WO2018062255A1

WO2018062255A1 - Copper alloy sheet for heat dissipation component, heat dissipation component, and method for producing heat dissipation component

Info

Publication number: WO2018062255A1
Application number: PCT/JP2017/034913
Authority: WO
Inventors: 大輔橋本; 昌泰西村
Original assignee: 株式会社神戸製鋼所
Priority date: 2016-09-29
Filing date: 2017-09-27
Publication date: 2018-04-05
Also published as: JP6446010B2; JP2018053310A; TW201827613A

Abstract

This copper alloy sheet for a heat dissipation component is characterized in that: the copper alloy sheet for a heat dissipation component comprises 0.05-0.9% by mass of Co, and 0.01-0.25% by mass of P, the balance being Cu and inevitable impurities; [Co]/[P] is 2-6 when [Co] represents the Co content and [P] represents the P content; the 0.2% proof stress is 100 MPa or more; the elongation is 3% or more; the bending workability is excellent; the 0.2% proof stress is 150 MPa or more and the conductivity is 70% IACS or more after heating at 850°C for 30 minutes followed by cooling with water and then an aging treatment of heating at 500°C for 2 hours; and a process of heating to a temperature of 600°C or higher and an aging treatment are included as part of a process for producing a heat dissipation component.

Description

Copper alloy plate for heat dissipation component, heat dissipation component, and manufacturing method of heat dissipation component

The present disclosure relates to a heat sink, a heat sink, a copper alloy plate for heat dissipating parts used for a heat pipe and the like for processing heat generated from a CPU of a computer, an LED lamp, and the like. In particular, the present invention relates to a copper alloy plate for a heat dissipation component that is used when a process of heating to a high temperature such as brazing, diffusion bonding, deaeration, or the like is included as part of the manufacturing process of the heat dissipation component.

The speed of operation and the increase in integration density of CPUs mounted on desk-type PCs, notebook-type PCs and the like are rapidly progressing, and the amount of heat generated from these CPUs is further increased. When the temperature of the CPU rises above a certain level, it causes malfunctions, thermal runaway, etc., so effective heat dissipation from a semiconductor device such as a CPU is a serious problem.
Heat sinks are used as heat dissipating parts that absorb the heat of semiconductor devices and dissipate them into the atmosphere. Since the heat sink is required to have high thermal conductivity, copper, aluminum, or the like having a high thermal conductivity is used as a material. However, the convective heat resistance limits the performance of the heat sink, and it has become difficult to satisfy the heat dissipation requirement of high-functional electronic components that increase the amount of heat generation.

For this reason, tubular heat pipes and flat heat pipes (vapor chambers) having high heat conductivity and heat transport capability have been proposed as heat dissipating parts having higher heat dissipating properties. The heat pipe exhibits higher heat dissipation characteristics than the heat sink by cyclically performing evaporation (heat absorption from the CPU) and condensation (release of absorbed heat) of the refrigerant sealed inside. It has also been proposed to solve the heat generation problem of semiconductor devices by combining heat pipes with heat radiating components such as heat sinks and fans.

As a material for heat dissipation parts used for heat dissipation plates, heat sinks, heat pipes, etc., pure copper (oxygen-free copper: C1020) plates or tubes having excellent conductivity and corrosion resistance are frequently used. In order to ensure moldability, soft annealed material (O material) or 1 / 4H tempered material is used as the material, but deformation and wrinkles are likely to occur in the manufacturing process of the heat dissipating parts described later, during punching processing There are problems such as burrs being easily generated and punching dies being easily worn. On the other hand, Patent Documents 1 and 2 describe an Fe—P-based copper alloy plate as a material for a heat dissipation component.

For heat sinks and heat sinks, pure copper plates are processed into a predetermined shape by press molding, punching, cutting, drilling, etching, etc., and then subjected to Ni plating and Sn plating as required before solder, brazing, adhesive, etc. To join with a semiconductor device such as a CPU.
A tubular heat pipe (see Patent Document 3) is formed by sintering copper powder in a tube to form a wick, heat-degassing treatment, brazing and sealing one end, and putting a refrigerant in the tube under vacuum or reduced pressure. And the other end is brazed and sealed.

The planar heat pipe (see Patent Documents 4 and 5) is a further improvement of the heat dissipation performance of the tubular heat pipe. In order to efficiently condense and evaporate the refrigerant, a flat heat pipe has been proposed in which the inner surface is roughened, grooved, and the like, similar to the tubular heat pipe. A method of brazing, etc. after joining two upper and lower pure copper plates that have undergone processing such as press molding, punching, cutting, etching, etc. by brazing, diffusion bonding, welding, etc. Seal with. A degassing process may be performed in a joining process.

Moreover, what was comprised from the outer surface member and the internal member accommodated in the inside of an outer surface member as a planar heat pipe is proposed. One or a plurality of internal members are arranged inside the outer surface member in order to promote condensation, evaporation, and transport of the refrigerant, and various shapes of fins, protrusions, holes, slits, and the like are processed. Also in this type of flat heat pipe, after placing the internal member inside the external surface member, the external surface member and the internal member are joined and integrated by a method such as brazing or diffusion bonding, brazing, etc. It seals by the method of.
When the heat generation of the electronic component further increases and exceeds the heat dissipation capability of the vapor chamber, a heat dissipation component having the same internal structure as the vapor chamber and continuously supplying the refrigerant from the outside is used (see Patent Document 6). ). This type of heat dissipation component does not require a low pressure inside the housing. The members used for the casing of this type of heat radiation component and the method for manufacturing the casing are basically the same as those of the vapor chamber.

