JPH07131182A - Manufacture of printed-circuit board - Google Patents

Abstract

PURPOSE:To perform continuously the formation of a copper foil by a heated roll and to contrive to improve the productivity of a printed-circuit board by a method wherein a first resin composition layer, which is soluble in an alkali aqueous solution and is small in fluidity at the time of heating and pressing by the heated roll, is formed on the roughened surface of the copper foil and a second resin composition layer, which is large in fluidity, is formed on this first layer. CONSTITUTION:A first resin composition layer 2, which is soluble in an alkali aqueous solution and is small in fluidity at the time of heating and pressing by a heated roll 16, is formed on the roughened surface of a copper foil 1 and a second resin composition layer 3, which is soluble in the alkali aqueous solution and is large in fluidity at the time of heating and pressing by the roll 16, is formed on this layer 2. The side of the resin of this copper-clad insulating sheet 4 is laminated on one surface or both surfaces of a double-sided or multilayer printed-wiring board by the roll 16. Then, an etching resist is formed on the surface copper foil 1 of the laminated sheet 4, a selective etching is performed, the exposed resin composition layers are dissolved with the alkali aqueous solution and an electromagnetic wave shielding layer is made to form.

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 printed circuit board suitable for high-density mounting with high productivity. In particular, the present invention provides a method for easily manufacturing a multilayer printed circuit board and a metal core printed circuit board having an electromagnetic wave shield layer having excellent physical properties and electrical properties.

[0002]

2. Description of the Related Art As electronic equipment becomes smaller and more multifunctional,
At present, printed circuit boards are becoming more dense. For example, thinning of conductor circuits, increase in number of layers, through via holes (hereinafter also referred to as "through holes"), blind via holes, burr via holes.
There are small-diameter, multi-layer, and thin via holes including interstitial via holes such as tools, and high-density mounting by surface mounting of small chip parts.

In order to explain a conventional method for manufacturing a multilayer printed circuit board having a blind via hole, schematic sectional views of respective steps are shown in FIGS. 1 to 7. As shown in Figure 1,
A plurality of inner layer panels 7 having copper wiring patterns 6 pre-formed by an etching method are prepared. For example, an epoxy glass prepreg 5 is provided between the outer layer copper foil 1 and the inner layer panels 7 and between the inner layer panels. Or two layers are laid up and heat-pressed at a temperature of 160 to 180 ° C. for 60 to 120 minutes at a pressing pressure of 15 to 50 kg / cm ² to form the inner layer wiring pattern and the balled via hole 22 shown in FIG. A copper clad laminate panel having is obtained. A vacuum hot press may be used when precision is required.

Next, when a conventional through hole 8 is provided by sequentially drilling holes at predetermined positions with a drill machine, the result is as shown in FIG. Subsequently, the blind via hole holes 20 and 23 are formed by drilling, as shown in FIG.

[0005] Hereinafter, the conventional electroless copper plating and electrolytic copper plating are performed to form the plated through holes 24, as shown in Fig. 5. After forming the etching resist 12 (Fig. 6), the subsequent etching is performed, and the final Specifically, when the film of the etching resist is stripped, the result is as shown in FIG. 7, and a multilayer printed circuit board having a lead via hole and a blind via hole is obtained.

In the conventional method for manufacturing a multilayer printed circuit board, a hot press, a vacuum hot press or the like is generally used as described above, so that the inner layer panel, 0.05 to 0.2 mm, is prepared in preparation for the hot press. It is necessary to lay up one or two thick prepregs, a copper foil, a release film, a mirror surface press plate, and the like, thermocompress them with a hot press or a vacuum heat press, and then take them out and dismantle them. This manufacturing method is usually batch production, and the number of steps is large and complicated. Although the automation of batch work improves productivity, the apparatus for this purpose is expensive and there is a problem that a large-sized heat press capable of thermocompression bonding in large quantities is required. In addition, a thin prepreg is required to manufacture a thin multilayer printed circuit board, but the glass fiber used for that purpose is a finer woven material, and its manufacturing requires high technology and high cost. Since a high-precision manufacturing apparatus is required, there is a problem that the cost of prepreg material increases.

Further, in order to form a blind via hole with a drill as described above, it is not possible to stack a plurality of panels like a normal through hole and it is necessary to drill one hole at a time. It takes a very long time to process, and the production efficiency is poor. In addition, in order to control the depth of the drill tip during drilling,
It is necessary to match the movement distance in the drilling direction, generally the Z-axis direction, with the depth of the copper wiring pattern on the inner layer panel surface. However, as described above, 0.1 to 0.5 mm
A drill with a small diameter has a large runout, and there are variations in the position of the copper wiring pattern in the Z-axis direction, so it is difficult to control accurately, and if the drilling is shallow, it will not be possible to reach the lower copper wiring pattern, If the drilling process is too deep, the copper wiring pattern will come into contact with the underlying copper wiring pattern, resulting in a short circuit defect.

On the other hand, in order to prevent the influence of electromagnetic waves on the printed circuit board, an insulating layer (interlayer insulating layer) on the surface of a conventional printed wiring board, a shield layer in which a copper paste is applied by a screen printing method, and An electromagnetic shield printed wiring board with an overcoat has been developed (Hanyu et al .:
National Technical Report
al Report) 35, No. 4, pages 76-82, 1989.
Year).

However, in this method, since the copper paste as the electromagnetic wave shield layer is formed by screen printing to a thickness of several tens of μm, the pattern forming accuracy is low and the gap between the copper paste and the transmission circuit pattern is small. Since it is large, there is a drawback that noise leaks from the gap and the electromagnetic wave shielding effect becomes insufficient. Also, when forming the undercoat insulation resist of the electromagnetic wave shield layer by screen printing, the end face part of the underlying conductor circuit becomes a blind spot with the screen, and the resist is liable to fade at this part, and the conductor circuit is completely insulated. It was difficult to coat with.

As a countermeasure against electromagnetic waves of a printed circuit board for solving the above problems, Japanese Patent Laid-Open No. 54-11967 has been proposed.
No. 3 and Japanese Unexamined Patent Publication No. 63-33898, a double-sided copper clad laminate having a metal conductor pattern, a metal foil and a prepreg are laminated by hot pressing to leave a metal foil on almost the entire surface. Then, there is disclosed a printed circuit board which is an electromagnetic wave shield layer or a manufacturing method thereof. By this method, a metal foil such as a copper foil having a smooth surface is formed, and therefore it is easy to form an etching resist and a metal foil with a relatively high precision by a photo method. However, this method requires hot pressing for 2-3 hours to laminate the copper foil, the prepreg and the double-sided copper clad laminate of the inner layer, and since it is batch production, mass productivity is poor, and the inner layer In order to electrically connect the ground layer and the surface metal foil of the panel for electric use, it is necessary to perform drilling for forming one hole at a time, which requires a lot of man-hours and a high manufacturing cost.

On the other hand, as a printed circuit board for heat dissipation, a surface-roughened metal panel in which through holes are previously formed is used.
A resin-impregnated fiber sheet having a thickness of 05 to 0.2 mm, for example, glass cloth epoxy resin prepreg and copper foil are overlaid and integrally molded by hot pressing, and after filling the resin in the hole, a through hole is provided at the hole position. A method of manufacturing a metal core printed circuit board by performing through-hole plating and patterning a surface copper foil by selective etching is known. However, this method has the drawback that batch production by hot pressing is difficult, and continuous production is difficult and the manufacturing cost is high, as in the conventional printed circuit board manufacturing method described above.

[0012]

As described above, a method of manufacturing a printed circuit board and a metal core printed circuit board having an electromagnetic wave shield layer which is excellent in physical properties and electrical properties, has stable quality, and is excellent in mass productivity is provided. It is not currently provided.

[0013]

According to the present invention, a layer of a first resin composition which is soluble in an alkaline aqueous solution and has low fluidity when heated and pressed by a hot roll is formed on a roughened surface of a copper foil. Then, the resin side of the copper clad insulating sheet formed by forming a layer of the second resin composition which is soluble in an alkaline aqueous solution and has a large fluidity at the time of heating and pressurizing with a hot roll on the layer Laminating one side or both sides of the printed wiring board (hereinafter referred to as "inner layer panel") with a heat roll; forming an etching resist on the surface copper foil of the laminated copper-clad insulating sheet, A step of removing the surface copper foil located above the ground part by etching; a step of dissolving the exposed resin composition layer with an alkaline aqueous solution to expose the conductor circuit pattern of the inner layer panel; It is exposed conductor circuit pattern and the surface copper white rabbit consisting electrically conductive is not a step of forming the electromagnetic shielding layer by a conductive material printed circuit board manufacturing method of the inner panel; reduction is to process.

