JPS63278296A - Printed-circuit board and its manufacture - Google Patents

Abstract

PURPOSE:To form a conductor part having a sharply square cross section by covering a non-plating region with a prescribed dielectric. CONSTITUTION:Conductor parts 23 are formed on the prescribed surface of a substrate 25 by using a conductive metal material which can be plated non- electrolytically. Plating control phases 24 composed of a derivative of a silane coupling agent are formed in non-plating regions 26. The plating control phases 24 have a function to prevent the non-plating regions 26 from being plated when the conductor parts 23 are formed by a non-electrolytic plating operation. In the conductor parts 23 which are grown on a plating region 27 sandwiched between these non-plating regions 26, their growth in a transverse direction is regulated by the plating control phases 24; accordingly, the conductor parts 23 having sharply square cross sections are formed.

Description

[Detailed description of the invention] <Industrial application field> The present invention relates to a printed circuit board and a method for manufacturing the same.

<Prior Art> A conventional printed circuit board 1 consists of a board section 3 and a conductor section 5, as shown in FIG. In the general etching method, the unnecessary parts of the copper-clad laminate are dissolved and removed using chemicals, and the conductor parts 5 are removed.
is formed. Furthermore, in the additive method, as shown in FIG.
The structure is such that a resin layer 15 covers a non-plated area (hereinafter referred to as a "non-plated area").

<Problems to be Solved by the Invention> Even with the conventional printed circuit board 1.11, it was possible to meet the needs of the past.

However, it has become impossible to adequately respond to the trend of miniaturization of printed circuit boards, which has accompanied the recent miniaturization and increase in density of devices.

In particular, when manufacturing by the etching method, when unnecessary parts of the copper foil are dissolved and removed using chemicals, as shown in Figure 14,
There is a tendency for the conductor portion 5 to erode in a reverse taper shape to the base (so-called undercut phenomenon). For this reason, when the spacing between the conductor parts 5.5 is narrowed due to miniaturization of the circuit, it is necessary to circulate and flow the above-mentioned chemicals to the fine details.
This tendency becomes even stronger, the base portion of the conductor portion 5 becomes noticeably thinner, and the adhesion strength between the conductor portion 5 and the substrate portion 3 is extremely reduced.

Further, during solder coating, which is generally applied, there is a drawback that the solder adheres to the blank part 4 of the substrate part 3, resulting in a short circuit.

Furthermore, in the printed circuit board 11 of FIG. 15, due to the presence of the resin layer 15, as the spacing between the conductor parts 17.17 becomes narrower, hydrogen gas generated in the plating reaction becomes less dissipated, and the conductor parts 17. There may be variations in the thickness of the resin layer 15.
There is a possibility that the conductor portions 17 and 17 may be plated in a mist, thereby impairing the insulation resistance between the conductor portions 17 and 17.

Therefore, this invention aims to (a) allow plating to be performed while promoting hydrogen gas dissipation by not providing any obstacles such as a resin layer, and (b) form microcircuits with uniform thickness without undercuts. It is an object of the present invention to provide a printed circuit board and a method for manufacturing the same that achieves (1) no adhesion of solder to parts outside conductor parts.

Means for Solving the Problems> In order to achieve the above object, the inventor of the present invention has made extensive studies and has come up with the following printed circuit board of the first invention.

The printed circuit board of the first invention comprises a substrate part and a conductor part formed by electroless plating, and the non-plated area on the protruding surface of the conductor part of the board part is covered with a derivative of a silane coupling agent. It is characterized by its configuration.

A second invention is a method for manufacturing a printed circuit board according to the first invention, comprising: (a) using a predetermined resin composition;
(a) applying a catalyst to the plating area of the substrate; (ii) removing the resin composition film; and (1) electroless plating. , and forming a conductor portion in the plating area of the substrate portion, in order.

A third invention is also a method for manufacturing a printed circuit board according to the first invention, which comprises: (a) roughening the surface of the board as a whole; and (b) using a specific catalytic ink. (1) developing and peeling off the catalytic ink and coating the non-plated areas with a silane wrapping agent derivative; (1) electroless plating. The method is characterized in that the method sequentially includes the step of forming a conductor portion in the plating area of the substrate portion.

Detailed explanation of the method The above means will be explained in detail below.

(1) Regarding the first invention (see FIG. 1) The substrate portion 25 is a plate-like member capable of supporting the conductor portion 23, and the material from which it is formed is not particularly limited. Examples include plastics, ceramics, glass, semiconductors, and laminates thereof. Furthermore, the protruding surface of the conductor portion 23 on the substrate portion 25 may be a curved surface.

The conductor portion 23 is formed on a predetermined surface of the substrate portion 25 (this is the conductor portion protrusion surface) using a conductive metal material that can be electrolessly plated.

