TWI628407B - Copper alloy plate and coil for heat dissipation parts - Google Patents

Abstract

The copper alloy plate for heat dissipation parts disclosed in the present invention contains Fe: 0.01 to 1.0 mass%, P: 0.01 to 0.20 mass%, Zn: 0.01 to 1.0 mass%, and Sn: 0.01 to 0.15 mass%, and the remainder is Cu. And the inevitable impurities. The tensile strength in the parallel direction of rolling is 410 MPa or more, the endurance is 390 MPa or more, and the elongation is 5% or more; the tensile strength in the direction perpendicular to the rolling is 420 MPa or more, the endurance is 400 MPa or more, and the elongation is 3% or more; The ratio is 75% IACS or more; the ratio R/t of the bending radius R to the sheet thickness t is set to 0.5, and the bending line is set to the right angle direction of the rolling to bend at a 90-degree bending limit. 70 mm or more; the bending line is set to a right angle direction for bending, and the bending width of the bending process is 20 mm or more.

Description

Copper alloy plate and coil for heat dissipation parts

The present invention relates to a copper alloy plate used for a heat dissipating component for dissipating heat of a CPU, a liquid crystal, or the like mounted on an electronic device such as a personal computer, a tablet terminal, a smart phone, a mobile phone, or a digital camera.

In an electronic device such as a personal computer, a tablet terminal, a smart phone, a mobile phone, a digital camera, a digital camera, or the like, a heat dissipating component that dissipates heat generated by an electronic component such as a CPU, a liquid crystal, or an image sensor mounted thereon is used. . The heat dissipating component is used to prevent excessive temperature rise of the electronic component and prevent thermal runaway of the electronic component so that it functions normally. The heat-dissipating parts are made of raw materials such as pure copper with high thermal conductivity, stainless steel with excellent strength and corrosion resistance, nickel silver, and lightweight aluminum alloy. These heat dissipating components not only function as a heat dissipating function, but also function as a structural member that protects the mounted electronic components from the forces applied to the electronic device.

For electronic components mounted on electronic equipment, high speed and high functionality are required, and the density of electronic components continues to grow. Therefore, the amount of heat generated by the electronic component is rapidly increased. In addition, in electronic machines Under the requirements of miniaturization, thinning, and light weight, thin-layering is also required for heat-dissipating parts. However, even if the heat dissipating component is thinned, it is required to maintain heat dissipation performance and structural strength.

The sheet of the raw material of the heat dissipating component is formed into a heat dissipating component by plastic working such as hemming bending (close bending), 90° bending, drawing, and the like. In the bending process, the width of the bent portion (the length of the bending line) is not more than several millimeters in the lead frame and the terminal. However, in the heat dissipating component, the width of the bent portion is not less than 20 mm. The larger the bending width, the less severely the bending workability of the sheet material is known, and the sheet for heat dissipating parts is required to have more severe bending workability than the sheet for the terminal and the lead frame.

As a raw material of the heat dissipating component, pure copper has excellent thermal conductivity, but has low strength and cannot thin the heat dissipating component. Stainless steel and nickel silver have low thermal conductivity (2~3% IACS) and are not suitable for heat dissipation parts for electronic parts with large heat dissipation. In aluminum alloys, the strength and thermal conductivity are insufficient. On the other hand, in the case of the copper alloy, there is disclosed an Fe-P-based copper alloy for a heat dissipating component, but there is no bending workability in the bending process in which the width of the bent portion is large. reveal.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2003-277853

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2014-189816

According to an embodiment of the present invention, it is an object of the invention to provide a copper alloy sheet for a heat dissipating component which has high strength and excellent bending workability in a bending process having a large width of a bent portion and heat dissipation.

A copper alloy sheet for a heat dissipating component according to an embodiment of the present invention is characterized in that it contains Fe: 0.01 to 1.0 mass%, P: 0.01 to 0.20 mass%, Zn: 0.01 to 1.0 mass%, and Sn: 0.01 to 0.15 mass%. And the remainder is composed of Cu and unavoidable impurities; the tensile strength in the parallel direction of rolling is 410 MPa or more, the yield strength is 390 MPa or more, and the elongation is 5% or more; The tensile strength is 420 MPa or more, the relief strength is 400 MPa or more, the elongation is 3% or more; the electrical conductivity is 75% IACS or more; the ratio of the bending radius R to the thickness t is R/t is set to 0.5, and the bending line is set. The bending width of the bending process is 70 mm or more when the bending is performed at a right angle of 90 degrees, and the bending width is 20 mm or more when the bending line is set to a right angle direction for bending.

The copper alloy may have one or more of Co, Al, Cr, Mg, Mn, Ca, Pb, Ni, Ti, Zr, Si, and Ag in a total amount of 0.3 mass% or less (Ni content is less than 0.1). Mass%).

On the surface of the above copper alloy sheet, a surface coating layer may be formed by plating or the like as needed, thereby improving corrosion resistance. Surface coating, can be considered A plating layer composed of any one of a Sn layer, a Cu-Sn alloy layer, Ni, Co, Fe, a Ni-Co alloy, and a Ni-Fe alloy.

According to the embodiment of the present invention, it is possible to provide a strength as a structural member, particularly capable of withstanding deformation and drop impact strength, withstand bending workability for processing into a complicated shape, and with respect to heat from a semiconductor element or the like. Copper alloy plate for heat dissipation parts with high heat dissipation. Further, when the surface coating layer is formed on the copper alloy sheet, the corrosion resistance can be improved, and the performance as a heat dissipating member can be prevented from being lowered even in a severe environment.

1‧‧‧V word module

2‧‧‧ Pressing the mold

3‧‧‧Test strips

Fig. 1 is a view showing the test method of the 90 degree bending test of the examples.

Hereinafter, the copper alloy sheet for heat dissipation parts according to the embodiment of the present invention will be described in detail.

