JP6327784B2 - Metal material for electronic parts and method for producing the same - Google Patents

Description

  The present invention relates to a metal material for electronic parts and a method for producing the same.

  For connectors that are connecting parts for automobiles or electronic devices, an underplating layer of Ni or Cu is formed on the surface of brass or phosphor bronze, and the purpose is to provide low contact resistance and high solder wettability thereon. A plating layer is formed. In recent years, the plating layer is also required to have a reduced insertion force when mating a male terminal and a female terminal formed by pressing a plating material. In addition, such a plating layer includes a relatively soft layer. In the case of such plating, when the plating material comes into contact with another object, there is a defect that the plating is damaged and powder is easily generated.

On the other hand, a technique is known in which an organic lubricant of 0.01 to 10 mg / dm ² is applied to the plating material to reduce the insertion force (Patent Document 1). A technique is also known in which an oil-based protective film having a thickness of 10 to 100 mm is applied to a Sn alloy plating material to reduce the risk of causing scratches on the plating layer surface during press working (Patent Document 2).

  Furthermore, when left in a high temperature environment, the metal of the plating is oxidized, which may cause problems such as increased contact resistance and discoloration of the plating surface. For this reason, when the presence state of oxygen atoms (O) existing on the outermost surface of the plating material is analyzed by ESCA (X-ray photoelectron spectrometer), the top of the binding energy of the 1s orbit of oxygen atoms (O) is A technique having low contact resistance, high solder wettability, and high heat resistance is also known when the thickness is 531 eV or more and 532 eV or less and the thickness of the plating layer is 0.4 μm or more and 2.0 μm or less (Patent Document 3).

JP 2003-183882 A JP 2010-149261 A JP 2010-202903 A

However, in the case of the techniques described in Patent Document 1 and Patent Document 2, depending on the type of the organic lubricant and the oil-based protective film, there is a problem that the surface is discolored after heating for a long time, resulting in high contact resistance and poor solder wettability. .
Further, in the case of the technique of Patent Document 3, there is a problem that a lot of metal powder is generated during the press working of the plating material, and a lot of roots caused by the powder are generated in the pressed plating material.
That is, the present invention has been made to solve the above problems, suppresses the generation of powder during press working, has low contact resistance and high solder wettability, and retains these characteristics even after prolonged heating. It is an object of the present invention to provide a metal material for electronic parts and a manufacturing method thereof.

  As a result of intensive studies, the inventors of the present invention formed a plating formed of In, Ag, Au, Pt, Pd, Ru, Rh, Os, Ir, or an alloy thereof on a metal base material, and on the plating. By performing an appropriate surface treatment with a surface treatment liquid containing P and C, and forming a surface treatment layer in which the binding energy peaks of P and C, and the existence region and concentration of P and C are appropriately controlled, It has been found that a metal material for electronic parts that suppresses the generation of powder during pressing, has low contact resistance and high solder wettability, and retains these characteristics even after long-time heating can be produced.

The present invention completed on the basis of the above knowledge is, in one aspect, a metal substrate, an underlayer formed on the metal substrate , Ni, Cr, Mn, Fe, Co, Sn formed on the underlayer. , Cu or a B layer formed of an alloy containing one or more of these elements, formed on the B layer, In, Ag, Au, Pt, Pd, Ru, Rh, Os, Ir or one of these elements When the elemental analysis of the surface treatment layer surface is performed by Survey measurement of XPS (X-ray photoelectron spectrometer), which includes the A layer formed of the alloy including the above and the surface treatment layer formed on the A layer. , The peak of 2S orbital bond energy (P2S) of phosphorus (P) is in the range of 186 to 192 eV, P is contained at 0.5 at% or more and less than 5.0 at%, and the bond energy (C1S of 1S orbital of carbon (C) ) Peak It is a metal material for electronic components that is 284 to 290 eV and contains C at least 35 at% and less than 80 at%.

  In one embodiment, the metal material for an electronic component according to the present invention is such that when elemental analysis of the surface of the surface treatment layer is performed by XPS depth measurement, C is in a region of 0.5 nm from the surface of the surface treatment layer. %, And a region containing 20 at% or more of C is less than 15 nm from the surface of the surface treatment layer, and a region containing 30 at% or more of oxygen (O) is less than 15 nm from the surface of the surface treatment layer. It is.

