JP2002226982A - Heat resistant film, its manufacturing method, and electrical and electronic parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a film having excellent heat resistance, formability and solderability, and used for coating the surface of a material, its manufacturing method, and further electrical and electronic parts coated with the film. SOLUTION: An Ni or Ni-alloy layer, a Cu layer and an Sn or Sn-alloy layer are applied to the surface of the material composed of copper alloy, etc., in the order named from the surface side. Then reflow treatment is applied at 300-900 deg.C for 1-300s. By this method, the heat resistant film having the following layers can be obtained: an Sn or Sn-alloy layer having a thickness X of 0.05-2 μm on the outermost surface side; an alloy layer containing an intermetallic compound composed essentially of Cu-Sn and having a thickness Y of 0.05-2 μm on the inner side; and further an Ni or Ni-alloy layer having a thickness Z of 0.01-1 μm on the inner side of the above layer ( where 0.2X<=Y<=5X and 0.05Y<=Z<=3Y are satisfied).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention requires both heat resistance and reduced wear and friction during insertion / removal, such as the surface of a multi-pin connector used for electric wiring of automobiles. Surfaces, such as charging sockets of electric vehicles, which have a large number of insertions and withdrawals and flow large currents; surfaces that require wear resistance by contacting rotating parts, such as motor brushes; and wear resistance, such as battery terminals TECHNICAL FIELD The present invention relates to a surface treatment of a surface that requires resistance and corrosion resistance, and a surface treatment of an electric / electronic component that further requires solderability such as connection of a printed circuit board, and a method of manufacturing the same.

[0002]

2. Description of the Related Art With the recent development of electronics,
Electrical wiring has become more complicated and highly integrated, and as a result, the number of pins of connectors has been increased. In addition, the thermal environment, such as heat generated by external heat or Joule heat, is becoming increasingly severe. A conventional Sn-plated connector has a problem in that the frictional force increases when inserting and removing the connector, and it becomes difficult to insert the connector. Further, the Sn-plated material is inferior in heat resistance because Cu diffuses from the raw material and the underlying plating due to the heat effect, and the contact resistance increases due to the formation of the Cu—Sn-based compound layer and its oxide film, and high humidity and high temperature. However, there is a problem that the solderability is deteriorated due to diffusion and oxidation. Conventionally, as a measure to reduce the insertion force of the terminal with multi-pin Sn plating, a hard Ni plating or the like is provided on the base of the Sn plating, or a Cu-Sn diffusion layer is provided to improve the hardness of the base and a diffusion barrier effect. A plan aimed at is proposed.

[0003]

However, when Sn plating is performed on Ni plating, the contact resistance of the Ni-Sn alloy or its oxide generated after the heating test is large, and the heat resistance is poor. When the terminal is inserted, Sn
Is excavated and Ni is exposed.
Oxide significantly deteriorates the contact resistance. Further, since the Ni base plating is usually applied to a thickness of about 1 to 2 μm, there is a disadvantage that cracks and the like are apt to occur during bending at the time of forming the terminal. N
Even if the thickness of the i-underlayer plating was reduced to about 0.5 μm, the increase in the contact resistance could not be solved. Cu-
Even when the Sn diffusion layer is used, the contact resistance increases due to long-term heating, or the solderability is poor. Also in the manufacturing method, Sn is left on the surface layer and Cu-Sn
As a method of providing a diffusion layer, there is a method of utilizing thermal diffusion, but it is difficult to control the thickness of the diffusion layer, and even if it is controlled, diffusion of the diffusion due to a temperature environment at the time of use cannot be avoided, and heat resistance is reduced. Inferior. The scheme of performing Sn plating after forming the Cu—Sn diffusion layer requires an extremely complicated process, and is not realistic because of poor cost and surface Sn adhesion and moldability. In addition, current electric vehicles require charging at least once a day, and it is necessary to ensure wear resistance of the charging socket components. 10 on it
Since a large current of A or more flows, the heat generation is large, and the conventional Sn
In a method such as plating, there are also problems such as peeling of plating. Furthermore, in connection with printed circuit boards, there is a demand for solderability that is even better than conventional Sn-plated materials because of the transition to high-temperature solder due to Pb-free and the transition to flux with low activity as environmental measures. . Specifically, it is necessary that the solderability is excellent without being reduced even by the humidity or high temperature during storage. It has become clear that conventional surface treatment methods cannot cope with the above problems. Also, in the surface treatment proposed by the present invention, coating of Sn or Sn alloy layer, Cu-Sn alloy layer or further Cu layer, and Ni or Ni alloy layer and the coating method thereof have been conventionally proposed, but all of them have been proposed. The optimal combination and the optimal thickness were not considered.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies to achieve the above object, and as a result, have found that the Sn or Sn alloy layer is formed on the outermost surface, and the Cu-Sn alloy layer (Cu ₃ S
_{n, Cu 4 Sn, Cu 6} Sn 5 or the like of the Cu-Sn intermetallic Cu-Sn which Ni alloy layer and underlying thermally diffused containing compound
An alloy layer such as -Ni, etc.), and possibly a Cu layer left by the reaction, and further, by appropriately forming a Ni or Ni alloy layer to a desired thickness inside the Cu layer, for example, Completed the present invention by finding that a surface treatment film having a surface having excellent heat resistance and a low coefficient of friction, excellent in abrasion resistance, and excellent in solderability, which is suitable for pin connectors and charging sockets of electric vehicles, etc., can be obtained. I came to.