<Composition of Copper Alloy Sheet>

The composition of the copper alloy contains Fe: 0.01 to 1.0 mass%, P: 0.01 to 0.20 mass%, Zn: 0.01 to 1.0 mass%, and Sn: 0.01 to 0.15 mass%, and the remainder consists of Cu and unavoidable impurities. The copper alloy may contain one or two kinds of Co, Al, Cr, Mg, Mn, Ca, Pb, Ni, Ti, Zr, Si, and Ag in a total amount of 0.3 mass% or less (excluding 0 mass%) as needed. The above is an accessory component (when Ni is contained, the Ni content is less than 0.1 mass% (excluding 0 mass%)).

Fe can increase the strength of the copper alloy by depositing an intermetallic compound with P described later. When the Fe content is less than 0.01 mass%, the amount of precipitation of the Fe-P compound is small, and the desired strength cannot be obtained. On the other hand, when the Fe content exceeds 1.0 mass%, the desired conductivity cannot be obtained. Therefore, the Fe content is set to 0.01 to 1.0 mass%. The lower limit of the Fe content is preferably 0.03 mass%, more preferably 0.05 mass%, and the upper limit of the Fe content is preferably 0.8 mass%, and particularly preferably 0.6 mass%.

P, forming an intermetallic compound with Fe and decomposing the parent phase of Cu, thereby increasing the strength. When the P content is less than 0.01 mass%, the precipitation of the Fe-P compound is insufficient, and the desired strength cannot be obtained. On the other hand, when the P content exceeds 0.20 mass%, the desired conductivity cannot be obtained. Therefore, the P content is set to 0.01 to 0.20 mass%. The lower limit of the P content is preferably 0.03 mass%, more preferably 0.05 mass%, and the upper limit of the P content is preferably 0.17 mass%, and particularly preferably 0.15 mass%.

Zn has the function of improving the heat-resistant peeling property of the solder, and has the function of maintaining the solder joint reliability at the time of component assembly and over time. However, when the content of Zn is less than 0.01 mass%, the heat-resistant peeling property of the solder cannot be sufficiently satisfied, and when it exceeds 1.0 mass%, the electrical conductivity and thermal conductivity of the copper alloy are deteriorated. The lower limit of the Zn content is preferably 0.03 mass%, particularly preferably The upper limit of the Zn content is preferably 0.05 mass%, and particularly preferably 0.6 mass%.

Sn is beneficial for increasing the strength of the copper alloy, and when the content of Sn is less than 0.01 mass%, sufficient strength cannot be obtained. Further, when the content of Sn exceeds 0.15 mass%, the electrical conductivity and thermal conductivity of the copper alloy are deteriorated. Therefore, the content of Sn is set to be 0.01 to 0.15 mass%. The lower limit of the Sn content is preferably 0.03 mass%, more preferably 0.05 mass%, and the upper limit of the Sn content is preferably 0.12 mass%, and particularly preferably 0.10 mass%.

In addition, Co, Al, Cr, Mg, Mn, Ca, Pb, Ni, Ti, Zr, Si, and Ag added as auxiliary components have the strength of the copper alloy and the hot rolling ductility at the time of manufacture. effect. However, when the total content of one or two or more of the above-mentioned subcomponents exceeds 0.3 mass%, the strength of the copper alloy can be increased, but the electrical conductivity and thermal conductivity are lowered. Therefore, the total content of the above-mentioned subcomponents is set to 0.3 mass% or less (excluding 0 mass%). However, when Ni is contained, the Ni content is set to be less than 0.1 mass% (excluding 0 mass%).

<Characteristics of Copper Alloy Sheets>

The heat dissipating component must have strength as a structural member, especially the strength that can withstand deformation and drop impact. If the tensile strength of the copper alloy sheet in the parallel direction is 410 MPa or more, the relief strength is 390 MPa or more, and the tensile strength in the right angle direction is 420 MPa or more, and the relief strength is 400 MPa or more, even if the heat dissipation part is thin. It also ensures the strength as a structural member. In addition, if the copper alloy sheet is rolled in parallel direction When the elongation is 5% or more and the elongation in the right-angle direction is 3% or more, the molding processability is not particularly caused when the heat-dissipating component is molded from the copper alloy sheet by bending or drawing. problem. The drop strength is the tensile strength at which a permanent elongation of 0.2% is produced in the tensile test.

When a heat-dissipating part is formed using a copper alloy plate as a raw material, in general, a copper alloy plate must have excellent bending workability. When the ratio R/t of the bending radius R to the thickness t is set to 0.5 and the bending line is set to the right angle of the rolling to perform the 90 degree bending of the copper alloy sheet, the bending width of the bending processing is 70 mm or more. Further, when the bending line is set to the right angle direction for bending and the bending width of the bending process is 20 mm or more, the production of the heat dissipating member is not hindered. When the bending width limit of the copper alloy sheet does not reach the above value, cracks or cracks may occur in the bent portion in the procedure for manufacturing the heat dissipating member, and it is difficult to form a complicated shape.

When the heat generated from the semiconductor element or the like is absorbed and released to the outside, the conductivity of the copper alloy sheet for the heat dissipating component is preferably more than 75% IACS, and the thermal conductivity exceeds 300 W/m‧K. The thermal conductivity can be converted from the conductivity according to the Wiedemann-Franz rule. If the conductivity is 75% IACS or more, the thermal conductivity is 300 W/m‧K or more.

<Method of Manufacturing Copper Alloy Sheet>

The copper alloy sheet according to the embodiment of the present invention can be produced by a process of melt casting, homogenization treatment, hot rolling, cold rolling, recrystallization tempering, cold rolling, aging tempering, and cold rolling.

The appropriate melt casting and hot rolling conditions are as follows, whereby precipitation of coarse Fe, Fe-P, Fe-P-O, or the like can be prevented.

