Classifications

• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C9/00—Alloys based on copper
  • C22C9/06—Alloys based on copper with nickel or cobalt as the next major constituent
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C5/00—Separating dispersed particles from liquids by electrostatic effect
  • B03C5/005—Dielectrophoresis, i.e. dielectric particles migrating towards the region of highest field strength
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B03—SEPARATION OF SOLID MATERIALS USING LIQUIDS OR USING PNEUMATIC TABLES OR JIGS; MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C—MAGNETIC OR ELECTROSTATIC SEPARATION OF SOLID MATERIALS FROM SOLID MATERIALS OR FLUIDS; SEPARATION BY HIGH-VOLTAGE ELECTRIC FIELDS
  • B03C5/00—Separating dispersed particles from liquids by electrostatic effect
  • B03C5/02—Separators
  • B03C5/022—Non-uniform field separators
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22C—ALLOYS
  • C22C9/00—Alloys based on copper
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
  • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
• • C—CHEMISTRY; METALLURGY
  • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
  • C22F—CHANGING THE PHYSICAL STRUCTURE OF NON-FERROUS METALS AND NON-FERROUS ALLOYS
  • C22F1/00—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working
  • C22F1/08—Changing the physical structure of non-ferrous metals or alloys by heat treatment or by hot or cold working of copper or alloys based thereon
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01R—ELECTRICALLY-CONDUCTIVE CONNECTIONS; STRUCTURAL ASSOCIATIONS OF A PLURALITY OF MUTUALLY-INSULATED ELECTRICAL CONNECTING ELEMENTS; COUPLING DEVICES; CURRENT COLLECTORS
  • H01R13/00—Details of coupling devices of the kinds covered by groups H01R12/70 or H01R24/00 - H01R33/00
  • H01R13/02—Contact members
  • H01R13/03—Contact members characterised by the material, e.g. plating, or coating materials

Definitions

• the present invention relates to a copper alloy of a Cu—Ni—Si system for an electrical and electronic device, and to a method for producing the same.
• the copper alloy is suitable for a lead frame of an electrical and electronic device, a connector, a terminal, a relay, a switch, or the like.
• the Corson alloy is an alloy of a Cu—Ni—Si system that has a higher strength due to a precipitation of elements such as Ni and Si. With the alloy, it is able to satisfy characteristics required for an electrical and electronic device. However, the Corson alloy has insufficient bending workability under a severe condition in which properties concurrently need to be improved.
• a copper alloy with improved bending workability there is proposed a substance that contains Ni between 2 and 4% (by mass), Si between 0.5 mass % and 1.0 mass %, Zn between 0.1 mass % and 1.0 mass %, Al, Mn, Cr, or the like, sulfur not more than 0.002 mass %, and a remaining portion comprised of Cu and an unavoidable impurity.
• a size of a precipitate is not bigger than 10 nm, and a distribution density of the precipitate is not lower than 1 ⁇ 10 5 pieces per ⁇ m 3 , and a hardness Hv is not softer than 220 (refer to Japanese Patent Application Publication No. 06-184680). However, it is not able to obtain sufficient bending workability.
• a copper alloy plate material that contains Ni between 4.0 mass % and 5.0 mass %, Si within a range for a ratio of Ni/Si between four and five, and a remaining portion formed of Cu and an unavoidable impurity.
• An average grain diameter of an Ni 2 Si precipitate of the alloy plate material is between 3 nm and 10 nm, and an average space of Ni 2 Si precipitate is not more than 25 nm after an accelerated aging and hardening (refer to Japanese Patent Application Publication No. 2005-089843 for instance).
• the alloy exhibits improved tensile strength and electrical conductivity.
• a copper alloy that contains Ni between 0.4 mass % and 4.8 mass %, Si between 0.1 mass % and 1.2 mass %, Mg or the like approximately 0.3 mass %, and a remaining portion formed of Cu and an unavoidable impurity.
• An average crystalline grain diameter is not larger than 1 ⁇ m, and crystalline grains with a grain diameters smaller than 3 ⁇ m occupy an area not smaller than 90% (refer to Japanese Patent Application Publication No. 2006-089763).
• the copper alloy has improved tensile strength, electrical conductivity and workability.
• Japanese Patent Application Publications No. 06-184680, No. 2005-089843 and No. 2006-089763 have disclosed a Corson alloy in which crystalline grains are minimized in order to improve strength. However, it has not been able to improve the electrical conductivity and the bending workability at the same time.
