JP2017031449A - Copper alloy for electronic and electrical device, copper alloy thin sheet for electronic and electrical device and conductive component and terminal for electronic and electrical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a copper alloy for electronic and electrical device surely and sufficiently excellent in heat resistance and stress relaxation resistance as well as excellent in strength.SOLUTION: A copper alloy contains Zn of over 2 mass% and 36.5 mass% or less, Sn of 0.1 mass% to 0.9 mass%, Ni of 0.15 mass% or more and less than 1.0 mass%, P of 0.005 mass% to 0.1 mass% and Fe of 0.001 mass% to 0.1 mass% and the balance Cu with inevitable impurities, satisfies, by atom ratio, 3<(Ni+Fe)/P<30, 0.3<Sn/(Ni+Fe)<2.7 and 0.002≤[Fe/Ni]<0.6 and has atom ratio of Fe content and Ni content in a [Ni,Fe]-P-based deposition containing Fe, Ni and P, [Fe/Ni]to atom ratio of Fe content and Ni content in whole alloy, [Fe/Ni] satisfying 5≤[Fe/Ni]/[Fe/Ni]≤200.SELECTED DRAWING: None

Description

  The present invention is for a Cu-Zn-Sn based electronic / electrical device used as a conductive part for electronic / electrical devices such as a connector of a semiconductor device, other terminals, or a movable conductive piece of an electromagnetic relay, or a lead frame. The present invention relates to a copper alloy, a copper alloy thin plate for electronic / electric equipment, a conductive component for electronic / electric equipment, and a terminal using the copper alloy.

From the viewpoints of strength, workability, cost balance, etc., Cu—Zn alloys have been widely used as the above-mentioned electronic / electrical conductive parts.
In addition, in the case of terminals such as connectors, in order to increase the reliability of contact with the conductive member on the other side, the surface of the base material (base plate) made of a Cu—Zn alloy should be used with tin (Sn) plating. There is. Cu-Zn-Sn alloys are used for conductive parts such as connectors with a Cu-Zn alloy as the base material and Sn plating on the surface, in order to improve the recyclability of Sn plating materials and improve the strength. There is a case.

  Here, for example, a conductive part for electronic and electrical equipment such as a connector is generally formed into a predetermined shape by punching a thin plate (rolled plate) having a thickness of about 0.05 to 3.0 mm, and at least a part thereof. It is manufactured by bending. In this case, it is used to contact the mating conductive member near the bent portion to obtain an electrical connection with the mating conductive member, and to maintain the contact state with the mating conductive material by the spring property of the bent portion. .

Due to the spring property of the bent part after bending, it is excellent in heat resistance and stress relaxation resistance in the case of connectors used to maintain contact with the mating conductive material near the bent part. Is required.
Thus, for example, Patent Documents 1 to 4 propose methods for improving the heat resistance and stress relaxation resistance of Cu—Zn—Sn alloys.

In Patent Document 1, it is said that the stress relaxation resistance can be improved by adding Ni to a Cu—Zn—Sn alloy to produce a Ni—P compound, and the addition of Fe is also stress relaxation resistance. It has been shown to be effective in improving the characteristics.
Patent Document 2 describes that strength, elasticity, and heat resistance can be improved by adding Ni and Fe together with P to a Cu—Zn—Sn alloy to form a compound.

Patent Document 3 describes that the stress relaxation resistance can be improved by adding Ni to the Cu-Zn-Sn alloy and adjusting the Ni / Sn ratio within a specific range. Further, it is described that the addition of a small amount of Fe is effective in improving the stress relaxation resistance.
Furthermore, in Patent Document 4 for lead frame materials, Ni and Fe are added to a Cu—Zn—Sn alloy together with P, and the atomic ratio of (Fe + Ni) / P is within a range of 0.2 to 3. It is described that the stress relaxation resistance can be improved by adjusting to the above and generating Fe-P compounds, Ni-P compounds, and Fe-Ni-P compounds.

JP-A-5-33087 JP 2006-283060 A Japanese Patent No. 3953357 Japanese Patent No. 3717321

By the way, recently, electronic and electric devices have been further reduced in size and weight, and in copper alloys for electronic and electric devices used for conductive parts for electronic and electric devices, further strength, bending workability, and heat resistance are achieved. There is a need for improved stress relaxation resistance.
However, in Patent Documents 1 and 2, only the individual contents of Ni, Fe, and P are considered, and the adjustment of such individual contents does not necessarily ensure the stress relaxation resistance. Could not be improved.
Patent Document 3 discloses that the Ni / Sn ratio is adjusted, but the relationship between the P compound and the stress relaxation resistance is not considered at all.
Furthermore, in Patent Document 4, although only the total amount of Fe, Ni, and P and the atomic ratio of (Fe + Ni) / P are adjusted, the heat resistance can be improved, but the stress relaxation resistance is sufficiently improved. It was not possible to plan.

  As described above, the conventionally proposed methods cannot sufficiently improve the heat resistance and stress relaxation resistance of the Cu—Zn—Sn alloy. For this reason, in the connector having the above-described structure, the residual stress is relaxed over time, particularly in a high temperature environment, and the contact pressure with the counterpart conductive member is not maintained, and inconveniences such as poor contact are likely to occur at an early stage. There was a problem. In order to avoid such a problem, conventionally, the thickness of the material has to be increased, leading to an increase in material cost and weight. Therefore, further improvement of heat resistance and stress relaxation resistance is desired.

  The present invention has been made in the background as described above, and has a heat resistance and stress relaxation resistance that is surely and sufficiently excellent, and a copper alloy for electronic and electrical equipment having excellent strength, It is an object of the present invention to provide a copper alloy thin plate for electronic / electric equipment, a conductive component for electronic / electric equipment, and a terminal.

As a result of intensive experiments and researches, the inventors of the present invention added a suitable amount of Ni, P, and Fe to a Cu—Zn—Sn alloy and precipitated it under the heat treatment conditions. By adjusting the Fe / Ni ratio of the alloy and the Fe / Ni ratio of the entire alloy within an appropriate range, a copper alloy having excellent strength and bending workability as well as reliably and sufficiently improving heat resistance and stress relaxation resistance can be obtained. I found out that I could get it.
Similarly, an appropriate amount of Ni, P, Fe, Co is added to the Cu—Zn—Sn alloy, and the (Fe + Co) / Ni ratio in the [Ni, (Co, Fe)] — P precipitates and the total alloy It has been found that by adjusting the (Fe + Co) / Ni ratio within an appropriate range, it is possible to reliably and sufficiently improve heat resistance and stress relaxation resistance and at the same time obtain a copper alloy having excellent strength and bending workability.
The present invention has been made based on these findings.