In the melt casting, Fe is added to a copper alloy melt of 1200 ° C or higher and melted, and then the melt temperature is maintained at 1200 ° C or higher and cast. The cooling of the ingot is carried out at a cooling rate of 1 ° C /sec or more at the time of solidification (when solid-liquid coexisting) and after solidification. Therefore, in continuous casting or semi-continuous casting, it is necessary to sufficiently perform primary cooling in the mold and secondary cooling directly under the mold.

In the homogenization treatment, the ingot is heated at 900 to 1000 ° C for 0.5 to 5 hours, and hot rolling is started at this temperature. The hot rolling end temperature is 650 ° C or higher, preferably 700 ° C or higher, and immediately after the hot rolling is completed, it is rapidly cooled (preferably water-cooled) at a cooling rate of 20 ° C /sec or more.

The processing rate per hot pass of the hot rolling is not only the hot rolling material, but also affects the toughness of the final product, homogenization and compaction of the structure. When the copper alloy sheet for a heat dissipating component according to the embodiment of the present invention is produced, the average value of the processing ratio per one pass of the hot rolling is preferably 20% or more, and the maximum processing ratio is 25% or more.

The reason is as follows.

When the rolling according to the rolling roll is applied, it is known that the compressive stress acts on the rolling direction from the surface of the ingot to the depth hc, and the tensile stress is in the rolling direction. In the rolling direction, it acts on the region from the depth hc to the central portion of the thickness of the ingot. In the region where the compressive stress acts, the shallower the depth from the surface, the greater the compressive stress. In the region where the tensile stress acts, the center of the thickness of the ingot is more Recently, the tensile stress is larger.

The change from the compressive stress to the depth hc of the tensile stress can be obtained by calculation of the rolling roll diameter and the rolling amount (thickness on the inlet side of the rolling roll - the thickness of the exit side of the rolling roll) (OGMuzalevskii) :Stal in English, June (1970), p. 455). According to this calculation formula, when the rolling roll diameter is constant, the larger the rolling reduction rate, the larger the hc. That is, the action area of the tensile stress inside the ingot becomes small.

In the ingot, there are defects such as micro-cavities, alloying elements, micro-segregation and intermediaries caused by shrinkage cavities or gases, and the defects are closer to the central portion of the ingot thickness. The complete elimination of these defects is extremely difficult to achieve in industry.

When the ingot is heated for the homogenization treatment, although the microsegregation is eliminated by the diffusion of the alloying elements, the microcavity inside the ingot is not eliminated. Instead, the Kirkendall Void is formed by homogenization treatment, so that the gas component dissolved in the ingot is precipitated at the interfacial-base metal interface or grain boundary, and therefore, the microcavity cavity inside the ingot is increased. The tendency.

As described above, since the microcavity and the interposer are present inside the ingot, it is preferable to increase the processing rate per one pass of the hot rolling in order to improve the internal quality of the hot rolled material. Therefore, the processing ratio per pass of the hot rolling is preferably 20% or more on average, and the maximum processing ratio is 25% or more. In addition, the average processing rate per one pass of the hot rolling is 25% or more, and the maximum processing rate is 30% or more. In addition, in practice, the processing rate per hot pass of the hot rolling is 35% or less, and the maximum processing rate is 45% or less.

Further, by increasing the processing rate per one pass of the hot rolling, the number of hot rolling delays can be reduced, and the hot rolling can be terminated at a higher temperature. Therefore, quenching (annealing) can be performed from a higher temperature, and the amount of solid solution of the alloying elements in the hot rolled material can be increased. As a result, the uniformity of the structure of the copper alloy sheet (product) after the cold rolling and the heat treatment which are successively performed can be improved, and good bending workability, drawing workability, and stretch workability can be obtained.

On the other hand, when a large rolling pressure is applied to the ingot at the initial stage of the hot rolling, cracking may occur in the rolling surface near the end surface of the ingot. Therefore, in actual operation, from the first pass to the third pass of the hot rolling, the rolling rate of the light working rate is generally performed.

However, when the rolling rate of the light working rate is continued in the initial stage of the hot rolling, the tensile stress acts on the region from the depth hc to the center of the ingot at each rolling pass, so that the inside of the ingot is The gap between the microcavity cavity or the intermediate-base material interface is increased to cause a fine crack. Then, even if the processing rate per pass is increased, the crushing delay of the generated crack is delayed, resulting in a decrease in the internal quality of the hot rolled material. For the copper alloy sheet produced by cold rolling and heat treatment of such a hot rolled material, it is difficult to perform severe processing such as wide bending, hemming bending, drawing processing, and stretching processing with a small bending R. .

Therefore, in the case of producing the copper alloy sheet for a heat dissipating component according to the embodiment of the present invention, it is preferable to set the average processing ratio of the first pass to the third pass to 10% in the initial stage of the hot rolling. Above 35%. The average processing ratio from the first pass to the third pass is preferably 12% or more and 30% or less, more preferably 15% or more and 25% or less.

When the processing rate at the initial stage of hot rolling is increased, hot rolling cracking of the ingot is likely to occur. In order to avoid this, it is preferred to roll the end face of the ingot by an edger before the start of the first pass. . By utilizing the edging device, the processing rate at the initial stage of rolling can be increased, and the occurrence of internal cracking at the initial stage of rolling can be prevented or reduced.

After the hot rolling is delayed, both sides are removed and cold rolling is performed at an appropriate rolling rate.

The recrystallization tempering is carried out in a continuous tempering furnace at a temperature ranging from 600 ° C to 850 ° C for 5 to 30 seconds so that the average crystal grain size after recrystallization and tempering is less than 20 μm. This recrystallization tempering is carried out to improve the elongation and bending workability of the copper alloy sheet (product). When the temperature of recrystallization tempering is less than 600 ° C or the holding time is less than 5 seconds, recrystallization is insufficient to deteriorate the bending workability of the copper alloy sheet (product). On the other hand, when the temperature of the recrystallization tempering exceeds 850 ° C or the holding time exceeds 30 seconds, the recrystallized grains are coarsened (the average crystal grain size is coarsened to 20 μm or more), and the copper alloy sheet (product) cannot obtain sufficient strength. . Further, in the wide bending, the bending workability is deteriorated.

