Plating film for metal sintering bonding, its manufacturing method, and semiconductor mounting substrate

Abstract

This provides a plating film that has excellent heat resistance and resistance to cold and thermal shock, and is suitable for metal sintering bonding. (A) A plating film for metal sintering bonding having an electroless nickel-phosphorus plating film, The phosphorus content of the (A) electroless nickel-phosphorus plating film is 4 mass% or less, assuming that the electroless nickel-phosphorus plating film is 100 mass%. A plating film for metal sinter bonding, characterized in that:

Description

[Technical field]

[0001] The present invention relates to a plating film, a manufacturing method thereof, and a semiconductor mounting substrate. [Background technology]

[0002] In recent years, next-generation power modules equipped with wide band gap power semiconductor elements such as SiC, GaN, etc., have been used. Such next-generation power modules are capable of operating in high-temperature environments of, for example, 200°C or higher, and therefore require peripheral members to have high heat resistance.

[0003] Conventionally, solder has been used to bond semiconductor elements to substrates, but solder has problems in that it is poor in heat resistance and resistance to thermal shock.

[0004] Metal sintering bonding using silver or copper particles has been attracting attention as an alternative joining technology to soldering. However, metal sintering bonding requires surface treatment of the members to be joined, such as substrates, and the coating formed by the surface treatment is also required to have heat resistance.

[0005] The present inventors have found that electroless nickel alloy plating is suitable as a surface treatment suitable for silver sinter bonding or copper sinter bonding. Examples of electroless nickel alloy plating include electroless nickel-phosphorus plating and electroless nickel-boron plating, and electroless nickel-phosphorus plating in particular has been put to practical use in a wide range of fields.

[0006] However, commonly used electroless nickel-phosphorus plating films with a phosphorus content of 6 to 12 mass % (see Patent Document 1) have poor heat resistance and thermal shock resistance, and cracks occur when used in high-temperature environments, which means that they cannot be used as peripheral components for next-generation power modules. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] JP 2023-090169 A Summary of the Invention [Problem to be solved by the invention]

[0008] An object of the present invention is to provide a plating film that is excellent in heat resistance and resistance to cold and hot shocks and is suitable for metal sinter bonding. [Means for solving the problem]

[0009] As a result of extensive research aimed at solving the above problems, the inventors have discovered that the above object can be achieved by (A) a plating film for metal sintering bonding having an electroless nickel-phosphorus plating film, in which the phosphorus content of the electroless nickel-phosphorus plating film is within a specific range, and have thus completed the present invention.

[0010] That is, the present invention relates to the following plating film, a method for producing the same, and a semiconductor mounting substrate. 1. (A) A plating film for metal sintering bonding having an electroless nickel-phosphorus plating film, The phosphorus content of the (A) electroless nickel-phosphorus plating film is 4 mass% or less, assuming that the electroless nickel-phosphorus plating film is 100 mass%. A plating film for metal sinter bonding, characterized in that: 2. The plating film for metal sintering bonding according to item 1, wherein the sulfur content of the (A) electroless nickel-phosphorus plating film is less than 0.0005% by mass, based on 100% by mass of the electroless nickel-phosphorus plating film. 3. The plating film for metal sintering bonding according to item 1 or 2, wherein the sulfur content of the (A) electroless nickel-phosphorus plating film is 0.0001 mass% or less, based on 100 mass% of the electroless nickel-phosphorus plating film. 4. The plating film for metal sintering bonding according to any one of items 1 to 3, wherein the thickness of the electroless nickel-phosphorus plating film (A) is 0.1 to 20 μm or less. 5. The plating film for metal sintering bonding according to any one of items 1 to 4, further comprising (B) an electroless silver plating film or an electroless gold plating film on the (A) electroless nickel-phosphorus plating film. 6. The plating film for metal sintering bonding according to item 5, wherein the (B) electroless silver plating film or electroless gold plating film has a thickness of 0.02 to 2 μm. 7. The plating film for metal sintering bonding according to item 5 or 6, further comprising a barrier metal layer (C) between the electroless nickel-phosphorus plating film (A) and the electroless silver plating film or the electroless gold plating film (B). 8. The plating film for metal sintering bonding according to item 7, wherein the barrier metal layer (C) is an electroless palladium plating film or an electroless palladium-phosphorus plating film. 9. The plating film for metal sintering bonding according to any one of items 1 to 9, which is for a metal sintered material containing silver and / or copper. 10. A method for producing a plating film for metal sintering bonding, which forms a plating film for metal sintering bonding on a substrate, comprising: (1) a step 1 of contacting a surface of a substrate with an electroless nickel-phosphorus plating solution to form an electroless nickel-phosphorus plating film (A) on the substrate; The phosphorus content of the (A) electroless nickel-phosphorus plating film is 4 mass% or less, assuming that the electroless nickel-phosphorus plating film is 100 mass%. The present invention relates to a method for producing a plating film for metal sinter bonding. 11. The manufacturing method according to item 10, further comprising step 2 of (2) contacting a surface of the electroless nickel-phosphorus plating film with an electroless silver plating solution or an electroless gold plating solution to form an electroless silver plating film or an electroless gold plating film (B) on the electroless nickel-phosphorus plating film (A). 12. On a substrate, (A) a plating film for metal sintering bonding having an electroless nickel-phosphorus plating film is laminated; A semiconductor element is provided on the plating film for metal sintering bonding via a metal sintered material layer, The phosphorus content of the (A) electroless nickel-phosphorus plating film is 4 mass% or less, assuming that the electroless nickel-phosphorus plating film is 100 mass%. A semiconductor mounting board comprising: Effect of the Invention

[0011] The plating film for metal sintering bonding of the present invention is excellent in heat resistance and resistance to cold and hot shocks. Therefore, it can be suitably used for metal sintering bonding used in next-generation power modules. In addition, the method for producing a plating film of the present invention can produce a plating film that is excellent in heat resistance and resistance to cold and hot shocks and can be suitably used for metal sintering bonding. Furthermore, the semiconductor mounting substrate of the present invention is excellent in heat resistance and resistance to cold and hot shocks. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] The present invention will be described in detail below.

[0013] In addition, in the plating film for metal sintering bonding of the present invention, when (A) the electroless nickel-phosphorus plating film is laminated on a substrate, the direction of the surface opposite to the side in contact with the substrate is sometimes referred to as the "upper" or "front surface," and the direction of the opposite side, i.e., the surface of (A) the electroless nickel-phosphorus plating film in contact with the substrate, is sometimes referred to as the "lower" or "rear surface."

[0014] 1. Plating film for metal sintering bonding The plating film for metal sintering bonding of the present invention (hereinafter also simply referred to as "plating film") is a plating film having an electroless nickel-phosphorus plating film (A) (hereinafter also referred to as "layer (A)"), and the phosphorus content of the electroless nickel-phosphorus plating film (A) is 4 mass% or less, with the electroless nickel-phosphorus plating film being 100 mass%. Since the plating film of the present invention has the above-mentioned layer (A), the layer (A) can suppress oxidation of the substrate, and can dissipate heat generated from the semiconductor element while fixing the semiconductor element via the metal sintered material, making it suitable for mounting the semiconductor element. In addition, the plating film of the present invention has excellent heat resistance and cold and thermal shock resistance because the phosphorus content of the layer (A) is 4 mass% or less, with the electroless nickel-phosphorus plating film being 100 mass%, and can be suitably used for metal sintering bonding.

[0015] Hereinafter, each plating film constituting the plating film for metal sintering bonding of the present invention will be described in detail.

[0016] ((A) Electroless nickel-phosphorus plating film) The plating film for metal sintering bonding of the present invention has (A) an electroless nickel-phosphorus plating film.

[0017] The phosphorus content of the electroless nickel-phosphorus plating film is 4% by mass or less, with the electroless nickel-phosphorus plating film being 100% by mass. If the phosphorus content exceeds 4% by mass, the heat resistance and cold / heat shock resistance are poor, and cracks occur in the plating film, resulting in insufficient bonding with the metal sintered material and making it unsuitable for mounting semiconductor elements. The phosphorus content is preferably 3% by mass or less, more preferably 2% by mass or less, and even more preferably 1% by mass or less. The lower limit of the phosphorus content is not particularly limited, and may be 0.1% by mass, 0.2% by mass, or 0.5% by mass. The phosphorus content of the electroless nickel-phosphorus plating film can be reduced by changing the composition of the electroless nickel-phosphorus plating or the plating conditions.

[0018] The sulfur content of the (A) layer is preferably less than 0.0005% by mass, more preferably 0.0002% by mass or less, even more preferably 0.0001% by mass or less, and particularly preferably 0% by mass, based on 100% by mass of the (A) electroless nickel-phosphorus plating film. By having the sulfur content of the (A) layer within the above range, the heat resistance and cold / heat shock resistance of the plating film of the present invention are further improved, and the occurrence of cracks can be suppressed, making it suitable for mounting semiconductor elements via a metal sintered material. The sulfur content can be reduced by reducing the amount of raw materials containing divalent sulfur in the composition of the electroless nickel-phosphorus plating solution for forming the (A) layer.

[0019] The thickness of Layer (A) is not particularly limited, but is preferably from 0.1 to 20 μm, more preferably from 0.2 to 10 μm, and even more preferably from 0.5 to 5 μm.

[0020] ((B) Electroless silver plating film or electroless gold plating film) The plating film for metal sintering bonding of the present invention may have an electroless silver plating film (B) or an electroless gold plating film (hereinafter, also referred to as "layer (B)") on layer (A). By having layer (B) in the plating film for metal sintering bonding of the present invention, the bonding with the metal sintered material is further improved, and the semiconductor element can be fixed via the metal sintered material while heat generated from the semiconductor element can be dissipated, making it more suitable for mounting the semiconductor element.

[0021] The thickness of the (B) layer is not particularly limited, and is preferably 0.02 to 2 μm from the viewpoint of being able to better fix the semiconductor element via the metal sintered material and to more easily dissipate heat generated from the semiconductor element while fixing the semiconductor element.

[0022] When the (B) layer is an electroless silver plating film, the thickness of the (B) layer is preferably 0.02 to 1 μm, more preferably 0.05 to 0.5 μm, and when the (B) layer is an electroless gold plating film, the thickness of the (B) layer is preferably 0.02 to 1 μm, more preferably 0.03 to 0.2 μm.

[0023] ((C) Barrier metal layer) The plating film for metal sintering bonding of the present invention may further have a barrier metal layer (C) (hereinafter, also referred to as "layer (C)") between layer (A) and layer (B). By having layer (C) in the plating film for metal sintering bonding of the present invention, surface diffusion of the base metal and corrosion of the nickel-phosphorus plating film due to electroless silver plating or electroless gold plating can be further suppressed, and therefore the bondability with the metal sintered material is further improved.

[0024] The (C) layer is not particularly limited, and may be a known plating film. Examples of the (C) layer include electroless palladium plating film, electroless palladium-phosphorus plating film, electroless platinum plating film, electroless cobalt-phosphorus plating film, and electroless cobalt-boron plating film. Among these, electroless palladium plating film and electroless palladium-phosphorus plating film are preferred from the viewpoint of further suppressing the surface diffusion of the base metal and the corrosion of the nickel-phosphorus plating film due to electroless silver plating or electroless gold plating.