That is, the present invention firstly comprises a Sn or Sn alloy layer having a thickness X of 0.05 to 2 μm on the outermost surface and a Cu—Sn having a thickness Y of 0.05 to 2 μm inside the layer. A heat-resistant coating comprising an alloy layer containing an intermetallic compound and a Ni or Ni alloy layer having a thickness Z of 0.01 to 1 μm formed inside the alloy layer;
3. The heat-resistant coating according to claim 1, wherein Y ≦ 5X and 0.05Y ≦ Z ≦ 3Y; third, a thickness between the alloy layer containing the intermetallic compound and the Ni or Ni alloy layer. 0.7μ
The heat-resistant film according to the first or second aspect, having a Cu layer of m or less; fourth, any one of the first to third aspects, wherein at least a surface layer of a material covered with the heat-resistant film is Cu or a Cu alloy. Fifthly, a heat treatment is performed after coating a Ni or Ni alloy layer, a Cu layer, a Sn or a Sn alloy layer on the surface of the material in order from the surface side, 6. A method for producing a heat-resistant coating according to any one of the above-described items 4 to 6; The first to first, characterized in that
4. The method for producing a heat-resistant film according to any one of 4.
On a material surface having a ten-point average roughness of 1.5 μm or less and a centerline average roughness of 0.15 μm or less in surface roughness, a Ni or Ni alloy layer, a Cu layer,
The method for producing a heat-resistant film according to any one of the first to fourth aspects, wherein a heat treatment is performed after coating the Sn or Sn alloy layer; Ni or N on the surface of the material having a thickness of 0.5 μm or less and a center line average roughness of 0.15 μm or less in order from the surface side.
The method for producing a heat-resistant film according to any one of the first to fourth aspects, wherein a reflow treatment is performed after covering the i-alloy layer, the Cu layer, the Sn or the Sn alloy layer;
The method for producing a heat-resistant film according to any one of claims 5 to 8, wherein a Cu or Cu alloy layer is previously coated on the surface of the material before coating with the i or Ni alloy layer; An electric / electronic component characterized by being coated with the heat-resistant film described in any one of (1) to (4).