The copper alloy for electronic / electrical equipment according to the present invention is more than 2 mass% of Zn and 36.5 mass% or less, Sn is 0.1 mass% or more and 0.9 mass% or less, and Ni is 0.15 mass% or more and less than 1.0 mass%. , P is contained in an amount of 0.005 mass% or more and 0.1 mass% or less, Fe is contained in an amount of 0.001 mass% or more and 0.1 mass% or less, the remainder is made of Cu and inevitable impurities, and the total content of Ni and Fe and P The ratio (Ni + Fe) / P to the content satisfies an atomic ratio of 3 <(Ni + Fe) / P <30, and the ratio of the Sn content to the total content of Ni and Fe Sn / (Ni + Fe) Satisfies 0.3 <Sn / (Ni + Fe) <2.7 in atomic ratio, and the ratio of Fe content to Ni content [Fe / Ni] is 0.002 ≦ [Fe Ni] <0.6, and the matrix has [Ni, Fe] -P-based precipitates containing Fe, Ni and P, and this [Ni, Fe] -P-based atomic ratio [Fe / Ni] _P in content and Ni of Fe precipitates in the relative atomic ratio of the content and the Ni content of Fe in the whole alloy [Fe / Ni], 5 ≦ [Fe / Ni] _P / [Fe / Ni] ≦ 200 is satisfied.

According to the copper alloy for electronic and electrical equipment having the above-described configuration, Ni and Fe are added together with P, and the addition ratio among Sn, Ni, Fe and P is regulated, and the precipitate is precipitated from the parent phase (mainly α phase). [Ni, Fe] -P-based precipitates containing Ni, Fe and P, and the Fe content and the Ni content atoms in the [Ni, Fe] -P-based precipitates The ratio [Fe / Ni] _P is 5 ≦ [Fe / Ni] _P / [Fe / Ni] ≦ 200 with respect to the atomic ratio [Fe / Ni] of the Fe content and the Ni content of the entire alloy. Since it is satisfied, the number density of [Ni, Fe] -P-based precipitates is ensured and the coarsening of the precipitates is suppressed, and the heat resistance and the stress relaxation resistance are excellent. .
Here, the [Ni, Fe] -P-based precipitates are ternary precipitates of Ni-Fe-P, and further, other elements such as Cu, Zn, Sn, and impurities as main components. It may contain multi-component precipitates containing O, S, C, Co, Cr, Mo, Mn, Mg, Zr, Ti and the like. The [Ni, Fe] -P-based precipitates exist in the form of phosphides or alloys in which phosphorus is dissolved.

Moreover, the copper alloy for electronic / electrical equipment according to the present invention is more than 2 mass% of Zn and 36.5 mass% or less, Sn is 0.1 mass% or more and 0.9 mass% or less, and Ni is 0.15 mass% or more and 1.0 mass%. %, P is contained in an amount of 0.005 mass% to 0.1 mass%, Fe and Co are contained, and the total content of Fe and Co is 0.001 mass% to 0.1 mass% (provided that Fe is added). 0.001 mass% or more and 0.1 mass% or less), the balance is made of Cu and inevitable impurities, and the ratio of the total content of Ni, Fe and Co to the content of P (Ni + Fe + Co) / P is An atomic ratio satisfying 3 <(Ni + Fe + Co) / P <30, and the ratio of Sn content to the total content of Ni, Fe and Co Sn / (N + Fe + Co) satisfies an atomic ratio of 0.3 <Sn / (Ni + Fe + Co) <2.7, and the ratio of the total content of Fe and Co to the content of Ni (Fe + Co) / Ni is an atomic ratio. 0.002 ≦ (Fe + Co) / Ni <0.6, and the parent phase contains at least one of Fe and Co and Ni and P [Ni, (Fe, Co)] − It has a P-based precipitate, and the atomic ratio of the total content of Fe and Co to the Ni content in this [Ni, (Fe, Co)]-P-based precipitate [(Fe + Co) / Ni] _P However, 5 ≦ [(Fe + Co) / Ni] _P / [(Fe + Co) / Ni] ≦ with respect to the atomic ratio [(Fe + Co) / Ni] of the total content of Fe and Co and Ni in the entire alloy It is characterized by satisfying 200.

According to the copper alloy for electronic and electrical equipment having the above-described configuration, Ni, Fe, and Co are added together with P, and the addition ratio among Sn, Ni, Fe, Co, and P is regulated, and the parent phase (α phase) (Ni, (Fe, Co))-P-based precipitates containing at least one of Fe and Co precipitated from Ni and P and Ni and P. The atomic ratio of the total content of Fe and Co and the content of Ni in the P-based precipitate [(Fe + Co) / Ni] _P is the atom of the total content of Fe and Co and the content of Ni in the entire alloy. Since the ratio [(Fe + Co) / Ni] satisfies 5 ≦ [(Fe + Co) / Ni] _P / [(Fe + Co) / Ni] ≦ 200, [Ni, (Fe, Co)] − The number density of P-based precipitates is ensured and the coarsening of the precipitates is suppressed. Becomes Rukoto, has excellent heat resistance and stress relaxation properties.
Here, the [Ni, (Fe, Co)]-P-based precipitates are Ni—Fe—P, Ni—Co—P ternary precipitates, or Ni—Fe—Co—P quaternary. And other elements such as Cu, Zn, Sn as main components, O, S, C, Cr, Mo, Mn, Mg, Zr, Ti and the like as main components. May be included. Moreover, this [Ni, (Fe, Co)]-P-based precipitate exists in the form of a phosphide or an alloy in which phosphorus is dissolved.

Here, in the copper alloy for electronic / electric equipment of the present invention, it is preferable that the [Ni, Fe] -P-based precipitate containing Fe, Ni, and P has an average particle size of 100 nm or less.
Moreover, in the copper alloy for electronic / electric equipment of the present invention, the average particle diameter of the [Ni, (Fe, Co)]-P-based precipitates containing at least one of Fe and Co and Ni and P is It is preferable to be 100 nm or less.
In these cases, the average particle diameter of the [Ni, Fe] -P-based precipitate containing Fe, Ni and P, or containing at least one of Fe and Co and Ni and P [Ni, ( Fe, Co)]-P-based precipitates have an average particle size of 100 nm or less, so fine [Ni, Fe] -P-based precipitates or [Ni, (Fe, Co)]-P-based precipitates Are distributed with a sufficient number density, and the heat resistance and the stress relaxation resistance can be reliably improved.

The copper alloy thin plate for electronic / electrical equipment of the present invention is made of the above-mentioned rolled material of copper alloy for electronic / electrical equipment, and has a thickness in the range of 0.05 mm to 3.0 mm.
The rolled sheet thin plate (strip material) having such a thickness can be suitably used for connectors, other terminals, movable conductive pieces of electromagnetic relays, lead frames, and the like.

The conductive component for electronic / electrical equipment of the present invention is characterized by comprising the above-described copper alloy thin plate for electronic / electrical equipment. The conductive parts for electronic / electrical equipment in the present invention include terminals, connectors, relays, lead frames and the like.
The terminal of the present invention is characterized by comprising the above-described copper alloy thin plate for electronic and electrical equipment. The terminals in the present invention include connectors and the like.
According to the conductive parts and terminals for electronic and electrical equipment having these configurations, the heat resistance and the stress relaxation resistance are particularly excellent, so that they can be used well even in a high temperature environment.

  According to the present invention, the heat resistance and the stress relaxation resistance are surely and sufficiently excellent, and the copper alloy for electronic / electric equipment having excellent strength, the copper alloy thin plate for electronic / electric equipment using the same, Conductive components and terminals for electrical equipment can be provided.

