JPH09232764A - Manufacture of multilayered printed-wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing a printed-wiring board, which hardly generates failure of insulation properties and a surface dent. SOLUTION: Metal foils with a resin, which are formed by applying a B stage-shaped (a semi-cured state) thermosetting resin, which is molten at a high temperature, on metal foils, are laminated on a board for internal layer use, which is formed with a circuit pattern, and are lamination-molded to manufacture a multilayer printed-wiring board. In this case, the metal foils with the resin are cut by a heated cutter blade.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer printed wiring board, and more particularly to a method for manufacturing a multilayer printed wiring board using a metal foil with a resin for multilayer molding.

[0002]

2. Description of the Related Art Conventionally, a resin-coated metal foil formed by applying an insulating resin to a metal foil is laid on a substrate for an inner layer on which a circuit pattern is formed and laminated to manufacture a multilayer printed wiring board. As a method, JP-A-5-206647
The contents are disclosed in the issue. Polyimide resin, epoxy resin, fluorine resin, etc. are used as the resin used in the method for manufacturing the multilayer printed wiring board.

As a method for producing the resin-coated metal foil,
An uncured or low molecular weight resin is dissolved or dispersed in a solvent to form a liquid, or a low molecular weight resin that is liquid at room temperature is selected, and this is applied to a metal foil, such as a copper foil, and dried at high temperature, and applied. The resin thus formed is semi-cured to increase the degree of curing to form a resin-coated copper foil.

As the inner layer substrate, a double-sided copper-clad laminate having a surface formed by etching to form a circuit and further subjected to a surface treatment called blackening treatment is used.

The metal foil with resin obtained as described above is cut to a desired size and further perforated, and the resin layer is placed inside on both sides of the inner layer substrate, or the resin-coated copper foil and inner layer are laminated. One or more glass cloth cloth resin impregnated prepregs are stacked between the substrates for use, and the layers are heated and pressed to form a multilayer.

However, the cut and punched metal foil with resin may cause peeling of resin powder or resin from the sheared surface. As a result, defective interlayer insulation of the obtained multi-layer substrate and defects due to surface lacquer during molding due to mixing of the peeled resin powder occur.

There is a demand for a method of manufacturing a printed wiring board that provides a resin-coated metal foil that does not peel off the resin powder or resin of the resin-coated metal foil as described above.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is possible to suppress defective interlayer insulation of printed wiring boards and generation of surface lacquer. An object of the present invention is to provide a method for manufacturing a multilayer printed wiring board using a resin-coated copper foil that prevents the powder and resin from peeling off.

[0009]

According to a first aspect of the present invention, there is provided a method for manufacturing a multilayer printed wiring board, comprising a metal foil made of a B-stage thermosetting resin that melts at a high temperature on an inner layer substrate having a circuit pattern formed thereon. In a method for producing a multilayer printed wiring board, which comprises laminating a resin-coated metal foil applied to a substrate and laminating-molding the resin-coated metal foil, the resin-coated metal foil is cut by a heated cutting blade. .

According to a second aspect of the present invention, there is provided a method for manufacturing a multilayer printed wiring board, comprising: a resin-coated metal obtained by coating a metal foil with a B-stage thermosetting resin that melts at high temperature on an inner layer substrate on which a circuit pattern is formed. A method for manufacturing a multilayer printed wiring board, comprising laminating foils and molding them to produce a multilayer printed wiring board, characterized in that a part or the whole surface of the resin-coated metal foil is heated and cut.

According to a third aspect of the present invention, there is provided a method for manufacturing a multilayer printed wiring board, comprising: a resin-coated metal obtained by coating a metal foil with a B-stage thermosetting resin that melts at high temperature on an inner layer substrate on which a circuit pattern is formed. A method for manufacturing a multilayer printed wiring board, comprising laminating foils and molding them to produce a multilayer printed wiring board, characterized in that the metal foil with resin is perforated by a heated cutting blade.