According to the present invention, since the copper foil of the electromagnetic wave shielding layer can be continuously formed by the hot roll, the productivity is remarkably improved as compared with the conventional method of laminating by hot press which is batch production. . Further, since the surface of the laminated copper foil is smooth, the resist can be easily formed during the selective etching, and a high-density pattern can be formed. Also, the electrical connection with the ground layer is made easy by forming a conductive material such as a silver paste, a copper paste, a conductive paste such as a solder paste, a molten metal such as solder, or a plated metal only in a necessary portion. Can be formed.

As the inner layer panel used in the method for producing a printed circuit board having an electromagnetic wave shielding layer according to the present invention, either one-sided or double-sided printed wiring board or a multilayer printed wiring board can be used. Moreover, even if the printed wiring board has plated through holes or non-plated through holes, the through holes can be filled with the resin composition, and the conductor circuit pattern of the outer layer can be easily formed on the copper foil thereon. Therefore, the degree of freedom in pattern design is significantly improved. Furthermore, a printed electronic component such as a printed resistor may be formed in advance on the inner layer panel. Also, through holes or blind holes of any shape are provided, small chip parts are mounted in the holes, and after laminating a copper clad insulating sheet and embedding the above chip parts with resin, surface copper foil Can be etched, and the resin composition thereunder can be dissolved in an alkaline aqueous solution to expose the terminal portion of the chip component, and then the surface conductor circuit pattern can be electrically connected with a conductive material.

Further, according to the present invention, a layer of the first resin composition having a low fluidity when heated and pressed by a hot roll is formed on the roughened surface of the copper foil, and the layer is heated by the hot roll. The resin side of the copper-clad insulating sheet formed by forming the layer of the second resin composition having a large fluidity at the time of heating and pressurizing is laminated on both sides of a metal panel in which through holes are formed in advance with a heat roll, and the metal panel is formed. A step of forming a laminated panel in which a resin is filled in the hole; a step of curing the resin composition; a step of forming a through hole having a smaller diameter than that in the resin filled hole of the laminated panel by drilling or the like A method of manufacturing a metal core printed circuit board, which comprises a step of electrically connecting the copper foils on both surfaces with a conductive material; and a step of forming a conductor circuit pattern on the surface copper foils by selective etching.

According to the above-described method of manufacturing a metal core printed circuit board, since the surface copper foil can be used as a copper-clad insulating sheet and can be continuously laminated with a hot roll, the conventional hot pressing can be performed in batch production. The productivity is remarkably improved as compared with the method of laminating in.

Further, according to the present invention, a layer of the first resin composition which is soluble in an alkaline aqueous solution and has a low fluidity when heated and pressed by a hot roll is formed on the roughened surface of the copper foil, and the layer is formed. The resin side of the copper-clad insulating sheet having a second resin composition layer which is soluble in an alkaline aqueous solution and has high fluidity when heated and pressed by a hot roll is formed on the resin side with a through hole formed in advance. A process of laminating both sides of the panel with hot rolls to create a laminated panel in which the holes in the metal panel are filled with resin; an etching resist is formed on the surface copper foil, and the copper foil at the position where the metal panel is exposed by etching And removing the exposed layer of the resin composition with an aqueous alkaline solution to expose the metal panel; curing the resin composition;
A step of forming a through hole having a diameter smaller than that of the resin-filled hole of the laminated panel; a step of electrically connecting copper foils on both surfaces with a conductive material; a semiconductor component is directly die-bonded to a metal panel. It is a method of manufacturing a metal core printed circuit board comprising steps.

In the above metal core printed circuit board, the heat radiating semiconductor component can be directly attached to the metal panel as the heat radiating medium, and mounting with a high heat radiating effect can be realized. Furthermore, according to the present invention, after repeating the above-mentioned lamination of the copper clad insulating sheet and selective etching of the surface copper foil, the unnecessary resin is alkali-dissolved, and electrical conduction between the layers is achieved by the conductive material. Multilayer printed circuit boards are also easy to manufacture. It is also possible to expose the metal panel and mount electronic parts directly on the metal panel by appropriately combining selective etching and alkali dissolution of the copper clad insulating sheet laminated on the metal panel, and to conduct the conductive pattern of the outer layer. And a metal panel can be electrically connected to form a ground circuit.

In the manufacture of the metal core printed circuit board of the present invention, a panel made of aluminum, iron, a silicon steel plate, brass, phosphor bronze or the like can be used as the metal panel. It is preferable that the surface of these is mechanically roughened in order to improve the adhesiveness with the resin and the solder heat resistance.
In addition, not only through holes but blind holes are provided in advance.
It is also possible to manufacture a printed circuit board having a built-in electronic component by using a metal panel having an electronic component inserted in the hole and combining the above-mentioned copper clad insulating sheet with laminating and etching / alkali dissolution.

In the present invention, the fact that the resin composition of the copper-clad insulating sheet has high fluidity when heated means that the copper-clad insulating sheet is laminated on a laminated plate having a conductor circuit pattern on its surface and heated and pressed by a heat roll. In the step of laminating the whole, that is, in the range of about 60 to 100 ° C. and an air pressure of 1 to 5 kg / cm ² , the resin composition melts and easily flows into a conductor circuit pattern such as a laminated board to form a concave portion of the pattern. It means that it can be filled.

The thickness of the layer of the first resin composition of the copper-clad insulating sheet is preferably 30 to 70 μm, more preferably 40 to 60 μm. Since the layer of the first resin composition is an interlayer insulating layer between the conductors of the printed circuit board to be obtained, if the thickness is thin, the electrical characteristics such as insulation resistance, withstand voltage, solder heat resistance, peeling strength, etc. If the physical properties cannot be obtained and it is too thick, it becomes difficult to remove the solvent in the coating process of the resin composition at the time of producing the copper-clad insulating sheet, and pinholes, bubbles, etc. easily occur in the resin and Interlayer insulation may be hindered. Further, if the insulating layer is thick, the material cost becomes high, and it takes a long time to coat and dry the coating, resulting in poor productivity.

The optimum thickness of the second resin composition layer of the copper clad insulating sheet is determined by the thickness and area of the conductor layer formed on the surface of the inner layer panel having the conductor circuit pattern to be laminated. Although it should be noted, it was found from the experimental experience of the present inventors that 10 to 70 μm can be applied to almost any conductor circuit pattern of a laminated plate. Generally, when copper foil is used as a conductor circuit pattern, 18 μm, 35 μm, 70
The thickness of the second resin composition is about 10 to 20 μm, and the thickness of the second resin composition layer is about 35 μm.
If the copper foil is about 20 to 40 μm, and the 70 μm is about 50 to 70 μm, the resin can be almost completely filled between the conductor circuit patterns, and the thickness is 0.1 to 0.6.
The resin can be flown in so as to completely fill the mmφ via hole.

Further, even when laminating a metal panel or a conductor circuit pattern on a smooth circuit having a flat surface embedded in a substrate of a laminated plate, at least in order to prevent air bubbles from being entrained during the heat roll, It is preferable to provide a thickness of 10 μm. In order to completely fill the through holes of the laminated plate with resin for forming the balled via holes, it is necessary to additionally apply the resin composition for the total volume of the holes to the resin layer.

The layers of the first and second resin compositions of the copper-clad insulating sheet used in the present invention are preferably composed of a base resin soluble in an alkaline aqueous solution (hereinafter simply referred to as "base resin"), Depending on its type and purpose, it can be obtained by blending necessary components selected from an adhesive reinforcing agent (crosslinking agent), an active energy ray curing reaction initiator, an active energy ray curing reaction accelerator and a curing agent. Further, a coloring pigment, a moisture resistant pigment, a defoaming agent, a leveling agent, a thixotropy imparting agent, a polymerization inhibitor or an anti-settling agent may be appropriately added.

As the base resin, a carboxyl group,
Non-photosensitive resin containing an alkali-soluble group such as a phenolic hydroxyl group, or an alkali-soluble group such as a carboxyl group or a phenolic hydroxyl group, and an acryloyl group or a methacryloyl group (hereinafter referred to as "(meth) acryloyl group" ), An internal olefin, an azide group, a cinnamic acid ester residue and the like, and a photosensitive resin containing a photopolymerizable or photodimerizable photosensitive group.

