JP3962751B2 - Copper alloy sheet for electric and electronic parts with bending workability - Google Patents

Description

The present invention relates to a copper alloy having high strength, high electrical conductivity, and excellent bending workability, for example, a copper alloy suitable as a material for a lead frame for a semiconductor device.
In addition to the lead frame for semiconductor devices, the copper alloy of the present invention can be used for various semiconductor parts, electrical / electronic parts materials such as printed wiring boards, switch parts, mechanical parts such as bus bars, terminals / connectors, etc. Although it is used for electric and electronic parts, in the following, as a typical application example, description will be made focusing on the case where it is used for a lead frame which is a semiconductor part.

  As a copper alloy for a semiconductor lead frame, a Cu—Fe—P based copper alloy containing Fe and P has been generally used. Examples of these Cu-Fe-P-based copper alloys include, for example, a copper alloy containing Fe: 0.05 to 0.15% and P: 0.025 to 0.040% (C19210 alloy), Fe: 2 An example is a copper alloy (CDA194 alloy) containing 0.1 to 2.6%, P: 0.015 to 0.15%, and Zn: 0.05 to 0.20%. These Cu-Fe-P-based copper alloys are excellent in strength, conductivity and thermal conductivity among copper alloys when an intermetallic compound such as Fe or Fe-P is precipitated in the copper matrix. Therefore, it is widely used as an international standard alloy.

  In recent years, along with the increase in capacity, size, and functionality of semiconductor devices used in electronic devices, lead frames used in semiconductor devices have become smaller in cross-sectional area, resulting in greater strength, conductivity, and thermal conductivity. Is required. Accordingly, copper alloy parts used in lead frames used in these semiconductor devices are required to have higher strength, higher conductivity, and thermal conductivity.

  For example, as a measure for increasing the strength and conductivity of a copper alloy plate used in a lead frame, the strength of the copper alloy plate is required to be 150 Hv or higher in hardness and 75% IACS or higher in conductivity. These increases in strength and conductivity apply not only to lead frames, but also to copper alloys used in conductive parts such as connectors, terminals, switches and relays in other electrical and electronic parts.

  The Cu-Fe-P-based copper alloy is characterized by high electrical conductivity. Conventionally, in order to increase the strength, the content of Fe and P can be increased, or a third such as Sn, Mg, Ca, etc. can be used. The element was added. However, increasing the amount of these elements increases the strength, but inevitably decreases the conductivity. For this reason, only by controlling the component composition in the copper alloy, there is a good balance between the increase in conductivity and the increase in strength required as the capacity, size and function of the semiconductor device described above are increased. It has been difficult to realize a Cu—Fe—P-based copper alloy satisfying both of these characteristics.

  Therefore, various proposals have conventionally been made to control the structure of Cu—Fe—P-based copper alloys and the precipitation state of crystal / precipitate particles. For example, an Fe—P-based compound of 0.2 μm or less is uniformly dispersed. Therefore, a high-strength, high-conductivity copper alloy has been proposed (see Patent Document 1).

  By the way, the copper alloy plates used for lead frames, terminals, connectors, switches, relays, etc. have excellent strength and durability, as well as withstand severe bending such as tight bending or 90 ° bending after notching. Bending workability has been required.

  However, the addition of the Sn or Mg solid solution strengthening element and the increase in the strength due to the increase in the cold rolling process rate inevitably involves the deterioration of the bending processability, so that both the required strength and the bending processability are achieved. I can't.

  On the other hand, it is known that bending workability can be improved to some extent by refining crystal grains and controlling the dispersion state of crystals and precipitates (see Patent Documents 2 and 3). However, in order to obtain a Cu-Fe-P-based high-strength material (copper alloy sheet hardness of 150 Hv or more and conductivity of 75% IACS or more) that can cope with the recent reduction in size and size of electronic components. It has become essential to increase the amount of work hardening due to the strong work of hot rolling.

  For this reason, in such a high-strength material, depending on the structure control means such as the refinement of crystal grains and the dispersion state control of crystals / precipitates described in Patent Documents 1, 2, 3 and the like, Bending workability cannot be sufficiently improved for severe bending such as 90 ° bending.

On the other hand, it has been proposed to control the texture in a Cu—Fe—P based copper alloy (see Patent Documents 4 and 5). More specifically, in Patent Document 4, the ratio of the X-ray diffraction intensity I (200) of the (200) plane and the X-ray diffraction intensity I (220) of the (220) plane of the copper alloy plate, I ( 200) / I (220) is 0.5 or more and 10 or less, or orientation density of Cube orientation: D (Cube orientation) is 1 or more and 50 or less, or orientation density of Cube orientation: D It has been proposed that the ratio of the (Cube orientation) to the orientation density of the S orientation: D (S orientation): D (Cube orientation) / D (S orientation) is 0.1 or more and 5 or less.
In Patent Document 5, the sum of the X-ray diffraction intensity I (200) of the (200) plane and the X-ray diffraction intensity I (311) of the (311) plane of the copper alloy plate and the X of the (220) plane are described. It has been proposed that the ratio [I (200) + I (311)] / I (220) to the line diffraction intensity I (220) is 0.4 or more.
Japanese Unexamined Patent Publication No. 2000-178670 (Claims) JP-A-6-235035 (Claims) JP 2001-279347 A (Claims) JP 2002-339028 A (Claims, paragraphs 0020 to 0030) JP 2000-328157 A (Claims, Examples)

