JP2001105555A - Adhesive film and method for manufacturing multi-layer printed wiring board using adhesive film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filmlike adhesive and a method for manufacturing a build-up type multi-layer printed substrate using the filmlike adhesive. SOLUTION: The adhesive film for interlayer insulation is structured of a support base film and an adhesive film which is laminated on the surface of the support base film and has the same as or a smaller area than the support base film and further, is composed of a hot-fluid/cold-solid heat-curable resin composition layer showing physical properties as shown in the oblique line region S in Fig. 1 in the relationship between temperature and melt viscosity and a solid state at normal temperatures, the surface of the resin composition being covered for protection with a stretch-forming-type polypropylene film having specified surface roughness. The adhesive film characterized by the described structure is laminated on a pattern-fabricated circuit substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a build-up type multilayer printed wiring board in which conductive circuit layers and insulating layers are alternately stacked, and to a film-like adhesive and a multilayer printed wiring board using the same. It concerns the manufacturing method.

[0002]

2. Description of the Related Art In recent years, a manufacturing technique of a build-up type multilayer printed wiring board in which organic insulating layers are alternately stacked on a conductor layer of an inner circuit board has attracted attention. JP-A-8-64
No. 960 discloses a method of manufacturing a multilayer printed wiring board by applying an undercoat adhesive, temporarily drying, bonding a film-like additive adhesive, heating and curing, roughening with an alkaline oxidizing agent, and forming a conductive layer by plating. Have been. Also,
The present inventors have also disclosed in Japanese Patent Application No. 9-357420 an interlayer adhesive film for a multilayer printed wiring board, which can simultaneously cover an inner layer circuit pattern and fill a resin in a surface via hole and / or a through hole simultaneously. A method for manufacturing a multilayer printed wiring board used is disclosed. The dry film for a printed wiring board such as the film of the invention basically has a structure of a support base film / resin composition / protective film and is wound up on a roll and stored. Usually, storage is performed in an atmosphere of refrigeration or less, but at that time, there is a problem that the protective film is peeled off from the resin surface and floating occurs. In use, a single-wafer process for an inner layer circuit may be used, and supply of a film in a sheet form has been strongly demanded for easy handling.

[0003]

Most of the protective film of a dry film for a printed wiring board is made of polyethylene. When a polyethylene protective film was used as the adhesive film disclosed in Japanese Patent Application No. 9-357420, the adhesion between the resin and the protective film was weak, and there were defective portions where floating occurred in the roll after refrigerated storage. In addition, if the film is cut into a sheet, the curl on the protective film side will be severe and resin cracks will occur during handling,
There is a problem in that it cannot be supplied in a state that can withstand practical use. The cause is that the resin composition of the present invention is a solid resin having no viscosity at room temperature. For this reason, heating was required for bonding the protective film, and the protective film was stretched during the thermal lamination, and was caused by the stress generated due to the difference in thermal expansion between the protective film, the supporting base film, and the resin. In view of the above problems, we have developed a build-up adhesive film that can be supplied in the form of a sheet without curling while the protective film adheres well to the resin surface, and a method of manufacturing a multilayer printed wiring board using the same. Is to do.

[0004]

According to the present invention, there is provided a support base film and a support base film laminated on the surface thereof, having the same or smaller area as the support base film, and having a relation between temperature and melt viscosity. In the adhesive film formed of a thermo-fluid, room-temperature solid thermosetting resin composition layer having the physical properties of the hatched area S, the surface of the resin composition is further subjected to arithmetic average roughness Ra; 0.1 μm or more; Height Rmax; 10
An interlayer insulating adhesive film having a structure protected by a stretch-molded polypropylene film having a surface roughness of not more than μm, and 1) the resin composition layer from which the protective film of the interlayer insulating adhesive film was peeled off, After directly covering at least the pattern processed portion with the resin composition layer on one or both sides of the patterned circuit board,
2) a step of heating and pressurizing and laminating an adhesive film temporarily bonded on one or both sides of the circuit board under vacuum conditions, 3) a supporting base film if necessary. A method for producing a multilayer printed wiring board, comprising a step of thermally curing and integrating the circuit board after peeling.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION A resin composition for forming a resin composition layer which is a thermofluid and solid at room temperature used in the present invention is softened by heating and has the ability to form a film. There is no particular limitation as long as the properties required for the interlayer insulating material such as the electrical properties are satisfied. The thickness of the resin composition layer is generally equal to or greater than the conductor thickness of the inner circuit board to be laminated, and is generally in the range of (conductor thickness + (10 to 120) μm).