• the present inventors have examined relations between components and compositions of a copper alloy, an average crystalline grain diameter, a standard deviation of a crystalline grain diameter, bending workability, or the like. As a result, it is found out that it becomes able to improve the bending workability without deteriorating strength and electrical conductivity by properly designing the relations. Moreover, further examinations are progressed with based on the findings, and the present invention is completed.
• a copper alloy for an electrical and electronic device includes: Ni between 1.5 mass % and 5.0 mass %; Si between 0.4 mass % and 1.5 mass %; and a remaining portion formed of Cu and an unavoidable impurity, wherein a mass ratio of Ni/Si is not smaller than two and not larger than seven, an average crystalline grain diameter is not smaller than 2 ⁇ m and not larger than 20 ⁇ m, and a standard deviation of the crystalline grain diameter is not larger than 10 ⁇ m.
• the average crystalline grain diameter is within a range not larger than 15 ⁇ m, and the standard deviation of the crystalline grain diameter is not larger than 8 ⁇ m.
• the average crystalline grain diameter is within a range not larger than 10 ⁇ m, and the standard deviation of the crystalline grain diameter is not larger than 5 ⁇ m.
• the copper alloy for the electrical and electronic device in one of the first to the third aspects further includes at least one element between 0.005 mass % and 2.0 mass %, that is selected from a group of Mg, Sn and Zn, and a remaining portion formed of Cu and an unavoidable impurity.
• the copper alloy for the electrical and electronic device in one of the first to the fourth aspects further includes at least one element between 0.005 mass % and 2.0 mass %, that is selected from a group of Ag, Co, Cr, Fe, Mn, P, Ti and Zr, and a remaining portion formed of Cu and an unavoidable impurity.
• a method for producing a copper alloy for an electrical and electronic device comprises at least the following steps of: casting a copper alloy which includes: Ni between 1.5 mass % and 5.0 mass %; Si between 0.4 mass % and 1.5 mass %; and a remaining portion formed of Cu and an unavoidable impurity, wherein a mass ratio of Ni/Si is not smaller than two and not larger than seven, and performing thereafter a hot working and then performing a cold working (Step a); performing a process of a re-crystallization heat treatment after performing the above defined Step a, with a temperature rising rate of not slower than 10° C. per second, to an end point temperature between 700° C.
• Step b 950° C., with a retention time between five seconds and 300 seconds, and with a cooling rate till 300° C. as not slower than 20° C. per second (Step b); and performing a process of an aging precipitation after performing the above defined Step b (Process C).
• the average crystalline grain diameter means an average value of the grain diameter of the individual crystals that exist in the texture of the copper alloy after the process to be solution heated and then to be recrystallized.
• the standard deviation of the crystalline grain diameter means a value that is evaluated with based on the individual crystalline grain diameters.
• the texture of the metal has a state obtained by performing the process of treating with heat (the process to be recrystallized), or by performing the processes of treating with heat, of aging, of annealing, or the like. It is able to observe the individual states by an optical microscope (OM), a scanning electron microscope (SEM), or the like.
• the copper alloy in accordance with the present invention there becomes to be improved in particular the bending workability by specifying properly the average crystalline grain diameter of the copper alloy of Cu—Ni—Si system and the standard deviation of the crystalline grains. And hence the alloy becomes useful for the application to an electrical and electronic device.
• the functions in accordance with the component elements, the advantages and each of the contents that comprise the copper alloy for an electrical and electronic device in accordance with the present invention will be described in detail below.
• Ni and Si contribute to an improvement of the strength by being precipitated as a chemical compound of Ni—Si.
• the reason that such Ni is designed to be specified between 1.5 mass % and 5.0 mass % and that Si is designed to be specified between 0.4 mass % and 1.5 mass % is that it is not able to obtain the strength as sufficiently if ether one is lower than each of the lower limits, respectively, or that the strength becomes to be saturated if ether one is higher than each of the upper limits respectively, and also that the electrical conductivity becomes to be decreased either. Moreover, a balance between the strength and the electrical conductivity becomes to be worsened drastically in a case where the ratio of Ni/Si is not within the range between two and seven.
• the substance is not applicable to an alloy for an electrical and electronic device that is required to have a strength as higher and an electrical conductivity as higher as well.
• the copper alloy in accordance with the present invention it becomes able to improve a material property by being contained at least any one nature of the elements that is selected from Mg, Sn and Zn in addition to the above mentioned alloy contents.
• Mg the same contributes to an improvement of the stress relaxation characteristic.
• Sn contributes to an improvement of the stress relaxation characteristic and an enhancement of the strength as well in a case of adding the same.
• Zn contributes to an improvement of a plating wettability thereon in a case of adding the same.