  In one embodiment of the metal material for electronic parts according to the present invention, when elemental analysis of the surface treatment layer surface is performed by XPS survey measurement, C is contained at 50 at% or more and less than 80 at%, and XPS depth measurement is performed. When elemental analysis is performed on the surface of the surface treatment layer, C is present in the region from the surface of the surface treatment layer to 0.5 nm from the surface of the surface treatment layer to 50 at% or more and less than 80 at%, and a region containing C at 20 at% or more It is 2 nm or more and less than 15 nm from the surface of the treatment layer.

  In still another embodiment of the metal material for electronic parts according to the present invention, the A layer contains 11 or more of In, Ag, Au, Pt, Pd, Ru, Rh, Os, Ir or a total of one or more of these elements. It is a layer containing at least mass%.

  In still another embodiment of the metal material for electronic parts according to the present invention, the A layer is a layer containing one or more elements selected from Ni, Cr, Mn, Fe, Co, Sn, and Cu.

  In still another embodiment of the metal material for electronic parts according to the present invention, the A layer contains at least 1% by mass in total of at least one element selected from Ni, Cr, Mn, Fe, Co, Sn, and Cu. It is a layer that contains.

  In still another embodiment of the metal material for electronic parts according to the present invention, the thickness of the A layer is 0.0012 μm or more.

  In still another embodiment of the metal material for electronic parts according to the present invention, the A layer is composed of two or more layers.

  In another embodiment of the metal material for electronic parts according to the present invention, the composition of the alloy of the B layer is 50% by mass or more in total of Ni, Cr, Mn, Fe, Co, Sn, Cu, 1 type selected from the group which consists of B, P, Sn, Zn, or 2 types or more is included.

  In still another embodiment of the metal material for electronic parts according to the present invention, the B layer is composed of two or more layers.

  In another aspect, the present invention is the method for producing a metal material for an electronic component according to the present invention, comprising a step of performing a surface treatment with a surface treatment liquid containing phosphorus and carbon on the A layer of the metal substrate. .

  In one embodiment of the method for producing a metal material for electronic parts according to the present invention, the surface treatment liquid contains a phosphate ester compound and a mercaptobenzothiazole compound.

  According to the present invention, there are provided a metal material for electronic parts that suppresses the generation of powder during press working, has low contact resistance and high solder wettability, and retains these characteristics even after long-time heating, and a method for manufacturing the same. be able to.

It is a schematic diagram which shows the structure of the metal material for electronic components which concerns on embodiment of this invention. It is a Survey measurement result of XPS (X-ray photoelectron spectrometer) according to the first embodiment. It is a depth measurement of XPS (X-ray photoelectron spectrometer) according to the first embodiment. It is the schematic regarding the powder generation | occurrence | production test of an Example. It is a test apparatus schematic regarding the dynamic friction coefficient measurement of an Example.

  Hereinafter, the metal material for electronic components according to the embodiment of the present invention will be described. As shown in FIG. 1, a metal material 10 for an electronic component according to the present embodiment includes a metal base 11 and a base layer 12, a B layer 13, and an A layer formed on the metal base 11 in this order. 14 and the surface treatment layer 15. The underlayer 12 and the B layer 13 are not essential components in the present invention.

(Metal base material)
Although it does not specifically limit as the metal base material 11, For example, when using for a connector material, copper or a copper alloy is preferable. This is because copper or a copper alloy has advantages of high conductivity, excellent spreadability, and good spring characteristics.

(Underlayer)
Although it does not specifically limit as the base layer 12, For example, it can form with 1 or more types of metals selected from the group which consists of Cr, Fe, Co, Ni, Cu, and Zn. The thickness of the underlayer 12 is preferably 0.2 to 5.0 μm. When the thickness of the underlayer 12 is less than 0.2 μm, the metal base material component diffuses into the A14 layer and the B layer 13, and there is a possibility that the contact resistance becomes high and the solder wettability is deteriorated. On the other hand, when the thickness of the underlayer 12 exceeds 5.0 μm, there is no problem in characteristics, but there is a problem that the cost is increased.

