TWI524823B - Method of manufacturing printed wiring board and printed wiring board obtained by the manufacturing method - Google Patents

Description

Printed wiring board manufacturing method and printed wiring board produced by the printed wiring board manufacturing method

The present invention relates to a method of producing a printed wiring board and a printed wiring board obtained by using the method of manufacturing the printed wiring board. In particular, a printed wiring board excellent in adhesion between the solder resist layer and the surface of the insulating resin layer exposed between the circuits.

Conventionally, a copper foil used for producing a copper-clad laminate is subjected to a roughening treatment on a surface of the copper foil bonded to the insulating resin layer, and the uneven shape of the roughening treatment is embedded in the surface state of the insulating resin layer. A physical anchoring effect is obtained, thereby bonding the insulating resin layer. Therefore, a portion of the copper foil layer is removed by forming an electric circuit on the copper-clad laminate using an etching method, and the insulating resin layer having the uneven shape to which the roughened shape is transferred is exposed. In the case of such an insulating resin layer having irregularities, the adhesion of the resin layer to the surface after the formation of the solder resist layer and the multilayering of the resin layer after the multilayering is good.

However, recently, the main portable electronic devices such as mobile phones, portable computers, portable music players, and digital cameras have become lighter and shorter, and also require multi-functionality. The built-in printed wiring boards are also light and short. At the same time, it is required to increase the wiring density to form a circuit that can cope with multi-function. In the production of such a printed wiring board, the copper foil of the copper-clad laminate is required to be thinned as much as possible, and it is often required to form a fine wiring having a good etching factor by flattening the copper foil and the insulating layer. No roughened copper foil. Here, the non-roughened copper foil means that the surface of the copper foil to which the insulating resin layer is bonded is not subjected to the roughening treatment. Therefore, the roughening treatment of the uneven shape in a state in which the surface of the insulating resin layer is not formed does not provide a physical anchoring effect between the copper foil and the insulating resin layer.

As a result, when a printed wiring board is produced by using a copper-clad laminate to which a roughened copper foil is bonded, a portion of the copper foil layer is removed by an etching method, and a flat insulating resin layer having no uneven shape is exposed, so that the anchor cannot be used. The effect is such that the adhesion to the solder resist layer or the insulating resin layer formed on the outer layer thereof is deteriorated. Therefore, when a heating step such as melting is applied in a moisture absorption state, there is a problem that the solder resist layer is peeled off from the insulating resin layer (delamination). A cross-sectional view of the printed wiring board in which delamination occurs is shown in Fig. 6. In Fig. 6, between the insulating resin layer material BM and the solder resist layer PSR, a space (delamination DL) is observed in the vicinity of the copper circuit CC.

Further, in the portion where the delamination occurs, surface layer migration easily occurs by energization of the circuit, and it is difficult to ensure long-term reliability as a printed wiring board. A technique for improving the moisture absorption and heat-resistance of the solder resist layer and the insulating resin layer is disclosed in, for example, the following Patent Document 1 (Japanese Patent Application Laid-Open Publication No. Hei No. No. 2008-16794) The technique of Document 2 (Japanese Patent Application: Application Publication No.: Patent Publication No. 2010-103153).

The purpose of Patent Document 1 is to provide a method for manufacturing a printed wiring board which is advantageous in forming fine wiring, electrical characteristics, and manufacturing cost, and which is highly reliable, and discloses a method for manufacturing a printed wiring board, which is based on a ten point average of the surface. A method of producing a printed wiring board having a metal foil having a roughness (Rz) of 2.0 μm or less has a step of applying a roughening treatment to a surface of a resin which is an interface with the solder resist layer, and is used as a coating or laminated solder resist layer. Handle before.

Further, in the example of Patent Document 1, a ruthenium coupling agent which is treated with an electrolytic copper foil (FO-WS-18, manufactured by Furukawa Circuit Foil Co., Ltd., thickness: 18 μm, Rz = 1.8 μm) is treated. On the next surface, a resin composition having a thickness of 3.0 μm was applied, and then dried at 160 ° C for about 10 minutes to leave a solvent-retained amount of 5% by weight or less of a copper foil adhered to the resin, and placed in a four-piece overlapping manner. Industrial company products glass cloth insulation Tg epoxy resin prepreg GEA-679F (thickness: 0.1 μm) under the conditions of 180 ° C, 2.5 MPa, press molding for 1 hour to manufacture copper-clad laminate, use The copper-clad laminate is obtained by removing an unnecessary portion of the copper foil with a ferric chloride-based etching solution or the like to obtain a printed wiring board, and treating the printed wiring board with 3% sodium hydroxide + 6% potassium permanganate aqueous solution for chemical treatment. On the roughened insulating resin substrate, SR-7200G (solder resist) manufactured by Hitachi Chemical Co., Ltd. was laminated, and treated at 121 ° C, humidity of 100%, and 2 atm for 2 hours, and then immersed in a solder bath of 260 ° C for 20 seconds. Clock, or treated at 121 ° C, humidity 100%, 2 atmospheres When the solder resist expansion and other issues also will not occur.

Further, the object of Patent Document 2 is to provide a metal foil having a small surface roughness which is adhered to the surface of the insulating layer, and it is possible to secure the adhesion of the solder resist layer on the insulating layer after removing the metal foil, and to trust the PCT. A circuit board having a fine circuit and having a low-frequency signal transmission loss is small, and a circuit board having a conductor pattern formed by laminating a metal foil formed by laminating a metal foil on an insulating layer to remove a metal foil is disclosed. A circuit board having a rough surface formed on a surface of an insulating layer exposed after removing a metal foil, and a method of manufacturing the same.

