TW201827613A - Copper alloy sheet for heat radiation component - Google Patents

Abstract

To provide a copper alloy sheet enabling a manufactured heat radiation component to have sufficient strength and heat radiation performance when a process for heating at a temperature of 600 DEG C or higher is included in a part of processes of manufacturing the heat radiation component. The copper alloy sheet for a heat radiation component is provided that contains Co:0.05 to 0.9 mass% and P:0.01 to 0.25 mass% and the balance Cu with inevitable impurities and that has [Co]/[P] of 2 to 6, where [Co] is content of Co and [P] is content of P. The copper alloy sheet for a heat radiation component has a 0.2% proof stress of 100 MPa or more, an elongation of 6% or more and excellent bending workability. After the copper alloy sheet is subjected to an aging treatment in which the copper alloy sheet is heated at 850 DEG C for 30 min, water-cooled, and then heated at 500 DEG C for 2 hr, the copper alloy sheet has a 0.2% proof stress of 150 MPa or more and an electric conductivity of 70%IACS or more. It is preferred that the copper alloy sheet for a heat radiation component further contains Zn of 1.0 mass% or less.

Description

Copper alloy plate for heat releasing element, heat releasing element, and manufacturing method of heat releasing element

[0001] The present disclosure relates to a copper alloy plate for a heat radiation element such as a heat release plate, a heat sheet, and a heat pipe that processes heat generated from a CPU of a computer, an LED lamp, or the like. In particular, it relates to a copper alloy sheet for a heat radiation element used as a part of a manufacturing process of a heat releasing element for a process including high temperature heating such as soldering, diffusion bonding, or degassing.

[0002] The speed of the operation speed of the CPU mounted on the disk type PC, the notebook PC, and the like, and the high density of the integrated body are rapidly increasing, and the amount of heat generated by the CPUs is further increased. When the temperature of the CPU rises to a certain temperature or higher, the heat radiation from the semiconductor device such as the CPU becomes a problem due to malfunction or thermal explosion. A heat sink has been used as a heat dissipating member that absorbs the heat of the semiconductor device and disperses it into the atmosphere. Since high heat conductivity is required for the hot sheet, copper, aluminum, or the like having a large thermal conductivity is used as the material. However, convective thermal impedance limits the performance of the thermal sheet, and it is difficult to meet the exothermic requirements of high-performance electronic components with increased heat generation. [0003] Therefore, as a heat releasing element having higher heat dissipation property, a tubular heat pipe and a flat heat pipe (a vapor chamber) having high heat conductivity and heat transfer capability have been proposed. The heat pipe is made to have a higher heat release characteristic than the heat sink due to the evaporation of the internally enclosed refrigerant (heat absorption from the CPU) and the condensation (release of the absorbed heat). Moreover, it has been proposed to solve the problem of heat generation in a semiconductor device by combining a heat pipe with a heat release element of a heat sheet or a fin. [0004] As a material of a heat releasing element used for a heat radiating plate, a heat radiating plate, a heat pipe, or the like, a plate or a tube made of pure copper (oxygen-free copper: C1020) excellent in electrical conductivity and corrosion resistance is used. In order to ensure the formability, a soft blunt material (O material) or a 1/4H tempering material is used as a material. However, in the production step of a heat releasing element to be described later, deformation and flaws are likely to occur, and it is easy to produce during press working. Burr, stamping die is easy to wear and other problems. On the other hand, in Patent Documents 1 and 2, a Fe-P-based copper alloy sheet is described as a raw material of a heat radiation element. [0005] The heat release plate and the heat dissipation plate are processed into a specific shape by press molding, press working, cutting, drilling, etching, or the like, and then, if necessary, Ni plating, Sn plating, solder, solder, and then The agent or the like is bonded to a semiconductor device such as a CPU. The tubular heat pipe (refer to Patent Document 3) is formed by sintering a copper powder in a tube to form a core, and after heating and degassing, one end is welded and sealed, and after the refrigerant is built in the tube under vacuum or reduced pressure, the other end is also welded and sealed. [0006] A planar heat pipe (refer to Patent Documents 4 and 5) is one in which the heat release performance of the tubular heat pipe is further improved. As the planar heat pipe, in order to efficiently condense and evaporate the refrigerant, it is proposed to perform roughening processing, groove processing, and the like on the inner surface similarly to the tubular heat pipe. The upper and lower two pure copper sheets subjected to press forming, press working, cutting, etching, and the like are joined by welding, diffusion bonding, welding, or the like, and the refrigerant is placed inside, and then sealed by welding or the like. The degassing treatment is sometimes performed in the joining step. Further, as the planar heat pipe, an external member and an internal member housed inside the outer member are proposed. In order to promote condensation, evaporation, and transportation of the refrigerant, fins, protrusions, holes, slits, and the like of various shapes are processed by one or a plurality of internal members disposed inside the external member. In the planar heat pipe of this type, after the internal member is placed inside the external member, the external member and the internal member are joined and integrated by welding or diffusion bonding, and after the refrigerant is placed, welding or the like is performed. And sealed. When the heat generation of the electronic component is further increased, the heat radiating element having the same internal structure as the heat equalizing plate and continuously supplying the refrigerant from the outside is used (refer to Patent Document 6). This type of heat release element does not require the interior of the frame to be low pressure. The member used for the frame of the heat radiating element of this type and the manufacturing method of the frame are basically the same as the heat equalizing plate. [PRIOR ART DOCUMENT] [Patent Document 1] [Patent Document 1] JP-A-2003-277815 (Patent Document 2) Japanese Patent Laid-Open Publication No. JP-A No. Hei. [Patent Document 4] Japanese Patent Laid-Open Publication No. JP-A No. 2014-134347 [Patent Document 5] International Publication No. 2014/171246