[0025] When the (C) layer contains phosphorus, for example, as an electroless palladium-phosphorus plating film, the phosphorus content in the (C) layer is preferably 0.1 to 2.0 mass%, and more preferably 0.5 to 1.5 mass%, based on 100 mass% of the (C) layer. By having the phosphorus content in the (C) layer within the above range, it is possible to further suppress the surface diffusion of the underlying metal and the corrosion of the nickel-phosphorus plating film due to electroless silver plating or electroless gold plating.

[0026] (Characteristics of plating film for metal sintering bonding) The thickness of the plating film for metal sintering bonding of the present invention is not particularly limited, and is preferably 1 to 10 μm, more preferably 1.5 to 8 μm, and even more preferably 2 to 5 μm. By having the thickness of the plating film for metal sintering bonding within the above range, the mounted semiconductor can be more firmly fixed and oxidation is further suppressed.

[0027] The plating film for metal sintering bonding of the present invention described above has the above-mentioned configuration, and therefore has excellent heat resistance and resistance to cold and thermal shock. Therefore, it can be suitably used for metal sintering bonding used in next-generation power modules. The plating film for metal sintering bonding of the present invention can be suitably used in particular for silver sintering bonding or copper sintering bonding. That is, the plating film for metal sintering bonding of the present invention is suitable for use as a metal sintered material containing silver and / or copper.

[0028] 2. Manufacturing method of plating film for metal sintering bonding The method for producing a plating film for metal sintering bonding of the present invention is a method for producing a plating film for metal sintering bonding on a substrate, and includes a step 1 of (1) contacting an electroless nickel-phosphorus plating solution with a surface of a substrate to form an electroless nickel-phosphorus plating film (A) on the substrate, the method being characterized in that the phosphorus content of the electroless nickel-phosphorus plating film (A) is 4 mass% or less, with the electroless nickel-phosphorus plating film being 100 mass%. According to the production method of the present invention, it is possible to produce the plating film for metal sintering bonding of the present invention, which has excellent heat resistance and cold and thermal shock resistance and can be suitably used for metal sintering bonding.

[0029] Each step will be described below.

[0030] (Process 1) Step 1 is a step of contacting the surface of a substrate with an electroless nickel-phosphorus plating solution to form (A) an electroless nickel-phosphorus plating film on the substrate.

[0031] The substrate (object to be plated) used in step 1 includes substrates used for electronic components such as semiconductors and circuits. Examples of such substrates include printed wiring boards, ceramic substrates, silicon substrates, metal substrates, etc. Specific examples include semiconductor chips (mainly back electrodes) and metal lead frames such as SiC, GaN, and Si, as well as insulating heat dissipation circuit substrates (ceramic substrates) such as DBC (Direct Bonded Copper) substrates, DBA (Direct Bonded Aluminum) substrates, and AMB (Active Metal Brazing) substrates, and heat dissipation substrates such as heat sinks. Examples of the material of the portion to be plated of the object to be plated include copper, copper alloys, aluminum, and aluminum alloys.

[0032] The electroless nickel-phosphorus plating solution used in step 1 is not particularly limited as long as it can adjust the phosphorus content of the electroless nickel-phosphorus plating film produced in step 1 to 4 mass% or less, with the electroless nickel-phosphorus plating film being 100 mass%. Examples of such electroless nickel-phosphorus plating solutions include electroless nickel-phosphorus plating solutions that contain a water-soluble nickel compound, a reducing agent, and a complexing agent, and that contain other additives as necessary. Hereinafter, such electroless nickel-phosphorus plating solutions will be described by way of example.

[0033] (Water-soluble nickel compounds) The water-soluble nickel compound contained in the electroless nickel-phosphorus plating solution used in the manufacturing method of the present invention is not particularly limited, and any known nickel compound used in electroless nickel-phosphorus plating solutions can be used. The water-soluble nickel compound is preferably, for example, water-soluble nickel inorganic salts such as nickel sulfate, nickel chloride, nickel hypophosphite, and nickel carbonate; water-soluble nickel organic salts such as nickel acetate and nickel malate, and hydrates thereof.

[0034] The water-soluble nickel compounds may be used alone or in combination of two or more.

[0035] The concentration of the water-soluble nickel compound in the electroless nickel-phosphorus plating solution is not particularly limited as long as it is within a range in which an electroless nickel-phosphorus plating film can be formed, and can be appropriately adjusted. The concentration of the water-soluble nickel compound is preferably, for example, about 0.01 g / L to 100 g / L, more preferably 0.5 to 50 g / L, and even more preferably 1 g / L to 10 g / L, as nickel metal. If the concentration of the water-soluble nickel compound is less than 0.01 g / L as nickel metal, the deposition rate may be slow, and if it exceeds 100 g / L, the bath stability may be reduced, so it is preferable to set it within the above range.

[0036] (reducing agent) The reducing agent is preferably at least one selected from the group consisting of hypophosphorous acid and hypophosphites (for example, sodium salts, potassium salts, ammonium salts, etc.).

[0037] The reducing agent may be used alone or in combination of two or more kinds.

[0038] The concentration of the reducing agent (hypophosphorous acid, hypophosphites, and hydrates thereof, etc.) in the electroless nickel-phosphorus plating solution is preferably about 0.5 g / L to 40 g / L, more preferably about 1 g / L to 20 g / L, and even more preferably about 2 g / L to 15 g / L. By setting the upper limit of the concentration within the above range, it becomes easy to adjust the phosphorus content of the electroless nickel-phosphorus plating film to 4 mass% or less. In addition, by setting the lower limit of the concentration within the above range, the deposition property of the electroless nickel-phosphorus plating can be more stabilized.

[0039] (Complexing Agent) The electroless nickel-phosphorus plating solution preferably contains, as a complexing agent, glycine, gluconate, etc. The gluconate is preferably, for example, a sodium salt, a potassium salt, an ammonium salt, etc.

[0040] The other complexing agents are preferably monocarboxylic acids such as formic acid and acetic acid or their salts (e.g., sodium salts, potassium salts, ammonium salts, etc.); dicarboxylic acids such as malonic acid, succinic acid, adipic acid, maleic acid, fumaric acid or their salts (e.g., sodium salts, potassium salts, ammonium salts, etc.); hydroxycarboxylic acids such as malic acid, lactic acid, glycolic acid, citric acid or their salts (e.g., sodium salts, potassium salts, ammonium salts, etc.); ethylenediaminediacetic acid, ethylenediaminetetraacetic acid or their salts (e.g., sodium salts, potassium salts, ammonium salts, etc.); amino acids such as alanine, arginine, etc.

[0041] The complexing agent may be used alone or in combination of two or more kinds.

[0042] The concentration of the complexing agent in the electroless nickel-phosphorus plating solution is not particularly limited and can be adjusted appropriately. The electroless nickel-phosphorus plating bath preferably contains about 1 g / L to 100 g / L of the complexing agent, more preferably about 2 g / L to 50 g / L, and even more preferably about 5 g / L to 30 g / L. If the concentration of the complexing agent is less than 1 g / L, the bath stability may decrease, and if it exceeds 100 g / L, the deposition rate may decrease, so it is preferable to set the concentration within the above range.

[0043] (Stabilizers, sulfur additives, pH adjusters, surfactants, etc.) In addition to the above-mentioned components, the electroless nickel-phosphorus plating solution may contain known additives used in electroless nickel-phosphorus plating solutions, if necessary, such as stabilizers, sulfur-based additives, pH adjusters, surfactants, etc.

[0044] Examples of the stabilizer include lead compounds (e.g., lead nitrate, lead acetate, etc.), cadmium compounds (e.g., cadmium nitrate, cadmium acetate, etc.), thallium compounds (e.g., thallium sulfate, thallium nitrate, etc.), antimony compounds (e.g., antimony chloride, potassium antimonyl tartrate, etc.), tellurium compounds (e.g., telluric acid, tellurium chloride, etc.), chromium compounds (e.g., chromium oxide, chromium sulfate, etc.), iron compounds (e.g., iron sulfate, iron chloride, etc.), manganese compounds (e.g., manganese sulfate, manganese nitrate, etc.), bismuth compounds (e.g., bismuth nitrate, bismuth acetate, etc.), tin compounds (e.g., tin sulfate, tin chloride, etc.), selenium compounds (e.g., selenic acid, selenious acid, etc.), cyanides (e.g., methyl cyanide, isopropyl cyanide, etc.), iodine compounds (e.g., potassium iodide, etc.), and the like.

[0045] The stabilizers may be used alone or in combination of two or more.

[0046] The concentration of the stabilizer in the electroless nickel-phosphorus plating solution is not particularly limited, and can be, for example, about 0.1 mg / L to 500 mg / L. In order to improve the stability of the electroless nickel-phosphorus plating solution, it is preferable to set the concentration of the stabilizer to about 0.1 mg / L or more. If the concentration of the stabilizer exceeds 500 mg / L, there may be some areas where the plating film is not formed (non-deposited areas), so it is preferable to set the concentration within the above range.

[0047] The sulfur-based additive is preferably a divalent sulfur-based compound such as thiourea. From the viewpoint of further reducing the sulfur content of the electroless nickel-phosphorus plating film, it is preferable to add the minimum amount necessary or none at all.

[0048] As the pH adjuster, for example, an acid such as hydrochloric acid, sulfuric acid, phosphoric acid, etc.; or an alkali such as sodium hydroxide, potassium hydroxide, ammonia water, etc. is preferably used.

[0049] The pH of the electroless nickel-phosphorus plating solution is preferably about 3 to 12, and more preferably about 4 to 9. The pH of the plating bath can be adjusted using the above-mentioned pH adjuster. If the pH is less than 3, non-precipitation may occur, and if it exceeds 12, the bath stability may decrease, so it is preferable to keep the pH within the above range.

[0050] As the surfactant, various surfactants such as nonionic, anionic, cationic, and amphoteric surfactants can be used. For example, aromatic or aliphatic sulfonic acid alkali salts, aromatic or aliphatic sulfonic acid alkali metal salts, etc. can be mentioned. The surfactant can be used alone or in combination of two or more. When two or more surfactants are used in combination, the mixing ratio is not particularly limited and can be appropriately determined.

[0051] The concentration of the surfactant in the electroless nickel-phosphorus plating solution is not particularly limited, and can be, for example, about 0.01 mg / L to 1000 mg / L. In order to further improve the effect of preventing pits in the electroless nickel-phosphorus plating solution, it is preferable to set the concentration of the surfactant to about 0.01 mg / L or more. When the concentration of the surfactant is 1000 mg / L or less, the decrease in deposition property due to foaming is further suppressed.

[0052] (Electroless nickel-phosphorus plating method) In step 1, the surface of the substrate is brought into contact with the electroless nickel-phosphorus plating solution.

[0053] The method for contacting the surface of the substrate with the electroless plating solution is not particularly limited and can be carried out according to a conventional method. In step 1, a preferred example is a method in which the substrate to be plated is immersed in the electroless nickel-phosphorus plating solution.

[0054] The plating conditions (eg, solution temperature, plating time, etc.) are not particularly limited as long as they are conditions that allow an electroless nickel-phosphorus plating film to be formed, and can be appropriately determined.

[0055] The temperature of the electroless nickel-phosphorus plating solution in step 1 can be appropriately determined depending on the composition of the electroless nickel-phosphorus plating solution, etc. For example, the temperature of the electroless nickel-phosphorus plating solution in the plating step can be preferably about 25° C. or higher, more preferably about 40° C. to 100° C., and even more preferably about 45° C. to 95° C. If the temperature is less than 25° C., the deposition rate of the plating film may be slow, resulting in a decrease in production efficiency, and therefore it is preferable to set the temperature within the above range.