It is a flowchart which shows the process example of the manufacturing method of the copper alloy for electronic and electric apparatuses of this invention.

Below, the copper alloy for electronic and electric apparatuses which is one Embodiment of this invention is demonstrated.
The copper alloy for electronic / electric equipment according to the present embodiment is more than 2 mass% of Zn and 36.5 mass% or less, Sn is 0.1 mass% or more and 0.9 mass% or less, and Ni is 0.15 mass% or more and 1.0 mass% or less. Less than P, 0.005 mass% or more and 0.1 mass% or less of P, 0.001 mass% or more and 0.1 mass% or less of Fe, and the balance of Cu and inevitable impurities.

The ratio of the total content of Ni and Fe to the content of P (Ni + Fe) / P is the atomic ratio as the content ratio between the alloy elements, and the following equation (1) 3 <(Ni + Fe ) / P <30 (1)
The filling,
Furthermore, the ratio Sn / (Ni + Fe) between the Sn content and the total content of Ni and Fe is the atomic ratio, and the following formula (2): 0.3 <Sn / (Ni + Fe) <2.7 (2) 2)
While satisfying
Ratio of Fe content and Ni content Fe / Ni is an atomic ratio expressed by the following equation (3): 0.002 ≦ Fe / Ni <0.6 (3)
It is determined to satisfy.

Here, in the copper alloy for electronic and electrical equipment according to the present embodiment, [Ni, Fe] -P-based precipitates containing Fe, Ni, and P are present in the matrix, and this [ The atomic ratio [Fe / Ni] _P between the Fe content and the Ni content in the Ni, Fe] -P-based precipitate is the atomic ratio [Fe / Ni] between the Fe content and the Ni content of the entire alloy. / Ni], the following equation (4) 5 ≦ [Fe / Ni] _P / [Fe / Ni] ≦ 200 (4)
Meet.

  In addition, the copper alloy for electronic / electric equipment according to the present embodiment may contain Co in addition to the above Zn, Sn, Ni, P, and Fe. In this case, the total content of Fe and Co is set to 0.001 mass% to 0.1 mass% (provided that Fe is contained in an amount of 0.001 mass% to 0.1 mass%).

In this case, as the content ratio between the alloy elements, the ratio of the total content of Ni, Fe and Co to the content of P (Ni + Fe + Co) / P is an atomic ratio, and the following equation (1 ′) 3 <(Ni + Fe + Co) / P <30 (1 ′)
The filling,
Furthermore, the ratio Sn / (Ni + Fe + Co) between the Sn content and the total content of Ni, Fe, and Co is an atomic ratio expressed by the following formula (2 ′): 0.3 <Sn / (Ni + Fe + Co) <2.7・ ・ Satisfy (2 '),
Furthermore, the ratio (Fe + Co) / Ni of the total content of Fe and Co and the content of Ni is an atomic ratio, and the following (3 ′) equation 0.002 ≦ (Fe + Co) / Ni <0.6 It is determined to satisfy (3 ′).

When Co is added, [Ni, (Fe, Co)]-P-based precipitates containing at least one of Fe and Co and Ni and P are present in the matrix, Ni, (Fe, Co)]-P atomic ratio between the total content of Fe and Co and the content of Ni in the precipitate [(Fe + Co) / Ni] _P is the total content of Fe and Co in the entire alloy The atomic ratio [(Fe + Co) / Ni] of the amount and the content of Ni, the following (4 ′) formula 5 ≦ [(Fe + Co) / Ni] _P / [(Fe + Co) / Ni] ≦ 200・ (4 ')
Meet.

  Here, the reason why the composition of the alloy and the composition in the precipitate are defined as described above will be described below.

(Zn: more than 2 mass% and 36.5 mass% or less)
Zn is a basic alloy element in the copper alloy which is the subject of this embodiment, and is an element effective in improving strength and springiness. Moreover, since Zn is cheaper than Cu, it is effective in reducing the material cost of the copper alloy. If Zn is 2 mass% or less, the effect of reducing the material cost cannot be sufficiently obtained. On the other hand, if Zn exceeds 36.5 mass%, corrosion resistance will fall and cold rolling property will also fall.
Therefore, the Zn content is within the range of more than 2 mass% and not more than 36.5 mass%. The Zn content is preferably in the range of 5 mass% to 33 mass%, more preferably in the range of 7 mass% to 27 mass%, even within the above range. More preferably, it is within the range of 7 mass% or more and 12 mass% or less.

(Sn: 0.1 mass% or more and 0.9 mass% or less)
The addition of Sn is effective in improving the strength and is advantageous for improving the recyclability of the Cu-Zn alloy material with Sn plating. Furthermore, it has been found by the present inventors that if Sn coexists with Ni, it contributes to the improvement of stress relaxation resistance. If Sn is less than 0.1 mass%, these effects cannot be sufficiently obtained. On the other hand, if Sn exceeds 0.9 mass%, hot workability and cold rollability are deteriorated, and hot rolling and cold rolling are performed. May cause cracking, and the electrical conductivity is also lowered.
Therefore, the Sn content is set within a range of 0.1 mass% to 0.9 mass%. The Sn content is particularly preferably in the range of 0.2 mass% to 0.8 mass% even within the above range.

(Ni: 0.15 mass% or more and less than 1.0 mass%)
Ni can be added together with P to precipitate Ni—P-based precipitates from the matrix (mainly α-phase), and when added together with Fe and P, [Ni, Fe] -P-based precipitation By adding the substance together with Fe and Co and P, the [Ni, (Fe, Co)]-P-based precipitate can be precipitated from the parent phase (mainly α-phase). These Ni-P-based precipitates, [Ni, Fe] -P-based precipitates, and [Ni, (Fe, Co)]-P-based precipitates are used to average the grain boundaries during recrystallization. The crystal grain size can be controlled, and the strength, bending workability, and stress corrosion cracking resistance can be improved. Furthermore, the presence of these precipitates can greatly improve the stress relaxation resistance. In addition, Ni can be improved by solid solution strengthening by coexisting with Sn, Fe, P and, if necessary, Co. Here, if the addition amount of Ni is less than 0.15 mass%, the stress relaxation resistance cannot be sufficiently improved. On the other hand, if the addition amount of Ni becomes 1.0 mass% or more, the solid solution Ni increases and the conductivity decreases, and the cost increases due to an increase in the amount of expensive Ni raw materials used.
Therefore, the Ni content is in the range of 0.15 mass% or more and less than 1.0 mass%. In addition, it is preferable to make content of Ni into the range of 0.2 mass% or more and less than 0.8 mass% especially also in said range.