Further, in the examples of Patent Document 2, GEA-679FG manufactured by Hitachi Chemical Co., Ltd. is used as an insulating layer on both sides of the inner core material to which the blackening treatment is applied, and the Hitachi Chemical Industry is bonded by hot pressing. The company's copper foil PF-E-3 with no profile is formed by a semi-additive method to form a conductor pattern on a printed wiring board, using oxygen as a plasma gas to output 1000 W at an ambient pressure of 100 Pa. After 5 minutes of oxygen plasma treatment, the surface of the conductor pattern was roughened by a chemical etching treatment (manufactured by MEC Co., Ltd., CZ-8100), and then, a dry film type solder resist was manufactured by Sun Ink Co., Ltd. The PER-800 AUS 402 was vacuum-laminated to form a printed wiring board, and the printed wiring board was observed by a solid microscope after being subjected to a pressure cooking test (PCT: 121 ° C, 100% RH, continuous holding at 96 atmospheres for 96 hours). There is no peeling between the insulating layer and the solder resist layer.

In other words, in the techniques described in Patent Document 1 and Patent Document 2, the metal foil is etched by using a metal foil laminate having a metal foil having a small surface roughness, and the surface of the exposed insulating layer is processed. This makes it possible to obtain the same degree of surface roughness as the exposed surface of the insulating resin layer having irregularities when the roughened copper foil is used, and to ensure good moisture absorption and heat resistance between the insulating resin layer and the solder resist layer. Sexuality.

In the invention disclosed in Patent Document 1 and Patent Document 2, a copper foil layer of a copper-clad laminate having a 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 formed. In the processing, it is possible to obtain a surface roughness state which is the same as the exposed surface of the insulating resin layer having the unevenness when the copper foil subjected to the roughening treatment is used, and the pressure cooking test method (121 ° C, 100% RH) described in Patent Document 1 is used. After treatment at 2 atmospheres for 2 hours, even if immersed in a solder bath at 260 ° C for 20 seconds, no speckled delamination of pores of 20 μm or more was observed between the insulating layer and the solder resist layer. occur.

However, as described in Patent Document 1 and Patent Document 2, the exposed and smooth surface of the insulating layer is processed to be the same as the exposed surface of the insulating resin layer having irregularities when the copper foil subjected to the roughening treatment is used. The degree of surface roughness causes an increase in the manufacturing cost of the printed wiring board, and also increases the management cost of the manufacturing conditions from the viewpoint of uniform roughening in the copper side.

Therefore, in order to reduce the manufacturing cost and the management cost of the printed wiring board, it is desirable to stably supply the surface of the insulating resin layer exposed between the circuits without being roughened. In the same manner as the invention described in Patent Document 2, a printed wiring board having excellent adhesion between the insulating resin layer and the solder resist layer is used.

As a result of active research, the present inventors focused on the anti-rust component of the copper foil remaining on the surface of the insulating resin layer exposed between the circuits after etching the copper foil with a copper etching solution, and considered the solder resist layer and the insulator resin. A method of stabilizing the moisture absorption and heat resistance of the surface of the layer.

The method for producing a printed wiring board according to the present invention is a method for producing a printed wiring board by bonding a copper-clad laminate obtained by laminating a non-roughened copper foil, which is characterized in that a copper etching solution is used. After etching the non-roughened copper foil to form a circuit, the surface of the insulating resin layer exposed between the circuits is subjected to a purification treatment, and the surface of the non-roughened copper foil remaining on the surface of the insulating resin is treated with a metal component. When the semi-quantitative analysis was carried out by an XPS analyzer (X-ray source: Al (kα), acceleration voltage: 15 kV, beam diameter: 50 μm), the surface-treated metal components were below the detection limit.

A method of producing a printed wiring board after forming a solder resist layer according to the present invention is the method for producing a printed wiring board after forming a solder resist layer according to the present invention, characterized in that it is subjected to purification treatment as described in the method for producing a printed wiring board Thereafter, a solder resist layer is formed.

The printed wiring board of the present invention is a printed wiring board obtained by forming a solder resist layer obtained by the method for producing a printed wiring board of the present invention, characterized in that the printed wiring board is at 121 ° C and humidity: After 5 hours of treatment under conditions of 100% and 2 atm., and immersing in a solder bath of 260 ° C for 60 seconds, no speckle delamination of 20 μm or more in diameter was observed between the solder resist layer and the surface of the insulating resin.

[Effects of the Invention]

By using the manufacturing method of the printed wiring board of the present invention, after the circuit etching is performed, the surface of the insulating resin exposed between the circuits is not roughened, and the pressure cooking test can be stably supplied (121 ° C, humidity: 100%, After the treatment under the conditions of 2 atm. for 5 hours), it was immersed in a solder bath of 260 ° C for 60 seconds or more, and a printed wiring board having a spot-like delamination of 20 μm or more in diameter did not occur.

In the printed wiring board obtained by the manufacturing method, the surface of the insulating resin exposed between the circuits is flat, and after the extremely severe pressure cooking test, the insulating resin layer and the solder resist layer which are not practically problematic are displayed. The characteristics of the spot-like delamination of 20 μm or more in diameter and excellent migration resistance are high-quality products excellent in long-term stability.