Certainly, as in Patent Document 4, the ratio of the X-ray diffraction intensity I (200) of the (200) plane and the X-ray diffraction intensity I (220) of the (220) plane of the copper alloy plate I (200) / I (220) or Cube orientation density: D (Cube orientation) or Cube orientation density: D (Cube orientation) to S orientation density: D (S orientation) ratio: D (Cube) By defining (azimuth) / D (S orientation), the bending workability can be improved.
Further, as in Patent Document 5, the sum of the (200) plane X-ray diffraction intensity I (200) and the (311) plane X-ray diffraction intensity I (311) of the copper alloy plate, and the (220) plane Even when the ratio [I (200) + I (311)] / I (220) to the X-ray diffraction intensity I (220) is 0.4 or more, the bending workability can be improved.

However, even in the improved copper alloy plate of Patent Document 4, the hardness of the copper alloy plate is about 150 Hv at the maximum, and the conductivity is about 65% IACS at the maximum, and the strength of the copper alloy plate is When it is increased to 150 Hv or more, the conductivity and particularly the bending workability are also lowered. That is, there is a big limit in the texture control of Patent Document 4, especially the bending workability of Cu-Fe-P-based high-strength materials (copper alloy sheet hardness 150 Hv or more, conductivity 75% IACS or more). It cannot be improved.
Also in the improved copper alloy plate of Patent Document 5, in the example, the conductivity of an example having a maximum tensile strength of 520 MPa is remarkably as low as about 35% IACS. On the other hand, in the example where the electrical conductivity is 75% IACS or more, the tensile strength is 480 MPa at the maximum, which is slightly higher than 150 Hv in the hardness of the copper alloy plate. For this reason, either strength or conductivity is sacrificed, and the texture control of Patent Document 5 cannot improve the bending workability of Cu-Fe-P-based high-strength materials.

  The present invention has been made to solve such a problem, and is to provide a Cu-Fe-P-based copper alloy sheet that achieves both high strength and high electrical conductivity and excellent bending workability. .

In order to achieve this object, the gist of the copper alloy plate for electric and electronic parts having bending workability according to the present invention is mass%, Fe: 0.01 to 3.0%, P: 0.01 to 0. .3% of copper alloy plate each comprising Cu and unavoidable impurities , the texture of which is an orientation distribution density of Brass orientation of 20 or less, and of Brass orientation, S orientation, and Copper orientation The sum of the orientation distribution densities is 10 or more and 50 or less.

  The present invention is preferably applied in order to improve the bending workability of a copper alloy plate for electric and electronic parts having a high strength and a high conductivity having a hardness of 150 Hv or more and a conductivity of 75% IACS or more. .

  Moreover, in order to achieve the said high intensity | strength and high electrical conductivity, this invention copper alloy plate may contain Sn: 0.001-0.5% by the mass% further.

  The copper alloy plate of the present invention can be applied to various electric and electronic parts, but is particularly preferably used for a semiconductor lead frame which is a semiconductor part.

  In the case of a normal copper alloy sheet, the texture called Cube orientation, Goss orientation, Brass orientation (hereinafter also referred to as B orientation), Copper orientation (hereinafter also referred to as Cu orientation), S orientation, etc. as shown below. And there are crystal planes corresponding to them.

  The formation of these textures differs depending on the processing and heat treatment methods even in the case of the same crystal system. In the case of the texture of the plate material by rolling, the rolling surface and the rolling direction are represented, the rolling surface is represented by {ABC}, and the rolling direction is represented by <DEF>. Based on this expression, each direction is expressed as follows.

Cube orientation {001} <100>
Goss direction {011} <100>
Rotated-Goss orientation {011} <011>
Brass direction (B direction) {011} <211>
Copper orientation (Cu orientation) {112} <111>
(Or D direction {4 4 11} <11 11 8>
S orientation {123} <634>
B / G direction {011} <511>
B / S orientation {168} <211>
P direction {011} <111>

  In the present invention, basically, the deviations within ± 10 ° from these crystal planes belong to the same crystal plane. Here, the B orientation, the Cu orientation, and the S orientation exist in a fiber texture (β-fiber) that continuously changes between the orientations.

  As described above, the texture of a normal copper alloy plate is composed of a considerable number of orientation factors. However, when these constituent ratios change, the plastic anisotropy of the plate changes and the workability such as bending changes.

  Patent Document 4 described above improves the bending workability and stabilizes by controlling the orientation density (hereinafter also referred to as D (Cube)) of the Cube orientation within the texture. Trying to achieve. This is aimed at uniform deformation during deformation during bending such as stamping in semiconductor lead frame applications.