[Problems to be Solved by the Invention] [0009] In the manufacturing steps of the heat radiation element, the heat radiation plate and the heat dissipation plate are heated to about 200 to 700 ° C by soldering or soldering. The tubular heat pipe and the planar heat pipe are heated to about 800 to 1000 ° C by a step of welding, diffusion bonding, welding, etc. using sintering, degassing, phosphor bronze solder (BCuP-2, etc.). For example, when a pure copper plate is used as a raw material of the heat pipe, the softening is intense when heated to a temperature of 600 ° C or higher. The crystallization of the crystal grains is also rushed. Therefore, when the heat sheet, the semiconductor device is mounted, or the PC frame is assembled, the heat pipe to be manufactured is easily deformed, the structure inside the heat pipe is changed, or the surface unevenness is increased, and there is a problem that the desired heat radiation performance cannot be exhibited. Further, in order to avoid such deformation, it is only necessary to increase the thickness of the pure copper plate, but if so, the quality and thickness of the heat pipe are increased. When the thickness is increased, there is a problem in that the gap inside the PC casing is made small and the convective heat transfer performance is lowered. Further, the copper alloy sheets (Cu-Fe-P alloys) described in Patent Documents 1 and 2 are also softened when heated at a temperature of 600 ° C or higher, and further have a lower electrical conductivity than pure copper. Therefore, when a planar heat pipe is produced by a process such as sintering, degassing, welding, diffusion bonding, or welding, it is easy to be deformed during transportation and processing of the heat pipe, assembly steps of the substrate, and the like. Further, since the electrical conductivity is lowered, the desired performance as a heat pipe cannot be exhibited. [0011] Embodiments of the present invention are directed to the above problems when a process for heating a temperature of a temperature of 600 ° C or higher is included in a part of a process for manufacturing a heat releasing element from a pure copper or copper alloy plate, and the object is to provide heating to 600. A heat-dissipating element manufactured by a process of a temperature above °C has a copper alloy plate having sufficient strength and heat release properties. [Means for Solving the Problem] [0012] The precipitation hardening type copper alloy is improved in strength and electrical conductivity by performing a melt treatment and aging treatment. However, after the precipitation hardening type copper alloy is introduced into the alloy by applying cold plastic processing to the plastic deformation of the precipitation portion, the aging treatment causes the strength and electrical conductivity to be improved by the aging treatment. Reduce the situation. When a heat releasing element such as a heat equalizing plate is produced by a heating step such as welding, diffusion bonding, or welding, plastic processing is not applied after the heating step. Therefore, when the heat radiating element is produced from the plate material of the hardened copper alloy, the strength and the electrical conductivity are not sufficiently improved even if the aging treatment is performed after the heating step corresponding to the melt treatment. On the other hand, the present inventors have found that in the Cu-Co-P alloy in the precipitation hardening type copper alloy, by limiting the composition range of Co and P and the Co/P ratio, even after the heating step, even if not applied When the aging treatment is performed by plastic working, the strength and electrical conductivity of the heat radiating element can be greatly improved, and thus the embodiment of the present invention is completed. [0013] The copper alloy sheet for a heat radiation element according to the embodiment of the present invention is used when a process including heating to 600 ° C or higher and an aging treatment is used as a part of a process for manufacturing a heat release element, which is from 0.05 to 0.9% by mass, P. : 0.01 to 0.25 mass%, the remainder is made of Cu and unavoidable impurities, and the Co content (% by mass) is [Co], and the P content (% by mass) is [P], [Co]/[P It is 2 to 6, 0.2% withstand strength of 100 MPa or more, and elongation of 3% or more, and has excellent bending workability. Further, the copper alloy sheet was heated at 850 ° C for 30 minutes, then water-cooled, and secondly heated at 500 ° C for 2 hours, the 0.2% proof stress after the aging treatment was 150 MPa or more, and the electrical conductivity was 70% IACS or more. Further, the 0.2% proof stress of the copper alloy sheet is 150 MPa or more, and the hardness is equivalent to Hv75 or more. When it is difficult to measure 0.2% of the endurance by the tensile test, it is estimated that the 0.2% proof stress is 150 MPa or more by measuring the Vicat hardness according to the regulation of JIS Z2244 (2009). [0014] The copper alloy sheet for a heat releasing element may further contain 1.0% by mass or less (excluding 0% by mass) of Zn as an alloying element, if necessary. In addition, the copper alloy sheet for a heat radiating element of the present embodiment may contain one of Fe, Ni, Si, Al, Mn, Cr, Sn, Ti, Zr, Ag, and Mg in a total amount of 0.005 to 0.5% by mass or less, as needed. Or two or more. The copper alloy sheet may further contain one or more of Fe, Ni, Si, Al, Mn, Cr, Sn, Ti, Zr, Ag, and Mg together with Zn. [Effect of the Invention] The copper alloy sheet according to the embodiment of the present invention is used when a process including heating to 600 ° C or higher and an aging treatment are used as a part of a process for manufacturing a heat releasing element. In other words, the heat-dissipating element produced by using the copper alloy sheet according to the embodiment of the present invention is heated to 600 ° C or higher at a high temperature, and is subjected to aging treatment without plastic processing to improve strength. Since the copper alloy sheet according to the embodiment of the present invention has a high strength (0.2% proof) of 100 MPa or more, the copper alloy sheet is not easily deformed during handling and handling when it is processed into a heat releasing element. Further, since it has an elongation of 3% or more and excellent bending workability, the above processing can be carried out without hindrance. [0016] The copper alloy sheet according to the embodiment of the present invention is heated at 850 ° C for 30 minutes, and when subjected to the aging treatment, the 0.2% proof stress is 150 MPa or more, and the electric conductivity is 70% IACS or more. Since the copper alloy sheet according to the embodiment of the present invention has high strength after the aging treatment, the heat radiating element such as the heat pipe manufactured using the copper alloy sheet is attached to the hot sheet, the semiconductor device, or the PC frame, etc., and the heat radiating element is not easily used. Deformation. Further, the copper alloy sheet according to the embodiment of the present invention has a lower electrical conductivity than a pure copper plate, but can be flaky due to the high strength after the aging treatment, and the amount of decrease in electrical conductivity can be compensated for in terms of heat release performance.