The non-photosensitive resin is, for example, a copolymer of acrylic acid or methacrylic acid (hereinafter referred to as "(meth) acrylic acid") and a vinyl monomer such as (meth) acrylic acid ester or styrene, Half ester obtained by adding alcohol to a copolymer of styrene and maleic anhydride (SMA1440, S manufactured by ATOCHEM)
MA17352, SMA2625, SMA3840 and M
ONSANTO SCRIPSET540, SCRI
PSET550, etc.), a copolymer of styrene and p-hydroxyphenylmaleimide, polyvinylphenol (Maruzen Petrochemical Co., Ltd. Marca Linker M, Marca Linker MB, etc.) or polyvinyl phenol and methylmethacrylate, hydroxyethylmethacrylate, styrene. ,
A copolymer with phenylmaleimide or the like, a novolac type phenol resin, a novolac type cresol resin, a ring-opening adduct of an alcoholic hydroxyl group-containing polymer and an acid anhydride, or the like can be used. Photosensitivity can be imparted by adding a polyfunctional monomer to the resin.

As the base resin, a resin having photosensitivity is preferable, and among them, the concentration of the photosensitive group is 0.1 to 1.
The range is preferably 0.0 meq / g, more preferably 0.3 to 8.0 meq / g, and particularly preferably 0.5 to.
It is 5.0 meq / g. If the concentration of the photosensitive group is too low, the photocurability will be poor, and if it is too high, the storage stability will be poor.

As the photosensitive resin, for example, epoxy acrylate and / or methacrylate (hereinafter “acrylate and / or methacrylate” is referred to as “(meth) acrylate”), a ring-opening adduct of an acid anhydride, and styrene. Half ester obtained by adding unsaturated alcohol to copolymer with maleic anhydride, copolymer of vinyl monomer such as (meth) acrylic acid and (meth) acrylic acid ester or styrene, copolymer of styrene and maleic anhydride Of alcohol-added half ester, copolymer of styrene and p-hydroxyphenylmaleimide, polyvinylphenol or its copolymer, novolac type phenol resin, novolac type cresol resin, alcoholic hydroxyl group-containing polymer and acid anhydride ring-opening Various polymers such as adducts , Glycidyl (meth)
Ring-opening adducts with glycidyl group-containing unsaturated compounds such as acrylates (hereinafter collectively referred to as "ring-opening adducts with polymers and glycidyl group-containing unsaturated compounds"), styrene and p.
-Hydroxyphenylmaleimide copolymer, polyvinylphenol or its copolymer, novolac-type phenol resin, novolac-type cresol resin, and some of the hydroxyl groups in the phenolic hydroxyl group-containing polymer, (meth) acrylic acid chloride, cinnamic acid Condensation reaction of a photosensitive group-containing acid chloride such as chloride, some of the hydroxyl groups of the alcoholic hydroxyl group-containing polymer, (meth) acrylic acid chloride, a photosensitive group-containing acid chloride such as cinnamic acid chloride is condensed, A ring-opening addition of an acid anhydride to the remaining hydroxyl group, an isocyanate group-containing (meth) acrylate was added to a part of the hydroxyl group of the alcoholic hydroxyl group-containing polymer, and an acid anhydride was ring-opening added to the remaining hydroxyl group. A copolymer of styrene and p-hydroxyphenylmaleimide, Polyvinylphenol or its copolymer, novolac type phenolic resin, novolac type cresol resin, etc. with some isocyanate groups containing (meth) acrylates added to some of the hydroxyl groups in the phenolic hydroxyl group containing polymer, epoxy (meth) Examples thereof include those in which an isocyanate group-containing (meth) acrylate is added to a part of the hydroxyl groups of acrylate, and an acid anhydride is ring-opened and added to all or a part of the remaining hydroxyl groups.

These manufacturing methods are as follows, for example. The half ester obtained by adding an unsaturated alcohol to a copolymer of styrene and maleic anhydride is obtained by adding an unsaturated alcohol such as hydroxyethyl (meth) acrylate to a copolymer of styrene and maleic anhydride. You can

The ring-opening adduct of the polymer and the unsaturated compound containing a glycidyl group is a solvent (for example, ethers such as diglyme, esters such as ethyl carbitol acetate, ethyl cellosolve acetate and isopropyl acetate, ketones such as methyl ethyl ketone and cyclohexanone). It is obtained by dissolving the above-mentioned various polymers in (a) and reacting glycidyl (meth) acrylate as it is or by diluting it with a solvent and dropping it.

At this time, a radical polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, phenothiazine, etc., is preferably 10 to 10,000 ppm, more preferably 30 to 5,000 ppm, particularly preferably 50 to 50 ppm.
It is added in the range of 2,000 ppm, and the reaction temperature is preferably room temperature to 170 ° C., more preferably 40 to 150 ° C., and particularly preferably 60 to 130 ° C. Further, it is preferable to add a quaternary ammonium salt such as tetrabutylammonium bromide or trimethylbenzylammonium chloride, a tertiary amine such as triethylamine, or the like as a catalyst. Glycidyl (meta) in alkali-soluble groups such as carboxyl and phenolic hydroxyl groups in polymers
When the epoxy group of the acrylate is subjected to ring-opening addition, a part of the alkali-soluble group may be left so that the acid value becomes appropriate, and the product can be used as it is. When the acid value becomes too small and the alkali solubility decreases, the acid value can be increased by ring-opening addition of an acid anhydride to the secondary hydroxyl group produced in the above reaction.

Some of the hydroxyl groups in the phenolic hydroxyl group-containing polymer such as copolymers of styrene and p-hydroxyphenylmaleimide, polyvinylphenol or its copolymers, novolac type phenol resins, novolac type cresol resins, and (meth) The synthesis of a product obtained by subjecting a photosensitive group-containing acid chloride such as acrylic acid chloride and cinnamic acid chloride to a condensation reaction is as follows. Solvents (methylene chloride, chloroform, toluene and other water immiscible solvents,
Alternatively, a phenolic hydroxyl group-containing polymer is dissolved in a solvent such as acetone, diglyme, or ethyl carbitol acetate that is miscible with water, and a basic compound such as sodium hydroxide, potassium hydroxide, calcium hydroxide or triethylamine, a photosensitive group-containing acid It is obtained by adding chloride and reacting at a reaction temperature of usually 0 to 100 ° C (preferably 0 to 50 ° C, more preferably 0 to 30 ° C). As the catalyst, a quaternary ammonium salt, a tertiary amine, a phosphoric acid ester, a phosphorous acid ester or the like may be used. When a solvent immiscible with water is used and an inorganic base is used, the reaction may be terminated quickly by adding water to the system.

For the purification, when a solvent immiscible with water is used, the reaction solution is washed with an acidic aqueous solution and then repeatedly washed with water, dehydrated and filtered. Further, the solvent after filtration is removed, or if necessary, reprecipitation purification is performed. When a water-miscible solvent is used, the reaction solution is mixed with an appropriate amount of water to precipitate the product as a solid. After repeated washing with water, it is dried. When a phenolic hydroxyl group, which is an alkali-soluble group in the polymer, is condensed with an acid chloride group, a part of the alkali-soluble group is left so that the acid value becomes appropriate.

A compound obtained by adding an isocyanate group-containing (meth) acrylate to a part of the hydroxyl groups of an alcoholic hydroxyl group-containing polymer and ring-opening addition of an acid anhydride to the remaining hydroxyl groups is a diisocyanate (two groups such as isophorone diisocyanate). (Compounds having different reactivity of the isocyanate group are desirable) are added to one of the isocyanate groups, and a (meth) acrylate containing a hydroxyl group such as hydroxyethyl (meth) acrylate is added. Under standard conditions, a tin compound such as dibutyltin dilaurate is used as a catalyst, and the reaction is carried out at about 60 to 80 ° C.

The epoxy resin used in the synthesis of the ring-opening adduct of epoxy (meth) acrylate and acid anhydride is an epoxy resin of phenol novolac type or cresol novolac type, polyvinylphenol skeleton, etc., and has a molecular weight of 1,000 or more. Preferably, more preferably 3,000
More preferably, it is 4,000 or more. When the molecular weight is small, the crosslink density does not increase and the heat resistance deteriorates.

The amount of (meth) acrylic acid used in the synthesis of the ring-opening adduct of epoxy (meth) acrylate and acid anhydride is preferably 0.98 to 1.10 equivalents of the epoxy group, more preferably 1 0.001 to 1.07, and particularly preferably 1.01 to 1.04. When the charged amount of (meth) acrylic acid is small, epoxy groups remain and storage stability deteriorates, and in extreme cases, gelation occurs during acid anhydride modification. On the other hand, if the amount is too large, the (meth) acrylic acid remains to generate odor and cause a decrease in heat resistance.