[0056] The treatment time in step 1 is not particularly limited, and may be the time required for forming an electroless plating film of a required thickness on the object to be plated. Specifically, the treatment time in the plating step may be appropriately determined depending on the composition of the plating bath, the type of the object to be plated, and the like, and may be, for example, preferably about 1 to 120 minutes, more preferably 3 to 60 minutes.

[0057] The electroless nickel-phosphorus plating film formed on the substrate by step 1 is the (A) electroless nickel-phosphorus plating film of the plating film for metal sintering bonding of the present invention, and has a phosphorus content of 4 mass% or less, assuming the electroless nickel-phosphorus plating film to be 100 mass%. The characteristics of the (A) electroless nickel-phosphorus plating film formed on the substrate by step 1 are the same as those described for the (A) electroless nickel-phosphorus plating film in the plating film for metal sintering bonding of the present invention.

[0058] (A) As a method for adjusting the phosphorus content in the electroless nickel-phosphorus plating film to 4 mass% or less, (i) a method for adjusting the content of a reducing agent in the electroless nickel-phosphorus plating solution can be mentioned. When the content of a reducing agent in the electroless nickel-phosphorus plating solution increases, the phosphorus content of the electroless nickel-phosphorus plating film formed increases, and when the content of a reducing agent in the electroless nickel-phosphorus plating solution decreases, the phosphorus content of the electroless nickel-phosphorus plating film decreases. In addition, as the above-mentioned adjustment method, (ii) a method for adjusting the pH of the electroless nickel-phosphorus plating solution in step 1 can be mentioned. When the pH is lowered, the phosphorus content of the electroless nickel-phosphorus plating film formed increases, and when the pH is higher, the phosphorus content of the electroless nickel-phosphorus plating film decreases. In addition, as the above-mentioned adjustment method, (iii) a method for adjusting the liquid temperature of the electroless nickel-phosphorus plating solution in step 1 can be mentioned. When the liquid temperature is higher, the phosphorus content of the electroless nickel-phosphorus plating film formed decreases, and when the liquid temperature is lowered, the phosphorus content of the electroless nickel-phosphorus plating film increases.

[0059] (A) As a method for adjusting the sulfur content in the electroless nickel-phosphorus plating film, there is a method for adjusting the content of divalent sulfur compounds, such as thiourea, in the electroless nickel-phosphorus plating solution. When the content of divalent sulfur compounds in the electroless nickel-phosphorus plating solution increases, the sulfur content of the electroless nickel-phosphorus plating film increases, and when the content of divalent sulfur compounds in the electroless nickel-phosphorus plating solution decreases, the sulfur content of the electroless nickel-phosphorus plating film decreases.

[0060] By the above-described step 1, (A) an electroless nickel-phosphorus plating film is formed on the substrate.

[0061] (Process 2) The manufacturing method of the present invention may further include, after step 1, step 2 of (2) contacting the surface of the electroless nickel-phosphorus plating film with an electroless silver plating solution or an electroless gold plating solution to form an electroless silver plating film or an electroless gold plating film (B) on the electroless nickel-phosphorus plating film (A).

[0062] The electroless silver plating solution or the electroless gold plating solution used in step 2 is not particularly limited, and any conventionally known solution may be used. The electroless silver plating solution and the electroless gold plating solution used in step 2 will be described below.

[0063] [Electroless silver plating solution] The electroless silver plating solution is not particularly limited, and for example, electroless silver plating solutions such as reduction precipitation type, displacement reduction precipitation type, and displacement precipitation type can be used. As the reduction precipitation type and displacement reduction precipitation type electroless silver plating solutions, electroless silver plating solutions containing a silver compound, a reducing agent, and a complexing agent and, if necessary, other additives can be used. As the displacement precipitation type electroless silver plating, electroless silver plating solutions containing a silver compound, a complexing agent, and, if necessary, other additives can be used. Hereinafter, such electroless silver plating solutions will be described by way of example.

[0064] (silver compound) The silver compound is not particularly limited as long as it is a water-soluble silver compound, and any known silver compound used in electroless silver plating solutions can be used. Examples of silver compounds include inorganic salts such as silver nitrate, silver sulfate, and silver iodide; and organic acid salts such as silver acetate and silver methanesulfonate.

[0065] The silver compounds may be used alone or in combination of two or more.

[0066] The concentration of the silver compound in the electroless silver plating solution is not particularly limited as long as it is within a range in which an electroless silver plating film can be formed, and can be appropriately adjusted. The concentration of the silver compound is preferably, for example, about 0.01 g / L to 20 g / L, more preferably 0.1 to 10 g / L, and even more preferably 0.2 g / L to 5 g / L, as silver metal. If the concentration of the silver compound is less than 0.01 g / L as silver metal, the deposition rate may be slow, and if it exceeds 20 g / L, the bath stability may be reduced, so it is preferable to set it within the above range.

[0067] (reducing agent) The reducing agent is preferably at least one selected from the group consisting of water-soluble aldehyde compounds, water-soluble hydrazine derivatives, boron hydride compounds, hypophosphorous acid, phosphorous acid, ascorbic acid, and salts thereof (e.g., sodium salts, potassium salts, ammonium salts, etc.). In addition, in the case of a displacement deposition type electroless silver plating solution, it is not necessary to contain a reducing agent.

[0068] The reducing agent may be used alone or in combination of two or more. 。

[0069] The concentration of the reducing agent in the electroless silver plating solution is preferably about 0.5 g / L to 15 g / L, more preferably about 1 g / L to 13 g / L, and even more preferably about 1.5 g / L to 10 g / L.

[0070] (Complexing Agent) The electroless silver plating solution preferably contains, as a complexing agent, an amide compound, an imide compound, a thiosulfate compound, a sulfurous compound, a sulfur-containing compound (a sulfur-containing compound other than thiosulfate compounds and sulfurous compounds), a nitrogen-containing compound (a nitrogen-containing compound other than amide compounds and imide compounds), or the like, and more preferably contains an amide compound or an imide compound.

[0071] Examples of the amide compound include cyclic amide compounds such as benzamide, N-methylpyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, pyrrolidone, N-butylpyrrolidone, 5-methylpyrrolidone, and N-methylpiperidinone; and chain amide compounds such as acetamide, formamide, N,N-dimethylformamide, N-methyl-N-phenylformamide, and N,N-diphenylformamide. These may be used alone or in combination of two or more. Among them, chain amide compounds are preferred, and acetamide and formamide are more preferred.

[0072] The imide compound is not particularly limited, and examples thereof include preferred cyclic imide compounds such as hydantoin, 5,5-dimethylhydantoin, 1-methylhydantoin, 1,3-dimethylhydantoin, glutarimide, and succinimide. More preferred are hydantoin, 5,5-dimethylhydantoin, 1-methylhydantoin, succinimide, 1,3-methylhydantoin, and glutarimide, and even more preferred are 1-methylhydantoin and succinimide.

[0073] The complexing agent may be used alone or in combination of two or more kinds.

[0074] The concentration of the complexing agent in the electroless silver plating solution is not particularly limited and can be adjusted appropriately. The electroless silver plating solution preferably contains about 1 g / L to 100 g / L of the complexing agent, more preferably about 2 g / L to 50 g / L, and even more preferably about 5 g / L to 30 g / L. If the concentration of the complexing agent is less than 1 g / L, the bath stability may decrease, and if it exceeds 100 g / L, the deposition rate may decrease, so it is preferable to set the concentration within the above range.

[0075] (stabilizers, pH adjusters, surfactants, etc.) In addition to the above-mentioned components, the electroless silver plating solution may contain, if necessary, known additives used in electroless silver plating solutions, such as stabilizers, pH adjusters, surfactants, etc.

[0076] Examples of the stabilizer include lead compounds (e.g., lead nitrate, lead acetate, etc.), cadmium compounds (e.g., cadmium nitrate, cadmium acetate, etc.), thallium compounds (e.g., thallium sulfate, thallium nitrate, etc.), antimony compounds (e.g., antimony chloride, potassium antimonyl tartrate, etc.), tellurium compounds (e.g., telluric acid, tellurium chloride, etc.), chromium compounds (e.g., chromium oxide, chromium sulfate, etc.), iron compounds (e.g., iron sulfate, iron chloride, etc.), manganese compounds (e.g., manganese sulfate, manganese nitrate, etc.), bismuth compounds (e.g., bismuth nitrate, bismuth acetate, etc.), tin compounds (e.g., tin sulfate, tin chloride, etc.), selenium compounds (e.g., selenic acid, selenious acid, etc.), cyanides (e.g., methyl cyanide, isopropyl cyanide, etc.), iodine compounds (e.g., potassium iodide, etc.), and the like.

[0077] The stabilizers may be used alone or in combination of two or more.

[0078] The concentration of the stabilizer in the electroless silver plating solution is not particularly limited and can be, for example, about 0.1 mg / L to 500 mg / L. In order to improve the stability of the electroless silver plating solution, it is preferable to set the concentration of the stabilizer to about 0.1 mg / L or more. If the concentration of the stabilizer exceeds 500 mg / L, there may be some areas where the plating film is not formed (non-deposited areas), so it is preferable to set the concentration within the above range.

[0079] As the pH adjuster, for example, an acid such as nitric acid, sulfuric acid, phosphoric acid, etc.; or an alkali such as sodium hydroxide, potassium hydroxide, ammonia water, etc. is preferably used.

[0080] The pH of the electroless silver plating solution is preferably about 1 to 12, and more preferably about 1.5 to 11. The pH of the plating bath can be adjusted using the above-mentioned pH adjuster. If the pH is less than 1, non-precipitation may occur, and if it exceeds 12, the bath stability may decrease, so it is preferable to keep the pH within the above range.

[0081] As the surfactant, various surfactants such as nonionic, anionic, cationic, and amphoteric surfactants can be used. For example, aromatic or aliphatic sulfonic acid alkali salts, aromatic or aliphatic sulfonic acid alkali metal salts, etc. can be mentioned. The surfactant can be used alone or in combination of two or more. When two or more surfactants are used in combination, the mixing ratio is not particularly limited and can be appropriately determined.

[0082] The concentration of the surfactant in the electroless silver plating solution is not particularly limited, and can be, for example, about 0.01 mg / L to 1000 mg / L. In order to further improve the effect of preventing pits in the electroless silver plating solution, it is preferable to set the concentration of the surfactant to about 0.01 mg / L or more. When the concentration of the surfactant is 1000 mg / L or less, the decrease in deposition property due to foaming is further suppressed.

[0083] (Electroless silver plating method) In step 2, the method for forming the electroless silver plating film on the electroless nickel-phosphorus plating film is not particularly limited, and examples thereof include a method in which an electroless silver plating solution is brought into contact with the surface of the electroless nickel-phosphorus plating film formed in step 1.

[0084] The method for contacting the surface of the electroless nickel-phosphorus plating film with the electroless silver plating solution is not particularly limited and can be carried out according to a conventional method. In step 2, a preferred example is a method of immersing the substrate on which the electroless nickel-phosphorus plating film is formed in the electroless silver plating solution.

[0085] The plating conditions (for example, solution temperature, plating time, etc.) are not particularly limited as long as they are conditions that allow the formation of an electroless silver plating film, and can be appropriately determined.

