JP2013125797A - Wiring board, method of manufacturing the same, and aqueous solution for silver ion diffusion suppression layer formation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wiring board in which silver ion migration between metal wiring made of silver or silver alloy is suppressed and insulation reliability between the metal wiring is more excellent, and also to provide a method of manufacturing the same.SOLUTION: A method of manufacturing a wiring board includes: a contact step in which an aqueous solution for silver ion diffusion suppression layer formation containing a compound represented by formula (1) and/or a compound represented by formula (2) and water is brought into contact with an insulation substrate with metal wiring having the insulation substrate and metal wiring made of silver or silver alloy disposed on the insulation substrate; and a cleaning step in which the insulation substrate with the metal wiring is cleaned using a solvent and a silver diffusion suppression layer covering the metal wiring in this order.

Description

  The present invention relates to a wiring board, a manufacturing method thereof, and an aqueous solution for forming a silver ion diffusion suppression layer used in the manufacturing method.

  Conventionally, wiring boards in which metal wiring is arranged on the surface of an insulating substrate have been widely used for electronic members and semiconductor elements. As the metal constituting the metal wiring, silver and copper having high conductivity are often used. However, these metals have a problem that ion migration is likely to occur, and silver is particularly prominent.

  On the other hand, in recent years, miniaturization of metal wiring has been advanced due to miniaturization of semiconductor integrated circuits and chip parts. Therefore, the interval between the metal wirings in the wiring board is narrowed, and a circuit short circuit due to ion migration is more likely to occur, and countermeasures are required.

  As a method for preventing migration of silver ions, a method of adsorbing a metal ion trapping agent that forms a hardly soluble metal salt on a metal wiring portion has been proposed (Patent Document 1). More specifically, in this document, a method of bringing a solution containing a compound A or B represented by the following formula into contact with a metal wiring portion is demonstrated.

JP 2009-188360 A

On the other hand, in recent years, miniaturization of metal wiring and narrowing between wirings have progressed more rapidly, and accordingly, further improvement in insulation reliability between metal wirings made of silver or a silver alloy in a wiring board is required. ing.
The present inventors provided a silver ion diffusion suppression layer on a metal wiring made of silver or a silver alloy using a solution containing the compound A or B described in Patent Document 1, and examined the insulation reliability thereof. . As a result, the connection of silver dendrite was confirmed between the metal wirings, and the migration suppression effect did not satisfy the level required recently, and further improvement was necessary.

In view of the above circumstances, an object of the present invention is to provide a wiring board in which migration of silver ions between metal wirings made of silver or a silver alloy is suppressed and insulation reliability between metal wirings is more excellent, and a method for manufacturing the same. And
Another object of the present invention is to provide an aqueous solution for forming a silver ion diffusion suppressing layer for forming a silver ion diffusion suppressing layer used when manufacturing the wiring board.

As a result of intensive studies, the present inventors have found that the insulation reliability between metal wirings is further improved by forming a silver ion diffusion suppression layer using an aqueous solution containing a compound having a predetermined structure.
That is, the present inventors have found that the above problem can be solved by the following configuration.

(1) An aqueous solution for forming a silver ion diffusion suppressing layer containing a compound represented by formula (1) and / or a compound represented by formula (2) and water, which will be described later, and an insulating substrate and an insulating substrate A contact step of contacting an insulating substrate with metal wiring having metal wiring made of silver or a silver alloy,
The manufacturing method of a wiring board which has the washing | cleaning process of wash | cleaning the insulating substrate with metal wiring using a solvent, and obtaining the silver ion diffusion suppression layer which covers metal wiring in this order.

(2) The method for manufacturing a wiring board according to (1), further comprising a heating step of performing a heat treatment on the insulating substrate with metal wiring including the silver ion diffusion suppression layer after the cleaning step.

(3) A wiring board comprising an insulating substrate, a metal wiring made of silver or a silver alloy disposed on the insulating substrate, and a silver ion diffusion suppression layer covering the metal wiring,
The wiring board in which a silver ion diffusion suppression layer contains the compound represented by Formula (1) mentioned later and / or the compound represented by Formula (2).

(4) Contains a compound represented by formula (1) and / or a compound represented by formula (2) and water, which will be described later, and suppresses migration of silver ions on the surface of a metal wiring made of silver or a silver alloy. An aqueous solution for forming a silver ion diffusion suppressing layer for forming a silver ion diffusion suppressing layer.

According to the present invention, it is an object to provide a wiring board in which migration of silver ions between metal wirings made of silver or a silver alloy is suppressed and insulation reliability between metal wirings is more excellent, and a manufacturing method thereof.
Moreover, according to this invention, the aqueous solution for silver ion diffusion suppression layer formation for forming the silver ion diffusion suppression layer used when manufacturing this wiring board can also be provided.

It is typical sectional drawing from the insulating board with a metal wiring to the wiring board with an insulating layer which shows each process in a manufacturing method of a wiring board with an insulating layer in order. It is typical sectional drawing showing another aspect of the insulated substrate with metal wiring.

Below, the suitable aspect of the aqueous solution for silver ion diffusion suppression layer formation used at the time of manufacture of the wiring board of this invention, its manufacturing method, and this wiring board is demonstrated.
First, the feature point compared with the prior art of this invention is explained in full detail.
When the solution containing the above-described compound A or B described in Patent Document 1 is used, the adhesion amount of the silver ion diffusion suppression layer formed on the metal wiring made of silver or a silver alloy is not necessarily sufficient, and the compound is Even if the adhered layer is formed, the silver ion migration suppressing effect is inferior.
On the other hand, in the present invention, by using an aqueous solution for forming a silver ion diffusion suppression layer containing water as a compound having a predetermined structure and a solvent, a sufficient amount of adhesion can be obtained on a metal wiring made of silver or a silver alloy. A silver ion diffusion suppression layer can be formed, and the silver ion migration suppression effect is also excellent. The reason why a silver ion diffusion suppressing layer having a sufficient adhesion amount can be formed in the present invention is that when a compound having a specific structure is brought into contact with a metal wiring made of silver or a silver alloy in water with a high dielectric constant, It is presumed that the film containing compound molecules is laminated in multiple layers.
On the other hand, when the ion diffusion suppression layer is formed on the copper-containing wiring by bringing the aqueous solution for forming the silver ion diffusion suppression layer of the present embodiment into contact with the copper-containing wiring made of copper or copper alloy, the copper ion migration suppressing effect Is not enough. That is, it has been found that the aqueous solution for forming a silver ion diffusion suppressing layer is effective for metal wiring made of silver or a silver alloy.