In the ring-opening addition of epoxy (meth) acrylate and acid anhydride, it is effective to add 30 to 300 ppm of hydroquinone as a radical polymerization inhibitor. Phenothiazine can be synthesized by adding about 500 ppm, but its storage stability is slightly worse than that of hydroquinone.

In the ring-opening addition of epoxy (meth) acrylate and acid anhydride, a quaternary ammonium salt such as tetrabutylammonium bromide is used as a catalyst in an amount of 0.1 to 0.1%.
It is effective to add 5.0%, preferably 0.3 to 2.0%. When the amount of the catalyst added is small, the reaction is slow, and when the amount is too large, it remains in the reaction product and the insulating property and the like deteriorate.

Acid anhydrides used in the synthesis of ring-opening adducts of epoxy (meth) acrylates and acid anhydrides include succinic anhydride, tetrahydrophthalic anhydride, trimellitic anhydride, methylhexahydrophthalic anhydride and the like. It is preferable because it has good alkali solubility and can be dissolved in sodium carbonate. Phthalic anhydride, itaconic anhydride, maleic anhydride and the like are difficult to dissolve in sodium carbonate, but can be dissolved by using sodium hydroxide. The acid anhydride is preferably used in the range of 0.2 to 0.95 equivalent of the epoxy group before the reaction. If it is less than 0.2 equivalent, it becomes difficult to dissolve in an alkaline aqueous solution, and if it exceeds 0.95 equivalent, unreacted acid anhydride remains, so that the physical properties of the composition such as heat resistance and electrical properties are deteriorated, which is not preferable.

The solvent used in the synthesis of the ring-opening adduct of epoxy (meth) acrylate and acid anhydride can sufficiently dissolve the raw materials and reaction products, and has a boiling point of not lower than the reaction temperature.
Those having no hydroxyl group can be used. A solvent having a hydroxyl group, such as butyl cellosolve, is not preferable because it may react with an acid anhydride to give a by-product that reduces heat resistance and the like. Preferred solvents include ethers such as diglyme, esters such as ethyl carbitol acetate, ethyl cellosolve acetate and isopropyl acetate, and ketones such as methyl ethyl ketone and cyclohexanone. Aromatic hydrocarbons and the like may be used together to the extent that the solubility of the reaction product is not hindered.

In the synthesis of the ring-opening adduct of epoxy (meth) acrylate and acid anhydride, the reaction temperature is preferably 60 to
It is carried out at 160 ° C, more preferably 70 to 140 ° C, particularly preferably 80 to 120 ° C. If the reaction temperature is too low, the reaction is slow, and if it is too high, gelation occurs or the storage stability of the reaction product deteriorates. The acid value of the reaction solution is analyzed over time, and when the acid value becomes almost zero, the (meth) acrylate reaction is terminated. The reaction time varies depending on the reaction temperature and the catalyst concentration, but is usually 4 to 30 hours. The acid anhydride modification reaction can be performed usually in 1 to 8 hours.

The synthesis of the ring-opening adduct of epoxy (meth) acrylate and acid anhydride consists of a two-step reaction as described above. In the previous reaction, the epoxy group of the epoxy resin and the carboxyl group of (meth) acrylic acid are used. By the reaction with, both are linked by an ester bond, and at the same time, a secondary hydroxyl group is generated. This reaction is exothermic. In the reaction in the latter stage, the secondary hydroxyl group produced previously and the acid anhydride react with each other to form an ester bond with each other, and at the same time, a carboxyl group is produced. The reaction is slightly exothermic.

As described above, many base resins which can be dissolved in an alkaline aqueous solution can be used, and they can be used in combination, but the first resin composition has excellent heat resistance and electric characteristics. As the base resin of
The ring-opening adduct of a polymer and a glycidyl group-containing unsaturated compound is used as the base resin of the second resin composition as a ring-opening adduct of an epoxy (meth) acrylate and an acid anhydride or a polymer and a glycidyl group-containing unsaturated compound. Ring-opening adducts with compounds are preferred. As is well known, these can be easily cured by active energy rays such as electron beams and ultraviolet rays, or by means such as heating.

The base resin preferably has a molecular weight (styrene-equivalent weight average molecular weight by gel permeation chromatography) in the range of 1,000 to 200,000, more preferably 2,000 to 100,00.
0, particularly preferably 5,000 to 80,000.
If the molecular weight is too small, heat resistance, water resistance, etc. deteriorate, and the fluidity becomes too large. If the molecular weight becomes too large, the alkali solubility will deteriorate.

The base resin has an acid value of 0.2 to 1
The range is preferably 0.0 meq / g, more preferably 0.4 to 5.0 meq / g, and particularly preferably 0.6 to
It is 3.0 meq / g. If the acid value is too small, the alkali solubility will be poor, and if it is too large, the water resistance will be poor.

A preferred example of the first resin composition used in the copper-clad insulating sheet of the present invention is a ring-opening adduct of the above-mentioned polymer as an alkali-soluble base resin and a glycidyl group-containing unsaturated compound, and has a molecular weight of 30,000
~ 80,000, acid value 0.6-2.5 meq / g, and if necessary, an adhesive reinforcing agent (crosslinking agent), an active energy ray curing reaction initiator / sensitizer, and a peroxide as a curing agent. Examples include oxides added.

As a preferred example of the second resin composition used in the copper-clad insulation sheet of the present invention, a ring-opening addition of the above-mentioned epoxy (meth) acrylate and acid anhydride as a base resin soluble in an alkaline aqueous solution is preferable. Ring-opening adduct of a compound or polymer with a glycidyl group-containing unsaturated compound,
Molecular weight 3,000-50,000, acid value 0.6-3.
Select 0 meq / g, and if necessary, an adhesive reinforcing agent (crosslinking agent), active energy ray curing reaction initiator,
As a sensitizer and a curing agent, those prepared by mixing peroxide and the like can be mentioned.

The second resin composition has a higher alkali solubility than the first resin composition by changing the base resin, the size of its molecular weight, the acid value, and the addition amount of the adhesive reinforcing agent (crosslinking agent). It is preferable to prepare it so that it is large, preferably twice or more. As a cross-linking agent, if a resin having a large fluidity is added before curing, the alkali permeability of the resin composition obtained will be improved, so that it is possible to enhance the fluidity at the time of heating and simultaneously enhance the alkali solubility.

As described above, the alkali solubility of the resin composition is adjusted by changing the molecular weight of the base resin, the acid value, the glass transition temperature, and the addition amount of the adhesive reinforcing agent / crosslinking agent. A resin composition layer having a long acidity can be obtained, but as the copper-clad insulating sheet used in the present invention, for example, a base resin having a low acid value is used for the first resin composition to obtain a high acid value. When the base resin is used as the second resin composition, the first resin composition is less dissolved even when the second resin composition is dissolved, and the undercut of the resin under the copper foil can be suppressed small. it can.

As a method of controlling the alkali solubility of the resin composition by changing the temperature of the alkaline aqueous solution, for example, a base resin having a large molecular weight is used as the first resin composition and a base resin having a small molecular weight is used as the second resin composition. There is a method of using the copper clad insulation sheet. According to this, the dissolution time of the second resin composition is shorter. The lower the normal temperature, the longer the alkali dissolution time. Therefore, the undercut of the layer of the first resin composition can be suppressed by lowering the alkali dissolution temperature to an alkali dissolution time that does not hinder work. Another method of controlling the alkali dissolution temperature is to use a base resin having a high glass transition temperature Tg in the first resin composition and to use Tg in the second resin composition.
Low base resins may be used. When Tg is high, the resin is hard and the permeability of the alkaline aqueous solution is poor, and it is necessary to raise the alkali dissolution temperature. However, when Tg is low, the permeability of the alkaline aqueous solution is improved and the alkali dissolution temperature can be lowered. it can.

To the resin composition used in the present invention, a photoreactive compound and / or a thermosetting resin can be added as an adhesive reinforcing agent or a crosslinking agent, the amount of which is 100 parts by weight of the solid content of the base resin. 40 to 250 parts by weight is preferable. As the photoreactive compound, polyether series, polyester series, unsaturated polyester series, urethane series, epoxy series, polyester / urethane series, polyacetal series, polybutadiene series and the like can be used. An example is 2-
Ethylhexyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2
Urethane acrylate as functional oligomer, 1,3
-Butanediol diacrylate, 1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, diethylene glycol diacrylate, neopentyl glycol diacrylate, polyethylene glycol 400 diacrylate, hydroxypivalic acid ester neopentyl glycol diacrylate, Examples thereof include trimethylolpropane triacrylate, pentaerythritol triacrylate, dipentaerythritol hexaacrylate, triallyl isocyanurate, and the adducts or condensates thereof. As the thermosetting resin, acrylic resin, urethane resin, epoxy resin, polyester resin, polyether resin, alkyd resin, polyvinyl chloride resin, fluorine resin, silicone resin,
Examples thereof include vinyl acetate resin and polyvinyl alcohol.