JP 2003-277853 A JP 2014-189816 A JP 2008-232563 A JP 2007-315745 A JP 2014-134347 A International Publication No. 2014/171276

In the manufacturing process of these heat radiating components, the heat radiating plate and the heat sink are heated to about 200 to 700 ° C. in the soldering and brazing processes. Tubular heat pipes and planar heat pipes are heated to about 800 to 1000 ° C. in steps such as sintering, degassing, brazing using phosphor copper brazing (BCuP-2, etc.), diffusion bonding, and welding.
For example, when a pure copper plate is used as the heat pipe material, the softening is severe when heated at a temperature of 600 ° C. or higher. In addition, the crystal grains become abruptly coarsened. For this reason, the manufactured heat pipe is easily deformed when it is attached to a heat sink, a semiconductor device, or incorporated into a PC case, and the structure inside the heat pipe changes, and the unevenness of the surface increases. There is a problem that the desired heat dissipation performance cannot be exhibited. Moreover, in order to avoid such a deformation | transformation, what is necessary is just to thicken the thickness of a pure copper plate, but if it does so, the mass and thickness of a heat pipe will increase. When the thickness increases, there is a problem that the gap inside the PC casing is reduced and the convective heat transfer performance is lowered.

Also, the copper alloy plates (Cu—Fe—P alloys) described in Patent Documents 1 and 2 are softened when heated at a temperature of 600 ° C. or higher, and the conductivity is greatly reduced as compared with pure copper. For this reason, for example, when a flat heat pipe is manufactured through processes such as sintering, degassing, brazing, diffusion bonding, welding, etc., it is easily deformed by the process of transporting and handling the heat pipe, incorporating it into the substrate, etc. . Moreover, the expected performance as a heat pipe cannot be obtained due to the decrease in conductivity.

The embodiment of the present invention has been made in view of the above problems when a process of heating to a temperature of 600 ° C. or higher is included in a part of the process of manufacturing a heat dissipation component from pure copper or a copper alloy plate. It aims at providing the copper alloy board which can give sufficient intensity | strength and heat dissipation performance to the thermal radiation component manufactured through the process heated to the above temperature.

A precipitation hardening type copper alloy improves strength and conductivity by performing an aging treatment after the solution treatment. However, the precipitation hardening type copper alloy, after solution treatment, after applying plastic working in the cold and introducing the plastic strain that becomes the precipitation site into the alloy, if not aging treatment, strength and conductivity by aging treatment The rate improvement effect may be low.
In the case of a heat-radiating component such as a vapor chamber manufactured through a heating process such as brazing, diffusion bonding, or welding, plastic processing is not applied after the heating process. Therefore, when the heat radiating component is manufactured from a plate material of a precipitation hardening type copper alloy, the strength and conductivity may not be sufficiently improved even if an aging treatment is performed after the heating step corresponding to the solution treatment.
On the other hand, the present inventors add plastic working after the heating step by limiting the composition range of Co and P and the Co / P ratio in the Cu—Cо—P alloy among precipitation hardening type copper alloys. Even when the aging treatment is performed without any problems, the inventors have found that the strength and conductivity of the heat dissipating component are greatly improved, and have reached the embodiments of the present invention.

The copper alloy plate for heat dissipation component according to the embodiment of the present invention is used when a process of heating to 600 ° C. or higher and an aging treatment are included as part of the process of manufacturing the heat dissipation component, Co: 0.05 to 0.9 mass%, P: 0.01 to 0.25 mass%, the balance is made of Cu and inevitable impurities, Co content (mass%) is [Co], P content (mass%) is [P ], [Co] / [P] is 2 to 6, 0.2% proof stress is 100 MPa or more, elongation is 3% or more, and has excellent bending workability. The copper alloy sheet has a 0.2% proof stress of 150 MPa or more and an electrical conductivity of 70% IACS or more after aging at 850 ° C. for 30 minutes, followed by water cooling and then heating at 500 ° C. for 2 hours. . A 0.2% proof stress of the copper alloy plate of 150 MPa or more corresponds to Hv75 or more in terms of hardness. When it is difficult to measure the 0.2% yield strength by a tensile test, it can be estimated whether the 0.2% yield strength is 150 MPa or more by measuring the Vickers hardness in accordance with the provisions of JISZ2244 (2009).

The copper alloy plate for a heat dissipation component can further contain 1.0% by mass or less (not including 0% by mass) of Zn as an alloy element, if necessary. Moreover, the copper alloy plate for heat radiating components according to the embodiment of the present invention further includes Fe, Ni, Si, Al, Mn, Cr, Sn, Ti, Zr, Ag, and Mg as alloy elements as necessary. One or two or more kinds can be contained in a total amount of 0.005 to 0.5% by mass or less. The copper alloy plate may contain one or more of Fe, Ni, Si, Al, Mn, Cr, Sn, Ti, Zr, Ag, and Mg and Zn at the same time.

The copper alloy plate which concerns on embodiment of this invention is used when the process and aging treatment which are heated to 600 degreeC or more are included as a part of process of manufacturing a thermal radiation component. That is, the heat-radiating component manufactured using the copper alloy plate according to the embodiment of the present invention is subjected to aging treatment without being subjected to plastic working after high-temperature heating to 600 ° C. or higher, and the strength is improved.
Since the copper alloy plate according to the embodiment of the present invention has a high strength (0.2% proof stress) of 100 MPa or more, the copper alloy plate is not easily deformed in conveyance and handling when the copper alloy plate is processed into a heat radiating component. Moreover, since it has an elongation of 3% or more and excellent bending workability, the processing can be performed without any trouble.

