JPH02219636A - Tacky heat resistant laminated sheet and its manufacture - Google Patents

Abstract

PURPOSE:To remove the shortage of adhesive strength, the insufficiency of dimensional stability or the shortage of fire retardance by a method in which a peelable sheet or a heat resistant resin film layer is coated with the resin solution containing phenoxyether copolymer and crosslinking agent, and is dried, whereby phenoxyether crosslinked copolymer layer in uncured state is formed, and then on the copolymer, a heat resistant resin film layer and a peelable sheet are respectively laminated. CONSTITUTION:The heat resistant laminated sheet of adhesion type is composed of a heat resistant resin layer 1, the crosslinked copolymer layer 2 of phenoxyether in uncured state and a peelable sheet 3. As the heat resistant resin layer 1, the film layer such as polyparaffin and resin, polyethersulfone resin and polyimide resin, etc., is used. The layer 2 of phenoxyether crosslinked copolymer is composed of the composition of phenoxyether copolymer and crosslinking agent. As the peelable sheet 3, paper, plastic sheet or the film whose surface is treated with silicone peeling agent on other peeling agent, is used.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to coverlay films or base films for FPCs (flexible printed circuit boards), TAB (
The present invention relates to an adhesive heat-resistant laminate sheet suitable for applications such as films for tape automated bonding, and a method for producing the same.

BACKGROUND ART Conventionally, polyimide films, polyester films, glass epoxy films, etc. have been used as coverlay films and base films for FPCs. (For example, "Electronic Technology", June 1985, special issue, 4
pp. 5-49, "Electronic Technology", 1987 edition, June special edition, 14
(Refer to pages 8-157) On pages 84-86 of "Plastics, Vol. 37, No. 7," an explanatory article about polyparabanic acid-based resins, including new engineering plastics, is published.
FP is one of the uses of polyparabanic acid resin film.
C base film or cover film is mentioned.

In Japanese Patent Publication No. 62-39103, thickness 25 to 130
Copper foil is attached to one side of the p-layer polyparabanic acid film via a heat-resistant adhesive layer, and a polyester film with a thickness of 25 to 250 p, m is attached to the other side via a heat-resistant adhesive layer. There is a disclosure regarding the attached composite film-based flexible copper clad board, and the heat-resistant adhesives include polyimide type, silicone type, phenol-butyral copolymer type, phenol-epoxy-butyral copolymer type, and phenol-epoxy-nitrile type. There is mention of the rubber copolymer type.

TAB is a technology that directly connects the electrodes of an IC chip and lead wires without using bonding wires such as gold wires. Conventionally, the films for this purpose have been made of resin films such as polyimide and copper foil. A laminated material is used.

Problems to be Solved by the Invention However, polyimide films, polyester films, glass epoxy films, polyparabanic acid resin films, polyparabanic acid resin//polyester composites used as FPC coverlay films, base films, or TAB films. Films generate formalin when bonded to metals such as copper foil, require the use of high-cost adhesives, lack adhesive strength, lack dimensional stability, or lack flame resistance. There were problems with this method, such as the fact that it could sometimes cause damage, and that there was room for improvement in terms of physical properties.

The present inventors discovered the special curing behavior of the phenoxy ether crosslinked polymer, its excellent adhesion to metals,
As a result of research into utilizing the excellent adhesion, electrical insulation, and other properties of heat-resistant resin films (particularly polyparabanic acid resin films), the present invention described below was discovered.

Means for Solving the Problems In other words, the adhesive heat-resistant laminate sheet of the present invention consists of a heat-resistant resin film layer (1)/substantially uncured heptanoxyether crosslinked polymer layer (2)/peelable. Sex sheet (3)
It is characterized by having a layered structure.

In addition, the method for manufacturing the adhesive heat-resistant laminate sheet of the present invention includes applying a resin solution containing a phenoxy ether polymer and a crosslinking agent onto a releasable sheet (3) or a heat-resistant resin film layer (1), and drying the adhesive layer. to form a substantially uncured phenoxy ether crosslinked polymer layer (2), and then a heat-resistant resin film layer (1) or a releasable sheet (3) is laminated thereon, respectively. It is something to do.