According to a fourth aspect of the present invention, there is provided a method for manufacturing a multilayer printed wiring board, comprising: a resin-coated metal in which a B-stage thermosetting resin that melts at high temperature is applied to a metal foil on an inner layer substrate on which a circuit pattern is formed. In a method for manufacturing a multilayer printed wiring board, which comprises stacking foils and molding them to manufacture a multilayer printed wiring board, a part or the whole surface of the metal foil with resin is heated to make holes.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be specifically described below.

The resin-coated metal foil is formed by applying a B-stage thermosetting resin to an aluminum foil or a copper foil. This thermosetting resin layer is formed of a thermosetting resin such as an epoxy resin or a polyimide resin, and is dissolved in an amine solvent such as DMF or DMAC or a ketone solvent such as MC, PC or MEK, and coated on a metal foil. Then, it is dried by heating to form a semi-cured (B-stage) resin layer.

As a method for forming the above-mentioned thermosetting resin layer on the surface of the metal foil, a liquid resin varnish is applied by a comma coater, a transfer coater, a curtain coater, etc., and the resin is continuously or discontinuously heat-dried and semicured. B stage.

Although not particularly limited, it is possible to disperse a filler such as an inorganic powder, an inorganic fiber, an organic powder or an organic fiber when the resin is dissolved in a solvent, if necessary.

The obtained resin-coated metal foil is used as a material for a multilayer printed wiring board, and is cut into desired dimensions.
Drilling is performed.

In the method for manufacturing a printed wiring board according to the present invention, in the step of cutting into a size suitable for multilayer molding,
Furthermore, in the process of making holes, by heating a part or all of the resin-coated metal foil or locally, the resin applied to the metal foil is softened, and even if it is sheared by the cutting blade, the viscosity is increased. It can be held, and it is possible to prevent the resin from cracking, peeling, and powder falling.

As the above cutting method, a rotary cutter, shearing, a rotary saw blade, or the like can be used.

This heat treatment is preferably carried out before or simultaneously with cutting or drilling, but it can also be carried out after cutting or drilling to prevent cracking, peeling and powder fall of the resin. it can.

Further, in the method for manufacturing a printed wiring board of the present invention, in the above-mentioned processing step, the cutting blade body for shearing is heated to soften the resin applied to the metal foil, thereby cracking or peeling the resin. It is possible to prevent powder falling. The cutting blade causes a temperature rise due to frictional heat with an object to be sheared during shearing, but this amount of heat is not sufficient to soften the resin, and in the present invention, the resin is heated by heating the cutting blade. The amount of heat for softening can be obtained.

By producing a multilayer printed wiring board using the resin-coated metal foil, resin powder falling off of the resin-coated metal foil is reduced, so scattering of resin powder generated during combination is reduced. Thus, the frequency of occurrence of surface sacking defects of the obtained multilayer printed wiring board can be significantly reduced. Moreover, since cracking and peeling of the resin can be reduced, the frequency of occurrence of insulation failure between layers can be significantly reduced, and a multilayer printed wiring board can be manufactured.

The present invention will be described below based on Examples and Comparative Examples, but these Examples do not limit the present invention.

[0024]

EXAMPLES AND COMPARATIVE EXAMPLES First, FR-4 type glass cloth base material epoxy resin copper-clad laminate (laminate thickness 1.0 m
m, the thickness of the copper foil is 18 μm), a circuit pattern is formed on one surface, and the other surface is removed by etching the copper foil over the entire surface to produce an inner layer substrate on which a circuit pattern has been formed. The surface of the pattern was subjected to blackening treatment.