  First, the aqueous solution for forming a silver ion diffusion suppressing layer used in the present invention will be described in detail, and then a method for manufacturing a wiring board will be described in detail.

<Aqueous solution for forming a silver ion diffusion suppression layer>
The aqueous solution for forming a silver ion diffusion suppression layer (aqueous solution for forming a migration suppression layer) of the present invention is a silver ion diffusion that suppresses migration of silver ions on a metal wiring made of silver or a silver alloy (hereinafter also simply referred to as metal wiring). It is a processing liquid for forming a suppression layer (migration suppression layer).
Below, the component contained in aqueous solution is explained in full detail.

[Compound represented by Formula (1) and / or Compound represented by Formula (2)]
The aqueous solution contains a compound represented by the formula (1) and / or a compound represented by the formula (2) (hereinafter also referred to as a compound X as a generic term for both compounds). Compound X interacts with the metal wiring via a sulfur atom or a nitrogen atom to form a silver ion diffusion suppression layer. These compounds have a monocyclic structure and the number of nitrogen atoms constituting the heterocyclic structure is 3 or less, and it is assumed that such a structure contributes to the effect of the present invention.

In formula (1), Z ₁ represents an atomic group that forms a triazine ring, a pyrimidine ring, or a 1,2,4-triazole ring together with the N═C—N moiety. Examples of atoms constituting this atomic group include a carbon atom, a nitrogen atom, and a hydrogen atom. Among them, in terms of silver ion migration inhibiting effect of the silver ion diffusion barrier layer is more excellent, Z ₁ is preferably formed of the triazine ring together with the N = C-N unit.

In formula (1), R ₁ is a substituent substituted on Z ₁ and represents a hydroxyl group, an amino group, or a mercapto group. In addition, when there are a plurality of R _{1 s} , they may be the same or different. Especially, a mercapto group is preferable at the point which the silver ion migration suppression effect of a silver ion diffusion suppression layer is more excellent.

  In formula (1), n represents the integer of 0-2.

In formula (2), Z ₂ represents an alkylene group having 2 to 3 carbon atoms. Especially, it is preferable that it is a C2-C2 alkylene group at the point which the silver ion migration inhibitory effect of a silver ion diffusion suppression layer is more excellent.

In formula (2), R ₂ represents an alkyl group or ═O (oxygen atom). When R ₂ is ═O, a carbonyl group is formed together with the carbon atom in Z ₂ . In addition, when there are a plurality of R _{2 s} , they may be the same or different.
As an alkyl group, C1-C4 is preferable and 1-2 are more preferable at the point which the silver ion migration suppression effect of a silver ion diffusion suppression layer is more excellent.

  In formula (2), m represents an integer of 0 to 3.

(Preferred embodiment (1))
When Z ₁ and N = C—N part together form a triazine ring, it is a compound represented by the following formula (3) in that the silver ion migration suppressing effect of the silver ion diffusion suppressing layer is more excellent. Is preferred. In formula (3), R ₁ is as defined above, and is more preferably a mercapto group in that the silver ion migration suppressing effect of the silver ion diffusion suppressing layer is more excellent.

(Preferred embodiment (2))
Other suitable embodiment, in that the silver ion migration inhibiting effect of the silver ion diffusion barrier layer is more excellent, include embodiments Z ₁ in the formula (1) constitutes a pyrimidine ring together with the N = C-N unit.

  Although the total content of the compound represented by Formula (1) and the compound represented by Formula (2) in the aqueous solution for forming a silver ion diffusion suppression layer is not particularly limited, the amount of adhesion of the silver ion diffusion suppression layer can be controlled. In view of easy handling, 0.001 to 10.0% by mass is preferable and 0.005 to 5.0% by mass is more preferable with respect to the total amount of the aqueous solution. When there is too much total content of these compounds, control of the adhesion amount of a silver ion diffusion suppression layer will become difficult. When the total content of these compounds is too small, it takes time until a silver ion diffusion suppressing layer having a desired adhesion amount is formed, resulting in poor productivity.

[Solvent: Water]
The aqueous solution for forming a silver ion diffusion suppressing layer contains water as a solvent. By using water having a high dielectric constant, the compound X described above can be laminated in a multilayer state on the surface of the metal wiring.
The water content in the aqueous solution for forming a silver ion diffusion suppression layer is not particularly limited, but is preferably 90.0 to 99.999% by mass, more preferably 95.0 to 99.995% by mass with respect to the total amount of the aqueous solution. preferable.

The aqueous solution for forming a silver ion diffusion suppression layer may contain an organic solvent as a solvent, but the solvent is substantially water in that the silver ion diffusion suppression layer has a more excellent silver ion migration suppression effect. Preferably there is. “Substantially” means that the content of water in all the solvents is 95% by mass or more, and preferably 99% by mass.
Examples of the organic solvent used include alcohol solvents (for example, methanol, ethanol, isopropanol), ketone solvents (for example, acetone, methyl ethyl ketone, cyclohexanone), amide solvents (for example, formamide, dimethylacetamide, N -Methylpyrrolidone), nitrile solvents (eg acetonitrile, propionitrile), ester solvents (eg methyl acetate, ethyl acetate), carbonate solvents (eg dimethyl carbonate, diethyl carbonate), ether solvents, halogens A solvent etc. are mentioned. Two or more of these solvents may be mixed and used.

It is preferable that silver ion is not substantially contained in the aqueous solution for silver ion diffusion suppression layer formation at the point which the silver ion migration suppression effect of a silver ion diffusion suppression layer is more excellent. When an excessive amount of silver ions is contained, a large amount of silver ions are contained in the silver ion diffusion suppressing layer, and the effect of suppressing migration of silver ions may be reduced.
In addition, that a silver ion is not contained substantially means that content of the silver ion in aqueous solution is 1 micromol / l or less, and it is more preferable that it is 0.1 micromol / l or less. Most preferably, it is 0 mol / l.

The pH of the aqueous solution for forming a silver ion diffusion suppression layer is not particularly limited, but 2 to 14 is preferable and 4 to 14 is more preferable in that the stability of the aqueous solution is more excellent.
The pH can be adjusted using a known acid (for example, hydrochloric acid or sulfuric acid) or a base (for example, sodium hydroxide, DBU (diazabicycloundecene), DBN (diazabicyclononene)). The pH can be measured using a known measurement means (for example, a pH meter (in the case of an aqueous solvent)).