A manufacturing method of a printed wiring board according to the present invention is a method for producing a printed wiring board by bonding a copper-clad laminate having no roughened copper foil, and is characterized in that the roughened copper foil is not used After the copper etching solution is etched to form the circuit, the surface of the insulating resin exposed between the circuits is subjected to a purification treatment, and the surface-treated metal component of the roughened copper foil remaining on the surface of the insulating resin after the purification treatment is applied by When the semi-quantitative analysis is performed on the XPS analyzer (X-ray source: Al (kα), acceleration voltage: 15 kV, beam diameter: 50 μm), the surface-treated metal components are below the detection limit. That is, the printed wiring board of the present invention is characterized in that the surface-treated metal component of the roughened copper foil remaining on the surface of the insulating resin exposed between the circuits is removed as much as possible after the circuit is formed by etching. The reason for this is that when the metal component remains on the surface of the insulating resin exposed between the circuits, the adhesion between the solder layer and the insulating resin layer is adversely affected, and the migration resistance at the time of energization is deteriorated. Further, by removing the residual metal component on the surface of the insulating resin layer exposed between the circuits, it is possible to carry out the roughening treatment to the extent of roughening of the surface of the insulating resin without using the conventional method. Good moisture absorption and heat-resistance are maintained between the solder resist layer provided on the surface and the insulating resin provided on the outer layer. Further, the moisture absorbing and heat-resistant adhesive system of the present invention is combined with a specific pressure cooking test and a welding heat resistance test.

First, the "copper-clad laminate obtained by laminating a non-roughened copper foil" used in the present invention will be described. The "copper-clad laminate made of a non-roughened copper foil" as used herein means a copper-clad laminate which is formed by using a copper foil having no roughened copper foil as the outermost layer, and includes a so-called single-sided sticker. A copper clad laminate of copper laminate, double-sided copper clad laminate, and multi-layer copper clad laminate with inner core substrate. Further, as the roughened copper foil, an electrolytic copper foil, a rolled copper foil, and an extremely thin copper foil with a carrier may be used, and the thickness thereof is not particularly limited.

Further, the surface treatment of the copper foil is not particularly limited, and as the rust preventive component, for example, a nickel-zinc alloy, a nickel-cobalt alloy, a nickel-zinc-bismuth alloy, a nickel-cobalt-molybdenum alloy, or the like may be used. Various alloys such as zinc-tin alloy and chromate treatment. Further, from the viewpoint of improving the adhesion between the copper foil and the insulating resin layer, an epoxy decane coupling agent, an amine decane coupling agent, a mercapto decane coupling agent or the like is preferably provided. The decane coupling agent treatment layer.

Next, the insulating resin layer used for the copper-clad laminate is not particularly limited as long as it is a resin component or a skeleton material such as a glass cloth or a glass nonwoven fabric disposed in the resin. Further, the insulating resin layer may contain filler particles.

However, when the adhesion between the roughened copper foil and the insulating resin layer is considered, when the roughened copper foil is disposed on the outermost layer of the copper-clad laminate, the roughened copper foil with the primer resin layer is used. good. The non-roughened copper foil with the undercoat resin layer is provided on one side of the copper foil which is not subjected to the roughening treatment, and is provided with an extremely thin undercoat resin layer for ensuring good adhesion to the resin substrate. Copper foil. For the non-roughened copper foil with a primer resin layer, for example, "Multi Foil G: MFG" manufactured by Mitsui Mining Co., Ltd., or "PF-E" manufactured by Hitachi Chemical Co., Ltd. Wait. In this case, the undercoat resin layer exhibits adhesion to both the copper foil and the insulating resin, and it is easy to ensure good adhesion of the roughened copper foil and the insulating resin layer.

In the method of manufacturing a printed wiring board of the present invention, a circuit can be formed using a subtractive method or a semi-additive method. According to the subtractive method, the roughened copper foil at the outermost layer of the copper-clad laminate is first etched with a copper etching solution, and the unnecessary copper foil portion is removed to form a circuit. As for the circuit forming method at this time, an etching photoresist layer is formed on the surface of the outer layer copper foil, and the etching photoresist pattern is formed by exposure and development, and then the circuit pattern is formed by using a copper etching solution, and finally the etching is removed. A photoresist that forms a circuit for printed wiring. Further, according to the semi-phase addition method, a hole is formed in a position where a through-hole is formed in a copper-clad laminate to which a roughened copper foil is attached. Then, electroless copper plating is applied to form a photoresist layer on the surface of the formed electroless copper plating layer, and the plated photoresist is exposed and developed. Then, the electroplated copper is formed into a circuit pattern, and after the plated photoresist layer is removed, the roughened copper foil is removed by etching using a copper etching solution, thereby forming a circuit for the printed wiring board.

In the method for producing a printed wiring board of the present invention, the type of the copper etching liquid such as the copper chloride etching solution, the ferric chloride etching solution, or the sulfuric acid-hydrogen peroxide-based etching liquid is not particularly limited, and can be used arbitrarily. However, it is preferable to use it as a copper etching liquid using a sulfuric acid-hydrogen peroxide type etching liquid. However, in the formation of a micro-pitch circuit, a "sulfuric acid-hydrogen peroxide-based etching liquid" is preferably used in the copper etching liquid, and therefore, an etching liquid generally used in the semi-phase addition method is also used. However, when a "sulfuric acid-hydrogen peroxide-based etching liquid" is used, copper is etched to form a circuit, and then the surface of the insulating resin exposed between the circuits is easily treated as a surface-treated metal component without roughening copper foil. It is considered that there is a tendency to etch a component such as nickel, molybdenum, cobalt, or tin which is difficult to remove. Therefore, the method for producing a printed wiring board according to the present invention can be said to be a method for producing a printed wiring board in which a "sulfuric acid-hydrogen peroxide-based etching liquid" is used in a copper etching liquid which is assumed to form a circuit.