After recrystallization and tempering, cold rolling can be carried out as needed. This cold rolling delay is performed, and the processing rate can be appropriately set within a range of 0 to 40% in such a manner that a predetermined processing ratio and a product sheet are obtained in the finish cooling and rolling described later.

Then aging and tempering. The aging and tempering conditions are preferably in the range of 1 to 10 hours at 400 to 575 °C. When the temperature of the aging treatment is less than 400 ° C or the holding time is less than 1 hour, the precipitation is insufficient and the copper bonding cannot be improved. The conductivity of the gold plate (product). On the other hand, when the temperature of the aging treatment exceeds 575 ° C or the holding time exceeds 10 hours, the precipitates are coarsened, and the copper alloy sheet (product) cannot obtain sufficient strength.

After aging and tempering, the cold rolling for refining is extended until the target thickness is reached. The rolling rate can be set at 30~85% depending on the product strength of the target.

After the fine cooling and rolling, short-time tempering can be performed as needed. The conditions for this short-term tempering are set at 250 to 450 ° C for 3 to 40 seconds. By performing short-term tempering under these conditions, the strain introduced in the fine cooling rolling is eliminated. In addition, under these conditions, the material does not soften and the strength is reduced less.

<Surface coating of copper alloy sheet>

By forming a surface coating layer on a copper alloy plate by plating or the like, the corrosion resistance of the heat dissipating component can be improved, and the performance as a heat dissipating component can be prevented from being lowered even in a severe environment.

The surface coating layer formed on the surface of the copper alloy sheet is preferably a Sn layer. When the thickness of the Sn layer is less than 0.2 μm, the improvement in corrosion resistance is insufficient, and when it exceeds 5 μm, the productivity is lowered to cause an increase in cost. Therefore, the thickness of the Sn layer is set to 0.2 to 5 μm. The Sn layer contains a Sn metal and a Sn alloy.

The surface coating layer may also form a Cu-Sn alloy layer under the Sn layer. When the thickness of the Cu—Sn alloy layer exceeds 3 μm, the bending workability and the like are lowered. Therefore, the thickness of the Cu—Sn alloy layer is set to 3 μm or less. Further, it is preferable to set the thickness of the Cu-Sn alloy layer to 0.1 μm or more. At this time, the thickness of the Sn layer is set to 0 to 5 μm (including the case where there is no Sn layer), and Cu-Sn is The total thickness of the alloy layer and the Sn layer is set to 0.2 μm or more. The upper limit of the total thickness is set to 8 μm.

In the present specification, the "thickness of the Cu-Sn alloy layer" is a thickness in terms of Sn obtained by measuring the amount of Sn in the Cu-Sn alloy layer using a fluorescent X-ray film thickness meter.

The Cu-Sn alloy layer can be exposed to the surface (refer to JP-A-2006-183068, JP-A-2013-185193, etc.). Since the Cu-Sn alloy layer is a hard Hv: 200 to 400, it has a damage suppression effect by the treatment. The surface exposure of the Cu-Sn alloy layer (the value obtained by multiplying the surface area per unit area exposed by the Cu-Sn alloy layer on the surface of the material by 100) may be 100% or 0%, preferably 50% or less. When there is no Sn layer on the Cu-Sn alloy layer (the thickness of the Sn layer is zero), the surface exposure rate of the Cu-Sn alloy layer is 100%. When the Cu-Sn alloy layer was not exposed, the surface exposure rate of the Cu-Sn alloy layer was 0%.

Below the Cu-Sn alloy layer, a plating layer composed of any one of Ni, Co, Fe, Ni-Co alloy, and Ni-Fe alloy may be formed as the underlayer. When the thickness of the plating layer exceeds 3 μm, the bending workability and the like are lowered, so the thickness is set to 3 μm or less. The thickness of this plating layer is preferably 0.1 μm or more.

A plating layer (excluding a Cu-Sn alloy layer and/or a Sn layer) composed of only Ni, Co, Fe, a Ni-Co alloy, and a Ni-Fe alloy can be formed as a surface coating layer. The thickness of the plating layer is set to 3 μm or less from the viewpoint of preventing deterioration of bending workability and the like. The thickness of this plating layer is preferably 0.1 μm or more.

Each of the surface coating layers described above can be formed by electrolytic plating, reflow plating, electroless plating, sputtering, or the like. The Cu-Sn alloy layer can be formed by applying Sn plating to the copper alloy plate of the base material, or performing Cu plating and Sn plating on the copper alloy base material, performing reflow processing or the like, and reacting Cu with Sn. The heating conditions for the reflow treatment are set to 230 to 600 ° C for 5 to 30 seconds.

[Example 1]

In a small electric furnace, a copper alloy having the composition shown in Nos. 1 to 23 of Table 1 was melted in the atmosphere and melted into an ingot having a thickness of 50 mm, a length of 80 mm, and a width of 200 mm. Then, the ingot was heated at 950 ° C for 1 hour, rolled to a thickness of 12 mm, and immediately immersed in water to be quenched. The hot rolling end temperature was 750 °C. Hot rolling roll, using roller diameter: 450mm Φ. The pass plan of the hot rolling is set to 5 times of refining, which is 50 mm → 42 mm (16.0%) → 34 mm (19.0%) → 26 mm (23.5%) → 18 mm (30.8%) → 12 mm (33.3%). The machining rate is indicated in brackets. The copper alloy of No. 1 to 23 has a hydrogen content of 0.5 to 1.0 mass ppm and an oxygen content of 4 to 18 mass ppm.