• each of the contents of the elements is excessively lower, it is not able to obtain each of the advantages.
• each of the contents is excessively higher, such as regarding the Mg there becomes to be increased an amount of oxides at a period of a process of casting, and then it becomes more difficult to perform the process of casting.
• Sn there becomes to be a cause to occur a crack at a period of a process of hot working, due to segregation at a period of the process of casting.
• Zn it is not able to predict any further improvement of the plating adherence thereon.
• any one of the sample substance is not desirable due to an occurrence of a drastic decreasing of the individual electrical conductivities respectively.
• the copper alloy in accordance with the present invention it is able to produce simply by selecting properly such as a condition of a process of a hot rolling, a condition of a process of a cold rolling, a condition of a process of a treating with heat to be recrystallized, a condition of a process of a treating with heat for aging, a condition of a final rolling, or the like.
• each of the elements contributes to an improvement of the bending workability and the strength, due to an effect of suppressing the grain diameters from becoming rougher and larger at a period of a process of treating with heat to be crystallized, because of being formed a chemical compound.
• any one of Fe, Ti and Zr contributes to an improvement of the strength in a case of adding each of the same, because of being formed a chemical compound.
• phosphorus contributes to suppress an amount of any of oxides at a period of a process of casting in a case of adding the same.
• Mn contributes to an improvement of the workability of a hot working in a case of adding the same.
• Ag in a case where each of the contents is excessively lower, it is not able to obtain each of the advantages.
• Ag in a case where each of the contents is excessively higher, regarding Ag, there becomes to bring about a problem from a point of view of manufacturing cost on the production.
• Co it is not able to predict any further improvement of the material property, due to the further difficulty of performing the process of treating with heat as sufficiently in order to solution heat the same.
• the copper alloy in accordance with the present invention it is able to produce simply by selecting properly such as a condition of a process of a hot rolling, a condition of a process of a cold rolling, a condition of a process of a treating with heat to be recrystallized, a condition of a process of a treating with heat for aging, a condition of a final rolling, or the like.
• Step a a method for producing the copper alloy in accordance with the present embodiment, it is desirable to comprise the above defined Step a, Step b and Process C, and it is further preferable in particular to make use of the following processes from (1) to (10) in order.
• Temperature rising rate it is desirable to design the temperature rising rate as not slower than 10° C. per second to an end point temperature, or it is further preferable to be designed as not slower than 10° C. per second but not faster than 100° C. per second.
• End point temperature it is desirable to be designed between 700° C. and 950° C.
• (3-3) Retention time it is desirable to be designed for between five seconds and 300 seconds.
• Cooling rate it is desirable to be designed as not slower than 20° C. per second till 300° C. for instance, or it is further preferable to be designed as not slower than 20° C. per second but not faster than 200° C. per second.
• Condition of temperature rising it is desirable for an end point temperature to be between 300° C. and 600° C., for an amount of time for treating to be between 0.5 hour and ten hours, for a temperature rising rate at the period to be as within a range between 2° C. and 25° C. per minute from a room temperature till reaching to the maximum temperature.
• Condition of cooling it is desirable at the period of falling the temperature to be performed within a range between 1 and 2° C. per minute for the temperature as not lower than 300° C. at an inside of a furnace.
• Process of annealing for reducing distortion it is desirable to perform a heating with a temperature at between 250° C. and 400° C. and with an amount of time for between 0.5 hour and five hours, or it is desirable to perform a heating with a temperature at between 600° C. and 800° C. and with an amount of time for between five seconds and 60 seconds as well.
• the average crystalline grain diameter of the copper alloy in accordance with the present invention is designed to be as not smaller than 2 ⁇ m and not larger than 20 ⁇ m. And, it is desirable to be as not larger than 15 ⁇ m, or it is further preferable to be as not larger than 10 ⁇ m.
• the average crystalline grain diameter is excessively smaller, there is observed a remaining of the texture to be worked at the last process, and then thereby there may be occurred a deterioration of bending workability as drastically.
• the average crystalline grain diameter is excessively larger on the contrary thereto, there becomes easier to be occurred a crack thereon at a period of bending work, and then thereby there becomes to be occurred a deterioration of bending workability.
• the standard deviation of the average crystalline grain diameter is designed to be as not larger than 10 ⁇ m.
• the deviation is excessively larger, there becomes to be a state where the grains individually having the larger grain diameters and the grains individually having the smaller grain diameters are coexisting together.