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The contents of the present invention will be specifically described.
You. The reason for limiting the numerical range of the present invention will be described. First,
The thickness of the Sn layer on the outermost surface is less than 0.05 μm.
If it is full, contact resistance stability and solderability will decrease.
You. In particular, the contact resistance at low loads tends to be unstable,
Reduced solderability due to humidity and temperature during storage
You. Also, H ₂S and SO₂Corrosion and in the presence of moisture
NH₃Deterioration of corrosion resistance such as corrosion by gas is a problem
You. If the thickness of the Sn layer exceeds 2 μm,
Increased insertion force resistance due to raised friction, reduced fatigue properties
In addition, problems such as economic disadvantage arise. Furthermore
Cu-Sn expansion obtained by heat treatment to be formed inside
Molding such as when the thickness of the spattered layer becomes too thick and cracks during processing
A decrease in workability is observed. Therefore, the thickness of the Sn layer
Is in the range of 0.05 to 2 μm. In addition, the preferred range
The range is 0.1 to 1 μm. Where S
The formation of the n-layer is performed by plating, hot dipping,
Or any other method such as cladding.
Plating is desirable in terms of control and cost. Also here
The thickness of the Sn layer has been completed by the diffusion treatment by heat treatment or the like.
Is the thickness of the Sn layer on the outermost surface after Cu-Sn intermetallic
This is the outer (surface side) portion of the compound layer. However, the diffusion process
20% by weight or less elements other than Sn
It's fine. Contains elements other than Sn in excess of 20 wt%
Then, there is a problem in solderability and contact resistance after long-term heating.
May occur. In addition, coat the outermost surface before diffusion treatment
Sn is Sn-Cu, Sn-Ag, Sn-Bi, S
Alloy plating of n-Zn, Sn-Pb, etc.
Melt immersion may be used. However, Cu-Sn metal inside
When performing diffusion treatment to provide an alloy layer containing
Initial heating, Cu, Ag, Bi, Zn, P in Sn
b, In, etc. are diffused to the outermost surface and soldered even if oxidized
It is important that the properties and contact resistance are not reduced.

[0007] Further, as a base of Sn coating, a thickness of 0.0
An alloy layer containing a Cu—Sn intermetallic compound of 5 to 2 μm is required. The alloy layer containing the Cu-Sn intermetallic compound is preferably formed by utilizing the diffusion of Cu from the underlying Cu coating, for example, Cu plating, by heat treatment and alloying with the Sn coated on the surface. Therefore, Cu remaining after the reaction is included. However, the plating thickness remaining as Cu is preferably 0.7 μm or less, more preferably 0.3 μm or less. Excess Cu is diffused by long-term heating,
By growing a Cu-Sn diffusion layer, the Sn thickness of the outermost layer is reduced, and the contact resistance and solderability are reduced. The alloy layer containing the Cu—Sn intermetallic compound thus obtained further effectively suppresses the diffusion of Ni from the inside (underlayer side), and has a Ni—Sn alloy layer or an oxide thereof on the surface. Formation is effectively suppressed. Thereby, an increase in contact resistance after long-term heating can be suppressed. Furthermore, hard Cu
The alloy layer containing the Sn-based intermetallic compound also contributes to the effect of reducing the insertion force. A thickness of 0.05 μm or more, and preferably 0.1 μm or more, is necessary for efficiently exhibiting such effects. However, if the alloy layer containing the Cu-Sn intermetallic compound is too thick, the workability is significantly reduced. In addition, since the Cu—Sn diffusion layer generated by diffusion increases the surface roughness, even if the Sn coating on the outermost layer is adjusted, the appearance is rough and the insertion force is likely to be adversely affected. Therefore, the preferred thickness of Cu-Sn is 2 μm or less, more preferably 1 μm or less. Further, the inside of the alloy layer containing the Cu-Sn intermetallic compound (base) needs to be coated with Ni or a Ni alloy layer. This Ni or Ni alloy layer is
In addition to effectively suppressing the diffusion of Cu when using copper or a copper alloy as the material, it also effectively suppresses the diffusion of additional elements in the copper alloy, and improves contact resistance, solderability, Effectively prevent reduction in heat adhesion. For example, Zn in brass and P in phosphor bronze. In addition, this Ni
Alternatively, the Ni alloy layer has an effect of improving insertion force resistance, heat resistance, corrosion resistance, and the like, in combination with an alloy layer containing a Cu-Sn intermetallic compound thereon. This Ni or Ni alloy layer is often formed by plating,
Similarly, any method may be used. The coating is made of Ni
However, a Ni alloy may be used. Ni by electroplating
Examples of the alloy include Ni-Co and Ni-P.
In addition, during the heat treatment for obtaining the Cu—Sn diffusion layer,
An alloy layer of Ni—Cu or the like may be formed by diffusing with u plating.