When the copper alloy plate according to the embodiment of the present invention is heated to 850 ° C. for 30 minutes and then subjected to an aging treatment, the 0.2% proof stress is 150 MPa or more and the conductivity is 70% IACS or more. Since the copper alloy plate according to the embodiment of the present invention has high strength after aging treatment, a heat dissipation component such as a heat pipe manufactured using the copper alloy plate is attached to a heat sink, a semiconductor device, or a PC housing When assembled in the heat sink, the heat dissipating component is hardly deformed. In addition, the copper alloy plate according to the embodiment of the present invention has a conductivity lower than that of a pure copper plate, but can be thinned because of its high strength after aging treatment, and can compensate for a decrease in conductivity in terms of heat dissipation performance. .

Hereinafter, the copper alloy plate for heat dissipation components according to the embodiment of the present invention will be described in more detail.
The copper alloy plate according to the embodiment of the present invention is processed into a predetermined shape by press molding, punching, cutting, etching, etc., and is subjected to high temperature heating (degassing, bonding (brazing, diffusion bonding, welding), sintering, etc. For heat dissipation). Although the heating conditions for the high-temperature heating differ depending on the type of the heat dissipating component and the manufacturing method, the embodiment of the present invention assumes the case where the high-temperature heating is performed at about 600 ° C. to 1050 ° C. A copper alloy plate according to an embodiment of the present invention is made of a Co—P based copper alloy having a composition to be described later, and when heated within the temperature range, at least a part of the Co—P compound precipitated in the base material before heating. Is dissolved in the base material, crystal grains grow, and softening and decrease in conductivity occur.

The copper alloy plate according to the embodiment of the present invention has a strength (0.2% proof stress) after heating at 850 ° C. for 30 minutes, followed by water cooling, and then aging treatment, 150 MPa or more, and a conductivity of 70% IACS or more. Heating at 850 ° C. for 30 minutes is a heating condition that assumes the above-described high-temperature heating process in the manufacture of a heat dissipation component. When the copper alloy plate according to the embodiment of the present invention is heated at high temperature under these conditions, the Co—P compound precipitated in the base material before heating is dissolved in the base material, crystal grains grow, soften, and conduct The rate drops. Next, when the copper alloy sheet is subjected to an aging treatment, a fine Co—P compound is precipitated. Thereby, the intensity | strength and electrical conductivity which were reduced by the said high temperature heating improve notably.

The aging treatment can be performed, for example, by (a) maintaining the precipitation temperature range for a certain time during the cooling step after high-temperature heating, (b) cooling to room temperature after high-temperature heating, and then reheating to the precipitation temperature range and holding for a certain time. (C) After the step (a), it can be carried out by a method such as reheating to the precipitation temperature range and holding for a certain time.
Specific aging treatment conditions include a condition of holding at a temperature range of 300 to 580 ° C. for 5 minutes to 10 hours. When priority is given to improving the strength, the temperature-time conditions at which fine Co-P compounds are generated. When priority is given to improving the conductivity, the temperature of over-aging that reduces Co and P dissolved in the base material is reduced. What is necessary is just to select time conditions suitably.

The copper alloy plate after the aging treatment has a lower electrical conductivity than the pure copper plate after high-temperature heating, but the strength is significantly higher than that of the pure copper plate. In order to acquire this effect, heat dissipation parts, such as a heat pipe manufactured using the copper alloy board concerning the embodiment of the present invention, are aging-treated after high temperature heating. The aging treatment conditions are as described above. The heat-dissipating component (copper alloy plate) after the aging treatment has high strength and can prevent deformation of the heat-dissipating component when it is attached to a heat sink, a semiconductor device, or incorporated in a PC housing or the like. In addition, since the copper alloy plate (after aging treatment) according to the embodiment of the present invention has higher strength than that of a pure copper plate, it can be thinned (0.1 to 1.0 mm thick). The heat dissipation performance of the parts can be improved, and the decrease in conductivity when compared with a pure copper plate can be compensated.
In addition, the copper alloy plate according to the embodiment of the present invention has a high-temperature heating temperature of less than 850 ° C. (600 ° C. or more) or more than 850 ° C. (1050 ° C. or less), after the aging treatment, at a pressure of 150 MPa or more. 2% yield strength and 70% IACS or higher conductivity can be achieved.

The copper alloy plate according to the embodiment of the present invention is processed into a heat radiation component by press molding, punching, cutting, etching, or the like before being heated at a high temperature of 600 ° C. or higher. It is preferable that the copper alloy plate has a strength that does not easily deform during conveyance and handling during the processing, and has mechanical characteristics that allow the processing to be performed without hindrance. More specifically, the copper alloy sheet according to the embodiment of the present invention has a 0.2% proof stress of 100 MPa or more and an elongation of 3% or more, and has excellent bending workability. If the above characteristics are satisfied, the tempering of the copper alloy sheet is not a problem. For example, any of a solution-treated material, an aging-treated material, and a cold-rolled aging-treated material can be used. The elongation is preferably 6% or more.