(P: 0.005 mass% or more and 0.1 mass% or less)
P has a high bonding property with Ni, and if an appropriate amount of P is contained together with Ni, Ni—P-based precipitates can be precipitated, and by adding together with Fe and P, [Ni, Fe] By adding the -P-based precipitate together with Fe and Co and P, the [Ni, (Fe, Co)]-P-based precipitate can be precipitated from the parent phase (mainly α-phase). The stress relaxation resistance can be improved by the presence of these Ni-P-based precipitates, [Ni, Fe] -P-based precipitates, and [Ni, (Fe, Co)]-P-based precipitates. Here, if the amount of P is less than 0.005 mass%, Ni—P-based precipitates, [Ni, Fe] -P-based precipitates, and [Ni, (Fe, Co)]-P-based precipitates are sufficiently precipitated. This makes it difficult to sufficiently improve the stress relaxation resistance. On the other hand, if the amount of P exceeds 0.1 mass%, the amount of P solid solution increases, and the electrical conductivity is lowered and the rollability is lowered to cause cold rolling cracks.
Therefore, the content of P is set in the range of 0.005 mass% to 0.1 mass%. The content of P is particularly preferably in the range of 0.01 mass% to 0.08 mass% even within the above range.
In addition, since P is an element which is inevitably mixed from the melting raw material of the copper alloy, it is desirable to appropriately select the melting raw material in order to regulate the P content as described above. .

(Fe: 0.001 mass% or more and 0.1 mass% or less)
When Fe is added together with Ni and P, [Ni, Fe] -P-based precipitates can be precipitated from the parent phase (mainly α-phase), and by adding a small amount of Co, [Ni, ( Fe, Co)]-P-based precipitates can be precipitated from the mother phase (mainly α-phase). The average crystal grain size is controlled by the effect of pinning the grain boundary during recrystallization with these [Ni, Fe] -P-based precipitates or [Ni, (Fe, Co)]-P-based precipitates. Strength, bending workability, and stress corrosion cracking resistance can be improved. Furthermore, the presence of these precipitates can greatly improve both the stress relaxation resistance and heat resistance characteristics. Here, if the Fe content is less than 0.001 mass%, the effect of improving both the stress relaxation resistance and the heat resistance by adding Fe cannot be obtained. On the other hand, if the Fe content exceeds 0.1 mass%, the effect of improving both the stress relaxation resistance and the heat resistance cannot be obtained, the amount of solid solution Fe increases, the conductivity decreases, and cold rolling is performed. The nature will also decline.
Therefore, in the present embodiment, when Fe is added, the content of Fe is set in the range of 0.001 mass% to 0.1 mass%. In addition, it is preferable to make content of Fe into the range of 0.002 mass% or more and 0.08 mass% or less especially also in said range.

(Total content of Fe and Co: 0.001 mass% or more and 0.1 mass% or less)
When Co is added, it is considered that a part of Fe is replaced by Co. By adding Fe and Co, [Ni, (Fe, Co)]-P-based precipitates can be precipitated from the matrix (mainly α-phase). This [Ni, (Fe, Co)]-P-based precipitate can control the average grain size by the effect of pinning the grain boundaries during recrystallization, and can provide strength, bending workability, and stress resistance. Corrosion cracking can be improved. Furthermore, the presence of the [Ni, (Fe, Co)]-P-based precipitates can greatly improve both the stress relaxation resistance and the heat resistance characteristics. Here, if the total content of Fe and Co is less than 0.001 mass%, the effect of improving both the stress relaxation resistance and the heat resistance by adding Fe and Co cannot be sufficiently obtained. On the other hand, if the total content of Fe and Co exceeds 0.1 mass%, further improvement effects of both the stress relaxation resistance and the heat resistance cannot be obtained, and the amount of solid solution Fe and solid solution Co increases and the conductivity is increased. Decreases, and the cold rolling property also decreases.
Therefore, in the present embodiment, when both Fe and Co are added, the Fe content is 0.001 mass% or more and 0.1 mass% or less, and the total content of Fe and Co is 0.001 mass% or more and 0. Within the range of 1 mass% or less. The total content of Fe and Co is particularly preferably 0.08 mass% or less even within the above range.

  The balance of the above elements may be basically Cu and inevitable impurities. Here, inevitable impurities include Co, Al, Ag, B, Ba, Hf, V, Nb, Ta, Mo, W, Re, Ru, Os, O, S, Se, Rh, Ir, Pd, and Pt. , Au, Cd, Ga, In, Li, Ge, As, Sb, Tl, Pb, Bi, C, Be, N, H, Hg, Mg, Ti, Cr, Zr, Ca, Sr, Y, Mn, Te , Si, Sc, and rare earth elements. These inevitable impurities are desirably 0.3 mass% or less in total.

  Furthermore, in the copper alloy for electronic and electrical equipment according to the present embodiment, not only the individual addition amount ranges of the respective alloy elements are adjusted as described above, but the mutual ratio of the content of each element is an atomic ratio. It is important to regulate the ratio so as to satisfy the expressions (1) to (4). Moreover, when adding Co, it is important to regulate so as to satisfy the expressions (1 ′) to (4 ′). Therefore, the reasons for limiting the equations (1) to (4) and (1 ′) to (4 ′) will be described below.

(1) Formula: 3 <(Ni + Fe) / P <30
When the (Ni + Fe) / P ratio is 3 or less, the stress relaxation resistance and the heat resistance decrease with an increase in the ratio of the solid solution P. At the same time, the conductivity decreases due to the solid solution P, and the rollability decreases. As a result, cold rolling cracks are likely to occur, and bending workability is also reduced. On the other hand, if the (Ni + Fe) / P ratio is 30 or more, the conductivity decreases due to an increase in the ratio of Ni and Fe dissolved in solid, and the amount of expensive Ni raw material used is relatively increased, leading to an increase in cost. . Therefore, the (Ni + Fe) / P ratio is regulated within the above range. The (Ni + Fe) / P ratio is preferably in the range of more than 3 and not more than 20 even in the above range. More preferably, it is in the range of more than 3 and 15 or less.

(2) Formula: 0.3 <Sn / (Ni + Fe) <2.7
When the Sn / (Ni + Fe) ratio is 0.3 or less, sufficient stress relaxation resistance and heat resistance improvement effect are not exhibited. On the other hand, when the Sn / (Ni + Fe) ratio is 2.7 or more, the relative amount of Ni is relatively small. However, the amount of Ni-P-based precipitates is reduced, and the improvement of both stress relaxation resistance and heat resistance cannot be obtained. Therefore, the Sn / (Ni + Fe) ratio is regulated within the above range. The Sn / (Ni + Fe) ratio is particularly preferably within the range of more than 0.3 and not more than 1.5 even within the above range.

(3) Formula: 0.002 ≦ Fe / Ni <0.6
When the Fe / Ni ratio is less than 0.002, the strength decreases and the amount of expensive Ni raw material used is relatively increased, leading to an increase in cost. On the other hand, when the Fe / Ni ratio is 0.6 or more, sufficient stress relaxation characteristics and heat resistance improvement effects are not exhibited. Therefore, the Fe / Ni ratio is regulated within the above range. Note that the Fe / Ni ratio is particularly preferably in the range of 0.002 to 0.4 even within the above range. More preferably, it is in the range of 0.002 to 0.2.