After the formation of the circuit is completed as described above, the surface-treated metal component remaining without the roughened copper foil remaining on the surface of the insulating resin exposed between the circuits is removed. This operation is called "purification processing". The degree of achievement of the purification treatment is based on an XPS analysis apparatus (X-ray source: Al (Kα), acceleration voltage: 15 kV, beam diameter: 50 μm) on the surface-treated metal of the roughened copper foil remaining on the surface of the insulating resin. The components were judged by semi-quantitative analysis. The reasons for using the above method are as follows. For example, the insulating resin layer exposed after purification is dissolved in concentrated sulfuric acid or the like, and it is an ideal method to confirm the amount of residual metal element by a direct analysis method of high sensitivity such as ICP analysis or atomic absorption spectrometry. However, such a chemical analysis method is cumbersome and time consuming, and thus may be carried out in a non-manufacturing step. On the other hand, depending on the method using the XPS analyzer, since the measurement can be easily performed, it can be carried out in the manufacturing step.

It is necessary to purify into the semi-quantitative analysis using the XPS analyzer, and the surface-treated metal component of the copper foil detectable by the insulating resin becomes below the detection limit. That is, if the metal component of the surface of the copper foil which can be detected is not left by this method, the surface of the insulating resin exposed between the circuits is not roughened, and the pressure cooking test (121 ° C, humidity 100%, 2 atmospheres) After the treatment under the conditions of 5 hours), the immersion in a solder bath at 260 ° C for 60 seconds or more can stably obtain the effect of not having a spot-like delamination of 20 μm or more in diameter between the insulating resin layer and the solder resist layer. .

Further, in the method for producing a printed wiring board of the present invention, the surface roughness (10-point average roughness Rzjis) of the surface of the insulating resin exposed before the purification treatment is exposed on the surface of the insulating resin between the circuits. In the case of Rz(S), when the value of the surface roughness (average roughness Rzjis of 10 points) of the exposed insulating resin surface after the purification treatment is Rz(C), the [Rz(C)/Rz(S) The value of ] is preferably 1.2 or less. In addition, Rz(C) and Rz(S) are values measured by a laser non-contact roughness tester in accordance with the Japanese Industrial Standard Specification (JIS B 0601 ₂₀₀₁ ) "Average Roughness of 10 Points (Rzjis)". The detection limit is about 0.02 μm.

In the invention of the present invention, the surface roughness of the surface of the insulating resin exposed between the circuits may increase as the method of the purification treatment is employed, indicating that the degree of increase in the surface roughness is [Rz(C)/Rz( S)] value. When the surface state changes to such an extent that the value of [Rz(C)/Rz(S)] exceeds 1.2, the undercut of the insulating resin layer of the supporting circuit may occur when, for example, plasma treatment is employed. As a result, the adhesion between the circuit and the insulating resin in the fine circuit is lowered, which is not preferable.

Further, at this time, the purification treatment is preferably carried out until Rz (C) is 1.8 μm or less. When the Rz (C) exceeds 1.8 μm, it is not preferable to set the over-etching time in the above-described half-addition process. Further, in order to form a finer circuit, Rz(C) is preferably 1.0 μm or less.

Here, a purification method of the purification treatment in the method for producing a printed wiring board of the present invention will be described. The "purification treatment" referred to herein is intended to remove metal components remaining on the surface of the insulating resin exposed between the circuits. Therefore, it can be suitably selected from the original physical treatment or chemical treatment method. Specifically, it can be subjected to plasma treatment such as ion beam method, RF beam method, plasma etching method, reactive ion etching method, reactive ion beam etching method, concentrated hydrochloric acid solution etching method or permanganic acid. Decontamination method and other appropriate choices. However, it is necessary to select a method for uniformly treating the surface of the printed wiring board on which the fine circuit is formed without causing damage to the circuit. In order to make the metal component remaining on the surface of the insulating resin exposed between the circuits, semi-quantitative analysis using an XPS analyzer, each surface-treated metal component is below the detection limit, and the surface roughness after the above-described purification treatment is obtained. It is better to use "plasma treatment" or "dissolve copper solution as much as possible".

In the above plasma treatment, if the selection freedom or the purification treatment ability of the ambient gas in the chamber is prioritized, it is preferable to use a reactive ion etching method. However, when the reactive ion etching method is employed, the printed wiring board to be cleaned must be processed on one side. As a result, the production efficiency of the entire purification treatment step is reduced, and the consumption of ambient gas is also increased. For this reason, plasma etching is performed under the condition that the input energy is set to 10 J/cm ² to 120 J/cm ² , and both sides of the printed wiring board are preferably treated. However, when the input energy is less than 10 J/cm ² , the amount of etching is small, and the metal component remaining on the surface of the insulating resin exposed between the circuits cannot be sufficiently removed, which is not preferable. On the other hand, when the input energy exceeds 120 J/cm ² , undercutting occurs in the insulating resin layer of the supporting circuit. As a result, in the fine circuit, the adhesion between the circuit and the insulating resin is lowered, which is not preferable. Moreover, in this case, the surface roughness of the surface of the insulating resin layer is also liable to be uneven.

In the method for producing a printed wiring board of the present invention, it is preferable to use a "mixed gas of O ₂ and CF ₄ " in the etching of the ambient gas in the chamber during plasma etching. As described above, according to the reactive ion etching method, the surface-treated metal component can be removed even if the type of the ambient gas in the chamber is not specified. However, in the plasma etching method, the etching property varies greatly depending on the type of the environmental gas. But using "a mixed gas of O ₂ and CF ₄ of", the function of the reaction with the metal ₄ to play the mixed gas of CF, O ₂ and play functionality imparting hydrophilicity of the resin surface, it can achieve good etch state.

