KR20130067302A - Method of manufacturing printed circuit board, and printed circuit board obtained using method of manufacturing printed circuit board - Google Patents

Abstract

Even if the surface roughness of the insulated resin layer exposed between circuits is small, it aims at providing the manufacturing method of the printed wiring board which has favorable adhesiveness of the insulated resin layer surface and a soldering resist layer. In order to achieve this object, a method of manufacturing a printed wiring board using a copper-clad laminate in which an uncoated copper foil is bonded, in which a circuit is formed by etching the uncoated copper foil with a copper etching solution. Subsequently, the surface treatment metal component of the said non-harmonized copper foil which remains on the surface of the said insulated resin which performed the purification process by performing the purification process on the surface of the insulated resin exposed between circuits, and XPS analyzer (X-ray source: Al (K ( _alpha)) And acceleration voltage: 15 kW, beam diameter: 50 µm), a method for producing a printed wiring board, or the like, wherein each surface-treated metal component is below a detection limit is employed.

Description

The printed wiring board obtained using the manufacturing method of a printed wiring board, and the manufacturing method of the printed wiring board {METHOD OF MANUFACTURING PRINTED CIRCUIT BOARD, AND PRINTED CIRCUIT BOARD OBTAINED USING METHOD OF MANUFACTURING PRINTED CIRCUIT BOARD}

This invention relates to the printed wiring board obtained using the manufacturing method of a printed wiring board, and the manufacturing method of the printed wiring board. In particular, it is related with the printed wiring board excellent in adhesiveness with the surface of the insulated resin layer exposed between a soldering resist layer and a circuit.

Conventionally, the copper foil used for manufacture of a copper-clad laminate performs a roughening process on the bonding surface with the insulated resin layer of the said copper foil, so that the uneven | corrugated shape of this roughening process may be dug into the surface of the insulated resin layer. This obtained the physical anchor effect and bonded the insulated resin layer. Therefore, in the site | part which formed the copper foil laminated board by the etching method and removed the copper foil layer, the insulated resin layer with the unevenness | corrugation to which roughening process shape was transferred was exposed. In the case of such an uneven insulating resin layer, the adhesiveness with the soldering resist layer provided after this on the surface and the resin layer laminated | stacked later at the time of multilayering was also favorable.

In recent years, however, multifunctionalization is required along with light and small and small, such as mobile phones, mobile computers, portable music players, and digital cameras, which are major portable electronic devices. There is a demand for circuit formation that can improve the performance and cope with multifunctionality. In manufacturing such a printed wiring board, it is required to form a fine wiring having a good etching factor by making the copper foil included in the copper foil laminated plate as thin as possible and flattening the contact surface between the copper foil and the insulating layer. Increasingly, copper foil is used. The non-harmonized copper foil here does not perform a roughening process on the bonding surface with the insulated resin layer of copper foil. Therefore, the roughening process of the uneven | corrugated shape which becomes the state which penetrates into the surface of the insulated resin layer is not formed, and a physical anchor effect cannot be obtained between copper foil and an insulated resin layer.

As a result, when a printed wiring board is manufactured using the copper foil laminated board which bonded the uncoated copper foil, the anchoring effect is not exhibited because the flat insulating resin layer which does not have an uneven shape exposes the site | part which formed the circuit by the etching method and removed the copper foil layer, Adhesiveness with the soldering resist layer and insulating resin layer formed in an outer layer will fall. Therefore, when a heating process such as fusing is performed in a hygroscopic state, a problem may occur in which a phenomenon (delamination) of the solder resist layer peels off from the insulating resin layer occurs. 6 shows a cross section of a printed wiring board on which delamination has occurred. In FIG. 6, it can be clearly observed that the space (delamination DL) exists between the insulating resin base material BM and the soldering resist PSR to the immediate side of the copper circuit CC.

In addition, in the site where the delamination has occurred, surface layer migration due to energization to the circuit easily occurs, and it is difficult to ensure long-term reliability as a printed wiring board. As a technique of improving the moisture absorption and heat resistance adhesiveness of such a soldering resist layer and an insulated resin layer, the technique disclosed by the following patent documents 1 and patent documents 2 is mentioned.

Patent Document 1 provides a method for producing a printed wiring board that is advantageous in terms of fine wiring formation, electrical characteristics, and manufacturing cost, and has a high reliability, and has a 10-point average roughness Rz of the surface of 2.0 µm or less. In the manufacturing method of the printed wiring board using metal foil, it discloses the manufacturing method of the printed wiring board which has the process of roughening on the resin surface used as an adhesive interface with a soldering resist layer as a pretreatment at the time of apply | coating or laminating | stacking a soldering resist, have.

And in the Example of this patent document 1, the thickness of a resin composition was made to the to-be-adhered surface treated with the silane coupling agent of the electrolytic copper foil (F0-WS-18, the product made from Furukawa Circuit Foil, 18 micrometers thickness, Rz = 1.8 micrometers). Glass-cloth insulation layer high Tg epoxy resin prep made of Hitachi Chemicals Co., Ltd. which laminated | stacked 4 sheets of copper foil with resin dried at 160 degreeC for 10 minutes so that it might become 3.0 micrometers, and the residual solvent became 5 weight% or less. Using the copper foil laminated board which was arrange | positioned above and below leg GEA-679F (thickness 0.1mm), and press-molded on 180 degreeC and 2.5 MPa conditions for 1 hour, the copper foil of the unnecessary part was removed by the iron chloride type etching liquid etc., Hitachi Chemical Co., Ltd. SR-7200G (solder resist) is laminated on the insulation resin board which we treated with 3% sodium hydroxide + 6% potassium permanganate aqueous solution, and chemically harmonized, and is 121 degrees Celsius, 100% of humidity, 2 standard atmosphere After treatment for 2 hours with a gun, there is a description that 20 seconds immersion in a solder bath at 260 ° C, or 196 hours at 121 ° C, 100% humidity and 2 atmospheres does not cause swelling or the like in the solder resist. .