Urethane acrylate is preferred as the above-mentioned adhesive reinforcing agent. The urethane acrylate has a function of particularly enhancing the adhesion between the surface copper foil and the resin layer, and as the acrylate, a non-yellowing / medium-hard type is preferable, and Aronix M manufactured by Toagosei Chemical Industry Co., Ltd. -1
100, Aronix M-1600, Aronix M-
1700 etc. are mentioned. It is preferable that 40 to 120 parts by weight of the urethane acrylate is added in one kind or two or more kinds to 100 parts by weight of the solid content of the base resin. When it exceeds 120 parts by weight, the solubility in an alkaline aqueous solution is deteriorated, and a resin residue is likely to occur. When a conductive material is formed to conduct electrical conduction between the inner layer conductor pattern and the outer layer copper foil, sufficient electrical continuity cannot be obtained if there is a resin residue. Four
If it is less than 0 part by weight, sufficient adhesion strength between the resin composition and the copper foil of the outer layer cannot be obtained.

As a reaction initiator for curing active energy rays such as ultraviolet rays and electron rays, benzoin ether type benzyl, benzoin, benzoin alkyl ether, 1-
Hydroxycyclohexyl phenyl ketone; benzyl dialkyl ketal as a ketal system; 2,2′-diallyl acetophenone, 2-hydroxyacetophenone, pt-butyltrichloroacetophenone, p-t-butyldichloroacetophenone as an acetophenone system; benzophenone as a benzophenone system, 4 -Chlorobenzophenone, 4,4'-dichlorobenzophenone, 4,
4'-bisdimethylaminobenzophenone, methyl o-benzoylbenzoate, 3,3'-dimethyl-4-methoxybenzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, dibenzosuberone, benzdimethylketal; thioxanthone as a thioxanthone system , 2-
Chlorthioxanthone, 2-alkylthioxanthone,
2,4-dialkylthioxanthone, 2-alkylanthraquinone, 2,2'-dichloro-4-phenoxyacetone and the like can be used. The amount is 1 base polymer solids
0.5 to 10 parts by weight is preferable with respect to 00 parts by weight.
If it is less than 0.5 part by weight, the reaction is not sufficiently initiated, and if it exceeds 10 parts by weight, the resin layer becomes brittle. When used by electron beam irradiation, the reaction initiator may be omitted.

As the sensitizer at the time of curing the active energy ray such as ultraviolet ray and electron beam, Nisso Cure EPA, EMA, IAMA, EHMA, MABP manufactured by Shin Nisso Kako Co., Ltd.
EABP, Kayakyu EPA manufactured by Nippon Kayaku Co., Ltd.,
DETX, DMBI, etc., Ward Blenkins
Opunt's Quantacure EPD, BEA, EO
B, DMB, etc., DABA manufactured by Osaka Organic Co., Ltd., PAA, DAA manufactured by Daito Chemical Co., Ltd., and the like. The addition amount is 0.5 to 1 with respect to 100 parts by weight of the solid content of the base polymer.
0 parts by weight is preferred. If it is less than 0.5 part by weight, the reaction rate of active energy ray curing is not improved, and if it exceeds 10 parts by weight, the reaction becomes faster and shelf life is shortened. If electron beam irradiation is used, the reaction sensitizer may be omitted.

Although peroxides can be used as the curing agent, in view of storage stability, alkyl peroxides such as dibutyl peroxide, butyl cumyl peroxide, dicumyl peroxide or aryl peroxides are preferable. The amount is preferably 1 to 10 parts by weight based on 100 parts by weight of the solid content of the base polymer.
If it is less than 1 part by weight, the curing time will be long, and if it exceeds 10 parts by weight, the shelf life will be short and the workability will be poor. A curing agent is not necessarily required when performing ultraviolet ray irradiation, electron beam irradiation, etc., but it is preferable to add a curing agent in order to enhance adhesion stability such as copper foil adhesion stability and solder heat resistance.

The copper clad insulating sheet of the present invention is prepared in advance and has a conductor circuit pattern on one or both sides of 0.1 to 0.1.
When the inner layer panel having a thickness of 1.6 mm is laminated with a heat roll on the surface having the conductor circuit pattern, the second resin composition flows between the conductor circuit patterns, and if there is a through hole, heating and pressing of the heat roll is performed. Second with more fluidity
The resin composition of (3) easily flows into the through holes, and the through holes are filled with the resin. Initially, it was expected that only the volume would flow due to the product of the thickness of the layer of the second resin composition and the land area of the conductor pattern around the through hole, but unexpectedly, the resin spreads to the opposite surface of the through hole. I knew I would reach it. The present invention utilizes this phenomenon for filling the resin of the lead via hole.

An etching resist is formed on the surface copper foil of the laminated copper-clad insulation sheet to remove the copper foil at the via hole position and unnecessary copper foil, and the copper-clad insulation sheet is laminated with a hot roll. The etching process may be repeated in sequence to form a multilayer printed circuit board. In this case, after laminating the copper clad insulating sheet of the outermost layer, the surface copper foil of the required portion of the via hole is removed by etching, and the exposed layer of the resin composition is dissolved in an alkaline aqueous solution to give an optional inner layer. Of the conductor circuit pattern of, the layer of the resin composition is cured by heating or active energy rays such as electron beams, the inner layer with the surface copper foil through the alkali-dissolved portion, these multiple copper body circuit pattern It is also possible to form a conductive material between them and electrically connect them.

In the method for producing a printed circuit board of the present invention, when a copper clad insulating sheet for forming an outer layer is laminated on an inner layer panel, the inner surface of the inner layer panel and the conductor layer of the copper clad insulating sheet are The thickness of the surface copper foil is preferably 20 to 70 μm. If it is less than 20 μm, the insulation resistance and withstand voltage between layers cannot be secured, and if it exceeds 70 μm, the undercut due to alkali dissolution when forming a via hole of small diameter becomes large, and the connection reliability by plating the via hole or conductive paste is sufficient. Is difficult to obtain.

The fluidity of the resin composition at the time of lamination with a hot roll can be controlled mainly by adjusting the molecular weight of the base resin. As mentioned above, the preferred molecular weight of the base resin used in the present invention is 1,0.
However, if it exceeds 30,000, the fluidity of the resin at the time of heating will almost disappear and the value will be 10.0.
From 00 to 30,000, fluidity is slightly generated,
Below 10,000, there is fluidity. However, as described above, when a large amount of a cross-linking agent having a large fluidity is added to the resin composition before curing, even if the molecular weight of the base polymer is large, the resin composition may have a large fluidity when heated. it can.

In the method for producing a printed circuit board of the present invention, the resin composition is cured mainly by heating, but irradiation with active energy rays such as electron beams is also possible. In the case of heating, the temperature is preferably in the range of 80 to 180 ° C, more preferably 150 to 170 ° C. If the temperature exceeds 180 ° C by heat curing, the insulating resin that constitutes the laminated layer having the conductor circuit pattern to be inner layer deteriorates, and if the temperature is less than 80 ° C, it takes time to cure and sufficient crosslinking occurs due to insufficient crosslinking. There is a fear of not.

Further, the resin composition around the via hole flows out at the time of heating, and the resin composition covers the surface of the underlying conductor circuit pattern in a portion where a large amount of flow occurs, so that conduction cannot be obtained even if the via hole is plated. Defects occur. Therefore, the resin composition is irradiated with ultraviolet rays or electron beams in a state where the resin composition starts to flow by heating, and the active energy ray is applied to the resin composition below the via hole formed in the copper foil or in the portion facing the via hole. By advancing the curing of the resin composition, a weir for the resin flow can be formed and the resin can be prevented from flowing more than necessary. In the case of electron beam irradiation, the condition of 180 to 300 kV and 10 to 30 Mrad is preferable, and not only the curing of the resin composition around the via hole but also the electron beam penetrating the copper foil to 18 to 35
The layer of resin composition underneath the μm copper foil can also be cured.

When the copper clad insulating sheet used in the method for producing a printed circuit board according to the present invention is laminated on an inner layer panel, the circuit pattern is provided in order to secure the adhesive force between the resin composition and the inner conductor circuit pattern. Surface roughening treatment,
It is preferable to perform black oxide treatment, brown oxide treatment, red oxide treatment and the like. Further, when the copper-clad insulating sheet is made the inner layer, it is preferable that the copper foil of the copper-clad insulating sheet is also subjected to these treatments in advance.