The present invention will be explained in detail below.

Film 1 Examples of the heat-resistant resin film layer (1) include film layers made of polyparabanic acid resin, polyether sulfone resin, polyimide resin, polyether ether ketone resin, polyester resin, and the like. The film layer (1) can be obtained by a casting method, an extrusion method, or other methods.

Among these resins, polyparabanic acid resin is particularly important, so the polyparabanic acid resin will be explained below.

Polyparabanic acid resin is produced by combining diisocyanate such as diphenylmethane diisocyanate, tolylene diisocyanate, diphenyl ether diisocyanate, and bitylylene diisocyanate with hydrocyanic acid in a highly polar solvent (for example, dimethylformamide) in the presence of a catalyst, as shown in the reaction formula below. It can be obtained by reacting to produce an intermediate polymer, which is then further hydrolyzed. During hydrolysis, it is possible to control the reaction conditions so that a small amount of active hydrogen remains. Polyparabanic acid resin can also be brominated.

Polyparabanic acid resin is a linear polymer as shown in the above formula, but when it is dried at high temperature, it partially undergoes a crosslinking reaction and becomes a three-dimensional structure.

The thickness of the heat-resistant resin film layer (1) is 5 to 2501 Lm, considering heat resistance, mechanical strength, flexibility, cost, etc.
In particular, it is desirable to set it to 10-125 Bm.

What is the 2-functionalized noxy ether crosslinked polymer layer (2)?

It refers to a layer formed from a composition of a phenoxy ether polymer represented by the following general formula and a crosslinking agent, and brominated phenoxy ether polymers that can impart flame retardancy are particularly important.

(In the formula, R' to R6 are each hydrogen, a lower alkyl group having 1 to 3 carbon atoms or Br, R is a fullylene group having 2 to 4 carbon atoms, m is an integer of O to 3, and n is an integer of 20 to 300. (respectively.) As a crosslinking agent, a group having high reaction activity with active hydrogen, such as an incyanate group, a carboxyl group, a reactive inducing group in a carboxyl group (such as a halide, an active amide, an active ester, an acid anhydride, etc.) is used as a crosslinking agent. )
, a compound having two or more mercapto groups, etc. is used. Polyisocyanates are particularly important, and in this case blocked polyisocyanates and microencapsulated polyisocyanates can also be used.

The thickness of the phenoxy ether crosslinked polymer layer (2) is 0.
．． It is appropriate to set it to 5 to 60 Bm, especially 1 to 30 pots. If the thickness is too thin, the adhesion to metal etc. will be impaired, and if it is too thick, the thermal stability and punching suitability will be reduced.

The removable sheets (3) include: ■Paper or plastic sheets or films whose surfaces are treated with silicone release agents or other release agents, ■Sheets that themselves have releasability, or Films, such as plastic sheets or films made of fluororesin, high-density polyethylene, etc. Plastic sheets or films molded by blending release agents, ■ Plastics made by graft polymerization of organopolysiloxane and polyolefin resin. A sheet or film is used.

Although there is no particular limitation on the thickness of the releasable sheet (3), it is usually about 12 to 250 Bm, particularly about 30 to 100 uL11.

11L2111 The adhesive heat-resistant laminate sheet of the present invention has a layer configuration of heat-resistant resin film layer (1)/substantially uncured phenoxy ether crosslinked polymer layer (2)/peelable sheet (3). have

FIG. 1 is a sectional view showing the layer structure of the adhesive heat-resistant laminate sheet of the present invention.

The adhesive heat-resistant laminate sheet having the above-mentioned layer structure typically includes:
Manufactured by the following method (1) or (2).

■ A resin solution containing a phenoxy ether polymer and a crosslinking agent is applied onto the removable sheet (3) and dried to form a substantially uncured phenoxy ether crosslinked polymer layer (2).
is formed, and then a heat-resistant resin film layer (
1) Layer.

■ A resin solution containing a phenoxy ether polymer and a cross-linking agent is applied onto the heat-resistant resin film layer (1) and dried to form a substantially uncured phenoxy ether cross-linked polymer layer (2). , then apply a releasable sheet (
3) Layer.