In addition, it is preferable that the pH of the aqueous solution for forming a silver ion diffusion suppression layer is alkaline in that the formation rate of the silver ion diffusion suppression layer is more excellent, and more specifically, it is preferably 10 or more, and more than 12 More preferably. The upper limit is not particularly limited, but is preferably 14 or less from the viewpoint of the stability of the aqueous solution.
In addition, when the compound represented by Formula (3) is contained in the aqueous solution for forming a silver ion diffusion suppression layer, the formation rate of the silver ion diffusion suppression layer is more excellent.

<Wiring board and manufacturing method thereof>
Next, the manufacturing method of the wiring board of the present invention will be described in detail, and the aspect of the wiring board manufactured thereafter will be described in detail.
The method for manufacturing a wiring board according to the present invention includes a contact process and a cleaning process in this order.
Below, with reference to drawings, the material used at each process and the procedure of a process are explained in full detail.

[Contact process]
In the contact step, an aqueous solution for forming a silver ion diffusion suppressing layer containing compound X and water is contacted with an insulating substrate and an insulating substrate with metal wiring having a metal wiring made of silver or a silver alloy disposed on the insulating substrate. It is a process to make. In this step, a silver ion diffusion suppression layer containing compound X is formed on the insulating substrate surface and the metal wiring surface by bringing the aqueous solution for forming a silver ion diffusion suppression layer into contact with the surface on the metal wiring side of the insulating substrate with metal wiring. The In other words, this step is a step of covering the surface on the metal wiring side (insulating substrate surface and metal wiring surface) of the insulating substrate with metal wiring with the compound X.
By this step, the silver ion diffusion suppression layer 16 containing the compound X is formed on the surface of the insulating substrate 12 and the surface of the metal wiring 14 of the insulating substrate 10 with metal wiring shown in FIG. B)). In particular, it is presumed that the compound X on the metal wiring 14 is bonded to the surface of the metal wiring 14 mainly through sulfur atoms or nitrogen atoms. In FIG. 1B, the silver ion diffusion suppression layer 16 is formed on the entire surface of the insulating substrate 12, but the present invention is not limited to this form, and the silver ion diffusion suppression layer 16 is formed on a part of the surface of the insulating substrate 12. The case where it is done is also included.
First, materials (such as an insulating substrate with metal wiring) used in this step will be described, and then the procedure of this step will be described.

[Insulated substrate with metal wiring]
The insulating substrate with metal wiring (inner layer substrate) used in this step has a metal wiring made of silver or a silver alloy disposed on the insulating substrate and the insulating substrate. FIG. 1A shows an embodiment of an insulating substrate with metal wiring. The insulating substrate 10 with metal wiring includes an insulating substrate 12 and a metal wiring 14 disposed on the insulating substrate 12. In FIG. 1A, the metal wiring 14 is provided only on one side of the substrate, but may be provided on both sides. That is, the insulating substrate 10 with metal wiring may be a single-sided substrate or a double-sided substrate.
In addition, when the metal wiring 14 exists on both surfaces of the insulating substrate 10, this process, the washing | cleaning process and insulating layer formation process mentioned later are implemented with respect to both surfaces of a board | substrate.

The insulating substrate is not particularly limited as long as it is insulative and can support metal wiring. For example, an organic substrate, a ceramic substrate, a glass substrate, or the like can be used.
The insulating substrate may have a structure in which at least two substrates selected from the group consisting of an organic substrate, a ceramic substrate, and a glass substrate are stacked.

Resin is mentioned as a material of an organic substrate, For example, it is preferable to use a thermosetting resin, a thermoplastic resin, or resin which mixed them. Examples of the thermosetting resin include phenol resin, urea resin, melamine resin, alkyd resin, acrylic resin, unsaturated polyester resin, diallyl phthalate resin, epoxy resin, silicone resin, furan resin, ketone resin, xylene resin, benzocyclo Examples include butene resin. Examples of the thermoplastic resin include polyimide resin, polyphenylene oxide resin, polyphenylene sulfide resin, aramid resin, and liquid crystal polymer.
In addition, as a material of the organic substrate, a glass woven fabric, a glass nonwoven fabric, an aramid woven fabric, an aramid nonwoven fabric, an aromatic polyamide woven fabric, a material impregnated with the above resin, or the like can be used.

The metal wiring is made of silver or a silver alloy. When the metal wiring is composed of a silver alloy, examples of the metal contained other than silver include tin, palladium, gold, nickel, and chromium.
The method for forming the metal wiring on the insulating substrate is not particularly limited, and a known method can be adopted. Typically, a subtractive method using an etching process, a semi-additive method using electrolytic plating, a method of producing a metal wiring using a silver paste, and the like can be given.

The width of the metal wiring is not particularly limited, but is preferably 0.1 to 1000 μm, more preferably 0.1 to 50 μm, and still more preferably 0.1 to 20 μm from the viewpoint of high integration of the wiring board.
The interval between the metal wirings is not particularly limited, but is preferably 0.1 to 1000 μm, more preferably 0.1 to 50 μm, and still more preferably 0.1 to 20 μm from the viewpoint of high integration of the wiring board.
Further, the pattern shape of the metal wiring is not particularly limited, and may be an arbitrary pattern. For example, a linear shape, a curved shape, a rectangular shape, a circular shape, and the like can be given.

  The thickness of the metal wiring is not particularly limited, but is preferably 0.1 to 1000 μm, more preferably 0.1 to 25 μm, and still more preferably 0.1 to 20 μm from the viewpoint of high integration of the wiring board.

  Note that the insulating substrate with metal wiring has a laminated structure having at least an insulating substrate and metal wiring, and it is sufficient that the metal wiring is disposed in the outermost layer, and other layers are disposed between the insulating substrate and the metal wiring. It may be.

  For example, as another form of the insulating substrate with metal wiring, another metal wiring 14a and an interlayer insulating layer 24 may be disposed between the insulating substrate 12 and the metal wiring 14 (see FIG. 2). Note that a plurality of other metal wirings 14a and interlayer insulating layers 24 may be alternately arranged.

  In addition, a through hole may be formed in the insulating substrate. When metal wiring is provided on both surfaces of the insulating substrate, the metal wiring on both surfaces may be made conductive by filling the through hole with a metal (for example, silver or silver alloy).

(Process procedure)
In this step, the method is not particularly limited as long as the insulating substrate with metal wiring can be brought into contact with the aqueous solution for forming a silver ion diffusion suppressing layer, and the aqueous solution for forming silver ion diffusion suppressing layer is applied onto the insulating substrate with metal wiring. A known method such as a method (specifically shower spraying, spray coating, spin coating, etc.) or a method of immersing an insulating substrate with metal wiring in an aqueous solution for forming a silver ion diffusion suppression layer (dip dipping). Can be adopted. Dip dipping is preferred because the amount of adhesion of the silver ion diffusion suppression layer can be more easily controlled.