In the method for producing a printed circuit board of the present invention, the layer of the resin composition for forming via holes can be dissolved with an organic solvent, but the use of an alkaline aqueous solution is more reliable and easier to work with. It is also appropriate from the above. This is because when the resin composition is dissolved in an organic solvent, the reaction is swelling and dissolution reaction, and the boundary of the resin after dissolution becomes rough instead of smooth, and there is a problem that the organic solvent remains near the boundary. Therefore, when plating the via hole after melting the resin, electroless plating is less likely to deposit due to the effect of the residual organic solvent and the resin boundary being rough, and the occurrence of pinholes in the plating Even in holes, residual organic solvent evaporates and voids,
Problems such as bubbles and blisters may occur, and these may make electrical and mechanical connections unstable due to via holes between conductor circuits between layers, resulting in unreliable connection. On the other hand, when the resin composition is dissolved in an alkaline aqueous solution, an alkali-soluble group such as a carboxyl group or a phenolic hydroxyl group reacts and dissolves, so that the dissolution rate is fast, and the resin composition is sequentially formed from a portion in contact with the alkaline aqueous solution. The boundaries of the resin become clear because they are dissolved. Moreover, unlike the organic solvent, it does not deteriorate the working environment.

When the surface copper foil is etched to form fine holes and the resin composition thereunder is alkali-dissolved to form the via holes, the via holes are formed in the conventional manufacturing process of the printed circuit board. It is further preferable in that the multilayer printed circuit board can be easily manufactured. That is, if an alkali-soluble etching resist is used for forming the copper foil micropores, the resin composition of the lower portion of the copper foil micropores is formed simultaneously with the resist in the film stripping step after copper foil etching. The layers can be dissolved. In the case where the alkali-developing dry film is used as a resist, the resist is removed with a sodium hydroxide aqueous solution for peeling, and at the same time, the layers of the first and second resin compositions under the fine holes of the copper foil are dissolved and removed. Is possible and more preferable.

When the layer of the resin composition having an alkali-soluble group having a carboxyl group or a phenolic hydroxyl group is dissolved in an aqueous alkaline solution and then washed with an acid such as dilute sulfuric acid, the alkaline component does not remain. Subsequent deposition of electroless plating is good, and defects such as voids, bubbles, and blisters do not occur, so that highly reliable via holes can be formed.

When the copper wiring pattern on the surface of the inner layer panel is subjected to blackening treatment or the like, if the resin composition in the via hole is dissolved, the blackening treatment will be oxidized if the via hole is neutralized with an acid. The copper coating melts and the copper color appears. When the resin remains on the surface of the blackening treatment film, the color of copper cannot be seen, and therefore the quality of the alkali dissolution can be judged by this neutralization treatment.

In the method for producing a printed circuit board of the present invention, copper foil is etched to form fine holes, and the layer of the resin composition in the fine holes is dissolved with an alkaline aqueous solution to expose the surface of the inner layer panel. As a method for electrically connecting the conductor circuit pattern and the surface copper foil, electroless plating and / or electrolytic plating, conductive paste of gold, silver, copper, solder or the like is used by screen printing, dispenser, pin printing or the like. The method of applying and drying and curing, or roll coating, dip coating, flow coating or the like of molten metal can be used.

In the method for producing a printed circuit board according to the present invention, the copper clad insulating sheet on which the first resin composition layer and the second resin composition layer are formed is separated so that the production can be continuously performed. It is preferable to wind the roll-shaped copper-clad insulating sheet in a roll form via a mold film or release paper, because the roll-shaped copper-clad insulating sheet can be continuously laminated on the inner layer panel or the like with a hot roll.

In the copper clad insulating sheet, a layer of the first and second resin compositions is formed on the mat surface of the copper foil, and a photosensitive resin is applied beforehand on the copper foil on the opposite surface of the copper foil. You can also keep it. The photosensitive resin can be used in place of a dry film or an etching resist after laminating a copper clad insulating sheet on the multilayer printed circuit board for the inner layer, and the step of forming the dry film or the etching resist in the manufacturing process of the multilayer printed circuit board can be performed. It can be omitted. Not only is the economy improved, but the use of this method also improves the yield, which can lead to superior quality.

[0071]

In the copper clad insulating sheet of the present invention, the first resin composition has a small resin flow during heating, while the second resin composition has a large resin flow during heating, so that the conductor circuit pattern is formed in the laminating step. The resin can permeate between the conductor circuit patterns of the inner layer panel having the above and the surface of the inner layer panel to fill the voids. At this time, if the inner printed circuit board has through holes, the second resin composition also flows into the through holes. Since the resin flow during heating of the first resin composition layer is small in the laminating step,
It is possible to secure the thickness of the insulating layer between the conductor circuit pattern surface on the surface of the inner layer panel and the copper foil on the surface of the copper-clad insulating sheet laminated thereon.

Example 1 (Synthesis of Base Resin) n-Butyl Methacrylate 40
Parts by weight, 15 parts by weight of methyl methacrylate, 1 styrene
A mixture of 0 parts by weight, 10 parts by weight of hydroxyethyl methacrylate, 25 parts by weight of methacrylic acid and 1 part by weight of azobisisobutylnitrile was placed in 120 parts by weight of propylene glycol monomethyl ether kept at 80 ° C. under a nitrogen gas atmosphere for 5 hours. It dripped over. Then, after aging for 1 hour, 0.5 part by weight of azobisisobutylnitrile was further added and aging was performed for 2 hours to synthesize a carboxyl group-containing methacrylic resin. Next, while blowing air, 20 parts by weight of glycidyl methacrylate, 1.5 parts by weight of tetrabutylammonium bromide and 0.15 parts by weight of hydroquinone as a polymerization inhibitor were added, and the mixture was reacted at 80 ° C. for 8 hours to give a molecular weight of 50,000.
A base resin having a carboxyl group of 0 to 70,000 and an unsaturated equivalent of 1.14 mol / kg was synthesized to prepare a base resin having an acid value of 1.2 meg / g.

(Preparation of First Resin Composition) 65 parts by weight of the above-mentioned base resin, 35 parts by weight of pentaerythritol triacrylate (Aronix M-305 manufactured by Toagosei Chemical Industry Co., Ltd.) as a crosslinking agent, and Japan as a curing agent. The first resin composition was prepared by thoroughly mixing 1.0 part by weight of YUKI CORPORATION's Perkmill D.

(Preparation of Second Resin Composition) 30 parts by weight of the above-mentioned base resin and Aronix M-30 as a crosslinking agent.
70 parts by weight of 5 and 1 of Percumil D as a curing agent.
A second resin composition was prepared by thoroughly mixing 0 parts by weight.

Regarding the copper-clad insulating sheet used in the present invention,
Description will be given based on the schematic sectional view shown in FIG.

(Preparation of Copper Clad Insulation Sheet) The matte surface of the copper foil 1 having a thickness of 35 μm is coated with the first resin composition using a comma coater and dried at 60 ° C. for 20 minutes to obtain a resin layer 2 having a thickness of 60 μm. Then, the second resin composition was similarly applied and dried on the layer of the first resin composition to form a resin layer 3 having a thickness of 30 μm, and a copper clad insulating sheet 4 was prepared.

A method for manufacturing a printed circuit board having an electromagnetic wave shield layer according to the present invention will be described with reference to the drawings. 8 to 14 are schematic cross-sectional views for explaining the manufacturing process and configuration.

As shown in FIGS. 8 and 9, a blackened inner layer panel 7 is prepared in which a plated through hole 24 and a copper wiring pattern 6 are formed on a glass epoxy double-sided copper clad plate having a plate thickness of 0.2 mm. On the surface of the copper wiring pattern 6 of the panel 7 for use, sodium chlorite 37 g / liter, sodium hydroxide 10 g / liter and trisodium phosphate 12
The solution was treated with a solution of a hydrate of 20 g / liter for 5 minutes at 95 ° C., washed well with water, dried and then blackened. Next, a copper-clad insulating sheet having a release film 21 on the surface of the inner layer panel 7 is placed at 75 ° C. and an air pressure of 3 kg / cm.
^In No. ² , lamination was performed with a 150 mmφ metal roll 16. Since the second resin composition layer 3 has a high fluidity, it flows between the copper wiring patterns 6 and into the through holes, and the first resin composition layer 2 has almost no resin flow. It comes into contact with 6.