Of course, it is also possible to perform plasma etching using CF ₄ gas first, and then use O ₂ as a plasma etching method for etching the ambient gas in the chamber. However, the use of "mixed gas of O ₂ and CF ₄ of the" atmosphere as the etch chamber, may, by a plasma etch play the above functions, it is better to simplification of procedures and equipment in terms of point of view.

Further, the gas partial pressure ratio [(CF ₄ partial pressure) / (O ₂ partial pressure)] of CF ₄ and O ₂ is preferably 0.2 to 5.0. When the value of the gas partial pressure ratio [(CF ₄ partial pressure) / (O ₂ partial pressure)] is less than 0.2, the function of reacting with the metal is not exhibited, which is not preferable. On the other hand, CF ₄ and O ₂ gas partial pressure ratio of [(CF ₄ partial pressure) / (partial pressure of O _2)] The value exceeds 5.0, the reaction of the metal with the function reaches saturation, since the O ₂ partial pressure, and It is not preferable to exhibit the hydrophilic function imparted to the surface of the resin.

Further, it is preferred that the plasma is etched in a range of from 0.5 Pa to 200 Pa in the etching chamber. When the gas pressure in the etching chamber is less than 5.0 Pa, the reaction gas is small and the etching rate is slow, and the productivity of the printed wiring board is extremely lowered. On the other hand, when the gas pressure in the etching chamber exceeds 200 Pa, the supply of plasma is difficult.

In the method for producing a printed wiring board of the present invention, when the plasma treatment is used as the purification treatment, it is preferred to perform wet cleaning after the plasma treatment. Here, after the plasma etching, since the insulating resin residue due to the plasma treatment remains on the surface of the insulating resin exposed between the circuits, the insulating resin residue is removed by wet cleaning. In this case, since the wet cleaning is performed for the purpose of removing the residue of the insulating resin due to the plasma treatment, it is not necessary to have the ability to dissolve and remove the metal component remaining on the surface of the insulating resin, and can be physically washed from high-pressure water spray or the like. It may be carried out by selecting a method suitable for the optimum effect in chemical washing such as drug treatment. Among them, in the wet cleaning of the present invention, it is preferred to use "cleaning solution containing a surfactant" and/or "copper microetching solution".

This wet cleaning is preferably carried out by "washing solution containing a surfactant" and then washed in the order of "copper micro-etching liquid". The reason for this is that by washing in advance with the "acid wash solution containing a surfactant", the residue on the surface of the printed wiring board after the plasma treatment can be removed, and the wettability of the surface of the printed wiring board and the solution can be improved. The "copper microetching liquid" to be used later can be distributed to all corners of the inter-circuit gap of the printed wiring board, and the residue can be surely removed.

The "surfactant" which can be used in the above-mentioned "acid wash solution containing a surfactant" may be any one of a nonionic surfactant, a cationic surfactant, and an amphoteric surfactant, or a mixture thereof. use.

The nonionic surfactant described herein refers to a surfactant having a hydrophilic group which is not ionized in water, and can be classified into an ester type, an ether type, an ester type, an ether type, and the like. Specifically, it is a higher alcohol, an alkylphenol, a fatty acid, an amine, an alkylenediamine, a fatty acid decylamine, a sulfonamide, a polyhydric alcohol, a glycoside derivative, or the like.

Further, the cationic surfactant refers to a surfactant having a property in which a portion having a hydrophobic group is ionized to a cation in a solution. More specifically, it is 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 imidazolium salt, stearylamine acetate, laurylamine acetate, and the like.

Next, the amphoteric surfactant refers to a surfactant having the property of an anionic surfactant in the alkaline field and having a cationic surfactant in the acidic field when dissolved in water. Specifically, it is an alkylcarboxybetaine type, an alkylaminocarboxylic acid type, an alkyl imidazoline type, etc.

The surfactant is contained in a solution of the surface of the washable printed wiring board such as sulfuric acid, hydrochloric acid, sulfuric acid-hydrogen peroxide solution or the like, so that the concentration of the surfactant is 0.1 g/L to 20 g/L. Wash the acidic solution. When the interface activator concentration at this time is less than 0.1 g/L, even if any of the above surfactants is used, the effect of improving the wetness of the surface of the printed wiring board after the plasma treatment and the solution cannot be obtained. On the other hand, even if the surfactant concentration exceeds 20 g/L, the effect of improving the wettability between the surface of the printed wiring board treated with the plasma and the solution is saturated, so that it is a waste of resources. The time for washing the surface of the printed wiring board after the plasma treatment with the acidic solution is preferably 15 seconds to 7 minutes. When the washing time was less than 15 seconds, the effect of improving the wettability of the surface of the printed wiring board after the plasma treatment and the solution could not be obtained. On the other hand, when the washing time exceeds 7 minutes, the circuit portion of the printed wiring board after the plasma treatment starts to be poorly etched.

The wet cleaning using the copper microetching liquid described above is performed by roughening the copper circuit by a thickness of 0.5 μm or more. When the copper circuit is etched to a thickness of 0.5 μm or more, the surface of the copper circuit can exhibit sufficient adhesion to the solder resist layer or the insulating resin layer at the time of multilayering. On the other hand, under the etching conditions, the contaminants remaining on the surface of the circuit, the etching residue, and the residue generated by the purification treatment of the surface of the insulating resin exposed between the circuits can be removed. As a result, the adhesion between the solder resist layer and the circuit surface and the adhesion between the insulating resin component and the circuit surface can be improved at the same time.