For the bending workability, it is required that no cracks occur at the bent part. Furthermore, it is preferable that rough skin does not occur at the bend line and its vicinity. Even in the case of copper alloy plates of the same material, the ease of occurrence of cracking and rough skin due to bending depends on the ratio R / t of the bending radius R and the plate thickness t. When manufacturing heat dissipation parts such as a vapor chamber using a copper alloy plate, the bending processability of the copper alloy plate is usually performed by bending the direction of the bend line in the rolling parallel direction and the perpendicular direction at R / t ≦ 2. In this case, it is required that no cracks occur. As the bending workability of the copper alloy plate, it is preferable that no crack is generated by bending of R / t ≦ 1.5, and it is more preferable that no crack is generated by bending of R / t ≦ 1.0. The bending workability of a copper alloy plate is generally tested with a test piece having a plate width of 10 mm (see the bending workability test in Examples described later). When bending copper alloy sheets, cracks are more likely to occur as the bending width increases. Therefore, if the bending width is particularly large as a heat-dissipating part, cracks will not occur when bending at R / t = 1.0. Is preferable, and it is more preferable that no crack is generated by bending with R / t = 0.5. In order not to cause rough skin at the bend line and the vicinity thereof, the average crystal grain size (cutting method) measured in the plate width direction on the surface of the copper alloy plate is preferably 20 μm or less, and 15 μm or less. Is more preferable, and it is still more preferable that it is 10 micrometers or less.

As described above, the heat dissipation component manufactured by processing the copper alloy plate according to the embodiment of the present invention is softened when heated to a temperature of 600 ° C. or higher. It is preferable that the heat dissipating component after high-temperature heating has a strength that does not easily deform during conveyance and handling when performing an aging treatment. For that purpose, it is preferable to have a 0.2% yield strength of 50 MPa or more at the stage of heating at 850 ° C. for 30 minutes and then water cooling.

The heat-radiating component manufactured using the copper alloy plate according to the embodiment of the present invention is subjected to an aging treatment, and if necessary, at least a part of the outer surface mainly for the purpose of improving corrosion resistance and solderability. An Sn coating layer is formed on the surface. The Sn coating layer includes electroplating, electroless plating, or those formed by heating to a melting point of Sn or lower or higher than the melting point of Sn. The Sn coating layer includes Sn metal and an Sn alloy, and the Sn alloy includes one or more of Bi, Ag, Cu, Ni, In, and Zn as alloy elements in addition to Sn in a total amount of 5% by mass or less. Things.

A base plating such as Ni, Co, Fe or the like can be formed under the Sn coating layer. These undercoats have a function as a barrier for preventing diffusion of Cu and alloy elements from the base material, and a function for preventing damage by increasing the surface hardness of the heat dissipation component. A Cu-Sn alloy layer is formed by plating Cu on the base plating, further plating Sn, and then performing a heat treatment to heat to a temperature lower than or higher than the melting point of Sn to form a Cu-Sn alloy layer and Sn A three-layer structure of the coating layer can also be used. The Cu—Sn alloy layer has a function as a barrier for preventing the diffusion of Cu and alloy elements from the base material, and a function for preventing damage by increasing the surface hardness of the heat dissipation component.

In addition, after the heat dissipation component manufactured using the copper alloy plate according to the embodiment of the present invention is subjected to an aging treatment, a Ni coating layer is formed on at least a part of the outer surface as necessary. The Ni coating layer has a barrier that prevents the diffusion of Cu and alloy elements from the base material, a damage prevention by increasing the surface hardness of the heat dissipation component, and a function of improving corrosion resistance.

Next, the composition of the copper alloy plate according to the embodiment of the present invention will be described.
The composition of the copper alloy according to the embodiment of the present invention is composed of Co: 0.05 to 0.9% by mass, P: 0.01 to 0.25% by mass, and the balance Cu and inevitable impurities. [Co] / [P] is 2 to 6, where [% by mass] is [Co] and the P content (% by mass) is [P].
Co forms a P compound (Co—P compound) with P and improves the strength and stress relaxation resistance of the copper alloy sheet. This P compound has a high solid solution temperature, and even if the copper alloy plate is heated to a high temperature of 600 ° C. or higher (for example, 850 ° C.), a part thereof exists relatively stably and the coarsening of the crystal grain size is prevented. On the other hand, the higher the heating temperature of the copper alloy plate, the higher the concentration of frozen vacancies after water cooling, and the more the nucleation sites of precipitates, the more the number density of precipitates can be increased by the subsequent aging treatment. Contributes to improvement in strength after aging treatment. If the Co content is less than 0.05% by mass or the P content is less than 0.01% by mass, the precipitation amount 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, a conductivity of 70% IACS or more cannot be achieved in the copper alloy after aging treatment. Moreover, a coarse oxide, a crystallized substance, a precipitate, etc. generate | occur | produce and hot workability falls, and the intensity | strength of a copper alloy board, stress relaxation resistance, and bending workability fall. Therefore, Co is 0.05 to 0.9 mass%, and the P content is 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.

For the above-described action, the P content is required within the above range. On the other hand, the P content that does not contribute to precipitation is preferably as small as possible within the range where hydrogen embrittlement can be prevented. From this point, the content ratio [Co] / [P] of Co and P is set to be in the range of 2-6. When [Co] / [P] is less than 2, the amount of P that does not contribute to the formation of the Co—P compound and dissolves in the base material increases, and when [Co] / [P] exceeds 6, The amount of Co dissolved in the base material increases, and in any case, the conductivity of the copper alloy sheet after the aging treatment cannot be made 70% IACS or more. When [Co] / [P] is less than 2 or exceeds 6, Co or P that does not contribute to the formation of the Co—P compound increases, and the strength of the copper alloy sheet after aging treatment is not 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, it is 4.5.