After the release film 21 is peeled off, the etching resist 13 is continuously formed on the copper clad insulating sheet (see FIG. 1).
0), the via hole portion and the unnecessary copper foil portion were dissolved and removed with a cupric chloride etching solution to form a copper foil pattern.

Next, the exposed resin layer of the blind via hole 9 portion and the plated through hole 24 is treated by spraying a 1% sodium carbonate solution at 40 ° C. for 3 minutes to dissolve it, followed by washing with water and a 10% sulfuric acid aqueous solution. By doing so, the copper foil pattern and the plated through holes 24 in the lower layer were exposed and film peeling was performed (FIG. 11).

Next, after irradiating the laminated panel with an electron beam, the surface copper foil of the outermost layer is etched to form a conductor circuit pattern, and the conductor circuit pattern under the blind via hole is electrically connected. The silver paste 13 for electrical connection was printed and heat-cured at 150 ° C. for 45 minutes. Further, an overcoat 14 that covers the silver paste 13 is formed, and a solder resist 25 is formed by printing as a protective film of the electromagnetic wave shield layer and a soldering prevention film, whereby a printed circuit board with an electromagnetic wave shield layer is obtained (FIG. 1).
2).

As shown in FIG. 13, the printed circuit board with the electromagnetic wave shield layer has exposed plated through holes 24.
The lead wire 17 of the electronic component with a lead wire 18 can be inserted into the portion and soldered. On the other hand, by changing the pattern of the etching resist on the copper clad laminated panel (FIG. 10), the terminal portion 27 of the chip component 26 can be directly connected to the conductor circuit pattern 6 of the inner layer panel with the solder 19 as shown in FIG. Alternatively, the solder connection may be performed at the same time when the electronic component with the lead wire is soldered. Furthermore,
When soldering, the conductor circuit pattern of the outer layer and the conductor circuit pattern of the inner layer panel can be simultaneously connected by soldering.

Example 2 A method of manufacturing a metal core printed circuit board according to the present invention will be described with reference to the drawings. 15 to 21 are schematic cross-sectional views for explaining the manufacturing process and configuration.

As shown in FIGS. 15 and 16, a copper-clad insulating sheet 4 is provided on the surface of an aluminum panel 28 having a thickness of 0.5 mm, which is provided with through holes 29 in advance and whose surface has been roughened by sandblasting, via a release film 21. Was continuously laminated on each side by a metal roll 16 at 75 ° C. under the same conditions as in Example 1 to prepare a metal core copper clad laminate panel (FIG. 17). At this time, the second resin composition of the copper-clad insulating sheet 4 flows and fills the inside of the through hole.

Next, the resin composition was thermally cured at 150 ° C. for 30 minutes, and then a through hole 30 having a diameter smaller than the hole diameter was drilled at the center position of the hole (FIG. 18).
Successively, well-known electroless copper plating and electrolytic copper plating were sequentially performed to form plated through holes 24 (FIG. 19).

Next, an etching resist 12 was formed (FIG. 20), unnecessary copper foil portions were dissolved and removed with a cupric chloride etching solution, and a copper wiring pattern was formed to obtain a metal core printed circuit board. (FIG. 21).

Example 3 Another metal core printed circuit board manufacturing method of the present invention will be described with reference to the drawings. 15 to 17 and FIG. 22 are schematic cross-sectional views for explaining the manufacturing process and configuration.

As shown in FIGS. 15 and 16, through-holes 29 are provided in advance, and the surface of a 0.5 mm thick phosphor bronze panel 28 roughened by sandblasting is placed on the surface of a copper clad insulating sheet via a release film 21. 4 was continuously laminated on one side by a metal roll 16 at 75 ° C. to prepare a metal core copper clad laminated panel as shown in FIG.

Next, an etching resist 12 is formed in order to remove the blind via hole portion and the unnecessary copper foil portion, etching is performed, and the copper clad insulating sheet 4 is laminated on the etching resist 12. The copper foil was removed by etching. The exposed resin layer is treated with a 1% sodium carbonate solution by spray injection at 40 ° C. for 3 minutes to dissolve it, and then washed with water and a 10% sulfuric acid aqueous solution to remove the lower copper wiring pattern and a part of the copper phosphate panel. Exposed and membrane stripped.

Next, after thermosetting at 150 ° C. for 30 minutes, a through hole 30 having a diameter smaller than the hole diameter was drilled at the center position of the hole filled with the resin. Successively, well-known electroless copper plating and electrolytic copper plating are sequentially performed,
A plated through hole was formed, a gold plating resist was formed, and gold plating was performed.

Next, the plating resist was peeled off to remove unnecessary copper foil portions other than gold plating by etching and dissolution to form a gold plating pattern, and a metal core multilayer printed circuit board having a metal core exposed was obtained. .

Next, after the silver paste is printed and dried as the die bond 31 on the exposed metal core portion to bond the IC bare chip 33, the electrode of the IC chip and the gold plating pattern are bonded by the gold wire 32, and the sealant 34 is formed. Was applied and heated at 150 ° C. for 10 minutes to prepare a metal core multilayer printed circuit board on which an IC bare chip was mounted.

[0093]

According to the method of manufacturing a printed circuit board of the present invention, a printed circuit board having an electromagnetic wave shield layer excellent in physical characteristics, electrical characteristics and reliability, and a metal core printed circuit board can be easily obtained. Further, it is possible to continuously form a baled via hole, an electromagnetic wave shield layer, and an insulation of a metal core with a hot roll without using a hot press as in the conventional case.

Moreover, as in the conventional case, one via hole is formed.
Instead of drilling holes one by one, it becomes possible to form blind holes or through holes all at once by dissolving the resin composition with alkali. Moreover, the resin composition between the conductor circuit patterns of the arbitrary layers can be dissolved to electrically connect the conductor circuit patterns of the arbitrary layers, which increases the degree of freedom in designing the printed circuit board. Thin mounting becomes possible. Furthermore, since a thin copper clad insulating sheet is used instead of the conventional thick prepreg, it is possible to manufacture a thin multilayer printed circuit board.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a structure before thermocompression bonding of an inner layer panel having a copper wiring pattern on its surface and a copper foil through a prepreg in a manufacturing process of a conventional multilayer printed wiring board having a blind via hole. It is a figure.

FIG. 2 is a schematic cross-sectional view showing the configuration of a copper clad laminate panel after being subjected to thermocompression bonding in the same manufacturing process.

FIG. 3 is a schematic sectional view showing the copper clad laminate panel after forming through holes by drilling in the same manufacturing process.

FIG. 4 is a schematic cross-sectional view showing the copper clad laminate panel after forming holes for blind via holes by drilling in the same manufacturing process.

FIG. 5 is a schematic cross-sectional view after a plating process in the manufacturing process.

FIG. 6 is a schematic cross-sectional view after forming an etching resist in the same manufacturing process.

FIG. 7 is a schematic cross-sectional view after unnecessary copper foil is removed by etching in the manufacturing process.

FIG. 8 is a schematic view showing a state in which a panel for inner layer having a plated through hole and a conductor circuit pattern and a copper clad insulating sheet are heated and pressure-bonded with a heat roll in the process of manufacturing a printed circuit board having an electromagnetic wave shielding layer of the present invention. FIG.

FIG. 10 is a schematic cross-sectional view after an inner layer panel having a plated through hole and a copper foil pattern and a copper clad insulating sheet are thermocompression bonded by a heat roll and an etching resist is formed in the manufacturing process.

FIG. 11 is a schematic cross-sectional view after the resin composition is alkali-dissolved and removed in the same manufacturing process.

FIG. 12 is a schematic cross-sectional view after conductive paste printing, overcoat formation, and solder resist formation in the manufacturing process.

FIG. 13 is a schematic cross-sectional view of a printed circuit board in a state in which an electronic component with a lead wire is inserted into a plated through hole for an inner layer and mounted by soldering in the same manufacturing process.

FIG. 14: In the same manufacturing process, insert the electronic component with a lead wire into the plated through hole for the inner layer and solder it,
It is a schematic sectional drawing of the printed circuit board which has an electromagnetic wave shield layer which shows the other Example of this invention in the state which mounted the chip component together.

FIG. 15 is a schematic cross-sectional view showing a step of heating and press-bonding a copper clad insulating sheet to a metal plate panel with a heating roll in the manufacturing process of the metal core printed circuit board of the present invention.

FIG. 16 is a schematic cross-sectional view showing a step of heating and press-bonding a copper clad insulating sheet to the other surface of the metal plate panel with a heating roll in the same manufacturing process.