Silane coupling agents refer to silane and other silicon compounds that have the ability to chemically bond organic polymers and inorganic materials. For example, triethoxymethylsilane, trimethoxymethylsilane, triethoxyphenylsilane, trimethoxyphenylsilane, triethoxyvinylsilane, α-aminopropyltriethoxysilane,
Examples include N-(β-aminoethyl)-α-aminopropyltrimethoxysilane, α-methacryloxypropyltrimethoxysilane, α-mercaptopropyltrimethoxysilane, and ureidopropyltriethoxysilane. In this specification, the silane coupling agent derivative refers to the silane coupling agent that is hydrolyzed by contact with water during the manufacturing process because this invention uses an aqueous treatment method. However, it mainly refers to substances modified to silanol, etc.

The plating control phase 24 as shown in FIG. 1 coated with such a derivative of a silane coupling agent has a function of preventing the non-plating area 26 from being plated when the conductor portion 23 is formed by electroless plating. have In other words, it has a function of repelling hydrogen atoms, hydrogen gas, metal ions, water molecules, etc. from the non-plating region 26. This behavior will be explained in detail in (b) below.

It has also been found that this plating control phase 24 has the property of not allowing any adhesive to adhere to the non-plating areas 26 when the printed circuit board is immersed in molten solder pot for solder coating. This is the non-plated area 26
This is thought to be due to the fact that it is coated with a derivative of a silane coupling agent or with silicon oxide that has been modified by being heated with molten solder (260° C.).

The conductor portion 23 growing on the plating region 27 sandwiched between the non-plating regions 26 like this is regulated in lateral growth by the plating control phase 24, resulting in a conductor with a sharp rectangular cross section. It is considered that the portion 23 is formed (see Table 2.3) (2) Regarding the second invention, (a) Step of coating the non-plated area 26 of the substrate portion 25 with a specific resin composition This resin The composition is: ■ Plating resist agent for acid plating,
The active ingredients are: (1) rosin, (2) a silane coupling agent, and (2) a sulfur compound that is added as necessary.

■For example, plating resist agent SPR-53 (trade name) manufactured by Sanei Chemical Co., Ltd. is used as a plating resist agent for acidic plating.
0CMT can be used.

This plating resist agent contains an inorganic filler.

It should be noted that the above plating resist agent for acidic plating alone cannot withstand the strong acidic solution such as the roughening solution used in the step (a) below.

■As for rosin, what is commonly called rosin (pine resin) and many types of rosin extracted from other plants are effective, and Canadian balsam extracted from Canadian maple is particularly preferred.

The amount of rosin blended is 3 to 5% by weight in the resin composition.
0%, preferably 15-30%.

If it is outside the range of 3 to 50%, the resin composition may be destroyed by the roughening liquid in the step (a) below.

(2) As the silane coupling agent, those mentioned above can be used. Its blending amount is 0% by weight in the resin composition.
．． It is 1 to 15.0%, preferably 1.5 to 5.0%. If it is less than 0.1%, there is a risk that plating will precipitate in non-plated areas, while if it exceeds 15.0%, there is a risk that plating will not be precipitated in plated areas, which are both undesirable.

This silane coupling agent is a general solvent for resin compositions (ethylene glycol monobutyl ether, 2-(2
-Ethoxyethoxy)ethanol, etc.). It also has good compatibility with (1) rosin described above and (2) sulfur compounds described below.

■Sulfur compounds include 2-mercaptobenzothiazole,
Examples include thiourea, methyl blue, methylene green, 2-imidazolidinethione, methyl orange, and taurine.

By adding this sulfur compound, the following (1)
In the electroless plating process, it is possible to reliably prevent plating from depositing on non-plated areas.

This is thought to be due to the fact that the sulfur compound is transferred to the non-plated area along with a bond with the functional group of the silane coupling agent.

In this way, sulfur compounds are added as needed.

The amount of this sulfur compound blended is 11 amounts, but it is 0.005 to 0.5% by weight based on the resin composition.
is within the range of If it is less than 0.005%, the above-mentioned prevention function may not be effective, and if it exceeds 0.5%, the sulfur component will act as a catalyst poison for formalin, which is a reducing agent, and cause plating to occur beyond the plating boundary line. Each of these is undesirable because electroless plating may not be possible due to reasons such as stopping the plating precipitation reaction because of the effect on the area.

Furthermore, if each of the above ■rosin, ■silane coupling agent, and ■sulfur compound is added alone to ■plating resist agent for acidic plating, the resin composition will not be able to withstand strong acidic solutions such as roughening solutions. (See each comparative example in Table 1).