If necessary, the copper alloy may further contain Zn: 1.0% by mass or less (excluding 0% by mass), or / and Fe, Ni, Sn, Si, Al, Mn, Cr, Ti, Zr, Ag. 1 or 2 or more of Mg can be contained in a total amount of 0.005 to 0.5% by mass. However, it must be avoided that the conductivity of the copper alloy sheet after the aging treatment falls below 70% IACS by adding these elements.
Zn has the effect | action which improves the heat-resistant peelability of the solder of a copper alloy board, and the heat-resistant peelability of Sn plating. When incorporating a heat dissipation component into a semiconductor device, soldering may be required, and after manufacturing the heat dissipation component, Sn plating may be performed to improve corrosion resistance. A copper alloy plate containing Zn is suitably used for manufacturing such a heat dissipation component. However, if the Zn content exceeds 1.0% by mass, the solder wettability decreases. Therefore, when Zn is contained, the Zn content is 1.0% by mass or less (not including 0% by mass). To do. 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 contribution to the improvement of the heat-resistant peelability is small, and the Zn content is preferably 0.01% by mass or more. As for Zn content, 0.05 mass% or more is more preferable, and 0.1 mass% or more is further more preferable.
In addition, when the copper alloy plate of embodiment of this invention contains Zn, when it heats at the temperature of 500 degreeC or more, Zn will vaporize depending on heating atmosphere, the surface property of a copper alloy plate will be reduced, or a heating furnace will be contaminated. There are things to do. From the viewpoint of preventing vaporization of Zn, the Zn content is preferably 0.5% by mass or less, more preferably 0.4% by mass or less, further preferably 0.3% by mass or less, and still more preferably. 0.2 mass% or less.

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, and therefore one or more of these elements are contained. , Added as needed. However, if the content of these elements is large, the electrical conductivity of the copper alloy sheet is lowered. Therefore, when one or more of these elements are added, the total content is 0.005 to 0.5 mass. % Range.
Of these elements, Fe and Ni form phosphides ((Ni, Fe) -P compounds) with P in the same manner as Co. The effect of improving the strength of the copper alloy sheet due to the formation of phosphide is greatest for Co, followed by Fe and Ni. Fe and Ni form an phosphide and P that did not form a phosphide with Co (reduced P dissolved in the base material), and have the effect of improving the strength of the copper alloy plate. Fe has an effect of suppressing grain coarsening during high-temperature heating. In order to obtain these 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 the decrease in conductivity, the Fe content is preferably 0.05% by mass or less, and the Ni content is preferably 0.1% by mass or less.

Sn and Mg are dissolved in the copper alloy matrix and have an effect of improving the strength and stress relaxation resistance of the copper alloy sheet. When the temperature or operating environment of the heat dissipating component is 80 ° C or higher, creep deformation occurs and the contact area with a heat source such as a CPU is reduced, reducing heat dissipation, but improving stress relaxation resistance. Thus, this phenomenon can be suppressed. In order to acquire this effect, it is preferable that Sn content is 0.02 mass% or more, and Mg content is 0.01 mass% or more. On the other hand, from the viewpoint of preventing a decrease in the conductivity of the copper alloy plate, 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 the effect of improving the strength and heat resistance of the copper alloy. In order to acquire this effect, it is preferable that content of Si, Al, and Mn is 0.01 mass% or more. On the other hand, from the viewpoint of preventing the decrease in conductivity of the copper alloy plate, the Si content is 0.2% by mass or less, the Al content is 0.2% by mass or less, and the Mn content is 0.1% by mass or less. It is preferable to do.

Cr, Ti, and Zr have the effect of improving the strength and heat resistance of the copper alloy and suppressing the coarsening of crystal grains during high-temperature heating. In order to acquire this effect, it is preferable that both Cr content and Ti content are 0.01 mass% or more, and Zr content is 0.005 mass% or more. On the other hand, from the viewpoint of preventing a decrease in conductivity of the copper alloy plate, the Cr content is 0.2% by mass or less, the Ti content is 0.1% by mass or less, and the Zr content is 0.05% by mass or less. It is preferable to do. These elements easily form inclusions such as oxides and sulfides of several μm to several tens of μm, and when the inclusions are present on the surface, the corrosion resistance of the copper alloy plate is lowered. When the content of the element is in the above range, no particular problem occurs.
Ag has the 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 mass%.

The inevitable impurities H, O, S, Pb, Bi, Sb, Se, As gather at the grain boundary when the copper alloy plate is heated to a temperature of 600 ° C. or higher for a long time, and the grain boundary during and after heating Since there is a possibility of causing cracks and grain boundary embrittlement, the content of these elements is preferably reduced. H is preferably less than 1.5 ppm (mass ppm, the same applies hereinafter), more preferably less than 1 ppm, because it collects at the grain boundaries and the interface between inclusions and the base material during heating and generates swelling. O is preferably less than 20 ppm, more preferably less than 15 ppm. S, Pb, Bi, Sb, Se, As are preferably less than 30 ppm in total, and more preferably less than 20 ppm. In particular, for Bi, Sb, Se and As, the total content of these elements is preferably less than 10 ppm, more preferably less than 5 ppm.

The copper alloy sheet according to the embodiment of the present invention comprises (1) hot rolling-cold rolling-annealing, (2) hot rolling-cold rolling-annealing-cold rolling after soaking the ingot. 3) It can be produced by processes such as hot rolling, cold rolling, annealing, cold rolling, and low temperature annealing. In the above (1) to (3), the cold rolling-annealing step may be performed a plurality of times.
The annealing includes softening annealing, recrystallization annealing, or precipitation annealing (aging treatment). In the case of softening annealing or recrystallization annealing, the heating temperature may be selected from the range of 600 to 950 ° C., and the heating time may be selected from the range of 5 seconds to 1 hour. When soft annealing or recrystallization annealing also serves as a solution treatment, continuous annealing is preferably performed at 600 to 950 ° C., preferably 670 to 900 ° C. for 3 minutes or less. In the case of an aging treatment, it is preferable to perform the aging treatment under a condition that the temperature is maintained at about 350 to 580 ° C. for 0.5 to 10 hours. When softening annealing or recrystallization annealing also serves as a solution treatment, this aging treatment can be performed in a later step.