Further, bisphenol A was applied to an electrolytic copper foil for electric use (GT-18μ manufactured by Furukawa Circuit Co., Ltd.) having a thickness of 18μ.
-Type epoxy resin and dicyandiamide as main components, F
Epoxy resin varnish commonly used in the production of R-4 type laminates was applied using a comma coater so that the resin thickness after drying would be 50μ, and at 20 ° C at 160 ° C.
The resin-coated copper foil was produced by drying and curing for a minute to bring it to the B stage state. (Example 1) The resin-coated copper foil was cut and punched while heating each blade to 120 ° C. (Example 2) When cutting and punching the resin-coated copper foil,
The entire surface of the resin-coated copper foil was heated to 90 ° C. (Example 3) At the time of cutting and punching the resin-coated copper foil,
Surface temperature around the cutting and drilling positions of resin-coated copper foil is 90
It was carried out by heating to ℃. (Example 4) After cutting and punching the resin-coated copper foil,
The entire surface of the resin-coated copper foil was heated to 110 ° C. (Example 5) After cutting and punching the resin-coated copper foil,
The periphery of the cutting and punching positions of the resin-coated copper foil was heated to 110 ° C. (Comparative Example) The resin-coated copper foil was cut and punched at room temperature using a processing blade at room temperature.

In the above-mentioned Examples 1 to 5 and Comparative Example, foreign matter on the copper foil surface was removed with a brush, wind, suction, solvent, detergent or adhesive, adhesive cloth, etc. before cutting and punching. It was cut and drilled.

The heating of the resin-coated copper foil and the heating of the cutting blade are not particularly limited, but hot air, far infrared rays, near infrared rays, laser heating or the like can be used.

The resin-coated copper foil obtained as described above and the inner layer substrate on which the circuit pattern is formed are laminated, sandwiched between stainless steel plates, and multilayered and cured by heating and pressing to form a multilayer board. After the formation, an outer layer circuit was formed, and a finishing process was performed to obtain a multilayer printed wiring board. Molding conditions are as follows: temperature 100 ° C., pressure 5 kg / cm ² for 50 minutes, then 180 ° C. 30 kg / cm ^2.
Complete curing was completed under the conditions described above to complete the multi-layer molding.

In the multilayer printed wiring board manufactured as described above, the resin powder generated during cutting and punching was measured, and the dent defect rate on the surface of the obtained multilayer board was evaluated. The manufacturing method was evaluated. The defect was judged to be defective when a dent having a diameter of 0.5 mm or more was formed on each molding surface. Table 1 shows the results.

[0030]

[Table 1]

[0031]

According to the method for manufacturing a multilayer printed wiring board according to the present invention, a part of the resin-coated metal foil is cut and cut at the time of cutting and punching the resin-coated metal foil in which the resin is applied to the metal foil,
Since the resin is softened by heating a part or all of the resin, cracking and peeling of the resin and dropping of resin powder that occur during processing can be reduced, and further, the occurrence of a dent defect rate during secondary molding can be reduced.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Nobumitsu Onishi 1048, Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Works Co., Ltd.

Claims (4)

[Claims] 1. A multilayer printed wiring board is obtained by laminating a resin-coated metal foil obtained by coating a metal foil with a B-stage-shaped thermosetting resin that melts at high temperature on an inner layer substrate on which a circuit pattern is formed. A method for manufacturing a multilayer printed wiring board, comprising: cutting the resin-coated metal foil with a heated cutting blade. 2. A multilayer printed wiring board is obtained by laminating a resin-coated metal foil obtained by coating a metal foil with a B-stage-shaped thermosetting resin that melts at high temperature on an inner layer substrate on which a circuit pattern is formed. A method for producing a multilayer printed wiring board, comprising: heating a part or the entire surface of the resin-coated metal foil to cut it. 3. A multi-layer printed wiring board is obtained by laminating a resin-coated metal foil obtained by applying a B-stage-shaped thermosetting resin that melts at high temperature onto a metal foil on an inner layer substrate on which a circuit pattern is formed, and laminate-molding the laminated metal foil. In the method for producing a multilayer printed wiring board to be produced, a method for producing a multilayer printed wiring board, characterized in that the metal foil with resin is punched with a heated cutting blade. 4. A multilayer printed wiring board is obtained by laminating a resin-coated metal foil obtained by applying a B-stage-shaped thermosetting resin that melts at high temperature onto a metal foil, and laminating the resin-coated metal foil on the inner layer substrate on which a circuit pattern is formed. A method for producing a multilayer printed wiring board, comprising: heating a part or the whole surface of the resin-coated metal foil to form a hole in the method for producing a multilayer printed wiring board to be produced.