[Table 1]

Next, both sides of the hot rolled material were respectively removed by about 1 mm to remove the oxide film, and cold rolling was performed.

Then, recrystallization tempering was performed at 720 ° C for 20 seconds. The plate after recrystallization and tempering is water-cooled. After recrystallization and tempering, the flatness measured on the surface of the board The average crystal grain size (measured by the cutting method defined by JISH0501 in the rolling parallel direction) was less than 20 μm.

Next, after performing a cold rolling elongation of 35% of the working rate, aging tempering was carried out under conditions of 500 ° C × 2 hours. Subsequently, the surface oxide was removed with a dilute sulfuric acid solution, and then a cold rolling was performed at a processing rate of 50% to prepare a copper alloy strip having a thickness of 0.2 mm. After the fine cooling and rolling, a short time tempering was performed at 350 ° C for 30 seconds.

Then, for the copper alloy (No. 24) having the same composition as No. 1, the hot rolling was performed in a different pass plan.

No.24's pass plan is set to 10 times of refining, from 50mm → 46mm (8.0%) → 41mm (10.9%) → 36mm (12.2%) → 31mm (13.9%) → 26mm (16.1%) → 22mm (15.4%)→19mm (13.6%)→16mm (15.8%)→14mm (12.5%)→12mm (14.3%) were implemented. The processing ratio is indicated in parentheses, and the average processing rate per pass is 13.3%. After the completion of the 5 passes, the furnace was again inserted into a furnace at 950 ° C to raise the temperature, and after 10 passes, it was immersed in water to be quenched. The temperature of the hot rolled material shortly after the end of 10 passes was 810 °C. In No. 24, the conditions of the process other than the hot rolling were the same as those of Nos. 1 to 23. In No. 24, after recrystallization tempering, the average crystal grain size measured on the surface of the plate was less than 20 μm (the measurement method was the same as that described previously).

The copper alloy strip (product sheet) obtained through the above process was used as a test material, and mechanical properties, electrical conductivity, bending margin width, and weldability were measured and evaluated by the following methods. In addition, according to the Wiedemann-Franz rule, the thermal conductivity is converted from the conductivity.

These results are shown in Table 2.

<Mechanical characteristics>

JIS No. 5 test piece was collected from each of the test materials so that the longitudinal direction was parallel and perpendicular to the rolling direction, and the tensile test was performed in accordance with the regulation of JIS Z 2241, and the direction parallel to the rolling direction (∥) and the vertical direction were measured. Tensile strength, lodging strength and elongation in the direction of rolling direction (⊥).

<Conductivity>

The conductivity was measured in accordance with the regulations of JISH0505. The measurement of the resistance was carried out using a four-terminal method using double bridge.

<90 degree bend bending margin width>

From the test materials, four-corner test pieces each having a width of 30 mm and a width of 10 to 100 mm (widths of 10, 15, 20, 25 ... every 5 mm to 100 mm) were produced (three for each width). The direction of the side of the test piece having a length of 30 mm was set to be parallel to the rolling direction of the test material. Using this test piece, the V-shaped module 1 and the pressing die 2 shown in Fig. 1 were placed in a hydraulic press, and the ratio R/t of the bending radius R to the thickness t was set to 0.5, and the bending line was set. The direction (the direction perpendicular to the paper surface in Fig. 1) is set to the width direction (Good Way bend) of the test piece 3 to perform the 90-degree bending. The width of the V-shaped module 1 and the pressing mold 2 (the thickness in the direction perpendicular to the paper surface in Fig. 1) was set to 120 mm. Further, the load of the hydraulic press was set to 1000 kgf (9800 N) per 10 mm of the width of the test piece.

After the bending test, the entire outer side of the bent portion of the test piece was observed with a 100-fold optical microscope, and the crack of one of the three test pieces was not observed as one pass, and the other was unacceptable. The maximum width of the qualified test piece was set to the bending margin width of the test material.

<Bending and bending width of dense bending>

A 4-sided test piece having a width of 30 mm and a width of 5 to 50 mm (widths of 5, 10, 15, 20, ..., every 5 mm to 50 mm) is produced from the test material in the same manner as the 90-degree bending. (each width is 3). The direction of the side of the test piece having a length of 30 mm was set to be parallel to the rolling direction. Using this test piece, the ratio R/t of the bending radius R to the thickness t was set to 2.0, and the direction of the bending line was set to the width direction of the test piece (Good Way), and was roughly bent according to the regulation of JIS Z2248. After 170 degrees, a close bend is made.

After the bending test, the presence or absence of cracking of the bent portion was observed with a 100-fold optical microscope, and it was found that none of the three test pieces failed to be observed at one place, and otherwise it was unacceptable. The maximum width of the qualified test piece was set to the bending margin width of the test material.

<welding evaluation>

The solder infiltration test according to the arc-shaped soldering test method was carried out using Sn-3Ag-0.5Cu solder. The active flux was dip-coated on a test piece of a size of 10 mm × 30 mm, and then immersed in a solder bath having a bath temperature of 265 ° C (immersion speed: 25 mm/sec, immersion depth: 12 mm, dipping) Time: 5.0 sec), and the zero crossing time (solder infiltration time) was measured. Those whose solder infiltration time is less than 1.5 seconds are evaluated as qualified (○), and those who are 1.5 seconds or longer are evaluated as unacceptable (×).

As shown in Tables 1 and 2, the alloy composition specified in the embodiment of the present invention has a hot rolling schedule in a preferred range (the average processing rate per pass is 20% or more). No. 1 to 14 having a maximum processing ratio of 25% or more, the tensile strength, the elongation strength, the elongation, the electrical conductivity, the 90-degree bending, and the bending margin width of the dense bending satisfy the present invention. The provisions of the embodiment.