The final cold rolling is preferably selected from a range of a processing rate of 5 to 80% in accordance with the target 0.2% proof stress and bending workability.
Low temperature annealing softens the copper alloy plate without recrystallization in order to restore the ductility of the copper alloy plate. In the case of continuous annealing, it is maintained at 300 to 650 ° C. for about 1 second to 5 minutes. It is good to set in. In the case of batch-type annealing, it is preferable that the solid temperature of the copper alloy plate is maintained at 250 ° C. to 400 ° C. for about 5 minutes to 1 hour.
By the above production method, a copper alloy plate having excellent bending workability with a 0.2% proof stress of 100 MPa or more and an elongation of 3% or more can be produced. Further, this copper alloy sheet has a 0.2% proof stress of 150 MPa or more and a conductivity of 70% IACS or more when aging treatment is performed at 850 ° C. for 30 minutes and then at 500 ° C. for 2 hours.
In order to enable good bonding (no bonding failure, high bonding strength, etc.) by a method such as diffusion bonding or brazing at a temperature of 600 ° C. or higher, the surface roughness of the copper alloy plate (product) is The arithmetic average roughness Ra is 0.3 μm or less, the maximum height roughness Rz is 1.5 μm or less, and the internal oxidation depth is 0.5 μm or less, preferably 0.3 μm or less.
To make the surface roughness of the copper alloy plate (product) Ra: 0.3 μm, Rz: 1.5 μm or less, the surface roughness in the roll axis direction of the rolling roll used for the final cold rolling is, for example, Ra: 0.15 μm Rz: 1.0 μm or less, or polishing such as buffing or electrolytic polishing may be performed on the copper alloy plate after the final cold rolling. In order to reduce the internal oxidation depth of the copper alloy sheet (product) to 0.5 μm or less, the annealing atmosphere should be reducible and the dew point should be −5 ° C. or less, or the annealed copper alloy sheet should be mechanically polished The generated internal oxide layer may be removed or thinned by electrolytic polishing (buffing, brushing, etc.).

As a standard manufacturing method, the copper alloy plate according to the embodiment of the present invention, as a standard manufacturing method, after soaking the ingot and hot rolling, cold rolling, recrystallization treatment with solution, cold rolling (can be omitted) ), Manufactured in the aging treatment process. Cold rolling after recrystallization treatment with solution treatment can be omitted. Further, after the aging treatment, cold rolling can be further performed. A copper alloy plate produced by this production method using a copper alloy having the above composition has high strength (0.2% proof stress is 300 MPa or more), elongation is 3% or more, and has excellent bending workability. Further, when this copper alloy sheet is heated at 850 ° C. for 30 minutes and then heated at 500 ° C. for 2 hours, it has a 0.2% proof stress of 150 MPa or more and a conductivity of 70% IACS or more.

Melting and casting can be performed by ordinary methods such as continuous casting and semi-continuous casting. In addition, it is preferable to use what has little S, Pb, Bi, Se, As content as a copper melt | dissolution raw material. In addition, it is preferable to reduce O and H by paying attention to red heat (removal of water) of charcoal coated on the molten copper alloy, metal, scrap raw material, cast iron, drying of the mold, deoxidation of the molten metal, and the like.

The homogenization treatment is preferably held for 30 minutes or more after the inside of the ingot reaches a temperature of 800 ° C. or higher. The holding time of the homogenization treatment is more preferably 1 hour or more, and further preferably 2 hours or more.
After the homogenization treatment, hot rolling is started at a temperature of 800 ° C. or higher. In order to prevent coarse Co—P precipitates from being formed on the hot rolled material, the hot rolling is preferably completed at a temperature of 600 ° C. or higher, and then rapidly cooled by a method such as water cooling. When the rapid cooling start temperature after hot rolling is lower than 600 ° C., coarse Co—P precipitates are formed, the structure tends to be non-uniform, and the strength of the copper alloy plate (product plate) decreases. The end temperature of hot rolling is preferably 600 ° C. or higher, and more preferably 700 ° C. or higher. In addition, the structure of the hot-rolled material rapidly cooled after hot rolling becomes a recrystallized structure. The recrystallization process accompanied by solutionization described later can also be performed by performing rapid cooling after hot rolling.

By applying a certain strain to the copper alloy sheet by cold rolling after hot rolling, a copper alloy sheet having a desired recrystallized structure (fine recrystallized structure) is obtained after the subsequent recrystallization process.
The recrystallization treatment with solution treatment is performed 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 preferable to carry out in a lower temperature region within the above temperature range, and when the content of Co and P is large, it is preferably carried out in a higher temperature region within the above temperature range. By this recrystallization treatment, Co and P can be dissolved in the copper alloy base material, and a recrystallized structure (crystal grain size of 1 to 20 μm) can be formed with good bending workability. When the temperature of this recrystallization process is lower than 600 ° C., the amount of Co and P dissolved in the base material decreases, and the strength after the aging process 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 become coarse.

After recrystallization treatment with solution, (a) aging treatment, (b) cold rolling and aging treatment, (c) after cold rolling and aging treatment, further cold rolling to product thickness, or ( d) After the step (c), low temperature annealing (recovery of ductility) is performed.
As described above, the aging treatment is performed under the condition of holding at a heating temperature of about 300 to 580 ° C. for 0.5 to 10 hours. If the heating temperature is less than 300 ° C., the amount of precipitation is small, and if it exceeds 580 ° C., the precipitate tends 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 holding time for the aging treatment is appropriately selected depending on the heating temperature, and is carried out within the range of 0.5 to 10 hours. If this holding time is less than 0.5 hours, precipitation is insufficient, and if it exceeds 10 hours, the amount of precipitation is saturated and productivity is lowered. The lower limit of the holding time is preferably 1 hour, more preferably 2 hours.