[0017] Hereinafter, a copper alloy sheet for a heat radiation element according to an embodiment of the present invention will be described in more detail. The copper alloy sheet according to the embodiment of the present invention is processed into a specific shape by press molding, press working, cutting, etching, or the like, and is heated by high temperature (for degassing, joining (welding, diffusion bonding, welding), sintering, etc.). ), finishing into an exothermic component. The heating conditions of the high-temperature heating vary depending on the type of the heat-releasing element and the manufacturing method. However, in the embodiment of the present invention, the high-temperature heating system is assumed to be performed at about 600 ° C to 1050 ° C. The copper alloy sheet according to the embodiment of the present invention is formed of a Co—P-based copper alloy having a composition described later, and when heated in the above temperature range, at least a part of the Co—P compound deposited on the base material before heating is solid-melted to the base material. The crystal grains grow, resulting in softening and a decrease in electrical conductivity. [0018] The copper alloy sheet according to the embodiment of the present invention is heated at 850 ° C for 30 minutes, then water-cooled, and the strength (0.2% proof) after the aging treatment is 150 MPa or more, and the electrical conductivity is 70% IACS or more. Heating at 850 ° C for 30 minutes is assumed to be the heating condition of the aforementioned high-temperature heating process in the manufacture of the heat releasing element. When the copper alloy sheet according to the embodiment of the present invention is heated at a high temperature under these conditions, the Co-P compound deposited on the base material before heating is solid-melted to the base material to grow the crystal grains to cause softening and a decrease in electrical conductivity. Next, when the copper alloy sheet is aged, a fine Co-P compound is precipitated. Thereby, the strength and electrical conductivity are remarkably improved by the aforementioned high temperature heating. [0019] The foregoing aging treatment can be carried out by, for example, the following methods: (a) maintaining a temperature range for a period of time in a cooling step after heating at a high temperature, (b) cooling to room temperature after heating at a high temperature, and then heating to a precipitation temperature. The range is maintained for a period of time, and (c) is heated to the precipitation temperature range for a period of time after the step (a). As specific aging treatment conditions, for example, the conditions are maintained in the temperature range of 300 to 580 ° C for 5 minutes to 10 hours. When the strength is increased as a priority, the temperature-time condition for forming the fine Co-P compound may be appropriately selected, and when the conductivity is increased, the excessive aging treatment for reducing the Co-P of the solid solution to the base material is appropriately selected. Temperature-time conditions are sufficient. [0020] Although the copper alloy sheet after the aging treatment has a lower electrical conductivity than the pure copper plate after the high temperature heating, the strength is remarkably higher than that of the pure copper plate. In order to obtain this effect, the heat radiation element such as the heat pipe manufactured by using the copper alloy sheet according to the embodiment of the present invention is heated at a high temperature and then subjected to aging treatment. The aging treatment conditions are as described above. The heat radiation element (copper alloy plate) after the aging treatment has high strength, and deformation of the heat radiation element can be prevented when it is mounted on a heat sheet or a semiconductor device or assembled in a PC frame or the like. Further, since the copper alloy sheet according to the embodiment of the present invention (after the aging treatment) has higher strength than the pure copper sheet, it can be thinned (0.1 to 1.0 mm thick), whereby the heat radiation performance of the heat radiating element is improved, and it is possible to make up for The conductivity is reduced when compared to a pure copper plate. Moreover, even if the temperature of the copper alloy sheet according to the embodiment of the present invention is not higher than 850 ° C (600 ° C or higher) or more than 850 ° C (1050 ° C or lower), after the aging treatment, 0.2% of the endurance of 150 MPa or more and 70 can be achieved. Conductivity above % IACS. [0021] The copper alloy sheet according to the embodiment of the present invention is processed into a heat radiation element by press molding, press working, cutting, etching, or the like before heating at a temperature of 600 ° C or higher. The copper alloy sheet preferably has the strength that is not easily deformed during transportation and handling during the above-described processing, and the mechanical properties of the above processing can be performed without any trouble. More specifically, the copper alloy sheet according to the embodiment of the present invention has an excellent bending workability of 0.2% withstand strength of 100 MPa or more and elongation of 3% or more. If the above characteristics are satisfied, the conditioning of the copper alloy sheet is not problematic. For example, the melt-treated material, the aging treatment, and the aging-treated material can be used for cold rolling. The elongation is preferably 6% or more. [0022] In view of the aforementioned bending workability, it is required that cracks do not occur in the bent portion. Furthermore, surface roughness does not preferably occur in the vicinity of the curve. Even in the case of a copper alloy plate of the same material, the occurrence of cracks and surface roughness due to bending depends on the ratio R/t of the bending radius R to the thickness t. When a copper alloy sheet is used to produce a heat radiating element such as a heat equalizing plate, the bending workability of the copper alloy sheet usually requires no cracking when the bending direction is the parallel direction of the rolling direction and the direction perpendicular to the direction of R/t ≦2. As the bending workability of the copper alloy sheet, it is preferable that cracking does not occur at the time of bending of R/t≦1.5, and it is more preferable that cracking does not occur when bending of R/t≦1.0. The bending workability of the copper alloy sheet is generally tested on a test piece having a plate width of 10 mm (refer to the bending workability test of the example described later). When the copper alloy sheet is bent, the larger the bending width, the more likely the crack occurs. Therefore, when the bending width of the heat