(B layer)
The B layer 13 is made of Ni, Cr, Mn, Fe, Sn, Co, Cu or an alloy thereof. By forming the B layer 13 using Ni, Cr, Mn, Fe, Co, Cu, or an alloy thereof, the thin B lubrication effect is improved by the formation of the hard B layer 13 and the low insertion / removability is improved. Prevents the constituent metal of the metal substrate 11 from diffusing into the A14 layer, and improves durability, such as suppressing an increase in contact resistance and a deterioration in solder wettability after the heat resistance test and gas corrosion resistance test.

  The alloy composition of the B layer 13 is 50% by mass or more in total of Ni, Cr, Mn, Fe, Co, Sn, and Cu, and is further selected from the group consisting of B, P, Sn, and Zn, or Two or more kinds may be included. When the alloy composition of the B layer 13 has such a configuration, the B layer 13 is further cured to further improve the thin film lubrication effect, thereby improving the low insertion / extraction property. Durability is further improved by further preventing the constituent metals from diffusing into the A14 layer and suppressing increase in contact resistance and deterioration of solder wettability after the heat resistance test and gas corrosion resistance test.

  The B layer 13 may be composed of two or more layers. Specifically, for example, different layers formed of various metals or alloys thereof may be divided and laminated. Further, a form in which some elements are diffused from one of the different layers to the other may be employed.

  The thickness of the B layer 13 is preferably 0.05 μm or more. When the thickness of the B layer 13 is less than 0.05 μm, the thin film lubrication effect by the hard B layer 13 is lowered, the low insertion / removal property is deteriorated, and the constituent metal of the metal substrate 11 is easily diffused into the A14 layer. Durability deteriorates, such as increased contact resistance after solderability test and gas corrosion resistance test and solder wettability.

The adhesion amount of Ni, Cr, Mn, Fe, Co, and Cu in the B layer 13 is preferably 0.03 mg / cm ² or more. Here, the reason for defining the amount of adhesion will be described. For example, when the thickness of the B layer 13 is measured with a fluorescent X-ray film thickness meter, an error occurs in the measured thickness value due to the alloy layer formed with the A layer 14, the B layer 13, the base material 11, and the like. There is. On the other hand, when controlling by the adhesion amount, more accurate quality control can be performed regardless of the formation state of the alloy layer. Further, if the adhesion amount is less than 0.03 mg / cm ² , the thin film lubrication effect by the hard lower layer (C layer) is lowered and the low insertion / removal property is deteriorated, and the constituent metal of the base material 11 is easily diffused into the A14 layer. Durability deteriorates, for example, contact resistance increases after heat resistance test and gas corrosion resistance test and solder wettability easily deteriorates.

(A layer)
The A layer 14 is made of In, Ag, Au, Pt, Pd, Ru, Rh, Os, Ir, or an alloy thereof. According to such a configuration, the metal substrate can be well protected from oxidation, and solder wettability can be improved.

  The A layer 14 may be composed of two or more layers. Specifically, for example, different layers formed of various metals or alloys thereof may be divided and laminated. Further, a form in which some elements are diffused from one of the different layers to the other may be employed.

  The A layer 14 is preferably a layer containing 11% by mass or more of In, Ag, Au, Pt, Pd, Ru, Rh, Os, Ir, or one or more of these elements in total. The A layer 14 is preferably a layer containing at least one element selected from Ni, Cr, Mn, Fe, Co, Sn, and Cu, and is selected from Ni, Cr, Mn, Fe, Co, Sn, and Cu. It is more preferable that the layer contains at least 1% by mass of one or more elements.

  The thickness of the A layer 14 is preferably 0.0012 μm or more. When the thickness of the A layer 14 is less than 0.0012 μm, sufficient gas corrosion resistance cannot be obtained, and the metal material for electronic parts is corroded when a gas corrosion test such as chlorine gas, sulfurous acid gas, hydrogen sulfide gas is performed. Thus, the contact resistance is greatly increased as compared to before the gas corrosion test. In order to obtain more sufficient gas corrosion resistance, a thickness of 0.01 μm or more is preferable. Further, when the thickness is increased, the adhesion wear is increased, and the insertion / extraction force is increased. In order to obtain more sufficient low insertion / extraction, it is preferably 3.0 μm or less, preferably 1.0 μm or less, preferably 0.2 μm or less, and 0.1 μm or less. More preferred.