The resin composition is, for example, an epoxy resin,
Acrylic resin, polyimide resin, polyamide imide resin, polycyanate resin, polyester resin,
Thermosetting polyphenylene ether resin system and the like,
These may be used in combination of two or more, or may be used as an adhesive film layer having a multilayer structure. Among them, an epoxy resin composition described in Japanese Patent Application No. 9-357420 is preferable for an epoxy resin system having excellent reliability and cost as an interlayer insulating material.

The preferred physical properties of the resin composition layer can be determined by measuring the dynamic viscoelastic modulus and showing the relationship between the temperature and the melt viscosity. The hatched area S in FIG. This is a preferred range of the composition layer. The dynamic viscoelasticity measurement is a curve (heating rate 5 ° C./min) measured using a model Rhesol-G3000 manufactured by UBM Corporation, and the upper limit of the dynamic viscoelasticity curve is average drying. The curve at the lower limit shows the physical properties of the resin composition layer treated at 100 ° C. for 5 minutes at a temperature of 100 ° C. for 10 minutes. The region sandwiched between the curves experimentally and having a melt viscosity of 100,000 Poise or less and a temperature of 140 ° C. or less represents the physical properties of the resin composition layer preferably used in the practice of the present invention. Melt viscosity 1
Above 10,000 Poise, the resin composition layer becomes hard and the adhesion between the pattern on the circuit board and the resin composition layer is poor when vacuum lamination of the adhesive film of the present invention is performed. Temperature 140 ° C
Manufacturing at the above temperature is not preferable because the obtained resin composition layer or laminated circuit board is easily damaged by high temperature.

The support base film used in the present invention can be prepared by applying a resin varnish dissolved in a predetermined organic solvent and then drying the solvent by heating and / or blowing with hot air by a known and conventional method. Examples of the supporting base film include polyolefins such as polyethylene and polyvinyl chloride, polyesters such as polyethylene terephthalate, polycarbonate, release paper, and metal foils such as copper foil and aluminum foil. The thickness of the supporting base film is generally from 10 to 150 μm.
In addition to mud treatment, corona treatment,
A release treatment may be performed.

Further, the surface of the resin composition has an arithmetic average roughness (Ra) of 0.1 μm or more and a maximum height of roughness (Rma).
x): A structure protected by a stretch-molded polypropylene film having a surface roughness of 10 μm or less improves the adhesion to the resin surface and enables supply in a sheet form.
If such a film is used, it does not expand or contract in the heat lamination process unlike polyethylene, so that stress is unlikely to occur, so that it does not curl even after being cut into a sheet.
In addition, since the protective film bites into the resin surface due to appropriate surface roughness, peeling is less likely to occur even during roll storage and after cutting into a sheet state. Specific examples include Oji Alphan MA-410 manufactured by Oji Paper Co., Ltd. The stretch molded polypropylene film,
Rather than mechanically roughening with an uneven drum as in matte-processed polyethylene, it is possible to achieve a very high degree of cleanliness by processing the resin in a matte tone by controlling the crystallinity of the resin, which is preferable for the present invention. The thickness of the protective film is generally 5 to 50 μm. After thermal lamination of the protective film, the adhesive film is wound into a roll. Thereafter, the sheet can be slit and supplied in a predetermined width and supplied in the form of a roll, or cut into a sheet of a predetermined size and supplied.