[0086] The temperature of the electroless silver plating solution in step 2 can be appropriately determined depending on the composition of the electroless silver plating solution, etc. For example, the temperature of the electroless silver plating solution in the plating step can be preferably about 25° C. or higher, more preferably about 30° C. to 80° C., and even more preferably about 40° C. to 75° C. If the temperature is less than 25° C., the deposition rate of the plating film may be slow, resulting in reduced production efficiency, and therefore it is preferable to keep the temperature within the above range.

[0087] The treatment time in step 2 is not particularly limited and may be the time required for forming an electroless silver plating film of a required thickness. Specifically, the treatment time in the plating step may be appropriately determined depending on the composition of the electroless silver plating solution, and may be, for example, preferably about 1 to 40 minutes, and more preferably 3 to 20 minutes.

[0088] Electroless silver plating formed by step 2 Coating is an electroless silver plating film as layer (B) which may be included in the plating film for metal sintering bonding of the present invention. The properties of the electroless silver plating film formed on the substrate by step 2 are the same as those described for layer (B) in the plating film for metal sintering bonding of the present invention.

[0089] [Electroless gold plating solution] The electroless gold plating solution is not particularly limited, and for example, electroless gold plating solutions of reduction precipitation type, displacement reduction precipitation type, displacement precipitation type, etc. can be used. As the reduction precipitation type and displacement reduction precipitation type electroless gold plating solutions, electroless gold plating solutions containing a gold compound, a reducing agent, and a complexing agent and, if necessary, other additives can be used. In addition, the displacement precipitation type electroless gold plating solution can be used. liquid As the electroless gold plating solution, an electroless gold plating solution containing a gold compound, a complexing agent, and optionally other additives can be used. Hereinafter, such an electroless gold plating solution will be described by way of example.

[0090] (gold compound) The gold compound is not particularly limited as long as it is a water-soluble gold compound, and any known gold compound used in electroless gold plating solutions can be used, including, for example, potassium gold sulfite, sodium gold sulfite, ammonium gold sulfite, potassium gold cyanide, sodium gold cyanide, and ammonium gold cyanide.

[0091] The gold compounds may be used alone or in combination of two or more.

[0092] The concentration of the gold compound in the electroless gold plating solution is not particularly limited as long as it is within a range in which an electroless gold plating film can be formed, and can be appropriately adjusted. The concentration of the gold compound is preferably, for example, about 0.01 g / L to 10 g / L, more preferably 0.2 to 5 g / L, and even more preferably 0.5 g / L to 2 g / L, in terms of gold metal. If the concentration of the gold compound is less than 0.01 g / L in terms of gold metal, the deposition rate may be slow, and if it exceeds 10 g / L, the cost becomes high, so it is preferable to set it within the above range.

[0093] (reducing agent) The reducing agent is not particularly limited, and the same reducing agents as those used in known electroless gold plating solutions can be used. For example, hydrazines such as hydrazine hydrate, hydrazine sulfate, neutral hydrazine sulfate, hydrazine maleate, and salts thereof; hydroxylamines and their salts; hydrazine derivatives such as adipic acid dihydrazide, isophthalic acid dihydrazide, and isopropyl hydrazine sulfate; ascorbic acid and its salts (sodium, potassium, ammonium salts, etc.); boron hydride compounds such as trimethylamine borane (TMAB) and dimethylamine borane (DMAB); thiourea; hypophosphorous acid and its salts (sodium, potassium, ammonium salts, etc.).

[0094] The reducing agent may be used alone or in combination of two or more. liquid In this case, the reducing agent may not be contained.

[0095] The concentration of the reducing agent in the electroless gold plating solution is preferably about 1 g / L to 15 g / L, more preferably about 2 g / L to 13 g / L, and even more preferably about 3 g / L to 10 g / L.

[0096] (Complexing Agent) The complexing agent is not particularly limited, and a complexing agent used in a known electroless gold plating solution can be used. For example, sulfites such as sodium sulfite, potassium sulfite, and ammonium sulfite; cyanides such as sodium cyanide and potassium cyanide; thiosulfates such as sodium thiosulfate, potassium thiosulfate, and ammonium thiosulfate; inorganic acids such as phosphoric acid and boric acid, and their salts (sodium salt, potassium salt, ammonium salt, etc.); hydroxycarboxylic acids such as citric acid, gluconic acid, tartaric acid, lactic acid, and malic acid, and their salts (sodium salt, potassium salt, ammonium salt, etc.); amine compounds such as ethylenediamine and triethanolamine; glycine, alanine, ethylenediaminetetraacetic acid, nitriloacetate, and the like. Risou Examples of the aminocarboxylic acids that can be used include acids and their salts (sodium salts, potassium salts, ammonium salts, etc.); phosphonic acids such as aminotrimethylenephosphonic acid, 1-hydroxyethylidene-1,1-diphosphonic acid, ethylenediaminetetramethylenephosphonic acid, and diethylenetriaminepenta(methylenephosphonic acid), and their salts (sodium salts, potassium salts, ammonium salts, etc.);

[0097] The complexing agent may be used alone or in combination of two or more kinds.

[0098] The concentration of the complexing agent in the electroless gold plating solution is not particularly limited and can be adjusted appropriately. The electroless gold plating solution contains the complexing agent preferably at about 1 g / L to 100 g / L, more preferably at about 2 g / L to 50 g / L, and even more preferably at about 5 g / L to 30 g / L. If the concentration of the complexing agent is less than 1 g / L, the bath stability may decrease, and if it exceeds 100 g / L, the deposition rate may decrease, so it is preferable to keep the concentration within the above range.

[0099] (stabilizers, pH adjusters, surfactants, etc.) In addition to the above-mentioned components, the electroless gold plating solution may contain known additives used in electroless gold plating solutions, such as stabilizers, pH adjusters, surfactants, etc., as necessary.

[0100] Examples of the stabilizer include lead compounds (e.g., lead nitrate, lead acetate, etc.), cadmium compounds (e.g., cadmium nitrate, cadmium acetate, etc.), thallium compounds (e.g., thallium sulfate, thallium nitrate, etc.), antimony compounds (e.g., antimony chloride, potassium antimonyl tartrate, etc.), tellurium compounds (e.g., telluric acid, tellurium chloride, etc.), chromium compounds (e.g., chromium oxide, chromium sulfate, etc.), iron compounds (e.g., iron sulfate, iron chloride, etc.), manganese compounds (e.g., manganese sulfate, manganese nitrate, etc.), bismuth compounds (e.g., bismuth nitrate, bismuth acetate, etc.), tin compounds (e.g., tin sulfate, tin chloride, etc.), selenium compounds (e.g., selenic acid, selenious acid, etc.), cyanides (e.g., methyl cyanide, isopropyl cyanide, etc.), iodine compounds (e.g., potassium iodide, etc.), and the like.

[0101] The stabilizers may be used alone or in combination of two or more.

[0102] The concentration of the stabilizer in the electroless gold plating solution is not particularly limited and can be, for example, about 0.1 mg / L to 500 mg / L. In order to improve the stability of the electroless gold plating solution, it is preferable to set the concentration of the stabilizer to about 0.1 mg / L or more. If the concentration of the stabilizer exceeds 500 mg / L, there may be some areas where the plating film is not formed (non-deposited areas), so it is preferable to set the concentration within the above range.

[0103] As the pH adjuster, for example, an acid such as hydrochloric acid, sulfuric acid, phosphoric acid, etc.; or an alkali such as sodium hydroxide, potassium hydroxide, ammonia water, etc. is preferably used.

[0104] The pH of the electroless gold plating solution is preferably about 3 to 12, and more preferably about 4 to 9. The pH of the plating bath can be adjusted using the above-mentioned pH adjuster. If the pH is less than 3, non-precipitation may occur, and if it exceeds 12, the bath stability may decrease, so it is preferable to keep the pH within the above range.

[0105] As the surfactant, various surfactants such as nonionic, anionic, cationic, and amphoteric surfactants can be used. For example, aromatic or aliphatic sulfonic acid alkali salts, aromatic or aliphatic sulfonic acid alkali metal salts, etc. can be mentioned. The surfactant can be used alone or in combination of two or more. When two or more surfactants are used in combination, the mixing ratio is not particularly limited and can be appropriately determined.

[0106] The concentration of the surfactant in the electroless gold plating solution is not particularly limited, and can be, for example, about 0.01 mg / L to 1000 mg / L. In order to further improve the effect of preventing pits in the electroless gold plating solution, it is preferable to set the concentration of the surfactant to about 0.01 mg / L or more. When the concentration of the surfactant is 1000 mg / L or less, the decrease in deposition property due to foaming is further suppressed.

[0107] (Electroless gold plating method) In step 2, the method for forming the electroless gold plating film on the electroless nickel-phosphorus plating film is not particularly limited, and examples thereof include a method in which an electroless gold plating solution is brought into contact with the surface of the electroless nickel-phosphorus plating film formed in step 1.

[0108] The method for bringing the surface of the electroless nickel-phosphorus plating film into contact with the electroless gold plating solution is not particularly limited and can be carried out according to a conventional method. In step 2, a preferred example is a method of immersing the substrate on which the electroless nickel-phosphorus plating film has been formed in the electroless gold plating solution.

[0109] The plating conditions (for example, solution temperature, plating time, etc.) are not particularly limited as long as they are conditions that allow the formation of an electroless gold plating film, and can be determined appropriately.

[0110] The temperature of the electroless gold plating solution in step 2 can be appropriately determined depending on the composition of the electroless gold plating solution, etc. For example, the temperature of the electroless gold plating solution in the plating step can be preferably about 25° C. or higher, more preferably about 40° C. to 90° C., and even more preferably about 45° C. to 85° C. If the temperature is less than 25° C., the deposition rate of the plating film may be slow, resulting in reduced production efficiency, and therefore it is preferable to keep the temperature within the above range.

[0111] The treatment time in step 2 is not particularly limited and may be the time required for forming an electroless gold plating film of a required thickness. Specifically, the treatment time in the plating step may be appropriately determined depending on the composition of the electroless gold plating solution, and may be, for example, preferably about 1 to 40 minutes, and more preferably 3 to 20 minutes.

[0112] The electroless gold plating film formed in step 2 is the electroless gold plating film as layer (B) that may be present in the plating film for metal sintering bonding of the present invention. The characteristics of the electroless gold plating film formed in step 2 are the same as those described for layer (B) in the plating film for metal sintering bonding of the present invention.

[0113] By the above-described step 2, (B) an electroless silver plating film or an electroless gold plating film is formed on (A) the electroless nickel-phosphorus plating film.

[0114] (Barrier metal layer formation process) The manufacturing method of the present invention may further include a barrier metal layer forming step between the above steps 1 and 2, in which a plating solution for forming a barrier metal layer is brought into contact with the surface of the electroless nickel-phosphorus plating film to form a barrier metal layer (C) on the electroless nickel-phosphorus plating film (A). By including the barrier metal layer forming step, the barrier metal layer (C) can be formed between the layer (A) and the layer (B).

[0115] The (C) barrier metal layer is not particularly limited, and may be a known plating film. Examples of the (C) layer include electroless palladium plating film, electroless palladium-phosphorus plating film, electroless platinum plating film, electroless cobalt-phosphorus plating film, and electroless cobalt-boron plating film. Among these, electroless palladium plating film and electroless palladium-phosphorus plating film are preferred from the viewpoint of further suppressing the surface diffusion of the base metal and the corrosion of the electroless nickel-phosphorus plating film due to electroless silver plating or electroless gold plating.