The adhesion amount of In, Ag, Au, Pt, Pd, Ru, Rh, Os, and Ir on the A layer 14 is preferably 1 μg / cm ² or more, preferably 2 μg / cm ² or more, and 7 μg / cm ^2. preferably at cm ² or more, preferably at 10 [mu] g / cm ² or more, preferably at 2000 [mu] g / cm ² or less, preferably at 1500 [mu] g / cm ² or less, the at 1000 [mu] g / cm ² or less Is preferably 500 μg / cm ² or less, preferably 300 μg / cm ² or less, more preferably 150 μg / cm ² or less, and even more preferably 75 μg / cm ² or less. Here, the reason for defining the amount of adhesion will be described. For example, when the thickness of the A layer 14 is measured with a fluorescent X-ray film thickness meter, an error occurs in the measured thickness value due to, for example, an alloy layer formed between the A layer 14 and the B layer 13 therebelow. There is a case. On the other hand, when controlling by the adhesion amount, more accurate quality control can be performed regardless of the formation state of the alloy layer. If the adhesion amount of the metal of the A layer 14 is less than 1 μg / cm ² , sufficient gas corrosion resistance cannot be obtained, and the metal material for electronic parts is subjected to a gas corrosion test such as chlorine gas, sulfurous acid gas, hydrogen sulfide gas. If it is carried out, it may corrode and the contact resistance may be greatly increased compared to before the gas corrosion test. For more sufficient gas corrosion resistance is obtained is preferably from 2 [mu] g / cm ² or more deposition amount, more preferably 7 [mu] g / cm ² or more deposition amount, more not less 10 [mu] g / cm ² or more preferable. Moreover, when the amount of adhesion increases, the adhesion wear increases and the insertion / extraction force increases. To obtain a more satisfactory low insertion resistance is preferably at 2000 [mu] g / cm ² or less, preferably at 1500 [mu] g / cm ² or less, preferably at 1000 [mu] g / cm ² or less, 500 [mu] g / cm ² or less It is preferably 300 μg / cm ² or less, more preferably 150 μg / cm ² or less, and even more preferably 75 μg / cm ² or less.

(Surface treatment layer)
The surface treatment layer 15 contains phosphorus (P) and carbon (C). If the surface treatment layer 15 does not contain phosphorus, the plating may be discolored by heating for a long time (155 ° C. × 16 h × atmosphere) and contact resistance and solder wettability may be deteriorated. Moreover, phosphorus has the effect of improving heat resistance. Moreover, when carbon is not included, there is much possibility of powder generation at the time of press working, and there is a possibility that the insertion force does not decrease.

(Qualitative analysis of surface treatment layer)
The metal material 10 for an electronic component according to the embodiment of the present invention has a 2S orbital binding energy of phosphorus (P) when elemental presence analysis of the surface treatment layer 15 is performed by Survey measurement of XPS (X-ray photoelectron spectrometer). The peak of (P2S) is at 186 to 192 eV, P is contained at 0.5 at% or more and less than 5.0 at%, the 1S orbital bond energy (C1S) peak of carbon (C) is at 284 to 290 eV, and C 35 at% or more and less than 80 at%.
In order to obtain a plating material that suppresses the generation of powder during pressing, has low contact resistance and high solder wettability, and retains these characteristics even after long-time heating, the binding energy of P 2S orbitals (P2S) It is essential that the peak of 186 to 192 eV is present, but even if the peak of the binding energy (P2S) is in such a range, if P is less than 0.5 at%, it is heated for a long time (155 ° C. × 16h × atmosphere) discolors the plating, and the contact resistance increases compared to before heating, resulting in poor heat resistance. Further, when P is present at 5.0 at or more, the contact resistance is increased due to the low conductivity of P.
Furthermore, in order to obtain a plating material that suppresses the generation of powder during pressing, has low contact resistance and high solder wettability, and retains these characteristics even after prolonged heating, the binding energy of C 1S orbitals ( Although it is essential that the peak of C1S) is in the range of 284 to 290 eV, even if the peak of the binding energy (C1S) is in such a range, if C is less than 35 at%, a large amount of powder is generated during pressing. , C is 80 at% or more, the contact resistance increases. Moreover, it is preferable for C to be 50 at% or more and less than 80 at% since the properties of the plating material are further improved and the insertion force is reduced.