  That is, if the Cube orientation develops too strongly and D (Cube) is higher than the appropriate range, the plastic anisotropy in the plate surface becomes strong, and there are places that are easily deformed and parts that are difficult to deform, Problems such as bending and burrs in the stamping process as described above are likely to occur. On the other hand, even if the Cube orientation is small, even if D (Cube) is lower than the appropriate range, the development of other crystal orientations becomes strong, and the same problem as above occurs due to another in-plane anisotropy. Yes.

  However, according to the knowledge of the present inventors, in such control of the Cube orientation, in particular, a Cu-Fe-P-based high-strength material having a copper alloy plate hardness of 150 Hv or more and a conductivity of 75% IACS or more. The bending workability cannot be improved.

  That is, first, in order to improve the bending workability while maintaining the high strength, the orientation distribution density of the Brass orientation (B orientation) is lowered. In addition, in order to combine the high strength and bending workability in a well-balanced manner, the sum of the orientation distribution densities of the B, S, and Cu orientations is controlled within a specific range.

  In the Cu-Fe-P-based copper alloy plate having a hardness of 150 Hv or more, among the textures described above, in particular, the orientation distribution density in the B direction, and further, the distribution density in the B orientation, the S orientation, and the Cu orientation are It greatly affects the strength. The larger the orientation distribution density of the B, S, and Cu orientations, the more the rolling texture is developed and the higher the strength.

  However, on the other hand, the bending workability decreases as the orientation distribution density of the B orientation increases or the sum of the orientation distribution densities of the B orientation, the S orientation, and the Cu orientation increases. On the other hand, the smaller the orientation distribution density of the B orientation, or the smaller the sum of orientation distribution densities of the B orientation, S orientation, and Cu orientation, the more random the crystal orientation and the lower the strength, improving the bending workability. To do.

  That is, in order to improve the bending workability while maintaining high strength in a Cu—Fe—P based copper alloy plate having a hardness of 150 Hv or more, the orientation distribution density of the B orientation is reduced, and the B orientation and S It is effective to control the sum of the orientation distribution density of the orientation and the Cu orientation within a specific range.

(Measurement of orientation distribution density)
The measurement of the orientation distribution density of the B orientation and the sum of the orientation distribution densities of the B orientation, the S orientation, and the Cu orientation in the present invention can be performed using a normal X-ray diffraction method.

  The orientation density of each of these orientations is determined by measuring the complete pole figure (Pole Figure) of (100), (110), (111), and then using the orientation distribution function (ODF). It is calculated | required by calculating the ratio of the intensity peak of each specific azimuth | direction (Cu azimuth | direction, B azimuth | direction, S azimuth | direction) with respect to the sum total of an intensity peak value. These measurement methods are disclosed in, for example, Nagashima Shinichi edited by “Aggregate”, published by Maruzen Co., Ltd., 1984, P8-44, Metallurgy Seminar “Aggregate”, Japan Institute of Metals, 1981, P3-7. ing.

  In addition, the orientation density of each of these orientations is determined by electron beam diffraction using TEM, SEM (Scanning Electron Microscopy) -ECP (Electron Chaneling Pattern), or SEM-EBSP (Electron Back Scattering (Scattered) Pattern, or EBSD (Also referred to as (Diffraction)) to obtain the orientation density using the crystal orientation distribution function based on the data measured using

  Since these orientation distributions change in the plate thickness direction, it is preferable to obtain them by taking an average for some points in the plate thickness direction. However, in the case of a copper alloy plate used for a semiconductor material such as a lead frame, it is a thin plate having a thickness of about 0.1 to 0.3 mmw. Therefore, even a value measured with the plate thickness can be evaluated.

(Significance of orientation distribution density)
In the present invention, as described above, in order to achieve both high strength and high conductivity of the Cu-Fe-P-based copper alloy plate and excellent bending workability, the development of the rolling texture is adjusted in a specific direction. To do. For this reason, the orientation distribution density of the B orientation is 20 or less, and the sum of the orientation distribution densities of the B orientation, the S orientation, and the Cu orientation is defined as 10 or more and 50 or less.

  In the usual Cu-Fe-P-based high-strength copper alloy plate (hardness of 150 Hv or more), which has increased the work hardening amount by strong cold rolling, which can cope with light and thin electronic components as described above, Inevitably, the rolling texture is too developed. For this reason, the orientation distribution density of the B orientation necessarily exceeds 20, and the sum of the orientation distribution densities of the B orientation, the S orientation, and the Cu orientation necessarily exceeds 50. This is the same even when the copper alloy plate of Patent Document 4 is strongly processed.

  The development of the rolling texture also affects other orientation densities such as the Cube orientation described above. However, particularly in the region of a high strength copper alloy plate having a hardness of 150 Hv or more, the development of the Cu, B, and S orientations has an effect on the bending workability compared to other orientations such as the Cube orientation described above. It is much bigger.

  As described above, when the orientation distribution density of the B orientation exceeds 20, or when the sum of orientation distribution densities of the B orientation, the S orientation, and the Cu orientation exceeds 50, as described in the examples described later, Bending workability cannot be improved at high strength.

  Therefore, in the present invention, the orientation distribution density of the B orientation is set to 20 or less, and the sum of the orientation distribution densities of the B orientation, the S orientation, and the Cu orientation is set to 50 or less. This makes it possible to improve the bending workability while maintaining the high strength as in the examples described later.