(4) Formula: 5 ≦ [Fe / Ni] _P / [Fe / Ni] ≦ 200
[Ni, Fe] -P atomic ratio between Fe content and Ni content in Fe-based precipitate [Fe / Ni] _P and atomic ratio between Fe content and Ni content in the entire alloy [ [Fe / Ni] is also important. When the [Fe / Ni] _P / [Fe / Ni] ratio is less than 5, the number density of [Ni, Fe] -P-based precipitates is lowered, and the stress relaxation resistance and heat resistance are sufficiently improved. I can't get it. On the other hand, when the [Fe / Ni] _P / [Fe / Ni] ratio is greater than 200, the precipitates become Fe—P based precipitates, the size of the precipitates increases, and the number density also decreases. Improvements in both relaxation characteristics and heat resistance cannot be obtained. Therefore, the [Fe / Ni] _P / [Fe / Ni] ratio is regulated within the above range. Note that the [Fe / Ni] _P / [Fe / Ni] ratio is particularly preferably in the range of 10 or more and 100 or less even in the above range. More preferably, it is in the range of more than 15 and 75 or less.

(1 ′) Formula: 3 <(Ni + Fe + Co) / P <30
When Fe and Co are added, it may be considered that a part of Ni is replaced by Fe and Co, and the formula (1 ′) basically conforms to the formula (1). Here, when the (Ni + Fe + Co) / P ratio is 3 or less, the stress relaxation resistance and the heat resistance decrease with an increase in the ratio of the solid solution P, and at the same time, the conductivity decreases due to the solid solution P, and the rollability. Decreases and cold rolling cracks are likely to occur, and bending workability also decreases. On the other hand, if the (Ni + Fe + Co) / P ratio is 30 or more, the conductivity decreases due to an increase in the proportion of Ni, Fe, and Co dissolved, and the amount of expensive Co and Ni raw materials used increases relatively. Increases costs. Therefore, the (Ni + Fe + Co) / P ratio is regulated within the above range. The (Ni + Fe + Co) / P ratio is preferably in the range of more than 3 and 20 or less even in the above range. More preferably, it is in the range of more than 3 and 15 or less.

(2 ′) Formula: 0.3 <Sn / (Ni + Fe + Co) <2.7
The formula (2 ′) when Fe and Co are added also conforms to the formula (2). When the Sn / (Ni + Fe + Co) ratio is 0.3 or less, sufficient stress relaxation resistance and heat resistance improvement effects are not exhibited. On the other hand, when the Sn / (Ni + Fe + Co) ratio is 2.7 or more, relatively When the amount of (Ni + Fe + Co) decreases, the amount of [Ni, (Fe, Co)]-P-based precipitates decreases, and the stress relaxation resistance and heat resistance deteriorate. Therefore, the Sn / (Ni + Fe + Co) ratio is regulated within the above range. The Sn / (Ni + Fe + Co) ratio is particularly preferably within the range of more than 0.3 and not more than 1.5 even within the above range.

(3 ′) Formula: 0.002 ≦ (Fe + Co) / Ni <0.6
When Fe and Co are added, the ratio between the total content of Fe and Co and the content of Ni is also important. When the (Fe + Co) / Ni ratio is 0.6 or more, the stress relaxation resistance and heat resistance are lowered, and the cost is increased due to an increase in the amount of expensive Co raw material used. When the (Fe + Co) / Ni ratio is less than 0.002, the strength decreases and the amount of expensive Ni raw material used is relatively increased, leading to an increase in cost. Therefore, the (Fe + Co) / Ni ratio is regulated within the above range. Note that the (Fe + Co) / Ni ratio is preferably in the range of 0.002 to 0.4, even within the above range. More preferably, it is in the range of 0.002 to 0.2.

(4 ′) Formula: 5 ≦ [(Fe + Co) / Ni] _P / [(Fe + Co) / Ni] ≦ 200
When Fe and Co are added, the atomic ratio [(Fe + Co) / Ni between the total content of Fe and Co and the content of Ni in the [Ni, (Fe, Co)]-P-based precipitates. The atomic ratio [(Fe + Co) / Ni] between _P and the total content of Fe and Co in the entire alloy and the content of Ni is also important. When the [(Fe + Co) / Ni] _P / [(Fe + Co) / Ni] ratio is less than 5, the number density of [Ni, (Fe, Co)]-P-based precipitates is reduced, The stress relaxation resistance and heat resistance cannot be improved. On the other hand, when the [(Fe + Co) / Ni] _P / [(Fe + Co) / Ni] ratio is greater than 200, the precipitate becomes a (Fe, Co) -P-based precipitate, and the size of the precipitate is Since it increases and the number density also decreases, the stress relaxation resistance and heat resistance cannot be improved.
Therefore, the [(Fe + Co) / Ni] _P / [(Fe + Co) / Ni] ratio is regulated within the above range. Note that the [(Fe + Co) / Ni] _P / [(Fe + Co) / Ni] ratio is particularly preferably in the range of 10 to 100, even within the above range. More preferably, it is in the range of more than 15 and 75 or less.

  As described above, each alloy element is adjusted not only for individual contents but also as a ratio between each element so as to satisfy the expressions (1) to (3) or (1 ′) to (3 ′). -In a copper alloy for electrical equipment, [Ni, Fe] -P-based precipitates or [Ni, (Fe, Co)]-P-based precipitates are dispersed and precipitated from the parent phase (mainly α-phase). . Then, by defining the composition ratio in the precipitate so as to satisfy the above-mentioned expression (4) or (4 ′), [Ni, Fe] -P-based precipitate or [Ni, (Fe, Co) It is considered that the size of the -P-based precipitate is miniaturized and the number density is secured, and the stress relaxation resistance and heat resistance are surely improved.

Moreover, in this embodiment, the average particle diameter of the [Ni, Fe] -P-based precipitate containing Fe, Ni, and P is 100 nm or less. Moreover, the average particle diameter of the [Ni, (Fe, Co)]-P-based precipitates containing Fe, Co, Ni, and P is 100 nm or less.
As described above, the average particle diameter of the [Ni, Fe] -P-based precipitate and the average particle diameter of the [Ni, (Fe, Co)]-P-based precipitate are reduced to 100 nm or less. It is considered that the stress relaxation characteristics and heat resistance are surely improved.

  Next, a preferred example of a method for producing a copper alloy for electronic / electric equipment according to the above-described embodiment will be described with reference to the flowchart shown in FIG.

[Melting / Casting Process: S01]
First, a molten copper alloy having the above-described component composition is melted. As the copper raw material, it is desirable to use 4NCu (oxygen-free copper or the like) having a purity of 99.99 mass% or more, but scrap may be used as a raw material. In addition, an atmospheric furnace may be used for melting, but an atmosphere furnace having a vacuum furnace, an inert gas atmosphere, or a reducing atmosphere may be used in order to suppress oxidation of the additive element.
Next, the component-adjusted copper alloy molten metal is cast by an appropriate casting method using a vertical casting furnace or a horizontal casting furnace, for example, a batch casting method such as die casting, a continuous casting method, a semi-continuous casting method, or the like. Thus, an ingot (for example, a slab-like ingot) is obtained.

[Heating step: S02]
Thereafter, if necessary, a homogenization heat treatment is performed in order to eliminate segregation of the ingot and make the ingot structure uniform. Alternatively, a solution heat treatment is performed to dissolve the crystallized product and the precipitate. The conditions for this heat treatment are not particularly limited. Usually, the heat treatment may be performed at 600 ° C. to 1000 ° C. for 1 second to 24 hours. If the holding temperature is less than 600 ° C. or the holding time is less than 5 minutes, a sufficient homogenizing effect or solution effect may not be obtained. On the other hand, if the holding temperature exceeds 1000 ° C., a part of the segregation site may be dissolved, and if the holding time exceeds 24 hours, only the cost increases. The cooling conditions after the heat treatment may be determined as appropriate, but usually water quenching may be performed. In addition, after the heating step S02, chamfering is performed as necessary.