Comparing ■ and ■, depending on the heat-resistant resin film layer (1), it may be affected by the solvent during the formation of the phenoxy ether crosslinked polymer layer (2), so from an industrial perspective, ■ is more commonly used. There is sex. In the case of (2), if the already formed phenoxy ether cross-linked polymer layer (2) is not affected, the heat-resistant resin film layer (1) is cast onto the phenoxy ether cross-linked polymer layer (2) by a casting method. It can also be formed directly.

The adhesive heat-resistant laminate sheet of the present invention is optimal as a coverlay film for FPC. It is useful as a base film for FPCs and a film for TAB, and is expected to have a variety of other applications, including films for electric wires and communication cables, and masking films (cosmetic or protective films) for imparting heat resistance.

Effects of action and invention In the present invention, the heat-resistant resin film layer (1) is.

It plays a role as a heat-resistant base material.

The phenoxy ether-based crosslinked polymer layer (2) plays the role of an adhesive for objects such as metals, that is, it exhibits tack strength at relatively low temperatures, so it can be temporarily bonded to objects, but it can also be pressure-bonded. The phenoxyether-based crosslinked polymer layer (2), which is completely cured by heating and plays the role of firmly adhering the object and the heat-resistant resin film layer (1), has a crosslinked structure and therefore has dimensional stability against heat. Also be good and relatively low cost! There are also advantages such as:

The releasable sheet (3) serves to protect the phenoxy ether crosslinked polymer layer (2) in a substantially uncured state.

When using the adhesive heat-resistant laminate sheet of the present invention, first peel off the releasable sheet (3) from the laminate sheet, and then apply the phenoxy ether crosslinked polymer layer (2) on the metal or other object. Glue the sides. If cross-linking promotion treatment such as heat treatment is performed after pasting, the phenoxy ether cross-linked polymer layer (2) can be completely cured and adhered to the target object, and the phenoxy ether cross-linked polymer layer (2) can be completely cured and the phenoxy ether cross-linked polymer layer (2) )/
A structure consisting of the heat-resistant resin film layer (1) is obtained.

The object to be pasted is important to be a metal surface such as a copper foil, a surface on which a copper foil pattern is formed, a copper wire, an aluminum foil, or an aluminum wire, but any material other than metal can be mentioned.

In particular, when the heat-resistant resin film layer (1) is a polyparabanic acid resin and the object is a metal, the polyparabanic acid resin has excellent heat resistance and electrical insulation properties (dielectric breakdown strength, dielectric constant, dielectric loss tangent, etc.). ), flame retardancy and other properties are taken advantage of, and the phenoxyether crosslinked polymer layer (2) has extremely excellent adhesion to both polyparabanic acid resin and metal, so it maximizes its effects. be able to.

Further, by brominating at least one of the polyparabanic acid resin and the phenoxy ether crosslinked polymer, the flame retardance of the resulting laminate sheet can be further improved.

Example Next, the present invention will be further explained with reference to Examples.

Hereinafter, "parts" and "1%" are expressed on a weight basis.

Example 1 As the releasable sheet (3), a polyester film having a thickness of 50 pts and subjected to a release treatment with silicone was used.

Using an applicator, apply a crosslinkable resin solution having a composition of:
The solvent was removed by drying at 80° C. for 15 minutes to form a substantially uncured (uncured or incompletely cured) phenoxy ether crosslinked polymer layer (2) with a thickness of about 12 g.

Next, on this phenoxyether crosslinked polymer layer (2), a heat-resistant resin film layer (1) with a thickness of 3 as an example is applied.
A 0 p, ts polyparabanic acid resin film (manufactured by Tonen Petrochemical Co., Ltd.) was pressure-bonded for 81 hours.

As a result, a heat-resistant laminated sheet shown in FIG. 1 having a layer structure of (1)/(2)/(3) was obtained.