On the other hand, No. 15 to 23, which does not have the alloy composition specified in the embodiment of the present invention, and No. 24, which has a hot rolling pass, which is out of the preferred range, has tensile strength, lodging strength, and elongation. Any one or more of the rate, the electrical conductivity, the 90-degree bending, the bending-limited width of the adhesive bending, and the weldability do not satisfy the specifications of the embodiment of the present invention.

No. 15, the Fe content is excessive, and the electrical conductivity and thermal conductivity are low.

No. 16, the content of Fe is insufficient, the tensile strength and the drop strength are low, and the electrical conductivity and thermal conductivity are low.

No. 17, P content is excessive, and electrical conductivity and thermal conductivity are low.

No. 18, P content is insufficient, and tensile strength and lodging strength are low.

No. 19, the Zn content is excessive, and the electrical conductivity and thermal conductivity are low.

No. 20, the Zn content was insufficient, and the weldability was poor.

No. 21, excess Sn content, low electrical conductivity and thermal conductivity, and the bending width of the 90-degree bend and the tight bend are also poor.

No. 22, the Sn content was insufficient, and the tensile strength and the fall strength were low.

No. 23, the total content of the subcomponents was excessive, and the electrical conductivity and thermal conductivity were low.

No.24, since the hot rolling schedule is out of the better range, The 90 degree bend and the tight bend have a small width.

[Embodiment 2]

The copper alloy of the composition (two kinds) shown in Table 3 was melted and melted into an ingot having a thickness of 200 mm, a width of 500 mm, and a length of 5000 mm. Then, the ingot was heated at 950 ° C for 1 hour, rolled to a thickness of 12 mm, and immediately immersed in water to be quenched. The hot rolling end temperature was 750 °C. Each time the hot rolling is performed, the thickness of the sheet is gradually thinned, and the temperature of the hot rolling is gradually decreased. The length of the hot rolled material at the end of the hot rolling is more than 80 m, and the hot rolling end temperature is different at both ends, but the hot rolling end temperature is determined at the lower end. temperature. In this embodiment, the difference in the hot rolling end temperature at both end portions is about 20 °C. The hot rolling schedule is set to 9 passes, 200mm → 177mm (11.5%) → 156mm (11.9%) → 123mm (21.2%) → 98mm (20.3%) → 72mm (26.5%) → 46mm (36.1%) → 27 mm (41.3%) → 18 mm (33.3%) → 12 mm (33.3%) was carried out. The processing ratio is indicated in parentheses, and the average processing rate per pass is 26.2%.

Next, both sides of the hot rolled material were respectively removed by about 1 mm to remove the oxide film, and cold rolling was performed.

The two kinds of cold rolled materials are divided into three (No. 25~27, 28~30), and No.25 and 28 are recrystallized and tempered at 720 °C for 20 seconds, and water cooling. No.26,29 Recrystallization tempering and water cooling were carried out, and No. 27 and 30 were subjected to recrystallization tempering and water cooling at 920 ° C for 30 seconds. In this stage, the average crystal grain size of the surface of No. 25-30 was determined (as specified by JISH0501). The cutting method is performed in the parallel direction of rolling. No. 25 and 27 which were recrystallized and tempered under appropriate conditions had an average crystal grain size of 10 μm, and No. 26 and 29 which were not subjected to recrystallization and tempering. Since the fiber structure was maintained, the average crystal grain size could not be measured. Further, the average crystal grain size of No. 27 and 30 in which the temperature of recrystallization tempering was too high was 30 μm, which was larger than an appropriate level (less than 20 μm).

Next, the sheets of Nos. 25 to 30 were subjected to cold rolling, aging tempering, pickling, fine cooling and rolling, and short-time tempering in the same processes and conditions as in [Example 1].

A copper alloy strip (product sheet) of No. 25 to 30 was used as a test material, and mechanical properties, electrical conductivity, bending margin width, and weldability were measured and evaluated by the same method as in Example 1. In addition, according to the Wiedemann-Franz rule, the thermal conductivity is converted from the conductivity. These results are shown in Table 4.

[Table 4]

No. 25 to 30 have the alloy composition defined in the embodiment of the present invention. As shown in Table 4, No. 25 and 28, which were subjected to recrystallization and tempering under appropriate conditions, were subjected to tensile strength, lodging strength, elongation, electrical conductivity, 90-degree bending, and bending of a dense bend. The width is limited to satisfy the requirements of the embodiments of the present invention. On the other hand, No. 25 and 28 which are not subjected to recrystallization and tempering, and No. 26 and 29 which are not suitable for recrystallization and tempering, the 90-degree bending and the bending margin limit of the dense bending, The provisions of the embodiments of the present invention are not satisfied.

[Example 3]

Next, a copper alloy strip (product sheet) of No. 7 shown in Table 1 was used as a test material, and one or two of Ni plating, Cu plating, Sn plating, and Ni-Co alloy plating were applied to the surface at a predetermined thickness. More than one species. These are all electrolytic plating, the plating bath composition and plating conditions of each plating are shown in Table 5, and the thickness of each plating layer is shown in Table 6.

No. 31 to 33, 36, 37, and 39 to 42 of Table 6 were subjected to Ni plating or Ni-Co plating (or not), and Cu plating and Sn plating were performed, followed by reflow processing. The thickness of each plating layer is the thickness after the reflow treatment. The reflow process is carried out at 450 ° C for 15 seconds, and the cooling system following the reflow process is configured to be water-cooled. This is because the reflow process is a general condition. The Cu-Sn layers of No. 31 to 33, 36, 37, and 39 to 42 are formed by reacting Cu electroplated Cu with Sn-plated Sn by a reflow process. Cu plating is destroyed by reflow processing.

No. 38 in Table 6 is for Ni plating, Cu plating, and Sn plating. After the passage of time, Cu electroplated Cu reacts with Sn-plated Sn to form a Cu-Sn alloy layer, and Cu plating is eliminated. The thickness of the Sn plating layer is the thickness after the Cu plating is extinguished.