Further, the material can be applied to materials other than iron and steel materials, copper such as stainless steel and aluminum alloy, and copper alloy. in this case,
In order to improve the adhesion of the Ni or Ni alloy film, Cu base plating can be performed.
Therefore, it is possible to effectively suppress the change in contact resistance and the deterioration in solderability during long-term heating because the diffusion of the solder can be effectively suppressed. In general, electrical and electronic components have their electrical conductivity, springiness,
Taking into account the required properties such as magnetism, the material is preferably copper or a copper alloy, but is not limited to this as described above. When the material is copper or a copper alloy, Ni or a Ni alloy, (Cu), an alloy containing a Cu-Sn intermetallic compound, Sn or a Sn alloy, or Cu or Cu from the base side
It is necessary to have a layer structure of an alloy, Ni or a Ni alloy, (Cu), an alloy containing a Cu-Sn intermetallic compound, or Sn or a Sn alloy. When the material is a copper alloy, Zn: 0.01 to 50 wt. Is preferred as a range of the additive element in terms of strength, elasticity, electric conductivity, workability, corrosion resistance and the like.
%, Sn: 0.1 to 12 wt%, Fe: 0.01 to 5 w
t%, Ni: 0.01 to 30 wt%, Co: 0.01 to
5 wt%, Ti: 0.01 to 5 wt%, Mg: 0.01
-3 wt%, Zr: 0.01-3 wt%, Ca: 0.0
1-1 wt%, Si: 0.01-5 wt%, Mn: 0.
01-20 wt%, Cd: 0.01-5 wt%, Al:
0.01 to 10 wt%, Pb: 0.01 to 5 wt%, B
i: 0.01 to 5 wt%, Be: 0.01 to 3 wt%,
Te: 0.01-1 wt%, Y: 0.01-5 wt%,
La: 0.01 to 5 wt%, Cr: 0.01 to 5 wt%
%, Ce: 0.01-5 wt%, Au: 0.01-5 w
t%, Ag: 0.01-5 wt%, P: 0.005-
Containing at least one element among 0.5 wt%,
It is desirable that the total amount is 0.01 to 50 wt%. In consideration of recyclability as a raw material, it is desirable that the copper alloy contains Ni and Sn.

Next, the thickness of each layer and the reason for the limitation will be described. The thickness of the outermost surface Sn or Sn alloy layer (X), the thickness of the inner alloy layer containing an intermetallic compound mainly composed of Cu-Sn (Y), the thickness of the Ni or Ni alloy layer inside thereof (Z) The optimum value of each thickness is as described above. However, it has been found that there is an interaction between the respective surface treatments and it is desirable to limit the thickness ratio. Specifically, it is suitable for the diffusion of each element by long-term heating, the response to electrical performance deterioration due to oxidation, the resistance to digging up at the time of terminal insertion, the increase of insertion force due to adhesion, the response to wear and corrosion, etc. That is, a film thickness ratio can be obtained. It is desirable that the film thickness ratio is as follows. 0.2X ≦ Y ≦ 5X (1) Equation 0.05Y ≦ Z ≦ 3Y (2) When the film thickness ratio exceeds the upper limit or is less than the lower limit,
Any one of contact resistance after heating, solderability after moisture resistance test, terminal insertion force resistance, abrasion amount, corrosion resistance, etc. is reduced, and all of them cannot be satisfied. Therefore, it is important to make the film thickness satisfying the expressions (1) and (2).