As the liquid temperature of the aqueous solution for forming a silver ion diffusion suppressing layer when coming into contact with the insulating substrate with metal wiring, a range of 5 to 60 ° C. is preferable in that the amount of adhesion of the silver ion diffusion suppressing layer can be more easily controlled. The range of 15-50 degreeC is more preferable, and the range of 20-40 degreeC is further more preferable.
The contact time is preferably in the range of 10 seconds to 12 hours, and more preferably in the range of 15 seconds to 6 hours, in terms of productivity and control of the amount of adhesion of the silver ion diffusion suppression layer.

[Washing process]
This step is a step of cleaning the insulating substrate with metal wiring using a solvent to obtain a silver ion diffusion suppression layer covering the metal wiring. By performing this step, the compound X other than the compound X bonded to the metal wiring (particularly the silver ion diffusion suppressing layer on the surface of the insulating substrate) can be washed away.
More specifically, as shown in FIG. 1C, by performing this step, the silver ion diffusion suppression layer 16 containing the compound X on the insulating substrate 12 is substantially removed, and the metal wiring 14 A silver ion diffusion suppressing layer 16 is formed on the surface.

  If a large amount of the compound X remains on the insulating substrate, adhesion failure occurs between the insulating layer provided on the insulating substrate with the metal wiring and the insulating substrate, causing a short circuit between the metal wirings. By carrying out this step, the compound X on the surface of the insulating substrate can be removed, and the insulation reliability between the metal wirings is ensured. During the implementation of this step, some of the excess compound X on the metal wiring may be removed by washing.

  Below, the material (solvent) used at this process is demonstrated, and the procedure of this process is demonstrated after that.

(Solvent (washing solvent))
The kind of the solvent (cleaning solvent) used in the cleaning process for cleaning the insulating substrate with metal wiring is not particularly limited as long as the solvent can remove the silver ion diffusion suppression layer on the insulating substrate. Especially, it is preferable that it is a solvent in which the compound X melt | dissolves. By using the solvent, the excess compound X on the insulating substrate with metal wiring can be removed more efficiently.
Examples of the solvent include water, alcohol solvents (eg, methanol, ethanol, propanol), ketone solvents (eg, acetone, methyl ethyl ketone, cyclohexanone), amide solvents (eg, formamide, dimethylacetamide, N-methylpyrrolidone). N-ethylpyrrolidone), nitrile solvents (eg acetonitrile, propionitrile), ester solvents (eg methyl acetate, ethyl acetate, γ-butyrolactone), carbonate solvents (eg dimethyl carbonate, diethyl carbonate), Ether solvents (eg cellosolve, tetrahydrofuran), halogen solvents, glycol ether solvents (eg dipropylene glycol methyl ether), glycol ester solvents (eg propylene) Glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate) and the like. Two or more of these solvents may be mixed and used.
Of these, water, alcohol solvents, ketone solvents (preferably cyclohexanone), glycol ester solvents (preferably propylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate), amides, are more excellent in the removability of compound X. System solvents (preferably N-ethylpyrrolidone) are preferable, water, alcohol solvents, or a mixture of water and alcohol solvents is more preferable, and water and alcohol systems are more preferable in terms of safety and flame retardancy. A mixed solution with a solvent is more preferable.

  Although the boiling point (25 degreeC, 1 atmosphere) of the solvent used is not restrict | limited in particular, 75-200 degreeC is preferable from a safety viewpoint, and 80-180 degreeC is more preferable.

(Process procedure)
The cleaning method performed in this step is not particularly limited, and a known method can be adopted. Examples thereof include a method of applying a solvent on an insulating substrate with metal wiring (on the surface on the metal wiring side), a method of immersing the insulating substrate with metal wiring in a solvent, and a shower method.
Moreover, as a liquid temperature of a solvent, the range of 5-60 degreeC is preferable at the point which is excellent in both the handleability and the removability of the compound X, and the range of 15-35 degreeC is more preferable.
Further, the contact time between the insulating substrate with metal wiring and the solvent is preferably in the range of 10 seconds to 10 minutes, and in the range of 15 seconds to 5 minutes, in terms of excellent balance between productivity and removability of the compound X. Is more preferable.

(Silver ion diffusion suppression layer)
By passing through the said process, as shown in FIG.1 (C), the silver ion diffusion suppression layer 16 which covers the metal wiring 14 surface can be formed.

  The content of compound X in the silver ion diffusion suppression layer is preferably 0.1 to 100% by mass with respect to the total amount of silver ion diffusion suppression layer, from the viewpoint that migration of silver ions can be further suppressed. More preferably, it is 100 mass%, and it is further more preferable that it is 50-100 mass%. In particular, it is preferable that the silver ion diffusion suppressing layer is substantially composed of the compound X. In addition, substantial means that content of the compound X in a silver ion diffusion suppression layer is 95 mass% or more with respect to the silver ion diffusion suppression layer whole quantity.

  It is preferable that silver ions or metallic silver is not substantially contained in the silver ion diffusion suppressing layer. If the silver ion diffusion suppressing layer contains excessive silver ions or metallic silver, the silver ion migration suppressing effect may be lowered.

The adhesion amount (total adhesion amount) of the compound represented by the formula (1) and the compound represented by the formula (2) on the surface of the metal wiring is the total surface area of the metal wiring from the point that migration of silver ions can be further suppressed. On the other hand, it is preferably 1.0 × 10 ⁻⁹ g / mm ² or more. Among these, 1.0 × 10 ⁻⁸ g / mm ² or more is more preferable, and 3.0 × 10 ⁻⁸ g / mm ² or more is particularly preferable in that the silver ion migration suppressing effect is more excellent. The upper limit is not particularly limited, but is preferably 1.0 × 10 ⁻⁶ g / mm ² or less, more preferably 5.0 × 10 ^{−7 in} terms of better adhesion to the insulating layer formed thereon. G / mm ² or less is more preferable.
The amount of adhesion can be measured by a known method (for example, an absorbance method). Specifically, the silver ion diffusion suppression layer present on the insulating substrate is first washed and removed with a solvent (for example, water) (extraction method using water). Then, the silver ion diffusion suppression layer on the metal wiring is extracted with an organic acid (for example, hydrochloric acid), the absorbance is measured, and the adhesion amount is calculated from the liquid amount and the application area.

  As described above, it is preferable that the silver ion diffusion suppression layer containing the compound X is substantially removed on the insulating substrate, but a part of the silver ion diffusion suppression layer is within the range not impairing the effect of the present invention. May remain.