releasing element is particularly large, it is preferable that the bending of R/t=1.0 does not occur, and it is better that R/t=0.5. The bending does not occur. Further, in order not to cause surface roughness in the vicinity of the bending line and the vicinity thereof, the average crystal grain size (cutting method) for measuring the width direction of the surface of the copper alloy sheet is preferably 20 μm or less, more preferably 15 μm or less, and more preferably It is 10 μm or less. [0023] As described above, the heat radiation element produced by processing the copper alloy sheet according to the embodiment of the present invention is softened when heated at a high temperature of 600 ° C or higher. The heat-dissipating element after the high-temperature heating preferably further has a strength which is not easily deformed during transportation and handling during the aging treatment. Therefore, the stage of water cooling after heating at 850 ° C for 30 minutes preferably has a resistance of 0.2% or more of 50 MPa or more. [0024] After the heat-treating element manufactured using the copper alloy sheet according to the embodiment of the present invention is subjected to the aging treatment, the Sn coating layer may be formed at least on one of the outer surfaces as needed for the purpose of improving corrosion resistance and weldability. The Sn coating layer is formed by electroplating, electroless plating, or the like, and is heated to a temperature equal to or lower than the melting point of Sn or a melting point or higher. The Sn coating layer contains a Sn metal and a Sn alloy, and the Sn alloy contains, for example, 5% by mass or less, and at least one of Bi, Ag, Cu, Ni, In, and Zn is used as an alloying element other than Sn. [0025] Under the Sn coating layer, a base plating of Ni, Co, Fe, or the like can be formed. These base plating functions as a barrier function for preventing diffusion of Cu and alloying elements from the base material, and have a function of preventing damage due to an increase in surface hardness of the heat radiation element. Cu may be plated on the base plating, and after plating with Sn, heat treatment to a temperature below the melting point of Sn or a melting point or higher may be performed to form a Cu-Sn alloy layer, thereby forming a base plating, a Cu-Sn alloy layer, and The Sn coating layer is composed of three layers. The Cu-Sn alloy layer has a barrier function of preventing diffusion of Cu and alloy elements from the base material, and has a function of preventing damage due to an increase in surface hardness of the heat radiation element. Further, after the heat radiation element manufactured using the copper alloy sheet according to the embodiment of the present invention is subjected to the aging treatment, the Ni coating layer may be formed at least in part of the outer surface as needed. The Ni coating layer has a barrier function of preventing diffusion of Cu and alloying elements from the base material, and has a function of preventing damage and an effect of improving corrosion resistance due to an increase in surface hardness of the heat releasing element. [0027] Next, the composition of the copper alloy sheet according to the embodiment of the present invention will be described. The composition of the copper alloy sheet according to the embodiment of the present invention is from 0.05 to 0.9% by mass, P: 0.01 to 0.25 mass%, and the remainder is formed of Cu and unavoidable impurities, and the Co content (% by mass) is set to [Co]. When the P content (% by mass) is set to [P], [Co]/[P] is 2 to 6. Co is formed between P and P to form a P compound (Co-P compound), which improves the strength and stress relaxation resistance of the copper alloy sheet. The P compound increases the solid solution temperature, and even if the copper alloy sheet is heated to a high temperature of 600 ° C or higher (for example, 850 ° C), it is somewhat stable, and coarsening of the crystal grain size is prevented. On the other hand, the higher the heating temperature of the copper alloy sheet, the higher the concentration of the frozen pores after the water cooling, and the increased nucleation sites of the precipitates, so that the number density of the precipitates can be increased by the continuous aging treatment. Helps increase the strength after aging treatment. When the Co content is less than 0.05% by mass or the P content is less than 0.01% by mass, the amount of precipitation of the P compound is small, and the strength and stress relaxation resistance of the copper alloy cannot be improved. On the other hand, when the Co content exceeds 0.9% by mass or the P content exceeds 0.25 % by mass, the conductivity of 70% IACS or more cannot be achieved in the copper alloy after the aging treatment. Further, coarse oxides, crystallizations, precipitates, and the like are formed, and the hot workability is lowered, and the strength, stress relaxation resistance, and bending workability of the copper alloy sheet are lowered. Therefore, Co is set to 0.05 to 0.9% by mass, and the P content is set to 0.01 to 0.25 mass%. The lower limit of the Co content is preferably 0.10% by mass, more preferably 0.15% by mass, and the upper limit is preferably 0.75% by mass, more preferably 0.60% by mass. The lower limit of the P content is preferably 0.02% by mass, more preferably 0.03% by mass, and the upper limit is preferably 0.23% by mass, more preferably 0.22% by mass. [0028] For the above action, the P content is necessarily in the above range, but on the other hand, the P content which does not contribute to precipitation is preferably as small as possible in the range in which hydrogen embrittlement can be prevented. Based on this, the content ratio of Co to P [Co]/[P] is in the range of 2 to 6. When [Co]/[P] is less than 2, the amount of P which is not solidified in the base material due to the formation of the Co-P compound is increased, and when [Co]/[P] exceeds 6, the Co is solidified in the base material. The amount of the copper alloy plate after the aging treatment cannot be made 70% IACS or more. Further, when [Co]/[P] is less than 2 or more than 6, the amount of Co or P which does not contribute to the formation of the Co-P compound is increased, and the strength after the aging treatment of the copper alloy sheet cannot be sufficiently improved. The lower limit of [Co]/[P] is preferably 2.2, more preferably 2.5, still more preferably 3.0, and the upper limit of [Co]/[P] is preferably 5.0, more preferably 4.5. [0029] The copper alloy may further contain Zn: 1.0% by mass or less (excluding 0% by mass) or/and may contain Fe, Ni, Sn, Si, Al, Mn, Cr, or 0.003 to 0.5% by mass, as needed. One or more of Ti, Zr, Ag, and Mg. However, by adding these elements, it is necessary to avoid the conductivity of the copper alloy sheet after