[0116] Hereinafter, an electroless palladium plating solution and an electroless palladium-phosphorus plating solution for forming an electroless palladium plating film and an electroless palladium-phosphorus plating film as a barrier metal layer will be described.

[0117] [Electroless palladium plating solution, electroless palladium-phosphorus plating solution] Examples of the electroless palladium plating solution and the electroless palladium-phosphorus plating solution include electroless palladium plating solutions and electroless palladium-phosphorus plating solutions that contain a palladium compound, a reducing agent, and a complexing agent, and that contain other additives as necessary. The electroless palladium plating solution and the electroless palladium-phosphorus plating solution are described below by way of example.

[0118] (Palladium compounds) The palladium compound is not particularly limited as long as it is a water-soluble palladium compound, and a known palladium compound used in an electroless palladium plating solution and an electroless palladium-phosphorus plating solution can be used. Examples of the palladium compound include palladium chloride, palladium sulfate, palladium acetate, and tetraamminepalladium dichloride.

[0119] The palladium compounds may be used alone or in combination of two or more.

[0120] The concentration of the palladium compound in the electroless palladium plating solution and the electroless palladium-phosphorus plating solution is not particularly limited as long as it is within the range in which the plating film can be formed, and can be appropriately adjusted. The concentration of the palladium compound is preferably, for example, about 0.01 g / L to 10 g / L, more preferably 0.2 to 5 g / L, and even more preferably 0.5 g / L to 2 g / L, as palladium metal. If the concentration of the palladium compound is less than 0.01 g / L as palladium metal, the deposition rate may be slow, and if it exceeds 10 g / L, the bath stability may be reduced, so it is preferable to set it to the above range.

[0121] (reducing agent) The reducing agent used in the electroless palladium plating solution is preferably formic acid, a water-soluble aldehyde compound, a water-soluble hydrazine derivative, or a boron hydride compound. The reducing agent used in the electroless palladium-phosphorus plating solution is preferably at least one selected from the group consisting of hypophosphorous acid and hypophosphites (e.g., sodium salt, potassium salt, ammonium salt, etc.), phosphorous acid and phosphites (e.g., sodium salt, potassium salt, ammonium salt, etc.).

[0122] The reducing agent may be used alone or in combination of two or more kinds.

[0123] The concentration of the reducing agent in the electroless palladium plating solution and the electroless palladium-phosphorus plating solution is preferably about 1 g / L to 100 g / L, more preferably about 2 g / L to 50 g / L, and even more preferably about 5 g / L to 40 g / L.

[0124] (Complexing Agent) The complexing agent is not particularly limited, and any complexing agent used in known electroless palladium plating solutions and electroless palladium-phosphorus plating solutions can be used. Examples of the complexing agent include amines such as ethylenediamine and diethylenetriamine, aminopolycarboxylic acids such as ethylenediaminediacetic acid, ethylenediaminetetraacetic acid, and diethylenetriaminepentaacetic acid, or salts thereof (e.g., sodium salts, potassium salts, ammonium salts, etc.), amino acids such as glycine, alanine, iminodiacetic acid, nitrilotriacetic acid, L-glutamic acid, L-glutamic acid diacetic acid, L-aspartic acid, and taurine, or salts thereof (e.g., sodium salts, potassium salts, ammonium salts, etc.), aminotrimethylenephosphonic acid, 1-hydroxyethylidene-1 ,1-diphosphonic acid, ethylenediaminetetramethylenephosphonic acid or their salts (e.g., sodium salts, potassium salts, ammonium salts), monocarboxylic acids such as acetic acid or their salts (e.g., sodium salts, potassium salts, ammonium salts, etc.); dicarboxylic acids such as malonic acid, succinic acid, adipic acid, maleic acid, fumaric acid or their salts (e.g., sodium salts, potassium salts, ammonium salts, etc.); hydroxycarboxylic acids such as malic acid, lactic acid, glycolic acid, citric acid or their salts (e.g., sodium salts, potassium salts, ammonium salts, etc.) can be used.

[0125] The complexing agent may be used alone or in combination of two or more kinds.

[0126] The concentration of the complexing agent in the electroless palladium plating solution and the electroless palladium-phosphorus plating solution is not particularly limited and can be adjusted appropriately. The electroless palladium plating solution and the electroless palladium-phosphorus plating solution contain the complexing agent preferably at about 1 g / L to 100 g / L, more preferably at about 2 g / L to 50 g / L, and even more preferably at about 5 g / L to 30 g / L. If the concentration of the complexing agent is less than 1 g / L, the bath stability may decrease, and if it exceeds 100 g / L, the deposition rate may decrease, so it is preferable to set the concentration within the above range.

[0127] (stabilizers, pH adjusters, surfactants, etc.) In addition to the above-mentioned components, the electroless palladium plating solution and the electroless palladium-phosphorus plating solution may contain known additives used in electroless palladium plating solutions and electroless palladium-phosphorus plating solutions, if necessary. Examples of the additives include a stabilizer, a pH adjuster, and a surfactant.

[0128] Examples of the stabilizer include lead compounds (e.g., lead nitrate, lead acetate, etc.), cadmium compounds (e.g., cadmium nitrate, cadmium acetate, etc.), thallium compounds (e.g., thallium sulfate, thallium nitrate, etc.), antimony compounds (e.g., antimony chloride, potassium antimonyl tartrate, etc.), tellurium compounds (e.g., telluric acid, tellurium chloride, etc.), chromium compounds (e.g., chromium oxide, chromium sulfate, etc.), iron compounds (e.g., iron sulfate, iron chloride, etc.), manganese compounds (e.g., manganese sulfate, manganese nitrate, etc.), bismuth compounds (e.g., bismuth nitrate, bismuth acetate, etc.), tin compounds (e.g., tin sulfate, tin chloride, etc.), selenium compounds (e.g., selenic acid, selenious acid, etc.), cyanides (e.g., methyl cyanide, isopropyl cyanide, etc.), iodine compounds (e.g., potassium iodide, etc.), and the like.

[0129] The stabilizers may be used alone or in combination of two or more.

[0130] The concentration of the stabilizer in the electroless palladium plating solution and the electroless palladium-phosphorus plating solution is not particularly limited, and can be, for example, about 0.1 mg / L to 500 mg / L. In order to improve the stability of the electroless palladium plating solution and the electroless palladium-phosphorus plating solution, it is preferable to set the concentration of the stabilizer to about 0.1 mg / L or more. If the concentration of the stabilizer exceeds 500 mg / L, there may be some places where the plating film is not formed (non-deposited places), so it is preferable to set the concentration within the above range.

[0131] As the pH adjuster, for example, an acid such as hydrochloric acid, sulfuric acid, phosphoric acid, etc.; or an alkali such as sodium hydroxide, potassium hydroxide, ammonia water, etc. is preferably used.

[0132] The pH of the electroless palladium plating solution and the electroless palladium-phosphorus plating solution is preferably about 3 to 12, and more preferably about 4 to 9. The pH of the plating bath can be adjusted using the above-mentioned pH adjuster. If the pH is less than 3, non-precipitation may occur, and if it exceeds 12, the bath stability may decrease, so it is preferable to keep the pH in the above range.

[0133] As the surfactant, various surfactants such as nonionic, anionic, cationic, and amphoteric surfactants can be used. For example, aromatic or aliphatic sulfonic acid alkali salts, aromatic or aliphatic sulfonic acid alkali metal salts, etc. can be mentioned. The surfactant can be used alone or in combination of two or more. When two or more surfactants are used in combination, the mixing ratio is not particularly limited and can be appropriately determined.

[0134] The concentration of the surfactant in the electroless palladium plating solution and the electroless palladium-phosphorus plating solution is not particularly limited, and may be, for example, about 0.01 mg / L to 1000 mg / L. In order to further improve the effect of preventing pits in the electroless palladium plating solution and the electroless palladium-phosphorus plating solution, it is preferable to set the concentration of the surfactant to about 0.01 mg / L or more. When the concentration of the surfactant is 1000 mg / L or less, the decrease in deposition property due to foaming is further suppressed.

[0135] (Method of forming a barrier metal layer) In the barrier metal layer forming step, for example, electroless palladium plating is applied to the electroless nickel-phosphorus plating film. Coating , and electroless palladium-phosphorus plating Coating The method for forming the electroless nickel-phosphorus plating film is not particularly limited, and examples thereof include a method of contacting the surface of the electroless nickel-phosphorus plating film formed in step 1 with an electroless palladium plating solution and an electroless palladium-phosphorus plating solution.

[0136] The method of bringing the surface of the electroless nickel-phosphorus plating film into contact with the electroless palladium plating solution and the electroless palladium-phosphorus plating solution is not particularly limited, and can be carried out according to a conventional method. In the barrier metal layer forming step, a preferred example is a method of immersing a substrate on which an electroless nickel-phosphorus plating film has been formed in the electroless palladium plating solution and the electroless palladium-phosphorus plating solution.

[0137] The plating conditions (eg, solution temperature, plating time, etc.) are not particularly limited as long as they are conditions under which an electroless palladium plating layer and an electroless palladium-phosphorus plating layer are formed, and can be appropriately determined.

[0138] The solution temperatures of the electroless palladium plating solution and the electroless palladium-phosphorus plating solution in the barrier metal layer forming step can be appropriately determined depending on the composition of the electroless palladium plating solution and the electroless palladium-phosphorus plating solution, etc. For example, the solution temperatures of the electroless palladium plating solution and the electroless palladium-phosphorus plating solution in the plating step can be preferably about 25° C. or higher, more preferably about 40° C. to 90° C., and even more preferably about 45° C. to 85° C. If the solution temperature is less than 25° C., the deposition rate of the plating film may be slow, and the production efficiency may decrease, so it is preferable to set the solution temperature within the above range.

[0139] The treatment time in the barrier metal layer forming step is not particularly limited, and may be the time required to form an electroless palladium plating layer or an electroless palladium-phosphorus plating layer having a required thickness. The treatment time in the plating step may be appropriately determined depending on the composition of the electroless palladium plating solution or the electroless palladium-phosphorus plating solution, and may be, for example, preferably about 1 to 40 minutes, more preferably 3 to 20 minutes.

[0140] The electroless palladium plating film and the electroless palladium-phosphorus plating film formed by the barrier metal layer forming step are the barrier metal layer as the layer (C) that may be included in the plating film for metal sintering bonding of the present invention. The characteristics of the barrier metal layer formed by the barrier metal layer forming step are the same as those described for the layer (C) in the plating film for metal sintering bonding of the present invention.

[0141] By the barrier metal layer forming step described above, a barrier metal layer (C) is formed on the electroless nickel-phosphorus plating film (A). By including the barrier metal layer forming step, the barrier metal layer (C) can be formed between the layer (A) and the layer (B).

[0142] 3. Semiconductor mounting board The semiconductor mounting substrate of the present invention is a semiconductor mounting substrate having (A) a plating film for metal sintering bonding having an electroless nickel-phosphorus plating film laminated on a substrate, and having a semiconductor element on the plating film for metal sintering bonding via a metal sintered material layer, and the phosphorus content of the (A) electroless nickel-phosphorus plating film is 4 mass% or less, assuming the electroless nickel-phosphorus plating film to be 100 mass%.

[0143] The semiconductor mounting board of the present invention has the above-mentioned plating film for metal sintering bonding of the present invention formed on a substrate, and a semiconductor element is bonded to the plating film for metal sintering bonding via a metal sintered material layer.