To manufacture a multilayer printed wiring board using the adhesive film of the present invention, the adhesive film is laminated on a patterned inner circuit board. To laminate, first, after removing the protective film, the resin composition layer surface of the adhesive film, which is almost the same area as the circuit board, is partially partially adhered so that no displacement occurs on one or both sides of the circuit board. I will do a piece. In the case of a roll-shaped film, a commercially available auto-cut laminator for dry film is used, and the roll-shaped adhesive film having a width of about the width of the substrate is heated and pressurized only in the temporary cut portion by the auto-cut laminator, and laminated. The roll is cut into a desired size without applying temperature and pressure. On the other hand, in the case of a sheet, the sheet can be used as it is after removal of the protective film, which is simple. Thereafter, the adhesive layers are bonded together while applying pressure and heat. The laminating conditions are as follows:
It is preferable that the layers are laminated under a reduced pressure at 130 ° C. and a pressure of 1 to 11 kgf / cm 2. The laminate may be a batch type or a continuous type with a roll. After lamination, it is cooled to around room temperature, the support film is peeled off if necessary, the epoxy resin composition is transferred onto the inner layer circuit board, and then cured by heating to produce a multilayer printed wiring board. In the case where the supporting base film is an adhesive film made of a metal foil, it is preferable to use the film after heating and curing without peeling.

Although the adhesive film of the present invention is effective when used as an interlayer adhesive film for build-up, it is also applicable to other adhesive films having heat fluidity, for example, dry films such as solder resist. Needless to say.

[0012]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0013]

[Adhesive film production example 1] Liquid bisphenol A type epoxy resin (Epicoat 82 manufactured by Yuka Shell Epoxy Co., Ltd.)
8EL) 20 parts, brominated bisphenol A type epoxy resin (YDB-500 manufactured by Toto Kasei Co., Ltd.) 20 parts, cresol novolak type epoxy resin (epoxy equivalent 215,
Softening point 78 ° C, Epicron N manufactured by Dainippon Ink and Chemicals, Inc.
-673) 20 parts, terminal epoxidized polybutadiene rubber (Denalex R-45EP manufactured by Nagase Kasei Kogyo Co., Ltd.)
T) and 15 parts thereof were heated and dissolved in MEK while stirring, and a brominated phenoxy resin varnish (nonvolatile content: 40% by weight, bromine content: 25% by weight, solvent composition, xylene: methoxypropanol: methyl ethyl ketone = 5: 2: 8,
50 parts of YPB-40-PXM40 manufactured by Toto Kasei Co., Ltd.
2,4 diamino-6- (2-methyl-1-imidazolylethyl) -1,3,5-triazine / isocyanuric acid adduct 4 parts as epoxy curing agent, further 2 parts of finely ground silica, 4 parts of antimony trioxide, 5 parts of calcium carbonate Was added to prepare a resin composition varnish. Put the varnish in thickness 2
It was applied on a 5 μm polyethylene terephthalate film by a die coater so that the resin thickness after drying became 70 μm, and dried at 80 to 120 ° C. (average 100 ° C.).
Thereafter, a stretch-molded polypropylene film as a protective film on the surface of the resin; Oji Alphan MA-410 (thickness: 15 μm; Ra; 0.15 μm or more; Rz; 6 μm or less) manufactured by Oji Paper Co., Ltd., and heat-laminated at 50 ° C. Got the roll. The mother roll was refrigerated at 5 ° C., returned to room temperature, and cut into a size of 507 × 330 mm to obtain a sheet-like adhesive film. The dynamic viscoelastic modulus of the resin composition layer of the adhesive film obtained as described above was measured using a model Rhesol-G3000 manufactured by UBM Corporation. In FIG. 1, the upper limit of the dynamic viscoelastic modulus curve is 10 minutes at an average drying temperature of 100 ° C., and the lower limit curve is the physical properties of the resin composition treated at an average drying temperature of 100 ° C. for 5 minutes.

[0014]

[Adhesive Film Production Example 2] A sheet-like adhesive film was obtained in exactly the same manner as in Adhesive Film Production Example 1, except that the supporting base film was changed from a polyethylene terephthalate film to a copper foil having a thickness of 18 µm.

[0015]

Comparative Example 1 A protective film of Production Example 1 of an adhesive film was formed from a stretch-molded polypropylene film and a polyethylene film having a thickness of 30 μm; GF-120 manufactured by Tamapoly Co., Ltd.
A mother roll was obtained in exactly the same manner except for changing to.
After the mother roll was refrigerated, partial lifting of the protective film was observed when the sheet was cut. Also, the cut sheet film has a strong curl inside the polyethylene,
The resin cracked during handling and was not practically usable.