Copper alloys having the compositions shown in Tables 1 and 2 were cast to produce ingots each having a thickness of 45 mm. In this copper alloy, H, which is an inevitable impurity, was less than 1 ppm, O was less than 15 ppm, and S, Pb, Bi, Sb, Se, and As were less than 20 ppm in total.
Each ingot was subjected to a soaking treatment at 965 ° C. for 3 hours, followed by hot rolling to obtain a hot-rolled material having a plate thickness of 15 mm, and quenching (water cooling) from a temperature of 650 ° C. or higher. After polishing both sides of the hot-rolled material after quenching by 1 mm, cold rolling was performed to a target plate thickness of 0.6 mm, and recrystallization treatment (with solution) was performed at 800 ° C. for 20 seconds. Next, after precipitation annealing at 500 ° C. for 2 hours, 50% finish cold rolling is performed to obtain a sheet thickness of 0.3 mm, and further, low-temperature annealing (distortion annealing) is performed at 330 ° C. for 20 seconds to produce a copper alloy sheet. did. In addition, the composition analyzed by each copper alloy plate with a plate thickness of 0.3 mm (only Comparative Example No. 2 was hot-rolled cracked material) was also the same as the values in Tables 1 and 2. The surface roughness of any copper alloy plate (excluding Comparative Example No. 2) is Ra: 0.08 to 0.15 μm, Rz: 0.8 to 1.2 μm, and the cross section of the plate thickness The internal oxidation depth measured by a scanning electron microscope (observation magnification: 15000 times) was 0.1 μm or less.

Using the obtained copper alloy plate as a test material, each measurement test of electrical conductivity, mechanical characteristics, bending workability, and solder wettability was performed in the following manner. The results are shown in Tables 3 and 4.
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, respectively. A measurement test was conducted. 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 nonferrous metal material conductivity measurement method defined in JIS-H0505.
(Mechanical properties)
A JIS No. 5 tensile test piece was cut out from the specimen so that the longitudinal direction was parallel to the rolling direction, and a tensile test was performed in accordance with JIS-Z2241, thereby measuring the yield strength and elongation. The yield strength is a tensile strength corresponding to a permanent elongation of 0.2%.

(Bending workability)
The measurement of the bending workability was carried out according to the W bending test method specified in JBMA-T307 standard of the copper elongation association. A test piece having a width of 10 mm and a length of 30 mm was cut out from each sample material, and a jig with R / t = 1.0 was used. W. (Good Way (bending axis is perpendicular to rolling direction)) and B.I. W. (Bad Way (bending axis is parallel to the rolling direction)) was performed. Next, the presence or absence of cracks in the bent portion was visually observed with a 100 × optical microscope. W. And B. W. P (P: Pass, pass), G. W. Or B. W. Those in which cracks occurred in one or both of these were evaluated as F (F: Fail, rejected).

(Solder wettability)
A strip-shaped test piece having a width of 10 mm and a length of 35 mm is collected from each sample material so that the longitudinal direction is parallel to the rolling direction, and dip-coated for 1 second on an inactive flux (α100 manufactured by Nippon α Metals Co., Ltd.). The solder wetting time was measured by the meniscograph method (according to JIS C0053 soldering test method (equilibrium method), SAT5100 manufactured by Reska Co., Ltd.). The solder used was Sn-3 mass% Ag-0.5 mass% Cu maintained at 260 ± 5 ° C., and the test was performed under the test conditions of an immersion speed of 25 mm / sec, an immersion depth of 5 mm, and an immersion time of 5 sec. A solder wetting time of 2 seconds or less was evaluated as having excellent solder wettability. Except for Comparative Example 5, the solder wetting time was 2 seconds or less.

The copper alloy sheets of Examples 1 to 18 shown in Tables 1 and 3 were subjected to an aging treatment in which the alloy composition satisfied the provisions of the embodiment of the present invention, heated at 850 ° C. for 30 minutes, and then heated at 500 ° C. for 2 hours. The later strength (0.2% proof stress) is 150 MPa or more, and the conductivity is 70% IACS or more. The copper alloy sheet before being heated at 850 ° C. has a strength (0.2% yield strength) of 100 MPa or more and an elongation of 3% or more, and is excellent in bending workability and solder wettability. Even after heating at 850 ° C., many have a strength of 50 MPa or more (0.2% yield strength). In addition, the yield strength value after aging treatment of Example 6 (Co and P contents close to the lower limit values) was 162 MPa, and the hardness was Hv83 (measured at a test force of 0.49 N).

On the other hand, the copper alloy sheets of Comparative Examples 1 to 8 shown in Tables 2 and 4 are inferior in some characteristics as shown below.
In Comparative Example 1, since the Co content is excessive, bending workability is inferior, and the strength and electrical conductivity after aging treatment are low.
In Comparative Example 2, since the P content was excessive, cracks occurred during hot rolling, and it was not possible to proceed to the process after hot rolling.
In Comparative Example 3, [Co] / [P] is high, and the strength and conductivity after the aging treatment are low.
In Comparative Example 4, [Co] / [P] is low, and the strength and conductivity after aging treatment are low.
In Comparative Example 5, the Zn content was excessive and the solder wettability was poor as described above.
In Comparative Example 6, since the sum of elements other than the main elements (Al, Mn, etc.) was excessive, the electrical conductivity after the aging treatment was low.
Since the comparative example 7 lacked P content, the intensity | strength and electrical conductivity after an aging treatment are low.
In Comparative Example 8, since the Co content was insufficient, the strength after the aging treatment was low.