the aging treatment being lower than 70% IACS. Zn has an effect of improving the heat-resistant peeling property of the solder of the copper alloy sheet and the heat-resistant peeling property of the Sn plating. When the heat radiation element is assembled in the semiconductor device, soldering is required, and after the heat radiation element is manufactured, Sn plating may be performed to improve corrosion resistance. When manufacturing such an exothermic element, it is preferred to use a copper alloy plate containing Zn. However, when the Zn content is more than 1.0% by mass, in order to reduce solder wettability, when Zn is contained, the Zn content is 1.0% by mass or less (excluding 0% by mass). The Zn content is preferably 0.7% by mass or less, more preferably 0.5% by mass or less. On the other hand, when the Zn content is less than 0.01% by mass, the improvement of the heat-resistant peeling property is small, and the Zn content is preferably 0.01% by mass or more. The Zn content is more preferably 0.05% by mass or more, further preferably 0.1% by mass or more. When the copper alloy sheet according to the embodiment of the present invention contains Zn, when it is heated at a temperature of 500 ° C or higher, Zn is vaporized by the heating environment, and the surface properties of the copper alloy sheet are lowered to contaminate the heating furnace. The Zn content is preferably 0.5% by mass or less, more preferably 0.4% by mass or less, still more preferably 0.3% by mass or less, and still more preferably 0.2% by mass or less, from the viewpoint of preventing Zn gasification. [0030] Since Fe, Ni, Sn, Si, Al, Mn, Cr, Ti, Zr, Ag, and Mg have an effect of improving the strength and heat resistance of the copper alloy, one or two of the elements are added as needed. More than one species. However, when the content of the elements is large, the electrical conductivity of the copper alloy sheet is lowered. When one or two or more of these elements are added, the total content thereof is in the range of 0.005 to 0.5% by mass. Among the above elements, Fe and Ni form a phosphorus compound ((Ni, Fe)-P compound) with P as well as P. The effect of increasing the strength of the copper alloy sheet due to the formation of the phosphide is Co, which is the largest, followed by Fe and Ni. Fe and Ni have an effect of forming a phosphide with P which does not form a phosphide with Co (a decrease in P which is solid-melted in the base material), and improving the strength of the copper alloy sheet. Further, Fe has an effect of suppressing coarsening of crystal grains at the time of high-temperature heating. In order to obtain such effects, the Fe content is preferably 0.01% by mass or more, and the Ni content is preferably 0.02% by mass or more. On the other hand, in order to suppress a decrease in electrical conductivity, the Fe content is preferably 0.05% by mass or less, and the Ni content is preferably 0.1% by mass or less. [0031] Sn and Mg have an effect of solid-melting in the mother phase of the copper alloy, and improving the strength and stress relaxation resistance of the copper alloy sheet. When the temperature of the heat releasing element or the use environment is 80 ° C or higher, creep deformation occurs, and the contact area with a heat source such as a CPU is small, and the heat radiation property is lowered. However, by suppressing the stress relaxation property, the phenomenon can be suppressed. In order to obtain this effect, the Sn content is preferably 0.02% by mass or more, and the Mg content is preferably 0.01% by mass or more. On the other hand, from the viewpoint of preventing a decrease in the electrical conductivity of the copper alloy sheet, the Sn content is preferably 0.2% by mass or less, and the Mg content is preferably 0.2% by mass or less. Si, Al, and Mn have an effect of improving the strength and heat resistance of the copper alloy. In order to obtain this effect, the content of Si, Al, and Mn is preferably 0.01% by mass or more. On the other hand, from the viewpoint of preventing a decrease in the electrical conductivity of the copper alloy sheet, the Si content is preferably 0.2% by mass or less, the Al content is preferably 0.2% by mass or less, and the Mn content is preferably 0.1% by mass or less. [0032] Cr, Ti, and Zr have an effect of improving the strength and heat resistance of the copper alloy and suppressing coarsening of crystal grains at the time of high-temperature heating. In order to obtain this effect, the Cr content and the Ti content are each preferably 0.01% by mass or more, and the Zr content is preferably 0.005% by mass or more. On the other hand, from the viewpoint of preventing the decrease in the electrical conductivity of the copper alloy sheet, the Cr content is preferably 0.2% by mass or less, the Ti content is preferably 0.1% by mass or less, and the Zr content is preferably 0.05% by mass or less. Moreover, these elements are likely to form a spacer such as an oxide system or a sulfide system of several μm to several 10 μm, and when the above-mentioned spacer is present on the surface, the corrosion resistance of the copper alloy sheet is lowered, but the content of the elements is reduced. When it is in the above range, no particular problem arises. Ag has an effect of improving the strength and heat resistance of the copper alloy. The Ag content is preferably in the range of 0.005 to 0.02% by mass. [0033] H, O, S, Pb, Bi, Sb, Se, and As, which are unavoidable impurities, accumulate at the grain boundary when the copper alloy plate is heated to a temperature of 600 ° C or more for a long time, and causes the particles to be heated and heated. The possibility of cracking and grain boundary embrittlement is good, so it is better to reduce the content of these elements. Since H accumulates at the interface between the grain boundary and the spacer and the base material during heating, it is preferably set to less than 1.5 ppm (mass ppm, the same hereinafter), more preferably less than 1 ppm. O is preferably set to less than 20 ppm, more preferably less than 15 ppm. The total of S, Pb, Bi, Sb, Se, and As is preferably less than 30 ppm, more preferably less than 20 ppm. In particular, in the case of Bi, Sb, Se, and As, the total content of these elements is preferably less than 10 ppm, more preferably less than 5 ppm. [0034] The copper alloy sheet according to the embodiment of the present invention may be subjected to heat treatment of the ingot, by (1) hot calendering-cold calendering-blown, (2) hot calendering-cold calendering-blown-cold calendering, (3) It is produced by the steps of hot rolling, cold rolling, burning, blunt cooling, cold rolling, low temperature burning, and the like. In the above (1) to (3), the step of cold rolling-blowning can be performed plural times. The aforementioned burnt