A manufacturing method of a printed wiring board after forming a solder resist layer: a method of manufacturing a printed wiring board after forming a solder resist layer of the present invention, characterized in that a printed wiring board manufactured by the method of performing the above-described purification processing is used A solder resist layer is formed. When the printed wiring board manufactured by the method of the above-described purification treatment is used, the metal component remaining on the surface of the insulating resin exposed between the circuits is below the detection limit of the semi-quantitative analysis using the XPS device, so that the solder resist can be obtained. A printed wiring board in which the adhesion between the layer and the insulating resin layer, the adhesion between the solder resist layer and the circuit surface, and the adhesion between the insulating resin component and the circuit surface are good, and the solder resist layer is formed.

The form of the printed wiring board after forming the solder resist layer: the printed wiring board after forming the solder resist layer is characterized by being held in a pressure cooker of 2 atm for 5 hours and then immersed in a solder bath of 260 ° C for 60 seconds. A spot-like delamination of 20 μm or more in diameter does not occur between the solder resist layer and the surface of the insulating resin. Therefore, even when treated at 121 ° C, humidity: 100%, and 2 atm. for 196 hours, no speckle-like delamination of 20 μm or more in diameter was caused between the solder resist layer and the surface of the insulating resin. The contents of the present invention will be more specifically described below using examples and comparative examples.

Example 1

[Manufacture of copper-clad laminate]

For the two surfaces of the prepreg (GHPL830-NS: manufactured by Mitsubishi Gas Chemical Co., Ltd.) having a thickness of 0.1 mm, the surface roughness (10-point average roughness Rzjis) is 0.37 μm. A non-roughened copper foil (MFG-DMT3F: manufactured by Mitsui Mining & Mining Co., Ltd.) with a primer resin layer coated with a primer resin on a copper foil, and a vacuum pressing device at a temperature of 220 ° C and a pressure of 4.0 MP The inside was molded for 90 minutes to obtain a copper-clad laminate having a thickness of 0.3 mm.

[Manufacture of printed wiring board]

A printed wiring board is manufactured using a semi-additive method. The manufacturing procedure of this printed wiring board is the same in both the embodiment and the comparative example. Forming a plating resist layer on the surface of the copper foil outside the copper-clad laminate, and exposing and developing the photoresist film using a photoresist pattern for forming a grid-like wiring having a line width/space width of 500 μm/1200 μm. The copper is plated to a total thickness of 15 μm. Then, after the plating resist was peeled off, a sulfuric acid-hydrogen peroxide-based etching liquid (CPE800: manufactured by Mitsubishi Gas Chemical Co., Ltd.) was used, and the exposed roughened copper foil was removed by etching to form a circuit. The printed wiring board thus manufactured was divided into the printed wiring board samples used in Example 1.

[purification treatment]

In the purification treatment of Example 1, the printed wiring board sample was immersed in 4 mol/L hydrochloric acid at 60 ° C for 60 minutes, washed with water, and dried to obtain a purification treatment sample.

[Evaluation of the surface of the insulating resin layer exposed between the circuits]

The surface of the purification treatment sample exposed before the purification treatment of the insulating resin layer between the circuits and the surface after the purification treatment is carried out by an XPS analyzer (X-ray source: Al(kα), acceleration voltage: 15 kV, wire diameter: 50 μm) The semi-quantitative analysis was carried out on the amount of residual metal components, and the surface roughness (Rzjis) thereof was measured. The surface state of the insulating resin is shown in Table 1 below.

[Evaluation of formation and delamination of solder resist layer]

In the above-mentioned purification treatment sample, the adhesion between the copper wiring and the solder resist layer was imparted, and the microetching liquid (CZ8101B: manufactured by MEC Co., Ltd.) was sprayed for 30 seconds, washed with water, and dried. A solder resist layer (AUS308: manufactured by Sun Ink Co., Ltd.) was formed on the purification treatment sample, and after PCT treatment at 121 ° C for 5 hours, it was immersed in a solder bath of 260 ° C for 60 seconds (hereinafter referred to as the operation). "PCT Welding Test"). For the cleaned sample after the PCT welding test, the occurrence of delamination was observed and evaluated by an 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 non-roughened copper foil with the primer resin layer used in Example 1 was replaced with MFG-DMT3F manufactured by Mitsui Mining Co., Ltd. and changed to PF manufactured by Hitachi Chemical Co., Ltd. A printed wiring board was produced in the same manner as in Example 1 except for -E-3.

The printed wiring board sample was subjected to a purification treatment in the same manner as in Example 1 to prepare a purification treatment sample, and the residual metal component of the surface of the insulating resin layer exposed between the circuits of the purification treatment sample was subjected to semi-quantitative analysis, and further measured. Surface roughness (Rzjis). Further, 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 is shown in Table 1 below, and the evaluation results of the delamination and the purification treatment conditions are shown in Table 2 to be described later.

Example 3

In the third embodiment, the sample of the printed wiring board manufactured in the first embodiment was used, and only the purification treatment conditions were changed.

In the purification treatment, the sample of the printed wiring board is placed in a chamber of [(CF ₄ partial pressure) / (O ₂ partial pressure)] = 0.33 and a gas pressure of 15 Pa, and the input energy is set to 40 J/cm ² . Slurry etching, followed by immersion in a 10% by mass solution containing MECLATE PC-316 (manufactured by MELTEX Co., Ltd.) as an acid component and ethylene glycol as a surfactant, followed by immersion for 5 minutes, followed by spraying The etching solution (CZ8101B: product of MEC Co., Ltd.) was dried for 30 seconds, and dried to obtain a purification treatment sample. The observation image of the scanning electron microscope exposed on the surface of the insulating resin layer between the circuits immediately after the formation of the circuit is shown in Fig. 3, and the scanning electron microscope which is exposed to the surface of the insulating resin layer between the circuits immediately after the plasma etching The observed image is shown in Fig. 2, and the observation image of the scanning electron microscope exposed on the surface of the insulating resin layer between the circuits immediately after micro-etching is shown in Fig. 1.