The thickness of each plating layer was measured by the following method.

<Sn layer>

First, a total thickness of the Sn layer (including the total thickness of the Sn layer of the Cu-Sn alloy layer) was measured using a fluorescent X-ray film thickness meter (Seiko Instruments Co., Ltd.; type SFT3200). Then, the mixture was immersed in a stripping solution containing p-nitrophenol and sodium hydroxide as a main component for 10 minutes, and the Sn layer was peeled off, and then the amount of Sn in the Cu-Sn alloy layer was measured using a fluorescent X-ray film thickness meter. The thickness of the Sn layer was calculated by subtracting the amount of Sn in the Cu-Sn alloy layer from the total thickness of the Sn layer thus obtained.

<Cu-Sn alloy layer>

After immersing in a peeling liquid containing p-nitrophenol and sodium hydroxide as a main component for 10 minutes, the Sn layer was peeled off, and the amount of Sn in the Cu-Sn alloy layer was measured using a fluorescent X-ray film thickness meter. The thickness of the Cu-Sn alloy layer is a thickness in terms of Sn.

<Ni layer and Ni-Co layer>

The thickness of the Ni layer and the Ni-Co alloy layer was measured using a fluorescent X-ray film thickness meter.

<Cu-Sn alloy layer exposure rate>

The surface of each test material (the one in which the Cu-Sn alloy layer was formed) after plating was observed by SEM (scanning electron microscope), and the surface composition image (×200) obtained in any three fields of view was binarized. deal with. Then by image Analytically, the average value of the surface exposure of the material of the Cu-Sn alloy coating layer in the above three fields of view was measured.

A test piece was produced from each of the test materials of Nos. 31 to 43, and the corrosion resistance and the bending workability were measured by the following methods.

<Corrosion resistance>

The corrosion resistance of the test material after electroplating was evaluated by a salt spray test. 99.0% deionized water (manufactured by Wako Pure Chemical Industries, Ltd.) containing 5% by mass of NaCl was used, and the test conditions were as follows: test temperature: 35 ° C ± 1 ° C, spray liquid pH: 6.5 to 7.2, spray pressure: 0.098 ±0.01 MPa, after 72 hours of spraying, it was washed with water and dried. Next, the surface of the test piece was observed with a stereoscopic microscope, and the presence or absence of corrosion (base metal corrosion and pitting corrosion of the plated surface) was observed.

<Evaluation of Bending Processability of Electroplating Materials>

A tetragonal test piece having a length of 30 mm and a width of 20 mm was produced from each of the test materials after plating (three test materials were used). The direction of the side of the test piece having a length of 30 mm was set to be parallel to the rolling direction of the test material (base metal). Using this test piece, the V-shaped module 1 and the pressing die 2 shown in Fig. 1 were placed in a hydraulic press, and the ratio R/t of the bending radius R to the thickness t was set to 2.0, and the bending line was set. The direction is set to be perpendicular to the direction of the rolling direction of the base material to perform a 90 degree bend. The load of the hydraulic molding machine was set to 1000 kgf (9800 N) per 10 mm of the width of the test piece.

After the bending test, the test piece was observed with a 100-fold optical microscope. The entire outer side of the bent portion was determined to have no crack at all of the three test pieces, and it was judged that there was crack even if one of the cracks was observed.

As shown in Fig. 6, in the plating composition and the thickness of each plating layer specified in the embodiment of the present invention, No. 31 to 40 were observed, and no corrosion of the base material was observed in the salt spray test, and it was not observed in the bending workability test. A rupture was observed. No. 33 of the underlayer composed of the Ni layer or the Ni-Co alloy layer was not formed, and No. 37 in which the Cu-Sn alloy layer was not exposed to the surface without leaving the Sn layer, although no corrosion of the base material was observed, but observation was observed. To pitting corrosion (the phenomenon that the surface of the coating layer is corroded in a punctiform manner).

On the other hand, the thickness of the plating layer was deviated from No. 41 to 43 of the embodiment of the present invention, and the base material was observed to be corroded in the salt spray test or cracked in the plating in the bending workability test.

In No. 41, the total thickness of the Cu-Sn alloy layer and the Sn layer was insufficient, and the base material was corroded.

No. 42 and 43, the thickness of the Cu-Sn alloy layer or the Ni layer was thick, and cracking occurred in the plating in the bending workability test.

The present invention relates to the following aspects.

Pattern 1:

A copper alloy plate for heat dissipating parts, characterized by containing Fe: 0.01~1.0 mass%, P: 0.01~0.20 mass%, Zn: 0.01~1.0 mass%, and Sn: 0.01~0.15 mass%, and the remaining part is Cu and inevitable impurities; The tensile strength in the parallel direction of rolling is 410 MPa or more, the undulation strength is 390 MPa or more, and the elongation is 5% or more; the tensile strength in the direction perpendicular to the rolling is 420 MPa or more, the lodging strength is 400 MPa or more, and the elongation is 3% or more. The conductivity is 75% IACS or more; the ratio R/t of the bending radius R to the thickness t is set to 0.5, and the bending line is set to the right angle of the rolling to bend the processing when the bending is 90 degrees. The width is 70 mm or more; the bending line is set to a right angle direction for bending, and the bending width of the bending process is 20 mm or more.

Pattern 2:

The copper alloy sheet for a heat dissipating component according to the aspect 1, wherein the total amount is 0.3 mass% or less, and one or two of Co, Al, Cr, Mg, Mn, Ca, Pb, Ti, Zr, Si, and Ag are further contained. More than one species.

Figure 3:

The copper alloy sheet for a heat dissipating component according to the aspect 1, wherein the total amount is 0.3 mass% or less, and one or two of Co, Al, Cr, Mg, Mn, Ca, Pb, Ti, Zr, Si, and Ag are further contained. Above and below 0.1% of Ni.