Next, according to the surface roughness of the material, JIS B
According to a measuring method based on No. 0601, the ten-point average roughness is 1.5 μm or less and the center line average roughness is 0.15 μm.
The following is preferred. By limiting the surface roughness of the material, the surface smoothness of each layer coated on the material is stabilized, and the adhesion and appearance are improved. When plating is performed, it is also effective in heat resistance and film thickness distribution. The surface roughness of the material is specified, in particular, by coating Cu or Cu alloy from the underlayer side in some cases, furthermore, Ni or Ni alloy, C
It contributes to the surface coated with u, Sn or Sn alloy and the appearance and surface roughness after heat treatment such as reflow performed thereafter. The surface roughness after reflow has a ten-point average roughness of 1.0
It is preferable that the center line average roughness is 0.1 μm or less. The thickness of the oxide film of the material itself is important in forming each layer. Especially in relation to pre-processing,
When a film is formed by a plating method, the adhesiveness, appearance, generation of voids during diffusion, and the like are affected.
It should be 0 nm or less, preferably 12 nm or less. Thus, a Sn or Sn alloy layer having a thickness of 0.05 to 2 μm on the outermost surface and a thickness of 0.05 to 2
μm and an alloy layer containing an intermetallic compound mainly composed of Cu—Sn satisfying the formula (1) or further Cu, and furthermore, 0.01 to 1 μm in thickness inside and satisfying the formula (2) A heat-resistant coating composed of a Ni or Ni alloy layer can be effectively obtained.

Next, the manufacturing method will be described. The method for effectively obtaining the configuration of the present invention will be described in detail below. First, a material whose surface roughness and oxide film thickness are adjusted is prepared, and if necessary, coated with Cu. When the material is copper or a copper alloy, the underlying Cu coating can be omitted. Hereinafter, plating, which is a desirable method of coating, will be described as an example. Material or C
Ni or Ni alloy is plated on the u-plated material.
However, it is necessary to sufficiently perform cleaning such as degreasing and pickling in consideration of adhesion. Next, Cu plating is performed. However, in order to improve the appearance and adhesion after plating of Cu, Ni
It is desirable to perform pickling between the steps of plating and Cu plating. Then, Sn or Sn alloy plating is performed on the outermost layer. Thus, it is important to take the basic structure of Ni, Cu, and Sn from the base side. Next, the intermediate plating Cu
Then, Sn on the outermost surface is diffused to obtain a Cu-Sn diffusion layer.
This treatment is desirably also used as a reflow treatment for melting Sn on the outermost surface. Specifically, a Sn and Cu-Sn diffusion layer having a desired thickness can be obtained by optimizing the heat pattern during the reflow treatment. However, the middle C
The u-plating only needs to have a thickness for forming the Cu—Sn diffusion layer, and is not necessary as an excess thickness left by the reaction. Specifically, the thickness remaining as Cu is 0.7 μm or less,
Further, the thickness is preferably 0.3 μm or less. Excess Cu diffuses due to long-term heating, grows a Cu—Sn diffusion layer, reduces the Sn thickness of the outermost layer, and lowers contact resistance and solderability. As the reflow treatment conditions, a temperature of 300 to 900 ° C. and a condition of 1 to 300 seconds are desirable. At a temperature lower than 300 ° C. or a temperature exceeding 900 ° C., it is difficult to simultaneously control both reflow and diffusion. The temperature factor is particularly important in terms of good surface condition and oxidation suppression, and in terms of controlling the thickness of the diffusion layer and suppressing abnormal diffusion in which the diffusion layer grows partly abruptly.
The atmosphere gas can be appropriately selected depending on the reflow method. The main reflow method includes a burner method, a hot air circulation method, an infrared method, and a Joule heat method, and any method may be used. However, the heating time differs depending on the method, but if it is less than 1 second, a sufficient diffusion layer cannot be obtained, and if it exceeds 300 seconds, the effect is saturated and the cost is disadvantageous.

The thickness of the oxide film after reflow of Sn is desirably as small as possible, but the thickness is desirably 30 nm or less. If the thickness of the oxide film on the surface exceeds 30 nm, the contact resistance increases and becomes extremely unstable, deteriorating the electrical performance. Further, the solderability and the adhesion of the oxide film may be deteriorated, and peeling may occur in subsequent processing. A more preferred oxide film thickness is 20 nm or less. Here, the oxide film is mainly composed of tin oxide.
Added to Cu, Cu in Cu-Sn diffusion layer, N
This includes those in which the i or Ni alloy element is diffused, or those in which the additive element contained in the copper-based alloy as the material is diffused forms a complex oxide with Sn. The oxide formed on such a surface is composed of an underlying Cu—Sn diffusion layer, N 2
In combination with the i or Ni alloy layer, there is an effect of improving wear resistance and slipperiness. However, since the surface oxide has an adverse effect on contact resistance and solderability, it is preferable to control the surface oxide thinly. When applied to the male and female terminals of an electric component, the coating configured as described above can be applied to either or both of the male and female sides.
Further, it may be applied to only necessary parts.