(Layer structure analysis of surface treatment layer)
When the element presence analysis of the surface treatment layer 15 is performed by XPS Depth measurement, the metal material 10 for an electronic component according to the embodiment of the present invention has 35 atoms in a region from the surface of the surface treatment layer 15 to 0.5 nm. %, And a region containing 20 at% or more of C is less than 15 nm from the surface of the surface treatment layer 15, and a region containing 30 at% or more of oxygen (O) is less than 15 nm from the surface of the surface treatment layer 15. Is preferred.
If C is present in the region from the surface of the surface treatment layer 15 to 0.5 nm at the outermost surface at less than 35 at%, a large amount of powder is generated during pressing, and if it is present at 80 at% or more, the contact resistance is increased. Further, when a region containing 20 at% or more of C exists at 15 nm or more from the surface of the surface treatment layer 15, the contact resistance of long-time heating (155 ° C. × 16 h × atmosphere) increases compared to before heating, Sexuality gets worse.
Further, when the region containing O at 30 at% or more exists at 15 nm or more from the surface of the surface treatment layer 15, the contact resistance is high, and the contact resistance after long-time heating (155 ° C. × 16 h × atmosphere) is compared with that before heating. As a result, the heat resistance deteriorates.
Further, C is present in the region from the surface of the surface treatment layer 15 to 0.5 nm or more and less than 50 at% and less than 80 at%, and the region containing C at least 20 at% is from 2 nm to 15 nm from the surface of the surface treatment layer 14. Further, it is preferable because the characteristics of the plating material are further improved and the insertion force is reduced.

(Method for producing metal material 10 for electronic parts)
The metal material 10 for electronic parts forms the base layer 12, the B layer 13, and the A layer 14 on the surface of the metal substrate 11, and further performs the surface lubrication treatment on the A layer 14 in order to form the surface treatment layer 15. It is obtained by forming. In addition, you may perform a reflow process as needed after A layer formation. Further, the surface lubrication treatment contains both phosphorus and carbon, and specifically, preferably contains a phosphate ester compound and a mercaptobenzothiazole compound. These concentrations vary depending on the form of the compound. For example, in the case of lauryl acid phosphate monoester, 0.1 to 3.0% by mass; in the case of mercaptobenzothiazole sodium salt, etc., 0.010 to 0 100% by mass. As reflow processing conditions, although it changes with plating thickness, it is appropriate to carry out at 230-700 degreeC for 0.3-120 second. In the phosphoric acid ester compound, phosphorus in the compound reacts with the constituent metal of the A layer 14 to form a protective film on the surface of the plating, and this protective film functions as a plating discoloration prevention. Further, the mercaptobenzothiazole compound reacts with the constituent metal of the A layer 14 to form a protective film on the surface of the plating, and this protective film has the effect of suppressing the generation of plating powder and further reducing the insertion force. is there. Examples of the phosphoric acid ester compound include lauryl acidic phosphoric acid monoester and lauryl acidic phosphoric acid diester. Examples of mercaptobenzothiazole compounds include mercaptobenzothiazole and mercaptobenzothiazole sodium salt.

(Use of metal materials for electronic parts)
The use of the metal material for electronic parts of the present invention is not particularly limited. For example, a connector terminal using the metal material for electronic parts as a contact part, an FFC terminal or FPC terminal using the metal material for electronic parts as a contact part, and an electronic part Electronic parts using metal materials for external connection as electrodes for external connection. In addition, about a terminal, it does not depend on the joining method with a wiring side, such as a crimp terminal, a solder terminal, and a press fit terminal. Examples of the external connection electrode include a connection component in which a surface treatment is performed on a tab and a material in which a surface treatment is applied to a semiconductor under bump metal.
Moreover, a connector may be produced using the connector terminal formed in this way, and an FFC or FPC may be produced using an FFC terminal or an FPC terminal.
In the connector, both the male terminal and the female terminal may be the metal material for electronic parts of the present invention, or only one of the male terminal and the female terminal. In addition, low insertion property is further improved by making both the male terminal and the female terminal into the metal material for electronic parts of the present invention.