[Optional process: Heating process]
The heating step is a step provided after the cleaning step and before the insulating layer forming step, which will be described later, and a step of performing a heat treatment on the insulating substrate with metal wiring (wiring substrate) having the silver ion diffusion suppression layer. It is. If moisture remains on the insulating substrate with metal wiring, migration of silver ions is promoted, and as a result, the insulation between the metal wiring may be impaired. Therefore, it is preferable to remove the water by providing this step. . In addition, this process is an arbitrary process, and when the solvent used at the said process is a solvent excellent in volatility etc., this process does not need to implement.

As heating conditions, it is carried out at 70 to 120 ° C. (preferably 80 ° C. to 110 ° C.) for 15 seconds to 10 minutes (preferably 30 seconds to 5 minutes) from the viewpoint of suppressing oxidation of silver in the metal wiring. It is preferable to do. If the heating temperature is too low or the heating time is too short, moisture removal may not be sufficient, and if the heating temperature is too high or the heating time is too long, a silver oxide film may be formed. is there.
The apparatus used for heating is not particularly limited, and a known heating apparatus such as a constant temperature layer or a heater can be used.

<Wiring board>
Through the above steps, as shown in FIG. 1C, a wiring including an insulating substrate 12, a metal wiring 14 disposed on the insulating substrate 12, and a silver ion diffusion suppression layer 16 covering the metal wiring 14. A substrate 18 is obtained. As shown in FIG. 1C, the silver ion diffusion suppression layer 16 is preferably formed substantially only on the surface of the metal wiring 14.

  In FIG. 1C, the metal wiring 14 has a single-layer wiring structure as an example, but the present invention is not limited to this. For example, a multilayer wiring board having a multilayer wiring structure can be manufactured by using a multilayer wiring board in which a plurality of metal wirings and insulating substrates are alternately laminated as an insulating substrate with metal wiring.

  The wiring board obtained by the production method of the present invention can be used for various applications and structures. Examples thereof include a plasma display panel panel substrate, a solar cell electrode substrate, a membrane wiring board, and a touch panel electrode substrate.

Other layers may be formed on the surface of the wiring board on the metal wiring side as necessary.
For example, as shown in FIG. 1D, an insulating layer 20 may be provided on the surface of the wiring board 18. By providing the insulating layer 20, the insulation reliability between the metal wirings 14 is further improved. The insulating layer and the method for forming the insulating layer will be described later.

  As another example, a metal oxide layer may be provided so as to cover the silver ion diffusion suppressing layer in the wiring board, and then an insulating layer may be further provided on the wiring board. In the case of this aspect, the silver ion diffusion suppression layer and the metal oxide layer are interposed between the insulating layer and the metal wiring.

[Insulating layer forming step]
Hereinafter, the insulating layer forming step for forming the insulating layer and the obtained wiring substrate with an insulating layer will be described in detail.
This step is a step of forming an insulating layer on the surface of the wiring board obtained in the above step on the metal wiring side. More specifically, as shown in FIG. 1D, the insulating layer 20 is provided on the insulating substrate 10 with metal wiring so as to be in contact with the metal wiring 14 covered with the silver ion diffusion suppressing layer 16, and is insulated. A wiring board 22 with a layer is obtained. By providing the insulating layer 20, the insulation reliability between the metal wirings 14 is further ensured. Moreover, since the insulating substrate 12 and the insulating layer 20 can be in direct contact, the adhesiveness of the insulating layer 20 is excellent.
Below, the material (insulating layer) used at this process is demonstrated, and the procedure of this process is demonstrated after that.

(Insulating layer)
As a material for the insulating layer, a known insulating material can be used. For example, epoxy resin, aramid resin, crystalline polyolefin resin, amorphous polyolefin resin, fluorine-containing resin (polytetrafluoroethylene, perfluorinated polyimide, perfluorinated amorphous resin, etc.), polyimide resin, polyether sulfone resin, polyphenylene Examples thereof include sulfide resin, polyether ether ketone resin, and acrylate resin.
Moreover, you may use what is called a transparent adhesive sheet (OCA) for optics as an insulating layer. As the OCA, a commercially available product may be used, and examples thereof include 8171CL series and 8146 series manufactured by 3M Corporation.
Moreover, you may use what is called a soldering resist layer as an insulating layer. A commercially available solder resist may be used, and examples thereof include PFR800, PSR4000 (trade name) manufactured by Taiyo Ink Manufacturing Co., Ltd., and SR7200G manufactured by Hitachi Chemical Co., Ltd.

Especially, it is preferable that an insulating layer contains resin which has an epoxy group or a (meth) acrylate group. The resin easily binds to the above-described silver ion diffusion suppressing layer, and as a result, the adhesion of the insulating layer is improved, and as a result, the silver ion migration suppressing effect is further improved.
The resin is preferably the main component of the insulating layer. The main component means that the total of the resins is 50% by mass or more with respect to the total amount of the insulating layer, and is preferably 60% by mass or more. In addition, as an upper limit, it is 100 mass%.

A known epoxy resin can be used as the resin having an epoxy group. For example, a glycidyl ether type epoxy resin, a glycidyl ester type epoxy resin, a glycidyl amine type epoxy resin, or the like can be used.
As the resin having a (meth) acrylate group, a known resin can be used. For example, an acrylate resin or a methacrylate resin can be used.

(Process procedure)
The method for forming the insulating layer on the wiring board is not particularly limited, and a known method can be employed. For example, a method of laminating a film of an insulating layer directly on a wiring substrate, a method of applying a composition for forming an insulating layer containing a component constituting the insulating layer on the wiring substrate, a composition of the wiring substrate for forming the insulating layer The method of immersing in a thing is mentioned.
In addition, the said composition for insulating layer formation may contain the solvent as needed. When using the composition for insulating layer formation containing a solvent, after arrange | positioning this composition on a wiring board, you may heat-process in order to remove a solvent as needed.
Moreover, after providing an insulating layer on a wiring board, you may give energy provision (for example, exposure or heat processing) with respect to an insulating layer as needed.

  The layer thickness of the insulating layer to be formed is not particularly limited, and is preferably 5 to 50 μm and more preferably 15 to 40 μm from the viewpoint of insulation reliability between metal wirings.

[Wiring board with insulating layer]
Through the above steps, as shown in FIG. 1 (D), an insulating substrate 12, a metal wiring 14 disposed on the insulating substrate 12, and an insulating layer 20 disposed on the metal wiring 14 are provided. A wiring substrate 22 with an insulating layer in which a silver ion diffusion suppressing layer 16 is interposed between the metal wiring 14 and the insulating layer 20 is obtained.