[Hot working process: S03]
Next, in order to increase the efficiency of rough machining and make the structure uniform, hot working may be performed on the ingot after the heating step S02 described above. The conditions for this hot working are not particularly limited, but it is usually preferable that the starting temperature is 600 ° C. or higher and 1000 ° C. or lower, the end temperature is 300 ° C. or higher and 850 ° C. or lower, and the processing rate is 10% or higher and 99% or lower. The ingot heating up to the hot working start temperature may also serve as the heating step S02 described above. That is, the hot working may be started at the above-described hot working start temperature without cooling to near room temperature after heating in the heating step S02. Cooling conditions after hot working may be determined as appropriate, but usually water quenching may be performed. In addition, after hot processing, it chamfers as needed. The hot working method is not particularly limited, but when the final shape is a plate or strip, hot rolling may be applied and rolled to a thickness of about 0.5 mm to 50 mm. Further, extrusion or groove rolling may be applied when the final shape is a wire or bar, and forging or pressing may be applied when the final shape is a bulk shape. Moreover, about the ingot produced with the horizontal type continuous casting method, it is usually unnecessary to perform a hot working process.

[Intermediate plastic working step: S04]
Next, intermediate plastic working is performed on the ingot subjected to the homogenization treatment in the heating step S02 or the hot work material subjected to the hot working step S03 such as hot rolling. The temperature condition in the intermediate plastic working step S04 is not particularly limited, but is preferably in the range of −200 ° C. to + 200 ° C. that is cold or warm working. The processing rate of the intermediate plastic processing is not particularly limited, but is usually about 10% to 99%. The processing method is not particularly limited, but when the final shape is a plate or strip, rolling may be applied and rolled to a thickness of about 0.05 mm to 15 mm. Further, extrusion or groove rolling can be applied when the final shape is a wire or bar, and forging or pressing can be applied when the final shape is a bulk shape.

[Intermediate heat treatment step: S05]
Next, an intermediate heat treatment that also serves as a solution heat treatment is performed after the intermediate plastic working step S04. By performing this intermediate heat treatment, fine [Ni, Fe] -P-based precipitates or [Ni, (Fe, Co)]-P-based precipitates are formed into a solution in the matrix phase. Here, in the intermediate heat treatment, a batch-type heating furnace may be used, or a continuous annealing line may be used. And when implementing intermediate heat processing using a batch type heating furnace, it is preferable to heat for 5 minutes or more and 24 hours or less at the temperature of 600 degreeC or more and 1000 degrees C or less. In addition, when the intermediate heat treatment is performed using the continuous annealing line, the heating ultimate temperature is set to 650 ° C. or more and 1000 ° C. or less, and the temperature within this range is not maintained or is maintained for 1 second or more and 5 minutes or less. It is preferable. As described above, the heat treatment conditions in the intermediate heat treatment step S05 vary depending on the specific means for performing the heat treatment.
The atmosphere for the intermediate heat treatment is preferably a non-oxidizing atmosphere (nitrogen gas atmosphere, inert gas atmosphere, or reducing atmosphere).
Although the cooling conditions after the intermediate heat treatment are not particularly limited, the cooling is usually performed at a cooling rate of about 2000 ° C./second to 100 ° C./hour.
Note that the intermediate plastic processing step S04 and the intermediate heat treatment step S05 may be repeated for thorough solution.

[Finish plastic working process: S06]
After the intermediate heat treatment step S05, finish plastic working is performed up to the final dimension and final shape. The processing method in finish plastic working is not particularly limited, but when the final product form is a plate or strip, rolling (cold rolling) is applied and rolled to a thickness of about 0.05 mm to 3.0 mm. That's fine. In addition, forging, pressing, groove rolling, or the like may be applied depending on the final product form. The processing rate may be appropriately selected according to the final plate thickness and final shape, but is preferably in the range of 1% to 80%. If the processing rate is less than 1%, the effect of improving the proof stress cannot be obtained sufficiently. On the other hand, if the processing rate exceeds 80%, the recrystallized structure is substantially lost to form a processed structure, and the bending workability decreases. There is a fear. The processing rate is preferably 5% to 80%, more preferably 10% to 80%. After the finish plastic working, it may be used as a product as it is, but it is usually preferable to perform a finish heat treatment.

[Finish heat treatment step: S07]
After the finish plastic working, a finish heat treatment step S07 is performed as necessary to improve the stress relaxation resistance and heat resistance and to perform low-temperature annealing hardening or to remove residual strain. The finish heat treatment is desirably performed at a temperature in the range of 250 ° C. to 600 ° C. for 1 hour to 48 hours. If the heat treatment temperature is high, heat treatment for a short time may be performed, and if the heat treatment temperature is low, heat treatment for a long time may be performed. If the temperature of the finish heat treatment is less than 250 ° C. or the finish heat treatment time is less than 1 hour, there is a possibility that a sufficient effect of removing the strain cannot be obtained. On the other hand, if the temperature of the finish heat treatment exceeds 600 ° C., recrystallization may occur, and if the finish heat treatment time exceeds 48 hours, only the cost increases.
In the present embodiment, the atomic ratio between the Fe content and the Ni content in the [Ni, Fe] -P-based precipitate is controlled by the rate of temperature rise. The temperature raising rate is desirably 0.1 ° C./min or more and 10 ° C./min or less.

As described above, the Cu—Zn—Sn alloy material in the final product form can be obtained. In particular, when rolling is applied as a processing method, a Cu—Zn—Sn alloy thin plate (strip material) having a thickness of about 0.05 mm to 3.0 mm can be obtained.
Such a thin plate may be used as it is for a conductive part for electronic / electric equipment, but Sn plating with a film thickness of about 0.1 to 10 μm is applied to one or both sides of the plate surface, and Sn plating is provided. The copper alloy strip is usually used for conductive parts for electronic and electrical equipment such as connectors and other terminals. In this case, the Sn plating method is not particularly limited. In some cases, a reflow treatment may be performed after electrolytic plating.

In the copper alloy for electronic and electrical equipment according to the present embodiment configured as described above, [Ni, Fe] -P-based precipitates are appropriately present from the parent phase mainly composed of α phase, and at the same time, [Ni , Fe] —P atomic ratio of Fe content to Ni content [Fe / Ni] _P is the atomic ratio of Fe content to Ni content of the whole alloy [Fe / Ni]. Ni] is in the range of 5 or more and 200 or less, so that the stress relaxation resistance and heat resistance are sufficiently excellent, and the strength (proof strength) is also high.