  EXAMPLES Examples of the present invention will be described below, but these are provided for better understanding of the present invention and are not intended to limit the present invention.

Brass (C2680) having a thickness of 0.3 mm was prepared as a metal substrate. Next, the A layer was formed on the surface of the metal base so as to have a predetermined target thickness by using electroplating or sputtering. Then, it heat-processed on the hotplate and annealed. In the case of providing the base layer and / or the B layer, the layer A was formed after the base layer and / or the B layer were provided on the surface of the metal substrate by electroplating or sputtering. Next, the lubricating treatment is carried out by electrolytic treatment using a lubricating treatment liquid containing lauryl acid phosphoric acid monoester (phosphate ester compound) and a sodium salt of mercaptobenzothiazole (mercaptobenzothiazole compound) on layer A. gave. More specifically, the following steps were sequentially performed on the metal substrate.
Plating material preparation procedure: electrolytic degreasing → water washing → pickling → water washing → (if necessary underlayer → water washing →) (if necessary B layer → (if necessary water washing)) → A layer → (if necessary water washing) → heat treatment → gradual Cold → Lubrication → Hot water → Water wash

In this way, Examples 1 to 20 and Comparative Examples 2 to 13 were produced by changing the adhesion amount and thickness of each element of plating of the A layer and B layer during the surface treatment, heat treatment conditions, and lubrication conditions, respectively. did. In Example 9, a Zn plating layer having a thickness of 0.5 μm was provided as a base layer. In Example 11, a Ni plating layer having a thickness of 0.3 μm was provided as a base layer.

(Plating thickness)
Then, about the produced sample, the thickness of B layer and A layer was measured with the fluorescent X ray film thickness meter (SEA5100 made from Seiko Instruments, collimator 0.1mm (PHI)). In addition, about the Example which heat-processed, the thickness of the B layer and A layer after heat processing was measured. In addition, when it is difficult to measure the thickness of the B layer and the A layer with a fluorescent X-ray film thickness meter, the cross section of the B layer and the A layer is subjected to line analysis using a scanning transmission electron microscope (STEM). , B layer and A layer can also be measured.

(External surface qualitative analysis and layer structure analysis of surface treatment layer)
The surface of the obtained sample was subjected to qualitative analysis by survey measurement by XPS analysis. The resolution of the qualitative analysis concentration was 0.1 at%. In addition, when it was difficult to determine the presence or absence of the peak of the binding energy (P2S) of the P 2S orbital or the peak of the binding energy (C1S) of the C 1S orbital, the number of analysis integrations was increased as necessary. In this example, the number of integration was set to 10 and the measurement was performed.
The layer structure was determined by measuring a depth profile by XPS analysis and analyzing the concentration of Sn, O, and Cu to determine the layer structure of the surface treatment layer. Concentration detection by XPS was performed by analyzing the concentration (at%) of each element with the total of designated elements as 100%. Further, the distance (nm) in the thickness direction in the XPS analysis corresponds to the distance on the horizontal axis of the chart (distance in terms of SiO ₂ ) in the XPS analysis.
As an XPS apparatus, ULVAC-PHI Co., Ltd. 5600MC was used, ultimate vacuum: 2.1 × 10 ⁻⁹ Torr, excitation source: monochromated AlKα, output: 210 W, detection area: 800 μmΦ, incident angle: 45 degrees, The take-off angle was 45 degrees, no neutralization gun was used, and the measurement was performed under the following sputtering conditions.
Ion species: Ar ⁺
Acceleration voltage: 3 kV
Sweep area: 3mm x 3mm
Rate: 2 nm / min. (SiO ₂ equivalent)

FIG. 2 is a survey measurement result by XPS analysis of Example 1. As can be seen from FIG. 2, the peak of P 2S orbital binding energy (P2S) is in the range of 186 to 192 eV, and P is present at 1 at%. It can also be seen that the peak of C 1S orbital binding energy (C1S orbital) is at 284 to 290 eV, and C is present at 45 at%.
FIG. 3 is a measurement result of a depth profile by XPS analysis of Example 1. FIG. 3 shows that carbon (C) is present at 50 at% or more on the outermost surface, and carbon (C) at 20 at% or more is present at 1.5 nm.