Moreover, even when the metal foil with the small surface roughness of the surface which contact | connects an insulating layer is used, patent document 2 can ensure the contact | adherence of the soldering resist on the insulating layer after metal foil removal, and it is excellent in reliability with respect to PCT, and fine wiring A circuit board having a conductor pattern formed by removing a metal foil of a laminated sheet with a metal foil in which a metal foil is bonded onto an insulating layer, for the purpose of providing a circuit board having a low transmission loss of a high frequency signal. The circuit board which provided the rough surface shape on the surface of the insulating layer which were made, and its manufacturing method are disclosed.

And in the Example of this patent document 2, the Hitachi Chemicals Co., Ltd. product profile free copper foil PF-E-3 was hot-pressed through the Hitachi Chemicals Co., Ltd. product GEA-679FG as an insulation layer on both surfaces of the inner-layer core material which performed blackening process. After bonding to the printed circuit board by bonding using a press and forming a conductor pattern by a semi-additive method, oxygen plasma treatment was performed for 5 minutes at an output 1000 W and an atmospheric pressure of 100 kPa using oxygen as a plasma gas. The roughening process of the conductor pattern surface is performed by the chemical etching process (CZ-8100 by MEC Co., Ltd.), and vacuum-laminated PFR-800 AUS402 by Taiyo Ink Manufacturing Co., Ltd. which is a dry film type soldering resist was produced. Printed wiring boards were subjected to a pressure cooker test (PCT): 121 ° C., 100% RH, 96 hours continuous at 2 atm), followed by a stereo microscope. Chalhae, a base material eopeotdago the peeling between the insulating layer and the solder resist.

That is, the technique of patent document 1 and patent document 2 has the unevenness | corrugation at the time of using the copper foil with which roughening process was performed by etching the metal foil of the metal foil bonding laminated board which used the metal foil with small surface roughness, and processing the surface of the exposed insulating layer. By obtaining the state which has the surface roughness of the level equivalent to the exposed surface of the insulated resin layer provided with, the favorable moisture absorption and heat resistant adhesiveness between an insulated resin layer and a soldering resist is ensured.

Obviously, as in the inventions disclosed in Patent Documents 1 and 2, the copper foil layer of the copper foil laminated plate using the copper foil having a small surface roughness is etched to form a circuit shape, and the surface of the insulating resin layer exposed between the circuits is processed. After obtaining the state which has the surface roughness of the level equivalent to the exposed surface of the insulated resin layer provided with the unevenness | corrugation in the case of using the copper foil to which the roughening process was performed, the pressure cooker test (121 degreeC, 100% of humidity, 2) described in patent document 1 Even after immersing in a 260 degreeC solder bath for 20 second after 2 hours of conditions on atmospheric pressure, generation | occurrence | production of spot shape lamination of 20 micrometers or more in diameter between an insulation layer and a soldering resist layer is not seen.

Patent Document 1: Japanese Patent Application Laid-Open No. 2008-16794 Patent Document 2: Japanese Patent Application Laid-Open No. 2010-103153

However, as described in Patent Literature 1 and Patent Literature 2, the surface roughness at the level equivalent to that of the exposed surface of the insulating resin layer having irregularities when the copper foil subjected to the roughening treatment was used by processing the exposed smooth insulating layer surface. It is not preferable to carry out processing until the manufacturing cost of a printed wiring board increases and the management cost of manufacturing conditions increases from a viewpoint of performing uniform roughening process in the same plane.

Therefore, in the market, in order to reduce the manufacturing cost and the management cost of a printed wiring board, the insulating resin layer equivalent to the invention of patent document 1 and patent document 2 and the flat surface without roughening the surface of the insulating resin layer exposed between circuits, The stable supply of the printed wiring board which has favorable adhesiveness of a soldering resist layer was calculated | required.

Therefore, as a result of earnest research, the present inventors pay attention to the rust-preventing component of the copper foil remaining on the surface of the insulating resin layer exposed between the circuits after the copper foil is etched with the copper etching solution, and the moisture absorption and heat resistance of the solder resist layer and the insulating resin surface. It came to invent the method of stabilizing adhesiveness.

The manufacturing method of the printed wiring board which concerns on this invention: The manufacturing method of the printed wiring board which concerns on this invention is a method of manufacturing a printed wiring board using the copper foil laminated board which bonded uncoated copper foil, Comprising: A circuit is etched by etching an uncoated copper foil with copper etching liquid. After formation, the surface treatment metal component of the said uncoated copper foil which remained in the surface of the said insulated resin which performed the purification process by performing the purification process on the surface of the insulated resin exposed between circuits, and XPS analyzer (X-ray source: Al (Kα) And acceleration voltage: 15 mA, beam diameter: 50 µm), characterized in that each surface-treated metal component is below the detection limit.

Manufacturing method of printed wiring board after soldering resist layer formation which concerns on this invention: The manufacturing method of the printed wiring board after formation of the soldering resist layer which concerns on this invention performs a soldering resist layer after performing the purification process demonstrated by the manufacturing method of the above-mentioned printed wiring board. It is characterized by forming.

Printed wiring board which concerns on this invention: The printed wiring board which concerns on this invention is a printed wiring board after formation of the soldering resist layer obtained by the manufacturing method of the printed wiring board which concerns on this invention, and it processes for 5 hours on condition of 121 degreeC, 100% of humidity, and 2 atmospheres. Subsequently, when immersed in a 260 degreeC solder bath for 60 second, spot delamination of 20 micrometers or more in diameter does not generate | occur | produce between a soldering resist layer and the insulating resin surface.

By using the manufacturing method of the printed wiring board which concerns on this invention, after carrying out a circuit etching, the pressure cooker test (121 degreeC, 100% of humidity, 5 atmospheres) on condition of 5 atmospheres, without harmonizing the surface of the insulating resin exposed between circuits. After time processing), even if it is immersed in a 260 degreeC solder bath for 60 second or more, the printed wiring board which does not produce the spot lamination of 20 micrometers or more in diameter can be stably supplied.