Of the copper alloy plates shown in Tables 1 and 2, representative examples (Examples 2 and 10, Comparative Examples 3 and 4) were heated at 1000 ° C. for 30 minutes and then water-cooled, and further heated at 500 ° C. for 2 hours (aging treatment). Then, using the copper alloy plate as a test material, each measurement test of conductivity and mechanical properties was performed by the method described in Example 1. The results are shown in Table 5.

As shown in Table 5, in Examples 2 and 10, the strength (0.2% yield strength) after heating at 1000 ° C. for 30 minutes and then aging treatment was 150 MPa or more, and the conductivity was 70% IACS or more. is there. When the individual numerical values shown in Table 5 are compared with the measurement results (see the table) after heating at 850 ° C. for 30 minutes and then aging treatment, the numerical values are not significantly different.
On the other hand, in Comparative Examples 3 and 4, the strength and conductivity after heating at 1000 ° C. for 30 minutes and then aging treatment reached the standard (0.2% proof stress is 150 MPa or more, conductivity is 70% IACS or more). Absent.

The disclosure of the present specification includes the following aspects.

Aspect 1:
Co: 0.05 to 0.9 mass%, P: 0.01 to 0.25 mass%, the balance is made of Cu and inevitable impurities, the Co content is [Co], and the P content is [P]. [Co] / [P] is 2 to 6, 0.2% proof stress is 100 MPa or more, elongation is 3% or more, has excellent bending workability, is heated at 850 ° C. for 30 minutes and then water-cooled. Then, after aging treatment at 500 ° C. for 2 hours, the 0.2% proof stress is 150 MPa or more and the conductivity is 70% IACS or more. A copper alloy sheet for a heat-dissipating component, characterized by including a process for aging and an aging treatment.

Aspect 2:
Furthermore, the copper alloy plate for heat-radiating components described in the aspect 1 is characterized by containing not more than 1.0% by mass of Zn (not including 0% by mass).

Aspect 3:
Further, it is characterized by containing 0.005 to 0.5 mass% in total of one or more of Fe, Ni, Sn, Si, Al, Mn, Cr, Ti, Zr, Ag, and Mg. The copper alloy plate for heat radiating components described in the aspect 1 or 2.

Aspect 4:
After processing the copper alloy plate for a heat-dissipating part described in any one of the aspects 1 to 3 into a predetermined shape, a process of heating to 600 ° C. or higher is performed, and then an aging treatment is performed without adding plastic processing to 150 MPa or higher A heat radiating component manufacturing method comprising obtaining a heat radiating component having a 0.2% proof stress and a conductivity of 70% IACS or higher.

Aspect 5:
After the aging treatment, the Sn covering layer is formed on at least a part of the outer surface of the heat dissipating component.

Aspect 6:
After the aging treatment, the Ni covering layer is formed on at least a part of the outer surface of the heat dissipating part.

This application is accompanied by a priority claim based on Japanese Patent Application No. 2016-190664, whose application date is September 29, 2016. Japanese Patent Application No. 2016-190664 is incorporated herein by reference.

Claims

Co: 0.05 to 0.9 mass%, P: 0.01 to 0.25 mass%, the balance is made of Cu and inevitable impurities, the Co content is [Co], and the P content is [P]. [Co] / [P] is 2-6, 0.2% proof stress is 100 MPa or more, elongation is 3% or more, has excellent bending workability, is heated at 850 ° C. for 30 minutes and then water-cooled. Then, after aging treatment at 500 ° C. for 2 hours, the 0.2% proof stress is 150 MPa or more and the conductivity is 70% IACS or more. A copper alloy sheet for a heat-dissipating component, characterized in that the process includes an aging process and an aging treatment.
Furthermore, the copper alloy plate for heat-radiating components according to claim 1, further comprising 1.0% by mass or less (not including 0% by mass) of Zn.
Further, it is characterized by containing 0.005 to 0.5 mass% in total of one or more of Fe, Ni, Sn, Si, Al, Mn, Cr, Ti, Zr, Ag, and Mg. The copper alloy plate for heat radiating components according to claim 1.
Further, it is characterized by containing 0.005 to 0.5 mass% in total of one or more of Fe, Ni, Sn, Si, Al, Mn, Cr, Ti, Zr, Ag, and Mg. The copper alloy plate for heat radiating components according to claim 2.
A copper alloy plate for a heat dissipation component according to any one of claims 1 to 4 is processed into a predetermined shape, and then subjected to a process of heating to 600 ° C or higher, followed by an aging treatment without applying plastic processing, and 150 MPa A method of manufacturing a heat dissipation component, characterized by obtaining a heat dissipation component having the above 0.2% proof stress and a conductivity of 70% IACS or higher.
6. The method of manufacturing a heat dissipation component according to claim 5, wherein an Sn coating layer is formed on at least a part of the outer surface of the heat dissipation component after the aging treatment.
6. The method of manufacturing a heat dissipation component according to claim 5, wherein a Ni coating layer is formed on at least a part of the outer surface of the heat dissipation component after the aging treatment.
A heat dissipating part manufactured from the copper alloy plate for heat dissipating parts according to any one of claims 1 to 4 and subjected to an aging treatment after a process of heating to 600 ° C or higher.
The heat dissipating component according to claim 8, wherein an Sn coating layer is formed on at least a part of the outer surface.
The heat dissipating component according to claim 8, wherein a Ni coating layer is formed on at least a part of the outer surface.