(Evaluation)
The following evaluation was performed for each sample.
A. Powder Generation Test A powder generation test was performed by the method shown in FIG. A sample was affixed on an iron plate (steel disk), and a 4.8 mmφ iron ball (steel ball) wrapped with 3 mm thick BC felt (trade name) manufactured by BWF (Germany) was placed on the sample. A load of 30 g was applied to the iron ball, and the iron ball was subjected to a powder generation test at a scanning distance of 10 mm and a reciprocating scanning frequency of 15 times. When powder could be visually confirmed on the pad after the test, the evaluation result was marked as x because powder was generated. On the other hand, when powder was not able to be confirmed, the evaluation result was set as (circle) not having generated powder.
B. Contact resistance The contact resistance was evaluated for samples before and after the atmospheric heating test (155 ° C. × 16 h). The measurement was performed by a 4-terminal method using a contact simulator CRS-1 manufactured by Yamazaki Seiki under the conditions of a contact load of 50 g and a current of 200 mA. Note that the target characteristic is 10 mΩ or less with no change in contact resistance before and after atmospheric heating.
C. Solder wettability The solder wettability was evaluated on the sample after plating. A solder checker (SAT-5000 manufactured by Reska Co., Ltd.) was used, and a commercially available RMA grade flux was used as the flux, and the solder wetting time was measured by the meniscograph method. In addition, Sn-3Ag-0.5Cu (250 degreeC) was used for the solder. The target solder wetting time is 3 seconds or less.
D. Insertion force The insertion force was evaluated using the dynamic friction coefficient as an alternative. A HEIDEN-14 type manufactured by Pingtung Science Co., Ltd. was used as a measuring device, and measurement was performed under the conditions of an indenter load of 500 g, a scanning distance of 100 mm, and a scanning speed of 50 mm / min. The target characteristic is a reduction of the dynamic friction coefficient by 20% or more as compared with Ni (0.3 μm) / Sn (1.0 μm) of Comparative Example 23.
Each condition and evaluation result are shown in Tables 1-8.

As is clear from Tables 1 to 8, in each Example satisfying the following conditions, no powder was generated in the powder generation test, and the target contact resistance and solder wettability were obtained.
When analyzing the presence of P on the outermost surface of the metal base material subjected to surface treatment by XPS survey measurement, the peak of P 2S orbital binding energy (P2S) is in the range of 186 to 192 eV, and P is 0.1. 5 at% or more and less than 5.0 at%, and when analyzing the C existence form on the outermost surface of the metal base material subjected to the surface treatment, there is a peak of C 1S orbital binding energy (C1S) at 284 to 290 eV , C is 35 at% or more and less than 80 at%.
In XPS depth measurement, C is present at 35 at% or more and less than 80 at% on the outermost surface, C region of 20 at% or more is less than 15 nm from the outermost surface, and O region of 30 at% or more from the outermost surface is 15 nm. Is less than.
Furthermore, the target low insertion force was obtained in Examples 7 and 8 that satisfy the following conditions.
In XPS survey measurement, C is 50 at% or more and less than 80 at%, and in XPS depth measurement, C is present on the outermost surface by 50 at% or more and less than 80 at%, and the region of C of 20 at% or more is 2 nm from the outermost surface. More than 15 nm.
In Example 1, the oxygen region of 30 at% or more was shallower than Example 20, and the contact resistance after heating in the atmosphere was less likely to increase compared to before heating.