The resin composition of the present invention is diluted with the above-mentioned solvent and screen printed onto the substrate portion 25 (see FIG. 2). The thickness of the coating 29 thus obtained is 4 to 7 μm. If it is less than 4 μm, there is a risk that it will be blurred by screen printing. 7
If the thickness exceeds μm, the resin composition is dense, so
Not necessary.

This resin composition has durability against the strongly acidic roughening liquid, catalyst liquid, and activation liquid used in steps (a) and (v) described below.

If we were to estimate the reason for this, it would be as follows (a) to (c).

(a) When a silane coupling agent is not added to the resin composition of coating 29, as shown in Figure 3, the grain boundaries of the inorganic filler (compounded in the plating resist agent) are oriented with the OH groups outward. It shows hydrophilicity. In contrast, silane coupling agents (e.g. trimethoxy(methyl)silane; C
When H3St (QCH3)3) is added, it is hydrolyzed by treatment with water in the process of the present invention,
As shown in FIG. 4, the grain boundaries of the inorganic filler are hydrophobic with the CH3 groups directed outward. Furthermore, the CH3 group increases the bonding strength between the inorganic filler and the organic component. For this reason, the coating 29
The film is formed on both the inner and outer surfaces with strong hydrophobicity and density, and is not attacked even when immersed in strong acidic solutions such as roughening solutions and catalyst solutions. Due to such characteristics of the coating 29, its thickness can be made as thin as possible. Therefore, it is suitable for negative printing of fine patterns.

(b) Next, the coating 29 contains a sufficient amount of silane coupling agent to have the denseness and chemical resistance performance described in (a) above. This slightly surplus silane coupling agent is firmly bonded to the interface of the non-plated area 26, and even after the coating 29 is peeled off with an alkaline aqueous solution,
A fixed film of silanol (a conductor of the silane coupling agent) generated by hydrolysis of the silane coupling agent can be left on the interface of the non-plating region 26 . Since the outermost shell phase of this silanol has H groups facing outward, it is hydrophobic and has the ability to repel hydrogen atoms, hydrogen gas, and metal ions, making it possible to completely control plating precipitation. I was able to confirm this through experiment. It has also been found that this function is also effective three-dimensionally, that is, in three-dimensional directions. Presuming this state, it is thought that the plating control phase 24 is formed on the non-plating region 26 in a semi-elliptical cross-sectional shape, like a water droplet on a lotus leaf seen in nature.

(c) When the surface of the dried coating 29 is treated with an acidic aqueous solution such as hydrochloric acid or sulfuric acid, the hydrophobic function is further enhanced, the characteristics described in (b) above are enhanced, and the surface of the coating 29 is made stronger. This is because the resin composition is influenced by acid groups and the effect is promoted, and the outermost monomolecular phase or a part of the phase of the silanolized phase on the surface of the coating 29 is converted into silica gel. Alternatively, it is thought that the bond between the silanol and the organic component becomes stronger (
B) Step of applying a catalyst to the plating region 27 of the substrate portion 25 First, it is necessary to roughen the plating region 27 of the substrate portion 25 with a roughening liquid. This roughening step can also be performed by roughening the entire surface of the substrate portion 25 before the step (a) above.
5 is resin-made rice, chromic acid + sulfuric acid, chromic acid + sulfuric acid +
When a mixed aqueous solution of phosphoric acid, sulfuric acid + phosphoric acid, etc. is used, and the substrate portion 25 is made of ceramics, glass, or semiconductor,
Use a hydrobutic acid solution, etc. When the substrate portion 25 is immersed in these roughening solutions, the plating area not protected by the coating 29 will be roughened.

Next, a catalyst is applied to the plating area.

For example, when palladium is used as a catalyst, there are two steps: immersing the substrate portion 25 in a mixed solution of palladium chloride and hydrochloric acid (catalyst liquid) to support palladium on the substrate portion 25; This step involves activating palladium by immersing it in (activation solution).

Of course, a process using a one-component catalyst solution may also be used.

In addition, there is no particular limitation on the type of catalyst.) (1) Step of removing the coating on the non-plating area 26 This step is as follows:
Even if the coating 29 has acid resistance, it will be decomposed by an alkaline aqueous solution, so the substrate portion 25 is immersed in an alkaline aqueous solution such as sodium hydroxide or sodium carbonate.