Similarly, when Fe and Co are added, [Ni, (Fe, Co)]-P-based precipitates are appropriately present from the matrix mainly composed of α phase, and at the same time, [Ni, (Fe, Co) The atomic ratio between the content of (Fe + Co) and the content of Ni in the -P-based precipitate [(Fe + Co) / Ni] _P is the atom between the content of (Fe + Co) and the content of Ni in the entire alloy. Since the ratio [(Fe + Co) / Ni] is in the range of 5 or more and 200 or less, the stress relaxation resistance and heat resistance are sufficiently excellent, and the strength (yield strength) is also high.

  Since the copper alloy thin plate for electronic / electric equipment according to the present embodiment is made of a rolled material of the above-mentioned copper alloy for electronic / electric equipment, it has excellent stress relaxation resistance and heat resistance, connectors, other terminals, It can be suitably used for bus bars, movable conductive pieces of electromagnetic relays, lead frames, and the like.

  The conductive member and terminal for electronic / electrical equipment according to the present embodiment are composed of the above-described copper alloy for electronic / electrical equipment and copper alloy thin plate for electronic / electrical equipment, so it has excellent stress relaxation resistance and heat resistance. Therefore, stress relaxation is less likely to occur over time or in a high temperature environment, and the strength (hardness) does not decrease significantly at high temperatures. In addition, it is possible to reduce the thickness of the conductive parts for electronic and electrical equipment and the terminals.

As mentioned above, although embodiment of this invention was described, this invention is not limited to this, It can change suitably in the range which does not deviate from the technical idea of the invention.
For example, although an example of the manufacturing method has been described, the present invention is not limited to this, and the finally obtained copper alloy for electronic / electric equipment has the composition range and the composition of precipitates defined in the present invention. It only has to be satisfied.

  Hereinafter, the result of the confirmation experiment conducted to confirm the effect of the present invention will be shown as an example of the present invention together with a comparative example. In addition, the following examples are for explaining the effects of the present invention, and the configurations, processes, and conditions described in the examples do not limit the technical scope of the present invention.

First, a raw material consisting of Cu-40 mass% Zn master alloy and oxygen-free copper (ASTM B152 C10100) with a purity of 99.99 mass% or more was prepared, charged in a high-purity graphite crucible, and N ₂ gas atmosphere. Melting was performed using a horizontal continuous casting furnace. Various additive elements were added into the molten copper alloy to melt the molten alloy having the composition shown in Table 1, and an ingot was produced using a carbon mold. Then, it cut | disconnected to thickness about 11 mm x width about 80 mm x length about 200 mm.
Next, each cut ingot was subjected to water quenching as a heat treatment (homogenization treatment) in an Ar gas atmosphere at 800 ° C. for 4 hours.

  Thereafter, surface grinding was performed, and intermediate plastic working and intermediate heat treatment were performed. Specifically, in the roughing, cold rolling was performed at a rolling rate of 95% so that the length direction of the ingot was the rolling direction. Thereafter, an intermediate heat treatment for solution treatment was carried out at 700 ° C. for a predetermined time so that the crystal grain size was about 20 μm, followed by water quenching. Thereafter, the rolled material was cut, and surface grinding was performed to remove the oxide film.

  Next, as finish plastic working, cold rolling was performed at a rolling rate of 50%. Then, it heated up to 350 degreeC with the temperature increase rate shown in Table 1, and finish-heat-treated for predetermined time, and water-quenched. Then, cutting and surface polishing were performed to produce a strip for characteristic evaluation having a thickness of 0.25 mm and a width of about 180 mm.

These strips for property evaluation were examined for mechanical properties (proof stress), stress relaxation resistance and heat resistance, and further observed for structure. The test method and measurement method for each evaluation item are as follows.

[Observation of crystal grain size]
Using the surface perpendicular to the rolling width direction, that is, the TD surface (Transverse direction) as the observation surface, mechanical polishing is performed using water-resistant abrasive paper and diamond abrasive grains, and then final polishing is performed using a colloidal silica solution. It was. After polishing, etching was performed using a mixed solution of sulfuric acid and nitric acid as a corrosive solution, and the metal structure was observed with an optical microscope. The crystal grain size conforms to the cutting method of JIS H 0501, draws line segments of predetermined lengths in the vertical and horizontal directions, counts the number of crystal grains that are completely cut, and averages the average value of the cutting lengths. The crystal grain size was used.

[Observation of precipitates]
About each strip for characteristic evaluation, using a transmission electron microscope (TEM: manufactured by Hitachi, H-800, HF-2200) and an EDX analyzer (manufactured by Noran, EDX analyzer SYSTEM SIX), precipitation was performed as follows. Object observation was performed.
After mechanical polishing using water-resistant abrasive paper and diamond abrasive grains from the front and back surfaces of the rolled material, a TEM observation sample was prepared by a twin jet method using an electrolytic solution. The TEM observation sample was produced from two places which entered 1/4 in the thickness direction from each of two places on the front and back surfaces of the rolled material. Electron beam diffraction is performed on 10 or more precipitates having a particle diameter of about 10 nm to 50 nm, and these precipitates are hexagonal crystals (space group: P-62m) having a Fe ₂ P-based or Ni ₂ P-based crystal structure. 189)) or a Co ₂ P-based or Fe ₂ P-based orthorhombic crystal (space group: P-nma (62)). After conducting electron diffraction, each precipitate was analyzed for the composition of the precipitate using EDX (energy dispersive X-ray spectroscopy). As a result, the precipitate was obtained from Fe, Co, and Ni. It was confirmed that it contains at least one element selected from the group and P, that is, a [Ni, (Fe, Co)]-P-based precipitate that has already been defined. Further, the Fe / Ni ratio or (Fe + Co) / Ni ratio in the precipitate was calculated from the composition analysis result of the EDX precipitate.

[Evaluation of heat resistance]
The heat resistance was evaluated according to JCBA T315: 2002 “Annealing and softening property test of copper and copper alloy strips” at a semi-softening temperature when heat treatment was performed for 1 hour at each temperature. The semi-softening temperature is the sum of the hardness of the strip for property evaluation and the hardness of the strip heat-treated at 700 ° C. for 1 hour in an electric furnace, and the temperature at which the hardness becomes half of the sum. It was. The actual semi-softening temperature was determined by plotting the hardness when carried out at 50 ° C. for 1 hour each in the temperature range of 200 to 700 ° C., creating a hardness-temperature curve, and determining from that curve.
The hardness is in accordance with the microhardness test method specified in JIS-Z2248, and the test load is 1.96 N (= 0.2 kgf) on the surface of the strip for property evaluation, that is, the ND surface (Normal Direction). ) To measure the Vickers hardness.

(Mechanical properties)
A No. 13B test piece defined in JIS Z 2201 was collected from the strip for characteristic evaluation, and Young's modulus E and 0.2% proof stress σ _0.2 were measured by the offset method of JIS-Z 2241. In addition, the test piece was extract | collected so that the tension direction of a tension test might become a direction orthogonal to the rolling direction of the strip for characteristic evaluation.