In the printed wiring board obtained by this manufacturing method, the surface of the insulated resin layer exposed between circuits is flat, and even after an extremely harsh pressure cooker test, a spot shape having a diameter of 20 µm or more between the insulated resin layer and the solder resist which becomes a practical problem. It exhibits the property that no delamination occurs and is also excellent in migration performance, resulting in a high quality product with excellent long-term stability of use.

1 is a scanning electron microscope observation image of the surface of an insulating resin layer exposed between circuits of a printed wiring board immediately after the micro etching in Example 3. FIG.
FIG. 2 is a scanning electron microscope observation image of the surface of the insulating resin layer exposed between the circuits of the printed wiring board immediately after the plasma etching in Example 3. FIG.
3 is a scanning electron microscope observation image of the surface of the insulating resin layer exposed between the circuits of the printed wiring board immediately after the circuit formation in Example 3. FIG.
4 is a surface observation image of the delamination generated in Comparative Example 1 observed from the solder resist layer side using transmitted light.
5 is a surface observation image of the delamination generated in Comparative Example 2 observed from the solder resist layer side using transmitted light.
6 is a cross-sectional observation image of a printed wiring board on which delamination has occurred.

Manufacture form of printed wiring board which concerns on this invention: The manufacturing method of the printed wiring board which concerns on this invention is a method of manufacturing a printed wiring board using the copper foil laminated board which bonded uncoated copper foil, Comprising: A circuit is etched by etching an uncoated copper foil with copper etching liquid. After formation, the surface treatment metal component of the said uncoated copper foil which remained in the surface of the said insulated resin which performed the purification process by performing the purification process on the surface of the insulated resin exposed between circuits, and XPS analyzer (X-ray source: Al (Kα) And acceleration voltage: 15 mA, beam diameter: 50 µm), characterized in that each surface-treated metal component is below the detection limit. That is, the characteristic of the printed wiring board which concerns on this invention is to remove as much as possible the surface-treated metal component of the uncoated copper foil which remain | survives on the insulating resin surface exposed between circuits after etching and forming a circuit. This is because if the metal component remains on the surface of the insulating resin layer exposed between the circuits, the adhesiveness between the solder resist layer and the insulating resin layer is adversely affected and the migration resistance at the time of energization is deteriorated. In addition, by removing the residual metal component of the surface of the insulating resin layer exposed between the circuits in this way, a soldering resist layer provided on the surface of the insulating resin layer is provided on the surface even without excessive roughening treatment up to the roughness level of the surface of the insulating resin employed in the conventional method. In addition, the moisture absorption and heat resistance adhesiveness between the insulating resin layers provided in the outer layer can be maintained satisfactorily. In addition, the moisture absorption and heat resistant adhesiveness in this invention are judged combining the predetermined pressure cooker test and the solder heat test.

First, the "copper foil laminated board which bonded the uncoated copper foil" used by this invention is demonstrated. The "copper laminated board which bonded the uncoated copper foil" here is a generic term of the copper foil laminated board which uses the uncoated copper foil as the outermost copper foil, and is what is called the single-sided copper foil laminated board, the double-sided copper foil laminated board, and the multilayer core containing the inner core base material. It is to include all the concepts of copper clad laminate. As the non-harmonized copper foil, an electrolytic copper foil, a rolled copper foil, and an ultrathin copper foil with a carrier can be used, and the thickness is not particularly limited.

Moreover, there is no special limitation also regarding the surface treatment of the said copper foil, As a rust prevention component, a nickel- zinc alloy, nickel- cobalt alloy, nickel- zinc- molybdenum alloy, nickel- cobalt- molybdenum alloy, zinc- tin alloy, chromate treatment It is also possible to use various alloys such as these. Moreover, it is also preferable from a viewpoint of adhesive improvement to provide silane coupling agent process layers, such as an epoxy silane coupling agent, an amino silane coupling agent, and a mercapto silane coupling agent, in the contact surface with the insulated resin layer of copper foil.

And the insulating resin layer used for manufacture of a copper foil laminated board does not have a restriction | limiting in particular also about the skeleton component, such as a glass cloth and a glass nonwoven fabric arrange | positioned in the resin component and resin. In addition, the said insulated resin layer may contain filler particle.

However, in consideration of the adhesiveness between the uncoated copper foil and the insulated resin layer, in order to provide an uncoated copper foil in the outermost layer of the copper foil laminate, it is preferable to use an uncoated copper foil with a primer resin layer. Unharmonized copper foil with a primer resin layer is copper foil which provided the ultra-thin primer resin layer for ensuring favorable adhesiveness with a resin base material on the single side | surface of the copper foil which has not performed the roughening process. As such an uncoated copper foil with a primer resin layer, Mitsui Metal Mining Co., Ltd. product "Multi Foil G: abbreviation MFG", Hitachi Chemical Co., Ltd. "PF-E", etc. can be used, for example. At this time, the primer resin layer exhibits adhesive force to both the copper foil and the insulating resin, and it becomes easy to ensure good adhesion between the uncoated copper foil and the insulating resin layer.

In the manufacturing method of the printed wiring board which concerns on this invention, a circuit can be formed using a subtractive method or a semi-additive method. In the subtractive method, first, an uncoated copper foil in the outermost layer of the copper foil laminate is etched with a copper etching solution to remove unnecessary copper foil portions to form a circuit. The circuit formation method at this time forms an etching resist layer on the surface of an outer layer copper foil, exposes and develops an etching resist pattern, forms a circuit pattern using the copper etching liquid, finally removes an etching resist, and forms the circuit of a printed wiring. Is formed. Moreover, if it is a semiadditive process, a hole is made in the position which forms the via hole of the copper foil laminated board which bonded uncoated copper foil. Then, electroless copper plating is performed, a plating resist layer is formed on the surface of the formed electroless copper plating layer, and a plating resist pattern is exposed and developed. Thereafter, copper is electroplated to form a circuit pattern, and after removing the plating resist, the circuit of the printed wiring board is formed by etching away the uncoated copper foil with the copper etching solution.