[0013]

EXAMPLES Examples of the present invention will be described below.

Example 1 Table 1 shows surface treatment materials No. 1 to 16 were prepared. However, all means for forming each layer were performed by electroplating. In particular,
Ni used a nickel sulfamate bath, Cu used a copper sulfate bath, and Sn used a sulfate bath. Also, pickling was performed before and after the Ni plating. However, no. 9, 10, 15
Is Ni, No. No. 11 represents Ni and Cu; 12 is C
u, No. No. 16 did not perform Sn plating (in Table 1, a bar is drawn for the film thickness). Material is 1 wt%
A rolled material of a copper alloy containing Ni, 0.9 wt% Sn, and 0.05 wt% P having a thickness of 0.25 mm is used. The surface roughness is a 10-point average roughness of 0.9 μm and a center line. Average roughness 0.0
The thickness of the oxide film of the material was about 7 nm, which was sufficiently smaller than 20 nm. Next, the reflow conditions were changed, a continuous reflow process was performed at 450 to 700 ° C. for 4 to 20 seconds, and a diffusion layer was formed simultaneously with the reflow process. The thickness of the oxide film on the outermost surface after the reflow was No. 1 from the measurement results of AES and ESCA. 1-14
Is about 3 to 8 nm; 15 and 16 are both about 15n
m, which was a value sufficiently smaller than 30 nm for each sample. In addition, the surface roughness has a ten-point average roughness of 0.2.
0.7 μm, and the center line average roughness is 0.05 to
It was 0.10 μm. The thickness of each layer was determined by dissolving one layer at a time from the surface side by an electrolytic method and measuring the thickness by an X-ray film thickness meter and an electrolytic method. Further, when the thickness is small, an analyzer such as an Auger electron spectrometer (AES) or a photoelectron spectrometer (ESCA) may be used in combination, or a cross section may be observed with a transmission electron microscope (TEE).
M) Observed and measured. The thickness of each layer was measured while confirming the consistency with the target amount of electrodeposition obtained by calculation. And the film (Sn <
0.05 μm, Cu-Sn <0.05 μm, Cu <0.
05 μm) is indicated as ND.

The test materials obtained as described above were measured for friction coefficient measurement, moldability, soldering test, heat resistance, contact resistance, and discoloration. Figure 1 shows the method of measuring the coefficient of friction.
As shown in the figure, a surface-treated plate material provided with three indents having an inner radius R = 1 mm is set as an upper side, and a lower surface plate material subjected to the same surface treatment is applied at a speed of 100 mm / min while applying a load of 15N. Was moved, the friction force was measured with a load cell, and the friction coefficient was calculated. The formability was determined by conducting a 90 ° W bending test (JIS H 3110, R = 0.2 mm, rolling direction and vertical direction),
It was observed and evaluated with a 4 × stereo microscope. In addition, cracks during indentation for friction coefficient measurement were also observed with a 24 × stereo microscope. Those in which cracks were not observed in both tests were evaluated as O, and those in which cracks were observed in either process were evaluated as X. Solderability is MIL
-Complies with STD-202F-208E, one for boiling steam
After a time exposure, they were tested with an inert flux. The test results were evaluated as ○ when 95% or more wet, and as X when less than 95% wet. 160 ° C, 10
After heating for 00 hours, 90 ° W bending test (JIS H
3110, R = 0.2 mm, rolling direction and vertical direction)
After performing the above, peeling was performed by tape and evaluated. If peeling did not occur due to peeling,
The mark and the one where peeling occurred were marked with x. At the same time, the degree of discoloration on the surface was visually observed, and those markedly discolored before heating were evaluated as x. The contact resistance test was performed by heating the sample at 160 ° C. for 1000 hours and then measuring the contact resistance by a four-terminal method using a low-current low-voltage measuring device. The maximum weight of the Au contact was 0.5 N, and the resistance value at this time was measured. Table 2 shows the evaluation results.