Further, the insulating layer in the obtained wiring board with an insulating layer may be partially removed by drilling or laser processing, and a semiconductor chip may be mounted and used as a circuit board.
For example, when using a solder resist as the insulating layer, place a mask with a predetermined pattern on the insulating layer, apply energy to cure, remove the insulating layer in the non-energy-applied region, and expose the metal wiring Let Next, after the exposed surface of the metal wiring is cleaned by a known method (for example, cleaning using sulfuric acid, soft etching agent, alkali, and surfactant), the semiconductor chip is mounted on the surface of the metal wiring.

Further, metal wiring may be further provided on the insulating layer of the obtained wiring board. The method for forming the metal wiring is not particularly limited, and a known method (plating treatment, sputtering treatment, etc.) can be used.
In this invention, the board | substrate which provided the metal wiring further on the insulating layer arrange | positioned in the outermost layer in the obtained wiring board with an insulating layer was used as a new insulating board with a metal wiring (inner layer board | substrate), and newly Insulating layers and metal wirings can be stacked in layers.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to these.

<Example 1>
Using a copper-clad laminate (manufactured by Hitachi Chemical Co., Ltd., MCL-E-679F, substrate: glass epoxy substrate), an insulating substrate with metal wiring having silver wiring of L / S = 200 μm / 200 μm was manufactured by screen printing. . The insulating substrate with metal wiring was produced by the following method.
After the copper foil of the copper clad laminate was peeled off by etching, a conductive silver paste (Fujikura Kasei FA-451) was patterned on the substrate through a metal mask using a screen printing apparatus.
Thereafter, heat treatment was performed at 150 ° C. for 30 minutes to cure the silver wiring, and a comb-shaped silver wiring board (insulating substrate with metal wiring) of L / S = 200 μm / 200 μm was obtained.

  Next, the obtained insulating substrate with metal wiring was prepared by using an aqueous solution containing compound 1 (thiocyanuric acid) (solvent: water, content of compound 1: 0.004% by mass relative to the total amount of the aqueous solution, liquid temperature: 25 ° C., It was immersed in pH: 3.7) for 1 hour. After the insulating substrate with metal wiring was taken out of the aqueous solution, the insulating substrate with metal wiring was washed with ethanol (liquid temperature: 25 ° C.) (contact time: 2 minutes). Further, the insulating substrate with metal wiring was then heat-treated at 100 ° C. for 2 minutes.

By performing reflectance measurement, it was confirmed that a silver ion diffusion suppression layer containing Compound 1 was formed on the silver wiring. From the absorbance measurement, the adhesion amount of Compound 1 was 9.2 × 10 ⁻⁸ g / mm ² .
In addition, by measuring the absorbance of the extract obtained by washing the insulating substrate with metal wiring with water, the silver ion diffusion suppression layer cannot be confirmed on the insulating substrate surface (surface between the silver wiring) of the insulating substrate with metal wiring. It was confirmed that it was removed by washing with ethanol.

  An insulating layer (PFR-800 manufactured by Taiyo Ink Co., Ltd.) is laminated on the surface of the insulating substrate with metal wiring subjected to heat treatment, and then exposed and baked to form a wiring substrate (insulating layer layer). Thickness: 35 μm). The following lifetime measurement was performed on the obtained wiring board.

(Measurement of substrate life by HAST test)
Using the obtained wiring board, lifetime measurement was performed under the conditions of humidity 85%, temperature 130 degrees, pressure 1.2 atm, and voltage 100 V (use apparatus: EHS-221MD, manufactured by espec).
As an evaluation method, first, without forming a silver ion diffusion suppressing layer on the insulating substrate with metal wiring used in Example 1, the insulating layer (PFR-800 manufactured by Taiyo Ink Co., Ltd.) was directly applied according to the procedure of Example 1. Using the comparative wiring board obtained by laminating, the lifetime was measured under the above conditions, and the time X until the resistance value between the silver wirings was 1 × 10 ⁹ Ω was measured.
Next, lifetime measurement was performed under the above conditions using the wiring substrate having the silver ion diffusion suppression layer obtained in Example 1, and the time Y until the resistance value between the silver wirings was 1 × 10 ⁹ Ω was measured.
Using the obtained time X and time Y, the lifetime improvement rate {(Y−X) / X−1} × 100 was calculated and evaluated according to the following criteria. Practically, it needs to be AC.
A: When the improvement rate is 200% or more B: When the improvement rate is 100% or more and less than 200% C: When the improvement rate is 50% or more and less than 100% D: When the improvement rate is less than 50% The results of the wiring board obtained in Example 1 are shown in Table 1.

<Example 2>
Instead of the aqueous solution containing compound 1 used in Example 1, an aqueous solution containing compound 2 (ethylenethiourea) (solvent: water, content of compound 2: 1.0% by mass relative to the total amount of aqueous solution, liquid temperature: 25 The wiring board was manufactured in accordance with the same procedure as in Example 1 except that the insulating substrate with metal wiring was immersed in the aqueous solution for 4 hours using a temperature and pH of 5.8), and the HAST test was conducted. did. Table 1 shows the results.

<Example 3>
Instead of the aqueous solution containing compound 1 used in Example 1, an aqueous solution containing compound 3 (2-mercaptopyrimidine) (solvent: water, content of compound 3: 0.01% by mass relative to the total amount of the aqueous solution, liquid temperature The wiring board was manufactured according to the same procedure as in Example 1 except that the insulating substrate with metal wiring was immersed in the aqueous solution for 2 hours using 25 ° C. and pH: 4.4). Carried out. Table 1 shows the results.

<Example 4>
Instead of the aqueous solution containing compound 1 used in Example 1, an aqueous solution containing compound 4 (3-mercapto-1,2,4-triazole) (solvent: water, content of compound 4: 3 with respect to the total amount of the aqueous solution) 0.0 mass%, liquid temperature: 25 ° C., pH: 4.0), and following the same procedure as in Example 1, except that the insulating substrate with metal wiring was immersed in the aqueous solution for 4 hours. Manufacturing was carried out and the above HAST test was carried out. Table 1 shows the results.

<Example 5>
Instead of the aqueous solution containing compound 1 used in Example 1, an aqueous solution containing compound 1 and compound 2 (solvent: water, content of compound 1: 0.004% by mass relative to the total amount of aqueous solution, content of compound 2 : 1.0 mass% with respect to the total amount of the aqueous solution, liquid temperature: 25 ° C., pH: 4.0), and the same as in Example 1 except that the insulating substrate with metal wiring was immersed in the aqueous solution for 1 hour The wiring board was manufactured according to the procedure of and the HAST test was performed. Table 1 shows the results.