  On the other hand, in order to make the sum of the orientation distribution densities of the B, S, and Cu orientations less than 10, the work hardening amount by cold rolling must be reduced. For this reason, when the sum of orientation distribution densities of the B, S, and Cu orientations is less than 10, although the bending workability can be improved as in the examples described later, the high strength cannot be maintained and the hardness is increased. Is less than 150 Hv. For this reason, the required strength is insufficient as a copper alloy for semiconductor lead frames.

(Component composition of copper alloy sheet)
The chemical component composition in the Cu—Fe—P based copper alloy plate of the present invention for satisfying the required strength and electrical conductivity for semiconductor lead frames and the like will be described below.

  In the present invention, in order to achieve high strength and high electrical conductivity with strength of 150 Hv or higher in hardness and electrical conductivity of 75% IACS or higher, the content of Fe is 0.01 to 3.0% by mass. And a basic composition consisting of the remainder Cu and inevitable impurities, with the P content in the range of 0.01 to 0.3%. With respect to this basic composition, one or two of Zn and Sn may be further contained within the following range. Further, other selectively added elements and impurity elements are allowed to be contained within a range that does not impair these characteristics. In addition, the display of the following content is all the mass%.

(Fe)
Fe is a main element that precipitates as Fe or an Fe-based intermetallic compound and improves the strength and heat resistance of the copper alloy. If the Fe content is less than 0.01%, depending on the production conditions, the amount of the precipitated particles produced is small and the improvement in conductivity is satisfied, but the contribution to strength improvement is insufficient and the strength is insufficient. On the other hand, if the Fe content exceeds 3.0%, the conductivity tends to decrease, and if the amount of precipitation is increased in order to increase the conductivity forcibly, conversely, growth and coarsening of the precipitated particles are caused. , Strength and bending workability are reduced. Therefore, the Fe content is in the range of 0.01 to 3.0%.

(P)
In addition to deoxidizing action, P is a main element that forms a compound with Fe to increase the strength of the copper alloy. If the P content is less than 0.01%, depending on the production conditions, precipitation of the compound is insufficient, so that the desired strength cannot be obtained. On the other hand, when the P content exceeds 0.3%, not only the conductivity is lowered but also the hot workability is lowered. Therefore, the P content is in the range of 0.01 to 0.3%.

(Zn)
Zn improves the heat-resistant peelability of copper alloy solder and Sn plating required for lead frames and the like. If the Zn content is less than 0.005%, the desired effect cannot be obtained. On the other hand, if it exceeds 3.0%, not only the solder wettability is lowered but also the conductivity is greatly lowered. Therefore, the Zn content in the case of selective inclusion is set to 0.005 to 3.0%.

(Sn)
Sn contributes to improving the strength of the copper alloy. When the Sn content is less than 0.001%, it does not contribute to high strength. On the other hand, when the Sn content is increased, the effect is saturated, and conversely, the conductivity is lowered and the bending workability is also deteriorated.
In this respect, Sn is selectively contained in the range of 0.001 to 0.5% in order to make the strength of the copper alloy plate 150Hv or more in hardness and 75% IACS or more in electrical conductivity. Further, in order to make the strength of the copper alloy plate higher, the hardness to be 190 Hv or more, and the conductivity to be 50% IACS or more, Sn is selectively in the range of more than 0.5% and 5.0% or less. To contain. As described above, the Sn content is selected from the range of 0.001 to 5.0% as a whole, depending on the balance of strength (hardness) and conductivity required for the application. .

(Mn, Mg, Ca content)
Since Mn, Mg and Ca contribute to the improvement of hot workability of the copper alloy, they are selectively contained when these effects are required. When the content of one or more of Mn, Mg, and Ca is less than 0.0001% in total, a desired effect cannot be obtained. On the other hand, when the total content exceeds 1.0%, coarse crystallized substances and oxides are generated, and not only the bending workability is lowered, but also the conductivity is severely lowered. Therefore, the content of these elements is selectively contained in the range of 0.0001 to 1.0% in total.

(Zr, Ag, Cr, Cd, Be, Ti, Co, Ni, Au, Pt amount)
Since these components have an effect of improving the strength of the copper alloy, they are selectively contained when these effects are required. When the content of one or more of these components is less than 0.001% in total, the desired effect cannot be obtained. On the other hand, if the total content exceeds 1.0%, coarse crystallized substances and oxides are generated and not only the bending workability is lowered, but also the electrical conductivity is severely lowered, which is not preferable. Therefore, the content of these elements is selectively contained in the range of 0.001 to 1.0% in total. In addition, when these components are contained with the said Mn, Mg, and Ca, the total content of these contained elements shall be 1.0% or less.

(Hf, Th, Li, Na, K, Sr, Pd, W, S, Si, C, Nb, Al, V, Y, Mo, Pb, In, Ga, Ge, As, Sb, Bi, Te, B , Misch metal amount)
These components are impurity elements, and when the total content of these elements exceeds 0.1%, coarse crystallized substances and oxides are formed, and bending workability is lowered. Therefore, the total content of these elements is preferably 0.1% or less.