The manufacturing method of the printed wiring board which concerns on this invention can be normally used without a restriction | limiting in particular about the kind of copper etching liquid, such as a copper chloride etching liquid, an iron chloride etching liquid, and a sulfuric acid-hydrogen peroxide type etching liquid. However, it is most preferable to apply when the sulfuric acid-hydrogen peroxide type etching liquid is used as the copper etching solution. Currently, the "sulfuric acid-hydrogen peroxide type etching liquid" is an etching solution generally used by the semiadditive process because it is very suitable for formation of a fine pitch circuit among copper etching solutions. However, when the sulfuric acid-hydrogen peroxide-based etching solution is used, nickel is considered to be relatively difficult to remove as a surface-treated metal component of an uncoated copper foil on the surface of the insulating resin exposed between the circuits after etching copper. , Components such as molybdenum, cobalt and tin tend to remain. Therefore, it can be said that the manufacturing method of the printed wiring board which concerns on this invention is suitable for the manufacturing method of the printed wiring board which assumed the case of using a "sulfuric acid-hydrogen peroxide type etching liquid" as a copper etching liquid when forming a circuit.

When circuit formation is complete | finished as mentioned above, the surface-treated metal component of the uncoated copper foil which remain | survives on the insulating resin surface exposed between circuits is removed after that. This operation is called "purification process." Achievement of the purification process semi-quantitatively analyzes the surface-treated metal component of the uncoated copper foil which remain | survives on the insulating resin surface by XPS analyzer (X-ray source: Al (Kα), acceleration voltage: 15 mA, beam diameter: 50 micrometers). To judge. The reason for using such a method is as follows. For example, it is ideal to dissolve the exposed insulating resin layer after purification with concentrated sulfuric acid or the like and to confirm the amount of remaining metal elements by using a high sensitivity direct analysis method such as ICP analysis or atomic absorption spectrometry. However, such a chemical analysis method is not a method which can be performed in a manufacturing process, because order is complicated and time-consuming. On the other hand, if it is a method using an XPS analysis apparatus, since it can measure easily, it can implement in a manufacturing process.

In semiquantitative analysis using an XPS analyzer, cleaning is necessary until the surface-treated metal component of the copper foil detected on the surface of the insulating resin falls below the detection limit. That is, if the surface-treated metal component of copper foil does not remain in the level which can be detected by this method, even if it does not harmonize the insulating resin surface exposed between circuits, the pressure cooker test (121 degreeC, 100% of humidity, 2 atmospheres) conditions This is because, even after being immersed in the solder bath at 260 ° C. for 60 seconds or more after 5 hours), the effect that spot delamination having a diameter of 20 μm or more does not occur between the insulating resin layer and the solder resist can be obtained stably.

Moreover, in the manufacturing method of the printed wiring board which concerns on this invention, the surface of the insulation resin exposed between circuits has the value of the surface roughness (10-point average roughness Rzjis) of the exposed insulation resin surface before the said purification process, Rz (S). When the value of the surface roughness (10-point average roughness Rzjis) of the exposed insulating resin surface after the purifying treatment is Rz (C), the value of [Rz (C) / Rz (S)] is set to 1.2 or less. desirable. On the other hand, Rz (C) and Rz (S) are values when '10 -point average roughness (Rzjis) 'determined by JIS standard (JIS B 0601 ₂₀₀₁ ) is measured using a laser non-contact illuminometer, and the lower limit of detection is about 0.02 μm. to be.

In the invention according to the present application, depending on the method used in the purification process, the surface roughness of the surface of the insulating resin exposed between circuits may increase, indicating that the degree of increase of the surface roughness is [Rz (C) / Rz (S)]. When the surface state changes to the level of this [Rz (C) / Rz (S)] exceeding 1.2, for example, when a plasma process is employ | adopted, undercut will generate | occur | produce in the insulating resin layer which supports a circuit. . As a result, since the adhesiveness of a circuit and an insulating resin falls in a fine circuit, it is unpreferable.

In addition, it is preferable at this time to purify so that Rz (C) may be 1.8 micrometers or less. When Rz (C) exceeds 1.8 micrometers, since the over etching time must be set long by the above-mentioned semiadditive method, it is not preferable. On the other hand, in order to form a finer circuit, it is more preferable that Rz (C) is 1.0 micrometer or less.

Here, in the manufacturing method of the printed wiring board which concerns on this invention, the purification method in the purification process is demonstrated. The term "purification treatment" as used herein is intended to remove metal components remaining on the surface of the insulating resin exposed between circuits. Therefore, in general, it can be appropriately selected from physical treatment and chemical treatment. Specifically, it is possible to appropriately select from plasma processing such as ion beam method, RF beam method, plasma etching, reactive ion etching, reactive ion beam etching, concentrated hydrochloric acid solution etching method, desmear method using permanganic acid, and the like. However, it is necessary to select a method capable of uniformly treating the surface of the printed wiring board on which the fine circuit is formed, without damaging the circuit. From this point of view, the metal component remaining on the surface of the insulating resin exposed between the circuits is determined by the semi-quantitative analysis using the XPS analysis device to make each surface treated metal component below the detection limit, and the surface roughness after the above-described purification treatment In order to obtain, it is preferable to use 'plasma treatment' or 'solution treatment which does not dissolve copper as much as possible'.

In the case of the above-mentioned plasma treatment, it is preferable to adopt the reactive ion etching method if priority is given to the freedom of selection and the purification treatment ability of the atmosphere gas in the chamber. However, if reactive ion etching is employed, it is necessary to process the printed wiring board to be purified one by one. As a result, not only the production efficiency falls but the consumption amount of atmospheric gas also increases as a whole purification process. For this reason, it is preferable to carry out plasma etching on the conditions which make input energy 10J / cm <2> -120J / cm <2>, and to purify both surfaces of a printed wiring board simultaneously. When the input energy is less than 10 J / cm 2, the amount of etching is small, which is not preferable because the metal components remaining on the surface of the insulating resin exposed between the circuits cannot be sufficiently removed. On the other hand, when input energy exceeds 120 J / cm <2>, undercut will generate | occur | produce in the insulated resin layer which supports a circuit. As a result, since the adhesiveness of a circuit and an insulating resin falls in a fine circuit, it is unpreferable. In addition, in such a case, the variation of the surface roughness also tends to occur on the surface of the insulating resin layer, which is not preferable.