<Example 6>
Instead of the aqueous solution containing compound 1 used in Example 1, an aqueous solution containing compound 5 (6-amino-1,3,5-triazine-2,4-dithiol) (solvent: water, content of compound 1: Example 3 except that 0.003% by mass with respect to the total amount of the aqueous solution, liquid temperature: 25 ° C., pH: 4.0) was used, and the insulating substrate with metal wiring was immersed in the aqueous solution for 1 hour. The wiring board was manufactured according to the procedure, and the HAST test was performed. Table 1 shows the results.

<Example 7>
Instead of the aqueous solution containing Compound 1 used in Example 1, an aqueous solution containing Compound 1 (solvent: water, content of Compound 1: 0.004% by mass relative to the total amount of the aqueous solution, liquid temperature: 25 ° C., pH: 13.5) was used, and a wiring board was manufactured according to the same procedure as in Example 1 except that the insulating board with metal wiring was immersed in the aqueous solution for 5 minutes, and the HAST test was performed. Table 1 shows the results.
In order to adjust pH, potassium hydroxide was added to the aqueous solution.

<Comparative Example 1>
Instead of the aqueous solution containing compound 1 used in Example 1, an aqueous solution containing compound 6 (3-mercapto-1,2-propanediol) (solvent: water, content of compound 6: 0. 5% by mass, liquid temperature: 25 ° C., pH: 5.0), and production of a wiring board according to the same procedure as in Example 1 except that the insulating board with metal wiring was immersed in the aqueous solution for 12 hours. And the above HAST test was carried out. Table 1 shows the results.

<Comparative example 2>
Instead of the aqueous solution containing compound 1 used in Example 1, an aqueous solution containing compound 7 (triazine) (solvent: water, content of compound 7: 1.0 mass% with respect to the total amount of aqueous solution, liquid temperature: 25 ° C. , PH: 8.8), and the wiring board was manufactured according to the same procedure as in Example 1 except that the insulating board with metal wiring was immersed in the aqueous solution for 12 hours, and the HAST test was performed. . Table 1 shows the results.

<Comparative Example 3>
Instead of the aqueous solution containing compound 1 used in Example 1, an aqueous solution containing compound 8 (mercaptobenzimidazole) (solvent: water, content of compound 8: 0.01% by mass relative to the total amount of the aqueous solution, liquid temperature: The wiring board was manufactured according to the same procedure as in Example 1 except that the insulating board with metal wiring was immersed in the aqueous solution for 12 hours using 25 ° C., pH: 6.7), and the HAST test was conducted. Carried out. Table 1 shows the results.

<Comparative example 4>
Instead of the aqueous solution containing Compound 1 used in Example 1, an aqueous solution containing Compound 9 (1-phenyl-5-mercaptotetrazole) (solvent: water, content of Compound 9: 0.02 mass relative to the total amount of the aqueous solution) %, Liquid temperature: 25 ° C., pH: 2.0), and the wiring board was manufactured according to the same procedure as in Example 1 except that the insulating board with metal wiring was immersed in the solution for 12 hours. The HAST test was conducted. Table 1 shows the results.

<Comparative Example 5>
Instead of the aqueous solution containing Compound 1 used in Example 1, an ethanol solution containing Compound 1 (solvent: ethanol, content of Compound 1: 0.004% by mass relative to the total amount of the solution, liquid temperature: 25 ° C.) A wiring board was produced according to the same procedure as in Example 1 except that it was used, and the HAST test was conducted. Table 1 shows the results.

<Comparative Example 6>
Instead of the aqueous solution containing compound 4 used in Example 4, an ethanol solution containing compound 4 (solvent: ethanol, content of compound 4: 3.8% by mass relative to the total amount of solution, liquid temperature: 25 ° C.) A wiring board was produced according to the same procedure as in Example 1 except that it was used, and the HAST test was conducted. Table 1 shows the results.

<Comparative Example 7>
In place of the insulating substrate with metal wiring having silver wiring used in Example 1, the HAST test using the insulating substrate with metal wiring having copper wiring was performed. Details of the procedure are given below.
First, an insulating substrate with metal wiring having a copper wiring of L / S = 23 μm / 27 μm was manufactured according to the following procedure.
A copper-clad laminate (MCL-E-679F, manufactured by Hitachi Chemical Co., Ltd., substrate: glass epoxy substrate) was acid-washed, washed with water, dried, and then dried film resist (DFR, trade name: RY3315, manufactured by Hitachi Chemical Co., Ltd.) ) Was laminated on a copper clad laminate with a vacuum laminator at a pressure of 0.2 MPa under the condition of 70 ° C. After lamination, the copper pattern forming portion was subjected to mask exposure with an exposure machine having a central wavelength of 365 nm under the condition of 70 mJ / cm ² . Then, it developed with 1% sodium hydrogen carbonate aqueous solution, washed with water, and obtained the plating resist pattern.
Through plating pretreatment and water washing, electrolytic plating was performed on the copper exposed between the resist patterns. At this time, an acidic solution of copper (II) sulfate was used as an electrolytic solution, a crude copper plate having a purity of about 99% was used as an anode, and a copper clad laminate was used as a cathode. By electrolysis at 50 to 60 ° C. and 0.2 to 0.5 V, copper was deposited on the cathode copper. Then, it washed with water and dried.
In order to remove the resist pattern, the substrate was immersed in a 4% NaOH aqueous solution at 45 ° C. for 60 seconds. Thereafter, the obtained substrate was washed with water and immersed in 1% sulfuric acid for 30 seconds. Thereafter, it was washed again with water.
The conductive copper between the copper patterns was quickly etched with an etching solution mainly composed of hydrogen peroxide and sulfuric acid, washed with water and dried. The surface roughness of the obtained copper wiring was Rz = 0.3 μm.
Next, after removing stains and the like on the surface of the copper wiring with a pretreatment agent (CA-5330, manufactured by Mec), the surface of the copper wiring was subjected to roughening with a roughening agent (CZ-8100, manufactured by Mec). . The surface roughness of the obtained copper wiring was Rz = 1.0 μm.