(Production conditions)
Next, preferable manufacturing conditions for making the copper alloy sheet structure the structure defined in the present invention will be described below. The copper alloy sheet of the present invention greatly changes the normal manufacturing process itself except for preferable conditions such as the processing rate (cold rolling ratio) in the final cold rolling and the low-temperature annealing in order to obtain the structure defined in the present invention. This is unnecessary and can be manufactured in the same process as the conventional method.

  That is, first, a molten copper alloy adjusted to the preferred component composition is cast. Then, after chamfering the ingot, it is heated or homogenized and then hot-rolled, and the hot-rolled plate is water-cooled.

  After that, the first cold rolling, which is said to be intermediate, is annealed, washed, and then finished (final) cold rolled and low-temperature annealed (final annealing, final annealing) to obtain a copper alloy sheet having a product thickness. . For example, in the case of a copper alloy plate used for a semiconductor material such as a lead frame, the product plate thickness is about 0.1 to 0.3 mm.

  In addition, you may perform the solution treatment of a copper alloy plate, and the quenching process by water cooling before primary cold rolling. At this time, the solution treatment temperature is selected from a range of 750 to 1000 ° C., for example.

  Here, in order to control the azimuth distribution density of the B azimuth to be 20 or less and the sum of the azimuth distribution densities of the B azimuth, S azimuth, and Cu azimuth to be 10 or more and 50 or less, it is 10 per pass. It is effective to perform the final cold rolling at a cold rolling rate of ˜50% and then perform the final annealing at a low temperature of 0.2 to 300 minutes at 100 to 400 ° C.

(Final cold rolling)
In order to obtain a Cu-Fe-P-based high-strength copper alloy sheet having a hardness of 150 Hv or more, the present invention also increases the amount of work hardening due to the strong work of the final cold rolling (high deposition of introduced dislocations by the Orowan mechanism). To do. However, it is preferable that the cold rolling rate per pass of the final cold rolling is 10 to 50% so that the rolling texture does not develop too much. The number of final cold rolling passes is preferably 3 to 4 times as usual, avoiding too few or too many passes.

  In the case of this normal number of passes, if the cold rolling rate per pass of final cold rolling exceeds 50%, depending on the composition of the copper alloy, production history and production conditions so far, the orientation of the B direction There is a high possibility that the distribution density exceeds 20, or the sum of the orientation distribution densities of the B, S, and Cu directions exceeds 50 and becomes large.

  On the other hand, if the cold rolling rate per pass of the final cold rolling is less than 10%, the sum of orientation distribution densities of the B, S, and Cu orientations tends to be less than 10, and the amount of work hardening by cold rolling is insufficient. Probability is high. For this reason, although bending workability can be improved, the said high intensity | strength cannot be maintained and possibility that hardness will be less than 150 Hv is high.

(Final annealing)
In the present invention, after the final cold rolling, it is preferable to control the texture by intentionally performing final annealing at a low temperature. In the manufacturing method of a copper alloy plate used for a normal lead frame, since the strength is reduced, the above-mentioned patent is applied except for the annealing (350 ° C. × 20 seconds) for removing strain applied in the embodiment of Patent Document 5. As in Reference 4, the final annealing is not performed after the final cold rolling. However, in the present invention, this strength reduction is suppressed by the cold rolling conditions and by lowering the final annealing. And by performing final annealing at low temperature, each orientation density is controlled in the said range, and an intensity | strength and bending workability improve.

  Under conditions where the annealing temperature is lower than 100 ° C, the annealing time is less than 0.2 minutes, or the conditions where this annealing is not performed, the structure and properties of the copper alloy sheet are almost the same as those after the final cold rolling. It is likely that it will not change. For this reason, the orientation density of the B orientation exceeds 20, or the sum of the orientation distribution densities of the B orientation, the S orientation, and the Cu orientation exceeds 50, and each orientation density cannot be controlled within the above range. High nature. Conversely, if annealing is performed at a temperature exceeding 400 ° C. or annealing time exceeding 300 minutes, recrystallization occurs, rearrangement of dislocations and recovery phenomenon occur excessively, and precipitates also become coarse. Therefore, there is a high possibility that the strength will decrease.

  Examples of the present invention will be described below. By changing the cold rolling rate per pass of final cold rolling and the temperature and time in final annealing, copper alloy sheets with various textures are manufactured, and properties such as hardness, conductivity, and bendability are produced. evaluated.

  Specifically, after each copper alloy having the chemical composition shown in Tables 1 and 2 was melted in a coreless furnace, it was ingoted by a semi-continuous casting method, and was 70 mm thick × 200 mm wide × 500 mm long. An ingot was obtained. Each ingot was chamfered on the surface and heated, and then hot rolled at a temperature of 950 ° C. to form a plate having a thickness of 16 mm, and rapidly cooled into water from a temperature of 750 ° C. or higher. Next, after removing the oxide scale, primary cold rolling (intermediate rolling) was performed. After chamfering the plate, final cold rolling was performed in which three passes of cold rolling were performed while intermediate annealing was performed, and then final annealing was performed to obtain a copper alloy plate having a thickness of about 0.15 mm.