At this time, the state of the interface between the coating 29 and the non-plating area 26 of the substrate portion 25 is determined by the silane coupling agent contained in the coating 29 (which does not participate in imparting the above-mentioned properties to the coating 29). plays an important role. That is, when the coating 29 is printed on the substrate part 25, one of the bonding groups of the organic and inorganic functional groups of the silane coupling agent acts selectively depending on the material of the substrate part 25. , which is firmly bonded to the substrate interface and covers the non-plated area 26. Therefore, when the coating 29 is removed with an alkaline aqueous solution, this interface is also hydrolyzed at the same time, so that the fixed silane coupling agent phase is denatured into silanol and left at the interface of the non-plated area 26. If the conductor phase of such a silane coupling agent forms a monomolecular thin phase, it can sufficiently exhibit the above-mentioned (b). In other words, the area around the non-plating region 26 can be made hydrophobic and the approach of hydrogen ions, hydrogen gas, and metal ions can be prevented, and deposition of plating on the non-plating region 26 can be prevented.

At this time, depending on whether the material of the substrate portion 25 is inorganic, organic, or a mixture of both, the amount of silane coupling agent mixed in the coating 29 must be mixed, but the non-plated A sufficient supply of bonding hands and an amount sufficient to form an inductive phase of the silane coupling agent at the interface of region 26 is required and is determined experimentally (see each example in Table 1).

(1) Plating area 2 of the substrate portion 25 is formed by electroless plating.
Step of forming conductor portion 23 on substrate 7 This step is performed by immersing substrate portion 25 in an electroless plating solution.

When the substrate portion 25 is immersed in the plating solution, hydrogen or hydrogen gas is generated from the plating area to which the catalyst is applied, and plating is started. At this time, the non-plating area 26 is
The plating control phase 24 described above is formed. Therefore, the plating is prevented from depositing in the non-plating area 26, and the plating control function has a three-dimensional effect on the boundary with the plating area 27, so that the plating protrudes into the non-plating area 26 and grows. be controlled. Therefore, the plating (conductor portion 23) can be formed into a predetermined rectangular cross section. Further, at this time, since the plating control phase 24 has a hydrogen gas repelling function, it promotes the dissipation of excess hydrogen gas generated from the plating region 27. Therefore, the plating regions 27 that are closely spaced at minute intervals can be efficiently deposited.

Note that the type of plating metal is not particularly limited, and is determined depending on the relationship with the catalyst.

Regarding the third invention (a) Process of roughening the entire conductor protruding surface of the substrate part 25 This process is performed by using a predetermined roughening solution as explained in the step (a) of the second invention. This is done by, for example, depping the substrate portion 25.

(b) A process of positive printing on the plating area of the substrate part 25 with a specific catalytic ink. The sulfur compound added is the active ingredient.

(2) Silver salts are not particularly limited, but include silver nitrate, silver sulfate, silver acetate, silver salts of benzoic acid and 2-hydroxybutanoic acid, and the like.

The blending amount is 0.2 to 0.0% by weight based on the catalytic ink.
8%, preferably 0.4-0.6%.

(2) Starch, dextrin, or a mixture thereof can be used as the starch-based binder.

The amount to be blended is such that the viscosity of the catalytic ink can be adjusted to a level that allows screen printing. 40-60%, preferably 45-55% by weight relative to the catalytic ink
%.

In such a starch-based binder, the amylose component is
A complex compound is formed with the silver salt described above and the silane coupling agent described below. The amylopectin component then becomes the skeleton. A silver salt-amylose-silane coupling agent complex compound is embedded in the structural space of the amylopectin skeleton. Note that the viscosity of this starch-based binder temporarily decreases due to the shearing force applied during printing.

(2) A silane coupling agent is added to form a complex compound with silver salt and amylose as described above. It is believed that the silane coupling agent is hydrolyzed to form a complex in the form of silanol. When determining the formulation of the catalytic ink, it is possible to use silanol as a base instead of the silane coupling agent, but the amount of silanol produced by hydrolyzing the silane coupling agent and the amount of silanol produced by hydrolysis Due to the lack of accuracy in determining the realistic relationship to the amount of water required, this specification uses a silane coupling agent as the basis. That is, in preparing the present catalytic ink, silanol can also be included as a component.

The blending amount of the silane coupling agent is 0.2 to 1.3% by weight, preferably 6.5 to 8% by weight based on the catalytic ink.
．． It is 5%. A small amount of less than 0.2% or a large amount of more than 1.3%, which would cause excessive complexation, are not preferred because the plating will not precipitate in the plating region 27. This is because the absolute amount of catalyst (Ag) is not adsorbed in the plating area 27 (less than 0.2%), and because the silver salt is overly ionized due to excessive complexation (more than 1.3%). It is thought that it depends on the case). In other words, due to the presence of the silane coupling agent, the functional groups of this agent are activated in the plating area 27.
It is presumed that silver salt, which is a catalyst precursor (an amount sufficient to function as a catalyst), is transferred and fixed onto the surface (roughened) of the silver salt, which is a catalyst precursor.

(2) Furthermore, by converting the silver salt into the above-mentioned complex compound, it will be reduced to Ag when exposed to light in the presence of an organic substance, so that it will no longer function as a catalytic ink. Therefore,
In order to improve storage stability, it is effective to add a colored sulfur compound such as methyl blue, which has light shielding properties and toxicity to the catalyst to prevent decomposition. Note that such a sulfur compound may not be blended. In addition, there are substances that impart light-shielding properties (dyes, etc.) to the catalytic ink, and substances that impart catalytic toxicity (such as dyes).
Formalin, etc.) can also be added separately.

As for the sulfur compound, those shown in the second invention can be used. The blending amount is 0.5 to 3.5% by weight relative to the catalytic ink. If it is less than 0.5% by weight, the light shielding effect is poor, and if it exceeds 3.5%,
Each of these is not preferred because the toxicity to the catalyst becomes too strong.

Water is used as a solvent for such catalytic inks. Further, in order to prevent water evaporation and control viscosity, it is effective to add polyvinyl alcohol, ethylene glycol, ethylene glycol monobutyl ether, 2-(2-ethoxyethoxy)ethanol, etc. to form an emulsion.

(1) A step of developing and peeling off the catalytic ink, and coating the non-plated areas with a silane wrapping agent derivative. This step involves immersing the substrate portion 25 printed with the catalytic ink in a developer solution. This is done by

The developer was an aqueous hydrochloric acid solution to which a Hesilan coupling agent and a reducing agent were added.

As this silane coupling agent, those mentioned above can be used, and are converted into silanol in an aqueous solution. Then, it is adsorbed (physical adsorption + chemical adsorption) to the non-plating area of the substrate portion 25 that has already been roughened. As a result, the non-plated area is coated with the silane coupling agent derivative.

On the other hand, the catalytic ink positively printed on the plating area 27 is
The silver salt (silane coupling agent, which forms a complex with amylose) efficiently migrates and bonds to the interface of the plating area 27 due to the function of the functional group of the silane coupling agent, so it oozes into the non-plating area. It is stably fixed without any problems. Next, when the substrate portion 25 is immersed in an aqueous hydrochloric acid solution, the catalytic ink has the property of swelling and gelling. This is because the silver salt, which is encapsulated in the amylopectin skeleton of the catalytic ink and becomes a solution, reacts with hydrochloric acid, turns into silver chloride, and swells, causing the structure of the ink film to gel (become brittle). It is presumed that this is the cause. The gelled structure of the catalytic ink is in a state where it collapses or easily collapses, and can be completely removed from the substrate portion 25 by washing with water. At this time, it is presumed that the silver salt stably adsorbed and fixed in the roughened surface area 27 is converted into a catalytic substrate by the reducing agent in the developer.

Note that, as the reducing agent, an agent capable of reducing silver salt, such as sodium sulfite, can be used. In the case of using sodium sulfite as an example, the amount to be added to the developer is 1
10 to 75 g per °C, preferably 30 to 50 g.

(1) Plating area 2 of the substrate portion 25 is formed by electroless plating.
Step of forming the conductor portion 23 on the substrate 7 This step is carried out in the same manner as in the second invention.

However, the plating metal is limited to Cu. This means that
This is due to the fact that the catalyst of the catalytic ink is a silver salt.

Note that when Ni plating or the like is performed, a Cu plating layer is formed in advance as a single primer layer, and a Ni plating layer or the like is deposited thereon.

<Effects of the Invention> As explained above, the printed circuit board according to the first invention includes a substrate portion and a conductor portion formed by electroless plating, and the conductor portion protruding surface of the substrate portion has a non-conductive surface. The plating area is coated with a silane coupling agent derivative. This allows the silane coupling agent to coat the non-plated areas when dipping the board into a molten solder bath for solder plating the conductor or mounting parts such as elements after forming the conductor. With derivatives,
It is possible to prevent the solder from adhering to non-plated areas. Therefore, troubles such as short circuits between strands of high-density wiring can be eliminated.

The printed circuit board of the first invention includes the following steps: (a) coating the non-plated areas of the substrate with a predetermined resin composition; (b) applying a catalyst to the plated areas of the substrate;
(1) a step of removing a film of a resin composition; and (1) a step of forming a conductor part in a plating area of a substrate part by electroless plating (a second method). invention), (a) a step of roughening the entire surface of the substrate portion, and (
b) A process of positive printing on the plated area of the substrate with a specific catalytic ink, and (1) developing and peeling off the catalytic ink, and coating the non-plated area with a silane coupling agent derivative. and (1) forming the conductor portion in the plating area of the substrate portion by electroless plating (third invention).

When manufacturing a printed circuit board in this manner, a plating control phase is formed by coating the non-plated region with a silane coupling agent derivative before forming the conductor portion. This plating control phase is thought to exist on the non-plated area in the shape of a lotus leaf,
Since the plating control function exerts its effect three-dimensionally, that is, in three dimensions, the lateral growth of the conductor growing in the plating area is restricted, and as a result, a conductor having a sharp rectangular cross section is formed. (See Table 2).

Therefore, the conductor portion can be formed as designed using electroless plating. Therefore, compared to the conventional printed circuit board in which the cross-sectional shape of the conductor section is unstable, the printed circuit board formed according to the 2.3 aspect of the present invention allows the pattern of the conductor section to be made finer.

<Example> Examples of the present invention will be described below.

First, a method for manufacturing a printed circuit board based on the second invention will be described.

(a) Step of coating the non-plated area of the substrate portion with a predetermined resin composition (see Figure 5.6) A resin composition having the formulation shown in Table 1 is prepared.

On the other hand, as the substrate part 35, an ABS plate (first
A 0.8 mm thick alumina ceramic (alumina purity: 96%) plate (represented as an inorganic material in Table 1) was prepared. Note that the vertical and horizontal lengths of the plate are not particularly limited.

A through hole 32 is bored into the substrate portion 35 as shown in FIG. Thereafter, as shown in FIG. 6, screen printing is performed using the resin composition shown in Table 1 to form a coating 39. On the surface of the substrate portion 35 , the surface covered with this film 39 becomes a non-plating region 36 .

- The distance between the coating 39 and other coatings 39 is at least 70 μm.
It can be narrowed to The thickness of the coating 39 should be at least 4 μm. This thickness is the thickness obtained by performing normal screen printing once. The fact that only a thin film can be printed in this way means that a clearer pattern can be obtained.

Thereafter, the substrate portion 35 provided with the coating 39 was heated at 120°C.
Dry for 15 to 20 minutes. Coating 39 in this state
(a) Step of applying a catalyst to the plating area 37 of the substrate portion 35 (see Fig. 7) In order to apply a catalyst, the plating area 37 is first roughened. There is a need.

A roughening liquid 1 having the following composition is prepared, and the organic substrate portion 35 is immersed therein for 10 to 20 minutes while maintaining the temperature at 45 to 60°C.

Roughening solution 1 Chromic acid trioxide 30 g Sulfuric acid (specific gravity;
1.84) 500 mfl phosphoric acid (specific gravity: 1.7) 100 mJl of water to make 1 fl - total 1°C On the other hand, when the substrate portion 35 is inorganic, the 46% hydrofluoric acid solution is kept at room temperature. and immersed in this for 10 to 20 minutes.

Thereafter, each substrate portion 35 (including the coating 39) was washed with water, and its condition was visually observed. In addition, the coating 39
The entire surface of the substrate portion 35 that does not have a rough surface is roughened (becomes a plating region 37).

The results are shown in Table 1.

From the results in Table 1, it can be seen that the resin compositions of Examples did not deteriorate and maintained their hydrophobicity. On the other hand, the resin composition of the comparative example disappeared.

According to the inventor's study, it has been confirmed that the resin composition of the example has corrosion resistance even with respect to roughening liquid 2.3 for organic substrate parts having the following composition. Chromic acid oxide 100 g Sulfuric acid (specific gravity;
1,84) 420 mfl phosphoric acid (specific gravity;
1.7) 1f for the entire 200mfl! , water ~ Total iJl Roughening liquid 3 Chromic acid trioxide 500 g Sulfuric acid (specific gravity;
1.84) 250 mfl Total amount of water to 1 fl: 1° C. Next, the substrate portion 25 is immersed in a catalyst liquid having the following composition.

Catalyst liquid P d C121, Og SnC12・2H2050g HCI (37% solution) 400mJ2 total amount i
Total water in ft 11 The conditions for immersion are 25-b. As a result, the catalyst substrate is adsorbed onto the plating region 37 of the substrate portion 35.

Almost no catalyst substrate is adsorbed on the surface of the coating 39. This is presumed to be due to electrochemical repulsion caused by the silane coupling agent in the resin composition forming the coating 39.

After washing the substrate portion 35 (including the coating 39) with water, the substrate portion 35 is immersed in an activation liquid having the following composition.

Activation liquid MCI (37% solution) 100mu total amount
Water as j2 ~ Total 1°C The immersion conditions are room temperature x 2 minutes. This activates the catalyst substrate in the plating area. Then wash with water.

(1) Step of removing the coating 39 of the resin composition (see FIG. 8) The substrate portion 35 (including the coating 39) is immersed in a stripping solution having the following composition.

Stripping liquid NaOH 200g Water with a total temperature of 1° C. ~ Total ifL The immersion conditions are room temperature x 2 to 3 minutes. As a result, the coating 39 is gelled and peeled off from the non-plated area 36 of the substrate portion 35 by washing with water.

Even if the coating 39 is peeled off from the non-plating area 36, the silane coupling agent derivative is transferred to the non-plating area 36, forming a plating control phase, as described above.

(1) The plating area 3 of the substrate portion 35 is formed by electroless plating.
7 (see FIG. 9) Electroless plating was performed under the following conditions using plating solutions 1, 2.3 having the following composition.

Mettsukin Yo 1 (Cu Metsuki) CuSO415H2010g EDTA-4Na 35 gHCH
O (37% aqueous solution) 10mJ12, 2°-Bi
py 10mJZK4 Fe
(CN)a ・3H2050mfl surfactant
Small amount Na OHp H12,4
Amount to be adjusted to 1°C total amount of water ~1. Q Paddy rice condition 70℃ x 50 hours Plating solution 2 (alkaline Ni plating) NiC12・6H2030g NaH2PO2' H2010g Na3 c6 Hs O7・2H2075gNH4Cl
50gN H40Hp H8
, 5 to 9.5 Amount of water whose total temperature is 1℃
~Total iIL Plating condition 90℃ x 10 hours Plating solution 3 (acidic Ni plating) Ni C12・6 H2030g NaH2PO2'H2010g Na,, c6Hs 07 ・2H2025gN H4C
1. Amount to adjust the pH to 5.0 to 6.0. Total amount of water is 1 fl. Plating condition: 90°C x 10 hours. As shown in FIG.
3 is formed.

The non-plated area 36 is coated with 8 conductors of silane coupling agent. Therefore, the non-plating area 36 is provided with a solder repelling phase (=plating control phase 34).

According to the inventor's study, the substrate portion 3 after the conductor portion 33 is formed.
When No. 5 was immersed in a molten solder bath for 10 seconds, no solder adhered to the non-plated area 36. This confirmed the effect of isolating the solder in the solder repellent phase in the non-plating area 36.

On the other hand, when an experiment similar to the above was conducted on a printed circuit board that was not coated with the silane coupling agent, solder adhered to various parts of the non-plated area 36.

The cross-sectional shape of the conductor portion 33 of the printed circuit board 31 of the example thus formed rose straight from the plating region 37. Table 2 shows the cross-sectional dimensions of the conductor portions formed using plating solution 2 on strip-shaped plating regions with widths of 250 μm and 500 μm. Each dimension of the conductor part was obtained by taking a microscopic photograph of the cross section of the conductor part and measuring it with a caliper. The resin composition used is one that covers the non-plated area, and is the same as Example 1.3 in Table 1.
5 was used.

The reason why the cross-sectional shape of the conductor portion rises straight from the plating region is considered to be due to the action of the plating control phase.

If electroless plating is performed while the non-plated area of the substrate is not coated with the silane coupling agent derivative, the width of the plating will increase within 5 to 10 minutes from the start of plating.
After 30 to 60 minutes, the entire surface of the board will become sticky.
It developed into.

Next, a method for manufacturing a printed circuit board based on the third invention will be described.

(A) Process of roughening the entire surface of the substrate portion 45 The material for forming the substrate portion 45, the roughening liquid, and the roughening conditions are the same as those in the second invention (see FIG. 10).

(a) Step of performing positive printing on the plating area 47 of the substrate portion 45 using a specific catalytic ink (see FIG. 11) The catalytic ink is prepared as follows.

Dissolve 500 g of starch and 2.5 g of methyl blue (sulfur compound component) in 500 g of deionized water. Then, the temperature is sequentially raised from 50° C. to 80° C. over approximately 2 hours, and concentrated until the total amount becomes 750 mu. A dark blue transparent viscous solution is then obtained. This is 30-4
After cooling to 0°C, 7.5% of N-(β-aminoethyl)-α-aminopropyltrimethoxysilane was added to this.
g, silver nitrate 5.0 g and ethylene glycol 40-65
Add g. The product thus obtained is referred to as catalytic ink I.

In the above, instead of 500 g of starch, 250 g of starch and 250 g of dextrin were used.
Let it be I.

Using this catalytic ink, a pattern is screen printed in a positive pattern on the already roughened substrate portion 45 (11th step).
(see figure). In the substrate portion 45, this catalytic ink 53
This is the partial hook area 47 on which is placed. And room temperature~
The catalytic ink 53 is left to dry in an atmosphere of 50°C.

(1) Step of developing and peeling off the catalytic ink 53 and coating the non-plating area 46 with a silane coupling agent derivative (see Figure 12) Prepare a developer with the following composition and apply it to the developer. The organic substrate portion 45 (including the catalytic ink 53) is immersed for 5 to 15 seconds.

Developer I MCI (35% solution) 100 mfl Silane coupling agent blended in catalytic ink 25 g HCHO (3
7% solution) 50mA sodium sulfite
20 g Deionized water to bring the total amount to 1℃
~Total 1° C. When the substrate portion is made of inorganic material, the amount of silane coupling agent is 32 g in the above formulation (this is referred to as developer 2).

By immersing in such a developer, the catalytic ink 53
At the same time, the non-plating area 47 is adsorbed with a derivative of the hesilan coupling agent, and the plating control phase 4 is transferred to the non-plating area 47.
4 will be formed.

Thereafter, when washed with water, only the gelled catalytic ink 53 is peeled off.

According to the studies of the present inventors, it was possible to use a different type of silane coupling agent to be blended in the developer than that blended in the catalytic ink.

(1) The plating area 4 of the substrate portion 45 is formed by electroless plating.
7 (see FIG. 13) The electroless plating operation in this step is carried out in the same manner as in the second invention.

The printed circuit board 41 thus obtained has the ability to repel solder in its non-plated region, similar to that obtained by the manufacturing method of the second invention.

Table 3 also shows the cross-sectional shape of the conductor portion 43 when the catalytic ink 53 is printed in a strip of constant width, in the same manner as in Table 2.

From the results in Table 3, it can be seen that even in the printed circuit board 41 obtained by the manufacturing method according to the third invention, the conductor portions rise straight from the plating region.

Table 2 Note) 1. In the comparative example, plating was performed without providing a plating control phase to the non-plated area.

2. The unit of each width in the table is μm.

3. Stickiness refers to the precipitation of plating over the entire surface of the substrate.

Table 3

[Brief explanation of drawings]

FIG. 1 is a sectional view of a printed circuit board 21 of the present invention, and FIG. 2 is a coating 2 formed by screen-printing a resin composition onto a substrate portion 25.
Figure 3 is a schematic diagram showing the inorganic filler in the resin composition when no silane coupling agent is blended, and Figure 4 is a cross-sectional view showing the state in which 9 is formed. FIG. 5 is a cross-sectional view showing the substrate portion 35 of the example, and FIG. 6 is a schematic diagram showing the inorganic filler in the resin composition. FIG. FIG. 7 is a sectional view showing a state in which a catalyst has been applied to the plating area 37 of the structure shown in FIG. 6, and FIG. 8 is a sectional view showing a state in which the coating 39 of the structure shown in FIG.
FIG. 9 is a sectional view showing the printed circuit board of the embodiment, FIG. 10 is a sectional view showing the board portion 45 of another embodiment, and FIG. ,
FIG. 12 is a cross-sectional view showing the developed state of the one in FIG. 11, FIG. 13 is a cross-sectional view showing a printed circuit board of another embodiment, and FIG. 14.15 is a printed circuit board 1.11 of a conventional example. FIG. 1.11, 21, 31.41... Printed circuit board, 3.13, 25, 35.45... Board section, 5.17, 23, 33.43... Conductor section. Patent application Hitotsu 1) Jo Figure 1O Figure 12 Figure 11 Figure 13 Figure 14 Figure 15

Claims (3)

[Claims] (1) Comprising a substrate portion and a conductor portion formed by electroless plating, and a non-plated area of the conductor portion protruding surface of the substrate portion is covered with a derivative of a silane coupling agent. A printed circuit board characterized by: (2) It comprises a substrate part and a conductor part formed by electroless plating, and a non-plated area on the protruding surface of the conductor part of the substrate part is covered with a derivative of a silane coupling agent. A method for manufacturing a printed circuit board, characterized by sequentially passing through the following steps (a) to (d): (a) plating resist agent for acid plating, rosin, silane coupling agent, and a step of coating the non-plated region of the substrate portion with a resin composition containing a sulfur compound as an active ingredient, which is added as necessary; (a) a step of applying a catalyst to the plating region of the substrate portion; (c) a step of removing the film of the resin composition; and (d) a step of forming the conductor portion in the plating region of the substrate portion by electroless plating. (3) It comprises a substrate part and a conductor part formed by electroless plating, and a non-plated area on the protruding surface of the conductor part of the substrate part is covered with a derivative of a silane coupling agent. A method for manufacturing a printed circuit board, the method comprising sequentially performing the following steps (a) to (d); )
A step of performing positive printing on the plating area of the substrate part with a water-soluble catalytic ink containing as active ingredients a silver salt, a starch-based binder, a silane coupling agent, and a sulfur compound added as necessary. (c) a step of developing and peeling off the catalytic ink; (d) a step of forming the conductor portion in the plating area of the substrate portion by electroless plating.