Next, the obtained insulating substrate with copper wiring was added to an aqueous solution containing compound 1 (solvent: water, content of compound 1: 0.009% by mass relative to the total amount of aqueous solution, liquid temperature: 25 ° C., pH: 4. 0) for 30 seconds. After the insulating substrate with metal wiring was taken out of the aqueous solution, the insulating substrate with metal wiring was washed with ethanol (liquid temperature: 25 ° C.) (contact time: 2 minutes). Further, after that, the insulating substrate with metal wiring was subjected to heat treatment at 100 ° C. for 2 minutes.
Thereafter, a wiring board was manufactured according to the same procedure as in Example 1, and the HAST test described above was performed. The results are shown in Table 1.
In addition, as a comparative wiring board at the time of performing the HAST test, an insulating layer (PFR-800 manufactured by Taiyo Ink Co., Ltd.) is directly laminated on the insulating board with metal wiring having the copper wiring prepared above according to the procedure of Example 1. The time X was measured using the wiring board with an insulating layer obtained in this manner.

<Comparative Example 8>
Instead of the aqueous solution containing Compound 1 used in Comparative Example 7, an aqueous solution containing Compound 3 (solvent: water, content of Compound 3: 0.01% by mass relative to the total amount of the aqueous solution, liquid temperature: 25 ° C., pH: 4.0), a wiring board was manufactured according to the same procedure as in Comparative Example 7 except that the insulating board with copper wiring was immersed for 3 minutes, and a HAST test was performed in the same manner as in Comparative Example 7. The results are shown in Table 1.

  “Adhesion amount” in Examples 1 to 7 and Comparative Examples 1 to 8 in Table 1 means the adhesion amount per unit area of the compound contained in the treatment liquid on the wiring.

As shown in Table 1 above, the wiring board obtained by the manufacturing method of the present invention showed excellent life measurement results, and was confirmed to be excellent in insulation reliability between silver wirings. In particular, in Examples 1, 6 and 7 (using the compound represented by formula (3)) and Example 3, the effect was excellent.
On the other hand, in Comparative Examples 1 to 4 in which the predetermined compound X was not used, Comparative Examples 5 to 6 in which the solvent of the aqueous solution was other than water, and Comparative Examples 7 to 8 in which the object to be treated was copper wiring, Insulation reliability between wires was inferior.
In particular, Comparative Examples 3 and 4 are compounds specifically disclosed in Japanese Patent Application Laid-Open No. 2009-188360, and it has been confirmed that the desired effects cannot be obtained even when the compounds are used.

<Example 8: Evaluation of adhesion rate>
Two substrates with a silver layer obtained by producing a silver layer (thickness: 350 nm) by sputtering on a substrate (silicon wafer) were prepared, and an aqueous solution (pH 3.7) containing Compound 1 used in Example 1 (Hereinafter referred to as aqueous solution X) and an aqueous solution (pH: 13.5) containing compound 1 used in Example 7 (hereinafter referred to as aqueous solution Y) were each immersed for 10 minutes. After removing the substrate with the silver layer from the aqueous solution, the substrate with the silver layer was washed with ethanol (liquid temperature: 25 ° C.) (contact time: 2 minutes). Then, when the adhesion amount of the compound 1 deposited on each board | substrate with a copper layer was measured, when using the aqueous solution X, it was 1.4 * 10 < ^-9 > g / mm < ² >, whereas aqueous solution Y was used. When used, it was 1.9 × 10 ⁻⁸ g / mm ² .
From these results, it was confirmed that when the pH of the aqueous solution for forming a silver ion diffusion suppression layer is high, the adhesion rate is increased.

10: Insulating substrate with metal wiring 12: Insulating substrate 14, 14a: Metal wiring 16: Silver ion diffusion suppression layer 18: Wiring substrate 20: Insulating layer 22: Wiring substrate with insulating layer 24: Interlayer insulating layer

Claims (4)

An aqueous solution for forming a silver ion diffusion suppressing layer containing a compound represented by the formula (1) and / or a compound represented by the formula (2) and water, and an insulating substrate and silver disposed on the insulating substrate or A contact step of contacting an insulating substrate with a metal wiring having a metal wiring made of a silver alloy;
A method for manufacturing a wiring board, comprising: a cleaning step of cleaning the insulating substrate with metal wiring using a solvent to obtain a silver ion diffusion suppression layer covering the metal wiring in this order.

(In formula (1), Z ₁ represents an atomic group that forms a triazine ring, a pyrimidine ring, or a 1,2,4-triazole ring together with the N═C—N moiety. R ₁ represents a hydroxyl group, an amino group, Alternatively, it represents a mercapto group, n represents an integer of 0 to 2. When there are a plurality of R _{1 s} , they may be the same or different.
In formula (2), Z ₂ represents an alkylene group having 2 to 3 carbon atoms. R ₂ represents an alkyl group or ═O. m represents an integer of 0 to 3. In addition, when there are a plurality of R _{2 s} , they may be the same or different. )   The manufacturing method of the wiring board of Claim 1 further equipped with the heating process which heat-processes the insulated substrate with a metal wiring provided with the said silver ion diffusion suppression layer after the said washing | cleaning process. A wiring board comprising an insulating substrate, a metal wiring made of silver or a silver alloy disposed on the insulating substrate, and a silver ion diffusion suppression layer covering the metal wiring,
The wiring board in which the silver ion diffusion suppressing layer contains a compound represented by Formula (1) and / or a compound represented by Formula (2).

(In formula (1), Z ₁ represents an atomic group that forms a triazine ring, a pyrimidine ring, or a 1,2,4-triazole ring together with the N═C—N moiety. R ₁ represents a hydroxyl group or an amino group. Or represents a mercapto group, n represents an integer of 0 to 2. In addition, when there are a plurality of R _{1 s} , they may be the same or different.
In formula (2), Z ₂ represents an alkylene group having 2 to 3 carbon atoms. R ₂ represents an alkyl group or ═O. m represents an integer of 0 to 3. In addition, when there are a plurality of R _{2 s} , they may be the same or different. ) Silver ion diffusion suppression containing a compound represented by the formula (1) and / or a compound represented by the formula (2) and water and suppressing migration of silver ions on the surface of a metal wiring made of silver or a silver alloy The aqueous solution for silver ion diffusion suppression layer formation used in order to form a layer.

(In Formula (1), Z ₁ represents an atomic group that forms a triazine ring, a pyrimidine ring, or a 1,2,4-triazole ring together with the N═C—N moiety. R ₁ represents a hydroxyl group, an amino group, or Represents a mercapto group, n represents an integer of 0 to 2. In addition, when there are a plurality of R _{1 s} , they may be the same or different.
In formula (2), Z ₂ represents an alkylene group having 2 to 3 carbon atoms. R ₂ represents an alkyl group or ═O. m represents an integer of 0 to 3. In addition, when there are a plurality of R _{2 s} , they may be the same or different. )