In each of the copper alloys shown in Tables 1 and 2, the remaining composition excluding the element amount described is Cu, and other impurity elements are Hf, Th, Li, Na, K, Sr, Pd, W, S, Si, C, Nb, Al, V, Y, Mo, Pb, In, Ga, Ge, As, Sb, Bi, Te, B, misch metal content, including the elements listed in Table 1, The total amount of all elements was 0.1% by mass or less.
Further, when one or more of Mn, Mg, and Ca are included, the total amount is in the range of 0.0001 to 1.0 mass%, and Zr, Ag, Cr, Cd, Be, Ti, Co, In the case of one or more of Ni, Au, and Pt, the total amount is in the range of 0.001 to 1.0% by mass, and the total amount of these elements is also 1.0% by mass or less. did.

  Tables 1 and 2 show the cold rolling rate (%) per pass of the final cold rolling and the temperature and time (° C. × min) in the final annealing, respectively.

  In each example, a sample was cut out of the copper alloy plate, the texture was measured, and the hardness measurement, conductivity measurement, bending test, and press formability test were performed on the copper alloy plate thus obtained. These results are shown in Tables 1 and 2, respectively.

  The above press formability test is intended to confirm whether the press formability, which is one of the characteristics necessary for the lead frame material, has been lowered due to the improvement of the bending workability.

(Measurement of texture)
For a copper alloy plate sample, a complete pole figure of (100), (110), and (111) is obtained by a normal X-ray diffraction method using Cu as a target, tube voltage of 50 KV, and tube current of 200 mA. Was measured. From this measurement result, using the crystal orientation distribution function (Orientation Distribution Function: ODF), the ratio of the intensity peak of each specific orientation to the sum of the intensity peak values of each orientation is calculated, and the orientation distribution density of B orientation, B The sum of the orientation distribution density of the orientation, S orientation, and Cu orientation was determined. For the X-ray diffraction intensity, the diffraction intensity of the (200) plane [= (100) plane], (220) plane [= (110) plane] was measured using a Rigaku X-ray diffractometer. The (200) plane / (220) plane X-ray diffraction intensity ratio was determined.

(Hardness measurement)
The hardness of the copper alloy plate sample was measured with a micro Vickers hardness tester by applying a load of 0.5 kg at four locations, and the hardness was an average value thereof.

(Conductivity measurement)
The electrical conductivity of the copper alloy sheet sample was calculated by an average cross-sectional area method by processing a strip-shaped test piece having a width of 10 mm and a length of 300 mm by milling, measuring the electric resistance with a double bridge type resistance measuring device.

(Evaluation test for bending workability)
The bending test of the copper alloy sheet sample was performed according to the Japan Copper and Brass Association technical standard. A specimen of width 10mm and length 30mm is taken from each sample, bent in a bad way (BW: bending axis is parallel to the rolling direction), and the ratio R / of the minimum bending radius R and sample thickness t where no cracks occur. Evaluation was made at t. When the value of R / t is 0, it means that 180 ° contact bending with a minimum bending radius R of 0 is possible. Smaller values of R / t are superior in bendability, and R / t of 1.0 or less can be said to have bendability that can cope with close contact bending or 90 ° bending after notching in an actual lead frame. .

  This bending workability is evaluated by the bending test as described in Patent Document 4 described above (bending at 90 ° at 0.25 mmR and observing the outer surface side of the bent portion with an optical microscope for the presence or absence of rough skin and the presence or absence of cracks. This is a stricter bending test condition corresponding to close bending or notching 90 ° after notching in an actual lead frame. Although the above-mentioned Patent Document 4 does not describe the specimen sampling direction, the normal bendability evaluation is G. W (the bending axis is perpendicular to the rolling direction). Therefore, it can be said that the bending test conditions of the present invention are severe also in this respect.

(Evaluation test of press formability)
A copper alloy plate sample was punched with a 0.3 mm wide lead by a mechanical press, and the flash height of the punched lead was measured to evaluate the pressability. At this time, the burr height was measured by a method of observing the burr surfaces of 10 leads with a scanning electron microscope, and was defined as an average value of the maximum burr heights. When the flash height is 3 μm or less, the press formability is excellent, ○, when the flash height is 3-6 μm, Δ, when the flash height exceeds 6 μm, the press formability is poor, and x, respectively. evaluated.

  As is apparent from Table 1, Invention Examples 1 to 7, which are copper alloys within the composition of the present invention, have a cold rolling rate (%) per pass of final cold rolling, temperature and time in final annealing (° C. × min. ) And the like are also manufactured within preferable conditions. For this reason, in the textures of Invention Examples 1 to 7, the orientation distribution density of the B orientation is 20 or less, and the sum of the orientation distribution densities of the B orientation, the S orientation, and the Cu orientation is 10 or more and 50 or less.

  As a result, Invention Examples 1 to 7 have a high strength and a high conductivity of 150 Hv or higher in hardness and 75% IACS or higher in conductivity, and are excellent in bending workability. In addition, the press formability, which is another important characteristic, is not deteriorated.

