthalate and Tris(
β-hydroxyester) isocyanurate 200g,
4 g of butyl titanate was added and dissolved. Next, after reacting at 220 to 240°C for about 3.5 hours while distilling m-cresol and the produced ethylene glycol out of the system, FC431 (fluorosurfactant, 3
(manufactured by M Company) was added thereto and stirred for about 15 minutes to obtain a polyesterimide resin. Obtained.

The resin was pulverized with a jet mill to an average particle size of 11 μm. 500g of this powder and 5g of lauryl sulfate ester soda
A thermosetting water-dispersed electrodeposition paint (B) having a non-volatile content of about 10% was produced by dispersing it in 45'OOg of ion-exchanged water containing:

Reference Example 3 Phenoxy resin (manufactured by UCC, PHK K) was ground to an average particle size of 14 μm using a jet mill, and this powder
g was dispersed in 4,500 g of ion-exchanged water containing 5 g% of sodium laurylbenzenesulfonate to produce a thermoplastic water-dispersed electrodeposition paint (C) with a nonvolatile content of about 10%. - Reference example 4 Polyether sulfone (Mitsui Toatsusha, Victrex)
was pulverized with a jet mill to an average particle size of 13 μm, and 500 g of this powder was mixed with 4.0 g of sodium laurylbenzenesulfonate.
g-FC431 (3M, fluorosurfactant) 1.0
4500 g of ion-exchanged water containing g - dispersed in the middle,
A thermoplastic water-dispersed electrodeposition paint (D) having a non-volatile content of about 10% was produced.

Examples 1 to 6 Flexible double-sided copper-clad boards were manufactured according to the manufacturing method shown in the figure using the electrodeposition paint, fiber base material, adhesive, and organic solvent shown in Table 1 under the conditions shown in Table 1. Copper foil (1) width 500m1I+,
It is a continuous foil with a thickness of 25 μm, and the applied voltage for electrodeposition coating is 50V. The properties of the obtained flexible double-sided copper clad board are also listed in Table 1.

From the above results, it can be seen that an excellent flexible double-sided copper-clad board can be obtained.

〔Effect of the invention〕

According to the present invention, two pieces of long copper foil with an insulating layer formed on one side by electrodeposition coating are bonded together.
This has the effect of providing a flexible double-sided copper-clad plate with no air bubbles, high reliability in voltage resistance, and excellent solder heat resistance and peel strength.

[Brief explanation of drawings]

The figure is a system diagram showing a method for manufacturing a flexible double-sided copper clad plate according to an embodiment of the present invention. In the figure, (1) is copper foil, (2) is fibrous base material, (3
) is an electrodeposition tank, (4) is a counter electrode, (5) is an electrodeposition paint, (
6) is an organic solvent vapor tank, (7) is a secondary baking furnace, (8) is a hot roller, (9) is a secondary baking furnace, and (10) is a winding machine.

Claims (4)

[Claims] (1) Flexible double-sided copper, characterized by bonding or fusing two single-sided copper-clad boards with an insulating layer formed on one side by electrodeposition coating on a long copper foil, overlapping the insulating layer surfaces. Method of manufacturing veneer. (2) A flexible double-sided structure according to claim 1, characterized in that when the insulating layer surfaces of two single-sided copper-clad boards are overlapped and bonded or fused, a fibrous base material is sandwiched therebetween. Method of manufacturing copper clad boards. (3) The method according to claim 1 or 2, characterized in that an adhesive is applied when the surfaces of the insulating layers of two single-sided copper-clad boards are overlapped and bonded or fused together. A method for manufacturing flexible double-sided copper clad plates. (4) Claims characterized in that when the insulating layer surfaces of two single-sided copper-clad boards are overlapped and bonded or fused, a fibrous base material coated with or impregnated with an adhesive is sandwiched. 2. A method for producing a flexible double-sided copper clad board according to item 1.