Then, in the same manner as in the first embodiment, the residual metal component of the surface of the insulating resin layer exposed between the circuits of the purification treatment sample was subjected to semi-quantitative analysis, and the surface roughness (Rzjis) thereof was measured. Further, 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 treatment sample is shown in Table 1 below, and the evaluation results of the delamination and the purification treatment conditions are shown in Table 2 to be described later.

Example 4

In the fourth embodiment, the sample of the printed wiring board manufactured in the first embodiment was used, and only the purification treatment conditions were changed.

In the purification treatment, the sample of the 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 at a liquid temperature of 45. The mixture was immersed for 5 minutes in a liquid phase (manufactured by Rohm and Haas Electronic Materials Co., Ltd.), washed with water, and dried to obtain a purification treatment sample.

Then, in the same manner as in the first embodiment, the amount of residual metal components on the surface of the insulating resin layer exposed between the circuits of the purification treatment sample was subjected to semi-quantitative analysis, and the surface roughness (Rzjis) thereof was measured. Further, 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 treatment sample is shown in Table 1 below, and the evaluation results of the delamination and the purification treatment conditions are shown in Table 2 to be described later.

Comparative example 1

In Comparative Example 1, the purification treatment carried out in Example 1 was not carried out. Then, the occurrence of delamination was evaluated in the same manner as in Example 1. The delamination occurred as seen from the surface of the solder resist layer using transmitted light is shown in Fig. 4. The surface state of the insulating resin layer exposed between the circuits is shown in Table 1 below, and the evaluation results of the delamination and the purification treatment conditions are shown in Table 2 to be described later.

Comparative example 2

In Comparative Example 2, the purification treatment time carried out in Example 1 was changed to 60 minutes to prepare a purification treatment sample. Then, in the same manner as in the first embodiment, the amount of residual metal components on the surface of the insulating resin layer exposed between the electrodes of the purification treatment sample was subjected to semi-quantitative analysis, and the surface roughness thereof was measured. Further, the occurrence of delamination was evaluated in the same manner as in Example 1. The delamination that occurred was shown in Fig. 5 as a surface observation image of the transmitted light viewed from the side of the solder resist layer. The surface state of the insulating resin layer exposed between the circuits is shown in Table 1 below, and the evaluation results of the delamination and the purification treatment conditions are shown in Table 2 to be described later.

Comparative example 3

In Comparative Example 3, in the purification treatment carried out in Example 3, the microetching treatment was omitted to prepare a purification treatment sample. Then, in the same manner as in the first embodiment, the amount of residual metal components on the surface of the insulating resin layer exposed between the electrodes of the purification treatment sample was subjected to semi-quantitative analysis, and the surface roughness thereof was measured. Further, 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 is shown in Table 1 below, and the evaluation results of the delamination and the purification treatment conditions are shown in Table 2 to be described later.

Comparative example 4

In Comparative Example 4, in the purification treatment carried out in Example 3, the plasma treatment was omitted, and a purification treatment sample was prepared. Then, in the same manner as in the first embodiment, the amount of residual metal components on the surface of the insulating resin layer exposed between the electrodes of the purification treatment sample was subjected to semi-quantitative analysis, and the surface roughness thereof was measured. Further, 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 is shown in Table 1 below, and the evaluation results of the delamination and the purification treatment conditions are shown in Table 2 to be described later.

[Comparison of Examples and Comparative Examples]

The surface state of the insulating resin layer exposed between the circuits shown in Table 1 and the results of the delamination evaluation and the purification treatment conditions shown in Table 2 were compared with the examples and the comparative examples.

Compare the presence or absence of delamination and purification treatment conditions. In the surface of the insulating resin layer after the purification treatment of this example, it was found that no residual metal component was detected. Moreover, with regard to the examples, the occurrence of delamination which is practically problematic has not been observed. On the other hand, in Comparative Example 2, even in Comparative Example 2 in which the amount of residual metal component after the purification treatment was 0.1 atom%, a speckle delamination of 50 μm or more was observed. Further, in Comparative Example 3 in which the amount of the residual metal component after the purification treatment was 5.4 at%, the spot-like delamination of 300 mm diameter was observed, and the residual metal component amount after the purification treatment was 8.0 atom%, Comparative Example 4 and In Comparative Example 1 in which the amount of residual metal component was 8.4 atom%, the speckle delamination exceeding 1.0 mm was observed. In other words, the more the residual metal component detected on the surface of the insulating resin after the purification treatment, the larger the spot diameter of the delamination.

On the other hand, when the ratio of Rz(C) to Rz(S) [Rz(C)/Rz(S)] is considered, the examples are in the range of 1.00 to 1.11, and the comparative examples are in the range of 1.00 to 1.05. Therefore, when the sample having a value of [Rz(C)/Rz(S)] of 1.00 and a sample exceeding 1.00 are compared with the purification treatment conditions, the sample subjected to plasma etching exceeds 1.00.