  On the other hand, the copper alloy of Comparative Example 8 has an Fe content of 0.006%, which is slightly lower than the lower limit of 0.01%. Since the manufacturing methods such as final cold rolling and final annealing are manufactured within preferable conditions, the texture is within the scope of the invention and is excellent in bending workability. However, the hardness is low, the electrical conductivity is low, and high strength and high electrical conductivity cannot be achieved.

  In the copper alloy of Comparative Example 9, the Fe content is 4.5%, which is out of the upper limit of 3.0%. Since the manufacturing methods such as final cold rolling and final annealing are manufactured within preferable conditions, the texture is within the scope of the invention and the hardness is high, but the conductivity is remarkably low and the bending workability is also inferior.

  The copper alloy of Comparative Example 10 has a P content of 0.007%, which is slightly lower than the lower limit of 0.01%. Since the manufacturing methods such as final cold rolling and final annealing are manufactured within preferable conditions, the texture is within the scope of the invention and is excellent in bending workability. However, the hardness is low, the electrical conductivity is low, and high strength and high electrical conductivity cannot be achieved.

  The copper alloy of Comparative Example 11 has a P content of 0.35%, which is higher than the upper limit of 0.3%. Since the manufacturing methods such as final cold rolling and final annealing are manufactured within preferable conditions, the texture is within the scope of the invention and the hardness is high, but the conductivity is remarkably low and the bending workability is also inferior.

  The copper alloy of Comparative Example 12 is a copper alloy within the composition of the present invention, and although the final cold rolling is produced within preferable conditions, it is not final annealed. For this reason, in the texture, the orientation distribution density of the B orientation is too high, and the sum of the orientation distribution densities of the B orientation, the S orientation, and the Cu orientation is too high. As a result, although the strength level is low, bending workability and electrical conductivity are remarkably inferior. This Comparative Example 12 corresponds to Invention Example 3 of Patent Document 4 in that the rolling conditions such as final cold rolling are slightly different, but the copper alloy composition and the final annealing are not performed.

  The copper alloy of Comparative Example 13 is a copper alloy within the composition of the present invention, but the temperature in the final annealing is too low and the time is too long. For this reason, although the hardness is high, the conductivity is remarkably low. In addition, the texture has an orientation distribution density in the B orientation that is too high, and the sum of orientation distribution densities in the B orientation, the S orientation, and the Cu orientation is too high. As a result, bending workability is remarkably inferior.

  Although the comparative example 14 is a copper alloy within the composition of the present invention and the final cold rolling is also manufactured under preferable conditions, the temperature in the final annealing is too high. For this reason, the hardness is as extremely low as 120 Hv. The texture also has good bendability because the sum of orientation distribution densities of the B, S, and Cu orientations is too low and the hardness is extremely low.

  Comparative Example 15 is a copper alloy within the composition of the present invention, and final cold rolling is also performed under preferable conditions, but is not final annealed. For this reason, in the texture, the orientation distribution density of the B orientation is too high, and the sum of the orientation distribution densities of the B orientation, the S orientation, and the Cu orientation is too high. As a result, bending workability and electrical conductivity are remarkably inferior. In addition, including this comparative example 15 and the said comparative example 12, it can be said that the example which is not finally annealed in this way is a typical example by the manufacturing method which does not carry out normal (normal) final annealing. Therefore, the significance of texture control by low temperature annealing in the present invention can be understood.

  Although the comparative example 16 is a copper alloy within the composition of the present invention, the cold rolling rate per pass of the final cold rolling is too low. For this reason, hardness is remarkably as low as 138Hv. The texture also has good bendability because the sum of orientation distribution densities of the B, S, and Cu orientations is too low and the hardness is extremely low.

  Although the comparative example 17 is a copper alloy within the composition of the present invention, the cold rolling rate per pass of the final cold rolling is too high. Although the orientation distribution density of the B orientation is too high and the sum of the orientation distribution densities of the B orientation, the S orientation, and the Cu orientation is within the range, the bending workability is extremely inferior. It can be said that this comparative example 17 is a typical example of this kind of conventional high strength copper alloy plate that obtains high strength by so-called cold-rolling strong processing.

  In addition, as is apparent from Table 2, Invention Examples 18 to 20 which are copper alloys within the composition of the present invention containing a selective additive element also have a cold rolling rate (%) per pass of the final cold rolling, and the final Manufacturing methods such as temperature and time (° C. × min) in annealing are also manufactured within preferable conditions. For this reason, the textures of Invention Examples 18 to 20 have an orientation distribution density of B orientation of 20 or less, and the sum of orientation distribution densities of B orientation, S orientation, and Cu orientation is 10 or more and 50 or less.

  As a result, the inventive examples 18 to 20 also have high strength and high conductivity of 150 Hv or more in hardness and 75% IACS or more in conductivity, and are excellent in bending workability. In addition, the press formability, which is another important characteristic, is not deteriorated.

  Furthermore, invention examples 21 to 24 in Table 2 are copper alloys within the composition of the present invention, but show a case where the content of Sn is relatively high. Inventive Examples 21 to 24 are manufactured under preferable conditions for manufacturing methods such as the cold rolling rate (%) per pass of the final cold rolling and the temperature and time (° C. × min) in the final annealing. For this reason, the texture has an orientation distribution density in the B direction of 20 or less, and the sum of the orientation distribution densities of the B orientation, the S orientation, and the Cu orientation is 10 or more and 50 or less.