Figure 4:

The copper alloy plate for a heat dissipating component according to any one of the above aspects, wherein a Sn layer having a thickness of 0.2 to 5 μm is formed on the surface.

Figure 5:

The copper alloy plate for heat dissipating parts according to any one of the above aspects, wherein a Cu-Sn alloy layer having a thickness of 3 μm or less and a Sn layer having a thickness of 0 to 5 μm are sequentially formed on the surface, Cu-Sn alloy. The total thickness of the layer and the Sn layer is 0.2 μm or more.

Figure 6:

The copper alloy plate for heat dissipating parts according to any one of the above aspects, wherein the surface is formed with Ni, Co, Fe, Ni-Co alloy and Ni-Fe alloy in a thickness of 3 μm or less. Any one of the plating layer and the Cu-Sn alloy layer having a thickness of 3 μm or less and the Sn layer having a thickness of 0 to 5 μm, and the total thickness of the Cu-Sn alloy layer and the Sn layer is 0.2 μm or more.

Aspect 7:

The copper alloy plate for heat dissipating parts according to any one of the above aspects, wherein the surface is formed of any one of Ni, Co, Fe, Ni-Co alloy and Ni-Fe alloy having a thickness of 3 μm or less. The plating layer formed.

Figure 8:

A copper alloy plate for a heat dissipating component according to the aspect 5 or 6, wherein the Cu-Sn alloy layer is exposed to the outermost surface, and the exposed area ratio is 50% or less.

Figure 9:

A heat dissipating component comprising the copper alloy plate for a heat dissipating component according to any one of the above aspects 1 to 8.

Aspect 10:

A coil material comprising the copper alloy sheet for a heat dissipating component according to any one of the above aspects 1 to 8.

The present application is filed on the basis of Japanese Patent Application No. 2016-034204, the entire disclosure of which is hereby incorporated by reference. Japanese Patent Application No. 2016-034204 is incorporated herein by reference.

Claims (20)

A copper alloy plate for heat dissipating parts, characterized by containing Fe: 0.01~1.0 mass%, P: 0.01~0.20 mass%, Zn: 0.01~1.0 mass%, and Sn: 0.01~0.15 mass%, and the remaining part is Cu and unavoidable impurities; tensile strength in the parallel direction of rolling is 410 MPa or more, endurance is 390 MPa or more, elongation is 5% or more; tensile strength in the right angle direction is 420 MPa or more, and endurance is 400 MPa or more. , the elongation is 3% or more; the electrical conductivity is 75% IACS or more; the ratio R/t of the bending radius R to the thickness t is set to 0.5, and the bending line is set to the right angle direction for bending at 90 degrees. In the case of the bending process, the width of the bending process is 70 mm or more; and the bending line is set to the direction of the right angle of the rolling to make the bending width of the bending process to be 20 mm or more. The copper alloy sheet for a heat dissipating component according to claim 1, wherein the conductivity is 75% IACS or more, and the total is 0.3 mass% or less, and further contains Co, Al, Cr, Mg, Mn, Ca, Pb, Ti. One or two or more kinds of Zr, Si, and Ag. The copper alloy sheet for heat-dissipating parts according to claim 1, wherein the conductivity is 75% IACS or more, and the total is 0.3 mass% or less. One or two or more kinds of Co, Al, Cr, Mg, Mn, Ca, Pb, Ti, Zr, Si, and Ag, and less than 0.1 mass% of Ni. The copper alloy plate for heat dissipating parts according to any one of claims 1 to 3, wherein a Sn layer having a thickness of 0.2 to 5 μm is formed on the surface. The copper alloy plate for heat dissipating parts according to any one of claims 1 to 3, wherein a Cu-Sn alloy layer having a thickness of 3 μm or less and a Sn layer having a thickness of 0 to 5 μm are sequentially formed on the surface, Cu-Sn alloy The total thickness of the layer and the Sn layer is 0.2 μm or more. The copper alloy sheet for heat dissipating parts according to any one of claims 1 to 3, wherein the surface is formed with Ni, Co, Fe, Ni-Co alloy and Ni-Fe alloy in a thickness of 3 μm or less. Any one of the plating layer and the Cu-Sn alloy layer having a thickness of 3 μm or less and the Sn layer having a thickness of 0 to 5 μm, and the total thickness of the Cu-Sn alloy layer and the Sn layer is 0.2 μm or more. The copper alloy plate for heat dissipating parts according to any one of claims 1 to 3, wherein any one of Ni, Co, Fe, Ni-Co alloy, and Ni-Fe alloy having a thickness of 3 μm or less is formed on the surface. The plating layer formed. A copper alloy plate for a heat dissipating component according to claim 5, wherein the Cu-Sn alloy layer is exposed to the outermost surface, and the exposed area ratio is 50% or less. A copper alloy plate for a heat dissipating component according to claim 6, wherein the Cu-Sn alloy layer is exposed to the outermost surface, and the exposed area ratio is 50% or less. A heat dissipating component comprising the copper alloy plate for a heat dissipating component according to any one of claims 1 to 3. A heat dissipating component comprising a copper alloy plate for a heat dissipating component according to claim 4. A heat dissipating component comprising a copper alloy plate for a heat dissipating component according to claim 5. A heat dissipating component comprising a copper alloy plate for a heat dissipating component according to claim 6. A heat dissipating component comprising a copper alloy plate for a heat dissipating component according to claim 7. A heat dissipating component comprising a copper alloy plate for a heat dissipating component according to claim 8. A heat dissipating component comprising a copper alloy plate for a heat dissipating component according to claim 9. A coil material comprising the copper alloy sheet for heat dissipation parts according to any one of claims 1 to 3. A coil material comprising the copper alloy sheet for heat dissipating parts according to claim 4. A coil material comprising the copper alloy sheet for a heat dissipating component according to claim 5. A coil material comprising the copper alloy sheet for heat dissipating parts according to claim 6.