According to line the plasma etching in the manufacturing method of the printed wiring board according to the present invention, it is preferable as the atmosphere gas in the etch chamber using the 'O ₂ and a mixed gas of CF _4'. As described above, in the reactive ion etching method, the surface-treated metal component can be removed without specifying the kind of the atmospheric gas in the chamber. However, in plasma etching, the etching property varies greatly depending on the type of the atmospheric gas. However, when employing the 'O gas mixture of ₂ and CF _4', the gas mixture CF ₄ will demonstrate the ability to react with the metal and, O ₂ are due to exhibit a function to impart hydrophilicity to the resin surface, good etching conditions Can be achieved.

Of course, it is also possible to employ a method of first performing plasma etching using CF ₄ gas, and then plasma etching using O ₂ gas as an atmosphere gas in the etching chamber. However, with the 'O ₂ and a mixed gas of CF _4' as the atmosphere gas in the etch chamber, since the above-mentioned functions to be exerted by a single plasma etching, it is preferred in terms of process and equipment simplified.

And it is preferable that the value of ratio [(CF ₄ partial pressure) / (O ₂ partial pressure)] of the gas partial pressure of CF ₄ and O ₂ is 0.2 to 5.0. When the value of the ratio ((CF ₄ partial pressure) / (O ₂ partial pressure)) of the gas partial pressure is less than 0.2, since the function of reacting with the metal cannot be exhibited, it is not preferable. On the other hand, when the ratio of the gas partial pressure of CF ₄ and O ₂ ((CF ₄ partial pressure) / (O ₂ partial pressure)) exceeds 5.0, the reaction with metals reaches saturation, and the O ₂ partial pressure is low. It is not preferable because it can not exert a function of imparting hydrophilicity to.

In addition, it is preferable to perform plasma etching in the range of 5.0 kPa-200 kPa of the atmospheric pressure in an etching chamber. When the atmospheric pressure in the etching chamber is less than 5.0 kPa, since the reaction gas is small, the etching rate is slow, and the productivity of the printed wiring board is extremely reduced, which is not preferable. On the other hand, if the air pressure in the etching chamber exceeds 200 kPa, the supply of plasma becomes difficult, which is not preferable.

In the manufacturing method of the printed wiring board which concerns on this invention, when plasma processing is employ | adopted as a purification process, it is preferable to perform wet cleaning after a plasma processing. After the plasma etching here, since the insulating resin residue produced by the plasma treatment remains on the surface of the insulating resin exposed between the circuits, the insulating resin residue is removed by wet cleaning. Since wet cleaning at this time aims at the removal of the insulated resin residue produced by the plasma process, it does not necessarily require the ability to dissolve and remove the metal component remaining on the surface of the insulated resin. What is necessary is just to select and implement the method of obtaining an optimal effect from chemical cleaning, such as chemical treatment. Especially, it is preferable to select the washing | cleaning using a "acid pickling solution containing surfactant" and / or the "micro etching solution" for the wet washing in this invention.

In this wet washing, it is preferable to carry out washing in the "acid pickling solution containing surfactant" and then washing in the "copper micro etching liquid." By washing in advance with a pickling solution containing a surfactant as described above, the residue on the surface of the printed wiring board after plasma treatment is removed, and the wettability of the surface of the printed wiring board and the solution is improved, and the microneedle used later is used. This is because the etchant 'spreads to every corner of the inter-circuit gap of the printed wiring board so that the residue can be reliably removed.

As the "surfactant" which can be used for the "acid pickling solution containing surfactant" mentioned above, any of a nonionic surfactant, a cationic surfactant, and an amphoteric surfactant can be selectively used, and these can also be mixed and used. Do.

The nonionic surfactant here has a hydrophilic group which does not ionize in water, and is classified into ester type, ether type, ester ether type, and others. Specific examples include higher alcohols, alkylphenols, fatty acids, amines, alkylenediamines, fatty acid amides, sulfonamides, polyhydric alcohols, and glucoside derivatives.

And a cationic surfactant is surfactant of the property in which the part with a hydrophobic group in a solution ionizes with a cation. More specifically, lauryl trimethyl ammonium salt, cetyl trimethyl ammonium salt, stearyl trimethyl ammonium salt, lauryl dimethyl ethyl ammonium salt, lauryl dimethyl ammonium betaine, stearyl dimethyl ammonium betaine, dimethyl-benzyl lauryl ammonium salt, octadecyl dimethyl benzyl Ammonium salt, trimethyl benzyl ammonium salt, triethyl benzyl ammonium salt, lauryl pyridinium salt, lauryl imidazolinium salt, stearyl amine acetate, lauryl amine acetate and the like.

Next, when it is dissolved in water, an amphoteric surfactant shows the property of an anionic surfactant in an alkaline region, and the property of a cationic surfactant in an acidic region. Specifically, alkyl carboxy betaine type, alkyl amino carboxylic acid type, alkyl imidazoline type and the like.

The above-mentioned surfactant is contained in a solution which can clean the printed wiring board surfaces, such as a sulfuric acid, hydrochloric acid, and a sulfuric acid-hydrogen peroxide aqueous solution, and it is added so that surfactant concentration may be 0.1 g / L-20 g / L, and it uses for washing | cleaning. An acidic solution is obtained. At this time, when the surfactant concentration is less than 0.1 g / L, the effect of improving the wettability of the printed wiring board surface and the solution after the plasma treatment cannot be obtained by using any of the surfactants described above. On the other hand, even if the concentration of the surfactant exceeds 20 g / L, the effect of improving the wettability of the printed wiring board surface and the solution after the plasma treatment is saturated and only a waste of resources. It is preferable that the cleaning time of the printed wiring board after plasma processing using this acidic solution is 15 second-7 minutes. When the cleaning time is less than 15 seconds, the effect of improving the wettability of the printed wiring board surface and the solution after the plasma treatment cannot be obtained. On the other hand, if the cleaning time exceeds 7 minutes, the erosion of the circuit portion of the printed wiring board after the plasma treatment starts, which is not preferable.