blunt includes softening and blunt, recrystallization blunt or precipitation blunt (aging treatment). When the softening is blunt or the recrystallization is blunt, the heating temperature can be selected from the range of 600 to 950 ° C, and the heating time can be selected from the range of 5 seconds to 1 hour. When the softening or blunt or recrystallization blunt is combined with the melt treatment, it should be continuously blunt at 600~950 °C, preferably 670~900 °C for 3 minutes or less. When aging treatment, it should be carried out under the condition of a temperature range of about 350 to 580 ° C for 0.5 to 10 hours. When the softening is blunt or the recrystallization is blunt and the melt treatment is performed, the aging treatment can be carried out in the subsequent step. [0035] The final cold rolling is suitable to match the target's 0.2% endurance and bending workability, and the self-processing rate is selected from the range of 5 to 80%. In order to restore the ductility of the copper alloy sheet without re-crystallizing the copper alloy sheet and softening it, it is preferable to maintain the temperature in the environment of 300 to 650 ° C for 1 second to 5 minutes depending on the continuous burning. . Moreover, the batch blunt condition should be determined so that the physical temperature of the copper alloy plate is maintained at 250 ° C ~ 400 ° C for 5 minutes ~ 1 hour. According to the above production method, a copper alloy sheet having excellent bending workability of 0.2% withstand strength of 100 MPa or more and elongation of 3% or more can be produced. Further, the copper alloy sheet was heated at 850 ° C for 30 minutes, and then heated at 500 ° C for 2 hours to have an electrical conductivity of 0.2% or more and a conductivity of 70% IACS or more. Further, the surface roughness of the copper alloy sheet (product) which can be joined by a method such as diffusion bonding or welding at a temperature of 600 ° C or higher (with no joint failure and high joint strength) is 0.3 in terms of arithmetic mean roughness Ra. The μm or less is 1.5 μm or less in terms of the maximum height roughness Rz, and the internal oxidation depth is 0.5 μm or less, and desirably 0.3 μm or less. When the surface roughness of the copper alloy sheet (product) is Ra: 0.3 μm and Rz: 1.5 μm or less, the surface roughness of the calender roll for the final cold rolling is, for example, Ra: 0.15 μm, Rz: 1.0. The grinding of the copper alloy sheet after the final cold rolling may be performed by grinding or polishing, electrolytic polishing or the like. Further, when the internal oxidation depth of the copper alloy sheet (product) is 0.5 μm or less, the blunt environment is set to be reductive, and the dew point is set to -5 ° C or lower, or the copper alloy sheet after burning is mechanically machined. Grinding (polishing, brushing, etc.) or electrolytic grinding to remove the resulting internal oxide layer or thinning. [0036] The copper alloy sheet according to the embodiment of the present invention is a standard production method in which the ingot is subjected to heat treatment, and after hot rolling, recrystallization treatment and cold rolling are performed by cold rolling and melt reduction (may be omitted). Manufactured by the steps of aging treatment. The cold rolling after the recrystallization treatment accompanying the melt can be omitted. Further, after the aging treatment, cold rolling may be further performed. The copper alloy sheet produced by the production method has a high strength (0.2% withstand force of 300 MPa or more) and an elongation of 3% or more, and has excellent bending workability. Further, the copper alloy sheet was heated at 850 ° C for 30 minutes, and then heated at 500 ° C for 2 hours to have an electrical conductivity of 0.2% or more and a conductivity of 70% IACS or more. [0037] Melting and casting can be carried out by a usual method such as continuous casting or semi-continuous casting. Further, as the copper melting raw material, those having a small content of S, Pb, Bi, Se, and As are preferably used. In addition, attention is paid to the red heating (moisture removal) of the charcoal coated with the copper alloy melt, the bare metal, the waste material, the casting water conduit, the drying of the mold, and the deoxidation of the melt, etc., and it is preferable to reduce O and H. [0038] The homogenization treatment is preferably carried out for 30 minutes or more after the inside of the ingot reaches a temperature of 500 ° C or higher. The holding time of the homogenization treatment is more preferably 1 hour or more, more preferably 2 hours or more. After the homogenization treatment, hot rolling is started at a temperature of 800 ° C or higher. It is preferred to terminate the hot rolling at a temperature of 600 ° C or higher without forming coarse Co-P precipitates in the hot rolled material, and to quench from the temperature by water cooling or the like. When the quenching start temperature after hot rolling is lower than 600 ° C, coarse Co-P precipitates are easily formed, the structure becomes uneven, and the strength of the copper alloy sheet (product sheet) is lowered. The end temperature of the hot rolling is preferably a temperature of 600 ° C or higher, more preferably 700 ° C or higher. Further, the structure of the hot rolled material which is quenched by hot rolling becomes a recrystallized structure. The recrystallization treatment accompanying the melting described later can also perform rapid cooling after hot rolling. [0039] After the cold rolling after hot rolling, a certain stress is applied to the copper alloy sheet, and after the recrystallization treatment, a copper alloy sheet having a desired recrystallized structure (fine recrystallized structure) is obtained. The recrystallization treatment accompanying the melt is carried out at 600 to 950 ° C, preferably at 670 to 900 ° C for 3 minutes or less. When the content of Co and P in the copper alloy is small, it is preferably carried out in a lower temperature region than in the above temperature range, and when the content of Co and P is large, it is preferably carried out in a higher temperature region than in the above temperature range. By this recrystallization treatment, Co and P are solid-melted in the copper alloy base material, and a recrystallized structure (crystal grain size: 1 to 20 μm) excellent in bending workability can be formed. When the recrystallization treatment temperature is lower than 600 ° C, the amount of solid solution of Co and P to the base material decreases, and the strength after the aging treatment decreases. On the other hand, when the temperature of the recrystallization treatment exceeds 950 ° C or the treatment time exceeds 3 minutes, the recrystallized grains are coarsened. [0040] After the recrystallization