[0144] The properties of the plating film for metal sinter bonding are the same as those described above in the description of the plating film for metal sinter bonding of the present invention.

[0145] In the semiconductor mounting board of the present invention, the semiconductor element is bonded via the metal sintered material layer.

[0146] As the sintering material for forming the metal sintering material layer, a sintering material paste containing metal powder and an organic solvent can be used.

[0147] The metal powder contained in the sintering material paste is not particularly limited, and any known metal powder used in conventional sintering materials can be used. Examples of such metals include silver, copper, and gold. Among these, copper and silver powders are preferred, and silver powder is more preferred.

[0148] The average particle size of the metal powder is not particularly limited, and any metal powder of a known size can be used. The average particle size of the metal powder is preferably on the order of several μm to mm.

[0149] The organic solvent contained in the sintering material paste is not particularly limited, and known organic solvents used in conventional sintering material pastes can be used. Examples of such organic solvents include methanol, ethanol, 1-propanol, 2-propanol, 2-butanol, 1-butanol, 2-methyl-1-propanol, 2-methyl-2-propanol, 1-pentanol, 1-octanol, toluene, diethylene glycol, triethylene glycol, ethylene glycol monomethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monomethyl ether, diethylene glycol monohexyl ether, terpineol, diethylene glycol methyl ether acetate terpineol, diisopropyl ether, tetrahydrofuran, and 1,4-dioxane. Among these, toluene, diethylene glycol, triethylene glycol, diethylene glycol monomethyl ether, terpineol, and diethylene glycol methyl ether acetate terpineol can be preferably used.

[0150] The heating temperature during metal sinter bonding is not particularly limited, and may be the same as that used for ordinary metal sinter bonding, which is about 100 to 450°C.

[0151] The pressure during metal sintering bonding may be either no pressure or pressure. When pressure is applied, the pressure is preferably about 0.1 MPa to 50 MPa, and more preferably about 0.2 MPa to 5 MPa.

[0152] The configuration of the semiconductor mounting board of the present invention may be such that at least a plating film for metal sintering bonding having an electroless nickel-phosphorus plating film (A) is laminated on a substrate, and a semiconductor element is provided on the plating film for metal sintering bonding via a metal sintered material layer. That is, the configuration of the semiconductor mounting board of the present invention may be such that at least a substrate / plating film for metal sintering bonding / metal sintered material layer / semiconductor element is provided, but the semiconductor element may also have a plating film for metal sintering bonding. That is, the configuration of the semiconductor mounting board of the present invention may be such that a substrate / plating film for metal sintering bonding / metal sintered material layer / plating film for metal sintering bonding / semiconductor element is provided, and more specifically, a substrate / (A) layer / metal sintered material layer / (A) layer / semiconductor element is provided.

[0153] The semiconductor mounting substrate of the present invention has the plating film for metal sintering bonding formed on a substrate, and a semiconductor element is bonded to the plating film for metal sintering bonding via a metal sintered material layer, so that the semiconductor mounting substrate of the present invention has excellent heat resistance and cold and thermal shock resistance. Such a semiconductor mounting substrate of the present invention can be suitably used as a next-generation power module capable of operating in a high-temperature environment.

[0154] The plating film for metal sintering bonding of the present invention has the above-mentioned configuration, and therefore has excellent heat resistance and cold and thermal shock resistance. Therefore, it can be suitably used for metal sintering bonding, and can also be used to form a bonded body between a substrate (e.g., an insulating heat dissipation circuit substrate such as a DBC substrate or a DBA substrate) and a substrate (e.g., a heat sink or heat sink). Examples of the configuration of such a bonded body include a substrate (e.g., an insulating heat dissipation circuit substrate such as a DBC substrate or a DBA substrate) / plating film for metal sintering bonding / metal sintered material layer / plating film for metal sintering bonding / substrate (e.g., a heat sink or heat sink). EXAMPLES

[0155] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.

[0156] In each of the Examples and Comparative Examples, a copper bulk material (30×30×3 mm) was used as the substrate (object to be plated). The substrate was pretreated by degreasing and acid activation treatment, and then by applying a palladium catalyst.

[0157] (Example 1) Plated material: electroless nickel-phosphorus plating film: electroless silver plating film

[0158] Formation of electroless nickel-phosphorus plating film An electroless nickel-phosphorus plating film was formed on the object to be plated by contacting the object with an electroless nickel-phosphorus plating solution having the following composition under the following plating conditions. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 20g / L, glycine 20g / L, lead acetate 0.5mg / L, and thiourea 0.1mg / L. After adding other trace additives, the pH is adjusted to 6.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 90℃ Contact time with plating solution: 20 minutes

[0159] Formation of electroless silver plating film The electroless nickel-phosphorus plating film formed on the substrate was brought into contact with an electroless silver plating solution having the following composition under the following plating conditions to form an electroless silver plating film on the electroless nickel-phosphorus plating film. Electroless silver plating formulation The basic composition is 1.7g / L silver nitrate, 1.5g / L water-soluble hydrazine derivative, 20g / L 1-methylhydantoin, 0.5mg / L lead acetate, and other trace additives. The pH is adjusted to 10 with nitric acid and sodium hydroxide. Electroless silver plating conditions Liquid temperature: 60℃ Contact time with plating solution: 20 minutes

[0160] As a result of the above, a plating film for metal sintering bonding was produced in which an electroless nickel-phosphorus plating film and an electroless silver plating film were formed in this order on an object to be plated. Electroless nickel-phosphorus plating film: phosphorus content 4% by mass, sulfur content 0.0003% by mass, thickness 4 μm Electroless silver plating film: thickness 0.2μm

[0161] (Example 2) Plated material: electroless nickel-phosphorus plating film: electroless silver plating film By changing the composition and plating conditions of the electroless nickel-phosphorus plating of Example 1 as follows, a plating film for metal sintering bonding was produced in which the following electroless nickel-phosphorus plating film and electroless silver plating film were formed in this order on the plated object. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 10g / L, glycine 20g / L, lead acetate 0.5mg / L, and thiourea 0.1mg / L. After adding other trace additives, the pH is adjusted to 6.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 90℃ Contact time with plating solution: 25 minutes Electroless nickel-phosphorus plating film: phosphorus content 2% by mass, sulfur content 0.0003% by mass, thickness 4μm Electroless silver plating film: thickness 0.2μm

[0162] (Example 3) Plated material: electroless nickel-phosphorus plating film: electroless silver plating film By changing the composition and plating conditions of the electroless nickel-phosphorus plating of Example 1 as follows, a plating film for metal sintering bonding was produced in which the following electroless nickel-phosphorus plating film and electroless silver plating film were formed in this order on the plated object. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 8g / L, glycine 20g / L, lead acetate 0.5mg / L, and other trace additives are added. The pH is adjusted to 6.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 90℃ Contact time with plating solution: 25 minutes Electroless nickel-phosphorus plating film: phosphorus content 2% by mass, sulfur content 0.0001% by mass, thickness 4μm Electroless silver plating film: thickness 0.2μm

[0163] (Example 4) Plated material: electroless nickel-phosphorus plating film: electroless silver plating film By changing the composition and plating conditions of the electroless nickel-phosphorus plating of Example 1 as follows, a plating film for metal sintering bonding was produced in which the following electroless nickel-phosphorus plating film and electroless silver plating film were formed in this order on the plated object. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 8g / L, glycine 20g / L, lead acetate 0.5mg / L, and other trace additives are added. The pH is adjusted to 6.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 90℃ Contact time with plating solution: 3.5 minutes Electroless nickel-phosphorus plating film: phosphorus content 2% by mass, sulfur content 0.0001% by mass, thickness 0.5 μm Electroless silver plating film: thickness 0.2μm

[0164] (Example 5) Plated object: electroless nickel-phosphorus plating film: electroless silver plating film By changing the composition and plating conditions of the electroless silver plating of Example 2 as follows, a plating film for metal sintering bonding was produced in which the following electroless nickel-phosphorus plating film and electroless silver plating film were formed in this order on the plated object. Electroless silver plating formulation The basic composition is 1.7g / L silver nitrate, 1.5g / L water-soluble hydrazine derivative, 20g / L 1-methylhydantoin, 0.5mg / L lead acetate, and other trace additives. The pH is adjusted to 10 with nitric acid and sodium hydroxide. Electroless silver plating conditions Liquid temperature: 60℃ Contact time with plating solution: 10 minutes Electroless nickel-phosphorus plating film: phosphorus content 2% by mass, sulfur content 0.0003% by mass, thickness 4μm Electroless silver plating film: thickness 0.1μm

[0165] (Example 6) Plated object: electroless nickel-phosphorus plating film: electroless gold plating film

[0166] Formation of electroless nickel-phosphorus plating film An electroless nickel-phosphorus plating film was formed on the object to be plated by contacting the object with an electroless nickel-phosphorus plating solution having the following composition under the following plating conditions. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 20g / L, glycine 20g / L, lead acetate 0.5mg / L, and thiourea 0.1mg / L. After adding other trace additives, the pH is adjusted to 6.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 90℃ Contact time with plating solution: 20 minutes

[0167] Formation of electroless gold plating film The electroless nickel-phosphorus plating film formed on the substrate was brought into contact with an electroless gold plating solution having the following composition under the following plating conditions to form an electroless gold plating film on the electroless nickel-phosphorus plating film. Electroless Gold Plating Formulation The basic composition is 1.8g / L potassium gold cyanide, 15g / L sodium ethylenediaminetetraacetate, and other trace additives, and then the pH is adjusted to 5.0 with sulfuric acid and ammonia water. Electroless Gold Plating Conditions Liquid temperature: 85℃ Contact time with plating solution: 10 minutes

[0168] As a result of the above, a plating film for metal sintering bonding was produced in which an electroless nickel-phosphorus plating film and an electroless gold plating film were formed in this order on the object to be plated. Electroless nickel-phosphorus plating film: phosphorus content 4% by mass, sulfur content 0.0003% by mass, thickness 4 μm Electroless gold plating film: thickness 0.05μm

[0169] (Example 7) Plated material: electroless nickel-phosphorus plating film: electroless gold plating film By changing the composition and plating conditions of the electroless nickel-phosphorus plating of Example 6 as follows, a plating film for metal sintering bonding was produced in which the following electroless nickel-phosphorus plating film and electroless gold plating film were formed in this order on the plated object. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 10g / L, glycine 20g / L, lead acetate 0.5mg / L, and thiourea 0.1mg / L. After adding other trace additives, the pH is adjusted to 6.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 90℃ Contact time with plating solution: 25 minutes Electroless nickel-phosphorus plating film: phosphorus content 2% by mass, sulfur content 0.0003% by mass, thickness 4μm Electroless gold plating film: thickness 0.05μm

[0170] (Example 8) Plated material: electroless nickel-phosphorus plating film: electroless palladium plating film-electroless silver plating film

[0171] Formation of electroless nickel-phosphorus plating film An electroless nickel-phosphorus plating film was formed on the object to be plated by bringing the object into contact with an electroless nickel-phosphorus plating solution having the following composition under the following conditions. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 10g / L, glycine 20g / L, lead acetate 0.5mg / L, and thiourea 0.1mg / L. After adding other trace additives, the pH is adjusted to 6.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 90℃ Contact time with plating solution: 25 minutes