In the wet washing | cleaning using the above-mentioned copper micro etching liquid, the said circuit is etched and matched 0.5 micrometer or more by mass conversion thickness. When the copper circuit is etched at a thickness of 0.5 µm or more, the surface of the circuit exhibits sufficient adhesive strength with a solder resist layer or an insulating resin layer when multilayered. On the other hand, if it is such an etching condition, removal of the contaminant which remains on a circuit surface, an etching residue, the residue by the cleaning process of the surface of the insulating resin exposed between circuits, etc. can also be carried out. As a result, the adhesiveness of a soldering resist layer and a circuit surface and the adhesiveness of an insulating resin component and a circuit surface improve simultaneously.

Manufacturing form of printed wiring board after soldering resist layer formation: The manufacturing method of the printed wiring board after soldering resist layer formation which concerns on this invention uses the printed wiring board manufactured by the method of performing the above-mentioned purification process, and places a soldering resist layer in a required place. It is characterized by forming. Thus, when the printed wiring board manufactured by the method of performing the above-mentioned purification process is used, since the metal component which remains on the surface of the insulating resin exposed between circuits is below the detection limit of the semi-quantitative analysis using XPS apparatus, soldering resist The printed wiring board after formation of the soldering resist layer with favorable adhesiveness of a layer and an insulating resin layer, adhesiveness of a soldering resist layer and a circuit surface, and adhesiveness of an insulating resin component and a circuit surface can be obtained.

Form of printed wiring board after solder resist layer formation: The printed wiring board after solder resist layer formation was stored in a pressure cooker at 2 atmospheres for 5 hours, and then immersed in a solder bath at 260 ° C. for 60 seconds. The spot lamination of the diameter of 20 micrometers or more does not arise between surfaces. Therefore, even when it is processed for 196 hours under conditions of 121 degreeC, 100% of humidity, and 2 atmospheres, the spot lamination of 20 micrometers or more in diameter does not generate | occur | produce between a soldering resist layer and the insulating resin surface. EMBODIMENT OF THE INVENTION Hereinafter, the content of this invention is demonstrated more concretely using an Example and a comparative example.

Example 1

[Production of Copper Clad Laminates]

With primer resin layer which applied primer resin to uncoated copper foil whose surface roughness (10-point average roughness Rzjis) is 0.37 micrometer on both surfaces which laminated | stacked three sheets of prepreg (GHPL830-NS: Mitsubishi Gas Chemical Co., Ltd.) of thickness 0.1mm. The uncoated copper foil (MFG-DMT3F: manufactured by Mitsui Metal Mining Co., Ltd.) was overlapped and molded for 90 minutes in a vacuum press apparatus having a temperature of 220 ° C. and a pressure of 4.0 MP, thereby producing a copper foil laminate having a thickness of 0.3 mm.

[Production of printed wiring board]

A printed wiring board shall be manufactured using the semiadditive process. Regarding the manufacturing procedure of a printed wiring board, both an Example and a comparative example are common. The plating resist layer is formed on the surface of the outer layer copper foil of the said copper foil laminated board, and it exposes and develops using the exposure film for resist patterns for forming the lattice wiring of 500 micrometers / 1200 micrometers of line width / space width, and total thickness is It electroplated copper so that it might be set to 15 micrometers. Then, after the plating resist was peeled off, the exposed uncoated copper foil was etched away using a sulfuric acid-hydrogen peroxide-based etching solution (CPE800: manufactured by Mitsubishi Gas Chemical Co., Ltd.) to form a circuit. The printed wiring board produced in this way was divided, and it was set as the printed wiring board sample used in Example 1.

[Cleaning Process]

In the purification process of Example 1, the above-mentioned printed wiring board sample was immersed in 60 mol of 4 mol / L hydrochloric acid for 60 minutes, and after washing with water, it dried and produced the purification process sample.

[Evaluation of Insulation Resin Layer Surface Exposed Between Circuits]

The surface of the insulating resin layer exposed between the circuits of the purification sample and the surface after the purification treatment and after the purification treatment is subjected to an XPS analysis device (X-ray source: Al (Kα), acceleration voltage: 15 Hz, beam diameter: 50 µm) and the residual metal component amount. Was analyzed semi-quantitatively to determine the surface roughness (Rzjis). The surface state of the insulated resin layer is shown in following Table 1.

[Formation of Solder Resist Layer and Evaluation of Delamination]

The above-mentioned purification process sample sprayed the micro etching liquid (CZ8101B: MEC Co., Ltd. product) for 30 second, and washed with water and dried in order to provide the adhesiveness of copper wiring and a soldering resist. A soldering resist (AUS308: manufactured by Taiyo Ink Co., Ltd.) was formed on this purification sample, and after 121 ° C x 5 hours of PCT treatment, it was immersed in a 260 ° C solder bath for 60 seconds (hereinafter, this operation was referred to as a 'PCT solder test' Is called). About the purification process sample after this PCT solder test, generation | occurrence | production of the delamination was observed and evaluated by the optical microscope. The evaluation results of the delamination and the purification treatment conditions are shown in Table 2 below.

Example 2

In Example 2, the uncoated copper foil with a primer resin layer used in Example 1 was used in the same manner as in Example 1 except that PF-E-3, manufactured by Hitachi Chemical Co., Ltd., was used in place of Mitsui Metal Mining Co., Ltd. MFG-DMT3F. The printed wiring board sample was produced.