treatment with the melt, (a) aging treatment, (b) cold rolling and aging treatment, (c) cold rolling and aging treatment, and then cold calendering to the thickness of the product, or (d) Low temperature burn-off (ductility recovery) was carried out after (c) above. The aging treatment is carried out under the conditions of a heating temperature of about 300 to 580 ° C for 0.5 to 10 hours as described above. When the heating temperature is less than 300 ° C, the amount of precipitation is small, and when it exceeds 580 ° C, the precipitate is liable to become coarse. The lower limit of the heating temperature is preferably 350 ° C, and the upper limit is preferably 570 ° C, more preferably 560 ° C. The retention time of the aging time is appropriately selected depending on the heating temperature, and is carried out in the range of 0.5 to 10 hours. When the retention time was less than 0.5 hours, the precipitation became insufficient, and even if the precipitation amount was saturated over 10 hours, the productivity was lowered. The lower limit of the holding time is preferably 1 hour, more preferably 2 hours. [Example 1] [0041] A copper alloy having a composition shown in Tables 1 and 2 was cast, and an ingot having a thickness of 45 mm was produced. In the copper alloy, H of the unavoidable impurities was less than 1 ppm, O was less than 15 ppm, and the total of S, Pb, Bi, Sb, Se, and As was less than 20 ppm. Each of the ingots was subjected to a soaking treatment at 965 ° C for 3 hours, followed by hot rolling to obtain a hot rolled material having a thickness of 15 mm, and quenched (water-cooled) from a temperature of 650 ° C or higher. After both surfaces of the hot rolled material after quenching were polished to 1 mm, cold-rolling was performed until the target thickness was 0.6 mm, and the film was kept at 800 ° C for 20 seconds for recrystallization treatment (with melt formation). Next, after 500 hours of precipitation at 500 ° C for 2 hours, 50% of the finishing cold rolling was applied to form a plate thickness of 0.3 mm, and further cold burning at 330 ° C for 20 seconds (stress elimination burnt) to produce a copper alloy. board. Further, the composition of each of the copper alloy sheets having a thickness of 0.3 mm (comparative example No. 2 hot-rolled cracked material) was also the same as the values of Tables 1 and 2. Further, regarding each of the copper alloy sheets (excluding Comparative Example No. 2), the surface roughness Ra: 0.08 to 0.15 μm, and Rz: 0.8 to 1.2 μm, and the thickness of the plate was examined by a scanning electron microscope (observation magnification: 15,000 times). The internal oxidation depth measured was 0.1 μm or less. [0042] [0043] [0044] Using the obtained copper alloy sheet as a test material, each measurement test of electrical conductivity, mechanical properties, bending workability, and solder wettability was carried out in the following manner. The results are shown in Tables 3 and 4. Further, the obtained copper alloy sheet was heated at 850 ° C for 30 minutes, and then water-cooled, and further heated at 500 ° C for 2 hours (aging precipitation treatment) as test materials, and each measurement test of electrical conductivity and mechanical properties was carried out. The results are shown in Tables 3 and 4. (Measurement of Conductivity) The conductivity was measured by a four-terminal method using a double bridge in accordance with the conductivity measurement method of a non-ferrous metal material specified in JIS-H0505. (Mechanical characteristics) A JIS No. 5 tensile test piece was cut out from the test piece so that the longitudinal direction thereof became a parallel direction of rolling, and a tensile test was carried out in accordance with JIS-Z2241, and the endurance and elongation were measured. Endurance is equivalent to a tensile strength of 0.2% of permanent elongation. (Bending Processability) The measurement of the bending workability was carried out in accordance with the W bending test method specified in the Copper Bronze Association Standard JBMA-T307. A test piece having a width of 10 mm and a length of 30 mm was cut out from each of the test materials, and a fixture of R/t = 1.0 was used to carry out GW (Good Way (vertical axis and rolling direction)) and BW (Bad Way (bending axis and rolling direction). Parallel))). Next, the crack was observed by visual observation of the bending portion by a 100-fold optical microscope, and those having neither GW nor BW cracked were evaluated as P (P: Pass, qualified), and one of GW and BW or both of them had a turtle. The cracker was evaluated as F (F: Fall, unqualified). (Solder Moisture Resistance) A short strip test piece having a width of 10 mm and a length of 35 mm was used in the longitudinal direction and the rolling direction of each of the test materials, and was used in an inactive flux (α100 manufactured by Japan's αMetallized Co., Ltd.). After dip coating for 1 second, the solder dampening time was measured by a menzograph method (according to JIS C0053 welding test method (balance method), SAT 5100 manufactured by RHESCA Co., Ltd.). The solder was used under the test conditions of Sn-3 mass% Ag-0.5 mass% Cu maintained at 260 ± 5 ° C, impregnation speed of 25 mm/sec, impregnation depth of 5 mm, and immersion time of 5 seconds. When the solder dampening time was 2 seconds or less, it was evaluated that the solder wettability was excellent. Further, in addition to Comparative Example 5, the solder dampening time was 2 seconds or shorter. [0048] [0049] [0050] The copper alloy plate alloy compositions of Examples 1 to 18 shown in Tables 1 and 3 satisfy the requirements of the embodiments of the present invention, and are heated at 850 ° C for 30 minutes, followed by heating at 500 ° C for 2 hours. The strength (0.2% proof) is 150 MPa or more, and the electric conductivity is 70% IACS or more. In addition, the copper alloy sheet before heating at 850 ° C has a characteristic strength (0.2% proof) of 100 MPa or more, an elongation of 3% or more, and excellent bending workability and solder wettability. After heating at 850 ° C, most of them have a strength of 50 MPa or more (0.2% proof). Further, in Example 6, the content of Co and P was close to the lower limit, the endurance value after the aging treatment was 162 MPa, and the hardness was Hv83 (measured at a test force of 0.49 N). On the other hand, in the copper alloy sheets of Comparative Examples 1 to 8 shown in Tables 2 and 4, some characteristics were inferior as shown below. In Comparative Example 1, since the Co content was excessive, the bending workability was poor, and the strength and conductivity after the aging treatment were low. In Comparative Example 1, since the P content was excessive, the hot pressing time was cracked, and the step after the hot rolling could not