From the comparison between the above-mentioned examples and the comparative examples, it is understood that the adhesion between the "solder resist layer" and the "surface of the insulating resin layer exposed between the circuits" is largely affected by the metal components remaining on the surface of the insulating resin layer exposed between the circuits. The impact. On the other hand, even if plasma etching is applied to the surface of the insulator resin, when the value of [Rz(C)/Rz(S)] is 1.2 or less, the micro shape changes, but the adhesion to the solder resist layer Sex has little effect. Therefore, it is possible to confirm the metal component remaining on the surface of the insulating resin layer exposed between the circuits, and to distinguish the "solder resist layer" from the "surface of the insulating resin layer exposed between the circuits" when the semi-quantitative analysis of XPS can be detected. The sex is getting worse.

[Industry possible use]

In the method for producing a printed wiring board according to the present invention, the printed wiring board having the metal element remaining on the exposed surface of the insulating resin is subjected to a purification treatment, and the amount of the remaining metal component is less than or equal to a limit value when subjected to semi-quantitative analysis by the XPS device. The surface of the insulating resin layer can be roughened, and good adhesion to the "solder resist layer" provided after the surface of the printed wiring board can be obtained. Therefore, it is possible to obtain a high-quality printed wiring board by providing good adhesion to the resin layer which is laminated after the "multilayer formation" which is provided after the surface of the printed wiring board.

BM. . . Insulating resin substrate

CC. . . Copper circuit

PSR. . . Solder resist layer

DL. . . Delamination

Fig. 1 is a scanning electron microscope observation image of the surface of an insulating resin exposed between circuits of a printed wiring board immediately after micro-etching in Example 3.

Fig. 2 is a scanning electron microscope observation image of the surface of the insulating resin exposed between the circuits of the printed wiring board immediately after plasma etching in Example 3.

Fig. 3 is a scanning electron microscope observation image of the surface of the insulating resin exposed between the circuits of the printed wiring board immediately after the circuit was formed in Example 3.

Fig. 4 is a view showing the delamination which occurred in Comparative Example 1, and the image was observed from the surface observed on the side of the solder resist layer using transmitted light.

Fig. 5 is a view showing the delamination which occurred in Comparative Example 2, and the image was observed from the surface observed on the side of the solder resist layer using transmitted light.

Fig. 6 is a cross-sectional observation image of a printed wiring board in which delamination occurred. In Fig. 6, BM denotes an insulating resin substrate, CC denotes a copper circuit, PSR denotes a solder resist layer, and DL denotes delamination.

Claims (11)

A method for producing a printed wiring board, which is a method of manufacturing a printed wiring board by using a copper-clad laminate obtained by laminating a non-roughened copper foil, wherein the method is characterized in that the roughened copper foil is not subjected to roughening treatment and The insulating resin layer is bonded, and the surface of the roughened copper foil is treated with a rust preventive component containing a metal selected from the group consisting of nickel, molybdenum, cobalt, and tin, and the roughened copper is not used. After the foil is etched by the copper etching solution to form a circuit, the surface of the insulating resin exposed between the circuits is subjected to a plasma treatment and washed with a copper microetching liquid as a purification treatment to leave the surface of the insulating resin to be subjected to the purification treatment. When the nickel, molybdenum, cobalt, tin or a mixed metal component thereof is subjected to semi-quantitative analysis by an XPS analyzer (X-ray source: A1 (K α), acceleration voltage: 15 kV, beam diameter: 50 μm), each surface-treated metal The component is below the detection limit value. The method of manufacturing a printed wiring board according to the first aspect of the invention, wherein the copper etching solution is etched into a sulfuric acid-hydrogen peroxide-based etching solution. The method of manufacturing a printed wiring board according to the first aspect of the invention, wherein the surface of the insulating resin exposed between the circuits is exposed to the surface roughness of the insulating resin surface between the circuits before the cleaning process (10 point average) Roughness: Rzjis) is set to Rz(S), and the surface roughness (10-point average roughness: Rzjis) of the surface of the insulating resin exposed between the circuits after the purification treatment is set to Rz (C). When the ratio of Rz(C) and Rz(S) [Rz(C)/Rz(S)] is 1.2 or less. The method for producing a printed wiring board according to the third aspect of the invention, wherein the purification treatment is such that the Rz (C) value is 1.8 μm or less. The method of manufacturing a printed wiring board according to the first aspect of the invention, wherein the plasma processing is performed by plasma etching under conditions of an input energy of 10 to 120 J/cm ² . The method for manufacturing a printed wiring board according to the first aspect of the invention, wherein the plasma treatment is based on a gas partial pressure ratio [(CF ₄ partial pressure) / (O ₂ partial pressure)] of CF ₄ and O ₂ Plasma etching performed in a CF ₄ /O ₂ gas atmosphere of 0.2 to 5.0 and a pressure of 5.0 Pa to 200 Pa. The method for producing a printed wiring board according to the first aspect of the invention is carried out after the plasma treatment, followed by washing with an acidic solution containing a surfactant and washing with a microetching solution using copper. The method for producing a printed wiring board according to the seventh aspect of the invention, wherein the cleaning using the copper micro-etching liquid is performed by etching the circuit in a mass-converted thickness of 0.5 μm or more. The method for producing a printed wiring board according to the first aspect of the invention, wherein the copper-clad laminate is obtained by using a non-roughened copper foil having a primer resin layer. A method of producing a printed wiring board after forming a solder resist layer, characterized in that in the method of manufacturing a printed wiring board according to the first aspect of the invention, after the purification treatment, a solder resist layer is formed. A printed wiring board obtained by forming a solder resist layer obtained by the method for producing a printed wiring board according to claim 10, which is characterized in that after being held in a pressure cooker of 2 atm for 5 hours, After immersing in a solder bath at 260 ° C for 60 seconds, no delamination of a spot having a diameter of 20 μm or more occurred between the solder resist layer and the surface of the insulating resin.