[0016]

[Table 1]

[0017]

[Table 2]

From the results shown in Tables 1 and 2, No. 1 according to the present invention was obtained. The materials Nos. 1 to 8 have a small coefficient of friction and are excellent, and are excellent in moldability, solderability, film adhesion after a heat test, contact resistance, and discoloration resistance. Therefore, it can be said that it has extremely excellent characteristics for recent applications such as a multi-pin connector, a charging socket, and a connection component of a printed circuit board. On the other hand, in the case of No. Nos. 9 and 10 have large friction coefficients and are inferior in contact resistance and discoloration after heating. No. Reference numeral 11 denotes a material in which a diffusion layer is formed by using Cu as a material and Sn on a surface without performing Cu for Ni plating and intermediate plating, but has a small coefficient of friction, but has solderability and contact resistance after heating. Inferior in discoloration. No intermediate plating of Cu was performed, and No. No. 12 is inferior in solderability, contact resistance after heating, and discoloration. No. No. 13 is inferior in moldability and has a thick Sn. No. 14 is inferior in friction coefficient, has no Ni layer, and has a thick Cu—Sn diffusion layer. 1
5 is moldability, solderability, contact resistance after heating,
Inferior in discoloration. No. without Sn. No. 16 is inferior in solderability, contact resistance after heating, and discoloration.

Example 2 As in Example 1, each layer was formed by electroplating. However, no. Nos. 17, 18, and 21 are made of a kind of brass (plate thickness 0.8 mm). 19, 2
Nos. 0 and 22 were made of phosphor bronze (plate thickness 0.2 mm).
In addition, each surface roughness has a ten-point average roughness of 1.0,
0.9 μm and center line average roughness 0.13, 0.08
μm, and the thickness of the oxide film of each material was about 8 nm, which was a value sufficiently smaller than 20 nm. Next, a reflow process is continuously performed at an atmosphere temperature of 350 to 800 ° C. for a time of 5 to 20 seconds, and Cu-S
The sample was prepared by forming n diffusion. The friction coefficient measurement, moldability, soldering test, heat resistance, contact resistance, and discoloration of the obtained test material were examined in the same manner as in Example 1.

[0020]

[Table 3]

[0021]

[Table 4]

As is clear from Tables 3 and 4, the No. 1 of the present invention is the same as that shown in FIG. Nos. 17 to 20 have a small coefficient of friction and are excellent, and are excellent in moldability, solderability, film adhesion after a heat test, contact resistance, and discoloration resistance. Therefore, it can be said that the effect of the present invention does not change even if the material is brass or phosphor bronze. On the other hand, in the case of No. Nos. 21 and 22 have large friction coefficients and are inferior in contact resistance and discoloration after heating. In particular, no. No. 22 was inferior in adhesion of the film after heating. 19 and 20, it is understood that the effect of the present invention is extremely large.

Example 3 Each layer was formed on the raw material used in Example 1 by electroplating in the same manner as in Example 1.
No. In Nos. 23, 24 and 27, the plating on the outermost surface was made of Sn alloy plating. In Nos. 23 and 27, the base was made of Ni, 2
In No. 4, the base was made of Ni alloy plating. No. 25, 26,
In No. 28, the plating on the outermost surface is Sn. 25, 26,
In both cases, the base was made of Ni alloy plating. As the Sn alloy plating, Sn-10 wt% Zn was plated using an organic complex salt bath. As Ni alloy plating, phosphorous acid was added to a Watt bath, and Ni-5 wt% P was plated. When the reflow conditions were appropriately selected and reflowed in the same manner as in Example 1, Zn of the Sn—Zn alloy plating diffused to the surface to form an oxide centering on zinc oxide. Did not give. The oxide film thickness is about 5
１１11 nm, a value thinner than 30 nm. In addition, No. 23 to 26 are Cu-Sn due to the heat effect of reflow.
A diffusion layer was formed. In Nos. 27 and 28, a Ni—Sn diffusion layer was formed instead of a Cu—Sn diffusion layer because there was no Cu layer.