[0172] Formation of electroless palladium plating film The electroless nickel-phosphorus plating film formed on the substrate was brought into contact with an electroless palladium plating solution having the following composition under the following conditions to form an electroless palladium plating film on the electroless nickel-phosphorus plating film. Electroless palladium plating formulation The basic composition is palladium chloride 1.5g / L, sodium formate 10g / L, ethylenediamine 15g / L, and other trace additives, and then the pH is adjusted to 6.0 with hydrochloric acid and ammonia water. Electroless palladium plating conditions Liquid temperature: 55℃ Contact time with plating solution: 10 minutes

[0173] Formation of electroless silver plating film The electroless palladium plating film formed as described above was brought into contact with an electroless silver plating solution having the following composition under the following conditions to form an electroless silver plating film on the electroless palladium plating film. Electroless silver plating formulation The basic composition is 1.7g / L silver nitrate, 1.5g / L water-soluble hydrazine derivative, 20g / L 1-methylhydantoin, 0.5mg / L lead acetate, and other trace additives. The pH is adjusted to 10 with nitric acid and sodium hydroxide. Electroless silver plating conditions Liquid temperature: 70℃ Contact time with plating solution: 20 minutes

[0174] As a result of the above, a plating film for metal sintering bonding was produced in which an electroless nickel-phosphorus plating film, an electroless palladium plating film, and an electroless silver plating film were formed in this order on the object to be plated. Electroless nickel-phosphorus plating film: phosphorus content 2% by mass, sulfur content 0.0003% by mass, thickness 4μm Electroless palladium plating film: thickness 0.1μm Electroless silver plating film: thickness 0.2μm

[0175] (Example 9) Plated material: Electroless nickel-phosphorus plating film: Electroless palladium plating film: Electroless gold plating film

[0176] Formation of electroless nickel-phosphorus plating film An electroless nickel-phosphorus plating film was formed on the object to be plated by bringing the object into contact with an electroless nickel-phosphorus plating solution having the following composition under the following conditions. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 10g / L, glycine 20g / L, lead acetate 0.5mg / L, and thiourea 0.1mg / L. After adding other trace additives, the pH is adjusted to 6.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 90℃ Contact time with plating solution: 25 minutes

[0177] Formation of electroless palladium plating film The electroless nickel-phosphorus plating film formed on the substrate was brought into contact with an electroless palladium plating solution having the following composition under the following conditions to form an electroless palladium plating film on the electroless nickel-phosphorus plating film. Electroless palladium plating formulation The basic composition is palladium chloride 1.5g / L, sodium formate 10g / L, ethylenediamine 15g / L, and other trace additives, and then the pH is adjusted to 6.0 with hydrochloric acid and ammonia water. Electroless palladium plating conditions Liquid temperature: 55℃ Contact time with plating solution: 10 minutes

[0178] Formation of electroless gold plating film The electroless palladium plating film formed as described above was brought into contact with an electroless gold plating solution having the following composition under the following conditions to form an electroless gold plating film on the electroless palladium plating film. Electroless Gold Plating Formulation The basic composition is 1.8g / L potassium gold cyanide, 15g / L sodium ethylenediaminetetraacetate, and other trace additives, and then the pH is adjusted to 5.0 with sulfuric acid and ammonia water. Electroless Gold Plating Conditions Liquid temperature: 90℃ Contact time with plating solution: 10 minutes

[0179] As a result of the above, a plating film for metal sintering bonding was produced in which an electroless nickel-phosphorus plating film, an electroless palladium plating film, and an electroless gold plating film were formed in this order on the object to be plated. Electroless nickel-phosphorus plating film: phosphorus content 2% by mass, sulfur content 0.0003% by mass, thickness 4μm Electroless palladium plating film: thickness 0.1μm Electroless gold plating film: thickness 0.05μm

[0180] (Example 10) Plated material: Electroless nickel-phosphorus plating film: Electroless palladium-phosphorus plating film: Electroless silver plating film

[0181] Formation of electroless nickel-phosphorus plating film An electroless nickel-phosphorus plating film was formed on an object to be plated by contacting the object with an electroless Ni-P plating solution having the following composition under the following conditions. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 10g / L, glycine 20g / L, lead acetate 0.5mg / L, and thiourea 0.1mg / L. After adding other trace additives, the pH is adjusted to 6.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 90℃ Contact time with plating solution: 25 minutes

[0182] Formation of electroless palladium-phosphorus plating film The electroless nickel-phosphorus plating film formed on the substrate was brought into contact with an electroless palladium-phosphorus plating solution having the following composition under the following conditions to form an electroless palladium-phosphorus plating film on the electroless nickel-phosphorus plating film. Electroless palladium-phosphorus plating formulation The basic composition is palladium chloride 1.5g / L, sodium hypophosphite 10g / L, ethylenediamine 15g / L, and other trace additives are added, and the pH is adjusted to 6.0 with hydrochloric acid and ammonia water. Electroless palladium-phosphorus plating conditions Liquid temperature: 60℃ Contact time with plating solution: 10 minutes

[0183] Formation of electroless silver plating film The electroless palladium-phosphorus plating film formed as described above was brought into contact with an electroless silver plating solution having the following composition under the following conditions to form an electroless silver plating film on the electroless palladium-phosphorus plating film. Electroless silver plating formulation The basic composition is 1.7g / L silver nitrate, 1.5g / L water-soluble hydrazine derivative, 20g / L 1-methylhydantoin, 0.5mg / L lead acetate, and other trace additives. The pH is adjusted to 10 with nitric acid and sodium hydroxide. Electroless silver plating conditions Liquid temperature: 70℃ Contact time with plating solution: 20 minutes

[0184] As a result of the above, a plating film for metal sintering bonding was produced in which an electroless nickel-phosphorus plating film, an electroless palladium-phosphorus plating film, and an electroless silver plating film were formed in this order on the object to be plated. Electroless nickel-phosphorus plating film: phosphorus content 2% by mass, sulfur content 0.0003% by mass, thickness 4μm Electroless palladium-phosphorus plating film: phosphorus content 1% by mass, thickness 0.1 μm Electroless silver plating film: thickness 0.2μm

[0185] (Example 11) Plated material: Electroless nickel-phosphorus plating film: Electroless palladium-phosphorus plating film: Electroless gold plating film

[0186] Formation of electroless nickel-phosphorus plating film An electroless nickel-phosphorus plating film was formed on an object to be plated by contacting the object with an electroless Ni-P plating solution having the following composition under the following conditions. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 10g / L, glycine 20g / L, lead acetate 0.5mg / L, and thiourea 0.1mg / L. After adding other trace additives, the pH is adjusted to 6.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 90℃ Contact time with plating solution: 25 minutes

[0187] Formation of electroless palladium-phosphorus plating film The electroless nickel-phosphorus plating film formed on the substrate was brought into contact with an electroless palladium-phosphorus plating solution having the following composition under the following conditions to form an electroless palladium-phosphorus plating film on the electroless nickel-phosphorus plating film. Electroless palladium-phosphorus plating formulation The basic composition is palladium chloride 1.5g / L, sodium hypophosphite 10g / L, ethylenediamine 15g / L, and other trace additives are added, and the pH is adjusted to 6.0 with hydrochloric acid and ammonia water. Electroless palladium-phosphorus plating conditions Liquid temperature: 60℃ Contact time with plating solution: 10 minutes

[0188] Formation of electroless gold plating film The electroless palladium-phosphorus plating film formed as described above was brought into contact with an electroless gold plating solution having the following composition under the following conditions to form an electroless gold plating film on the electroless palladium-phosphorus plating film. Electroless Gold Plating Formulation The basic composition is 1.8g / L potassium gold cyanide, 15g / L sodium ethylenediaminetetraacetate, and other trace additives, and then the pH is adjusted to 5.0 with sulfuric acid and ammonia water. Electroless Gold Plating Conditions Liquid temperature: 90℃ Contact time with plating solution: 10 minutes

[0189] As a result of the above, a plating film for metal sintering bonding was produced in which an electroless nickel-phosphorus plating film, an electroless palladium-phosphorus plating film, and an electroless gold plating film were formed in this order on the object to be plated. Electroless nickel-phosphorus plating film: phosphorus content 2% by mass, sulfur content 0.0003% by mass, thickness 4μm Electroless palladium-phosphorus plating film: phosphorus content 1% by mass, thickness 0.1 μm Electroless gold plating film: thickness 0.05μm

[0190] (Example 12) Plated object: electroless nickel-phosphorus plating film

[0191] Formation of electroless nickel-phosphorus plating film An electroless nickel-phosphorus plating film was formed on the object to be plated by bringing the object into contact with an electroless nickel-phosphorus plating solution having the following composition under the following conditions. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 20g / L, glycine 20g / L, lead acetate 0.5mg / L, and thiourea 0.1mg / L. After adding other trace additives, the pH is adjusted to 6.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 90℃ Contact time with plating solution: 20 minutes

[0192] As a result of the above, a plating film for metal sintering bonding was produced in which the following electroless nickel-phosphorus plating film was formed on the object to be plated. Electroless nickel-phosphorus plating film: phosphorus content 4% by mass, sulfur content 0.0003% by mass, thickness 4 μm

[0193] (Example 13) Plated object: electroless nickel-phosphorus plating film

[0194] Formation of electroless nickel-phosphorus plating film An electroless nickel-phosphorus plating film was formed on the object to be plated by bringing the object into contact with an electroless nickel-phosphorus plating solution having the following composition under the following conditions. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 10g / L, glycine 20g / L, lead acetate 0.5mg / L, and thiourea 0.1mg / L. After adding other trace additives, the pH is adjusted to 6.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 90℃ Contact time with plating solution: 25 minutes

[0195] As a result of the above, a plating film for metal sintering bonding was produced in which the following electroless nickel-phosphorus plating film was formed on the object to be plated. Electroless nickel-phosphorus plating film: phosphorus content 2% by mass, sulfur content 0.0003% by mass, thickness 4μm

[0196] (Example 14) Plated object: electroless nickel-phosphorus plating film

[0197] Formation of electroless nickel-phosphorus plating film An electroless nickel-phosphorus plating film was formed on the object to be plated by bringing the object into contact with an electroless nickel-phosphorus plating solution having the following composition under the following conditions. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 8g / L, glycine 20g / L, lead acetate 0.5mg / L, and other trace additives are added. The pH is adjusted to 6.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 90℃ Contact time with plating solution: 25 minutes

[0198] As a result of the above, a plating film for metal sintering bonding was produced in which the following electroless nickel-phosphorus plating film was formed on the object to be plated. Electroless nickel-phosphorus plating film: phosphorus content 2% by mass, sulfur content 0.0001% by mass, thickness 4μm

[0199] (Comparative Example 1) Plated object: Electroless nickel-phosphorus plating film: Electroless silver plating film

[0200] Formation of electroless nickel-phosphorus plating film An electroless nickel-phosphorus plating film was formed on the object to be plated by contacting the object with an electroless nickel-phosphorus plating solution having the following composition under the following plating conditions. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 25g / L, malic acid 15g / L, lead acetate 0.5mg / L, and other trace additives are added. The pH is adjusted to 4.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 90℃ Contact time with plating solution: 20 minutes

[0201] Formation of electroless silver plating film The electroless nickel-phosphorus plating film formed on the substrate was brought into contact with an electroless silver plating solution having the following composition under the following plating conditions to form an electroless silver plating film on the electroless nickel-phosphorus plating film. Electroless silver plating formulation The basic composition is 1.7g / L silver nitrate, 1.5g / L water-soluble hydrazine derivative, 20g / L 1-methylhydantoin, 0.5mg / L lead acetate, and other trace additives. The pH is adjusted to 10 with nitric acid and sodium hydroxide. Electroless silver plating conditions Liquid temperature: 60℃ Contact time with plating solution: 20 minutes