  As a result, Invention Examples Invention Examples 21 to 24 have a high strength of 190 Hv or more, an electrical conductivity of 50% IACS or more, and excellent bending workability. In addition, the press formability, which is another important characteristic, is not deteriorated.

  In the copper alloy of Comparative Example 25, as in Comparative Example 11, the P content deviates from the upper limit of 0.3%. Since manufacturing methods such as final cold rolling and final annealing are manufactured within preferable conditions, the texture is within the scope of the invention, but the conductivity is remarkably low for the hardness and the bending workability is also inferior.

  In the copper alloy of Comparative Example 26, as in Comparative Example 9, the Fe content is higher than the upper limit of 3.0%. Since manufacturing methods such as final cold rolling and final annealing are manufactured within preferable conditions, the texture is within the scope of the invention, but the conductivity is remarkably low for the hardness and the bending workability is also inferior.

  The copper alloy of Comparative Example 27 is a copper alloy within the composition of the present invention, but, as in Comparative Example 13, the temperature in the final annealing is too low and the time is too long. For this reason, electrical conductivity is remarkably low for the hardness. In addition, the texture has an orientation distribution density in the B orientation that is too high, and the sum of orientation distribution densities in the B orientation, the S orientation, and the Cu orientation is too high. As a result, bending workability is remarkably inferior.

  Comparative Example 28 is a copper alloy within the composition of the present invention, and final cold rolling is also performed under preferable conditions. However, as in Comparative Examples 12 and 15, final annealing is not performed. For this reason, in the texture, the orientation distribution density of the B orientation is too high, and the sum of the orientation distribution densities of the B orientation, the S orientation, and the Cu orientation is too high. As a result, the hardness is low and the bending workability is poor.

  From the above results, in order to obtain high strength and high electrical conductivity, and to improve the bending workability, the composition of the copper alloy sheet of the present invention, the critical significance of the texture and the texture The significance of preferred production conditions is supported.

  As described above, according to the present invention, a Cu-Fe-P-based copper alloy that achieves both high strength and high conductivity and excellent bending workability without reducing other properties such as press formability. Board can be provided. As a result, for electrical and electronic parts that have been reduced in size and weight, in addition to semiconductor device lead frames, lead frames, connectors, terminals, switches, relays, etc. have high strength and high conductivity, and severe bending workability. It can be applied to the required use.

Claims (11)

A copper alloy plate containing, by mass%, Fe: 0.01 to 3.0%, P: 0.01 to 0.3%, and the balance Cu and unavoidable impurities , Copper for electrical and electronic parts having bending workability, characterized in that the orientation distribution density of the Brass orientation is 20 or less and the sum of the orientation distribution densities of the Brass orientation, the S orientation, and the Copper orientation is 10 or more and 50 or less Alloy plate.   The copper alloy plate according to claim 1, wherein the copper alloy plate further contains Sn: 0.001 to 0.5% by mass.   The copper alloy plate for electric and electronic parts according to claim 1 or 2, wherein the copper alloy plate has a hardness of 150 Hv or more and a conductivity of 75% IACS or more.   The copper alloy plate according to claim 1, wherein the copper alloy plate further contains Sn: more than 0.5% and 5.0% or less by mass%.   The copper alloy plate for electric and electronic parts according to claim 4, wherein the copper alloy plate has a hardness of 190 Hv or more and a conductivity of 50% IACS or more.   The copper alloy plate according to any one of claims 1 to 5, wherein the copper alloy plate further contains Zn: 0.005 to 3.0% by mass.   7. The copper alloy plate according to claim 1, further comprising 0.0001 to 1.0% of one or more of Mn, Mg, and Ca in total by mass%. Copper alloy plate for electrical and electronic parts.   The copper alloy plate is further 0.001 to 1.0% in total of one or more of Zr, Ag, Cr, Cd, Be, Ti, Co, Ni, Au, and Pt in mass%. The copper alloy plate for electrical and electronic parts according to any one of claims 1 to 7.   The copper alloy plate is further, by mass%, one or more of Mn, Mg, and Ca in a total of 0.0001 to 1.0%, Zr, Ag, Cr, Cd, Be, Ti, One or two or more of Co, Ni, Au, and Pt are respectively added in a total amount of 0.001 to 1.0%, and the total content of these elements is 1.0% or less. Item 9. The copper alloy sheet for electrical and electronic parts according to any one of Items 1 to 8.   The copper alloy plate is Hf, Th, Li, Na, K, Sr, Pd, W, S, Si, C, Nb, Al, V, Y, Mo, Pb, In, Ga, Ge, As, Sb, The copper alloy plate for electrical and electronic parts according to any one of claims 1 to 9, wherein the content of Bi, Te, B, and Misch metal is 0.1% by mass or less in total of these elements.   The copper alloy plate for electrical and electronic parts according to any one of claims 1 to 10, wherein the copper alloy plate is for a semiconductor lead frame.