Purification treatment was performed on the printed wiring board sample described above in the same manner as in Example 1 to prepare a purification treatment sample, and semi-quantitative analysis of the residual metal component amount on the surface of the insulating resin layer exposed between the circuits of the purification treatment sample was performed to determine the surface roughness (Rzjis). ) Was measured. In addition, the occurrence of delamination was evaluated in the same manner as in Example 1. The surface state of the insulated resin layer exposed between circuits is shown in following Table 1, and the evaluation result of a lamination and the purification process conditions are shown in following Table 2.

Example 3

In Example 3, only the purification process conditions were changed using the sample of the printed wiring board produced in Example 1.

In the purification process, plasma etching was performed under the condition that the input energy was 40 J / cm 2 in a chamber in which the sample of the above-described printed wiring board was set to [(CF ₄ partial pressure) / (O ₂ partial pressure)] = 0.33 and atmospheric pressure of 15 kPa. Next, after immersing in a 10 mass% solution of Melplate PC-316 (Meltex Co., Ltd.) containing sulfuric acid as an acid component and ethylene glycol as a surfactant for 5 minutes, the micro-etching solution (CZ8101B : MK Corporation) was sprayed for 30 seconds, washed with water and dried to prepare a purification sample. The scanning electron microscope observation image of the surface of the insulated resin layer exposed between the circuits immediately after circuit formation in FIG. 3, and the scanning electron microscope observation image of the surface of the insulated resin layer exposed between the circuits immediately after plasma etching are shown in FIG. The scanning electron microscope observation image of the surface of the insulated resin layer exposed between the circuits immediately after micro etching is shown in FIG.

Thereafter, in the same manner as in Example 1, the amount of residual metal component on the surface of the insulating resin layer exposed between the circuits of the purification sample was semi-quantitatively analyzed, and the surface roughness Rzjis was again measured. In addition, the occurrence of delamination was evaluated in the same manner as in Example 1. The surface state of the insulating resin layer exposed between the circuits of the purification process sample is shown in Table 1 below, and the evaluation results of the delamination and the purification process conditions are shown in Table 2 below.

Example 4

In Example 3, only the purification process conditions were changed using the sample of the printed wiring board produced in Example 1.

In the purification process, the sample of the above-described printed wiring board was immersed in a potassium permanganate (KMnO ₄ ) solution (manufactured by Rohm and Haas Electronic Materials Co., Ltd.) at a liquid temperature of 80 ° C. for 1 minute, and then neutralized at a liquid temperature of 45 ° C. It was immersed in liquid (Rom and Haas Electronic Materials Co., Ltd.) for 5 minutes, and it washed with water, dried, and produced the purification process sample.

Thereafter, in the same manner as in Example 1, the amount of residual metal component on the surface of the insulating resin layer exposed between the circuits of the purification sample was semi-quantitatively analyzed, and the surface roughness Rzjis was again measured. In addition, the occurrence of delamination was evaluated in the same manner as in Example 1. The surface state of the insulating resin layer exposed between the circuits of the purification process sample is shown in Table 1 below, and the evaluation results of the delamination and the purification process conditions are shown in Table 2 below.

Comparative example

Comparative Example 1

In Comparative Example 1, the purification treatment performed in Example 1 was not performed. And generation | occurrence | production of delamination was evaluated similarly to Example 1. The surface observation image which observed the generated delamination from the soldering resist side using transmitted light is shown in FIG. The surface state of the insulated resin layer exposed between circuits is shown in following Table 1, and the evaluation result of a lamination and the purification process conditions are shown in following Table 2.

Comparative Example 2

In the comparative example 2, the purification process sample which changed the purification process time 60 minutes performed in Example 1 to 10 minutes was produced. Thereafter, in the same manner as in Example 1, the amount of residual metal component on the surface of the insulating resin layer exposed between the circuits of the purification sample was semi-quantitatively analyzed, and the surface roughness was again measured. In addition, the occurrence of delamination was evaluated in the same manner as in Example 1. The surface observation image which observed the generated delamination from the soldering resist layer side using transmitted light is shown in FIG. The surface state of the insulated resin layer exposed between circuits is shown in following Table 1, and the evaluation result of a lamination and the purification process conditions are shown in following Table 2.

[Comparative Example 3]

In the comparative example 3, the purification process sample which abbreviate | omitted micro-etching in the purification process performed in Example 3 was produced. Thereafter, in the same manner as in Example 1, the amount of residual metal component on the surface of the insulating resin layer exposed between the circuits of the purification sample was semi-quantitatively analyzed, and the surface roughness was again measured. In addition, the occurrence of delamination was evaluated in the same manner as in Example 1. The surface state of the insulated resin layer exposed between circuits is shown in following Table 1, and the evaluation result of a lamination and the purification process conditions are shown in following Table 2.

[Comparative Example 4]

In the comparative example 4, the purification process sample which abbreviate | omitted plasma etching by the purification process performed in Example 3 was produced. Thereafter, in the same manner as in Example 1, the amount of residual metal component on the surface of the insulating resin layer exposed between the circuits of the purification sample was semi-quantitatively analyzed, and the surface roughness was again measured. In addition, the occurrence of delamination was evaluated in the same manner as in Example 1. The surface state of the insulated resin layer exposed between circuits is shown in following Table 1, and the evaluation result of a lamination and the purification process conditions are shown in following Table 2.

[Contrast with Example and Comparative Example]

An Example and a comparative example are compared with the surface state of the insulated resin layer exposed between the circuits shown in Table 1, the evaluation result of the delamination shown in Table 2, and purification process conditions.