In the survey measurement, Comparative Example 2 in which P at% was high had high contact resistance.
In the survey measurement, in Comparative Example 3 in which C at% was low, powder was generated in the powder generation test.
In the survey measurement, in Comparative Example 4 in which C at% was high, the contact resistance after atmospheric heating increased compared to that before heating.
In the survey measurement, in Comparative Example 5 in which the peak of the binding energy (P2S) of the 2S orbit of P is not in the range of 186 to 192 eV, the contact resistance after the atmospheric heating increased as compared with that before the heating.
In Survey measurement, Comparative Example 6 in which at% of phosphorus was high had high contact resistance.
In Comparative Example 7 in which the at% of carbon was low in the survey measurement, powder was generated in the powder generation test.
In the survey measurement, in Comparative Example 8 in which the carbon at% was high, the contact resistance after atmospheric heating increased compared with that before heating.
In the survey measurement, in Comparative Examples 9 to 13 in which the carbon at% was low, powder was generated in the powder generation test.

DESCRIPTION OF SYMBOLS 10 Metal material 11 for electronic components Metal base material 12 Underlayer 13 B layer 14 A layer 15 Surface treatment layer

Claims (12)

Metal substrate,
An underlayer formed on the metal substrate;
B layer formed on the underlayer and formed of Ni, Cr, Mn, Fe, Co, Sn, Cu or an alloy containing one or more of these elements,
An A layer formed on the B layer, formed of In, Ag, Au, Pt, Pd, Ru, Rh, Os, Ir, or an alloy containing one or more of these elements; and
A surface treatment layer formed on the A layer;
When the elemental analysis of the surface treatment layer surface was performed by Survey measurement of XPS (X-ray photoelectron spectrometer),
The peak of the binding energy (P2S) of 2S orbitals of phosphorus (P) is 186 to 192 eV, P is contained at 0.5 at% or more and less than 5.0 at%,
A metal material for electronic parts having a peak of binding energy (C1S) of 1S orbital of carbon (C) at 284 to 290 eV and containing C at least 35 at% and less than 80 at%. When the elemental analysis of the surface treatment layer surface was performed by XPS depth measurement,
C is present in the region from 0.5 to 80 at% from the surface of the surface treatment layer to less than 15 atm, and the region containing C at least 20 at% is less than 15 nm from the surface of the surface treatment layer;
The metal material for an electronic component according to claim 1, wherein a region containing oxygen (O) of 30 at% or more is less than 15 nm from the surface of the surface treatment layer. When elemental analysis of the surface treatment layer surface is performed by Survey measurement of XPS, C is contained at 50 at% or more and less than 80 at%,
When elemental analysis of the surface treatment layer surface was performed by XPS Depth measurement, C was present in the region from the surface of the surface treatment layer to 0.5 nm to 50 at% to less than 80 at%, and C was 20 at% or more. The metal material for electronic components according to claim 2, wherein a region to be included is 2 nm or more and less than 15 nm from the surface of the surface treatment layer.   4. The layer according to claim 1, wherein the A layer is a layer containing 11% by mass or more in total of In, Ag, Au, Pt, Pd, Ru, Rh, Os, Ir, or one or more of these elements. Metal materials for electronic parts.   The metal material for electronic parts according to any one of claims 1 to 4, wherein the A layer is a layer containing one or more elements selected from Ni, Cr, Mn, Fe, Co, Sn, and Cu. Said layer A Ni, Cr, Mn, Fe, Co, Sn, electronic component according to any one of claims 1 to 5, which is a layer containing 1 wt% or more in total of one or more elements selected from Cu Metal material.   The metal material for electronic components according to claim 1, wherein the thickness of the A layer is 0.0012 μm or more.   The metal material for electronic parts according to claim 1, wherein the A layer is composed of two or more layers. The alloy composition of the B layer is 50% by mass or more in total of Ni, Cr, Mn, Fe, Co, Sn, and Cu, and is further selected from the group consisting of B, P, Sn, and Zn, or the metal material for electronic component according to claim 1 comprising two or more. The metal material for electronic components according to claim 1, wherein the B layer is composed of two or more layers. The manufacturing method of the metal material for electronic components in any one of Claims 1-10 including the process of surface-treating with the surface treatment liquid containing phosphorus and carbon on the said A layer of the said metal base material. The said surface treatment liquid is a manufacturing method of the metal material for electronic components of Claim 11 containing a phosphate ester type compound and a mercaptobenzothiazole type compound.