• any one of the grains individually having the larger grain diameters exists at around a top of the bended part, there may be occurred a crack on a bended surface, or there may be occurred a peeling of the plating off from a part at around a corrugation as largely wrinkled that may be created at around the grain having the larger grain diameter at a period of bending.
• the copper alloy for an electrical and electronic device in accordance with the present invention becomes to be superior in the strength, the electrical conductivity and in the processing characteristics for the bending in particular. And then it becomes able to apply the same as preferred to the usage for the electrical device and for the electronic device, such as a lead frame, a connector, a terminal, a relay, a switch, or the like. Moreover, by making use of the method for producing the same in accordance with the present invention, it becomes able to produce further efficiently the above mentioned copper alloy for an electrical and electronic device that has the above mentioned superior properties. Furthermore, it becomes able to apply the method as preferred to a mass production as well.
• each of the test pieces At first there is performed a finishing for each of the test pieces to have individual mirror finished surfaces for individual cut faces thereon that are in a right angle to the rolling direction, by making use of a wet polishing and then by making use of a buffing. And then thereafter there is performed a corrosion on the polished surfaces for a several seconds with making use of a weak acid. Moreover, there is performed taking some photographs by making use of an optical microscope (OM) at a magnifying power between 50 times and 600 times and of a scanning electron microscope (SEM) at a magnifying power between 400 times and 5000 times. And hence there is performed a measurement for a grain diameter on the individual cut faces by making use of a crosscut method as pursuant to JIS H0501. And then thereby there becomes to be calculated an average grain diameter.
• OM optical microscope
• SEM scanning electron microscope
• a standard deviation of the grain diameters by performing the measurement for each of the grain diameters as one by one. Still further, there is assumed a population parameter of the measurements as to be 200 in the case of evaluating the standard deviation of the grain diameters. Furthermore, there is performed a measurement of a grain diameter in a sample that is before performing the rolling (that corresponds to the time when the process of treating with heat to be recrystallized is finished) regarding the grain cannot help but become to be flat after performing the rolling in accordance with the above mentioned measurement of the grain diameters.
• a plating of bright tin to have a thickness of approximately 1 ⁇ m on each of the test pieces that individually have the dimensions of 30 mm by 10 mm. And then thereafter there is performed a keeping warm of each of the test pieces in an atmosphere at a temperature of approximately 150° C. with an amount of time for 1000 hours. Moreover, there is performed thereafter a bending thereon with an angle to be 180 degrees and then the same is bended again to be an initial form respectively. Further, there is performed an observation by visually regarding a state of an adherence between the bended part and the plating of tin thereon.
• each of the copper alloys in accordance with the present invention has the characteristics of alloy as sufficient on the practical use regarding each of the items of the evaluation.
• the individual samples in accordance with Comparative example have the ratio of Ni/Si as larger than 7.0, and also each of the samples is inferior thereto in the tensile strength and in the 0.2% yield strength either respectively.
• the concentration of Ni becomes to be lower than 1.5 mass % as given in accordance with the copper alloy samples 27 and 31 for example (for both as Comparative examples)
• the copper alloy samples 52 through 59 it is designed to have individually the amount of addition of the above mentioned any one of the elements that is selected as excessively larger (as Reference examples). And hence in accordance with such as the copper alloy sample 53 for instance, it is not able to perform the hot working due to the occurrence of the cracks thereon. Still further, in accordance with the copper alloy samples 54, 58 and 59, it is not able to obtain any one of samples due to the occurrence of the oxides to be generated as a large amount at the period of the process of the casting.
• the copper alloy samples 60 through 67 (Examples) on the contrary thereto, that there are performed the process individually by making use of the temperature rising rate, the retention time and the temperature falling rate within the specification of the method for producing the copper alloy in accordance with the present invention, it is found out that it becomes able to obtain each of the characteristics of alloy for each of Examples to be as excellent regarding each of the items of the evaluation.
• the copper alloy for an electrical and electronic device in accordance with the present invention becomes to be applicable as preferred to the usage for the electrical device and for the electronic device, such as a lead frame, a connector, a terminal, a relay, a switch, or the like. Moreover, the method for producing the same in accordance with the present invention becomes to be preferable as the method by which it becomes able to produce further efficiently the above mentioned copper alloy for an electrical and electronic device.

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• 2008
  • 2008-03-25 JP JP2008079256A patent/JP5170881B2/ja active Active
  • 2008-03-26 WO PCT/JP2008/055785 patent/WO2008126681A1/fr not_active Ceased
  • 2008-03-26 CN CN200880017586A patent/CN101680057A/zh active Pending
  • 2008-03-26 US US12/593,024 patent/US20100193092A1/en not_active Abandoned
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