[Stress relaxation resistance]
The stress relaxation resistance test was conducted by applying a stress according to a method according to the Japan Copper and Brass Association Technical Standard JCBA-T309: 2004 cantilever screw method, and a Zn amount exceeding 2 mass% and less than 15 mass% (Table 4). -6, those entered in the column of "2-15 Zn evaluation") after holding for 500 hours at a temperature of 150 ° C, a sample having a Zn content of 15 mass% or more and 36.5 mass% or less ("15 of Tables 4-6" For the item “-36.5 Zn Evaluation”, the residual stress ratio after holding at 120 ° C. for 500 hours was measured.
As a test method, a specimen (width 10 mm) is taken from each characteristic evaluation strip in a direction orthogonal to the rolling direction, and the initial deflection displacement is set so that the maximum surface stress of the specimen is 80% of the proof stress. The span length was adjusted to 2 mm. The maximum surface stress is determined by the following equation.
Maximum surface stress (MPa) = 1.5 Etδ ₀ / Ls ²
However,
E: Young's modulus (MPa)
t: sample thickness (t = 0.25 mm)
δ ₀ : Initial deflection displacement (2 mm)
Ls: Span length (mm)
It is.
The residual stress rate was calculated using the following formula.
Residual stress rate (%) = (1−δt / δ ₀ ) × 100
However,
δt: Permanent deflection displacement after holding at 120 ° C. for 500 h or after holding at 150 ° C. for 500 h (mm) −Permanent deflection displacement after holding for 24 h at room temperature (mm)
δ ₀ : Initial deflection displacement (mm)
It is.
Those having a residual stress rate of 80% or more were evaluated as ◯, and those having a residual stress ratio of less than 80% were evaluated as ×.

  The evaluation results are shown in Tables 4, 5, and 6.

In Comparative Example 101, the atomic ratio [(Fe + Co) / Ni] _P of the total content of Fe and Co to the Ni content in the [Ni, (Co, Fe)]-P-based precipitates and the total alloy [(Fe + Co) / Ni] _P / [(Fe + Co) / Ni], which is the ratio of the total content of Fe and Co to the atomic ratio of Ni content [(Fe + Co) / Ni] is more than the scope of the present invention. Low, heat resistance and stress relaxation resistance were insufficient.
In Comparative Example 102, the atomic ratio [Fe / Ni] _P between the Fe content and the Ni content in the [Ni, Fe] -P-based precipitates, the Fe content and the Ni content in the entire alloy [Fe / Ni] _P / [Fe / Ni], which is a ratio to the atomic ratio [Fe / Ni], is higher than the range of the present invention, and the heat resistance and the stress relaxation resistance were insufficient.

In Comparative Example 103, the Fe content was larger than the range of the present invention, and the heat resistance and the stress relaxation resistance were insufficient.
In Comparative Example 104, Fe was not added, and heat resistance and stress relaxation resistance were insufficient.
In Comparative Example 105, P was not added, and heat resistance and stress relaxation resistance were insufficient.
In Comparative Example 106, the Ni content is less than the range of the present invention, and the atomic ratios of (Ni + Fe) / P, Sn / (Ni + Fe) and Fe / Ni are also outside the range of the present invention, and heat resistance and stress resistance The relaxation properties were insufficient.

On the other hand, not only the individual content of each alloy element is within the range defined by the present invention, but also the ratio between each alloy component is within the range defined by the present invention, and [Ni, [Fe / Ni] atomic ratio of Fe content and Ni content in Fe] -P-based precipitate [Fe / Ni] _P , atomic ratio of Fe content and Ni content of the whole alloy [Fe / Ni] [Fe / Ni] _P / [Fe / Ni], or the atomic ratio of the total content of Fe and Co to the Ni content in the [Ni, (Co, Fe)]-P precipitates [(Fe + Co) / Ni] _P is the ratio of the total content of Fe and Co in the whole alloy to the atomic ratio [(Fe + Co) / Ni] of the Ni content [[Fe + Co) / Ni] _P / [ In the examples of the present invention in which (Fe + Co) / Ni] is within the scope of the present invention, Is excellent in heat and stress relaxation property, it is fully applicable confirmed the connector and other terminals.

Claims (5)

Zn exceeds 2 mass% to 36.5 mass% or less, Sn ranges from 0.1 mass% to 0.9 mass%, Ni ranges from 0.15 mass% to less than 1.0 mass%, and P ranges from 0.005 mass% to 0.1 mass%. , Fe is contained 0.001 mass% or more and 0.1 mass% or less, and the balance consists of Cu and inevitable impurities,
The ratio of the total content of Ni and Fe to the content of P (Ni + Fe) / P is the atomic ratio,
3 <(Ni + Fe) / P <30
The filling,
And the ratio Sn / (Ni + Fe) between the content of Sn and the total content of Ni and Fe is the atomic ratio,
0.3 <Sn / (Ni + Fe) <2.7
While satisfying
The ratio of Fe content to Ni content [Fe / Ni] is the atomic ratio,
0.002 ≦ [Fe / Ni] <0.6
The filling,
Further, the matrix has [Ni, Fe] -P-based precipitates containing Fe, Ni, and P, and the content of Fe in the [Ni, Fe] -P-based precipitates is Atomic ratio of Fe content [Fe / Ni] _P is compared to the Fe content of the entire alloy and the atomic ratio of Ni content [Fe / Ni].
5 ≦ [Fe / Ni] _P / [Fe / Ni] ≦ 200
A copper alloy for electronic and electrical equipment characterized by satisfying Zn exceeds 2 mass% to 36.5 mass% or less, Sn ranges from 0.1 mass% to 0.9 mass%, Ni ranges from 0.15 mass% to less than 1.0 mass%, and P ranges from 0.005 mass% to 0.1 mass%. In addition, Fe and Co are contained, and the total content of Fe and Co is 0.001 mass% to 0.1 mass% (provided that Fe is contained in an amount of 0.001 mass% to 0.1 mass%). The balance consists of Cu and inevitable impurities,
The ratio of the total content of Ni, Fe and Co to the content of P (Ni + Fe + Co) / P is the atomic ratio,
3 <(Ni + Fe + Co) / P <30
The filling,
And the ratio Sn / (Ni + Fe + Co) of the content of Sn and the total content of Ni, Fe and Co is an atomic ratio,
0.3 <Sn / (Ni + Fe + Co) <2.7
While satisfying
The ratio of the total content of Fe and Co to the content of Ni (Fe + Co) / Ni is the atomic ratio,
0.002 ≦ (Fe + Co) / Ni <0.6
The filling,
Furthermore, the matrix has [Ni, (Fe, Co)]-P-based precipitates containing at least one of Fe and Co and Ni and P, and this [Ni, (Fe, Co)]-P atomic ratio of the total content of Fe and Co to the content of Ni and the content of Ni [(Fe + Co) / Ni] _P is the total content of Fe and Co in the entire alloy and the content of Ni. For the atomic ratio [(Fe + Co) / Ni],
5 ≦ [(Fe + Co) / Ni] _P / [(Fe + Co) / Ni] ≦ 200
A copper alloy for electronic and electrical equipment characterized by satisfying It consists of a rolled material of a copper alloy for electronic and electrical equipment according to claim 1 or claim 2,
A copper alloy thin plate for electronic and electrical equipment, wherein the thickness is in the range of 0.05 mm to 3.0 mm.   A conductive component for electronic / electric equipment comprising the copper alloy thin plate for electronic / electric equipment according to claim 3.   A terminal comprising the copper alloy thin plate for electronic and electrical equipment according to claim 3.

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