[0016]

Comparative Example 2 The protective film of Production Example 2 for the adhesive film was formed from a stretch-molded polypropylene film and a polyethylene film having a thickness of 25 μm;
A mother roll was obtained in exactly the same manner except for changing to.
After the mother roll was refrigerated, partial lifting of the protective film was observed when the sheet was cut. Also, the cut sheet film has a strong curl inside the polyethylene,
The copper foil was wrinkled and was not practically usable.

[0017]

[Production Example 1] The protective film of the sheet-like adhesive film obtained in Production Example 2 was peeled off from a patterned 510 x 340 mm glass epoxy inner layer circuit board (conductor thickness 35 µm), and then the resin side was used as a pattern surface and both sides of the substrate were used. To a single sheet. Next, both sides were simultaneously laminated by a vacuum applicator 725 manufactured by Morton International, Inc. at a degree of vacuum of 1 mbar and a temperature of 90 ° C. for 15 seconds. Then, at 120 ° C for 30 minutes,
The resultant was thermally cured at 70 ° C. for 30 minutes to obtain a multilayer printed wiring board.

From the results of Comparative Examples 1 and 2, when the polyethylene protective film was used, the protective film was partially lifted, and when the film was cut into a sheet, the curl on the protective film side was severe. It could not be supplied in a form that could withstand practical use. As is clear from the results of Examples 1 and 2 and Production Example 1, according to the method of the present invention, a roll-like film having a protective film adhered well can be obtained, and can be supplied in a sheet form without curling. An adhesive film for build-up can be manufactured, and a multilayer printed wiring board can be manufactured using the adhesive film.

[0019]

According to the method of the present invention, an adhesive film having heat fluidity can be supplied in a sheet form without curling, together with a roll form to which a protective film is well bonded, and can be easily used by using this. It is possible to manufacture multilayer printed wiring boards.

[Brief description of the drawings]

FIG. 1 shows a dynamic viscoelastic modulus measurement.
This is a curve measured using a model Rhesol-G3000 manufactured by M Co., Ltd., and the average drying temperature of the curve (1) at the upper limit of the dynamic viscoelastic modulus is 10
At 0 ° C. for 10 minutes, the lower curve (2) also shows an average drying temperature of 1
It shows the physical properties of the resin composition treated at 00 ° C. for 5 minutes. The measurement conditions were as follows: heating rate 5 ° C / min, starting temperature 60 ° C
The measurement temperature interval is 2.5 ° C and the vibration is 1 Hz / deg.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (reference) // C09J 7/02 C09J 7/02 Z F term (reference) 4F100 AB33A AK01B AK07C AK42A AK53B AT00A AT00C BA03 BA07 BA10A BA10C BA13 DD07C EC052 EJ08 EJ172 EJ242 EJ37C EJ422 EJ911 GB43 JB12B JL02 JL05 JL14C YY00C 4J004 AA10 AA11 AA13 AA14 AA15 AB05 CA08 CC02 DA02 DB02 FA05 GA01 5E346 AA12 AA15 BB01 DD06 CC08 DA02 DB02 FA02 CA01 CA46 5G333 AA03 AB13 AB21 AB22 BA03 CB08 DA03 DA11 DA17 DB02 FB02 FB11 FB27

Claims (4)

[Claims] 1. A support base film and a surface thereof are laminated, have the same or smaller area as the support base film, and determine the properties of the hatched region S in FIG. In an adhesive film comprising a thermosetting resin composition layer having a thermofluidity and a solid at room temperature, the surface of the resin composition further has an arithmetic average roughness Ra: 0.1 μm or more;
An adhesive film for interlayer insulation, having a structure protected by a stretch-molded polypropylene film having a maximum height of roughness Rmax: 10 μm or less. 2. The adhesive film for interlayer insulation according to claim 1, wherein the supporting base film is a metal foil. 3. The adhesive film for interlayer insulation according to claim 1, wherein the adhesive film is in a sheet form. 4. The resin composition layer obtained by peeling off the protective film of the adhesive film for interlayer insulation according to claim 1 on at least one side or both sides of a patterned circuit board. A step of directly bonding and partially bonding these parts after directly covering the resin composition layer with the resin composition layer, and 2) heating the adhesive film temporarily bonded to one or both surfaces of the circuit board under vacuum conditions; Pressurizing and laminating; 3) a method for producing a multilayer printed wiring board, comprising a step of, after peeling off a supporting base film if necessary, thermally curing the circuit board to integrate it.