Prepare for the presence of delamination and the purification treatment conditions. From the surface of the insulated resin layer after the purification process of this example, it can be seen that no residual metal component was detected. In addition, with respect to the embodiment, no occurrence of delamination at a level that is problematic in practical use is observed. On the other hand, in the comparative example, spot delamination of 50 micrometers or more in diameter was observed also in the case of the comparative example 2 in which residual metal component amount after a purification process is the lowest as 0.1 atom%. In Comparative Example 3 in which the residual metal component amount after the purification treatment was 5.4 atom%, spot delamination was observed at a level of 300 µm in diameter, and the purification treatment was not performed with Comparative Example 4 in which the residual metal component amount after the purification treatment was 8.0 atom%. In Comparative Example 1 in which the amount of the residual metal component not present was 8.4 atom%, spot-shaped delamination exceeding 1.0 mm was observed. That is, the larger the amount of residual metal components detected on the surface of the insulating resin after the purification treatment, the larger the spot diameter of the delamination is seen.

On the other hand, considering the value of [Rz (C) / Rz (S)] which is the ratio of Rz (C) and Rz (S), it is the range of 1.00-1.11 in an Example, and the range of 1.00-1.05 in a comparative example. Therefore, when the value of [Rz (C) / Rz (S)] is 1.00 and the sample more than 1.00 is compared with the purification process conditions, the plasma-etched sample exceeds 1.00.

From the contrast of the above-described examples and comparative examples, the adhesion between the 'solder resist' and the 'surface of the insulating resin layer exposed between the circuits' is greatly influenced by the metal component remaining on the surface of the insulating resin layer exposed between the circuits. . On the other hand, even if plasma etching is performed on the surface of the insulating resin, the micro-shape is changed in the range where the value of [Rz (C) / Rz (S)] is less than 1.2, but hardly affects the adhesion with the solder resist. It can be said. Therefore, when the metal component remaining on the surface of the insulating resin layer exposed between the circuits is detected by XPS semiquantitative analysis, the adhesion between the 'solder resist' and the 'surface of the insulating resin layer exposed between the circuits' becomes poor. I could confirm that.

&Lt; Industrial Availability &gt;

In the method for manufacturing a printed wiring board according to the present invention, the number of insulated water is reduced by subjecting the printed wiring board to which the metal element remains on the exposed surface of the insulating resin to be below the quantitative limit by semi-quantitative analysis using the XPS apparatus. It is possible to obtain good adhesion with the 'solder resist layer' provided after the surface of the printed wiring board without roughening the ground layer surface. Therefore, good adhesiveness can also be obtained with the "resin layer laminated | stacked later in the case of multilayering" provided after the surface of a printed wiring board, and a high quality printed wiring board can be provided.

BM Insulation Resin Base
CC copper circuit
PSR Solder Resist
DL Delamination

Claims (14)

As a method of manufacturing a printed wiring board using a copper-clad laminate bonded to an unharmonized copper foil,
After etching the said non-harmonized copper foil with copper etching liquid, and forming a circuit, the purification process is given to the surface of the insulated resin exposed between circuits,
Semi-quantitative analysis of the surface-treated metal component of the non-harmonized copper foil remaining on the surface of the insulated resin subjected to the purification treatment with an XPS analyzer (X-ray source: Al (Kα), acceleration voltage: 15 Hz, beam diameter: 50 µm) When it does, each surface treatment metal component is below a detection limit, The manufacturing method of the printed wiring board characterized by the above-mentioned. The method of claim 1,
A sulfuric acid-hydrogen peroxide-based etching solution is used as the copper etching solution. The method according to claim 1 or 2,
The surface of the insulated resin surface exposed between the circuits has a surface roughness (10-point average roughness Rzjis) of the exposed insulated resin surface before the purification treatment as Rz (S), and the surface roughness of the exposed insulated resin surface after the purification treatment. When the value of (10-point average roughness Rzjis) is set to Rz (C), the value of [Rz (C) / Rz (S)], which is the ratio of Rz (C) and Rz (S), is set to 1.2 or less. The manufacturing method of the printed wiring board to say. The method of claim 3,
The purification process is carried out so that said Rz (C) may be 1.8 micrometers or less. 5. The method according to any one of claims 1 to 4,
The said purification process is a plasma process, The manufacturing method of the printed wiring board characterized by the above-mentioned. The method of claim 5,
The said plasma processing is a manufacturing method of the printed wiring board which carries out plasma etching on the conditions which made input energy 10-120 J / cm <2>. The method according to claim 5 or 6,
The plasma treatment is a CF ₄ / O ₂ gas atmosphere having a ratio of the gas partial pressure of CF ₄ and O ₂ ((CF ₄ partial pressure) / (O ₂ partial pressure)) of 0.2 to 5.0 and atmospheric pressure of 5.0 kPa to 200 kPa. It is plasma etching performed in the middle, The manufacturing method of the printed wiring board characterized by the above-mentioned. 8. The method according to any one of claims 5 to 7,
The said purification process is a manufacturing method of the printed wiring board which performs a wet cleaning after a plasma process. 9. The method of claim 8,
The said wet washing | cleaning is washing | cleaning using the acidic solution containing surfactant, The manufacturing method of the printed wiring board characterized by the above-mentioned. 9. The method of claim 8,
The said wet washing | cleaning is a manufacturing method of the printed wiring board which combines the washing | cleaning using the acidic solution containing the said surfactant, and the washing | cleaning using the copper micro etching liquid. The method of claim 10,
The wet cleaning is a method for manufacturing a printed wiring board, wherein the copper circuit is etched and roughened by a thickness of 0.5 µm or more in terms of mass conversion thickness. 12. The method according to any one of claims 1 to 11,
The said copper foil laminated board is a manufacturing method of the printed wiring board using what was obtained using the non-harmonic copper foil with a primer resin layer. In the manufacturing method of the printed wiring board of any one of Claims 1-12,
A soldering resist layer is formed after performing the said purification process, The manufacturing method of the printed wiring board after soldering resist layer formation. As a printed wiring board after the soldering resist layer formation obtained by the manufacturing method of the printed wiring board of Claim 13,
After 5 hours of storage in a pressure cooker at 2 atmospheres, when immersed in a 260 ° C. solder bath for 60 seconds, no spot delamination with a diameter of 20 μm or more occurred between the solder resist layer and the insulating resin surface. The printed wiring board characterized by the above-mentioned.

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