be performed. Comparative Example 3 was high in [Co]/[P], and the strength and electrical conductivity after the aging treatment were low. In Comparative Example 4, [Co]/[P] was low, and the strength and electrical conductivity after the aging treatment were low. Comparative Example 5 was that the Zn content was excessive, and the solder wettability was poor as described above. In Comparative Example 6, since the total amount of elements other than the main elements (Al, Mn, etc.) was excessive, the electrical conductivity after the aging treatment was low. In Comparative Example 7, since the P content was insufficient, the strength and electrical conductivity after the aging treatment were low. In Comparative Example 8, since the Co content was insufficient, the strength after the aging treatment was low. [Example 2] [0052] The representative of the copper alloy sheets shown in Tables 1 and 2 (Examples 2, 10, Comparative Examples 3 and 4) were heated at 1000 ° C for 30 minutes, then water-cooled, and further at 500 ° C. After heating for 2 hours (aging treatment), the copper alloy sheet was used as a test material, and each measurement test of electrical conductivity and mechanical properties was carried out by the method described in Example 1. The results are shown in Table 5. [0053] As shown in Table 5, Examples 2 and 10 were heated at 1000 ° C for 30 minutes, and then the strength (0.2% proof) after the aging treatment was 150 MPa or more, and the electric conductivity was 70% IACS or more. The values shown in Table 5 were compared with those at 850 ° C for 30 minutes, and the results of the subsequent aging treatment (reference table) were not significantly different. On the other hand, Comparative Examples 3 and 4 were heated at 1000 ° C for 30 minutes, and then the strength and electrical conductivity after the aging treatment were not up to the standard (0.2% proof stress was 150 MPa or more, and electrical conductivity was 70% IACS or more). [0055] The disclosure of the present specification includes the following aspects. Aspect 1: A copper alloy plate for an exothermic element, characterized by Co: 0.05 to 0.9% by mass, P: 0.01 to 0.25 mass%, and the remainder is formed of Cu and inevitable impurities, and the Co content is set to [Co ] When the P content is [P], [Co]/[P] is 2 to 6, 0.2% withstand strength is 100 MPa or more, elongation is 3% or more, and it has excellent bending workability, and is heated at 850 ° C for 30 minutes. After water cooling, followed by heating at 500 ° C for 2 hours, the 0.2% endurance of the aging treatment is 150 MPa or more, and the electrical conductivity is 70% IACS or more. In one part of the process of manufacturing the exothermic element, the process of heating to 600 ° C or more is included. . Aspect 2: A copper alloy plate for a heat releasing element of the aspect 1, which further contains 1.0% by mass or less (excluding 0% by mass) of Zn. Aspect 3: A copper alloy plate for a heat releasing element according to claim 1 or 2, which further contains Fe, Ni, Sn, Si, Al, Mn, Cr, Ti, Zr, Ag, Mg in a total amount of 0.005 to 0.5% by mass One or two or more. Aspect 4: A method for producing an exothermic element, characterized in that the exothermic element according to any one of the aspects 1 to 3 is processed into a specific shape by a copper alloy sheet, and then heated to a temperature of 600 ° C or higher, and then The aging treatment is performed by applying plastic working to obtain a heat releasing element having a resistance of 0.2% or more and a conductivity of 70% IACS or more. Aspect 5: The method for producing a heat releasing member according to Aspect 4, wherein after the aging treatment, at least a portion of the outer surface of the heat releasing member forms a Sn coating layer. Aspect 6: The method for producing a heat releasing member according to aspect 4, wherein after the aging treatment, at least a portion of the outer surface of the heat releasing member forms a Ni coating layer. [0056] The present application claims priority on the basis of the Japanese Patent Application No. 2016-190664, filed on Sep. 26, 2016. Japanese Patent Application No. 2016-190664 is incorporated herein by reference.

Claims (10)

A copper alloy plate for an exothermic element, characterized by Co: 0.05 to 0.9% by mass, P: 0.01 to 0.25 mass%, and the remainder is formed of Cu and inevitable impurities, and the Co content is set to [Co], P content. When it is set to [P], [Co]/[P] is 2 to 6, 0.2% of endurance is 100 MPa or more, elongation is 3% or more, and it has excellent bending workability. After heating at 850 ° C for 30 minutes, it is water-cooled, followed by water cooling. After the aging treatment at 500 ° C for 2 hours, the 0.2% proof stress is 150 MPa or more, and the electric conductivity is 70% IACS or more. One part of the process for manufacturing the heat releasing element includes a process of heating to 600 ° C or more and an aging treatment. The copper alloy plate for a heat radiation element according to claim 1, further comprising 1.0% by mass or less (excluding 0% by mass) of Zn. The copper alloy sheet for a heat radiation element according to claim 1, wherein one or two of Fe, Ni, Sn, Si, Al, Mn, Cr, Ti, Zr, Ag, and Mg are further contained in a total amount of 0.005 to 0.5% by mass. the above. The copper alloy sheet for a heat radiation element according to claim 2, which further contains one or two of Fe, Ni, Sn, Si, Al, Mn, Cr, Ti, Zr, Ag, and Mg in a total amount of 0.005 to 0.5% by mass. the above. A method for producing a heat releasing element, characterized in that the copper alloy sheet for a heat releasing element according to any one of claims 1 to 4 is processed into a specific shape, and then heated to a temperature of 600 ° C or more, followed by no plastic working. The aging treatment was carried out to obtain an exothermic element having a resistance of 0.2% or more and a conductivity of 70% IACS or more. The method of manufacturing a heat releasing element according to claim 5, wherein after the aging treatment, at least a portion of the outer surface of the heat releasing member is formed with a Sn coating layer. A method of producing a heat releasing element according to claim 5, wherein after the aging treatment, at least a portion of the outer surface of the heat releasing member forms a Ni coating layer. A heat releasing element characterized by being produced from a copper alloy sheet for a heat releasing element according to any one of claims 1 to 4, which is subjected to an aging treatment after being heated to a temperature of 600 ° C or higher. The heat release element of claim 8, wherein the Sn coating layer is formed on at least a portion of the outer surface. The exothermic element of claim 8 wherein at least a portion of the outer surface forms a Ni coating.