[0024]

[Table 5]

[0025]

[Table 6]

As evident from Tables 5 and 6, the No. 1 of the present invention Nos. 23 to 26 have a small coefficient of friction and are excellent, and are excellent in moldability, solderability, film adhesion after a heat test, contact resistance, and discoloration resistance. Therefore, it can be said that the effect of the present invention does not change even if the Sn layer on the surface is made of a Sn alloy or the Ni layer is made of a Ni alloy. In contrast, C
No. having no u-Sn intermediate layer. No. 27 was inferior in solderability and contact resistance after heating. 28 is moldability,
Poor in solderability, film adhesion after heating, contact resistance and discoloration. Therefore, it is understood that the effect of the present invention is extremely large.

[0027]

As is apparent from the above examples, the surface treatment and the method for producing the same according to the present invention, and the electric and electronic parts obtained by these methods have the following advantages:
It has excellent solderability and excellent adhesion, contact resistance, and discoloration resistance after long-term heating, making it a connector material that can respond to recent high-density automotive electrical components, as well as abrasion resistance and solderability. It is excellent as a material for electric and electronic parts, such as a connector for connecting a printed circuit board, which is required.

[Brief description of the drawings]

FIG. 1 is a diagram showing a method for measuring a coefficient of friction.

[Description of Signs] 1 Upper specimen with indent 2 Lower specimen 3 Weight (15N) 4 Horizontal base 5 Pulley 6 Load cell

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroto Narue 1-8-2 Marunouchi, Chiyoda-ku, Tokyo Dowa Mining Co., Ltd. (72) Inventor Taichi Ozaki 145-1 Tokiwacho, Hamamatsu-shi, Shizuoka Japan F-term (reference) in Auri Brass, Inc. 4K024 AA03 AA07 AA09 AB03 BA01 BB09 BC01 DB02 GA16 4K044 AA01 AB02 BA06 BA10 BB04 BC11 CA18 CA42 CA62 5E063 GA08 GA09 XA01

Claims (10)

[Claims] 1. An S layer having a thickness X of 0.05 to 2 μm on the outermost surface.
n or Sn alloy layer, thickness Y of 0.05 to 2 inside
A heat-resistant film comprising an alloy layer containing an intermetallic compound mainly composed of Cu-Sn having a thickness of μm, and a Ni or Ni alloy layer having a thickness Z of 0.01 to 1 μm formed inside the alloy layer. 2.X ≦ Y ≦ 5X and 0.05Y
The heat-resistant film according to claim 1, wherein ≤ Z ≤ 3Y. 3. An alloy layer containing the intermetallic compound and the N
C having a thickness of 0.7 μm or less between the i or Ni alloy layer
3. The heat-resistant coating according to claim 1, comprising a u layer. 4. The method according to claim 1, wherein at least a surface layer of the material covered with the heat-resistant film is Cu or a Cu alloy.
3. The heat-resistant film according to any one of 3. 5. A heat treatment is performed after a Ni or Ni alloy layer, a Cu layer, a Sn or a Sn alloy layer is coated on the surface of the material in order from the surface side.
The method for producing a heat-resistant film according to any one of the above. 6. The method according to claim 1, wherein a reflow process is performed on the surface of the material in order from the surface side with a Ni or Ni alloy layer, a Cu layer, a Sn or a Sn alloy layer. The method for producing a heat-resistant film described in Crab. 7. The ten-point average roughness of the surface roughness is 1.5.
μm or less and a center line average roughness of 0.15 μm or less, a Ni or Ni alloy layer, a Cu layer, a Sn or a Sn alloy layer are coated in this order from the surface side, and then heat-treated. The method for producing a heat-resistant film according to claim 1. 8. The ten-point average roughness of the surface roughness is 1.5.
μm or less and a center line average roughness of 0.15 μm or less, on the surface of the material, Ni or Ni alloy layer, Cu layer, Sn or Sn alloy layer is coated in order from the surface side and then subjected to reflow treatment. The method for producing a heat-resistant film according to any one of claims 1 to 4, characterized in that: 9. The method according to claim 5, wherein a Cu or Cu alloy layer is previously coated on the surface of the material before the Ni or Ni alloy layer is coated. 10. An electric / electronic component comprising a material surface coated with the heat-resistant film according to claim 1. Description: