TWI396774B - A substrate manufacturing method and a copper surface treatment agent used therefor - Google Patents

Description

Method for manufacturing substrate and copper surface treatment agent used therefor

The present invention relates to a method for producing a substrate for a resin layer (particularly, a solder resist layer, a barrier layer for pattern formation) and a copper or copper alloy layer, and a copper surface treatment agent used therefor.

When a printed circuit board is conventionally produced and a resist layer made of a resin such as a resist layer or a solder resist layer is formed on the surface of copper or a copper alloy, roughening treatment is performed in order to improve adhesion. The roughening treatment is mechanical treatment such as buffing, scrubbing polishing, roughening of etching (sulfuric acid, hydrogen peroxide-based microetching agent, persulfate-based microetching agent), and the like.

When the surface of the copper is roughened, the adhesion between the solder resist layer and the resist layer and copper can be improved. However, since the surface area becomes large, if it is left unattended, it will oxidize and discolor, and as time passes, The adhesion to the resin is lowered, so it is necessary to prevent such oxidation.

In particular, the following problems occur before soldering.

(1) When a solder resist layer is provided in a state where discoloration occurs, it is easy to cause a malfunction in the visual inspection of an automatic optical inspection machine (AOI).

(2) The solder resist needs to be hardened by heating after coating, but if the solder resist is applied to each side and then hardened, the copper surface not coated with the solder resist is exposed to a high temperature and exposed to a high temperature. It is easily oxidized, resulting in a decrease in adhesion to the solder resist layer.

Therefore, the technique for adhering to the copper surface and the solder resist does not only require the function of improving the adhesion, but also requires oxidation resistance and discoloration resistance.

From the conventional technique for improving the adhesion between the copper surface and the resin, a technique of treating the copper surface with an azole compound is known. Patent Document 1 proposes a technique in which a copper surface is treated with various azoles such as benzotriazole to be bonded to a polyimide resin. Patent Document 2 proposes a method of treating a copper surface with an azole compound and a decane coupling agent for the purpose of oxidation resistance, solder heat resistance, and durability. Patent Document 3 proposes a method of treating a copper surface with a tetrazole compound for the purpose of having a rust preventing effect and improving copper-resin adhesion. Patent Document 4 proposes a method in which an aminotetrazole and an aminotriazole are used to enhance the adhesion of a high glass transition temperature (Tg) resin to copper.

[Patent Document 1] Japanese Patent Laid-Open Publication No. Hei. No. Hei. No. Hei. No. Hei. No. Hei. No. Hei.

However, such conventional techniques, for example, Patent Document 1 only pays attention to the adhesion to the polyimide resin, but has insufficient problems in terms of improving the adhesion to the solder resist layer. According to Patent Document 2, since only the azole compound is used, the effect of improving the adhesion is insufficient, so that there is a problem that a decane coupling agent is required. When a decane coupling agent is used, since the stability of the liquid is not good, it is difficult to put it into practical use. Further, the methods of Patent Documents 3 to 4 are insufficient in improving the adhesion to the solder resist resin and the discoloration resistance.

In order to solve the conventional problems, the present invention provides a substrate manufacturing method for improving the adhesion between copper and resin on the surface of a copper or copper alloy to form an organic film for improving adhesion, and a copper surface treatment agent used therefor. .

The method for producing a substrate of the present invention comprises the steps of contacting a treatment liquid containing an aminotetrazole compound, an aminotriazole compound, and an alkylamine derivative on at least one side of a surface of a copper or copper alloy, and contacting the surface The step of forming a barrier layer on the surface of the copper or copper alloy of the treatment liquid.

The copper surface treatment agent of the present invention is used for lifting the surface of the copper or copper alloy and the barrier layer, characterized in that it comprises 0.05% by weight (wt%) or more of the aminotetrazole compound and 0.1% by weight of the aminotriazole compound. The above alkylamine derivative is 0.1% by weight to 10% by weight, and the remainder is water.

In the present invention, an organic film is formed on the surface of copper or a copper alloy by contacting an aqueous solution in which an aminotetrazole compound, an aminotriazole compound, and an alkylamine derivative are mixed with a copper or copper alloy surface. The copper-resin adhesion can be improved by allowing the organic film to exist on the surface of the copper or copper alloy.

The organic film is formed on the copper surface by coordination bonding of copper on the copper surface with an organic substance. When the organic film is formed, the alkylamine derivative functions to promote the formation of a coordination bond between copper and an organic substance on the copper surface, so that a uniform organic film can be formed on the copper surface at a high density.

The copper surface treatment agent of the present invention contains the treatment liquid of the present invention as a constituent element. The treatment liquid of the present invention is an aqueous solution containing an aminotetrazole compound, an aminotriazole compound, and an alkylamine derivative. The components contained in the treatment liquid and their concentrations are as follows.

(1) Aminotetrazole compound: at least 0.05% by weight or more, preferably 0.1% by weight to 5% by weight, more preferably 0.1% by weight to 3% by weight.

(2) The aminotriazole compound: at least 0.1% by weight or more, preferably 0.3% by weight to 5% by weight, more preferably 0.3% by weight to 3% by weight.

(3) Alkylamine derivative: 0.1% by weight to 10% by weight, preferably 0.3% by weight to 7% by weight, more preferably 0.3% by weight to 5% by weight.

(4) The remaining part is water.

If the concentration of the aminotetrazole compound is less than 0.05% by weight, sufficient effects cannot be obtained in terms of improving the adhesion to the barrier layer. Further, when the concentration of the aminotriazole compound is less than 0.1% by weight, the effect of preventing discoloration due to oxidation of the copper surface cannot be sufficiently obtained.

When the concentration of the alkylamine derivative is less than 0.1% by weight, the film formation promoting effect cannot be obtained, and since the film density is insufficient and the film cannot be uniformly formed on the surface of the copper or copper alloy, the copper or copper alloy surface cannot be sufficiently prevented. The effect of discoloration caused by oxidation. Moreover, the adhesion of the copper or copper alloy surface to the barrier layer cannot be improved. When more than 10% by weight is added, the alkylamine derivative may adhere to the surface of the copper or copper alloy to hinder the formation of the film, so that the anti-tarnishing effect of the surface of the desired copper or copper alloy cannot be sufficiently obtained, and copper or The adhesion of the copper alloy surface to the barrier layer.

The adhesion and anti-tarnishing effect can be simultaneously improved by simultaneously presenting the aminotetrazole compound and the aminotriazole compound. In particular, the concentration ratio of the aminotetrazole compound:aminotriazole compound is in the range of 1:1 to 1:3 by weight ratio, and it is effective to simultaneously improve the adhesion and the anti-tarnishing effect.

After the barrier layer is formed on at least one surface of the copper or copper alloy surface, a step of thermally hardening at 100 ° C to 200 ° C may be performed. In this case, since the surface of the copper or copper alloy in which the barrier layer is not formed in particular is placed in an environment which is easily oxidized by heating, the surface of the copper or copper alloy can be treated as a pretreatment by the above treatment liquid to prevent oxidation.

When the barrier layer is a solder resist layer, in particular, the surface of the copper or copper alloy can be prevented from being oxidized by the treatment liquid, thereby preventing discoloration from the solder resist layer and an appearance inspection machine such as AOI inspection. Malfunction.

Before the treatment with the above treatment liquid, the surface of the copper or copper alloy is roughened by etching, since the roughened surface is particularly susceptible to oxidation, the oxidation resistance of the treatment liquid is high, and the barrier layer is followed by The multiplication effect is improved.

The roughened surface at this time is preferable because the surface having the L value of 50 to 75 can be further improved in adhesion.

The L value at this time refers to the value of the color shading of the L*a*b* color system measured by the color difference color difference meter. The closer the L value is to 100, the lighter the color (higher whiteness), and the closer the L value is to zero, the thicker (high chroma). This value is related to the roughness of the roughened surface. The lower the value, the higher the roughness, and the higher the value, the lower the roughness.

When the pH of the surface of the copper or copper alloy is treated with the above treatment liquid, when it is used in the range of pH 8 to pH 12, the film adhesion is good, which is preferable. When the pH is not reached 8, the density of the film becomes low and it is difficult to improve the adhesion. On the other hand, when pH is 12 or more, since it becomes a strong alkali, the processing environment will deteriorate, and handling of a liquid will become difficult.

Hereinafter, a method of producing each component of the treatment liquid and the substrate will be described.

(1) treatment liquid

(a) a compound of an aminotetrazole compound selected from the group consisting of an aminotetrazole compound, for example, 5-amino-1H-tetrazole (formal name of aminotetrazole), 1-methyl-5-amino group IV Azole, 1-ethyl-5-aminotetrazole, α-benzyl-5-aminotetrazole, β-benzyl-5-aminotetrazole, 1-(β-aminoethyl)tetra Oxazole and the like. Other substituents may be provided as long as they have the effects of the present invention. Further, it may be a hydrate. Among the above aminotetrazole compounds, those having an aminotetrazole and a carbon number of 1 to 5 and having a short-chain alkyl group are preferred.

(b) Aminotriazole, an aminotriazole derivative, an aminotriazole or an aminotriazole derivative, preferably, for example, 3-amino-1,2,4-triazole or 4-amine Base-1,2,4-triazole, 3-amino-5-methyltriazole, 3-amino-5-ethyltriazole, 3,5-diamino-1,2,4-tri Oxazole, 3-amino-1,2,4-triazole-5-carboxylic acid, 5-amino-1,2,3,4-thiatriazole and the like. Other substituents may be provided as long as they have the effects of the present invention.

(c) an alkylamine derivative (wherein the carbon number of the alkyl group is in the range of 4 to 18) alkylamine derivative, which may be lauric acid diethanolamide or polyethylene oxide oleate Polyethylene oxide stearylamine, N,N-bis(2-hydroxyethyl)-N-cyclohexylamine, and the like. Among them, in particular, in the case of using N,N-bis(2-hydroxyethyl)-N-cyclohexylamine, it is preferred that the pH adjuster having a pH adjusted to the above preferred range can also act simultaneously.

(d) Other components In order to assist the aqueous solution of the aminotetrazole or the like, or to uniformly treat the copper surface, a water-soluble solvent such as an alcohol or a metal salt such as sodium sulfate, ammonium sulfate, ammonium chloride or sodium chloride may be appropriately added. , ammonia, etc.

(e) pH adjustment The pH adjuster may be, for example, sodium hydroxide, ammonia, monoethanolamine, cyclohexylamine ethylene oxide or the like.

(2) Method of manufacturing substrate

(a) Copper or copper alloy surface The copper surface to be treated by the method of the present invention is a conductor surface such as a printed circuit board, and a copper surface adjacent to the solder resist layer or a barrier layer for pattern formation to form a pattern Then the copper surface and so on.

The surface of the copper or copper alloy may be microetched, electroplated, electrolessly plated, oxidized (black oxide, brown oxide), oxidized to improve adhesion to the barrier layer. The refining method, the brushing method, the jet washing method, and the like are used for roughening.

The microetching method may, for example, be an organic acid-copper ion type etchant, a sulfuric acid-hydrogen peroxide type etchant, a persulfate type etchant, a copper chloride type etchant, or a ferric chloride type etchant. Etching treatment is performed.

Among them, the etching treatment of the organic acid-copper ion type etchant is particularly preferable because it has a high effect of improving the adhesion between the surface of the copper or copper alloy and the solder resist layer and the barrier layer for pattern formation.

The surface of the roughened copper or copper alloy is preferably roughened to a surface having an L value of 50 to 75. If it is in this range, the adhesion to the barrier layer can be particularly improved.

(b) Surface treatment The above treatment liquid is brought into contact with the copper surface for surface treatment. The method of applying the treatment liquid to the surface of the copper is not particularly limited. For example, it may be applied by a spray (shower) method, a dipping method, or the like, followed by washing with water and drying.

The treatment liquid is preferably used in the range of pH 8 to pH 12, more preferably pH 9 to 11. If it is used in this range, the film adhesion can be improved.

(c) Formation of barrier layer An organic film was formed on the surface of the copper surface subjected to the above surface treatment. A barrier layer is formed through the film. The barrier layer is, for example, a solder resist such as a liquid solder resist, a dry film solder resist, a barrier layer for pattern formation of a liquid or dry film type, or the like.

In particular, the liquid solder resist is heat-hardened by heating to 100 to 200 ° C after coating. In the case of forming a substrate of a solder resist layer on both sides, a solder resist may be first applied to one side of the copper surface to be thermally hardened, and then a solder resist layer may be formed on the other side, and a copper or copper alloy surface not coated with a solder resist may be applied. Exposure to heat in an exposed state causes thermal oxidation of the copper surface to cause discoloration.

When thermal oxidation occurs under the solder resist layer, the adhesion to the solder resist layer is lowered. Further, if the solder resist layer is directly provided in a state of discoloration, the color of the appearance on the solder resist layer is darkened. When the AOI inspection machine performs an appearance inspection on the self-resisting solder layer, if the color is dark, malfunction may occur.

The surface of the copper treated by the treatment liquid of the present invention is suitable for the treatment before the solder resist because it can effectively prevent oxidation and discoloration when the solder resist is thermally hardened.

(Example)

The invention will be more specifically described below by way of examples.

(Examples 1 to 8 and Comparative Examples 1 to 6) The copper on the surface of the copper-clad laminate (FR-4) for a printed circuit board was etched by "MECetch BOND CZ-8100" (trade name, manufactured by MEC Co., Ltd.). Forming a roughened surface. Further, the L value was measured on the surface of the copper treated in the above manner by a color difference meter ("CR-300", trade name of Konica Minolta Co., Ltd.), and the results are shown in Table 1. Further, in Example 2 and Comparative Example 6, this etching treatment was not performed.

Next, an aqueous solution having the composition shown in the following Table 1 was adjusted, and the etched laminated plate was immersed in the aqueous solution at 20 ° C for 15 seconds, and then washed with water and dried. Further, Comparative Examples 5 and 6 did not perform this treatment.

Then, in order to perform the step of exposing to heat again in a state where the solder resist layer forming step was exposed to the copper surface, the obtained laminated board was placed in a hot air drying oven at 150 ° C for 40 minutes. A solder resist ("PSR-4000", manufactured by Sun Ink Manufacturing Co., Ltd.) was applied to one side of the laminate, and hardened (pre-hardened), exposed, developed, and cured (post-hardened) to form a solder resist layer.

(1) Color change confirmation test The laminated board self-resisting solder layer (SR) was observed, and the inspection result of the discoloration degree is shown in Table 1. A indicates no discoloration at all, B indicates a small degree of discoloration, C indicates a large degree of discoloration, and D indicates severe discoloration.

(2) Adhesion test (peeling test) The solder resist layer of the obtained laminate was cut into a width of 1 mm by a cutter, and immersed in 5 wt% hydrochloric acid at room temperature for 10 minutes, followed by washing with water and drying. The adhesive tape was sufficiently adhered to the portion of the cross-cut solder resist layer, and then peeled off, and the adhesion was checked depending on the degree of peeling of the solder resist layer. The results are shown in Table 1. A indicates no peeling, B indicates some peeling, and the degree of peeling is small, C indicates a large degree of peeling, and D indicates complete peeling.

As is clear from Table 1, the discoloration confirmation test and the adhesion test of Examples 1 to 8 were all above B.

On the other hand, in Comparative Example 1, since the aminotriazole compound was not added, the degree of discoloration was large (C), which was not preferable.

Further, in Comparative Example 2, since the aminotetrazolium compound was not added, the adhesion to the solder resist layer was low (in C), and peeling occurred in the peeling test, which was not preferable.

Further, in Comparative Examples 3 to 4, since the alkylamine derivative was not added, good results were not obtained in the color change confirmation test.

Further, in Comparative Examples 5 to 6, since the treatment liquid was not used in particular, no satisfactory results were obtained in the color change confirmation test and the adhesion test.

Claims (9)

A method for producing a substrate, comprising the steps of: contacting a treatment liquid containing an aminotetrazole compound, an aminotriazole compound, and an alkylamine derivative with at least one side of a surface of a copper or copper alloy; and contacting the a step of forming a barrier layer on the surface of the copper or copper alloy of the treatment liquid, wherein the treatment liquid comprises 0.05 wt% to 5 wt% of the aminotetrazole compound, 0.1 wt% to 5 wt% of the aminotriazole compound, and 0.3 wt% of the alkylamine derivative. %~7wt% and the rest is water. The method for producing a substrate according to claim 1, wherein the barrier layer is formed on at least one surface of the copper or copper alloy, and the resin of the barrier layer is heated to a range of from 100 ° C to 200 ° C for thermal curing. The method of manufacturing a substrate according to claim 1, wherein the barrier layer is a solder resist layer. The method for producing a substrate according to the first aspect of the invention, wherein the surface of the copper or copper alloy is roughened by etching before the treatment with the treatment liquid. The method for producing a substrate according to the fourth aspect of the invention, wherein the surface of the copper or copper alloy is roughened to an L value of 50 to 75. The method for producing a substrate according to the first aspect of the invention, wherein the treatment liquid is used in a range of pH 8 to pH 12. The method for producing a substrate according to the first aspect of the invention, wherein the ratio of the concentration of the aminotetrazole compound: the aminotriazole compound to the weight ratio In the range of 1:1~1:3. A copper surface treatment agent for lifting a copper or copper alloy surface and a barrier layer, comprising: an aminotetrazole compound of 0.05 wt% to 5 wt%, and an aminotriazole compound of 0.1 wt% to 5 wt% The alkylamine derivative is 0.3 wt% to 7 wt%, and the remainder is water. The copper surface treatment agent of claim 8, wherein the copper surface treatment agent is in the range of pH 8 to pH 12.