This laminated sheet was used as a coverlay film for IFPC. That is, using a commercially available copper-clad laminate having a polyimide film as a base film, after performing surface cleaning, resist printing, exposure, development, etching, and washing with water according to a conventional method, peelability from the above-mentioned laminate sheet that had been punched in advance was determined. While peeling and removing the sheet (3), the phenoxyether crosslinked polymer layer (2) side was layered, and the temperature was 1.
The phenoxy ether crosslinked polymer layer (2) was almost completely cured by heating under pressure at 75° C. for 3 minutes. The adhesion to the patterned copper-clad laminate was satisfactory.

Further, the above laminated sheet was used as a base film of FPC. That is, the releasable sheet (
3) was peeled off and the phenoxy ether crosslinked polymer layer (2) side was adhered to one side of a 15#L thick electrolytic copper foil. After pasting, pressure heating was performed at a temperature of 180° C. for 1 minute to almost completely cure the phenoxy ether crosslinked polymer layer (2).

Regarding the heat resistance of the obtained copper-clad laminate, in the solder bath test, there was no abnormality at 260° C. for 10 seconds, and there was no abnormality at 270° C. for 5 seconds.

The peel strength between (1) and (2) was 1.3 kg/cm'', and it was impossible to peel between copper surfaces 1 and (2).

Example 2 A brominated resin having the following structure was used as the phenoxyether resin in the crosslinkable resin solution for forming the phenoxyether crosslinked polymer layer (2), and 1/3 amount of Coronate L as the crosslinking agent was used. Example 1 described above was repeated, except that the polyparabanic acid resin was substituted with a block polyisocyanate and a brominated polyparabanic acid resin was used as the polyparabanic acid resin for forming the heat-resistant resin film layer (1).

The obtained laminate sheet had heat resistance and adhesive properties similar to those of Example 1, and also had good flame retardancy.

Examples 3 to 5 As the heat-resistant resin film layer (1), instead of the polyparabanic acid resin film, a polyether sulfone film (actual mm3) with a thickness of 50 ILjl, J! ! (1)/(2)/(3) in the same manner as in Example 1 using a polyimide film with 125 layers (Example 4) and a polyetheretherketone film (Example 5) with a thickness of 30 layers.
A heat-resistant laminated sheet having a layer structure of

When these laminate sheets were used as coverlay films for FPC, the adhesion to patterned copper-clad laminates was satisfactory in all cases.

These laminated sheets were also used as base films for FPC. The heat resistance of the obtained copper-clad laminates was determined by a solder bath test at 260°C for 5 seconds.The peel strength between (1) and (2) was 1.0 to 1.5 kg.
/c-, and the copper surface /(2) could not be peeled off.

Example 6 As the heat-resistant resin film layer (1), a polyparabanic acid resin film was used with a thickness of 50. Using a hazy polyester film, carry out (1) l (2) in the same manner as in Example 1.
A heat-resistant laminated sheet having a layer structure of /(3,) was obtained.

The adhesion of this mW receipt FPC with a patterned copper-clad laminate when used as a coverlay film is as follows:
Similar to Example 1, the results were satisfactory.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing the layer structure of the adhesive heat-resistant laminate sheet of the present invention. (1) Heat-resistant resin film layer. (2)...substantially uncured phenoxy ether crosslinked polymer layer, (3)...peelable sheet Figure 1

Claims (1)

[Claims] 1. Adhesive heat-resistant adhesive having a layer structure of heat-resistant resin film layer (1)/substantially uncured phenoxy ether crosslinked polymer layer (2)/peelable sheet (3) laminated sheet. 2. The heat-resistant resin film layer (1) is a film layer of a resin selected from the group consisting of polyparabanic acid resin, polyether sulfone resin, polyimide resin, polyether ether ketone resin, and polyester resin. The adhesive heat-resistant laminate sheet according to claim 1. 3. Peelable sheet (3) or heat-resistant resin film layer (
1) A resin solution containing a phenoxy ether polymer and a crosslinking agent is applied on top and dried to form a substantially uncured phenoxy ether crosslinked polymer layer (2), and then a heat resistant layer is applied on top of the phenoxy ether crosslinked polymer layer (2). 1. A method for producing an adhesive heat-resistant laminate sheet, which comprises laminating a thermoplastic resin film layer (1) or a releasable sheet (3).