FIG. 17 is a schematic cross-sectional view showing a state in which copper clad insulating sheets are laminated on both sides of a metal plate panel in the same manufacturing process.

FIG. 18 is a schematic cross-sectional view showing a state in which a through hole is provided in the manufacturing process.

FIG. 19 is a schematic cross-sectional view showing a state in which a plated through hole is formed in the manufacturing process.

FIG. 20 is a schematic cross-sectional view showing a state where an etching resist is formed in the manufacturing process.

FIG. 21 is a plan view showing the removal of unnecessary copper foil in the manufacturing process,
It is a schematic sectional drawing which shows the state which formed the conductor pattern by stripping the film.

FIG. 22 is a schematic cross-sectional view showing a state in which an IC chip is mounted on a metal core multilayer printed circuit board which is another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Copper foil 2 Layer of 1st resin composition 3 Layer of 2nd resin composition 4 Copper-clad insulating sheet 5 Prepreg 6 Copper wiring pattern (conductor circuit pattern) 7 Panel for inner layers 8 Through hole 12 Etching resist 13 Silver Paste 14 Overcoat (Solder resist) 15 Overcoat 16 Metal roll 17 Lead wire 18 Electronic component 19 Solder 20 Hole for blind via hole 21 Release film 22 Ballide via hole 23 Hole for blind via hole 24 Plating through hole 25 Solder resist 26 Chip component 27 Terminal part 28 Metal plate panel 29 Through hole 30 Through hole 31 Die bond 32 Gold wire 33 Semiconductor component 34 Encapsulating material

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[Procedure amendment]

[Submission date] October 18, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] Brief description of the drawing

[Correction method] Change

[Correction content]

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing a structure before thermocompression bonding of an inner layer panel having a copper wiring pattern on its surface and a copper foil through a prepreg in a manufacturing process of a conventional multilayer printed wiring board having a blind via hole. It is a figure.

FIG. 2 is a schematic cross-sectional view showing the configuration of a copper clad laminate panel after being subjected to thermocompression bonding in the same manufacturing process.

FIG. 3 is a schematic sectional view showing the copper clad laminate panel after forming through holes by drilling in the same manufacturing process.

FIG. 4 is a schematic cross-sectional view showing the copper clad laminate panel after forming holes for blind via holes by drilling in the same manufacturing process.

FIG. 5 is a schematic cross-sectional view after a plating process in the manufacturing process.

FIG. 6 is a schematic cross-sectional view after forming an etching resist in the same manufacturing process.

FIG. 7 is a schematic cross-sectional view after unnecessary copper foil is removed by etching in the manufacturing process.

FIG. 8 is a schematic view showing a state in which a panel for an inner layer having a plated through hole and a conductor circuit pattern and a copper clad insulating sheet are heated and pressure bonded by a heat roll in the process of manufacturing a printed circuit board having an electromagnetic wave shield layer of the present invention. FIG.

FIG. 9 is a schematic cross-sectional view showing a state in which a copper clad insulating sheet is heated and pressure-bonded to the other surface of the inner layer panel by a heating roll in the same manufacturing process.

FIG. 10 is a schematic cross-sectional view after an inner layer panel having a plated through hole and a copper foil pattern and a copper clad insulating sheet are thermocompression bonded by a heat roll and an etching resist is formed in the manufacturing process.

FIG. 11 is a schematic cross-sectional view after the resin composition is dissolved and removed by alkali in the same manufacturing process.

FIG. 12 is a schematic cross-sectional view after conductive paste printing, overcoat formation, and solder resist formation in the manufacturing process.

FIG. 13 is a schematic cross-sectional view of a printed circuit board in a state in which an electronic component with a lead wire is inserted into a plated through hole for an inner layer and mounted by soldering in the same manufacturing process.

FIG. 14: In the same manufacturing process, insert the electronic component with a lead wire into the plated through hole for the inner layer and solder it,
It is a schematic sectional drawing of the printed circuit board which has an electromagnetic wave shield layer which shows the other Example of this invention in the state which mounted the chip component together.

FIG. 15 is a schematic cross-sectional view showing a step of thermocompression bonding a copper clad insulating sheet to a metal plate panel with a heating roll in the process of manufacturing the metal core printed circuit board of the present invention.

FIG. 16 is a schematic cross-sectional view showing a step of heating and press-bonding a copper clad insulating sheet to the other surface of the metal plate panel with a heating roll in the same manufacturing process.

FIG. 17 is a schematic cross-sectional view showing a state in which copper clad insulating sheets are laminated on both sides of a metal plate panel in the same manufacturing process.

FIG. 18 is a schematic cross-sectional view showing a state in which a through hole is provided in the manufacturing process.

FIG. 19 is a schematic cross-sectional view showing a state in which a plated through hole is formed in the manufacturing process.

FIG. 20 is a schematic cross-sectional view showing a state where an etching resist is formed in the manufacturing process.

FIG. 21 is a plan view showing the removal of unnecessary copper foil in the manufacturing process,
It is a schematic sectional drawing which shows the state which formed the conductor pattern by stripping the film.

FIG. 22 is a schematic cross-sectional view showing a state in which an IC chip is mounted on a metal core multilayer printed circuit board which is another embodiment of the present invention.

[Explanation of reference numerals] 1 copper foil 2 layer of first resin composition 3 layer of second resin composition 4 copper-clad insulating sheet 5 prepreg 6 copper wiring pattern (conductor circuit pattern) 7 inner layer panel 8 through hole 12 Etching Resist 13 Silver Paste 14 Overcoat (Solder Resist) 15 Overcoat 16 Metal Roll 17 Lead Wire 18 Electronic Component 19 Solder 20 Hole for Blind Via Hole 21 Release Film 22 Ballide Via Hole 23 Hole for Blind Via Hole 24 Plating Through Hole 25 Solder Resist 26 Chip Component 27 Terminal Part 28 Metal Plate Panel 29 Through Hole 30 Through Hole 31 Die Bond 32 Gold Wire 33 Semiconductor Component 34 Sealing Material

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location H05K 3/46 N 6921-4E

Claims (3)

[Claims] 1. A layer of a first resin composition, which is soluble in an aqueous alkali solution and has low fluidity when heated and pressed by a hot roll, is formed on a roughened surface of a copper foil, and an alkali is formed on the layer. It is soluble in aqueous solution and has high fluidity when heated and pressed by hot rolls.
The step of laminating the resin side of the copper-clad insulating sheet formed by forming a layer of the resin composition on both sides or one side or both sides of a multilayer printed wiring board with a heat roll; A step of forming an etching resist on the surface of the printed wiring board and removing the surface copper foil located above the ground portion of the printed wiring board by etching; Exposing the conductor circuit pattern;
A method for producing a printed circuit board, which comprises a step of curing a resin composition; and a step of electrically connecting an exposed conductor circuit pattern of the printed wiring board and surface copper foil with a conductive substance to form an electromagnetic wave shield layer. 2. A layer of a first resin composition having a low fluidity when heated and pressed by a hot roll is formed on a roughened surface of a copper foil, and the layer is heated and pressed by a hot roll on the layer. The resin side of the copper-clad insulating sheet formed with the layer of the second resin composition having a large fluidity is laminated on both sides of a metal panel in which through holes are formed in advance with a heat roll, A step of forming a resin-filled laminated panel in the resin; a step of curing the resin composition; a step of forming a through hole having a diameter smaller than that of the resin-filled hole of the laminated panel; A method of manufacturing a metal core printed circuit board, which comprises the step of electrically connecting with a conductive material; the step of forming a conductor circuit pattern on the surface copper foil by selective etching. 3. A layer of a first resin composition which is soluble in an alkaline aqueous solution and has low fluidity when heated and pressed by a hot roll is formed on a roughened surface of a copper foil, and an alkali is formed on the layer. It is soluble in aqueous solution and has high fluidity when heated and pressed by hot rolls.
A laminated panel in which the resin side of a copper-clad insulating sheet formed by forming a layer of the resin composition is laminated on both sides of a metal panel in which a through hole is formed in advance with hot rolls, and the resin is filled in the hole of the metal panel. A step of forming an etching resist on the surface copper foil, removing the copper foil at the position where the metal panel is exposed by etching, and dissolving and removing the exposed resin composition layer with an alkaline aqueous solution to expose the metal panel. A step of curing the resin composition; a step of forming a through hole having a diameter smaller than that in the resin-filled hole of the laminated panel; a step of electrically connecting copper foils on both surfaces with a conductive material A method of manufacturing a metal core printed circuit board, which comprises a step of directly die bonding a semiconductor component to a metal panel.