[0202] As a result of the above, a plating film for metal sintering bonding was produced in which an electroless nickel-phosphorus plating film and an electroless silver plating film were formed in this order on an object to be plated. Electroless nickel-phosphorus plating film: Phosphorus content 10% by mass, sulfur content 0.0001% by mass, thickness 4 μm Electroless silver plating film: thickness 0.2μm

[0203] (Comparative Example 2) Plated object: Electroless nickel-phosphorus plating film: Electroless silver plating film By changing the composition and plating conditions of the electroless nickel-phosphorus plating of Comparative Example 1 as follows, a plating film for metal sintering bonding was produced in which the following electroless nickel-phosphorus plating film and electroless silver plating film were formed in this order on the plated object. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 25g / L, malic acid 15g / L, lead acetate 0.5mg / L, and thiourea 0.1mg / L. After adding other trace additives, the pH is adjusted to 4.8 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 85℃ Contact time with plating solution: 20 minutes Electroless nickel-phosphorus plating film: phosphorus content 7% by mass, sulfur content 0.0001% by mass, thickness 4μm Electroless silver plating film: thickness 0.2μm

[0204] (Comparative Example 3) Plated object: Electroless nickel-phosphorus plating film: Electroless silver plating film By changing the composition and plating conditions of the electroless nickel-phosphorus plating of Comparative Example 1 as follows, a plating film for metal sintering bonding was produced in which the following electroless nickel-phosphorus plating film and electroless silver plating film were formed in this order on the plated object. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 25g / L, malic acid 15g / L, lead acetate 0.5mg / L, and thiourea 0.2mg / L. After adding other trace additives, the pH is adjusted to 4.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 85℃ Contact time with plating solution: 20 minutes Electroless nickel-phosphorus plating film: phosphorus content 7% by mass, sulfur content 0.0003% by mass, thickness 4 μm Electroless silver plating film: thickness 0.2μm

[0205] (Comparative Example 4) Plated object: Electroless silver plating film

[0206] Formation of electroless silver plating film An electroless silver plating film was formed on the object to be plated by bringing the object into contact with an electroless silver plating solution having the following composition under the following plating conditions. Electroless silver plating formulation The basic composition is 1.7g / L silver nitrate, 1.5g / L water-soluble hydrazine derivative, 20g / L 1-methylhydantoin, 0.5mg / L lead acetate, and other trace additives. The pH is adjusted to 10 with nitric acid and sodium hydroxide. Electroless silver plating conditions Liquid temperature: 60℃ Contact time with plating solution: 20 minutes

[0207] As a result of the above, a plating film for metal sintering bonding was produced in which the following electroless silver plating film was formed on the object to be plated. Electroless silver plating film: thickness 0.2μm

[0208] (Comparative Example 5) Plated object: Electroless silver plating film

[0209] Formation of electroless silver plating film An electroless silver plating film was formed on the object to be plated by bringing the object into contact with an electroless silver plating solution having the following composition under the following plating conditions. Electroless silver plating formulation The basic composition is 1.7g / L silver nitrate, 1.5g / L water-soluble hydrazine derivative, 20g / L 1-methylhydantoin, 0.5mg / L lead acetate, and other trace additives. The pH is adjusted to 10 with nitric acid and sodium hydroxide. Electroless silver plating conditions Liquid temperature: 70℃ Contact time with plating solution: 40 minutes

[0210] As a result of the above, a plating film for metal sintering bonding was produced in which the following electroless silver plating film was formed on the object to be plated. Electroless silver plating film: thickness 1.0μm

[0211] (Comparative Example 6) Plated object: Electroless nickel-phosphorus plating film

[0212] Formation of electroless nickel-phosphorus plating film An electroless nickel-phosphorus plating film was formed on the object to be plated by bringing the object into contact with an electroless nickel-phosphorus plating solution having the following composition under the following conditions. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 25g / L, malic acid 15g / L, lead acetate 0.5mg / L, and other trace additives. The pH is adjusted to 4.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 90℃ Contact time with plating solution: 20 minutes

[0213] As a result of the above, a plating film for metal sintering bonding was produced in which the following electroless nickel-phosphorus plating film was formed on the object to be plated. Electroless nickel-phosphorus plating film: Phosphorus content 10% by mass, sulfur content 0.0001% by mass, thickness 4 μm

[0214] (Comparative Example 7) Plated object: Electroless nickel-phosphorus plating film

[0215] Formation of electroless nickel-phosphorus plating film An electroless nickel-phosphorus plating film was formed on the object to be plated by bringing the object into contact with an electroless nickel-phosphorus plating solution having the following composition under the following conditions. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 25g / L, malic acid 15g / L, lead acetate 0.5mg / L, and thiourea 0.1mg / L. After adding other trace additives, the pH is adjusted to 4.8 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 85℃ Contact time with plating solution: 20 minutes

[0216] As a result of the above, a plating film for metal sintering bonding was produced in which the following electroless nickel-phosphorus plating film was formed on the object to be plated. Electroless nickel-phosphorus plating film: phosphorus content 7% by mass, sulfur content 0.0001% by mass, thickness 4μm

[0217] (Comparative Example 8) Plated object: Electroless nickel-phosphorus plating film

[0218] Formation of electroless nickel-phosphorus plating film An electroless nickel-phosphorus plating film was formed on the object to be plated by bringing the object into contact with an electroless nickel-phosphorus plating solution having the following composition under the following conditions. Electroless Nickel-Phosphorus Plating Formulation The basic composition is nickel sulfate 6H2O 22.5g / L, sodium hypophosphite 25g / L, malic acid 15g / L, lead acetate 0.5mg / L, and thiourea 0.2mg / L. After adding other trace additives, the pH is adjusted to 4.5 with sulfuric acid and ammonia water. Electroless nickel-phosphorus plating conditions Liquid temperature: 85℃ Contact time with plating solution: 20 minutes

[0219] As a result of the above, a plating film for metal sintering bonding was produced in which the following electroless nickel-phosphorus plating film was formed on the object to be plated. Electroless nickel-phosphorus plating film: phosphorus content 7% by mass, sulfur content 0.0003% by mass, thickness 4 μm

[0220] (Comparative Example 9) Plated object as is (copper bulk material)

[0221] (Evaluation method) The following evaluations were carried out for the examples and comparative examples.

[0222] Sample preparation for measuring the bond strength of silver sintered bonds A semiconductor element was mounted on the metal sintering bonding plating film produced in each Example and Comparative Example via a silver sintering material. Specifically, a paste material in which micron-sized silver flakes (manufactured by Fukuda Metal Foil and Powder Co., Ltd.) and an ether solvent (manufactured by Daicel Corporation) were mixed was used as the silver sintering material. A SiC dummy chip (3 mm x 3 mm x 1 mm) on which a titanium / silver sputtered film (0.1 μm / 1.0 μm) was formed was used as the semiconductor element. A sample for evaluating silver sintering bonding was prepared by bonding a metal sintering bonding plating film formed on a substrate and a SiC dummy chip on which a titanium / silver sputtered film was formed using a silver sintering material. The bonding conditions for Examples 1 to 11 and Comparative Examples 1 to 5 were no pressure, air atmosphere, 250°C, and 30 minutes, and the bonding conditions for Examples 12 to 14 and Comparative Examples 6 to 9 were 1 MPa pressure, air atmosphere, 250°C, and 30 minutes.

[0223] Bonding strength measurement A shear test was conducted on the above-mentioned evaluation samples using a bond tester (Nordson DAGE 4000Plus) to measure the bonding strength between the plating film for metal sintering bonding and the silver sintered material. The shear test was conducted immediately after silver sintering bonding and after heat treatment at 300℃ for 500 hours, and the initial bondability and bondability after heat treatment were evaluated according to the following evaluation criteria. 30MPa or more: Good bonding strength Less than 30Mpa: Insufficient bonding strength

[0224] The results are shown in Table 1.

[0225] [Table 1]

[0226] From the results in Table 1, it was found that in Examples 1 to 14, the initial bondability and bondability after heat treatment were excellent, and the bond strength was not significantly reduced even by heat treatment, so that the plated films had excellent heat resistance and resistance to cold and hot shocks and were suitable for metal sintering bonding.

[0227] In contrast to this, in Comparative Examples 1 to 9, the bondability after heat treatment was significantly lower than the initial bondability, and it was found that these examples were inferior to Examples 1 to 14 in heat resistance and thermal shock resistance.

Claims

1. (A) A plating film for metal sintering bonding having an electroless nickel-phosphorus plating film, The phosphorus content of the (A) electroless nickel-phosphorus plating film is 4% by mass or less, with the electroless nickel-phosphorus plating film being 100% by mass; Further, the electroless nickel-phosphorus plating film (A) has an electroless silver plating film (B). A plating film for metal sinter bonding, characterized in that:

2. The plating film for metal sintering bonding according to claim 1, wherein the sulfur content of the (A) electroless nickel-phosphorus plating film is less than 0.0005% by mass, with the electroless nickel-phosphorus plating film being 100% by mass.

3. The plating film for metal sintering bonding according to claim 1, wherein the sulfur content of the (A) electroless nickel-phosphorus plating film is 0.0001 mass% or less, with the electroless nickel-phosphorus plating film being 100 mass%.

4. The plating film for metal sintering bonding according to claim 1, wherein the thickness of the electroless nickel-phosphorus plating film (A) is 0.1 to 20 μm or less.

5. The plating film for metal sintering bonding according to claim 1, wherein the thickness of the electroless silver plating film (B) is 0.02 to 2 μm.

6. The plating film for metal sintering bonding according to claim 1, further comprising a barrier metal layer (C) between the electroless nickel-phosphorus plating film (A) and the electroless silver plating film (B).

7. 7. The plating film for metal sintering bonding according to claim 6, wherein the barrier metal layer (C) is an electroless palladium plating film or an electroless palladium-phosphorus plating film.

8. The plating film for metal sintering bonding according to claim 1, which is for a metal sintered material containing silver and / or copper.

9. A method for producing a plating film for metal sintering bonding, which forms a plating film for metal sintering bonding on a substrate, comprising: (1) A process for producing an electroless nickel-phosphorus plating film on a surface of a substrate by contacting the surface of the substrate with an electroless nickel-phosphorus plating solution, The method further includes a step (2) of contacting a surface of the electroless nickel-phosphorus plating film with an electroless silver plating solution to form an electroless silver plating film (B) on the electroless nickel-phosphorus plating film (A), The phosphorus content of the (A) electroless nickel-phosphorus plating film is 4% by mass or less, assuming that the electroless nickel-phosphorus plating film is 100% by mass. The present invention relates to a method for producing a plating film for metal sinter bonding.

10. A plating film for metal sintering bonding having (A) an electroless nickel-phosphorus plating film and (B) an electroless silver plating film on the (A) electroless nickel-phosphorus plating film is laminated on a substrate; A semiconductor element is provided on the plating film for metal sintering bonding via a metal sintered material layer, The phosphorus content of the (A) electroless nickel-phosphorus plating film is 4% by mass or less, assuming that the electroless nickel-phosphorus plating film is 100% by mass. A semiconductor mounting board comprising:

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